18 /* uncomment this for packet level debugging */
19 /* #define DUMP_PACKETS */
21 #define logevent(s) { logevent(s); \
22 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
23 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
25 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
26 (s ? sk_close(s), s = NULL : 0), \
27 connection_fatal msg )
29 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
30 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
31 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
32 #define SSH1_CMSG_USER 4 /* 0x4 */
33 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
34 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
35 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
36 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
37 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
38 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
39 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
40 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
41 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
42 #define SSH1_SMSG_FAILURE 15 /* 0xf */
43 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
44 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
45 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
46 #define SSH1_CMSG_EOF 19 /* 0x13 */
47 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
48 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
49 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
50 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
51 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
52 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
53 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
54 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
55 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
56 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
57 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
58 #define SSH1_MSG_IGNORE 32 /* 0x20 */
59 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
60 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
61 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
62 #define SSH1_MSG_DEBUG 36 /* 0x24 */
63 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
64 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
65 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
66 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
67 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
68 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
69 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
71 #define SSH1_AUTH_TIS 5 /* 0x5 */
72 #define SSH1_AUTH_CCARD 16 /* 0x10 */
74 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
75 /* Mask for protoflags we will echo back to server if seen */
76 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
78 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
79 #define SSH2_MSG_IGNORE 2 /* 0x2 */
80 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
81 #define SSH2_MSG_DEBUG 4 /* 0x4 */
82 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
83 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
84 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
85 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
86 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
87 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
88 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
89 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
90 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
91 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
92 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
93 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
94 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
95 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
96 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
97 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
98 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
99 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
100 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
101 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
102 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
103 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
104 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
105 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
106 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
107 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
108 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
109 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
110 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
111 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
112 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
113 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
115 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
131 static const char *const ssh2_disconnect_reasons[] = {
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
150 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
155 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
158 * Various remote-bug flags.
160 #define BUG_CHOKES_ON_SSH1_IGNORE 1
161 #define BUG_SSH2_HMAC 2
163 #define GET_32BIT(cp) \
164 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
165 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
166 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
167 ((unsigned long)(unsigned char)(cp)[3]))
169 #define PUT_32BIT(cp, value) { \
170 (cp)[0] = (unsigned char)((value) >> 24); \
171 (cp)[1] = (unsigned char)((value) >> 16); \
172 (cp)[2] = (unsigned char)((value) >> 8); \
173 (cp)[3] = (unsigned char)(value); }
175 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
177 /* Coroutine mechanics for the sillier bits of the code */
178 #define crBegin1 static int crLine = 0;
179 #define crBegin2 switch(crLine) { case 0:;
180 #define crBegin crBegin1; crBegin2;
181 #define crFinish(z) } crLine = 0; return (z)
182 #define crFinishV } crLine = 0; return
183 #define crReturn(z) \
185 crLine=__LINE__; return (z); case __LINE__:;\
189 crLine=__LINE__; return; case __LINE__:;\
191 #define crStop(z) do{ crLine = 0; return (z); }while(0)
192 #define crStopV do{ crLine = 0; return; }while(0)
193 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
194 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
196 extern char *x11_init(Socket *, char *, void *);
197 extern void x11_close(Socket);
198 extern void x11_send(Socket, char *, int);
199 extern void x11_invent_auth(char *, int, char *, int);
201 extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
202 extern char *pfd_addforward(char *desthost, int destport, int port);
203 extern void pfd_close(Socket s);
204 extern void pfd_send(Socket s, char *data, int len);
205 extern void pfd_confirm(Socket s);
208 * Ciphers for SSH2. We miss out single-DES because it isn't
209 * supported; also 3DES and Blowfish are both done differently from
210 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
211 * endianness and different-sized keys.)
213 const static struct ssh2_ciphers *ciphers[] = {
219 const static struct ssh_kex *kex_algs[] = {
220 &ssh_diffiehellman_gex,
224 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
226 static void nullmac_key(unsigned char *key)
229 static void nullmac_generate(unsigned char *blk, int len,
233 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
237 const static struct ssh_mac ssh_mac_none = {
238 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
240 const static struct ssh_mac *macs[] = {
241 &ssh_sha1, &ssh_md5, &ssh_mac_none
243 const static struct ssh_mac *buggymacs[] = {
244 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
247 static void ssh_comp_none_init(void)
250 static int ssh_comp_none_block(unsigned char *block, int len,
251 unsigned char **outblock, int *outlen)
255 static int ssh_comp_none_disable(void)
259 const static struct ssh_compress ssh_comp_none = {
261 ssh_comp_none_init, ssh_comp_none_block,
262 ssh_comp_none_init, ssh_comp_none_block,
263 ssh_comp_none_disable
265 extern const struct ssh_compress ssh_zlib;
266 const static struct ssh_compress *compressions[] = {
267 &ssh_zlib, &ssh_comp_none
270 enum { /* channel types */
275 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
279 * 2-3-4 tree storing channels.
282 unsigned remoteid, localid;
285 struct ssh2_data_channel {
286 unsigned char *outbuffer;
287 unsigned outbuflen, outbufsize;
288 unsigned remwindow, remmaxpkt;
291 struct ssh_agent_channel {
292 unsigned char *message;
293 unsigned char msglen[4];
294 int lensofar, totallen;
296 struct ssh_x11_channel {
299 struct ssh_pfd_channel {
306 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
307 * 2 use this structure in different ways, reflecting SSH 2's
308 * altogether saner approach to port forwarding.
310 * In SSH 1, you arrange a remote forwarding by sending the server
311 * the remote port number, and the local destination host:port.
312 * When a connection comes in, the server sends you back that
313 * host:port pair, and you connect to it. This is a ready-made
314 * security hole if you're not on the ball: a malicious server
315 * could send you back _any_ host:port pair, so if you trustingly
316 * connect to the address it gives you then you've just opened the
317 * entire inside of your corporate network just by connecting
318 * through it to a dodgy SSH server. Hence, we must store a list of
319 * host:port pairs we _are_ trying to forward to, and reject a
320 * connection request from the server if it's not in the list.
322 * In SSH 2, each side of the connection minds its own business and
323 * doesn't send unnecessary information to the other. You arrange a
324 * remote forwarding by sending the server just the remote port
325 * number. When a connection comes in, the server tells you which
326 * of its ports was connected to; and _you_ have to remember what
327 * local host:port pair went with that port number.
329 * Hence: in SSH 1 this structure stores host:port pairs we intend
330 * to allow connections to, and is indexed by those host:port
331 * pairs. In SSH 2 it stores a mapping from source port to
332 * destination host:port pair, and is indexed by source port.
334 struct ssh_rportfwd {
335 unsigned sport, dport;
348 static SHA_State exhash, exhashbase;
350 static Socket s = NULL;
352 static unsigned char session_key[32];
353 static int ssh1_compressing;
354 static int ssh1_remote_protoflags;
355 static int ssh1_local_protoflags;
356 static int ssh_agentfwd_enabled;
357 static int ssh_X11_fwd_enabled;
358 static int ssh_remote_bugs;
359 static const struct ssh_cipher *cipher = NULL;
360 static const struct ssh2_cipher *cscipher = NULL;
361 static const struct ssh2_cipher *sccipher = NULL;
362 static const struct ssh_mac *csmac = NULL;
363 static const struct ssh_mac *scmac = NULL;
364 static const struct ssh_compress *cscomp = NULL;
365 static const struct ssh_compress *sccomp = NULL;
366 static const struct ssh_kex *kex = NULL;
367 static const struct ssh_signkey *hostkey = NULL;
368 static unsigned char ssh2_session_id[20];
369 int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
372 static char *savedhost;
373 static int savedport;
374 static int ssh_send_ok;
375 static int ssh_echoing, ssh_editing;
377 static tree234 *ssh_channels; /* indexed by local id */
378 static struct ssh_channel *mainchan; /* primary session channel */
380 static tree234 *ssh_rportfwds;
384 SSH_STATE_BEFORE_SIZE,
388 } ssh_state = SSH_STATE_PREPACKET;
390 static int size_needed = FALSE, eof_needed = FALSE;
392 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
393 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
394 static unsigned char *deferred_send_data = NULL;
395 static int deferred_len = 0, deferred_size = 0;
397 static int ssh_version;
398 static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
399 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
400 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
401 static void ssh_size(void);
402 static void ssh_special(Telnet_Special);
403 static void ssh2_try_send(struct ssh_channel *c);
404 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
407 static int (*s_rdpkt) (unsigned char **data, int *datalen);
409 static struct rdpkt1_state_tag {
410 long len, pad, biglen, to_read;
411 unsigned long realcrc, gotcrc;
417 static struct rdpkt2_state_tag {
418 long len, pad, payload, packetlen, maclen;
421 unsigned long incoming_sequence;
424 static int ssh_channelcmp(void *av, void *bv)
426 struct ssh_channel *a = (struct ssh_channel *) av;
427 struct ssh_channel *b = (struct ssh_channel *) bv;
428 if (a->localid < b->localid)
430 if (a->localid > b->localid)
434 static int ssh_channelfind(void *av, void *bv)
436 unsigned *a = (unsigned *) av;
437 struct ssh_channel *b = (struct ssh_channel *) bv;
445 static int ssh_rportcmp_ssh1(void *av, void *bv)
447 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
448 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
450 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
451 return i < 0 ? -1 : +1;
452 if (a->dport > b->dport)
454 if (a->dport < b->dport)
459 static int ssh_rportcmp_ssh2(void *av, void *bv)
461 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
462 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
464 if (a->sport > b->sport)
466 if (a->sport < b->sport)
471 static int alloc_channel_id(void)
473 const unsigned CHANNEL_NUMBER_OFFSET = 256;
474 unsigned low, high, mid;
476 struct ssh_channel *c;
479 * First-fit allocation of channel numbers: always pick the
480 * lowest unused one. To do this, binary-search using the
481 * counted B-tree to find the largest channel ID which is in a
482 * contiguous sequence from the beginning. (Precisely
483 * everything in that sequence must have ID equal to its tree
484 * index plus CHANNEL_NUMBER_OFFSET.)
486 tsize = count234(ssh_channels);
490 while (high - low > 1) {
491 mid = (high + low) / 2;
492 c = index234(ssh_channels, mid);
493 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
494 low = mid; /* this one is fine */
496 high = mid; /* this one is past it */
499 * Now low points to either -1, or the tree index of the
500 * largest ID in the initial sequence.
503 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
504 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
506 return low + 1 + CHANNEL_NUMBER_OFFSET;
509 static void c_write(char *buf, int len)
511 if ((flags & FLAG_STDERR)) {
513 for (i = 0; i < len; i++)
515 fputc(buf[i], stderr);
518 from_backend(1, buf, len);
521 static void c_write_untrusted(char *buf, int len)
524 for (i = 0; i < len; i++) {
527 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
532 static void c_write_str(char *buf)
534 c_write(buf, strlen(buf));
538 * Collect incoming data in the incoming packet buffer.
539 * Decipher and verify the packet when it is completely read.
540 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
541 * Update the *data and *datalen variables.
542 * Return the additional nr of bytes needed, or 0 when
543 * a complete packet is available.
545 static int ssh1_rdpkt(unsigned char **data, int *datalen)
547 struct rdpkt1_state_tag *st = &rdpkt1_state;
556 for (st->i = st->len = 0; st->i < 4; st->i++) {
557 while ((*datalen) == 0)
559 st->len = (st->len << 8) + **data;
560 (*data)++, (*datalen)--;
564 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
565 st->len = 0x300; /* big enough to carry to end */
569 st->pad = 8 - (st->len % 8);
570 st->biglen = st->len + st->pad;
571 pktin.length = st->len - 5;
573 if (pktin.maxlen < st->biglen) {
574 pktin.maxlen = st->biglen;
575 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
576 srealloc(pktin.data, st->biglen + APIEXTRA));
578 fatalbox("Out of memory");
581 st->to_read = st->biglen;
583 while (st->to_read > 0) {
584 st->chunk = st->to_read;
585 while ((*datalen) == 0)
586 crReturn(st->to_read);
587 if (st->chunk > (*datalen))
588 st->chunk = (*datalen);
589 memcpy(st->p, *data, st->chunk);
591 *datalen -= st->chunk;
593 st->to_read -= st->chunk;
597 cipher->decrypt(pktin.data, st->biglen);
599 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
600 dmemdump(pktin.data, st->biglen);
603 st->realcrc = crc32(pktin.data, st->biglen - 4);
604 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
605 if (st->gotcrc != st->realcrc) {
606 bombout(("Incorrect CRC received on packet"));
610 pktin.body = pktin.data + st->pad + 1;
612 if (ssh1_compressing) {
613 unsigned char *decompblk;
616 debug(("Packet payload pre-decompression:\n"));
617 dmemdump(pktin.body - 1, pktin.length + 1);
619 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
620 &decompblk, &decomplen);
622 if (pktin.maxlen < st->pad + decomplen) {
623 pktin.maxlen = st->pad + decomplen;
624 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
625 pktin.body = pktin.data + st->pad + 1;
627 fatalbox("Out of memory");
630 memcpy(pktin.body - 1, decompblk, decomplen);
632 pktin.length = decomplen - 1;
634 debug(("Packet payload post-decompression:\n"));
635 dmemdump(pktin.body - 1, pktin.length + 1);
639 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
640 pktin.type == SSH1_SMSG_STDERR_DATA ||
641 pktin.type == SSH1_MSG_DEBUG ||
642 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
643 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
644 long strlen = GET_32BIT(pktin.body);
645 if (strlen + 4 != pktin.length) {
646 bombout(("Received data packet with bogus string length"));
651 pktin.type = pktin.body[-1];
653 if (pktin.type == SSH1_MSG_DEBUG) {
654 /* log debug message */
656 int strlen = GET_32BIT(pktin.body);
657 strcpy(buf, "Remote: ");
660 memcpy(buf + 8, pktin.body + 4, strlen);
661 buf[8 + strlen] = '\0';
664 } else if (pktin.type == SSH1_MSG_IGNORE) {
669 if (pktin.type == SSH1_MSG_DISCONNECT) {
670 /* log reason code in disconnect message */
672 unsigned msglen = GET_32BIT(pktin.body);
674 strcpy(buf, "Remote sent disconnect: ");
675 nowlen = strlen(buf);
676 if (msglen > sizeof(buf) - nowlen - 1)
677 msglen = sizeof(buf) - nowlen - 1;
678 memcpy(buf + nowlen, pktin.body + 4, msglen);
679 buf[nowlen + msglen] = '\0';
686 static int ssh2_rdpkt(unsigned char **data, int *datalen)
688 struct rdpkt2_state_tag *st = &rdpkt2_state;
696 st->cipherblk = sccipher->blksize;
699 if (st->cipherblk < 8)
702 if (pktin.maxlen < st->cipherblk) {
703 pktin.maxlen = st->cipherblk;
706 NULL ? smalloc(st->cipherblk +
707 APIEXTRA) : srealloc(pktin.data,
711 fatalbox("Out of memory");
715 * Acquire and decrypt the first block of the packet. This will
716 * contain the length and padding details.
718 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
719 while ((*datalen) == 0)
720 crReturn(st->cipherblk - st->i);
721 pktin.data[st->i] = *(*data)++;
725 if (!memcmp(pktin.data, "Remo", 4)) { /* "Remo"te server has closed ... */
730 sccipher->decrypt(pktin.data, st->cipherblk);
733 * Now get the length and padding figures.
735 st->len = GET_32BIT(pktin.data);
736 st->pad = pktin.data[4];
739 * This enables us to deduce the payload length.
741 st->payload = st->len - st->pad - 1;
743 pktin.length = st->payload + 5;
746 * So now we can work out the total packet length.
748 st->packetlen = st->len + 4;
749 st->maclen = scmac ? scmac->len : 0;
752 * Adjust memory allocation if packet is too big.
754 if (pktin.maxlen < st->packetlen + st->maclen) {
755 pktin.maxlen = st->packetlen + st->maclen;
758 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
763 fatalbox("Out of memory");
767 * Read and decrypt the remainder of the packet.
769 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
771 while ((*datalen) == 0)
772 crReturn(st->packetlen + st->maclen - st->i);
773 pktin.data[st->i] = *(*data)++;
776 /* Decrypt everything _except_ the MAC. */
778 sccipher->decrypt(pktin.data + st->cipherblk,
779 st->packetlen - st->cipherblk);
782 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
783 dmemdump(pktin.data, st->packetlen);
790 && !scmac->verify(pktin.data, st->len + 4,
791 st->incoming_sequence)) {
792 bombout(("Incorrect MAC received on packet"));
795 st->incoming_sequence++; /* whether or not we MACed */
798 * Decompress packet payload.
801 unsigned char *newpayload;
803 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
804 &newpayload, &newlen)) {
805 if (pktin.maxlen < newlen + 5) {
806 pktin.maxlen = newlen + 5;
809 NULL ? smalloc(pktin.maxlen +
810 APIEXTRA) : srealloc(pktin.data,
814 fatalbox("Out of memory");
816 pktin.length = 5 + newlen;
817 memcpy(pktin.data + 5, newpayload, newlen);
819 debug(("Post-decompression payload:\n"));
820 dmemdump(pktin.data + 5, newlen);
828 pktin.type = pktin.data[5];
830 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
831 goto next_packet; /* FIXME: print DEBUG message */
833 if (pktin.type == SSH2_MSG_DISCONNECT) {
834 /* log reason code in disconnect message */
836 int reason = GET_32BIT(pktin.data + 6);
837 unsigned msglen = GET_32BIT(pktin.data + 10);
839 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
840 sprintf(buf, "Received disconnect message (%s)",
841 ssh2_disconnect_reasons[reason]);
843 sprintf(buf, "Received disconnect message (unknown type %d)",
847 strcpy(buf, "Disconnection message text: ");
848 nowlen = strlen(buf);
849 if (msglen > sizeof(buf) - nowlen - 1)
850 msglen = sizeof(buf) - nowlen - 1;
851 memcpy(buf + nowlen, pktin.data + 14, msglen);
852 buf[nowlen + msglen] = '\0';
859 static void ssh1_pktout_size(int len)
863 len += 5; /* type and CRC */
867 pktout.length = len - 5;
868 if (pktout.maxlen < biglen) {
869 pktout.maxlen = biglen;
871 /* Allocate enough buffer space for extra block
872 * for MS CryptEncrypt() */
873 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
874 srealloc(pktout.data, biglen + 12));
876 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
877 srealloc(pktout.data, biglen + 4));
880 fatalbox("Out of memory");
882 pktout.body = pktout.data + 4 + pad + 1;
885 static void s_wrpkt_start(int type, int len)
887 ssh1_pktout_size(len);
891 static int s_wrpkt_prepare(void)
893 int pad, len, biglen, i;
896 pktout.body[-1] = pktout.type;
899 debug(("Packet payload pre-compression:\n"));
900 dmemdump(pktout.body - 1, pktout.length + 1);
903 if (ssh1_compressing) {
904 unsigned char *compblk;
906 zlib_compress_block(pktout.body - 1, pktout.length + 1,
908 ssh1_pktout_size(complen - 1);
909 memcpy(pktout.body - 1, compblk, complen);
912 debug(("Packet payload post-compression:\n"));
913 dmemdump(pktout.body - 1, pktout.length + 1);
917 len = pktout.length + 5; /* type and CRC */
921 for (i = 0; i < pad; i++)
922 pktout.data[i + 4] = random_byte();
923 crc = crc32(pktout.data + 4, biglen - 4);
924 PUT_32BIT(pktout.data + biglen, crc);
925 PUT_32BIT(pktout.data, len);
928 debug(("Sending packet len=%d\n", biglen + 4));
929 dmemdump(pktout.data, biglen + 4);
932 cipher->encrypt(pktout.data + 4, biglen);
937 static void s_wrpkt(void)
940 len = s_wrpkt_prepare();
941 sk_write(s, pktout.data, len);
944 static void s_wrpkt_defer(void)
947 len = s_wrpkt_prepare();
948 if (deferred_len + len > deferred_size) {
949 deferred_size = deferred_len + len + 128;
950 deferred_send_data = srealloc(deferred_send_data, deferred_size);
952 memcpy(deferred_send_data + deferred_len, pktout.data, len);
957 * Construct a packet with the specified contents.
959 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
961 unsigned char *p, *argp, argchar;
962 unsigned long argint;
963 int pktlen, argtype, arglen;
967 while ((argtype = va_arg(ap1, int)) != PKT_END) {
970 (void) va_arg(ap1, int);
974 (void) va_arg(ap1, char);
978 (void) va_arg(ap1, unsigned char *);
979 arglen = va_arg(ap1, int);
983 argp = va_arg(ap1, unsigned char *);
984 arglen = strlen(argp);
985 pktlen += 4 + arglen;
988 bn = va_arg(ap1, Bignum);
989 pktlen += ssh1_bignum_length(bn);
996 s_wrpkt_start(pkttype, pktlen);
999 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1002 argint = va_arg(ap2, int);
1003 PUT_32BIT(p, argint);
1007 argchar = va_arg(ap2, unsigned char);
1012 argp = va_arg(ap2, unsigned char *);
1013 arglen = va_arg(ap2, int);
1014 memcpy(p, argp, arglen);
1018 argp = va_arg(ap2, unsigned char *);
1019 arglen = strlen(argp);
1020 PUT_32BIT(p, arglen);
1021 memcpy(p + 4, argp, arglen);
1025 bn = va_arg(ap2, Bignum);
1026 p += ssh1_write_bignum(p, bn);
1032 static void send_packet(int pkttype, ...)
1035 va_start(ap1, pkttype);
1036 va_start(ap2, pkttype);
1037 construct_packet(pkttype, ap1, ap2);
1041 static void defer_packet(int pkttype, ...)
1044 va_start(ap1, pkttype);
1045 va_start(ap2, pkttype);
1046 construct_packet(pkttype, ap1, ap2);
1050 static int ssh_versioncmp(char *a, char *b)
1053 unsigned long av, bv;
1055 av = strtoul(a, &ae, 10);
1056 bv = strtoul(b, &be, 10);
1058 return (av < bv ? -1 : +1);
1063 av = strtoul(ae, &ae, 10);
1064 bv = strtoul(be, &be, 10);
1066 return (av < bv ? -1 : +1);
1072 * Utility routines for putting an SSH-protocol `string' and
1073 * `uint32' into a SHA state.
1076 static void sha_string(SHA_State * s, void *str, int len)
1078 unsigned char lenblk[4];
1079 PUT_32BIT(lenblk, len);
1080 SHA_Bytes(s, lenblk, 4);
1081 SHA_Bytes(s, str, len);
1084 static void sha_uint32(SHA_State * s, unsigned i)
1086 unsigned char intblk[4];
1087 PUT_32BIT(intblk, i);
1088 SHA_Bytes(s, intblk, 4);
1092 * SSH2 packet construction functions.
1094 static void ssh2_pkt_ensure(int length)
1096 if (pktout.maxlen < length) {
1097 pktout.maxlen = length + 256;
1100 NULL ? smalloc(pktout.maxlen +
1101 APIEXTRA) : srealloc(pktout.data,
1105 fatalbox("Out of memory");
1108 static void ssh2_pkt_adddata(void *data, int len)
1110 pktout.length += len;
1111 ssh2_pkt_ensure(pktout.length);
1112 memcpy(pktout.data + pktout.length - len, data, len);
1114 static void ssh2_pkt_addbyte(unsigned char byte)
1116 ssh2_pkt_adddata(&byte, 1);
1118 static void ssh2_pkt_init(int pkt_type)
1121 ssh2_pkt_addbyte((unsigned char) pkt_type);
1123 static void ssh2_pkt_addbool(unsigned char value)
1125 ssh2_pkt_adddata(&value, 1);
1127 static void ssh2_pkt_adduint32(unsigned long value)
1130 PUT_32BIT(x, value);
1131 ssh2_pkt_adddata(x, 4);
1133 static void ssh2_pkt_addstring_start(void)
1135 ssh2_pkt_adduint32(0);
1136 pktout.savedpos = pktout.length;
1138 static void ssh2_pkt_addstring_str(char *data)
1140 ssh2_pkt_adddata(data, strlen(data));
1141 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1142 pktout.length - pktout.savedpos);
1144 static void ssh2_pkt_addstring_data(char *data, int len)
1146 ssh2_pkt_adddata(data, len);
1147 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1148 pktout.length - pktout.savedpos);
1150 static void ssh2_pkt_addstring(char *data)
1152 ssh2_pkt_addstring_start();
1153 ssh2_pkt_addstring_str(data);
1155 static char *ssh2_mpint_fmt(Bignum b, int *len)
1158 int i, n = (bignum_bitcount(b) + 7) / 8;
1161 fatalbox("out of memory");
1163 for (i = 1; i <= n; i++)
1164 p[i] = bignum_byte(b, n - i);
1166 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1168 memmove(p, p + i, n + 1 - i);
1172 static void ssh2_pkt_addmp(Bignum b)
1176 p = ssh2_mpint_fmt(b, &len);
1177 ssh2_pkt_addstring_start();
1178 ssh2_pkt_addstring_data(p, len);
1183 * Construct an SSH2 final-form packet: compress it, encrypt it,
1184 * put the MAC on it. Final packet, ready to be sent, is stored in
1185 * pktout.data. Total length is returned.
1187 static int ssh2_pkt_construct(void)
1189 int cipherblk, maclen, padding, i;
1190 static unsigned long outgoing_sequence = 0;
1193 * Compress packet payload.
1196 debug(("Pre-compression payload:\n"));
1197 dmemdump(pktout.data + 5, pktout.length - 5);
1200 unsigned char *newpayload;
1202 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
1203 &newpayload, &newlen)) {
1205 ssh2_pkt_adddata(newpayload, newlen);
1211 * Add padding. At least four bytes, and must also bring total
1212 * length (minus MAC) up to a multiple of the block size.
1214 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1215 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1218 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1219 maclen = csmac ? csmac->len : 0;
1220 ssh2_pkt_ensure(pktout.length + padding + maclen);
1221 pktout.data[4] = padding;
1222 for (i = 0; i < padding; i++)
1223 pktout.data[pktout.length + i] = random_byte();
1224 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1226 csmac->generate(pktout.data, pktout.length + padding,
1228 outgoing_sequence++; /* whether or not we MACed */
1231 debug(("Sending packet len=%d\n", pktout.length + padding));
1232 dmemdump(pktout.data, pktout.length + padding);
1236 cscipher->encrypt(pktout.data, pktout.length + padding);
1238 /* Ready-to-send packet starts at pktout.data. We return length. */
1239 return pktout.length + padding + maclen;
1243 * Construct and send an SSH2 packet immediately.
1245 static void ssh2_pkt_send(void)
1247 int len = ssh2_pkt_construct();
1248 sk_write(s, pktout.data, len);
1252 * Construct an SSH2 packet and add it to a deferred data block.
1253 * Useful for sending multiple packets in a single sk_write() call,
1254 * to prevent a traffic-analysing listener from being able to work
1255 * out the length of any particular packet (such as the password
1258 * Note that because SSH2 sequence-numbers its packets, this can
1259 * NOT be used as an m4-style `defer' allowing packets to be
1260 * constructed in one order and sent in another.
1262 static void ssh2_pkt_defer(void)
1264 int len = ssh2_pkt_construct();
1265 if (deferred_len + len > deferred_size) {
1266 deferred_size = deferred_len + len + 128;
1267 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1269 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1270 deferred_len += len;
1274 * Send the whole deferred data block constructed by
1275 * ssh2_pkt_defer() or SSH1's defer_packet().
1277 static void ssh_pkt_defersend(void)
1279 sk_write(s, deferred_send_data, deferred_len);
1280 deferred_len = deferred_size = 0;
1281 sfree(deferred_send_data);
1282 deferred_send_data = NULL;
1286 void bndebug(char *string, Bignum b)
1290 p = ssh2_mpint_fmt(b, &len);
1291 debug(("%s", string));
1292 for (i = 0; i < len; i++)
1293 debug((" %02x", p[i]));
1299 static void sha_mpint(SHA_State * s, Bignum b)
1303 p = ssh2_mpint_fmt(b, &len);
1304 sha_string(s, p, len);
1309 * SSH2 packet decode functions.
1311 static unsigned long ssh2_pkt_getuint32(void)
1313 unsigned long value;
1314 if (pktin.length - pktin.savedpos < 4)
1315 return 0; /* arrgh, no way to decline (FIXME?) */
1316 value = GET_32BIT(pktin.data + pktin.savedpos);
1317 pktin.savedpos += 4;
1320 static int ssh2_pkt_getbool(void)
1322 unsigned long value;
1323 if (pktin.length - pktin.savedpos < 1)
1324 return 0; /* arrgh, no way to decline (FIXME?) */
1325 value = pktin.data[pktin.savedpos] != 0;
1329 static void ssh2_pkt_getstring(char **p, int *length)
1332 if (pktin.length - pktin.savedpos < 4)
1334 *length = GET_32BIT(pktin.data + pktin.savedpos);
1335 pktin.savedpos += 4;
1336 if (pktin.length - pktin.savedpos < *length)
1338 *p = pktin.data + pktin.savedpos;
1339 pktin.savedpos += *length;
1341 static Bignum ssh2_pkt_getmp(void)
1347 ssh2_pkt_getstring(&p, &length);
1351 bombout(("internal error: Can't handle negative mpints"));
1354 b = bignum_from_bytes(p, length);
1359 * Examine the remote side's version string and compare it against
1360 * a list of known buggy implementations.
1362 static void ssh_detect_bugs(char *vstring)
1364 char *imp; /* pointer to implementation part */
1366 imp += strcspn(imp, "-");
1369 imp += strcspn(imp, "-");
1373 ssh_remote_bugs = 0;
1375 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1376 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1377 !strcmp(imp, "1.2.22")) {
1379 * These versions don't support SSH1_MSG_IGNORE, so we have
1380 * to use a different defence against password length
1383 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1384 logevent("We believe remote version has SSH1 ignore bug");
1387 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1388 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1389 !strncmp(imp, "2.1 ", 4)) {
1391 * These versions have the HMAC bug.
1393 ssh_remote_bugs |= BUG_SSH2_HMAC;
1394 logevent("We believe remote version has SSH2 HMAC bug");
1398 static int do_ssh_init(unsigned char c)
1401 static char version[10];
1402 static char *vstring;
1403 static int vstrsize;
1409 /* Search for the string "SSH-" in the input. */
1412 static const int transS[] = { 1, 2, 2, 1 };
1413 static const int transH[] = { 0, 0, 3, 0 };
1414 static const int transminus[] = { 0, 0, 0, -1 };
1425 crReturn(1); /* get another character */
1428 vstring = smalloc(16);
1430 strcpy(vstring, "SSH-");
1434 crReturn(1); /* get another char */
1435 if (vslen >= vstrsize - 1) {
1437 vstring = srealloc(vstring, vstrsize);
1439 vstring[vslen++] = c;
1444 } else if (i < sizeof(version) - 1)
1446 } else if (c == '\n')
1450 ssh_agentfwd_enabled = FALSE;
1451 rdpkt2_state.incoming_sequence = 0;
1454 vlog = smalloc(20 + vslen);
1455 sprintf(vlog, "Server version: %s", vstring);
1456 ssh_detect_bugs(vstring);
1457 vlog[strcspn(vlog, "\r\n")] = '\0';
1462 * Server version "1.99" means we can choose whether we use v1
1463 * or v2 protocol. Choice is based on cfg.sshprot.
1465 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1467 * This is a v2 server. Begin v2 protocol.
1469 char verstring[80], vlog[100];
1470 sprintf(verstring, "SSH-2.0-%s", sshver);
1471 SHA_Init(&exhashbase);
1473 * Hash our version string and their version string.
1475 sha_string(&exhashbase, verstring, strlen(verstring));
1476 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1477 sprintf(vlog, "We claim version: %s", verstring);
1479 strcat(verstring, "\n");
1480 logevent("Using SSH protocol version 2");
1481 sk_write(s, verstring, strlen(verstring));
1482 ssh_protocol = ssh2_protocol;
1484 s_rdpkt = ssh2_rdpkt;
1487 * This is a v1 server. Begin v1 protocol.
1489 char verstring[80], vlog[100];
1490 sprintf(verstring, "SSH-%s-%s",
1491 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1493 sprintf(vlog, "We claim version: %s", verstring);
1495 strcat(verstring, "\n");
1496 logevent("Using SSH protocol version 1");
1497 sk_write(s, verstring, strlen(verstring));
1498 ssh_protocol = ssh1_protocol;
1500 s_rdpkt = ssh1_rdpkt;
1502 ssh_state = SSH_STATE_BEFORE_SIZE;
1509 static void ssh_gotdata(unsigned char *data, int datalen)
1514 * To begin with, feed the characters one by one to the
1515 * protocol initialisation / selection function do_ssh_init().
1516 * When that returns 0, we're done with the initial greeting
1517 * exchange and can move on to packet discipline.
1522 crReturnV; /* more data please */
1523 ret = do_ssh_init(*data);
1531 * We emerge from that loop when the initial negotiation is
1532 * over and we have selected an s_rdpkt function. Now pass
1533 * everything to s_rdpkt, and then pass the resulting packets
1534 * to the proper protocol handler.
1539 while (datalen > 0) {
1540 if (s_rdpkt(&data, &datalen) == 0) {
1541 ssh_protocol(NULL, 0, 1);
1542 if (ssh_state == SSH_STATE_CLOSED) {
1552 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1555 ssh_state = SSH_STATE_CLOSED;
1561 /* A socket error has occurred. */
1562 connection_fatal(error_msg);
1564 /* Otherwise, the remote side closed the connection normally. */
1569 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1571 ssh_gotdata(data, len);
1572 if (ssh_state == SSH_STATE_CLOSED) {
1583 * Connect to specified host and port.
1584 * Returns an error message, or NULL on success.
1585 * Also places the canonical host name into `realhost'. It must be
1586 * freed by the caller.
1588 static char *connect_to_host(char *host, int port, char **realhost)
1590 static struct plug_function_table fn_table = {
1593 }, *fn_table_ptr = &fn_table;
1602 savedhost = smalloc(1 + strlen(host));
1604 fatalbox("Out of memory");
1605 strcpy(savedhost, host);
1608 port = 22; /* default ssh port */
1621 addr = sk_namelookup(host, realhost);
1622 if ((err = sk_addr_error(addr)))
1626 *realhost = strdup(FWhost);
1632 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
1633 if ((err = sk_socket_error(s)))
1637 sk_write(s, "connect ", 8);
1638 sk_write(s, FWhost, strlen(FWhost));
1641 sprintf(buf, " %d\n", FWport);
1642 sk_write(s, buf, strlen(buf));
1650 * Handle the key exchange and user authentication phases.
1652 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1656 static unsigned char *rsabuf, *keystr1, *keystr2;
1657 unsigned char cookie[8];
1658 struct RSAKey servkey, hostkey;
1659 struct MD5Context md5c;
1660 static unsigned long supported_ciphers_mask, supported_auths_mask;
1661 static int tried_publickey;
1662 static unsigned char session_id[16];
1663 static int cipher_type;
1664 static char username[100];
1671 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1672 bombout(("Public key packet not received"));
1676 logevent("Received public keys");
1678 memcpy(cookie, pktin.body, 8);
1680 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1681 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
1684 * Log the host key fingerprint.
1688 logevent("Host key fingerprint is:");
1689 strcpy(logmsg, " ");
1690 hostkey.comment = NULL;
1691 rsa_fingerprint(logmsg + strlen(logmsg),
1692 sizeof(logmsg) - strlen(logmsg), &hostkey);
1696 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1697 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1698 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
1700 ssh1_local_protoflags =
1701 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1702 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1705 MD5Update(&md5c, keystr2, hostkey.bytes);
1706 MD5Update(&md5c, keystr1, servkey.bytes);
1707 MD5Update(&md5c, pktin.body, 8);
1708 MD5Final(session_id, &md5c);
1710 for (i = 0; i < 32; i++)
1711 session_key[i] = random_byte();
1713 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1715 rsabuf = smalloc(len);
1717 fatalbox("Out of memory");
1720 * Verify the host key.
1724 * First format the key into a string.
1726 int len = rsastr_len(&hostkey);
1727 char fingerprint[100];
1728 char *keystr = smalloc(len);
1730 fatalbox("Out of memory");
1731 rsastr_fmt(keystr, &hostkey);
1732 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1733 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1738 for (i = 0; i < 32; i++) {
1739 rsabuf[i] = session_key[i];
1741 rsabuf[i] ^= session_id[i];
1744 if (hostkey.bytes > servkey.bytes) {
1745 rsaencrypt(rsabuf, 32, &servkey);
1746 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1748 rsaencrypt(rsabuf, 32, &hostkey);
1749 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1752 logevent("Encrypted session key");
1754 switch (cfg.cipher) {
1755 case CIPHER_BLOWFISH:
1756 cipher_type = SSH_CIPHER_BLOWFISH;
1759 cipher_type = SSH_CIPHER_DES;
1762 cipher_type = SSH_CIPHER_3DES;
1765 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1766 cipher_type = SSH_CIPHER_3DES;
1769 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1771 ("Selected cipher not supported, falling back to 3DES\r\n");
1772 cipher_type = SSH_CIPHER_3DES;
1773 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1774 bombout(("Server violates SSH 1 protocol by "
1775 "not supporting 3DES encryption"));
1779 switch (cipher_type) {
1780 case SSH_CIPHER_3DES:
1781 logevent("Using 3DES encryption");
1783 case SSH_CIPHER_DES:
1784 logevent("Using single-DES encryption");
1786 case SSH_CIPHER_BLOWFISH:
1787 logevent("Using Blowfish encryption");
1791 send_packet(SSH1_CMSG_SESSION_KEY,
1792 PKT_CHAR, cipher_type,
1793 PKT_DATA, cookie, 8,
1794 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
1795 PKT_DATA, rsabuf, len,
1796 PKT_INT, ssh1_local_protoflags, PKT_END);
1798 logevent("Trying to enable encryption...");
1802 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
1803 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
1804 cipher->sesskey(session_key);
1808 if (pktin.type != SSH1_SMSG_SUCCESS) {
1809 bombout(("Encryption not successfully enabled"));
1813 logevent("Successfully started encryption");
1819 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
1821 if (!ssh_get_line("login as: ",
1822 username, sizeof(username), FALSE)) {
1824 * get_line failed to get a username.
1827 logevent("No username provided. Abandoning session.");
1828 ssh_state = SSH_STATE_CLOSED;
1832 c_write_str("login as: ");
1835 crWaitUntil(!ispkt);
1837 switch (c = *in++) {
1846 c_write_str("\b \b");
1853 c_write_str("\b \b");
1863 if (((c >= ' ' && c <= '~') ||
1864 ((unsigned char) c >= 160))
1865 && pos < sizeof(username)-1) {
1866 username[pos++] = c;
1872 c_write_str("\r\n");
1873 username[strcspn(username, "\n\r")] = '\0';
1876 strncpy(username, cfg.username, 99);
1877 username[99] = '\0';
1880 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
1882 char userlog[22 + sizeof(username)];
1883 sprintf(userlog, "Sent username \"%s\"", username);
1885 if (flags & FLAG_INTERACTIVE &&
1886 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1887 strcat(userlog, "\r\n");
1888 c_write_str(userlog);
1895 tried_publickey = 0;
1897 while (pktin.type == SSH1_SMSG_FAILURE) {
1898 static char password[100];
1899 static char prompt[200];
1902 static int pwpkt_type;
1904 * Show password prompt, having first obtained it via a TIS
1905 * or CryptoCard exchange if we're doing TIS or CryptoCard
1908 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1909 if (agent_exists()) {
1911 * Attempt RSA authentication using Pageant.
1913 static unsigned char request[5], *response, *p;
1914 static int responselen;
1915 static int i, nkeys;
1916 static int authed = FALSE;
1919 logevent("Pageant is running. Requesting keys.");
1921 /* Request the keys held by the agent. */
1922 PUT_32BIT(request, 1);
1923 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
1924 agent_query(request, 5, &r, &responselen);
1925 response = (unsigned char *) r;
1926 if (response && responselen >= 5 &&
1927 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
1929 nkeys = GET_32BIT(p);
1933 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
1936 for (i = 0; i < nkeys; i++) {
1937 static struct RSAKey key;
1938 static Bignum challenge;
1939 static char *commentp;
1940 static int commentlen;
1944 sprintf(buf, "Trying Pageant key #%d", i);
1948 p += ssh1_read_bignum(p, &key.exponent);
1949 p += ssh1_read_bignum(p, &key.modulus);
1950 commentlen = GET_32BIT(p);
1954 send_packet(SSH1_CMSG_AUTH_RSA,
1955 PKT_BIGNUM, key.modulus, PKT_END);
1957 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1958 logevent("Key refused");
1961 logevent("Received RSA challenge");
1962 ssh1_read_bignum(pktin.body, &challenge);
1964 char *agentreq, *q, *ret;
1967 len = 1 + 4; /* message type, bit count */
1968 len += ssh1_bignum_length(key.exponent);
1969 len += ssh1_bignum_length(key.modulus);
1970 len += ssh1_bignum_length(challenge);
1971 len += 16; /* session id */
1972 len += 4; /* response format */
1973 agentreq = smalloc(4 + len);
1974 PUT_32BIT(agentreq, len);
1976 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
1977 PUT_32BIT(q, bignum_bitcount(key.modulus));
1979 q += ssh1_write_bignum(q, key.exponent);
1980 q += ssh1_write_bignum(q, key.modulus);
1981 q += ssh1_write_bignum(q, challenge);
1982 memcpy(q, session_id, 16);
1984 PUT_32BIT(q, 1); /* response format */
1985 agent_query(agentreq, len + 4, &vret, &retlen);
1989 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
1990 logevent("Sending Pageant's response");
1991 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1992 PKT_DATA, ret + 5, 16,
1996 if (pktin.type == SSH1_SMSG_SUCCESS) {
1998 ("Pageant's response accepted");
1999 if (flags & FLAG_VERBOSE) {
2001 ("Authenticated using RSA key \"");
2002 c_write(commentp, commentlen);
2003 c_write_str("\" from agent\r\n");
2008 ("Pageant's response not accepted");
2011 ("Pageant failed to answer challenge");
2015 logevent("No reply received from Pageant");
2018 freebn(key.exponent);
2019 freebn(key.modulus);
2028 if (*cfg.keyfile && !tried_publickey)
2029 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2031 if (pktin.type == SSH1_SMSG_FAILURE &&
2033 (supported_auths_mask & (1 << SSH1_AUTH_TIS))) {
2034 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2035 logevent("Requested TIS authentication");
2036 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2038 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2039 logevent("TIS authentication declined");
2040 if (flags & FLAG_INTERACTIVE)
2041 c_write_str("TIS authentication refused.\r\n");
2043 int challengelen = ((pktin.body[0] << 24) |
2044 (pktin.body[1] << 16) |
2045 (pktin.body[2] << 8) |
2047 logevent("Received TIS challenge");
2048 if (challengelen > sizeof(prompt) - 1)
2049 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2050 memcpy(prompt, pktin.body + 4, challengelen);
2051 prompt[challengelen] = '\0';
2054 if (pktin.type == SSH1_SMSG_FAILURE &&
2056 (supported_auths_mask & (1 << SSH1_AUTH_CCARD))) {
2057 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2058 logevent("Requested CryptoCard authentication");
2059 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2061 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2062 logevent("CryptoCard authentication declined");
2063 c_write_str("CryptoCard authentication refused.\r\n");
2065 int challengelen = ((pktin.body[0] << 24) |
2066 (pktin.body[1] << 16) |
2067 (pktin.body[2] << 8) |
2069 logevent("Received CryptoCard challenge");
2070 if (challengelen > sizeof(prompt) - 1)
2071 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2072 memcpy(prompt, pktin.body + 4, challengelen);
2073 strncpy(prompt + challengelen, "\r\nResponse : ",
2074 sizeof(prompt) - challengelen);
2075 prompt[sizeof(prompt) - 1] = '\0';
2078 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2079 sprintf(prompt, "%.90s@%.90s's password: ",
2080 username, savedhost);
2082 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2083 char *comment = NULL;
2084 if (flags & FLAG_VERBOSE)
2085 c_write_str("Trying public key authentication.\r\n");
2086 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2087 if (flags & FLAG_VERBOSE)
2088 c_write_str("No passphrase required.\r\n");
2091 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2096 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2098 * get_line failed to get a password (for example
2099 * because one was supplied on the command line
2100 * which has already failed to work). Terminate.
2102 send_packet(SSH1_MSG_DISCONNECT,
2103 PKT_STR, "No more passwords available to try",
2105 connection_fatal("Unable to authenticate");
2106 ssh_state = SSH_STATE_CLOSED;
2110 c_write_str(prompt);
2114 crWaitUntil(!ispkt);
2116 switch (c = *in++) {
2137 if (pos < sizeof(password)-1)
2138 password[pos++] = c;
2142 c_write_str("\r\n");
2146 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2148 * Try public key authentication with the specified
2151 static struct RSAKey pubkey;
2152 static Bignum challenge, response;
2154 static unsigned char buffer[32];
2156 tried_publickey = 1;
2157 i = loadrsakey(cfg.keyfile, &pubkey, password);
2159 c_write_str("Couldn't load public key from ");
2160 c_write_str(cfg.keyfile);
2161 c_write_str(".\r\n");
2162 continue; /* go and try password */
2165 c_write_str("Wrong passphrase.\r\n");
2166 tried_publickey = 0;
2167 continue; /* try again */
2171 * Send a public key attempt.
2173 send_packet(SSH1_CMSG_AUTH_RSA,
2174 PKT_BIGNUM, pubkey.modulus, PKT_END);
2177 if (pktin.type == SSH1_SMSG_FAILURE) {
2178 c_write_str("Server refused our public key.\r\n");
2179 continue; /* go and try password */
2181 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2182 bombout(("Bizarre response to offer of public key"));
2185 ssh1_read_bignum(pktin.body, &challenge);
2186 response = rsadecrypt(challenge, &pubkey);
2187 freebn(pubkey.private_exponent); /* burn the evidence */
2189 for (i = 0; i < 32; i++) {
2190 buffer[i] = bignum_byte(response, 31 - i);
2194 MD5Update(&md5c, buffer, 32);
2195 MD5Update(&md5c, session_id, 16);
2196 MD5Final(buffer, &md5c);
2198 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2199 PKT_DATA, buffer, 16, PKT_END);
2202 if (pktin.type == SSH1_SMSG_FAILURE) {
2203 if (flags & FLAG_VERBOSE)
2205 ("Failed to authenticate with our public key.\r\n");
2206 continue; /* go and try password */
2207 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2209 ("Bizarre response to RSA authentication response"));
2213 break; /* we're through! */
2215 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2217 * Defence against traffic analysis: we send a
2218 * whole bunch of packets containing strings of
2219 * different lengths. One of these strings is the
2220 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2221 * The others are all random data in
2222 * SSH1_MSG_IGNORE packets. This way a passive
2223 * listener can't tell which is the password, and
2224 * hence can't deduce the password length.
2226 * Anybody with a password length greater than 16
2227 * bytes is going to have enough entropy in their
2228 * password that a listener won't find it _that_
2229 * much help to know how long it is. So what we'll
2232 * - if password length < 16, we send 15 packets
2233 * containing string lengths 1 through 15
2235 * - otherwise, we let N be the nearest multiple
2236 * of 8 below the password length, and send 8
2237 * packets containing string lengths N through
2238 * N+7. This won't obscure the order of
2239 * magnitude of the password length, but it will
2240 * introduce a bit of extra uncertainty.
2242 * A few servers (the old 1.2.18 through 1.2.22)
2243 * can't deal with SSH1_MSG_IGNORE. For these
2244 * servers, we need an alternative defence. We make
2245 * use of the fact that the password is interpreted
2246 * as a C string: so we can append a NUL, then some
2249 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
2254 len = strlen(password);
2255 if (len < sizeof(string)) {
2257 strcpy(string, password);
2258 len++; /* cover the zero byte */
2259 while (len < sizeof(string)) {
2260 string[len++] = (char) random_byte();
2265 send_packet(pwpkt_type, PKT_INT, len,
2266 PKT_DATA, s, len, PKT_END);
2268 int bottom, top, pwlen, i;
2271 pwlen = strlen(password);
2273 bottom = 0; /* zero length passwords are OK! :-) */
2276 bottom = pwlen & ~7;
2280 assert(pwlen >= bottom && pwlen <= top);
2282 randomstr = smalloc(top + 1);
2284 for (i = bottom; i <= top; i++) {
2286 defer_packet(pwpkt_type, PKT_STR, password,
2289 for (j = 0; j < i; j++) {
2291 randomstr[j] = random_byte();
2292 } while (randomstr[j] == '\0');
2294 randomstr[i] = '\0';
2295 defer_packet(SSH1_MSG_IGNORE,
2296 PKT_STR, randomstr, PKT_END);
2299 ssh_pkt_defersend();
2302 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2305 logevent("Sent password");
2306 memset(password, 0, strlen(password));
2308 if (pktin.type == SSH1_SMSG_FAILURE) {
2309 if (flags & FLAG_VERBOSE)
2310 c_write_str("Access denied\r\n");
2311 logevent("Authentication refused");
2312 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2313 logevent("Received disconnect request");
2314 ssh_state = SSH_STATE_CLOSED;
2316 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2317 bombout(("Strange packet received, type %d", pktin.type));
2322 logevent("Authentication successful");
2327 void sshfwd_close(struct ssh_channel *c)
2329 if (c && !c->closes) {
2330 if (ssh_version == 1) {
2331 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2334 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2335 ssh2_pkt_adduint32(c->remoteid);
2339 if (c->type == CHAN_X11) {
2341 logevent("Forwarded X11 connection terminated");
2342 } else if (c->type == CHAN_SOCKDATA) {
2344 logevent("Forwarded port closed");
2349 void sshfwd_write(struct ssh_channel *c, char *buf, int len)
2351 if (ssh_version == 1) {
2352 send_packet(SSH1_MSG_CHANNEL_DATA,
2353 PKT_INT, c->remoteid,
2354 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2356 ssh2_add_channel_data(c, buf, len);
2361 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2367 while (!do_ssh1_login(in, inlen, ispkt)) {
2370 if (ssh_state == SSH_STATE_CLOSED)
2373 if (cfg.agentfwd && agent_exists()) {
2374 logevent("Requesting agent forwarding");
2375 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2379 if (pktin.type != SSH1_SMSG_SUCCESS
2380 && pktin.type != SSH1_SMSG_FAILURE) {
2381 bombout(("Protocol confusion"));
2383 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2384 logevent("Agent forwarding refused");
2386 logevent("Agent forwarding enabled");
2387 ssh_agentfwd_enabled = TRUE;
2391 if (cfg.x11_forward) {
2392 char proto[20], data[64];
2393 logevent("Requesting X11 forwarding");
2394 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2395 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2396 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2397 PKT_STR, proto, PKT_STR, data,
2398 PKT_INT, 0, PKT_END);
2400 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2401 PKT_STR, proto, PKT_STR, data, PKT_END);
2406 if (pktin.type != SSH1_SMSG_SUCCESS
2407 && pktin.type != SSH1_SMSG_FAILURE) {
2408 bombout(("Protocol confusion"));
2410 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2411 logevent("X11 forwarding refused");
2413 logevent("X11 forwarding enabled");
2414 ssh_X11_fwd_enabled = TRUE;
2422 char sports[256], dports[256], host[256];
2425 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
2426 /* Add port forwardings. */
2431 while (*e && *e != '\t')
2437 while (*e && *e != ':')
2447 dport = atoi(dports);
2448 sport = atoi(sports);
2449 if (sport && dport) {
2451 pfd_addforward(host, dport, sport);
2452 sprintf(buf, "Local port %d forwarding to %s:%d",
2453 sport, host, dport);
2456 struct ssh_rportfwd *pf;
2457 pf = smalloc(sizeof(*pf));
2458 strcpy(pf->dhost, host);
2460 if (add234(ssh_rportfwds, pf) != pf) {
2462 "Duplicate remote port forwarding to %s:%d",
2467 sprintf(buf, "Requesting remote port %d forward to %s:%d",
2468 sport, host, dport);
2470 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
2482 send_packet(SSH1_CMSG_REQUEST_PTY,
2483 PKT_STR, cfg.termtype,
2484 PKT_INT, rows, PKT_INT, cols,
2485 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2486 ssh_state = SSH_STATE_INTERMED;
2490 if (pktin.type != SSH1_SMSG_SUCCESS
2491 && pktin.type != SSH1_SMSG_FAILURE) {
2492 bombout(("Protocol confusion"));
2494 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2495 c_write_str("Server refused to allocate pty\r\n");
2496 ssh_editing = ssh_echoing = 1;
2498 logevent("Allocated pty");
2500 ssh_editing = ssh_echoing = 1;
2503 if (cfg.compression) {
2504 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2508 if (pktin.type != SSH1_SMSG_SUCCESS
2509 && pktin.type != SSH1_SMSG_FAILURE) {
2510 bombout(("Protocol confusion"));
2512 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2513 c_write_str("Server refused to compress\r\n");
2515 logevent("Started compression");
2516 ssh1_compressing = TRUE;
2517 zlib_compress_init();
2518 zlib_decompress_init();
2521 if (*cfg.remote_cmd_ptr)
2522 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd_ptr,
2525 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2526 logevent("Started session");
2528 ssh_state = SSH_STATE_SESSION;
2532 ssh_special(TS_EOF);
2534 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
2536 ssh_channels = newtree234(ssh_channelcmp);
2540 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2541 pktin.type == SSH1_SMSG_STDERR_DATA) {
2542 long len = GET_32BIT(pktin.body);
2543 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2544 pktin.body + 4, len);
2545 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2546 ssh_state = SSH_STATE_CLOSED;
2547 logevent("Received disconnect request");
2549 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2550 /* Remote side is trying to open a channel to talk to our
2551 * X-Server. Give them back a local channel number. */
2552 struct ssh_channel *c;
2554 logevent("Received X11 connect request");
2555 /* Refuse if X11 forwarding is disabled. */
2556 if (!ssh_X11_fwd_enabled) {
2557 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2558 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2559 logevent("Rejected X11 connect request");
2561 c = smalloc(sizeof(struct ssh_channel));
2563 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2564 logevent("opening X11 forward connection failed");
2566 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2567 PKT_INT, GET_32BIT(pktin.body),
2571 ("opening X11 forward connection succeeded");
2572 c->remoteid = GET_32BIT(pktin.body);
2573 c->localid = alloc_channel_id();
2575 c->type = CHAN_X11; /* identify channel type */
2576 add234(ssh_channels, c);
2577 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2578 PKT_INT, c->remoteid, PKT_INT,
2579 c->localid, PKT_END);
2580 logevent("Opened X11 forward channel");
2583 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2584 /* Remote side is trying to open a channel to talk to our
2585 * agent. Give them back a local channel number. */
2586 struct ssh_channel *c;
2588 /* Refuse if agent forwarding is disabled. */
2589 if (!ssh_agentfwd_enabled) {
2590 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2591 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2593 c = smalloc(sizeof(struct ssh_channel));
2594 c->remoteid = GET_32BIT(pktin.body);
2595 c->localid = alloc_channel_id();
2597 c->type = CHAN_AGENT; /* identify channel type */
2598 c->u.a.lensofar = 0;
2599 add234(ssh_channels, c);
2600 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2601 PKT_INT, c->remoteid, PKT_INT, c->localid,
2604 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
2605 /* Remote side is trying to open a channel to talk to a
2606 * forwarded port. Give them back a local channel number. */
2607 struct ssh_channel *c;
2608 struct ssh_rportfwd pf;
2610 char host[256], buf[1024];
2612 c = smalloc(sizeof(struct ssh_channel));
2614 hostsize = GET_32BIT(pktin.body+4);
2615 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
2616 if (h+1 < host+sizeof(host))
2621 port = GET_32BIT(p);
2623 strcpy(pf.dhost, host);
2626 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
2627 sprintf(buf, "Rejected remote port open request for %s:%d",
2630 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2631 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2633 sprintf(buf, "Received remote port open request for %s:%d",
2636 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
2639 sprintf(buf, "Port open failed: %s", e);
2642 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2643 PKT_INT, GET_32BIT(pktin.body),
2646 c->remoteid = GET_32BIT(pktin.body);
2647 c->localid = alloc_channel_id();
2649 c->type = CHAN_SOCKDATA; /* identify channel type */
2650 add234(ssh_channels, c);
2651 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2652 PKT_INT, c->remoteid, PKT_INT,
2653 c->localid, PKT_END);
2654 logevent("Forwarded port opened successfully");
2658 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
2659 unsigned int remoteid = GET_32BIT(pktin.body);
2660 unsigned int localid = GET_32BIT(pktin.body+4);
2661 struct ssh_channel *c;
2663 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2664 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2665 c->remoteid = localid;
2666 c->type = CHAN_SOCKDATA;
2667 pfd_confirm(c->u.pfd.s);
2670 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2671 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
2672 /* Remote side closes a channel. */
2673 unsigned i = GET_32BIT(pktin.body);
2674 struct ssh_channel *c;
2675 c = find234(ssh_channels, &i, ssh_channelfind);
2679 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2680 if (!(c->closes & closetype))
2681 send_packet(pktin.type, PKT_INT, c->remoteid,
2683 if ((c->closes == 0) && (c->type == CHAN_X11)) {
2684 logevent("Forwarded X11 connection terminated");
2685 assert(c->u.x11.s != NULL);
2686 x11_close(c->u.x11.s);
2689 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
2690 logevent("Forwarded port closed");
2691 assert(c->u.pfd.s != NULL);
2692 pfd_close(c->u.pfd.s);
2695 c->closes |= closetype;
2696 if (c->closes == 3) {
2697 del234(ssh_channels, c);
2701 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2702 /* Data sent down one of our channels. */
2703 int i = GET_32BIT(pktin.body);
2704 int len = GET_32BIT(pktin.body + 4);
2705 unsigned char *p = pktin.body + 8;
2706 struct ssh_channel *c;
2707 c = find234(ssh_channels, &i, ssh_channelfind);
2711 x11_send(c->u.x11.s, p, len);
2714 pfd_send(c->u.pfd.s, p, len);
2717 /* Data for an agent message. Buffer it. */
2719 if (c->u.a.lensofar < 4) {
2720 int l = min(4 - c->u.a.lensofar, len);
2721 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
2725 c->u.a.lensofar += l;
2727 if (c->u.a.lensofar == 4) {
2729 4 + GET_32BIT(c->u.a.msglen);
2730 c->u.a.message = smalloc(c->u.a.totallen);
2731 memcpy(c->u.a.message, c->u.a.msglen, 4);
2733 if (c->u.a.lensofar >= 4 && len > 0) {
2735 min(c->u.a.totallen - c->u.a.lensofar,
2737 memcpy(c->u.a.message + c->u.a.lensofar, p,
2741 c->u.a.lensofar += l;
2743 if (c->u.a.lensofar == c->u.a.totallen) {
2744 void *reply, *sentreply;
2746 agent_query(c->u.a.message,
2747 c->u.a.totallen, &reply,
2752 /* Fake SSH_AGENT_FAILURE. */
2753 sentreply = "\0\0\0\1\5";
2756 send_packet(SSH1_MSG_CHANNEL_DATA,
2757 PKT_INT, c->remoteid,
2759 PKT_DATA, sentreply, replylen,
2763 sfree(c->u.a.message);
2764 c->u.a.lensofar = 0;
2770 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
2771 /* may be from EXEC_SHELL on some servers */
2772 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2773 /* may be from EXEC_SHELL on some servers
2774 * if no pty is available or in other odd cases. Ignore */
2775 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2776 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
2778 bombout(("Strange packet received: type %d", pktin.type));
2783 int len = min(inlen, 512);
2784 send_packet(SSH1_CMSG_STDIN_DATA,
2785 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2796 * Utility routine for decoding comma-separated strings in KEXINIT.
2798 static int in_commasep_string(char *needle, char *haystack, int haylen)
2800 int needlen = strlen(needle);
2803 * Is it at the start of the string?
2805 if (haylen >= needlen && /* haystack is long enough */
2806 !memcmp(needle, haystack, needlen) && /* initial match */
2807 (haylen == needlen || haystack[needlen] == ',')
2808 /* either , or EOS follows */
2812 * If not, search for the next comma and resume after that.
2813 * If no comma found, terminate.
2815 while (haylen > 0 && *haystack != ',')
2816 haylen--, haystack++;
2819 haylen--, haystack++; /* skip over comma itself */
2824 * SSH2 key creation method.
2826 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
2830 /* First 20 bytes. */
2833 SHA_Bytes(&s, H, 20);
2834 SHA_Bytes(&s, &chr, 1);
2835 SHA_Bytes(&s, sessid, 20);
2836 SHA_Final(&s, keyspace);
2837 /* Next 20 bytes. */
2840 SHA_Bytes(&s, H, 20);
2841 SHA_Bytes(&s, keyspace, 20);
2842 SHA_Final(&s, keyspace + 20);
2846 * Handle the SSH2 transport layer.
2848 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
2850 static int i, j, len, nbits, pbits;
2852 static Bignum p, g, e, f, K;
2853 static int kex_init_value, kex_reply_value;
2854 static const struct ssh_mac **maclist;
2856 static const struct ssh2_cipher *cscipher_tobe = NULL;
2857 static const struct ssh2_cipher *sccipher_tobe = NULL;
2858 static const struct ssh_mac *csmac_tobe = NULL;
2859 static const struct ssh_mac *scmac_tobe = NULL;
2860 static const struct ssh_compress *cscomp_tobe = NULL;
2861 static const struct ssh_compress *sccomp_tobe = NULL;
2862 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
2863 static int hostkeylen, siglen;
2864 static void *hkey; /* actual host key */
2865 static unsigned char exchange_hash[20];
2866 static unsigned char keyspace[40];
2867 static const struct ssh2_ciphers *preferred_cipher;
2868 static const struct ssh_compress *preferred_comp;
2869 static int first_kex;
2876 * Set up the preferred cipher and compression.
2878 if (cfg.cipher == CIPHER_BLOWFISH) {
2879 preferred_cipher = &ssh2_blowfish;
2880 } else if (cfg.cipher == CIPHER_DES) {
2881 logevent("Single DES not supported in SSH2; using 3DES");
2882 preferred_cipher = &ssh2_3des;
2883 } else if (cfg.cipher == CIPHER_3DES) {
2884 preferred_cipher = &ssh2_3des;
2885 } else if (cfg.cipher == CIPHER_AES) {
2886 preferred_cipher = &ssh2_aes;
2888 /* Shouldn't happen, but we do want to initialise to _something_. */
2889 preferred_cipher = &ssh2_3des;
2891 if (cfg.compression)
2892 preferred_comp = &ssh_zlib;
2894 preferred_comp = &ssh_comp_none;
2897 * Be prepared to work around the buggy MAC problem.
2899 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
2900 maclist = buggymacs, nmacs = lenof(buggymacs);
2902 maclist = macs, nmacs = lenof(macs);
2906 * Construct and send our key exchange packet.
2908 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2909 for (i = 0; i < 16; i++)
2910 ssh2_pkt_addbyte((unsigned char) random_byte());
2911 /* List key exchange algorithms. */
2912 ssh2_pkt_addstring_start();
2913 for (i = 0; i < lenof(kex_algs); i++) {
2914 ssh2_pkt_addstring_str(kex_algs[i]->name);
2915 if (i < lenof(kex_algs) - 1)
2916 ssh2_pkt_addstring_str(",");
2918 /* List server host key algorithms. */
2919 ssh2_pkt_addstring_start();
2920 for (i = 0; i < lenof(hostkey_algs); i++) {
2921 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2922 if (i < lenof(hostkey_algs) - 1)
2923 ssh2_pkt_addstring_str(",");
2925 /* List client->server encryption algorithms. */
2926 ssh2_pkt_addstring_start();
2927 for (i = 0; i < lenof(ciphers) + 1; i++) {
2928 const struct ssh2_ciphers *c =
2929 i == 0 ? preferred_cipher : ciphers[i - 1];
2930 for (j = 0; j < c->nciphers; j++) {
2931 ssh2_pkt_addstring_str(c->list[j]->name);
2932 if (i < lenof(ciphers) || j < c->nciphers - 1)
2933 ssh2_pkt_addstring_str(",");
2936 /* List server->client encryption algorithms. */
2937 ssh2_pkt_addstring_start();
2938 for (i = 0; i < lenof(ciphers) + 1; i++) {
2939 const struct ssh2_ciphers *c =
2940 i == 0 ? preferred_cipher : ciphers[i - 1];
2941 for (j = 0; j < c->nciphers; j++) {
2942 ssh2_pkt_addstring_str(c->list[j]->name);
2943 if (i < lenof(ciphers) || j < c->nciphers - 1)
2944 ssh2_pkt_addstring_str(",");
2947 /* List client->server MAC algorithms. */
2948 ssh2_pkt_addstring_start();
2949 for (i = 0; i < nmacs; i++) {
2950 ssh2_pkt_addstring_str(maclist[i]->name);
2952 ssh2_pkt_addstring_str(",");
2954 /* List server->client MAC algorithms. */
2955 ssh2_pkt_addstring_start();
2956 for (i = 0; i < nmacs; i++) {
2957 ssh2_pkt_addstring_str(maclist[i]->name);
2959 ssh2_pkt_addstring_str(",");
2961 /* List client->server compression algorithms. */
2962 ssh2_pkt_addstring_start();
2963 for (i = 0; i < lenof(compressions) + 1; i++) {
2964 const struct ssh_compress *c =
2965 i == 0 ? preferred_comp : compressions[i - 1];
2966 ssh2_pkt_addstring_str(c->name);
2967 if (i < lenof(compressions))
2968 ssh2_pkt_addstring_str(",");
2970 /* List server->client compression algorithms. */
2971 ssh2_pkt_addstring_start();
2972 for (i = 0; i < lenof(compressions) + 1; i++) {
2973 const struct ssh_compress *c =
2974 i == 0 ? preferred_comp : compressions[i - 1];
2975 ssh2_pkt_addstring_str(c->name);
2976 if (i < lenof(compressions))
2977 ssh2_pkt_addstring_str(",");
2979 /* List client->server languages. Empty list. */
2980 ssh2_pkt_addstring_start();
2981 /* List server->client languages. Empty list. */
2982 ssh2_pkt_addstring_start();
2983 /* First KEX packet does _not_ follow, because we're not that brave. */
2984 ssh2_pkt_addbool(FALSE);
2986 ssh2_pkt_adduint32(0);
2988 exhash = exhashbase;
2989 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
2995 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
2998 * Now examine the other side's KEXINIT to see what we're up
3001 if (pktin.type != SSH2_MSG_KEXINIT) {
3002 bombout(("expected key exchange packet from server"));
3007 cscipher_tobe = NULL;
3008 sccipher_tobe = NULL;
3013 pktin.savedpos += 16; /* skip garbage cookie */
3014 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3015 for (i = 0; i < lenof(kex_algs); i++) {
3016 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3021 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3022 for (i = 0; i < lenof(hostkey_algs); i++) {
3023 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3024 hostkey = hostkey_algs[i];
3028 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
3029 for (i = 0; i < lenof(ciphers) + 1; i++) {
3030 const struct ssh2_ciphers *c =
3031 i == 0 ? preferred_cipher : ciphers[i - 1];
3032 for (j = 0; j < c->nciphers; j++) {
3033 if (in_commasep_string(c->list[j]->name, str, len)) {
3034 cscipher_tobe = c->list[j];
3041 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3042 for (i = 0; i < lenof(ciphers) + 1; i++) {
3043 const struct ssh2_ciphers *c =
3044 i == 0 ? preferred_cipher : ciphers[i - 1];
3045 for (j = 0; j < c->nciphers; j++) {
3046 if (in_commasep_string(c->list[j]->name, str, len)) {
3047 sccipher_tobe = c->list[j];
3054 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3055 for (i = 0; i < nmacs; i++) {
3056 if (in_commasep_string(maclist[i]->name, str, len)) {
3057 csmac_tobe = maclist[i];
3061 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3062 for (i = 0; i < nmacs; i++) {
3063 if (in_commasep_string(maclist[i]->name, str, len)) {
3064 scmac_tobe = maclist[i];
3068 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3069 for (i = 0; i < lenof(compressions) + 1; i++) {
3070 const struct ssh_compress *c =
3071 i == 0 ? preferred_comp : compressions[i - 1];
3072 if (in_commasep_string(c->name, str, len)) {
3077 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3078 for (i = 0; i < lenof(compressions) + 1; i++) {
3079 const struct ssh_compress *c =
3080 i == 0 ? preferred_comp : compressions[i - 1];
3081 if (in_commasep_string(c->name, str, len)) {
3088 * Work out the number of bits of key we will need from the key
3089 * exchange. We start with the maximum key length of either
3095 csbits = cscipher_tobe->keylen;
3096 scbits = sccipher_tobe->keylen;
3097 nbits = (csbits > scbits ? csbits : scbits);
3099 /* The keys only have 160-bit entropy, since they're based on
3100 * a SHA-1 hash. So cap the key size at 160 bits. */
3105 * If we're doing Diffie-Hellman group exchange, start by
3106 * requesting a group.
3108 if (kex == &ssh_diffiehellman_gex) {
3109 logevent("Doing Diffie-Hellman group exchange");
3111 * Work out how big a DH group we will need to allow that
3114 pbits = 512 << ((nbits - 1) / 64);
3115 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3116 ssh2_pkt_adduint32(pbits);
3120 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3121 bombout(("expected key exchange group packet from server"));
3124 p = ssh2_pkt_getmp();
3125 g = ssh2_pkt_getmp();
3126 dh_setup_group(p, g);
3127 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3128 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3131 kex_init_value = SSH2_MSG_KEXDH_INIT;
3132 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3135 logevent("Doing Diffie-Hellman key exchange");
3137 * Now generate and send e for Diffie-Hellman.
3139 e = dh_create_e(nbits * 2);
3140 ssh2_pkt_init(kex_init_value);
3145 if (pktin.type != kex_reply_value) {
3146 bombout(("expected key exchange reply packet from server"));
3149 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3150 f = ssh2_pkt_getmp();
3151 ssh2_pkt_getstring(&sigdata, &siglen);
3155 sha_string(&exhash, hostkeydata, hostkeylen);
3156 if (kex == &ssh_diffiehellman_gex) {
3157 sha_uint32(&exhash, pbits);
3158 sha_mpint(&exhash, p);
3159 sha_mpint(&exhash, g);
3161 sha_mpint(&exhash, e);
3162 sha_mpint(&exhash, f);
3163 sha_mpint(&exhash, K);
3164 SHA_Final(&exhash, exchange_hash);
3169 debug(("Exchange hash is:\n"));
3170 dmemdump(exchange_hash, 20);
3173 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3175 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3176 bombout(("Server's host key did not match the signature supplied"));
3181 * Expect SSH2_MSG_NEWKEYS from server.
3184 if (pktin.type != SSH2_MSG_NEWKEYS) {
3185 bombout(("expected new-keys packet from server"));
3190 * Authenticate remote host: verify host key. (We've already
3191 * checked the signature of the exchange hash.)
3193 keystr = hostkey->fmtkey(hkey);
3194 fingerprint = hostkey->fingerprint(hkey);
3195 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3196 keystr, fingerprint);
3197 if (first_kex) { /* don't bother logging this in rekeys */
3198 logevent("Host key fingerprint is:");
3199 logevent(fingerprint);
3203 hostkey->freekey(hkey);
3206 * Send SSH2_MSG_NEWKEYS.
3208 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3212 * Create and initialise session keys.
3214 cscipher = cscipher_tobe;
3215 sccipher = sccipher_tobe;
3218 cscomp = cscomp_tobe;
3219 sccomp = sccomp_tobe;
3220 cscomp->compress_init();
3221 sccomp->decompress_init();
3223 * Set IVs after keys. Here we use the exchange hash from the
3224 * _first_ key exchange.
3227 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3228 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3229 cscipher->setcskey(keyspace);
3230 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3231 sccipher->setsckey(keyspace);
3232 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3233 cscipher->setcsiv(keyspace);
3234 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3235 sccipher->setsciv(keyspace);
3236 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3237 csmac->setcskey(keyspace);
3238 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3239 scmac->setsckey(keyspace);
3242 * If this is the first key exchange phase, we must pass the
3243 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3244 * wants to see it but because it will need time to initialise
3245 * itself before it sees an actual packet. In subsequent key
3246 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3247 * it would only confuse the layer above.
3255 * Now we're encrypting. Begin returning 1 to the protocol main
3256 * function so that other things can run on top of the
3257 * transport. If we ever see a KEXINIT, we must go back to the
3260 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3263 logevent("Server initiated key re-exchange");
3264 goto begin_key_exchange;
3270 * Add data to an SSH2 channel output buffer.
3272 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3275 if (c->v2.outbufsize < c->v2.outbuflen + len) {
3276 c->v2.outbufsize = c->v2.outbuflen + len + 1024;
3277 c->v2.outbuffer = srealloc(c->v2.outbuffer, c->v2.outbufsize);
3279 memcpy(c->v2.outbuffer + c->v2.outbuflen, buf, len);
3280 c->v2.outbuflen += len;
3284 * Attempt to send data on an SSH2 channel.
3286 static void ssh2_try_send(struct ssh_channel *c)
3288 while (c->v2.remwindow > 0 && c->v2.outbuflen > 0) {
3289 unsigned len = c->v2.remwindow;
3290 if (len > c->v2.outbuflen)
3291 len = c->v2.outbuflen;
3292 if (len > c->v2.remmaxpkt)
3293 len = c->v2.remmaxpkt;
3294 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3295 ssh2_pkt_adduint32(c->remoteid);
3296 ssh2_pkt_addstring_start();
3297 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
3299 c->v2.outbuflen -= len;
3300 memmove(c->v2.outbuffer, c->v2.outbuffer + len, c->v2.outbuflen);
3301 c->v2.remwindow -= len;
3306 * Handle the SSH2 userauth and connection layers.
3308 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3311 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
3313 AUTH_KEYBOARD_INTERACTIVE
3317 AUTH_TYPE_PUBLICKEY,
3318 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3319 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
3321 AUTH_TYPE_KEYBOARD_INTERACTIVE,
3322 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3324 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
3325 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
3326 static int kbd_inter_running;
3327 static int we_are_in;
3328 static int num_prompts, echo;
3329 static char username[100];
3330 static char pwprompt[200];
3331 static char password[100];
3336 * Request userauth protocol, and await a response to it.
3338 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3339 ssh2_pkt_addstring("ssh-userauth");
3341 crWaitUntilV(ispkt);
3342 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
3343 bombout(("Server refused user authentication protocol"));
3348 * We repeat this whole loop, including the username prompt,
3349 * until we manage a successful authentication. If the user
3350 * types the wrong _password_, they are sent back to the
3351 * beginning to try another username. (If they specify a
3352 * username in the config, they are never asked, even if they
3353 * do give a wrong password.)
3355 * I think this best serves the needs of
3357 * - the people who have no configuration, no keys, and just
3358 * want to try repeated (username,password) pairs until they
3359 * type both correctly
3361 * - people who have keys and configuration but occasionally
3362 * need to fall back to passwords
3364 * - people with a key held in Pageant, who might not have
3365 * logged in to a particular machine before; so they want to
3366 * type a username, and then _either_ their key will be
3367 * accepted, _or_ they will type a password. If they mistype
3368 * the username they will want to be able to get back and
3379 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
3381 if (!ssh_get_line("login as: ",
3382 username, sizeof(username), FALSE)) {
3384 * get_line failed to get a username.
3387 logevent("No username provided. Abandoning session.");
3388 ssh_state = SSH_STATE_CLOSED;
3392 c_write_str("login as: ");
3395 crWaitUntilV(!ispkt);
3397 switch (c = *in++) {
3406 c_write_str("\b \b");
3413 c_write_str("\b \b");
3423 if (((c >= ' ' && c <= '~') ||
3424 ((unsigned char) c >= 160))
3425 && pos < sizeof(username)-1) {
3426 username[pos++] = c;
3433 c_write_str("\r\n");
3434 username[strcspn(username, "\n\r")] = '\0';
3437 strncpy(username, cfg.username, 99);
3438 username[99] = '\0';
3439 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3440 sprintf(stuff, "Using username \"%s\".\r\n", username);
3446 * Send an authentication request using method "none": (a)
3447 * just in case it succeeds, and (b) so that we know what
3448 * authentication methods we can usefully try next.
3450 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3451 ssh2_pkt_addstring(username);
3452 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3453 ssh2_pkt_addstring("none"); /* method */
3455 type = AUTH_TYPE_NONE;
3459 tried_pubkey_config = FALSE;
3460 tried_agent = FALSE;
3461 tried_keyb_inter = FALSE;
3462 kbd_inter_running = FALSE;
3466 * Wait for the result of the last authentication request.
3469 crWaitUntilV(ispkt);
3470 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
3474 * Don't show the banner if we're operating in
3475 * non-verbose non-interactive mode. (It's probably
3476 * a script, which means nobody will read the
3477 * banner _anyway_, and moreover the printing of
3478 * the banner will screw up processing on the
3479 * output of (say) plink.)
3481 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3482 ssh2_pkt_getstring(&banner, &size);
3484 c_write_untrusted(banner, size);
3486 crWaitUntilV(ispkt);
3488 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3489 logevent("Access granted");
3494 if (kbd_inter_running &&
3495 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
3497 * This is a further prompt in keyboard-interactive
3498 * authentication. Do nothing.
3500 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
3501 bombout(("Strange packet received during authentication: type %d",
3509 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3510 * we can look at the string in it and know what we can
3511 * helpfully try next.
3513 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
3516 ssh2_pkt_getstring(&methods, &methlen);
3517 kbd_inter_running = FALSE;
3518 if (!ssh2_pkt_getbool()) {
3520 * We have received an unequivocal Access
3521 * Denied. This can translate to a variety of
3524 * - if we'd just tried "none" authentication,
3525 * it's not worth printing anything at all
3527 * - if we'd just tried a public key _offer_,
3528 * the message should be "Server refused our
3529 * key" (or no message at all if the key
3530 * came from Pageant)
3532 * - if we'd just tried anything else, the
3533 * message really should be "Access denied".
3535 * Additionally, if we'd just tried password
3536 * authentication, we should break out of this
3537 * whole loop so as to go back to the username
3540 if (type == AUTH_TYPE_NONE) {
3542 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3543 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3544 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3545 c_write_str("Server refused our key\r\n");
3546 logevent("Server refused public key");
3547 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
3548 /* server declined keyboard-interactive; ignore */
3550 c_write_str("Access denied\r\n");
3551 logevent("Access denied");
3552 if (type == AUTH_TYPE_PASSWORD) {
3558 c_write_str("Further authentication required\r\n");
3559 logevent("Further authentication required");
3563 in_commasep_string("publickey", methods, methlen);
3565 in_commasep_string("password", methods, methlen);
3567 in_commasep_string("password", methods, methlen);
3569 in_commasep_string("keyboard-interactive", methods, methlen);
3574 if (!method && can_keyb_inter && !tried_keyb_inter) {
3575 method = AUTH_KEYBOARD_INTERACTIVE;
3576 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
3577 tried_keyb_inter = TRUE;
3579 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3580 ssh2_pkt_addstring(username);
3581 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3582 ssh2_pkt_addstring("keyboard-interactive"); /* method */
3583 ssh2_pkt_addstring(""); /* lang */
3584 ssh2_pkt_addstring("");
3587 crWaitUntilV(ispkt);
3588 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
3589 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
3591 logevent("Keyboard-interactive authentication refused");
3592 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
3596 kbd_inter_running = TRUE;
3599 if (kbd_inter_running) {
3600 method = AUTH_KEYBOARD_INTERACTIVE;
3601 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
3602 tried_keyb_inter = TRUE;
3604 /* We've got packet with that "interactive" info
3605 dump banners, and set its prompt as ours */
3607 char *name, *inst, *lang, *prompt;
3608 int name_len, inst_len, lang_len, prompt_len;
3609 ssh2_pkt_getstring(&name, &name_len);
3610 ssh2_pkt_getstring(&inst, &inst_len);
3611 ssh2_pkt_getstring(&lang, &lang_len);
3613 c_write_untrusted(name, name_len);
3615 c_write_untrusted(inst, inst_len);
3616 num_prompts = ssh2_pkt_getuint32();
3618 ssh2_pkt_getstring(&prompt, &prompt_len);
3619 strncpy(pwprompt, prompt, sizeof(pwprompt));
3622 echo = ssh2_pkt_getbool();
3626 if (!method && can_pubkey && agent_exists() && !tried_agent) {
3628 * Attempt public-key authentication using Pageant.
3630 static unsigned char request[5], *response, *p;
3631 static int responselen;
3632 static int i, nkeys;
3633 static int authed = FALSE;
3638 logevent("Pageant is running. Requesting keys.");
3640 /* Request the keys held by the agent. */
3641 PUT_32BIT(request, 1);
3642 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3643 agent_query(request, 5, &r, &responselen);
3644 response = (unsigned char *) r;
3645 if (response && responselen >= 5 &&
3646 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
3648 nkeys = GET_32BIT(p);
3652 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3655 for (i = 0; i < nkeys; i++) {
3656 static char *pkblob, *alg, *commentp;
3657 static int pklen, alglen, commentlen;
3658 static int siglen, retlen, len;
3659 static char *q, *agentreq, *ret;
3664 sprintf(buf, "Trying Pageant key #%d", i);
3667 pklen = GET_32BIT(p);
3671 alglen = GET_32BIT(pkblob);
3673 commentlen = GET_32BIT(p);
3677 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3678 ssh2_pkt_addstring(username);
3679 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3680 ssh2_pkt_addstring("publickey"); /* method */
3681 ssh2_pkt_addbool(FALSE); /* no signature included */
3682 ssh2_pkt_addstring_start();
3683 ssh2_pkt_addstring_data(alg, alglen);
3684 ssh2_pkt_addstring_start();
3685 ssh2_pkt_addstring_data(pkblob, pklen);
3688 crWaitUntilV(ispkt);
3689 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3690 logevent("Key refused");
3694 if (flags & FLAG_VERBOSE) {
3696 ("Authenticating with public key \"");
3697 c_write(commentp, commentlen);
3698 c_write_str("\" from agent\r\n");
3702 * Server is willing to accept the key.
3703 * Construct a SIGN_REQUEST.
3705 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3706 ssh2_pkt_addstring(username);
3707 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3708 ssh2_pkt_addstring("publickey"); /* method */
3709 ssh2_pkt_addbool(TRUE);
3710 ssh2_pkt_addstring_start();
3711 ssh2_pkt_addstring_data(alg, alglen);
3712 ssh2_pkt_addstring_start();
3713 ssh2_pkt_addstring_data(pkblob, pklen);
3715 siglen = pktout.length - 5 + 4 + 20;
3716 len = 1; /* message type */
3717 len += 4 + pklen; /* key blob */
3718 len += 4 + siglen; /* data to sign */
3719 len += 4; /* flags */
3720 agentreq = smalloc(4 + len);
3721 PUT_32BIT(agentreq, len);
3723 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3724 PUT_32BIT(q, pklen);
3726 memcpy(q, pkblob, pklen);
3728 PUT_32BIT(q, siglen);
3730 /* Now the data to be signed... */
3733 memcpy(q, ssh2_session_id, 20);
3735 memcpy(q, pktout.data + 5, pktout.length - 5);
3736 q += pktout.length - 5;
3737 /* And finally the (zero) flags word. */
3739 agent_query(agentreq, len + 4, &vret, &retlen);
3743 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3744 logevent("Sending Pageant's response");
3745 ssh2_pkt_addstring_start();
3746 ssh2_pkt_addstring_data(ret + 9,
3754 ("Pageant failed to answer challenge");
3764 if (!method && can_pubkey && *cfg.keyfile
3765 && !tried_pubkey_config) {
3766 unsigned char *pub_blob;
3767 char *algorithm, *comment;
3770 tried_pubkey_config = TRUE;
3773 * Try the public key supplied in the configuration.
3775 * First, offer the public blob to see if the server is
3776 * willing to accept it.
3778 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3781 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3782 ssh2_pkt_addstring(username);
3783 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3784 ssh2_pkt_addstring("publickey"); /* method */
3785 ssh2_pkt_addbool(FALSE); /* no signature included */
3786 ssh2_pkt_addstring(algorithm);
3787 ssh2_pkt_addstring_start();
3788 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3790 logevent("Offered public key"); /* FIXME */
3792 crWaitUntilV(ispkt);
3793 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3795 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
3796 continue; /* key refused; give up on it */
3799 logevent("Offer of public key accepted");
3801 * Actually attempt a serious authentication using
3804 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
3806 "Passphrase for key \"%.100s\": ",
3812 c_write_str("Authenticating with public key \"");
3813 c_write_str(comment);
3814 c_write_str("\"\r\n");
3815 method = AUTH_PUBLICKEY_FILE;
3819 if (!method && can_passwd) {
3820 method = AUTH_PASSWORD;
3821 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
3828 if (!ssh_get_line(pwprompt, password,
3829 sizeof(password), TRUE)) {
3831 * get_line failed to get a password (for
3832 * example because one was supplied on the
3833 * command line which has already failed to
3836 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3837 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3839 ("No more passwords available to try");
3840 ssh2_pkt_addstring("en"); /* language tag */
3842 connection_fatal("Unable to authenticate");
3843 ssh_state = SSH_STATE_CLOSED;
3850 c_write_untrusted(pwprompt, strlen(pwprompt));
3855 crWaitUntilV(!ispkt);
3857 switch (c = *in++) {
3878 if (pos < sizeof(password)-1)
3879 password[pos++] = c;
3883 c_write_str("\r\n");
3887 if (method == AUTH_PUBLICKEY_FILE) {
3889 * We have our passphrase. Now try the actual authentication.
3891 struct ssh2_userkey *key;
3893 key = ssh2_load_userkey(cfg.keyfile, password);
3894 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3895 if (key == SSH2_WRONG_PASSPHRASE) {
3896 c_write_str("Wrong passphrase\r\n");
3897 tried_pubkey_config = FALSE;
3899 c_write_str("Unable to load private key\r\n");
3900 tried_pubkey_config = TRUE;
3902 /* Send a spurious AUTH_NONE to return to the top. */
3903 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3904 ssh2_pkt_addstring(username);
3905 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3906 ssh2_pkt_addstring("none"); /* method */
3908 type = AUTH_TYPE_NONE;
3910 unsigned char *blob, *sigdata;
3911 int blob_len, sigdata_len;
3914 * We have loaded the private key and the server
3915 * has announced that it's willing to accept it.
3916 * Hallelujah. Generate a signature and send it.
3918 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3919 ssh2_pkt_addstring(username);
3920 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3921 ssh2_pkt_addstring("publickey"); /* method */
3922 ssh2_pkt_addbool(TRUE);
3923 ssh2_pkt_addstring(key->alg->name);
3924 blob = key->alg->public_blob(key->data, &blob_len);
3925 ssh2_pkt_addstring_start();
3926 ssh2_pkt_addstring_data(blob, blob_len);
3930 * The data to be signed is:
3934 * followed by everything so far placed in the
3937 sigdata_len = pktout.length - 5 + 4 + 20;
3938 sigdata = smalloc(sigdata_len);
3939 PUT_32BIT(sigdata, 20);
3940 memcpy(sigdata + 4, ssh2_session_id, 20);
3941 memcpy(sigdata + 24, pktout.data + 5,
3944 key->alg->sign(key->data, sigdata, sigdata_len,
3946 ssh2_pkt_addstring_start();
3947 ssh2_pkt_addstring_data(blob, blob_len);
3952 type = AUTH_TYPE_PUBLICKEY;
3954 } else if (method == AUTH_PASSWORD) {
3956 * We send the password packet lumped tightly together with
3957 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3958 * string long enough to make the total length of the two
3959 * packets constant. This should ensure that a passive
3960 * listener doing traffic analyis can't work out the length
3963 * For this to work, we need an assumption about the
3964 * maximum length of the password packet. I think 256 is
3965 * pretty conservative. Anyone using a password longer than
3966 * that probably doesn't have much to worry about from
3967 * people who find out how long their password is!
3969 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3970 ssh2_pkt_addstring(username);
3971 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3972 ssh2_pkt_addstring("password");
3973 ssh2_pkt_addbool(FALSE);
3974 ssh2_pkt_addstring(password);
3977 * We'll include a string that's an exact multiple of the
3978 * cipher block size. If the cipher is NULL for some
3979 * reason, we don't do this trick at all because we gain
3985 stringlen = (256 - deferred_len);
3986 stringlen += cscipher->blksize - 1;
3987 stringlen -= (stringlen % cscipher->blksize);
3990 * Temporarily disable actual compression,
3991 * so we can guarantee to get this string
3992 * exactly the length we want it. The
3993 * compression-disabling routine should
3994 * return an integer indicating how many
3995 * bytes we should adjust our string length
3998 stringlen -= cscomp->disable_compression();
4000 ssh2_pkt_init(SSH2_MSG_IGNORE);
4001 ssh2_pkt_addstring_start();
4002 for (i = 0; i < stringlen; i++) {
4003 char c = (char) random_byte();
4004 ssh2_pkt_addstring_data(&c, 1);
4008 ssh_pkt_defersend();
4009 logevent("Sent password");
4010 type = AUTH_TYPE_PASSWORD;
4011 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4012 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4013 ssh2_pkt_adduint32(num_prompts);
4014 ssh2_pkt_addstring(password);
4015 memset(password, 0, sizeof(password));
4017 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4020 ("No supported authentication methods left to try!\r\n");
4022 ("No supported authentications offered. Disconnecting");
4023 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4024 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4026 ("No supported authentication methods available");
4027 ssh2_pkt_addstring("en"); /* language tag */
4029 ssh_state = SSH_STATE_CLOSED;
4033 } while (!we_are_in);
4036 * Now we're authenticated for the connection protocol. The
4037 * connection protocol will automatically have started at this
4038 * point; there's no need to send SERVICE_REQUEST.
4042 * So now create a channel with a session in it.
4044 ssh_channels = newtree234(ssh_channelcmp);
4045 mainchan = smalloc(sizeof(struct ssh_channel));
4046 mainchan->localid = alloc_channel_id();
4047 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4048 ssh2_pkt_addstring("session");
4049 ssh2_pkt_adduint32(mainchan->localid);
4050 ssh2_pkt_adduint32(0x8000UL); /* our window size */
4051 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4053 crWaitUntilV(ispkt);
4054 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4055 bombout(("Server refused to open a session"));
4057 /* FIXME: error data comes back in FAILURE packet */
4059 if (ssh2_pkt_getuint32() != mainchan->localid) {
4060 bombout(("Server's channel confirmation cited wrong channel"));
4063 mainchan->remoteid = ssh2_pkt_getuint32();
4064 mainchan->type = CHAN_MAINSESSION;
4065 mainchan->closes = 0;
4066 mainchan->v2.remwindow = ssh2_pkt_getuint32();
4067 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
4068 mainchan->v2.outbuffer = NULL;
4069 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
4070 add234(ssh_channels, mainchan);
4071 logevent("Opened channel for session");
4074 * Potentially enable X11 forwarding.
4076 if (cfg.x11_forward) {
4077 char proto[20], data[64];
4078 logevent("Requesting X11 forwarding");
4079 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4080 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4081 ssh2_pkt_adduint32(mainchan->remoteid);
4082 ssh2_pkt_addstring("x11-req");
4083 ssh2_pkt_addbool(1); /* want reply */
4084 ssh2_pkt_addbool(0); /* many connections */
4085 ssh2_pkt_addstring(proto);
4086 ssh2_pkt_addstring(data);
4087 ssh2_pkt_adduint32(0); /* screen number */
4091 crWaitUntilV(ispkt);
4092 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4093 unsigned i = ssh2_pkt_getuint32();
4094 struct ssh_channel *c;
4095 c = find234(ssh_channels, &i, ssh_channelfind);
4097 continue; /* nonexistent channel */
4098 c->v2.remwindow += ssh2_pkt_getuint32();
4100 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4102 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4103 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4104 bombout(("Server got confused by X11 forwarding request"));
4107 logevent("X11 forwarding refused");
4109 logevent("X11 forwarding enabled");
4110 ssh_X11_fwd_enabled = TRUE;
4115 * Enable port forwardings.
4118 static char *e; /* preserve across crReturn */
4122 char sports[256], dports[256], host[256];
4125 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4126 /* Add port forwardings. */
4131 while (*e && *e != '\t')
4137 while (*e && *e != ':')
4147 dport = atoi(dports);
4148 sport = atoi(sports);
4149 if (sport && dport) {
4151 pfd_addforward(host, dport, sport);
4152 sprintf(buf, "Local port %d forwarding to %s:%d",
4153 sport, host, dport);
4156 struct ssh_rportfwd *pf;
4157 pf = smalloc(sizeof(*pf));
4158 strcpy(pf->dhost, host);
4161 if (add234(ssh_rportfwds, pf) != pf) {
4163 "Duplicate remote port forwarding to %s:%d",
4168 sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)",
4169 sport, host, dport);
4171 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4172 ssh2_pkt_addstring("tcpip-forward");
4173 ssh2_pkt_addbool(1);/* want reply */
4174 ssh2_pkt_addstring("127.0.0.1");
4175 ssh2_pkt_adduint32(sport);
4179 crWaitUntilV(ispkt);
4180 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4181 unsigned i = ssh2_pkt_getuint32();
4182 struct ssh_channel *c;
4183 c = find234(ssh_channels, &i, ssh_channelfind);
4185 continue;/* nonexistent channel */
4186 c->v2.remwindow += ssh2_pkt_getuint32();
4188 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4190 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
4191 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
4192 bombout(("Server got confused by port forwarding request"));
4195 logevent("Server refused this port forwarding");
4197 logevent("Remote port forwarding enabled");
4206 * Potentially enable agent forwarding.
4208 if (cfg.agentfwd && agent_exists()) {
4209 logevent("Requesting OpenSSH-style agent forwarding");
4210 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4211 ssh2_pkt_adduint32(mainchan->remoteid);
4212 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4213 ssh2_pkt_addbool(1); /* want reply */
4217 crWaitUntilV(ispkt);
4218 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4219 unsigned i = ssh2_pkt_getuint32();
4220 struct ssh_channel *c;
4221 c = find234(ssh_channels, &i, ssh_channelfind);
4223 continue; /* nonexistent channel */
4224 c->v2.remwindow += ssh2_pkt_getuint32();
4226 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4228 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4229 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4231 ("Server got confused by agent forwarding request"));
4234 logevent("Agent forwarding refused");
4236 logevent("Agent forwarding enabled");
4237 ssh_agentfwd_enabled = TRUE;
4242 * Now allocate a pty for the session.
4245 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4246 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4247 ssh2_pkt_addstring("pty-req");
4248 ssh2_pkt_addbool(1); /* want reply */
4249 ssh2_pkt_addstring(cfg.termtype);
4250 ssh2_pkt_adduint32(cols);
4251 ssh2_pkt_adduint32(rows);
4252 ssh2_pkt_adduint32(0); /* pixel width */
4253 ssh2_pkt_adduint32(0); /* pixel height */
4254 ssh2_pkt_addstring_start();
4255 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4257 ssh_state = SSH_STATE_INTERMED;
4260 crWaitUntilV(ispkt);
4261 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4262 unsigned i = ssh2_pkt_getuint32();
4263 struct ssh_channel *c;
4264 c = find234(ssh_channels, &i, ssh_channelfind);
4266 continue; /* nonexistent channel */
4267 c->v2.remwindow += ssh2_pkt_getuint32();
4269 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4271 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4272 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4273 bombout(("Server got confused by pty request"));
4276 c_write_str("Server refused to allocate pty\r\n");
4277 ssh_editing = ssh_echoing = 1;
4279 logevent("Allocated pty");
4282 ssh_editing = ssh_echoing = 1;
4286 * Start a shell or a remote command.
4288 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4289 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4290 if (cfg.ssh_subsys) {
4291 ssh2_pkt_addstring("subsystem");
4292 ssh2_pkt_addbool(1); /* want reply */
4293 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
4294 } else if (*cfg.remote_cmd_ptr) {
4295 ssh2_pkt_addstring("exec");
4296 ssh2_pkt_addbool(1); /* want reply */
4297 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
4299 ssh2_pkt_addstring("shell");
4300 ssh2_pkt_addbool(1); /* want reply */
4304 crWaitUntilV(ispkt);
4305 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4306 unsigned i = ssh2_pkt_getuint32();
4307 struct ssh_channel *c;
4308 c = find234(ssh_channels, &i, ssh_channelfind);
4310 continue; /* nonexistent channel */
4311 c->v2.remwindow += ssh2_pkt_getuint32();
4313 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4314 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4315 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4316 bombout(("Server got confused by shell/command request"));
4319 bombout(("Server refused to start a shell/command"));
4322 logevent("Started a shell/command");
4325 ssh_state = SSH_STATE_SESSION;
4329 ssh_special(TS_EOF);
4334 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
4337 static int try_send;
4341 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
4342 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
4345 unsigned i = ssh2_pkt_getuint32();
4346 struct ssh_channel *c;
4347 c = find234(ssh_channels, &i, ssh_channelfind);
4349 continue; /* nonexistent channel */
4350 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
4351 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
4352 continue; /* extended but not stderr */
4353 ssh2_pkt_getstring(&data, &length);
4356 case CHAN_MAINSESSION:
4357 from_backend(pktin.type ==
4358 SSH2_MSG_CHANNEL_EXTENDED_DATA, data,
4362 x11_send(c->u.x11.s, data, length);
4365 pfd_send(c->u.pfd.s, data, length);
4368 while (length > 0) {
4369 if (c->u.a.lensofar < 4) {
4370 int l = min(4 - c->u.a.lensofar, length);
4371 memcpy(c->u.a.msglen + c->u.a.lensofar,
4375 c->u.a.lensofar += l;
4377 if (c->u.a.lensofar == 4) {
4379 4 + GET_32BIT(c->u.a.msglen);
4380 c->u.a.message = smalloc(c->u.a.totallen);
4381 memcpy(c->u.a.message, c->u.a.msglen, 4);
4383 if (c->u.a.lensofar >= 4 && length > 0) {
4385 min(c->u.a.totallen - c->u.a.lensofar,
4387 memcpy(c->u.a.message + c->u.a.lensofar,
4391 c->u.a.lensofar += l;
4393 if (c->u.a.lensofar == c->u.a.totallen) {
4394 void *reply, *sentreply;
4396 agent_query(c->u.a.message,
4397 c->u.a.totallen, &reply,
4402 /* Fake SSH_AGENT_FAILURE. */
4403 sentreply = "\0\0\0\1\5";
4406 ssh2_add_channel_data(c, sentreply,
4411 sfree(c->u.a.message);
4412 c->u.a.lensofar = 0;
4418 * Enlarge the window again at the remote
4419 * side, just in case it ever runs down and
4420 * they fail to send us any more data.
4422 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4423 ssh2_pkt_adduint32(c->remoteid);
4424 ssh2_pkt_adduint32(length);
4427 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
4428 ssh_state = SSH_STATE_CLOSED;
4429 logevent("Received disconnect message");
4431 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
4432 continue; /* exit status et al; ignore (FIXME?) */
4433 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
4434 unsigned i = ssh2_pkt_getuint32();
4435 struct ssh_channel *c;
4437 c = find234(ssh_channels, &i, ssh_channelfind);
4439 continue; /* nonexistent channel */
4441 if (c->type == CHAN_X11) {
4443 * Remote EOF on an X11 channel means we should
4444 * wrap up and close the channel ourselves.
4446 x11_close(c->u.x11.s);
4448 } else if (c->type == CHAN_AGENT) {
4450 } else if (c->type == CHAN_SOCKDATA) {
4451 pfd_close(c->u.pfd.s);
4454 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
4455 unsigned i = ssh2_pkt_getuint32();
4456 struct ssh_channel *c;
4458 c = find234(ssh_channels, &i, ssh_channelfind);
4460 continue; /* nonexistent channel */
4461 if (c->closes == 0) {
4462 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4463 ssh2_pkt_adduint32(c->remoteid);
4466 /* Do pre-close processing on the channel. */
4468 case CHAN_MAINSESSION:
4469 break; /* nothing to see here, move along */
4477 del234(ssh_channels, c);
4478 sfree(c->v2.outbuffer);
4482 * See if that was the last channel left open.
4484 if (count234(ssh_channels) == 0) {
4485 logevent("All channels closed. Disconnecting");
4486 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4487 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4488 ssh2_pkt_addstring("All open channels closed");
4489 ssh2_pkt_addstring("en"); /* language tag */
4491 ssh_state = SSH_STATE_CLOSED;
4494 continue; /* remote sends close; ignore (FIXME) */
4495 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4496 unsigned i = ssh2_pkt_getuint32();
4497 struct ssh_channel *c;
4498 c = find234(ssh_channels, &i, ssh_channelfind);
4500 continue; /* nonexistent channel */
4501 c->v2.remwindow += ssh2_pkt_getuint32();
4503 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4504 unsigned i = ssh2_pkt_getuint32();
4505 struct ssh_channel *c;
4506 c = find234(ssh_channels, &i, ssh_channelfind);
4508 continue; /* nonexistent channel */
4509 if (c->type != CHAN_SOCKDATA_DORMANT)
4510 continue; /* dunno why they're confirming this */
4511 c->remoteid = ssh2_pkt_getuint32();
4512 c->type = CHAN_SOCKDATA;
4514 c->v2.remwindow = ssh2_pkt_getuint32();
4515 c->v2.remmaxpkt = ssh2_pkt_getuint32();
4516 c->v2.outbuffer = NULL;
4517 c->v2.outbuflen = c->v2.outbufsize = 0;
4518 pfd_confirm(c->u.pfd.s);
4519 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
4523 struct ssh_channel *c;
4524 unsigned remid, winsize, pktsize;
4525 ssh2_pkt_getstring(&type, &typelen);
4526 c = smalloc(sizeof(struct ssh_channel));
4528 remid = ssh2_pkt_getuint32();
4529 winsize = ssh2_pkt_getuint32();
4530 pktsize = ssh2_pkt_getuint32();
4532 if (typelen == 3 && !memcmp(type, "x11", 3)) {
4533 if (!ssh_X11_fwd_enabled)
4534 error = "X11 forwarding is not enabled";
4535 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
4537 error = "Unable to open an X11 connection";
4541 } else if (typelen == 15 &&
4542 !memcmp(type, "forwarded-tcpip", 15)) {
4543 struct ssh_rportfwd pf, *realpf;
4546 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
4547 pf.sport = ssh2_pkt_getuint32();
4548 realpf = find234(ssh_rportfwds, &pf, NULL);
4549 if (realpf == NULL) {
4550 error = "Remote port is not recognised";
4552 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
4555 sprintf(buf, "Received remote port open request for %s:%d",
4556 realpf->dhost, realpf->dport);
4559 sprintf(buf, "Port open failed: %s", e);
4561 error = "Port open failed";
4563 logevent("Forwarded port opened successfully");
4564 c->type = CHAN_SOCKDATA;
4567 } else if (typelen == 22 &&
4568 !memcmp(type, "auth-agent@openssh.com", 3)) {
4569 if (!ssh_agentfwd_enabled)
4570 error = "Agent forwarding is not enabled";
4572 c->type = CHAN_AGENT; /* identify channel type */
4573 c->u.a.lensofar = 0;
4576 error = "Unsupported channel type requested";
4579 c->remoteid = remid;
4581 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
4582 ssh2_pkt_adduint32(c->remoteid);
4583 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
4584 ssh2_pkt_addstring(error);
4585 ssh2_pkt_addstring("en"); /* language tag */
4589 c->localid = alloc_channel_id();
4591 c->v2.remwindow = winsize;
4592 c->v2.remmaxpkt = pktsize;
4593 c->v2.outbuffer = NULL;
4594 c->v2.outbuflen = c->v2.outbufsize = 0;
4595 add234(ssh_channels, c);
4596 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
4597 ssh2_pkt_adduint32(c->remoteid);
4598 ssh2_pkt_adduint32(c->localid);
4599 ssh2_pkt_adduint32(0x8000UL); /* our window size */
4600 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4604 bombout(("Strange packet received: type %d", pktin.type));
4609 * We have spare data. Add it to the channel buffer.
4611 ssh2_add_channel_data(mainchan, in, inlen);
4616 struct ssh_channel *c;
4618 * Try to send data on all channels if we can.
4620 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++)
4629 * Handle the top-level SSH2 protocol.
4631 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
4633 if (do_ssh2_transport(in, inlen, ispkt) == 0)
4635 do_ssh2_authconn(in, inlen, ispkt);
4639 * Called to set up the connection.
4641 * Returns an error message, or NULL on success.
4643 static char *ssh_init(char *host, int port, char **realhost)
4648 if (crypto_startup() == 0)
4649 return "Microsoft high encryption pack not installed!";
4656 p = connect_to_host(host, port, realhost);
4664 * Called to send data down the Telnet connection.
4666 static void ssh_send(char *buf, int len)
4668 if (s == NULL || ssh_protocol == NULL)
4671 ssh_protocol(buf, len, 0);
4675 * Called to set the size of the window from SSH's POV.
4677 static void ssh_size(void)
4679 switch (ssh_state) {
4680 case SSH_STATE_BEFORE_SIZE:
4681 case SSH_STATE_PREPACKET:
4682 case SSH_STATE_CLOSED:
4683 break; /* do nothing */
4684 case SSH_STATE_INTERMED:
4685 size_needed = TRUE; /* buffer for later */
4687 case SSH_STATE_SESSION:
4689 if (ssh_version == 1) {
4690 send_packet(SSH1_CMSG_WINDOW_SIZE,
4691 PKT_INT, rows, PKT_INT, cols,
4692 PKT_INT, 0, PKT_INT, 0, PKT_END);
4694 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4695 ssh2_pkt_adduint32(mainchan->remoteid);
4696 ssh2_pkt_addstring("window-change");
4697 ssh2_pkt_addbool(0);
4698 ssh2_pkt_adduint32(cols);
4699 ssh2_pkt_adduint32(rows);
4700 ssh2_pkt_adduint32(0);
4701 ssh2_pkt_adduint32(0);
4710 * Send Telnet special codes. TS_EOF is useful for `plink', so you
4711 * can send an EOF and collect resulting output (e.g. `plink
4714 static void ssh_special(Telnet_Special code)
4716 if (code == TS_EOF) {
4717 if (ssh_state != SSH_STATE_SESSION) {
4719 * Buffer the EOF in case we are pre-SESSION, so we can
4720 * send it as soon as we reach SESSION.
4726 if (ssh_version == 1) {
4727 send_packet(SSH1_CMSG_EOF, PKT_END);
4729 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4730 ssh2_pkt_adduint32(mainchan->remoteid);
4733 logevent("Sent EOF message");
4734 } else if (code == TS_PING) {
4735 if (ssh_state == SSH_STATE_CLOSED
4736 || ssh_state == SSH_STATE_PREPACKET) return;
4737 if (ssh_version == 1) {
4738 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
4740 ssh2_pkt_init(SSH2_MSG_IGNORE);
4741 ssh2_pkt_addstring_start();
4749 void *new_sock_channel(Socket s)
4751 struct ssh_channel *c;
4752 c = smalloc(sizeof(struct ssh_channel));
4755 c->remoteid = -1; /* to be set when open confirmed */
4756 c->localid = alloc_channel_id();
4758 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
4760 add234(ssh_channels, c);
4765 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
4767 struct ssh_channel *c = (struct ssh_channel *)channel;
4770 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
4773 if (ssh_version == 1) {
4774 send_packet(SSH1_MSG_PORT_OPEN,
4775 PKT_INT, c->localid,
4778 //PKT_STR, <org:orgport>,
4781 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4782 ssh2_pkt_addstring("direct-tcpip");
4783 ssh2_pkt_adduint32(c->localid);
4784 ssh2_pkt_adduint32(0x8000UL); /* our window size */
4785 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4786 ssh2_pkt_addstring(hostname);
4787 ssh2_pkt_adduint32(port);
4789 * We make up values for the originator data; partly it's
4790 * too much hassle to keep track, and partly I'm not
4791 * convinced the server should be told details like that
4792 * about my local network configuration.
4794 ssh2_pkt_addstring("client-side-connection");
4795 ssh2_pkt_adduint32(0);
4801 static Socket ssh_socket(void)
4806 static int ssh_sendok(void)
4811 static int ssh_ldisc(int option)
4813 if (option == LD_ECHO)
4815 if (option == LD_EDIT)
4820 Backend ssh_backend = {