X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/cdcbdf3b83c8a1e4db0b149e818cd24e3596cf2c..247308b5cf8a51eba882abf13c5572ba8f83d0ea:/ssh.c diff --git a/ssh.c b/ssh.c index b0f16518..51bbf44e 100644 --- a/ssh.c +++ b/ssh.c @@ -15,16 +15,25 @@ #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); } } +/* logevent, only printf-formatted. */ +void logeventf(char *fmt, ...) +{ + va_list ap; + char stuff[200]; + + va_start(ap, fmt); + vsprintf(stuff, fmt, ap); + va_end(ap); + logevent(stuff); +} + #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \ (s ? sk_close(s), s = NULL : 0), \ - connection_fatal msg ) + logeventf msg, connection_fatal msg ) #define SSH1_MSG_DISCONNECT 1 /* 0x1 */ #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ @@ -112,6 +121,17 @@ #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 */ @@ -159,6 +179,100 @@ static const char *const ssh2_disconnect_reasons[] = { */ #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 + +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) | \ @@ -208,6 +322,18 @@ extern void pfd_confirm(Socket s); extern void pfd_unthrottle(Socket s); extern void pfd_override_throttle(Socket s, int enable); +static void ssh2_pkt_init(int pkt_type); +static void ssh2_pkt_addbool(unsigned char value); +static void ssh2_pkt_adduint32(unsigned long value); +static void ssh2_pkt_addstring_start(void); +static void ssh2_pkt_addstring_str(char *data); +static void ssh2_pkt_addstring_data(char *data, int len); +static void ssh2_pkt_addstring(char *data); +static char *ssh2_mpint_fmt(Bignum b, int *len); +static void ssh2_pkt_addmp(Bignum b); +static int ssh2_pkt_construct(void); +static void ssh2_pkt_send(void); + /* * Buffer management constants. There are several of these for * various different purposes: @@ -233,18 +359,6 @@ extern void pfd_override_throttle(Socket s, int enable); #define SSH_MAX_BACKLOG 32768 #define OUR_V2_WINSIZE 16384 -/* - * Ciphers for SSH2. We miss out single-DES because it isn't - * supported; also 3DES and Blowfish are both done differently from - * SSH1. (3DES uses outer chaining; Blowfish has the opposite - * endianness and different-sized keys.) - */ -const static struct ssh2_ciphers *ciphers[] = { - &ssh2_aes, - &ssh2_blowfish, - &ssh2_3des, -}; - const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman_gex, &ssh_diffiehellman @@ -410,6 +524,7 @@ 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; @@ -607,12 +722,6 @@ static int ssh1_rdpkt(unsigned char **data, int *datalen) (*data)++, (*datalen)--; } -#ifdef FWHACK - if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */ - st->len = 0x300; /* big enough to carry to end */ - } -#endif - st->pad = 8 - (st->len % 8); st->biglen = st->len + st->pad; pktin.length = st->len - 5; @@ -640,12 +749,13 @@ static int ssh1_rdpkt(unsigned char **data, int *datalen) st->to_read -= st->chunk; } + if (cipher && detect_attack(pktin.data, st->biglen, NULL)) { + bombout(("Network attack (CRC compensation) detected!")); + crReturn(0); + } + 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); @@ -659,10 +769,6 @@ 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); @@ -677,35 +783,34 @@ 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 || pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE || pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) { - long strlen = GET_32BIT(pktin.body); - if (strlen + 4 != pktin.length) { + long stringlen = GET_32BIT(pktin.body); + if (stringlen + 4 != pktin.length) { bombout(("Received data packet with bogus string length")); crReturn(0); } } - pktin.type = pktin.body[-1]; - if (pktin.type == SSH1_MSG_DEBUG) { /* log debug message */ char buf[80]; - int strlen = GET_32BIT(pktin.body); + int stringlen = GET_32BIT(pktin.body); strcpy(buf, "Remote: "); - if (strlen > 70) - strlen = 70; - memcpy(buf + 8, pktin.body + 4, strlen); - buf[8 + strlen] = '\0'; + if (stringlen > 70) + stringlen = 70; + memcpy(buf + 8, pktin.body + 4, stringlen); + buf[8 + stringlen] = '\0'; logevent(buf); goto next_packet; } else if (pktin.type == SSH1_MSG_IGNORE) { @@ -724,7 +829,9 @@ static int ssh1_rdpkt(unsigned char **data, int *datalen) msglen = sizeof(buf) - nowlen - 1; memcpy(buf + nowlen, pktin.body + 4, msglen); buf[nowlen + msglen] = '\0'; - logevent(buf); + /* logevent(buf); (this is now done within the bombout macro) */ + bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen)); + crReturn(0); } crFinish(0); @@ -768,11 +875,7 @@ static int ssh2_rdpkt(unsigned char **data, int *datalen) pktin.data[st->i] = *(*data)++; (*datalen)--; } -#ifdef FWHACK - if (!memcmp(pktin.data, "Remo", 4)) { /* "Remo"te server has closed ... */ - /* FIXME */ - } -#endif + if (sccipher) sccipher->decrypt(pktin.data, st->cipherblk); @@ -825,11 +928,6 @@ 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. */ @@ -862,11 +960,6 @@ 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); } } @@ -874,30 +967,108 @@ static int ssh2_rdpkt(unsigned char **data, int *datalen) pktin.savedpos = 6; pktin.type = pktin.data[5]; - if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG) - goto next_packet; /* FIXME: print DEBUG message */ - - if (pktin.type == SSH2_MSG_DISCONNECT) { - /* log reason code in disconnect message */ - char buf[256]; - int reason = GET_32BIT(pktin.data + 6); - unsigned msglen = GET_32BIT(pktin.data + 10); - unsigned nowlen; - if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) { - sprintf(buf, "Received disconnect message (%s)", - ssh2_disconnect_reasons[reason]); - } else { - sprintf(buf, "Received disconnect message (unknown type %d)", - reason); + log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type), + pktin.data+6, pktin.length-6); + + switch (pktin.type) { + /* + * These packets we must handle instantly. + */ + case SSH2_MSG_DISCONNECT: + { + /* log reason code in disconnect message */ + char buf[256]; + int reason = GET_32BIT(pktin.data + 6); + unsigned msglen = GET_32BIT(pktin.data + 10); + unsigned nowlen; + if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) { + sprintf(buf, "Received disconnect message (%s)", + ssh2_disconnect_reasons[reason]); + } else { + sprintf(buf, "Received disconnect message (unknown type %d)", + reason); + } + logevent(buf); + strcpy(buf, "Disconnection message text: "); + nowlen = strlen(buf); + if (msglen > sizeof(buf) - nowlen - 1) + msglen = sizeof(buf) - nowlen - 1; + memcpy(buf + nowlen, pktin.data + 14, msglen); + buf[nowlen + msglen] = '\0'; + 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", + buf+nowlen)); + crReturn(0); + } + break; + case SSH2_MSG_IGNORE: + goto next_packet; + case SSH2_MSG_DEBUG: + { + /* log the debug message */ + char buf[512]; + /* int display = pktin.body[6]; */ + int stringlen = GET_32BIT(pktin.data+7); + int prefix; + strcpy(buf, "Remote debug message: "); + prefix = strlen(buf); + if (stringlen > sizeof(buf)-prefix-1) + stringlen = sizeof(buf)-prefix-1; + memcpy(buf + prefix, pktin.data + 11, stringlen); + buf[prefix + stringlen] = '\0'; + logevent(buf); } - logevent(buf); - strcpy(buf, "Disconnection message text: "); - nowlen = strlen(buf); - if (msglen > sizeof(buf) - nowlen - 1) - msglen = sizeof(buf) - nowlen - 1; - memcpy(buf + nowlen, pktin.data + 14, msglen); - buf[nowlen + msglen] = '\0'; - logevent(buf); + goto next_packet; /* FIXME: print the debug message */ + + /* + * These packets we need do nothing about here. + */ + case SSH2_MSG_UNIMPLEMENTED: + case SSH2_MSG_SERVICE_REQUEST: + case SSH2_MSG_SERVICE_ACCEPT: + case SSH2_MSG_KEXINIT: + case SSH2_MSG_NEWKEYS: + case SSH2_MSG_KEXDH_INIT: + case SSH2_MSG_KEXDH_REPLY: + /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */ + /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */ + case SSH2_MSG_KEX_DH_GEX_INIT: + case SSH2_MSG_KEX_DH_GEX_REPLY: + case SSH2_MSG_USERAUTH_REQUEST: + case SSH2_MSG_USERAUTH_FAILURE: + case SSH2_MSG_USERAUTH_SUCCESS: + case SSH2_MSG_USERAUTH_BANNER: + case SSH2_MSG_USERAUTH_PK_OK: + /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */ + /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */ + case SSH2_MSG_USERAUTH_INFO_RESPONSE: + case SSH2_MSG_GLOBAL_REQUEST: + case SSH2_MSG_REQUEST_SUCCESS: + case SSH2_MSG_REQUEST_FAILURE: + case SSH2_MSG_CHANNEL_OPEN: + case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION: + case SSH2_MSG_CHANNEL_OPEN_FAILURE: + case SSH2_MSG_CHANNEL_WINDOW_ADJUST: + case SSH2_MSG_CHANNEL_DATA: + case SSH2_MSG_CHANNEL_EXTENDED_DATA: + case SSH2_MSG_CHANNEL_EOF: + case SSH2_MSG_CHANNEL_CLOSE: + case SSH2_MSG_CHANNEL_REQUEST: + case SSH2_MSG_CHANNEL_SUCCESS: + case SSH2_MSG_CHANNEL_FAILURE: + break; + + /* + * For anything else we send SSH2_MSG_UNIMPLEMENTED. + */ + default: + ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED); + ssh2_pkt_adduint32(st->incoming_sequence - 1); + ssh2_pkt_send(); + break; } crFinish(0); @@ -942,10 +1113,8 @@ static int s_wrpkt_prepare(void) pktout.body[-1] = pktout.type; -#ifdef DUMP_PACKETS - debug(("Packet payload pre-compression:\n")); - dmemdump(pktout.body - 1, pktout.length + 1); -#endif + log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type), + pktout.body, pktout.length); if (ssh1_compressing) { unsigned char *compblk; @@ -955,10 +1124,6 @@ static int s_wrpkt_prepare(void) ssh1_pktout_size(complen - 1); memcpy(pktout.body - 1, compblk, complen); sfree(compblk); -#ifdef DUMP_PACKETS - debug(("Packet payload post-compression:\n")); - dmemdump(pktout.body - 1, pktout.length + 1); -#endif } len = pktout.length + 5; /* type and CRC */ @@ -971,10 +1136,6 @@ 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); @@ -1238,13 +1399,12 @@ 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. */ -#ifdef DUMP_PACKETS - debug(("Pre-compression payload:\n")); - dmemdump(pktout.data + 5, pktout.length - 5); -#endif { unsigned char *newpayload; int newlen; @@ -1276,11 +1436,6 @@ 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); @@ -1420,17 +1575,15 @@ static void ssh_detect_bugs(char *vstring) char *imp; /* pointer to implementation part */ imp = vstring; imp += strcspn(imp, "-"); - if (*imp) - imp++; + if (*imp) imp++; imp += strcspn(imp, "-"); - if (*imp) - imp++; + if (*imp) imp++; ssh_remote_bugs = 0; if (!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, "1.2.22") || !strcmp(imp, "Cisco-1.25")) { /* * These versions don't support SSH1_MSG_IGNORE, so we have * to use a different defence against password length @@ -1440,6 +1593,26 @@ static void ssh_detect_bugs(char *vstring) logevent("We believe remote version has SSH1 ignore bug"); } + if (!strcmp(imp, "Cisco-1.25")) { + /* + * 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 SSH1 password"); + } + + if (!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 RSA authentication"); + } + if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) || !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) || !strncmp(imp, "2.1 ", 4)) { @@ -1481,8 +1654,8 @@ static int do_ssh_init(unsigned char c) crReturn(1); /* get another character */ } - vstring = smalloc(16); vstrsize = 16; + vstring = smalloc(vstrsize); strcpy(vstring, "SSH-"); vslen = 4; i = 0; @@ -1508,10 +1681,10 @@ static int do_ssh_init(unsigned char c) vstring[vslen] = 0; vlog = smalloc(20 + vslen); + vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */ sprintf(vlog, "Server version: %s", vstring); - ssh_detect_bugs(vstring); - vlog[strcspn(vlog, "\r\n")] = '\0'; logevent(vlog); + ssh_detect_bugs(vstring); sfree(vlog); /* @@ -1594,6 +1767,9 @@ static void ssh_gotdata(unsigned char *data, int datalen) while (1) { while (datalen > 0) { if (s_rdpkt(&data, &datalen) == 0) { + if (ssh_state == SSH_STATE_CLOSED) { + return; + } ssh_protocol(NULL, 0, 1); if (ssh_state == SSH_STATE_CLOSED) { return; @@ -1615,6 +1791,7 @@ static int ssh_closing(Plug plug, char *error_msg, int error_code, } if (error_msg) { /* A socket error has occurred. */ + logevent(error_msg); connection_fatal(error_msg); } else { /* Otherwise, the remote side closed the connection normally. */ @@ -1651,7 +1828,7 @@ static void ssh_sent(Plug plug, int bufsize) * Also places the canonical host name into `realhost'. It must be * freed by the caller. */ -static char *connect_to_host(char *host, int port, char **realhost) +static char *connect_to_host(char *host, int port, char **realhost, int nodelay) { static struct plug_function_table fn_table = { ssh_closing, @@ -1686,6 +1863,11 @@ static char *connect_to_host(char *host, int port, char **realhost) /* * Try to find host. */ + { + char buf[200]; + sprintf(buf, "Looking up host \"%.170s\"", host); + logevent(buf); + } addr = sk_namelookup(host, realhost); if ((err = sk_addr_error(addr))) return err; @@ -1697,9 +1879,17 @@ static char *connect_to_host(char *host, int port, char **realhost) /* * Open socket. */ - s = sk_new(addr, port, 0, 1, &fn_table_ptr); - if ((err = sk_socket_error(s))) + { + char buf[200], addrbuf[100]; + sk_getaddr(addr, addrbuf, 100); + sprintf(buf, "Connecting to %.100s port %d", addrbuf, port); + logevent(buf); + } + s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr); + if ((err = sk_socket_error(s))) { + s = NULL; return err; + } #ifdef FWHACK sk_write(s, "connect ", 8); @@ -1776,10 +1966,13 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) struct RSAKey servkey, hostkey; struct MD5Context md5c; static unsigned long supported_ciphers_mask, supported_auths_mask; - static int tried_publickey; + static int tried_publickey, tried_agent; + static int tis_auth_refused, ccard_auth_refused; static unsigned char session_id[16]; static int cipher_type; static char username[100]; + static void *publickey_blob; + int publickey_bloblen; crBegin; @@ -1988,8 +2181,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) break; case 3: case 4: - random_save_seed(); - exit(0); + cleanup_exit(0); break; default: if (((c >= ' ' && c <= '~') || @@ -2024,7 +2216,19 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) crWaitUntil(ispkt); - tried_publickey = 0; + if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) { + /* We must not attempt PK auth. Pretend we've already tried it. */ + tried_publickey = tried_agent = 1; + } else { + tried_publickey = tried_agent = 0; + } + tis_auth_refused = ccard_auth_refused = 0; + /* Load the public half of cfg.keyfile so we notice if it's in Pageant */ + if (*cfg.keyfile) { + if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen)) + publickey_blob = NULL; + } else + publickey_blob = NULL; while (pktin.type == SSH1_SMSG_FAILURE) { static char password[100]; @@ -2032,13 +2236,9 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) static int pos; static char c; static int pwpkt_type; - /* - * Show password prompt, having first obtained it via a TIS - * or CryptoCard exchange if we're doing TIS or CryptoCard - * authentication. - */ pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; - if (agent_exists()) { + + if (agent_exists() && !tried_agent) { /* * Attempt RSA authentication using Pageant. */ @@ -2048,6 +2248,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) static int authed = FALSE; void *r; + tried_agent = 1; logevent("Pageant is running. Requesting keys."); /* Request the keys held by the agent. */ @@ -2076,6 +2277,11 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) sprintf(buf, "Trying Pageant key #%d", i); logevent(buf); } + if (publickey_blob && + !memcmp(p, publickey_blob, publickey_bloblen)) { + logevent("This key matches configured key file"); + tried_publickey = 1; + } p += 4; p += ssh1_read_bignum(p, &key.exponent); p += ssh1_read_bignum(p, &key.modulus); @@ -2160,9 +2366,9 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) if (*cfg.keyfile && !tried_publickey) pwpkt_type = SSH1_CMSG_AUTH_RSA; - if (pktin.type == SSH1_SMSG_FAILURE && - cfg.try_tis_auth && - (supported_auths_mask & (1 << SSH1_AUTH_TIS))) { + if (cfg.try_tis_auth && + (supported_auths_mask & (1 << SSH1_AUTH_TIS)) && + !tis_auth_refused) { pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE; logevent("Requested TIS authentication"); send_packet(SSH1_CMSG_AUTH_TIS, PKT_END); @@ -2171,6 +2377,8 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) logevent("TIS authentication declined"); if (flags & FLAG_INTERACTIVE) c_write_str("TIS authentication refused.\r\n"); + tis_auth_refused = 1; + continue; } else { int challengelen = ((pktin.body[0] << 24) | (pktin.body[1] << 16) | @@ -2180,12 +2388,17 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) if (challengelen > sizeof(prompt) - 1) challengelen = sizeof(prompt) - 1; /* prevent overrun */ memcpy(prompt, pktin.body + 4, challengelen); - prompt[challengelen] = '\0'; + /* Prompt heuristic comes from OpenSSH */ + strncpy(prompt + challengelen, + memchr(prompt, '\n', challengelen) ? + "": "\r\nResponse: ", + (sizeof prompt) - challengelen); + prompt[(sizeof prompt) - 1] = '\0'; } } - if (pktin.type == SSH1_SMSG_FAILURE && - cfg.try_tis_auth && - (supported_auths_mask & (1 << SSH1_AUTH_CCARD))) { + if (cfg.try_tis_auth && + (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) && + !ccard_auth_refused) { pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE; logevent("Requested CryptoCard authentication"); send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END); @@ -2193,6 +2406,8 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) { logevent("CryptoCard authentication declined"); c_write_str("CryptoCard authentication refused.\r\n"); + ccard_auth_refused = 1; + continue; } else { int challengelen = ((pktin.body[0] << 24) | (pktin.body[1] << 16) | @@ -2202,7 +2417,9 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) if (challengelen > sizeof(prompt) - 1) challengelen = sizeof(prompt) - 1; /* prevent overrun */ memcpy(prompt, pktin.body + 4, challengelen); - strncpy(prompt + challengelen, "\r\nResponse : ", + strncpy(prompt + challengelen, + memchr(prompt, '\n', challengelen) ? + "" : "\r\nResponse: ", sizeof(prompt) - challengelen); prompt[sizeof(prompt) - 1] = '\0'; } @@ -2224,6 +2441,11 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) sfree(comment); } + /* + * Show password prompt, having first obtained it via a TIS + * or CryptoCard exchange if we're doing TIS or CryptoCard + * authentication. + */ if (ssh_get_line) { if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) { /* @@ -2234,12 +2456,15 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) send_packet(SSH1_MSG_DISCONNECT, PKT_STR, "No more passwords available to try", PKT_END); + logevent("Unable to authenticate"); connection_fatal("Unable to authenticate"); ssh_state = SSH_STATE_CLOSED; crReturn(1); } } else { - c_write_str(prompt); + /* Prompt may have come from server. We've munged it a bit, so + * we know it to be zero-terminated at least once. */ + c_write_untrusted(prompt, strlen(prompt)); pos = 0; ssh_send_ok = 1; while (pos >= 0) { @@ -2262,8 +2487,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) break; case 3: case 4: - random_save_seed(); - exit(0); + cleanup_exit(0); break; default: if (pos < sizeof(password)-1) @@ -2288,7 +2512,7 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) tried_publickey = 1; i = loadrsakey(cfg.keyfile, &pubkey, password); if (i == 0) { - c_write_str("Couldn't load public key from "); + c_write_str("Couldn't load private key from "); c_write_str(cfg.keyfile); c_write_str(".\r\n"); continue; /* go and try password */ @@ -2377,26 +2601,17 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) * use of the fact that the password is interpreted * as a C string: so we can append a NUL, then some * random data. + * + * One server (a Cisco one) can deal with neither + * SSH1_MSG_IGNORE _nor_ a padded password string. + * For this server we are left with no defences + * against password length sniffing. */ - if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) { - char string[64]; - char *s; - int len; - - len = strlen(password); - if (len < sizeof(string)) { - s = string; - strcpy(string, password); - len++; /* cover the zero byte */ - while (len < sizeof(string)) { - string[len++] = (char) random_byte(); - } - } else { - s = password; - } - send_packet(pwpkt_type, PKT_INT, len, - PKT_DATA, s, len, PKT_END); - } else { + if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) { + /* + * The server can deal with SSH1_MSG_IGNORE, so + * we can use the primary defence. + */ int bottom, top, pwlen, i; char *randomstr; @@ -2428,7 +2643,45 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) PKT_STR, randomstr, PKT_END); } } + logevent("Sending password with camouflage packets"); ssh_pkt_defersend(); + } + 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 *s; + int len; + + len = strlen(password); + if (len < sizeof(string)) { + s = string; + strcpy(string, password); + len++; /* cover the zero byte */ + while (len < sizeof(string)) { + string[len++] = (char) random_byte(); + } + } else { + s = password; + } + logevent("Sending length-padded password"); + send_packet(pwpkt_type, PKT_INT, len, + PKT_DATA, s, len, PKT_END); + } else { + /* + * The server has _both_ + * BUG_CHOKES_ON_SSH1_IGNORE and + * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is + * therefore nothing we can do. + */ + int len; + len = strlen(password); + logevent("Sending unpadded password"); + send_packet(pwpkt_type, PKT_INT, len, + PKT_DATA, password, len, PKT_END); } } else { send_packet(pwpkt_type, PKT_STR, password, PKT_END); @@ -2459,19 +2712,29 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) void sshfwd_close(struct ssh_channel *c) { if (c && !c->closes) { - if (ssh_version == 1) { - send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, - PKT_END); - } else { - ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); - ssh2_pkt_adduint32(c->remoteid); - ssh2_pkt_send(); + /* + * If the channel's remoteid is -1, 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->remoteid != -1) { + if (ssh_version == 1) { + send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, + PKT_END); + } else { + ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); + ssh2_pkt_adduint32(c->remoteid); + ssh2_pkt_send(); + } } c->closes = 1; if (c->type == CHAN_X11) { c->u.x11.s = NULL; logevent("Forwarded X11 connection terminated"); - } else if (c->type == CHAN_SOCKDATA) { + } else if (c->type == CHAN_SOCKDATA || + c->type == CHAN_SOCKDATA_DORMANT) { c->u.pfd.s = NULL; logevent("Forwarded port closed"); } @@ -2697,7 +2960,7 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) if (eof_needed) ssh_special(TS_EOF); - ldisc_send(NULL, 0); /* cause ldisc to notice changes */ + ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */ ssh_send_ok = 1; ssh_channels = newtree234(ssh_channelcmp); while (1) { @@ -2709,7 +2972,7 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) int bufsize = from_backend(pktin.type == SSH1_SMSG_STDERR_DATA, pktin.body + 4, len); - if (bufsize > SSH1_BUFFER_LIMIT) { + if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) { ssh1_stdout_throttling = 1; ssh1_throttle(+1); } @@ -2838,9 +3101,21 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) if (c && c->type == CHAN_SOCKDATA_DORMANT) { c->remoteid = localid; c->type = CHAN_SOCKDATA; + c->v.v1.throttling = 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(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, + PKT_END); + } + } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) { unsigned int remoteid = GET_32BIT(pktin.body); unsigned int localid = GET_32BIT(pktin.body+4); @@ -2955,7 +3230,7 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) bufsize = 0; /* agent channels never back up */ break; } - if (bufsize > SSH1_BUFFER_LIMIT) { + if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) { c->v.v1.throttling = 1; ssh1_throttle(+1); } @@ -2966,7 +3241,21 @@ 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 + * 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_state = SSH_STATE_CLOSED; + crReturnV; } else { bombout(("Strange packet received: type %d", pktin.type)); crReturnV; @@ -3060,6 +3349,7 @@ static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) static int n_preferred_ciphers; static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX]; static const struct ssh_compress *preferred_comp; + static int cipherstr_started; static int first_kex; crBegin; @@ -3077,7 +3367,10 @@ static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) n_preferred_ciphers++; break; case CIPHER_DES: - /* Not supported in SSH2; silently drop */ + if (cfg.ssh2_des_cbc) { + preferred_ciphers[n_preferred_ciphers] = &ssh2_des; + n_preferred_ciphers++; + } break; case CIPHER_3DES: preferred_ciphers[n_preferred_ciphers] = &ssh2_3des; @@ -3137,24 +3430,28 @@ static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) } /* List client->server encryption algorithms. */ ssh2_pkt_addstring_start(); + cipherstr_started = 0; for (i = 0; i < n_preferred_ciphers; i++) { const struct ssh2_ciphers *c = preferred_ciphers[i]; if (!c) continue; /* warning flag */ for (j = 0; j < c->nciphers; j++) { - ssh2_pkt_addstring_str(c->list[j]->name); - if (i < n_preferred_ciphers || j < c->nciphers - 1) + if (cipherstr_started) ssh2_pkt_addstring_str(","); + ssh2_pkt_addstring_str(c->list[j]->name); + cipherstr_started = 1; } } /* List server->client encryption algorithms. */ ssh2_pkt_addstring_start(); + cipherstr_started = 0; for (i = 0; i < n_preferred_ciphers; i++) { const struct ssh2_ciphers *c = preferred_ciphers[i]; if (!c) continue; /* warning flag */ for (j = 0; j < c->nciphers; j++) { - ssh2_pkt_addstring_str(c->list[j]->name); - if (i < n_preferred_ciphers || j < c->nciphers - 1) + if (cipherstr_started) ssh2_pkt_addstring_str(","); + ssh2_pkt_addstring_str(c->list[j]->name); + cipherstr_started = 1; } } /* List client->server MAC algorithms. */ @@ -3258,6 +3555,11 @@ static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) break; } } + if (!cscipher_tobe) { + bombout(("Couldn't agree a client-to-server cipher (available: %s)", str)); + crReturn(0); + } + ssh2_pkt_getstring(&str, &len); /* server->client cipher */ warn = 0; for (i = 0; i < n_preferred_ciphers; i++) { @@ -3278,6 +3580,11 @@ static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) break; } } + if (!sccipher_tobe) { + bombout(("Couldn't agree a server-to-client cipher (available: %s)", str)); + crReturn(0); + } + ssh2_pkt_getstring(&str, &len); /* client->server mac */ for (i = 0; i < nmacs; i++) { if (in_commasep_string(maclist[i]->name, str, len)) { @@ -3334,6 +3641,7 @@ 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. @@ -3354,6 +3662,7 @@ 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; @@ -3405,15 +3714,6 @@ static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) } /* - * Expect SSH2_MSG_NEWKEYS from server. - */ - crWaitUntil(ispkt); - if (pktin.type != SSH2_MSG_NEWKEYS) { - bombout(("expected new-keys packet from server")); - crReturn(0); - } - - /* * Authenticate remote host: verify host key. (We've already * checked the signature of the exchange hash.) */ @@ -3436,6 +3736,15 @@ static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) ssh2_pkt_send(); /* + * Expect SSH2_MSG_NEWKEYS from server. + */ + crWaitUntil(ispkt); + if (pktin.type != SSH2_MSG_NEWKEYS) { + bombout(("expected new-keys packet from server")); + crReturn(0); + } + + /* * Create and initialise session keys. */ cscipher = cscipher_tobe; @@ -3536,6 +3845,14 @@ static int ssh2_try_send(struct ssh_channel *c) */ static void ssh2_set_window(struct ssh_channel *c, unsigned newwin) { + /* + * 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 (newwin > c->v.v2.locwindow) { ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); ssh2_pkt_adduint32(c->remoteid); @@ -3570,8 +3887,11 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) static int we_are_in; static int num_prompts, echo; static char username[100]; + static int got_username; static char pwprompt[200]; static char password[100]; + static void *publickey_blob; + static int publickey_bloblen; crBegin; @@ -3611,6 +3931,8 @@ 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'; + got_username = FALSE; do { static int pos; static char c; @@ -3619,7 +3941,13 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) * Get a username. */ pos = 0; - if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { + if (got_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)) { @@ -3659,8 +3987,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) break; case 3: case 4: - random_save_seed(); - exit(0); + cleanup_exit(0); break; default: if (((c >= ' ' && c <= '~') || @@ -3684,12 +4011,15 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) c_write_str(stuff); } } + 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_ctx &= ~SSH2_PKTCTX_AUTH_MASK; + ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); ssh2_pkt_addstring(username); ssh2_pkt_addstring("ssh-connection"); /* service requested */ @@ -3703,6 +4033,12 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) tried_agent = FALSE; tried_keyb_inter = FALSE; kbd_inter_running = FALSE; + /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */ + if (*cfg.keyfile) { + publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL, + &publickey_bloblen); + } else + publickey_blob = NULL; while (1) { /* @@ -3806,65 +4142,12 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) in_commasep_string("publickey", methods, methlen); can_passwd = in_commasep_string("password", methods, methlen); - can_passwd = - in_commasep_string("password", methods, methlen); - can_keyb_inter = + can_keyb_inter = cfg.try_ki_auth && in_commasep_string("keyboard-interactive", methods, methlen); } method = 0; - - if (!method && can_keyb_inter && !tried_keyb_inter) { - method = AUTH_KEYBOARD_INTERACTIVE; - type = AUTH_TYPE_KEYBOARD_INTERACTIVE; - tried_keyb_inter = TRUE; - - ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); - ssh2_pkt_addstring(username); - ssh2_pkt_addstring("ssh-connection"); /* service requested */ - ssh2_pkt_addstring("keyboard-interactive"); /* method */ - ssh2_pkt_addstring(""); /* lang */ - ssh2_pkt_addstring(""); - ssh2_pkt_send(); - - crWaitUntilV(ispkt); - if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) { - if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) - gotit = TRUE; - logevent("Keyboard-interactive authentication refused"); - type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; - continue; - } - - kbd_inter_running = TRUE; - } - - if (kbd_inter_running) { - method = AUTH_KEYBOARD_INTERACTIVE; - type = AUTH_TYPE_KEYBOARD_INTERACTIVE; - tried_keyb_inter = TRUE; - - /* We've got packet with that "interactive" info - dump banners, and set its prompt as ours */ - { - char *name, *inst, *lang, *prompt; - int name_len, inst_len, lang_len, prompt_len; - ssh2_pkt_getstring(&name, &name_len); - ssh2_pkt_getstring(&inst, &inst_len); - ssh2_pkt_getstring(&lang, &lang_len); - if (name_len > 0) - c_write_untrusted(name, name_len); - if (inst_len > 0) - c_write_untrusted(inst, inst_len); - num_prompts = ssh2_pkt_getuint32(); - - ssh2_pkt_getstring(&prompt, &prompt_len); - strncpy(pwprompt, prompt, sizeof(pwprompt)); - need_pw = TRUE; - - echo = ssh2_pkt_getbool(); - } - } + ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; if (!method && can_pubkey && agent_exists() && !tried_agent) { /* @@ -3876,6 +4159,8 @@ 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."); @@ -3909,6 +4194,12 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) } pklen = GET_32BIT(p); p += 4; + if (publickey_blob && + pklen == publickey_bloblen && + !memcmp(p, publickey_blob, publickey_bloblen)) { + logevent("This key matches configured key file"); + tried_pubkey_config = 1; + } pkblob = p; p += pklen; alglen = GET_32BIT(pkblob); @@ -4012,6 +4303,8 @@ 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. * @@ -4059,8 +4352,67 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) } } + if (!method && can_keyb_inter && !tried_keyb_inter) { + method = AUTH_KEYBOARD_INTERACTIVE; + 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 */ + ssh2_pkt_addstring("keyboard-interactive"); /* method */ + ssh2_pkt_addstring(""); /* lang */ + ssh2_pkt_addstring(""); + ssh2_pkt_send(); + + crWaitUntilV(ispkt); + if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) { + if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) + gotit = TRUE; + logevent("Keyboard-interactive authentication refused"); + type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; + continue; + } + + kbd_inter_running = TRUE; + } + + if (kbd_inter_running) { + method = AUTH_KEYBOARD_INTERACTIVE; + 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 */ + { + char *name, *inst, *lang, *prompt; + int name_len, inst_len, lang_len, prompt_len; + ssh2_pkt_getstring(&name, &name_len); + ssh2_pkt_getstring(&inst, &inst_len); + ssh2_pkt_getstring(&lang, &lang_len); + if (name_len > 0) + c_write_untrusted(name, name_len); + if (inst_len > 0) + c_write_untrusted(inst, inst_len); + num_prompts = ssh2_pkt_getuint32(); + + ssh2_pkt_getstring(&prompt, &prompt_len); + strncpy(pwprompt, prompt, sizeof(pwprompt)); + pwprompt[prompt_len < sizeof(pwprompt) ? + prompt_len : sizeof(pwprompt)-1] = '\0'; + need_pw = TRUE; + + echo = ssh2_pkt_getbool(); + } + } + if (!method && can_passwd) { method = AUTH_PASSWORD; + ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD; sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost); need_pw = TRUE; @@ -4082,6 +4434,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) ("No more passwords available to try"); ssh2_pkt_addstring("en"); /* language tag */ ssh2_pkt_send(); + logevent("Unable to authenticate"); connection_fatal("Unable to authenticate"); ssh_state = SSH_STATE_CLOSED; crReturnV; @@ -4114,8 +4467,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) break; case 3: case 4: - random_save_seed(); - exit(0); + cleanup_exit(0); break; default: if (pos < sizeof(password)-1) @@ -4344,7 +4696,8 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { - bombout(("Server got confused by X11 forwarding request")); + bombout(("Unexpected response to X11 forwarding request:" + " packet type %d", pktin.type)); crReturnV; } logevent("X11 forwarding refused"); @@ -4414,7 +4767,10 @@ 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(); @@ -4432,7 +4788,9 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) { if (pktin.type != SSH2_MSG_REQUEST_FAILURE) { - bombout(("Server got confused by port forwarding request")); + bombout(("Unexpected response to port " + "forwarding request: packet type %d", + pktin.type)); crReturnV; } logevent("Server refused this port forwarding"); @@ -4470,8 +4828,8 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { - bombout( - ("Server got confused by agent forwarding request")); + bombout(("Unexpected response to agent forwarding request:" + " packet type %d", pktin.type)); crReturnV; } logevent("Agent forwarding refused"); @@ -4513,7 +4871,8 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { - bombout(("Server got confused by pty request")); + bombout(("Unexpected response to pty request:" + " packet type %d", pktin.type)); crReturnV; } c_write_str("Server refused to allocate pty\r\n"); @@ -4570,7 +4929,8 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST); if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) { if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) { - bombout(("Server got confused by shell/command request")); + bombout(("Unexpected response to shell/command request:" + " packet type %d", pktin.type)); crReturnV; } /* @@ -4601,7 +4961,7 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) /* * Transfer data! */ - ldisc_send(NULL, 0); /* cause ldisc to notice changes */ + ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */ ssh_send_ok = 1; while (1) { static int try_send; @@ -4699,8 +5059,6 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) ssh_state = SSH_STATE_CLOSED; logevent("Received disconnect message"); crReturnV; - } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { - continue; /* exit status et al; ignore (FIXME?) */ } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) { unsigned i = ssh2_pkt_getuint32(); struct ssh_channel *c; @@ -4760,12 +5118,25 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) * See if that was the last channel left open. */ if (count234(ssh_channels) == 0) { +#if 0 + /* + * We used to send SSH_MSG_DISCONNECT here, + * because I'd believed that _every_ conforming + * SSH2 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. + */ logevent("All channels closed. Disconnecting"); ssh2_pkt_init(SSH2_MSG_DISCONNECT); ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); ssh2_pkt_addstring("All open channels closed"); ssh2_pkt_addstring("en"); /* language tag */ ssh2_pkt_send(); +#endif ssh_state = SSH_STATE_CLOSED; crReturnV; } @@ -4788,11 +5159,22 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) continue; /* dunno why they're confirming this */ c->remoteid = ssh2_pkt_getuint32(); c->type = CHAN_SOCKDATA; - c->closes = 0; c->v.v2.remwindow = ssh2_pkt_getuint32(); c->v.v2.remmaxpkt = ssh2_pkt_getuint32(); bufchain_init(&c->v.v2.outbuffer); - pfd_confirm(c->u.pfd.s); + 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. + */ + ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); + ssh2_pkt_adduint32(c->remoteid); + ssh2_pkt_send(); + } } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) { unsigned i = ssh2_pkt_getuint32(); struct ssh_channel *c; @@ -4808,6 +5190,84 @@ static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt) del234(ssh_channels, c); sfree(c); + } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { + unsigned localid; + char *type; + int typelen, want_reply; + struct ssh_channel *c; + + localid = ssh2_pkt_getuint32(); + ssh2_pkt_getstring(&type, &typelen); + want_reply = ssh2_pkt_getbool(); + + /* + * First, check that the channel exists. Otherwise, + * we can instantly disconnect with a rude message. + */ + c = find234(ssh_channels, &localid, ssh_channelfind); + if (!c) { + char buf[80]; + sprintf(buf, "Received channel request for nonexistent" + " channel %d", localid); + logevent(buf); + ssh2_pkt_init(SSH2_MSG_DISCONNECT); + ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION); + ssh2_pkt_addstring(buf); + ssh2_pkt_addstring("en"); /* language tag */ + ssh2_pkt_send(); + connection_fatal("%s", buf); + ssh_state = SSH_STATE_CLOSED; + crReturnV; + } + + /* + * Having got the channel number, we now look at + * the request type string to see if it's something + * we recognise. + */ + 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_GLOBAL_REQUEST) { + char *type; + int typelen, want_reply; + + ssh2_pkt_getstring(&type, &typelen); + want_reply = ssh2_pkt_getbool(); + + /* + * 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) { + ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE); + ssh2_pkt_send(); + } } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) { char *type; int typelen; @@ -4951,7 +5411,7 @@ static void ssh2_protocol(unsigned char *in, int inlen, int ispkt) * * Returns an error message, or NULL on success. */ -static char *ssh_init(char *host, int port, char **realhost) +static char *ssh_init(char *host, int port, char **realhost, int nodelay) { char *p; @@ -4967,7 +5427,7 @@ static char *ssh_init(char *host, int port, char **realhost) ssh_overall_bufsize = 0; ssh_fallback_cmd = 0; - p = connect_to_host(host, port, realhost); + p = connect_to_host(host, port, realhost, nodelay); if (p != NULL) return p; @@ -5115,7 +5575,7 @@ void *new_sock_channel(Socket s) void ssh_unthrottle(int bufsize) { if (ssh_version == 1) { - if (bufsize < SSH1_BUFFER_LIMIT) { + if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) { ssh1_stdout_throttling = 0; ssh1_throttle(-1); } @@ -5181,6 +5641,11 @@ static int ssh_ldisc(int option) return FALSE; } +static int ssh_return_exitcode(void) +{ + return ssh_exitcode; +} + Backend ssh_backend = { ssh_init, ssh_send, @@ -5188,6 +5653,7 @@ Backend ssh_backend = { ssh_size, ssh_special, ssh_socket, + ssh_return_exitcode, ssh_sendok, ssh_ldisc, ssh_unthrottle,