diff options
Diffstat (limited to 'tools/plink/ssh.c')
| -rwxr-xr-x[-rw-r--r--] | tools/plink/ssh.c | 21304 |
1 files changed, 11140 insertions, 10164 deletions
diff --git a/tools/plink/ssh.c b/tools/plink/ssh.c index bdbbc4fd5..cef4455e8 100644..100755 --- a/tools/plink/ssh.c +++ b/tools/plink/ssh.c @@ -1,10164 +1,11140 @@ -/*
- * SSH backend.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <stdarg.h>
-#include <assert.h>
-#include <limits.h>
-#include <signal.h>
-
-#include "putty.h"
-#include "tree234.h"
-#include "ssh.h"
-#ifndef NO_GSSAPI
-#include "sshgssc.h"
-#include "sshgss.h"
-#endif
-
-#ifndef FALSE
-#define FALSE 0
-#endif
-#ifndef TRUE
-#define TRUE 1
-#endif
-
-#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
-#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
-#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
-#define SSH1_CMSG_USER 4 /* 0x4 */
-#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
-#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
-#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
-#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
-#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
-#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
-#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
-#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
-#define SSH1_SMSG_SUCCESS 14 /* 0xe */
-#define SSH1_SMSG_FAILURE 15 /* 0xf */
-#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
-#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
-#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
-#define SSH1_CMSG_EOF 19 /* 0x13 */
-#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
-#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
-#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
-#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
-#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
-#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
-#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
-#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
-#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
-#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
-#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
-#define SSH1_MSG_IGNORE 32 /* 0x20 */
-#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
-#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
-#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
-#define SSH1_MSG_DEBUG 36 /* 0x24 */
-#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
-#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
-#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
-#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
-#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
-#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
-#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
-
-#define SSH1_AUTH_RHOSTS 1 /* 0x1 */
-#define SSH1_AUTH_RSA 2 /* 0x2 */
-#define SSH1_AUTH_PASSWORD 3 /* 0x3 */
-#define SSH1_AUTH_RHOSTS_RSA 4 /* 0x4 */
-#define SSH1_AUTH_TIS 5 /* 0x5 */
-#define SSH1_AUTH_CCARD 16 /* 0x10 */
-
-#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
-/* Mask for protoflags we will echo back to server if seen */
-#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
-
-#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
-#define SSH2_MSG_IGNORE 2 /* 0x2 */
-#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
-#define SSH2_MSG_DEBUG 4 /* 0x4 */
-#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
-#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
-#define SSH2_MSG_KEXINIT 20 /* 0x14 */
-#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
-#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
-#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
-#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
-#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
-#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
-#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
-#define SSH2_MSG_KEXRSA_PUBKEY 30 /* 0x1e */
-#define SSH2_MSG_KEXRSA_SECRET 31 /* 0x1f */
-#define SSH2_MSG_KEXRSA_DONE 32 /* 0x20 */
-#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
-#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
-#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
-#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
-#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
-#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
-#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
-#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
-#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
-#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
-#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
-#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
-#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
-#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
-#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
-#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
-#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
-#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
-#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
-#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
-#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
-#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
-#define SSH2_MSG_USERAUTH_GSSAPI_RESPONSE 60
-#define SSH2_MSG_USERAUTH_GSSAPI_TOKEN 61
-#define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE 63
-#define SSH2_MSG_USERAUTH_GSSAPI_ERROR 64
-#define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK 65
-#define SSH2_MSG_USERAUTH_GSSAPI_MIC 66
-
-/*
- * Packet type contexts, so that ssh2_pkt_type can correctly decode
- * the ambiguous type numbers back into the correct type strings.
- */
-typedef enum {
- SSH2_PKTCTX_NOKEX,
- SSH2_PKTCTX_DHGROUP,
- SSH2_PKTCTX_DHGEX,
- SSH2_PKTCTX_RSAKEX
-} Pkt_KCtx;
-typedef enum {
- SSH2_PKTCTX_NOAUTH,
- SSH2_PKTCTX_PUBLICKEY,
- SSH2_PKTCTX_PASSWORD,
- SSH2_PKTCTX_GSSAPI,
- SSH2_PKTCTX_KBDINTER
-} Pkt_ACtx;
-
-#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
-#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
-#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
-#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
-#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
-#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
-#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
-#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
-#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
-#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
-#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
-#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
-#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
-#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
-#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
-
-static const char *const ssh2_disconnect_reasons[] = {
- NULL,
- "host not allowed to connect",
- "protocol error",
- "key exchange failed",
- "host authentication failed",
- "MAC error",
- "compression error",
- "service not available",
- "protocol version not supported",
- "host key not verifiable",
- "connection lost",
- "by application",
- "too many connections",
- "auth cancelled by user",
- "no more auth methods available",
- "illegal user name",
-};
-
-#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
-#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
-#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
-#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
-
-#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
-
-/*
- * Various remote-bug flags.
- */
-#define BUG_CHOKES_ON_SSH1_IGNORE 1
-#define BUG_SSH2_HMAC 2
-#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
-#define BUG_CHOKES_ON_RSA 8
-#define BUG_SSH2_RSA_PADDING 16
-#define BUG_SSH2_DERIVEKEY 32
-#define BUG_SSH2_REKEY 64
-#define BUG_SSH2_PK_SESSIONID 128
-#define BUG_SSH2_MAXPKT 256
-#define BUG_CHOKES_ON_SSH2_IGNORE 512
-
-/*
- * Codes for terminal modes.
- * Most of these are the same in SSH-1 and SSH-2.
- * This list is derived from RFC 4254 and
- * SSH-1 RFC-1.2.31.
- */
-static const struct {
- const char* const mode;
- int opcode;
- enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
-} ssh_ttymodes[] = {
- /* "V" prefix discarded for special characters relative to SSH specs */
- { "INTR", 1, TTY_OP_CHAR },
- { "QUIT", 2, TTY_OP_CHAR },
- { "ERASE", 3, TTY_OP_CHAR },
- { "KILL", 4, TTY_OP_CHAR },
- { "EOF", 5, TTY_OP_CHAR },
- { "EOL", 6, TTY_OP_CHAR },
- { "EOL2", 7, TTY_OP_CHAR },
- { "START", 8, TTY_OP_CHAR },
- { "STOP", 9, TTY_OP_CHAR },
- { "SUSP", 10, TTY_OP_CHAR },
- { "DSUSP", 11, TTY_OP_CHAR },
- { "REPRINT", 12, TTY_OP_CHAR },
- { "WERASE", 13, TTY_OP_CHAR },
- { "LNEXT", 14, TTY_OP_CHAR },
- { "FLUSH", 15, TTY_OP_CHAR },
- { "SWTCH", 16, TTY_OP_CHAR },
- { "STATUS", 17, TTY_OP_CHAR },
- { "DISCARD", 18, TTY_OP_CHAR },
- { "IGNPAR", 30, TTY_OP_BOOL },
- { "PARMRK", 31, TTY_OP_BOOL },
- { "INPCK", 32, TTY_OP_BOOL },
- { "ISTRIP", 33, TTY_OP_BOOL },
- { "INLCR", 34, TTY_OP_BOOL },
- { "IGNCR", 35, TTY_OP_BOOL },
- { "ICRNL", 36, TTY_OP_BOOL },
- { "IUCLC", 37, TTY_OP_BOOL },
- { "IXON", 38, TTY_OP_BOOL },
- { "IXANY", 39, TTY_OP_BOOL },
- { "IXOFF", 40, TTY_OP_BOOL },
- { "IMAXBEL", 41, TTY_OP_BOOL },
- { "ISIG", 50, TTY_OP_BOOL },
- { "ICANON", 51, TTY_OP_BOOL },
- { "XCASE", 52, TTY_OP_BOOL },
- { "ECHO", 53, TTY_OP_BOOL },
- { "ECHOE", 54, TTY_OP_BOOL },
- { "ECHOK", 55, TTY_OP_BOOL },
- { "ECHONL", 56, TTY_OP_BOOL },
- { "NOFLSH", 57, TTY_OP_BOOL },
- { "TOSTOP", 58, TTY_OP_BOOL },
- { "IEXTEN", 59, TTY_OP_BOOL },
- { "ECHOCTL", 60, TTY_OP_BOOL },
- { "ECHOKE", 61, TTY_OP_BOOL },
- { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
- { "OPOST", 70, TTY_OP_BOOL },
- { "OLCUC", 71, TTY_OP_BOOL },
- { "ONLCR", 72, TTY_OP_BOOL },
- { "OCRNL", 73, TTY_OP_BOOL },
- { "ONOCR", 74, TTY_OP_BOOL },
- { "ONLRET", 75, TTY_OP_BOOL },
- { "CS7", 90, TTY_OP_BOOL },
- { "CS8", 91, TTY_OP_BOOL },
- { "PARENB", 92, TTY_OP_BOOL },
- { "PARODD", 93, TTY_OP_BOOL }
-};
-
-/* Miscellaneous other tty-related constants. */
-#define SSH_TTY_OP_END 0
-/* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
-#define SSH1_TTY_OP_ISPEED 192
-#define SSH1_TTY_OP_OSPEED 193
-#define SSH2_TTY_OP_ISPEED 128
-#define SSH2_TTY_OP_OSPEED 129
-
-/* Helper functions for parsing tty-related config. */
-static unsigned int ssh_tty_parse_specchar(char *s)
-{
- unsigned int ret;
- if (*s) {
- char *next = NULL;
- ret = ctrlparse(s, &next);
- if (!next) ret = s[0];
- } else {
- ret = 255; /* special value meaning "don't set" */
- }
- return ret;
-}
-static unsigned int ssh_tty_parse_boolean(char *s)
-{
- if (stricmp(s, "yes") == 0 ||
- stricmp(s, "on") == 0 ||
- stricmp(s, "true") == 0 ||
- stricmp(s, "+") == 0)
- return 1; /* true */
- else if (stricmp(s, "no") == 0 ||
- stricmp(s, "off") == 0 ||
- stricmp(s, "false") == 0 ||
- stricmp(s, "-") == 0)
- return 0; /* false */
- else
- return (atoi(s) != 0);
-}
-
-#define translate(x) if (type == x) return #x
-#define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
-#define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
-static char *ssh1_pkt_type(int type)
-{
- translate(SSH1_MSG_DISCONNECT);
- translate(SSH1_SMSG_PUBLIC_KEY);
- translate(SSH1_CMSG_SESSION_KEY);
- translate(SSH1_CMSG_USER);
- translate(SSH1_CMSG_AUTH_RSA);
- translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
- translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
- translate(SSH1_CMSG_AUTH_PASSWORD);
- translate(SSH1_CMSG_REQUEST_PTY);
- translate(SSH1_CMSG_WINDOW_SIZE);
- translate(SSH1_CMSG_EXEC_SHELL);
- translate(SSH1_CMSG_EXEC_CMD);
- translate(SSH1_SMSG_SUCCESS);
- translate(SSH1_SMSG_FAILURE);
- translate(SSH1_CMSG_STDIN_DATA);
- translate(SSH1_SMSG_STDOUT_DATA);
- translate(SSH1_SMSG_STDERR_DATA);
- translate(SSH1_CMSG_EOF);
- translate(SSH1_SMSG_EXIT_STATUS);
- translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
- translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
- translate(SSH1_MSG_CHANNEL_DATA);
- translate(SSH1_MSG_CHANNEL_CLOSE);
- translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
- translate(SSH1_SMSG_X11_OPEN);
- translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
- translate(SSH1_MSG_PORT_OPEN);
- translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
- translate(SSH1_SMSG_AGENT_OPEN);
- translate(SSH1_MSG_IGNORE);
- translate(SSH1_CMSG_EXIT_CONFIRMATION);
- translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
- translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
- translate(SSH1_MSG_DEBUG);
- translate(SSH1_CMSG_REQUEST_COMPRESSION);
- translate(SSH1_CMSG_AUTH_TIS);
- translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
- translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
- translate(SSH1_CMSG_AUTH_CCARD);
- translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
- translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
- return "unknown";
-}
-static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
-{
- translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
- translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
- translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
- translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
- translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
- translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
- translate(SSH2_MSG_DISCONNECT);
- translate(SSH2_MSG_IGNORE);
- translate(SSH2_MSG_UNIMPLEMENTED);
- translate(SSH2_MSG_DEBUG);
- translate(SSH2_MSG_SERVICE_REQUEST);
- translate(SSH2_MSG_SERVICE_ACCEPT);
- translate(SSH2_MSG_KEXINIT);
- translate(SSH2_MSG_NEWKEYS);
- translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
- translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
- translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
- translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
- translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
- translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
- translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
- translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
- translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
- translate(SSH2_MSG_USERAUTH_REQUEST);
- translate(SSH2_MSG_USERAUTH_FAILURE);
- translate(SSH2_MSG_USERAUTH_SUCCESS);
- translate(SSH2_MSG_USERAUTH_BANNER);
- translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
- translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
- translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
- translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
- translate(SSH2_MSG_GLOBAL_REQUEST);
- translate(SSH2_MSG_REQUEST_SUCCESS);
- translate(SSH2_MSG_REQUEST_FAILURE);
- translate(SSH2_MSG_CHANNEL_OPEN);
- translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
- translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
- translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
- translate(SSH2_MSG_CHANNEL_DATA);
- translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
- translate(SSH2_MSG_CHANNEL_EOF);
- translate(SSH2_MSG_CHANNEL_CLOSE);
- translate(SSH2_MSG_CHANNEL_REQUEST);
- translate(SSH2_MSG_CHANNEL_SUCCESS);
- translate(SSH2_MSG_CHANNEL_FAILURE);
- return "unknown";
-}
-#undef translate
-#undef translatec
-
-/* Enumeration values for fields in SSH-1 packets */
-enum {
- PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
- /* These values are for communicating relevant semantics of
- * fields to the packet logging code. */
- PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
-};
-
-/*
- * Coroutine mechanics for the sillier bits of the code. If these
- * macros look impenetrable to you, you might find it helpful to
- * read
- *
- * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
- *
- * which explains the theory behind these macros.
- *
- * In particular, if you are getting `case expression not constant'
- * errors when building with MS Visual Studio, this is because MS's
- * Edit and Continue debugging feature causes their compiler to
- * violate ANSI C. To disable Edit and Continue debugging:
- *
- * - right-click ssh.c in the FileView
- * - click Settings
- * - select the C/C++ tab and the General category
- * - under `Debug info:', select anything _other_ than `Program
- * Database for Edit and Continue'.
- */
-#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
-#define crState(t) \
- struct t *s; \
- if (!ssh->t) ssh->t = snew(struct t); \
- s = ssh->t;
-#define crFinish(z) } *crLine = 0; return (z); }
-#define crFinishV } *crLine = 0; return; }
-#define crReturn(z) \
- do {\
- *crLine =__LINE__; return (z); case __LINE__:;\
- } while (0)
-#define crReturnV \
- do {\
- *crLine=__LINE__; return; case __LINE__:;\
- } while (0)
-#define crStop(z) do{ *crLine = 0; return (z); }while(0)
-#define crStopV do{ *crLine = 0; return; }while(0)
-#define crWaitUntil(c) do { crReturn(0); } while (!(c))
-#define crWaitUntilV(c) do { crReturnV; } while (!(c))
-
-typedef struct ssh_tag *Ssh;
-struct Packet;
-
-static struct Packet *ssh1_pkt_init(int pkt_type);
-static struct Packet *ssh2_pkt_init(int pkt_type);
-static void ssh_pkt_ensure(struct Packet *, int length);
-static void ssh_pkt_adddata(struct Packet *, void *data, int len);
-static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
-static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
-static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
-static void ssh_pkt_addstring_start(struct Packet *);
-static void ssh_pkt_addstring_str(struct Packet *, char *data);
-static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
-static void ssh_pkt_addstring(struct Packet *, char *data);
-static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
-static void ssh1_pkt_addmp(struct Packet *, Bignum b);
-static void ssh2_pkt_addmp(struct Packet *, Bignum b);
-static int ssh2_pkt_construct(Ssh, struct Packet *);
-static void ssh2_pkt_send(Ssh, struct Packet *);
-static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
-static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
- struct Packet *pktin);
-static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
- struct Packet *pktin);
-static void ssh2_channel_check_close(struct ssh_channel *c);
-static void ssh_channel_destroy(struct ssh_channel *c);
-
-/*
- * Buffer management constants. There are several of these for
- * various different purposes:
- *
- * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
- * on a local data stream before we throttle the whole SSH
- * connection (in SSH-1 only). Throttling the whole connection is
- * pretty drastic so we set this high in the hope it won't
- * happen very often.
- *
- * - SSH_MAX_BACKLOG is the amount of backlog that must build up
- * on the SSH connection itself before we defensively throttle
- * _all_ local data streams. This is pretty drastic too (though
- * thankfully unlikely in SSH-2 since the window mechanism should
- * ensure that the server never has any need to throttle its end
- * of the connection), so we set this high as well.
- *
- * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
- * channels.
- *
- * - OUR_V2_BIGWIN is the window size we advertise for the only
- * channel in a simple connection. It must be <= INT_MAX.
- *
- * - OUR_V2_MAXPKT is the official "maximum packet size" we send
- * to the remote side. This actually has nothing to do with the
- * size of the _packet_, but is instead a limit on the amount
- * of data we're willing to receive in a single SSH2 channel
- * data message.
- *
- * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
- * _packet_ we're prepared to cope with. It must be a multiple
- * of the cipher block size, and must be at least 35000.
- */
-
-#define SSH1_BUFFER_LIMIT 32768
-#define SSH_MAX_BACKLOG 32768
-#define OUR_V2_WINSIZE 16384
-#define OUR_V2_BIGWIN 0x7fffffff
-#define OUR_V2_MAXPKT 0x4000UL
-#define OUR_V2_PACKETLIMIT 0x9000UL
-
-const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
-
-const static struct ssh_mac *macs[] = {
- &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
-};
-const static struct ssh_mac *buggymacs[] = {
- &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
-};
-
-static void *ssh_comp_none_init(void)
-{
- return NULL;
-}
-static void ssh_comp_none_cleanup(void *handle)
-{
-}
-static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
- unsigned char **outblock, int *outlen)
-{
- return 0;
-}
-static int ssh_comp_none_disable(void *handle)
-{
- return 0;
-}
-const static struct ssh_compress ssh_comp_none = {
- "none", NULL,
- ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
- ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
- ssh_comp_none_disable, NULL
-};
-extern const struct ssh_compress ssh_zlib;
-const static struct ssh_compress *compressions[] = {
- &ssh_zlib, &ssh_comp_none
-};
-
-enum { /* channel types */
- CHAN_MAINSESSION,
- CHAN_X11,
- CHAN_AGENT,
- CHAN_SOCKDATA,
- CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
- /*
- * CHAN_ZOMBIE is used to indicate a channel for which we've
- * already destroyed the local data source: for instance, if a
- * forwarded port experiences a socket error on the local side, we
- * immediately destroy its local socket and turn the SSH channel
- * into CHAN_ZOMBIE.
- */
- CHAN_ZOMBIE
-};
-
-/*
- * little structure to keep track of outstanding WINDOW_ADJUSTs
- */
-struct winadj {
- struct winadj *next;
- unsigned size;
-};
-
-/*
- * 2-3-4 tree storing channels.
- */
-struct ssh_channel {
- Ssh ssh; /* pointer back to main context */
- unsigned remoteid, localid;
- int type;
- /* True if we opened this channel but server hasn't confirmed. */
- int halfopen;
- /*
- * In SSH-1, this value contains four bits:
- *
- * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
- * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
- * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
- * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
- *
- * A channel is completely finished with when all four bits are set.
- *
- * In SSH-2, the four bits mean:
- *
- * 1 We have sent SSH2_MSG_CHANNEL_EOF.
- * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
- * 4 We have received SSH2_MSG_CHANNEL_EOF.
- * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
- *
- * A channel is completely finished with when we have both sent
- * and received CLOSE.
- *
- * The symbolic constants below use the SSH-2 terminology, which
- * is a bit confusing in SSH-1, but we have to use _something_.
- */
-#define CLOSES_SENT_EOF 1
-#define CLOSES_SENT_CLOSE 2
-#define CLOSES_RCVD_EOF 4
-#define CLOSES_RCVD_CLOSE 8
- int closes;
-
- /*
- * This flag indicates that an EOF is pending on the outgoing side
- * of the channel: that is, wherever we're getting the data for
- * this channel has sent us some data followed by EOF. We can't
- * actually send the EOF until we've finished sending the data, so
- * we set this flag instead to remind us to do so once our buffer
- * is clear.
- */
- int pending_eof;
-
- /*
- * True if this channel is causing the underlying connection to be
- * throttled.
- */
- int throttling_conn;
- union {
- struct ssh2_data_channel {
- bufchain outbuffer;
- unsigned remwindow, remmaxpkt;
- /* locwindow is signed so we can cope with excess data. */
- int locwindow, locmaxwin;
- /*
- * remlocwin is the amount of local window that we think
- * the remote end had available to it after it sent the
- * last data packet or window adjust ack.
- */
- int remlocwin;
- /*
- * These store the list of window adjusts that haven't
- * been acked.
- */
- struct winadj *winadj_head, *winadj_tail;
- enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
- } v2;
- } v;
- union {
- struct ssh_agent_channel {
- unsigned char *message;
- unsigned char msglen[4];
- unsigned lensofar, totallen;
- } a;
- struct ssh_x11_channel {
- Socket s;
- } x11;
- struct ssh_pfd_channel {
- Socket s;
- } pfd;
- } u;
-};
-
-/*
- * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
- * use this structure in different ways, reflecting SSH-2's
- * altogether saner approach to port forwarding.
- *
- * In SSH-1, you arrange a remote forwarding by sending the server
- * the remote port number, and the local destination host:port.
- * When a connection comes in, the server sends you back that
- * host:port pair, and you connect to it. This is a ready-made
- * security hole if you're not on the ball: a malicious server
- * could send you back _any_ host:port pair, so if you trustingly
- * connect to the address it gives you then you've just opened the
- * entire inside of your corporate network just by connecting
- * through it to a dodgy SSH server. Hence, we must store a list of
- * host:port pairs we _are_ trying to forward to, and reject a
- * connection request from the server if it's not in the list.
- *
- * In SSH-2, each side of the connection minds its own business and
- * doesn't send unnecessary information to the other. You arrange a
- * remote forwarding by sending the server just the remote port
- * number. When a connection comes in, the server tells you which
- * of its ports was connected to; and _you_ have to remember what
- * local host:port pair went with that port number.
- *
- * Hence, in SSH-1 this structure is indexed by destination
- * host:port pair, whereas in SSH-2 it is indexed by source port.
- */
-struct ssh_portfwd; /* forward declaration */
-
-struct ssh_rportfwd {
- unsigned sport, dport;
- char dhost[256];
- char *sportdesc;
- struct ssh_portfwd *pfrec;
-};
-#define free_rportfwd(pf) ( \
- ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
-
-/*
- * Separately to the rportfwd tree (which is for looking up port
- * open requests from the server), a tree of _these_ structures is
- * used to keep track of all the currently open port forwardings,
- * so that we can reconfigure in mid-session if the user requests
- * it.
- */
-struct ssh_portfwd {
- enum { DESTROY, KEEP, CREATE } status;
- int type;
- unsigned sport, dport;
- char *saddr, *daddr;
- char *sserv, *dserv;
- struct ssh_rportfwd *remote;
- int addressfamily;
- void *local;
-};
-#define free_portfwd(pf) ( \
- ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
- sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
-
-struct Packet {
- long length; /* length of `data' actually used */
- long forcepad; /* SSH-2: force padding to at least this length */
- int type; /* only used for incoming packets */
- unsigned long sequence; /* SSH-2 incoming sequence number */
- unsigned char *data; /* allocated storage */
- unsigned char *body; /* offset of payload within `data' */
- long savedpos; /* temporary index into `data' (for strings) */
- long maxlen; /* amount of storage allocated for `data' */
- long encrypted_len; /* for SSH-2 total-size counting */
-
- /*
- * State associated with packet logging
- */
- int logmode;
- int nblanks;
- struct logblank_t *blanks;
-};
-
-static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
- struct Packet *pktin);
-static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
- struct Packet *pktin);
-static void ssh1_protocol_setup(Ssh ssh);
-static void ssh2_protocol_setup(Ssh ssh);
-static void ssh_size(void *handle, int width, int height);
-static void ssh_special(void *handle, Telnet_Special);
-static int ssh2_try_send(struct ssh_channel *c);
-static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
-static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
-static void ssh2_set_window(struct ssh_channel *c, int newwin);
-static int ssh_sendbuffer(void *handle);
-static int ssh_do_close(Ssh ssh, int notify_exit);
-static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
-static int ssh2_pkt_getbool(struct Packet *pkt);
-static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
-static void ssh2_timer(void *ctx, long now);
-static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
- struct Packet *pktin);
-
-struct rdpkt1_state_tag {
- long len, pad, biglen, to_read;
- unsigned long realcrc, gotcrc;
- unsigned char *p;
- int i;
- int chunk;
- struct Packet *pktin;
-};
-
-struct rdpkt2_state_tag {
- long len, pad, payload, packetlen, maclen;
- int i;
- int cipherblk;
- unsigned long incoming_sequence;
- struct Packet *pktin;
-};
-
-typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
-typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
-
-struct queued_handler;
-struct queued_handler {
- int msg1, msg2;
- chandler_fn_t handler;
- void *ctx;
- struct queued_handler *next;
-};
-
-struct ssh_tag {
- const struct plug_function_table *fn;
- /* the above field _must_ be first in the structure */
-
- char *v_c, *v_s;
- void *exhash;
-
- Socket s;
-
- void *ldisc;
- void *logctx;
-
- unsigned char session_key[32];
- int v1_compressing;
- int v1_remote_protoflags;
- int v1_local_protoflags;
- int agentfwd_enabled;
- int X11_fwd_enabled;
- int remote_bugs;
- const struct ssh_cipher *cipher;
- void *v1_cipher_ctx;
- void *crcda_ctx;
- const struct ssh2_cipher *cscipher, *sccipher;
- void *cs_cipher_ctx, *sc_cipher_ctx;
- const struct ssh_mac *csmac, *scmac;
- void *cs_mac_ctx, *sc_mac_ctx;
- const struct ssh_compress *cscomp, *sccomp;
- void *cs_comp_ctx, *sc_comp_ctx;
- const struct ssh_kex *kex;
- const struct ssh_signkey *hostkey;
- unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
- int v2_session_id_len;
- void *kex_ctx;
-
- char *savedhost;
- int savedport;
- int send_ok;
- int echoing, editing;
-
- void *frontend;
-
- int ospeed, ispeed; /* temporaries */
- int term_width, term_height;
-
- tree234 *channels; /* indexed by local id */
- struct ssh_channel *mainchan; /* primary session channel */
- int ncmode; /* is primary channel direct-tcpip? */
- int exitcode;
- int close_expected;
- int clean_exit;
-
- tree234 *rportfwds, *portfwds;
-
- enum {
- SSH_STATE_PREPACKET,
- SSH_STATE_BEFORE_SIZE,
- SSH_STATE_INTERMED,
- SSH_STATE_SESSION,
- SSH_STATE_CLOSED
- } state;
-
- int size_needed, eof_needed;
- int sent_console_eof;
- int got_pty; /* affects EOF behaviour on main channel */
-
- struct Packet **queue;
- int queuelen, queuesize;
- int queueing;
- unsigned char *deferred_send_data;
- int deferred_len, deferred_size;
-
- /*
- * Gross hack: pscp will try to start SFTP but fall back to
- * scp1 if that fails. This variable is the means by which
- * scp.c can reach into the SSH code and find out which one it
- * got.
- */
- int fallback_cmd;
-
- bufchain banner; /* accumulates banners during do_ssh2_authconn */
-
- Pkt_KCtx pkt_kctx;
- Pkt_ACtx pkt_actx;
-
- struct X11Display *x11disp;
-
- int version;
- int conn_throttle_count;
- int overall_bufsize;
- int throttled_all;
- int v1_stdout_throttling;
- unsigned long v2_outgoing_sequence;
-
- int ssh1_rdpkt_crstate;
- int ssh2_rdpkt_crstate;
- int do_ssh_init_crstate;
- int ssh_gotdata_crstate;
- int do_ssh1_login_crstate;
- int do_ssh1_connection_crstate;
- int do_ssh2_transport_crstate;
- int do_ssh2_authconn_crstate;
-
- void *do_ssh_init_state;
- void *do_ssh1_login_state;
- void *do_ssh2_transport_state;
- void *do_ssh2_authconn_state;
-
- struct rdpkt1_state_tag rdpkt1_state;
- struct rdpkt2_state_tag rdpkt2_state;
-
- /* SSH-1 and SSH-2 use this for different things, but both use it */
- int protocol_initial_phase_done;
-
- void (*protocol) (Ssh ssh, void *vin, int inlen,
- struct Packet *pkt);
- struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
-
- /*
- * We maintain our own copy of a Conf structure here. That way,
- * when we're passed a new one for reconfiguration, we can check
- * the differences and potentially reconfigure port forwardings
- * etc in mid-session.
- */
- Conf *conf;
-
- /*
- * Values cached out of conf so as to avoid the tree234 lookup
- * cost every time they're used.
- */
- int logomitdata;
-
- /*
- * Dynamically allocated username string created during SSH
- * login. Stored in here rather than in the coroutine state so
- * that it'll be reliably freed if we shut down the SSH session
- * at some unexpected moment.
- */
- char *username;
-
- /*
- * Used to transfer data back from async callbacks.
- */
- void *agent_response;
- int agent_response_len;
- int user_response;
-
- /*
- * The SSH connection can be set as `frozen', meaning we are
- * not currently accepting incoming data from the network. This
- * is slightly more serious than setting the _socket_ as
- * frozen, because we may already have had data passed to us
- * from the network which we need to delay processing until
- * after the freeze is lifted, so we also need a bufchain to
- * store that data.
- */
- int frozen;
- bufchain queued_incoming_data;
-
- /*
- * Dispatch table for packet types that we may have to deal
- * with at any time.
- */
- handler_fn_t packet_dispatch[256];
-
- /*
- * Queues of one-off handler functions for success/failure
- * indications from a request.
- */
- struct queued_handler *qhead, *qtail;
-
- /*
- * This module deals with sending keepalives.
- */
- Pinger pinger;
-
- /*
- * Track incoming and outgoing data sizes and time, for
- * size-based rekeys.
- */
- unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
- unsigned long max_data_size;
- int kex_in_progress;
- long next_rekey, last_rekey;
- char *deferred_rekey_reason; /* points to STATIC string; don't free */
-
- /*
- * Fully qualified host name, which we need if doing GSSAPI.
- */
- char *fullhostname;
-
-#ifndef NO_GSSAPI
- /*
- * GSSAPI libraries for this session.
- */
- struct ssh_gss_liblist *gsslibs;
-#endif
-};
-
-#define logevent(s) logevent(ssh->frontend, s)
-
-/* logevent, only printf-formatted. */
-static void logeventf(Ssh ssh, const char *fmt, ...)
-{
- va_list ap;
- char *buf;
-
- va_start(ap, fmt);
- buf = dupvprintf(fmt, ap);
- va_end(ap);
- logevent(buf);
- sfree(buf);
-}
-
-#define bombout(msg) \
- do { \
- char *text = dupprintf msg; \
- ssh_do_close(ssh, FALSE); \
- logevent(text); \
- connection_fatal(ssh->frontend, "%s", text); \
- sfree(text); \
- } while (0)
-
-/* Functions to leave bits out of the SSH packet log file. */
-
-static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
-{
- if (conf_get_int(ssh->conf, CONF_logomitpass))
- pkt->logmode = blanktype;
-}
-
-static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
-{
- if (ssh->logomitdata)
- pkt->logmode = blanktype;
-}
-
-static void end_log_omission(Ssh ssh, struct Packet *pkt)
-{
- pkt->logmode = PKTLOG_EMIT;
-}
-
-/* Helper function for common bits of parsing ttymodes. */
-static void parse_ttymodes(Ssh ssh,
- void (*do_mode)(void *data, char *mode, char *val),
- void *data)
-{
- char *key, *val;
-
- for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
- val != NULL;
- val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
- /*
- * val[0] is either 'V', indicating that an explicit value
- * follows it, or 'A' indicating that we should pass the
- * value through from the local environment via get_ttymode.
- */
- if (val[0] == 'A')
- val = get_ttymode(ssh->frontend, key);
- else
- val++; /* skip the 'V' */
- if (val)
- do_mode(data, key, val);
- }
-}
-
-static int ssh_channelcmp(void *av, void *bv)
-{
- struct ssh_channel *a = (struct ssh_channel *) av;
- struct ssh_channel *b = (struct ssh_channel *) bv;
- if (a->localid < b->localid)
- return -1;
- if (a->localid > b->localid)
- return +1;
- return 0;
-}
-static int ssh_channelfind(void *av, void *bv)
-{
- unsigned *a = (unsigned *) av;
- struct ssh_channel *b = (struct ssh_channel *) bv;
- if (*a < b->localid)
- return -1;
- if (*a > b->localid)
- return +1;
- return 0;
-}
-
-static int ssh_rportcmp_ssh1(void *av, void *bv)
-{
- struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
- struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
- int i;
- if ( (i = strcmp(a->dhost, b->dhost)) != 0)
- return i < 0 ? -1 : +1;
- if (a->dport > b->dport)
- return +1;
- if (a->dport < b->dport)
- return -1;
- return 0;
-}
-
-static int ssh_rportcmp_ssh2(void *av, void *bv)
-{
- struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
- struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
-
- if (a->sport > b->sport)
- return +1;
- if (a->sport < b->sport)
- return -1;
- return 0;
-}
-
-/*
- * Special form of strcmp which can cope with NULL inputs. NULL is
- * defined to sort before even the empty string.
- */
-static int nullstrcmp(const char *a, const char *b)
-{
- if (a == NULL && b == NULL)
- return 0;
- if (a == NULL)
- return -1;
- if (b == NULL)
- return +1;
- return strcmp(a, b);
-}
-
-static int ssh_portcmp(void *av, void *bv)
-{
- struct ssh_portfwd *a = (struct ssh_portfwd *) av;
- struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
- int i;
- if (a->type > b->type)
- return +1;
- if (a->type < b->type)
- return -1;
- if (a->addressfamily > b->addressfamily)
- return +1;
- if (a->addressfamily < b->addressfamily)
- return -1;
- if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
- return i < 0 ? -1 : +1;
- if (a->sport > b->sport)
- return +1;
- if (a->sport < b->sport)
- return -1;
- if (a->type != 'D') {
- if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
- return i < 0 ? -1 : +1;
- if (a->dport > b->dport)
- return +1;
- if (a->dport < b->dport)
- return -1;
- }
- return 0;
-}
-
-static int alloc_channel_id(Ssh ssh)
-{
- const unsigned CHANNEL_NUMBER_OFFSET = 256;
- unsigned low, high, mid;
- int tsize;
- struct ssh_channel *c;
-
- /*
- * First-fit allocation of channel numbers: always pick the
- * lowest unused one. To do this, binary-search using the
- * counted B-tree to find the largest channel ID which is in a
- * contiguous sequence from the beginning. (Precisely
- * everything in that sequence must have ID equal to its tree
- * index plus CHANNEL_NUMBER_OFFSET.)
- */
- tsize = count234(ssh->channels);
-
- low = -1;
- high = tsize;
- while (high - low > 1) {
- mid = (high + low) / 2;
- c = index234(ssh->channels, mid);
- if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
- low = mid; /* this one is fine */
- else
- high = mid; /* this one is past it */
- }
- /*
- * Now low points to either -1, or the tree index of the
- * largest ID in the initial sequence.
- */
- {
- unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
- assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
- }
- return low + 1 + CHANNEL_NUMBER_OFFSET;
-}
-
-static void c_write_stderr(int trusted, const char *buf, int len)
-{
- int i;
- for (i = 0; i < len; i++)
- if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
- fputc(buf[i], stderr);
- fflush(stderr);
-}
-
-static void c_write(Ssh ssh, const char *buf, int len)
-{
- if (flags & FLAG_STDERR)
- c_write_stderr(1, buf, len);
- else
- from_backend(ssh->frontend, 1, buf, len);
-}
-
-static void c_write_untrusted(Ssh ssh, const char *buf, int len)
-{
- if (flags & FLAG_STDERR)
- c_write_stderr(0, buf, len);
- else
- from_backend_untrusted(ssh->frontend, buf, len);
-}
-
-static void c_write_str(Ssh ssh, const char *buf)
-{
- c_write(ssh, buf, strlen(buf));
-}
-
-static void ssh_free_packet(struct Packet *pkt)
-{
- sfree(pkt->data);
- sfree(pkt);
-}
-static struct Packet *ssh_new_packet(void)
-{
- struct Packet *pkt = snew(struct Packet);
-
- pkt->body = pkt->data = NULL;
- pkt->maxlen = 0;
- pkt->logmode = PKTLOG_EMIT;
- pkt->nblanks = 0;
- pkt->blanks = NULL;
-
- return pkt;
-}
-
-/*
- * Collect incoming data in the incoming packet buffer.
- * Decipher and verify the packet when it is completely read.
- * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
- * Update the *data and *datalen variables.
- * Return a Packet structure when a packet is completed.
- */
-static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
-{
- struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
-
- crBegin(ssh->ssh1_rdpkt_crstate);
-
- st->pktin = ssh_new_packet();
-
- st->pktin->type = 0;
- st->pktin->length = 0;
-
- for (st->i = st->len = 0; st->i < 4; st->i++) {
- while ((*datalen) == 0)
- crReturn(NULL);
- st->len = (st->len << 8) + **data;
- (*data)++, (*datalen)--;
- }
-
- st->pad = 8 - (st->len % 8);
- st->biglen = st->len + st->pad;
- st->pktin->length = st->len - 5;
-
- if (st->biglen < 0) {
- bombout(("Extremely large packet length from server suggests"
- " data stream corruption"));
- ssh_free_packet(st->pktin);
- crStop(NULL);
- }
-
- st->pktin->maxlen = st->biglen;
- st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
-
- st->to_read = st->biglen;
- st->p = st->pktin->data;
- while (st->to_read > 0) {
- st->chunk = st->to_read;
- while ((*datalen) == 0)
- crReturn(NULL);
- if (st->chunk > (*datalen))
- st->chunk = (*datalen);
- memcpy(st->p, *data, st->chunk);
- *data += st->chunk;
- *datalen -= st->chunk;
- st->p += st->chunk;
- st->to_read -= st->chunk;
- }
-
- if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
- st->biglen, NULL)) {
- bombout(("Network attack (CRC compensation) detected!"));
- ssh_free_packet(st->pktin);
- crStop(NULL);
- }
-
- if (ssh->cipher)
- ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
-
- st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
- st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
- if (st->gotcrc != st->realcrc) {
- bombout(("Incorrect CRC received on packet"));
- ssh_free_packet(st->pktin);
- crStop(NULL);
- }
-
- st->pktin->body = st->pktin->data + st->pad + 1;
- st->pktin->savedpos = 0;
-
- if (ssh->v1_compressing) {
- unsigned char *decompblk;
- int decomplen;
- if (!zlib_decompress_block(ssh->sc_comp_ctx,
- st->pktin->body - 1, st->pktin->length + 1,
- &decompblk, &decomplen)) {
- bombout(("Zlib decompression encountered invalid data"));
- ssh_free_packet(st->pktin);
- crStop(NULL);
- }
-
- if (st->pktin->maxlen < st->pad + decomplen) {
- st->pktin->maxlen = st->pad + decomplen;
- st->pktin->data = sresize(st->pktin->data,
- st->pktin->maxlen + APIEXTRA,
- unsigned char);
- st->pktin->body = st->pktin->data + st->pad + 1;
- }
-
- memcpy(st->pktin->body - 1, decompblk, decomplen);
- sfree(decompblk);
- st->pktin->length = decomplen - 1;
- }
-
- st->pktin->type = st->pktin->body[-1];
-
- /*
- * Log incoming packet, possibly omitting sensitive fields.
- */
- if (ssh->logctx) {
- int nblanks = 0;
- struct logblank_t blank;
- if (ssh->logomitdata) {
- int do_blank = FALSE, blank_prefix = 0;
- /* "Session data" packets - omit the data field */
- if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
- (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
- do_blank = TRUE; blank_prefix = 4;
- } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
- do_blank = TRUE; blank_prefix = 8;
- }
- if (do_blank) {
- blank.offset = blank_prefix;
- blank.len = st->pktin->length;
- blank.type = PKTLOG_OMIT;
- nblanks = 1;
- }
- }
- log_packet(ssh->logctx,
- PKT_INCOMING, st->pktin->type,
- ssh1_pkt_type(st->pktin->type),
- st->pktin->body, st->pktin->length,
- nblanks, &blank, NULL);
- }
-
- crFinish(st->pktin);
-}
-
-static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
-{
- struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
-
- crBegin(ssh->ssh2_rdpkt_crstate);
-
- st->pktin = ssh_new_packet();
-
- st->pktin->type = 0;
- st->pktin->length = 0;
- if (ssh->sccipher)
- st->cipherblk = ssh->sccipher->blksize;
- else
- st->cipherblk = 8;
- if (st->cipherblk < 8)
- st->cipherblk = 8;
- st->maclen = ssh->scmac ? ssh->scmac->len : 0;
-
- if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
- ssh->scmac) {
- /*
- * When dealing with a CBC-mode cipher, we want to avoid the
- * possibility of an attacker's tweaking the ciphertext stream
- * so as to cause us to feed the same block to the block
- * cipher more than once and thus leak information
- * (VU#958563). The way we do this is not to take any
- * decisions on the basis of anything we've decrypted until
- * we've verified it with a MAC. That includes the packet
- * length, so we just read data and check the MAC repeatedly,
- * and when the MAC passes, see if the length we've got is
- * plausible.
- */
-
- /* May as well allocate the whole lot now. */
- st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
- unsigned char);
-
- /* Read an amount corresponding to the MAC. */
- for (st->i = 0; st->i < st->maclen; st->i++) {
- while ((*datalen) == 0)
- crReturn(NULL);
- st->pktin->data[st->i] = *(*data)++;
- (*datalen)--;
- }
-
- st->packetlen = 0;
- {
- unsigned char seq[4];
- ssh->scmac->start(ssh->sc_mac_ctx);
- PUT_32BIT(seq, st->incoming_sequence);
- ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
- }
-
- for (;;) { /* Once around this loop per cipher block. */
- /* Read another cipher-block's worth, and tack it onto the end. */
- for (st->i = 0; st->i < st->cipherblk; st->i++) {
- while ((*datalen) == 0)
- crReturn(NULL);
- st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
- (*datalen)--;
- }
- /* Decrypt one more block (a little further back in the stream). */
- ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
- st->pktin->data + st->packetlen,
- st->cipherblk);
- /* Feed that block to the MAC. */
- ssh->scmac->bytes(ssh->sc_mac_ctx,
- st->pktin->data + st->packetlen, st->cipherblk);
- st->packetlen += st->cipherblk;
- /* See if that gives us a valid packet. */
- if (ssh->scmac->verresult(ssh->sc_mac_ctx,
- st->pktin->data + st->packetlen) &&
- (st->len = GET_32BIT(st->pktin->data)) + 4 == st->packetlen)
- break;
- if (st->packetlen >= OUR_V2_PACKETLIMIT) {
- bombout(("No valid incoming packet found"));
- ssh_free_packet(st->pktin);
- crStop(NULL);
- }
- }
- st->pktin->maxlen = st->packetlen + st->maclen;
- st->pktin->data = sresize(st->pktin->data,
- st->pktin->maxlen + APIEXTRA,
- unsigned char);
- } else {
- st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
-
- /*
- * Acquire and decrypt the first block of the packet. This will
- * contain the length and padding details.
- */
- for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
- while ((*datalen) == 0)
- crReturn(NULL);
- st->pktin->data[st->i] = *(*data)++;
- (*datalen)--;
- }
-
- if (ssh->sccipher)
- ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
- st->pktin->data, st->cipherblk);
-
- /*
- * Now get the length figure.
- */
- st->len = GET_32BIT(st->pktin->data);
-
- /*
- * _Completely_ silly lengths should be stomped on before they
- * do us any more damage.
- */
- if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
- (st->len + 4) % st->cipherblk != 0) {
- bombout(("Incoming packet was garbled on decryption"));
- ssh_free_packet(st->pktin);
- crStop(NULL);
- }
-
- /*
- * So now we can work out the total packet length.
- */
- st->packetlen = st->len + 4;
-
- /*
- * Allocate memory for the rest of the packet.
- */
- st->pktin->maxlen = st->packetlen + st->maclen;
- st->pktin->data = sresize(st->pktin->data,
- st->pktin->maxlen + APIEXTRA,
- unsigned char);
-
- /*
- * Read and decrypt the remainder of the packet.
- */
- for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
- st->i++) {
- while ((*datalen) == 0)
- crReturn(NULL);
- st->pktin->data[st->i] = *(*data)++;
- (*datalen)--;
- }
- /* Decrypt everything _except_ the MAC. */
- if (ssh->sccipher)
- ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
- st->pktin->data + st->cipherblk,
- st->packetlen - st->cipherblk);
-
- /*
- * Check the MAC.
- */
- if (ssh->scmac
- && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
- st->len + 4, st->incoming_sequence)) {
- bombout(("Incorrect MAC received on packet"));
- ssh_free_packet(st->pktin);
- crStop(NULL);
- }
- }
- /* Get and sanity-check the amount of random padding. */
- st->pad = st->pktin->data[4];
- if (st->pad < 4 || st->len - st->pad < 1) {
- bombout(("Invalid padding length on received packet"));
- ssh_free_packet(st->pktin);
- crStop(NULL);
- }
- /*
- * This enables us to deduce the payload length.
- */
- st->payload = st->len - st->pad - 1;
-
- st->pktin->length = st->payload + 5;
- st->pktin->encrypted_len = st->packetlen;
-
- st->pktin->sequence = st->incoming_sequence++;
-
- /*
- * Decompress packet payload.
- */
- {
- unsigned char *newpayload;
- int newlen;
- if (ssh->sccomp &&
- ssh->sccomp->decompress(ssh->sc_comp_ctx,
- st->pktin->data + 5, st->pktin->length - 5,
- &newpayload, &newlen)) {
- if (st->pktin->maxlen < newlen + 5) {
- st->pktin->maxlen = newlen + 5;
- st->pktin->data = sresize(st->pktin->data,
- st->pktin->maxlen + APIEXTRA,
- unsigned char);
- }
- st->pktin->length = 5 + newlen;
- memcpy(st->pktin->data + 5, newpayload, newlen);
- sfree(newpayload);
- }
- }
-
- st->pktin->savedpos = 6;
- st->pktin->body = st->pktin->data;
- st->pktin->type = st->pktin->data[5];
-
- /*
- * Log incoming packet, possibly omitting sensitive fields.
- */
- if (ssh->logctx) {
- int nblanks = 0;
- struct logblank_t blank;
- if (ssh->logomitdata) {
- int do_blank = FALSE, blank_prefix = 0;
- /* "Session data" packets - omit the data field */
- if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
- do_blank = TRUE; blank_prefix = 8;
- } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
- do_blank = TRUE; blank_prefix = 12;
- }
- if (do_blank) {
- blank.offset = blank_prefix;
- blank.len = (st->pktin->length-6) - blank_prefix;
- blank.type = PKTLOG_OMIT;
- nblanks = 1;
- }
- }
- log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
- ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
- st->pktin->type),
- st->pktin->data+6, st->pktin->length-6,
- nblanks, &blank, &st->pktin->sequence);
- }
-
- crFinish(st->pktin);
-}
-
-static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
-{
- int pad, biglen, i, pktoffs;
- unsigned long crc;
-#ifdef __SC__
- /*
- * XXX various versions of SC (including 8.8.4) screw up the
- * register allocation in this function and use the same register
- * (D6) for len and as a temporary, with predictable results. The
- * following sledgehammer prevents this.
- */
- volatile
-#endif
- int len;
-
- if (ssh->logctx)
- log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
- ssh1_pkt_type(pkt->data[12]),
- pkt->body, pkt->length - (pkt->body - pkt->data),
- pkt->nblanks, pkt->blanks, NULL);
- sfree(pkt->blanks); pkt->blanks = NULL;
- pkt->nblanks = 0;
-
- if (ssh->v1_compressing) {
- unsigned char *compblk;
- int complen;
- zlib_compress_block(ssh->cs_comp_ctx,
- pkt->data + 12, pkt->length - 12,
- &compblk, &complen);
- ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
- memcpy(pkt->data + 12, compblk, complen);
- sfree(compblk);
- pkt->length = complen + 12;
- }
-
- ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
- pkt->length += 4;
- len = pkt->length - 4 - 8; /* len(type+data+CRC) */
- pad = 8 - (len % 8);
- pktoffs = 8 - pad;
- biglen = len + pad; /* len(padding+type+data+CRC) */
-
- for (i = pktoffs; i < 4+8; i++)
- pkt->data[i] = random_byte();
- crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
- PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
- PUT_32BIT(pkt->data + pktoffs, len);
-
- if (ssh->cipher)
- ssh->cipher->encrypt(ssh->v1_cipher_ctx,
- pkt->data + pktoffs + 4, biglen);
-
- if (offset_p) *offset_p = pktoffs;
- return biglen + 4; /* len(length+padding+type+data+CRC) */
-}
-
-static int s_write(Ssh ssh, void *data, int len)
-{
- if (ssh->logctx)
- log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
- 0, NULL, NULL);
- return sk_write(ssh->s, (char *)data, len);
-}
-
-static void s_wrpkt(Ssh ssh, struct Packet *pkt)
-{
- int len, backlog, offset;
- len = s_wrpkt_prepare(ssh, pkt, &offset);
- backlog = s_write(ssh, pkt->data + offset, len);
- if (backlog > SSH_MAX_BACKLOG)
- ssh_throttle_all(ssh, 1, backlog);
- ssh_free_packet(pkt);
-}
-
-static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
-{
- int len, offset;
- len = s_wrpkt_prepare(ssh, pkt, &offset);
- if (ssh->deferred_len + len > ssh->deferred_size) {
- ssh->deferred_size = ssh->deferred_len + len + 128;
- ssh->deferred_send_data = sresize(ssh->deferred_send_data,
- ssh->deferred_size,
- unsigned char);
- }
- memcpy(ssh->deferred_send_data + ssh->deferred_len,
- pkt->data + offset, len);
- ssh->deferred_len += len;
- ssh_free_packet(pkt);
-}
-
-/*
- * Construct a SSH-1 packet with the specified contents.
- * (This all-at-once interface used to be the only one, but now SSH-1
- * packets can also be constructed incrementally.)
- */
-static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
-{
- int argtype;
- Bignum bn;
- struct Packet *pkt;
-
- pkt = ssh1_pkt_init(pkttype);
-
- while ((argtype = va_arg(ap, int)) != PKT_END) {
- unsigned char *argp, argchar;
- char *sargp;
- unsigned long argint;
- int arglen;
- switch (argtype) {
- /* Actual fields in the packet */
- case PKT_INT:
- argint = va_arg(ap, int);
- ssh_pkt_adduint32(pkt, argint);
- break;
- case PKT_CHAR:
- argchar = (unsigned char) va_arg(ap, int);
- ssh_pkt_addbyte(pkt, argchar);
- break;
- case PKT_DATA:
- argp = va_arg(ap, unsigned char *);
- arglen = va_arg(ap, int);
- ssh_pkt_adddata(pkt, argp, arglen);
- break;
- case PKT_STR:
- sargp = va_arg(ap, char *);
- ssh_pkt_addstring(pkt, sargp);
- break;
- case PKT_BIGNUM:
- bn = va_arg(ap, Bignum);
- ssh1_pkt_addmp(pkt, bn);
- break;
- /* Tokens for modifications to packet logging */
- case PKTT_PASSWORD:
- dont_log_password(ssh, pkt, PKTLOG_BLANK);
- break;
- case PKTT_DATA:
- dont_log_data(ssh, pkt, PKTLOG_OMIT);
- break;
- case PKTT_OTHER:
- end_log_omission(ssh, pkt);
- break;
- }
- }
-
- return pkt;
-}
-
-static void send_packet(Ssh ssh, int pkttype, ...)
-{
- struct Packet *pkt;
- va_list ap;
- va_start(ap, pkttype);
- pkt = construct_packet(ssh, pkttype, ap);
- va_end(ap);
- s_wrpkt(ssh, pkt);
-}
-
-static void defer_packet(Ssh ssh, int pkttype, ...)
-{
- struct Packet *pkt;
- va_list ap;
- va_start(ap, pkttype);
- pkt = construct_packet(ssh, pkttype, ap);
- va_end(ap);
- s_wrpkt_defer(ssh, pkt);
-}
-
-static int ssh_versioncmp(char *a, char *b)
-{
- char *ae, *be;
- unsigned long av, bv;
-
- av = strtoul(a, &ae, 10);
- bv = strtoul(b, &be, 10);
- if (av != bv)
- return (av < bv ? -1 : +1);
- if (*ae == '.')
- ae++;
- if (*be == '.')
- be++;
- av = strtoul(ae, &ae, 10);
- bv = strtoul(be, &be, 10);
- if (av != bv)
- return (av < bv ? -1 : +1);
- return 0;
-}
-
-/*
- * Utility routines for putting an SSH-protocol `string' and
- * `uint32' into a hash state.
- */
-static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
-{
- unsigned char lenblk[4];
- PUT_32BIT(lenblk, len);
- h->bytes(s, lenblk, 4);
- h->bytes(s, str, len);
-}
-
-static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
-{
- unsigned char intblk[4];
- PUT_32BIT(intblk, i);
- h->bytes(s, intblk, 4);
-}
-
-/*
- * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
- */
-static void ssh_pkt_ensure(struct Packet *pkt, int length)
-{
- if (pkt->maxlen < length) {
- unsigned char *body = pkt->body;
- int offset = body ? body - pkt->data : 0;
- pkt->maxlen = length + 256;
- pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
- if (body) pkt->body = pkt->data + offset;
- }
-}
-static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
-{
- if (pkt->logmode != PKTLOG_EMIT) {
- pkt->nblanks++;
- pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
- assert(pkt->body);
- pkt->blanks[pkt->nblanks-1].offset = pkt->length -
- (pkt->body - pkt->data);
- pkt->blanks[pkt->nblanks-1].len = len;
- pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
- }
- pkt->length += len;
- ssh_pkt_ensure(pkt, pkt->length);
- memcpy(pkt->data + pkt->length - len, data, len);
-}
-static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
-{
- ssh_pkt_adddata(pkt, &byte, 1);
-}
-static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
-{
- ssh_pkt_adddata(pkt, &value, 1);
-}
-static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
-{
- unsigned char x[4];
- PUT_32BIT(x, value);
- ssh_pkt_adddata(pkt, x, 4);
-}
-static void ssh_pkt_addstring_start(struct Packet *pkt)
-{
- ssh_pkt_adduint32(pkt, 0);
- pkt->savedpos = pkt->length;
-}
-static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
-{
- ssh_pkt_adddata(pkt, data, strlen(data));
- PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
-}
-static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
-{
- ssh_pkt_adddata(pkt, data, len);
- PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
-}
-static void ssh_pkt_addstring(struct Packet *pkt, char *data)
-{
- ssh_pkt_addstring_start(pkt);
- ssh_pkt_addstring_str(pkt, data);
-}
-static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
-{
- int len = ssh1_bignum_length(b);
- unsigned char *data = snewn(len, unsigned char);
- (void) ssh1_write_bignum(data, b);
- ssh_pkt_adddata(pkt, data, len);
- sfree(data);
-}
-static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
-{
- unsigned char *p;
- int i, n = (bignum_bitcount(b) + 7) / 8;
- p = snewn(n + 1, unsigned char);
- p[0] = 0;
- for (i = 1; i <= n; i++)
- p[i] = bignum_byte(b, n - i);
- i = 0;
- while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
- i++;
- memmove(p, p + i, n + 1 - i);
- *len = n + 1 - i;
- return p;
-}
-static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
-{
- unsigned char *p;
- int len;
- p = ssh2_mpint_fmt(b, &len);
- ssh_pkt_addstring_start(pkt);
- ssh_pkt_addstring_data(pkt, (char *)p, len);
- sfree(p);
-}
-
-static struct Packet *ssh1_pkt_init(int pkt_type)
-{
- struct Packet *pkt = ssh_new_packet();
- pkt->length = 4 + 8; /* space for length + max padding */
- ssh_pkt_addbyte(pkt, pkt_type);
- pkt->body = pkt->data + pkt->length;
- return pkt;
-}
-
-/* For legacy code (SSH-1 and -2 packet construction used to be separate) */
-#define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
-#define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
-#define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
-#define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
-#define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
-#define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
-#define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
-#define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
-
-static struct Packet *ssh2_pkt_init(int pkt_type)
-{
- struct Packet *pkt = ssh_new_packet();
- pkt->length = 5; /* space for packet length + padding length */
- pkt->forcepad = 0;
- ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
- pkt->body = pkt->data + pkt->length; /* after packet type */
- return pkt;
-}
-
-/*
- * Construct an SSH-2 final-form packet: compress it, encrypt it,
- * put the MAC on it. Final packet, ready to be sent, is stored in
- * pkt->data. Total length is returned.
- */
-static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
-{
- int cipherblk, maclen, padding, i;
-
- if (ssh->logctx)
- log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
- ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
- pkt->body, pkt->length - (pkt->body - pkt->data),
- pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence);
- sfree(pkt->blanks); pkt->blanks = NULL;
- pkt->nblanks = 0;
-
- /*
- * Compress packet payload.
- */
- {
- unsigned char *newpayload;
- int newlen;
- if (ssh->cscomp &&
- ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
- pkt->length - 5,
- &newpayload, &newlen)) {
- pkt->length = 5;
- ssh2_pkt_adddata(pkt, newpayload, newlen);
- sfree(newpayload);
- }
- }
-
- /*
- * Add padding. At least four bytes, and must also bring total
- * length (minus MAC) up to a multiple of the block size.
- * If pkt->forcepad is set, make sure the packet is at least that size
- * after padding.
- */
- cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
- cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
- padding = 4;
- if (pkt->length + padding < pkt->forcepad)
- padding = pkt->forcepad - pkt->length;
- padding +=
- (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
- assert(padding <= 255);
- maclen = ssh->csmac ? ssh->csmac->len : 0;
- ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
- pkt->data[4] = padding;
- for (i = 0; i < padding; i++)
- pkt->data[pkt->length + i] = random_byte();
- PUT_32BIT(pkt->data, pkt->length + padding - 4);
- if (ssh->csmac)
- ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
- pkt->length + padding,
- ssh->v2_outgoing_sequence);
- ssh->v2_outgoing_sequence++; /* whether or not we MACed */
-
- if (ssh->cscipher)
- ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
- pkt->data, pkt->length + padding);
-
- pkt->encrypted_len = pkt->length + padding;
-
- /* Ready-to-send packet starts at pkt->data. We return length. */
- return pkt->length + padding + maclen;
-}
-
-/*
- * Routines called from the main SSH code to send packets. There
- * are quite a few of these, because we have two separate
- * mechanisms for delaying the sending of packets:
- *
- * - In order to send an IGNORE message and a password message in
- * a single fixed-length blob, we require the ability to
- * concatenate the encrypted forms of those two packets _into_ a
- * single blob and then pass it to our <network.h> transport
- * layer in one go. Hence, there's a deferment mechanism which
- * works after packet encryption.
- *
- * - In order to avoid sending any connection-layer messages
- * during repeat key exchange, we have to queue up any such
- * outgoing messages _before_ they are encrypted (and in
- * particular before they're allocated sequence numbers), and
- * then send them once we've finished.
- *
- * I call these mechanisms `defer' and `queue' respectively, so as
- * to distinguish them reasonably easily.
- *
- * The functions send_noqueue() and defer_noqueue() free the packet
- * structure they are passed. Every outgoing packet goes through
- * precisely one of these functions in its life; packets passed to
- * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
- * these or get queued, and then when the queue is later emptied
- * the packets are all passed to defer_noqueue().
- *
- * When using a CBC-mode cipher, it's necessary to ensure that an
- * attacker can't provide data to be encrypted using an IV that they
- * know. We ensure this by prefixing each packet that might contain
- * user data with an SSH_MSG_IGNORE. This is done using the deferral
- * mechanism, so in this case send_noqueue() ends up redirecting to
- * defer_noqueue(). If you don't like this inefficiency, don't use
- * CBC.
- */
-
-static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
-static void ssh_pkt_defersend(Ssh);
-
-/*
- * Send an SSH-2 packet immediately, without queuing or deferring.
- */
-static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
-{
- int len;
- int backlog;
- if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
- /* We need to send two packets, so use the deferral mechanism. */
- ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
- ssh_pkt_defersend(ssh);
- return;
- }
- len = ssh2_pkt_construct(ssh, pkt);
- backlog = s_write(ssh, pkt->data, len);
- if (backlog > SSH_MAX_BACKLOG)
- ssh_throttle_all(ssh, 1, backlog);
-
- ssh->outgoing_data_size += pkt->encrypted_len;
- if (!ssh->kex_in_progress &&
- ssh->max_data_size != 0 &&
- ssh->outgoing_data_size > ssh->max_data_size)
- do_ssh2_transport(ssh, "too much data sent", -1, NULL);
-
- ssh_free_packet(pkt);
-}
-
-/*
- * Defer an SSH-2 packet.
- */
-static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
-{
- int len;
- if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
- ssh->deferred_len == 0 && !noignore &&
- !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
- /*
- * Interpose an SSH_MSG_IGNORE to ensure that user data don't
- * get encrypted with a known IV.
- */
- struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
- ssh2_pkt_addstring_start(ipkt);
- ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
- }
- len = ssh2_pkt_construct(ssh, pkt);
- if (ssh->deferred_len + len > ssh->deferred_size) {
- ssh->deferred_size = ssh->deferred_len + len + 128;
- ssh->deferred_send_data = sresize(ssh->deferred_send_data,
- ssh->deferred_size,
- unsigned char);
- }
- memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
- ssh->deferred_len += len;
- ssh->deferred_data_size += pkt->encrypted_len;
- ssh_free_packet(pkt);
-}
-
-/*
- * Queue an SSH-2 packet.
- */
-static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
-{
- assert(ssh->queueing);
-
- if (ssh->queuelen >= ssh->queuesize) {
- ssh->queuesize = ssh->queuelen + 32;
- ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
- }
-
- ssh->queue[ssh->queuelen++] = pkt;
-}
-
-/*
- * Either queue or send a packet, depending on whether queueing is
- * set.
- */
-static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
-{
- if (ssh->queueing)
- ssh2_pkt_queue(ssh, pkt);
- else
- ssh2_pkt_send_noqueue(ssh, pkt);
-}
-
-/*
- * Either queue or defer a packet, depending on whether queueing is
- * set.
- */
-static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
-{
- if (ssh->queueing)
- ssh2_pkt_queue(ssh, pkt);
- else
- ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
-}
-
-/*
- * Send the whole deferred data block constructed by
- * ssh2_pkt_defer() or SSH-1's defer_packet().
- *
- * The expected use of the defer mechanism is that you call
- * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
- * not currently queueing, this simply sets up deferred_send_data
- * and then sends it. If we _are_ currently queueing, the calls to
- * ssh2_pkt_defer() put the deferred packets on to the queue
- * instead, and therefore ssh_pkt_defersend() has no deferred data
- * to send. Hence, there's no need to make it conditional on
- * ssh->queueing.
- */
-static void ssh_pkt_defersend(Ssh ssh)
-{
- int backlog;
- backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
- ssh->deferred_len = ssh->deferred_size = 0;
- sfree(ssh->deferred_send_data);
- ssh->deferred_send_data = NULL;
- if (backlog > SSH_MAX_BACKLOG)
- ssh_throttle_all(ssh, 1, backlog);
-
- ssh->outgoing_data_size += ssh->deferred_data_size;
- if (!ssh->kex_in_progress &&
- ssh->max_data_size != 0 &&
- ssh->outgoing_data_size > ssh->max_data_size)
- do_ssh2_transport(ssh, "too much data sent", -1, NULL);
- ssh->deferred_data_size = 0;
-}
-
-/*
- * Send a packet whose length needs to be disguised (typically
- * passwords or keyboard-interactive responses).
- */
-static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
- int padsize)
-{
-#if 0
- if (0) {
- /*
- * The simplest way to do this is to adjust the
- * variable-length padding field in the outgoing packet.
- *
- * Currently compiled out, because some Cisco SSH servers
- * don't like excessively padded packets (bah, why's it
- * always Cisco?)
- */
- pkt->forcepad = padsize;
- ssh2_pkt_send(ssh, pkt);
- } else
-#endif
- {
- /*
- * If we can't do that, however, an alternative approach is
- * to use the pkt_defer mechanism to bundle the packet
- * tightly together with an SSH_MSG_IGNORE such that their
- * combined length is a constant. So first we construct the
- * final form of this packet and defer its sending.
- */
- ssh2_pkt_defer(ssh, pkt);
-
- /*
- * Now construct an SSH_MSG_IGNORE which includes a string
- * that's an exact multiple of the cipher block size. (If
- * the cipher is NULL so that the block size is
- * unavailable, we don't do this trick at all, because we
- * gain nothing by it.)
- */
- if (ssh->cscipher &&
- !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
- int stringlen, i;
-
- stringlen = (256 - ssh->deferred_len);
- stringlen += ssh->cscipher->blksize - 1;
- stringlen -= (stringlen % ssh->cscipher->blksize);
- if (ssh->cscomp) {
- /*
- * Temporarily disable actual compression, so we
- * can guarantee to get this string exactly the
- * length we want it. The compression-disabling
- * routine should return an integer indicating how
- * many bytes we should adjust our string length
- * by.
- */
- stringlen -=
- ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
- }
- pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
- ssh2_pkt_addstring_start(pkt);
- for (i = 0; i < stringlen; i++) {
- char c = (char) random_byte();
- ssh2_pkt_addstring_data(pkt, &c, 1);
- }
- ssh2_pkt_defer(ssh, pkt);
- }
- ssh_pkt_defersend(ssh);
- }
-}
-
-/*
- * Send all queued SSH-2 packets. We send them by means of
- * ssh2_pkt_defer_noqueue(), in case they included a pair of
- * packets that needed to be lumped together.
- */
-static void ssh2_pkt_queuesend(Ssh ssh)
-{
- int i;
-
- assert(!ssh->queueing);
-
- for (i = 0; i < ssh->queuelen; i++)
- ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
- ssh->queuelen = 0;
-
- ssh_pkt_defersend(ssh);
-}
-
-#if 0
-void bndebug(char *string, Bignum b)
-{
- unsigned char *p;
- int i, len;
- p = ssh2_mpint_fmt(b, &len);
- debug(("%s", string));
- for (i = 0; i < len; i++)
- debug((" %02x", p[i]));
- debug(("\n"));
- sfree(p);
-}
-#endif
-
-static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
-{
- unsigned char *p;
- int len;
- p = ssh2_mpint_fmt(b, &len);
- hash_string(h, s, p, len);
- sfree(p);
-}
-
-/*
- * Packet decode functions for both SSH-1 and SSH-2.
- */
-static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
-{
- unsigned long value;
- if (pkt->length - pkt->savedpos < 4)
- return 0; /* arrgh, no way to decline (FIXME?) */
- value = GET_32BIT(pkt->body + pkt->savedpos);
- pkt->savedpos += 4;
- return value;
-}
-static int ssh2_pkt_getbool(struct Packet *pkt)
-{
- unsigned long value;
- if (pkt->length - pkt->savedpos < 1)
- return 0; /* arrgh, no way to decline (FIXME?) */
- value = pkt->body[pkt->savedpos] != 0;
- pkt->savedpos++;
- return value;
-}
-static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
-{
- int len;
- *p = NULL;
- *length = 0;
- if (pkt->length - pkt->savedpos < 4)
- return;
- len = GET_32BIT(pkt->body + pkt->savedpos);
- if (len < 0)
- return;
- *length = len;
- pkt->savedpos += 4;
- if (pkt->length - pkt->savedpos < *length)
- return;
- *p = (char *)(pkt->body + pkt->savedpos);
- pkt->savedpos += *length;
-}
-static void *ssh_pkt_getdata(struct Packet *pkt, int length)
-{
- if (pkt->length - pkt->savedpos < length)
- return NULL;
- pkt->savedpos += length;
- return pkt->body + (pkt->savedpos - length);
-}
-static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
- unsigned char **keystr)
-{
- int j;
-
- j = makekey(pkt->body + pkt->savedpos,
- pkt->length - pkt->savedpos,
- key, keystr, 0);
-
- if (j < 0)
- return FALSE;
-
- pkt->savedpos += j;
- assert(pkt->savedpos < pkt->length);
-
- return TRUE;
-}
-static Bignum ssh1_pkt_getmp(struct Packet *pkt)
-{
- int j;
- Bignum b;
-
- j = ssh1_read_bignum(pkt->body + pkt->savedpos,
- pkt->length - pkt->savedpos, &b);
-
- if (j < 0)
- return NULL;
-
- pkt->savedpos += j;
- return b;
-}
-static Bignum ssh2_pkt_getmp(struct Packet *pkt)
-{
- char *p;
- int length;
- Bignum b;
-
- ssh_pkt_getstring(pkt, &p, &length);
- if (!p)
- return NULL;
- if (p[0] & 0x80)
- return NULL;
- b = bignum_from_bytes((unsigned char *)p, length);
- return b;
-}
-
-/*
- * Helper function to add an SSH-2 signature blob to a packet.
- * Expects to be shown the public key blob as well as the signature
- * blob. Normally works just like ssh2_pkt_addstring, but will
- * fiddle with the signature packet if necessary for
- * BUG_SSH2_RSA_PADDING.
- */
-static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
- void *pkblob_v, int pkblob_len,
- void *sigblob_v, int sigblob_len)
-{
- unsigned char *pkblob = (unsigned char *)pkblob_v;
- unsigned char *sigblob = (unsigned char *)sigblob_v;
-
- /* dmemdump(pkblob, pkblob_len); */
- /* dmemdump(sigblob, sigblob_len); */
-
- /*
- * See if this is in fact an ssh-rsa signature and a buggy
- * server; otherwise we can just do this the easy way.
- */
- if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
- (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
- int pos, len, siglen;
-
- /*
- * Find the byte length of the modulus.
- */
-
- pos = 4+7; /* skip over "ssh-rsa" */
- pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
- len = GET_32BIT(pkblob+pos); /* find length of modulus */
- pos += 4; /* find modulus itself */
- while (len > 0 && pkblob[pos] == 0)
- len--, pos++;
- /* debug(("modulus length is %d\n", len)); */
-
- /*
- * Now find the signature integer.
- */
- pos = 4+7; /* skip over "ssh-rsa" */
- siglen = GET_32BIT(sigblob+pos);
- /* debug(("signature length is %d\n", siglen)); */
-
- if (len != siglen) {
- unsigned char newlen[4];
- ssh2_pkt_addstring_start(pkt);
- ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
- /* dmemdump(sigblob, pos); */
- pos += 4; /* point to start of actual sig */
- PUT_32BIT(newlen, len);
- ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
- /* dmemdump(newlen, 4); */
- newlen[0] = 0;
- while (len-- > siglen) {
- ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
- /* dmemdump(newlen, 1); */
- }
- ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
- /* dmemdump(sigblob+pos, siglen); */
- return;
- }
-
- /* Otherwise fall through and do it the easy way. */
- }
-
- ssh2_pkt_addstring_start(pkt);
- ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
-}
-
-/*
- * Examine the remote side's version string and compare it against
- * a list of known buggy implementations.
- */
-static void ssh_detect_bugs(Ssh ssh, char *vstring)
-{
- char *imp; /* pointer to implementation part */
- imp = vstring;
- imp += strcspn(imp, "-");
- if (*imp) imp++;
- imp += strcspn(imp, "-");
- if (*imp) imp++;
-
- ssh->remote_bugs = 0;
-
- /*
- * General notes on server version strings:
- * - Not all servers reporting "Cisco-1.25" have all the bugs listed
- * here -- in particular, we've heard of one that's perfectly happy
- * with SSH1_MSG_IGNOREs -- but this string never seems to change,
- * so we can't distinguish them.
- */
- if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
- (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
- (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
- !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
- !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
- !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
- /*
- * These versions don't support SSH1_MSG_IGNORE, so we have
- * to use a different defence against password length
- * sniffing.
- */
- ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
- logevent("We believe remote version has SSH-1 ignore bug");
- }
-
- if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
- (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
- (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
- /*
- * These versions need a plain password sent; they can't
- * handle having a null and a random length of data after
- * the password.
- */
- ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
- logevent("We believe remote version needs a plain SSH-1 password");
- }
-
- if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
- (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
- (!strcmp(imp, "Cisco-1.25")))) {
- /*
- * These versions apparently have no clue whatever about
- * RSA authentication and will panic and die if they see
- * an AUTH_RSA message.
- */
- ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
- logevent("We believe remote version can't handle SSH-1 RSA authentication");
- }
-
- if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
- (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
- !wc_match("* VShell", imp) &&
- (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
- wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
- wc_match("2.1 *", imp)))) {
- /*
- * These versions have the HMAC bug.
- */
- ssh->remote_bugs |= BUG_SSH2_HMAC;
- logevent("We believe remote version has SSH-2 HMAC bug");
- }
-
- if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
- (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
- !wc_match("* VShell", imp) &&
- (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
- /*
- * These versions have the key-derivation bug (failing to
- * include the literal shared secret in the hashes that
- * generate the keys).
- */
- ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
- logevent("We believe remote version has SSH-2 key-derivation bug");
- }
-
- if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
- (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
- (wc_match("OpenSSH_2.[5-9]*", imp) ||
- wc_match("OpenSSH_3.[0-2]*", imp)))) {
- /*
- * These versions have the SSH-2 RSA padding bug.
- */
- ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
- logevent("We believe remote version has SSH-2 RSA padding bug");
- }
-
- if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
- (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
- wc_match("OpenSSH_2.[0-2]*", imp))) {
- /*
- * These versions have the SSH-2 session-ID bug in
- * public-key authentication.
- */
- ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
- logevent("We believe remote version has SSH-2 public-key-session-ID bug");
- }
-
- if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
- (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
- (wc_match("DigiSSH_2.0", imp) ||
- wc_match("OpenSSH_2.[0-4]*", imp) ||
- wc_match("OpenSSH_2.5.[0-3]*", imp) ||
- wc_match("Sun_SSH_1.0", imp) ||
- wc_match("Sun_SSH_1.0.1", imp) ||
- /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
- wc_match("WeOnlyDo-*", imp)))) {
- /*
- * These versions have the SSH-2 rekey bug.
- */
- ssh->remote_bugs |= BUG_SSH2_REKEY;
- logevent("We believe remote version has SSH-2 rekey bug");
- }
-
- if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
- (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
- (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
- wc_match("1.36 sshlib: GlobalScape", imp)))) {
- /*
- * This version ignores our makpkt and needs to be throttled.
- */
- ssh->remote_bugs |= BUG_SSH2_MAXPKT;
- logevent("We believe remote version ignores SSH-2 maximum packet size");
- }
-
- if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
- /*
- * Servers that don't support SSH2_MSG_IGNORE. Currently,
- * none detected automatically.
- */
- ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
- logevent("We believe remote version has SSH-2 ignore bug");
- }
-}
-
-/*
- * The `software version' part of an SSH version string is required
- * to contain no spaces or minus signs.
- */
-static void ssh_fix_verstring(char *str)
-{
- /* Eat "SSH-<protoversion>-". */
- assert(*str == 'S'); str++;
- assert(*str == 'S'); str++;
- assert(*str == 'H'); str++;
- assert(*str == '-'); str++;
- while (*str && *str != '-') str++;
- assert(*str == '-'); str++;
-
- /* Convert minus signs and spaces in the remaining string into
- * underscores. */
- while (*str) {
- if (*str == '-' || *str == ' ')
- *str = '_';
- str++;
- }
-}
-
-/*
- * Send an appropriate SSH version string.
- */
-static void ssh_send_verstring(Ssh ssh, char *svers)
-{
- char *verstring;
-
- if (ssh->version == 2) {
- /*
- * Construct a v2 version string.
- */
- verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
- } else {
- /*
- * Construct a v1 version string.
- */
- verstring = dupprintf("SSH-%s-%s\012",
- (ssh_versioncmp(svers, "1.5") <= 0 ?
- svers : "1.5"),
- sshver);
- }
-
- ssh_fix_verstring(verstring);
-
- if (ssh->version == 2) {
- size_t len;
- /*
- * Record our version string.
- */
- len = strcspn(verstring, "\015\012");
- ssh->v_c = snewn(len + 1, char);
- memcpy(ssh->v_c, verstring, len);
- ssh->v_c[len] = 0;
- }
-
- logeventf(ssh, "We claim version: %.*s",
- strcspn(verstring, "\015\012"), verstring);
- s_write(ssh, verstring, strlen(verstring));
- sfree(verstring);
-}
-
-static int do_ssh_init(Ssh ssh, unsigned char c)
-{
- struct do_ssh_init_state {
- int vslen;
- char version[10];
- char *vstring;
- int vstrsize;
- int i;
- int proto1, proto2;
- };
- crState(do_ssh_init_state);
-
- crBegin(ssh->do_ssh_init_crstate);
-
- /* Search for a line beginning with the string "SSH-" in the input. */
- for (;;) {
- if (c != 'S') goto no;
- crReturn(1);
- if (c != 'S') goto no;
- crReturn(1);
- if (c != 'H') goto no;
- crReturn(1);
- if (c != '-') goto no;
- break;
- no:
- while (c != '\012')
- crReturn(1);
- crReturn(1);
- }
-
- s->vstrsize = 16;
- s->vstring = snewn(s->vstrsize, char);
- strcpy(s->vstring, "SSH-");
- s->vslen = 4;
- s->i = 0;
- while (1) {
- crReturn(1); /* get another char */
- if (s->vslen >= s->vstrsize - 1) {
- s->vstrsize += 16;
- s->vstring = sresize(s->vstring, s->vstrsize, char);
- }
- s->vstring[s->vslen++] = c;
- if (s->i >= 0) {
- if (c == '-') {
- s->version[s->i] = '\0';
- s->i = -1;
- } else if (s->i < sizeof(s->version) - 1)
- s->version[s->i++] = c;
- } else if (c == '\012')
- break;
- }
-
- ssh->agentfwd_enabled = FALSE;
- ssh->rdpkt2_state.incoming_sequence = 0;
-
- s->vstring[s->vslen] = 0;
- s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
- logeventf(ssh, "Server version: %s", s->vstring);
- ssh_detect_bugs(ssh, s->vstring);
-
- /*
- * Decide which SSH protocol version to support.
- */
-
- /* Anything strictly below "2.0" means protocol 1 is supported. */
- s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
- /* Anything greater or equal to "1.99" means protocol 2 is supported. */
- s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
-
- if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
- bombout(("SSH protocol version 1 required by user but not provided by server"));
- crStop(0);
- }
- if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
- bombout(("SSH protocol version 2 required by user but not provided by server"));
- crStop(0);
- }
-
- if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
- ssh->version = 2;
- else
- ssh->version = 1;
-
- logeventf(ssh, "Using SSH protocol version %d", ssh->version);
-
- /* Send the version string, if we haven't already */
- if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
- ssh_send_verstring(ssh, s->version);
-
- if (ssh->version == 2) {
- size_t len;
- /*
- * Record their version string.
- */
- len = strcspn(s->vstring, "\015\012");
- ssh->v_s = snewn(len + 1, char);
- memcpy(ssh->v_s, s->vstring, len);
- ssh->v_s[len] = 0;
-
- /*
- * Initialise SSH-2 protocol.
- */
- ssh->protocol = ssh2_protocol;
- ssh2_protocol_setup(ssh);
- ssh->s_rdpkt = ssh2_rdpkt;
- } else {
- /*
- * Initialise SSH-1 protocol.
- */
- ssh->protocol = ssh1_protocol;
- ssh1_protocol_setup(ssh);
- ssh->s_rdpkt = ssh1_rdpkt;
- }
- if (ssh->version == 2)
- do_ssh2_transport(ssh, NULL, -1, NULL);
-
- update_specials_menu(ssh->frontend);
- ssh->state = SSH_STATE_BEFORE_SIZE;
- ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
-
- sfree(s->vstring);
-
- crFinish(0);
-}
-
-static void ssh_process_incoming_data(Ssh ssh,
- unsigned char **data, int *datalen)
-{
- struct Packet *pktin;
-
- pktin = ssh->s_rdpkt(ssh, data, datalen);
- if (pktin) {
- ssh->protocol(ssh, NULL, 0, pktin);
- ssh_free_packet(pktin);
- }
-}
-
-static void ssh_queue_incoming_data(Ssh ssh,
- unsigned char **data, int *datalen)
-{
- bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
- *data += *datalen;
- *datalen = 0;
-}
-
-static void ssh_process_queued_incoming_data(Ssh ssh)
-{
- void *vdata;
- unsigned char *data;
- int len, origlen;
-
- while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
- bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
- data = vdata;
- origlen = len;
-
- while (!ssh->frozen && len > 0)
- ssh_process_incoming_data(ssh, &data, &len);
-
- if (origlen > len)
- bufchain_consume(&ssh->queued_incoming_data, origlen - len);
- }
-}
-
-static void ssh_set_frozen(Ssh ssh, int frozen)
-{
- if (ssh->s)
- sk_set_frozen(ssh->s, frozen);
- ssh->frozen = frozen;
-}
-
-static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
-{
- /* Log raw data, if we're in that mode. */
- if (ssh->logctx)
- log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
- 0, NULL, NULL);
-
- crBegin(ssh->ssh_gotdata_crstate);
-
- /*
- * To begin with, feed the characters one by one to the
- * protocol initialisation / selection function do_ssh_init().
- * When that returns 0, we're done with the initial greeting
- * exchange and can move on to packet discipline.
- */
- while (1) {
- int ret; /* need not be kept across crReturn */
- if (datalen == 0)
- crReturnV; /* more data please */
- ret = do_ssh_init(ssh, *data);
- data++;
- datalen--;
- if (ret == 0)
- break;
- }
-
- /*
- * We emerge from that loop when the initial negotiation is
- * over and we have selected an s_rdpkt function. Now pass
- * everything to s_rdpkt, and then pass the resulting packets
- * to the proper protocol handler.
- */
-
- while (1) {
- while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
- if (ssh->frozen) {
- ssh_queue_incoming_data(ssh, &data, &datalen);
- /* This uses up all data and cannot cause anything interesting
- * to happen; indeed, for anything to happen at all, we must
- * return, so break out. */
- break;
- } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
- /* This uses up some or all data, and may freeze the
- * session. */
- ssh_process_queued_incoming_data(ssh);
- } else {
- /* This uses up some or all data, and may freeze the
- * session. */
- ssh_process_incoming_data(ssh, &data, &datalen);
- }
- /* FIXME this is probably EBW. */
- if (ssh->state == SSH_STATE_CLOSED)
- return;
- }
- /* We're out of data. Go and get some more. */
- crReturnV;
- }
- crFinishV;
-}
-
-static int ssh_do_close(Ssh ssh, int notify_exit)
-{
- int ret = 0;
- struct ssh_channel *c;
-
- ssh->state = SSH_STATE_CLOSED;
- expire_timer_context(ssh);
- if (ssh->s) {
- sk_close(ssh->s);
- ssh->s = NULL;
- if (notify_exit)
- notify_remote_exit(ssh->frontend);
- else
- ret = 1;
- }
- /*
- * Now we must shut down any port- and X-forwarded channels going
- * through this connection.
- */
- if (ssh->channels) {
- while (NULL != (c = index234(ssh->channels, 0))) {
- switch (c->type) {
- case CHAN_X11:
- x11_close(c->u.x11.s);
- break;
- case CHAN_SOCKDATA:
- case CHAN_SOCKDATA_DORMANT:
- pfd_close(c->u.pfd.s);
- break;
- }
- del234(ssh->channels, c); /* moving next one to index 0 */
- if (ssh->version == 2)
- bufchain_clear(&c->v.v2.outbuffer);
- sfree(c);
- }
- }
- /*
- * Go through port-forwardings, and close any associated
- * listening sockets.
- */
- if (ssh->portfwds) {
- struct ssh_portfwd *pf;
- while (NULL != (pf = index234(ssh->portfwds, 0))) {
- /* Dispose of any listening socket. */
- if (pf->local)
- pfd_terminate(pf->local);
- del234(ssh->portfwds, pf); /* moving next one to index 0 */
- free_portfwd(pf);
- }
- freetree234(ssh->portfwds);
- ssh->portfwds = NULL;
- }
-
- return ret;
-}
-
-static void ssh_log(Plug plug, int type, SockAddr addr, int port,
- const char *error_msg, int error_code)
-{
- Ssh ssh = (Ssh) plug;
- char addrbuf[256], *msg;
-
- sk_getaddr(addr, addrbuf, lenof(addrbuf));
-
- if (type == 0)
- msg = dupprintf("Connecting to %s port %d", addrbuf, port);
- else
- msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
-
- logevent(msg);
- sfree(msg);
-}
-
-static int ssh_closing(Plug plug, const char *error_msg, int error_code,
- int calling_back)
-{
- Ssh ssh = (Ssh) plug;
- int need_notify = ssh_do_close(ssh, FALSE);
-
- if (!error_msg) {
- if (!ssh->close_expected)
- error_msg = "Server unexpectedly closed network connection";
- else
- error_msg = "Server closed network connection";
- }
-
- if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
- ssh->exitcode = 0;
-
- if (need_notify)
- notify_remote_exit(ssh->frontend);
-
- if (error_msg)
- logevent(error_msg);
- if (!ssh->close_expected || !ssh->clean_exit)
- connection_fatal(ssh->frontend, "%s", error_msg);
- return 0;
-}
-
-static int ssh_receive(Plug plug, int urgent, char *data, int len)
-{
- Ssh ssh = (Ssh) plug;
- ssh_gotdata(ssh, (unsigned char *)data, len);
- if (ssh->state == SSH_STATE_CLOSED) {
- ssh_do_close(ssh, TRUE);
- return 0;
- }
- return 1;
-}
-
-static void ssh_sent(Plug plug, int bufsize)
-{
- Ssh ssh = (Ssh) plug;
- /*
- * If the send backlog on the SSH socket itself clears, we
- * should unthrottle the whole world if it was throttled.
- */
- if (bufsize < SSH_MAX_BACKLOG)
- ssh_throttle_all(ssh, 0, bufsize);
-}
-
-/*
- * Connect to specified host and port.
- * Returns an error message, or NULL on success.
- * Also places the canonical host name into `realhost'. It must be
- * freed by the caller.
- */
-static const char *connect_to_host(Ssh ssh, char *host, int port,
- char **realhost, int nodelay, int keepalive)
-{
- static const struct plug_function_table fn_table = {
- ssh_log,
- ssh_closing,
- ssh_receive,
- ssh_sent,
- NULL
- };
-
- SockAddr addr;
- const char *err;
- char *loghost;
- int addressfamily, sshprot;
-
- loghost = conf_get_str(ssh->conf, CONF_loghost);
- if (*loghost) {
- char *colon;
-
- ssh->savedhost = dupstr(loghost);
- ssh->savedport = 22; /* default ssh port */
-
- /*
- * A colon suffix on savedhost also lets us affect
- * savedport.
- *
- * (FIXME: do something about IPv6 address literals here.)
- */
- colon = strrchr(ssh->savedhost, ':');
- if (colon) {
- *colon++ = '\0';
- if (*colon)
- ssh->savedport = atoi(colon);
- }
- } else {
- ssh->savedhost = dupstr(host);
- if (port < 0)
- port = 22; /* default ssh port */
- ssh->savedport = port;
- }
-
- /*
- * Try to find host.
- */
- addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
- logeventf(ssh, "Looking up host \"%s\"%s", host,
- (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
- (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
- addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
- if ((err = sk_addr_error(addr)) != NULL) {
- sk_addr_free(addr);
- return err;
- }
- ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
-
- /*
- * Open socket.
- */
- ssh->fn = &fn_table;
- ssh->s = new_connection(addr, *realhost, port,
- 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf);
- if ((err = sk_socket_error(ssh->s)) != NULL) {
- ssh->s = NULL;
- notify_remote_exit(ssh->frontend);
- return err;
- }
-
- /*
- * If the SSH version number's fixed, set it now, and if it's SSH-2,
- * send the version string too.
- */
- sshprot = conf_get_int(ssh->conf, CONF_sshprot);
- if (sshprot == 0)
- ssh->version = 1;
- if (sshprot == 3) {
- ssh->version = 2;
- ssh_send_verstring(ssh, NULL);
- }
-
- /*
- * loghost, if configured, overrides realhost.
- */
- if (*loghost) {
- sfree(*realhost);
- *realhost = dupstr(loghost);
- }
-
- return NULL;
-}
-
-/*
- * Throttle or unthrottle the SSH connection.
- */
-static void ssh_throttle_conn(Ssh ssh, int adjust)
-{
- int old_count = ssh->conn_throttle_count;
- ssh->conn_throttle_count += adjust;
- assert(ssh->conn_throttle_count >= 0);
- if (ssh->conn_throttle_count && !old_count) {
- ssh_set_frozen(ssh, 1);
- } else if (!ssh->conn_throttle_count && old_count) {
- ssh_set_frozen(ssh, 0);
- }
-}
-
-/*
- * Throttle or unthrottle _all_ local data streams (for when sends
- * on the SSH connection itself back up).
- */
-static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
-{
- int i;
- struct ssh_channel *c;
-
- if (enable == ssh->throttled_all)
- return;
- ssh->throttled_all = enable;
- ssh->overall_bufsize = bufsize;
- if (!ssh->channels)
- return;
- for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
- switch (c->type) {
- case CHAN_MAINSESSION:
- /*
- * This is treated separately, outside the switch.
- */
- break;
- case CHAN_X11:
- x11_override_throttle(c->u.x11.s, enable);
- break;
- case CHAN_AGENT:
- /* Agent channels require no buffer management. */
- break;
- case CHAN_SOCKDATA:
- pfd_override_throttle(c->u.pfd.s, enable);
- break;
- }
- }
-}
-
-static void ssh_agent_callback(void *sshv, void *reply, int replylen)
-{
- Ssh ssh = (Ssh) sshv;
-
- ssh->agent_response = reply;
- ssh->agent_response_len = replylen;
-
- if (ssh->version == 1)
- do_ssh1_login(ssh, NULL, -1, NULL);
- else
- do_ssh2_authconn(ssh, NULL, -1, NULL);
-}
-
-static void ssh_dialog_callback(void *sshv, int ret)
-{
- Ssh ssh = (Ssh) sshv;
-
- ssh->user_response = ret;
-
- if (ssh->version == 1)
- do_ssh1_login(ssh, NULL, -1, NULL);
- else
- do_ssh2_transport(ssh, NULL, -1, NULL);
-
- /*
- * This may have unfrozen the SSH connection, so do a
- * queued-data run.
- */
- ssh_process_queued_incoming_data(ssh);
-}
-
-static void ssh_agentf_callback(void *cv, void *reply, int replylen)
-{
- struct ssh_channel *c = (struct ssh_channel *)cv;
- Ssh ssh = c->ssh;
- void *sentreply = reply;
-
- if (!sentreply) {
- /* Fake SSH_AGENT_FAILURE. */
- sentreply = "\0\0\0\1\5";
- replylen = 5;
- }
- if (ssh->version == 2) {
- ssh2_add_channel_data(c, sentreply, replylen);
- ssh2_try_send(c);
- } else {
- send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
- PKT_INT, c->remoteid,
- PKT_INT, replylen,
- PKTT_DATA,
- PKT_DATA, sentreply, replylen,
- PKTT_OTHER,
- PKT_END);
- }
- if (reply)
- sfree(reply);
-}
-
-/*
- * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
- * non-NULL, otherwise just close the connection. `client_reason' == NULL
- * => log `wire_reason'.
- */
-static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
- int code, int clean_exit)
-{
- char *error;
- if (!client_reason)
- client_reason = wire_reason;
- if (client_reason)
- error = dupprintf("Disconnected: %s", client_reason);
- else
- error = dupstr("Disconnected");
- if (wire_reason) {
- if (ssh->version == 1) {
- send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
- PKT_END);
- } else if (ssh->version == 2) {
- struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
- ssh2_pkt_adduint32(pktout, code);
- ssh2_pkt_addstring(pktout, wire_reason);
- ssh2_pkt_addstring(pktout, "en"); /* language tag */
- ssh2_pkt_send_noqueue(ssh, pktout);
- }
- }
- ssh->close_expected = TRUE;
- ssh->clean_exit = clean_exit;
- ssh_closing((Plug)ssh, error, 0, 0);
- sfree(error);
-}
-
-/*
- * Handle the key exchange and user authentication phases.
- */
-static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
- struct Packet *pktin)
-{
- int i, j, ret;
- unsigned char cookie[8], *ptr;
- struct RSAKey servkey, hostkey;
- struct MD5Context md5c;
- struct do_ssh1_login_state {
- int len;
- unsigned char *rsabuf, *keystr1, *keystr2;
- unsigned long supported_ciphers_mask, supported_auths_mask;
- int tried_publickey, tried_agent;
- int tis_auth_refused, ccard_auth_refused;
- unsigned char session_id[16];
- int cipher_type;
- void *publickey_blob;
- int publickey_bloblen;
- char *publickey_comment;
- int publickey_encrypted;
- prompts_t *cur_prompt;
- char c;
- int pwpkt_type;
- unsigned char request[5], *response, *p;
- int responselen;
- int keyi, nkeys;
- int authed;
- struct RSAKey key;
- Bignum challenge;
- char *commentp;
- int commentlen;
- int dlgret;
- Filename *keyfile;
- };
- crState(do_ssh1_login_state);
-
- crBegin(ssh->do_ssh1_login_crstate);
-
- if (!pktin)
- crWaitUntil(pktin);
-
- if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
- bombout(("Public key packet not received"));
- crStop(0);
- }
-
- logevent("Received public keys");
-
- ptr = ssh_pkt_getdata(pktin, 8);
- if (!ptr) {
- bombout(("SSH-1 public key packet stopped before random cookie"));
- crStop(0);
- }
- memcpy(cookie, ptr, 8);
-
- if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
- !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
- bombout(("Failed to read SSH-1 public keys from public key packet"));
- crStop(0);
- }
-
- /*
- * Log the host key fingerprint.
- */
- {
- char logmsg[80];
- logevent("Host key fingerprint is:");
- strcpy(logmsg, " ");
- hostkey.comment = NULL;
- rsa_fingerprint(logmsg + strlen(logmsg),
- sizeof(logmsg) - strlen(logmsg), &hostkey);
- logevent(logmsg);
- }
-
- ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
- s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
- s->supported_auths_mask = ssh_pkt_getuint32(pktin);
- if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
- s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
-
- ssh->v1_local_protoflags =
- ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
- ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
-
- MD5Init(&md5c);
- MD5Update(&md5c, s->keystr2, hostkey.bytes);
- MD5Update(&md5c, s->keystr1, servkey.bytes);
- MD5Update(&md5c, cookie, 8);
- MD5Final(s->session_id, &md5c);
-
- for (i = 0; i < 32; i++)
- ssh->session_key[i] = random_byte();
-
- /*
- * Verify that the `bits' and `bytes' parameters match.
- */
- if (hostkey.bits > hostkey.bytes * 8 ||
- servkey.bits > servkey.bytes * 8) {
- bombout(("SSH-1 public keys were badly formatted"));
- crStop(0);
- }
-
- s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
-
- s->rsabuf = snewn(s->len, unsigned char);
-
- /*
- * Verify the host key.
- */
- {
- /*
- * First format the key into a string.
- */
- int len = rsastr_len(&hostkey);
- char fingerprint[100];
- char *keystr = snewn(len, char);
- rsastr_fmt(keystr, &hostkey);
- rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
-
- ssh_set_frozen(ssh, 1);
- s->dlgret = verify_ssh_host_key(ssh->frontend,
- ssh->savedhost, ssh->savedport,
- "rsa", keystr, fingerprint,
- ssh_dialog_callback, ssh);
- sfree(keystr);
- if (s->dlgret < 0) {
- do {
- crReturn(0);
- if (pktin) {
- bombout(("Unexpected data from server while waiting"
- " for user host key response"));
- crStop(0);
- }
- } while (pktin || inlen > 0);
- s->dlgret = ssh->user_response;
- }
- ssh_set_frozen(ssh, 0);
-
- if (s->dlgret == 0) {
- ssh_disconnect(ssh, "User aborted at host key verification",
- NULL, 0, TRUE);
- crStop(0);
- }
- }
-
- for (i = 0; i < 32; i++) {
- s->rsabuf[i] = ssh->session_key[i];
- if (i < 16)
- s->rsabuf[i] ^= s->session_id[i];
- }
-
- if (hostkey.bytes > servkey.bytes) {
- ret = rsaencrypt(s->rsabuf, 32, &servkey);
- if (ret)
- ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
- } else {
- ret = rsaencrypt(s->rsabuf, 32, &hostkey);
- if (ret)
- ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
- }
- if (!ret) {
- bombout(("SSH-1 public key encryptions failed due to bad formatting"));
- crStop(0);
- }
-
- logevent("Encrypted session key");
-
- {
- int cipher_chosen = 0, warn = 0;
- char *cipher_string = NULL;
- int i;
- for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
- int next_cipher = conf_get_int_int(ssh->conf,
- CONF_ssh_cipherlist, i);
- if (next_cipher == CIPHER_WARN) {
- /* If/when we choose a cipher, warn about it */
- warn = 1;
- } else if (next_cipher == CIPHER_AES) {
- /* XXX Probably don't need to mention this. */
- logevent("AES not supported in SSH-1, skipping");
- } else {
- switch (next_cipher) {
- case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
- cipher_string = "3DES"; break;
- case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
- cipher_string = "Blowfish"; break;
- case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
- cipher_string = "single-DES"; break;
- }
- if (s->supported_ciphers_mask & (1 << s->cipher_type))
- cipher_chosen = 1;
- }
- }
- if (!cipher_chosen) {
- if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
- bombout(("Server violates SSH-1 protocol by not "
- "supporting 3DES encryption"));
- else
- /* shouldn't happen */
- bombout(("No supported ciphers found"));
- crStop(0);
- }
-
- /* Warn about chosen cipher if necessary. */
- if (warn) {
- ssh_set_frozen(ssh, 1);
- s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
- ssh_dialog_callback, ssh);
- if (s->dlgret < 0) {
- do {
- crReturn(0);
- if (pktin) {
- bombout(("Unexpected data from server while waiting"
- " for user response"));
- crStop(0);
- }
- } while (pktin || inlen > 0);
- s->dlgret = ssh->user_response;
- }
- ssh_set_frozen(ssh, 0);
- if (s->dlgret == 0) {
- ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
- 0, TRUE);
- crStop(0);
- }
- }
- }
-
- switch (s->cipher_type) {
- case SSH_CIPHER_3DES:
- logevent("Using 3DES encryption");
- break;
- case SSH_CIPHER_DES:
- logevent("Using single-DES encryption");
- break;
- case SSH_CIPHER_BLOWFISH:
- logevent("Using Blowfish encryption");
- break;
- }
-
- send_packet(ssh, SSH1_CMSG_SESSION_KEY,
- PKT_CHAR, s->cipher_type,
- PKT_DATA, cookie, 8,
- PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
- PKT_DATA, s->rsabuf, s->len,
- PKT_INT, ssh->v1_local_protoflags, PKT_END);
-
- logevent("Trying to enable encryption...");
-
- sfree(s->rsabuf);
-
- ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
- s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
- &ssh_3des);
- ssh->v1_cipher_ctx = ssh->cipher->make_context();
- ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
- logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
-
- ssh->crcda_ctx = crcda_make_context();
- logevent("Installing CRC compensation attack detector");
-
- if (servkey.modulus) {
- sfree(servkey.modulus);
- servkey.modulus = NULL;
- }
- if (servkey.exponent) {
- sfree(servkey.exponent);
- servkey.exponent = NULL;
- }
- if (hostkey.modulus) {
- sfree(hostkey.modulus);
- hostkey.modulus = NULL;
- }
- if (hostkey.exponent) {
- sfree(hostkey.exponent);
- hostkey.exponent = NULL;
- }
- crWaitUntil(pktin);
-
- if (pktin->type != SSH1_SMSG_SUCCESS) {
- bombout(("Encryption not successfully enabled"));
- crStop(0);
- }
-
- logevent("Successfully started encryption");
-
- fflush(stdout); /* FIXME eh? */
- {
- if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
- int ret; /* need not be kept over crReturn */
- s->cur_prompt = new_prompts(ssh->frontend);
- s->cur_prompt->to_server = TRUE;
- s->cur_prompt->name = dupstr("SSH login name");
- add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
- ret = get_userpass_input(s->cur_prompt, NULL, 0);
- while (ret < 0) {
- ssh->send_ok = 1;
- crWaitUntil(!pktin);
- ret = get_userpass_input(s->cur_prompt, in, inlen);
- ssh->send_ok = 0;
- }
- if (!ret) {
- /*
- * Failed to get a username. Terminate.
- */
- free_prompts(s->cur_prompt);
- ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
- crStop(0);
- }
- ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
- free_prompts(s->cur_prompt);
- }
-
- send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
- {
- char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
- logevent(userlog);
- if (flags & FLAG_INTERACTIVE &&
- (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
- c_write_str(ssh, userlog);
- c_write_str(ssh, "\r\n");
- }
- sfree(userlog);
- }
- }
-
- crWaitUntil(pktin);
-
- if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
- /* We must not attempt PK auth. Pretend we've already tried it. */
- s->tried_publickey = s->tried_agent = 1;
- } else {
- s->tried_publickey = s->tried_agent = 0;
- }
- s->tis_auth_refused = s->ccard_auth_refused = 0;
- /*
- * Load the public half of any configured keyfile for later use.
- */
- s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
- if (!filename_is_null(s->keyfile)) {
- int keytype;
- logeventf(ssh, "Reading private key file \"%.150s\"",
- filename_to_str(s->keyfile));
- keytype = key_type(s->keyfile);
- if (keytype == SSH_KEYTYPE_SSH1) {
- const char *error;
- if (rsakey_pubblob(s->keyfile,
- &s->publickey_blob, &s->publickey_bloblen,
- &s->publickey_comment, &error)) {
- s->publickey_encrypted = rsakey_encrypted(s->keyfile,
- NULL);
- } else {
- char *msgbuf;
- logeventf(ssh, "Unable to load private key (%s)", error);
- msgbuf = dupprintf("Unable to load private key file "
- "\"%.150s\" (%s)\r\n",
- filename_to_str(s->keyfile),
- error);
- c_write_str(ssh, msgbuf);
- sfree(msgbuf);
- s->publickey_blob = NULL;
- }
- } else {
- char *msgbuf;
- logeventf(ssh, "Unable to use this key file (%s)",
- key_type_to_str(keytype));
- msgbuf = dupprintf("Unable to use key file \"%.150s\""
- " (%s)\r\n",
- filename_to_str(s->keyfile),
- key_type_to_str(keytype));
- c_write_str(ssh, msgbuf);
- sfree(msgbuf);
- s->publickey_blob = NULL;
- }
- } else
- s->publickey_blob = NULL;
-
- while (pktin->type == SSH1_SMSG_FAILURE) {
- s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
-
- if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
- /*
- * Attempt RSA authentication using Pageant.
- */
- void *r;
-
- s->authed = FALSE;
- s->tried_agent = 1;
- logevent("Pageant is running. Requesting keys.");
-
- /* Request the keys held by the agent. */
- PUT_32BIT(s->request, 1);
- s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
- if (!agent_query(s->request, 5, &r, &s->responselen,
- ssh_agent_callback, ssh)) {
- do {
- crReturn(0);
- if (pktin) {
- bombout(("Unexpected data from server while waiting"
- " for agent response"));
- crStop(0);
- }
- } while (pktin || inlen > 0);
- r = ssh->agent_response;
- s->responselen = ssh->agent_response_len;
- }
- s->response = (unsigned char *) r;
- if (s->response && s->responselen >= 5 &&
- s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
- s->p = s->response + 5;
- s->nkeys = GET_32BIT(s->p);
- s->p += 4;
- logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
- for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
- unsigned char *pkblob = s->p;
- s->p += 4;
- {
- int n, ok = FALSE;
- do { /* do while (0) to make breaking easy */
- n = ssh1_read_bignum
- (s->p, s->responselen-(s->p-s->response),
- &s->key.exponent);
- if (n < 0)
- break;
- s->p += n;
- n = ssh1_read_bignum
- (s->p, s->responselen-(s->p-s->response),
- &s->key.modulus);
- if (n < 0)
- break;
- s->p += n;
- if (s->responselen - (s->p-s->response) < 4)
- break;
- s->commentlen = GET_32BIT(s->p);
- s->p += 4;
- if (s->responselen - (s->p-s->response) <
- s->commentlen)
- break;
- s->commentp = (char *)s->p;
- s->p += s->commentlen;
- ok = TRUE;
- } while (0);
- if (!ok) {
- logevent("Pageant key list packet was truncated");
- break;
- }
- }
- if (s->publickey_blob) {
- if (!memcmp(pkblob, s->publickey_blob,
- s->publickey_bloblen)) {
- logeventf(ssh, "Pageant key #%d matches "
- "configured key file", s->keyi);
- s->tried_publickey = 1;
- } else
- /* Skip non-configured key */
- continue;
- }
- logeventf(ssh, "Trying Pageant key #%d", s->keyi);
- send_packet(ssh, SSH1_CMSG_AUTH_RSA,
- PKT_BIGNUM, s->key.modulus, PKT_END);
- crWaitUntil(pktin);
- if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
- logevent("Key refused");
- continue;
- }
- logevent("Received RSA challenge");
- if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
- bombout(("Server's RSA challenge was badly formatted"));
- crStop(0);
- }
-
- {
- char *agentreq, *q, *ret;
- void *vret;
- int len, retlen;
- len = 1 + 4; /* message type, bit count */
- len += ssh1_bignum_length(s->key.exponent);
- len += ssh1_bignum_length(s->key.modulus);
- len += ssh1_bignum_length(s->challenge);
- len += 16; /* session id */
- len += 4; /* response format */
- agentreq = snewn(4 + len, char);
- PUT_32BIT(agentreq, len);
- q = agentreq + 4;
- *q++ = SSH1_AGENTC_RSA_CHALLENGE;
- PUT_32BIT(q, bignum_bitcount(s->key.modulus));
- q += 4;
- q += ssh1_write_bignum(q, s->key.exponent);
- q += ssh1_write_bignum(q, s->key.modulus);
- q += ssh1_write_bignum(q, s->challenge);
- memcpy(q, s->session_id, 16);
- q += 16;
- PUT_32BIT(q, 1); /* response format */
- if (!agent_query(agentreq, len + 4, &vret, &retlen,
- ssh_agent_callback, ssh)) {
- sfree(agentreq);
- do {
- crReturn(0);
- if (pktin) {
- bombout(("Unexpected data from server"
- " while waiting for agent"
- " response"));
- crStop(0);
- }
- } while (pktin || inlen > 0);
- vret = ssh->agent_response;
- retlen = ssh->agent_response_len;
- } else
- sfree(agentreq);
- ret = vret;
- if (ret) {
- if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
- logevent("Sending Pageant's response");
- send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
- PKT_DATA, ret + 5, 16,
- PKT_END);
- sfree(ret);
- crWaitUntil(pktin);
- if (pktin->type == SSH1_SMSG_SUCCESS) {
- logevent
- ("Pageant's response accepted");
- if (flags & FLAG_VERBOSE) {
- c_write_str(ssh, "Authenticated using"
- " RSA key \"");
- c_write(ssh, s->commentp,
- s->commentlen);
- c_write_str(ssh, "\" from agent\r\n");
- }
- s->authed = TRUE;
- } else
- logevent
- ("Pageant's response not accepted");
- } else {
- logevent
- ("Pageant failed to answer challenge");
- sfree(ret);
- }
- } else {
- logevent("No reply received from Pageant");
- }
- }
- freebn(s->key.exponent);
- freebn(s->key.modulus);
- freebn(s->challenge);
- if (s->authed)
- break;
- }
- sfree(s->response);
- if (s->publickey_blob && !s->tried_publickey)
- logevent("Configured key file not in Pageant");
- } else {
- logevent("Failed to get reply from Pageant");
- }
- if (s->authed)
- break;
- }
- if (s->publickey_blob && !s->tried_publickey) {
- /*
- * Try public key authentication with the specified
- * key file.
- */
- int got_passphrase; /* need not be kept over crReturn */
- if (flags & FLAG_VERBOSE)
- c_write_str(ssh, "Trying public key authentication.\r\n");
- s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
- logeventf(ssh, "Trying public key \"%s\"",
- filename_to_str(s->keyfile));
- s->tried_publickey = 1;
- got_passphrase = FALSE;
- while (!got_passphrase) {
- /*
- * Get a passphrase, if necessary.
- */
- char *passphrase = NULL; /* only written after crReturn */
- const char *error;
- if (!s->publickey_encrypted) {
- if (flags & FLAG_VERBOSE)
- c_write_str(ssh, "No passphrase required.\r\n");
- passphrase = NULL;
- } else {
- int ret; /* need not be kept over crReturn */
- s->cur_prompt = new_prompts(ssh->frontend);
- s->cur_prompt->to_server = FALSE;
- s->cur_prompt->name = dupstr("SSH key passphrase");
- add_prompt(s->cur_prompt,
- dupprintf("Passphrase for key \"%.100s\": ",
- s->publickey_comment), FALSE);
- ret = get_userpass_input(s->cur_prompt, NULL, 0);
- while (ret < 0) {
- ssh->send_ok = 1;
- crWaitUntil(!pktin);
- ret = get_userpass_input(s->cur_prompt, in, inlen);
- ssh->send_ok = 0;
- }
- if (!ret) {
- /* Failed to get a passphrase. Terminate. */
- free_prompts(s->cur_prompt);
- ssh_disconnect(ssh, NULL, "Unable to authenticate",
- 0, TRUE);
- crStop(0);
- }
- passphrase = dupstr(s->cur_prompt->prompts[0]->result);
- free_prompts(s->cur_prompt);
- }
- /*
- * Try decrypting key with passphrase.
- */
- s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
- ret = loadrsakey(s->keyfile, &s->key, passphrase,
- &error);
- if (passphrase) {
- memset(passphrase, 0, strlen(passphrase));
- sfree(passphrase);
- }
- if (ret == 1) {
- /* Correct passphrase. */
- got_passphrase = TRUE;
- } else if (ret == 0) {
- c_write_str(ssh, "Couldn't load private key from ");
- c_write_str(ssh, filename_to_str(s->keyfile));
- c_write_str(ssh, " (");
- c_write_str(ssh, error);
- c_write_str(ssh, ").\r\n");
- got_passphrase = FALSE;
- break; /* go and try something else */
- } else if (ret == -1) {
- c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
- got_passphrase = FALSE;
- /* and try again */
- } else {
- assert(0 && "unexpected return from loadrsakey()");
- got_passphrase = FALSE; /* placate optimisers */
- }
- }
-
- if (got_passphrase) {
-
- /*
- * Send a public key attempt.
- */
- send_packet(ssh, SSH1_CMSG_AUTH_RSA,
- PKT_BIGNUM, s->key.modulus, PKT_END);
-
- crWaitUntil(pktin);
- if (pktin->type == SSH1_SMSG_FAILURE) {
- c_write_str(ssh, "Server refused our public key.\r\n");
- continue; /* go and try something else */
- }
- if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
- bombout(("Bizarre response to offer of public key"));
- crStop(0);
- }
-
- {
- int i;
- unsigned char buffer[32];
- Bignum challenge, response;
-
- if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
- bombout(("Server's RSA challenge was badly formatted"));
- crStop(0);
- }
- response = rsadecrypt(challenge, &s->key);
- freebn(s->key.private_exponent);/* burn the evidence */
-
- for (i = 0; i < 32; i++) {
- buffer[i] = bignum_byte(response, 31 - i);
- }
-
- MD5Init(&md5c);
- MD5Update(&md5c, buffer, 32);
- MD5Update(&md5c, s->session_id, 16);
- MD5Final(buffer, &md5c);
-
- send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
- PKT_DATA, buffer, 16, PKT_END);
-
- freebn(challenge);
- freebn(response);
- }
-
- crWaitUntil(pktin);
- if (pktin->type == SSH1_SMSG_FAILURE) {
- if (flags & FLAG_VERBOSE)
- c_write_str(ssh, "Failed to authenticate with"
- " our public key.\r\n");
- continue; /* go and try something else */
- } else if (pktin->type != SSH1_SMSG_SUCCESS) {
- bombout(("Bizarre response to RSA authentication response"));
- crStop(0);
- }
-
- break; /* we're through! */
- }
-
- }
-
- /*
- * Otherwise, try various forms of password-like authentication.
- */
- s->cur_prompt = new_prompts(ssh->frontend);
-
- if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
- (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
- !s->tis_auth_refused) {
- s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
- logevent("Requested TIS authentication");
- send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
- crWaitUntil(pktin);
- if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
- logevent("TIS authentication declined");
- if (flags & FLAG_INTERACTIVE)
- c_write_str(ssh, "TIS authentication refused.\r\n");
- s->tis_auth_refused = 1;
- continue;
- } else {
- char *challenge;
- int challengelen;
- char *instr_suf, *prompt;
-
- ssh_pkt_getstring(pktin, &challenge, &challengelen);
- if (!challenge) {
- bombout(("TIS challenge packet was badly formed"));
- crStop(0);
- }
- logevent("Received TIS challenge");
- s->cur_prompt->to_server = TRUE;
- s->cur_prompt->name = dupstr("SSH TIS authentication");
- /* Prompt heuristic comes from OpenSSH */
- if (memchr(challenge, '\n', challengelen)) {
- instr_suf = dupstr("");
- prompt = dupprintf("%.*s", challengelen, challenge);
- } else {
- instr_suf = dupprintf("%.*s", challengelen, challenge);
- prompt = dupstr("Response: ");
- }
- s->cur_prompt->instruction =
- dupprintf("Using TIS authentication.%s%s",
- (*instr_suf) ? "\n" : "",
- instr_suf);
- s->cur_prompt->instr_reqd = TRUE;
- add_prompt(s->cur_prompt, prompt, FALSE);
- sfree(instr_suf);
- }
- }
- if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
- (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
- !s->ccard_auth_refused) {
- s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
- logevent("Requested CryptoCard authentication");
- send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
- crWaitUntil(pktin);
- if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
- logevent("CryptoCard authentication declined");
- c_write_str(ssh, "CryptoCard authentication refused.\r\n");
- s->ccard_auth_refused = 1;
- continue;
- } else {
- char *challenge;
- int challengelen;
- char *instr_suf, *prompt;
-
- ssh_pkt_getstring(pktin, &challenge, &challengelen);
- if (!challenge) {
- bombout(("CryptoCard challenge packet was badly formed"));
- crStop(0);
- }
- logevent("Received CryptoCard challenge");
- s->cur_prompt->to_server = TRUE;
- s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
- s->cur_prompt->name_reqd = FALSE;
- /* Prompt heuristic comes from OpenSSH */
- if (memchr(challenge, '\n', challengelen)) {
- instr_suf = dupstr("");
- prompt = dupprintf("%.*s", challengelen, challenge);
- } else {
- instr_suf = dupprintf("%.*s", challengelen, challenge);
- prompt = dupstr("Response: ");
- }
- s->cur_prompt->instruction =
- dupprintf("Using CryptoCard authentication.%s%s",
- (*instr_suf) ? "\n" : "",
- instr_suf);
- s->cur_prompt->instr_reqd = TRUE;
- add_prompt(s->cur_prompt, prompt, FALSE);
- sfree(instr_suf);
- }
- }
- if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
- if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
- bombout(("No supported authentication methods available"));
- crStop(0);
- }
- s->cur_prompt->to_server = TRUE;
- s->cur_prompt->name = dupstr("SSH password");
- add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
- ssh->username, ssh->savedhost),
- FALSE);
- }
-
- /*
- * Show password prompt, having first obtained it via a TIS
- * or CryptoCard exchange if we're doing TIS or CryptoCard
- * authentication.
- */
- {
- int ret; /* need not be kept over crReturn */
- ret = get_userpass_input(s->cur_prompt, NULL, 0);
- while (ret < 0) {
- ssh->send_ok = 1;
- crWaitUntil(!pktin);
- ret = get_userpass_input(s->cur_prompt, in, inlen);
- ssh->send_ok = 0;
- }
- if (!ret) {
- /*
- * Failed to get a password (for example
- * because one was supplied on the command line
- * which has already failed to work). Terminate.
- */
- free_prompts(s->cur_prompt);
- ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
- crStop(0);
- }
- }
-
- if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
- /*
- * Defence against traffic analysis: we send a
- * whole bunch of packets containing strings of
- * different lengths. One of these strings is the
- * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
- * The others are all random data in
- * SSH1_MSG_IGNORE packets. This way a passive
- * listener can't tell which is the password, and
- * hence can't deduce the password length.
- *
- * Anybody with a password length greater than 16
- * bytes is going to have enough entropy in their
- * password that a listener won't find it _that_
- * much help to know how long it is. So what we'll
- * do is:
- *
- * - if password length < 16, we send 15 packets
- * containing string lengths 1 through 15
- *
- * - otherwise, we let N be the nearest multiple
- * of 8 below the password length, and send 8
- * packets containing string lengths N through
- * N+7. This won't obscure the order of
- * magnitude of the password length, but it will
- * introduce a bit of extra uncertainty.
- *
- * A few servers can't deal with SSH1_MSG_IGNORE, at
- * least in this context. For these servers, we need
- * an alternative defence. We make use of the fact
- * that the password is interpreted as a C string:
- * so we can append a NUL, then some random data.
- *
- * A few servers can deal with neither SSH1_MSG_IGNORE
- * here _nor_ a padded password string.
- * For these servers we are left with no defences
- * against password length sniffing.
- */
- if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
- !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
- /*
- * The server can deal with SSH1_MSG_IGNORE, so
- * we can use the primary defence.
- */
- int bottom, top, pwlen, i;
- char *randomstr;
-
- pwlen = strlen(s->cur_prompt->prompts[0]->result);
- if (pwlen < 16) {
- bottom = 0; /* zero length passwords are OK! :-) */
- top = 15;
- } else {
- bottom = pwlen & ~7;
- top = bottom + 7;
- }
-
- assert(pwlen >= bottom && pwlen <= top);
-
- randomstr = snewn(top + 1, char);
-
- for (i = bottom; i <= top; i++) {
- if (i == pwlen) {
- defer_packet(ssh, s->pwpkt_type,
- PKTT_PASSWORD, PKT_STR,
- s->cur_prompt->prompts[0]->result,
- PKTT_OTHER, PKT_END);
- } else {
- for (j = 0; j < i; j++) {
- do {
- randomstr[j] = random_byte();
- } while (randomstr[j] == '\0');
- }
- randomstr[i] = '\0';
- defer_packet(ssh, SSH1_MSG_IGNORE,
- PKT_STR, randomstr, PKT_END);
- }
- }
- logevent("Sending password with camouflage packets");
- ssh_pkt_defersend(ssh);
- sfree(randomstr);
- }
- else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
- /*
- * The server can't deal with SSH1_MSG_IGNORE
- * but can deal with padded passwords, so we
- * can use the secondary defence.
- */
- char string[64];
- char *ss;
- int len;
-
- len = strlen(s->cur_prompt->prompts[0]->result);
- if (len < sizeof(string)) {
- ss = string;
- strcpy(string, s->cur_prompt->prompts[0]->result);
- len++; /* cover the zero byte */
- while (len < sizeof(string)) {
- string[len++] = (char) random_byte();
- }
- } else {
- ss = s->cur_prompt->prompts[0]->result;
- }
- logevent("Sending length-padded password");
- send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
- PKT_INT, len, PKT_DATA, ss, len,
- PKTT_OTHER, PKT_END);
- } else {
- /*
- * The server is believed unable to cope with
- * any of our password camouflage methods.
- */
- int len;
- len = strlen(s->cur_prompt->prompts[0]->result);
- logevent("Sending unpadded password");
- send_packet(ssh, s->pwpkt_type,
- PKTT_PASSWORD, PKT_INT, len,
- PKT_DATA, s->cur_prompt->prompts[0]->result, len,
- PKTT_OTHER, PKT_END);
- }
- } else {
- send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
- PKT_STR, s->cur_prompt->prompts[0]->result,
- PKTT_OTHER, PKT_END);
- }
- logevent("Sent password");
- free_prompts(s->cur_prompt);
- crWaitUntil(pktin);
- if (pktin->type == SSH1_SMSG_FAILURE) {
- if (flags & FLAG_VERBOSE)
- c_write_str(ssh, "Access denied\r\n");
- logevent("Authentication refused");
- } else if (pktin->type != SSH1_SMSG_SUCCESS) {
- bombout(("Strange packet received, type %d", pktin->type));
- crStop(0);
- }
- }
-
- /* Clear up */
- if (s->publickey_blob) {
- sfree(s->publickey_blob);
- sfree(s->publickey_comment);
- }
-
- logevent("Authentication successful");
-
- crFinish(1);
-}
-
-static void ssh_channel_try_eof(struct ssh_channel *c)
-{
- Ssh ssh = c->ssh;
- assert(c->pending_eof); /* precondition for calling us */
- if (c->halfopen)
- return; /* can't close: not even opened yet */
- if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
- return; /* can't send EOF: pending outgoing data */
-
- if (ssh->version == 1) {
- send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
- PKT_END);
- c->closes |= CLOSES_SENT_EOF;
- } else {
- struct Packet *pktout;
- pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
- ssh2_pkt_adduint32(pktout, c->remoteid);
- ssh2_pkt_send(ssh, pktout);
- c->closes |= CLOSES_SENT_EOF;
- if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes)) {
- /*
- * Also send MSG_CLOSE.
- */
- pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
- ssh2_pkt_adduint32(pktout, c->remoteid);
- ssh2_pkt_send(ssh, pktout);
- c->closes |= CLOSES_SENT_CLOSE;
- }
- }
- c->pending_eof = FALSE; /* we've sent it now */
-}
-
-void sshfwd_write_eof(struct ssh_channel *c)
-{
- Ssh ssh = c->ssh;
-
- if (ssh->state == SSH_STATE_CLOSED)
- return;
-
- if (c->closes & CLOSES_SENT_EOF)
- return;
-
- c->pending_eof = TRUE;
- ssh_channel_try_eof(c);
-}
-
-void sshfwd_unclean_close(struct ssh_channel *c)
-{
- Ssh ssh = c->ssh;
- struct Packet *pktout;
-
- if (ssh->state == SSH_STATE_CLOSED)
- return;
-
- if (c->closes & CLOSES_SENT_CLOSE)
- return;
-
- pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
- ssh2_pkt_adduint32(pktout, c->remoteid);
- ssh2_pkt_send(ssh, pktout);
- c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
- switch (c->type) {
- case CHAN_X11:
- x11_close(c->u.x11.s);
- break;
- case CHAN_SOCKDATA:
- case CHAN_SOCKDATA_DORMANT:
- pfd_close(c->u.pfd.s);
- break;
- }
- c->type = CHAN_ZOMBIE;
- ssh2_channel_check_close(c);
-}
-
-int sshfwd_write(struct ssh_channel *c, char *buf, int len)
-{
- Ssh ssh = c->ssh;
-
- if (ssh->state == SSH_STATE_CLOSED)
- return 0;
-
- if (ssh->version == 1) {
- send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
- PKT_INT, c->remoteid,
- PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
- PKTT_OTHER, PKT_END);
- /*
- * In SSH-1 we can return 0 here - implying that forwarded
- * connections are never individually throttled - because
- * the only circumstance that can cause throttling will be
- * the whole SSH connection backing up, in which case
- * _everything_ will be throttled as a whole.
- */
- return 0;
- } else {
- ssh2_add_channel_data(c, buf, len);
- return ssh2_try_send(c);
- }
-}
-
-void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
-{
- Ssh ssh = c->ssh;
- int buflimit;
-
- if (ssh->state == SSH_STATE_CLOSED)
- return;
-
- if (ssh->version == 1) {
- buflimit = SSH1_BUFFER_LIMIT;
- } else {
- buflimit = c->v.v2.locmaxwin;
- ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
- }
- if (c->throttling_conn && bufsize <= buflimit) {
- c->throttling_conn = 0;
- ssh_throttle_conn(ssh, -1);
- }
-}
-
-static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
-{
- struct queued_handler *qh = ssh->qhead;
-
- assert(qh != NULL);
-
- assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
-
- if (qh->msg1 > 0) {
- assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
- ssh->packet_dispatch[qh->msg1] = NULL;
- }
- if (qh->msg2 > 0) {
- assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
- ssh->packet_dispatch[qh->msg2] = NULL;
- }
-
- if (qh->next) {
- ssh->qhead = qh->next;
-
- if (ssh->qhead->msg1 > 0) {
- assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
- ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
- }
- if (ssh->qhead->msg2 > 0) {
- assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
- ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
- }
- } else {
- ssh->qhead = ssh->qtail = NULL;
- ssh->packet_dispatch[pktin->type] = NULL;
- }
-
- qh->handler(ssh, pktin, qh->ctx);
-
- sfree(qh);
-}
-
-static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
- chandler_fn_t handler, void *ctx)
-{
- struct queued_handler *qh;
-
- qh = snew(struct queued_handler);
- qh->msg1 = msg1;
- qh->msg2 = msg2;
- qh->handler = handler;
- qh->ctx = ctx;
- qh->next = NULL;
-
- if (ssh->qtail == NULL) {
- ssh->qhead = qh;
-
- if (qh->msg1 > 0) {
- assert(ssh->packet_dispatch[qh->msg1] == NULL);
- ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
- }
- if (qh->msg2 > 0) {
- assert(ssh->packet_dispatch[qh->msg2] == NULL);
- ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
- }
- } else {
- ssh->qtail->next = qh;
- }
- ssh->qtail = qh;
-}
-
-static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
-{
- struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
-
- if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
- SSH2_MSG_REQUEST_SUCCESS)) {
- logeventf(ssh, "Remote port forwarding from %s enabled",
- pf->sportdesc);
- } else {
- logeventf(ssh, "Remote port forwarding from %s refused",
- pf->sportdesc);
-
- rpf = del234(ssh->rportfwds, pf);
- assert(rpf == pf);
- pf->pfrec->remote = NULL;
- free_rportfwd(pf);
- }
-}
-
-static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
-{
- struct ssh_portfwd *epf;
- int i;
- char *key, *val;
-
- if (!ssh->portfwds) {
- ssh->portfwds = newtree234(ssh_portcmp);
- } else {
- /*
- * Go through the existing port forwardings and tag them
- * with status==DESTROY. Any that we want to keep will be
- * re-enabled (status==KEEP) as we go through the
- * configuration and find out which bits are the same as
- * they were before.
- */
- struct ssh_portfwd *epf;
- int i;
- for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
- epf->status = DESTROY;
- }
-
- for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
- val != NULL;
- val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
- char *kp, *kp2, *vp, *vp2;
- char address_family, type;
- int sport,dport,sserv,dserv;
- char *sports, *dports, *saddr, *host;
-
- kp = key;
-
- address_family = 'A';
- type = 'L';
- if (*kp == 'A' || *kp == '4' || *kp == '6')
- address_family = *kp++;
- if (*kp == 'L' || *kp == 'R')
- type = *kp++;
-
- if ((kp2 = strchr(kp, ':')) != NULL) {
- /*
- * There's a colon in the middle of the source port
- * string, which means that the part before it is
- * actually a source address.
- */
- saddr = dupprintf("%.*s", (int)(kp2 - kp), kp);
- sports = kp2+1;
- } else {
- saddr = NULL;
- sports = kp;
- }
- sport = atoi(sports);
- sserv = 0;
- if (sport == 0) {
- sserv = 1;
- sport = net_service_lookup(sports);
- if (!sport) {
- logeventf(ssh, "Service lookup failed for source"
- " port \"%s\"", sports);
- }
- }
-
- if (type == 'L' && !strcmp(val, "D")) {
- /* dynamic forwarding */
- host = NULL;
- dports = NULL;
- dport = -1;
- dserv = 0;
- type = 'D';
- } else {
- /* ordinary forwarding */
- vp = val;
- vp2 = vp + strcspn(vp, ":");
- host = dupprintf("%.*s", (int)(vp2 - vp), vp);
- if (vp2)
- vp2++;
- dports = vp2;
- dport = atoi(dports);
- dserv = 0;
- if (dport == 0) {
- dserv = 1;
- dport = net_service_lookup(dports);
- if (!dport) {
- logeventf(ssh, "Service lookup failed for destination"
- " port \"%s\"", dports);
- }
- }
- }
-
- if (sport && dport) {
- /* Set up a description of the source port. */
- struct ssh_portfwd *pfrec, *epfrec;
-
- pfrec = snew(struct ssh_portfwd);
- pfrec->type = type;
- pfrec->saddr = saddr;
- pfrec->sserv = sserv ? dupstr(sports) : NULL;
- pfrec->sport = sport;
- pfrec->daddr = host;
- pfrec->dserv = dserv ? dupstr(dports) : NULL;
- pfrec->dport = dport;
- pfrec->local = NULL;
- pfrec->remote = NULL;
- pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
- address_family == '6' ? ADDRTYPE_IPV6 :
- ADDRTYPE_UNSPEC);
-
- epfrec = add234(ssh->portfwds, pfrec);
- if (epfrec != pfrec) {
- if (epfrec->status == DESTROY) {
- /*
- * We already have a port forwarding up and running
- * with precisely these parameters. Hence, no need
- * to do anything; simply re-tag the existing one
- * as KEEP.
- */
- epfrec->status = KEEP;
- }
- /*
- * Anything else indicates that there was a duplicate
- * in our input, which we'll silently ignore.
- */
- free_portfwd(pfrec);
- } else {
- pfrec->status = CREATE;
- }
- } else {
- sfree(saddr);
- sfree(host);
- }
- }
-
- /*
- * Now go through and destroy any port forwardings which were
- * not re-enabled.
- */
- for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
- if (epf->status == DESTROY) {
- char *message;
-
- message = dupprintf("%s port forwarding from %s%s%d",
- epf->type == 'L' ? "local" :
- epf->type == 'R' ? "remote" : "dynamic",
- epf->saddr ? epf->saddr : "",
- epf->saddr ? ":" : "",
- epf->sport);
-
- if (epf->type != 'D') {
- char *msg2 = dupprintf("%s to %s:%d", message,
- epf->daddr, epf->dport);
- sfree(message);
- message = msg2;
- }
-
- logeventf(ssh, "Cancelling %s", message);
- sfree(message);
-
- /* epf->remote or epf->local may be NULL if setting up a
- * forwarding failed. */
- if (epf->remote) {
- struct ssh_rportfwd *rpf = epf->remote;
- struct Packet *pktout;
-
- /*
- * Cancel the port forwarding at the server
- * end.
- */
- if (ssh->version == 1) {
- /*
- * We cannot cancel listening ports on the
- * server side in SSH-1! There's no message
- * to support it. Instead, we simply remove
- * the rportfwd record from the local end
- * so that any connections the server tries
- * to make on it are rejected.
- */
- } else {
- pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
- ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
- ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
- if (epf->saddr) {
- ssh2_pkt_addstring(pktout, epf->saddr);
- } else if (conf_get_int(conf, CONF_rport_acceptall)) {
- /* XXX: rport_acceptall may not represent
- * what was used to open the original connection,
- * since it's reconfigurable. */
- ssh2_pkt_addstring(pktout, "0.0.0.0");
- } else {
- ssh2_pkt_addstring(pktout, "127.0.0.1");
- }
- ssh2_pkt_adduint32(pktout, epf->sport);
- ssh2_pkt_send(ssh, pktout);
- }
-
- del234(ssh->rportfwds, rpf);
- free_rportfwd(rpf);
- } else if (epf->local) {
- pfd_terminate(epf->local);
- }
-
- delpos234(ssh->portfwds, i);
- free_portfwd(epf);
- i--; /* so we don't skip one in the list */
- }
-
- /*
- * And finally, set up any new port forwardings (status==CREATE).
- */
- for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
- if (epf->status == CREATE) {
- char *sportdesc, *dportdesc;
- sportdesc = dupprintf("%s%s%s%s%d%s",
- epf->saddr ? epf->saddr : "",
- epf->saddr ? ":" : "",
- epf->sserv ? epf->sserv : "",
- epf->sserv ? "(" : "",
- epf->sport,
- epf->sserv ? ")" : "");
- if (epf->type == 'D') {
- dportdesc = NULL;
- } else {
- dportdesc = dupprintf("%s:%s%s%d%s",
- epf->daddr,
- epf->dserv ? epf->dserv : "",
- epf->dserv ? "(" : "",
- epf->dport,
- epf->dserv ? ")" : "");
- }
-
- if (epf->type == 'L') {
- const char *err = pfd_addforward(epf->daddr, epf->dport,
- epf->saddr, epf->sport,
- ssh, conf,
- &epf->local,
- epf->addressfamily);
-
- logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
- epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
- epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
- sportdesc, dportdesc,
- err ? " failed: " : "", err ? err : "");
- } else if (epf->type == 'D') {
- const char *err = pfd_addforward(NULL, -1,
- epf->saddr, epf->sport,
- ssh, conf,
- &epf->local,
- epf->addressfamily);
-
- logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
- epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
- epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
- sportdesc,
- err ? " failed: " : "", err ? err : "");
- } else {
- struct ssh_rportfwd *pf;
-
- /*
- * Ensure the remote port forwardings tree exists.
- */
- if (!ssh->rportfwds) {
- if (ssh->version == 1)
- ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
- else
- ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
- }
-
- pf = snew(struct ssh_rportfwd);
- strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
- pf->dhost[lenof(pf->dhost)-1] = '\0';
- pf->dport = epf->dport;
- pf->sport = epf->sport;
- if (add234(ssh->rportfwds, pf) != pf) {
- logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
- epf->daddr, epf->dport);
- sfree(pf);
- } else {
- logeventf(ssh, "Requesting remote port %s"
- " forward to %s", sportdesc, dportdesc);
-
- pf->sportdesc = sportdesc;
- sportdesc = NULL;
- epf->remote = pf;
- pf->pfrec = epf;
-
- if (ssh->version == 1) {
- send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
- PKT_INT, epf->sport,
- PKT_STR, epf->daddr,
- PKT_INT, epf->dport,
- PKT_END);
- ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
- SSH1_SMSG_FAILURE,
- ssh_rportfwd_succfail, pf);
- } else {
- struct Packet *pktout;
- pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
- ssh2_pkt_addstring(pktout, "tcpip-forward");
- ssh2_pkt_addbool(pktout, 1);/* want reply */
- if (epf->saddr) {
- ssh2_pkt_addstring(pktout, epf->saddr);
- } else if (conf_get_int(conf, CONF_rport_acceptall)) {
- ssh2_pkt_addstring(pktout, "0.0.0.0");
- } else {
- ssh2_pkt_addstring(pktout, "127.0.0.1");
- }
- ssh2_pkt_adduint32(pktout, epf->sport);
- ssh2_pkt_send(ssh, pktout);
-
- ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
- SSH2_MSG_REQUEST_FAILURE,
- ssh_rportfwd_succfail, pf);
- }
- }
- }
- sfree(sportdesc);
- sfree(dportdesc);
- }
-}
-
-static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
-{
- char *string;
- int stringlen, bufsize;
-
- ssh_pkt_getstring(pktin, &string, &stringlen);
- if (string == NULL) {
- bombout(("Incoming terminal data packet was badly formed"));
- return;
- }
-
- bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
- string, stringlen);
- if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
- ssh->v1_stdout_throttling = 1;
- ssh_throttle_conn(ssh, +1);
- }
-}
-
-static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
-{
- /* Remote side is trying to open a channel to talk to our
- * X-Server. Give them back a local channel number. */
- struct ssh_channel *c;
- int remoteid = ssh_pkt_getuint32(pktin);
-
- logevent("Received X11 connect request");
- /* Refuse if X11 forwarding is disabled. */
- if (!ssh->X11_fwd_enabled) {
- send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
- PKT_INT, remoteid, PKT_END);
- logevent("Rejected X11 connect request");
- } else {
- c = snew(struct ssh_channel);
- c->ssh = ssh;
-
- if (x11_init(&c->u.x11.s, ssh->x11disp, c,
- NULL, -1, ssh->conf) != NULL) {
- logevent("Opening X11 forward connection failed");
- sfree(c);
- send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
- PKT_INT, remoteid, PKT_END);
- } else {
- logevent
- ("Opening X11 forward connection succeeded");
- c->remoteid = remoteid;
- c->halfopen = FALSE;
- c->localid = alloc_channel_id(ssh);
- c->closes = 0;
- c->pending_eof = FALSE;
- c->throttling_conn = 0;
- c->type = CHAN_X11; /* identify channel type */
- add234(ssh->channels, c);
- send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
- PKT_INT, c->remoteid, PKT_INT,
- c->localid, PKT_END);
- logevent("Opened X11 forward channel");
- }
- }
-}
-
-static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
-{
- /* Remote side is trying to open a channel to talk to our
- * agent. Give them back a local channel number. */
- struct ssh_channel *c;
- int remoteid = ssh_pkt_getuint32(pktin);
-
- /* Refuse if agent forwarding is disabled. */
- if (!ssh->agentfwd_enabled) {
- send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
- PKT_INT, remoteid, PKT_END);
- } else {
- c = snew(struct ssh_channel);
- c->ssh = ssh;
- c->remoteid = remoteid;
- c->halfopen = FALSE;
- c->localid = alloc_channel_id(ssh);
- c->closes = 0;
- c->pending_eof = FALSE;
- c->throttling_conn = 0;
- c->type = CHAN_AGENT; /* identify channel type */
- c->u.a.lensofar = 0;
- c->u.a.message = NULL;
- add234(ssh->channels, c);
- send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
- PKT_INT, c->remoteid, PKT_INT, c->localid,
- PKT_END);
- }
-}
-
-static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
-{
- /* Remote side is trying to open a channel to talk to a
- * forwarded port. Give them back a local channel number. */
- struct ssh_channel *c;
- struct ssh_rportfwd pf, *pfp;
- int remoteid;
- int hostsize, port;
- char *host;
- const char *e;
- c = snew(struct ssh_channel);
- c->ssh = ssh;
-
- remoteid = ssh_pkt_getuint32(pktin);
- ssh_pkt_getstring(pktin, &host, &hostsize);
- port = ssh_pkt_getuint32(pktin);
-
- if (hostsize >= lenof(pf.dhost))
- hostsize = lenof(pf.dhost)-1;
- memcpy(pf.dhost, host, hostsize);
- pf.dhost[hostsize] = '\0';
- pf.dport = port;
- pfp = find234(ssh->rportfwds, &pf, NULL);
-
- if (pfp == NULL) {
- logeventf(ssh, "Rejected remote port open request for %s:%d",
- pf.dhost, port);
- send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
- PKT_INT, remoteid, PKT_END);
- } else {
- logeventf(ssh, "Received remote port open request for %s:%d",
- pf.dhost, port);
- e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
- c, ssh->conf, pfp->pfrec->addressfamily);
- if (e != NULL) {
- logeventf(ssh, "Port open failed: %s", e);
- sfree(c);
- send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
- PKT_INT, remoteid, PKT_END);
- } else {
- c->remoteid = remoteid;
- c->halfopen = FALSE;
- c->localid = alloc_channel_id(ssh);
- c->closes = 0;
- c->pending_eof = FALSE;
- c->throttling_conn = 0;
- c->type = CHAN_SOCKDATA; /* identify channel type */
- add234(ssh->channels, c);
- send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
- PKT_INT, c->remoteid, PKT_INT,
- c->localid, PKT_END);
- logevent("Forwarded port opened successfully");
- }
- }
-}
-
-static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
-{
- unsigned int remoteid = ssh_pkt_getuint32(pktin);
- unsigned int localid = ssh_pkt_getuint32(pktin);
- struct ssh_channel *c;
-
- c = find234(ssh->channels, &remoteid, ssh_channelfind);
- if (c && c->type == CHAN_SOCKDATA_DORMANT) {
- c->remoteid = localid;
- c->halfopen = FALSE;
- c->type = CHAN_SOCKDATA;
- c->throttling_conn = 0;
- pfd_confirm(c->u.pfd.s);
- }
-
- if (c && c->pending_eof) {
- /*
- * We have a pending close on this channel,
- * which we decided on before the server acked
- * the channel open. So now we know the
- * remoteid, we can close it again.
- */
- ssh_channel_try_eof(c);
- }
-}
-
-static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
-{
- unsigned int remoteid = ssh_pkt_getuint32(pktin);
- struct ssh_channel *c;
-
- c = find234(ssh->channels, &remoteid, ssh_channelfind);
- if (c && c->type == CHAN_SOCKDATA_DORMANT) {
- logevent("Forwarded connection refused by server");
- pfd_close(c->u.pfd.s);
- del234(ssh->channels, c);
- sfree(c);
- }
-}
-
-static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
-{
- /* Remote side closes a channel. */
- unsigned i = ssh_pkt_getuint32(pktin);
- struct ssh_channel *c;
- c = find234(ssh->channels, &i, ssh_channelfind);
- if (c && !c->halfopen) {
-
- if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
- !(c->closes & CLOSES_RCVD_EOF)) {
- /*
- * Received CHANNEL_CLOSE, which we translate into
- * outgoing EOF.
- */
- int send_close = FALSE;
-
- c->closes |= CLOSES_RCVD_EOF;
-
- switch (c->type) {
- case CHAN_X11:
- if (c->u.x11.s)
- x11_send_eof(c->u.x11.s);
- else
- send_close = TRUE;
- case CHAN_SOCKDATA:
- if (c->u.pfd.s)
- x11_send_eof(c->u.pfd.s);
- else
- send_close = TRUE;
- case CHAN_AGENT:
- send_close = TRUE;
- }
-
- if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
- send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
- PKT_END);
- c->closes |= CLOSES_SENT_EOF;
- }
- }
-
- if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
- !(c->closes & CLOSES_RCVD_CLOSE)) {
-
- if (!(c->closes & CLOSES_SENT_EOF)) {
- bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
- " for which we never sent CHANNEL_CLOSE\n", i));
- }
-
- c->closes |= CLOSES_RCVD_CLOSE;
- }
-
- if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
- !(c->closes & CLOSES_SENT_CLOSE)) {
- send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
- PKT_INT, c->remoteid, PKT_END);
- c->closes |= CLOSES_SENT_CLOSE;
- }
-
- if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
- ssh_channel_destroy(c);
- } else {
- bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
- pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
- "_CONFIRMATION", c ? "half-open" : "nonexistent",
- i));
- }
-}
-
-static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
-{
- /* Data sent down one of our channels. */
- int i = ssh_pkt_getuint32(pktin);
- char *p;
- int len;
- struct ssh_channel *c;
-
- ssh_pkt_getstring(pktin, &p, &len);
-
- c = find234(ssh->channels, &i, ssh_channelfind);
- if (c) {
- int bufsize = 0;
- switch (c->type) {
- case CHAN_X11:
- bufsize = x11_send(c->u.x11.s, p, len);
- break;
- case CHAN_SOCKDATA:
- bufsize = pfd_send(c->u.pfd.s, p, len);
- break;
- case CHAN_AGENT:
- /* Data for an agent message. Buffer it. */
- while (len > 0) {
- if (c->u.a.lensofar < 4) {
- unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
- memcpy(c->u.a.msglen + c->u.a.lensofar, p,
- l);
- p += l;
- len -= l;
- c->u.a.lensofar += l;
- }
- if (c->u.a.lensofar == 4) {
- c->u.a.totallen =
- 4 + GET_32BIT(c->u.a.msglen);
- c->u.a.message = snewn(c->u.a.totallen,
- unsigned char);
- memcpy(c->u.a.message, c->u.a.msglen, 4);
- }
- if (c->u.a.lensofar >= 4 && len > 0) {
- unsigned int l =
- min(c->u.a.totallen - c->u.a.lensofar,
- (unsigned)len);
- memcpy(c->u.a.message + c->u.a.lensofar, p,
- l);
- p += l;
- len -= l;
- c->u.a.lensofar += l;
- }
- if (c->u.a.lensofar == c->u.a.totallen) {
- void *reply;
- int replylen;
- if (agent_query(c->u.a.message,
- c->u.a.totallen,
- &reply, &replylen,
- ssh_agentf_callback, c))
- ssh_agentf_callback(c, reply, replylen);
- sfree(c->u.a.message);
- c->u.a.lensofar = 0;
- }
- }
- bufsize = 0; /* agent channels never back up */
- break;
- }
- if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
- c->throttling_conn = 1;
- ssh_throttle_conn(ssh, +1);
- }
- }
-}
-
-static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
-{
- ssh->exitcode = ssh_pkt_getuint32(pktin);
- logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
- send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
- /*
- * In case `helpful' firewalls or proxies tack
- * extra human-readable text on the end of the
- * session which we might mistake for another
- * encrypted packet, we close the session once
- * we've sent EXIT_CONFIRMATION.
- */
- ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
-}
-
-/* Helper function to deal with sending tty modes for REQUEST_PTY */
-static void ssh1_send_ttymode(void *data, char *mode, char *val)
-{
- struct Packet *pktout = (struct Packet *)data;
- int i = 0;
- unsigned int arg = 0;
- while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
- if (i == lenof(ssh_ttymodes)) return;
- switch (ssh_ttymodes[i].type) {
- case TTY_OP_CHAR:
- arg = ssh_tty_parse_specchar(val);
- break;
- case TTY_OP_BOOL:
- arg = ssh_tty_parse_boolean(val);
- break;
- }
- ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
- ssh2_pkt_addbyte(pktout, arg);
-}
-
-
-static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
- struct Packet *pktin)
-{
- crBegin(ssh->do_ssh1_connection_crstate);
-
- ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
- ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
- ssh1_smsg_stdout_stderr_data;
-
- ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
- ssh1_msg_channel_open_confirmation;
- ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
- ssh1_msg_channel_open_failure;
- ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
- ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
- ssh1_msg_channel_close;
- ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
- ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
-
- if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
- logevent("Requesting agent forwarding");
- send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
- do {
- crReturnV;
- } while (!pktin);
- if (pktin->type != SSH1_SMSG_SUCCESS
- && pktin->type != SSH1_SMSG_FAILURE) {
- bombout(("Protocol confusion"));
- crStopV;
- } else if (pktin->type == SSH1_SMSG_FAILURE) {
- logevent("Agent forwarding refused");
- } else {
- logevent("Agent forwarding enabled");
- ssh->agentfwd_enabled = TRUE;
- ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
- }
- }
-
- if (conf_get_int(ssh->conf, CONF_x11_forward) &&
- (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
- conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
- logevent("Requesting X11 forwarding");
- /*
- * Note that while we blank the X authentication data here, we don't
- * take any special action to blank the start of an X11 channel,
- * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
- * without having session blanking enabled is likely to leak your
- * cookie into the log.
- */
- if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
- send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
- PKT_STR, ssh->x11disp->remoteauthprotoname,
- PKTT_PASSWORD,
- PKT_STR, ssh->x11disp->remoteauthdatastring,
- PKTT_OTHER,
- PKT_INT, ssh->x11disp->screennum,
- PKT_END);
- } else {
- send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
- PKT_STR, ssh->x11disp->remoteauthprotoname,
- PKTT_PASSWORD,
- PKT_STR, ssh->x11disp->remoteauthdatastring,
- PKTT_OTHER,
- PKT_END);
- }
- do {
- crReturnV;
- } while (!pktin);
- if (pktin->type != SSH1_SMSG_SUCCESS
- && pktin->type != SSH1_SMSG_FAILURE) {
- bombout(("Protocol confusion"));
- crStopV;
- } else if (pktin->type == SSH1_SMSG_FAILURE) {
- logevent("X11 forwarding refused");
- } else {
- logevent("X11 forwarding enabled");
- ssh->X11_fwd_enabled = TRUE;
- ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
- }
- }
-
- ssh_setup_portfwd(ssh, ssh->conf);
- ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
-
- if (!conf_get_int(ssh->conf, CONF_nopty)) {
- struct Packet *pkt;
- /* Unpick the terminal-speed string. */
- /* XXX perhaps we should allow no speeds to be sent. */
- ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
- sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
- /* Send the pty request. */
- pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
- ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
- ssh_pkt_adduint32(pkt, ssh->term_height);
- ssh_pkt_adduint32(pkt, ssh->term_width);
- ssh_pkt_adduint32(pkt, 0); /* width in pixels */
- ssh_pkt_adduint32(pkt, 0); /* height in pixels */
- parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
- ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
- ssh_pkt_adduint32(pkt, ssh->ispeed);
- ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
- ssh_pkt_adduint32(pkt, ssh->ospeed);
- ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
- s_wrpkt(ssh, pkt);
- ssh->state = SSH_STATE_INTERMED;
- do {
- crReturnV;
- } while (!pktin);
- if (pktin->type != SSH1_SMSG_SUCCESS
- && pktin->type != SSH1_SMSG_FAILURE) {
- bombout(("Protocol confusion"));
- crStopV;
- } else if (pktin->type == SSH1_SMSG_FAILURE) {
- c_write_str(ssh, "Server refused to allocate pty\r\n");
- ssh->editing = ssh->echoing = 1;
- } else {
- logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
- ssh->ospeed, ssh->ispeed);
- ssh->got_pty = TRUE;
- }
- } else {
- ssh->editing = ssh->echoing = 1;
- }
-
- if (conf_get_int(ssh->conf, CONF_compression)) {
- send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
- do {
- crReturnV;
- } while (!pktin);
- if (pktin->type != SSH1_SMSG_SUCCESS
- && pktin->type != SSH1_SMSG_FAILURE) {
- bombout(("Protocol confusion"));
- crStopV;
- } else if (pktin->type == SSH1_SMSG_FAILURE) {
- c_write_str(ssh, "Server refused to compress\r\n");
- }
- logevent("Started compression");
- ssh->v1_compressing = TRUE;
- ssh->cs_comp_ctx = zlib_compress_init();
- logevent("Initialised zlib (RFC1950) compression");
- ssh->sc_comp_ctx = zlib_decompress_init();
- logevent("Initialised zlib (RFC1950) decompression");
- }
-
- /*
- * Start the shell or command.
- *
- * Special case: if the first-choice command is an SSH-2
- * subsystem (hence not usable here) and the second choice
- * exists, we fall straight back to that.
- */
- {
- char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
-
- if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
- conf_get_str(ssh->conf, CONF_remote_cmd2)) {
- cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
- ssh->fallback_cmd = TRUE;
- }
- if (*cmd)
- send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
- else
- send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
- logevent("Started session");
- }
-
- ssh->state = SSH_STATE_SESSION;
- if (ssh->size_needed)
- ssh_size(ssh, ssh->term_width, ssh->term_height);
- if (ssh->eof_needed)
- ssh_special(ssh, TS_EOF);
-
- if (ssh->ldisc)
- ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
- ssh->send_ok = 1;
- ssh->channels = newtree234(ssh_channelcmp);
- while (1) {
-
- /*
- * By this point, most incoming packets are already being
- * handled by the dispatch table, and we need only pay
- * attention to the unusual ones.
- */
-
- crReturnV;
- if (pktin) {
- if (pktin->type == SSH1_SMSG_SUCCESS) {
- /* may be from EXEC_SHELL on some servers */
- } else if (pktin->type == SSH1_SMSG_FAILURE) {
- /* may be from EXEC_SHELL on some servers
- * if no pty is available or in other odd cases. Ignore */
- } else {
- bombout(("Strange packet received: type %d", pktin->type));
- crStopV;
- }
- } else {
- while (inlen > 0) {
- int len = min(inlen, 512);
- send_packet(ssh, SSH1_CMSG_STDIN_DATA,
- PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
- PKTT_OTHER, PKT_END);
- in += len;
- inlen -= len;
- }
- }
- }
-
- crFinishV;
-}
-
-/*
- * Handle the top-level SSH-2 protocol.
- */
-static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
-{
- char *msg;
- int msglen;
-
- ssh_pkt_getstring(pktin, &msg, &msglen);
- logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
-}
-
-static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
-{
- /* log reason code in disconnect message */
- char *msg;
- int msglen;
-
- ssh_pkt_getstring(pktin, &msg, &msglen);
- bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
-}
-
-static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
-{
- /* Do nothing, because we're ignoring it! Duhh. */
-}
-
-static void ssh1_protocol_setup(Ssh ssh)
-{
- int i;
-
- /*
- * Most messages are handled by the coroutines.
- */
- for (i = 0; i < 256; i++)
- ssh->packet_dispatch[i] = NULL;
-
- /*
- * These special message types we install handlers for.
- */
- ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
- ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
- ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
-}
-
-static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
- struct Packet *pktin)
-{
- unsigned char *in=(unsigned char*)vin;
- if (ssh->state == SSH_STATE_CLOSED)
- return;
-
- if (pktin && ssh->packet_dispatch[pktin->type]) {
- ssh->packet_dispatch[pktin->type](ssh, pktin);
- return;
- }
-
- if (!ssh->protocol_initial_phase_done) {
- if (do_ssh1_login(ssh, in, inlen, pktin))
- ssh->protocol_initial_phase_done = TRUE;
- else
- return;
- }
-
- do_ssh1_connection(ssh, in, inlen, pktin);
-}
-
-/*
- * Utility routine for decoding comma-separated strings in KEXINIT.
- */
-static int in_commasep_string(char *needle, char *haystack, int haylen)
-{
- int needlen;
- if (!needle || !haystack) /* protect against null pointers */
- return 0;
- needlen = strlen(needle);
- while (1) {
- /*
- * Is it at the start of the string?
- */
- if (haylen >= needlen && /* haystack is long enough */
- !memcmp(needle, haystack, needlen) && /* initial match */
- (haylen == needlen || haystack[needlen] == ',')
- /* either , or EOS follows */
- )
- return 1;
- /*
- * If not, search for the next comma and resume after that.
- * If no comma found, terminate.
- */
- while (haylen > 0 && *haystack != ',')
- haylen--, haystack++;
- if (haylen == 0)
- return 0;
- haylen--, haystack++; /* skip over comma itself */
- }
-}
-
-/*
- * Similar routine for checking whether we have the first string in a list.
- */
-static int first_in_commasep_string(char *needle, char *haystack, int haylen)
-{
- int needlen;
- if (!needle || !haystack) /* protect against null pointers */
- return 0;
- needlen = strlen(needle);
- /*
- * Is it at the start of the string?
- */
- if (haylen >= needlen && /* haystack is long enough */
- !memcmp(needle, haystack, needlen) && /* initial match */
- (haylen == needlen || haystack[needlen] == ',')
- /* either , or EOS follows */
- )
- return 1;
- return 0;
-}
-
-
-/*
- * SSH-2 key creation method.
- * (Currently assumes 2 lots of any hash are sufficient to generate
- * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
- */
-#define SSH2_MKKEY_ITERS (2)
-static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
- unsigned char *keyspace)
-{
- const struct ssh_hash *h = ssh->kex->hash;
- void *s;
- /* First hlen bytes. */
- s = h->init();
- if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
- hash_mpint(h, s, K);
- h->bytes(s, H, h->hlen);
- h->bytes(s, &chr, 1);
- h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
- h->final(s, keyspace);
- /* Next hlen bytes. */
- s = h->init();
- if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
- hash_mpint(h, s, K);
- h->bytes(s, H, h->hlen);
- h->bytes(s, keyspace, h->hlen);
- h->final(s, keyspace + h->hlen);
-}
-
-/*
- * Handle the SSH-2 transport layer.
- */
-static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
- struct Packet *pktin)
-{
- unsigned char *in = (unsigned char *)vin;
- struct do_ssh2_transport_state {
- int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
- Bignum p, g, e, f, K;
- void *our_kexinit;
- int our_kexinitlen;
- int kex_init_value, kex_reply_value;
- const struct ssh_mac **maclist;
- int nmacs;
- const struct ssh2_cipher *cscipher_tobe;
- const struct ssh2_cipher *sccipher_tobe;
- const struct ssh_mac *csmac_tobe;
- const struct ssh_mac *scmac_tobe;
- const struct ssh_compress *cscomp_tobe;
- const struct ssh_compress *sccomp_tobe;
- char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
- int hostkeylen, siglen, rsakeylen;
- void *hkey; /* actual host key */
- void *rsakey; /* for RSA kex */
- unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
- int n_preferred_kex;
- const struct ssh_kexes *preferred_kex[KEX_MAX];
- int n_preferred_ciphers;
- const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
- const struct ssh_compress *preferred_comp;
- int userauth_succeeded; /* for delayed compression */
- int pending_compression;
- int got_session_id, activated_authconn;
- struct Packet *pktout;
- int dlgret;
- int guessok;
- int ignorepkt;
- };
- crState(do_ssh2_transport_state);
-
- crBegin(ssh->do_ssh2_transport_crstate);
-
- s->cscipher_tobe = s->sccipher_tobe = NULL;
- s->csmac_tobe = s->scmac_tobe = NULL;
- s->cscomp_tobe = s->sccomp_tobe = NULL;
-
- s->got_session_id = s->activated_authconn = FALSE;
- s->userauth_succeeded = FALSE;
- s->pending_compression = FALSE;
-
- /*
- * Be prepared to work around the buggy MAC problem.
- */
- if (ssh->remote_bugs & BUG_SSH2_HMAC)
- s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
- else
- s->maclist = macs, s->nmacs = lenof(macs);
-
- begin_key_exchange:
- ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
- {
- int i, j, commalist_started;
-
- /*
- * Set up the preferred key exchange. (NULL => warn below here)
- */
- s->n_preferred_kex = 0;
- for (i = 0; i < KEX_MAX; i++) {
- switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
- case KEX_DHGEX:
- s->preferred_kex[s->n_preferred_kex++] =
- &ssh_diffiehellman_gex;
- break;
- case KEX_DHGROUP14:
- s->preferred_kex[s->n_preferred_kex++] =
- &ssh_diffiehellman_group14;
- break;
- case KEX_DHGROUP1:
- s->preferred_kex[s->n_preferred_kex++] =
- &ssh_diffiehellman_group1;
- break;
- case KEX_RSA:
- s->preferred_kex[s->n_preferred_kex++] =
- &ssh_rsa_kex;
- break;
- case KEX_WARN:
- /* Flag for later. Don't bother if it's the last in
- * the list. */
- if (i < KEX_MAX - 1) {
- s->preferred_kex[s->n_preferred_kex++] = NULL;
- }
- break;
- }
- }
-
- /*
- * Set up the preferred ciphers. (NULL => warn below here)
- */
- s->n_preferred_ciphers = 0;
- for (i = 0; i < CIPHER_MAX; i++) {
- switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
- case CIPHER_BLOWFISH:
- s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
- break;
- case CIPHER_DES:
- if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
- s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
- }
- break;
- case CIPHER_3DES:
- s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
- break;
- case CIPHER_AES:
- s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
- break;
- case CIPHER_ARCFOUR:
- s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
- break;
- case CIPHER_WARN:
- /* Flag for later. Don't bother if it's the last in
- * the list. */
- if (i < CIPHER_MAX - 1) {
- s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
- }
- break;
- }
- }
-
- /*
- * Set up preferred compression.
- */
- if (conf_get_int(ssh->conf, CONF_compression))
- s->preferred_comp = &ssh_zlib;
- else
- s->preferred_comp = &ssh_comp_none;
-
- /*
- * Enable queueing of outgoing auth- or connection-layer
- * packets while we are in the middle of a key exchange.
- */
- ssh->queueing = TRUE;
-
- /*
- * Flag that KEX is in progress.
- */
- ssh->kex_in_progress = TRUE;
-
- /*
- * Construct and send our key exchange packet.
- */
- s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
- for (i = 0; i < 16; i++)
- ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
- /* List key exchange algorithms. */
- ssh2_pkt_addstring_start(s->pktout);
- commalist_started = 0;
- for (i = 0; i < s->n_preferred_kex; i++) {
- const struct ssh_kexes *k = s->preferred_kex[i];
- if (!k) continue; /* warning flag */
- for (j = 0; j < k->nkexes; j++) {
- if (commalist_started)
- ssh2_pkt_addstring_str(s->pktout, ",");
- ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
- commalist_started = 1;
- }
- }
- /* List server host key algorithms. */
- ssh2_pkt_addstring_start(s->pktout);
- for (i = 0; i < lenof(hostkey_algs); i++) {
- ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
- if (i < lenof(hostkey_algs) - 1)
- ssh2_pkt_addstring_str(s->pktout, ",");
- }
- /* List client->server encryption algorithms. */
- ssh2_pkt_addstring_start(s->pktout);
- commalist_started = 0;
- for (i = 0; i < s->n_preferred_ciphers; i++) {
- const struct ssh2_ciphers *c = s->preferred_ciphers[i];
- if (!c) continue; /* warning flag */
- for (j = 0; j < c->nciphers; j++) {
- if (commalist_started)
- ssh2_pkt_addstring_str(s->pktout, ",");
- ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
- commalist_started = 1;
- }
- }
- /* List server->client encryption algorithms. */
- ssh2_pkt_addstring_start(s->pktout);
- commalist_started = 0;
- for (i = 0; i < s->n_preferred_ciphers; i++) {
- const struct ssh2_ciphers *c = s->preferred_ciphers[i];
- if (!c) continue; /* warning flag */
- for (j = 0; j < c->nciphers; j++) {
- if (commalist_started)
- ssh2_pkt_addstring_str(s->pktout, ",");
- ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
- commalist_started = 1;
- }
- }
- /* List client->server MAC algorithms. */
- ssh2_pkt_addstring_start(s->pktout);
- for (i = 0; i < s->nmacs; i++) {
- ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
- if (i < s->nmacs - 1)
- ssh2_pkt_addstring_str(s->pktout, ",");
- }
- /* List server->client MAC algorithms. */
- ssh2_pkt_addstring_start(s->pktout);
- for (i = 0; i < s->nmacs; i++) {
- ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
- if (i < s->nmacs - 1)
- ssh2_pkt_addstring_str(s->pktout, ",");
- }
- /* List client->server compression algorithms,
- * then server->client compression algorithms. (We use the
- * same set twice.) */
- for (j = 0; j < 2; j++) {
- ssh2_pkt_addstring_start(s->pktout);
- assert(lenof(compressions) > 1);
- /* Prefer non-delayed versions */
- ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
- /* We don't even list delayed versions of algorithms until
- * they're allowed to be used, to avoid a race. See the end of
- * this function. */
- if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
- ssh2_pkt_addstring_str(s->pktout, ",");
- ssh2_pkt_addstring_str(s->pktout,
- s->preferred_comp->delayed_name);
- }
- for (i = 0; i < lenof(compressions); i++) {
- const struct ssh_compress *c = compressions[i];
- if (c != s->preferred_comp) {
- ssh2_pkt_addstring_str(s->pktout, ",");
- ssh2_pkt_addstring_str(s->pktout, c->name);
- if (s->userauth_succeeded && c->delayed_name) {
- ssh2_pkt_addstring_str(s->pktout, ",");
- ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
- }
- }
- }
- }
- /* List client->server languages. Empty list. */
- ssh2_pkt_addstring_start(s->pktout);
- /* List server->client languages. Empty list. */
- ssh2_pkt_addstring_start(s->pktout);
- /* First KEX packet does _not_ follow, because we're not that brave. */
- ssh2_pkt_addbool(s->pktout, FALSE);
- /* Reserved. */
- ssh2_pkt_adduint32(s->pktout, 0);
- }
-
- s->our_kexinitlen = s->pktout->length - 5;
- s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
- memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
-
- ssh2_pkt_send_noqueue(ssh, s->pktout);
-
- if (!pktin)
- crWaitUntil(pktin);
-
- /*
- * Now examine the other side's KEXINIT to see what we're up
- * to.
- */
- {
- char *str, *preferred;
- int i, j, len;
-
- if (pktin->type != SSH2_MSG_KEXINIT) {
- bombout(("expected key exchange packet from server"));
- crStop(0);
- }
- ssh->kex = NULL;
- ssh->hostkey = NULL;
- s->cscipher_tobe = NULL;
- s->sccipher_tobe = NULL;
- s->csmac_tobe = NULL;
- s->scmac_tobe = NULL;
- s->cscomp_tobe = NULL;
- s->sccomp_tobe = NULL;
- s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
-
- pktin->savedpos += 16; /* skip garbage cookie */
- ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
-
- preferred = NULL;
- for (i = 0; i < s->n_preferred_kex; i++) {
- const struct ssh_kexes *k = s->preferred_kex[i];
- if (!k) {
- s->warn_kex = TRUE;
- } else {
- for (j = 0; j < k->nkexes; j++) {
- if (!preferred) preferred = k->list[j]->name;
- if (in_commasep_string(k->list[j]->name, str, len)) {
- ssh->kex = k->list[j];
- break;
- }
- }
- }
- if (ssh->kex)
- break;
- }
- if (!ssh->kex) {
- bombout(("Couldn't agree a key exchange algorithm (available: %s)",
- str ? str : "(null)"));
- crStop(0);
- }
- /*
- * Note that the server's guess is considered wrong if it doesn't match
- * the first algorithm in our list, even if it's still the algorithm
- * we end up using.
- */
- s->guessok = first_in_commasep_string(preferred, str, len);
- ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
- for (i = 0; i < lenof(hostkey_algs); i++) {
- if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
- ssh->hostkey = hostkey_algs[i];
- break;
- }
- }
- s->guessok = s->guessok &&
- first_in_commasep_string(hostkey_algs[0]->name, str, len);
- ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
- for (i = 0; i < s->n_preferred_ciphers; i++) {
- const struct ssh2_ciphers *c = s->preferred_ciphers[i];
- if (!c) {
- s->warn_cscipher = TRUE;
- } else {
- for (j = 0; j < c->nciphers; j++) {
- if (in_commasep_string(c->list[j]->name, str, len)) {
- s->cscipher_tobe = c->list[j];
- break;
- }
- }
- }
- if (s->cscipher_tobe)
- break;
- }
- if (!s->cscipher_tobe) {
- bombout(("Couldn't agree a client-to-server cipher (available: %s)",
- str ? str : "(null)"));
- crStop(0);
- }
-
- ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
- for (i = 0; i < s->n_preferred_ciphers; i++) {
- const struct ssh2_ciphers *c = s->preferred_ciphers[i];
- if (!c) {
- s->warn_sccipher = TRUE;
- } else {
- for (j = 0; j < c->nciphers; j++) {
- if (in_commasep_string(c->list[j]->name, str, len)) {
- s->sccipher_tobe = c->list[j];
- break;
- }
- }
- }
- if (s->sccipher_tobe)
- break;
- }
- if (!s->sccipher_tobe) {
- bombout(("Couldn't agree a server-to-client cipher (available: %s)",
- str ? str : "(null)"));
- crStop(0);
- }
-
- ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
- for (i = 0; i < s->nmacs; i++) {
- if (in_commasep_string(s->maclist[i]->name, str, len)) {
- s->csmac_tobe = s->maclist[i];
- break;
- }
- }
- ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
- for (i = 0; i < s->nmacs; i++) {
- if (in_commasep_string(s->maclist[i]->name, str, len)) {
- s->scmac_tobe = s->maclist[i];
- break;
- }
- }
- ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
- for (i = 0; i < lenof(compressions) + 1; i++) {
- const struct ssh_compress *c =
- i == 0 ? s->preferred_comp : compressions[i - 1];
- if (in_commasep_string(c->name, str, len)) {
- s->cscomp_tobe = c;
- break;
- } else if (in_commasep_string(c->delayed_name, str, len)) {
- if (s->userauth_succeeded) {
- s->cscomp_tobe = c;
- break;
- } else {
- s->pending_compression = TRUE; /* try this later */
- }
- }
- }
- ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
- for (i = 0; i < lenof(compressions) + 1; i++) {
- const struct ssh_compress *c =
- i == 0 ? s->preferred_comp : compressions[i - 1];
- if (in_commasep_string(c->name, str, len)) {
- s->sccomp_tobe = c;
- break;
- } else if (in_commasep_string(c->delayed_name, str, len)) {
- if (s->userauth_succeeded) {
- s->sccomp_tobe = c;
- break;
- } else {
- s->pending_compression = TRUE; /* try this later */
- }
- }
- }
- if (s->pending_compression) {
- logevent("Server supports delayed compression; "
- "will try this later");
- }
- ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
- ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
- s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
-
- if (s->warn_kex) {
- ssh_set_frozen(ssh, 1);
- s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
- ssh->kex->name,
- ssh_dialog_callback, ssh);
- if (s->dlgret < 0) {
- do {
- crReturn(0);
- if (pktin) {
- bombout(("Unexpected data from server while"
- " waiting for user response"));
- crStop(0);
- }
- } while (pktin || inlen > 0);
- s->dlgret = ssh->user_response;
- }
- ssh_set_frozen(ssh, 0);
- if (s->dlgret == 0) {
- ssh_disconnect(ssh, "User aborted at kex warning", NULL,
- 0, TRUE);
- crStop(0);
- }
- }
-
- if (s->warn_cscipher) {
- ssh_set_frozen(ssh, 1);
- s->dlgret = askalg(ssh->frontend,
- "client-to-server cipher",
- s->cscipher_tobe->name,
- ssh_dialog_callback, ssh);
- if (s->dlgret < 0) {
- do {
- crReturn(0);
- if (pktin) {
- bombout(("Unexpected data from server while"
- " waiting for user response"));
- crStop(0);
- }
- } while (pktin || inlen > 0);
- s->dlgret = ssh->user_response;
- }
- ssh_set_frozen(ssh, 0);
- if (s->dlgret == 0) {
- ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
- 0, TRUE);
- crStop(0);
- }
- }
-
- if (s->warn_sccipher) {
- ssh_set_frozen(ssh, 1);
- s->dlgret = askalg(ssh->frontend,
- "server-to-client cipher",
- s->sccipher_tobe->name,
- ssh_dialog_callback, ssh);
- if (s->dlgret < 0) {
- do {
- crReturn(0);
- if (pktin) {
- bombout(("Unexpected data from server while"
- " waiting for user response"));
- crStop(0);
- }
- } while (pktin || inlen > 0);
- s->dlgret = ssh->user_response;
- }
- ssh_set_frozen(ssh, 0);
- if (s->dlgret == 0) {
- ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
- 0, TRUE);
- crStop(0);
- }
- }
-
- ssh->exhash = ssh->kex->hash->init();
- hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
- hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
- hash_string(ssh->kex->hash, ssh->exhash,
- s->our_kexinit, s->our_kexinitlen);
- sfree(s->our_kexinit);
- if (pktin->length > 5)
- hash_string(ssh->kex->hash, ssh->exhash,
- pktin->data + 5, pktin->length - 5);
-
- if (s->ignorepkt) /* first_kex_packet_follows */
- crWaitUntil(pktin); /* Ignore packet */
- }
-
- if (ssh->kex->main_type == KEXTYPE_DH) {
- /*
- * Work out the number of bits of key we will need from the
- * key exchange. We start with the maximum key length of
- * either cipher...
- */
- {
- int csbits, scbits;
-
- csbits = s->cscipher_tobe->keylen;
- scbits = s->sccipher_tobe->keylen;
- s->nbits = (csbits > scbits ? csbits : scbits);
- }
- /* The keys only have hlen-bit entropy, since they're based on
- * a hash. So cap the key size at hlen bits. */
- if (s->nbits > ssh->kex->hash->hlen * 8)
- s->nbits = ssh->kex->hash->hlen * 8;
-
- /*
- * If we're doing Diffie-Hellman group exchange, start by
- * requesting a group.
- */
- if (!ssh->kex->pdata) {
- logevent("Doing Diffie-Hellman group exchange");
- ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
- /*
- * Work out how big a DH group we will need to allow that
- * much data.
- */
- s->pbits = 512 << ((s->nbits - 1) / 64);
- s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
- ssh2_pkt_adduint32(s->pktout, s->pbits);
- ssh2_pkt_send_noqueue(ssh, s->pktout);
-
- crWaitUntil(pktin);
- if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
- bombout(("expected key exchange group packet from server"));
- crStop(0);
- }
- s->p = ssh2_pkt_getmp(pktin);
- s->g = ssh2_pkt_getmp(pktin);
- if (!s->p || !s->g) {
- bombout(("unable to read mp-ints from incoming group packet"));
- crStop(0);
- }
- ssh->kex_ctx = dh_setup_gex(s->p, s->g);
- s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
- s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
- } else {
- ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
- ssh->kex_ctx = dh_setup_group(ssh->kex);
- s->kex_init_value = SSH2_MSG_KEXDH_INIT;
- s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
- logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
- ssh->kex->groupname);
- }
-
- logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
- ssh->kex->hash->text_name);
- /*
- * Now generate and send e for Diffie-Hellman.
- */
- set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
- s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
- s->pktout = ssh2_pkt_init(s->kex_init_value);
- ssh2_pkt_addmp(s->pktout, s->e);
- ssh2_pkt_send_noqueue(ssh, s->pktout);
-
- set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
- crWaitUntil(pktin);
- if (pktin->type != s->kex_reply_value) {
- bombout(("expected key exchange reply packet from server"));
- crStop(0);
- }
- set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
- ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
- s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
- s->f = ssh2_pkt_getmp(pktin);
- if (!s->f) {
- bombout(("unable to parse key exchange reply packet"));
- crStop(0);
- }
- ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
-
- s->K = dh_find_K(ssh->kex_ctx, s->f);
-
- /* We assume everything from now on will be quick, and it might
- * involve user interaction. */
- set_busy_status(ssh->frontend, BUSY_NOT);
-
- hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
- if (!ssh->kex->pdata) {
- hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
- hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
- hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
- }
- hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
- hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
-
- dh_cleanup(ssh->kex_ctx);
- freebn(s->f);
- if (!ssh->kex->pdata) {
- freebn(s->g);
- freebn(s->p);
- }
- } else {
- logeventf(ssh, "Doing RSA key exchange with hash %s",
- ssh->kex->hash->text_name);
- ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
- /*
- * RSA key exchange. First expect a KEXRSA_PUBKEY packet
- * from the server.
- */
- crWaitUntil(pktin);
- if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
- bombout(("expected RSA public key packet from server"));
- crStop(0);
- }
-
- ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
- hash_string(ssh->kex->hash, ssh->exhash,
- s->hostkeydata, s->hostkeylen);
- s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
-
- {
- char *keydata;
- ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
- s->rsakeydata = snewn(s->rsakeylen, char);
- memcpy(s->rsakeydata, keydata, s->rsakeylen);
- }
-
- s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
- if (!s->rsakey) {
- sfree(s->rsakeydata);
- bombout(("unable to parse RSA public key from server"));
- crStop(0);
- }
-
- hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
-
- /*
- * Next, set up a shared secret K, of precisely KLEN -
- * 2*HLEN - 49 bits, where KLEN is the bit length of the
- * RSA key modulus and HLEN is the bit length of the hash
- * we're using.
- */
- {
- int klen = ssh_rsakex_klen(s->rsakey);
- int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
- int i, byte = 0;
- unsigned char *kstr1, *kstr2, *outstr;
- int kstr1len, kstr2len, outstrlen;
-
- s->K = bn_power_2(nbits - 1);
-
- for (i = 0; i < nbits; i++) {
- if ((i & 7) == 0) {
- byte = random_byte();
- }
- bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
- }
-
- /*
- * Encode this as an mpint.
- */
- kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
- kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
- PUT_32BIT(kstr2, kstr1len);
- memcpy(kstr2 + 4, kstr1, kstr1len);
-
- /*
- * Encrypt it with the given RSA key.
- */
- outstrlen = (klen + 7) / 8;
- outstr = snewn(outstrlen, unsigned char);
- ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
- outstr, outstrlen, s->rsakey);
-
- /*
- * And send it off in a return packet.
- */
- s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
- ssh2_pkt_addstring_start(s->pktout);
- ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
- ssh2_pkt_send_noqueue(ssh, s->pktout);
-
- hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
-
- sfree(kstr2);
- sfree(kstr1);
- sfree(outstr);
- }
-
- ssh_rsakex_freekey(s->rsakey);
-
- crWaitUntil(pktin);
- if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
- sfree(s->rsakeydata);
- bombout(("expected signature packet from server"));
- crStop(0);
- }
-
- ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
-
- sfree(s->rsakeydata);
- }
-
- hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
- assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
- ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
-
- ssh->kex_ctx = NULL;
-
-#if 0
- debug(("Exchange hash is:\n"));
- dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
-#endif
-
- if (!s->hkey ||
- !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
- (char *)s->exchange_hash,
- ssh->kex->hash->hlen)) {
- bombout(("Server's host key did not match the signature supplied"));
- crStop(0);
- }
-
- /*
- * Authenticate remote host: verify host key. (We've already
- * checked the signature of the exchange hash.)
- */
- s->keystr = ssh->hostkey->fmtkey(s->hkey);
- s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
- ssh_set_frozen(ssh, 1);
- s->dlgret = verify_ssh_host_key(ssh->frontend,
- ssh->savedhost, ssh->savedport,
- ssh->hostkey->keytype, s->keystr,
- s->fingerprint,
- ssh_dialog_callback, ssh);
- if (s->dlgret < 0) {
- do {
- crReturn(0);
- if (pktin) {
- bombout(("Unexpected data from server while waiting"
- " for user host key response"));
- crStop(0);
- }
- } while (pktin || inlen > 0);
- s->dlgret = ssh->user_response;
- }
- ssh_set_frozen(ssh, 0);
- if (s->dlgret == 0) {
- ssh_disconnect(ssh, "User aborted at host key verification", NULL,
- 0, TRUE);
- crStop(0);
- }
- if (!s->got_session_id) { /* don't bother logging this in rekeys */
- logevent("Host key fingerprint is:");
- logevent(s->fingerprint);
- }
- sfree(s->fingerprint);
- sfree(s->keystr);
- ssh->hostkey->freekey(s->hkey);
-
- /*
- * The exchange hash from the very first key exchange is also
- * the session id, used in session key construction and
- * authentication.
- */
- if (!s->got_session_id) {
- assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
- memcpy(ssh->v2_session_id, s->exchange_hash,
- sizeof(s->exchange_hash));
- ssh->v2_session_id_len = ssh->kex->hash->hlen;
- assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
- s->got_session_id = TRUE;
- }
-
- /*
- * Send SSH2_MSG_NEWKEYS.
- */
- s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
- ssh2_pkt_send_noqueue(ssh, s->pktout);
- ssh->outgoing_data_size = 0; /* start counting from here */
-
- /*
- * We've sent client NEWKEYS, so create and initialise
- * client-to-server session keys.
- */
- if (ssh->cs_cipher_ctx)
- ssh->cscipher->free_context(ssh->cs_cipher_ctx);
- ssh->cscipher = s->cscipher_tobe;
- ssh->cs_cipher_ctx = ssh->cscipher->make_context();
-
- if (ssh->cs_mac_ctx)
- ssh->csmac->free_context(ssh->cs_mac_ctx);
- ssh->csmac = s->csmac_tobe;
- ssh->cs_mac_ctx = ssh->csmac->make_context();
-
- if (ssh->cs_comp_ctx)
- ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
- ssh->cscomp = s->cscomp_tobe;
- ssh->cs_comp_ctx = ssh->cscomp->compress_init();
-
- /*
- * Set IVs on client-to-server keys. Here we use the exchange
- * hash from the _first_ key exchange.
- */
- {
- unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
- assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
- ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
- assert((ssh->cscipher->keylen+7) / 8 <=
- ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
- ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
- ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
- assert(ssh->cscipher->blksize <=
- ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
- ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
- ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
- assert(ssh->csmac->len <=
- ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
- ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
- memset(keyspace, 0, sizeof(keyspace));
- }
-
- logeventf(ssh, "Initialised %.200s client->server encryption",
- ssh->cscipher->text_name);
- logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
- ssh->csmac->text_name);
- if (ssh->cscomp->text_name)
- logeventf(ssh, "Initialised %s compression",
- ssh->cscomp->text_name);
-
- /*
- * Now our end of the key exchange is complete, we can send all
- * our queued higher-layer packets.
- */
- ssh->queueing = FALSE;
- ssh2_pkt_queuesend(ssh);
-
- /*
- * Expect SSH2_MSG_NEWKEYS from server.
- */
- crWaitUntil(pktin);
- if (pktin->type != SSH2_MSG_NEWKEYS) {
- bombout(("expected new-keys packet from server"));
- crStop(0);
- }
- ssh->incoming_data_size = 0; /* start counting from here */
-
- /*
- * We've seen server NEWKEYS, so create and initialise
- * server-to-client session keys.
- */
- if (ssh->sc_cipher_ctx)
- ssh->sccipher->free_context(ssh->sc_cipher_ctx);
- ssh->sccipher = s->sccipher_tobe;
- ssh->sc_cipher_ctx = ssh->sccipher->make_context();
-
- if (ssh->sc_mac_ctx)
- ssh->scmac->free_context(ssh->sc_mac_ctx);
- ssh->scmac = s->scmac_tobe;
- ssh->sc_mac_ctx = ssh->scmac->make_context();
-
- if (ssh->sc_comp_ctx)
- ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
- ssh->sccomp = s->sccomp_tobe;
- ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
-
- /*
- * Set IVs on server-to-client keys. Here we use the exchange
- * hash from the _first_ key exchange.
- */
- {
- unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
- assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
- ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
- assert((ssh->sccipher->keylen+7) / 8 <=
- ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
- ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
- ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
- assert(ssh->sccipher->blksize <=
- ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
- ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
- ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
- assert(ssh->scmac->len <=
- ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
- ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
- memset(keyspace, 0, sizeof(keyspace));
- }
- logeventf(ssh, "Initialised %.200s server->client encryption",
- ssh->sccipher->text_name);
- logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
- ssh->scmac->text_name);
- if (ssh->sccomp->text_name)
- logeventf(ssh, "Initialised %s decompression",
- ssh->sccomp->text_name);
-
- /*
- * Free shared secret.
- */
- freebn(s->K);
-
- /*
- * Key exchange is over. Loop straight back round if we have a
- * deferred rekey reason.
- */
- if (ssh->deferred_rekey_reason) {
- logevent(ssh->deferred_rekey_reason);
- pktin = NULL;
- ssh->deferred_rekey_reason = NULL;
- goto begin_key_exchange;
- }
-
- /*
- * Otherwise, schedule a timer for our next rekey.
- */
- ssh->kex_in_progress = FALSE;
- ssh->last_rekey = GETTICKCOUNT();
- if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
- ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
- ssh2_timer, ssh);
-
- /*
- * If this is the first key exchange phase, we must pass the
- * SSH2_MSG_NEWKEYS packet to the next layer, not because it
- * wants to see it but because it will need time to initialise
- * itself before it sees an actual packet. In subsequent key
- * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
- * it would only confuse the layer above.
- */
- if (s->activated_authconn) {
- crReturn(0);
- }
- s->activated_authconn = TRUE;
-
- /*
- * Now we're encrypting. Begin returning 1 to the protocol main
- * function so that other things can run on top of the
- * transport. If we ever see a KEXINIT, we must go back to the
- * start.
- *
- * We _also_ go back to the start if we see pktin==NULL and
- * inlen negative, because this is a special signal meaning
- * `initiate client-driven rekey', and `in' contains a message
- * giving the reason for the rekey.
- *
- * inlen==-1 means always initiate a rekey;
- * inlen==-2 means that userauth has completed successfully and
- * we should consider rekeying (for delayed compression).
- */
- while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
- (!pktin && inlen < 0))) {
- wait_for_rekey:
- crReturn(1);
- }
- if (pktin) {
- logevent("Server initiated key re-exchange");
- } else {
- if (inlen == -2) {
- /*
- * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
- * delayed compression, if it's available.
- *
- * draft-miller-secsh-compression-delayed-00 says that you
- * negotiate delayed compression in the first key exchange, and
- * both sides start compressing when the server has sent
- * USERAUTH_SUCCESS. This has a race condition -- the server
- * can't know when the client has seen it, and thus which incoming
- * packets it should treat as compressed.
- *
- * Instead, we do the initial key exchange without offering the
- * delayed methods, but note if the server offers them; when we
- * get here, if a delayed method was available that was higher
- * on our list than what we got, we initiate a rekey in which we
- * _do_ list the delayed methods (and hopefully get it as a
- * result). Subsequent rekeys will do the same.
- */
- assert(!s->userauth_succeeded); /* should only happen once */
- s->userauth_succeeded = TRUE;
- if (!s->pending_compression)
- /* Can't see any point rekeying. */
- goto wait_for_rekey; /* this is utterly horrid */
- /* else fall through to rekey... */
- s->pending_compression = FALSE;
- }
- /*
- * Now we've decided to rekey.
- *
- * Special case: if the server bug is set that doesn't
- * allow rekeying, we give a different log message and
- * continue waiting. (If such a server _initiates_ a rekey,
- * we process it anyway!)
- */
- if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
- logeventf(ssh, "Server bug prevents key re-exchange (%s)",
- (char *)in);
- /* Reset the counters, so that at least this message doesn't
- * hit the event log _too_ often. */
- ssh->outgoing_data_size = 0;
- ssh->incoming_data_size = 0;
- if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
- ssh->next_rekey =
- schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
- ssh2_timer, ssh);
- }
- goto wait_for_rekey; /* this is still utterly horrid */
- } else {
- logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
- }
- }
- goto begin_key_exchange;
-
- crFinish(1);
-}
-
-/*
- * Add data to an SSH-2 channel output buffer.
- */
-static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
- int len)
-{
- bufchain_add(&c->v.v2.outbuffer, buf, len);
-}
-
-/*
- * Attempt to send data on an SSH-2 channel.
- */
-static int ssh2_try_send(struct ssh_channel *c)
-{
- Ssh ssh = c->ssh;
- struct Packet *pktout;
- int ret;
-
- while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
- int len;
- void *data;
- bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
- if ((unsigned)len > c->v.v2.remwindow)
- len = c->v.v2.remwindow;
- if ((unsigned)len > c->v.v2.remmaxpkt)
- len = c->v.v2.remmaxpkt;
- pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
- ssh2_pkt_adduint32(pktout, c->remoteid);
- ssh2_pkt_addstring_start(pktout);
- dont_log_data(ssh, pktout, PKTLOG_OMIT);
- ssh2_pkt_addstring_data(pktout, data, len);
- end_log_omission(ssh, pktout);
- ssh2_pkt_send(ssh, pktout);
- bufchain_consume(&c->v.v2.outbuffer, len);
- c->v.v2.remwindow -= len;
- }
-
- /*
- * After having sent as much data as we can, return the amount
- * still buffered.
- */
- ret = bufchain_size(&c->v.v2.outbuffer);
-
- /*
- * And if there's no data pending but we need to send an EOF, send
- * it.
- */
- if (!ret && c->pending_eof)
- ssh_channel_try_eof(c);
-
- return ret;
-}
-
-static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
-{
- int bufsize;
- if (c->closes & CLOSES_SENT_EOF)
- return; /* don't send on channels we've EOFed */
- bufsize = ssh2_try_send(c);
- if (bufsize == 0) {
- switch (c->type) {
- case CHAN_MAINSESSION:
- /* stdin need not receive an unthrottle
- * notification since it will be polled */
- break;
- case CHAN_X11:
- x11_unthrottle(c->u.x11.s);
- break;
- case CHAN_AGENT:
- /* agent sockets are request/response and need no
- * buffer management */
- break;
- case CHAN_SOCKDATA:
- pfd_unthrottle(c->u.pfd.s);
- break;
- }
- }
-}
-
-/*
- * Set up most of a new ssh_channel for SSH-2.
- */
-static void ssh2_channel_init(struct ssh_channel *c)
-{
- Ssh ssh = c->ssh;
- c->localid = alloc_channel_id(ssh);
- c->closes = 0;
- c->pending_eof = FALSE;
- c->throttling_conn = FALSE;
- c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
- conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
- c->v.v2.winadj_head = c->v.v2.winadj_tail = NULL;
- c->v.v2.throttle_state = UNTHROTTLED;
- bufchain_init(&c->v.v2.outbuffer);
-}
-
-/*
- * Potentially enlarge the window on an SSH-2 channel.
- */
-static void ssh2_set_window(struct ssh_channel *c, int newwin)
-{
- Ssh ssh = c->ssh;
-
- /*
- * Never send WINDOW_ADJUST for a channel that the remote side has
- * already sent EOF on; there's no point, since it won't be
- * sending any more data anyway. Ditto if _we've_ already sent
- * CLOSE.
- */
- if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
- return;
-
- /*
- * If the remote end has a habit of ignoring maxpkt, limit the
- * window so that it has no choice (assuming it doesn't ignore the
- * window as well).
- */
- if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
- newwin = OUR_V2_MAXPKT;
-
- /*
- * Only send a WINDOW_ADJUST if there's significantly more window
- * available than the other end thinks there is. This saves us
- * sending a WINDOW_ADJUST for every character in a shell session.
- *
- * "Significant" is arbitrarily defined as half the window size.
- */
- if (newwin / 2 >= c->v.v2.locwindow) {
- struct Packet *pktout;
- struct winadj *wa;
-
- /*
- * In order to keep track of how much window the client
- * actually has available, we'd like it to acknowledge each
- * WINDOW_ADJUST. We can't do that directly, so we accompany
- * it with a CHANNEL_REQUEST that has to be acknowledged.
- *
- * This is only necessary if we're opening the window wide.
- * If we're not, then throughput is being constrained by
- * something other than the maximum window size anyway.
- *
- * We also only send this if the main channel has finished its
- * initial CHANNEL_REQUESTs and installed the default
- * CHANNEL_FAILURE handler, so as not to risk giving it
- * unexpected CHANNEL_FAILUREs.
- */
- if (newwin == c->v.v2.locmaxwin &&
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE]) {
- pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(pktout, c->remoteid);
- ssh2_pkt_addstring(pktout, "winadj@putty.projects.tartarus.org");
- ssh2_pkt_addbool(pktout, TRUE);
- ssh2_pkt_send(ssh, pktout);
-
- /*
- * CHANNEL_FAILURE doesn't come with any indication of
- * what message caused it, so we have to keep track of the
- * outstanding CHANNEL_REQUESTs ourselves.
- */
- wa = snew(struct winadj);
- wa->size = newwin - c->v.v2.locwindow;
- wa->next = NULL;
- if (!c->v.v2.winadj_head)
- c->v.v2.winadj_head = wa;
- else
- c->v.v2.winadj_tail->next = wa;
- c->v.v2.winadj_tail = wa;
- if (c->v.v2.throttle_state != UNTHROTTLED)
- c->v.v2.throttle_state = UNTHROTTLING;
- } else {
- /* Pretend the WINDOW_ADJUST was acked immediately. */
- c->v.v2.remlocwin = newwin;
- c->v.v2.throttle_state = THROTTLED;
- }
- pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
- ssh2_pkt_adduint32(pktout, c->remoteid);
- ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
- ssh2_pkt_send(ssh, pktout);
- c->v.v2.locwindow = newwin;
- }
-}
-
-/*
- * Find the channel associated with a message. If there's no channel,
- * or it's not properly open, make a noise about it and return NULL.
- */
-static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
-{
- unsigned localid = ssh_pkt_getuint32(pktin);
- struct ssh_channel *c;
-
- c = find234(ssh->channels, &localid, ssh_channelfind);
- if (!c ||
- (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
- pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
- char *buf = dupprintf("Received %s for %s channel %u",
- ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
- pktin->type),
- c ? "half-open" : "nonexistent", localid);
- ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
- sfree(buf);
- return NULL;
- }
- return c;
-}
-
-static int ssh2_handle_winadj_response(struct ssh_channel *c)
-{
- struct winadj *wa = c->v.v2.winadj_head;
- if (!wa)
- return FALSE;
- c->v.v2.winadj_head = wa->next;
- c->v.v2.remlocwin += wa->size;
- sfree(wa);
- /*
- * winadj messages are only sent when the window is fully open, so
- * if we get an ack of one, we know any pending unthrottle is
- * complete.
- */
- if (c->v.v2.throttle_state == UNTHROTTLING)
- c->v.v2.throttle_state = UNTHROTTLED;
- /*
- * We may now initiate channel-closing procedures, if that winadj
- * was the last thing outstanding before we send CHANNEL_CLOSE.
- */
- ssh2_channel_check_close(c);
- return TRUE;
-}
-
-static void ssh2_msg_channel_success(Ssh ssh, struct Packet *pktin)
-{
- /*
- * This should never get called. All channel requests are either
- * sent with want_reply false, are sent before this handler gets
- * installed, or are "winadj@putty" requests, which servers should
- * never respond to with success.
- *
- * However, at least one server ("boks_sshd") is known to return
- * SUCCESS for channel requests it's never heard of, such as
- * "winadj@putty". Raised with foxt.com as bug 090916-090424, but
- * for the sake of a quiet life, we handle it just the same as the
- * expected FAILURE.
- */
- struct ssh_channel *c;
-
- c = ssh2_channel_msg(ssh, pktin);
- if (!c)
- return;
- if (!ssh2_handle_winadj_response(c))
- ssh_disconnect(ssh, NULL,
- "Received unsolicited SSH_MSG_CHANNEL_SUCCESS",
- SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
-}
-
-static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin)
-{
- /*
- * The only time this should get called is for "winadj@putty"
- * messages sent above. All other channel requests are either
- * sent with want_reply false or are sent before this handler gets
- * installed.
- */
- struct ssh_channel *c;
-
- c = ssh2_channel_msg(ssh, pktin);
- if (!c)
- return;
- if (!ssh2_handle_winadj_response(c))
- ssh_disconnect(ssh, NULL,
- "Received unsolicited SSH_MSG_CHANNEL_FAILURE",
- SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
-}
-
-static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
-{
- struct ssh_channel *c;
- c = ssh2_channel_msg(ssh, pktin);
- if (!c)
- return;
- if (!(c->closes & CLOSES_SENT_EOF)) {
- c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
- ssh2_try_send_and_unthrottle(ssh, c);
- }
-}
-
-static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
-{
- char *data;
- int length;
- struct ssh_channel *c;
- c = ssh2_channel_msg(ssh, pktin);
- if (!c)
- return;
- if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
- ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
- return; /* extended but not stderr */
- ssh_pkt_getstring(pktin, &data, &length);
- if (data) {
- int bufsize = 0;
- c->v.v2.locwindow -= length;
- c->v.v2.remlocwin -= length;
- switch (c->type) {
- case CHAN_MAINSESSION:
- bufsize =
- from_backend(ssh->frontend, pktin->type ==
- SSH2_MSG_CHANNEL_EXTENDED_DATA,
- data, length);
- break;
- case CHAN_X11:
- bufsize = x11_send(c->u.x11.s, data, length);
- break;
- case CHAN_SOCKDATA:
- bufsize = pfd_send(c->u.pfd.s, data, length);
- break;
- case CHAN_AGENT:
- while (length > 0) {
- if (c->u.a.lensofar < 4) {
- unsigned int l = min(4 - c->u.a.lensofar,
- (unsigned)length);
- memcpy(c->u.a.msglen + c->u.a.lensofar,
- data, l);
- data += l;
- length -= l;
- c->u.a.lensofar += l;
- }
- if (c->u.a.lensofar == 4) {
- c->u.a.totallen =
- 4 + GET_32BIT(c->u.a.msglen);
- c->u.a.message = snewn(c->u.a.totallen,
- unsigned char);
- memcpy(c->u.a.message, c->u.a.msglen, 4);
- }
- if (c->u.a.lensofar >= 4 && length > 0) {
- unsigned int l =
- min(c->u.a.totallen - c->u.a.lensofar,
- (unsigned)length);
- memcpy(c->u.a.message + c->u.a.lensofar,
- data, l);
- data += l;
- length -= l;
- c->u.a.lensofar += l;
- }
- if (c->u.a.lensofar == c->u.a.totallen) {
- void *reply;
- int replylen;
- if (agent_query(c->u.a.message,
- c->u.a.totallen,
- &reply, &replylen,
- ssh_agentf_callback, c))
- ssh_agentf_callback(c, reply, replylen);
- sfree(c->u.a.message);
- c->u.a.message = NULL;
- c->u.a.lensofar = 0;
- }
- }
- bufsize = 0;
- break;
- }
- /*
- * If it looks like the remote end hit the end of its window,
- * and we didn't want it to do that, think about using a
- * larger window.
- */
- if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
- c->v.v2.locmaxwin < 0x40000000)
- c->v.v2.locmaxwin += OUR_V2_WINSIZE;
- /*
- * If we are not buffering too much data,
- * enlarge the window again at the remote side.
- * If we are buffering too much, we may still
- * need to adjust the window if the server's
- * sent excess data.
- */
- ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
- c->v.v2.locmaxwin - bufsize : 0);
- /*
- * If we're either buffering way too much data, or if we're
- * buffering anything at all and we're in "simple" mode,
- * throttle the whole channel.
- */
- if ((bufsize > c->v.v2.locmaxwin ||
- (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) &&
- !c->throttling_conn) {
- c->throttling_conn = 1;
- ssh_throttle_conn(ssh, +1);
- }
- }
-}
-
-static void ssh_channel_destroy(struct ssh_channel *c)
-{
- Ssh ssh = c->ssh;
-
- switch (c->type) {
- case CHAN_MAINSESSION:
- ssh->mainchan = NULL;
- update_specials_menu(ssh->frontend);
- break;
- case CHAN_X11:
- if (c->u.x11.s != NULL)
- x11_close(c->u.x11.s);
- logevent("Forwarded X11 connection terminated");
- break;
- case CHAN_AGENT:
- sfree(c->u.a.message);
- break;
- case CHAN_SOCKDATA:
- if (c->u.pfd.s != NULL)
- pfd_close(c->u.pfd.s);
- logevent("Forwarded port closed");
- break;
- }
-
- del234(ssh->channels, c);
- if (ssh->version == 2)
- bufchain_clear(&c->v.v2.outbuffer);
- sfree(c);
-
- /*
- * See if that was the last channel left open.
- * (This is only our termination condition if we're
- * not running in -N mode.)
- */
- if (ssh->version == 2 &&
- !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
- count234(ssh->channels) == 0) {
- /*
- * We used to send SSH_MSG_DISCONNECT here,
- * because I'd believed that _every_ conforming
- * SSH-2 connection had to end with a disconnect
- * being sent by at least one side; apparently
- * I was wrong and it's perfectly OK to
- * unceremoniously slam the connection shut
- * when you're done, and indeed OpenSSH feels
- * this is more polite than sending a
- * DISCONNECT. So now we don't.
- */
- ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
- }
-}
-
-static void ssh2_channel_check_close(struct ssh_channel *c)
-{
- Ssh ssh = c->ssh;
- struct Packet *pktout;
-
- if ((c->closes & (CLOSES_SENT_EOF | CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
- == (CLOSES_SENT_EOF | CLOSES_RCVD_EOF) && !c->v.v2.winadj_head) {
- /*
- * We have both sent and received EOF, and we have no
- * outstanding winadj channel requests, which means the
- * channel is in final wind-up. But we haven't sent CLOSE, so
- * let's do so now.
- */
- pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
- ssh2_pkt_adduint32(pktout, c->remoteid);
- ssh2_pkt_send(ssh, pktout);
- c->closes |= CLOSES_SENT_CLOSE;
- }
-
- if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
- /*
- * We have both sent and received CLOSE, which means we're
- * completely done with the channel.
- */
- ssh_channel_destroy(c);
- }
-}
-
-static void ssh2_channel_got_eof(struct ssh_channel *c)
-{
- if (c->closes & CLOSES_RCVD_EOF)
- return; /* already seen EOF */
- c->closes |= CLOSES_RCVD_EOF;
-
- if (c->type == CHAN_X11) {
- x11_send_eof(c->u.x11.s);
- } else if (c->type == CHAN_AGENT) {
- /* Manufacture an outgoing EOF in response to the incoming one. */
- sshfwd_write_eof(c);
- } else if (c->type == CHAN_SOCKDATA) {
- pfd_send_eof(c->u.pfd.s);
- } else if (c->type == CHAN_MAINSESSION) {
- Ssh ssh = c->ssh;
-
- if (!ssh->sent_console_eof &&
- (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
- /*
- * Either from_backend_eof told us that the front end
- * wants us to close the outgoing side of the connection
- * as soon as we see EOF from the far end, or else we've
- * unilaterally decided to do that because we've allocated
- * a remote pty and hence EOF isn't a particularly
- * meaningful concept.
- */
- sshfwd_write_eof(c);
- }
- ssh->sent_console_eof = TRUE;
- }
-
- ssh2_channel_check_close(c);
-}
-
-static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
-{
- struct ssh_channel *c;
-
- c = ssh2_channel_msg(ssh, pktin);
- if (!c)
- return;
- ssh2_channel_got_eof(c);
-}
-
-static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
-{
- struct ssh_channel *c;
-
- c = ssh2_channel_msg(ssh, pktin);
- if (!c)
- return;
-
- /*
- * When we receive CLOSE on a channel, we assume it comes with an
- * implied EOF if we haven't seen EOF yet.
- */
- ssh2_channel_got_eof(c);
-
- /*
- * And we also send an outgoing EOF, if we haven't already, on the
- * assumption that CLOSE is a pretty forceful announcement that
- * the remote side is doing away with the entire channel. (If it
- * had wanted to send us EOF and continue receiving data from us,
- * it would have just sent CHANNEL_EOF.)
- */
- if (!(c->closes & CLOSES_SENT_EOF)) {
- /*
- * Make sure we don't read any more from whatever our local
- * data source is for this channel.
- */
- switch (c->type) {
- case CHAN_MAINSESSION:
- ssh->send_ok = 0; /* stop trying to read from stdin */
- break;
- case CHAN_X11:
- x11_override_throttle(c->u.x11.s, 1);
- break;
- case CHAN_SOCKDATA:
- pfd_override_throttle(c->u.pfd.s, 1);
- break;
- }
-
- /*
- * Send outgoing EOF.
- */
- sshfwd_write_eof(c);
- }
-
- /*
- * Now process the actual close.
- */
- if (!(c->closes & CLOSES_RCVD_CLOSE)) {
- c->closes |= CLOSES_RCVD_CLOSE;
- ssh2_channel_check_close(c);
- }
-}
-
-static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
-{
- struct ssh_channel *c;
-
- c = ssh2_channel_msg(ssh, pktin);
- if (!c)
- return;
- if (c->type != CHAN_SOCKDATA_DORMANT)
- return; /* dunno why they're confirming this */
- c->remoteid = ssh_pkt_getuint32(pktin);
- c->halfopen = FALSE;
- c->type = CHAN_SOCKDATA;
- c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
- c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
- if (c->u.pfd.s)
- pfd_confirm(c->u.pfd.s);
- if (c->pending_eof)
- ssh_channel_try_eof(c);
-}
-
-static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
-{
- static const char *const reasons[] = {
- "<unknown reason code>",
- "Administratively prohibited",
- "Connect failed",
- "Unknown channel type",
- "Resource shortage",
- };
- unsigned reason_code;
- char *reason_string;
- int reason_length;
- struct ssh_channel *c;
- c = ssh2_channel_msg(ssh, pktin);
- if (!c)
- return;
- if (c->type != CHAN_SOCKDATA_DORMANT)
- return; /* dunno why they're failing this */
-
- reason_code = ssh_pkt_getuint32(pktin);
- if (reason_code >= lenof(reasons))
- reason_code = 0; /* ensure reasons[reason_code] in range */
- ssh_pkt_getstring(pktin, &reason_string, &reason_length);
- logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
- reasons[reason_code], reason_length, reason_string);
-
- pfd_close(c->u.pfd.s);
-
- del234(ssh->channels, c);
- sfree(c);
-}
-
-static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
-{
- char *type;
- int typelen, want_reply;
- int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
- struct ssh_channel *c;
- struct Packet *pktout;
-
- c = ssh2_channel_msg(ssh, pktin);
- if (!c)
- return;
- ssh_pkt_getstring(pktin, &type, &typelen);
- want_reply = ssh2_pkt_getbool(pktin);
-
- /*
- * Having got the channel number, we now look at
- * the request type string to see if it's something
- * we recognise.
- */
- if (c == ssh->mainchan) {
- /*
- * We recognise "exit-status" and "exit-signal" on
- * the primary channel.
- */
- if (typelen == 11 &&
- !memcmp(type, "exit-status", 11)) {
-
- ssh->exitcode = ssh_pkt_getuint32(pktin);
- logeventf(ssh, "Server sent command exit status %d",
- ssh->exitcode);
- reply = SSH2_MSG_CHANNEL_SUCCESS;
-
- } else if (typelen == 11 &&
- !memcmp(type, "exit-signal", 11)) {
-
- int is_plausible = TRUE, is_int = FALSE;
- char *fmt_sig = "", *fmt_msg = "";
- char *msg;
- int msglen = 0, core = FALSE;
- /* ICK: older versions of OpenSSH (e.g. 3.4p1)
- * provide an `int' for the signal, despite its
- * having been a `string' in the drafts of RFC 4254 since at
- * least 2001. (Fixed in session.c 1.147.) Try to
- * infer which we can safely parse it as. */
- {
- unsigned char *p = pktin->body +
- pktin->savedpos;
- long len = pktin->length - pktin->savedpos;
- unsigned long num = GET_32BIT(p); /* what is it? */
- /* If it's 0, it hardly matters; assume string */
- if (num == 0) {
- is_int = FALSE;
- } else {
- int maybe_int = FALSE, maybe_str = FALSE;
-#define CHECK_HYPOTHESIS(offset, result) \
- do { \
- long q = offset; \
- if (q >= 0 && q+4 <= len) { \
- q = q + 4 + GET_32BIT(p+q); \
- if (q >= 0 && q+4 <= len && \
- ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
- result = TRUE; \
- } \
- } while(0)
- CHECK_HYPOTHESIS(4+1, maybe_int);
- CHECK_HYPOTHESIS(4+num+1, maybe_str);
-#undef CHECK_HYPOTHESIS
- if (maybe_int && !maybe_str)
- is_int = TRUE;
- else if (!maybe_int && maybe_str)
- is_int = FALSE;
- else
- /* Crikey. Either or neither. Panic. */
- is_plausible = FALSE;
- }
- }
- ssh->exitcode = 128; /* means `unknown signal' */
- if (is_plausible) {
- if (is_int) {
- /* Old non-standard OpenSSH. */
- int signum = ssh_pkt_getuint32(pktin);
- fmt_sig = dupprintf(" %d", signum);
- ssh->exitcode = 128 + signum;
- } else {
- /* As per RFC 4254. */
- char *sig;
- int siglen;
- ssh_pkt_getstring(pktin, &sig, &siglen);
- /* Signal name isn't supposed to be blank, but
- * let's cope gracefully if it is. */
- if (siglen) {
- fmt_sig = dupprintf(" \"%.*s\"",
- siglen, sig);
- }
-
- /*
- * Really hideous method of translating the
- * signal description back into a locally
- * meaningful number.
- */
-
- if (0)
- ;
-#define TRANSLATE_SIGNAL(s) \
- else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
- ssh->exitcode = 128 + SIG ## s
-#ifdef SIGABRT
- TRANSLATE_SIGNAL(ABRT);
-#endif
-#ifdef SIGALRM
- TRANSLATE_SIGNAL(ALRM);
-#endif
-#ifdef SIGFPE
- TRANSLATE_SIGNAL(FPE);
-#endif
-#ifdef SIGHUP
- TRANSLATE_SIGNAL(HUP);
-#endif
-#ifdef SIGILL
- TRANSLATE_SIGNAL(ILL);
-#endif
-#ifdef SIGINT
- TRANSLATE_SIGNAL(INT);
-#endif
-#ifdef SIGKILL
- TRANSLATE_SIGNAL(KILL);
-#endif
-#ifdef SIGPIPE
- TRANSLATE_SIGNAL(PIPE);
-#endif
-#ifdef SIGQUIT
- TRANSLATE_SIGNAL(QUIT);
-#endif
-#ifdef SIGSEGV
- TRANSLATE_SIGNAL(SEGV);
-#endif
-#ifdef SIGTERM
- TRANSLATE_SIGNAL(TERM);
-#endif
-#ifdef SIGUSR1
- TRANSLATE_SIGNAL(USR1);
-#endif
-#ifdef SIGUSR2
- TRANSLATE_SIGNAL(USR2);
-#endif
-#undef TRANSLATE_SIGNAL
- else
- ssh->exitcode = 128;
- }
- core = ssh2_pkt_getbool(pktin);
- ssh_pkt_getstring(pktin, &msg, &msglen);
- if (msglen) {
- fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
- }
- /* ignore lang tag */
- } /* else don't attempt to parse */
- logeventf(ssh, "Server exited on signal%s%s%s",
- fmt_sig, core ? " (core dumped)" : "",
- fmt_msg);
- if (*fmt_sig) sfree(fmt_sig);
- if (*fmt_msg) sfree(fmt_msg);
- reply = SSH2_MSG_CHANNEL_SUCCESS;
-
- }
- } else {
- /*
- * This is a channel request we don't know
- * about, so we now either ignore the request
- * or respond with CHANNEL_FAILURE, depending
- * on want_reply.
- */
- reply = SSH2_MSG_CHANNEL_FAILURE;
- }
- if (want_reply) {
- pktout = ssh2_pkt_init(reply);
- ssh2_pkt_adduint32(pktout, c->remoteid);
- ssh2_pkt_send(ssh, pktout);
- }
-}
-
-static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
-{
- char *type;
- int typelen, want_reply;
- struct Packet *pktout;
-
- ssh_pkt_getstring(pktin, &type, &typelen);
- want_reply = ssh2_pkt_getbool(pktin);
-
- /*
- * We currently don't support any global requests
- * at all, so we either ignore the request or
- * respond with REQUEST_FAILURE, depending on
- * want_reply.
- */
- if (want_reply) {
- pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
- ssh2_pkt_send(ssh, pktout);
- }
-}
-
-static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
-{
- char *type;
- int typelen;
- char *peeraddr;
- int peeraddrlen;
- int peerport;
- char *error = NULL;
- struct ssh_channel *c;
- unsigned remid, winsize, pktsize;
- struct Packet *pktout;
-
- ssh_pkt_getstring(pktin, &type, &typelen);
- c = snew(struct ssh_channel);
- c->ssh = ssh;
-
- remid = ssh_pkt_getuint32(pktin);
- winsize = ssh_pkt_getuint32(pktin);
- pktsize = ssh_pkt_getuint32(pktin);
-
- if (typelen == 3 && !memcmp(type, "x11", 3)) {
- char *addrstr;
- const char *x11err;
-
- ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
- addrstr = snewn(peeraddrlen+1, char);
- memcpy(addrstr, peeraddr, peeraddrlen);
- addrstr[peeraddrlen] = '\0';
- peerport = ssh_pkt_getuint32(pktin);
-
- logeventf(ssh, "Received X11 connect request from %s:%d",
- addrstr, peerport);
-
- if (!ssh->X11_fwd_enabled)
- error = "X11 forwarding is not enabled";
- else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
- addrstr, peerport, ssh->conf)) != NULL) {
- logeventf(ssh, "Local X11 connection failed: %s", x11err);
- error = "Unable to open an X11 connection";
- } else {
- logevent("Opening X11 forward connection succeeded");
- c->type = CHAN_X11;
- }
-
- sfree(addrstr);
- } else if (typelen == 15 &&
- !memcmp(type, "forwarded-tcpip", 15)) {
- struct ssh_rportfwd pf, *realpf;
- char *dummy;
- int dummylen;
- ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
- pf.sport = ssh_pkt_getuint32(pktin);
- ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
- peerport = ssh_pkt_getuint32(pktin);
- realpf = find234(ssh->rportfwds, &pf, NULL);
- logeventf(ssh, "Received remote port %d open request "
- "from %s:%d", pf.sport, peeraddr, peerport);
- if (realpf == NULL) {
- error = "Remote port is not recognised";
- } else {
- const char *e = pfd_newconnect(&c->u.pfd.s,
- realpf->dhost,
- realpf->dport, c,
- ssh->conf,
- realpf->pfrec->addressfamily);
- logeventf(ssh, "Attempting to forward remote port to "
- "%s:%d", realpf->dhost, realpf->dport);
- if (e != NULL) {
- logeventf(ssh, "Port open failed: %s", e);
- error = "Port open failed";
- } else {
- logevent("Forwarded port opened successfully");
- c->type = CHAN_SOCKDATA;
- }
- }
- } else if (typelen == 22 &&
- !memcmp(type, "auth-agent@openssh.com", 22)) {
- if (!ssh->agentfwd_enabled)
- error = "Agent forwarding is not enabled";
- else {
- c->type = CHAN_AGENT; /* identify channel type */
- c->u.a.lensofar = 0;
- }
- } else {
- error = "Unsupported channel type requested";
- }
-
- c->remoteid = remid;
- c->halfopen = FALSE;
- if (error) {
- pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
- ssh2_pkt_adduint32(pktout, c->remoteid);
- ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
- ssh2_pkt_addstring(pktout, error);
- ssh2_pkt_addstring(pktout, "en"); /* language tag */
- ssh2_pkt_send(ssh, pktout);
- logeventf(ssh, "Rejected channel open: %s", error);
- sfree(c);
- } else {
- ssh2_channel_init(c);
- c->v.v2.remwindow = winsize;
- c->v.v2.remmaxpkt = pktsize;
- add234(ssh->channels, c);
- pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
- ssh2_pkt_adduint32(pktout, c->remoteid);
- ssh2_pkt_adduint32(pktout, c->localid);
- ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
- ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
- ssh2_pkt_send(ssh, pktout);
- }
-}
-
-/*
- * Buffer banner messages for later display at some convenient point,
- * if we're going to display them.
- */
-static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
-{
- /* Arbitrary limit to prevent unbounded inflation of buffer */
- if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
- bufchain_size(&ssh->banner) <= 131072) {
- char *banner = NULL;
- int size = 0;
- ssh_pkt_getstring(pktin, &banner, &size);
- if (banner)
- bufchain_add(&ssh->banner, banner, size);
- }
-}
-
-/* Helper function to deal with sending tty modes for "pty-req" */
-static void ssh2_send_ttymode(void *data, char *mode, char *val)
-{
- struct Packet *pktout = (struct Packet *)data;
- int i = 0;
- unsigned int arg = 0;
- while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
- if (i == lenof(ssh_ttymodes)) return;
- switch (ssh_ttymodes[i].type) {
- case TTY_OP_CHAR:
- arg = ssh_tty_parse_specchar(val);
- break;
- case TTY_OP_BOOL:
- arg = ssh_tty_parse_boolean(val);
- break;
- }
- ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
- ssh2_pkt_adduint32(pktout, arg);
-}
-
-/*
- * Handle the SSH-2 userauth and connection layers.
- */
-static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
- struct Packet *pktin)
-{
- struct do_ssh2_authconn_state {
- enum {
- AUTH_TYPE_NONE,
- AUTH_TYPE_PUBLICKEY,
- AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
- AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
- AUTH_TYPE_PASSWORD,
- AUTH_TYPE_GSSAPI, /* always QUIET */
- AUTH_TYPE_KEYBOARD_INTERACTIVE,
- AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
- } type;
- int done_service_req;
- int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
- int tried_pubkey_config, done_agent;
-#ifndef NO_GSSAPI
- int can_gssapi;
- int tried_gssapi;
-#endif
- int kbd_inter_refused;
- int we_are_in, userauth_success;
- prompts_t *cur_prompt;
- int num_prompts;
- char *username;
- char *password;
- int got_username;
- void *publickey_blob;
- int publickey_bloblen;
- int publickey_encrypted;
- char *publickey_algorithm;
- char *publickey_comment;
- unsigned char agent_request[5], *agent_response, *agentp;
- int agent_responselen;
- unsigned char *pkblob_in_agent;
- int keyi, nkeys;
- char *pkblob, *alg, *commentp;
- int pklen, alglen, commentlen;
- int siglen, retlen, len;
- char *q, *agentreq, *ret;
- int try_send;
- int num_env, env_left, env_ok;
- struct Packet *pktout;
- Filename *keyfile;
-#ifndef NO_GSSAPI
- struct ssh_gss_library *gsslib;
- Ssh_gss_ctx gss_ctx;
- Ssh_gss_buf gss_buf;
- Ssh_gss_buf gss_rcvtok, gss_sndtok;
- Ssh_gss_name gss_srv_name;
- Ssh_gss_stat gss_stat;
-#endif
- };
- crState(do_ssh2_authconn_state);
-
- crBegin(ssh->do_ssh2_authconn_crstate);
-
- s->done_service_req = FALSE;
- s->we_are_in = s->userauth_success = FALSE;
-#ifndef NO_GSSAPI
- s->tried_gssapi = FALSE;
-#endif
-
- if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
- /*
- * Request userauth protocol, and await a response to it.
- */
- s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
- ssh2_pkt_addstring(s->pktout, "ssh-userauth");
- ssh2_pkt_send(ssh, s->pktout);
- crWaitUntilV(pktin);
- if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
- s->done_service_req = TRUE;
- }
- if (!s->done_service_req) {
- /*
- * Request connection protocol directly, without authentication.
- */
- s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
- ssh2_pkt_addstring(s->pktout, "ssh-connection");
- ssh2_pkt_send(ssh, s->pktout);
- crWaitUntilV(pktin);
- if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
- s->we_are_in = TRUE; /* no auth required */
- } else {
- bombout(("Server refused service request"));
- crStopV;
- }
- }
-
- /* Arrange to be able to deal with any BANNERs that come in.
- * (We do this now as packets may come in during the next bit.) */
- bufchain_init(&ssh->banner);
- ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
- ssh2_msg_userauth_banner;
-
- /*
- * Misc one-time setup for authentication.
- */
- s->publickey_blob = NULL;
- if (!s->we_are_in) {
-
- /*
- * Load the public half of any configured public key file
- * for later use.
- */
- s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
- if (!filename_is_null(s->keyfile)) {
- int keytype;
- logeventf(ssh, "Reading private key file \"%.150s\"",
- filename_to_str(s->keyfile));
- keytype = key_type(s->keyfile);
- if (keytype == SSH_KEYTYPE_SSH2) {
- const char *error;
- s->publickey_blob =
- ssh2_userkey_loadpub(s->keyfile,
- &s->publickey_algorithm,
- &s->publickey_bloblen,
- &s->publickey_comment, &error);
- if (s->publickey_blob) {
- s->publickey_encrypted =
- ssh2_userkey_encrypted(s->keyfile, NULL);
- } else {
- char *msgbuf;
- logeventf(ssh, "Unable to load private key (%s)",
- error);
- msgbuf = dupprintf("Unable to load private key file "
- "\"%.150s\" (%s)\r\n",
- filename_to_str(s->keyfile),
- error);
- c_write_str(ssh, msgbuf);
- sfree(msgbuf);
- }
- } else {
- char *msgbuf;
- logeventf(ssh, "Unable to use this key file (%s)",
- key_type_to_str(keytype));
- msgbuf = dupprintf("Unable to use key file \"%.150s\""
- " (%s)\r\n",
- filename_to_str(s->keyfile),
- key_type_to_str(keytype));
- c_write_str(ssh, msgbuf);
- sfree(msgbuf);
- s->publickey_blob = NULL;
- }
- }
-
- /*
- * Find out about any keys Pageant has (but if there's a
- * public key configured, filter out all others).
- */
- s->nkeys = 0;
- s->agent_response = NULL;
- s->pkblob_in_agent = NULL;
- if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
-
- void *r;
-
- logevent("Pageant is running. Requesting keys.");
-
- /* Request the keys held by the agent. */
- PUT_32BIT(s->agent_request, 1);
- s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
- if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
- ssh_agent_callback, ssh)) {
- do {
- crReturnV;
- if (pktin) {
- bombout(("Unexpected data from server while"
- " waiting for agent response"));
- crStopV;
- }
- } while (pktin || inlen > 0);
- r = ssh->agent_response;
- s->agent_responselen = ssh->agent_response_len;
- }
- s->agent_response = (unsigned char *) r;
- if (s->agent_response && s->agent_responselen >= 5 &&
- s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
- int keyi;
- unsigned char *p;
- p = s->agent_response + 5;
- s->nkeys = GET_32BIT(p);
- p += 4;
- logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
- if (s->publickey_blob) {
- /* See if configured key is in agent. */
- for (keyi = 0; keyi < s->nkeys; keyi++) {
- s->pklen = GET_32BIT(p);
- if (s->pklen == s->publickey_bloblen &&
- !memcmp(p+4, s->publickey_blob,
- s->publickey_bloblen)) {
- logeventf(ssh, "Pageant key #%d matches "
- "configured key file", keyi);
- s->keyi = keyi;
- s->pkblob_in_agent = p;
- break;
- }
- p += 4 + s->pklen;
- p += GET_32BIT(p) + 4; /* comment */
- }
- if (!s->pkblob_in_agent) {
- logevent("Configured key file not in Pageant");
- s->nkeys = 0;
- }
- }
- } else {
- logevent("Failed to get reply from Pageant");
- }
- }
-
- }
-
- /*
- * We repeat this whole loop, including the username prompt,
- * until we manage a successful authentication. If the user
- * types the wrong _password_, they can be sent back to the
- * beginning to try another username, if this is configured on.
- * (If they specify a username in the config, they are never
- * asked, even if they do give a wrong password.)
- *
- * I think this best serves the needs of
- *
- * - the people who have no configuration, no keys, and just
- * want to try repeated (username,password) pairs until they
- * type both correctly
- *
- * - people who have keys and configuration but occasionally
- * need to fall back to passwords
- *
- * - people with a key held in Pageant, who might not have
- * logged in to a particular machine before; so they want to
- * type a username, and then _either_ their key will be
- * accepted, _or_ they will type a password. If they mistype
- * the username they will want to be able to get back and
- * retype it!
- */
- s->got_username = FALSE;
- while (!s->we_are_in) {
- /*
- * Get a username.
- */
- if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
- /*
- * We got a username last time round this loop, and
- * with change_username turned off we don't try to get
- * it again.
- */
- } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
- int ret; /* need not be kept over crReturn */
- s->cur_prompt = new_prompts(ssh->frontend);
- s->cur_prompt->to_server = TRUE;
- s->cur_prompt->name = dupstr("SSH login name");
- add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
- ret = get_userpass_input(s->cur_prompt, NULL, 0);
- while (ret < 0) {
- ssh->send_ok = 1;
- crWaitUntilV(!pktin);
- ret = get_userpass_input(s->cur_prompt, in, inlen);
- ssh->send_ok = 0;
- }
- if (!ret) {
- /*
- * get_userpass_input() failed to get a username.
- * Terminate.
- */
- free_prompts(s->cur_prompt);
- ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
- crStopV;
- }
- ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
- free_prompts(s->cur_prompt);
- } else {
- char *stuff;
- if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
- stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
- c_write_str(ssh, stuff);
- sfree(stuff);
- }
- }
- s->got_username = TRUE;
-
- /*
- * Send an authentication request using method "none": (a)
- * just in case it succeeds, and (b) so that we know what
- * authentication methods we can usefully try next.
- */
- ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
-
- s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
- ssh2_pkt_addstring(s->pktout, ssh->username);
- ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
- ssh2_pkt_addstring(s->pktout, "none"); /* method */
- ssh2_pkt_send(ssh, s->pktout);
- s->type = AUTH_TYPE_NONE;
- s->gotit = FALSE;
- s->we_are_in = FALSE;
-
- s->tried_pubkey_config = FALSE;
- s->kbd_inter_refused = FALSE;
-
- /* Reset agent request state. */
- s->done_agent = FALSE;
- if (s->agent_response) {
- if (s->pkblob_in_agent) {
- s->agentp = s->pkblob_in_agent;
- } else {
- s->agentp = s->agent_response + 5 + 4;
- s->keyi = 0;
- }
- }
-
- while (1) {
- char *methods = NULL;
- int methlen = 0;
-
- /*
- * Wait for the result of the last authentication request.
- */
- if (!s->gotit)
- crWaitUntilV(pktin);
- /*
- * Now is a convenient point to spew any banner material
- * that we've accumulated. (This should ensure that when
- * we exit the auth loop, we haven't any left to deal
- * with.)
- */
- {
- int size = bufchain_size(&ssh->banner);
- /*
- * Don't show the banner if we're operating in
- * non-verbose non-interactive mode. (It's probably
- * a script, which means nobody will read the
- * banner _anyway_, and moreover the printing of
- * the banner will screw up processing on the
- * output of (say) plink.)
- */
- if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
- char *banner = snewn(size, char);
- bufchain_fetch(&ssh->banner, banner, size);
- c_write_untrusted(ssh, banner, size);
- sfree(banner);
- }
- bufchain_clear(&ssh->banner);
- }
- if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
- logevent("Access granted");
- s->we_are_in = s->userauth_success = TRUE;
- break;
- }
-
- if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
- bombout(("Strange packet received during authentication: "
- "type %d", pktin->type));
- crStopV;
- }
-
- s->gotit = FALSE;
-
- /*
- * OK, we're now sitting on a USERAUTH_FAILURE message, so
- * we can look at the string in it and know what we can
- * helpfully try next.
- */
- if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
- ssh_pkt_getstring(pktin, &methods, &methlen);
- if (!ssh2_pkt_getbool(pktin)) {
- /*
- * We have received an unequivocal Access
- * Denied. This can translate to a variety of
- * messages, or no message at all.
- *
- * For forms of authentication which are attempted
- * implicitly, by which I mean without printing
- * anything in the window indicating that we're
- * trying them, we should never print 'Access
- * denied'.
- *
- * If we do print a message saying that we're
- * attempting some kind of authentication, it's OK
- * to print a followup message saying it failed -
- * but the message may sometimes be more specific
- * than simply 'Access denied'.
- *
- * Additionally, if we'd just tried password
- * authentication, we should break out of this
- * whole loop so as to go back to the username
- * prompt (iff we're configured to allow
- * username change attempts).
- */
- if (s->type == AUTH_TYPE_NONE) {
- /* do nothing */
- } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
- s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
- if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
- c_write_str(ssh, "Server refused our key\r\n");
- logevent("Server refused our key");
- } else if (s->type == AUTH_TYPE_PUBLICKEY) {
- /* This _shouldn't_ happen except by a
- * protocol bug causing client and server to
- * disagree on what is a correct signature. */
- c_write_str(ssh, "Server refused public-key signature"
- " despite accepting key!\r\n");
- logevent("Server refused public-key signature"
- " despite accepting key!");
- } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
- /* quiet, so no c_write */
- logevent("Server refused keyboard-interactive authentication");
- } else if (s->type==AUTH_TYPE_GSSAPI) {
- /* always quiet, so no c_write */
- /* also, the code down in the GSSAPI block has
- * already logged this in the Event Log */
- } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
- logevent("Keyboard-interactive authentication failed");
- c_write_str(ssh, "Access denied\r\n");
- } else {
- assert(s->type == AUTH_TYPE_PASSWORD);
- logevent("Password authentication failed");
- c_write_str(ssh, "Access denied\r\n");
-
- if (conf_get_int(ssh->conf, CONF_change_username)) {
- /* XXX perhaps we should allow
- * keyboard-interactive to do this too? */
- s->we_are_in = FALSE;
- break;
- }
- }
- } else {
- c_write_str(ssh, "Further authentication required\r\n");
- logevent("Further authentication required");
- }
-
- s->can_pubkey =
- in_commasep_string("publickey", methods, methlen);
- s->can_passwd =
- in_commasep_string("password", methods, methlen);
- s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
- in_commasep_string("keyboard-interactive", methods, methlen);
-#ifndef NO_GSSAPI
- if (!ssh->gsslibs)
- ssh->gsslibs = ssh_gss_setup(ssh->conf);
- s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
- in_commasep_string("gssapi-with-mic", methods, methlen) &&
- ssh->gsslibs->nlibraries > 0;
-#endif
- }
-
- ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
-
- if (s->can_pubkey && !s->done_agent && s->nkeys) {
-
- /*
- * Attempt public-key authentication using a key from Pageant.
- */
-
- ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
-
- logeventf(ssh, "Trying Pageant key #%d", s->keyi);
-
- /* Unpack key from agent response */
- s->pklen = GET_32BIT(s->agentp);
- s->agentp += 4;
- s->pkblob = (char *)s->agentp;
- s->agentp += s->pklen;
- s->alglen = GET_32BIT(s->pkblob);
- s->alg = s->pkblob + 4;
- s->commentlen = GET_32BIT(s->agentp);
- s->agentp += 4;
- s->commentp = (char *)s->agentp;
- s->agentp += s->commentlen;
- /* s->agentp now points at next key, if any */
-
- /* See if server will accept it */
- s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
- ssh2_pkt_addstring(s->pktout, ssh->username);
- ssh2_pkt_addstring(s->pktout, "ssh-connection");
- /* service requested */
- ssh2_pkt_addstring(s->pktout, "publickey");
- /* method */
- ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
- ssh2_pkt_addstring_start(s->pktout);
- ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
- ssh2_pkt_addstring_start(s->pktout);
- ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
- ssh2_pkt_send(ssh, s->pktout);
- s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
-
- crWaitUntilV(pktin);
- if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
-
- /* Offer of key refused. */
- s->gotit = TRUE;
-
- } else {
-
- void *vret;
-
- if (flags & FLAG_VERBOSE) {
- c_write_str(ssh, "Authenticating with "
- "public key \"");
- c_write(ssh, s->commentp, s->commentlen);
- c_write_str(ssh, "\" from agent\r\n");
- }
-
- /*
- * Server is willing to accept the key.
- * Construct a SIGN_REQUEST.
- */
- s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
- ssh2_pkt_addstring(s->pktout, ssh->username);
- ssh2_pkt_addstring(s->pktout, "ssh-connection");
- /* service requested */
- ssh2_pkt_addstring(s->pktout, "publickey");
- /* method */
- ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
- ssh2_pkt_addstring_start(s->pktout);
- ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
- ssh2_pkt_addstring_start(s->pktout);
- ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
-
- /* Ask agent for signature. */
- s->siglen = s->pktout->length - 5 + 4 +
- ssh->v2_session_id_len;
- if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
- s->siglen -= 4;
- s->len = 1; /* message type */
- s->len += 4 + s->pklen; /* key blob */
- s->len += 4 + s->siglen; /* data to sign */
- s->len += 4; /* flags */
- s->agentreq = snewn(4 + s->len, char);
- PUT_32BIT(s->agentreq, s->len);
- s->q = s->agentreq + 4;
- *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
- PUT_32BIT(s->q, s->pklen);
- s->q += 4;
- memcpy(s->q, s->pkblob, s->pklen);
- s->q += s->pklen;
- PUT_32BIT(s->q, s->siglen);
- s->q += 4;
- /* Now the data to be signed... */
- if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
- PUT_32BIT(s->q, ssh->v2_session_id_len);
- s->q += 4;
- }
- memcpy(s->q, ssh->v2_session_id,
- ssh->v2_session_id_len);
- s->q += ssh->v2_session_id_len;
- memcpy(s->q, s->pktout->data + 5,
- s->pktout->length - 5);
- s->q += s->pktout->length - 5;
- /* And finally the (zero) flags word. */
- PUT_32BIT(s->q, 0);
- if (!agent_query(s->agentreq, s->len + 4,
- &vret, &s->retlen,
- ssh_agent_callback, ssh)) {
- do {
- crReturnV;
- if (pktin) {
- bombout(("Unexpected data from server"
- " while waiting for agent"
- " response"));
- crStopV;
- }
- } while (pktin || inlen > 0);
- vret = ssh->agent_response;
- s->retlen = ssh->agent_response_len;
- }
- s->ret = vret;
- sfree(s->agentreq);
- if (s->ret) {
- if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
- logevent("Sending Pageant's response");
- ssh2_add_sigblob(ssh, s->pktout,
- s->pkblob, s->pklen,
- s->ret + 9,
- GET_32BIT(s->ret + 5));
- ssh2_pkt_send(ssh, s->pktout);
- s->type = AUTH_TYPE_PUBLICKEY;
- } else {
- /* FIXME: less drastic response */
- bombout(("Pageant failed to answer challenge"));
- crStopV;
- }
- }
- }
-
- /* Do we have any keys left to try? */
- if (s->pkblob_in_agent) {
- s->done_agent = TRUE;
- s->tried_pubkey_config = TRUE;
- } else {
- s->keyi++;
- if (s->keyi >= s->nkeys)
- s->done_agent = TRUE;
- }
-
- } else if (s->can_pubkey && s->publickey_blob &&
- !s->tried_pubkey_config) {
-
- struct ssh2_userkey *key; /* not live over crReturn */
- char *passphrase; /* not live over crReturn */
-
- ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
-
- s->tried_pubkey_config = TRUE;
-
- /*
- * Try the public key supplied in the configuration.
- *
- * First, offer the public blob to see if the server is
- * willing to accept it.
- */
- s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
- ssh2_pkt_addstring(s->pktout, ssh->username);
- ssh2_pkt_addstring(s->pktout, "ssh-connection");
- /* service requested */
- ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
- ssh2_pkt_addbool(s->pktout, FALSE);
- /* no signature included */
- ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
- ssh2_pkt_addstring_start(s->pktout);
- ssh2_pkt_addstring_data(s->pktout,
- (char *)s->publickey_blob,
- s->publickey_bloblen);
- ssh2_pkt_send(ssh, s->pktout);
- logevent("Offered public key");
-
- crWaitUntilV(pktin);
- if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
- /* Key refused. Give up. */
- s->gotit = TRUE; /* reconsider message next loop */
- s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
- continue; /* process this new message */
- }
- logevent("Offer of public key accepted");
-
- /*
- * Actually attempt a serious authentication using
- * the key.
- */
- if (flags & FLAG_VERBOSE) {
- c_write_str(ssh, "Authenticating with public key \"");
- c_write_str(ssh, s->publickey_comment);
- c_write_str(ssh, "\"\r\n");
- }
- key = NULL;
- while (!key) {
- const char *error; /* not live over crReturn */
- if (s->publickey_encrypted) {
- /*
- * Get a passphrase from the user.
- */
- int ret; /* need not be kept over crReturn */
- s->cur_prompt = new_prompts(ssh->frontend);
- s->cur_prompt->to_server = FALSE;
- s->cur_prompt->name = dupstr("SSH key passphrase");
- add_prompt(s->cur_prompt,
- dupprintf("Passphrase for key \"%.100s\": ",
- s->publickey_comment),
- FALSE);
- ret = get_userpass_input(s->cur_prompt, NULL, 0);
- while (ret < 0) {
- ssh->send_ok = 1;
- crWaitUntilV(!pktin);
- ret = get_userpass_input(s->cur_prompt,
- in, inlen);
- ssh->send_ok = 0;
- }
- if (!ret) {
- /* Failed to get a passphrase. Terminate. */
- free_prompts(s->cur_prompt);
- ssh_disconnect(ssh, NULL,
- "Unable to authenticate",
- SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
- TRUE);
- crStopV;
- }
- passphrase =
- dupstr(s->cur_prompt->prompts[0]->result);
- free_prompts(s->cur_prompt);
- } else {
- passphrase = NULL; /* no passphrase needed */
- }
-
- /*
- * Try decrypting the key.
- */
- s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
- key = ssh2_load_userkey(s->keyfile, passphrase, &error);
- if (passphrase) {
- /* burn the evidence */
- memset(passphrase, 0, strlen(passphrase));
- sfree(passphrase);
- }
- if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
- if (passphrase &&
- (key == SSH2_WRONG_PASSPHRASE)) {
- c_write_str(ssh, "Wrong passphrase\r\n");
- key = NULL;
- /* and loop again */
- } else {
- c_write_str(ssh, "Unable to load private key (");
- c_write_str(ssh, error);
- c_write_str(ssh, ")\r\n");
- key = NULL;
- break; /* try something else */
- }
- }
- }
-
- if (key) {
- unsigned char *pkblob, *sigblob, *sigdata;
- int pkblob_len, sigblob_len, sigdata_len;
- int p;
-
- /*
- * We have loaded the private key and the server
- * has announced that it's willing to accept it.
- * Hallelujah. Generate a signature and send it.
- */
- s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
- ssh2_pkt_addstring(s->pktout, ssh->username);
- ssh2_pkt_addstring(s->pktout, "ssh-connection");
- /* service requested */
- ssh2_pkt_addstring(s->pktout, "publickey");
- /* method */
- ssh2_pkt_addbool(s->pktout, TRUE);
- /* signature follows */
- ssh2_pkt_addstring(s->pktout, key->alg->name);
- pkblob = key->alg->public_blob(key->data,
- &pkblob_len);
- ssh2_pkt_addstring_start(s->pktout);
- ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
- pkblob_len);
-
- /*
- * The data to be signed is:
- *
- * string session-id
- *
- * followed by everything so far placed in the
- * outgoing packet.
- */
- sigdata_len = s->pktout->length - 5 + 4 +
- ssh->v2_session_id_len;
- if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
- sigdata_len -= 4;
- sigdata = snewn(sigdata_len, unsigned char);
- p = 0;
- if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
- PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
- p += 4;
- }
- memcpy(sigdata+p, ssh->v2_session_id,
- ssh->v2_session_id_len);
- p += ssh->v2_session_id_len;
- memcpy(sigdata+p, s->pktout->data + 5,
- s->pktout->length - 5);
- p += s->pktout->length - 5;
- assert(p == sigdata_len);
- sigblob = key->alg->sign(key->data, (char *)sigdata,
- sigdata_len, &sigblob_len);
- ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
- sigblob, sigblob_len);
- sfree(pkblob);
- sfree(sigblob);
- sfree(sigdata);
-
- ssh2_pkt_send(ssh, s->pktout);
- logevent("Sent public key signature");
- s->type = AUTH_TYPE_PUBLICKEY;
- key->alg->freekey(key->data);
- }
-
-#ifndef NO_GSSAPI
- } else if (s->can_gssapi && !s->tried_gssapi) {
-
- /* GSSAPI Authentication */
-
- int micoffset, len;
- char *data;
- Ssh_gss_buf mic;
- s->type = AUTH_TYPE_GSSAPI;
- s->tried_gssapi = TRUE;
- s->gotit = TRUE;
- ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
-
- /*
- * Pick the highest GSS library on the preference
- * list.
- */
- {
- int i, j;
- s->gsslib = NULL;
- for (i = 0; i < ngsslibs; i++) {
- int want_id = conf_get_int_int(ssh->conf,
- CONF_ssh_gsslist, i);
- for (j = 0; j < ssh->gsslibs->nlibraries; j++)
- if (ssh->gsslibs->libraries[j].id == want_id) {
- s->gsslib = &ssh->gsslibs->libraries[j];
- goto got_gsslib; /* double break */
- }
- }
- got_gsslib:
- /*
- * We always expect to have found something in
- * the above loop: we only came here if there
- * was at least one viable GSS library, and the
- * preference list should always mention
- * everything and only change the order.
- */
- assert(s->gsslib);
- }
-
- if (s->gsslib->gsslogmsg)
- logevent(s->gsslib->gsslogmsg);
-
- /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
- s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
- ssh2_pkt_addstring(s->pktout, ssh->username);
- ssh2_pkt_addstring(s->pktout, "ssh-connection");
- ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
- logevent("Attempting GSSAPI authentication");
-
- /* add mechanism info */
- s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
-
- /* number of GSSAPI mechanisms */
- ssh2_pkt_adduint32(s->pktout,1);
-
- /* length of OID + 2 */
- ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
- ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
-
- /* length of OID */
- ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
-
- ssh_pkt_adddata(s->pktout, s->gss_buf.value,
- s->gss_buf.length);
- ssh2_pkt_send(ssh, s->pktout);
- crWaitUntilV(pktin);
- if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
- logevent("GSSAPI authentication request refused");
- continue;
- }
-
- /* check returned packet ... */
-
- ssh_pkt_getstring(pktin, &data, &len);
- s->gss_rcvtok.value = data;
- s->gss_rcvtok.length = len;
- if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
- ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
- ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
- memcmp((char *)s->gss_rcvtok.value + 2,
- s->gss_buf.value,s->gss_buf.length) ) {
- logevent("GSSAPI authentication - wrong response from server");
- continue;
- }
-
- /* now start running */
- s->gss_stat = s->gsslib->import_name(s->gsslib,
- ssh->fullhostname,
- &s->gss_srv_name);
- if (s->gss_stat != SSH_GSS_OK) {
- if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
- logevent("GSSAPI import name failed - Bad service name");
- else
- logevent("GSSAPI import name failed");
- continue;
- }
-
- /* fetch TGT into GSS engine */
- s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
-
- if (s->gss_stat != SSH_GSS_OK) {
- logevent("GSSAPI authentication failed to get credentials");
- s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
- continue;
- }
-
- /* initial tokens are empty */
- SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
- SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
-
- /* now enter the loop */
- do {
- s->gss_stat = s->gsslib->init_sec_context
- (s->gsslib,
- &s->gss_ctx,
- s->gss_srv_name,
- conf_get_int(ssh->conf, CONF_gssapifwd),
- &s->gss_rcvtok,
- &s->gss_sndtok);
-
- if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
- s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
- logevent("GSSAPI authentication initialisation failed");
-
- if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
- &s->gss_buf) == SSH_GSS_OK) {
- logevent(s->gss_buf.value);
- sfree(s->gss_buf.value);
- }
-
- break;
- }
- logevent("GSSAPI authentication initialised");
-
- /* Client and server now exchange tokens until GSSAPI
- * no longer says CONTINUE_NEEDED */
-
- if (s->gss_sndtok.length != 0) {
- s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
- ssh_pkt_addstring_start(s->pktout);
- ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
- ssh2_pkt_send(ssh, s->pktout);
- s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
- }
-
- if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
- crWaitUntilV(pktin);
- if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
- logevent("GSSAPI authentication - bad server response");
- s->gss_stat = SSH_GSS_FAILURE;
- break;
- }
- ssh_pkt_getstring(pktin, &data, &len);
- s->gss_rcvtok.value = data;
- s->gss_rcvtok.length = len;
- }
- } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
-
- if (s->gss_stat != SSH_GSS_OK) {
- s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
- s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
- continue;
- }
- logevent("GSSAPI authentication loop finished OK");
-
- /* Now send the MIC */
-
- s->pktout = ssh2_pkt_init(0);
- micoffset = s->pktout->length;
- ssh_pkt_addstring_start(s->pktout);
- ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
- ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
- ssh_pkt_addstring(s->pktout, ssh->username);
- ssh_pkt_addstring(s->pktout, "ssh-connection");
- ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
-
- s->gss_buf.value = (char *)s->pktout->data + micoffset;
- s->gss_buf.length = s->pktout->length - micoffset;
-
- s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
- s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
- ssh_pkt_addstring_start(s->pktout);
- ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
- ssh2_pkt_send(ssh, s->pktout);
- s->gsslib->free_mic(s->gsslib, &mic);
-
- s->gotit = FALSE;
-
- s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
- s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
- continue;
-#endif
- } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
-
- /*
- * Keyboard-interactive authentication.
- */
-
- s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
-
- ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
-
- s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
- ssh2_pkt_addstring(s->pktout, ssh->username);
- ssh2_pkt_addstring(s->pktout, "ssh-connection");
- /* service requested */
- ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
- /* method */
- ssh2_pkt_addstring(s->pktout, ""); /* lang */
- ssh2_pkt_addstring(s->pktout, ""); /* submethods */
- ssh2_pkt_send(ssh, s->pktout);
-
- logevent("Attempting keyboard-interactive authentication");
-
- crWaitUntilV(pktin);
- if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
- /* Server is not willing to do keyboard-interactive
- * at all (or, bizarrely but legally, accepts the
- * user without actually issuing any prompts).
- * Give up on it entirely. */
- s->gotit = TRUE;
- s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
- s->kbd_inter_refused = TRUE; /* don't try it again */
- continue;
- }
-
- /*
- * Loop while the server continues to send INFO_REQUESTs.
- */
- while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
-
- char *name, *inst, *lang;
- int name_len, inst_len, lang_len;
- int i;
-
- /*
- * We've got a fresh USERAUTH_INFO_REQUEST.
- * Get the preamble and start building a prompt.
- */
- ssh_pkt_getstring(pktin, &name, &name_len);
- ssh_pkt_getstring(pktin, &inst, &inst_len);
- ssh_pkt_getstring(pktin, &lang, &lang_len);
- s->cur_prompt = new_prompts(ssh->frontend);
- s->cur_prompt->to_server = TRUE;
-
- /*
- * Get any prompt(s) from the packet.
- */
- s->num_prompts = ssh_pkt_getuint32(pktin);
- for (i = 0; i < s->num_prompts; i++) {
- char *prompt;
- int prompt_len;
- int echo;
- static char noprompt[] =
- "<server failed to send prompt>: ";
-
- ssh_pkt_getstring(pktin, &prompt, &prompt_len);
- echo = ssh2_pkt_getbool(pktin);
- if (!prompt_len) {
- prompt = noprompt;
- prompt_len = lenof(noprompt)-1;
- }
- add_prompt(s->cur_prompt,
- dupprintf("%.*s", prompt_len, prompt),
- echo);
- }
-
- if (name_len) {
- /* FIXME: better prefix to distinguish from
- * local prompts? */
- s->cur_prompt->name =
- dupprintf("SSH server: %.*s", name_len, name);
- s->cur_prompt->name_reqd = TRUE;
- } else {
- s->cur_prompt->name =
- dupstr("SSH server authentication");
- s->cur_prompt->name_reqd = FALSE;
- }
- /* We add a prefix to try to make it clear that a prompt
- * has come from the server.
- * FIXME: ugly to print "Using..." in prompt _every_
- * time round. Can this be done more subtly? */
- /* Special case: for reasons best known to themselves,
- * some servers send k-i requests with no prompts and
- * nothing to display. Keep quiet in this case. */
- if (s->num_prompts || name_len || inst_len) {
- s->cur_prompt->instruction =
- dupprintf("Using keyboard-interactive authentication.%s%.*s",
- inst_len ? "\n" : "", inst_len, inst);
- s->cur_prompt->instr_reqd = TRUE;
- } else {
- s->cur_prompt->instr_reqd = FALSE;
- }
-
- /*
- * Display any instructions, and get the user's
- * response(s).
- */
- {
- int ret; /* not live over crReturn */
- ret = get_userpass_input(s->cur_prompt, NULL, 0);
- while (ret < 0) {
- ssh->send_ok = 1;
- crWaitUntilV(!pktin);
- ret = get_userpass_input(s->cur_prompt, in, inlen);
- ssh->send_ok = 0;
- }
- if (!ret) {
- /*
- * Failed to get responses. Terminate.
- */
- free_prompts(s->cur_prompt);
- ssh_disconnect(ssh, NULL, "Unable to authenticate",
- SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
- TRUE);
- crStopV;
- }
- }
-
- /*
- * Send the response(s) to the server.
- */
- s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
- ssh2_pkt_adduint32(s->pktout, s->num_prompts);
- for (i=0; i < s->num_prompts; i++) {
- dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
- ssh2_pkt_addstring(s->pktout,
- s->cur_prompt->prompts[i]->result);
- end_log_omission(ssh, s->pktout);
- }
- ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
-
- /*
- * Free the prompts structure from this iteration.
- * If there's another, a new one will be allocated
- * when we return to the top of this while loop.
- */
- free_prompts(s->cur_prompt);
-
- /*
- * Get the next packet in case it's another
- * INFO_REQUEST.
- */
- crWaitUntilV(pktin);
-
- }
-
- /*
- * We should have SUCCESS or FAILURE now.
- */
- s->gotit = TRUE;
-
- } else if (s->can_passwd) {
-
- /*
- * Plain old password authentication.
- */
- int ret; /* not live over crReturn */
- int changereq_first_time; /* not live over crReturn */
-
- ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
-
- s->cur_prompt = new_prompts(ssh->frontend);
- s->cur_prompt->to_server = TRUE;
- s->cur_prompt->name = dupstr("SSH password");
- add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
- ssh->username,
- ssh->savedhost),
- FALSE);
-
- ret = get_userpass_input(s->cur_prompt, NULL, 0);
- while (ret < 0) {
- ssh->send_ok = 1;
- crWaitUntilV(!pktin);
- ret = get_userpass_input(s->cur_prompt, in, inlen);
- ssh->send_ok = 0;
- }
- if (!ret) {
- /*
- * Failed to get responses. Terminate.
- */
- free_prompts(s->cur_prompt);
- ssh_disconnect(ssh, NULL, "Unable to authenticate",
- SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
- TRUE);
- crStopV;
- }
- /*
- * Squirrel away the password. (We may need it later if
- * asked to change it.)
- */
- s->password = dupstr(s->cur_prompt->prompts[0]->result);
- free_prompts(s->cur_prompt);
-
- /*
- * Send the password packet.
- *
- * We pad out the password packet to 256 bytes to make
- * it harder for an attacker to find the length of the
- * user's password.
- *
- * Anyone using a password longer than 256 bytes
- * probably doesn't have much to worry about from
- * people who find out how long their password is!
- */
- s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
- ssh2_pkt_addstring(s->pktout, ssh->username);
- ssh2_pkt_addstring(s->pktout, "ssh-connection");
- /* service requested */
- ssh2_pkt_addstring(s->pktout, "password");
- ssh2_pkt_addbool(s->pktout, FALSE);
- dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
- ssh2_pkt_addstring(s->pktout, s->password);
- end_log_omission(ssh, s->pktout);
- ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
- logevent("Sent password");
- s->type = AUTH_TYPE_PASSWORD;
-
- /*
- * Wait for next packet, in case it's a password change
- * request.
- */
- crWaitUntilV(pktin);
- changereq_first_time = TRUE;
-
- while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
-
- /*
- * We're being asked for a new password
- * (perhaps not for the first time).
- * Loop until the server accepts it.
- */
-
- int got_new = FALSE; /* not live over crReturn */
- char *prompt; /* not live over crReturn */
- int prompt_len; /* not live over crReturn */
-
- {
- char *msg;
- if (changereq_first_time)
- msg = "Server requested password change";
- else
- msg = "Server rejected new password";
- logevent(msg);
- c_write_str(ssh, msg);
- c_write_str(ssh, "\r\n");
- }
-
- ssh_pkt_getstring(pktin, &prompt, &prompt_len);
-
- s->cur_prompt = new_prompts(ssh->frontend);
- s->cur_prompt->to_server = TRUE;
- s->cur_prompt->name = dupstr("New SSH password");
- s->cur_prompt->instruction =
- dupprintf("%.*s", prompt_len, prompt);
- s->cur_prompt->instr_reqd = TRUE;
- /*
- * There's no explicit requirement in the protocol
- * for the "old" passwords in the original and
- * password-change messages to be the same, and
- * apparently some Cisco kit supports password change
- * by the user entering a blank password originally
- * and the real password subsequently, so,
- * reluctantly, we prompt for the old password again.
- *
- * (On the other hand, some servers don't even bother
- * to check this field.)
- */
- add_prompt(s->cur_prompt,
- dupstr("Current password (blank for previously entered password): "),
- FALSE);
- add_prompt(s->cur_prompt, dupstr("Enter new password: "),
- FALSE);
- add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
- FALSE);
-
- /*
- * Loop until the user manages to enter the same
- * password twice.
- */
- while (!got_new) {
-
- ret = get_userpass_input(s->cur_prompt, NULL, 0);
- while (ret < 0) {
- ssh->send_ok = 1;
- crWaitUntilV(!pktin);
- ret = get_userpass_input(s->cur_prompt, in, inlen);
- ssh->send_ok = 0;
- }
- if (!ret) {
- /*
- * Failed to get responses. Terminate.
- */
- /* burn the evidence */
- free_prompts(s->cur_prompt);
- memset(s->password, 0, strlen(s->password));
- sfree(s->password);
- ssh_disconnect(ssh, NULL, "Unable to authenticate",
- SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
- TRUE);
- crStopV;
- }
-
- /*
- * If the user specified a new original password
- * (IYSWIM), overwrite any previously specified
- * one.
- * (A side effect is that the user doesn't have to
- * re-enter it if they louse up the new password.)
- */
- if (s->cur_prompt->prompts[0]->result[0]) {
- memset(s->password, 0, strlen(s->password));
- /* burn the evidence */
- sfree(s->password);
- s->password =
- dupstr(s->cur_prompt->prompts[0]->result);
- }
-
- /*
- * Check the two new passwords match.
- */
- got_new = (strcmp(s->cur_prompt->prompts[1]->result,
- s->cur_prompt->prompts[2]->result)
- == 0);
- if (!got_new)
- /* They don't. Silly user. */
- c_write_str(ssh, "Passwords do not match\r\n");
-
- }
-
- /*
- * Send the new password (along with the old one).
- * (see above for padding rationale)
- */
- s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
- ssh2_pkt_addstring(s->pktout, ssh->username);
- ssh2_pkt_addstring(s->pktout, "ssh-connection");
- /* service requested */
- ssh2_pkt_addstring(s->pktout, "password");
- ssh2_pkt_addbool(s->pktout, TRUE);
- dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
- ssh2_pkt_addstring(s->pktout, s->password);
- ssh2_pkt_addstring(s->pktout,
- s->cur_prompt->prompts[1]->result);
- free_prompts(s->cur_prompt);
- end_log_omission(ssh, s->pktout);
- ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
- logevent("Sent new password");
-
- /*
- * Now see what the server has to say about it.
- * (If it's CHANGEREQ again, it's not happy with the
- * new password.)
- */
- crWaitUntilV(pktin);
- changereq_first_time = FALSE;
-
- }
-
- /*
- * We need to reexamine the current pktin at the top
- * of the loop. Either:
- * - we weren't asked to change password at all, in
- * which case it's a SUCCESS or FAILURE with the
- * usual meaning
- * - we sent a new password, and the server was
- * either OK with it (SUCCESS or FAILURE w/partial
- * success) or unhappy with the _old_ password
- * (FAILURE w/o partial success)
- * In any of these cases, we go back to the top of
- * the loop and start again.
- */
- s->gotit = TRUE;
-
- /*
- * We don't need the old password any more, in any
- * case. Burn the evidence.
- */
- memset(s->password, 0, strlen(s->password));
- sfree(s->password);
-
- } else {
- char *str = dupprintf("No supported authentication methods available"
- " (server sent: %.*s)",
- methlen, methods);
-
- ssh_disconnect(ssh, str,
- "No supported authentication methods available",
- SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
- FALSE);
- sfree(str);
-
- crStopV;
-
- }
-
- }
- }
- ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
-
- /* Clear up various bits and pieces from authentication. */
- if (s->publickey_blob) {
- sfree(s->publickey_blob);
- sfree(s->publickey_comment);
- }
- if (s->agent_response)
- sfree(s->agent_response);
-
- if (s->userauth_success) {
- /*
- * We've just received USERAUTH_SUCCESS, and we haven't sent any
- * packets since. Signal the transport layer to consider enacting
- * delayed compression.
- *
- * (Relying on we_are_in is not sufficient, as
- * draft-miller-secsh-compression-delayed is quite clear that it
- * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
- * become set for other reasons.)
- */
- do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
- }
-
- /*
- * Now the connection protocol has started, one way or another.
- */
-
- ssh->channels = newtree234(ssh_channelcmp);
-
- /*
- * Set up handlers for some connection protocol messages, so we
- * don't have to handle them repeatedly in this coroutine.
- */
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
- ssh2_msg_channel_window_adjust;
- ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
- ssh2_msg_global_request;
-
- /*
- * Create the main session channel.
- */
- if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
- ssh->mainchan = NULL;
- } else if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
- /*
- * Just start a direct-tcpip channel and use it as the main
- * channel.
- */
- ssh->mainchan = snew(struct ssh_channel);
- ssh->mainchan->ssh = ssh;
- ssh2_channel_init(ssh->mainchan);
- logeventf(ssh,
- "Opening direct-tcpip channel to %s:%d in place of session",
- conf_get_str(ssh->conf, CONF_ssh_nc_host),
- conf_get_int(ssh->conf, CONF_ssh_nc_port));
- s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
- ssh2_pkt_addstring(s->pktout, "direct-tcpip");
- ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
- ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
- ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
- ssh2_pkt_addstring(s->pktout, conf_get_str(ssh->conf, CONF_ssh_nc_host));
- ssh2_pkt_adduint32(s->pktout, conf_get_int(ssh->conf, CONF_ssh_nc_port));
- /*
- * There's nothing meaningful to put in the originator
- * fields, but some servers insist on syntactically correct
- * information.
- */
- ssh2_pkt_addstring(s->pktout, "0.0.0.0");
- ssh2_pkt_adduint32(s->pktout, 0);
- ssh2_pkt_send(ssh, s->pktout);
-
- crWaitUntilV(pktin);
- if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
- bombout(("Server refused to open a direct-tcpip channel"));
- crStopV;
- /* FIXME: error data comes back in FAILURE packet */
- }
- if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
- bombout(("Server's channel confirmation cited wrong channel"));
- crStopV;
- }
- ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
- ssh->mainchan->halfopen = FALSE;
- ssh->mainchan->type = CHAN_MAINSESSION;
- ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
- ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
- add234(ssh->channels, ssh->mainchan);
- update_specials_menu(ssh->frontend);
- logevent("Opened direct-tcpip channel");
- ssh->ncmode = TRUE;
- } else {
- ssh->mainchan = snew(struct ssh_channel);
- ssh->mainchan->ssh = ssh;
- ssh2_channel_init(ssh->mainchan);
- s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
- ssh2_pkt_addstring(s->pktout, "session");
- ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
- ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
- ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
- ssh2_pkt_send(ssh, s->pktout);
- crWaitUntilV(pktin);
- if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
- bombout(("Server refused to open a session"));
- crStopV;
- /* FIXME: error data comes back in FAILURE packet */
- }
- if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
- bombout(("Server's channel confirmation cited wrong channel"));
- crStopV;
- }
- ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
- ssh->mainchan->halfopen = FALSE;
- ssh->mainchan->type = CHAN_MAINSESSION;
- ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
- ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
- add234(ssh->channels, ssh->mainchan);
- update_specials_menu(ssh->frontend);
- logevent("Opened channel for session");
- ssh->ncmode = FALSE;
- }
-
- /*
- * Now we have a channel, make dispatch table entries for
- * general channel-based messages.
- */
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
- ssh2_msg_channel_data;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
- ssh2_msg_channel_open_confirmation;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
- ssh2_msg_channel_open_failure;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
- ssh2_msg_channel_request;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
- ssh2_msg_channel_open;
-
- if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) {
- /*
- * This message indicates to the server that we promise
- * not to try to run any other channel in parallel with
- * this one, so it's safe for it to advertise a very large
- * window and leave the flow control to TCP.
- */
- s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
- ssh2_pkt_addstring(s->pktout, "simple@putty.projects.tartarus.org");
- ssh2_pkt_addbool(s->pktout, 0); /* no reply */
- ssh2_pkt_send(ssh, s->pktout);
- }
-
- /*
- * Potentially enable X11 forwarding.
- */
- if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_x11_forward) &&
- (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
- conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
- logevent("Requesting X11 forwarding");
- s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
- ssh2_pkt_addstring(s->pktout, "x11-req");
- ssh2_pkt_addbool(s->pktout, 1); /* want reply */
- ssh2_pkt_addbool(s->pktout, 0); /* many connections */
- ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthprotoname);
- /*
- * Note that while we blank the X authentication data here, we don't
- * take any special action to blank the start of an X11 channel,
- * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
- * without having session blanking enabled is likely to leak your
- * cookie into the log.
- */
- dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
- ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthdatastring);
- end_log_omission(ssh, s->pktout);
- ssh2_pkt_adduint32(s->pktout, ssh->x11disp->screennum);
- ssh2_pkt_send(ssh, s->pktout);
-
- crWaitUntilV(pktin);
-
- if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
- if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
- bombout(("Unexpected response to X11 forwarding request:"
- " packet type %d", pktin->type));
- crStopV;
- }
- logevent("X11 forwarding refused");
- } else {
- logevent("X11 forwarding enabled");
- ssh->X11_fwd_enabled = TRUE;
- }
- }
-
- /*
- * Enable port forwardings.
- */
- ssh_setup_portfwd(ssh, ssh->conf);
-
- /*
- * Potentially enable agent forwarding.
- */
- if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
- logevent("Requesting OpenSSH-style agent forwarding");
- s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
- ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
- ssh2_pkt_addbool(s->pktout, 1); /* want reply */
- ssh2_pkt_send(ssh, s->pktout);
-
- crWaitUntilV(pktin);
-
- if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
- if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
- bombout(("Unexpected response to agent forwarding request:"
- " packet type %d", pktin->type));
- crStopV;
- }
- logevent("Agent forwarding refused");
- } else {
- logevent("Agent forwarding enabled");
- ssh->agentfwd_enabled = TRUE;
- }
- }
-
- /*
- * Now allocate a pty for the session.
- */
- if (ssh->mainchan && !ssh->ncmode && !conf_get_int(ssh->conf, CONF_nopty)) {
- /* Unpick the terminal-speed string. */
- /* XXX perhaps we should allow no speeds to be sent. */
- ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
- sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
- /* Build the pty request. */
- s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
- ssh2_pkt_addstring(s->pktout, "pty-req");
- ssh2_pkt_addbool(s->pktout, 1); /* want reply */
- ssh2_pkt_addstring(s->pktout, conf_get_str(ssh->conf, CONF_termtype));
- ssh2_pkt_adduint32(s->pktout, ssh->term_width);
- ssh2_pkt_adduint32(s->pktout, ssh->term_height);
- ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
- ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
- ssh2_pkt_addstring_start(s->pktout);
- parse_ttymodes(ssh, ssh2_send_ttymode, (void *)s->pktout);
- ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
- ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
- ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
- ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
- ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
- ssh2_pkt_send(ssh, s->pktout);
- ssh->state = SSH_STATE_INTERMED;
-
- crWaitUntilV(pktin);
-
- if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
- if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
- bombout(("Unexpected response to pty request:"
- " packet type %d", pktin->type));
- crStopV;
- }
- c_write_str(ssh, "Server refused to allocate pty\r\n");
- ssh->editing = ssh->echoing = 1;
- } else {
- logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
- ssh->ospeed, ssh->ispeed);
- ssh->got_pty = TRUE;
- }
- } else {
- ssh->editing = ssh->echoing = 1;
- }
-
- /*
- * Send environment variables.
- *
- * Simplest thing here is to send all the requests at once, and
- * then wait for a whole bunch of successes or failures.
- */
- if (ssh->mainchan && !ssh->ncmode) {
- char *key, *val;
-
- s->num_env = 0;
-
- for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
- val != NULL;
- val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
- s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
- ssh2_pkt_addstring(s->pktout, "env");
- ssh2_pkt_addbool(s->pktout, 1); /* want reply */
- ssh2_pkt_addstring(s->pktout, key);
- ssh2_pkt_addstring(s->pktout, val);
- ssh2_pkt_send(ssh, s->pktout);
-
- s->num_env++;
- }
-
- if (s->num_env) {
- logeventf(ssh, "Sent %d environment variables", s->num_env);
-
- s->env_ok = 0;
- s->env_left = s->num_env;
-
- while (s->env_left > 0) {
- crWaitUntilV(pktin);
-
- if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
- if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
- bombout(("Unexpected response to environment request:"
- " packet type %d", pktin->type));
- crStopV;
- }
- } else {
- s->env_ok++;
- }
-
- s->env_left--;
- }
-
- if (s->env_ok == s->num_env) {
- logevent("All environment variables successfully set");
- } else if (s->env_ok == 0) {
- logevent("All environment variables refused");
- c_write_str(ssh, "Server refused to set environment variables\r\n");
- } else {
- logeventf(ssh, "%d environment variables refused",
- s->num_env - s->env_ok);
- c_write_str(ssh, "Server refused to set all environment variables\r\n");
- }
- }
- }
-
- /*
- * Start a shell or a remote command. We may have to attempt
- * this twice if the config data has provided a second choice
- * of command.
- */
- if (ssh->mainchan && !ssh->ncmode) while (1) {
- int subsys;
- char *cmd;
-
- if (ssh->fallback_cmd) {
- subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
- cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
- } else {
- subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
- cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
- }
-
- s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
- if (subsys) {
- ssh2_pkt_addstring(s->pktout, "subsystem");
- ssh2_pkt_addbool(s->pktout, 1); /* want reply */
- ssh2_pkt_addstring(s->pktout, cmd);
- } else if (*cmd) {
- ssh2_pkt_addstring(s->pktout, "exec");
- ssh2_pkt_addbool(s->pktout, 1); /* want reply */
- ssh2_pkt_addstring(s->pktout, cmd);
- } else {
- ssh2_pkt_addstring(s->pktout, "shell");
- ssh2_pkt_addbool(s->pktout, 1); /* want reply */
- }
- ssh2_pkt_send(ssh, s->pktout);
-
- crWaitUntilV(pktin);
-
- if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
- if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
- bombout(("Unexpected response to shell/command request:"
- " packet type %d", pktin->type));
- crStopV;
- }
- /*
- * We failed to start the command. If this is the
- * fallback command, we really are finished; if it's
- * not, and if the fallback command exists, try falling
- * back to it before complaining.
- */
- if (!ssh->fallback_cmd &&
- *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
- logevent("Primary command failed; attempting fallback");
- ssh->fallback_cmd = TRUE;
- continue;
- }
- bombout(("Server refused to start a shell/command"));
- crStopV;
- } else {
- logevent("Started a shell/command");
- }
- break;
- }
-
- ssh->state = SSH_STATE_SESSION;
- if (ssh->size_needed)
- ssh_size(ssh, ssh->term_width, ssh->term_height);
- if (ssh->eof_needed)
- ssh_special(ssh, TS_EOF);
-
- /*
- * All the initial channel requests are done, so install the default
- * failure handler.
- */
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_success;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_failure;
-
- /*
- * Transfer data!
- */
- if (ssh->ldisc)
- ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
- if (ssh->mainchan)
- ssh->send_ok = 1;
- while (1) {
- crReturnV;
- s->try_send = FALSE;
- if (pktin) {
-
- /*
- * _All_ the connection-layer packets we expect to
- * receive are now handled by the dispatch table.
- * Anything that reaches here must be bogus.
- */
-
- bombout(("Strange packet received: type %d", pktin->type));
- crStopV;
- } else if (ssh->mainchan) {
- /*
- * We have spare data. Add it to the channel buffer.
- */
- ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
- s->try_send = TRUE;
- }
- if (s->try_send) {
- int i;
- struct ssh_channel *c;
- /*
- * Try to send data on all channels if we can.
- */
- for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
- ssh2_try_send_and_unthrottle(ssh, c);
- }
- }
-
- crFinishV;
-}
-
-/*
- * Handlers for SSH-2 messages that might arrive at any moment.
- */
-static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
-{
- /* log reason code in disconnect message */
- char *buf, *msg;
- int reason, msglen;
-
- reason = ssh_pkt_getuint32(pktin);
- ssh_pkt_getstring(pktin, &msg, &msglen);
-
- if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
- buf = dupprintf("Received disconnect message (%s)",
- ssh2_disconnect_reasons[reason]);
- } else {
- buf = dupprintf("Received disconnect message (unknown"
- " type %d)", reason);
- }
- logevent(buf);
- sfree(buf);
- buf = dupprintf("Disconnection message text: %.*s",
- msglen, msg);
- logevent(buf);
- bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
- reason,
- (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
- ssh2_disconnect_reasons[reason] : "unknown",
- msglen, msg));
- sfree(buf);
-}
-
-static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
-{
- /* log the debug message */
- char *msg;
- int msglen;
-
- /* XXX maybe we should actually take notice of the return value */
- ssh2_pkt_getbool(pktin);
- ssh_pkt_getstring(pktin, &msg, &msglen);
-
- logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
-}
-
-static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
-{
- struct Packet *pktout;
- pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
- ssh2_pkt_adduint32(pktout, pktin->sequence);
- /*
- * UNIMPLEMENTED messages MUST appear in the same order as the
- * messages they respond to. Hence, never queue them.
- */
- ssh2_pkt_send_noqueue(ssh, pktout);
-}
-
-/*
- * Handle the top-level SSH-2 protocol.
- */
-static void ssh2_protocol_setup(Ssh ssh)
-{
- int i;
-
- /*
- * Most messages cause SSH2_MSG_UNIMPLEMENTED.
- */
- for (i = 0; i < 256; i++)
- ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
-
- /*
- * Any message we actually understand, we set to NULL so that
- * the coroutines will get it.
- */
- ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
- ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
- ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
- ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
- ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
- ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
- ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
- /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
- /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
- ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
- ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
- ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
- ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
- ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
- ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
- ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
- /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
- /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
- ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
- ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
- ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
- ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
- ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
-
- /*
- * These special message types we install handlers for.
- */
- ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
- ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
- ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
-}
-
-static void ssh2_timer(void *ctx, long now)
-{
- Ssh ssh = (Ssh)ctx;
-
- if (ssh->state == SSH_STATE_CLOSED)
- return;
-
- if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
- now - ssh->next_rekey >= 0) {
- do_ssh2_transport(ssh, "timeout", -1, NULL);
- }
-}
-
-static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
- struct Packet *pktin)
-{
- unsigned char *in = (unsigned char *)vin;
- if (ssh->state == SSH_STATE_CLOSED)
- return;
-
- if (pktin) {
- ssh->incoming_data_size += pktin->encrypted_len;
- if (!ssh->kex_in_progress &&
- ssh->max_data_size != 0 &&
- ssh->incoming_data_size > ssh->max_data_size)
- do_ssh2_transport(ssh, "too much data received", -1, NULL);
- }
-
- if (pktin && ssh->packet_dispatch[pktin->type]) {
- ssh->packet_dispatch[pktin->type](ssh, pktin);
- return;
- }
-
- if (!ssh->protocol_initial_phase_done ||
- (pktin && pktin->type >= 20 && pktin->type < 50)) {
- if (do_ssh2_transport(ssh, in, inlen, pktin) &&
- !ssh->protocol_initial_phase_done) {
- ssh->protocol_initial_phase_done = TRUE;
- /*
- * Allow authconn to initialise itself.
- */
- do_ssh2_authconn(ssh, NULL, 0, NULL);
- }
- } else {
- do_ssh2_authconn(ssh, in, inlen, pktin);
- }
-}
-
-static void ssh_cache_conf_values(Ssh ssh)
-{
- ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
-}
-
-/*
- * Called to set up the connection.
- *
- * Returns an error message, or NULL on success.
- */
-static const char *ssh_init(void *frontend_handle, void **backend_handle,
- Conf *conf, char *host, int port, char **realhost,
- int nodelay, int keepalive)
-{
- const char *p;
- Ssh ssh;
-
- ssh = snew(struct ssh_tag);
- ssh->conf = conf_copy(conf);
- ssh_cache_conf_values(ssh);
- ssh->version = 0; /* when not ready yet */
- ssh->s = NULL;
- ssh->cipher = NULL;
- ssh->v1_cipher_ctx = NULL;
- ssh->crcda_ctx = NULL;
- ssh->cscipher = NULL;
- ssh->cs_cipher_ctx = NULL;
- ssh->sccipher = NULL;
- ssh->sc_cipher_ctx = NULL;
- ssh->csmac = NULL;
- ssh->cs_mac_ctx = NULL;
- ssh->scmac = NULL;
- ssh->sc_mac_ctx = NULL;
- ssh->cscomp = NULL;
- ssh->cs_comp_ctx = NULL;
- ssh->sccomp = NULL;
- ssh->sc_comp_ctx = NULL;
- ssh->kex = NULL;
- ssh->kex_ctx = NULL;
- ssh->hostkey = NULL;
- ssh->exitcode = -1;
- ssh->close_expected = FALSE;
- ssh->clean_exit = FALSE;
- ssh->state = SSH_STATE_PREPACKET;
- ssh->size_needed = FALSE;
- ssh->eof_needed = FALSE;
- ssh->ldisc = NULL;
- ssh->logctx = NULL;
- ssh->deferred_send_data = NULL;
- ssh->deferred_len = 0;
- ssh->deferred_size = 0;
- ssh->fallback_cmd = 0;
- ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
- ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
- ssh->x11disp = NULL;
- ssh->v1_compressing = FALSE;
- ssh->v2_outgoing_sequence = 0;
- ssh->ssh1_rdpkt_crstate = 0;
- ssh->ssh2_rdpkt_crstate = 0;
- ssh->do_ssh_init_crstate = 0;
- ssh->ssh_gotdata_crstate = 0;
- ssh->do_ssh1_connection_crstate = 0;
- ssh->do_ssh1_login_crstate = 0;
- ssh->do_ssh2_transport_crstate = 0;
- ssh->do_ssh2_authconn_crstate = 0;
- ssh->do_ssh_init_state = NULL;
- ssh->do_ssh1_login_state = NULL;
- ssh->do_ssh2_transport_state = NULL;
- ssh->do_ssh2_authconn_state = NULL;
- ssh->v_c = NULL;
- ssh->v_s = NULL;
- ssh->mainchan = NULL;
- ssh->throttled_all = 0;
- ssh->v1_stdout_throttling = 0;
- ssh->queue = NULL;
- ssh->queuelen = ssh->queuesize = 0;
- ssh->queueing = FALSE;
- ssh->qhead = ssh->qtail = NULL;
- ssh->deferred_rekey_reason = NULL;
- bufchain_init(&ssh->queued_incoming_data);
- ssh->frozen = FALSE;
- ssh->username = NULL;
- ssh->sent_console_eof = FALSE;
- ssh->got_pty = FALSE;
-
- *backend_handle = ssh;
-
-#ifdef MSCRYPTOAPI
- if (crypto_startup() == 0)
- return "Microsoft high encryption pack not installed!";
-#endif
-
- ssh->frontend = frontend_handle;
- ssh->term_width = conf_get_int(ssh->conf, CONF_width);
- ssh->term_height = conf_get_int(ssh->conf, CONF_height);
-
- ssh->channels = NULL;
- ssh->rportfwds = NULL;
- ssh->portfwds = NULL;
-
- ssh->send_ok = 0;
- ssh->editing = 0;
- ssh->echoing = 0;
- ssh->conn_throttle_count = 0;
- ssh->overall_bufsize = 0;
- ssh->fallback_cmd = 0;
-
- ssh->protocol = NULL;
-
- ssh->protocol_initial_phase_done = FALSE;
-
- ssh->pinger = NULL;
-
- ssh->incoming_data_size = ssh->outgoing_data_size =
- ssh->deferred_data_size = 0L;
- ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
- CONF_ssh_rekey_data));
- ssh->kex_in_progress = FALSE;
-
-#ifndef NO_GSSAPI
- ssh->gsslibs = NULL;
-#endif
-
- p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
- if (p != NULL)
- return p;
-
- random_ref();
-
- return NULL;
-}
-
-static void ssh_free(void *handle)
-{
- Ssh ssh = (Ssh) handle;
- struct ssh_channel *c;
- struct ssh_rportfwd *pf;
-
- if (ssh->v1_cipher_ctx)
- ssh->cipher->free_context(ssh->v1_cipher_ctx);
- if (ssh->cs_cipher_ctx)
- ssh->cscipher->free_context(ssh->cs_cipher_ctx);
- if (ssh->sc_cipher_ctx)
- ssh->sccipher->free_context(ssh->sc_cipher_ctx);
- if (ssh->cs_mac_ctx)
- ssh->csmac->free_context(ssh->cs_mac_ctx);
- if (ssh->sc_mac_ctx)
- ssh->scmac->free_context(ssh->sc_mac_ctx);
- if (ssh->cs_comp_ctx) {
- if (ssh->cscomp)
- ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
- else
- zlib_compress_cleanup(ssh->cs_comp_ctx);
- }
- if (ssh->sc_comp_ctx) {
- if (ssh->sccomp)
- ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
- else
- zlib_decompress_cleanup(ssh->sc_comp_ctx);
- }
- if (ssh->kex_ctx)
- dh_cleanup(ssh->kex_ctx);
- sfree(ssh->savedhost);
-
- while (ssh->queuelen-- > 0)
- ssh_free_packet(ssh->queue[ssh->queuelen]);
- sfree(ssh->queue);
-
- while (ssh->qhead) {
- struct queued_handler *qh = ssh->qhead;
- ssh->qhead = qh->next;
- sfree(ssh->qhead);
- }
- ssh->qhead = ssh->qtail = NULL;
-
- if (ssh->channels) {
- while ((c = delpos234(ssh->channels, 0)) != NULL) {
- switch (c->type) {
- case CHAN_X11:
- if (c->u.x11.s != NULL)
- x11_close(c->u.x11.s);
- break;
- case CHAN_SOCKDATA:
- case CHAN_SOCKDATA_DORMANT:
- if (c->u.pfd.s != NULL)
- pfd_close(c->u.pfd.s);
- break;
- }
- sfree(c);
- }
- freetree234(ssh->channels);
- ssh->channels = NULL;
- }
-
- if (ssh->rportfwds) {
- while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
- free_rportfwd(pf);
- freetree234(ssh->rportfwds);
- ssh->rportfwds = NULL;
- }
- sfree(ssh->deferred_send_data);
- if (ssh->x11disp)
- x11_free_display(ssh->x11disp);
- sfree(ssh->do_ssh_init_state);
- sfree(ssh->do_ssh1_login_state);
- sfree(ssh->do_ssh2_transport_state);
- sfree(ssh->do_ssh2_authconn_state);
- sfree(ssh->v_c);
- sfree(ssh->v_s);
- sfree(ssh->fullhostname);
- if (ssh->crcda_ctx) {
- crcda_free_context(ssh->crcda_ctx);
- ssh->crcda_ctx = NULL;
- }
- if (ssh->s)
- ssh_do_close(ssh, TRUE);
- expire_timer_context(ssh);
- if (ssh->pinger)
- pinger_free(ssh->pinger);
- bufchain_clear(&ssh->queued_incoming_data);
- sfree(ssh->username);
- conf_free(ssh->conf);
-#ifndef NO_GSSAPI
- if (ssh->gsslibs)
- ssh_gss_cleanup(ssh->gsslibs);
-#endif
- sfree(ssh);
-
- random_unref();
-}
-
-/*
- * Reconfigure the SSH backend.
- */
-static void ssh_reconfig(void *handle, Conf *conf)
-{
- Ssh ssh = (Ssh) handle;
- char *rekeying = NULL, rekey_mandatory = FALSE;
- unsigned long old_max_data_size;
- int i, rekey_time;
-
- pinger_reconfig(ssh->pinger, ssh->conf, conf);
- if (ssh->portfwds)
- ssh_setup_portfwd(ssh, conf);
-
- rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
- if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
- rekey_time != 0) {
- long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
- long now = GETTICKCOUNT();
-
- if (new_next - now < 0) {
- rekeying = "timeout shortened";
- } else {
- ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
- }
- }
-
- old_max_data_size = ssh->max_data_size;
- ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
- CONF_ssh_rekey_data));
- if (old_max_data_size != ssh->max_data_size &&
- ssh->max_data_size != 0) {
- if (ssh->outgoing_data_size > ssh->max_data_size ||
- ssh->incoming_data_size > ssh->max_data_size)
- rekeying = "data limit lowered";
- }
-
- if (conf_get_int(ssh->conf, CONF_compression) !=
- conf_get_int(conf, CONF_compression)) {
- rekeying = "compression setting changed";
- rekey_mandatory = TRUE;
- }
-
- for (i = 0; i < CIPHER_MAX; i++)
- if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
- conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
- rekeying = "cipher settings changed";
- rekey_mandatory = TRUE;
- }
- if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
- conf_get_int(conf, CONF_ssh2_des_cbc)) {
- rekeying = "cipher settings changed";
- rekey_mandatory = TRUE;
- }
-
- conf_free(ssh->conf);
- ssh->conf = conf_copy(conf);
- ssh_cache_conf_values(ssh);
-
- if (rekeying) {
- if (!ssh->kex_in_progress) {
- do_ssh2_transport(ssh, rekeying, -1, NULL);
- } else if (rekey_mandatory) {
- ssh->deferred_rekey_reason = rekeying;
- }
- }
-}
-
-/*
- * Called to send data down the SSH connection.
- */
-static int ssh_send(void *handle, char *buf, int len)
-{
- Ssh ssh = (Ssh) handle;
-
- if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
- return 0;
-
- ssh->protocol(ssh, (unsigned char *)buf, len, 0);
-
- return ssh_sendbuffer(ssh);
-}
-
-/*
- * Called to query the current amount of buffered stdin data.
- */
-static int ssh_sendbuffer(void *handle)
-{
- Ssh ssh = (Ssh) handle;
- int override_value;
-
- if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
- return 0;
-
- /*
- * If the SSH socket itself has backed up, add the total backup
- * size on that to any individual buffer on the stdin channel.
- */
- override_value = 0;
- if (ssh->throttled_all)
- override_value = ssh->overall_bufsize;
-
- if (ssh->version == 1) {
- return override_value;
- } else if (ssh->version == 2) {
- if (!ssh->mainchan)
- return override_value;
- else
- return (override_value +
- bufchain_size(&ssh->mainchan->v.v2.outbuffer));
- }
-
- return 0;
-}
-
-/*
- * Called to set the size of the window from SSH's POV.
- */
-static void ssh_size(void *handle, int width, int height)
-{
- Ssh ssh = (Ssh) handle;
- struct Packet *pktout;
-
- ssh->term_width = width;
- ssh->term_height = height;
-
- switch (ssh->state) {
- case SSH_STATE_BEFORE_SIZE:
- case SSH_STATE_PREPACKET:
- case SSH_STATE_CLOSED:
- break; /* do nothing */
- case SSH_STATE_INTERMED:
- ssh->size_needed = TRUE; /* buffer for later */
- break;
- case SSH_STATE_SESSION:
- if (!conf_get_int(ssh->conf, CONF_nopty)) {
- if (ssh->version == 1) {
- send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
- PKT_INT, ssh->term_height,
- PKT_INT, ssh->term_width,
- PKT_INT, 0, PKT_INT, 0, PKT_END);
- } else if (ssh->mainchan) {
- pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
- ssh2_pkt_addstring(pktout, "window-change");
- ssh2_pkt_addbool(pktout, 0);
- ssh2_pkt_adduint32(pktout, ssh->term_width);
- ssh2_pkt_adduint32(pktout, ssh->term_height);
- ssh2_pkt_adduint32(pktout, 0);
- ssh2_pkt_adduint32(pktout, 0);
- ssh2_pkt_send(ssh, pktout);
- }
- }
- break;
- }
-}
-
-/*
- * Return a list of the special codes that make sense in this
- * protocol.
- */
-static const struct telnet_special *ssh_get_specials(void *handle)
-{
- static const struct telnet_special ssh1_ignore_special[] = {
- {"IGNORE message", TS_NOP}
- };
- static const struct telnet_special ssh2_ignore_special[] = {
- {"IGNORE message", TS_NOP},
- };
- static const struct telnet_special ssh2_rekey_special[] = {
- {"Repeat key exchange", TS_REKEY},
- };
- static const struct telnet_special ssh2_session_specials[] = {
- {NULL, TS_SEP},
- {"Break", TS_BRK},
- /* These are the signal names defined by RFC 4254.
- * They include all the ISO C signals, but are a subset of the POSIX
- * required signals. */
- {"SIGINT (Interrupt)", TS_SIGINT},
- {"SIGTERM (Terminate)", TS_SIGTERM},
- {"SIGKILL (Kill)", TS_SIGKILL},
- {"SIGQUIT (Quit)", TS_SIGQUIT},
- {"SIGHUP (Hangup)", TS_SIGHUP},
- {"More signals", TS_SUBMENU},
- {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
- {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
- {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
- {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
- {NULL, TS_EXITMENU}
- };
- static const struct telnet_special specials_end[] = {
- {NULL, TS_EXITMENU}
- };
- /* XXX review this length for any changes: */
- static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
- lenof(ssh2_rekey_special) +
- lenof(ssh2_session_specials) +
- lenof(specials_end)];
- Ssh ssh = (Ssh) handle;
- int i = 0;
-#define ADD_SPECIALS(name) \
- do { \
- assert((i + lenof(name)) <= lenof(ssh_specials)); \
- memcpy(&ssh_specials[i], name, sizeof name); \
- i += lenof(name); \
- } while(0)
-
- if (ssh->version == 1) {
- /* Don't bother offering IGNORE if we've decided the remote
- * won't cope with it, since we wouldn't bother sending it if
- * asked anyway. */
- if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
- ADD_SPECIALS(ssh1_ignore_special);
- } else if (ssh->version == 2) {
- if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
- ADD_SPECIALS(ssh2_ignore_special);
- if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
- ADD_SPECIALS(ssh2_rekey_special);
- if (ssh->mainchan)
- ADD_SPECIALS(ssh2_session_specials);
- } /* else we're not ready yet */
-
- if (i) {
- ADD_SPECIALS(specials_end);
- return ssh_specials;
- } else {
- return NULL;
- }
-#undef ADD_SPECIALS
-}
-
-/*
- * Send special codes. TS_EOF is useful for `plink', so you
- * can send an EOF and collect resulting output (e.g. `plink
- * hostname sort').
- */
-static void ssh_special(void *handle, Telnet_Special code)
-{
- Ssh ssh = (Ssh) handle;
- struct Packet *pktout;
-
- if (code == TS_EOF) {
- if (ssh->state != SSH_STATE_SESSION) {
- /*
- * Buffer the EOF in case we are pre-SESSION, so we can
- * send it as soon as we reach SESSION.
- */
- if (code == TS_EOF)
- ssh->eof_needed = TRUE;
- return;
- }
- if (ssh->version == 1) {
- send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
- } else if (ssh->mainchan) {
- sshfwd_write_eof(ssh->mainchan);
- ssh->send_ok = 0; /* now stop trying to read from stdin */
- }
- logevent("Sent EOF message");
- } else if (code == TS_PING || code == TS_NOP) {
- if (ssh->state == SSH_STATE_CLOSED
- || ssh->state == SSH_STATE_PREPACKET) return;
- if (ssh->version == 1) {
- if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
- send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
- } else {
- if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
- pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
- ssh2_pkt_addstring_start(pktout);
- ssh2_pkt_send_noqueue(ssh, pktout);
- }
- }
- } else if (code == TS_REKEY) {
- if (!ssh->kex_in_progress && ssh->version == 2) {
- do_ssh2_transport(ssh, "at user request", -1, NULL);
- }
- } else if (code == TS_BRK) {
- if (ssh->state == SSH_STATE_CLOSED
- || ssh->state == SSH_STATE_PREPACKET) return;
- if (ssh->version == 1) {
- logevent("Unable to send BREAK signal in SSH-1");
- } else if (ssh->mainchan) {
- pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
- ssh2_pkt_addstring(pktout, "break");
- ssh2_pkt_addbool(pktout, 0);
- ssh2_pkt_adduint32(pktout, 0); /* default break length */
- ssh2_pkt_send(ssh, pktout);
- }
- } else {
- /* Is is a POSIX signal? */
- char *signame = NULL;
- if (code == TS_SIGABRT) signame = "ABRT";
- if (code == TS_SIGALRM) signame = "ALRM";
- if (code == TS_SIGFPE) signame = "FPE";
- if (code == TS_SIGHUP) signame = "HUP";
- if (code == TS_SIGILL) signame = "ILL";
- if (code == TS_SIGINT) signame = "INT";
- if (code == TS_SIGKILL) signame = "KILL";
- if (code == TS_SIGPIPE) signame = "PIPE";
- if (code == TS_SIGQUIT) signame = "QUIT";
- if (code == TS_SIGSEGV) signame = "SEGV";
- if (code == TS_SIGTERM) signame = "TERM";
- if (code == TS_SIGUSR1) signame = "USR1";
- if (code == TS_SIGUSR2) signame = "USR2";
- /* The SSH-2 protocol does in principle support arbitrary named
- * signals, including signame@domain, but we don't support those. */
- if (signame) {
- /* It's a signal. */
- if (ssh->version == 2 && ssh->mainchan) {
- pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
- ssh2_pkt_addstring(pktout, "signal");
- ssh2_pkt_addbool(pktout, 0);
- ssh2_pkt_addstring(pktout, signame);
- ssh2_pkt_send(ssh, pktout);
- logeventf(ssh, "Sent signal SIG%s", signame);
- }
- } else {
- /* Never heard of it. Do nothing */
- }
- }
-}
-
-void *new_sock_channel(void *handle, Socket s)
-{
- Ssh ssh = (Ssh) handle;
- struct ssh_channel *c;
- c = snew(struct ssh_channel);
-
- c->ssh = ssh;
- ssh2_channel_init(c);
- c->halfopen = TRUE;
- c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
- c->u.pfd.s = s;
- add234(ssh->channels, c);
- return c;
-}
-
-/*
- * This is called when stdout/stderr (the entity to which
- * from_backend sends data) manages to clear some backlog.
- */
-static void ssh_unthrottle(void *handle, int bufsize)
-{
- Ssh ssh = (Ssh) handle;
- int buflimit;
-
- if (ssh->version == 1) {
- if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
- ssh->v1_stdout_throttling = 0;
- ssh_throttle_conn(ssh, -1);
- }
- } else {
- if (ssh->mainchan) {
- ssh2_set_window(ssh->mainchan,
- bufsize < ssh->mainchan->v.v2.locmaxwin ?
- ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
- if (conf_get_int(ssh->conf, CONF_ssh_simple))
- buflimit = 0;
- else
- buflimit = ssh->mainchan->v.v2.locmaxwin;
- if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
- ssh->mainchan->throttling_conn = 0;
- ssh_throttle_conn(ssh, -1);
- }
- }
- }
-}
-
-void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
-{
- struct ssh_channel *c = (struct ssh_channel *)channel;
- Ssh ssh = c->ssh;
- struct Packet *pktout;
-
- logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
-
- if (ssh->version == 1) {
- send_packet(ssh, SSH1_MSG_PORT_OPEN,
- PKT_INT, c->localid,
- PKT_STR, hostname,
- PKT_INT, port,
- /* PKT_STR, <org:orgport>, */
- PKT_END);
- } else {
- pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
- ssh2_pkt_addstring(pktout, "direct-tcpip");
- ssh2_pkt_adduint32(pktout, c->localid);
- ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
- ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
- ssh2_pkt_addstring(pktout, hostname);
- ssh2_pkt_adduint32(pktout, port);
- /*
- * We make up values for the originator data; partly it's
- * too much hassle to keep track, and partly I'm not
- * convinced the server should be told details like that
- * about my local network configuration.
- * The "originator IP address" is syntactically a numeric
- * IP address, and some servers (e.g., Tectia) get upset
- * if it doesn't match this syntax.
- */
- ssh2_pkt_addstring(pktout, "0.0.0.0");
- ssh2_pkt_adduint32(pktout, 0);
- ssh2_pkt_send(ssh, pktout);
- }
-}
-
-static int ssh_connected(void *handle)
-{
- Ssh ssh = (Ssh) handle;
- return ssh->s != NULL;
-}
-
-static int ssh_sendok(void *handle)
-{
- Ssh ssh = (Ssh) handle;
- return ssh->send_ok;
-}
-
-static int ssh_ldisc(void *handle, int option)
-{
- Ssh ssh = (Ssh) handle;
- if (option == LD_ECHO)
- return ssh->echoing;
- if (option == LD_EDIT)
- return ssh->editing;
- return FALSE;
-}
-
-static void ssh_provide_ldisc(void *handle, void *ldisc)
-{
- Ssh ssh = (Ssh) handle;
- ssh->ldisc = ldisc;
-}
-
-static void ssh_provide_logctx(void *handle, void *logctx)
-{
- Ssh ssh = (Ssh) handle;
- ssh->logctx = logctx;
-}
-
-static int ssh_return_exitcode(void *handle)
-{
- Ssh ssh = (Ssh) handle;
- if (ssh->s != NULL)
- return -1;
- else
- return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
-}
-
-/*
- * cfg_info for SSH is the currently running version of the
- * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
- */
-static int ssh_cfg_info(void *handle)
-{
- Ssh ssh = (Ssh) handle;
- return ssh->version;
-}
-
-/*
- * Gross hack: pscp will try to start SFTP but fall back to scp1 if
- * that fails. This variable is the means by which scp.c can reach
- * into the SSH code and find out which one it got.
- */
-extern int ssh_fallback_cmd(void *handle)
-{
- Ssh ssh = (Ssh) handle;
- return ssh->fallback_cmd;
-}
-
-Backend ssh_backend = {
- ssh_init,
- ssh_free,
- ssh_reconfig,
- ssh_send,
- ssh_sendbuffer,
- ssh_size,
- ssh_special,
- ssh_get_specials,
- ssh_connected,
- ssh_return_exitcode,
- ssh_sendok,
- ssh_ldisc,
- ssh_provide_ldisc,
- ssh_provide_logctx,
- ssh_unthrottle,
- ssh_cfg_info,
- "ssh",
- PROT_SSH,
- 22
-};
+/* + * SSH backend. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <stdarg.h> +#include <assert.h> +#include <limits.h> +#include <signal.h> + +#include "putty.h" +#include "tree234.h" +#include "ssh.h" +#ifndef NO_GSSAPI +#include "sshgssc.h" +#include "sshgss.h" +#endif + +#ifndef FALSE +#define FALSE 0 +#endif +#ifndef TRUE +#define TRUE 1 +#endif + +/* + * Packet type contexts, so that ssh2_pkt_type can correctly decode + * the ambiguous type numbers back into the correct type strings. + */ +typedef enum { + SSH2_PKTCTX_NOKEX, + SSH2_PKTCTX_DHGROUP, + SSH2_PKTCTX_DHGEX, + SSH2_PKTCTX_RSAKEX +} Pkt_KCtx; +typedef enum { + SSH2_PKTCTX_NOAUTH, + SSH2_PKTCTX_PUBLICKEY, + SSH2_PKTCTX_PASSWORD, + SSH2_PKTCTX_GSSAPI, + SSH2_PKTCTX_KBDINTER +} Pkt_ACtx; + +static const char *const ssh2_disconnect_reasons[] = { + NULL, + "host not allowed to connect", + "protocol error", + "key exchange failed", + "host authentication failed", + "MAC error", + "compression error", + "service not available", + "protocol version not supported", + "host key not verifiable", + "connection lost", + "by application", + "too many connections", + "auth cancelled by user", + "no more auth methods available", + "illegal user name", +}; + +/* + * Various remote-bug flags. + */ +#define BUG_CHOKES_ON_SSH1_IGNORE 1 +#define BUG_SSH2_HMAC 2 +#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4 +#define BUG_CHOKES_ON_RSA 8 +#define BUG_SSH2_RSA_PADDING 16 +#define BUG_SSH2_DERIVEKEY 32 +#define BUG_SSH2_REKEY 64 +#define BUG_SSH2_PK_SESSIONID 128 +#define BUG_SSH2_MAXPKT 256 +#define BUG_CHOKES_ON_SSH2_IGNORE 512 +#define BUG_CHOKES_ON_WINADJ 1024 + +/* + * Codes for terminal modes. + * Most of these are the same in SSH-1 and SSH-2. + * This list is derived from RFC 4254 and + * SSH-1 RFC-1.2.31. + */ +static const struct { + const char* const mode; + int opcode; + enum { TTY_OP_CHAR, TTY_OP_BOOL } type; +} ssh_ttymodes[] = { + /* "V" prefix discarded for special characters relative to SSH specs */ + { "INTR", 1, TTY_OP_CHAR }, + { "QUIT", 2, TTY_OP_CHAR }, + { "ERASE", 3, TTY_OP_CHAR }, + { "KILL", 4, TTY_OP_CHAR }, + { "EOF", 5, TTY_OP_CHAR }, + { "EOL", 6, TTY_OP_CHAR }, + { "EOL2", 7, TTY_OP_CHAR }, + { "START", 8, TTY_OP_CHAR }, + { "STOP", 9, TTY_OP_CHAR }, + { "SUSP", 10, TTY_OP_CHAR }, + { "DSUSP", 11, TTY_OP_CHAR }, + { "REPRINT", 12, TTY_OP_CHAR }, + { "WERASE", 13, TTY_OP_CHAR }, + { "LNEXT", 14, TTY_OP_CHAR }, + { "FLUSH", 15, TTY_OP_CHAR }, + { "SWTCH", 16, TTY_OP_CHAR }, + { "STATUS", 17, TTY_OP_CHAR }, + { "DISCARD", 18, TTY_OP_CHAR }, + { "IGNPAR", 30, TTY_OP_BOOL }, + { "PARMRK", 31, TTY_OP_BOOL }, + { "INPCK", 32, TTY_OP_BOOL }, + { "ISTRIP", 33, TTY_OP_BOOL }, + { "INLCR", 34, TTY_OP_BOOL }, + { "IGNCR", 35, TTY_OP_BOOL }, + { "ICRNL", 36, TTY_OP_BOOL }, + { "IUCLC", 37, TTY_OP_BOOL }, + { "IXON", 38, TTY_OP_BOOL }, + { "IXANY", 39, TTY_OP_BOOL }, + { "IXOFF", 40, TTY_OP_BOOL }, + { "IMAXBEL", 41, TTY_OP_BOOL }, + { "ISIG", 50, TTY_OP_BOOL }, + { "ICANON", 51, TTY_OP_BOOL }, + { "XCASE", 52, TTY_OP_BOOL }, + { "ECHO", 53, TTY_OP_BOOL }, + { "ECHOE", 54, TTY_OP_BOOL }, + { "ECHOK", 55, TTY_OP_BOOL }, + { "ECHONL", 56, TTY_OP_BOOL }, + { "NOFLSH", 57, TTY_OP_BOOL }, + { "TOSTOP", 58, TTY_OP_BOOL }, + { "IEXTEN", 59, TTY_OP_BOOL }, + { "ECHOCTL", 60, TTY_OP_BOOL }, + { "ECHOKE", 61, TTY_OP_BOOL }, + { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */ + { "OPOST", 70, TTY_OP_BOOL }, + { "OLCUC", 71, TTY_OP_BOOL }, + { "ONLCR", 72, TTY_OP_BOOL }, + { "OCRNL", 73, TTY_OP_BOOL }, + { "ONOCR", 74, TTY_OP_BOOL }, + { "ONLRET", 75, TTY_OP_BOOL }, + { "CS7", 90, TTY_OP_BOOL }, + { "CS8", 91, TTY_OP_BOOL }, + { "PARENB", 92, TTY_OP_BOOL }, + { "PARODD", 93, TTY_OP_BOOL } +}; + +/* Miscellaneous other tty-related constants. */ +#define SSH_TTY_OP_END 0 +/* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */ +#define SSH1_TTY_OP_ISPEED 192 +#define SSH1_TTY_OP_OSPEED 193 +#define SSH2_TTY_OP_ISPEED 128 +#define SSH2_TTY_OP_OSPEED 129 + +/* Helper functions for parsing tty-related config. */ +static unsigned int ssh_tty_parse_specchar(char *s) +{ + unsigned int ret; + if (*s) { + char *next = NULL; + ret = ctrlparse(s, &next); + if (!next) ret = s[0]; + } else { + ret = 255; /* special value meaning "don't set" */ + } + return ret; +} +static unsigned int ssh_tty_parse_boolean(char *s) +{ + if (stricmp(s, "yes") == 0 || + stricmp(s, "on") == 0 || + stricmp(s, "true") == 0 || + stricmp(s, "+") == 0) + return 1; /* true */ + else if (stricmp(s, "no") == 0 || + stricmp(s, "off") == 0 || + stricmp(s, "false") == 0 || + stricmp(s, "-") == 0) + return 0; /* false */ + else + return (atoi(s) != 0); +} + +#define translate(x) if (type == x) return #x +#define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x +#define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x +static char *ssh1_pkt_type(int type) +{ + translate(SSH1_MSG_DISCONNECT); + translate(SSH1_SMSG_PUBLIC_KEY); + translate(SSH1_CMSG_SESSION_KEY); + translate(SSH1_CMSG_USER); + translate(SSH1_CMSG_AUTH_RSA); + translate(SSH1_SMSG_AUTH_RSA_CHALLENGE); + translate(SSH1_CMSG_AUTH_RSA_RESPONSE); + translate(SSH1_CMSG_AUTH_PASSWORD); + translate(SSH1_CMSG_REQUEST_PTY); + translate(SSH1_CMSG_WINDOW_SIZE); + translate(SSH1_CMSG_EXEC_SHELL); + translate(SSH1_CMSG_EXEC_CMD); + translate(SSH1_SMSG_SUCCESS); + translate(SSH1_SMSG_FAILURE); + translate(SSH1_CMSG_STDIN_DATA); + translate(SSH1_SMSG_STDOUT_DATA); + translate(SSH1_SMSG_STDERR_DATA); + translate(SSH1_CMSG_EOF); + translate(SSH1_SMSG_EXIT_STATUS); + translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION); + translate(SSH1_MSG_CHANNEL_OPEN_FAILURE); + translate(SSH1_MSG_CHANNEL_DATA); + translate(SSH1_MSG_CHANNEL_CLOSE); + translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION); + translate(SSH1_SMSG_X11_OPEN); + translate(SSH1_CMSG_PORT_FORWARD_REQUEST); + translate(SSH1_MSG_PORT_OPEN); + translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING); + translate(SSH1_SMSG_AGENT_OPEN); + translate(SSH1_MSG_IGNORE); + translate(SSH1_CMSG_EXIT_CONFIRMATION); + translate(SSH1_CMSG_X11_REQUEST_FORWARDING); + translate(SSH1_CMSG_AUTH_RHOSTS_RSA); + translate(SSH1_MSG_DEBUG); + translate(SSH1_CMSG_REQUEST_COMPRESSION); + translate(SSH1_CMSG_AUTH_TIS); + translate(SSH1_SMSG_AUTH_TIS_CHALLENGE); + translate(SSH1_CMSG_AUTH_TIS_RESPONSE); + translate(SSH1_CMSG_AUTH_CCARD); + translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE); + translate(SSH1_CMSG_AUTH_CCARD_RESPONSE); + return "unknown"; +} +static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type) +{ + translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI); + translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI); + translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI); + translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI); + translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI); + translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI); + translate(SSH2_MSG_DISCONNECT); + translate(SSH2_MSG_IGNORE); + translate(SSH2_MSG_UNIMPLEMENTED); + translate(SSH2_MSG_DEBUG); + translate(SSH2_MSG_SERVICE_REQUEST); + translate(SSH2_MSG_SERVICE_ACCEPT); + translate(SSH2_MSG_KEXINIT); + translate(SSH2_MSG_NEWKEYS); + translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP); + translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP); + translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX); + translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX); + translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX); + translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX); + translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX); + translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX); + translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX); + translate(SSH2_MSG_USERAUTH_REQUEST); + translate(SSH2_MSG_USERAUTH_FAILURE); + translate(SSH2_MSG_USERAUTH_SUCCESS); + translate(SSH2_MSG_USERAUTH_BANNER); + translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY); + translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD); + translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER); + translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER); + translate(SSH2_MSG_GLOBAL_REQUEST); + translate(SSH2_MSG_REQUEST_SUCCESS); + translate(SSH2_MSG_REQUEST_FAILURE); + translate(SSH2_MSG_CHANNEL_OPEN); + translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); + translate(SSH2_MSG_CHANNEL_OPEN_FAILURE); + translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST); + translate(SSH2_MSG_CHANNEL_DATA); + translate(SSH2_MSG_CHANNEL_EXTENDED_DATA); + translate(SSH2_MSG_CHANNEL_EOF); + translate(SSH2_MSG_CHANNEL_CLOSE); + translate(SSH2_MSG_CHANNEL_REQUEST); + translate(SSH2_MSG_CHANNEL_SUCCESS); + translate(SSH2_MSG_CHANNEL_FAILURE); + return "unknown"; +} +#undef translate +#undef translatec + +/* Enumeration values for fields in SSH-1 packets */ +enum { + PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM, +}; + +/* + * Coroutine mechanics for the sillier bits of the code. If these + * macros look impenetrable to you, you might find it helpful to + * read + * + * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html + * + * which explains the theory behind these macros. + * + * In particular, if you are getting `case expression not constant' + * errors when building with MS Visual Studio, this is because MS's + * Edit and Continue debugging feature causes their compiler to + * violate ANSI C. To disable Edit and Continue debugging: + * + * - right-click ssh.c in the FileView + * - click Settings + * - select the C/C++ tab and the General category + * - under `Debug info:', select anything _other_ than `Program + * Database for Edit and Continue'. + */ +#define crBegin(v) { int *crLine = &v; switch(v) { case 0:; +#define crBeginState crBegin(s->crLine) +#define crStateP(t, v) \ + struct t *s; \ + if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \ + s = (v); +#define crState(t) crStateP(t, ssh->t) +#define crFinish(z) } *crLine = 0; return (z); } +#define crFinishV } *crLine = 0; return; } +#define crFinishFree(z) } sfree(s); return (z); } +#define crFinishFreeV } sfree(s); return; } +#define crReturn(z) \ + do {\ + *crLine =__LINE__; return (z); case __LINE__:;\ + } while (0) +#define crReturnV \ + do {\ + *crLine=__LINE__; return; case __LINE__:;\ + } while (0) +#define crStop(z) do{ *crLine = 0; return (z); }while(0) +#define crStopV do{ *crLine = 0; return; }while(0) +#define crWaitUntil(c) do { crReturn(0); } while (!(c)) +#define crWaitUntilV(c) do { crReturnV; } while (!(c)) + +struct Packet; + +static struct Packet *ssh1_pkt_init(int pkt_type); +static struct Packet *ssh2_pkt_init(int pkt_type); +static void ssh_pkt_ensure(struct Packet *, int length); +static void ssh_pkt_adddata(struct Packet *, const void *data, int len); +static void ssh_pkt_addbyte(struct Packet *, unsigned char value); +static void ssh2_pkt_addbool(struct Packet *, unsigned char value); +static void ssh_pkt_adduint32(struct Packet *, unsigned long value); +static void ssh_pkt_addstring_start(struct Packet *); +static void ssh_pkt_addstring_str(struct Packet *, const char *data); +static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len); +static void ssh_pkt_addstring(struct Packet *, const char *data); +static unsigned char *ssh2_mpint_fmt(Bignum b, int *len); +static void ssh1_pkt_addmp(struct Packet *, Bignum b); +static void ssh2_pkt_addmp(struct Packet *, Bignum b); +static int ssh2_pkt_construct(Ssh, struct Packet *); +static void ssh2_pkt_send(Ssh, struct Packet *); +static void ssh2_pkt_send_noqueue(Ssh, struct Packet *); +static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, + struct Packet *pktin); +static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, + struct Packet *pktin); +static void ssh2_channel_check_close(struct ssh_channel *c); +static void ssh_channel_destroy(struct ssh_channel *c); + +/* + * Buffer management constants. There are several of these for + * various different purposes: + * + * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up + * on a local data stream before we throttle the whole SSH + * connection (in SSH-1 only). Throttling the whole connection is + * pretty drastic so we set this high in the hope it won't + * happen very often. + * + * - SSH_MAX_BACKLOG is the amount of backlog that must build up + * on the SSH connection itself before we defensively throttle + * _all_ local data streams. This is pretty drastic too (though + * thankfully unlikely in SSH-2 since the window mechanism should + * ensure that the server never has any need to throttle its end + * of the connection), so we set this high as well. + * + * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2 + * channels. + * + * - OUR_V2_BIGWIN is the window size we advertise for the only + * channel in a simple connection. It must be <= INT_MAX. + * + * - OUR_V2_MAXPKT is the official "maximum packet size" we send + * to the remote side. This actually has nothing to do with the + * size of the _packet_, but is instead a limit on the amount + * of data we're willing to receive in a single SSH2 channel + * data message. + * + * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH + * _packet_ we're prepared to cope with. It must be a multiple + * of the cipher block size, and must be at least 35000. + */ + +#define SSH1_BUFFER_LIMIT 32768 +#define SSH_MAX_BACKLOG 32768 +#define OUR_V2_WINSIZE 16384 +#define OUR_V2_BIGWIN 0x7fffffff +#define OUR_V2_MAXPKT 0x4000UL +#define OUR_V2_PACKETLIMIT 0x9000UL + +const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; + +const static struct ssh_mac *macs[] = { + &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5 +}; +const static struct ssh_mac *buggymacs[] = { + &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5 +}; + +static void *ssh_comp_none_init(void) +{ + return NULL; +} +static void ssh_comp_none_cleanup(void *handle) +{ +} +static int ssh_comp_none_block(void *handle, unsigned char *block, int len, + unsigned char **outblock, int *outlen) +{ + return 0; +} +static int ssh_comp_none_disable(void *handle) +{ + return 0; +} +const static struct ssh_compress ssh_comp_none = { + "none", NULL, + ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block, + ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block, + ssh_comp_none_disable, NULL +}; +extern const struct ssh_compress ssh_zlib; +const static struct ssh_compress *compressions[] = { + &ssh_zlib, &ssh_comp_none +}; + +enum { /* channel types */ + CHAN_MAINSESSION, + CHAN_X11, + CHAN_AGENT, + CHAN_SOCKDATA, + CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */ + /* + * CHAN_SHARING indicates a channel which is tracked here on + * behalf of a connection-sharing downstream. We do almost nothing + * with these channels ourselves: all messages relating to them + * get thrown straight to sshshare.c and passed on almost + * unmodified to downstream. + */ + CHAN_SHARING, + /* + * CHAN_ZOMBIE is used to indicate a channel for which we've + * already destroyed the local data source: for instance, if a + * forwarded port experiences a socket error on the local side, we + * immediately destroy its local socket and turn the SSH channel + * into CHAN_ZOMBIE. + */ + CHAN_ZOMBIE +}; + +typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin); +typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx); +typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *); + +/* + * Each channel has a queue of outstanding CHANNEL_REQUESTS and their + * handlers. + */ +struct outstanding_channel_request { + cchandler_fn_t handler; + void *ctx; + struct outstanding_channel_request *next; +}; + +/* + * 2-3-4 tree storing channels. + */ +struct ssh_channel { + Ssh ssh; /* pointer back to main context */ + unsigned remoteid, localid; + int type; + /* True if we opened this channel but server hasn't confirmed. */ + int halfopen; + /* + * In SSH-1, this value contains four bits: + * + * 1 We have sent SSH1_MSG_CHANNEL_CLOSE. + * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION. + * 4 We have received SSH1_MSG_CHANNEL_CLOSE. + * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION. + * + * A channel is completely finished with when all four bits are set. + * + * In SSH-2, the four bits mean: + * + * 1 We have sent SSH2_MSG_CHANNEL_EOF. + * 2 We have sent SSH2_MSG_CHANNEL_CLOSE. + * 4 We have received SSH2_MSG_CHANNEL_EOF. + * 8 We have received SSH2_MSG_CHANNEL_CLOSE. + * + * A channel is completely finished with when we have both sent + * and received CLOSE. + * + * The symbolic constants below use the SSH-2 terminology, which + * is a bit confusing in SSH-1, but we have to use _something_. + */ +#define CLOSES_SENT_EOF 1 +#define CLOSES_SENT_CLOSE 2 +#define CLOSES_RCVD_EOF 4 +#define CLOSES_RCVD_CLOSE 8 + int closes; + + /* + * This flag indicates that an EOF is pending on the outgoing side + * of the channel: that is, wherever we're getting the data for + * this channel has sent us some data followed by EOF. We can't + * actually send the EOF until we've finished sending the data, so + * we set this flag instead to remind us to do so once our buffer + * is clear. + */ + int pending_eof; + + /* + * True if this channel is causing the underlying connection to be + * throttled. + */ + int throttling_conn; + union { + struct ssh2_data_channel { + bufchain outbuffer; + unsigned remwindow, remmaxpkt; + /* locwindow is signed so we can cope with excess data. */ + int locwindow, locmaxwin; + /* + * remlocwin is the amount of local window that we think + * the remote end had available to it after it sent the + * last data packet or window adjust ack. + */ + int remlocwin; + /* + * These store the list of channel requests that haven't + * been acked. + */ + struct outstanding_channel_request *chanreq_head, *chanreq_tail; + enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state; + } v2; + } v; + union { + struct ssh_agent_channel { + unsigned char *message; + unsigned char msglen[4]; + unsigned lensofar, totallen; + int outstanding_requests; + } a; + struct ssh_x11_channel { + struct X11Connection *xconn; + int initial; + } x11; + struct ssh_pfd_channel { + struct PortForwarding *pf; + } pfd; + struct ssh_sharing_channel { + void *ctx; + } sharing; + } u; +}; + +/* + * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2 + * use this structure in different ways, reflecting SSH-2's + * altogether saner approach to port forwarding. + * + * In SSH-1, you arrange a remote forwarding by sending the server + * the remote port number, and the local destination host:port. + * When a connection comes in, the server sends you back that + * host:port pair, and you connect to it. This is a ready-made + * security hole if you're not on the ball: a malicious server + * could send you back _any_ host:port pair, so if you trustingly + * connect to the address it gives you then you've just opened the + * entire inside of your corporate network just by connecting + * through it to a dodgy SSH server. Hence, we must store a list of + * host:port pairs we _are_ trying to forward to, and reject a + * connection request from the server if it's not in the list. + * + * In SSH-2, each side of the connection minds its own business and + * doesn't send unnecessary information to the other. You arrange a + * remote forwarding by sending the server just the remote port + * number. When a connection comes in, the server tells you which + * of its ports was connected to; and _you_ have to remember what + * local host:port pair went with that port number. + * + * Hence, in SSH-1 this structure is indexed by destination + * host:port pair, whereas in SSH-2 it is indexed by source port. + */ +struct ssh_portfwd; /* forward declaration */ + +struct ssh_rportfwd { + unsigned sport, dport; + char *shost, *dhost; + char *sportdesc; + void *share_ctx; + struct ssh_portfwd *pfrec; +}; + +static void free_rportfwd(struct ssh_rportfwd *pf) +{ + if (pf) { + sfree(pf->sportdesc); + sfree(pf->shost); + sfree(pf->dhost); + sfree(pf); + } +} + +/* + * Separately to the rportfwd tree (which is for looking up port + * open requests from the server), a tree of _these_ structures is + * used to keep track of all the currently open port forwardings, + * so that we can reconfigure in mid-session if the user requests + * it. + */ +struct ssh_portfwd { + enum { DESTROY, KEEP, CREATE } status; + int type; + unsigned sport, dport; + char *saddr, *daddr; + char *sserv, *dserv; + struct ssh_rportfwd *remote; + int addressfamily; + struct PortListener *local; +}; +#define free_portfwd(pf) ( \ + ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \ + sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) ) + +struct Packet { + long length; /* length of packet: see below */ + long forcepad; /* SSH-2: force padding to at least this length */ + int type; /* only used for incoming packets */ + unsigned long sequence; /* SSH-2 incoming sequence number */ + unsigned char *data; /* allocated storage */ + unsigned char *body; /* offset of payload within `data' */ + long savedpos; /* dual-purpose saved packet position: see below */ + long maxlen; /* amount of storage allocated for `data' */ + long encrypted_len; /* for SSH-2 total-size counting */ + + /* + * A note on the 'length' and 'savedpos' fields above. + * + * Incoming packets are set up so that pkt->length is measured + * relative to pkt->body, which itself points to a few bytes after + * pkt->data (skipping some uninteresting header fields including + * the packet type code). The ssh_pkt_get* functions all expect + * this setup, and they also use pkt->savedpos to indicate how far + * through the packet being decoded they've got - and that, too, + * is an offset from pkt->body rather than pkt->data. + * + * During construction of an outgoing packet, however, pkt->length + * is measured relative to the base pointer pkt->data, and + * pkt->body is not really used for anything until the packet is + * ready for sending. In this mode, pkt->savedpos is reused as a + * temporary variable by the addstring functions, which write out + * a string length field and then keep going back and updating it + * as more data is appended to the subsequent string data field; + * pkt->savedpos stores the offset (again relative to pkt->data) + * of the start of the string data field. + */ + + /* Extra metadata used in SSH packet logging mode, allowing us to + * log in the packet header line that the packet came from a + * connection-sharing downstream and what if anything unusual was + * done to it. The additional_log_text field is expected to be a + * static string - it will not be freed. */ + unsigned downstream_id; + const char *additional_log_text; +}; + +static void ssh1_protocol(Ssh ssh, void *vin, int inlen, + struct Packet *pktin); +static void ssh2_protocol(Ssh ssh, void *vin, int inlen, + struct Packet *pktin); +static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen, + struct Packet *pktin); +static void ssh1_protocol_setup(Ssh ssh); +static void ssh2_protocol_setup(Ssh ssh); +static void ssh2_bare_connection_protocol_setup(Ssh ssh); +static void ssh_size(void *handle, int width, int height); +static void ssh_special(void *handle, Telnet_Special); +static int ssh2_try_send(struct ssh_channel *c); +static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len); +static void ssh_throttle_all(Ssh ssh, int enable, int bufsize); +static void ssh2_set_window(struct ssh_channel *c, int newwin); +static int ssh_sendbuffer(void *handle); +static int ssh_do_close(Ssh ssh, int notify_exit); +static unsigned long ssh_pkt_getuint32(struct Packet *pkt); +static int ssh2_pkt_getbool(struct Packet *pkt); +static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length); +static void ssh2_timer(void *ctx, unsigned long now); +static void do_ssh2_transport(Ssh ssh, void *vin, int inlen, + struct Packet *pktin); +static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin); + +struct rdpkt1_state_tag { + long len, pad, biglen, to_read; + unsigned long realcrc, gotcrc; + unsigned char *p; + int i; + int chunk; + struct Packet *pktin; +}; + +struct rdpkt2_state_tag { + long len, pad, payload, packetlen, maclen; + int i; + int cipherblk; + unsigned long incoming_sequence; + struct Packet *pktin; +}; + +struct rdpkt2_bare_state_tag { + char length[4]; + long packetlen; + int i; + unsigned long incoming_sequence; + struct Packet *pktin; +}; + +struct queued_handler; +struct queued_handler { + int msg1, msg2; + chandler_fn_t handler; + void *ctx; + struct queued_handler *next; +}; + +struct ssh_tag { + const struct plug_function_table *fn; + /* the above field _must_ be first in the structure */ + + char *v_c, *v_s; + void *exhash; + + Socket s; + + void *ldisc; + void *logctx; + + unsigned char session_key[32]; + int v1_compressing; + int v1_remote_protoflags; + int v1_local_protoflags; + int agentfwd_enabled; + int X11_fwd_enabled; + int remote_bugs; + const struct ssh_cipher *cipher; + void *v1_cipher_ctx; + void *crcda_ctx; + const struct ssh2_cipher *cscipher, *sccipher; + void *cs_cipher_ctx, *sc_cipher_ctx; + const struct ssh_mac *csmac, *scmac; + void *cs_mac_ctx, *sc_mac_ctx; + const struct ssh_compress *cscomp, *sccomp; + void *cs_comp_ctx, *sc_comp_ctx; + const struct ssh_kex *kex; + const struct ssh_signkey *hostkey; + char *hostkey_str; /* string representation, for easy checking in rekeys */ + unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN]; + int v2_session_id_len; + void *kex_ctx; + + int bare_connection; + int attempting_connshare; + void *connshare; + + char *savedhost; + int savedport; + int send_ok; + int echoing, editing; + + void *frontend; + + int ospeed, ispeed; /* temporaries */ + int term_width, term_height; + + tree234 *channels; /* indexed by local id */ + struct ssh_channel *mainchan; /* primary session channel */ + int ncmode; /* is primary channel direct-tcpip? */ + int exitcode; + int close_expected; + int clean_exit; + + tree234 *rportfwds, *portfwds; + + enum { + SSH_STATE_PREPACKET, + SSH_STATE_BEFORE_SIZE, + SSH_STATE_INTERMED, + SSH_STATE_SESSION, + SSH_STATE_CLOSED + } state; + + int size_needed, eof_needed; + int sent_console_eof; + int got_pty; /* affects EOF behaviour on main channel */ + + struct Packet **queue; + int queuelen, queuesize; + int queueing; + unsigned char *deferred_send_data; + int deferred_len, deferred_size; + + /* + * Gross hack: pscp will try to start SFTP but fall back to + * scp1 if that fails. This variable is the means by which + * scp.c can reach into the SSH code and find out which one it + * got. + */ + int fallback_cmd; + + bufchain banner; /* accumulates banners during do_ssh2_authconn */ + + Pkt_KCtx pkt_kctx; + Pkt_ACtx pkt_actx; + + struct X11Display *x11disp; + struct X11FakeAuth *x11auth; + tree234 *x11authtree; + + int version; + int conn_throttle_count; + int overall_bufsize; + int throttled_all; + int v1_stdout_throttling; + unsigned long v2_outgoing_sequence; + + int ssh1_rdpkt_crstate; + int ssh2_rdpkt_crstate; + int ssh2_bare_rdpkt_crstate; + int ssh_gotdata_crstate; + int do_ssh1_connection_crstate; + + void *do_ssh_init_state; + void *do_ssh1_login_state; + void *do_ssh2_transport_state; + void *do_ssh2_authconn_state; + void *do_ssh_connection_init_state; + + struct rdpkt1_state_tag rdpkt1_state; + struct rdpkt2_state_tag rdpkt2_state; + struct rdpkt2_bare_state_tag rdpkt2_bare_state; + + /* SSH-1 and SSH-2 use this for different things, but both use it */ + int protocol_initial_phase_done; + + void (*protocol) (Ssh ssh, void *vin, int inlen, + struct Packet *pkt); + struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen); + int (*do_ssh_init)(Ssh ssh, unsigned char c); + + /* + * We maintain our own copy of a Conf structure here. That way, + * when we're passed a new one for reconfiguration, we can check + * the differences and potentially reconfigure port forwardings + * etc in mid-session. + */ + Conf *conf; + + /* + * Values cached out of conf so as to avoid the tree234 lookup + * cost every time they're used. + */ + int logomitdata; + + /* + * Dynamically allocated username string created during SSH + * login. Stored in here rather than in the coroutine state so + * that it'll be reliably freed if we shut down the SSH session + * at some unexpected moment. + */ + char *username; + + /* + * Used to transfer data back from async callbacks. + */ + void *agent_response; + int agent_response_len; + int user_response; + + /* + * The SSH connection can be set as `frozen', meaning we are + * not currently accepting incoming data from the network. This + * is slightly more serious than setting the _socket_ as + * frozen, because we may already have had data passed to us + * from the network which we need to delay processing until + * after the freeze is lifted, so we also need a bufchain to + * store that data. + */ + int frozen; + bufchain queued_incoming_data; + + /* + * Dispatch table for packet types that we may have to deal + * with at any time. + */ + handler_fn_t packet_dispatch[256]; + + /* + * Queues of one-off handler functions for success/failure + * indications from a request. + */ + struct queued_handler *qhead, *qtail; + handler_fn_t q_saved_handler1, q_saved_handler2; + + /* + * This module deals with sending keepalives. + */ + Pinger pinger; + + /* + * Track incoming and outgoing data sizes and time, for + * size-based rekeys. + */ + unsigned long incoming_data_size, outgoing_data_size, deferred_data_size; + unsigned long max_data_size; + int kex_in_progress; + unsigned long next_rekey, last_rekey; + char *deferred_rekey_reason; /* points to STATIC string; don't free */ + + /* + * Fully qualified host name, which we need if doing GSSAPI. + */ + char *fullhostname; + +#ifndef NO_GSSAPI + /* + * GSSAPI libraries for this session. + */ + struct ssh_gss_liblist *gsslibs; +#endif +}; + +#define logevent(s) logevent(ssh->frontend, s) + +/* logevent, only printf-formatted. */ +static void logeventf(Ssh ssh, const char *fmt, ...) +{ + va_list ap; + char *buf; + + va_start(ap, fmt); + buf = dupvprintf(fmt, ap); + va_end(ap); + logevent(buf); + sfree(buf); +} + +static void bomb_out(Ssh ssh, char *text) +{ + ssh_do_close(ssh, FALSE); + logevent(text); + connection_fatal(ssh->frontend, "%s", text); + sfree(text); +} + +#define bombout(msg) bomb_out(ssh, dupprintf msg) + +/* Helper function for common bits of parsing ttymodes. */ +static void parse_ttymodes(Ssh ssh, + void (*do_mode)(void *data, char *mode, char *val), + void *data) +{ + char *key, *val; + + for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key); + val != NULL; + val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) { + /* + * val[0] is either 'V', indicating that an explicit value + * follows it, or 'A' indicating that we should pass the + * value through from the local environment via get_ttymode. + */ + if (val[0] == 'A') { + val = get_ttymode(ssh->frontend, key); + if (val) { + do_mode(data, key, val); + sfree(val); + } + } else + do_mode(data, key, val + 1); /* skip the 'V' */ + } +} + +static int ssh_channelcmp(void *av, void *bv) +{ + struct ssh_channel *a = (struct ssh_channel *) av; + struct ssh_channel *b = (struct ssh_channel *) bv; + if (a->localid < b->localid) + return -1; + if (a->localid > b->localid) + return +1; + return 0; +} +static int ssh_channelfind(void *av, void *bv) +{ + unsigned *a = (unsigned *) av; + struct ssh_channel *b = (struct ssh_channel *) bv; + if (*a < b->localid) + return -1; + if (*a > b->localid) + return +1; + return 0; +} + +static int ssh_rportcmp_ssh1(void *av, void *bv) +{ + struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; + struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; + int i; + if ( (i = strcmp(a->dhost, b->dhost)) != 0) + return i < 0 ? -1 : +1; + if (a->dport > b->dport) + return +1; + if (a->dport < b->dport) + return -1; + return 0; +} + +static int ssh_rportcmp_ssh2(void *av, void *bv) +{ + struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; + struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; + int i; + if ( (i = strcmp(a->shost, b->shost)) != 0) + return i < 0 ? -1 : +1; + if (a->sport > b->sport) + return +1; + if (a->sport < b->sport) + return -1; + return 0; +} + +/* + * Special form of strcmp which can cope with NULL inputs. NULL is + * defined to sort before even the empty string. + */ +static int nullstrcmp(const char *a, const char *b) +{ + if (a == NULL && b == NULL) + return 0; + if (a == NULL) + return -1; + if (b == NULL) + return +1; + return strcmp(a, b); +} + +static int ssh_portcmp(void *av, void *bv) +{ + struct ssh_portfwd *a = (struct ssh_portfwd *) av; + struct ssh_portfwd *b = (struct ssh_portfwd *) bv; + int i; + if (a->type > b->type) + return +1; + if (a->type < b->type) + return -1; + if (a->addressfamily > b->addressfamily) + return +1; + if (a->addressfamily < b->addressfamily) + return -1; + if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0) + return i < 0 ? -1 : +1; + if (a->sport > b->sport) + return +1; + if (a->sport < b->sport) + return -1; + if (a->type != 'D') { + if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0) + return i < 0 ? -1 : +1; + if (a->dport > b->dport) + return +1; + if (a->dport < b->dport) + return -1; + } + return 0; +} + +static int alloc_channel_id(Ssh ssh) +{ + const unsigned CHANNEL_NUMBER_OFFSET = 256; + unsigned low, high, mid; + int tsize; + struct ssh_channel *c; + + /* + * First-fit allocation of channel numbers: always pick the + * lowest unused one. To do this, binary-search using the + * counted B-tree to find the largest channel ID which is in a + * contiguous sequence from the beginning. (Precisely + * everything in that sequence must have ID equal to its tree + * index plus CHANNEL_NUMBER_OFFSET.) + */ + tsize = count234(ssh->channels); + + low = -1; + high = tsize; + while (high - low > 1) { + mid = (high + low) / 2; + c = index234(ssh->channels, mid); + if (c->localid == mid + CHANNEL_NUMBER_OFFSET) + low = mid; /* this one is fine */ + else + high = mid; /* this one is past it */ + } + /* + * Now low points to either -1, or the tree index of the + * largest ID in the initial sequence. + */ + { + unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET; + assert(NULL == find234(ssh->channels, &i, ssh_channelfind)); + } + return low + 1 + CHANNEL_NUMBER_OFFSET; +} + +static void c_write_stderr(int trusted, const char *buf, int len) +{ + int i; + for (i = 0; i < len; i++) + if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60))) + fputc(buf[i], stderr); + fflush(stderr); +} + +static void c_write(Ssh ssh, const char *buf, int len) +{ + if (flags & FLAG_STDERR) + c_write_stderr(1, buf, len); + else + from_backend(ssh->frontend, 1, buf, len); +} + +static void c_write_untrusted(Ssh ssh, const char *buf, int len) +{ + if (flags & FLAG_STDERR) + c_write_stderr(0, buf, len); + else + from_backend_untrusted(ssh->frontend, buf, len); +} + +static void c_write_str(Ssh ssh, const char *buf) +{ + c_write(ssh, buf, strlen(buf)); +} + +static void ssh_free_packet(struct Packet *pkt) +{ + sfree(pkt->data); + sfree(pkt); +} +static struct Packet *ssh_new_packet(void) +{ + struct Packet *pkt = snew(struct Packet); + + pkt->body = pkt->data = NULL; + pkt->maxlen = 0; + + return pkt; +} + +static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt) +{ + int nblanks = 0; + struct logblank_t blanks[4]; + char *str; + int slen; + + pkt->savedpos = 0; + + if (ssh->logomitdata && + (pkt->type == SSH1_SMSG_STDOUT_DATA || + pkt->type == SSH1_SMSG_STDERR_DATA || + pkt->type == SSH1_MSG_CHANNEL_DATA)) { + /* "Session data" packets - omit the data string. */ + if (pkt->type == SSH1_MSG_CHANNEL_DATA) + ssh_pkt_getuint32(pkt); /* skip channel id */ + blanks[nblanks].offset = pkt->savedpos + 4; + blanks[nblanks].type = PKTLOG_OMIT; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = slen; + nblanks++; + } + } + log_packet(ssh->logctx, PKT_INCOMING, pkt->type, + ssh1_pkt_type(pkt->type), + pkt->body, pkt->length, nblanks, blanks, NULL, + 0, NULL); +} + +static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt) +{ + int nblanks = 0; + struct logblank_t blanks[4]; + char *str; + int slen; + + /* + * For outgoing packets, pkt->length represents the length of the + * whole packet starting at pkt->data (including some header), and + * pkt->body refers to the point within that where the log-worthy + * payload begins. However, incoming packets expect pkt->length to + * represent only the payload length (that is, it's measured from + * pkt->body not from pkt->data). Temporarily adjust our outgoing + * packet to conform to the incoming-packet semantics, so that we + * can analyse it with the ssh_pkt_get functions. + */ + pkt->length -= (pkt->body - pkt->data); + pkt->savedpos = 0; + + if (ssh->logomitdata && + (pkt->type == SSH1_CMSG_STDIN_DATA || + pkt->type == SSH1_MSG_CHANNEL_DATA)) { + /* "Session data" packets - omit the data string. */ + if (pkt->type == SSH1_MSG_CHANNEL_DATA) + ssh_pkt_getuint32(pkt); /* skip channel id */ + blanks[nblanks].offset = pkt->savedpos + 4; + blanks[nblanks].type = PKTLOG_OMIT; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = slen; + nblanks++; + } + } + + if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD || + pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE || + pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) && + conf_get_int(ssh->conf, CONF_logomitpass)) { + /* If this is a password or similar packet, blank the password(s). */ + blanks[nblanks].offset = 0; + blanks[nblanks].len = pkt->length; + blanks[nblanks].type = PKTLOG_BLANK; + nblanks++; + } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING && + conf_get_int(ssh->conf, CONF_logomitpass)) { + /* + * If this is an X forwarding request packet, blank the fake + * auth data. + * + * Note that while we blank the X authentication data here, we + * don't take any special action to blank the start of an X11 + * channel, so using MIT-MAGIC-COOKIE-1 and actually opening + * an X connection without having session blanking enabled is + * likely to leak your cookie into the log. + */ + pkt->savedpos = 0; + ssh_pkt_getstring(pkt, &str, &slen); + blanks[nblanks].offset = pkt->savedpos; + blanks[nblanks].type = PKTLOG_BLANK; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset; + nblanks++; + } + } + + log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12], + ssh1_pkt_type(pkt->data[12]), + pkt->body, pkt->length, + nblanks, blanks, NULL, 0, NULL); + + /* + * Undo the above adjustment of pkt->length, to put the packet + * back in the state we found it. + */ + pkt->length += (pkt->body - pkt->data); +} + +/* + * Collect incoming data in the incoming packet buffer. + * Decipher and verify the packet when it is completely read. + * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. + * Update the *data and *datalen variables. + * Return a Packet structure when a packet is completed. + */ +static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen) +{ + struct rdpkt1_state_tag *st = &ssh->rdpkt1_state; + + crBegin(ssh->ssh1_rdpkt_crstate); + + st->pktin = ssh_new_packet(); + + st->pktin->type = 0; + st->pktin->length = 0; + + for (st->i = st->len = 0; st->i < 4; st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->len = (st->len << 8) + **data; + (*data)++, (*datalen)--; + } + + st->pad = 8 - (st->len % 8); + st->biglen = st->len + st->pad; + st->pktin->length = st->len - 5; + + if (st->biglen < 0) { + bombout(("Extremely large packet length from server suggests" + " data stream corruption")); + ssh_free_packet(st->pktin); + crStop(NULL); + } + + st->pktin->maxlen = st->biglen; + st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char); + + st->to_read = st->biglen; + st->p = st->pktin->data; + while (st->to_read > 0) { + st->chunk = st->to_read; + while ((*datalen) == 0) + crReturn(NULL); + if (st->chunk > (*datalen)) + st->chunk = (*datalen); + memcpy(st->p, *data, st->chunk); + *data += st->chunk; + *datalen -= st->chunk; + st->p += st->chunk; + st->to_read -= st->chunk; + } + + if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data, + st->biglen, NULL)) { + bombout(("Network attack (CRC compensation) detected!")); + ssh_free_packet(st->pktin); + crStop(NULL); + } + + if (ssh->cipher) + ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen); + + st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4); + st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4); + if (st->gotcrc != st->realcrc) { + bombout(("Incorrect CRC received on packet")); + ssh_free_packet(st->pktin); + crStop(NULL); + } + + st->pktin->body = st->pktin->data + st->pad + 1; + + if (ssh->v1_compressing) { + unsigned char *decompblk; + int decomplen; + if (!zlib_decompress_block(ssh->sc_comp_ctx, + st->pktin->body - 1, st->pktin->length + 1, + &decompblk, &decomplen)) { + bombout(("Zlib decompression encountered invalid data")); + ssh_free_packet(st->pktin); + crStop(NULL); + } + + if (st->pktin->maxlen < st->pad + decomplen) { + st->pktin->maxlen = st->pad + decomplen; + st->pktin->data = sresize(st->pktin->data, + st->pktin->maxlen + APIEXTRA, + unsigned char); + st->pktin->body = st->pktin->data + st->pad + 1; + } + + memcpy(st->pktin->body - 1, decompblk, decomplen); + sfree(decompblk); + st->pktin->length = decomplen - 1; + } + + st->pktin->type = st->pktin->body[-1]; + + /* + * Now pktin->body and pktin->length identify the semantic content + * of the packet, excluding the initial type byte. + */ + + if (ssh->logctx) + ssh1_log_incoming_packet(ssh, st->pktin); + + st->pktin->savedpos = 0; + + crFinish(st->pktin); +} + +static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt) +{ + int nblanks = 0; + struct logblank_t blanks[4]; + char *str; + int slen; + + pkt->savedpos = 0; + + if (ssh->logomitdata && + (pkt->type == SSH2_MSG_CHANNEL_DATA || + pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) { + /* "Session data" packets - omit the data string. */ + ssh_pkt_getuint32(pkt); /* skip channel id */ + if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) + ssh_pkt_getuint32(pkt); /* skip extended data type */ + blanks[nblanks].offset = pkt->savedpos + 4; + blanks[nblanks].type = PKTLOG_OMIT; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = slen; + nblanks++; + } + } + + log_packet(ssh->logctx, PKT_INCOMING, pkt->type, + ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type), + pkt->body, pkt->length, nblanks, blanks, &pkt->sequence, + 0, NULL); +} + +static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt) +{ + int nblanks = 0; + struct logblank_t blanks[4]; + char *str; + int slen; + + /* + * For outgoing packets, pkt->length represents the length of the + * whole packet starting at pkt->data (including some header), and + * pkt->body refers to the point within that where the log-worthy + * payload begins. However, incoming packets expect pkt->length to + * represent only the payload length (that is, it's measured from + * pkt->body not from pkt->data). Temporarily adjust our outgoing + * packet to conform to the incoming-packet semantics, so that we + * can analyse it with the ssh_pkt_get functions. + */ + pkt->length -= (pkt->body - pkt->data); + pkt->savedpos = 0; + + if (ssh->logomitdata && + (pkt->type == SSH2_MSG_CHANNEL_DATA || + pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) { + /* "Session data" packets - omit the data string. */ + ssh_pkt_getuint32(pkt); /* skip channel id */ + if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) + ssh_pkt_getuint32(pkt); /* skip extended data type */ + blanks[nblanks].offset = pkt->savedpos + 4; + blanks[nblanks].type = PKTLOG_OMIT; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = slen; + nblanks++; + } + } + + if (pkt->type == SSH2_MSG_USERAUTH_REQUEST && + conf_get_int(ssh->conf, CONF_logomitpass)) { + /* If this is a password packet, blank the password(s). */ + pkt->savedpos = 0; + ssh_pkt_getstring(pkt, &str, &slen); + ssh_pkt_getstring(pkt, &str, &slen); + ssh_pkt_getstring(pkt, &str, &slen); + if (slen == 8 && !memcmp(str, "password", 8)) { + ssh2_pkt_getbool(pkt); + /* Blank the password field. */ + blanks[nblanks].offset = pkt->savedpos; + blanks[nblanks].type = PKTLOG_BLANK; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset; + nblanks++; + /* If there's another password field beyond it (change of + * password), blank that too. */ + ssh_pkt_getstring(pkt, &str, &slen); + if (str) + blanks[nblanks-1].len = + pkt->savedpos - blanks[nblanks].offset; + } + } + } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER && + pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE && + conf_get_int(ssh->conf, CONF_logomitpass)) { + /* If this is a keyboard-interactive response packet, blank + * the responses. */ + pkt->savedpos = 0; + ssh_pkt_getuint32(pkt); + blanks[nblanks].offset = pkt->savedpos; + blanks[nblanks].type = PKTLOG_BLANK; + while (1) { + ssh_pkt_getstring(pkt, &str, &slen); + if (!str) + break; + } + blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset; + nblanks++; + } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST && + conf_get_int(ssh->conf, CONF_logomitpass)) { + /* + * If this is an X forwarding request packet, blank the fake + * auth data. + * + * Note that while we blank the X authentication data here, we + * don't take any special action to blank the start of an X11 + * channel, so using MIT-MAGIC-COOKIE-1 and actually opening + * an X connection without having session blanking enabled is + * likely to leak your cookie into the log. + */ + pkt->savedpos = 0; + ssh_pkt_getuint32(pkt); + ssh_pkt_getstring(pkt, &str, &slen); + if (slen == 7 && !memcmp(str, "x11-req", 0)) { + ssh2_pkt_getbool(pkt); + ssh2_pkt_getbool(pkt); + ssh_pkt_getstring(pkt, &str, &slen); + blanks[nblanks].offset = pkt->savedpos; + blanks[nblanks].type = PKTLOG_BLANK; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset; + nblanks++; + } + } + } + + log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5], + ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]), + pkt->body, pkt->length, nblanks, blanks, + &ssh->v2_outgoing_sequence, + pkt->downstream_id, pkt->additional_log_text); + + /* + * Undo the above adjustment of pkt->length, to put the packet + * back in the state we found it. + */ + pkt->length += (pkt->body - pkt->data); +} + +static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) +{ + struct rdpkt2_state_tag *st = &ssh->rdpkt2_state; + + crBegin(ssh->ssh2_rdpkt_crstate); + + st->pktin = ssh_new_packet(); + + st->pktin->type = 0; + st->pktin->length = 0; + if (ssh->sccipher) + st->cipherblk = ssh->sccipher->blksize; + else + st->cipherblk = 8; + if (st->cipherblk < 8) + st->cipherblk = 8; + st->maclen = ssh->scmac ? ssh->scmac->len : 0; + + if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) && + ssh->scmac) { + /* + * When dealing with a CBC-mode cipher, we want to avoid the + * possibility of an attacker's tweaking the ciphertext stream + * so as to cause us to feed the same block to the block + * cipher more than once and thus leak information + * (VU#958563). The way we do this is not to take any + * decisions on the basis of anything we've decrypted until + * we've verified it with a MAC. That includes the packet + * length, so we just read data and check the MAC repeatedly, + * and when the MAC passes, see if the length we've got is + * plausible. + */ + + /* May as well allocate the whole lot now. */ + st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA, + unsigned char); + + /* Read an amount corresponding to the MAC. */ + for (st->i = 0; st->i < st->maclen; st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->pktin->data[st->i] = *(*data)++; + (*datalen)--; + } + + st->packetlen = 0; + { + unsigned char seq[4]; + ssh->scmac->start(ssh->sc_mac_ctx); + PUT_32BIT(seq, st->incoming_sequence); + ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4); + } + + for (;;) { /* Once around this loop per cipher block. */ + /* Read another cipher-block's worth, and tack it onto the end. */ + for (st->i = 0; st->i < st->cipherblk; st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++; + (*datalen)--; + } + /* Decrypt one more block (a little further back in the stream). */ + ssh->sccipher->decrypt(ssh->sc_cipher_ctx, + st->pktin->data + st->packetlen, + st->cipherblk); + /* Feed that block to the MAC. */ + ssh->scmac->bytes(ssh->sc_mac_ctx, + st->pktin->data + st->packetlen, st->cipherblk); + st->packetlen += st->cipherblk; + /* See if that gives us a valid packet. */ + if (ssh->scmac->verresult(ssh->sc_mac_ctx, + st->pktin->data + st->packetlen) && + ((st->len = toint(GET_32BIT(st->pktin->data))) == + st->packetlen-4)) + break; + if (st->packetlen >= OUR_V2_PACKETLIMIT) { + bombout(("No valid incoming packet found")); + ssh_free_packet(st->pktin); + crStop(NULL); + } + } + st->pktin->maxlen = st->packetlen + st->maclen; + st->pktin->data = sresize(st->pktin->data, + st->pktin->maxlen + APIEXTRA, + unsigned char); + } else { + st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char); + + /* + * Acquire and decrypt the first block of the packet. This will + * contain the length and padding details. + */ + for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->pktin->data[st->i] = *(*data)++; + (*datalen)--; + } + + if (ssh->sccipher) + ssh->sccipher->decrypt(ssh->sc_cipher_ctx, + st->pktin->data, st->cipherblk); + + /* + * Now get the length figure. + */ + st->len = toint(GET_32BIT(st->pktin->data)); + + /* + * _Completely_ silly lengths should be stomped on before they + * do us any more damage. + */ + if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT || + (st->len + 4) % st->cipherblk != 0) { + bombout(("Incoming packet was garbled on decryption")); + ssh_free_packet(st->pktin); + crStop(NULL); + } + + /* + * So now we can work out the total packet length. + */ + st->packetlen = st->len + 4; + + /* + * Allocate memory for the rest of the packet. + */ + st->pktin->maxlen = st->packetlen + st->maclen; + st->pktin->data = sresize(st->pktin->data, + st->pktin->maxlen + APIEXTRA, + unsigned char); + + /* + * Read and decrypt the remainder of the packet. + */ + for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; + st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->pktin->data[st->i] = *(*data)++; + (*datalen)--; + } + /* Decrypt everything _except_ the MAC. */ + if (ssh->sccipher) + ssh->sccipher->decrypt(ssh->sc_cipher_ctx, + st->pktin->data + st->cipherblk, + st->packetlen - st->cipherblk); + + /* + * Check the MAC. + */ + if (ssh->scmac + && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, + st->len + 4, st->incoming_sequence)) { + bombout(("Incorrect MAC received on packet")); + ssh_free_packet(st->pktin); + crStop(NULL); + } + } + /* Get and sanity-check the amount of random padding. */ + st->pad = st->pktin->data[4]; + if (st->pad < 4 || st->len - st->pad < 1) { + bombout(("Invalid padding length on received packet")); + ssh_free_packet(st->pktin); + crStop(NULL); + } + /* + * This enables us to deduce the payload length. + */ + st->payload = st->len - st->pad - 1; + + st->pktin->length = st->payload + 5; + st->pktin->encrypted_len = st->packetlen; + + st->pktin->sequence = st->incoming_sequence++; + + st->pktin->length = st->packetlen - st->pad; + assert(st->pktin->length >= 0); + + /* + * Decompress packet payload. + */ + { + unsigned char *newpayload; + int newlen; + if (ssh->sccomp && + ssh->sccomp->decompress(ssh->sc_comp_ctx, + st->pktin->data + 5, st->pktin->length - 5, + &newpayload, &newlen)) { + if (st->pktin->maxlen < newlen + 5) { + st->pktin->maxlen = newlen + 5; + st->pktin->data = sresize(st->pktin->data, + st->pktin->maxlen + APIEXTRA, + unsigned char); + } + st->pktin->length = 5 + newlen; + memcpy(st->pktin->data + 5, newpayload, newlen); + sfree(newpayload); + } + } + + /* + * pktin->body and pktin->length should identify the semantic + * content of the packet, excluding the initial type byte. + */ + st->pktin->type = st->pktin->data[5]; + st->pktin->body = st->pktin->data + 6; + st->pktin->length -= 6; + assert(st->pktin->length >= 0); /* one last double-check */ + + if (ssh->logctx) + ssh2_log_incoming_packet(ssh, st->pktin); + + st->pktin->savedpos = 0; + + crFinish(st->pktin); +} + +static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh, unsigned char **data, + int *datalen) +{ + struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state; + + crBegin(ssh->ssh2_bare_rdpkt_crstate); + + /* + * Read the packet length field. + */ + for (st->i = 0; st->i < 4; st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->length[st->i] = *(*data)++; + (*datalen)--; + } + + st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length)); + if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) { + bombout(("Invalid packet length received")); + crStop(NULL); + } + + st->pktin = ssh_new_packet(); + st->pktin->data = snewn(st->packetlen, unsigned char); + + st->pktin->encrypted_len = st->packetlen; + + st->pktin->sequence = st->incoming_sequence++; + + /* + * Read the remainder of the packet. + */ + for (st->i = 0; st->i < st->packetlen; st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->pktin->data[st->i] = *(*data)++; + (*datalen)--; + } + + /* + * pktin->body and pktin->length should identify the semantic + * content of the packet, excluding the initial type byte. + */ + st->pktin->type = st->pktin->data[0]; + st->pktin->body = st->pktin->data + 1; + st->pktin->length = st->packetlen - 1; + + /* + * Log incoming packet, possibly omitting sensitive fields. + */ + if (ssh->logctx) + ssh2_log_incoming_packet(ssh, st->pktin); + + st->pktin->savedpos = 0; + + crFinish(st->pktin); +} + +static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p) +{ + int pad, biglen, i, pktoffs; + unsigned long crc; +#ifdef __SC__ + /* + * XXX various versions of SC (including 8.8.4) screw up the + * register allocation in this function and use the same register + * (D6) for len and as a temporary, with predictable results. The + * following sledgehammer prevents this. + */ + volatile +#endif + int len; + + if (ssh->logctx) + ssh1_log_outgoing_packet(ssh, pkt); + + if (ssh->v1_compressing) { + unsigned char *compblk; + int complen; + zlib_compress_block(ssh->cs_comp_ctx, + pkt->data + 12, pkt->length - 12, + &compblk, &complen); + ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */ + memcpy(pkt->data + 12, compblk, complen); + sfree(compblk); + pkt->length = complen + 12; + } + + ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */ + pkt->length += 4; + len = pkt->length - 4 - 8; /* len(type+data+CRC) */ + pad = 8 - (len % 8); + pktoffs = 8 - pad; + biglen = len + pad; /* len(padding+type+data+CRC) */ + + for (i = pktoffs; i < 4+8; i++) + pkt->data[i] = random_byte(); + crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */ + PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc); + PUT_32BIT(pkt->data + pktoffs, len); + + if (ssh->cipher) + ssh->cipher->encrypt(ssh->v1_cipher_ctx, + pkt->data + pktoffs + 4, biglen); + + if (offset_p) *offset_p = pktoffs; + return biglen + 4; /* len(length+padding+type+data+CRC) */ +} + +static int s_write(Ssh ssh, void *data, int len) +{ + if (ssh->logctx) + log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len, + 0, NULL, NULL, 0, NULL); + if (!ssh->s) + return 0; + return sk_write(ssh->s, (char *)data, len); +} + +static void s_wrpkt(Ssh ssh, struct Packet *pkt) +{ + int len, backlog, offset; + len = s_wrpkt_prepare(ssh, pkt, &offset); + backlog = s_write(ssh, pkt->data + offset, len); + if (backlog > SSH_MAX_BACKLOG) + ssh_throttle_all(ssh, 1, backlog); + ssh_free_packet(pkt); +} + +static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt) +{ + int len, offset; + len = s_wrpkt_prepare(ssh, pkt, &offset); + if (ssh->deferred_len + len > ssh->deferred_size) { + ssh->deferred_size = ssh->deferred_len + len + 128; + ssh->deferred_send_data = sresize(ssh->deferred_send_data, + ssh->deferred_size, + unsigned char); + } + memcpy(ssh->deferred_send_data + ssh->deferred_len, + pkt->data + offset, len); + ssh->deferred_len += len; + ssh_free_packet(pkt); +} + +/* + * Construct a SSH-1 packet with the specified contents. + * (This all-at-once interface used to be the only one, but now SSH-1 + * packets can also be constructed incrementally.) + */ +static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap) +{ + int argtype; + Bignum bn; + struct Packet *pkt; + + pkt = ssh1_pkt_init(pkttype); + + while ((argtype = va_arg(ap, int)) != PKT_END) { + unsigned char *argp, argchar; + char *sargp; + unsigned long argint; + int arglen; + switch (argtype) { + /* Actual fields in the packet */ + case PKT_INT: + argint = va_arg(ap, int); + ssh_pkt_adduint32(pkt, argint); + break; + case PKT_CHAR: + argchar = (unsigned char) va_arg(ap, int); + ssh_pkt_addbyte(pkt, argchar); + break; + case PKT_DATA: + argp = va_arg(ap, unsigned char *); + arglen = va_arg(ap, int); + ssh_pkt_adddata(pkt, argp, arglen); + break; + case PKT_STR: + sargp = va_arg(ap, char *); + ssh_pkt_addstring(pkt, sargp); + break; + case PKT_BIGNUM: + bn = va_arg(ap, Bignum); + ssh1_pkt_addmp(pkt, bn); + break; + } + } + + return pkt; +} + +static void send_packet(Ssh ssh, int pkttype, ...) +{ + struct Packet *pkt; + va_list ap; + va_start(ap, pkttype); + pkt = construct_packet(ssh, pkttype, ap); + va_end(ap); + s_wrpkt(ssh, pkt); +} + +static void defer_packet(Ssh ssh, int pkttype, ...) +{ + struct Packet *pkt; + va_list ap; + va_start(ap, pkttype); + pkt = construct_packet(ssh, pkttype, ap); + va_end(ap); + s_wrpkt_defer(ssh, pkt); +} + +static int ssh_versioncmp(char *a, char *b) +{ + char *ae, *be; + unsigned long av, bv; + + av = strtoul(a, &ae, 10); + bv = strtoul(b, &be, 10); + if (av != bv) + return (av < bv ? -1 : +1); + if (*ae == '.') + ae++; + if (*be == '.') + be++; + av = strtoul(ae, &ae, 10); + bv = strtoul(be, &be, 10); + if (av != bv) + return (av < bv ? -1 : +1); + return 0; +} + +/* + * Utility routines for putting an SSH-protocol `string' and + * `uint32' into a hash state. + */ +static void hash_string(const struct ssh_hash *h, void *s, void *str, int len) +{ + unsigned char lenblk[4]; + PUT_32BIT(lenblk, len); + h->bytes(s, lenblk, 4); + h->bytes(s, str, len); +} + +static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i) +{ + unsigned char intblk[4]; + PUT_32BIT(intblk, i); + h->bytes(s, intblk, 4); +} + +/* + * Packet construction functions. Mostly shared between SSH-1 and SSH-2. + */ +static void ssh_pkt_ensure(struct Packet *pkt, int length) +{ + if (pkt->maxlen < length) { + unsigned char *body = pkt->body; + int offset = body ? body - pkt->data : 0; + pkt->maxlen = length + 256; + pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char); + if (body) pkt->body = pkt->data + offset; + } +} +static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len) +{ + pkt->length += len; + ssh_pkt_ensure(pkt, pkt->length); + memcpy(pkt->data + pkt->length - len, data, len); +} +static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte) +{ + ssh_pkt_adddata(pkt, &byte, 1); +} +static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value) +{ + ssh_pkt_adddata(pkt, &value, 1); +} +static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value) +{ + unsigned char x[4]; + PUT_32BIT(x, value); + ssh_pkt_adddata(pkt, x, 4); +} +static void ssh_pkt_addstring_start(struct Packet *pkt) +{ + ssh_pkt_adduint32(pkt, 0); + pkt->savedpos = pkt->length; +} +static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data) +{ + ssh_pkt_adddata(pkt, data, strlen(data)); + PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos); +} +static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data, + int len) +{ + ssh_pkt_adddata(pkt, data, len); + PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos); +} +static void ssh_pkt_addstring(struct Packet *pkt, const char *data) +{ + ssh_pkt_addstring_start(pkt); + ssh_pkt_addstring_str(pkt, data); +} +static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b) +{ + int len = ssh1_bignum_length(b); + unsigned char *data = snewn(len, unsigned char); + (void) ssh1_write_bignum(data, b); + ssh_pkt_adddata(pkt, data, len); + sfree(data); +} +static unsigned char *ssh2_mpint_fmt(Bignum b, int *len) +{ + unsigned char *p; + int i, n = (bignum_bitcount(b) + 7) / 8; + p = snewn(n + 1, unsigned char); + p[0] = 0; + for (i = 1; i <= n; i++) + p[i] = bignum_byte(b, n - i); + i = 0; + while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0) + i++; + memmove(p, p + i, n + 1 - i); + *len = n + 1 - i; + return p; +} +static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b) +{ + unsigned char *p; + int len; + p = ssh2_mpint_fmt(b, &len); + ssh_pkt_addstring_start(pkt); + ssh_pkt_addstring_data(pkt, (char *)p, len); + sfree(p); +} + +static struct Packet *ssh1_pkt_init(int pkt_type) +{ + struct Packet *pkt = ssh_new_packet(); + pkt->length = 4 + 8; /* space for length + max padding */ + ssh_pkt_addbyte(pkt, pkt_type); + pkt->body = pkt->data + pkt->length; + pkt->type = pkt_type; + pkt->downstream_id = 0; + pkt->additional_log_text = NULL; + return pkt; +} + +/* For legacy code (SSH-1 and -2 packet construction used to be separate) */ +#define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length) +#define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len) +#define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte) +#define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value) +#define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt) +#define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data) +#define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len) +#define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data) + +static struct Packet *ssh2_pkt_init(int pkt_type) +{ + struct Packet *pkt = ssh_new_packet(); + pkt->length = 5; /* space for packet length + padding length */ + pkt->forcepad = 0; + pkt->type = pkt_type; + ssh_pkt_addbyte(pkt, (unsigned char) pkt_type); + pkt->body = pkt->data + pkt->length; /* after packet type */ + pkt->downstream_id = 0; + pkt->additional_log_text = NULL; + return pkt; +} + +/* + * Construct an SSH-2 final-form packet: compress it, encrypt it, + * put the MAC on it. Final packet, ready to be sent, is stored in + * pkt->data. Total length is returned. + */ +static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) +{ + int cipherblk, maclen, padding, i; + + if (ssh->logctx) + ssh2_log_outgoing_packet(ssh, pkt); + + if (ssh->bare_connection) { + /* + * Trivial packet construction for the bare connection + * protocol. + */ + PUT_32BIT(pkt->data + 1, pkt->length - 5); + pkt->body = pkt->data + 1; + ssh->v2_outgoing_sequence++; /* only for diagnostics, really */ + return pkt->length - 1; + } + + /* + * Compress packet payload. + */ + { + unsigned char *newpayload; + int newlen; + if (ssh->cscomp && + ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5, + pkt->length - 5, + &newpayload, &newlen)) { + pkt->length = 5; + ssh2_pkt_adddata(pkt, newpayload, newlen); + sfree(newpayload); + } + } + + /* + * Add padding. At least four bytes, and must also bring total + * length (minus MAC) up to a multiple of the block size. + * If pkt->forcepad is set, make sure the packet is at least that size + * after padding. + */ + cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */ + cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ + padding = 4; + if (pkt->length + padding < pkt->forcepad) + padding = pkt->forcepad - pkt->length; + padding += + (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk; + assert(padding <= 255); + maclen = ssh->csmac ? ssh->csmac->len : 0; + ssh2_pkt_ensure(pkt, pkt->length + padding + maclen); + pkt->data[4] = padding; + for (i = 0; i < padding; i++) + pkt->data[pkt->length + i] = random_byte(); + PUT_32BIT(pkt->data, pkt->length + padding - 4); + if (ssh->csmac) + ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data, + pkt->length + padding, + ssh->v2_outgoing_sequence); + ssh->v2_outgoing_sequence++; /* whether or not we MACed */ + + if (ssh->cscipher) + ssh->cscipher->encrypt(ssh->cs_cipher_ctx, + pkt->data, pkt->length + padding); + + pkt->encrypted_len = pkt->length + padding; + + /* Ready-to-send packet starts at pkt->data. We return length. */ + pkt->body = pkt->data; + return pkt->length + padding + maclen; +} + +/* + * Routines called from the main SSH code to send packets. There + * are quite a few of these, because we have two separate + * mechanisms for delaying the sending of packets: + * + * - In order to send an IGNORE message and a password message in + * a single fixed-length blob, we require the ability to + * concatenate the encrypted forms of those two packets _into_ a + * single blob and then pass it to our <network.h> transport + * layer in one go. Hence, there's a deferment mechanism which + * works after packet encryption. + * + * - In order to avoid sending any connection-layer messages + * during repeat key exchange, we have to queue up any such + * outgoing messages _before_ they are encrypted (and in + * particular before they're allocated sequence numbers), and + * then send them once we've finished. + * + * I call these mechanisms `defer' and `queue' respectively, so as + * to distinguish them reasonably easily. + * + * The functions send_noqueue() and defer_noqueue() free the packet + * structure they are passed. Every outgoing packet goes through + * precisely one of these functions in its life; packets passed to + * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of + * these or get queued, and then when the queue is later emptied + * the packets are all passed to defer_noqueue(). + * + * When using a CBC-mode cipher, it's necessary to ensure that an + * attacker can't provide data to be encrypted using an IV that they + * know. We ensure this by prefixing each packet that might contain + * user data with an SSH_MSG_IGNORE. This is done using the deferral + * mechanism, so in this case send_noqueue() ends up redirecting to + * defer_noqueue(). If you don't like this inefficiency, don't use + * CBC. + */ + +static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int); +static void ssh_pkt_defersend(Ssh); + +/* + * Send an SSH-2 packet immediately, without queuing or deferring. + */ +static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt) +{ + int len; + int backlog; + if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) { + /* We need to send two packets, so use the deferral mechanism. */ + ssh2_pkt_defer_noqueue(ssh, pkt, FALSE); + ssh_pkt_defersend(ssh); + return; + } + len = ssh2_pkt_construct(ssh, pkt); + backlog = s_write(ssh, pkt->body, len); + if (backlog > SSH_MAX_BACKLOG) + ssh_throttle_all(ssh, 1, backlog); + + ssh->outgoing_data_size += pkt->encrypted_len; + if (!ssh->kex_in_progress && + !ssh->bare_connection && + ssh->max_data_size != 0 && + ssh->outgoing_data_size > ssh->max_data_size) + do_ssh2_transport(ssh, "too much data sent", -1, NULL); + + ssh_free_packet(pkt); +} + +/* + * Defer an SSH-2 packet. + */ +static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore) +{ + int len; + if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) && + ssh->deferred_len == 0 && !noignore && + !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { + /* + * Interpose an SSH_MSG_IGNORE to ensure that user data don't + * get encrypted with a known IV. + */ + struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE); + ssh2_pkt_addstring_start(ipkt); + ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE); + } + len = ssh2_pkt_construct(ssh, pkt); + if (ssh->deferred_len + len > ssh->deferred_size) { + ssh->deferred_size = ssh->deferred_len + len + 128; + ssh->deferred_send_data = sresize(ssh->deferred_send_data, + ssh->deferred_size, + unsigned char); + } + memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len); + ssh->deferred_len += len; + ssh->deferred_data_size += pkt->encrypted_len; + ssh_free_packet(pkt); +} + +/* + * Queue an SSH-2 packet. + */ +static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt) +{ + assert(ssh->queueing); + + if (ssh->queuelen >= ssh->queuesize) { + ssh->queuesize = ssh->queuelen + 32; + ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *); + } + + ssh->queue[ssh->queuelen++] = pkt; +} + +/* + * Either queue or send a packet, depending on whether queueing is + * set. + */ +static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt) +{ + if (ssh->queueing) + ssh2_pkt_queue(ssh, pkt); + else + ssh2_pkt_send_noqueue(ssh, pkt); +} + +/* + * Either queue or defer a packet, depending on whether queueing is + * set. + */ +static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt) +{ + if (ssh->queueing) + ssh2_pkt_queue(ssh, pkt); + else + ssh2_pkt_defer_noqueue(ssh, pkt, FALSE); +} + +/* + * Send the whole deferred data block constructed by + * ssh2_pkt_defer() or SSH-1's defer_packet(). + * + * The expected use of the defer mechanism is that you call + * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If + * not currently queueing, this simply sets up deferred_send_data + * and then sends it. If we _are_ currently queueing, the calls to + * ssh2_pkt_defer() put the deferred packets on to the queue + * instead, and therefore ssh_pkt_defersend() has no deferred data + * to send. Hence, there's no need to make it conditional on + * ssh->queueing. + */ +static void ssh_pkt_defersend(Ssh ssh) +{ + int backlog; + backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len); + ssh->deferred_len = ssh->deferred_size = 0; + sfree(ssh->deferred_send_data); + ssh->deferred_send_data = NULL; + if (backlog > SSH_MAX_BACKLOG) + ssh_throttle_all(ssh, 1, backlog); + + ssh->outgoing_data_size += ssh->deferred_data_size; + if (!ssh->kex_in_progress && + !ssh->bare_connection && + ssh->max_data_size != 0 && + ssh->outgoing_data_size > ssh->max_data_size) + do_ssh2_transport(ssh, "too much data sent", -1, NULL); + ssh->deferred_data_size = 0; +} + +/* + * Send a packet whose length needs to be disguised (typically + * passwords or keyboard-interactive responses). + */ +static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt, + int padsize) +{ +#if 0 + if (0) { + /* + * The simplest way to do this is to adjust the + * variable-length padding field in the outgoing packet. + * + * Currently compiled out, because some Cisco SSH servers + * don't like excessively padded packets (bah, why's it + * always Cisco?) + */ + pkt->forcepad = padsize; + ssh2_pkt_send(ssh, pkt); + } else +#endif + { + /* + * If we can't do that, however, an alternative approach is + * to use the pkt_defer mechanism to bundle the packet + * tightly together with an SSH_MSG_IGNORE such that their + * combined length is a constant. So first we construct the + * final form of this packet and defer its sending. + */ + ssh2_pkt_defer(ssh, pkt); + + /* + * Now construct an SSH_MSG_IGNORE which includes a string + * that's an exact multiple of the cipher block size. (If + * the cipher is NULL so that the block size is + * unavailable, we don't do this trick at all, because we + * gain nothing by it.) + */ + if (ssh->cscipher && + !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { + int stringlen, i; + + stringlen = (256 - ssh->deferred_len); + stringlen += ssh->cscipher->blksize - 1; + stringlen -= (stringlen % ssh->cscipher->blksize); + if (ssh->cscomp) { + /* + * Temporarily disable actual compression, so we + * can guarantee to get this string exactly the + * length we want it. The compression-disabling + * routine should return an integer indicating how + * many bytes we should adjust our string length + * by. + */ + stringlen -= + ssh->cscomp->disable_compression(ssh->cs_comp_ctx); + } + pkt = ssh2_pkt_init(SSH2_MSG_IGNORE); + ssh2_pkt_addstring_start(pkt); + for (i = 0; i < stringlen; i++) { + char c = (char) random_byte(); + ssh2_pkt_addstring_data(pkt, &c, 1); + } + ssh2_pkt_defer(ssh, pkt); + } + ssh_pkt_defersend(ssh); + } +} + +/* + * Send all queued SSH-2 packets. We send them by means of + * ssh2_pkt_defer_noqueue(), in case they included a pair of + * packets that needed to be lumped together. + */ +static void ssh2_pkt_queuesend(Ssh ssh) +{ + int i; + + assert(!ssh->queueing); + + for (i = 0; i < ssh->queuelen; i++) + ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE); + ssh->queuelen = 0; + + ssh_pkt_defersend(ssh); +} + +#if 0 +void bndebug(char *string, Bignum b) +{ + unsigned char *p; + int i, len; + p = ssh2_mpint_fmt(b, &len); + debug(("%s", string)); + for (i = 0; i < len; i++) + debug((" %02x", p[i])); + debug(("\n")); + sfree(p); +} +#endif + +static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b) +{ + unsigned char *p; + int len; + p = ssh2_mpint_fmt(b, &len); + hash_string(h, s, p, len); + sfree(p); +} + +/* + * Packet decode functions for both SSH-1 and SSH-2. + */ +static unsigned long ssh_pkt_getuint32(struct Packet *pkt) +{ + unsigned long value; + if (pkt->length - pkt->savedpos < 4) + return 0; /* arrgh, no way to decline (FIXME?) */ + value = GET_32BIT(pkt->body + pkt->savedpos); + pkt->savedpos += 4; + return value; +} +static int ssh2_pkt_getbool(struct Packet *pkt) +{ + unsigned long value; + if (pkt->length - pkt->savedpos < 1) + return 0; /* arrgh, no way to decline (FIXME?) */ + value = pkt->body[pkt->savedpos] != 0; + pkt->savedpos++; + return value; +} +static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length) +{ + int len; + *p = NULL; + *length = 0; + if (pkt->length - pkt->savedpos < 4) + return; + len = toint(GET_32BIT(pkt->body + pkt->savedpos)); + if (len < 0) + return; + *length = len; + pkt->savedpos += 4; + if (pkt->length - pkt->savedpos < *length) + return; + *p = (char *)(pkt->body + pkt->savedpos); + pkt->savedpos += *length; +} +static void *ssh_pkt_getdata(struct Packet *pkt, int length) +{ + if (pkt->length - pkt->savedpos < length) + return NULL; + pkt->savedpos += length; + return pkt->body + (pkt->savedpos - length); +} +static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key, + unsigned char **keystr) +{ + int j; + + j = makekey(pkt->body + pkt->savedpos, + pkt->length - pkt->savedpos, + key, keystr, 0); + + if (j < 0) + return FALSE; + + pkt->savedpos += j; + assert(pkt->savedpos < pkt->length); + + return TRUE; +} +static Bignum ssh1_pkt_getmp(struct Packet *pkt) +{ + int j; + Bignum b; + + j = ssh1_read_bignum(pkt->body + pkt->savedpos, + pkt->length - pkt->savedpos, &b); + + if (j < 0) + return NULL; + + pkt->savedpos += j; + return b; +} +static Bignum ssh2_pkt_getmp(struct Packet *pkt) +{ + char *p; + int length; + Bignum b; + + ssh_pkt_getstring(pkt, &p, &length); + if (!p) + return NULL; + if (p[0] & 0x80) + return NULL; + b = bignum_from_bytes((unsigned char *)p, length); + return b; +} + +/* + * Helper function to add an SSH-2 signature blob to a packet. + * Expects to be shown the public key blob as well as the signature + * blob. Normally works just like ssh2_pkt_addstring, but will + * fiddle with the signature packet if necessary for + * BUG_SSH2_RSA_PADDING. + */ +static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt, + void *pkblob_v, int pkblob_len, + void *sigblob_v, int sigblob_len) +{ + unsigned char *pkblob = (unsigned char *)pkblob_v; + unsigned char *sigblob = (unsigned char *)sigblob_v; + + /* dmemdump(pkblob, pkblob_len); */ + /* dmemdump(sigblob, sigblob_len); */ + + /* + * See if this is in fact an ssh-rsa signature and a buggy + * server; otherwise we can just do this the easy way. + */ + if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 && + (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) { + int pos, len, siglen; + + /* + * Find the byte length of the modulus. + */ + + pos = 4+7; /* skip over "ssh-rsa" */ + len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */ + if (len < 0 || len > pkblob_len - pos - 4) + goto give_up; + pos += 4 + len; /* skip over exponent */ + if (pkblob_len - pos < 4) + goto give_up; + len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */ + if (len < 0 || len > pkblob_len - pos - 4) + goto give_up; + pos += 4; /* find modulus itself */ + while (len > 0 && pkblob[pos] == 0) + len--, pos++; + /* debug(("modulus length is %d\n", len)); */ + + /* + * Now find the signature integer. + */ + pos = 4+7; /* skip over "ssh-rsa" */ + if (sigblob_len < pos+4) + goto give_up; + siglen = toint(GET_32BIT(sigblob+pos)); + if (siglen != sigblob_len - pos - 4) + goto give_up; + /* debug(("signature length is %d\n", siglen)); */ + + if (len != siglen) { + unsigned char newlen[4]; + ssh2_pkt_addstring_start(pkt); + ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos); + /* dmemdump(sigblob, pos); */ + pos += 4; /* point to start of actual sig */ + PUT_32BIT(newlen, len); + ssh2_pkt_addstring_data(pkt, (char *)newlen, 4); + /* dmemdump(newlen, 4); */ + newlen[0] = 0; + while (len-- > siglen) { + ssh2_pkt_addstring_data(pkt, (char *)newlen, 1); + /* dmemdump(newlen, 1); */ + } + ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen); + /* dmemdump(sigblob+pos, siglen); */ + return; + } + + /* Otherwise fall through and do it the easy way. We also come + * here as a fallback if we discover above that the key blob + * is misformatted in some way. */ + give_up:; + } + + ssh2_pkt_addstring_start(pkt); + ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len); +} + +/* + * Examine the remote side's version string and compare it against + * a list of known buggy implementations. + */ +static void ssh_detect_bugs(Ssh ssh, char *vstring) +{ + char *imp; /* pointer to implementation part */ + imp = vstring; + imp += strcspn(imp, "-"); + if (*imp) imp++; + imp += strcspn(imp, "-"); + if (*imp) imp++; + + ssh->remote_bugs = 0; + + /* + * General notes on server version strings: + * - Not all servers reporting "Cisco-1.25" have all the bugs listed + * here -- in particular, we've heard of one that's perfectly happy + * with SSH1_MSG_IGNOREs -- but this string never seems to change, + * so we can't distinguish them. + */ + if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO && + (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") || + !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") || + !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") || + !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) { + /* + * These versions don't support SSH1_MSG_IGNORE, so we have + * to use a different defence against password length + * sniffing. + */ + ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE; + logevent("We believe remote version has SSH-1 ignore bug"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO && + (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) { + /* + * These versions need a plain password sent; they can't + * handle having a null and a random length of data after + * the password. + */ + ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD; + logevent("We believe remote version needs a plain SSH-1 password"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO && + (!strcmp(imp, "Cisco-1.25")))) { + /* + * These versions apparently have no clue whatever about + * RSA authentication and will panic and die if they see + * an AUTH_RSA message. + */ + ssh->remote_bugs |= BUG_CHOKES_ON_RSA; + logevent("We believe remote version can't handle SSH-1 RSA authentication"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO && + !wc_match("* VShell", imp) && + (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) || + wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) || + wc_match("2.1 *", imp)))) { + /* + * These versions have the HMAC bug. + */ + ssh->remote_bugs |= BUG_SSH2_HMAC; + logevent("We believe remote version has SSH-2 HMAC bug"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO && + !wc_match("* VShell", imp) && + (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) { + /* + * These versions have the key-derivation bug (failing to + * include the literal shared secret in the hashes that + * generate the keys). + */ + ssh->remote_bugs |= BUG_SSH2_DERIVEKEY; + logevent("We believe remote version has SSH-2 key-derivation bug"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO && + (wc_match("OpenSSH_2.[5-9]*", imp) || + wc_match("OpenSSH_3.[0-2]*", imp) || + wc_match("mod_sftp/0.[0-8]*", imp) || + wc_match("mod_sftp/0.9.[0-8]", imp)))) { + /* + * These versions have the SSH-2 RSA padding bug. + */ + ssh->remote_bugs |= BUG_SSH2_RSA_PADDING; + logevent("We believe remote version has SSH-2 RSA padding bug"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO && + wc_match("OpenSSH_2.[0-2]*", imp))) { + /* + * These versions have the SSH-2 session-ID bug in + * public-key authentication. + */ + ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID; + logevent("We believe remote version has SSH-2 public-key-session-ID bug"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO && + (wc_match("DigiSSH_2.0", imp) || + wc_match("OpenSSH_2.[0-4]*", imp) || + wc_match("OpenSSH_2.5.[0-3]*", imp) || + wc_match("Sun_SSH_1.0", imp) || + wc_match("Sun_SSH_1.0.1", imp) || + /* All versions <= 1.2.6 (they changed their format in 1.2.7) */ + wc_match("WeOnlyDo-*", imp)))) { + /* + * These versions have the SSH-2 rekey bug. + */ + ssh->remote_bugs |= BUG_SSH2_REKEY; + logevent("We believe remote version has SSH-2 rekey bug"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO && + (wc_match("1.36_sshlib GlobalSCAPE", imp) || + wc_match("1.36 sshlib: GlobalScape", imp)))) { + /* + * This version ignores our makpkt and needs to be throttled. + */ + ssh->remote_bugs |= BUG_SSH2_MAXPKT; + logevent("We believe remote version ignores SSH-2 maximum packet size"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) { + /* + * Servers that don't support SSH2_MSG_IGNORE. Currently, + * none detected automatically. + */ + ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE; + logevent("We believe remote version has SSH-2 ignore bug"); + } + + if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) { + /* + * Servers that don't support our winadj request for one + * reason or another. Currently, none detected automatically. + */ + ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ; + logevent("We believe remote version has winadj bug"); + } +} + +/* + * The `software version' part of an SSH version string is required + * to contain no spaces or minus signs. + */ +static void ssh_fix_verstring(char *str) +{ + /* Eat "<protoversion>-". */ + while (*str && *str != '-') str++; + assert(*str == '-'); str++; + + /* Convert minus signs and spaces in the remaining string into + * underscores. */ + while (*str) { + if (*str == '-' || *str == ' ') + *str = '_'; + str++; + } +} + +/* + * Send an appropriate SSH version string. + */ +static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers) +{ + char *verstring; + + if (ssh->version == 2) { + /* + * Construct a v2 version string. + */ + verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver); + } else { + /* + * Construct a v1 version string. + */ + assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */ + verstring = dupprintf("SSH-%s-%s\012", + (ssh_versioncmp(svers, "1.5") <= 0 ? + svers : "1.5"), + sshver); + } + + ssh_fix_verstring(verstring + strlen(protoname)); + + if (ssh->version == 2) { + size_t len; + /* + * Record our version string. + */ + len = strcspn(verstring, "\015\012"); + ssh->v_c = snewn(len + 1, char); + memcpy(ssh->v_c, verstring, len); + ssh->v_c[len] = 0; + } + + logeventf(ssh, "We claim version: %.*s", + strcspn(verstring, "\015\012"), verstring); + s_write(ssh, verstring, strlen(verstring)); + sfree(verstring); +} + +static int do_ssh_init(Ssh ssh, unsigned char c) +{ + static const char protoname[] = "SSH-"; + + struct do_ssh_init_state { + int crLine; + int vslen; + char version[10]; + char *vstring; + int vstrsize; + int i; + int proto1, proto2; + }; + crState(do_ssh_init_state); + + crBeginState; + + /* Search for a line beginning with the protocol name prefix in + * the input. */ + for (;;) { + for (s->i = 0; protoname[s->i]; s->i++) { + if ((char)c != protoname[s->i]) goto no; + crReturn(1); + } + break; + no: + while (c != '\012') + crReturn(1); + crReturn(1); + } + + s->vstrsize = sizeof(protoname) + 16; + s->vstring = snewn(s->vstrsize, char); + strcpy(s->vstring, protoname); + s->vslen = strlen(protoname); + s->i = 0; + while (1) { + if (s->vslen >= s->vstrsize - 1) { + s->vstrsize += 16; + s->vstring = sresize(s->vstring, s->vstrsize, char); + } + s->vstring[s->vslen++] = c; + if (s->i >= 0) { + if (c == '-') { + s->version[s->i] = '\0'; + s->i = -1; + } else if (s->i < sizeof(s->version) - 1) + s->version[s->i++] = c; + } else if (c == '\012') + break; + crReturn(1); /* get another char */ + } + + ssh->agentfwd_enabled = FALSE; + ssh->rdpkt2_state.incoming_sequence = 0; + + s->vstring[s->vslen] = 0; + s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */ + logeventf(ssh, "Server version: %s", s->vstring); + ssh_detect_bugs(ssh, s->vstring); + + /* + * Decide which SSH protocol version to support. + */ + + /* Anything strictly below "2.0" means protocol 1 is supported. */ + s->proto1 = ssh_versioncmp(s->version, "2.0") < 0; + /* Anything greater or equal to "1.99" means protocol 2 is supported. */ + s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0; + + if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) { + bombout(("SSH protocol version 1 required by user but not provided by server")); + crStop(0); + } + if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) { + bombout(("SSH protocol version 2 required by user but not provided by server")); + crStop(0); + } + + if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1)) + ssh->version = 2; + else + ssh->version = 1; + + logeventf(ssh, "Using SSH protocol version %d", ssh->version); + + /* Send the version string, if we haven't already */ + if (conf_get_int(ssh->conf, CONF_sshprot) != 3) + ssh_send_verstring(ssh, protoname, s->version); + + if (ssh->version == 2) { + size_t len; + /* + * Record their version string. + */ + len = strcspn(s->vstring, "\015\012"); + ssh->v_s = snewn(len + 1, char); + memcpy(ssh->v_s, s->vstring, len); + ssh->v_s[len] = 0; + + /* + * Initialise SSH-2 protocol. + */ + ssh->protocol = ssh2_protocol; + ssh2_protocol_setup(ssh); + ssh->s_rdpkt = ssh2_rdpkt; + } else { + /* + * Initialise SSH-1 protocol. + */ + ssh->protocol = ssh1_protocol; + ssh1_protocol_setup(ssh); + ssh->s_rdpkt = ssh1_rdpkt; + } + if (ssh->version == 2) + do_ssh2_transport(ssh, NULL, -1, NULL); + + update_specials_menu(ssh->frontend); + ssh->state = SSH_STATE_BEFORE_SIZE; + ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh); + + sfree(s->vstring); + + crFinish(0); +} + +static int do_ssh_connection_init(Ssh ssh, unsigned char c) +{ + /* + * Ordinary SSH begins with the banner "SSH-x.y-...". This is just + * the ssh-connection part, extracted and given a trivial binary + * packet protocol, so we replace 'SSH-' at the start with a new + * name. In proper SSH style (though of course this part of the + * proper SSH protocol _isn't_ subject to this kind of + * DNS-domain-based extension), we define the new name in our + * extension space. + */ + static const char protoname[] = + "SSHCONNECTION@putty.projects.tartarus.org-"; + + struct do_ssh_connection_init_state { + int crLine; + int vslen; + char version[10]; + char *vstring; + int vstrsize; + int i; + }; + crState(do_ssh_connection_init_state); + + crBeginState; + + /* Search for a line beginning with the protocol name prefix in + * the input. */ + for (;;) { + for (s->i = 0; protoname[s->i]; s->i++) { + if ((char)c != protoname[s->i]) goto no; + crReturn(1); + } + break; + no: + while (c != '\012') + crReturn(1); + crReturn(1); + } + + s->vstrsize = sizeof(protoname) + 16; + s->vstring = snewn(s->vstrsize, char); + strcpy(s->vstring, protoname); + s->vslen = strlen(protoname); + s->i = 0; + while (1) { + if (s->vslen >= s->vstrsize - 1) { + s->vstrsize += 16; + s->vstring = sresize(s->vstring, s->vstrsize, char); + } + s->vstring[s->vslen++] = c; + if (s->i >= 0) { + if (c == '-') { + s->version[s->i] = '\0'; + s->i = -1; + } else if (s->i < sizeof(s->version) - 1) + s->version[s->i++] = c; + } else if (c == '\012') + break; + crReturn(1); /* get another char */ + } + + ssh->agentfwd_enabled = FALSE; + ssh->rdpkt2_bare_state.incoming_sequence = 0; + + s->vstring[s->vslen] = 0; + s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */ + logeventf(ssh, "Server version: %s", s->vstring); + ssh_detect_bugs(ssh, s->vstring); + + /* + * Decide which SSH protocol version to support. This is easy in + * bare ssh-connection mode: only 2.0 is legal. + */ + if (ssh_versioncmp(s->version, "2.0") < 0) { + bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol")); + crStop(0); + } + if (conf_get_int(ssh->conf, CONF_sshprot) == 0) { + bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode")); + crStop(0); + } + + ssh->version = 2; + + logeventf(ssh, "Using bare ssh-connection protocol"); + + /* Send the version string, if we haven't already */ + ssh_send_verstring(ssh, protoname, s->version); + + /* + * Initialise bare connection protocol. + */ + ssh->protocol = ssh2_bare_connection_protocol; + ssh2_bare_connection_protocol_setup(ssh); + ssh->s_rdpkt = ssh2_bare_connection_rdpkt; + + update_specials_menu(ssh->frontend); + ssh->state = SSH_STATE_BEFORE_SIZE; + ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh); + + /* + * Get authconn (really just conn) under way. + */ + do_ssh2_authconn(ssh, NULL, 0, NULL); + + sfree(s->vstring); + + crFinish(0); +} + +static void ssh_process_incoming_data(Ssh ssh, + unsigned char **data, int *datalen) +{ + struct Packet *pktin; + + pktin = ssh->s_rdpkt(ssh, data, datalen); + if (pktin) { + ssh->protocol(ssh, NULL, 0, pktin); + ssh_free_packet(pktin); + } +} + +static void ssh_queue_incoming_data(Ssh ssh, + unsigned char **data, int *datalen) +{ + bufchain_add(&ssh->queued_incoming_data, *data, *datalen); + *data += *datalen; + *datalen = 0; +} + +static void ssh_process_queued_incoming_data(Ssh ssh) +{ + void *vdata; + unsigned char *data; + int len, origlen; + + while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) { + bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len); + data = vdata; + origlen = len; + + while (!ssh->frozen && len > 0) + ssh_process_incoming_data(ssh, &data, &len); + + if (origlen > len) + bufchain_consume(&ssh->queued_incoming_data, origlen - len); + } +} + +static void ssh_set_frozen(Ssh ssh, int frozen) +{ + if (ssh->s) + sk_set_frozen(ssh->s, frozen); + ssh->frozen = frozen; +} + +static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) +{ + /* Log raw data, if we're in that mode. */ + if (ssh->logctx) + log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen, + 0, NULL, NULL, 0, NULL); + + crBegin(ssh->ssh_gotdata_crstate); + + /* + * To begin with, feed the characters one by one to the + * protocol initialisation / selection function do_ssh_init(). + * When that returns 0, we're done with the initial greeting + * exchange and can move on to packet discipline. + */ + while (1) { + int ret; /* need not be kept across crReturn */ + if (datalen == 0) + crReturnV; /* more data please */ + ret = ssh->do_ssh_init(ssh, *data); + data++; + datalen--; + if (ret == 0) + break; + } + + /* + * We emerge from that loop when the initial negotiation is + * over and we have selected an s_rdpkt function. Now pass + * everything to s_rdpkt, and then pass the resulting packets + * to the proper protocol handler. + */ + + while (1) { + while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) { + if (ssh->frozen) { + ssh_queue_incoming_data(ssh, &data, &datalen); + /* This uses up all data and cannot cause anything interesting + * to happen; indeed, for anything to happen at all, we must + * return, so break out. */ + break; + } else if (bufchain_size(&ssh->queued_incoming_data) > 0) { + /* This uses up some or all data, and may freeze the + * session. */ + ssh_process_queued_incoming_data(ssh); + } else { + /* This uses up some or all data, and may freeze the + * session. */ + ssh_process_incoming_data(ssh, &data, &datalen); + } + /* FIXME this is probably EBW. */ + if (ssh->state == SSH_STATE_CLOSED) + return; + } + /* We're out of data. Go and get some more. */ + crReturnV; + } + crFinishV; +} + +static int ssh_do_close(Ssh ssh, int notify_exit) +{ + int ret = 0; + struct ssh_channel *c; + + ssh->state = SSH_STATE_CLOSED; + expire_timer_context(ssh); + if (ssh->s) { + sk_close(ssh->s); + ssh->s = NULL; + if (notify_exit) + notify_remote_exit(ssh->frontend); + else + ret = 1; + } + /* + * Now we must shut down any port- and X-forwarded channels going + * through this connection. + */ + if (ssh->channels) { + while (NULL != (c = index234(ssh->channels, 0))) { + switch (c->type) { + case CHAN_X11: + x11_close(c->u.x11.xconn); + break; + case CHAN_SOCKDATA: + case CHAN_SOCKDATA_DORMANT: + pfd_close(c->u.pfd.pf); + break; + } + del234(ssh->channels, c); /* moving next one to index 0 */ + if (ssh->version == 2) + bufchain_clear(&c->v.v2.outbuffer); + sfree(c); + } + } + /* + * Go through port-forwardings, and close any associated + * listening sockets. + */ + if (ssh->portfwds) { + struct ssh_portfwd *pf; + while (NULL != (pf = index234(ssh->portfwds, 0))) { + /* Dispose of any listening socket. */ + if (pf->local) + pfl_terminate(pf->local); + del234(ssh->portfwds, pf); /* moving next one to index 0 */ + free_portfwd(pf); + } + freetree234(ssh->portfwds); + ssh->portfwds = NULL; + } + + return ret; +} + +static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port, + const char *error_msg, int error_code) +{ + Ssh ssh = (Ssh) plug; + char addrbuf[256], *msg; + + if (ssh->attempting_connshare) { + /* + * While we're attempting connection sharing, don't loudly log + * everything that happens. Real TCP connections need to be + * logged when we _start_ trying to connect, because it might + * be ages before they respond if something goes wrong; but + * connection sharing is local and quick to respond, and it's + * sufficient to simply wait and see whether it worked + * afterwards. + */ + } else { + sk_getaddr(addr, addrbuf, lenof(addrbuf)); + + if (type == 0) { + if (sk_addr_needs_port(addr)) { + msg = dupprintf("Connecting to %s port %d", addrbuf, port); + } else { + msg = dupprintf("Connecting to %s", addrbuf); + } + } else { + msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg); + } + + logevent(msg); + sfree(msg); + } +} + +void ssh_connshare_log(Ssh ssh, int event, const char *logtext, + const char *ds_err, const char *us_err) +{ + if (event == SHARE_NONE) { + /* In this case, 'logtext' is an error message indicating a + * reason why connection sharing couldn't be set up _at all_. + * Failing that, ds_err and us_err indicate why we couldn't be + * a downstream and an upstream respectively. */ + if (logtext) { + logeventf(ssh, "Could not set up connection sharing: %s", logtext); + } else { + if (ds_err) + logeventf(ssh, "Could not set up connection sharing" + " as downstream: %s", ds_err); + if (us_err) + logeventf(ssh, "Could not set up connection sharing" + " as upstream: %s", us_err); + } + } else if (event == SHARE_DOWNSTREAM) { + /* In this case, 'logtext' is a local endpoint address */ + logeventf(ssh, "Using existing shared connection at %s", logtext); + /* Also we should mention this in the console window to avoid + * confusing users as to why this window doesn't behave the + * usual way. */ + if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { + c_write_str(ssh,"Reusing a shared connection to this server.\r\n"); + } + } else if (event == SHARE_UPSTREAM) { + /* In this case, 'logtext' is a local endpoint address too */ + logeventf(ssh, "Sharing this connection at %s", logtext); + } +} + +static int ssh_closing(Plug plug, const char *error_msg, int error_code, + int calling_back) +{ + Ssh ssh = (Ssh) plug; + int need_notify = ssh_do_close(ssh, FALSE); + + if (!error_msg) { + if (!ssh->close_expected) + error_msg = "Server unexpectedly closed network connection"; + else + error_msg = "Server closed network connection"; + } + + if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0) + ssh->exitcode = 0; + + if (need_notify) + notify_remote_exit(ssh->frontend); + + if (error_msg) + logevent(error_msg); + if (!ssh->close_expected || !ssh->clean_exit) + connection_fatal(ssh->frontend, "%s", error_msg); + return 0; +} + +static int ssh_receive(Plug plug, int urgent, char *data, int len) +{ + Ssh ssh = (Ssh) plug; + ssh_gotdata(ssh, (unsigned char *)data, len); + if (ssh->state == SSH_STATE_CLOSED) { + ssh_do_close(ssh, TRUE); + return 0; + } + return 1; +} + +static void ssh_sent(Plug plug, int bufsize) +{ + Ssh ssh = (Ssh) plug; + /* + * If the send backlog on the SSH socket itself clears, we + * should unthrottle the whole world if it was throttled. + */ + if (bufsize < SSH_MAX_BACKLOG) + ssh_throttle_all(ssh, 0, bufsize); +} + +/* + * Connect to specified host and port. + * Returns an error message, or NULL on success. + * Also places the canonical host name into `realhost'. It must be + * freed by the caller. + */ +static const char *connect_to_host(Ssh ssh, char *host, int port, + char **realhost, int nodelay, int keepalive) +{ + static const struct plug_function_table fn_table = { + ssh_socket_log, + ssh_closing, + ssh_receive, + ssh_sent, + NULL + }; + + SockAddr addr; + const char *err; + char *loghost; + int addressfamily, sshprot; + + loghost = conf_get_str(ssh->conf, CONF_loghost); + if (*loghost) { + char *tmphost; + char *colon; + + tmphost = dupstr(loghost); + ssh->savedport = 22; /* default ssh port */ + + /* + * A colon suffix on the hostname string also lets us affect + * savedport. (Unless there are multiple colons, in which case + * we assume this is an unbracketed IPv6 literal.) + */ + colon = host_strrchr(tmphost, ':'); + if (colon && colon == host_strchr(tmphost, ':')) { + *colon++ = '\0'; + if (*colon) + ssh->savedport = atoi(colon); + } + + ssh->savedhost = host_strduptrim(tmphost); + sfree(tmphost); + } else { + ssh->savedhost = host_strduptrim(host); + if (port < 0) + port = 22; /* default ssh port */ + ssh->savedport = port; + } + + ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */ + + /* + * Try connection-sharing, in case that means we don't open a + * socket after all. ssh_connection_sharing_init will connect to a + * previously established upstream if it can, and failing that, + * establish a listening socket for _us_ to be the upstream. In + * the latter case it will return NULL just as if it had done + * nothing, because here we only need to care if we're a + * downstream and need to do our connection setup differently. + */ + ssh->connshare = NULL; + ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */ + ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport, + ssh->conf, ssh, &ssh->connshare); + ssh->attempting_connshare = FALSE; + if (ssh->s != NULL) { + /* + * We are a downstream. + */ + ssh->bare_connection = TRUE; + ssh->do_ssh_init = do_ssh_connection_init; + ssh->fullhostname = NULL; + *realhost = dupstr(host); /* best we can do */ + } else { + /* + * We're not a downstream, so open a normal socket. + */ + ssh->do_ssh_init = do_ssh_init; + + /* + * Try to find host. + */ + addressfamily = conf_get_int(ssh->conf, CONF_addressfamily); + logeventf(ssh, "Looking up host \"%s\"%s", host, + (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" : + (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : ""))); + addr = name_lookup(host, port, realhost, ssh->conf, addressfamily); + if ((err = sk_addr_error(addr)) != NULL) { + sk_addr_free(addr); + return err; + } + ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */ + + ssh->s = new_connection(addr, *realhost, port, + 0, 1, nodelay, keepalive, + (Plug) ssh, ssh->conf); + if ((err = sk_socket_error(ssh->s)) != NULL) { + ssh->s = NULL; + notify_remote_exit(ssh->frontend); + return err; + } + } + + /* + * If the SSH version number's fixed, set it now, and if it's SSH-2, + * send the version string too. + */ + sshprot = conf_get_int(ssh->conf, CONF_sshprot); + if (sshprot == 0) + ssh->version = 1; + if (sshprot == 3 && !ssh->bare_connection) { + ssh->version = 2; + ssh_send_verstring(ssh, "SSH-", NULL); + } + + /* + * loghost, if configured, overrides realhost. + */ + if (*loghost) { + sfree(*realhost); + *realhost = dupstr(loghost); + } + + return NULL; +} + +/* + * Throttle or unthrottle the SSH connection. + */ +static void ssh_throttle_conn(Ssh ssh, int adjust) +{ + int old_count = ssh->conn_throttle_count; + ssh->conn_throttle_count += adjust; + assert(ssh->conn_throttle_count >= 0); + if (ssh->conn_throttle_count && !old_count) { + ssh_set_frozen(ssh, 1); + } else if (!ssh->conn_throttle_count && old_count) { + ssh_set_frozen(ssh, 0); + } +} + +/* + * Throttle or unthrottle _all_ local data streams (for when sends + * on the SSH connection itself back up). + */ +static void ssh_throttle_all(Ssh ssh, int enable, int bufsize) +{ + int i; + struct ssh_channel *c; + + if (enable == ssh->throttled_all) + return; + ssh->throttled_all = enable; + ssh->overall_bufsize = bufsize; + if (!ssh->channels) + return; + for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) { + switch (c->type) { + case CHAN_MAINSESSION: + /* + * This is treated separately, outside the switch. + */ + break; + case CHAN_X11: + x11_override_throttle(c->u.x11.xconn, enable); + break; + case CHAN_AGENT: + /* Agent channels require no buffer management. */ + break; + case CHAN_SOCKDATA: + pfd_override_throttle(c->u.pfd.pf, enable); + break; + } + } +} + +static void ssh_agent_callback(void *sshv, void *reply, int replylen) +{ + Ssh ssh = (Ssh) sshv; + + ssh->agent_response = reply; + ssh->agent_response_len = replylen; + + if (ssh->version == 1) + do_ssh1_login(ssh, NULL, -1, NULL); + else + do_ssh2_authconn(ssh, NULL, -1, NULL); +} + +static void ssh_dialog_callback(void *sshv, int ret) +{ + Ssh ssh = (Ssh) sshv; + + ssh->user_response = ret; + + if (ssh->version == 1) + do_ssh1_login(ssh, NULL, -1, NULL); + else + do_ssh2_transport(ssh, NULL, -1, NULL); + + /* + * This may have unfrozen the SSH connection, so do a + * queued-data run. + */ + ssh_process_queued_incoming_data(ssh); +} + +static void ssh_agentf_callback(void *cv, void *reply, int replylen) +{ + struct ssh_channel *c = (struct ssh_channel *)cv; + Ssh ssh = c->ssh; + void *sentreply = reply; + + c->u.a.outstanding_requests--; + if (!sentreply) { + /* Fake SSH_AGENT_FAILURE. */ + sentreply = "\0\0\0\1\5"; + replylen = 5; + } + if (ssh->version == 2) { + ssh2_add_channel_data(c, sentreply, replylen); + ssh2_try_send(c); + } else { + send_packet(ssh, SSH1_MSG_CHANNEL_DATA, + PKT_INT, c->remoteid, + PKT_INT, replylen, + PKT_DATA, sentreply, replylen, + PKT_END); + } + if (reply) + sfree(reply); + /* + * If we've already seen an incoming EOF but haven't sent an + * outgoing one, this may be the moment to send it. + */ + if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF)) + sshfwd_write_eof(c); +} + +/* + * Client-initiated disconnection. Send a DISCONNECT if `wire_reason' + * non-NULL, otherwise just close the connection. `client_reason' == NULL + * => log `wire_reason'. + */ +static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason, + int code, int clean_exit) +{ + char *error; + if (!client_reason) + client_reason = wire_reason; + if (client_reason) + error = dupprintf("Disconnected: %s", client_reason); + else + error = dupstr("Disconnected"); + if (wire_reason) { + if (ssh->version == 1) { + send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason, + PKT_END); + } else if (ssh->version == 2) { + struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT); + ssh2_pkt_adduint32(pktout, code); + ssh2_pkt_addstring(pktout, wire_reason); + ssh2_pkt_addstring(pktout, "en"); /* language tag */ + ssh2_pkt_send_noqueue(ssh, pktout); + } + } + ssh->close_expected = TRUE; + ssh->clean_exit = clean_exit; + ssh_closing((Plug)ssh, error, 0, 0); + sfree(error); +} + +/* + * Handle the key exchange and user authentication phases. + */ +static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, + struct Packet *pktin) +{ + int i, j, ret; + unsigned char cookie[8], *ptr; + struct MD5Context md5c; + struct do_ssh1_login_state { + int crLine; + int len; + unsigned char *rsabuf, *keystr1, *keystr2; + unsigned long supported_ciphers_mask, supported_auths_mask; + int tried_publickey, tried_agent; + int tis_auth_refused, ccard_auth_refused; + unsigned char session_id[16]; + int cipher_type; + void *publickey_blob; + int publickey_bloblen; + char *publickey_comment; + int publickey_encrypted; + prompts_t *cur_prompt; + char c; + int pwpkt_type; + unsigned char request[5], *response, *p; + int responselen; + int keyi, nkeys; + int authed; + struct RSAKey key; + Bignum challenge; + char *commentp; + int commentlen; + int dlgret; + Filename *keyfile; + struct RSAKey servkey, hostkey; + }; + crState(do_ssh1_login_state); + + crBeginState; + + if (!pktin) + crWaitUntil(pktin); + + if (pktin->type != SSH1_SMSG_PUBLIC_KEY) { + bombout(("Public key packet not received")); + crStop(0); + } + + logevent("Received public keys"); + + ptr = ssh_pkt_getdata(pktin, 8); + if (!ptr) { + bombout(("SSH-1 public key packet stopped before random cookie")); + crStop(0); + } + memcpy(cookie, ptr, 8); + + if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) || + !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) { + bombout(("Failed to read SSH-1 public keys from public key packet")); + crStop(0); + } + + /* + * Log the host key fingerprint. + */ + { + char logmsg[80]; + logevent("Host key fingerprint is:"); + strcpy(logmsg, " "); + s->hostkey.comment = NULL; + rsa_fingerprint(logmsg + strlen(logmsg), + sizeof(logmsg) - strlen(logmsg), &s->hostkey); + logevent(logmsg); + } + + ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin); + s->supported_ciphers_mask = ssh_pkt_getuint32(pktin); + s->supported_auths_mask = ssh_pkt_getuint32(pktin); + if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) + s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA); + + ssh->v1_local_protoflags = + ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED; + ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER; + + MD5Init(&md5c); + MD5Update(&md5c, s->keystr2, s->hostkey.bytes); + MD5Update(&md5c, s->keystr1, s->servkey.bytes); + MD5Update(&md5c, cookie, 8); + MD5Final(s->session_id, &md5c); + + for (i = 0; i < 32; i++) + ssh->session_key[i] = random_byte(); + + /* + * Verify that the `bits' and `bytes' parameters match. + */ + if (s->hostkey.bits > s->hostkey.bytes * 8 || + s->servkey.bits > s->servkey.bytes * 8) { + bombout(("SSH-1 public keys were badly formatted")); + crStop(0); + } + + s->len = (s->hostkey.bytes > s->servkey.bytes ? + s->hostkey.bytes : s->servkey.bytes); + + s->rsabuf = snewn(s->len, unsigned char); + + /* + * Verify the host key. + */ + { + /* + * First format the key into a string. + */ + int len = rsastr_len(&s->hostkey); + char fingerprint[100]; + char *keystr = snewn(len, char); + rsastr_fmt(keystr, &s->hostkey); + rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey); + + ssh_set_frozen(ssh, 1); + s->dlgret = verify_ssh_host_key(ssh->frontend, + ssh->savedhost, ssh->savedport, + "rsa", keystr, fingerprint, + ssh_dialog_callback, ssh); + sfree(keystr); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while waiting" + " for user host key response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at host key verification", + NULL, 0, TRUE); + crStop(0); + } + } + + for (i = 0; i < 32; i++) { + s->rsabuf[i] = ssh->session_key[i]; + if (i < 16) + s->rsabuf[i] ^= s->session_id[i]; + } + + if (s->hostkey.bytes > s->servkey.bytes) { + ret = rsaencrypt(s->rsabuf, 32, &s->servkey); + if (ret) + ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey); + } else { + ret = rsaencrypt(s->rsabuf, 32, &s->hostkey); + if (ret) + ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey); + } + if (!ret) { + bombout(("SSH-1 public key encryptions failed due to bad formatting")); + crStop(0); + } + + logevent("Encrypted session key"); + + { + int cipher_chosen = 0, warn = 0; + char *cipher_string = NULL; + int i; + for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) { + int next_cipher = conf_get_int_int(ssh->conf, + CONF_ssh_cipherlist, i); + if (next_cipher == CIPHER_WARN) { + /* If/when we choose a cipher, warn about it */ + warn = 1; + } else if (next_cipher == CIPHER_AES) { + /* XXX Probably don't need to mention this. */ + logevent("AES not supported in SSH-1, skipping"); + } else { + switch (next_cipher) { + case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES; + cipher_string = "3DES"; break; + case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH; + cipher_string = "Blowfish"; break; + case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES; + cipher_string = "single-DES"; break; + } + if (s->supported_ciphers_mask & (1 << s->cipher_type)) + cipher_chosen = 1; + } + } + if (!cipher_chosen) { + if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0) + bombout(("Server violates SSH-1 protocol by not " + "supporting 3DES encryption")); + else + /* shouldn't happen */ + bombout(("No supported ciphers found")); + crStop(0); + } + + /* Warn about chosen cipher if necessary. */ + if (warn) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, "cipher", cipher_string, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while waiting" + " for user response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at cipher warning", NULL, + 0, TRUE); + crStop(0); + } + } + } + + switch (s->cipher_type) { + case SSH_CIPHER_3DES: + logevent("Using 3DES encryption"); + break; + case SSH_CIPHER_DES: + logevent("Using single-DES encryption"); + break; + case SSH_CIPHER_BLOWFISH: + logevent("Using Blowfish encryption"); + break; + } + + send_packet(ssh, SSH1_CMSG_SESSION_KEY, + PKT_CHAR, s->cipher_type, + PKT_DATA, cookie, 8, + PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF, + PKT_DATA, s->rsabuf, s->len, + PKT_INT, ssh->v1_local_protoflags, PKT_END); + + logevent("Trying to enable encryption..."); + + sfree(s->rsabuf); + + ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 : + s->cipher_type == SSH_CIPHER_DES ? &ssh_des : + &ssh_3des); + ssh->v1_cipher_ctx = ssh->cipher->make_context(); + ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key); + logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name); + + ssh->crcda_ctx = crcda_make_context(); + logevent("Installing CRC compensation attack detector"); + + if (s->servkey.modulus) { + sfree(s->servkey.modulus); + s->servkey.modulus = NULL; + } + if (s->servkey.exponent) { + sfree(s->servkey.exponent); + s->servkey.exponent = NULL; + } + if (s->hostkey.modulus) { + sfree(s->hostkey.modulus); + s->hostkey.modulus = NULL; + } + if (s->hostkey.exponent) { + sfree(s->hostkey.exponent); + s->hostkey.exponent = NULL; + } + crWaitUntil(pktin); + + if (pktin->type != SSH1_SMSG_SUCCESS) { + bombout(("Encryption not successfully enabled")); + crStop(0); + } + + logevent("Successfully started encryption"); + + fflush(stdout); /* FIXME eh? */ + { + if ((ssh->username = get_remote_username(ssh->conf)) == NULL) { + int ret; /* need not be kept over crReturn */ + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH login name"); + add_prompt(s->cur_prompt, dupstr("login as: "), TRUE); + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntil(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* + * Failed to get a username. Terminate. + */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE); + crStop(0); + } + ssh->username = dupstr(s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); + } + + send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END); + { + char *userlog = dupprintf("Sent username \"%s\"", ssh->username); + logevent(userlog); + if (flags & FLAG_INTERACTIVE && + (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) { + c_write_str(ssh, userlog); + c_write_str(ssh, "\r\n"); + } + sfree(userlog); + } + } + + crWaitUntil(pktin); + + if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) { + /* We must not attempt PK auth. Pretend we've already tried it. */ + s->tried_publickey = s->tried_agent = 1; + } else { + s->tried_publickey = s->tried_agent = 0; + } + s->tis_auth_refused = s->ccard_auth_refused = 0; + /* + * Load the public half of any configured keyfile for later use. + */ + s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); + if (!filename_is_null(s->keyfile)) { + int keytype; + logeventf(ssh, "Reading private key file \"%.150s\"", + filename_to_str(s->keyfile)); + keytype = key_type(s->keyfile); + if (keytype == SSH_KEYTYPE_SSH1) { + const char *error; + if (rsakey_pubblob(s->keyfile, + &s->publickey_blob, &s->publickey_bloblen, + &s->publickey_comment, &error)) { + s->publickey_encrypted = rsakey_encrypted(s->keyfile, + NULL); + } else { + char *msgbuf; + logeventf(ssh, "Unable to load private key (%s)", error); + msgbuf = dupprintf("Unable to load private key file " + "\"%.150s\" (%s)\r\n", + filename_to_str(s->keyfile), + error); + c_write_str(ssh, msgbuf); + sfree(msgbuf); + s->publickey_blob = NULL; + } + } else { + char *msgbuf; + logeventf(ssh, "Unable to use this key file (%s)", + key_type_to_str(keytype)); + msgbuf = dupprintf("Unable to use key file \"%.150s\"" + " (%s)\r\n", + filename_to_str(s->keyfile), + key_type_to_str(keytype)); + c_write_str(ssh, msgbuf); + sfree(msgbuf); + s->publickey_blob = NULL; + } + } else + s->publickey_blob = NULL; + + while (pktin->type == SSH1_SMSG_FAILURE) { + s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; + + if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) { + /* + * Attempt RSA authentication using Pageant. + */ + void *r; + + s->authed = FALSE; + s->tried_agent = 1; + logevent("Pageant is running. Requesting keys."); + + /* Request the keys held by the agent. */ + PUT_32BIT(s->request, 1); + s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES; + if (!agent_query(s->request, 5, &r, &s->responselen, + ssh_agent_callback, ssh)) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while waiting" + " for agent response")); + crStop(0); + } + } while (pktin || inlen > 0); + r = ssh->agent_response; + s->responselen = ssh->agent_response_len; + } + s->response = (unsigned char *) r; + if (s->response && s->responselen >= 5 && + s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) { + s->p = s->response + 5; + s->nkeys = toint(GET_32BIT(s->p)); + if (s->nkeys < 0) { + logeventf(ssh, "Pageant reported negative key count %d", + s->nkeys); + s->nkeys = 0; + } + s->p += 4; + logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys); + for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { + unsigned char *pkblob = s->p; + s->p += 4; + { + int n, ok = FALSE; + do { /* do while (0) to make breaking easy */ + n = ssh1_read_bignum + (s->p, toint(s->responselen-(s->p-s->response)), + &s->key.exponent); + if (n < 0) + break; + s->p += n; + n = ssh1_read_bignum + (s->p, toint(s->responselen-(s->p-s->response)), + &s->key.modulus); + if (n < 0) + break; + s->p += n; + if (s->responselen - (s->p-s->response) < 4) + break; + s->commentlen = toint(GET_32BIT(s->p)); + s->p += 4; + if (s->commentlen < 0 || + toint(s->responselen - (s->p-s->response)) < + s->commentlen) + break; + s->commentp = (char *)s->p; + s->p += s->commentlen; + ok = TRUE; + } while (0); + if (!ok) { + logevent("Pageant key list packet was truncated"); + break; + } + } + if (s->publickey_blob) { + if (!memcmp(pkblob, s->publickey_blob, + s->publickey_bloblen)) { + logeventf(ssh, "Pageant key #%d matches " + "configured key file", s->keyi); + s->tried_publickey = 1; + } else + /* Skip non-configured key */ + continue; + } + logeventf(ssh, "Trying Pageant key #%d", s->keyi); + send_packet(ssh, SSH1_CMSG_AUTH_RSA, + PKT_BIGNUM, s->key.modulus, PKT_END); + crWaitUntil(pktin); + if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { + logevent("Key refused"); + continue; + } + logevent("Received RSA challenge"); + if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) { + bombout(("Server's RSA challenge was badly formatted")); + crStop(0); + } + + { + char *agentreq, *q, *ret; + void *vret; + int len, retlen; + len = 1 + 4; /* message type, bit count */ + len += ssh1_bignum_length(s->key.exponent); + len += ssh1_bignum_length(s->key.modulus); + len += ssh1_bignum_length(s->challenge); + len += 16; /* session id */ + len += 4; /* response format */ + agentreq = snewn(4 + len, char); + PUT_32BIT(agentreq, len); + q = agentreq + 4; + *q++ = SSH1_AGENTC_RSA_CHALLENGE; + PUT_32BIT(q, bignum_bitcount(s->key.modulus)); + q += 4; + q += ssh1_write_bignum(q, s->key.exponent); + q += ssh1_write_bignum(q, s->key.modulus); + q += ssh1_write_bignum(q, s->challenge); + memcpy(q, s->session_id, 16); + q += 16; + PUT_32BIT(q, 1); /* response format */ + if (!agent_query(agentreq, len + 4, &vret, &retlen, + ssh_agent_callback, ssh)) { + sfree(agentreq); + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server" + " while waiting for agent" + " response")); + crStop(0); + } + } while (pktin || inlen > 0); + vret = ssh->agent_response; + retlen = ssh->agent_response_len; + } else + sfree(agentreq); + ret = vret; + if (ret) { + if (ret[4] == SSH1_AGENT_RSA_RESPONSE) { + logevent("Sending Pageant's response"); + send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE, + PKT_DATA, ret + 5, 16, + PKT_END); + sfree(ret); + crWaitUntil(pktin); + if (pktin->type == SSH1_SMSG_SUCCESS) { + logevent + ("Pageant's response accepted"); + if (flags & FLAG_VERBOSE) { + c_write_str(ssh, "Authenticated using" + " RSA key \""); + c_write(ssh, s->commentp, + s->commentlen); + c_write_str(ssh, "\" from agent\r\n"); + } + s->authed = TRUE; + } else + logevent + ("Pageant's response not accepted"); + } else { + logevent + ("Pageant failed to answer challenge"); + sfree(ret); + } + } else { + logevent("No reply received from Pageant"); + } + } + freebn(s->key.exponent); + freebn(s->key.modulus); + freebn(s->challenge); + if (s->authed) + break; + } + sfree(s->response); + if (s->publickey_blob && !s->tried_publickey) + logevent("Configured key file not in Pageant"); + } else { + logevent("Failed to get reply from Pageant"); + } + if (s->authed) + break; + } + if (s->publickey_blob && !s->tried_publickey) { + /* + * Try public key authentication with the specified + * key file. + */ + int got_passphrase; /* need not be kept over crReturn */ + if (flags & FLAG_VERBOSE) + c_write_str(ssh, "Trying public key authentication.\r\n"); + s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); + logeventf(ssh, "Trying public key \"%s\"", + filename_to_str(s->keyfile)); + s->tried_publickey = 1; + got_passphrase = FALSE; + while (!got_passphrase) { + /* + * Get a passphrase, if necessary. + */ + char *passphrase = NULL; /* only written after crReturn */ + const char *error; + if (!s->publickey_encrypted) { + if (flags & FLAG_VERBOSE) + c_write_str(ssh, "No passphrase required.\r\n"); + passphrase = NULL; + } else { + int ret; /* need not be kept over crReturn */ + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = FALSE; + s->cur_prompt->name = dupstr("SSH key passphrase"); + add_prompt(s->cur_prompt, + dupprintf("Passphrase for key \"%.100s\": ", + s->publickey_comment), FALSE); + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntil(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* Failed to get a passphrase. Terminate. */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, "Unable to authenticate", + 0, TRUE); + crStop(0); + } + passphrase = dupstr(s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); + } + /* + * Try decrypting key with passphrase. + */ + s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); + ret = loadrsakey(s->keyfile, &s->key, passphrase, + &error); + if (passphrase) { + smemclr(passphrase, strlen(passphrase)); + sfree(passphrase); + } + if (ret == 1) { + /* Correct passphrase. */ + got_passphrase = TRUE; + } else if (ret == 0) { + c_write_str(ssh, "Couldn't load private key from "); + c_write_str(ssh, filename_to_str(s->keyfile)); + c_write_str(ssh, " ("); + c_write_str(ssh, error); + c_write_str(ssh, ").\r\n"); + got_passphrase = FALSE; + break; /* go and try something else */ + } else if (ret == -1) { + c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */ + got_passphrase = FALSE; + /* and try again */ + } else { + assert(0 && "unexpected return from loadrsakey()"); + got_passphrase = FALSE; /* placate optimisers */ + } + } + + if (got_passphrase) { + + /* + * Send a public key attempt. + */ + send_packet(ssh, SSH1_CMSG_AUTH_RSA, + PKT_BIGNUM, s->key.modulus, PKT_END); + + crWaitUntil(pktin); + if (pktin->type == SSH1_SMSG_FAILURE) { + c_write_str(ssh, "Server refused our public key.\r\n"); + continue; /* go and try something else */ + } + if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) { + bombout(("Bizarre response to offer of public key")); + crStop(0); + } + + { + int i; + unsigned char buffer[32]; + Bignum challenge, response; + + if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) { + bombout(("Server's RSA challenge was badly formatted")); + crStop(0); + } + response = rsadecrypt(challenge, &s->key); + freebn(s->key.private_exponent);/* burn the evidence */ + + for (i = 0; i < 32; i++) { + buffer[i] = bignum_byte(response, 31 - i); + } + + MD5Init(&md5c); + MD5Update(&md5c, buffer, 32); + MD5Update(&md5c, s->session_id, 16); + MD5Final(buffer, &md5c); + + send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE, + PKT_DATA, buffer, 16, PKT_END); + + freebn(challenge); + freebn(response); + } + + crWaitUntil(pktin); + if (pktin->type == SSH1_SMSG_FAILURE) { + if (flags & FLAG_VERBOSE) + c_write_str(ssh, "Failed to authenticate with" + " our public key.\r\n"); + continue; /* go and try something else */ + } else if (pktin->type != SSH1_SMSG_SUCCESS) { + bombout(("Bizarre response to RSA authentication response")); + crStop(0); + } + + break; /* we're through! */ + } + + } + + /* + * Otherwise, try various forms of password-like authentication. + */ + s->cur_prompt = new_prompts(ssh->frontend); + + if (conf_get_int(ssh->conf, CONF_try_tis_auth) && + (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) && + !s->tis_auth_refused) { + s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; + logevent("Requested TIS authentication"); + send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END); + crWaitUntil(pktin); + if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) { + logevent("TIS authentication declined"); + if (flags & FLAG_INTERACTIVE) + c_write_str(ssh, "TIS authentication refused.\r\n"); + s->tis_auth_refused = 1; + continue; + } else { + char *challenge; + int challengelen; + char *instr_suf, *prompt; + + ssh_pkt_getstring(pktin, &challenge, &challengelen); + if (!challenge) { + bombout(("TIS challenge packet was badly formed")); + crStop(0); + } + logevent("Received TIS challenge"); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH TIS authentication"); + /* Prompt heuristic comes from OpenSSH */ + if (memchr(challenge, '\n', challengelen)) { + instr_suf = dupstr(""); + prompt = dupprintf("%.*s", challengelen, challenge); + } else { + instr_suf = dupprintf("%.*s", challengelen, challenge); + prompt = dupstr("Response: "); + } + s->cur_prompt->instruction = + dupprintf("Using TIS authentication.%s%s", + (*instr_suf) ? "\n" : "", + instr_suf); + s->cur_prompt->instr_reqd = TRUE; + add_prompt(s->cur_prompt, prompt, FALSE); + sfree(instr_suf); + } + } + if (conf_get_int(ssh->conf, CONF_try_tis_auth) && + (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) && + !s->ccard_auth_refused) { + s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; + logevent("Requested CryptoCard authentication"); + send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END); + crWaitUntil(pktin); + if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { + logevent("CryptoCard authentication declined"); + c_write_str(ssh, "CryptoCard authentication refused.\r\n"); + s->ccard_auth_refused = 1; + continue; + } else { + char *challenge; + int challengelen; + char *instr_suf, *prompt; + + ssh_pkt_getstring(pktin, &challenge, &challengelen); + if (!challenge) { + bombout(("CryptoCard challenge packet was badly formed")); + crStop(0); + } + logevent("Received CryptoCard challenge"); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH CryptoCard authentication"); + s->cur_prompt->name_reqd = FALSE; + /* Prompt heuristic comes from OpenSSH */ + if (memchr(challenge, '\n', challengelen)) { + instr_suf = dupstr(""); + prompt = dupprintf("%.*s", challengelen, challenge); + } else { + instr_suf = dupprintf("%.*s", challengelen, challenge); + prompt = dupstr("Response: "); + } + s->cur_prompt->instruction = + dupprintf("Using CryptoCard authentication.%s%s", + (*instr_suf) ? "\n" : "", + instr_suf); + s->cur_prompt->instr_reqd = TRUE; + add_prompt(s->cur_prompt, prompt, FALSE); + sfree(instr_suf); + } + } + if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { + if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) { + bombout(("No supported authentication methods available")); + crStop(0); + } + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH password"); + add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ", + ssh->username, ssh->savedhost), + FALSE); + } + + /* + * Show password prompt, having first obtained it via a TIS + * or CryptoCard exchange if we're doing TIS or CryptoCard + * authentication. + */ + { + int ret; /* need not be kept over crReturn */ + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntil(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* + * Failed to get a password (for example + * because one was supplied on the command line + * which has already failed to work). Terminate. + */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE); + crStop(0); + } + } + + if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) { + /* + * Defence against traffic analysis: we send a + * whole bunch of packets containing strings of + * different lengths. One of these strings is the + * password, in a SSH1_CMSG_AUTH_PASSWORD packet. + * The others are all random data in + * SSH1_MSG_IGNORE packets. This way a passive + * listener can't tell which is the password, and + * hence can't deduce the password length. + * + * Anybody with a password length greater than 16 + * bytes is going to have enough entropy in their + * password that a listener won't find it _that_ + * much help to know how long it is. So what we'll + * do is: + * + * - if password length < 16, we send 15 packets + * containing string lengths 1 through 15 + * + * - otherwise, we let N be the nearest multiple + * of 8 below the password length, and send 8 + * packets containing string lengths N through + * N+7. This won't obscure the order of + * magnitude of the password length, but it will + * introduce a bit of extra uncertainty. + * + * A few servers can't deal with SSH1_MSG_IGNORE, at + * least in this context. For these servers, we need + * an alternative defence. We make use of the fact + * that the password is interpreted as a C string: + * so we can append a NUL, then some random data. + * + * A few servers can deal with neither SSH1_MSG_IGNORE + * here _nor_ a padded password string. + * For these servers we are left with no defences + * against password length sniffing. + */ + if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) && + !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { + /* + * The server can deal with SSH1_MSG_IGNORE, so + * we can use the primary defence. + */ + int bottom, top, pwlen, i; + char *randomstr; + + pwlen = strlen(s->cur_prompt->prompts[0]->result); + if (pwlen < 16) { + bottom = 0; /* zero length passwords are OK! :-) */ + top = 15; + } else { + bottom = pwlen & ~7; + top = bottom + 7; + } + + assert(pwlen >= bottom && pwlen <= top); + + randomstr = snewn(top + 1, char); + + for (i = bottom; i <= top; i++) { + if (i == pwlen) { + defer_packet(ssh, s->pwpkt_type, + PKT_STR,s->cur_prompt->prompts[0]->result, + PKT_END); + } else { + for (j = 0; j < i; j++) { + do { + randomstr[j] = random_byte(); + } while (randomstr[j] == '\0'); + } + randomstr[i] = '\0'; + defer_packet(ssh, SSH1_MSG_IGNORE, + PKT_STR, randomstr, PKT_END); + } + } + logevent("Sending password with camouflage packets"); + ssh_pkt_defersend(ssh); + sfree(randomstr); + } + else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) { + /* + * The server can't deal with SSH1_MSG_IGNORE + * but can deal with padded passwords, so we + * can use the secondary defence. + */ + char string[64]; + char *ss; + int len; + + len = strlen(s->cur_prompt->prompts[0]->result); + if (len < sizeof(string)) { + ss = string; + strcpy(string, s->cur_prompt->prompts[0]->result); + len++; /* cover the zero byte */ + while (len < sizeof(string)) { + string[len++] = (char) random_byte(); + } + } else { + ss = s->cur_prompt->prompts[0]->result; + } + logevent("Sending length-padded password"); + send_packet(ssh, s->pwpkt_type, + PKT_INT, len, PKT_DATA, ss, len, + PKT_END); + } else { + /* + * The server is believed unable to cope with + * any of our password camouflage methods. + */ + int len; + len = strlen(s->cur_prompt->prompts[0]->result); + logevent("Sending unpadded password"); + send_packet(ssh, s->pwpkt_type, + PKT_INT, len, + PKT_DATA, s->cur_prompt->prompts[0]->result, len, + PKT_END); + } + } else { + send_packet(ssh, s->pwpkt_type, + PKT_STR, s->cur_prompt->prompts[0]->result, + PKT_END); + } + logevent("Sent password"); + free_prompts(s->cur_prompt); + crWaitUntil(pktin); + if (pktin->type == SSH1_SMSG_FAILURE) { + if (flags & FLAG_VERBOSE) + c_write_str(ssh, "Access denied\r\n"); + logevent("Authentication refused"); + } else if (pktin->type != SSH1_SMSG_SUCCESS) { + bombout(("Strange packet received, type %d", pktin->type)); + crStop(0); + } + } + + /* Clear up */ + if (s->publickey_blob) { + sfree(s->publickey_blob); + sfree(s->publickey_comment); + } + + logevent("Authentication successful"); + + crFinish(1); +} + +static void ssh_channel_try_eof(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + assert(c->pending_eof); /* precondition for calling us */ + if (c->halfopen) + return; /* can't close: not even opened yet */ + if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0) + return; /* can't send EOF: pending outgoing data */ + + c->pending_eof = FALSE; /* we're about to send it */ + if (ssh->version == 1) { + send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, + PKT_END); + c->closes |= CLOSES_SENT_EOF; + } else { + struct Packet *pktout; + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_send(ssh, pktout); + c->closes |= CLOSES_SENT_EOF; + ssh2_channel_check_close(c); + } +} + +Conf *sshfwd_get_conf(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + return ssh->conf; +} + +void sshfwd_write_eof(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + + if (ssh->state == SSH_STATE_CLOSED) + return; + + if (c->closes & CLOSES_SENT_EOF) + return; + + c->pending_eof = TRUE; + ssh_channel_try_eof(c); +} + +void sshfwd_unclean_close(struct ssh_channel *c, const char *err) +{ + Ssh ssh = c->ssh; + + if (ssh->state == SSH_STATE_CLOSED) + return; + + switch (c->type) { + case CHAN_X11: + x11_close(c->u.x11.xconn); + logeventf(ssh, "Forwarded X11 connection terminated due to local " + "error: %s", err); + break; + case CHAN_SOCKDATA: + case CHAN_SOCKDATA_DORMANT: + pfd_close(c->u.pfd.pf); + logeventf(ssh, "Forwarded port closed due to local error: %s", err); + break; + } + c->type = CHAN_ZOMBIE; + c->pending_eof = FALSE; /* this will confuse a zombie channel */ + + ssh2_channel_check_close(c); +} + +int sshfwd_write(struct ssh_channel *c, char *buf, int len) +{ + Ssh ssh = c->ssh; + + if (ssh->state == SSH_STATE_CLOSED) + return 0; + + if (ssh->version == 1) { + send_packet(ssh, SSH1_MSG_CHANNEL_DATA, + PKT_INT, c->remoteid, + PKT_INT, len, PKT_DATA, buf, len, + PKT_END); + /* + * In SSH-1 we can return 0 here - implying that forwarded + * connections are never individually throttled - because + * the only circumstance that can cause throttling will be + * the whole SSH connection backing up, in which case + * _everything_ will be throttled as a whole. + */ + return 0; + } else { + ssh2_add_channel_data(c, buf, len); + return ssh2_try_send(c); + } +} + +void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) +{ + Ssh ssh = c->ssh; + int buflimit; + + if (ssh->state == SSH_STATE_CLOSED) + return; + + if (ssh->version == 1) { + buflimit = SSH1_BUFFER_LIMIT; + } else { + buflimit = c->v.v2.locmaxwin; + ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0); + } + if (c->throttling_conn && bufsize <= buflimit) { + c->throttling_conn = 0; + ssh_throttle_conn(ssh, -1); + } +} + +static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin) +{ + struct queued_handler *qh = ssh->qhead; + + assert(qh != NULL); + + assert(pktin->type == qh->msg1 || pktin->type == qh->msg2); + + if (qh->msg1 > 0) { + assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler); + ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1; + } + if (qh->msg2 > 0) { + assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler); + ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2; + } + + if (qh->next) { + ssh->qhead = qh->next; + + if (ssh->qhead->msg1 > 0) { + ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1]; + ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler; + } + if (ssh->qhead->msg2 > 0) { + ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2]; + ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler; + } + } else { + ssh->qhead = ssh->qtail = NULL; + } + + qh->handler(ssh, pktin, qh->ctx); + + sfree(qh); +} + +static void ssh_queue_handler(Ssh ssh, int msg1, int msg2, + chandler_fn_t handler, void *ctx) +{ + struct queued_handler *qh; + + qh = snew(struct queued_handler); + qh->msg1 = msg1; + qh->msg2 = msg2; + qh->handler = handler; + qh->ctx = ctx; + qh->next = NULL; + + if (ssh->qtail == NULL) { + ssh->qhead = qh; + + if (qh->msg1 > 0) { + ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1]; + ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler; + } + if (qh->msg2 > 0) { + ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2]; + ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler; + } + } else { + ssh->qtail->next = qh; + } + ssh->qtail = qh; +} + +static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx) +{ + struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx; + + if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS : + SSH2_MSG_REQUEST_SUCCESS)) { + logeventf(ssh, "Remote port forwarding from %s enabled", + pf->sportdesc); + } else { + logeventf(ssh, "Remote port forwarding from %s refused", + pf->sportdesc); + + rpf = del234(ssh->rportfwds, pf); + assert(rpf == pf); + pf->pfrec->remote = NULL; + free_rportfwd(pf); + } +} + +int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport, + void *share_ctx) +{ + struct ssh_rportfwd *pf = snew(struct ssh_rportfwd); + pf->dhost = NULL; + pf->dport = 0; + pf->share_ctx = share_ctx; + pf->shost = dupstr(shost); + pf->sport = sport; + pf->sportdesc = NULL; + if (!ssh->rportfwds) { + assert(ssh->version == 2); + ssh->rportfwds = newtree234(ssh_rportcmp_ssh2); + } + if (add234(ssh->rportfwds, pf) != pf) { + sfree(pf->shost); + sfree(pf); + return FALSE; + } + return TRUE; +} + +static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin, + void *ctx) +{ + share_got_pkt_from_server(ctx, pktin->type, + pktin->body, pktin->length); +} + +void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx) +{ + ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE, + ssh_sharing_global_request_response, share_ctx); +} + +static void ssh_setup_portfwd(Ssh ssh, Conf *conf) +{ + struct ssh_portfwd *epf; + int i; + char *key, *val; + + if (!ssh->portfwds) { + ssh->portfwds = newtree234(ssh_portcmp); + } else { + /* + * Go through the existing port forwardings and tag them + * with status==DESTROY. Any that we want to keep will be + * re-enabled (status==KEEP) as we go through the + * configuration and find out which bits are the same as + * they were before. + */ + struct ssh_portfwd *epf; + int i; + for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) + epf->status = DESTROY; + } + + for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key); + val != NULL; + val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) { + char *kp, *kp2, *vp, *vp2; + char address_family, type; + int sport,dport,sserv,dserv; + char *sports, *dports, *saddr, *host; + + kp = key; + + address_family = 'A'; + type = 'L'; + if (*kp == 'A' || *kp == '4' || *kp == '6') + address_family = *kp++; + if (*kp == 'L' || *kp == 'R') + type = *kp++; + + if ((kp2 = host_strchr(kp, ':')) != NULL) { + /* + * There's a colon in the middle of the source port + * string, which means that the part before it is + * actually a source address. + */ + char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp); + saddr = host_strduptrim(saddr_tmp); + sfree(saddr_tmp); + sports = kp2+1; + } else { + saddr = NULL; + sports = kp; + } + sport = atoi(sports); + sserv = 0; + if (sport == 0) { + sserv = 1; + sport = net_service_lookup(sports); + if (!sport) { + logeventf(ssh, "Service lookup failed for source" + " port \"%s\"", sports); + } + } + + if (type == 'L' && !strcmp(val, "D")) { + /* dynamic forwarding */ + host = NULL; + dports = NULL; + dport = -1; + dserv = 0; + type = 'D'; + } else { + /* ordinary forwarding */ + vp = val; + vp2 = vp + host_strcspn(vp, ":"); + host = dupprintf("%.*s", (int)(vp2 - vp), vp); + if (*vp2) + vp2++; + dports = vp2; + dport = atoi(dports); + dserv = 0; + if (dport == 0) { + dserv = 1; + dport = net_service_lookup(dports); + if (!dport) { + logeventf(ssh, "Service lookup failed for destination" + " port \"%s\"", dports); + } + } + } + + if (sport && dport) { + /* Set up a description of the source port. */ + struct ssh_portfwd *pfrec, *epfrec; + + pfrec = snew(struct ssh_portfwd); + pfrec->type = type; + pfrec->saddr = saddr; + pfrec->sserv = sserv ? dupstr(sports) : NULL; + pfrec->sport = sport; + pfrec->daddr = host; + pfrec->dserv = dserv ? dupstr(dports) : NULL; + pfrec->dport = dport; + pfrec->local = NULL; + pfrec->remote = NULL; + pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 : + address_family == '6' ? ADDRTYPE_IPV6 : + ADDRTYPE_UNSPEC); + + epfrec = add234(ssh->portfwds, pfrec); + if (epfrec != pfrec) { + if (epfrec->status == DESTROY) { + /* + * We already have a port forwarding up and running + * with precisely these parameters. Hence, no need + * to do anything; simply re-tag the existing one + * as KEEP. + */ + epfrec->status = KEEP; + } + /* + * Anything else indicates that there was a duplicate + * in our input, which we'll silently ignore. + */ + free_portfwd(pfrec); + } else { + pfrec->status = CREATE; + } + } else { + sfree(saddr); + sfree(host); + } + } + + /* + * Now go through and destroy any port forwardings which were + * not re-enabled. + */ + for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) + if (epf->status == DESTROY) { + char *message; + + message = dupprintf("%s port forwarding from %s%s%d", + epf->type == 'L' ? "local" : + epf->type == 'R' ? "remote" : "dynamic", + epf->saddr ? epf->saddr : "", + epf->saddr ? ":" : "", + epf->sport); + + if (epf->type != 'D') { + char *msg2 = dupprintf("%s to %s:%d", message, + epf->daddr, epf->dport); + sfree(message); + message = msg2; + } + + logeventf(ssh, "Cancelling %s", message); + sfree(message); + + /* epf->remote or epf->local may be NULL if setting up a + * forwarding failed. */ + if (epf->remote) { + struct ssh_rportfwd *rpf = epf->remote; + struct Packet *pktout; + + /* + * Cancel the port forwarding at the server + * end. + */ + if (ssh->version == 1) { + /* + * We cannot cancel listening ports on the + * server side in SSH-1! There's no message + * to support it. Instead, we simply remove + * the rportfwd record from the local end + * so that any connections the server tries + * to make on it are rejected. + */ + } else { + pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); + ssh2_pkt_addstring(pktout, "cancel-tcpip-forward"); + ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */ + if (epf->saddr) { + ssh2_pkt_addstring(pktout, epf->saddr); + } else if (conf_get_int(conf, CONF_rport_acceptall)) { + /* XXX: rport_acceptall may not represent + * what was used to open the original connection, + * since it's reconfigurable. */ + ssh2_pkt_addstring(pktout, ""); + } else { + ssh2_pkt_addstring(pktout, "localhost"); + } + ssh2_pkt_adduint32(pktout, epf->sport); + ssh2_pkt_send(ssh, pktout); + } + + del234(ssh->rportfwds, rpf); + free_rportfwd(rpf); + } else if (epf->local) { + pfl_terminate(epf->local); + } + + delpos234(ssh->portfwds, i); + free_portfwd(epf); + i--; /* so we don't skip one in the list */ + } + + /* + * And finally, set up any new port forwardings (status==CREATE). + */ + for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) + if (epf->status == CREATE) { + char *sportdesc, *dportdesc; + sportdesc = dupprintf("%s%s%s%s%d%s", + epf->saddr ? epf->saddr : "", + epf->saddr ? ":" : "", + epf->sserv ? epf->sserv : "", + epf->sserv ? "(" : "", + epf->sport, + epf->sserv ? ")" : ""); + if (epf->type == 'D') { + dportdesc = NULL; + } else { + dportdesc = dupprintf("%s:%s%s%d%s", + epf->daddr, + epf->dserv ? epf->dserv : "", + epf->dserv ? "(" : "", + epf->dport, + epf->dserv ? ")" : ""); + } + + if (epf->type == 'L') { + char *err = pfl_listen(epf->daddr, epf->dport, + epf->saddr, epf->sport, + ssh, conf, &epf->local, + epf->addressfamily); + + logeventf(ssh, "Local %sport %s forwarding to %s%s%s", + epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " : + epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "", + sportdesc, dportdesc, + err ? " failed: " : "", err ? err : ""); + if (err) + sfree(err); + } else if (epf->type == 'D') { + char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport, + ssh, conf, &epf->local, + epf->addressfamily); + + logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s", + epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " : + epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "", + sportdesc, + err ? " failed: " : "", err ? err : ""); + + if (err) + sfree(err); + } else { + struct ssh_rportfwd *pf; + + /* + * Ensure the remote port forwardings tree exists. + */ + if (!ssh->rportfwds) { + if (ssh->version == 1) + ssh->rportfwds = newtree234(ssh_rportcmp_ssh1); + else + ssh->rportfwds = newtree234(ssh_rportcmp_ssh2); + } + + pf = snew(struct ssh_rportfwd); + pf->share_ctx = NULL; + pf->dhost = dupstr(epf->daddr); + pf->dport = epf->dport; + if (epf->saddr) { + pf->shost = dupstr(epf->saddr); + } else if (conf_get_int(conf, CONF_rport_acceptall)) { + pf->shost = dupstr(""); + } else { + pf->shost = dupstr("localhost"); + } + pf->sport = epf->sport; + if (add234(ssh->rportfwds, pf) != pf) { + logeventf(ssh, "Duplicate remote port forwarding to %s:%d", + epf->daddr, epf->dport); + sfree(pf); + } else { + logeventf(ssh, "Requesting remote port %s" + " forward to %s", sportdesc, dportdesc); + + pf->sportdesc = sportdesc; + sportdesc = NULL; + epf->remote = pf; + pf->pfrec = epf; + + if (ssh->version == 1) { + send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST, + PKT_INT, epf->sport, + PKT_STR, epf->daddr, + PKT_INT, epf->dport, + PKT_END); + ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS, + SSH1_SMSG_FAILURE, + ssh_rportfwd_succfail, pf); + } else { + struct Packet *pktout; + pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); + ssh2_pkt_addstring(pktout, "tcpip-forward"); + ssh2_pkt_addbool(pktout, 1);/* want reply */ + ssh2_pkt_addstring(pktout, pf->shost); + ssh2_pkt_adduint32(pktout, pf->sport); + ssh2_pkt_send(ssh, pktout); + + ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, + SSH2_MSG_REQUEST_FAILURE, + ssh_rportfwd_succfail, pf); + } + } + } + sfree(sportdesc); + sfree(dportdesc); + } +} + +static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin) +{ + char *string; + int stringlen, bufsize; + + ssh_pkt_getstring(pktin, &string, &stringlen); + if (string == NULL) { + bombout(("Incoming terminal data packet was badly formed")); + return; + } + + bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA, + string, stringlen); + if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) { + ssh->v1_stdout_throttling = 1; + ssh_throttle_conn(ssh, +1); + } +} + +static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin) +{ + /* Remote side is trying to open a channel to talk to our + * X-Server. Give them back a local channel number. */ + struct ssh_channel *c; + int remoteid = ssh_pkt_getuint32(pktin); + + logevent("Received X11 connect request"); + /* Refuse if X11 forwarding is disabled. */ + if (!ssh->X11_fwd_enabled) { + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, + PKT_INT, remoteid, PKT_END); + logevent("Rejected X11 connect request"); + } else { + c = snew(struct ssh_channel); + c->ssh = ssh; + + c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1); + c->remoteid = remoteid; + c->halfopen = FALSE; + c->localid = alloc_channel_id(ssh); + c->closes = 0; + c->pending_eof = FALSE; + c->throttling_conn = 0; + c->type = CHAN_X11; /* identify channel type */ + add234(ssh->channels, c); + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, + PKT_INT, c->remoteid, PKT_INT, + c->localid, PKT_END); + logevent("Opened X11 forward channel"); + } +} + +static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin) +{ + /* Remote side is trying to open a channel to talk to our + * agent. Give them back a local channel number. */ + struct ssh_channel *c; + int remoteid = ssh_pkt_getuint32(pktin); + + /* Refuse if agent forwarding is disabled. */ + if (!ssh->agentfwd_enabled) { + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, + PKT_INT, remoteid, PKT_END); + } else { + c = snew(struct ssh_channel); + c->ssh = ssh; + c->remoteid = remoteid; + c->halfopen = FALSE; + c->localid = alloc_channel_id(ssh); + c->closes = 0; + c->pending_eof = FALSE; + c->throttling_conn = 0; + c->type = CHAN_AGENT; /* identify channel type */ + c->u.a.lensofar = 0; + c->u.a.message = NULL; + c->u.a.outstanding_requests = 0; + add234(ssh->channels, c); + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, + PKT_INT, c->remoteid, PKT_INT, c->localid, + PKT_END); + } +} + +static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin) +{ + /* Remote side is trying to open a channel to talk to a + * forwarded port. Give them back a local channel number. */ + struct ssh_rportfwd pf, *pfp; + int remoteid; + int hostsize, port; + char *host; + char *err; + + remoteid = ssh_pkt_getuint32(pktin); + ssh_pkt_getstring(pktin, &host, &hostsize); + port = ssh_pkt_getuint32(pktin); + + pf.dhost = dupprintf("%.*s", hostsize, host); + pf.dport = port; + pfp = find234(ssh->rportfwds, &pf, NULL); + + if (pfp == NULL) { + logeventf(ssh, "Rejected remote port open request for %s:%d", + pf.dhost, port); + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, + PKT_INT, remoteid, PKT_END); + } else { + struct ssh_channel *c = snew(struct ssh_channel); + c->ssh = ssh; + + logeventf(ssh, "Received remote port open request for %s:%d", + pf.dhost, port); + err = pfd_connect(&c->u.pfd.pf, pf.dhost, port, + c, ssh->conf, pfp->pfrec->addressfamily); + if (err != NULL) { + logeventf(ssh, "Port open failed: %s", err); + sfree(err); + sfree(c); + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, + PKT_INT, remoteid, PKT_END); + } else { + c->remoteid = remoteid; + c->halfopen = FALSE; + c->localid = alloc_channel_id(ssh); + c->closes = 0; + c->pending_eof = FALSE; + c->throttling_conn = 0; + c->type = CHAN_SOCKDATA; /* identify channel type */ + add234(ssh->channels, c); + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, + PKT_INT, c->remoteid, PKT_INT, + c->localid, PKT_END); + logevent("Forwarded port opened successfully"); + } + } + + sfree(pf.dhost); +} + +static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) +{ + unsigned int remoteid = ssh_pkt_getuint32(pktin); + unsigned int localid = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + + c = find234(ssh->channels, &remoteid, ssh_channelfind); + if (c && c->type == CHAN_SOCKDATA_DORMANT) { + c->remoteid = localid; + c->halfopen = FALSE; + c->type = CHAN_SOCKDATA; + c->throttling_conn = 0; + pfd_confirm(c->u.pfd.pf); + } + + if (c && c->pending_eof) { + /* + * We have a pending close on this channel, + * which we decided on before the server acked + * the channel open. So now we know the + * remoteid, we can close it again. + */ + ssh_channel_try_eof(c); + } +} + +static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) +{ + unsigned int remoteid = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + + c = find234(ssh->channels, &remoteid, ssh_channelfind); + if (c && c->type == CHAN_SOCKDATA_DORMANT) { + logevent("Forwarded connection refused by server"); + pfd_close(c->u.pfd.pf); + del234(ssh->channels, c); + sfree(c); + } +} + +static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin) +{ + /* Remote side closes a channel. */ + unsigned i = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + c = find234(ssh->channels, &i, ssh_channelfind); + if (c && !c->halfopen) { + + if (pktin->type == SSH1_MSG_CHANNEL_CLOSE && + !(c->closes & CLOSES_RCVD_EOF)) { + /* + * Received CHANNEL_CLOSE, which we translate into + * outgoing EOF. + */ + int send_close = FALSE; + + c->closes |= CLOSES_RCVD_EOF; + + switch (c->type) { + case CHAN_X11: + if (c->u.x11.xconn) + x11_send_eof(c->u.x11.xconn); + else + send_close = TRUE; + break; + case CHAN_SOCKDATA: + if (c->u.pfd.pf) + pfd_send_eof(c->u.pfd.pf); + else + send_close = TRUE; + break; + case CHAN_AGENT: + send_close = TRUE; + break; + } + + if (send_close && !(c->closes & CLOSES_SENT_EOF)) { + send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, + PKT_END); + c->closes |= CLOSES_SENT_EOF; + } + } + + if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION && + !(c->closes & CLOSES_RCVD_CLOSE)) { + + if (!(c->closes & CLOSES_SENT_EOF)) { + bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d" + " for which we never sent CHANNEL_CLOSE\n", i)); + } + + c->closes |= CLOSES_RCVD_CLOSE; + } + + if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) && + !(c->closes & CLOSES_SENT_CLOSE)) { + send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION, + PKT_INT, c->remoteid, PKT_END); + c->closes |= CLOSES_SENT_CLOSE; + } + + if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) + ssh_channel_destroy(c); + } else { + bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n", + pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" : + "_CONFIRMATION", c ? "half-open" : "nonexistent", + i)); + } +} + +static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin) +{ + /* Data sent down one of our channels. */ + int i = ssh_pkt_getuint32(pktin); + char *p; + int len; + struct ssh_channel *c; + + ssh_pkt_getstring(pktin, &p, &len); + + c = find234(ssh->channels, &i, ssh_channelfind); + if (c) { + int bufsize = 0; + switch (c->type) { + case CHAN_X11: + bufsize = x11_send(c->u.x11.xconn, p, len); + break; + case CHAN_SOCKDATA: + bufsize = pfd_send(c->u.pfd.pf, p, len); + break; + case CHAN_AGENT: + /* Data for an agent message. Buffer it. */ + while (len > 0) { + if (c->u.a.lensofar < 4) { + unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len); + memcpy(c->u.a.msglen + c->u.a.lensofar, p, + l); + p += l; + len -= l; + c->u.a.lensofar += l; + } + if (c->u.a.lensofar == 4) { + c->u.a.totallen = + 4 + GET_32BIT(c->u.a.msglen); + c->u.a.message = snewn(c->u.a.totallen, + unsigned char); + memcpy(c->u.a.message, c->u.a.msglen, 4); + } + if (c->u.a.lensofar >= 4 && len > 0) { + unsigned int l = + min(c->u.a.totallen - c->u.a.lensofar, + (unsigned)len); + memcpy(c->u.a.message + c->u.a.lensofar, p, + l); + p += l; + len -= l; + c->u.a.lensofar += l; + } + if (c->u.a.lensofar == c->u.a.totallen) { + void *reply; + int replylen; + c->u.a.outstanding_requests++; + if (agent_query(c->u.a.message, + c->u.a.totallen, + &reply, &replylen, + ssh_agentf_callback, c)) + ssh_agentf_callback(c, reply, replylen); + sfree(c->u.a.message); + c->u.a.lensofar = 0; + } + } + bufsize = 0; /* agent channels never back up */ + break; + } + if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) { + c->throttling_conn = 1; + ssh_throttle_conn(ssh, +1); + } + } +} + +static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin) +{ + ssh->exitcode = ssh_pkt_getuint32(pktin); + logeventf(ssh, "Server sent command exit status %d", ssh->exitcode); + send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); + /* + * In case `helpful' firewalls or proxies tack + * extra human-readable text on the end of the + * session which we might mistake for another + * encrypted packet, we close the session once + * we've sent EXIT_CONFIRMATION. + */ + ssh_disconnect(ssh, NULL, NULL, 0, TRUE); +} + +/* Helper function to deal with sending tty modes for REQUEST_PTY */ +static void ssh1_send_ttymode(void *data, char *mode, char *val) +{ + struct Packet *pktout = (struct Packet *)data; + int i = 0; + unsigned int arg = 0; + while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++; + if (i == lenof(ssh_ttymodes)) return; + switch (ssh_ttymodes[i].type) { + case TTY_OP_CHAR: + arg = ssh_tty_parse_specchar(val); + break; + case TTY_OP_BOOL: + arg = ssh_tty_parse_boolean(val); + break; + } + ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode); + ssh2_pkt_addbyte(pktout, arg); +} + +int ssh_agent_forwarding_permitted(Ssh ssh) +{ + return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists(); +} + +static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, + struct Packet *pktin) +{ + crBegin(ssh->do_ssh1_connection_crstate); + + ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] = + ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] = + ssh1_smsg_stdout_stderr_data; + + ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] = + ssh1_msg_channel_open_confirmation; + ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] = + ssh1_msg_channel_open_failure; + ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] = + ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] = + ssh1_msg_channel_close; + ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data; + ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status; + + if (ssh_agent_forwarding_permitted(ssh)) { + logevent("Requesting agent forwarding"); + send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); + do { + crReturnV; + } while (!pktin); + if (pktin->type != SSH1_SMSG_SUCCESS + && pktin->type != SSH1_SMSG_FAILURE) { + bombout(("Protocol confusion")); + crStopV; + } else if (pktin->type == SSH1_SMSG_FAILURE) { + logevent("Agent forwarding refused"); + } else { + logevent("Agent forwarding enabled"); + ssh->agentfwd_enabled = TRUE; + ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open; + } + } + + if (conf_get_int(ssh->conf, CONF_x11_forward)) { + ssh->x11disp = + x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display), + ssh->conf); + if (!ssh->x11disp) { + /* FIXME: return an error message from x11_setup_display */ + logevent("X11 forwarding not enabled: unable to" + " initialise X display"); + } else { + ssh->x11auth = x11_invent_fake_auth + (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth)); + ssh->x11auth->disp = ssh->x11disp; + + logevent("Requesting X11 forwarding"); + if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) { + send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, + PKT_STR, ssh->x11auth->protoname, + PKT_STR, ssh->x11auth->datastring, + PKT_INT, ssh->x11disp->screennum, + PKT_END); + } else { + send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, + PKT_STR, ssh->x11auth->protoname, + PKT_STR, ssh->x11auth->datastring, + PKT_END); + } + do { + crReturnV; + } while (!pktin); + if (pktin->type != SSH1_SMSG_SUCCESS + && pktin->type != SSH1_SMSG_FAILURE) { + bombout(("Protocol confusion")); + crStopV; + } else if (pktin->type == SSH1_SMSG_FAILURE) { + logevent("X11 forwarding refused"); + } else { + logevent("X11 forwarding enabled"); + ssh->X11_fwd_enabled = TRUE; + ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open; + } + } + } + + ssh_setup_portfwd(ssh, ssh->conf); + ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open; + + if (!conf_get_int(ssh->conf, CONF_nopty)) { + struct Packet *pkt; + /* Unpick the terminal-speed string. */ + /* XXX perhaps we should allow no speeds to be sent. */ + ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */ + sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed); + /* Send the pty request. */ + pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY); + ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype)); + ssh_pkt_adduint32(pkt, ssh->term_height); + ssh_pkt_adduint32(pkt, ssh->term_width); + ssh_pkt_adduint32(pkt, 0); /* width in pixels */ + ssh_pkt_adduint32(pkt, 0); /* height in pixels */ + parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt); + ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED); + ssh_pkt_adduint32(pkt, ssh->ispeed); + ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED); + ssh_pkt_adduint32(pkt, ssh->ospeed); + ssh_pkt_addbyte(pkt, SSH_TTY_OP_END); + s_wrpkt(ssh, pkt); + ssh->state = SSH_STATE_INTERMED; + do { + crReturnV; + } while (!pktin); + if (pktin->type != SSH1_SMSG_SUCCESS + && pktin->type != SSH1_SMSG_FAILURE) { + bombout(("Protocol confusion")); + crStopV; + } else if (pktin->type == SSH1_SMSG_FAILURE) { + c_write_str(ssh, "Server refused to allocate pty\r\n"); + ssh->editing = ssh->echoing = 1; + } else { + logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", + ssh->ospeed, ssh->ispeed); + ssh->got_pty = TRUE; + } + } else { + ssh->editing = ssh->echoing = 1; + } + + if (conf_get_int(ssh->conf, CONF_compression)) { + send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END); + do { + crReturnV; + } while (!pktin); + if (pktin->type != SSH1_SMSG_SUCCESS + && pktin->type != SSH1_SMSG_FAILURE) { + bombout(("Protocol confusion")); + crStopV; + } else if (pktin->type == SSH1_SMSG_FAILURE) { + c_write_str(ssh, "Server refused to compress\r\n"); + } + logevent("Started compression"); + ssh->v1_compressing = TRUE; + ssh->cs_comp_ctx = zlib_compress_init(); + logevent("Initialised zlib (RFC1950) compression"); + ssh->sc_comp_ctx = zlib_decompress_init(); + logevent("Initialised zlib (RFC1950) decompression"); + } + + /* + * Start the shell or command. + * + * Special case: if the first-choice command is an SSH-2 + * subsystem (hence not usable here) and the second choice + * exists, we fall straight back to that. + */ + { + char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd); + + if (conf_get_int(ssh->conf, CONF_ssh_subsys) && + conf_get_str(ssh->conf, CONF_remote_cmd2)) { + cmd = conf_get_str(ssh->conf, CONF_remote_cmd2); + ssh->fallback_cmd = TRUE; + } + if (*cmd) + send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END); + else + send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END); + logevent("Started session"); + } + + ssh->state = SSH_STATE_SESSION; + if (ssh->size_needed) + ssh_size(ssh, ssh->term_width, ssh->term_height); + if (ssh->eof_needed) + ssh_special(ssh, TS_EOF); + + if (ssh->ldisc) + ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */ + ssh->send_ok = 1; + ssh->channels = newtree234(ssh_channelcmp); + while (1) { + + /* + * By this point, most incoming packets are already being + * handled by the dispatch table, and we need only pay + * attention to the unusual ones. + */ + + crReturnV; + if (pktin) { + if (pktin->type == SSH1_SMSG_SUCCESS) { + /* may be from EXEC_SHELL on some servers */ + } else if (pktin->type == SSH1_SMSG_FAILURE) { + /* may be from EXEC_SHELL on some servers + * if no pty is available or in other odd cases. Ignore */ + } else { + bombout(("Strange packet received: type %d", pktin->type)); + crStopV; + } + } else { + while (inlen > 0) { + int len = min(inlen, 512); + send_packet(ssh, SSH1_CMSG_STDIN_DATA, + PKT_INT, len, PKT_DATA, in, len, + PKT_END); + in += len; + inlen -= len; + } + } + } + + crFinishV; +} + +/* + * Handle the top-level SSH-2 protocol. + */ +static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin) +{ + char *msg; + int msglen; + + ssh_pkt_getstring(pktin, &msg, &msglen); + logeventf(ssh, "Remote debug message: %.*s", msglen, msg); +} + +static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin) +{ + /* log reason code in disconnect message */ + char *msg; + int msglen; + + ssh_pkt_getstring(pktin, &msg, &msglen); + bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg)); +} + +static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin) +{ + /* Do nothing, because we're ignoring it! Duhh. */ +} + +static void ssh1_protocol_setup(Ssh ssh) +{ + int i; + + /* + * Most messages are handled by the coroutines. + */ + for (i = 0; i < 256; i++) + ssh->packet_dispatch[i] = NULL; + + /* + * These special message types we install handlers for. + */ + ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect; + ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore; + ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug; +} + +static void ssh1_protocol(Ssh ssh, void *vin, int inlen, + struct Packet *pktin) +{ + unsigned char *in=(unsigned char*)vin; + if (ssh->state == SSH_STATE_CLOSED) + return; + + if (pktin && ssh->packet_dispatch[pktin->type]) { + ssh->packet_dispatch[pktin->type](ssh, pktin); + return; + } + + if (!ssh->protocol_initial_phase_done) { + if (do_ssh1_login(ssh, in, inlen, pktin)) + ssh->protocol_initial_phase_done = TRUE; + else + return; + } + + do_ssh1_connection(ssh, in, inlen, pktin); +} + +/* + * Utility routine for decoding comma-separated strings in KEXINIT. + */ +static int in_commasep_string(char *needle, char *haystack, int haylen) +{ + int needlen; + if (!needle || !haystack) /* protect against null pointers */ + return 0; + needlen = strlen(needle); + while (1) { + /* + * Is it at the start of the string? + */ + if (haylen >= needlen && /* haystack is long enough */ + !memcmp(needle, haystack, needlen) && /* initial match */ + (haylen == needlen || haystack[needlen] == ',') + /* either , or EOS follows */ + ) + return 1; + /* + * If not, search for the next comma and resume after that. + * If no comma found, terminate. + */ + while (haylen > 0 && *haystack != ',') + haylen--, haystack++; + if (haylen == 0) + return 0; + haylen--, haystack++; /* skip over comma itself */ + } +} + +/* + * Similar routine for checking whether we have the first string in a list. + */ +static int first_in_commasep_string(char *needle, char *haystack, int haylen) +{ + int needlen; + if (!needle || !haystack) /* protect against null pointers */ + return 0; + needlen = strlen(needle); + /* + * Is it at the start of the string? + */ + if (haylen >= needlen && /* haystack is long enough */ + !memcmp(needle, haystack, needlen) && /* initial match */ + (haylen == needlen || haystack[needlen] == ',') + /* either , or EOS follows */ + ) + return 1; + return 0; +} + + +/* + * SSH-2 key creation method. + * (Currently assumes 2 lots of any hash are sufficient to generate + * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.) + */ +#define SSH2_MKKEY_ITERS (2) +static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr, + unsigned char *keyspace) +{ + const struct ssh_hash *h = ssh->kex->hash; + void *s; + /* First hlen bytes. */ + s = h->init(); + if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) + hash_mpint(h, s, K); + h->bytes(s, H, h->hlen); + h->bytes(s, &chr, 1); + h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len); + h->final(s, keyspace); + /* Next hlen bytes. */ + s = h->init(); + if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) + hash_mpint(h, s, K); + h->bytes(s, H, h->hlen); + h->bytes(s, keyspace, h->hlen); + h->final(s, keyspace + h->hlen); +} + +/* + * Handle the SSH-2 transport layer. + */ +static void do_ssh2_transport(Ssh ssh, void *vin, int inlen, + struct Packet *pktin) +{ + unsigned char *in = (unsigned char *)vin; + struct do_ssh2_transport_state { + int crLine; + int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher; + Bignum p, g, e, f, K; + void *our_kexinit; + int our_kexinitlen; + int kex_init_value, kex_reply_value; + const struct ssh_mac **maclist; + int nmacs; + const struct ssh2_cipher *cscipher_tobe; + const struct ssh2_cipher *sccipher_tobe; + const struct ssh_mac *csmac_tobe; + const struct ssh_mac *scmac_tobe; + const struct ssh_compress *cscomp_tobe; + const struct ssh_compress *sccomp_tobe; + char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint; + int hostkeylen, siglen, rsakeylen; + void *hkey; /* actual host key */ + void *rsakey; /* for RSA kex */ + unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN]; + int n_preferred_kex; + const struct ssh_kexes *preferred_kex[KEX_MAX]; + int n_preferred_ciphers; + const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX]; + const struct ssh_compress *preferred_comp; + int userauth_succeeded; /* for delayed compression */ + int pending_compression; + int got_session_id, activated_authconn; + struct Packet *pktout; + int dlgret; + int guessok; + int ignorepkt; + }; + crState(do_ssh2_transport_state); + + assert(!ssh->bare_connection); + + crBeginState; + + s->cscipher_tobe = s->sccipher_tobe = NULL; + s->csmac_tobe = s->scmac_tobe = NULL; + s->cscomp_tobe = s->sccomp_tobe = NULL; + + s->got_session_id = s->activated_authconn = FALSE; + s->userauth_succeeded = FALSE; + s->pending_compression = FALSE; + + /* + * Be prepared to work around the buggy MAC problem. + */ + if (ssh->remote_bugs & BUG_SSH2_HMAC) + s->maclist = buggymacs, s->nmacs = lenof(buggymacs); + else + s->maclist = macs, s->nmacs = lenof(macs); + + begin_key_exchange: + ssh->pkt_kctx = SSH2_PKTCTX_NOKEX; + { + int i, j, k, commalist_started; + + /* + * Set up the preferred key exchange. (NULL => warn below here) + */ + s->n_preferred_kex = 0; + for (i = 0; i < KEX_MAX; i++) { + switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) { + case KEX_DHGEX: + s->preferred_kex[s->n_preferred_kex++] = + &ssh_diffiehellman_gex; + break; + case KEX_DHGROUP14: + s->preferred_kex[s->n_preferred_kex++] = + &ssh_diffiehellman_group14; + break; + case KEX_DHGROUP1: + s->preferred_kex[s->n_preferred_kex++] = + &ssh_diffiehellman_group1; + break; + case KEX_RSA: + s->preferred_kex[s->n_preferred_kex++] = + &ssh_rsa_kex; + break; + case KEX_WARN: + /* Flag for later. Don't bother if it's the last in + * the list. */ + if (i < KEX_MAX - 1) { + s->preferred_kex[s->n_preferred_kex++] = NULL; + } + break; + } + } + + /* + * Set up the preferred ciphers. (NULL => warn below here) + */ + s->n_preferred_ciphers = 0; + for (i = 0; i < CIPHER_MAX; i++) { + switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) { + case CIPHER_BLOWFISH: + s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish; + break; + case CIPHER_DES: + if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) { + s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des; + } + break; + case CIPHER_3DES: + s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des; + break; + case CIPHER_AES: + s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes; + break; + case CIPHER_ARCFOUR: + s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour; + break; + case CIPHER_WARN: + /* Flag for later. Don't bother if it's the last in + * the list. */ + if (i < CIPHER_MAX - 1) { + s->preferred_ciphers[s->n_preferred_ciphers++] = NULL; + } + break; + } + } + + /* + * Set up preferred compression. + */ + if (conf_get_int(ssh->conf, CONF_compression)) + s->preferred_comp = &ssh_zlib; + else + s->preferred_comp = &ssh_comp_none; + + /* + * Enable queueing of outgoing auth- or connection-layer + * packets while we are in the middle of a key exchange. + */ + ssh->queueing = TRUE; + + /* + * Flag that KEX is in progress. + */ + ssh->kex_in_progress = TRUE; + + /* + * Construct and send our key exchange packet. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT); + for (i = 0; i < 16; i++) + ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte()); + /* List key exchange algorithms. */ + ssh2_pkt_addstring_start(s->pktout); + commalist_started = 0; + for (i = 0; i < s->n_preferred_kex; i++) { + const struct ssh_kexes *k = s->preferred_kex[i]; + if (!k) continue; /* warning flag */ + for (j = 0; j < k->nkexes; j++) { + if (commalist_started) + ssh2_pkt_addstring_str(s->pktout, ","); + ssh2_pkt_addstring_str(s->pktout, k->list[j]->name); + commalist_started = 1; + } + } + /* List server host key algorithms. */ + if (!s->got_session_id) { + /* + * In the first key exchange, we list all the algorithms + * we're prepared to cope with. + */ + ssh2_pkt_addstring_start(s->pktout); + for (i = 0; i < lenof(hostkey_algs); i++) { + ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name); + if (i < lenof(hostkey_algs) - 1) + ssh2_pkt_addstring_str(s->pktout, ","); + } + } else { + /* + * In subsequent key exchanges, we list only the kex + * algorithm that was selected in the first key exchange, + * so that we keep getting the same host key and hence + * don't have to interrupt the user's session to ask for + * reverification. + */ + assert(ssh->kex); + ssh2_pkt_addstring(s->pktout, ssh->hostkey->name); + } + /* List encryption algorithms (client->server then server->client). */ + for (k = 0; k < 2; k++) { + ssh2_pkt_addstring_start(s->pktout); + commalist_started = 0; + for (i = 0; i < s->n_preferred_ciphers; i++) { + const struct ssh2_ciphers *c = s->preferred_ciphers[i]; + if (!c) continue; /* warning flag */ + for (j = 0; j < c->nciphers; j++) { + if (commalist_started) + ssh2_pkt_addstring_str(s->pktout, ","); + ssh2_pkt_addstring_str(s->pktout, c->list[j]->name); + commalist_started = 1; + } + } + } + /* List MAC algorithms (client->server then server->client). */ + for (j = 0; j < 2; j++) { + ssh2_pkt_addstring_start(s->pktout); + for (i = 0; i < s->nmacs; i++) { + ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name); + if (i < s->nmacs - 1) + ssh2_pkt_addstring_str(s->pktout, ","); + } + } + /* List client->server compression algorithms, + * then server->client compression algorithms. (We use the + * same set twice.) */ + for (j = 0; j < 2; j++) { + ssh2_pkt_addstring_start(s->pktout); + assert(lenof(compressions) > 1); + /* Prefer non-delayed versions */ + ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name); + /* We don't even list delayed versions of algorithms until + * they're allowed to be used, to avoid a race. See the end of + * this function. */ + if (s->userauth_succeeded && s->preferred_comp->delayed_name) { + ssh2_pkt_addstring_str(s->pktout, ","); + ssh2_pkt_addstring_str(s->pktout, + s->preferred_comp->delayed_name); + } + for (i = 0; i < lenof(compressions); i++) { + const struct ssh_compress *c = compressions[i]; + if (c != s->preferred_comp) { + ssh2_pkt_addstring_str(s->pktout, ","); + ssh2_pkt_addstring_str(s->pktout, c->name); + if (s->userauth_succeeded && c->delayed_name) { + ssh2_pkt_addstring_str(s->pktout, ","); + ssh2_pkt_addstring_str(s->pktout, c->delayed_name); + } + } + } + } + /* List client->server languages. Empty list. */ + ssh2_pkt_addstring_start(s->pktout); + /* List server->client languages. Empty list. */ + ssh2_pkt_addstring_start(s->pktout); + /* First KEX packet does _not_ follow, because we're not that brave. */ + ssh2_pkt_addbool(s->pktout, FALSE); + /* Reserved. */ + ssh2_pkt_adduint32(s->pktout, 0); + } + + s->our_kexinitlen = s->pktout->length - 5; + s->our_kexinit = snewn(s->our_kexinitlen, unsigned char); + memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen); + + ssh2_pkt_send_noqueue(ssh, s->pktout); + + if (!pktin) + crWaitUntilV(pktin); + + /* + * Now examine the other side's KEXINIT to see what we're up + * to. + */ + { + char *str, *preferred; + int i, j, len; + + if (pktin->type != SSH2_MSG_KEXINIT) { + bombout(("expected key exchange packet from server")); + crStopV; + } + ssh->kex = NULL; + ssh->hostkey = NULL; + s->cscipher_tobe = NULL; + s->sccipher_tobe = NULL; + s->csmac_tobe = NULL; + s->scmac_tobe = NULL; + s->cscomp_tobe = NULL; + s->sccomp_tobe = NULL; + s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE; + + pktin->savedpos += 16; /* skip garbage cookie */ + ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */ + + preferred = NULL; + for (i = 0; i < s->n_preferred_kex; i++) { + const struct ssh_kexes *k = s->preferred_kex[i]; + if (!k) { + s->warn_kex = TRUE; + } else { + for (j = 0; j < k->nkexes; j++) { + if (!preferred) preferred = k->list[j]->name; + if (in_commasep_string(k->list[j]->name, str, len)) { + ssh->kex = k->list[j]; + break; + } + } + } + if (ssh->kex) + break; + } + if (!ssh->kex) { + bombout(("Couldn't agree a key exchange algorithm (available: %s)", + str ? str : "(null)")); + crStopV; + } + /* + * Note that the server's guess is considered wrong if it doesn't match + * the first algorithm in our list, even if it's still the algorithm + * we end up using. + */ + s->guessok = first_in_commasep_string(preferred, str, len); + ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */ + for (i = 0; i < lenof(hostkey_algs); i++) { + if (in_commasep_string(hostkey_algs[i]->name, str, len)) { + ssh->hostkey = hostkey_algs[i]; + break; + } + } + if (!ssh->hostkey) { + bombout(("Couldn't agree a host key algorithm (available: %s)", + str ? str : "(null)")); + crStopV; + } + + s->guessok = s->guessok && + first_in_commasep_string(hostkey_algs[0]->name, str, len); + ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */ + for (i = 0; i < s->n_preferred_ciphers; i++) { + const struct ssh2_ciphers *c = s->preferred_ciphers[i]; + if (!c) { + s->warn_cscipher = TRUE; + } else { + for (j = 0; j < c->nciphers; j++) { + if (in_commasep_string(c->list[j]->name, str, len)) { + s->cscipher_tobe = c->list[j]; + break; + } + } + } + if (s->cscipher_tobe) + break; + } + if (!s->cscipher_tobe) { + bombout(("Couldn't agree a client-to-server cipher (available: %s)", + str ? str : "(null)")); + crStopV; + } + + ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */ + for (i = 0; i < s->n_preferred_ciphers; i++) { + const struct ssh2_ciphers *c = s->preferred_ciphers[i]; + if (!c) { + s->warn_sccipher = TRUE; + } else { + for (j = 0; j < c->nciphers; j++) { + if (in_commasep_string(c->list[j]->name, str, len)) { + s->sccipher_tobe = c->list[j]; + break; + } + } + } + if (s->sccipher_tobe) + break; + } + if (!s->sccipher_tobe) { + bombout(("Couldn't agree a server-to-client cipher (available: %s)", + str ? str : "(null)")); + crStopV; + } + + ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */ + for (i = 0; i < s->nmacs; i++) { + if (in_commasep_string(s->maclist[i]->name, str, len)) { + s->csmac_tobe = s->maclist[i]; + break; + } + } + ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */ + for (i = 0; i < s->nmacs; i++) { + if (in_commasep_string(s->maclist[i]->name, str, len)) { + s->scmac_tobe = s->maclist[i]; + break; + } + } + ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */ + for (i = 0; i < lenof(compressions) + 1; i++) { + const struct ssh_compress *c = + i == 0 ? s->preferred_comp : compressions[i - 1]; + if (in_commasep_string(c->name, str, len)) { + s->cscomp_tobe = c; + break; + } else if (in_commasep_string(c->delayed_name, str, len)) { + if (s->userauth_succeeded) { + s->cscomp_tobe = c; + break; + } else { + s->pending_compression = TRUE; /* try this later */ + } + } + } + ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */ + for (i = 0; i < lenof(compressions) + 1; i++) { + const struct ssh_compress *c = + i == 0 ? s->preferred_comp : compressions[i - 1]; + if (in_commasep_string(c->name, str, len)) { + s->sccomp_tobe = c; + break; + } else if (in_commasep_string(c->delayed_name, str, len)) { + if (s->userauth_succeeded) { + s->sccomp_tobe = c; + break; + } else { + s->pending_compression = TRUE; /* try this later */ + } + } + } + if (s->pending_compression) { + logevent("Server supports delayed compression; " + "will try this later"); + } + ssh_pkt_getstring(pktin, &str, &len); /* client->server language */ + ssh_pkt_getstring(pktin, &str, &len); /* server->client language */ + s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok; + + ssh->exhash = ssh->kex->hash->init(); + hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c)); + hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s)); + hash_string(ssh->kex->hash, ssh->exhash, + s->our_kexinit, s->our_kexinitlen); + sfree(s->our_kexinit); + /* Include the type byte in the hash of server's KEXINIT */ + hash_string(ssh->kex->hash, ssh->exhash, + pktin->body - 1, pktin->length + 1); + + if (s->warn_kex) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, "key-exchange algorithm", + ssh->kex->name, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for user response")); + crStopV; + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at kex warning", NULL, + 0, TRUE); + crStopV; + } + } + + if (s->warn_cscipher) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, + "client-to-server cipher", + s->cscipher_tobe->name, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for user response")); + crStopV; + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at cipher warning", NULL, + 0, TRUE); + crStopV; + } + } + + if (s->warn_sccipher) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, + "server-to-client cipher", + s->sccipher_tobe->name, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for user response")); + crStopV; + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at cipher warning", NULL, + 0, TRUE); + crStopV; + } + } + + if (s->ignorepkt) /* first_kex_packet_follows */ + crWaitUntilV(pktin); /* Ignore packet */ + } + + if (ssh->kex->main_type == KEXTYPE_DH) { + /* + * Work out the number of bits of key we will need from the + * key exchange. We start with the maximum key length of + * either cipher... + */ + { + int csbits, scbits; + + csbits = s->cscipher_tobe->keylen; + scbits = s->sccipher_tobe->keylen; + s->nbits = (csbits > scbits ? csbits : scbits); + } + /* The keys only have hlen-bit entropy, since they're based on + * a hash. So cap the key size at hlen bits. */ + if (s->nbits > ssh->kex->hash->hlen * 8) + s->nbits = ssh->kex->hash->hlen * 8; + + /* + * If we're doing Diffie-Hellman group exchange, start by + * requesting a group. + */ + if (!ssh->kex->pdata) { + logevent("Doing Diffie-Hellman group exchange"); + ssh->pkt_kctx = SSH2_PKTCTX_DHGEX; + /* + * Work out how big a DH group we will need to allow that + * much data. + */ + s->pbits = 512 << ((s->nbits - 1) / 64); + s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST); + ssh2_pkt_adduint32(s->pktout, s->pbits); + ssh2_pkt_send_noqueue(ssh, s->pktout); + + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) { + bombout(("expected key exchange group packet from server")); + crStopV; + } + s->p = ssh2_pkt_getmp(pktin); + s->g = ssh2_pkt_getmp(pktin); + if (!s->p || !s->g) { + bombout(("unable to read mp-ints from incoming group packet")); + crStopV; + } + ssh->kex_ctx = dh_setup_gex(s->p, s->g); + s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; + s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; + } else { + ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP; + ssh->kex_ctx = dh_setup_group(ssh->kex); + s->kex_init_value = SSH2_MSG_KEXDH_INIT; + s->kex_reply_value = SSH2_MSG_KEXDH_REPLY; + logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"", + ssh->kex->groupname); + } + + logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s", + ssh->kex->hash->text_name); + /* + * Now generate and send e for Diffie-Hellman. + */ + set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */ + s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2); + s->pktout = ssh2_pkt_init(s->kex_init_value); + ssh2_pkt_addmp(s->pktout, s->e); + ssh2_pkt_send_noqueue(ssh, s->pktout); + + set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */ + crWaitUntilV(pktin); + if (pktin->type != s->kex_reply_value) { + bombout(("expected key exchange reply packet from server")); + crStopV; + } + set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */ + ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen); + s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen); + s->f = ssh2_pkt_getmp(pktin); + if (!s->f) { + bombout(("unable to parse key exchange reply packet")); + crStopV; + } + ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen); + + s->K = dh_find_K(ssh->kex_ctx, s->f); + + /* We assume everything from now on will be quick, and it might + * involve user interaction. */ + set_busy_status(ssh->frontend, BUSY_NOT); + + hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen); + if (!ssh->kex->pdata) { + hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits); + hash_mpint(ssh->kex->hash, ssh->exhash, s->p); + hash_mpint(ssh->kex->hash, ssh->exhash, s->g); + } + hash_mpint(ssh->kex->hash, ssh->exhash, s->e); + hash_mpint(ssh->kex->hash, ssh->exhash, s->f); + + dh_cleanup(ssh->kex_ctx); + freebn(s->f); + if (!ssh->kex->pdata) { + freebn(s->g); + freebn(s->p); + } + } else { + logeventf(ssh, "Doing RSA key exchange with hash %s", + ssh->kex->hash->text_name); + ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX; + /* + * RSA key exchange. First expect a KEXRSA_PUBKEY packet + * from the server. + */ + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) { + bombout(("expected RSA public key packet from server")); + crStopV; + } + + ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen); + hash_string(ssh->kex->hash, ssh->exhash, + s->hostkeydata, s->hostkeylen); + s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen); + + { + char *keydata; + ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen); + s->rsakeydata = snewn(s->rsakeylen, char); + memcpy(s->rsakeydata, keydata, s->rsakeylen); + } + + s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen); + if (!s->rsakey) { + sfree(s->rsakeydata); + bombout(("unable to parse RSA public key from server")); + crStopV; + } + + hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen); + + /* + * Next, set up a shared secret K, of precisely KLEN - + * 2*HLEN - 49 bits, where KLEN is the bit length of the + * RSA key modulus and HLEN is the bit length of the hash + * we're using. + */ + { + int klen = ssh_rsakex_klen(s->rsakey); + int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49); + int i, byte = 0; + unsigned char *kstr1, *kstr2, *outstr; + int kstr1len, kstr2len, outstrlen; + + s->K = bn_power_2(nbits - 1); + + for (i = 0; i < nbits; i++) { + if ((i & 7) == 0) { + byte = random_byte(); + } + bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1); + } + + /* + * Encode this as an mpint. + */ + kstr1 = ssh2_mpint_fmt(s->K, &kstr1len); + kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char); + PUT_32BIT(kstr2, kstr1len); + memcpy(kstr2 + 4, kstr1, kstr1len); + + /* + * Encrypt it with the given RSA key. + */ + outstrlen = (klen + 7) / 8; + outstr = snewn(outstrlen, unsigned char); + ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len, + outstr, outstrlen, s->rsakey); + + /* + * And send it off in a return packet. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen); + ssh2_pkt_send_noqueue(ssh, s->pktout); + + hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen); + + sfree(kstr2); + sfree(kstr1); + sfree(outstr); + } + + ssh_rsakex_freekey(s->rsakey); + + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_KEXRSA_DONE) { + sfree(s->rsakeydata); + bombout(("expected signature packet from server")); + crStopV; + } + + ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen); + + sfree(s->rsakeydata); + } + + hash_mpint(ssh->kex->hash, ssh->exhash, s->K); + assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash)); + ssh->kex->hash->final(ssh->exhash, s->exchange_hash); + + ssh->kex_ctx = NULL; + +#if 0 + debug(("Exchange hash is:\n")); + dmemdump(s->exchange_hash, ssh->kex->hash->hlen); +#endif + + if (!s->hkey || + !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen, + (char *)s->exchange_hash, + ssh->kex->hash->hlen)) { + bombout(("Server's host key did not match the signature supplied")); + crStopV; + } + + s->keystr = ssh->hostkey->fmtkey(s->hkey); + if (!s->got_session_id) { + /* + * Authenticate remote host: verify host key. (We've already + * checked the signature of the exchange hash.) + */ + s->fingerprint = ssh->hostkey->fingerprint(s->hkey); + ssh_set_frozen(ssh, 1); + s->dlgret = verify_ssh_host_key(ssh->frontend, + ssh->savedhost, ssh->savedport, + ssh->hostkey->keytype, s->keystr, + s->fingerprint, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server while waiting" + " for user host key response")); + crStopV; + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at host key verification", NULL, + 0, TRUE); + crStopV; + } + logevent("Host key fingerprint is:"); + logevent(s->fingerprint); + sfree(s->fingerprint); + /* + * Save this host key, to check against the one presented in + * subsequent rekeys. + */ + ssh->hostkey_str = s->keystr; + } else { + /* + * In a rekey, we never present an interactive host key + * verification request to the user. Instead, we simply + * enforce that the key we're seeing this time is identical to + * the one we saw before. + */ + if (strcmp(ssh->hostkey_str, s->keystr)) { + bombout(("Host key was different in repeat key exchange")); + crStopV; + } + sfree(s->keystr); + } + ssh->hostkey->freekey(s->hkey); + + /* + * The exchange hash from the very first key exchange is also + * the session id, used in session key construction and + * authentication. + */ + if (!s->got_session_id) { + assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id)); + memcpy(ssh->v2_session_id, s->exchange_hash, + sizeof(s->exchange_hash)); + ssh->v2_session_id_len = ssh->kex->hash->hlen; + assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id)); + s->got_session_id = TRUE; + } + + /* + * Send SSH2_MSG_NEWKEYS. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS); + ssh2_pkt_send_noqueue(ssh, s->pktout); + ssh->outgoing_data_size = 0; /* start counting from here */ + + /* + * We've sent client NEWKEYS, so create and initialise + * client-to-server session keys. + */ + if (ssh->cs_cipher_ctx) + ssh->cscipher->free_context(ssh->cs_cipher_ctx); + ssh->cscipher = s->cscipher_tobe; + ssh->cs_cipher_ctx = ssh->cscipher->make_context(); + + if (ssh->cs_mac_ctx) + ssh->csmac->free_context(ssh->cs_mac_ctx); + ssh->csmac = s->csmac_tobe; + ssh->cs_mac_ctx = ssh->csmac->make_context(); + + if (ssh->cs_comp_ctx) + ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); + ssh->cscomp = s->cscomp_tobe; + ssh->cs_comp_ctx = ssh->cscomp->compress_init(); + + /* + * Set IVs on client-to-server keys. Here we use the exchange + * hash from the _first_ key exchange. + */ + { + unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS]; + assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace); + assert((ssh->cscipher->keylen+7) / 8 <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace); + assert(ssh->cscipher->blksize <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace); + assert(ssh->csmac->len <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace); + smemclr(keyspace, sizeof(keyspace)); + } + + logeventf(ssh, "Initialised %.200s client->server encryption", + ssh->cscipher->text_name); + logeventf(ssh, "Initialised %.200s client->server MAC algorithm", + ssh->csmac->text_name); + if (ssh->cscomp->text_name) + logeventf(ssh, "Initialised %s compression", + ssh->cscomp->text_name); + + /* + * Now our end of the key exchange is complete, we can send all + * our queued higher-layer packets. + */ + ssh->queueing = FALSE; + ssh2_pkt_queuesend(ssh); + + /* + * Expect SSH2_MSG_NEWKEYS from server. + */ + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_NEWKEYS) { + bombout(("expected new-keys packet from server")); + crStopV; + } + ssh->incoming_data_size = 0; /* start counting from here */ + + /* + * We've seen server NEWKEYS, so create and initialise + * server-to-client session keys. + */ + if (ssh->sc_cipher_ctx) + ssh->sccipher->free_context(ssh->sc_cipher_ctx); + ssh->sccipher = s->sccipher_tobe; + ssh->sc_cipher_ctx = ssh->sccipher->make_context(); + + if (ssh->sc_mac_ctx) + ssh->scmac->free_context(ssh->sc_mac_ctx); + ssh->scmac = s->scmac_tobe; + ssh->sc_mac_ctx = ssh->scmac->make_context(); + + if (ssh->sc_comp_ctx) + ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx); + ssh->sccomp = s->sccomp_tobe; + ssh->sc_comp_ctx = ssh->sccomp->decompress_init(); + + /* + * Set IVs on server-to-client keys. Here we use the exchange + * hash from the _first_ key exchange. + */ + { + unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS]; + assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace); + assert((ssh->sccipher->keylen+7) / 8 <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace); + assert(ssh->sccipher->blksize <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace); + ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace); + assert(ssh->scmac->len <= + ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); + ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace); + smemclr(keyspace, sizeof(keyspace)); + } + logeventf(ssh, "Initialised %.200s server->client encryption", + ssh->sccipher->text_name); + logeventf(ssh, "Initialised %.200s server->client MAC algorithm", + ssh->scmac->text_name); + if (ssh->sccomp->text_name) + logeventf(ssh, "Initialised %s decompression", + ssh->sccomp->text_name); + + /* + * Free shared secret. + */ + freebn(s->K); + + /* + * Key exchange is over. Loop straight back round if we have a + * deferred rekey reason. + */ + if (ssh->deferred_rekey_reason) { + logevent(ssh->deferred_rekey_reason); + pktin = NULL; + ssh->deferred_rekey_reason = NULL; + goto begin_key_exchange; + } + + /* + * Otherwise, schedule a timer for our next rekey. + */ + ssh->kex_in_progress = FALSE; + ssh->last_rekey = GETTICKCOUNT(); + if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) + ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC, + ssh2_timer, ssh); + + /* + * Now we're encrypting. Begin returning 1 to the protocol main + * function so that other things can run on top of the + * transport. If we ever see a KEXINIT, we must go back to the + * start. + * + * We _also_ go back to the start if we see pktin==NULL and + * inlen negative, because this is a special signal meaning + * `initiate client-driven rekey', and `in' contains a message + * giving the reason for the rekey. + * + * inlen==-1 means always initiate a rekey; + * inlen==-2 means that userauth has completed successfully and + * we should consider rekeying (for delayed compression). + */ + while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) || + (!pktin && inlen < 0))) { + wait_for_rekey: + if (!ssh->protocol_initial_phase_done) { + ssh->protocol_initial_phase_done = TRUE; + /* + * Allow authconn to initialise itself. + */ + do_ssh2_authconn(ssh, NULL, 0, NULL); + } + crReturnV; + } + if (pktin) { + logevent("Server initiated key re-exchange"); + } else { + if (inlen == -2) { + /* + * authconn has seen a USERAUTH_SUCCEEDED. Time to enable + * delayed compression, if it's available. + * + * draft-miller-secsh-compression-delayed-00 says that you + * negotiate delayed compression in the first key exchange, and + * both sides start compressing when the server has sent + * USERAUTH_SUCCESS. This has a race condition -- the server + * can't know when the client has seen it, and thus which incoming + * packets it should treat as compressed. + * + * Instead, we do the initial key exchange without offering the + * delayed methods, but note if the server offers them; when we + * get here, if a delayed method was available that was higher + * on our list than what we got, we initiate a rekey in which we + * _do_ list the delayed methods (and hopefully get it as a + * result). Subsequent rekeys will do the same. + */ + assert(!s->userauth_succeeded); /* should only happen once */ + s->userauth_succeeded = TRUE; + if (!s->pending_compression) + /* Can't see any point rekeying. */ + goto wait_for_rekey; /* this is utterly horrid */ + /* else fall through to rekey... */ + s->pending_compression = FALSE; + } + /* + * Now we've decided to rekey. + * + * Special case: if the server bug is set that doesn't + * allow rekeying, we give a different log message and + * continue waiting. (If such a server _initiates_ a rekey, + * we process it anyway!) + */ + if ((ssh->remote_bugs & BUG_SSH2_REKEY)) { + logeventf(ssh, "Server bug prevents key re-exchange (%s)", + (char *)in); + /* Reset the counters, so that at least this message doesn't + * hit the event log _too_ often. */ + ssh->outgoing_data_size = 0; + ssh->incoming_data_size = 0; + if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) { + ssh->next_rekey = + schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC, + ssh2_timer, ssh); + } + goto wait_for_rekey; /* this is still utterly horrid */ + } else { + logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in); + } + } + goto begin_key_exchange; + + crFinishV; +} + +/* + * Add data to an SSH-2 channel output buffer. + */ +static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, + int len) +{ + bufchain_add(&c->v.v2.outbuffer, buf, len); +} + +/* + * Attempt to send data on an SSH-2 channel. + */ +static int ssh2_try_send(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + struct Packet *pktout; + int ret; + + while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) { + int len; + void *data; + bufchain_prefix(&c->v.v2.outbuffer, &data, &len); + if ((unsigned)len > c->v.v2.remwindow) + len = c->v.v2.remwindow; + if ((unsigned)len > c->v.v2.remmaxpkt) + len = c->v.v2.remmaxpkt; + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_addstring_start(pktout); + ssh2_pkt_addstring_data(pktout, data, len); + ssh2_pkt_send(ssh, pktout); + bufchain_consume(&c->v.v2.outbuffer, len); + c->v.v2.remwindow -= len; + } + + /* + * After having sent as much data as we can, return the amount + * still buffered. + */ + ret = bufchain_size(&c->v.v2.outbuffer); + + /* + * And if there's no data pending but we need to send an EOF, send + * it. + */ + if (!ret && c->pending_eof) + ssh_channel_try_eof(c); + + return ret; +} + +static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c) +{ + int bufsize; + if (c->closes & CLOSES_SENT_EOF) + return; /* don't send on channels we've EOFed */ + bufsize = ssh2_try_send(c); + if (bufsize == 0) { + switch (c->type) { + case CHAN_MAINSESSION: + /* stdin need not receive an unthrottle + * notification since it will be polled */ + break; + case CHAN_X11: + x11_unthrottle(c->u.x11.xconn); + break; + case CHAN_AGENT: + /* agent sockets are request/response and need no + * buffer management */ + break; + case CHAN_SOCKDATA: + pfd_unthrottle(c->u.pfd.pf); + break; + } + } +} + +static int ssh_is_simple(Ssh ssh) +{ + /* + * We use the 'simple' variant of the SSH protocol if we're asked + * to, except not if we're also doing connection-sharing (either + * tunnelling our packets over an upstream or expecting to be + * tunnelled over ourselves), since then the assumption that we + * have only one channel to worry about is not true after all. + */ + return (conf_get_int(ssh->conf, CONF_ssh_simple) && + !ssh->bare_connection && !ssh->connshare); +} + +/* + * Set up most of a new ssh_channel for SSH-2. + */ +static void ssh2_channel_init(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + c->localid = alloc_channel_id(ssh); + c->closes = 0; + c->pending_eof = FALSE; + c->throttling_conn = FALSE; + c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin = + ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE; + c->v.v2.chanreq_head = NULL; + c->v.v2.throttle_state = UNTHROTTLED; + bufchain_init(&c->v.v2.outbuffer); +} + +/* + * Construct the common parts of a CHANNEL_OPEN. + */ +static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type) +{ + struct Packet *pktout; + + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); + ssh2_pkt_addstring(pktout, type); + ssh2_pkt_adduint32(pktout, c->localid); + ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */ + ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */ + return pktout; +} + +/* + * CHANNEL_FAILURE doesn't come with any indication of what message + * caused it, so we have to keep track of the outstanding + * CHANNEL_REQUESTs ourselves. + */ +static void ssh2_queue_chanreq_handler(struct ssh_channel *c, + cchandler_fn_t handler, void *ctx) +{ + struct outstanding_channel_request *ocr = + snew(struct outstanding_channel_request); + + assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE))); + ocr->handler = handler; + ocr->ctx = ctx; + ocr->next = NULL; + if (!c->v.v2.chanreq_head) + c->v.v2.chanreq_head = ocr; + else + c->v.v2.chanreq_tail->next = ocr; + c->v.v2.chanreq_tail = ocr; +} + +/* + * Construct the common parts of a CHANNEL_REQUEST. If handler is not + * NULL then a reply will be requested and the handler will be called + * when it arrives. The returned packet is ready to have any + * request-specific data added and be sent. Note that if a handler is + * provided, it's essential that the request actually be sent. + * + * The handler will usually be passed the response packet in pktin. + * If pktin is NULL, this means that no reply will ever be forthcoming + * (e.g. because the entire connection is being destroyed) and the + * handler should free any storage it's holding. + */ +static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type, + cchandler_fn_t handler, void *ctx) +{ + struct Packet *pktout; + + assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE))); + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_addstring(pktout, type); + ssh2_pkt_addbool(pktout, handler != NULL); + if (handler != NULL) + ssh2_queue_chanreq_handler(c, handler, ctx); + return pktout; +} + +/* + * Potentially enlarge the window on an SSH-2 channel. + */ +static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *, + void *); +static void ssh2_set_window(struct ssh_channel *c, int newwin) +{ + Ssh ssh = c->ssh; + + /* + * Never send WINDOW_ADJUST for a channel that the remote side has + * already sent EOF on; there's no point, since it won't be + * sending any more data anyway. Ditto if _we've_ already sent + * CLOSE. + */ + if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE)) + return; + + /* + * Also, never widen the window for an X11 channel when we're + * still waiting to see its initial auth and may yet hand it off + * to a downstream. + */ + if (c->type == CHAN_X11 && c->u.x11.initial) + return; + + /* + * If the remote end has a habit of ignoring maxpkt, limit the + * window so that it has no choice (assuming it doesn't ignore the + * window as well). + */ + if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT) + newwin = OUR_V2_MAXPKT; + + /* + * Only send a WINDOW_ADJUST if there's significantly more window + * available than the other end thinks there is. This saves us + * sending a WINDOW_ADJUST for every character in a shell session. + * + * "Significant" is arbitrarily defined as half the window size. + */ + if (newwin / 2 >= c->v.v2.locwindow) { + struct Packet *pktout; + unsigned *up; + + /* + * In order to keep track of how much window the client + * actually has available, we'd like it to acknowledge each + * WINDOW_ADJUST. We can't do that directly, so we accompany + * it with a CHANNEL_REQUEST that has to be acknowledged. + * + * This is only necessary if we're opening the window wide. + * If we're not, then throughput is being constrained by + * something other than the maximum window size anyway. + */ + if (newwin == c->v.v2.locmaxwin && + !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) { + up = snew(unsigned); + *up = newwin - c->v.v2.locwindow; + pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org", + ssh2_handle_winadj_response, up); + ssh2_pkt_send(ssh, pktout); + + if (c->v.v2.throttle_state != UNTHROTTLED) + c->v.v2.throttle_state = UNTHROTTLING; + } else { + /* Pretend the WINDOW_ADJUST was acked immediately. */ + c->v.v2.remlocwin = newwin; + c->v.v2.throttle_state = THROTTLED; + } + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow); + ssh2_pkt_send(ssh, pktout); + c->v.v2.locwindow = newwin; + } +} + +/* + * Find the channel associated with a message. If there's no channel, + * or it's not properly open, make a noise about it and return NULL. + */ +static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin) +{ + unsigned localid = ssh_pkt_getuint32(pktin); + struct ssh_channel *c; + + c = find234(ssh->channels, &localid, ssh_channelfind); + if (!c || + (c->type != CHAN_SHARING && c->halfopen && + pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION && + pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) { + char *buf = dupprintf("Received %s for %s channel %u", + ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, + pktin->type), + c ? "half-open" : "nonexistent", localid); + ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); + sfree(buf); + return NULL; + } + return c; +} + +static void ssh2_handle_winadj_response(struct ssh_channel *c, + struct Packet *pktin, void *ctx) +{ + unsigned *sizep = ctx; + + /* + * Winadj responses should always be failures. However, at least + * one server ("boks_sshd") is known to return SUCCESS for channel + * requests it's never heard of, such as "winadj@putty". Raised + * with foxt.com as bug 090916-090424, but for the sake of a quiet + * life, we don't worry about what kind of response we got. + */ + + c->v.v2.remlocwin += *sizep; + sfree(sizep); + /* + * winadj messages are only sent when the window is fully open, so + * if we get an ack of one, we know any pending unthrottle is + * complete. + */ + if (c->v.v2.throttle_state == UNTHROTTLING) + c->v.v2.throttle_state = UNTHROTTLED; +} + +static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin) +{ + struct ssh_channel *c = ssh2_channel_msg(ssh, pktin); + struct outstanding_channel_request *ocr; + + if (!c) return; + if (c->type == CHAN_SHARING) { + share_got_pkt_from_server(c->u.sharing.ctx, pktin->type, + pktin->body, pktin->length); + return; + } + ocr = c->v.v2.chanreq_head; + if (!ocr) { + ssh2_msg_unexpected(ssh, pktin); + return; + } + ocr->handler(c, pktin, ocr->ctx); + c->v.v2.chanreq_head = ocr->next; + sfree(ocr); + /* + * We may now initiate channel-closing procedures, if that + * CHANNEL_REQUEST was the last thing outstanding before we send + * CHANNEL_CLOSE. + */ + ssh2_channel_check_close(c); +} + +static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin) +{ + struct ssh_channel *c; + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + if (c->type == CHAN_SHARING) { + share_got_pkt_from_server(c->u.sharing.ctx, pktin->type, + pktin->body, pktin->length); + return; + } + if (!(c->closes & CLOSES_SENT_EOF)) { + c->v.v2.remwindow += ssh_pkt_getuint32(pktin); + ssh2_try_send_and_unthrottle(ssh, c); + } +} + +static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin) +{ + char *data; + int length; + struct ssh_channel *c; + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + if (c->type == CHAN_SHARING) { + share_got_pkt_from_server(c->u.sharing.ctx, pktin->type, + pktin->body, pktin->length); + return; + } + if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA && + ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR) + return; /* extended but not stderr */ + ssh_pkt_getstring(pktin, &data, &length); + if (data) { + int bufsize = 0; + c->v.v2.locwindow -= length; + c->v.v2.remlocwin -= length; + switch (c->type) { + case CHAN_MAINSESSION: + bufsize = + from_backend(ssh->frontend, pktin->type == + SSH2_MSG_CHANNEL_EXTENDED_DATA, + data, length); + break; + case CHAN_X11: + bufsize = x11_send(c->u.x11.xconn, data, length); + break; + case CHAN_SOCKDATA: + bufsize = pfd_send(c->u.pfd.pf, data, length); + break; + case CHAN_AGENT: + while (length > 0) { + if (c->u.a.lensofar < 4) { + unsigned int l = min(4 - c->u.a.lensofar, + (unsigned)length); + memcpy(c->u.a.msglen + c->u.a.lensofar, + data, l); + data += l; + length -= l; + c->u.a.lensofar += l; + } + if (c->u.a.lensofar == 4) { + c->u.a.totallen = + 4 + GET_32BIT(c->u.a.msglen); + c->u.a.message = snewn(c->u.a.totallen, + unsigned char); + memcpy(c->u.a.message, c->u.a.msglen, 4); + } + if (c->u.a.lensofar >= 4 && length > 0) { + unsigned int l = + min(c->u.a.totallen - c->u.a.lensofar, + (unsigned)length); + memcpy(c->u.a.message + c->u.a.lensofar, + data, l); + data += l; + length -= l; + c->u.a.lensofar += l; + } + if (c->u.a.lensofar == c->u.a.totallen) { + void *reply; + int replylen; + c->u.a.outstanding_requests++; + if (agent_query(c->u.a.message, + c->u.a.totallen, + &reply, &replylen, + ssh_agentf_callback, c)) + ssh_agentf_callback(c, reply, replylen); + sfree(c->u.a.message); + c->u.a.message = NULL; + c->u.a.lensofar = 0; + } + } + bufsize = 0; + break; + } + /* + * If it looks like the remote end hit the end of its window, + * and we didn't want it to do that, think about using a + * larger window. + */ + if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED && + c->v.v2.locmaxwin < 0x40000000) + c->v.v2.locmaxwin += OUR_V2_WINSIZE; + /* + * If we are not buffering too much data, + * enlarge the window again at the remote side. + * If we are buffering too much, we may still + * need to adjust the window if the server's + * sent excess data. + */ + ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ? + c->v.v2.locmaxwin - bufsize : 0); + /* + * If we're either buffering way too much data, or if we're + * buffering anything at all and we're in "simple" mode, + * throttle the whole channel. + */ + if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0)) + && !c->throttling_conn) { + c->throttling_conn = 1; + ssh_throttle_conn(ssh, +1); + } + } +} + +static void ssh_check_termination(Ssh ssh) +{ + if (ssh->version == 2 && + !conf_get_int(ssh->conf, CONF_ssh_no_shell) && + count234(ssh->channels) == 0 && + !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) { + /* + * We used to send SSH_MSG_DISCONNECT here, because I'd + * believed that _every_ conforming SSH-2 connection had to + * end with a disconnect being sent by at least one side; + * apparently I was wrong and it's perfectly OK to + * unceremoniously slam the connection shut when you're done, + * and indeed OpenSSH feels this is more polite than sending a + * DISCONNECT. So now we don't. + */ + ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE); + } +} + +void ssh_sharing_downstream_connected(Ssh ssh, unsigned id) +{ + logeventf(ssh, "Connection sharing downstream #%u connected", id); +} + +void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id) +{ + logeventf(ssh, "Connection sharing downstream #%u disconnected", id); + ssh_check_termination(ssh); +} + +void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...) +{ + va_list ap; + char *buf; + + va_start(ap, logfmt); + buf = dupvprintf(logfmt, ap); + va_end(ap); + if (id) + logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf); + else + logeventf(ssh, "Connection sharing: %s", buf); + sfree(buf); +} + +static void ssh_channel_destroy(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + + switch (c->type) { + case CHAN_MAINSESSION: + ssh->mainchan = NULL; + update_specials_menu(ssh->frontend); + break; + case CHAN_X11: + if (c->u.x11.xconn != NULL) + x11_close(c->u.x11.xconn); + logevent("Forwarded X11 connection terminated"); + break; + case CHAN_AGENT: + sfree(c->u.a.message); + break; + case CHAN_SOCKDATA: + if (c->u.pfd.pf != NULL) + pfd_close(c->u.pfd.pf); + logevent("Forwarded port closed"); + break; + } + + del234(ssh->channels, c); + if (ssh->version == 2) { + bufchain_clear(&c->v.v2.outbuffer); + assert(c->v.v2.chanreq_head == NULL); + } + sfree(c); + + /* + * If that was the last channel left open, we might need to + * terminate. + */ + ssh_check_termination(ssh); +} + +static void ssh2_channel_check_close(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + struct Packet *pktout; + + if (c->halfopen) { + /* + * If we've sent out our own CHANNEL_OPEN but not yet seen + * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then + * it's too early to be sending close messages of any kind. + */ + return; + } + + if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) || + c->type == CHAN_ZOMBIE) && + !c->v.v2.chanreq_head && + !(c->closes & CLOSES_SENT_CLOSE)) { + /* + * We have both sent and received EOF (or the channel is a + * zombie), and we have no outstanding channel requests, which + * means the channel is in final wind-up. But we haven't sent + * CLOSE, so let's do so now. + */ + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_send(ssh, pktout); + c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE; + } + + if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) { + assert(c->v.v2.chanreq_head == NULL); + /* + * We have both sent and received CLOSE, which means we're + * completely done with the channel. + */ + ssh_channel_destroy(c); + } +} + +static void ssh2_channel_got_eof(struct ssh_channel *c) +{ + if (c->closes & CLOSES_RCVD_EOF) + return; /* already seen EOF */ + c->closes |= CLOSES_RCVD_EOF; + + if (c->type == CHAN_X11) { + x11_send_eof(c->u.x11.xconn); + } else if (c->type == CHAN_AGENT) { + if (c->u.a.outstanding_requests == 0) { + /* Manufacture an outgoing EOF in response to the incoming one. */ + sshfwd_write_eof(c); + } + } else if (c->type == CHAN_SOCKDATA) { + pfd_send_eof(c->u.pfd.pf); + } else if (c->type == CHAN_MAINSESSION) { + Ssh ssh = c->ssh; + + if (!ssh->sent_console_eof && + (from_backend_eof(ssh->frontend) || ssh->got_pty)) { + /* + * Either from_backend_eof told us that the front end + * wants us to close the outgoing side of the connection + * as soon as we see EOF from the far end, or else we've + * unilaterally decided to do that because we've allocated + * a remote pty and hence EOF isn't a particularly + * meaningful concept. + */ + sshfwd_write_eof(c); + } + ssh->sent_console_eof = TRUE; + } + + ssh2_channel_check_close(c); +} + +static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin) +{ + struct ssh_channel *c; + + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + if (c->type == CHAN_SHARING) { + share_got_pkt_from_server(c->u.sharing.ctx, pktin->type, + pktin->body, pktin->length); + return; + } + ssh2_channel_got_eof(c); +} + +static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) +{ + struct ssh_channel *c; + + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + if (c->type == CHAN_SHARING) { + share_got_pkt_from_server(c->u.sharing.ctx, pktin->type, + pktin->body, pktin->length); + return; + } + + /* + * When we receive CLOSE on a channel, we assume it comes with an + * implied EOF if we haven't seen EOF yet. + */ + ssh2_channel_got_eof(c); + + /* + * And we also send an outgoing EOF, if we haven't already, on the + * assumption that CLOSE is a pretty forceful announcement that + * the remote side is doing away with the entire channel. (If it + * had wanted to send us EOF and continue receiving data from us, + * it would have just sent CHANNEL_EOF.) + */ + if (!(c->closes & CLOSES_SENT_EOF)) { + /* + * Make sure we don't read any more from whatever our local + * data source is for this channel. + */ + switch (c->type) { + case CHAN_MAINSESSION: + ssh->send_ok = 0; /* stop trying to read from stdin */ + break; + case CHAN_X11: + x11_override_throttle(c->u.x11.xconn, 1); + break; + case CHAN_SOCKDATA: + pfd_override_throttle(c->u.pfd.pf, 1); + break; + } + + /* + * Abandon any buffered data we still wanted to send to this + * channel. Receiving a CHANNEL_CLOSE is an indication that + * the server really wants to get on and _destroy_ this + * channel, and it isn't going to send us any further + * WINDOW_ADJUSTs to permit us to send pending stuff. + */ + bufchain_clear(&c->v.v2.outbuffer); + + /* + * Send outgoing EOF. + */ + sshfwd_write_eof(c); + } + + /* + * Now process the actual close. + */ + if (!(c->closes & CLOSES_RCVD_CLOSE)) { + c->closes |= CLOSES_RCVD_CLOSE; + ssh2_channel_check_close(c); + } +} + +static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) +{ + struct ssh_channel *c; + + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + if (c->type == CHAN_SHARING) { + share_got_pkt_from_server(c->u.sharing.ctx, pktin->type, + pktin->body, pktin->length); + return; + } + assert(c->halfopen); /* ssh2_channel_msg will have enforced this */ + c->remoteid = ssh_pkt_getuint32(pktin); + c->halfopen = FALSE; + c->v.v2.remwindow = ssh_pkt_getuint32(pktin); + c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); + + if (c->type == CHAN_SOCKDATA_DORMANT) { + c->type = CHAN_SOCKDATA; + if (c->u.pfd.pf) + pfd_confirm(c->u.pfd.pf); + } else if (c->type == CHAN_ZOMBIE) { + /* + * This case can occur if a local socket error occurred + * between us sending out CHANNEL_OPEN and receiving + * OPEN_CONFIRMATION. In this case, all we can do is + * immediately initiate close proceedings now that we know the + * server's id to put in the close message. + */ + ssh2_channel_check_close(c); + } else { + /* + * We never expect to receive OPEN_CONFIRMATION for any + * *other* channel type (since only local-to-remote port + * forwardings cause us to send CHANNEL_OPEN after the main + * channel is live - all other auxiliary channel types are + * initiated from the server end). It's safe to enforce this + * by assertion rather than by ssh_disconnect, because the + * real point is that we never constructed a half-open channel + * structure in the first place with any type other than the + * above. + */ + assert(!"Funny channel type in ssh2_msg_channel_open_confirmation"); + } + + if (c->pending_eof) + ssh_channel_try_eof(c); /* in case we had a pending EOF */ +} + +static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) +{ + static const char *const reasons[] = { + "<unknown reason code>", + "Administratively prohibited", + "Connect failed", + "Unknown channel type", + "Resource shortage", + }; + unsigned reason_code; + char *reason_string; + int reason_length; + struct ssh_channel *c; + + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + if (c->type == CHAN_SHARING) { + share_got_pkt_from_server(c->u.sharing.ctx, pktin->type, + pktin->body, pktin->length); + return; + } + assert(c->halfopen); /* ssh2_channel_msg will have enforced this */ + + if (c->type == CHAN_SOCKDATA_DORMANT) { + reason_code = ssh_pkt_getuint32(pktin); + if (reason_code >= lenof(reasons)) + reason_code = 0; /* ensure reasons[reason_code] in range */ + ssh_pkt_getstring(pktin, &reason_string, &reason_length); + logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]", + reasons[reason_code], reason_length, reason_string); + + pfd_close(c->u.pfd.pf); + } else if (c->type == CHAN_ZOMBIE) { + /* + * This case can occur if a local socket error occurred + * between us sending out CHANNEL_OPEN and receiving + * OPEN_FAILURE. In this case, we need do nothing except allow + * the code below to throw the half-open channel away. + */ + } else { + /* + * We never expect to receive OPEN_FAILURE for any *other* + * channel type (since only local-to-remote port forwardings + * cause us to send CHANNEL_OPEN after the main channel is + * live - all other auxiliary channel types are initiated from + * the server end). It's safe to enforce this by assertion + * rather than by ssh_disconnect, because the real point is + * that we never constructed a half-open channel structure in + * the first place with any type other than the above. + */ + assert(!"Funny channel type in ssh2_msg_channel_open_failure"); + } + + del234(ssh->channels, c); + sfree(c); +} + +static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) +{ + char *type; + int typelen, want_reply; + int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */ + struct ssh_channel *c; + struct Packet *pktout; + + c = ssh2_channel_msg(ssh, pktin); + if (!c) + return; + if (c->type == CHAN_SHARING) { + share_got_pkt_from_server(c->u.sharing.ctx, pktin->type, + pktin->body, pktin->length); + return; + } + ssh_pkt_getstring(pktin, &type, &typelen); + want_reply = ssh2_pkt_getbool(pktin); + + /* + * Having got the channel number, we now look at + * the request type string to see if it's something + * we recognise. + */ + if (c == ssh->mainchan) { + /* + * We recognise "exit-status" and "exit-signal" on + * the primary channel. + */ + if (typelen == 11 && + !memcmp(type, "exit-status", 11)) { + + ssh->exitcode = ssh_pkt_getuint32(pktin); + logeventf(ssh, "Server sent command exit status %d", + ssh->exitcode); + reply = SSH2_MSG_CHANNEL_SUCCESS; + + } else if (typelen == 11 && + !memcmp(type, "exit-signal", 11)) { + + int is_plausible = TRUE, is_int = FALSE; + char *fmt_sig = "", *fmt_msg = ""; + char *msg; + int msglen = 0, core = FALSE; + /* ICK: older versions of OpenSSH (e.g. 3.4p1) + * provide an `int' for the signal, despite its + * having been a `string' in the drafts of RFC 4254 since at + * least 2001. (Fixed in session.c 1.147.) Try to + * infer which we can safely parse it as. */ + { + unsigned char *p = pktin->body + + pktin->savedpos; + long len = pktin->length - pktin->savedpos; + unsigned long num = GET_32BIT(p); /* what is it? */ + /* If it's 0, it hardly matters; assume string */ + if (num == 0) { + is_int = FALSE; + } else { + int maybe_int = FALSE, maybe_str = FALSE; +#define CHECK_HYPOTHESIS(offset, result) \ + do \ + { \ + int q = toint(offset); \ + if (q >= 0 && q+4 <= len) { \ + q = toint(q + 4 + GET_32BIT(p+q)); \ + if (q >= 0 && q+4 <= len && \ + ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \ + q == len) \ + result = TRUE; \ + } \ + } while(0) + CHECK_HYPOTHESIS(4+1, maybe_int); + CHECK_HYPOTHESIS(4+num+1, maybe_str); +#undef CHECK_HYPOTHESIS + if (maybe_int && !maybe_str) + is_int = TRUE; + else if (!maybe_int && maybe_str) + is_int = FALSE; + else + /* Crikey. Either or neither. Panic. */ + is_plausible = FALSE; + } + } + ssh->exitcode = 128; /* means `unknown signal' */ + if (is_plausible) { + if (is_int) { + /* Old non-standard OpenSSH. */ + int signum = ssh_pkt_getuint32(pktin); + fmt_sig = dupprintf(" %d", signum); + ssh->exitcode = 128 + signum; + } else { + /* As per RFC 4254. */ + char *sig; + int siglen; + ssh_pkt_getstring(pktin, &sig, &siglen); + /* Signal name isn't supposed to be blank, but + * let's cope gracefully if it is. */ + if (siglen) { + fmt_sig = dupprintf(" \"%.*s\"", + siglen, sig); + } + + /* + * Really hideous method of translating the + * signal description back into a locally + * meaningful number. + */ + + if (0) + ; +#define TRANSLATE_SIGNAL(s) \ + else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \ + ssh->exitcode = 128 + SIG ## s +#ifdef SIGABRT + TRANSLATE_SIGNAL(ABRT); +#endif +#ifdef SIGALRM + TRANSLATE_SIGNAL(ALRM); +#endif +#ifdef SIGFPE + TRANSLATE_SIGNAL(FPE); +#endif +#ifdef SIGHUP + TRANSLATE_SIGNAL(HUP); +#endif +#ifdef SIGILL + TRANSLATE_SIGNAL(ILL); +#endif +#ifdef SIGINT + TRANSLATE_SIGNAL(INT); +#endif +#ifdef SIGKILL + TRANSLATE_SIGNAL(KILL); +#endif +#ifdef SIGPIPE + TRANSLATE_SIGNAL(PIPE); +#endif +#ifdef SIGQUIT + TRANSLATE_SIGNAL(QUIT); +#endif +#ifdef SIGSEGV + TRANSLATE_SIGNAL(SEGV); +#endif +#ifdef SIGTERM + TRANSLATE_SIGNAL(TERM); +#endif +#ifdef SIGUSR1 + TRANSLATE_SIGNAL(USR1); +#endif +#ifdef SIGUSR2 + TRANSLATE_SIGNAL(USR2); +#endif +#undef TRANSLATE_SIGNAL + else + ssh->exitcode = 128; + } + core = ssh2_pkt_getbool(pktin); + ssh_pkt_getstring(pktin, &msg, &msglen); + if (msglen) { + fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg); + } + /* ignore lang tag */ + } /* else don't attempt to parse */ + logeventf(ssh, "Server exited on signal%s%s%s", + fmt_sig, core ? " (core dumped)" : "", + fmt_msg); + if (*fmt_sig) sfree(fmt_sig); + if (*fmt_msg) sfree(fmt_msg); + reply = SSH2_MSG_CHANNEL_SUCCESS; + + } + } else { + /* + * This is a channel request we don't know + * about, so we now either ignore the request + * or respond with CHANNEL_FAILURE, depending + * on want_reply. + */ + reply = SSH2_MSG_CHANNEL_FAILURE; + } + if (want_reply) { + pktout = ssh2_pkt_init(reply); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_send(ssh, pktout); + } +} + +static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin) +{ + char *type; + int typelen, want_reply; + struct Packet *pktout; + + ssh_pkt_getstring(pktin, &type, &typelen); + want_reply = ssh2_pkt_getbool(pktin); + + /* + * We currently don't support any global requests + * at all, so we either ignore the request or + * respond with REQUEST_FAILURE, depending on + * want_reply. + */ + if (want_reply) { + pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE); + ssh2_pkt_send(ssh, pktout); + } +} + +struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype, + void *share_cs, + void *share_chan) +{ + struct X11FakeAuth *auth; + + /* + * Make up a new set of fake X11 auth data, and add it to the tree + * of currently valid ones with an indication of the sharing + * context that it's relevant to. + */ + auth = x11_invent_fake_auth(ssh->x11authtree, authtype); + auth->share_cs = share_cs; + auth->share_chan = share_chan; + + return auth; +} + +void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth) +{ + del234(ssh->x11authtree, auth); + x11_free_fake_auth(auth); +} + +static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) +{ + char *type; + int typelen; + char *peeraddr; + int peeraddrlen; + int peerport; + char *error = NULL; + struct ssh_channel *c; + unsigned remid, winsize, pktsize; + unsigned our_winsize_override = 0; + struct Packet *pktout; + + ssh_pkt_getstring(pktin, &type, &typelen); + c = snew(struct ssh_channel); + c->ssh = ssh; + + remid = ssh_pkt_getuint32(pktin); + winsize = ssh_pkt_getuint32(pktin); + pktsize = ssh_pkt_getuint32(pktin); + + if (typelen == 3 && !memcmp(type, "x11", 3)) { + char *addrstr; + + ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen); + addrstr = snewn(peeraddrlen+1, char); + memcpy(addrstr, peeraddr, peeraddrlen); + addrstr[peeraddrlen] = '\0'; + peerport = ssh_pkt_getuint32(pktin); + + logeventf(ssh, "Received X11 connect request from %s:%d", + addrstr, peerport); + + if (!ssh->X11_fwd_enabled && !ssh->connshare) + error = "X11 forwarding is not enabled"; + else { + c->u.x11.xconn = x11_init(ssh->x11authtree, c, + addrstr, peerport); + c->type = CHAN_X11; + c->u.x11.initial = TRUE; + + /* + * If we are a connection-sharing upstream, then we should + * initially present a very small window, adequate to take + * the X11 initial authorisation packet but not much more. + * Downstream will then present us a larger window (by + * fiat of the connection-sharing protocol) and we can + * guarantee to send a positive-valued WINDOW_ADJUST. + */ + if (ssh->connshare) + our_winsize_override = 128; + + logevent("Opened X11 forward channel"); + } + + sfree(addrstr); + } else if (typelen == 15 && + !memcmp(type, "forwarded-tcpip", 15)) { + struct ssh_rportfwd pf, *realpf; + char *shost; + int shostlen; + ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */ + pf.shost = dupprintf("%.*s", shostlen, shost); + pf.sport = ssh_pkt_getuint32(pktin); + ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen); + peerport = ssh_pkt_getuint32(pktin); + realpf = find234(ssh->rportfwds, &pf, NULL); + logeventf(ssh, "Received remote port %s:%d open request " + "from %s:%d", pf.shost, pf.sport, peeraddr, peerport); + sfree(pf.shost); + + if (realpf == NULL) { + error = "Remote port is not recognised"; + } else { + char *err; + + if (realpf->share_ctx) { + /* + * This port forwarding is on behalf of a + * connection-sharing downstream, so abandon our own + * channel-open procedure and just pass the message on + * to sshshare.c. + */ + share_got_pkt_from_server(realpf->share_ctx, pktin->type, + pktin->body, pktin->length); + sfree(c); + return; + } + + err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport, + c, ssh->conf, realpf->pfrec->addressfamily); + logeventf(ssh, "Attempting to forward remote port to " + "%s:%d", realpf->dhost, realpf->dport); + if (err != NULL) { + logeventf(ssh, "Port open failed: %s", err); + sfree(err); + error = "Port open failed"; + } else { + logevent("Forwarded port opened successfully"); + c->type = CHAN_SOCKDATA; + } + } + } else if (typelen == 22 && + !memcmp(type, "auth-agent@openssh.com", 22)) { + if (!ssh->agentfwd_enabled) + error = "Agent forwarding is not enabled"; + else { + c->type = CHAN_AGENT; /* identify channel type */ + c->u.a.lensofar = 0; + c->u.a.message = NULL; + c->u.a.outstanding_requests = 0; + } + } else { + error = "Unsupported channel type requested"; + } + + c->remoteid = remid; + c->halfopen = FALSE; + if (error) { + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED); + ssh2_pkt_addstring(pktout, error); + ssh2_pkt_addstring(pktout, "en"); /* language tag */ + ssh2_pkt_send(ssh, pktout); + logeventf(ssh, "Rejected channel open: %s", error); + sfree(c); + } else { + ssh2_channel_init(c); + c->v.v2.remwindow = winsize; + c->v.v2.remmaxpkt = pktsize; + if (our_winsize_override) { + c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin = + our_winsize_override; + } + add234(ssh->channels, c); + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_adduint32(pktout, c->localid); + ssh2_pkt_adduint32(pktout, c->v.v2.locwindow); + ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */ + ssh2_pkt_send(ssh, pktout); + } +} + +void sshfwd_x11_sharing_handover(struct ssh_channel *c, + void *share_cs, void *share_chan, + const char *peer_addr, int peer_port, + int endian, int protomajor, int protominor, + const void *initial_data, int initial_len) +{ + /* + * This function is called when we've just discovered that an X + * forwarding channel on which we'd been handling the initial auth + * ourselves turns out to be destined for a connection-sharing + * downstream. So we turn the channel into a CHAN_SHARING, meaning + * that we completely stop tracking windows and buffering data and + * just pass more or less unmodified SSH messages back and forth. + */ + c->type = CHAN_SHARING; + c->u.sharing.ctx = share_cs; + share_setup_x11_channel(share_cs, share_chan, + c->localid, c->remoteid, c->v.v2.remwindow, + c->v.v2.remmaxpkt, c->v.v2.locwindow, + peer_addr, peer_port, endian, + protomajor, protominor, + initial_data, initial_len); +} + +void sshfwd_x11_is_local(struct ssh_channel *c) +{ + /* + * This function is called when we've just discovered that an X + * forwarding channel is _not_ destined for a connection-sharing + * downstream but we're going to handle it ourselves. We stop + * presenting a cautiously small window and go into ordinary data + * exchange mode. + */ + c->u.x11.initial = FALSE; + ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE); +} + +/* + * Buffer banner messages for later display at some convenient point, + * if we're going to display them. + */ +static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin) +{ + /* Arbitrary limit to prevent unbounded inflation of buffer */ + if (conf_get_int(ssh->conf, CONF_ssh_show_banner) && + bufchain_size(&ssh->banner) <= 131072) { + char *banner = NULL; + int size = 0; + ssh_pkt_getstring(pktin, &banner, &size); + if (banner) + bufchain_add(&ssh->banner, banner, size); + } +} + +/* Helper function to deal with sending tty modes for "pty-req" */ +static void ssh2_send_ttymode(void *data, char *mode, char *val) +{ + struct Packet *pktout = (struct Packet *)data; + int i = 0; + unsigned int arg = 0; + while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++; + if (i == lenof(ssh_ttymodes)) return; + switch (ssh_ttymodes[i].type) { + case TTY_OP_CHAR: + arg = ssh_tty_parse_specchar(val); + break; + case TTY_OP_BOOL: + arg = ssh_tty_parse_boolean(val); + break; + } + ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode); + ssh2_pkt_adduint32(pktout, arg); +} + +static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin, + void *ctx) +{ + struct ssh2_setup_x11_state { + int crLine; + }; + Ssh ssh = c->ssh; + struct Packet *pktout; + crStateP(ssh2_setup_x11_state, ctx); + + crBeginState; + + logevent("Requesting X11 forwarding"); + pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req", + ssh2_setup_x11, s); + ssh2_pkt_addbool(pktout, 0); /* many connections */ + ssh2_pkt_addstring(pktout, ssh->x11auth->protoname); + ssh2_pkt_addstring(pktout, ssh->x11auth->datastring); + ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum); + ssh2_pkt_send(ssh, pktout); + + /* Wait to be called back with either a response packet, or NULL + * meaning clean up and free our data */ + crReturnV; + + if (pktin) { + if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) { + logevent("X11 forwarding enabled"); + ssh->X11_fwd_enabled = TRUE; + } else + logevent("X11 forwarding refused"); + } + + crFinishFreeV; +} + +static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin, + void *ctx) +{ + struct ssh2_setup_agent_state { + int crLine; + }; + Ssh ssh = c->ssh; + struct Packet *pktout; + crStateP(ssh2_setup_agent_state, ctx); + + crBeginState; + + logevent("Requesting OpenSSH-style agent forwarding"); + pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com", + ssh2_setup_agent, s); + ssh2_pkt_send(ssh, pktout); + + /* Wait to be called back with either a response packet, or NULL + * meaning clean up and free our data */ + crReturnV; + + if (pktin) { + if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) { + logevent("Agent forwarding enabled"); + ssh->agentfwd_enabled = TRUE; + } else + logevent("Agent forwarding refused"); + } + + crFinishFreeV; +} + +static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin, + void *ctx) +{ + struct ssh2_setup_pty_state { + int crLine; + }; + Ssh ssh = c->ssh; + struct Packet *pktout; + crStateP(ssh2_setup_pty_state, ctx); + + crBeginState; + + /* Unpick the terminal-speed string. */ + /* XXX perhaps we should allow no speeds to be sent. */ + ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */ + sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed); + /* Build the pty request. */ + pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req", + ssh2_setup_pty, s); + ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype)); + ssh2_pkt_adduint32(pktout, ssh->term_width); + ssh2_pkt_adduint32(pktout, ssh->term_height); + ssh2_pkt_adduint32(pktout, 0); /* pixel width */ + ssh2_pkt_adduint32(pktout, 0); /* pixel height */ + ssh2_pkt_addstring_start(pktout); + parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout); + ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED); + ssh2_pkt_adduint32(pktout, ssh->ispeed); + ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED); + ssh2_pkt_adduint32(pktout, ssh->ospeed); + ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */ + ssh2_pkt_send(ssh, pktout); + ssh->state = SSH_STATE_INTERMED; + + /* Wait to be called back with either a response packet, or NULL + * meaning clean up and free our data */ + crReturnV; + + if (pktin) { + if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) { + logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", + ssh->ospeed, ssh->ispeed); + ssh->got_pty = TRUE; + } else { + c_write_str(ssh, "Server refused to allocate pty\r\n"); + ssh->editing = ssh->echoing = 1; + } + } + + crFinishFreeV; +} + +static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin, + void *ctx) +{ + struct ssh2_setup_env_state { + int crLine; + int num_env, env_left, env_ok; + }; + Ssh ssh = c->ssh; + struct Packet *pktout; + crStateP(ssh2_setup_env_state, ctx); + + crBeginState; + + /* + * Send environment variables. + * + * Simplest thing here is to send all the requests at once, and + * then wait for a whole bunch of successes or failures. + */ + s->num_env = 0; + { + char *key, *val; + + for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key); + val != NULL; + val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) { + pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s); + ssh2_pkt_addstring(pktout, key); + ssh2_pkt_addstring(pktout, val); + ssh2_pkt_send(ssh, pktout); + + s->num_env++; + } + if (s->num_env) + logeventf(ssh, "Sent %d environment variables", s->num_env); + } + + if (s->num_env) { + s->env_ok = 0; + s->env_left = s->num_env; + + while (s->env_left > 0) { + /* Wait to be called back with either a response packet, + * or NULL meaning clean up and free our data */ + crReturnV; + if (!pktin) goto out; + if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) + s->env_ok++; + s->env_left--; + } + + if (s->env_ok == s->num_env) { + logevent("All environment variables successfully set"); + } else if (s->env_ok == 0) { + logevent("All environment variables refused"); + c_write_str(ssh, "Server refused to set environment variables\r\n"); + } else { + logeventf(ssh, "%d environment variables refused", + s->num_env - s->env_ok); + c_write_str(ssh, "Server refused to set all environment variables\r\n"); + } + } + out:; + crFinishFreeV; +} + +/* + * Handle the SSH-2 userauth and connection layers. + */ +static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin) +{ + do_ssh2_authconn(ssh, NULL, 0, pktin); +} + +static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin, + void *ctx) +{ + do_ssh2_authconn(c->ssh, NULL, 0, pktin); +} + +static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, + struct Packet *pktin) +{ + struct do_ssh2_authconn_state { + int crLine; + enum { + AUTH_TYPE_NONE, + AUTH_TYPE_PUBLICKEY, + AUTH_TYPE_PUBLICKEY_OFFER_LOUD, + AUTH_TYPE_PUBLICKEY_OFFER_QUIET, + AUTH_TYPE_PASSWORD, + AUTH_TYPE_GSSAPI, /* always QUIET */ + AUTH_TYPE_KEYBOARD_INTERACTIVE, + AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET + } type; + int done_service_req; + int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter; + int tried_pubkey_config, done_agent; +#ifndef NO_GSSAPI + int can_gssapi; + int tried_gssapi; +#endif + int kbd_inter_refused; + int we_are_in, userauth_success; + prompts_t *cur_prompt; + int num_prompts; + char *username; + char *password; + int got_username; + void *publickey_blob; + int publickey_bloblen; + int publickey_encrypted; + char *publickey_algorithm; + char *publickey_comment; + unsigned char agent_request[5], *agent_response, *agentp; + int agent_responselen; + unsigned char *pkblob_in_agent; + int keyi, nkeys; + char *pkblob, *alg, *commentp; + int pklen, alglen, commentlen; + int siglen, retlen, len; + char *q, *agentreq, *ret; + int try_send; + struct Packet *pktout; + Filename *keyfile; +#ifndef NO_GSSAPI + struct ssh_gss_library *gsslib; + Ssh_gss_ctx gss_ctx; + Ssh_gss_buf gss_buf; + Ssh_gss_buf gss_rcvtok, gss_sndtok; + Ssh_gss_name gss_srv_name; + Ssh_gss_stat gss_stat; +#endif + }; + crState(do_ssh2_authconn_state); + + crBeginState; + + /* Register as a handler for all the messages this coroutine handles. */ + ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn; + /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */ + /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */ + ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn; + + s->done_service_req = FALSE; + s->we_are_in = s->userauth_success = FALSE; + s->agent_response = NULL; +#ifndef NO_GSSAPI + s->tried_gssapi = FALSE; +#endif + + if (!ssh->bare_connection) { + if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) { + /* + * Request userauth protocol, and await a response to it. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); + ssh2_pkt_addstring(s->pktout, "ssh-userauth"); + ssh2_pkt_send(ssh, s->pktout); + crWaitUntilV(pktin); + if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) + s->done_service_req = TRUE; + } + if (!s->done_service_req) { + /* + * Request connection protocol directly, without authentication. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + ssh2_pkt_send(ssh, s->pktout); + crWaitUntilV(pktin); + if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) { + s->we_are_in = TRUE; /* no auth required */ + } else { + bombout(("Server refused service request")); + crStopV; + } + } + } else { + s->we_are_in = TRUE; + } + + /* Arrange to be able to deal with any BANNERs that come in. + * (We do this now as packets may come in during the next bit.) */ + bufchain_init(&ssh->banner); + ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = + ssh2_msg_userauth_banner; + + /* + * Misc one-time setup for authentication. + */ + s->publickey_blob = NULL; + if (!s->we_are_in) { + + /* + * Load the public half of any configured public key file + * for later use. + */ + s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); + if (!filename_is_null(s->keyfile)) { + int keytype; + logeventf(ssh, "Reading private key file \"%.150s\"", + filename_to_str(s->keyfile)); + keytype = key_type(s->keyfile); + if (keytype == SSH_KEYTYPE_SSH2) { + const char *error; + s->publickey_blob = + ssh2_userkey_loadpub(s->keyfile, + &s->publickey_algorithm, + &s->publickey_bloblen, + &s->publickey_comment, &error); + if (s->publickey_blob) { + s->publickey_encrypted = + ssh2_userkey_encrypted(s->keyfile, NULL); + } else { + char *msgbuf; + logeventf(ssh, "Unable to load private key (%s)", + error); + msgbuf = dupprintf("Unable to load private key file " + "\"%.150s\" (%s)\r\n", + filename_to_str(s->keyfile), + error); + c_write_str(ssh, msgbuf); + sfree(msgbuf); + } + } else { + char *msgbuf; + logeventf(ssh, "Unable to use this key file (%s)", + key_type_to_str(keytype)); + msgbuf = dupprintf("Unable to use key file \"%.150s\"" + " (%s)\r\n", + filename_to_str(s->keyfile), + key_type_to_str(keytype)); + c_write_str(ssh, msgbuf); + sfree(msgbuf); + s->publickey_blob = NULL; + } + } + + /* + * Find out about any keys Pageant has (but if there's a + * public key configured, filter out all others). + */ + s->nkeys = 0; + s->agent_response = NULL; + s->pkblob_in_agent = NULL; + if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) { + + void *r; + + logevent("Pageant is running. Requesting keys."); + + /* Request the keys held by the agent. */ + PUT_32BIT(s->agent_request, 1); + s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; + if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen, + ssh_agent_callback, ssh)) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for agent response")); + crStopV; + } + } while (pktin || inlen > 0); + r = ssh->agent_response; + s->agent_responselen = ssh->agent_response_len; + } + s->agent_response = (unsigned char *) r; + if (s->agent_response && s->agent_responselen >= 5 && + s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) { + int keyi; + unsigned char *p; + p = s->agent_response + 5; + s->nkeys = toint(GET_32BIT(p)); + + /* + * Vet the Pageant response to ensure that the key + * count and blob lengths make sense. + */ + if (s->nkeys < 0) { + logeventf(ssh, "Pageant response contained a negative" + " key count %d", s->nkeys); + s->nkeys = 0; + goto done_agent_query; + } else { + unsigned char *q = p + 4; + int lenleft = s->agent_responselen - 5 - 4; + + for (keyi = 0; keyi < s->nkeys; keyi++) { + int bloblen, commentlen; + if (lenleft < 4) { + logeventf(ssh, "Pageant response was truncated"); + s->nkeys = 0; + goto done_agent_query; + } + bloblen = toint(GET_32BIT(q)); + if (bloblen < 0 || bloblen > lenleft) { + logeventf(ssh, "Pageant response was truncated"); + s->nkeys = 0; + goto done_agent_query; + } + lenleft -= 4 + bloblen; + q += 4 + bloblen; + commentlen = toint(GET_32BIT(q)); + if (commentlen < 0 || commentlen > lenleft) { + logeventf(ssh, "Pageant response was truncated"); + s->nkeys = 0; + goto done_agent_query; + } + lenleft -= 4 + commentlen; + q += 4 + commentlen; + } + } + + p += 4; + logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys); + if (s->publickey_blob) { + /* See if configured key is in agent. */ + for (keyi = 0; keyi < s->nkeys; keyi++) { + s->pklen = toint(GET_32BIT(p)); + if (s->pklen == s->publickey_bloblen && + !memcmp(p+4, s->publickey_blob, + s->publickey_bloblen)) { + logeventf(ssh, "Pageant key #%d matches " + "configured key file", keyi); + s->keyi = keyi; + s->pkblob_in_agent = p; + break; + } + p += 4 + s->pklen; + p += toint(GET_32BIT(p)) + 4; /* comment */ + } + if (!s->pkblob_in_agent) { + logevent("Configured key file not in Pageant"); + s->nkeys = 0; + } + } + } else { + logevent("Failed to get reply from Pageant"); + } + done_agent_query:; + } + + } + + /* + * We repeat this whole loop, including the username prompt, + * until we manage a successful authentication. If the user + * types the wrong _password_, they can be sent back to the + * beginning to try another username, if this is configured on. + * (If they specify a username in the config, they are never + * asked, even if they do give a wrong password.) + * + * I think this best serves the needs of + * + * - the people who have no configuration, no keys, and just + * want to try repeated (username,password) pairs until they + * type both correctly + * + * - people who have keys and configuration but occasionally + * need to fall back to passwords + * + * - people with a key held in Pageant, who might not have + * logged in to a particular machine before; so they want to + * type a username, and then _either_ their key will be + * accepted, _or_ they will type a password. If they mistype + * the username they will want to be able to get back and + * retype it! + */ + s->got_username = FALSE; + while (!s->we_are_in) { + /* + * Get a username. + */ + if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) { + /* + * We got a username last time round this loop, and + * with change_username turned off we don't try to get + * it again. + */ + } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) { + int ret; /* need not be kept over crReturn */ + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH login name"); + add_prompt(s->cur_prompt, dupstr("login as: "), TRUE); + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* + * get_userpass_input() failed to get a username. + * Terminate. + */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE); + crStopV; + } + ssh->username = dupstr(s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); + } else { + char *stuff; + if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { + stuff = dupprintf("Using username \"%s\".\r\n", ssh->username); + c_write_str(ssh, stuff); + sfree(stuff); + } + } + s->got_username = TRUE; + + /* + * Send an authentication request using method "none": (a) + * just in case it succeeds, and (b) so that we know what + * authentication methods we can usefully try next. + */ + ssh->pkt_actx = SSH2_PKTCTX_NOAUTH; + + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */ + ssh2_pkt_addstring(s->pktout, "none"); /* method */ + ssh2_pkt_send(ssh, s->pktout); + s->type = AUTH_TYPE_NONE; + s->gotit = FALSE; + s->we_are_in = FALSE; + + s->tried_pubkey_config = FALSE; + s->kbd_inter_refused = FALSE; + + /* Reset agent request state. */ + s->done_agent = FALSE; + if (s->agent_response) { + if (s->pkblob_in_agent) { + s->agentp = s->pkblob_in_agent; + } else { + s->agentp = s->agent_response + 5 + 4; + s->keyi = 0; + } + } + + while (1) { + char *methods = NULL; + int methlen = 0; + + /* + * Wait for the result of the last authentication request. + */ + if (!s->gotit) + crWaitUntilV(pktin); + /* + * Now is a convenient point to spew any banner material + * that we've accumulated. (This should ensure that when + * we exit the auth loop, we haven't any left to deal + * with.) + */ + { + int size = bufchain_size(&ssh->banner); + /* + * Don't show the banner if we're operating in + * non-verbose non-interactive mode. (It's probably + * a script, which means nobody will read the + * banner _anyway_, and moreover the printing of + * the banner will screw up processing on the + * output of (say) plink.) + */ + if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) { + char *banner = snewn(size, char); + bufchain_fetch(&ssh->banner, banner, size); + c_write_untrusted(ssh, banner, size); + sfree(banner); + } + bufchain_clear(&ssh->banner); + } + if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) { + logevent("Access granted"); + s->we_are_in = s->userauth_success = TRUE; + break; + } + + if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) { + bombout(("Strange packet received during authentication: " + "type %d", pktin->type)); + crStopV; + } + + s->gotit = FALSE; + + /* + * OK, we're now sitting on a USERAUTH_FAILURE message, so + * we can look at the string in it and know what we can + * helpfully try next. + */ + if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) { + ssh_pkt_getstring(pktin, &methods, &methlen); + if (!ssh2_pkt_getbool(pktin)) { + /* + * We have received an unequivocal Access + * Denied. This can translate to a variety of + * messages, or no message at all. + * + * For forms of authentication which are attempted + * implicitly, by which I mean without printing + * anything in the window indicating that we're + * trying them, we should never print 'Access + * denied'. + * + * If we do print a message saying that we're + * attempting some kind of authentication, it's OK + * to print a followup message saying it failed - + * but the message may sometimes be more specific + * than simply 'Access denied'. + * + * Additionally, if we'd just tried password + * authentication, we should break out of this + * whole loop so as to go back to the username + * prompt (iff we're configured to allow + * username change attempts). + */ + if (s->type == AUTH_TYPE_NONE) { + /* do nothing */ + } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD || + s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) { + if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD) + c_write_str(ssh, "Server refused our key\r\n"); + logevent("Server refused our key"); + } else if (s->type == AUTH_TYPE_PUBLICKEY) { + /* This _shouldn't_ happen except by a + * protocol bug causing client and server to + * disagree on what is a correct signature. */ + c_write_str(ssh, "Server refused public-key signature" + " despite accepting key!\r\n"); + logevent("Server refused public-key signature" + " despite accepting key!"); + } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) { + /* quiet, so no c_write */ + logevent("Server refused keyboard-interactive authentication"); + } else if (s->type==AUTH_TYPE_GSSAPI) { + /* always quiet, so no c_write */ + /* also, the code down in the GSSAPI block has + * already logged this in the Event Log */ + } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) { + logevent("Keyboard-interactive authentication failed"); + c_write_str(ssh, "Access denied\r\n"); + } else { + assert(s->type == AUTH_TYPE_PASSWORD); + logevent("Password authentication failed"); + c_write_str(ssh, "Access denied\r\n"); + + if (conf_get_int(ssh->conf, CONF_change_username)) { + /* XXX perhaps we should allow + * keyboard-interactive to do this too? */ + s->we_are_in = FALSE; + break; + } + } + } else { + c_write_str(ssh, "Further authentication required\r\n"); + logevent("Further authentication required"); + } + + s->can_pubkey = + in_commasep_string("publickey", methods, methlen); + s->can_passwd = + in_commasep_string("password", methods, methlen); + s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) && + in_commasep_string("keyboard-interactive", methods, methlen); +#ifndef NO_GSSAPI + if (!ssh->gsslibs) + ssh->gsslibs = ssh_gss_setup(ssh->conf); + s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) && + in_commasep_string("gssapi-with-mic", methods, methlen) && + ssh->gsslibs->nlibraries > 0; +#endif + } + + ssh->pkt_actx = SSH2_PKTCTX_NOAUTH; + + if (s->can_pubkey && !s->done_agent && s->nkeys) { + + /* + * Attempt public-key authentication using a key from Pageant. + */ + + ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY; + + logeventf(ssh, "Trying Pageant key #%d", s->keyi); + + /* Unpack key from agent response */ + s->pklen = toint(GET_32BIT(s->agentp)); + s->agentp += 4; + s->pkblob = (char *)s->agentp; + s->agentp += s->pklen; + s->alglen = toint(GET_32BIT(s->pkblob)); + s->alg = s->pkblob + 4; + s->commentlen = toint(GET_32BIT(s->agentp)); + s->agentp += 4; + s->commentp = (char *)s->agentp; + s->agentp += s->commentlen; + /* s->agentp now points at next key, if any */ + + /* See if server will accept it */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "publickey"); + /* method */ + ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */ + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen); + ssh2_pkt_send(ssh, s->pktout); + s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET; + + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) { + + /* Offer of key refused. */ + s->gotit = TRUE; + + } else { + + void *vret; + + if (flags & FLAG_VERBOSE) { + c_write_str(ssh, "Authenticating with " + "public key \""); + c_write(ssh, s->commentp, s->commentlen); + c_write_str(ssh, "\" from agent\r\n"); + } + + /* + * Server is willing to accept the key. + * Construct a SIGN_REQUEST. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "publickey"); + /* method */ + ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */ + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen); + + /* Ask agent for signature. */ + s->siglen = s->pktout->length - 5 + 4 + + ssh->v2_session_id_len; + if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) + s->siglen -= 4; + s->len = 1; /* message type */ + s->len += 4 + s->pklen; /* key blob */ + s->len += 4 + s->siglen; /* data to sign */ + s->len += 4; /* flags */ + s->agentreq = snewn(4 + s->len, char); + PUT_32BIT(s->agentreq, s->len); + s->q = s->agentreq + 4; + *s->q++ = SSH2_AGENTC_SIGN_REQUEST; + PUT_32BIT(s->q, s->pklen); + s->q += 4; + memcpy(s->q, s->pkblob, s->pklen); + s->q += s->pklen; + PUT_32BIT(s->q, s->siglen); + s->q += 4; + /* Now the data to be signed... */ + if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { + PUT_32BIT(s->q, ssh->v2_session_id_len); + s->q += 4; + } + memcpy(s->q, ssh->v2_session_id, + ssh->v2_session_id_len); + s->q += ssh->v2_session_id_len; + memcpy(s->q, s->pktout->data + 5, + s->pktout->length - 5); + s->q += s->pktout->length - 5; + /* And finally the (zero) flags word. */ + PUT_32BIT(s->q, 0); + if (!agent_query(s->agentreq, s->len + 4, + &vret, &s->retlen, + ssh_agent_callback, ssh)) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server" + " while waiting for agent" + " response")); + crStopV; + } + } while (pktin || inlen > 0); + vret = ssh->agent_response; + s->retlen = ssh->agent_response_len; + } + s->ret = vret; + sfree(s->agentreq); + if (s->ret) { + if (s->retlen >= 9 && + s->ret[4] == SSH2_AGENT_SIGN_RESPONSE && + GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) { + logevent("Sending Pageant's response"); + ssh2_add_sigblob(ssh, s->pktout, + s->pkblob, s->pklen, + s->ret + 9, + GET_32BIT(s->ret + 5)); + ssh2_pkt_send(ssh, s->pktout); + s->type = AUTH_TYPE_PUBLICKEY; + } else { + /* FIXME: less drastic response */ + bombout(("Pageant failed to answer challenge")); + crStopV; + } + } + } + + /* Do we have any keys left to try? */ + if (s->pkblob_in_agent) { + s->done_agent = TRUE; + s->tried_pubkey_config = TRUE; + } else { + s->keyi++; + if (s->keyi >= s->nkeys) + s->done_agent = TRUE; + } + + } else if (s->can_pubkey && s->publickey_blob && + !s->tried_pubkey_config) { + + struct ssh2_userkey *key; /* not live over crReturn */ + char *passphrase; /* not live over crReturn */ + + ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY; + + s->tried_pubkey_config = TRUE; + + /* + * Try the public key supplied in the configuration. + * + * First, offer the public blob to see if the server is + * willing to accept it. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "publickey"); /* method */ + ssh2_pkt_addbool(s->pktout, FALSE); + /* no signature included */ + ssh2_pkt_addstring(s->pktout, s->publickey_algorithm); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, + (char *)s->publickey_blob, + s->publickey_bloblen); + ssh2_pkt_send(ssh, s->pktout); + logevent("Offered public key"); + + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) { + /* Key refused. Give up. */ + s->gotit = TRUE; /* reconsider message next loop */ + s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD; + continue; /* process this new message */ + } + logevent("Offer of public key accepted"); + + /* + * Actually attempt a serious authentication using + * the key. + */ + if (flags & FLAG_VERBOSE) { + c_write_str(ssh, "Authenticating with public key \""); + c_write_str(ssh, s->publickey_comment); + c_write_str(ssh, "\"\r\n"); + } + key = NULL; + while (!key) { + const char *error; /* not live over crReturn */ + if (s->publickey_encrypted) { + /* + * Get a passphrase from the user. + */ + int ret; /* need not be kept over crReturn */ + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = FALSE; + s->cur_prompt->name = dupstr("SSH key passphrase"); + add_prompt(s->cur_prompt, + dupprintf("Passphrase for key \"%.100s\": ", + s->publickey_comment), + FALSE); + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, + in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* Failed to get a passphrase. Terminate. */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, + "Unable to authenticate", + SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, + TRUE); + crStopV; + } + passphrase = + dupstr(s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); + } else { + passphrase = NULL; /* no passphrase needed */ + } + + /* + * Try decrypting the key. + */ + s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); + key = ssh2_load_userkey(s->keyfile, passphrase, &error); + if (passphrase) { + /* burn the evidence */ + smemclr(passphrase, strlen(passphrase)); + sfree(passphrase); + } + if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { + if (passphrase && + (key == SSH2_WRONG_PASSPHRASE)) { + c_write_str(ssh, "Wrong passphrase\r\n"); + key = NULL; + /* and loop again */ + } else { + c_write_str(ssh, "Unable to load private key ("); + c_write_str(ssh, error); + c_write_str(ssh, ")\r\n"); + key = NULL; + break; /* try something else */ + } + } + } + + if (key) { + unsigned char *pkblob, *sigblob, *sigdata; + int pkblob_len, sigblob_len, sigdata_len; + int p; + + /* + * We have loaded the private key and the server + * has announced that it's willing to accept it. + * Hallelujah. Generate a signature and send it. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "publickey"); + /* method */ + ssh2_pkt_addbool(s->pktout, TRUE); + /* signature follows */ + ssh2_pkt_addstring(s->pktout, key->alg->name); + pkblob = key->alg->public_blob(key->data, + &pkblob_len); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, + pkblob_len); + + /* + * The data to be signed is: + * + * string session-id + * + * followed by everything so far placed in the + * outgoing packet. + */ + sigdata_len = s->pktout->length - 5 + 4 + + ssh->v2_session_id_len; + if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID) + sigdata_len -= 4; + sigdata = snewn(sigdata_len, unsigned char); + p = 0; + if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) { + PUT_32BIT(sigdata+p, ssh->v2_session_id_len); + p += 4; + } + memcpy(sigdata+p, ssh->v2_session_id, + ssh->v2_session_id_len); + p += ssh->v2_session_id_len; + memcpy(sigdata+p, s->pktout->data + 5, + s->pktout->length - 5); + p += s->pktout->length - 5; + assert(p == sigdata_len); + sigblob = key->alg->sign(key->data, (char *)sigdata, + sigdata_len, &sigblob_len); + ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len, + sigblob, sigblob_len); + sfree(pkblob); + sfree(sigblob); + sfree(sigdata); + + ssh2_pkt_send(ssh, s->pktout); + logevent("Sent public key signature"); + s->type = AUTH_TYPE_PUBLICKEY; + key->alg->freekey(key->data); + } + +#ifndef NO_GSSAPI + } else if (s->can_gssapi && !s->tried_gssapi) { + + /* GSSAPI Authentication */ + + int micoffset, len; + char *data; + Ssh_gss_buf mic; + s->type = AUTH_TYPE_GSSAPI; + s->tried_gssapi = TRUE; + s->gotit = TRUE; + ssh->pkt_actx = SSH2_PKTCTX_GSSAPI; + + /* + * Pick the highest GSS library on the preference + * list. + */ + { + int i, j; + s->gsslib = NULL; + for (i = 0; i < ngsslibs; i++) { + int want_id = conf_get_int_int(ssh->conf, + CONF_ssh_gsslist, i); + for (j = 0; j < ssh->gsslibs->nlibraries; j++) + if (ssh->gsslibs->libraries[j].id == want_id) { + s->gsslib = &ssh->gsslibs->libraries[j]; + goto got_gsslib; /* double break */ + } + } + got_gsslib: + /* + * We always expect to have found something in + * the above loop: we only came here if there + * was at least one viable GSS library, and the + * preference list should always mention + * everything and only change the order. + */ + assert(s->gsslib); + } + + if (s->gsslib->gsslogmsg) + logevent(s->gsslib->gsslogmsg); + + /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + ssh2_pkt_addstring(s->pktout, "gssapi-with-mic"); + logevent("Attempting GSSAPI authentication"); + + /* add mechanism info */ + s->gsslib->indicate_mech(s->gsslib, &s->gss_buf); + + /* number of GSSAPI mechanisms */ + ssh2_pkt_adduint32(s->pktout,1); + + /* length of OID + 2 */ + ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2); + ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE); + + /* length of OID */ + ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length); + + ssh_pkt_adddata(s->pktout, s->gss_buf.value, + s->gss_buf.length); + ssh2_pkt_send(ssh, s->pktout); + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) { + logevent("GSSAPI authentication request refused"); + continue; + } + + /* check returned packet ... */ + + ssh_pkt_getstring(pktin, &data, &len); + s->gss_rcvtok.value = data; + s->gss_rcvtok.length = len; + if (s->gss_rcvtok.length != s->gss_buf.length + 2 || + ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE || + ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length || + memcmp((char *)s->gss_rcvtok.value + 2, + s->gss_buf.value,s->gss_buf.length) ) { + logevent("GSSAPI authentication - wrong response from server"); + continue; + } + + /* now start running */ + s->gss_stat = s->gsslib->import_name(s->gsslib, + ssh->fullhostname, + &s->gss_srv_name); + if (s->gss_stat != SSH_GSS_OK) { + if (s->gss_stat == SSH_GSS_BAD_HOST_NAME) + logevent("GSSAPI import name failed - Bad service name"); + else + logevent("GSSAPI import name failed"); + continue; + } + + /* fetch TGT into GSS engine */ + s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx); + + if (s->gss_stat != SSH_GSS_OK) { + logevent("GSSAPI authentication failed to get credentials"); + s->gsslib->release_name(s->gsslib, &s->gss_srv_name); + continue; + } + + /* initial tokens are empty */ + SSH_GSS_CLEAR_BUF(&s->gss_rcvtok); + SSH_GSS_CLEAR_BUF(&s->gss_sndtok); + + /* now enter the loop */ + do { + s->gss_stat = s->gsslib->init_sec_context + (s->gsslib, + &s->gss_ctx, + s->gss_srv_name, + conf_get_int(ssh->conf, CONF_gssapifwd), + &s->gss_rcvtok, + &s->gss_sndtok); + + if (s->gss_stat!=SSH_GSS_S_COMPLETE && + s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) { + logevent("GSSAPI authentication initialisation failed"); + + if (s->gsslib->display_status(s->gsslib, s->gss_ctx, + &s->gss_buf) == SSH_GSS_OK) { + logevent(s->gss_buf.value); + sfree(s->gss_buf.value); + } + + break; + } + logevent("GSSAPI authentication initialised"); + + /* Client and server now exchange tokens until GSSAPI + * no longer says CONTINUE_NEEDED */ + + if (s->gss_sndtok.length != 0) { + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); + ssh_pkt_addstring_start(s->pktout); + ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length); + ssh2_pkt_send(ssh, s->pktout); + s->gsslib->free_tok(s->gsslib, &s->gss_sndtok); + } + + if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) { + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) { + logevent("GSSAPI authentication - bad server response"); + s->gss_stat = SSH_GSS_FAILURE; + break; + } + ssh_pkt_getstring(pktin, &data, &len); + s->gss_rcvtok.value = data; + s->gss_rcvtok.length = len; + } + } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED); + + if (s->gss_stat != SSH_GSS_OK) { + s->gsslib->release_name(s->gsslib, &s->gss_srv_name); + s->gsslib->release_cred(s->gsslib, &s->gss_ctx); + continue; + } + logevent("GSSAPI authentication loop finished OK"); + + /* Now send the MIC */ + + s->pktout = ssh2_pkt_init(0); + micoffset = s->pktout->length; + ssh_pkt_addstring_start(s->pktout); + ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len); + ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST); + ssh_pkt_addstring(s->pktout, ssh->username); + ssh_pkt_addstring(s->pktout, "ssh-connection"); + ssh_pkt_addstring(s->pktout, "gssapi-with-mic"); + + s->gss_buf.value = (char *)s->pktout->data + micoffset; + s->gss_buf.length = s->pktout->length - micoffset; + + s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic); + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC); + ssh_pkt_addstring_start(s->pktout); + ssh_pkt_addstring_data(s->pktout, mic.value, mic.length); + ssh2_pkt_send(ssh, s->pktout); + s->gsslib->free_mic(s->gsslib, &mic); + + s->gotit = FALSE; + + s->gsslib->release_name(s->gsslib, &s->gss_srv_name); + s->gsslib->release_cred(s->gsslib, &s->gss_ctx); + continue; +#endif + } else if (s->can_keyb_inter && !s->kbd_inter_refused) { + + /* + * Keyboard-interactive authentication. + */ + + s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; + + ssh->pkt_actx = SSH2_PKTCTX_KBDINTER; + + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); + /* method */ + ssh2_pkt_addstring(s->pktout, ""); /* lang */ + ssh2_pkt_addstring(s->pktout, ""); /* submethods */ + ssh2_pkt_send(ssh, s->pktout); + + logevent("Attempting keyboard-interactive authentication"); + + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) { + /* Server is not willing to do keyboard-interactive + * at all (or, bizarrely but legally, accepts the + * user without actually issuing any prompts). + * Give up on it entirely. */ + s->gotit = TRUE; + s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; + s->kbd_inter_refused = TRUE; /* don't try it again */ + continue; + } + + /* + * Loop while the server continues to send INFO_REQUESTs. + */ + while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) { + + char *name, *inst, *lang; + int name_len, inst_len, lang_len; + int i; + + /* + * We've got a fresh USERAUTH_INFO_REQUEST. + * Get the preamble and start building a prompt. + */ + ssh_pkt_getstring(pktin, &name, &name_len); + ssh_pkt_getstring(pktin, &inst, &inst_len); + ssh_pkt_getstring(pktin, &lang, &lang_len); + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + + /* + * Get any prompt(s) from the packet. + */ + s->num_prompts = ssh_pkt_getuint32(pktin); + for (i = 0; i < s->num_prompts; i++) { + char *prompt; + int prompt_len; + int echo; + static char noprompt[] = + "<server failed to send prompt>: "; + + ssh_pkt_getstring(pktin, &prompt, &prompt_len); + echo = ssh2_pkt_getbool(pktin); + if (!prompt_len) { + prompt = noprompt; + prompt_len = lenof(noprompt)-1; + } + add_prompt(s->cur_prompt, + dupprintf("%.*s", prompt_len, prompt), + echo); + } + + if (name_len) { + /* FIXME: better prefix to distinguish from + * local prompts? */ + s->cur_prompt->name = + dupprintf("SSH server: %.*s", name_len, name); + s->cur_prompt->name_reqd = TRUE; + } else { + s->cur_prompt->name = + dupstr("SSH server authentication"); + s->cur_prompt->name_reqd = FALSE; + } + /* We add a prefix to try to make it clear that a prompt + * has come from the server. + * FIXME: ugly to print "Using..." in prompt _every_ + * time round. Can this be done more subtly? */ + /* Special case: for reasons best known to themselves, + * some servers send k-i requests with no prompts and + * nothing to display. Keep quiet in this case. */ + if (s->num_prompts || name_len || inst_len) { + s->cur_prompt->instruction = + dupprintf("Using keyboard-interactive authentication.%s%.*s", + inst_len ? "\n" : "", inst_len, inst); + s->cur_prompt->instr_reqd = TRUE; + } else { + s->cur_prompt->instr_reqd = FALSE; + } + + /* + * Display any instructions, and get the user's + * response(s). + */ + { + int ret; /* not live over crReturn */ + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* + * Failed to get responses. Terminate. + */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, "Unable to authenticate", + SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, + TRUE); + crStopV; + } + } + + /* + * Send the response(s) to the server. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE); + ssh2_pkt_adduint32(s->pktout, s->num_prompts); + for (i=0; i < s->num_prompts; i++) { + ssh2_pkt_addstring(s->pktout, + s->cur_prompt->prompts[i]->result); + } + ssh2_pkt_send_with_padding(ssh, s->pktout, 256); + + /* + * Free the prompts structure from this iteration. + * If there's another, a new one will be allocated + * when we return to the top of this while loop. + */ + free_prompts(s->cur_prompt); + + /* + * Get the next packet in case it's another + * INFO_REQUEST. + */ + crWaitUntilV(pktin); + + } + + /* + * We should have SUCCESS or FAILURE now. + */ + s->gotit = TRUE; + + } else if (s->can_passwd) { + + /* + * Plain old password authentication. + */ + int ret; /* not live over crReturn */ + int changereq_first_time; /* not live over crReturn */ + + ssh->pkt_actx = SSH2_PKTCTX_PASSWORD; + + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("SSH password"); + add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ", + ssh->username, + ssh->savedhost), + FALSE); + + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* + * Failed to get responses. Terminate. + */ + free_prompts(s->cur_prompt); + ssh_disconnect(ssh, NULL, "Unable to authenticate", + SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, + TRUE); + crStopV; + } + /* + * Squirrel away the password. (We may need it later if + * asked to change it.) + */ + s->password = dupstr(s->cur_prompt->prompts[0]->result); + free_prompts(s->cur_prompt); + + /* + * Send the password packet. + * + * We pad out the password packet to 256 bytes to make + * it harder for an attacker to find the length of the + * user's password. + * + * Anyone using a password longer than 256 bytes + * probably doesn't have much to worry about from + * people who find out how long their password is! + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "password"); + ssh2_pkt_addbool(s->pktout, FALSE); + ssh2_pkt_addstring(s->pktout, s->password); + ssh2_pkt_send_with_padding(ssh, s->pktout, 256); + logevent("Sent password"); + s->type = AUTH_TYPE_PASSWORD; + + /* + * Wait for next packet, in case it's a password change + * request. + */ + crWaitUntilV(pktin); + changereq_first_time = TRUE; + + while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) { + + /* + * We're being asked for a new password + * (perhaps not for the first time). + * Loop until the server accepts it. + */ + + int got_new = FALSE; /* not live over crReturn */ + char *prompt; /* not live over crReturn */ + int prompt_len; /* not live over crReturn */ + + { + char *msg; + if (changereq_first_time) + msg = "Server requested password change"; + else + msg = "Server rejected new password"; + logevent(msg); + c_write_str(ssh, msg); + c_write_str(ssh, "\r\n"); + } + + ssh_pkt_getstring(pktin, &prompt, &prompt_len); + + s->cur_prompt = new_prompts(ssh->frontend); + s->cur_prompt->to_server = TRUE; + s->cur_prompt->name = dupstr("New SSH password"); + s->cur_prompt->instruction = + dupprintf("%.*s", prompt_len, prompt); + s->cur_prompt->instr_reqd = TRUE; + /* + * There's no explicit requirement in the protocol + * for the "old" passwords in the original and + * password-change messages to be the same, and + * apparently some Cisco kit supports password change + * by the user entering a blank password originally + * and the real password subsequently, so, + * reluctantly, we prompt for the old password again. + * + * (On the other hand, some servers don't even bother + * to check this field.) + */ + add_prompt(s->cur_prompt, + dupstr("Current password (blank for previously entered password): "), + FALSE); + add_prompt(s->cur_prompt, dupstr("Enter new password: "), + FALSE); + add_prompt(s->cur_prompt, dupstr("Confirm new password: "), + FALSE); + + /* + * Loop until the user manages to enter the same + * password twice. + */ + while (!got_new) { + + ret = get_userpass_input(s->cur_prompt, NULL, 0); + while (ret < 0) { + ssh->send_ok = 1; + crWaitUntilV(!pktin); + ret = get_userpass_input(s->cur_prompt, in, inlen); + ssh->send_ok = 0; + } + if (!ret) { + /* + * Failed to get responses. Terminate. + */ + /* burn the evidence */ + free_prompts(s->cur_prompt); + smemclr(s->password, strlen(s->password)); + sfree(s->password); + ssh_disconnect(ssh, NULL, "Unable to authenticate", + SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, + TRUE); + crStopV; + } + + /* + * If the user specified a new original password + * (IYSWIM), overwrite any previously specified + * one. + * (A side effect is that the user doesn't have to + * re-enter it if they louse up the new password.) + */ + if (s->cur_prompt->prompts[0]->result[0]) { + smemclr(s->password, strlen(s->password)); + /* burn the evidence */ + sfree(s->password); + s->password = + dupstr(s->cur_prompt->prompts[0]->result); + } + + /* + * Check the two new passwords match. + */ + got_new = (strcmp(s->cur_prompt->prompts[1]->result, + s->cur_prompt->prompts[2]->result) + == 0); + if (!got_new) + /* They don't. Silly user. */ + c_write_str(ssh, "Passwords do not match\r\n"); + + } + + /* + * Send the new password (along with the old one). + * (see above for padding rationale) + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + ssh2_pkt_addstring(s->pktout, ssh->username); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + /* service requested */ + ssh2_pkt_addstring(s->pktout, "password"); + ssh2_pkt_addbool(s->pktout, TRUE); + ssh2_pkt_addstring(s->pktout, s->password); + ssh2_pkt_addstring(s->pktout, + s->cur_prompt->prompts[1]->result); + free_prompts(s->cur_prompt); + ssh2_pkt_send_with_padding(ssh, s->pktout, 256); + logevent("Sent new password"); + + /* + * Now see what the server has to say about it. + * (If it's CHANGEREQ again, it's not happy with the + * new password.) + */ + crWaitUntilV(pktin); + changereq_first_time = FALSE; + + } + + /* + * We need to reexamine the current pktin at the top + * of the loop. Either: + * - we weren't asked to change password at all, in + * which case it's a SUCCESS or FAILURE with the + * usual meaning + * - we sent a new password, and the server was + * either OK with it (SUCCESS or FAILURE w/partial + * success) or unhappy with the _old_ password + * (FAILURE w/o partial success) + * In any of these cases, we go back to the top of + * the loop and start again. + */ + s->gotit = TRUE; + + /* + * We don't need the old password any more, in any + * case. Burn the evidence. + */ + smemclr(s->password, strlen(s->password)); + sfree(s->password); + + } else { + char *str = dupprintf("No supported authentication methods available" + " (server sent: %.*s)", + methlen, methods); + + ssh_disconnect(ssh, str, + "No supported authentication methods available", + SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE, + FALSE); + sfree(str); + + crStopV; + + } + + } + } + ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL; + + /* Clear up various bits and pieces from authentication. */ + if (s->publickey_blob) { + sfree(s->publickey_blob); + sfree(s->publickey_comment); + } + if (s->agent_response) + sfree(s->agent_response); + + if (s->userauth_success && !ssh->bare_connection) { + /* + * We've just received USERAUTH_SUCCESS, and we haven't sent any + * packets since. Signal the transport layer to consider enacting + * delayed compression. + * + * (Relying on we_are_in is not sufficient, as + * draft-miller-secsh-compression-delayed is quite clear that it + * triggers on USERAUTH_SUCCESS specifically, and we_are_in can + * become set for other reasons.) + */ + do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL); + } + + ssh->channels = newtree234(ssh_channelcmp); + + /* + * Set up handlers for some connection protocol messages, so we + * don't have to handle them repeatedly in this coroutine. + */ + ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = + ssh2_msg_channel_window_adjust; + ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = + ssh2_msg_global_request; + + /* + * Create the main session channel. + */ + if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) { + ssh->mainchan = NULL; + } else { + ssh->mainchan = snew(struct ssh_channel); + ssh->mainchan->ssh = ssh; + ssh2_channel_init(ssh->mainchan); + + if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) { + /* + * Just start a direct-tcpip channel and use it as the main + * channel. + */ + ssh_send_port_open(ssh->mainchan, + conf_get_str(ssh->conf, CONF_ssh_nc_host), + conf_get_int(ssh->conf, CONF_ssh_nc_port), + "main channel"); + ssh->ncmode = TRUE; + } else { + s->pktout = ssh2_chanopen_init(ssh->mainchan, "session"); + logevent("Opening session as main channel"); + ssh2_pkt_send(ssh, s->pktout); + ssh->ncmode = FALSE; + } + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { + bombout(("Server refused to open channel")); + crStopV; + /* FIXME: error data comes back in FAILURE packet */ + } + if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) { + bombout(("Server's channel confirmation cited wrong channel")); + crStopV; + } + ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin); + ssh->mainchan->halfopen = FALSE; + ssh->mainchan->type = CHAN_MAINSESSION; + ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin); + ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); + add234(ssh->channels, ssh->mainchan); + update_specials_menu(ssh->frontend); + logevent("Opened main channel"); + } + + /* + * Now we have a channel, make dispatch table entries for + * general channel-based messages. + */ + ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = + ssh2_msg_channel_data; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = + ssh2_msg_channel_open_confirmation; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = + ssh2_msg_channel_open_failure; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = + ssh2_msg_channel_request; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = + ssh2_msg_channel_open; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response; + + /* + * Now the connection protocol is properly up and running, with + * all those dispatch table entries, so it's safe to let + * downstreams start trying to open extra channels through us. + */ + if (ssh->connshare) + share_activate(ssh->connshare, ssh->v_s); + + if (ssh->mainchan && ssh_is_simple(ssh)) { + /* + * This message indicates to the server that we promise + * not to try to run any other channel in parallel with + * this one, so it's safe for it to advertise a very large + * window and leave the flow control to TCP. + */ + s->pktout = ssh2_chanreq_init(ssh->mainchan, + "simple@putty.projects.tartarus.org", + NULL, NULL); + ssh2_pkt_send(ssh, s->pktout); + } + + /* + * Enable port forwardings. + */ + ssh_setup_portfwd(ssh, ssh->conf); + + if (ssh->mainchan && !ssh->ncmode) { + /* + * Send the CHANNEL_REQUESTS for the main session channel. + * Each one is handled by its own little asynchronous + * co-routine. + */ + + /* Potentially enable X11 forwarding. */ + if (conf_get_int(ssh->conf, CONF_x11_forward)) { + ssh->x11disp = + x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display), + ssh->conf); + if (!ssh->x11disp) { + /* FIXME: return an error message from x11_setup_display */ + logevent("X11 forwarding not enabled: unable to" + " initialise X display"); + } else { + ssh->x11auth = x11_invent_fake_auth + (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth)); + ssh->x11auth->disp = ssh->x11disp; + + ssh2_setup_x11(ssh->mainchan, NULL, NULL); + } + } + + /* Potentially enable agent forwarding. */ + if (ssh_agent_forwarding_permitted(ssh)) + ssh2_setup_agent(ssh->mainchan, NULL, NULL); + + /* Now allocate a pty for the session. */ + if (!conf_get_int(ssh->conf, CONF_nopty)) + ssh2_setup_pty(ssh->mainchan, NULL, NULL); + + /* Send environment variables. */ + ssh2_setup_env(ssh->mainchan, NULL, NULL); + + /* + * Start a shell or a remote command. We may have to attempt + * this twice if the config data has provided a second choice + * of command. + */ + while (1) { + int subsys; + char *cmd; + + if (ssh->fallback_cmd) { + subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2); + cmd = conf_get_str(ssh->conf, CONF_remote_cmd2); + } else { + subsys = conf_get_int(ssh->conf, CONF_ssh_subsys); + cmd = conf_get_str(ssh->conf, CONF_remote_cmd); + } + + if (subsys) { + s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem", + ssh2_response_authconn, NULL); + ssh2_pkt_addstring(s->pktout, cmd); + } else if (*cmd) { + s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec", + ssh2_response_authconn, NULL); + ssh2_pkt_addstring(s->pktout, cmd); + } else { + s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell", + ssh2_response_authconn, NULL); + } + ssh2_pkt_send(ssh, s->pktout); + + crWaitUntilV(pktin); + + if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { + if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { + bombout(("Unexpected response to shell/command request:" + " packet type %d", pktin->type)); + crStopV; + } + /* + * We failed to start the command. If this is the + * fallback command, we really are finished; if it's + * not, and if the fallback command exists, try falling + * back to it before complaining. + */ + if (!ssh->fallback_cmd && + *conf_get_str(ssh->conf, CONF_remote_cmd2)) { + logevent("Primary command failed; attempting fallback"); + ssh->fallback_cmd = TRUE; + continue; + } + bombout(("Server refused to start a shell/command")); + crStopV; + } else { + logevent("Started a shell/command"); + } + break; + } + } else { + ssh->editing = ssh->echoing = TRUE; + } + + ssh->state = SSH_STATE_SESSION; + if (ssh->size_needed) + ssh_size(ssh, ssh->term_width, ssh->term_height); + if (ssh->eof_needed) + ssh_special(ssh, TS_EOF); + + /* + * Transfer data! + */ + if (ssh->ldisc) + ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */ + if (ssh->mainchan) + ssh->send_ok = 1; + while (1) { + crReturnV; + s->try_send = FALSE; + if (pktin) { + + /* + * _All_ the connection-layer packets we expect to + * receive are now handled by the dispatch table. + * Anything that reaches here must be bogus. + */ + + bombout(("Strange packet received: type %d", pktin->type)); + crStopV; + } else if (ssh->mainchan) { + /* + * We have spare data. Add it to the channel buffer. + */ + ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen); + s->try_send = TRUE; + } + if (s->try_send) { + int i; + struct ssh_channel *c; + /* + * Try to send data on all channels if we can. + */ + for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) + ssh2_try_send_and_unthrottle(ssh, c); + } + } + + crFinishV; +} + +/* + * Handlers for SSH-2 messages that might arrive at any moment. + */ +static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin) +{ + /* log reason code in disconnect message */ + char *buf, *msg; + int reason, msglen; + + reason = ssh_pkt_getuint32(pktin); + ssh_pkt_getstring(pktin, &msg, &msglen); + + if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) { + buf = dupprintf("Received disconnect message (%s)", + ssh2_disconnect_reasons[reason]); + } else { + buf = dupprintf("Received disconnect message (unknown" + " type %d)", reason); + } + logevent(buf); + sfree(buf); + buf = dupprintf("Disconnection message text: %.*s", + msglen, msg); + logevent(buf); + bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"", + reason, + (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ? + ssh2_disconnect_reasons[reason] : "unknown", + msglen, msg)); + sfree(buf); +} + +static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin) +{ + /* log the debug message */ + char *msg; + int msglen; + + /* XXX maybe we should actually take notice of the return value */ + ssh2_pkt_getbool(pktin); + ssh_pkt_getstring(pktin, &msg, &msglen); + + logeventf(ssh, "Remote debug message: %.*s", msglen, msg); +} + +static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin) +{ + do_ssh2_transport(ssh, NULL, 0, pktin); +} + +/* + * Called if we receive a packet that isn't allowed by the protocol. + * This only applies to packets whose meaning PuTTY understands. + * Entirely unknown packets are handled below. + */ +static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin) +{ + char *buf = dupprintf("Server protocol violation: unexpected %s packet", + ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, + pktin->type)); + ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); + sfree(buf); +} + +static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin) +{ + struct Packet *pktout; + pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED); + ssh2_pkt_adduint32(pktout, pktin->sequence); + /* + * UNIMPLEMENTED messages MUST appear in the same order as the + * messages they respond to. Hence, never queue them. + */ + ssh2_pkt_send_noqueue(ssh, pktout); +} + +/* + * Handle the top-level SSH-2 protocol. + */ +static void ssh2_protocol_setup(Ssh ssh) +{ + int i; + + /* + * Most messages cause SSH2_MSG_UNIMPLEMENTED. + */ + for (i = 0; i < 256; i++) + ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented; + + /* + * Initially, we only accept transport messages (and a few generic + * ones). do_ssh2_authconn will add more when it starts. + * Messages that are understood but not currently acceptable go to + * ssh2_msg_unexpected. + */ + ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport; + ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport; + ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport; + ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport; + /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */ + /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */ + ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport; + ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected; + /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */ + /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */ + ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected; + + /* + * These messages have a special handler from the start. + */ + ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect; + ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */ + ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug; +} + +static void ssh2_bare_connection_protocol_setup(Ssh ssh) +{ + int i; + + /* + * Most messages cause SSH2_MSG_UNIMPLEMENTED. + */ + for (i = 0; i < 256; i++) + ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented; + + /* + * Initially, we set all ssh-connection messages to 'unexpected'; + * do_ssh2_authconn will fill things in properly. We also handle a + * couple of messages from the transport protocol which aren't + * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG, + * DISCONNECT). + */ + ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected; + + ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected; + + /* + * These messages have a special handler from the start. + */ + ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect; + ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; + ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug; +} + +static void ssh2_timer(void *ctx, unsigned long now) +{ + Ssh ssh = (Ssh)ctx; + + if (ssh->state == SSH_STATE_CLOSED) + return; + + if (!ssh->kex_in_progress && !ssh->bare_connection && + conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 && + now == ssh->next_rekey) { + do_ssh2_transport(ssh, "timeout", -1, NULL); + } +} + +static void ssh2_protocol(Ssh ssh, void *vin, int inlen, + struct Packet *pktin) +{ + unsigned char *in = (unsigned char *)vin; + if (ssh->state == SSH_STATE_CLOSED) + return; + + if (pktin) { + ssh->incoming_data_size += pktin->encrypted_len; + if (!ssh->kex_in_progress && + ssh->max_data_size != 0 && + ssh->incoming_data_size > ssh->max_data_size) + do_ssh2_transport(ssh, "too much data received", -1, NULL); + } + + if (pktin) + ssh->packet_dispatch[pktin->type](ssh, pktin); + else if (!ssh->protocol_initial_phase_done) + do_ssh2_transport(ssh, in, inlen, pktin); + else + do_ssh2_authconn(ssh, in, inlen, pktin); +} + +static void ssh2_bare_connection_protocol(Ssh ssh, void *vin, int inlen, + struct Packet *pktin) +{ + unsigned char *in = (unsigned char *)vin; + if (ssh->state == SSH_STATE_CLOSED) + return; + + if (pktin) + ssh->packet_dispatch[pktin->type](ssh, pktin); + else + do_ssh2_authconn(ssh, in, inlen, pktin); +} + +static void ssh_cache_conf_values(Ssh ssh) +{ + ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata); +} + +/* + * Called to set up the connection. + * + * Returns an error message, or NULL on success. + */ +static const char *ssh_init(void *frontend_handle, void **backend_handle, + Conf *conf, char *host, int port, char **realhost, + int nodelay, int keepalive) +{ + const char *p; + Ssh ssh; + + ssh = snew(struct ssh_tag); + ssh->conf = conf_copy(conf); + ssh_cache_conf_values(ssh); + ssh->version = 0; /* when not ready yet */ + ssh->s = NULL; + ssh->cipher = NULL; + ssh->v1_cipher_ctx = NULL; + ssh->crcda_ctx = NULL; + ssh->cscipher = NULL; + ssh->cs_cipher_ctx = NULL; + ssh->sccipher = NULL; + ssh->sc_cipher_ctx = NULL; + ssh->csmac = NULL; + ssh->cs_mac_ctx = NULL; + ssh->scmac = NULL; + ssh->sc_mac_ctx = NULL; + ssh->cscomp = NULL; + ssh->cs_comp_ctx = NULL; + ssh->sccomp = NULL; + ssh->sc_comp_ctx = NULL; + ssh->kex = NULL; + ssh->kex_ctx = NULL; + ssh->hostkey = NULL; + ssh->hostkey_str = NULL; + ssh->exitcode = -1; + ssh->close_expected = FALSE; + ssh->clean_exit = FALSE; + ssh->state = SSH_STATE_PREPACKET; + ssh->size_needed = FALSE; + ssh->eof_needed = FALSE; + ssh->ldisc = NULL; + ssh->logctx = NULL; + ssh->deferred_send_data = NULL; + ssh->deferred_len = 0; + ssh->deferred_size = 0; + ssh->fallback_cmd = 0; + ssh->pkt_kctx = SSH2_PKTCTX_NOKEX; + ssh->pkt_actx = SSH2_PKTCTX_NOAUTH; + ssh->x11disp = NULL; + ssh->x11auth = NULL; + ssh->x11authtree = newtree234(x11_authcmp); + ssh->v1_compressing = FALSE; + ssh->v2_outgoing_sequence = 0; + ssh->ssh1_rdpkt_crstate = 0; + ssh->ssh2_rdpkt_crstate = 0; + ssh->ssh2_bare_rdpkt_crstate = 0; + ssh->ssh_gotdata_crstate = 0; + ssh->do_ssh1_connection_crstate = 0; + ssh->do_ssh_init_state = NULL; + ssh->do_ssh_connection_init_state = NULL; + ssh->do_ssh1_login_state = NULL; + ssh->do_ssh2_transport_state = NULL; + ssh->do_ssh2_authconn_state = NULL; + ssh->v_c = NULL; + ssh->v_s = NULL; + ssh->mainchan = NULL; + ssh->throttled_all = 0; + ssh->v1_stdout_throttling = 0; + ssh->queue = NULL; + ssh->queuelen = ssh->queuesize = 0; + ssh->queueing = FALSE; + ssh->qhead = ssh->qtail = NULL; + ssh->deferred_rekey_reason = NULL; + bufchain_init(&ssh->queued_incoming_data); + ssh->frozen = FALSE; + ssh->username = NULL; + ssh->sent_console_eof = FALSE; + ssh->got_pty = FALSE; + ssh->bare_connection = FALSE; + ssh->attempting_connshare = FALSE; + + *backend_handle = ssh; + +#ifdef MSCRYPTOAPI + if (crypto_startup() == 0) + return "Microsoft high encryption pack not installed!"; +#endif + + ssh->frontend = frontend_handle; + ssh->term_width = conf_get_int(ssh->conf, CONF_width); + ssh->term_height = conf_get_int(ssh->conf, CONF_height); + + ssh->channels = NULL; + ssh->rportfwds = NULL; + ssh->portfwds = NULL; + + ssh->send_ok = 0; + ssh->editing = 0; + ssh->echoing = 0; + ssh->conn_throttle_count = 0; + ssh->overall_bufsize = 0; + ssh->fallback_cmd = 0; + + ssh->protocol = NULL; + + ssh->protocol_initial_phase_done = FALSE; + + ssh->pinger = NULL; + + ssh->incoming_data_size = ssh->outgoing_data_size = + ssh->deferred_data_size = 0L; + ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf, + CONF_ssh_rekey_data)); + ssh->kex_in_progress = FALSE; + +#ifndef NO_GSSAPI + ssh->gsslibs = NULL; +#endif + + p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive); + if (p != NULL) + return p; + + random_ref(); + + return NULL; +} + +static void ssh_free(void *handle) +{ + Ssh ssh = (Ssh) handle; + struct ssh_channel *c; + struct ssh_rportfwd *pf; + struct X11FakeAuth *auth; + + if (ssh->v1_cipher_ctx) + ssh->cipher->free_context(ssh->v1_cipher_ctx); + if (ssh->cs_cipher_ctx) + ssh->cscipher->free_context(ssh->cs_cipher_ctx); + if (ssh->sc_cipher_ctx) + ssh->sccipher->free_context(ssh->sc_cipher_ctx); + if (ssh->cs_mac_ctx) + ssh->csmac->free_context(ssh->cs_mac_ctx); + if (ssh->sc_mac_ctx) + ssh->scmac->free_context(ssh->sc_mac_ctx); + if (ssh->cs_comp_ctx) { + if (ssh->cscomp) + ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); + else + zlib_compress_cleanup(ssh->cs_comp_ctx); + } + if (ssh->sc_comp_ctx) { + if (ssh->sccomp) + ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx); + else + zlib_decompress_cleanup(ssh->sc_comp_ctx); + } + if (ssh->kex_ctx) + dh_cleanup(ssh->kex_ctx); + sfree(ssh->savedhost); + + while (ssh->queuelen-- > 0) + ssh_free_packet(ssh->queue[ssh->queuelen]); + sfree(ssh->queue); + + while (ssh->qhead) { + struct queued_handler *qh = ssh->qhead; + ssh->qhead = qh->next; + sfree(qh); + } + ssh->qhead = ssh->qtail = NULL; + + if (ssh->channels) { + while ((c = delpos234(ssh->channels, 0)) != NULL) { + switch (c->type) { + case CHAN_X11: + if (c->u.x11.xconn != NULL) + x11_close(c->u.x11.xconn); + break; + case CHAN_SOCKDATA: + case CHAN_SOCKDATA_DORMANT: + if (c->u.pfd.pf != NULL) + pfd_close(c->u.pfd.pf); + break; + } + if (ssh->version == 2) { + struct outstanding_channel_request *ocr, *nocr; + ocr = c->v.v2.chanreq_head; + while (ocr) { + ocr->handler(c, NULL, ocr->ctx); + nocr = ocr->next; + sfree(ocr); + ocr = nocr; + } + bufchain_clear(&c->v.v2.outbuffer); + } + sfree(c); + } + freetree234(ssh->channels); + ssh->channels = NULL; + } + + if (ssh->connshare) + sharestate_free(ssh->connshare); + + if (ssh->rportfwds) { + while ((pf = delpos234(ssh->rportfwds, 0)) != NULL) + free_rportfwd(pf); + freetree234(ssh->rportfwds); + ssh->rportfwds = NULL; + } + sfree(ssh->deferred_send_data); + if (ssh->x11disp) + x11_free_display(ssh->x11disp); + while ((auth = delpos234(ssh->x11authtree, 0)) != NULL) + x11_free_fake_auth(auth); + freetree234(ssh->x11authtree); + sfree(ssh->do_ssh_init_state); + sfree(ssh->do_ssh1_login_state); + sfree(ssh->do_ssh2_transport_state); + sfree(ssh->do_ssh2_authconn_state); + sfree(ssh->v_c); + sfree(ssh->v_s); + sfree(ssh->fullhostname); + sfree(ssh->hostkey_str); + if (ssh->crcda_ctx) { + crcda_free_context(ssh->crcda_ctx); + ssh->crcda_ctx = NULL; + } + if (ssh->s) + ssh_do_close(ssh, TRUE); + expire_timer_context(ssh); + if (ssh->pinger) + pinger_free(ssh->pinger); + bufchain_clear(&ssh->queued_incoming_data); + sfree(ssh->username); + conf_free(ssh->conf); +#ifndef NO_GSSAPI + if (ssh->gsslibs) + ssh_gss_cleanup(ssh->gsslibs); +#endif + sfree(ssh); + + random_unref(); +} + +/* + * Reconfigure the SSH backend. + */ +static void ssh_reconfig(void *handle, Conf *conf) +{ + Ssh ssh = (Ssh) handle; + char *rekeying = NULL, rekey_mandatory = FALSE; + unsigned long old_max_data_size; + int i, rekey_time; + + pinger_reconfig(ssh->pinger, ssh->conf, conf); + if (ssh->portfwds) + ssh_setup_portfwd(ssh, conf); + + rekey_time = conf_get_int(conf, CONF_ssh_rekey_time); + if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time && + rekey_time != 0) { + unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC; + unsigned long now = GETTICKCOUNT(); + + if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) { + rekeying = "timeout shortened"; + } else { + ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh); + } + } + + old_max_data_size = ssh->max_data_size; + ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf, + CONF_ssh_rekey_data)); + if (old_max_data_size != ssh->max_data_size && + ssh->max_data_size != 0) { + if (ssh->outgoing_data_size > ssh->max_data_size || + ssh->incoming_data_size > ssh->max_data_size) + rekeying = "data limit lowered"; + } + + if (conf_get_int(ssh->conf, CONF_compression) != + conf_get_int(conf, CONF_compression)) { + rekeying = "compression setting changed"; + rekey_mandatory = TRUE; + } + + for (i = 0; i < CIPHER_MAX; i++) + if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) != + conf_get_int_int(conf, CONF_ssh_cipherlist, i)) { + rekeying = "cipher settings changed"; + rekey_mandatory = TRUE; + } + if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) != + conf_get_int(conf, CONF_ssh2_des_cbc)) { + rekeying = "cipher settings changed"; + rekey_mandatory = TRUE; + } + + conf_free(ssh->conf); + ssh->conf = conf_copy(conf); + ssh_cache_conf_values(ssh); + + if (!ssh->bare_connection && rekeying) { + if (!ssh->kex_in_progress) { + do_ssh2_transport(ssh, rekeying, -1, NULL); + } else if (rekey_mandatory) { + ssh->deferred_rekey_reason = rekeying; + } + } +} + +/* + * Called to send data down the SSH connection. + */ +static int ssh_send(void *handle, char *buf, int len) +{ + Ssh ssh = (Ssh) handle; + + if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL) + return 0; + + ssh->protocol(ssh, (unsigned char *)buf, len, 0); + + return ssh_sendbuffer(ssh); +} + +/* + * Called to query the current amount of buffered stdin data. + */ +static int ssh_sendbuffer(void *handle) +{ + Ssh ssh = (Ssh) handle; + int override_value; + + if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL) + return 0; + + /* + * If the SSH socket itself has backed up, add the total backup + * size on that to any individual buffer on the stdin channel. + */ + override_value = 0; + if (ssh->throttled_all) + override_value = ssh->overall_bufsize; + + if (ssh->version == 1) { + return override_value; + } else if (ssh->version == 2) { + if (!ssh->mainchan) + return override_value; + else + return (override_value + + bufchain_size(&ssh->mainchan->v.v2.outbuffer)); + } + + return 0; +} + +/* + * Called to set the size of the window from SSH's POV. + */ +static void ssh_size(void *handle, int width, int height) +{ + Ssh ssh = (Ssh) handle; + struct Packet *pktout; + + ssh->term_width = width; + ssh->term_height = height; + + switch (ssh->state) { + case SSH_STATE_BEFORE_SIZE: + case SSH_STATE_PREPACKET: + case SSH_STATE_CLOSED: + break; /* do nothing */ + case SSH_STATE_INTERMED: + ssh->size_needed = TRUE; /* buffer for later */ + break; + case SSH_STATE_SESSION: + if (!conf_get_int(ssh->conf, CONF_nopty)) { + if (ssh->version == 1) { + send_packet(ssh, SSH1_CMSG_WINDOW_SIZE, + PKT_INT, ssh->term_height, + PKT_INT, ssh->term_width, + PKT_INT, 0, PKT_INT, 0, PKT_END); + } else if (ssh->mainchan) { + pktout = ssh2_chanreq_init(ssh->mainchan, "window-change", + NULL, NULL); + ssh2_pkt_adduint32(pktout, ssh->term_width); + ssh2_pkt_adduint32(pktout, ssh->term_height); + ssh2_pkt_adduint32(pktout, 0); + ssh2_pkt_adduint32(pktout, 0); + ssh2_pkt_send(ssh, pktout); + } + } + break; + } +} + +/* + * Return a list of the special codes that make sense in this + * protocol. + */ +static const struct telnet_special *ssh_get_specials(void *handle) +{ + static const struct telnet_special ssh1_ignore_special[] = { + {"IGNORE message", TS_NOP} + }; + static const struct telnet_special ssh2_ignore_special[] = { + {"IGNORE message", TS_NOP}, + }; + static const struct telnet_special ssh2_rekey_special[] = { + {"Repeat key exchange", TS_REKEY}, + }; + static const struct telnet_special ssh2_session_specials[] = { + {NULL, TS_SEP}, + {"Break", TS_BRK}, + /* These are the signal names defined by RFC 4254. + * They include all the ISO C signals, but are a subset of the POSIX + * required signals. */ + {"SIGINT (Interrupt)", TS_SIGINT}, + {"SIGTERM (Terminate)", TS_SIGTERM}, + {"SIGKILL (Kill)", TS_SIGKILL}, + {"SIGQUIT (Quit)", TS_SIGQUIT}, + {"SIGHUP (Hangup)", TS_SIGHUP}, + {"More signals", TS_SUBMENU}, + {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM}, + {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL}, + {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV}, + {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2}, + {NULL, TS_EXITMENU} + }; + static const struct telnet_special specials_end[] = { + {NULL, TS_EXITMENU} + }; + /* XXX review this length for any changes: */ + static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) + + lenof(ssh2_rekey_special) + + lenof(ssh2_session_specials) + + lenof(specials_end)]; + Ssh ssh = (Ssh) handle; + int i = 0; +#define ADD_SPECIALS(name) \ + do { \ + assert((i + lenof(name)) <= lenof(ssh_specials)); \ + memcpy(&ssh_specials[i], name, sizeof name); \ + i += lenof(name); \ + } while(0) + + if (ssh->version == 1) { + /* Don't bother offering IGNORE if we've decided the remote + * won't cope with it, since we wouldn't bother sending it if + * asked anyway. */ + if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) + ADD_SPECIALS(ssh1_ignore_special); + } else if (ssh->version == 2) { + if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) + ADD_SPECIALS(ssh2_ignore_special); + if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection) + ADD_SPECIALS(ssh2_rekey_special); + if (ssh->mainchan) + ADD_SPECIALS(ssh2_session_specials); + } /* else we're not ready yet */ + + if (i) { + ADD_SPECIALS(specials_end); + return ssh_specials; + } else { + return NULL; + } +#undef ADD_SPECIALS +} + +/* + * Send special codes. TS_EOF is useful for `plink', so you + * can send an EOF and collect resulting output (e.g. `plink + * hostname sort'). + */ +static void ssh_special(void *handle, Telnet_Special code) +{ + Ssh ssh = (Ssh) handle; + struct Packet *pktout; + + if (code == TS_EOF) { + if (ssh->state != SSH_STATE_SESSION) { + /* + * Buffer the EOF in case we are pre-SESSION, so we can + * send it as soon as we reach SESSION. + */ + if (code == TS_EOF) + ssh->eof_needed = TRUE; + return; + } + if (ssh->version == 1) { + send_packet(ssh, SSH1_CMSG_EOF, PKT_END); + } else if (ssh->mainchan) { + sshfwd_write_eof(ssh->mainchan); + ssh->send_ok = 0; /* now stop trying to read from stdin */ + } + logevent("Sent EOF message"); + } else if (code == TS_PING || code == TS_NOP) { + if (ssh->state == SSH_STATE_CLOSED + || ssh->state == SSH_STATE_PREPACKET) return; + if (ssh->version == 1) { + if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) + send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); + } else { + if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { + pktout = ssh2_pkt_init(SSH2_MSG_IGNORE); + ssh2_pkt_addstring_start(pktout); + ssh2_pkt_send_noqueue(ssh, pktout); + } + } + } else if (code == TS_REKEY) { + if (!ssh->kex_in_progress && !ssh->bare_connection && + ssh->version == 2) { + do_ssh2_transport(ssh, "at user request", -1, NULL); + } + } else if (code == TS_BRK) { + if (ssh->state == SSH_STATE_CLOSED + || ssh->state == SSH_STATE_PREPACKET) return; + if (ssh->version == 1) { + logevent("Unable to send BREAK signal in SSH-1"); + } else if (ssh->mainchan) { + pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL); + ssh2_pkt_adduint32(pktout, 0); /* default break length */ + ssh2_pkt_send(ssh, pktout); + } + } else { + /* Is is a POSIX signal? */ + char *signame = NULL; + if (code == TS_SIGABRT) signame = "ABRT"; + if (code == TS_SIGALRM) signame = "ALRM"; + if (code == TS_SIGFPE) signame = "FPE"; + if (code == TS_SIGHUP) signame = "HUP"; + if (code == TS_SIGILL) signame = "ILL"; + if (code == TS_SIGINT) signame = "INT"; + if (code == TS_SIGKILL) signame = "KILL"; + if (code == TS_SIGPIPE) signame = "PIPE"; + if (code == TS_SIGQUIT) signame = "QUIT"; + if (code == TS_SIGSEGV) signame = "SEGV"; + if (code == TS_SIGTERM) signame = "TERM"; + if (code == TS_SIGUSR1) signame = "USR1"; + if (code == TS_SIGUSR2) signame = "USR2"; + /* The SSH-2 protocol does in principle support arbitrary named + * signals, including signame@domain, but we don't support those. */ + if (signame) { + /* It's a signal. */ + if (ssh->version == 2 && ssh->mainchan) { + pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL); + ssh2_pkt_addstring(pktout, signame); + ssh2_pkt_send(ssh, pktout); + logeventf(ssh, "Sent signal SIG%s", signame); + } + } else { + /* Never heard of it. Do nothing */ + } + } +} + +void *new_sock_channel(void *handle, struct PortForwarding *pf) +{ + Ssh ssh = (Ssh) handle; + struct ssh_channel *c; + c = snew(struct ssh_channel); + + c->ssh = ssh; + ssh2_channel_init(c); + c->halfopen = TRUE; + c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */ + c->u.pfd.pf = pf; + add234(ssh->channels, c); + return c; +} + +unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx) +{ + struct ssh_channel *c; + c = snew(struct ssh_channel); + + c->ssh = ssh; + ssh2_channel_init(c); + c->type = CHAN_SHARING; + c->u.sharing.ctx = sharing_ctx; + add234(ssh->channels, c); + return c->localid; +} + +void ssh_delete_sharing_channel(Ssh ssh, unsigned localid) +{ + struct ssh_channel *c; + + c = find234(ssh->channels, &localid, ssh_channelfind); + if (c) + ssh_channel_destroy(c); +} + +void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type, + const void *data, int datalen, + const char *additional_log_text) +{ + struct Packet *pkt; + + pkt = ssh2_pkt_init(type); + pkt->downstream_id = id; + pkt->additional_log_text = additional_log_text; + ssh2_pkt_adddata(pkt, data, datalen); + ssh2_pkt_send(ssh, pkt); +} + +/* + * This is called when stdout/stderr (the entity to which + * from_backend sends data) manages to clear some backlog. + */ +static void ssh_unthrottle(void *handle, int bufsize) +{ + Ssh ssh = (Ssh) handle; + int buflimit; + + if (ssh->version == 1) { + if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) { + ssh->v1_stdout_throttling = 0; + ssh_throttle_conn(ssh, -1); + } + } else { + if (ssh->mainchan) { + ssh2_set_window(ssh->mainchan, + bufsize < ssh->mainchan->v.v2.locmaxwin ? + ssh->mainchan->v.v2.locmaxwin - bufsize : 0); + if (ssh_is_simple(ssh)) + buflimit = 0; + else + buflimit = ssh->mainchan->v.v2.locmaxwin; + if (ssh->mainchan->throttling_conn && bufsize <= buflimit) { + ssh->mainchan->throttling_conn = 0; + ssh_throttle_conn(ssh, -1); + } + } + } + + /* + * Now process any SSH connection data that was stashed in our + * queue while we were frozen. + */ + ssh_process_queued_incoming_data(ssh); +} + +void ssh_send_port_open(void *channel, char *hostname, int port, char *org) +{ + struct ssh_channel *c = (struct ssh_channel *)channel; + Ssh ssh = c->ssh; + struct Packet *pktout; + + logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org); + + if (ssh->version == 1) { + send_packet(ssh, SSH1_MSG_PORT_OPEN, + PKT_INT, c->localid, + PKT_STR, hostname, + PKT_INT, port, + /* PKT_STR, <org:orgport>, */ + PKT_END); + } else { + pktout = ssh2_chanopen_init(c, "direct-tcpip"); + { + char *trimmed_host = host_strduptrim(hostname); + ssh2_pkt_addstring(pktout, trimmed_host); + sfree(trimmed_host); + } + ssh2_pkt_adduint32(pktout, port); + /* + * We make up values for the originator data; partly it's + * too much hassle to keep track, and partly I'm not + * convinced the server should be told details like that + * about my local network configuration. + * The "originator IP address" is syntactically a numeric + * IP address, and some servers (e.g., Tectia) get upset + * if it doesn't match this syntax. + */ + ssh2_pkt_addstring(pktout, "0.0.0.0"); + ssh2_pkt_adduint32(pktout, 0); + ssh2_pkt_send(ssh, pktout); + } +} + +static int ssh_connected(void *handle) +{ + Ssh ssh = (Ssh) handle; + return ssh->s != NULL; +} + +static int ssh_sendok(void *handle) +{ + Ssh ssh = (Ssh) handle; + return ssh->send_ok; +} + +static int ssh_ldisc(void *handle, int option) +{ + Ssh ssh = (Ssh) handle; + if (option == LD_ECHO) + return ssh->echoing; + if (option == LD_EDIT) + return ssh->editing; + return FALSE; +} + +static void ssh_provide_ldisc(void *handle, void *ldisc) +{ + Ssh ssh = (Ssh) handle; + ssh->ldisc = ldisc; +} + +static void ssh_provide_logctx(void *handle, void *logctx) +{ + Ssh ssh = (Ssh) handle; + ssh->logctx = logctx; +} + +static int ssh_return_exitcode(void *handle) +{ + Ssh ssh = (Ssh) handle; + if (ssh->s != NULL) + return -1; + else + return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX); +} + +/* + * cfg_info for SSH is the currently running version of the + * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.) + */ +static int ssh_cfg_info(void *handle) +{ + Ssh ssh = (Ssh) handle; + return ssh->version; +} + +/* + * Gross hack: pscp will try to start SFTP but fall back to scp1 if + * that fails. This variable is the means by which scp.c can reach + * into the SSH code and find out which one it got. + */ +extern int ssh_fallback_cmd(void *handle) +{ + Ssh ssh = (Ssh) handle; + return ssh->fallback_cmd; +} + +Backend ssh_backend = { + ssh_init, + ssh_free, + ssh_reconfig, + ssh_send, + ssh_sendbuffer, + ssh_size, + ssh_special, + ssh_get_specials, + ssh_connected, + ssh_return_exitcode, + ssh_sendok, + ssh_ldisc, + ssh_provide_ldisc, + ssh_provide_logctx, + ssh_unthrottle, + ssh_cfg_info, + "ssh", + PROT_SSH, + 22 +}; |