X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/ca2914d11e55cda342e3c1a25ffbe68b4b6cb653..d8d6c7e50e1fcf5171ec15f8a3e9bdcd141f0b64:/ssh.c diff --git a/ssh.c b/ssh.c index fe163c0b..e0fed88b 100644 --- a/ssh.c +++ b/ssh.c @@ -15,9 +15,6 @@ #define TRUE 1 #endif -/* uncomment this for packet level debugging */ -/* #define DUMP_PACKETS */ - #define logevent(s) { logevent(s); \ if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \ { fprintf(stderr, "%s\n", s); fflush(stderr); } } @@ -112,6 +109,17 @@ #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ +/* + * Packet type contexts, so that ssh2_pkt_type can correctly decode + * the ambiguous type numbers back into the correct type strings. + */ +#define SSH2_PKTCTX_DHGROUP1 0x0001 +#define SSH2_PKTCTX_DHGEX 0x0002 +#define SSH2_PKTCTX_PUBLICKEY 0x0010 +#define SSH2_PKTCTX_PASSWORD 0x0020 +#define SSH2_PKTCTX_KBDINTER 0x0040 +#define SSH2_PKTCTX_AUTH_MASK 0x00F0 + #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 */ @@ -161,6 +169,97 @@ static const char *const ssh2_disconnect_reasons[] = { #define BUG_SSH2_HMAC 2 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4 +static int ssh_pkt_ctx = 0; + +#define translate(x) if (type == x) return #x +#define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x +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"; +} +char *ssh2_pkt_type(int type) +{ + 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); + translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1); + translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1); + translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX); + translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX); + translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX); + translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX); + translate(SSH2_MSG_USERAUTH_REQUEST); + translate(SSH2_MSG_USERAUTH_FAILURE); + translate(SSH2_MSG_USERAUTH_SUCCESS); + translate(SSH2_MSG_USERAUTH_BANNER); + translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY); + translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD); + translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER); + translatec(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 #define GET_32BIT(cp) \ (((unsigned long)(unsigned char)(cp)[0] << 24) | \ @@ -400,6 +499,7 @@ static int ssh_echoing, ssh_editing; static tree234 *ssh_channels; /* indexed by local id */ static struct ssh_channel *mainchan; /* primary session channel */ +static int ssh_exitcode = -1; static tree234 *ssh_rportfwds; @@ -626,10 +726,6 @@ static int ssh1_rdpkt(unsigned char **data, int *datalen) if (cipher) cipher->decrypt(pktin.data, st->biglen); -#ifdef DUMP_PACKETS - debug(("Got packet len=%d pad=%d\n", st->len, st->pad)); - dmemdump(pktin.data, st->biglen); -#endif st->realcrc = crc32(pktin.data, st->biglen - 4); st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4); @@ -643,10 +739,6 @@ static int ssh1_rdpkt(unsigned char **data, int *datalen) if (ssh1_compressing) { unsigned char *decompblk; int decomplen; -#ifdef DUMP_PACKETS - debug(("Packet payload pre-decompression:\n")); - dmemdump(pktin.body - 1, pktin.length + 1); -#endif zlib_decompress_block(pktin.body - 1, pktin.length + 1, &decompblk, &decomplen); @@ -661,12 +753,13 @@ static int ssh1_rdpkt(unsigned char **data, int *datalen) memcpy(pktin.body - 1, decompblk, decomplen); sfree(decompblk); pktin.length = decomplen - 1; -#ifdef DUMP_PACKETS - debug(("Packet payload post-decompression:\n")); - dmemdump(pktin.body - 1, pktin.length + 1); -#endif } + pktin.type = pktin.body[-1]; + + log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type), + pktin.body, pktin.length); + if (pktin.type == SSH1_SMSG_STDOUT_DATA || pktin.type == SSH1_SMSG_STDERR_DATA || pktin.type == SSH1_MSG_DEBUG || @@ -679,8 +772,6 @@ static int ssh1_rdpkt(unsigned char **data, int *datalen) } } - pktin.type = pktin.body[-1]; - if (pktin.type == SSH1_MSG_DEBUG) { /* log debug message */ char buf[80]; @@ -807,11 +898,6 @@ static int ssh2_rdpkt(unsigned char **data, int *datalen) sccipher->decrypt(pktin.data + st->cipherblk, st->packetlen - st->cipherblk); -#ifdef DUMP_PACKETS - debug(("Got packet len=%d pad=%d\n", st->len, st->pad)); - dmemdump(pktin.data, st->packetlen); -#endif - /* * Check the MAC. */ @@ -844,11 +930,6 @@ static int ssh2_rdpkt(unsigned char **data, int *datalen) } pktin.length = 5 + newlen; memcpy(pktin.data + 5, newpayload, newlen); -#ifdef DUMP_PACKETS - debug(("Post-decompression payload:\n")); - dmemdump(pktin.data + 5, newlen); -#endif - sfree(newpayload); } } @@ -856,6 +937,9 @@ static int ssh2_rdpkt(unsigned char **data, int *datalen) pktin.savedpos = 6; pktin.type = pktin.data[5]; + log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type), + pktin.data+6, pktin.length-6); + if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG) goto next_packet; /* FIXME: print DEBUG message */ @@ -930,13 +1014,12 @@ static int s_wrpkt_prepare(void) pktout.body[-1] = pktout.type; + log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type), + pktout.body, pktout.length); + if (ssh1_compressing) { unsigned char *compblk; int complen; -#ifdef DUMP_PACKETS - debug(("Packet payload pre-compression:\n")); - dmemdump(pktout.body - 1, pktout.length + 1); -#endif zlib_compress_block(pktout.body - 1, pktout.length + 1, &compblk, &complen); ssh1_pktout_size(complen - 1); @@ -954,10 +1037,6 @@ static int s_wrpkt_prepare(void) PUT_32BIT(pktout.data + biglen, crc); PUT_32BIT(pktout.data, len); -#ifdef DUMP_PACKETS - debug(("Sending packet len=%d\n", biglen + 4)); - dmemdump(pktout.data, biglen + 4); -#endif if (cipher) cipher->encrypt(pktout.data + 4, biglen); @@ -1221,18 +1300,15 @@ static int ssh2_pkt_construct(void) int cipherblk, maclen, padding, i; static unsigned long outgoing_sequence = 0; + log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]), + pktout.data + 6, pktout.length - 6); + /* * Compress packet payload. */ { unsigned char *newpayload; int newlen; -#ifdef DUMP_PACKETS - if (cscomp && cscomp != &ssh_comp_none) { - debug(("Pre-compression payload:\n")); - dmemdump(pktout.data + 5, pktout.length - 5); - } -#endif if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5, &newpayload, &newlen)) { pktout.length = 5; @@ -1261,11 +1337,6 @@ static int ssh2_pkt_construct(void) outgoing_sequence); outgoing_sequence++; /* whether or not we MACed */ -#ifdef DUMP_PACKETS - debug(("Sending packet len=%d\n", pktout.length + padding)); - dmemdump(pktout.data, pktout.length + padding); -#endif - if (cscipher) cscipher->encrypt(pktout.data, pktout.length + padding); @@ -3040,6 +3111,11 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) /* may be from EXEC_SHELL on some servers * if no pty is available or in other odd cases. Ignore */ } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { + char buf[100]; + ssh_exitcode = GET_32BIT(pktin.body); + sprintf(buf, "Server sent command exit status %d", + ssh_exitcode); + logevent(buf); send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); /* * In case `helpful' firewalls or proxies tack @@ -3435,6 +3511,7 @@ static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) */ if (kex == &ssh_diffiehellman_gex) { logevent("Doing Diffie-Hellman group exchange"); + ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX; /* * Work out how big a DH group we will need to allow that * much data. @@ -3455,6 +3532,7 @@ static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY; } else { + ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1; dh_setup_group1(); kex_init_value = SSH2_MSG_KEXDH_INIT; kex_reply_value = SSH2_MSG_KEXDH_REPLY; @@ -3712,6 +3790,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) * the username they will want to be able to get back and * retype it! */ + username[0] = '\0'; do { static int pos; static char c; @@ -3720,7 +3799,13 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) * Get a username. */ pos = 0; - if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { + if (*username && !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 ((flags & FLAG_INTERACTIVE) && !*cfg.username) { if (ssh_get_line) { if (!ssh_get_line("login as: ", username, sizeof(username), FALSE)) { @@ -3791,6 +3876,8 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) * just in case it succeeds, and (b) so that we know what * authentication methods we can usefully try next. */ + ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); ssh2_pkt_addstring(username); ssh2_pkt_addstring("ssh-connection"); /* service requested */ @@ -3912,6 +3999,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) } method = 0; + ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; if (!method && can_pubkey && agent_exists() && !tried_agent) { /* @@ -3923,6 +4011,8 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) static int authed = FALSE; void *r; + ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; + tried_agent = TRUE; logevent("Pageant is running. Requesting keys."); @@ -4059,6 +4149,8 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) tried_pubkey_config = TRUE; + ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY; + /* * Try the public key supplied in the configuration. * @@ -4111,6 +4203,8 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) type = AUTH_TYPE_KEYBOARD_INTERACTIVE; tried_keyb_inter = TRUE; + ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER; + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); ssh2_pkt_addstring(username); ssh2_pkt_addstring("ssh-connection"); /* service requested */ @@ -4136,6 +4230,8 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) type = AUTH_TYPE_KEYBOARD_INTERACTIVE; tried_keyb_inter = TRUE; + ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER; + /* We've got packet with that "interactive" info dump banners, and set its prompt as ours */ { @@ -4162,6 +4258,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) if (!method && can_passwd) { method = AUTH_PASSWORD; + ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD; sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost); need_pw = TRUE; @@ -4516,7 +4613,10 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); ssh2_pkt_addstring("tcpip-forward"); ssh2_pkt_addbool(1);/* want reply */ - ssh2_pkt_addstring("127.0.0.1"); + if (cfg.rport_acceptall) + ssh2_pkt_addstring("0.0.0.0"); + else + ssh2_pkt_addstring("127.0.0.1"); ssh2_pkt_adduint32(sport); ssh2_pkt_send(); @@ -4967,14 +5067,35 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) } /* - * We don't recognise any form of channel request, - * so we now either ignore the request or respond - * with CHANNEL_FAILURE, depending on want_reply. + * Having got the channel number, we now look at + * the request type string to see if it's something + * we recognise. */ - if (want_reply) { - ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE); - ssh2_pkt_adduint32(c->remoteid); - ssh2_pkt_send(); + if (typelen == 11 && !memcmp(type, "exit-status", 11) && + c == mainchan) { + /* We recognise "exit-status" on the primary channel. */ + char buf[100]; + ssh_exitcode = ssh2_pkt_getuint32(); + sprintf(buf, "Server sent command exit status %d", + ssh_exitcode); + logevent(buf); + if (want_reply) { + ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS); + ssh2_pkt_adduint32(c->remoteid); + ssh2_pkt_send(); + } + } 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. + */ + if (want_reply) { + ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE); + ssh2_pkt_adduint32(c->remoteid); + ssh2_pkt_send(); + } } } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) { char *type; @@ -5349,6 +5470,11 @@ static int ssh_ldisc(int option) return FALSE; } +static int ssh_return_exitcode(void) +{ + return ssh_exitcode; +} + Backend ssh_backend = { ssh_init, ssh_send, @@ -5356,6 +5482,7 @@ Backend ssh_backend = { ssh_size, ssh_special, ssh_socket, + ssh_return_exitcode, ssh_sendok, ssh_ldisc, ssh_unthrottle,