From 8fd6c61557d06a2434cf0e296df38f218ba2c186 Mon Sep 17 00:00:00 2001 From: marha Date: Fri, 19 Nov 2010 10:48:58 +0000 Subject: Remove tools again. Should have done it with svn merge --reintegrate --- tools/plink/ssh.c | 9737 ----------------------------------------------------- 1 file changed, 9737 deletions(-) delete mode 100644 tools/plink/ssh.c (limited to 'tools/plink/ssh.c') diff --git a/tools/plink/ssh.c b/tools/plink/ssh.c deleted file mode 100644 index 89c0433ca..000000000 --- a/tools/plink/ssh.c +++ /dev/null @@ -1,9737 +0,0 @@ -/* - * SSH backend. - */ - -#include -#include -#include -#include -#include -#include - -#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 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--". */ - 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[] = { - "", - "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[] = - ": "; - - 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, , */ - 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 -}; -- cgit v1.2.3