diff options
Diffstat (limited to 'tools/plink/ssh.c')
| -rw-r--r-- | tools/plink/ssh.c | 9737 |
1 files changed, 9737 insertions, 0 deletions
diff --git a/tools/plink/ssh.c b/tools/plink/ssh.c new file mode 100644 index 000000000..89c0433ca --- /dev/null +++ b/tools/plink/ssh.c @@ -0,0 +1,9737 @@ +/*
+ * 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 "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
+
+/*
+ * 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);
+
+/*
+ * 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
+
+/* Maximum length of passwords/passphrases (arbitrary) */
+#define SSH_MAX_PASSWORD_LEN 100
+
+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",
+ 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 */
+};
+
+/*
+ * 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.
+ */
+ int closes;
+ /*
+ * 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;
+
+ 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 a full _copy_ of a Config structure here, not
+ * merely a pointer to it. 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.
+ */
+ Config cfg;
+
+ /*
+ * 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;
+};
+
+#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 (ssh->cfg.logomitpass)
+ pkt->logmode = blanktype;
+}
+
+static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
+{
+ if (ssh->cfg.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 cfg.ttymodes. */
+static void parse_ttymodes(Ssh ssh, char *modes,
+ void (*do_mode)(void *data, char *mode, char *val),
+ void *data)
+{
+ while (*modes) {
+ char *t = strchr(modes, '\t');
+ char *m = snewn(t-modes+1, char);
+ char *val;
+ strncpy(m, modes, t-modes);
+ m[t-modes] = '\0';
+ if (*(t+1) == 'A')
+ val = get_ttymode(ssh->frontend, m);
+ else
+ val = dupstr(t+2);
+ if (val)
+ do_mode(data, m, val);
+ sfree(m);
+ sfree(val);
+ modes += strlen(modes) + 1;
+ }
+}
+
+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);
+}
+
+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->cfg.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->cfg.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) {
+ /*
+ * 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) {
+ 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 (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
+ (ssh->cfg.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 (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
+ (ssh->cfg.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 (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
+ (ssh->cfg.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 (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
+ (ssh->cfg.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 (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
+ (ssh->cfg.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 (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
+ (ssh->cfg.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 (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
+ (ssh->cfg.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 (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
+ (ssh->cfg.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 (ssh->cfg.sshbug_maxpkt2 == FORCE_ON ||
+ (ssh->cfg.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");
+ }
+}
+
+/*
+ * 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 (ssh->cfg.sshprot == 0 && !s->proto1) {
+ bombout(("SSH protocol version 1 required by user but not provided by server"));
+ crStop(0);
+ }
+ if (ssh->cfg.sshprot == 3 && !s->proto2) {
+ bombout(("SSH protocol version 2 required by user but not provided by server"));
+ crStop(0);
+ }
+
+ if (s->proto2 && (ssh->cfg.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 (ssh->cfg.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->cfg, &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:
+ 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);
+ }
+ }
+
+ 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;
+
+ if (*ssh->cfg.loghost) {
+ char *colon;
+
+ ssh->savedhost = dupstr(ssh->cfg.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.
+ */
+ logeventf(ssh, "Looking up host \"%s\"%s", host,
+ (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
+ (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
+ addr = name_lookup(host, port, realhost, &ssh->cfg,
+ ssh->cfg.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->cfg);
+ 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.
+ */
+ if (ssh->cfg.sshprot == 0)
+ ssh->version = 1;
+ if (ssh->cfg.sshprot == 3) {
+ ssh->version = 2;
+ ssh_send_verstring(ssh, NULL);
+ }
+
+ /*
+ * loghost, if configured, overrides realhost.
+ */
+ if (*ssh->cfg.loghost) {
+ sfree(*realhost);
+ *realhost = dupstr(ssh->cfg.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;
+ char username[100];
+ 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;
+ };
+ 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 = ssh->cfg.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 (!get_remote_username(&ssh->cfg, s->username,
+ sizeof(s->username))) {
+ 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,
+ lenof(s->username));
+ 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);
+ }
+ memcpy(s->username, s->cur_prompt->prompts[0]->result,
+ lenof(s->username));
+ free_prompts(s->cur_prompt);
+ }
+
+ send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
+ {
+ char *userlog = dupprintf("Sent username \"%s\"", s->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.
+ */
+ if (!filename_is_null(ssh->cfg.keyfile)) {
+ int keytype;
+ logeventf(ssh, "Reading private key file \"%.150s\"",
+ filename_to_str(&ssh->cfg.keyfile));
+ keytype = key_type(&ssh->cfg.keyfile);
+ if (keytype == SSH_KEYTYPE_SSH1) {
+ const char *error;
+ if (rsakey_pubblob(&ssh->cfg.keyfile,
+ &s->publickey_blob, &s->publickey_bloblen,
+ &s->publickey_comment, &error)) {
+ s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.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(&ssh->cfg.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(&ssh->cfg.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 (ssh->cfg.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");
+ }
+ 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");
+ logeventf(ssh, "Trying public key \"%s\"",
+ filename_to_str(&ssh->cfg.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, SSH_MAX_PASSWORD_LEN);
+ 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.
+ */
+ ret = loadrsakey(&ssh->cfg.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(&ssh->cfg.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 (ssh->cfg.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, SSH_MAX_PASSWORD_LEN);
+ sfree(instr_suf);
+ }
+ }
+ if (ssh->cfg.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, SSH_MAX_PASSWORD_LEN);
+ 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("%.90s@%.90s's password: ",
+ s->username, ssh->savedhost),
+ FALSE, SSH_MAX_PASSWORD_LEN);
+ }
+
+ /*
+ * 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);
+}
+
+void sshfwd_close(struct ssh_channel *c)
+{
+ Ssh ssh = c->ssh;
+
+ if (ssh->state == SSH_STATE_CLOSED)
+ return;
+
+ if (c && !c->closes) {
+ /*
+ * If halfopen is true, we have sent
+ * CHANNEL_OPEN for this channel, but it hasn't even been
+ * acknowledged by the server. So we must set a close flag
+ * on it now, and then when the server acks the channel
+ * open, we can close it then.
+ */
+ if (!c->halfopen) {
+ if (ssh->version == 1) {
+ send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
+ PKT_END);
+ } else {
+ struct Packet *pktout;
+ pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
+ ssh2_pkt_adduint32(pktout, c->remoteid);
+ ssh2_pkt_send(ssh, pktout);
+ }
+ }
+ c->closes = 1; /* sent MSG_CLOSE */
+ if (c->type == CHAN_X11) {
+ c->u.x11.s = NULL;
+ logevent("Forwarded X11 connection terminated");
+ } else if (c->type == CHAN_SOCKDATA ||
+ c->type == CHAN_SOCKDATA_DORMANT) {
+ c->u.pfd.s = NULL;
+ logevent("Forwarded port closed");
+ }
+ }
+}
+
+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);
+ free_rportfwd(pf);
+ }
+}
+
+static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
+{
+ const char *portfwd_strptr = cfg->portfwd;
+ struct ssh_portfwd *epf;
+ int i;
+
+ 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;
+ }
+
+ while (*portfwd_strptr) {
+ char address_family, type;
+ int sport,dport,sserv,dserv;
+ char sports[256], dports[256], saddr[256], host[256];
+ int n;
+
+ address_family = 'A';
+ type = 'L';
+ if (*portfwd_strptr == 'A' ||
+ *portfwd_strptr == '4' ||
+ *portfwd_strptr == '6')
+ address_family = *portfwd_strptr++;
+ if (*portfwd_strptr == 'L' ||
+ *portfwd_strptr == 'R' ||
+ *portfwd_strptr == 'D')
+ type = *portfwd_strptr++;
+
+ saddr[0] = '\0';
+
+ n = 0;
+ while (*portfwd_strptr && *portfwd_strptr != '\t') {
+ if (*portfwd_strptr == ':') {
+ /*
+ * We've seen a colon in the middle of the
+ * source port number. This means that
+ * everything we've seen until now is the
+ * source _address_, so we'll move it into
+ * saddr and start sports from the beginning
+ * again.
+ */
+ portfwd_strptr++;
+ sports[n] = '\0';
+ if (ssh->version == 1 && type == 'R') {
+ logeventf(ssh, "SSH-1 cannot handle remote source address "
+ "spec \"%s\"; ignoring", sports);
+ } else
+ strcpy(saddr, sports);
+ n = 0;
+ }
+ if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
+ }
+ sports[n] = 0;
+ if (type != 'D') {
+ if (*portfwd_strptr == '\t')
+ portfwd_strptr++;
+ n = 0;
+ while (*portfwd_strptr && *portfwd_strptr != ':') {
+ if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
+ }
+ host[n] = 0;
+ if (*portfwd_strptr == ':')
+ portfwd_strptr++;
+ n = 0;
+ while (*portfwd_strptr) {
+ if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
+ }
+ dports[n] = 0;
+ portfwd_strptr++;
+ 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);
+ }
+ }
+ } else {
+ while (*portfwd_strptr) portfwd_strptr++;
+ host[0] = 0;
+ dports[0] = 0;
+ dport = dserv = -1;
+ portfwd_strptr++; /* eat the NUL and move to next one */
+ }
+ 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 (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 ? dupstr(saddr) : NULL;
+ pfrec->sserv = sserv ? dupstr(sports) : NULL;
+ pfrec->sport = sport;
+ pfrec->daddr = *host ? dupstr(host) : NULL;
+ 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) {
+ /*
+ * We already have a port forwarding with precisely
+ * these parameters. Hence, no need to do anything;
+ * simply tag the existing one as KEEP.
+ */
+ epfrec->status = KEEP;
+ free_portfwd(pfrec);
+ } else {
+ pfrec->status = CREATE;
+ }
+ }
+ }
+
+ /*
+ * 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);
+
+ 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 (ssh->cfg.rport_acceptall) {
+ /* XXX: ssh->cfg.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, cfg,
+ &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, cfg,
+ &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 (cfg->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->cfg) != 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->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->throttling_conn = 0;
+ c->type = CHAN_AGENT; /* identify channel type */
+ c->u.a.lensofar = 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_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->cfg, 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->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->closes) {
+ /*
+ * 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.
+ */
+ send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
+ PKT_INT, c->remoteid, PKT_END);
+ }
+}
+
+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) {
+ int closetype;
+ closetype =
+ (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
+
+ if ((c->closes == 0) && (c->type == CHAN_X11)) {
+ logevent("Forwarded X11 connection terminated");
+ assert(c->u.x11.s != NULL);
+ x11_close(c->u.x11.s);
+ c->u.x11.s = NULL;
+ }
+ if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
+ logevent("Forwarded port closed");
+ assert(c->u.pfd.s != NULL);
+ pfd_close(c->u.pfd.s);
+ c->u.pfd.s = NULL;
+ }
+
+ c->closes |= (closetype << 2); /* seen this message */
+ if (!(c->closes & closetype)) {
+ send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
+ PKT_END);
+ c->closes |= closetype; /* sent it too */
+ }
+
+ if (c->closes == 15) {
+ del234(ssh->channels, c);
+ sfree(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 (ssh->cfg.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 (ssh->cfg.x11_forward &&
+ (ssh->x11disp = x11_setup_display(ssh->cfg.x11_display,
+ ssh->cfg.x11_auth, &ssh->cfg))) {
+ 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->cfg);
+ ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
+
+ if (!ssh->cfg.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(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
+ /* Send the pty request. */
+ pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
+ ssh_pkt_addstring(pkt, ssh->cfg.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, ssh->cfg.ttymodes,
+ 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;
+ }
+ logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
+ ssh->ospeed, ssh->ispeed);
+ } else {
+ ssh->editing = ssh->echoing = 1;
+ }
+
+ if (ssh->cfg.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 = ssh->cfg.remote_cmd_ptr;
+
+ if (!cmd) cmd = ssh->cfg.remote_cmd;
+
+ if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
+ cmd = ssh->cfg.remote_cmd_ptr2;
+ 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 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;
+
+ /*
+ * 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 (ssh->cfg.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 (ssh->cfg.ssh_cipherlist[i]) {
+ case CIPHER_BLOWFISH:
+ s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
+ break;
+ case CIPHER_DES:
+ if (ssh->cfg.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 (ssh->cfg.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. */
+ ssh2_pkt_addstring_start(s->pktout);
+ assert(lenof(compressions) > 1);
+ ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->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);
+ }
+ }
+ /* List server->client compression algorithms. */
+ ssh2_pkt_addstring_start(s->pktout);
+ assert(lenof(compressions) > 1);
+ ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->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);
+ }
+ }
+ /* 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;
+ }
+ }
+ 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;
+ }
+ }
+ 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 (ssh->cfg.ssh_rekey_time != 0)
+ ssh->next_rekey = schedule_timer(ssh->cfg.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==-1, because this is a special signal meaning
+ * `initiate client-driven rekey', and `in' contains a message
+ * giving the reason for the rekey.
+ */
+ while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
+ (!pktin && inlen == -1))) {
+ wait_for_rekey:
+ crReturn(1);
+ }
+ if (pktin) {
+ logevent("Server initiated key re-exchange");
+ } else {
+ /*
+ * 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 (ssh->cfg.ssh_rekey_time != 0) {
+ ssh->next_rekey =
+ schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
+ ssh2_timer, ssh);
+ }
+ goto wait_for_rekey; /* this is 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;
+
+ 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.
+ */
+ return bufchain_size(&c->v.v2.outbuffer);
+}
+
+static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
+{
+ int bufsize;
+ if (c->closes)
+ return; /* don't send on closing channels */
+ 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->throttling_conn = FALSE;
+ c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
+ ssh->cfg.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
+ * already thinks it's closed; there's no point, since it won't
+ * be sending any more data anyway.
+ */
+ if (c->closes != 0)
+ 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 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 or are sent before this handler gets
+ * installed.
+ */
+ struct ssh_channel *c;
+ struct winadj *wa;
+
+ c = ssh2_channel_msg(ssh, pktin);
+ if (!c)
+ return;
+ wa = c->v.v2.winadj_head;
+ if (wa)
+ ssh_disconnect(ssh, NULL, "Received SSH_MSG_CHANNEL_SUCCESS for "
+ "\"winadj@putty.projects.tartarus.org\"",
+ SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
+ else
+ 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;
+ struct winadj *wa;
+
+ c = ssh2_channel_msg(ssh, pktin);
+ if (!c)
+ return;
+ wa = c->v.v2.winadj_head;
+ if (!wa) {
+ ssh_disconnect(ssh, NULL,
+ "Received unsolicited SSH_MSG_CHANNEL_FAILURE",
+ SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
+ return;
+ }
+ 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;
+}
+
+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) {
+ c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
+ ssh2_try_send_and_unthrottle(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.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->cfg.ssh_simple && bufsize > 0)) &&
+ !c->throttling_conn) {
+ c->throttling_conn = 1;
+ ssh_throttle_conn(ssh, +1);
+ }
+ }
+}
+
+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_X11) {
+ /*
+ * Remote EOF on an X11 channel means we should
+ * wrap up and close the channel ourselves.
+ */
+ x11_close(c->u.x11.s);
+ sshfwd_close(c);
+ } else if (c->type == CHAN_AGENT) {
+ sshfwd_close(c);
+ } else if (c->type == CHAN_SOCKDATA) {
+ pfd_close(c->u.pfd.s);
+ sshfwd_close(c);
+ }
+}
+
+static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
+{
+ struct ssh_channel *c;
+ struct Packet *pktout;
+
+ c = ssh2_channel_msg(ssh, pktin);
+ if (!c)
+ return;
+ /* Do pre-close processing on the channel. */
+ 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);
+ sshfwd_close(c);
+ break;
+ case CHAN_AGENT:
+ sshfwd_close(c);
+ break;
+ case CHAN_SOCKDATA:
+ if (c->u.pfd.s != NULL)
+ pfd_close(c->u.pfd.s);
+ sshfwd_close(c);
+ break;
+ }
+ if (c->closes == 0) {
+ pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
+ ssh2_pkt_adduint32(pktout, c->remoteid);
+ ssh2_pkt_send(ssh, pktout);
+ }
+ del234(ssh->channels, c);
+ 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->cfg.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_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
+{
+ struct ssh_channel *c;
+ struct Packet *pktout;
+
+ 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->closes) {
+ /*
+ * 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.
+ */
+ pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
+ ssh2_pkt_adduint32(pktout, c->remoteid);
+ ssh2_pkt_send(ssh, pktout);
+ }
+}
+
+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->cfg)) != 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->cfg,
+ 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.
+ */
+static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
+{
+ /* Arbitrary limit to prevent unbounded inflation of buffer */
+ if (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,
+ 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;
+ prompts_t *cur_prompt;
+ int num_prompts;
+ char username[100];
+ 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;
+#ifndef NO_GSSAPI
+ 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 = FALSE;
+#ifndef NO_GSSAPI
+ s->tried_gssapi = FALSE;
+#endif
+
+ if (!ssh->cfg.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.
+ */
+ if (!filename_is_null(ssh->cfg.keyfile)) {
+ int keytype;
+ logeventf(ssh, "Reading private key file \"%.150s\"",
+ filename_to_str(&ssh->cfg.keyfile));
+ keytype = key_type(&ssh->cfg.keyfile);
+ if (keytype == SSH_KEYTYPE_SSH2) {
+ const char *error;
+ s->publickey_blob =
+ ssh2_userkey_loadpub(&ssh->cfg.keyfile,
+ &s->publickey_algorithm,
+ &s->publickey_bloblen,
+ &s->publickey_comment, &error);
+ if (s->publickey_blob) {
+ s->publickey_encrypted =
+ ssh2_userkey_encrypted(&ssh->cfg.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(&ssh->cfg.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(&ssh->cfg.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 (ssh->cfg.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;
+ }
+ }
+ }
+ }
+
+ }
+
+ /*
+ * 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->username[0] = '\0';
+ s->got_username = FALSE;
+ while (!s->we_are_in) {
+ /*
+ * Get a username.
+ */
+ if (s->got_username && !ssh->cfg.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 (!get_remote_username(&ssh->cfg, s->username,
+ sizeof(s->username))) {
+ 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,
+ lenof(s->username));
+ 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;
+ }
+ memcpy(s->username, s->cur_prompt->prompts[0]->result,
+ lenof(s->username));
+ free_prompts(s->cur_prompt);
+ } else {
+ char *stuff;
+ if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
+ stuff = dupprintf("Using username \"%s\".\r\n", s->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, s->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) {
+ /*
+ * 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 = 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) {
+ char *methods;
+ int methlen;
+ 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:
+ *
+ * - if we'd just tried "none" authentication,
+ * it's not worth printing anything at all
+ *
+ * - if we'd just tried a public key _offer_,
+ * the message should be "Server refused our
+ * key" (or no message at all if the key
+ * came from Pageant)
+ *
+ * - if we'd just tried anything else, the
+ * message really should be "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 public key");
+ } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
+ /* server declined keyboard-interactive; ignore */
+ } else {
+ c_write_str(ssh, "Access denied\r\n");
+ logevent("Access denied");
+ if (s->type == AUTH_TYPE_PASSWORD &&
+ ssh->cfg.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 = ssh->cfg.try_ki_auth &&
+ in_commasep_string("keyboard-interactive", methods, methlen);
+#ifndef NO_GSSAPI
+ s->can_gssapi = ssh->cfg.try_gssapi_auth &&
+ in_commasep_string("gssapi-with-mic", methods, methlen) &&
+ ssh_gss_init();
+#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, s->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, s->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, s->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, SSH_MAX_PASSWORD_LEN);
+ 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.
+ */
+ key = ssh2_load_userkey(&ssh->cfg.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, s->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);
+ 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;
+
+ /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
+ s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+ ssh2_pkt_addstring(s->pktout, s->username);
+ ssh2_pkt_addstring(s->pktout, "ssh-connection");
+ ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
+
+ /* add mechanism info */
+ ssh_gss_indicate_mech(&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 = ssh_gss_import_name(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 = ssh_gss_acquire_cred(&s->gss_ctx);
+
+ if (s->gss_stat != SSH_GSS_OK) {
+ logevent("GSSAPI authentication failed to get credentials");
+ ssh_gss_release_name(&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 = ssh_gss_init_sec_context(&s->gss_ctx,
+ s->gss_srv_name,
+ ssh->cfg.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 (ssh_gss_display_status(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);
+ ssh_gss_free_tok(&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) {
+ ssh_gss_release_name(&s->gss_srv_name);
+ ssh_gss_release_cred(&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, s->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;
+
+ ssh_gss_get_mic(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);
+ ssh_gss_free_mic(&mic);
+
+ s->gotit = FALSE;
+
+ ssh_gss_release_name(&s->gss_srv_name);
+ ssh_gss_release_cred(&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, s->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);
+
+ 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;
+ if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
+ logevent("Keyboard-interactive authentication refused");
+ 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, SSH_MAX_PASSWORD_LEN);
+ }
+
+ 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);
+
+ /*
+ * 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("%.90s@%.90s's password: ",
+ s->username,
+ ssh->savedhost),
+ FALSE, SSH_MAX_PASSWORD_LEN);
+
+ 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, s->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, SSH_MAX_PASSWORD_LEN);
+ add_prompt(s->cur_prompt, dupstr("Enter new password: "),
+ FALSE, SSH_MAX_PASSWORD_LEN);
+ add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
+ FALSE, SSH_MAX_PASSWORD_LEN);
+
+ /*
+ * 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, s->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 {
+
+ ssh_disconnect(ssh, NULL,
+ "No supported authentication methods available",
+ SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
+ FALSE);
+ 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);
+
+ /*
+ * 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 (ssh->cfg.ssh_no_shell) {
+ ssh->mainchan = NULL;
+ } else if (*ssh->cfg.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",
+ ssh->cfg.ssh_nc_host, ssh->cfg.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, ssh->cfg.ssh_nc_host);
+ ssh2_pkt_adduint32(s->pktout, ssh->cfg.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 && ssh->cfg.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 && ssh->cfg.x11_forward &&
+ (ssh->x11disp = x11_setup_display(ssh->cfg.x11_display,
+ ssh->cfg.x11_auth, &ssh->cfg))) {
+ 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->cfg);
+
+ /*
+ * Potentially enable agent forwarding.
+ */
+ if (ssh->mainchan && !ssh->ncmode && ssh->cfg.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 && !ssh->cfg.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(ssh->cfg.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, ssh->cfg.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, ssh->cfg.ttymodes,
+ 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);
+ }
+ } 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 && *ssh->cfg.environmt) {
+ char *e = ssh->cfg.environmt;
+ char *var, *varend, *val;
+
+ s->num_env = 0;
+
+ while (*e) {
+ var = e;
+ while (*e && *e != '\t') e++;
+ varend = e;
+ if (*e == '\t') e++;
+ val = e;
+ while (*e) e++;
+ e++;
+
+ 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_start(s->pktout);
+ ssh2_pkt_addstring_data(s->pktout, var, varend-var);
+ ssh2_pkt_addstring(s->pktout, val);
+ ssh2_pkt_send(ssh, s->pktout);
+
+ 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 = ssh->cfg.ssh_subsys2;
+ cmd = ssh->cfg.remote_cmd_ptr2;
+ } else {
+ subsys = ssh->cfg.ssh_subsys;
+ cmd = ssh->cfg.remote_cmd_ptr;
+ if (!cmd) cmd = ssh->cfg.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 && ssh->cfg.remote_cmd_ptr2 != NULL) {
+ 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(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;
+ int always_display;
+
+ /* XXX maybe we should actually take notice of this */
+ always_display = 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 && ssh->cfg.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);
+ }
+}
+
+/*
+ * 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,
+ Config *cfg,
+ char *host, int port, char **realhost, int nodelay,
+ int keepalive)
+{
+ const char *p;
+ Ssh ssh;
+
+ ssh = snew(struct ssh_tag);
+ ssh->cfg = *cfg; /* STRUCTURE COPY */
+ 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;
+
+ *backend_handle = ssh;
+
+#ifdef MSCRYPTOAPI
+ if (crypto_startup() == 0)
+ return "Microsoft high encryption pack not installed!";
+#endif
+
+ ssh->frontend = frontend_handle;
+ ssh->term_width = ssh->cfg.width;
+ ssh->term_height = ssh->cfg.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(ssh->cfg.ssh_rekey_data);
+ ssh->kex_in_progress = FALSE;
+
+ 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:
+ 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)
+ sfree(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);
+
+ random_unref();
+}
+
+/*
+ * Reconfigure the SSH backend.
+ */
+static void ssh_reconfig(void *handle, Config *cfg)
+{
+ Ssh ssh = (Ssh) handle;
+ char *rekeying = NULL, rekey_mandatory = FALSE;
+ unsigned long old_max_data_size;
+
+ pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
+ if (ssh->portfwds)
+ ssh_setup_portfwd(ssh, cfg);
+
+ if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
+ cfg->ssh_rekey_time != 0) {
+ long new_next = ssh->last_rekey + cfg->ssh_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(cfg->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 (ssh->cfg.compression != cfg->compression) {
+ rekeying = "compression setting changed";
+ rekey_mandatory = TRUE;
+ }
+
+ if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
+ memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
+ sizeof(ssh->cfg.ssh_cipherlist))) {
+ rekeying = "cipher settings changed";
+ rekey_mandatory = TRUE;
+ }
+
+ ssh->cfg = *cfg; /* STRUCTURE COPY */
+
+ 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 || ssh->mainchan->closes > 0)
+ 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 (!ssh->cfg.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_transport_specials[] = {
+ {"IGNORE message", TS_NOP},
+ {"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_transport_specials) +
+ 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) {
+ ADD_SPECIALS(ssh2_transport_specials);
+ 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) {
+ struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
+ ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
+ ssh2_pkt_send(ssh, pktout);
+ 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 {
+ 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 (ssh->cfg.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
+};
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