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Ooh. Actually, that vulnerability is further-reaching than I
[u/mdw/putty] / ssh.c
CommitLineData
374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
4d331a77 5#ifndef AUTO_WINSOCK
6#ifdef WINSOCK_TWO
7#include <winsock2.h>
8#else
374330e2 9#include <winsock.h>
4d331a77 10#endif
11#endif
374330e2 12
13#include "putty.h"
dacbd0e8 14#include "tree234.h"
fb09bf1c 15#include "ssh.h"
374330e2 16
17#ifndef FALSE
18#define FALSE 0
19#endif
20#ifndef TRUE
21#define TRUE 1
22#endif
23
fb09bf1c 24#define logevent(s) { logevent(s); \
67779be7 25 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
fb09bf1c 26 fprintf(stderr, "%s\n", s); }
27
cf6e59d6 28#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, closesocket(s), \
8d5de777 29 s = INVALID_SOCKET, connection_fatal msg )
30
d211621f 31#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
32#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
33#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
34#define SSH1_CMSG_USER 4 /* 0x4 */
35#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
36#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
37#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
38#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
39#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
40#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
41#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
42#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
43#define SSH1_SMSG_SUCCESS 14 /* 0xe */
44#define SSH1_SMSG_FAILURE 15 /* 0xf */
45#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
46#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
47#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
48#define SSH1_CMSG_EOF 19 /* 0x13 */
49#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
50#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
51#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
52#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
53#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
54#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
55#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
56#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
57#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
58#define SSH1_MSG_IGNORE 32 /* 0x20 */
59#define SSH1_MSG_DEBUG 36 /* 0x24 */
60#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
61#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
62#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
63#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
64#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
65#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
66
67#define SSH1_AUTH_TIS 5 /* 0x5 */
68#define SSH1_AUTH_CCARD 16 /* 0x10 */
69
70#define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
71#define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
72#define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
73#define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
74#define SSH_AGENT_FAILURE 5 /* 0x5 */
75#define SSH_AGENT_SUCCESS 6 /* 0x6 */
76#define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
77#define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
78
79#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
80#define SSH2_MSG_IGNORE 2 /* 0x2 */
81#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
82#define SSH2_MSG_DEBUG 4 /* 0x4 */
83#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
84#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
85#define SSH2_MSG_KEXINIT 20 /* 0x14 */
86#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
87#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
88#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
89#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
95#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
96#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
97#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
98#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
99#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
100#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
101#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
102#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
103#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
104#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
105#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
106#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
107#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
108#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
109
110#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
111#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
112#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
113#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
114
115#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 116
117#define GET_32BIT(cp) \
118 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
119 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
120 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
121 ((unsigned long)(unsigned char)(cp)[3]))
122
123#define PUT_32BIT(cp, value) { \
124 (cp)[0] = (unsigned char)((value) >> 24); \
125 (cp)[1] = (unsigned char)((value) >> 16); \
126 (cp)[2] = (unsigned char)((value) >> 8); \
127 (cp)[3] = (unsigned char)(value); }
128
7cca0d81 129enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 130
374330e2 131/* Coroutine mechanics for the sillier bits of the code */
132#define crBegin1 static int crLine = 0;
133#define crBegin2 switch(crLine) { case 0:;
134#define crBegin crBegin1; crBegin2;
135#define crFinish(z) } crLine = 0; return (z)
136#define crFinishV } crLine = 0; return
137#define crReturn(z) \
138 do {\
139 crLine=__LINE__; return (z); case __LINE__:;\
140 } while (0)
141#define crReturnV \
142 do {\
143 crLine=__LINE__; return; case __LINE__:;\
144 } while (0)
145#define crStop(z) do{ crLine = 0; return (z); }while(0)
146#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 147#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 148#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 149
57476f6b 150extern const struct ssh_cipher ssh_3des;
151extern const struct ssh_cipher ssh_3des_ssh2;
152extern const struct ssh_cipher ssh_des;
153extern const struct ssh_cipher ssh_blowfish_ssh1;
154extern const struct ssh_cipher ssh_blowfish_ssh2;
e5574168 155
5e8358ad 156/*
157 * Ciphers for SSH2. We miss out single-DES because it isn't
158 * supported; also 3DES and Blowfish are both done differently from
159 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
160 * endianness and different-sized keys.)
5e8358ad 161 */
57476f6b 162const static struct ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 };
e5574168 163
57476f6b 164extern const struct ssh_kex ssh_diffiehellman;
165const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
e5574168 166
57476f6b 167extern const struct ssh_hostkey ssh_dss;
168const static struct ssh_hostkey *hostkey_algs[] = { &ssh_dss };
e5574168 169
8b2715b2 170extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy;
e5574168 171
d39f364a 172static void nullmac_key(unsigned char *key) { }
e5574168 173static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
174static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
57476f6b 175const static struct ssh_mac ssh_mac_none = {
d39f364a 176 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 177};
8b2715b2 178const static struct ssh_mac *macs[] = {
179 &ssh_sha1, &ssh_md5, &ssh_mac_none };
180const static struct ssh_mac *buggymacs[] = {
181 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
e5574168 182
57476f6b 183const static struct ssh_compress ssh_comp_none = {
e5574168 184 "none"
185};
57476f6b 186const static struct ssh_compress *compressions[] = { &ssh_comp_none };
374330e2 187
dacbd0e8 188/*
189 * 2-3-4 tree storing channels.
190 */
191struct ssh_channel {
d211621f 192 unsigned remoteid, localid;
dacbd0e8 193 int type;
194 int closes;
195 union {
196 struct ssh_agent_channel {
197 unsigned char *message;
198 unsigned char msglen[4];
199 int lensofar, totallen;
200 } a;
d211621f 201 struct ssh2_data_channel {
202 unsigned char *outbuffer;
203 unsigned outbuflen, outbufsize;
204 unsigned remwindow, remmaxpkt;
205 } v2;
dacbd0e8 206 } u;
207};
57476f6b 208
209struct Packet {
210 long length;
211 int type;
212 unsigned char *data;
213 unsigned char *body;
214 long savedpos;
215 long maxlen;
216};
217
218static SHA_State exhash;
219
220static SOCKET s = INVALID_SOCKET;
221
222static unsigned char session_key[32];
223static const struct ssh_cipher *cipher = NULL;
224static const struct ssh_cipher *cscipher = NULL;
225static const struct ssh_cipher *sccipher = NULL;
226static const struct ssh_mac *csmac = NULL;
227static const struct ssh_mac *scmac = NULL;
228static const struct ssh_compress *cscomp = NULL;
229static const struct ssh_compress *sccomp = NULL;
230static const struct ssh_kex *kex = NULL;
231static const struct ssh_hostkey *hostkey = NULL;
232int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
233
234static char *savedhost;
235static int savedport;
236static int ssh_send_ok;
237
dacbd0e8 238static tree234 *ssh_channels; /* indexed by local id */
57476f6b 239static struct ssh_channel *mainchan; /* primary session channel */
240
241static enum {
242 SSH_STATE_BEFORE_SIZE,
243 SSH_STATE_INTERMED,
244 SSH_STATE_SESSION,
245 SSH_STATE_CLOSED
246} ssh_state = SSH_STATE_BEFORE_SIZE;
247
248static int size_needed = FALSE;
249
250static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
251static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
252
253static int ssh_version;
254static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
255static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
256static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
257static void ssh_size(void);
258
259static int (*s_rdpkt)(unsigned char **data, int *datalen);
260
261static struct rdpkt1_state_tag {
262 long len, pad, biglen, to_read;
263 unsigned long realcrc, gotcrc;
264 unsigned char *p;
265 int i;
266 int chunk;
267} rdpkt1_state;
268
960e736a 269static struct rdpkt2_state_tag {
270 long len, pad, payload, packetlen, maclen;
271 int i;
272 int cipherblk;
273 unsigned long incoming_sequence;
274} rdpkt2_state;
275
dacbd0e8 276static int ssh_channelcmp(void *av, void *bv) {
277 struct ssh_channel *a = (struct ssh_channel *)av;
278 struct ssh_channel *b = (struct ssh_channel *)bv;
279 if (a->localid < b->localid) return -1;
280 if (a->localid > b->localid) return +1;
281 return 0;
282}
283static int ssh_channelfind(void *av, void *bv) {
d211621f 284 unsigned *a = (unsigned *)av;
dacbd0e8 285 struct ssh_channel *b = (struct ssh_channel *)bv;
286 if (*a < b->localid) return -1;
287 if (*a > b->localid) return +1;
288 return 0;
289}
290
374330e2 291static void s_write (char *buf, int len) {
292 while (len > 0) {
293 int i = send (s, buf, len, 0);
4017be6d 294 noise_ultralight(i);
8d5de777 295 if (i <= 0) {
296 bombout(("Lost connection while sending"));
297 return;
298 }
374330e2 299 if (i > 0)
300 len -= i, buf += i;
301 }
302}
303
304static int s_read (char *buf, int len) {
305 int ret = 0;
306 while (len > 0) {
307 int i = recv (s, buf, len, 0);
4017be6d 308 noise_ultralight(i);
374330e2 309 if (i > 0)
310 len -= i, buf += i, ret += i;
311 else
312 return i;
313 }
314 return ret;
315}
316
317static void c_write (char *buf, int len) {
67779be7 318 if ((flags & FLAG_STDERR)) {
4017be6d 319 int i;
320 for (i = 0; i < len; i++)
321 if (buf[i] != '\r')
322 fputc(buf[i], stderr);
fb09bf1c 323 return;
324 }
fe50e814 325 from_backend(1, buf, len);
3bdaf79d 326}
327
fb09bf1c 328/*
329 * Collect incoming data in the incoming packet buffer.
e5574168 330 * Decipher and verify the packet when it is completely read.
331 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 332 * Update the *data and *datalen variables.
333 * Return the additional nr of bytes needed, or 0 when
334 * a complete packet is available.
335 */
e5574168 336static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 337{
57476f6b 338 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 339
340 crBegin;
374330e2 341
fb09bf1c 342next_packet:
37508af4 343
fb09bf1c 344 pktin.type = 0;
345 pktin.length = 0;
374330e2 346
57476f6b 347 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 348 while ((*datalen) == 0)
57476f6b 349 crReturn(4-st->i);
350 st->len = (st->len << 8) + **data;
fb09bf1c 351 (*data)++, (*datalen)--;
352 }
374330e2 353
fb09bf1c 354#ifdef FWHACK
57476f6b 355 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
356 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 357 }
358#endif
374330e2 359
57476f6b 360 st->pad = 8 - (st->len % 8);
361 st->biglen = st->len + st->pad;
362 pktin.length = st->len - 5;
fb09bf1c 363
57476f6b 364 if (pktin.maxlen < st->biglen) {
365 pktin.maxlen = st->biglen;
366 pktin.data = (pktin.data == NULL ? malloc(st->biglen+APIEXTRA) :
367 realloc(pktin.data, st->biglen+APIEXTRA));
fb09bf1c 368 if (!pktin.data)
369 fatalbox("Out of memory");
370 }
374330e2 371
57476f6b 372 st->to_read = st->biglen;
373 st->p = pktin.data;
374 while (st->to_read > 0) {
375 st->chunk = st->to_read;
fb09bf1c 376 while ((*datalen) == 0)
57476f6b 377 crReturn(st->to_read);
378 if (st->chunk > (*datalen))
379 st->chunk = (*datalen);
380 memcpy(st->p, *data, st->chunk);
381 *data += st->chunk;
382 *datalen -= st->chunk;
383 st->p += st->chunk;
384 st->to_read -= st->chunk;
fb09bf1c 385 }
374330e2 386
fb09bf1c 387 if (cipher)
57476f6b 388 cipher->decrypt(pktin.data, st->biglen);
698a5108 389#if 0
390 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
391 for (st->i = 0; st->i < st->biglen; st->i++)
392 debug((" %02x", (unsigned char)pktin.data[st->i]));
393 debug(("\r\n"));
394#endif
374330e2 395
57476f6b 396 pktin.type = pktin.data[st->pad];
397 pktin.body = pktin.data + st->pad + 1;
374330e2 398
57476f6b 399 st->realcrc = crc32(pktin.data, st->biglen-4);
400 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
401 if (st->gotcrc != st->realcrc) {
8d5de777 402 bombout(("Incorrect CRC received on packet"));
403 crReturn(0);
fb09bf1c 404 }
572f871e 405
e5574168 406 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
407 pktin.type == SSH1_SMSG_STDERR_DATA ||
408 pktin.type == SSH1_MSG_DEBUG ||
18515c51 409 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
410 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 411 long strlen = GET_32BIT(pktin.body);
8d5de777 412 if (strlen + 4 != pktin.length) {
413 bombout(("Received data packet with bogus string length"));
414 crReturn(0);
415 }
fb09bf1c 416 }
417
e5574168 418 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 419 /* log debug message */
420 char buf[80];
421 int strlen = GET_32BIT(pktin.body);
422 strcpy(buf, "Remote: ");
423 if (strlen > 70) strlen = 70;
424 memcpy(buf+8, pktin.body+4, strlen);
425 buf[8+strlen] = '\0';
426 logevent(buf);
427 goto next_packet;
e5574168 428 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 429 /* do nothing */
430 goto next_packet;
431 }
432
433 crFinish(0);
434}
435
e5574168 436static int ssh2_rdpkt(unsigned char **data, int *datalen)
437{
960e736a 438 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 439
440 crBegin;
441
442next_packet:
e5574168 443 pktin.type = 0;
444 pktin.length = 0;
960e736a 445 if (sccipher)
446 st->cipherblk = sccipher->blksize;
e5574168 447 else
960e736a 448 st->cipherblk = 8;
449 if (st->cipherblk < 8)
450 st->cipherblk = 8;
451
452 if (pktin.maxlen < st->cipherblk) {
453 pktin.maxlen = st->cipherblk;
454 pktin.data = (pktin.data == NULL ? malloc(st->cipherblk+APIEXTRA) :
455 realloc(pktin.data, st->cipherblk+APIEXTRA));
e5574168 456 if (!pktin.data)
457 fatalbox("Out of memory");
458 }
459
460 /*
461 * Acquire and decrypt the first block of the packet. This will
462 * contain the length and padding details.
463 */
960e736a 464 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 465 while ((*datalen) == 0)
960e736a 466 crReturn(st->cipherblk-st->i);
467 pktin.data[st->i] = *(*data)++;
e5574168 468 (*datalen)--;
469 }
470#ifdef FWHACK
471 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
472 /* FIXME */
473 }
474#endif
475 if (sccipher)
960e736a 476 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 477
478 /*
479 * Now get the length and padding figures.
480 */
960e736a 481 st->len = GET_32BIT(pktin.data);
482 st->pad = pktin.data[4];
e5574168 483
484 /*
485 * This enables us to deduce the payload length.
486 */
960e736a 487 st->payload = st->len - st->pad - 1;
e5574168 488
960e736a 489 pktin.length = st->payload + 5;
e5574168 490
491 /*
492 * So now we can work out the total packet length.
493 */
960e736a 494 st->packetlen = st->len + 4;
495 st->maclen = scmac ? scmac->len : 0;
e5574168 496
497 /*
498 * Adjust memory allocation if packet is too big.
499 */
960e736a 500 if (pktin.maxlen < st->packetlen+st->maclen) {
501 pktin.maxlen = st->packetlen+st->maclen;
59dcd2a8 502 pktin.data = (pktin.data == NULL ? malloc(pktin.maxlen+APIEXTRA) :
503 realloc(pktin.data, pktin.maxlen+APIEXTRA));
e5574168 504 if (!pktin.data)
505 fatalbox("Out of memory");
506 }
507
508 /*
509 * Read and decrypt the remainder of the packet.
510 */
960e736a 511 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
e5574168 512 while ((*datalen) == 0)
960e736a 513 crReturn(st->packetlen + st->maclen - st->i);
514 pktin.data[st->i] = *(*data)++;
e5574168 515 (*datalen)--;
516 }
517 /* Decrypt everything _except_ the MAC. */
518 if (sccipher)
960e736a 519 sccipher->decrypt(pktin.data + st->cipherblk,
520 st->packetlen - st->cipherblk);
e5574168 521
7cca0d81 522#if 0
960e736a 523 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
524 for (st->i = 0; st->i < st->packetlen; st->i++)
525 debug((" %02x", (unsigned char)pktin.data[st->i]));
d39f364a 526 debug(("\r\n"));
7cca0d81 527#endif
d39f364a 528
e5574168 529 /*
530 * Check the MAC.
531 */
960e736a 532 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
8d5de777 533 bombout(("Incorrect MAC received on packet"));
534 crReturn(0);
535 }
960e736a 536 st->incoming_sequence++; /* whether or not we MACed */
e5574168 537
538 pktin.savedpos = 6;
539 pktin.type = pktin.data[5];
e5574168 540
7cca0d81 541 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
542 goto next_packet; /* FIXME: print DEBUG message */
e5574168 543
544 crFinish(0);
545}
546
fb09bf1c 547static void ssh_gotdata(unsigned char *data, int datalen)
548{
549 while (datalen > 0) {
85ee8208 550 if ( s_rdpkt(&data, &datalen) == 0 ) {
374330e2 551 ssh_protocol(NULL, 0, 1);
85ee8208 552 if (ssh_state == SSH_STATE_CLOSED) {
553 return;
554 }
555 }
374330e2 556 }
374330e2 557}
558
fb09bf1c 559
374330e2 560static void s_wrpkt_start(int type, int len) {
561 int pad, biglen;
562
563 len += 5; /* type and CRC */
564 pad = 8 - (len%8);
565 biglen = len + pad;
566
567 pktout.length = len-5;
568 if (pktout.maxlen < biglen) {
569 pktout.maxlen = biglen;
8f203108 570#ifdef MSCRYPTOAPI
fb09bf1c 571 /* Allocate enough buffer space for extra block
8f203108 572 * for MS CryptEncrypt() */
fb09bf1c 573 pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
574 realloc(pktout.data, biglen+12));
8f203108 575#else
c1f5f956 576 pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
577 realloc(pktout.data, biglen+4));
8f203108 578#endif
374330e2 579 if (!pktout.data)
580 fatalbox("Out of memory");
581 }
582
583 pktout.type = type;
584 pktout.body = pktout.data+4+pad+1;
585}
586
587static void s_wrpkt(void) {
588 int pad, len, biglen, i;
589 unsigned long crc;
590
591 len = pktout.length + 5; /* type and CRC */
592 pad = 8 - (len%8);
593 biglen = len + pad;
594
595 pktout.body[-1] = pktout.type;
596 for (i=0; i<pad; i++)
597 pktout.data[i+4] = random_byte();
598 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 599 PUT_32BIT(pktout.data+biglen, crc);
600 PUT_32BIT(pktout.data, len);
374330e2 601
698a5108 602#if 0
603 debug(("Sending packet len=%d\r\n", biglen+4));
604 for (i = 0; i < biglen+4; i++)
605 debug((" %02x", (unsigned char)pktout.data[i]));
606 debug(("\r\n"));
607#endif
374330e2 608 if (cipher)
609 cipher->encrypt(pktout.data+4, biglen);
610
611 s_write(pktout.data, biglen+4);
612}
613
fb09bf1c 614/*
615 * Construct a packet with the specified contents and
616 * send it to the server.
617 */
618static void send_packet(int pkttype, ...)
619{
620 va_list args;
621 unsigned char *p, *argp, argchar;
622 unsigned long argint;
623 int pktlen, argtype, arglen;
7cca0d81 624 Bignum bn;
fb09bf1c 625
626 pktlen = 0;
627 va_start(args, pkttype);
628 while ((argtype = va_arg(args, int)) != PKT_END) {
629 switch (argtype) {
630 case PKT_INT:
631 (void) va_arg(args, int);
632 pktlen += 4;
633 break;
634 case PKT_CHAR:
635 (void) va_arg(args, char);
636 pktlen++;
637 break;
638 case PKT_DATA:
639 (void) va_arg(args, unsigned char *);
640 arglen = va_arg(args, int);
641 pktlen += arglen;
642 break;
643 case PKT_STR:
644 argp = va_arg(args, unsigned char *);
645 arglen = strlen(argp);
646 pktlen += 4 + arglen;
647 break;
7cca0d81 648 case PKT_BIGNUM:
649 bn = va_arg(args, Bignum);
5c58ad2d 650 pktlen += ssh1_bignum_length(bn);
7cca0d81 651 break;
fb09bf1c 652 default:
653 assert(0);
654 }
655 }
656 va_end(args);
657
658 s_wrpkt_start(pkttype, pktlen);
659 p = pktout.body;
660
661 va_start(args, pkttype);
662 while ((argtype = va_arg(args, int)) != PKT_END) {
663 switch (argtype) {
664 case PKT_INT:
665 argint = va_arg(args, int);
666 PUT_32BIT(p, argint);
667 p += 4;
668 break;
669 case PKT_CHAR:
670 argchar = va_arg(args, unsigned char);
671 *p = argchar;
672 p++;
673 break;
674 case PKT_DATA:
675 argp = va_arg(args, unsigned char *);
676 arglen = va_arg(args, int);
677 memcpy(p, argp, arglen);
678 p += arglen;
679 break;
680 case PKT_STR:
681 argp = va_arg(args, unsigned char *);
682 arglen = strlen(argp);
683 PUT_32BIT(p, arglen);
684 memcpy(p + 4, argp, arglen);
685 p += 4 + arglen;
686 break;
7cca0d81 687 case PKT_BIGNUM:
688 bn = va_arg(args, Bignum);
5c58ad2d 689 p += ssh1_write_bignum(p, bn);
7cca0d81 690 break;
fb09bf1c 691 }
692 }
693 va_end(args);
694
695 s_wrpkt();
696}
697
698
699/*
700 * Connect to specified host and port.
701 * Returns an error message, or NULL on success.
702 * Also places the canonical host name into `realhost'.
703 */
704static char *connect_to_host(char *host, int port, char **realhost)
705{
706 SOCKADDR_IN addr;
707 struct hostent *h;
708 unsigned long a;
709#ifdef FWHACK
710 char *FWhost;
711 int FWport;
712#endif
713
714 savedhost = malloc(1+strlen(host));
715 if (!savedhost)
716 fatalbox("Out of memory");
717 strcpy(savedhost, host);
718
719 if (port < 0)
720 port = 22; /* default ssh port */
d4857987 721 savedport = port;
fb09bf1c 722
723#ifdef FWHACK
724 FWhost = host;
725 FWport = port;
726 host = FWSTR;
727 port = 23;
728#endif
729
730 /*
731 * Try to find host.
732 */
733 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
734 if ( (h = gethostbyname(host)) == NULL)
735 switch (WSAGetLastError()) {
736 case WSAENETDOWN: return "Network is down";
737 case WSAHOST_NOT_FOUND: case WSANO_DATA:
738 return "Host does not exist";
739 case WSATRY_AGAIN: return "Host not found";
740 default: return "gethostbyname: unknown error";
741 }
742 memcpy (&a, h->h_addr, sizeof(a));
743 *realhost = h->h_name;
744 } else
745 *realhost = host;
746#ifdef FWHACK
747 *realhost = FWhost;
748#endif
749 a = ntohl(a);
750
751 /*
752 * Open socket.
753 */
754 s = socket(AF_INET, SOCK_STREAM, 0);
755 if (s == INVALID_SOCKET)
756 switch (WSAGetLastError()) {
757 case WSAENETDOWN: return "Network is down";
758 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
759 default: return "socket(): unknown error";
760 }
761
762 /*
763 * Bind to local address.
764 */
765 addr.sin_family = AF_INET;
766 addr.sin_addr.s_addr = htonl(INADDR_ANY);
767 addr.sin_port = htons(0);
768 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
769 switch (WSAGetLastError()) {
770 case WSAENETDOWN: return "Network is down";
771 default: return "bind(): unknown error";
772 }
773
774 /*
775 * Connect to remote address.
776 */
777 addr.sin_addr.s_addr = htonl(a);
778 addr.sin_port = htons((short)port);
779 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
780 switch (WSAGetLastError()) {
781 case WSAENETDOWN: return "Network is down";
782 case WSAECONNREFUSED: return "Connection refused";
783 case WSAENETUNREACH: return "Network is unreachable";
784 case WSAEHOSTUNREACH: return "No route to host";
785 default: return "connect(): unknown error";
786 }
787
788#ifdef FWHACK
789 send(s, "connect ", 8, 0);
790 send(s, FWhost, strlen(FWhost), 0);
791 {
792 char buf[20];
793 sprintf(buf, " %d\n", FWport);
794 send (s, buf, strlen(buf), 0);
795 }
796#endif
797
798 return NULL;
799}
800
9697bfd2 801static int ssh_versioncmp(char *a, char *b) {
802 char *ae, *be;
803 unsigned long av, bv;
804
43aa02a7 805 av = strtoul(a, &ae, 10);
806 bv = strtoul(b, &be, 10);
9697bfd2 807 if (av != bv) return (av < bv ? -1 : +1);
808 if (*ae == '.') ae++;
809 if (*be == '.') be++;
43aa02a7 810 av = strtoul(ae, &ae, 10);
811 bv = strtoul(be, &be, 10);
9697bfd2 812 if (av != bv) return (av < bv ? -1 : +1);
813 return 0;
814}
815
e5574168 816
817/*
818 * Utility routine for putting an SSH-protocol `string' into a SHA
819 * state.
820 */
821#include <stdio.h>
75cab814 822static void sha_string(SHA_State *s, void *str, int len) {
e5574168 823 unsigned char lenblk[4];
e5574168 824 PUT_32BIT(lenblk, len);
e5574168 825 SHA_Bytes(s, lenblk, 4);
e5574168 826 SHA_Bytes(s, str, len);
827}
828
7cca0d81 829/*
830 * SSH2 packet construction functions.
831 */
75cab814 832static void ssh2_pkt_adddata(void *data, int len) {
7cca0d81 833 pktout.length += len;
834 if (pktout.maxlen < pktout.length) {
835 pktout.maxlen = pktout.length + 256;
836 pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) :
837 realloc(pktout.data, pktout.maxlen+APIEXTRA));
838 if (!pktout.data)
839 fatalbox("Out of memory");
840 }
841 memcpy(pktout.data+pktout.length-len, data, len);
842}
75cab814 843static void ssh2_pkt_addbyte(unsigned char byte) {
7cca0d81 844 ssh2_pkt_adddata(&byte, 1);
845}
75cab814 846static void ssh2_pkt_init(int pkt_type) {
7cca0d81 847 pktout.length = 5;
848 ssh2_pkt_addbyte((unsigned char)pkt_type);
849}
75cab814 850static void ssh2_pkt_addbool(unsigned char value) {
7cca0d81 851 ssh2_pkt_adddata(&value, 1);
852}
75cab814 853static void ssh2_pkt_adduint32(unsigned long value) {
7cca0d81 854 unsigned char x[4];
855 PUT_32BIT(x, value);
856 ssh2_pkt_adddata(x, 4);
857}
75cab814 858static void ssh2_pkt_addstring_start(void) {
7cca0d81 859 ssh2_pkt_adduint32(0);
860 pktout.savedpos = pktout.length;
861}
75cab814 862static void ssh2_pkt_addstring_str(char *data) {
7cca0d81 863 ssh2_pkt_adddata(data, strlen(data));
864 PUT_32BIT(pktout.data + pktout.savedpos - 4,
865 pktout.length - pktout.savedpos);
866}
75cab814 867static void ssh2_pkt_addstring_data(char *data, int len) {
7cca0d81 868 ssh2_pkt_adddata(data, len);
869 PUT_32BIT(pktout.data + pktout.savedpos - 4,
870 pktout.length - pktout.savedpos);
871}
75cab814 872static void ssh2_pkt_addstring(char *data) {
7cca0d81 873 ssh2_pkt_addstring_start();
874 ssh2_pkt_addstring_str(data);
875}
75cab814 876static char *ssh2_mpint_fmt(Bignum b, int *len) {
7cca0d81 877 unsigned char *p;
878 int i, n = b[0];
879 p = malloc(n * 2 + 1);
880 if (!p)
881 fatalbox("out of memory");
882 p[0] = 0;
883 for (i = 0; i < n; i++) {
884 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
885 p[i*2+2] = (b[n-i] ) & 0xFF;
886 }
887 i = 0;
888 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
889 i++;
890 memmove(p, p+i, n*2+1-i);
891 *len = n*2+1-i;
892 return p;
893}
75cab814 894static void ssh2_pkt_addmp(Bignum b) {
7cca0d81 895 unsigned char *p;
896 int len;
897 p = ssh2_mpint_fmt(b, &len);
898 ssh2_pkt_addstring_start();
899 ssh2_pkt_addstring_data(p, len);
900 free(p);
901}
75cab814 902static void ssh2_pkt_send(void) {
7cca0d81 903 int cipherblk, maclen, padding, i;
904 static unsigned long outgoing_sequence = 0;
905
906 /*
907 * Add padding. At least four bytes, and must also bring total
908 * length (minus MAC) up to a multiple of the block size.
909 */
910 cipherblk = cipher ? cipher->blksize : 8; /* block size */
911 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
912 padding = 4;
913 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
914 pktout.data[4] = padding;
915 for (i = 0; i < padding; i++)
916 pktout.data[pktout.length + i] = random_byte();
917 PUT_32BIT(pktout.data, pktout.length + padding - 4);
918 if (csmac)
919 csmac->generate(pktout.data, pktout.length + padding,
920 outgoing_sequence);
921 outgoing_sequence++; /* whether or not we MACed */
922
923#if 0
924 debug(("Sending packet len=%d\r\n", pktout.length+padding));
925 for (i = 0; i < pktout.length+padding; i++)
926 debug((" %02x", (unsigned char)pktout.data[i]));
927 debug(("\r\n"));
928#endif
929
930 if (cscipher)
931 cscipher->encrypt(pktout.data, pktout.length + padding);
932 maclen = csmac ? csmac->len : 0;
933
934 s_write(pktout.data, pktout.length + padding + maclen);
935}
936
937#if 0
938void bndebug(char *string, Bignum b) {
939 unsigned char *p;
940 int i, len;
941 p = ssh2_mpint_fmt(b, &len);
942 debug(("%s", string));
943 for (i = 0; i < len; i++)
944 debug((" %02x", p[i]));
945 debug(("\r\n"));
946 free(p);
947}
948#endif
949
75cab814 950static void sha_mpint(SHA_State *s, Bignum b) {
7cca0d81 951 unsigned char *p;
952 int len;
953 p = ssh2_mpint_fmt(b, &len);
954 sha_string(s, p, len);
955 free(p);
956}
957
958/*
959 * SSH2 packet decode functions.
960 */
75cab814 961static unsigned long ssh2_pkt_getuint32(void) {
7cca0d81 962 unsigned long value;
963 if (pktin.length - pktin.savedpos < 4)
964 return 0; /* arrgh, no way to decline (FIXME?) */
965 value = GET_32BIT(pktin.data+pktin.savedpos);
966 pktin.savedpos += 4;
967 return value;
968}
75cab814 969static void ssh2_pkt_getstring(char **p, int *length) {
7cca0d81 970 *p = NULL;
971 if (pktin.length - pktin.savedpos < 4)
972 return;
973 *length = GET_32BIT(pktin.data+pktin.savedpos);
974 pktin.savedpos += 4;
975 if (pktin.length - pktin.savedpos < *length)
976 return;
977 *p = pktin.data+pktin.savedpos;
978 pktin.savedpos += *length;
979}
75cab814 980static Bignum ssh2_pkt_getmp(void) {
7cca0d81 981 char *p;
982 int i, j, length;
983 Bignum b;
984
985 ssh2_pkt_getstring(&p, &length);
986 if (!p)
987 return NULL;
8d5de777 988 if (p[0] & 0x80) {
989 bombout(("internal error: Can't handle negative mpints"));
990 return NULL;
991 }
7cca0d81 992 b = newbn((length+1)/2);
993 for (i = 0; i < length; i++) {
994 j = length - 1 - i;
995 if (j & 1)
996 b[j/2+1] |= ((unsigned char)p[i]) << 8;
997 else
998 b[j/2+1] |= ((unsigned char)p[i]);
999 }
1000 return b;
1001}
1002
374330e2 1003static int do_ssh_init(void) {
c5e9c988 1004 char c, *vsp;
374330e2 1005 char version[10];
c5e9c988 1006 char vstring[80];
1007 char vlog[sizeof(vstring)+20];
374330e2 1008 int i;
1009
1010#ifdef FWHACK
1011 i = 0;
1012 while (s_read(&c, 1) == 1) {
1013 if (c == 'S' && i < 2) i++;
1014 else if (c == 'S' && i == 2) i = 2;
1015 else if (c == 'H' && i == 2) break;
1016 else i = 0;
1017 }
1018#else
1019 if (s_read(&c,1) != 1 || c != 'S') return 0;
1020 if (s_read(&c,1) != 1 || c != 'S') return 0;
1021 if (s_read(&c,1) != 1 || c != 'H') return 0;
1022#endif
c5e9c988 1023 strcpy(vstring, "SSH-");
1024 vsp = vstring+4;
374330e2 1025 if (s_read(&c,1) != 1 || c != '-') return 0;
1026 i = 0;
1027 while (1) {
1028 if (s_read(&c,1) != 1)
1029 return 0;
c5e9c988 1030 if (vsp < vstring+sizeof(vstring)-1)
1031 *vsp++ = c;
374330e2 1032 if (i >= 0) {
1033 if (c == '-') {
1034 version[i] = '\0';
1035 i = -1;
1036 } else if (i < sizeof(version)-1)
1037 version[i++] = c;
1038 }
1039 else if (c == '\n')
1040 break;
1041 }
1042
960e736a 1043 rdpkt2_state.incoming_sequence = 0;
1044
c5e9c988 1045 *vsp = 0;
1046 sprintf(vlog, "Server version: %s", vstring);
1047 vlog[strcspn(vlog, "\r\n")] = '\0';
1048 logevent(vlog);
1049
adf799dd 1050 /*
1051 * Server version "1.99" means we can choose whether we use v1
1052 * or v2 protocol. Choice is based on cfg.sshprot.
1053 */
1054 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 1055 /*
1056 * This is a v2 server. Begin v2 protocol.
1057 */
1058 char *verstring = "SSH-2.0-PuTTY";
1059 SHA_Init(&exhash);
1060 /*
1061 * Hash our version string and their version string.
1062 */
1063 sha_string(&exhash, verstring, strlen(verstring));
1064 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
1065 sprintf(vstring, "%s\n", verstring);
1066 sprintf(vlog, "We claim version: %s", verstring);
1067 logevent(vlog);
1068 logevent("Using SSH protocol version 2");
1069 s_write(vstring, strlen(vstring));
1070 ssh_protocol = ssh2_protocol;
6abbf9e3 1071 ssh_version = 2;
e5574168 1072 s_rdpkt = ssh2_rdpkt;
1073 } else {
1074 /*
1075 * This is a v1 server. Begin v1 protocol.
1076 */
1077 sprintf(vstring, "SSH-%s-PuTTY\n",
1078 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1079 sprintf(vlog, "We claim version: %s", vstring);
1080 vlog[strcspn(vlog, "\r\n")] = '\0';
1081 logevent(vlog);
1082 logevent("Using SSH protocol version 1");
1083 s_write(vstring, strlen(vstring));
1084 ssh_protocol = ssh1_protocol;
6abbf9e3 1085 ssh_version = 1;
e5574168 1086 s_rdpkt = ssh1_rdpkt;
1087 }
8ccc75b0 1088 ssh_send_ok = 0;
fef97f43 1089 return 1;
374330e2 1090}
1091
fb09bf1c 1092/*
1093 * Handle the key exchange and user authentication phases.
1094 */
e5574168 1095static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1096{
374330e2 1097 int i, j, len;
374330e2 1098 unsigned char *rsabuf, *keystr1, *keystr2;
1099 unsigned char cookie[8];
1100 struct RSAKey servkey, hostkey;
1101 struct MD5Context md5c;
ccbfb941 1102 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1103 static int tried_publickey;
1104 static unsigned char session_id[16];
bea1ef5f 1105 int cipher_type;
b585ec46 1106 static char username[100];
374330e2 1107
374330e2 1108 crBegin;
1109
fb09bf1c 1110 if (!ispkt) crWaitUntil(ispkt);
374330e2 1111
8d5de777 1112 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1113 bombout(("Public key packet not received"));
1114 crReturn(0);
1115 }
374330e2 1116
c5e9c988 1117 logevent("Received public keys");
374330e2 1118
c5e9c988 1119 memcpy(cookie, pktin.body, 8);
374330e2 1120
7cca0d81 1121 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1122 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1123
c5e9c988 1124 /*
1c2a93c4 1125 * Log the host key fingerprint.
c5e9c988 1126 */
c5e9c988 1127 {
1128 char logmsg[80];
1c2a93c4 1129 logevent("Host key fingerprint is:");
c5e9c988 1130 strcpy(logmsg, " ");
1c2a93c4 1131 hostkey.comment = NULL;
1132 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1133 &hostkey);
c5e9c988 1134 logevent(logmsg);
1135 }
1136
fb09bf1c 1137 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1138 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1139
c5e9c988 1140 MD5Init(&md5c);
374330e2 1141 MD5Update(&md5c, keystr2, hostkey.bytes);
1142 MD5Update(&md5c, keystr1, servkey.bytes);
1143 MD5Update(&md5c, pktin.body, 8);
374330e2 1144 MD5Final(session_id, &md5c);
1145
1146 for (i=0; i<32; i++)
1147 session_key[i] = random_byte();
1148
1149 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1150
1151 rsabuf = malloc(len);
1152 if (!rsabuf)
1153 fatalbox("Out of memory");
1154
89ee5268 1155 /*
1156 * Verify the host key.
1157 */
1158 {
1159 /*
1160 * First format the key into a string.
1161 */
1162 int len = rsastr_len(&hostkey);
d5859615 1163 char fingerprint[100];
89ee5268 1164 char *keystr = malloc(len);
1165 if (!keystr)
1166 fatalbox("Out of memory");
1167 rsastr_fmt(keystr, &hostkey);
d5859615 1168 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1169 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
89ee5268 1170 free(keystr);
1171 }
374330e2 1172
1173 for (i=0; i<32; i++) {
1174 rsabuf[i] = session_key[i];
1175 if (i < 16)
1176 rsabuf[i] ^= session_id[i];
1177 }
1178
1179 if (hostkey.bytes > servkey.bytes) {
1180 rsaencrypt(rsabuf, 32, &servkey);
1181 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1182 } else {
1183 rsaencrypt(rsabuf, 32, &hostkey);
1184 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1185 }
1186
c5e9c988 1187 logevent("Encrypted session key");
1188
bea1ef5f 1189 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1190 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1191 SSH_CIPHER_3DES;
1192 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1193 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1194 cipher_type = SSH_CIPHER_3DES;
1195 }
c5e9c988 1196 switch (cipher_type) {
1197 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1198 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1199 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1200 }
bea1ef5f 1201
e5574168 1202 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1203 PKT_CHAR, cipher_type,
1204 PKT_DATA, cookie, 8,
1205 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1206 PKT_DATA, rsabuf, len,
1207 PKT_INT, 0,
1208 PKT_END);
1209
c5e9c988 1210 logevent("Trying to enable encryption...");
374330e2 1211
1212 free(rsabuf);
1213
5e8358ad 1214 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1215 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1216 &ssh_3des;
374330e2 1217 cipher->sesskey(session_key);
1218
fb09bf1c 1219 crWaitUntil(ispkt);
374330e2 1220
8d5de777 1221 if (pktin.type != SSH1_SMSG_SUCCESS) {
1222 bombout(("Encryption not successfully enabled"));
1223 crReturn(0);
1224 }
374330e2 1225
c5e9c988 1226 logevent("Successfully started encryption");
1227
374330e2 1228 fflush(stdout);
1229 {
374330e2 1230 static int pos = 0;
1231 static char c;
67779be7 1232 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1233 c_write("login as: ", 10);
67779be7 1234 ssh_send_ok = 1;
374330e2 1235 while (pos >= 0) {
fb09bf1c 1236 crWaitUntil(!ispkt);
374330e2 1237 while (inlen--) switch (c = *in++) {
1238 case 10: case 13:
1239 username[pos] = 0;
1240 pos = -1;
1241 break;
1242 case 8: case 127:
1243 if (pos > 0) {
1244 c_write("\b \b", 3);
1245 pos--;
1246 }
1247 break;
1248 case 21: case 27:
1249 while (pos > 0) {
1250 c_write("\b \b", 3);
1251 pos--;
1252 }
1253 break;
1254 case 3: case 4:
1255 random_save_seed();
1256 exit(0);
1257 break;
1258 default:
40d24aa6 1259 if (((c >= ' ' && c <= '~') ||
1260 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1261 username[pos++] = c;
1262 c_write(&c, 1);
1263 }
1264 break;
1265 }
1266 }
1267 c_write("\r\n", 2);
1268 username[strcspn(username, "\n\r")] = '\0';
1269 } else {
1270 char stuff[200];
1271 strncpy(username, cfg.username, 99);
1272 username[99] = '\0';
67779be7 1273 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
fb09bf1c 1274 sprintf(stuff, "Sent username \"%s\".\r\n", username);
4017be6d 1275 c_write(stuff, strlen(stuff));
fb09bf1c 1276 }
374330e2 1277 }
fb09bf1c 1278
e5574168 1279 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1280 {
1281 char userlog[20+sizeof(username)];
1282 sprintf(userlog, "Sent username \"%s\"", username);
1283 logevent(userlog);
1284 }
374330e2 1285 }
1286
fb09bf1c 1287 crWaitUntil(ispkt);
374330e2 1288
7cca0d81 1289 tried_publickey = 0;
1290
e5574168 1291 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1292 static char password[100];
a52f067e 1293 static char prompt[200];
374330e2 1294 static int pos;
1295 static char c;
ccbfb941 1296 static int pwpkt_type;
ccbfb941 1297 /*
1298 * Show password prompt, having first obtained it via a TIS
18515c51 1299 * or CryptoCard exchange if we're doing TIS or CryptoCard
1300 * authentication.
ccbfb941 1301 */
e5574168 1302 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1303 if (agent_exists()) {
1304 /*
1305 * Attempt RSA authentication using Pageant.
1306 */
1307 static unsigned char request[5], *response, *p;
1308 static int responselen;
1309 static int i, nkeys;
1310 static int authed = FALSE;
1311 void *r;
1312
1313 logevent("Pageant is running. Requesting keys.");
1314
1315 /* Request the keys held by the agent. */
1316 PUT_32BIT(request, 1);
1317 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1318 agent_query(request, 5, &r, &responselen);
1319 response = (unsigned char *)r;
1320 if (response) {
1321 p = response + 5;
1322 nkeys = GET_32BIT(p); p += 4;
1323 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1324 logevent(buf); }
1325 for (i = 0; i < nkeys; i++) {
1326 static struct RSAKey key;
1327 static Bignum challenge;
b8bb811a 1328 static char *commentp;
1329 static int commentlen;
5c58ad2d 1330
1331 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1332 logevent(buf); }
1333 p += 4;
1334 p += ssh1_read_bignum(p, &key.exponent);
1335 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1336 commentlen = GET_32BIT(p); p += 4;
1337 commentp = p; p += commentlen;
5c58ad2d 1338 send_packet(SSH1_CMSG_AUTH_RSA,
1339 PKT_BIGNUM, key.modulus, PKT_END);
1340 crWaitUntil(ispkt);
1341 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1342 logevent("Key refused");
1343 continue;
1344 }
1345 logevent("Received RSA challenge");
1346 ssh1_read_bignum(pktin.body, &challenge);
1347 {
1348 char *agentreq, *q, *ret;
1349 int len, retlen;
1350 len = 1 + 4; /* message type, bit count */
1351 len += ssh1_bignum_length(key.exponent);
1352 len += ssh1_bignum_length(key.modulus);
1353 len += ssh1_bignum_length(challenge);
1354 len += 16; /* session id */
1355 len += 4; /* response format */
1356 agentreq = malloc(4 + len);
1357 PUT_32BIT(agentreq, len);
1358 q = agentreq + 4;
1359 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1360 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1361 q += 4;
1362 q += ssh1_write_bignum(q, key.exponent);
1363 q += ssh1_write_bignum(q, key.modulus);
1364 q += ssh1_write_bignum(q, challenge);
1365 memcpy(q, session_id, 16); q += 16;
1366 PUT_32BIT(q, 1); /* response format */
1367 agent_query(agentreq, len+4, &ret, &retlen);
1368 free(agentreq);
1369 if (ret) {
1370 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1371 logevent("Sending Pageant's response");
1372 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1373 PKT_DATA, ret+5, 16, PKT_END);
1374 free(ret);
1375 crWaitUntil(ispkt);
1376 if (pktin.type == SSH1_SMSG_SUCCESS) {
1377 logevent("Pageant's response accepted");
c4fa2fce 1378 if (flags & FLAG_VERBOSE) {
1379 c_write("Authenticated using RSA key \"",
1380 29);
1381 c_write(commentp, commentlen);
1382 c_write("\" from agent\r\n", 14);
1383 }
5c58ad2d 1384 authed = TRUE;
1385 } else
1386 logevent("Pageant's response not accepted");
1387 } else {
1388 logevent("Pageant failed to answer challenge");
1389 free(ret);
1390 }
1391 } else {
1392 logevent("No reply received from Pageant");
1393 }
1394 }
1395 freebn(key.exponent);
1396 freebn(key.modulus);
1397 freebn(challenge);
1398 if (authed)
1399 break;
1400 }
1401 }
1402 if (authed)
1403 break;
1404 }
7cca0d81 1405 if (*cfg.keyfile && !tried_publickey)
1406 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1407
a52f067e 1408 if (pktin.type == SSH1_SMSG_FAILURE &&
1409 cfg.try_tis_auth &&
1410 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1411 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1412 logevent("Requested TIS authentication");
1413 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1414 crWaitUntil(ispkt);
1415 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1416 logevent("TIS authentication declined");
1417 if (flags & FLAG_INTERACTIVE)
1418 c_write("TIS authentication refused.\r\n", 29);
1419 } else {
1420 int challengelen = ((pktin.body[0] << 24) |
1421 (pktin.body[1] << 16) |
1422 (pktin.body[2] << 8) |
1423 (pktin.body[3]));
1424 logevent("Received TIS challenge");
1425 if (challengelen > sizeof(prompt)-1)
1426 challengelen = sizeof(prompt)-1; /* prevent overrun */
1427 memcpy(prompt, pktin.body+4, challengelen);
1428 prompt[challengelen] = '\0';
1429 }
1430 }
1431 if (pktin.type == SSH1_SMSG_FAILURE &&
1432 cfg.try_tis_auth &&
1433 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1434 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1435 logevent("Requested CryptoCard authentication");
1436 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1437 crWaitUntil(ispkt);
1438 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1439 logevent("CryptoCard authentication declined");
1440 c_write("CryptoCard authentication refused.\r\n", 29);
1441 } else {
1442 int challengelen = ((pktin.body[0] << 24) |
1443 (pktin.body[1] << 16) |
1444 (pktin.body[2] << 8) |
1445 (pktin.body[3]));
1446 logevent("Received CryptoCard challenge");
1447 if (challengelen > sizeof(prompt)-1)
1448 challengelen = sizeof(prompt)-1; /* prevent overrun */
1449 memcpy(prompt, pktin.body+4, challengelen);
1450 strncpy(prompt + challengelen, "\r\nResponse : ",
1451 sizeof(prompt)-challengelen);
1452 prompt[sizeof(prompt)-1] = '\0';
1453 }
1454 }
1455 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1456 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1457 username, savedhost);
a52f067e 1458 }
1459 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1460 char *comment = NULL;
1461 if (flags & FLAG_VERBOSE)
1462 c_write("Trying public key authentication.\r\n", 35);
1463 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1464 if (flags & FLAG_VERBOSE)
1465 c_write("No passphrase required.\r\n", 25);
1466 goto tryauth;
1467 }
1468 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1469 free(comment);
1470 }
1471
d8426c54 1472 if (ssh_get_password) {
85ee8208 1473 if (!ssh_get_password(prompt, password, sizeof(password))) {
1474 /*
1475 * get_password failed to get a password (for
1476 * example because one was supplied on the command
1477 * line which has already failed to work).
1478 * Terminate.
1479 */
1480 logevent("No more passwords to try");
1481 ssh_state = SSH_STATE_CLOSED;
1482 crReturn(1);
1483 }
fb09bf1c 1484 } else {
a52f067e 1485 c_write(prompt, strlen(prompt));
7cca0d81 1486 pos = 0;
67779be7 1487 ssh_send_ok = 1;
7cca0d81 1488 while (pos >= 0) {
1489 crWaitUntil(!ispkt);
1490 while (inlen--) switch (c = *in++) {
1491 case 10: case 13:
1492 password[pos] = 0;
1493 pos = -1;
1494 break;
1495 case 8: case 127:
1496 if (pos > 0)
1497 pos--;
1498 break;
1499 case 21: case 27:
1500 pos = 0;
1501 break;
1502 case 3: case 4:
1503 random_save_seed();
1504 exit(0);
1505 break;
1506 default:
1507 if (((c >= ' ' && c <= '~') ||
1508 ((unsigned char)c >= 160)) && pos < sizeof(password))
1509 password[pos++] = c;
1510 break;
1511 }
1512 }
1513 c_write("\r\n", 2);
a52f067e 1514 }
fb09bf1c 1515
7cca0d81 1516 tryauth:
1517 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1518 /*
1519 * Try public key authentication with the specified
1520 * key file.
1521 */
1522 static struct RSAKey pubkey;
1523 static Bignum challenge, response;
1524 static int i;
1525 static unsigned char buffer[32];
1526
1527 tried_publickey = 1;
6e522441 1528 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
7cca0d81 1529 if (i == 0) {
1530 c_write("Couldn't load public key from ", 30);
1531 c_write(cfg.keyfile, strlen(cfg.keyfile));
1532 c_write(".\r\n", 3);
1533 continue; /* go and try password */
1534 }
1535 if (i == -1) {
1536 c_write("Wrong passphrase.\r\n", 19);
1537 tried_publickey = 0;
1538 continue; /* try again */
1539 }
1540
1541 /*
1542 * Send a public key attempt.
1543 */
1544 send_packet(SSH1_CMSG_AUTH_RSA,
1545 PKT_BIGNUM, pubkey.modulus, PKT_END);
1546
1547 crWaitUntil(ispkt);
1548 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1549 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1550 continue; /* go and try password */
1551 }
8d5de777 1552 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1553 bombout(("Bizarre response to offer of public key"));
1554 crReturn(0);
1555 }
7cca0d81 1556 ssh1_read_bignum(pktin.body, &challenge);
1557 response = rsadecrypt(challenge, &pubkey);
1558 freebn(pubkey.private_exponent); /* burn the evidence */
1559
1560 for (i = 0; i < 32; i += 2) {
1561 buffer[i] = response[16-i/2] >> 8;
1562 buffer[i+1] = response[16-i/2] & 0xFF;
1563 }
1564
1565 MD5Init(&md5c);
1566 MD5Update(&md5c, buffer, 32);
1567 MD5Update(&md5c, session_id, 16);
1568 MD5Final(buffer, &md5c);
1569
1570 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1571 PKT_DATA, buffer, 16, PKT_END);
1572
1573 crWaitUntil(ispkt);
1574 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1575 if (flags & FLAG_VERBOSE)
1576 c_write("Failed to authenticate with our public key.\r\n",
1577 45);
7cca0d81 1578 continue; /* go and try password */
1579 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1580 bombout(("Bizarre response to RSA authentication response"));
1581 crReturn(0);
7cca0d81 1582 }
1583
1584 break; /* we're through! */
1585 } else {
1586 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1587 }
c5e9c988 1588 logevent("Sent password");
374330e2 1589 memset(password, 0, strlen(password));
fb09bf1c 1590 crWaitUntil(ispkt);
e5574168 1591 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1592 if (flags & FLAG_VERBOSE)
1593 c_write("Access denied\r\n", 15);
c5e9c988 1594 logevent("Authentication refused");
e5574168 1595 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1596 logevent("Received disconnect request");
85ee8208 1597 ssh_state = SSH_STATE_CLOSED;
1598 crReturn(1);
e5574168 1599 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1600 bombout(("Strange packet received, type %d", pktin.type));
1601 crReturn(0);
374330e2 1602 }
1603 }
1604
c5e9c988 1605 logevent("Authentication successful");
1606
fb09bf1c 1607 crFinish(1);
1608}
1609
e5574168 1610static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1611 crBegin;
1612
1613 random_init();
1614
e5574168 1615 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1616 crReturnV;
85ee8208 1617 }
1618 if (ssh_state == SSH_STATE_CLOSED)
1619 crReturnV;
fb09bf1c 1620
979310f1 1621 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1622 logevent("Requesting agent forwarding");
1623 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1624 do { crReturnV; } while (!ispkt);
1625 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1626 bombout(("Protocol confusion"));
1627 crReturnV;
dacbd0e8 1628 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1629 logevent("Agent forwarding refused");
1630 } else
1631 logevent("Agent forwarding enabled");
1632 }
1633
fef97f43 1634 if (!cfg.nopty) {
e5574168 1635 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1636 PKT_STR, cfg.termtype,
1637 PKT_INT, rows, PKT_INT, cols,
1638 PKT_INT, 0, PKT_INT, 0,
1639 PKT_CHAR, 0,
1640 PKT_END);
fef97f43 1641 ssh_state = SSH_STATE_INTERMED;
1642 do { crReturnV; } while (!ispkt);
e5574168 1643 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1644 bombout(("Protocol confusion"));
1645 crReturnV;
e5574168 1646 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1647 c_write("Server refused to allocate pty\r\n", 32);
1648 }
c5e9c988 1649 logevent("Allocated pty");
374330e2 1650 }
1651
6abbf9e3 1652 if (*cfg.remote_cmd)
1653 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1654 else
1655 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1656 logevent("Started session");
374330e2 1657
1658 ssh_state = SSH_STATE_SESSION;
1659 if (size_needed)
1660 ssh_size();
1661
8ccc75b0 1662 ssh_send_ok = 1;
dacbd0e8 1663 ssh_channels = newtree234(ssh_channelcmp);
6f34e365 1664 begin_session();
374330e2 1665 while (1) {
1666 crReturnV;
1667 if (ispkt) {
e5574168 1668 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1669 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1670 long len = GET_32BIT(pktin.body);
fe50e814 1671 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1672 pktin.body+4, len);
e5574168 1673 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1674 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1675 logevent("Received disconnect request");
dacbd0e8 1676 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1677 /* Remote side is trying to open a channel to talk to our
1678 * agent. Give them back a local channel number. */
d211621f 1679 unsigned i = 1;
dacbd0e8 1680 struct ssh_channel *c;
1681 enum234 e;
1682 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1683 if (c->localid > i)
1684 break; /* found a free number */
1685 i = c->localid + 1;
1686 }
1687 c = malloc(sizeof(struct ssh_channel));
1688 c->remoteid = GET_32BIT(pktin.body);
1689 c->localid = i;
b8bb811a 1690 c->closes = 0;
dacbd0e8 1691 c->type = SSH1_SMSG_AGENT_OPEN; /* identify channel type */
bb487ce2 1692 c->u.a.lensofar = 0;
dacbd0e8 1693 add234(ssh_channels, c);
1694 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1695 PKT_INT, c->remoteid, PKT_INT, c->localid,
1696 PKT_END);
1697 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1698 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1699 /* Remote side closes a channel. */
d211621f 1700 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1701 struct ssh_channel *c;
1702 c = find234(ssh_channels, &i, ssh_channelfind);
1703 if (c) {
1704 int closetype;
1705 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1706 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1707 c->closes |= closetype;
1708 if (c->closes == 3) {
1709 del234(ssh_channels, c);
1710 free(c);
1711 }
1712 }
1713 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1714 /* Data sent down one of our channels. */
1715 int i = GET_32BIT(pktin.body);
1716 int len = GET_32BIT(pktin.body+4);
1717 unsigned char *p = pktin.body+8;
1718 struct ssh_channel *c;
1719 c = find234(ssh_channels, &i, ssh_channelfind);
1720 if (c) {
1721 switch(c->type) {
1722 case SSH1_SMSG_AGENT_OPEN:
1723 /* Data for an agent message. Buffer it. */
1724 while (len > 0) {
1725 if (c->u.a.lensofar < 4) {
1726 int l = min(4 - c->u.a.lensofar, len);
1727 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
1728 p += l; len -= l; c->u.a.lensofar += l;
1729 }
1730 if (c->u.a.lensofar == 4) {
1731 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
1732 c->u.a.message = malloc(c->u.a.totallen);
1733 memcpy(c->u.a.message, c->u.a.msglen, 4);
1734 }
1735 if (c->u.a.lensofar >= 4 && len > 0) {
1736 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
1737 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
1738 p += l; len -= l; c->u.a.lensofar += l;
1739 }
1740 if (c->u.a.lensofar == c->u.a.totallen) {
1741 void *reply, *sentreply;
1742 int replylen;
1743 agent_query(c->u.a.message, c->u.a.totallen,
1744 &reply, &replylen);
1745 if (reply)
1746 sentreply = reply;
1747 else {
1748 /* Fake SSH_AGENT_FAILURE. */
1749 sentreply = "\0\0\0\1\5";
1750 replylen = 5;
1751 }
1752 send_packet(SSH1_MSG_CHANNEL_DATA,
1753 PKT_INT, c->remoteid,
1754 PKT_INT, replylen,
1755 PKT_DATA, sentreply, replylen,
1756 PKT_END);
1757 if (reply)
1758 free(reply);
1759 free(c->u.a.message);
1760 c->u.a.lensofar = 0;
1761 }
1762 }
1763 break;
1764 }
1765 }
e5574168 1766 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 1767 /* may be from EXEC_SHELL on some servers */
e5574168 1768 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 1769 /* may be from EXEC_SHELL on some servers
374330e2 1770 * if no pty is available or in other odd cases. Ignore */
e5574168 1771 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1772 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 1773 } else {
8d5de777 1774 bombout(("Strange packet received: type %d", pktin.type));
1775 crReturnV;
374330e2 1776 }
1777 } else {
e5574168 1778 send_packet(SSH1_CMSG_STDIN_DATA,
fb09bf1c 1779 PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
374330e2 1780 }
1781 }
1782
1783 crFinishV;
1784}
1785
1786/*
e5574168 1787 * Utility routine for decoding comma-separated strings in KEXINIT.
1788 */
75cab814 1789static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 1790 int needlen = strlen(needle);
1791 while (1) {
1792 /*
1793 * Is it at the start of the string?
1794 */
1795 if (haylen >= needlen && /* haystack is long enough */
1796 !memcmp(needle, haystack, needlen) && /* initial match */
1797 (haylen == needlen || haystack[needlen] == ',')
1798 /* either , or EOS follows */
1799 )
1800 return 1;
1801 /*
1802 * If not, search for the next comma and resume after that.
1803 * If no comma found, terminate.
1804 */
1805 while (haylen > 0 && *haystack != ',')
1806 haylen--, haystack++;
1807 if (haylen == 0)
1808 return 0;
1809 haylen--, haystack++; /* skip over comma itself */
1810 }
1811}
1812
1813/*
d39f364a 1814 * SSH2 key creation method.
1815 */
75cab814 1816static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
d39f364a 1817 SHA_State s;
1818 /* First 20 bytes. */
1819 SHA_Init(&s);
1820 sha_mpint(&s, K);
1821 SHA_Bytes(&s, H, 20);
1822 SHA_Bytes(&s, &chr, 1);
1823 SHA_Bytes(&s, H, 20);
1824 SHA_Final(&s, keyspace);
1825 /* Next 20 bytes. */
1826 SHA_Init(&s);
1827 sha_mpint(&s, K);
1828 SHA_Bytes(&s, H, 20);
1829 SHA_Bytes(&s, keyspace, 20);
1830 SHA_Final(&s, keyspace+20);
1831}
1832
1833/*
7cca0d81 1834 * Handle the SSH2 transport layer.
e5574168 1835 */
7cca0d81 1836static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 1837{
1838 static int i, len;
1839 static char *str;
1840 static Bignum e, f, K;
7591b9ff 1841 static const struct ssh_mac **maclist;
8b2715b2 1842 static int nmacs;
57476f6b 1843 static const struct ssh_cipher *cscipher_tobe = NULL;
1844 static const struct ssh_cipher *sccipher_tobe = NULL;
1845 static const struct ssh_mac *csmac_tobe = NULL;
1846 static const struct ssh_mac *scmac_tobe = NULL;
1847 static const struct ssh_compress *cscomp_tobe = NULL;
1848 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 1849 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 1850 static int hostkeylen, siglen;
1851 static unsigned char exchange_hash[20];
d39f364a 1852 static unsigned char keyspace[40];
57476f6b 1853 static const struct ssh_cipher *preferred_cipher;
e5574168 1854
1855 crBegin;
7cca0d81 1856 random_init();
e5574168 1857
5e8358ad 1858 /*
1859 * Set up the preferred cipher.
1860 */
1861 if (cfg.cipher == CIPHER_BLOWFISH) {
57476f6b 1862 preferred_cipher = &ssh_blowfish_ssh2;
5e8358ad 1863 } else if (cfg.cipher == CIPHER_DES) {
1864 logevent("Single DES not supported in SSH2; using 3DES");
57476f6b 1865 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1866 } else if (cfg.cipher == CIPHER_3DES) {
57476f6b 1867 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1868 } else {
1869 /* Shouldn't happen, but we do want to initialise to _something_. */
57476f6b 1870 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1871 }
1872
7591b9ff 1873 /*
1874 * Be prepared to work around the buggy MAC problem.
1875 */
1876 if (cfg.buggymac)
8b2715b2 1877 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 1878 else
8b2715b2 1879 maclist = macs, nmacs = lenof(macs);
7591b9ff 1880
7cca0d81 1881 begin_key_exchange:
e5574168 1882 /*
1883 * Construct and send our key exchange packet.
1884 */
1885 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1886 for (i = 0; i < 16; i++)
1887 ssh2_pkt_addbyte((unsigned char)random_byte());
1888 /* List key exchange algorithms. */
1889 ssh2_pkt_addstring_start();
1890 for (i = 0; i < lenof(kex_algs); i++) {
1891 ssh2_pkt_addstring_str(kex_algs[i]->name);
1892 if (i < lenof(kex_algs)-1)
1893 ssh2_pkt_addstring_str(",");
1894 }
1895 /* List server host key algorithms. */
1896 ssh2_pkt_addstring_start();
1897 for (i = 0; i < lenof(hostkey_algs); i++) {
1898 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1899 if (i < lenof(hostkey_algs)-1)
1900 ssh2_pkt_addstring_str(",");
1901 }
1902 /* List client->server encryption algorithms. */
1903 ssh2_pkt_addstring_start();
729e54b4 1904 for (i = 0; i < lenof(ciphers)+1; i++) {
1905 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1906 ssh2_pkt_addstring_str(c->name);
729e54b4 1907 if (i < lenof(ciphers))
e5574168 1908 ssh2_pkt_addstring_str(",");
1909 }
1910 /* List server->client encryption algorithms. */
1911 ssh2_pkt_addstring_start();
729e54b4 1912 for (i = 0; i < lenof(ciphers)+1; i++) {
1913 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1914 ssh2_pkt_addstring_str(c->name);
729e54b4 1915 if (i < lenof(ciphers))
e5574168 1916 ssh2_pkt_addstring_str(",");
1917 }
1918 /* List client->server MAC algorithms. */
1919 ssh2_pkt_addstring_start();
8b2715b2 1920 for (i = 0; i < nmacs; i++) {
7591b9ff 1921 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 1922 if (i < nmacs-1)
e5574168 1923 ssh2_pkt_addstring_str(",");
1924 }
1925 /* List server->client MAC algorithms. */
1926 ssh2_pkt_addstring_start();
8b2715b2 1927 for (i = 0; i < nmacs; i++) {
7591b9ff 1928 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 1929 if (i < nmacs-1)
e5574168 1930 ssh2_pkt_addstring_str(",");
1931 }
1932 /* List client->server compression algorithms. */
1933 ssh2_pkt_addstring_start();
1934 for (i = 0; i < lenof(compressions); i++) {
1935 ssh2_pkt_addstring_str(compressions[i]->name);
1936 if (i < lenof(compressions)-1)
1937 ssh2_pkt_addstring_str(",");
1938 }
1939 /* List server->client compression algorithms. */
1940 ssh2_pkt_addstring_start();
1941 for (i = 0; i < lenof(compressions); i++) {
1942 ssh2_pkt_addstring_str(compressions[i]->name);
1943 if (i < lenof(compressions)-1)
1944 ssh2_pkt_addstring_str(",");
1945 }
1946 /* List client->server languages. Empty list. */
1947 ssh2_pkt_addstring_start();
1948 /* List server->client languages. Empty list. */
1949 ssh2_pkt_addstring_start();
1950 /* First KEX packet does _not_ follow, because we're not that brave. */
1951 ssh2_pkt_addbool(FALSE);
1952 /* Reserved. */
1953 ssh2_pkt_adduint32(0);
1954 sha_string(&exhash, pktout.data+5, pktout.length-5);
1955 ssh2_pkt_send();
1956
1957 if (!ispkt) crWaitUntil(ispkt);
1958 sha_string(&exhash, pktin.data+5, pktin.length-5);
1959
1960 /*
1961 * Now examine the other side's KEXINIT to see what we're up
1962 * to.
1963 */
7cca0d81 1964 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 1965 bombout(("expected key exchange packet from server"));
1966 crReturn(0);
7cca0d81 1967 }
e5574168 1968 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1969 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1970 pktin.savedpos += 16; /* skip garbage cookie */
1971 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1972 for (i = 0; i < lenof(kex_algs); i++) {
1973 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1974 kex = kex_algs[i];
1975 break;
1976 }
1977 }
1978 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1979 for (i = 0; i < lenof(hostkey_algs); i++) {
1980 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1981 hostkey = hostkey_algs[i];
1982 break;
1983 }
1984 }
1985 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 1986 for (i = 0; i < lenof(ciphers)+1; i++) {
1987 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1988 if (in_commasep_string(c->name, str, len)) {
729e54b4 1989 cscipher_tobe = c;
e5574168 1990 break;
1991 }
1992 }
1993 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
729e54b4 1994 for (i = 0; i < lenof(ciphers)+1; i++) {
1995 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1996 if (in_commasep_string(c->name, str, len)) {
729e54b4 1997 sccipher_tobe = c;
e5574168 1998 break;
1999 }
2000 }
2001 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 2002 for (i = 0; i < nmacs; i++) {
7591b9ff 2003 if (in_commasep_string(maclist[i]->name, str, len)) {
2004 csmac_tobe = maclist[i];
e5574168 2005 break;
2006 }
2007 }
2008 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 2009 for (i = 0; i < nmacs; i++) {
7591b9ff 2010 if (in_commasep_string(maclist[i]->name, str, len)) {
2011 scmac_tobe = maclist[i];
e5574168 2012 break;
2013 }
2014 }
2015 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2016 for (i = 0; i < lenof(compressions); i++) {
2017 if (in_commasep_string(compressions[i]->name, str, len)) {
2018 cscomp_tobe = compressions[i];
2019 break;
2020 }
2021 }
2022 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2023 for (i = 0; i < lenof(compressions); i++) {
2024 if (in_commasep_string(compressions[i]->name, str, len)) {
2025 sccomp_tobe = compressions[i];
2026 break;
2027 }
2028 }
e5574168 2029
2030 /*
2031 * Currently we only support Diffie-Hellman and DSS, so let's
2032 * bomb out if those aren't selected.
2033 */
8d5de777 2034 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2035 bombout(("internal fault: chaos in SSH 2 transport layer"));
2036 crReturn(0);
2037 }
e5574168 2038
2039 /*
2040 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2041 */
2042 e = dh_create_e();
e5574168 2043 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2044 ssh2_pkt_addmp(e);
2045 ssh2_pkt_send();
2046
2047 crWaitUntil(ispkt);
7cca0d81 2048 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2049 bombout(("expected key exchange packet from server"));
2050 crReturn(0);
7cca0d81 2051 }
e5574168 2052 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2053 f = ssh2_pkt_getmp();
e5574168 2054 ssh2_pkt_getstring(&sigdata, &siglen);
2055
2056 K = dh_find_K(f);
e5574168 2057
2058 sha_string(&exhash, hostkeydata, hostkeylen);
2059 sha_mpint(&exhash, e);
2060 sha_mpint(&exhash, f);
2061 sha_mpint(&exhash, K);
2062 SHA_Final(&exhash, exchange_hash);
2063
7cca0d81 2064#if 0
e5574168 2065 debug(("Exchange hash is:\r\n"));
2066 for (i = 0; i < 20; i++)
2067 debug((" %02x", exchange_hash[i]));
2068 debug(("\r\n"));
7cca0d81 2069#endif
2070
2071 hostkey->setkey(hostkeydata, hostkeylen);
8d5de777 2072 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20)) {
2073 bombout(("Server failed host key check"));
2074 crReturn(0);
2075 }
e5574168 2076
2077 /*
7cca0d81 2078 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2079 */
7cca0d81 2080 crWaitUntil(ispkt);
8d5de777 2081 if (pktin.type != SSH2_MSG_NEWKEYS) {
2082 bombout(("expected new-keys packet from server"));
2083 crReturn(0);
2084 }
d39f364a 2085
2086 /*
7cca0d81 2087 * Authenticate remote host: verify host key. (We've already
2088 * checked the signature of the exchange hash.)
e5574168 2089 */
7cca0d81 2090 keystr = hostkey->fmtkey();
d5859615 2091 fingerprint = hostkey->fingerprint();
d4857987 2092 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2093 keystr, fingerprint);
d5859615 2094 logevent("Host key fingerprint is:");
2095 logevent(fingerprint);
2096 free(fingerprint);
7cca0d81 2097 free(keystr);
d39f364a 2098
2099 /*
7cca0d81 2100 * Send SSH2_MSG_NEWKEYS.
d39f364a 2101 */
2102 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2103 ssh2_pkt_send();
d39f364a 2104
2105 /*
2106 * Create and initialise session keys.
2107 */
2108 cscipher = cscipher_tobe;
2109 sccipher = sccipher_tobe;
2110 csmac = csmac_tobe;
2111 scmac = scmac_tobe;
2112 cscomp = cscomp_tobe;
2113 sccomp = sccomp_tobe;
2114 /*
2115 * Set IVs after keys.
2116 */
2117 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
2118 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
2119 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2120 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2121 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2122 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2123
033b4cef 2124 /*
7cca0d81 2125 * Now we're encrypting. Begin returning 1 to the protocol main
2126 * function so that other things can run on top of the
2127 * transport. If we ever see a KEXINIT, we must go back to the
2128 * start.
033b4cef 2129 */
7cca0d81 2130 do {
2131 crReturn(1);
2132 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2133 goto begin_key_exchange;
e5574168 2134
2135 crFinish(1);
2136}
2137
7cca0d81 2138/*
2139 * Handle the SSH2 userauth and connection layers.
2140 */
2141static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2142{
7cca0d81 2143 static unsigned long remote_winsize;
2144 static unsigned long remote_maxpkt;
2145
e5574168 2146 crBegin;
2147
7cca0d81 2148 /*
2149 * Request userauth protocol, and await a response to it.
2150 */
2151 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2152 ssh2_pkt_addstring("ssh-userauth");
2153 ssh2_pkt_send();
2154 crWaitUntilV(ispkt);
8d5de777 2155 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2156 bombout(("Server refused user authentication protocol"));
2157 crReturnV;
2158 }
7cca0d81 2159
2160 /*
2161 * FIXME: currently we support only password authentication.
2162 * (This places us technically in violation of the SSH2 spec.
2163 * We must fix this.)
2164 */
2165 while (1) {
2166 /*
2167 * Get a username and a password.
2168 */
2169 static char username[100];
2170 static char password[100];
2171 static int pos = 0;
2172 static char c;
e5574168 2173
67779be7 2174 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2175 c_write("login as: ", 10);
67779be7 2176 ssh_send_ok = 1;
7cca0d81 2177 while (pos >= 0) {
2178 crWaitUntilV(!ispkt);
2179 while (inlen--) switch (c = *in++) {
2180 case 10: case 13:
2181 username[pos] = 0;
2182 pos = -1;
2183 break;
2184 case 8: case 127:
2185 if (pos > 0) {
2186 c_write("\b \b", 3);
2187 pos--;
2188 }
2189 break;
2190 case 21: case 27:
2191 while (pos > 0) {
2192 c_write("\b \b", 3);
2193 pos--;
2194 }
2195 break;
2196 case 3: case 4:
2197 random_save_seed();
2198 exit(0);
2199 break;
2200 default:
2201 if (((c >= ' ' && c <= '~') ||
2202 ((unsigned char)c >= 160)) && pos < 40) {
2203 username[pos++] = c;
2204 c_write(&c, 1);
2205 }
2206 break;
2207 }
2208 }
2209 c_write("\r\n", 2);
2210 username[strcspn(username, "\n\r")] = '\0';
2211 } else {
2212 char stuff[200];
2213 strncpy(username, cfg.username, 99);
2214 username[99] = '\0';
67779be7 2215 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2216 sprintf(stuff, "Using username \"%s\".\r\n", username);
2217 c_write(stuff, strlen(stuff));
2218 }
2219 }
2220
d8426c54 2221 if (ssh_get_password) {
7cca0d81 2222 char prompt[200];
b585ec46 2223 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
7cca0d81 2224 if (!ssh_get_password(prompt, password, sizeof(password))) {
2225 /*
2226 * get_password failed to get a password (for
2227 * example because one was supplied on the command
2228 * line which has already failed to work).
2229 * Terminate.
2230 */
2231 logevent("No more passwords to try");
2232 ssh_state = SSH_STATE_CLOSED;
2233 crReturnV;
2234 }
2235 } else {
2236 c_write("password: ", 10);
67779be7 2237 ssh_send_ok = 1;
7cca0d81 2238
2239 pos = 0;
2240 while (pos >= 0) {
2241 crWaitUntilV(!ispkt);
2242 while (inlen--) switch (c = *in++) {
2243 case 10: case 13:
2244 password[pos] = 0;
2245 pos = -1;
2246 break;
2247 case 8: case 127:
2248 if (pos > 0)
2249 pos--;
2250 break;
2251 case 21: case 27:
2252 pos = 0;
2253 break;
2254 case 3: case 4:
2255 random_save_seed();
2256 exit(0);
2257 break;
2258 default:
2259 if (((c >= ' ' && c <= '~') ||
2260 ((unsigned char)c >= 160)) && pos < 40)
2261 password[pos++] = c;
2262 break;
2263 }
2264 }
2265 c_write("\r\n", 2);
2266 }
2267
2268 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2269 ssh2_pkt_addstring(username);
2270 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2271 ssh2_pkt_addstring("password");
2272 ssh2_pkt_addbool(FALSE);
2273 ssh2_pkt_addstring(password);
2274 ssh2_pkt_send();
2275
2276 crWaitUntilV(ispkt);
2277 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2278 c_write("Access denied\r\n", 15);
2279 logevent("Authentication refused");
2280 } else
2281 break;
2282 }
2283
2284 /*
2285 * Now we're authenticated for the connection protocol. The
2286 * connection protocol will automatically have started at this
2287 * point; there's no need to send SERVICE_REQUEST.
2288 */
2289
2290 /*
2291 * So now create a channel with a session in it.
2292 */
d211621f 2293 mainchan = malloc(sizeof(struct ssh_channel));
2294 mainchan->localid = 100; /* as good as any */
7cca0d81 2295 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2296 ssh2_pkt_addstring("session");
d211621f 2297 ssh2_pkt_adduint32(mainchan->localid);
cf6e59d6 2298 ssh2_pkt_adduint32(0x8000UL); /* our window size */
d211621f 2299 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2300 ssh2_pkt_send();
2301 crWaitUntilV(ispkt);
2302 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2303 bombout(("Server refused to open a session"));
2304 crReturnV;
7cca0d81 2305 /* FIXME: error data comes back in FAILURE packet */
2306 }
d211621f 2307 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2308 bombout(("Server's channel confirmation cited wrong channel"));
2309 crReturnV;
7cca0d81 2310 }
d211621f 2311 mainchan->remoteid = ssh2_pkt_getuint32();
2312 mainchan->u.v2.remwindow = ssh2_pkt_getuint32();
2313 mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32();
2314 mainchan->u.v2.outbuffer = NULL;
2315 mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0;
7cca0d81 2316 logevent("Opened channel for session");
2317
2318 /*
2319 * Now allocate a pty for the session.
2320 */
67779be7 2321 if (!cfg.nopty) {
2322 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2323 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2324 ssh2_pkt_addstring("pty-req");
2325 ssh2_pkt_addbool(1); /* want reply */
2326 ssh2_pkt_addstring(cfg.termtype);
2327 ssh2_pkt_adduint32(cols);
2328 ssh2_pkt_adduint32(rows);
2329 ssh2_pkt_adduint32(0); /* pixel width */
2330 ssh2_pkt_adduint32(0); /* pixel height */
2331 ssh2_pkt_addstring_start();
2332 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2333 ssh2_pkt_send();
7cca0d81 2334
67779be7 2335 do {
2336 crWaitUntilV(ispkt);
2337 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2338 /* FIXME: be able to handle other channels here */
2339 if (ssh2_pkt_getuint32() != mainchan->localid)
2340 continue; /* wrong channel */
2341 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2342 }
2343 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2344
67779be7 2345 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2346 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2347 bombout(("Server got confused by pty request"));
2348 crReturnV;
67779be7 2349 }
2350 c_write("Server refused to allocate pty\r\n", 32);
2351 } else {
2352 logevent("Allocated pty");
7cca0d81 2353 }
7cca0d81 2354 }
2355
2356 /*
67779be7 2357 * Start a shell or a remote command.
7cca0d81 2358 */
2359 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2360 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2361 if (*cfg.remote_cmd) {
2362 ssh2_pkt_addstring("exec");
2363 ssh2_pkt_addbool(1); /* want reply */
2364 ssh2_pkt_addstring(cfg.remote_cmd);
2365 } else {
2366 ssh2_pkt_addstring("shell");
2367 ssh2_pkt_addbool(1); /* want reply */
2368 }
7cca0d81 2369 ssh2_pkt_send();
d211621f 2370 do {
7cca0d81 2371 crWaitUntilV(ispkt);
d211621f 2372 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2373 /* FIXME: be able to handle other channels here */
2374 if (ssh2_pkt_getuint32() != mainchan->localid)
2375 continue; /* wrong channel */
2376 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2377 }
7cca0d81 2378 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2379 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2380 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2381 bombout(("Server got confused by shell/command request"));
2382 crReturnV;
7cca0d81 2383 }
8d5de777 2384 bombout(("Server refused to start a shell/command"));
2385 crReturnV;
7cca0d81 2386 } else {
8d5de777 2387 logevent("Started a shell/command");
7cca0d81 2388 }
2389
2390 /*
2391 * Transfer data!
2392 */
8ccc75b0 2393 ssh_send_ok = 1;
6f34e365 2394 begin_session();
7cca0d81 2395 while (1) {
d211621f 2396 static int try_send;
e5574168 2397 crReturnV;
d211621f 2398 try_send = FALSE;
7cca0d81 2399 if (ispkt) {
2400 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2401 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2402 char *data;
2403 int length;
d211621f 2404 /* FIXME: be able to handle other channels here */
2405 if (ssh2_pkt_getuint32() != mainchan->localid)
7cca0d81 2406 continue; /* wrong channel */
2407 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2408 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2409 continue; /* extended but not stderr */
2410 ssh2_pkt_getstring(&data, &length);
d211621f 2411 if (data) {
fe50e814 2412 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
2413 data, length);
d211621f 2414 /*
2415 * Enlarge the window again at the remote side,
2416 * just in case it ever runs down and they fail
2417 * to send us any more data.
2418 */
2419 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2420 ssh2_pkt_adduint32(mainchan->remoteid);
2421 ssh2_pkt_adduint32(length);
2422 ssh2_pkt_send();
2423 }
7cca0d81 2424 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2425 ssh_state = SSH_STATE_CLOSED;
d211621f 2426 logevent("Received disconnect message");
7cca0d81 2427 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2428 continue; /* exit status et al; ignore (FIXME?) */
d211621f 2429 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2430 continue; /* remote sends EOF; ignore */
2431 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
2432 /* FIXME: be able to handle other channels here */
2433 if (ssh2_pkt_getuint32() != mainchan->localid)
2434 continue; /* wrong channel */
2435 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2436 ssh2_pkt_adduint32(mainchan->remoteid);
2437 ssh2_pkt_send();
2438 /* FIXME: mark the channel as closed */
2439 if (1 /* FIXME: "all channels are closed" */) {
2440 logevent("All channels closed. Disconnecting");
2441 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2442 ssh2_pkt_send();
cf6e59d6 2443 ssh_state = SSH_STATE_CLOSED;
2444 closesocket(s);
2445 s = INVALID_SOCKET;
d211621f 2446 }
2447 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2448 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
d211621f 2449 /* FIXME: be able to handle other channels here */
2450 if (ssh2_pkt_getuint32() != mainchan->localid)
2451 continue; /* wrong channel */
2452 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2453 try_send = TRUE;
7cca0d81 2454 } else {
8d5de777 2455 bombout(("Strange packet received: type %d", pktin.type));
2456 crReturnV;
7cca0d81 2457 }
2458 } else {
d211621f 2459 /*
2460 * We have spare data. Add it to the channel buffer.
2461 */
2462 if (mainchan->u.v2.outbufsize <
2463 mainchan->u.v2.outbuflen + inlen) {
2464 mainchan->u.v2.outbufsize =
2465 mainchan->u.v2.outbuflen + inlen + 1024;
2466 mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer,
2467 mainchan->u.v2.outbufsize);
2468 }
2469 memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen,
2470 in, inlen);
2471 mainchan->u.v2.outbuflen += inlen;
2472 try_send = TRUE;
7cca0d81 2473 }
d211621f 2474 if (try_send) {
2475 /*
2476 * Try to send data on the channel if we can. (FIXME:
2477 * on _all_ channels.)
2478 */
2479 while (mainchan->u.v2.remwindow > 0 &&
2480 mainchan->u.v2.outbuflen > 0) {
2481 unsigned len = mainchan->u.v2.remwindow;
2482 if (len > mainchan->u.v2.outbuflen)
2483 len = mainchan->u.v2.outbuflen;
2484 if (len > mainchan->u.v2.remmaxpkt)
2485 len = mainchan->u.v2.remmaxpkt;
2486 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2487 ssh2_pkt_adduint32(mainchan->remoteid);
2488 ssh2_pkt_addstring_start();
2489 ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len);
2490 ssh2_pkt_send();
2491 mainchan->u.v2.outbuflen -= len;
2492 memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len,
2493 mainchan->u.v2.outbuflen);
2494 mainchan->u.v2.remwindow -= len;
2495 }
2496 }
e5574168 2497 }
2498
2499 crFinishV;
2500}
2501
2502/*
7cca0d81 2503 * Handle the top-level SSH2 protocol.
2504 */
2505static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2506{
2507 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2508 return;
2509 do_ssh2_authconn(in, inlen, ispkt);
2510}
2511
2512/*
374330e2 2513 * Called to set up the connection. Will arrange for WM_NETEVENT
2514 * messages to be passed to the specified window, whose window
2515 * procedure should then call telnet_msg().
2516 *
2517 * Returns an error message, or NULL on success.
374330e2 2518 */
2519static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
fb09bf1c 2520 char *p;
8f203108 2521
2522#ifdef MSCRYPTOAPI
2523 if(crypto_startup() == 0)
2524 return "Microsoft high encryption pack not installed!";
2525#endif
374330e2 2526
fb09bf1c 2527 p = connect_to_host(host, port, realhost);
2528 if (p != NULL)
2529 return p;
374330e2 2530
2531 if (!do_ssh_init())
2532 return "Protocol initialisation error";
2533
4017be6d 2534 if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
374330e2 2535 switch (WSAGetLastError()) {
2536 case WSAENETDOWN: return "Network is down";
2537 default: return "WSAAsyncSelect(): unknown error";
2538 }
2539
2540 return NULL;
2541}
2542
2543/*
2544 * Process a WM_NETEVENT message. Will return 0 if the connection
2545 * has closed, or <0 for a socket error.
2546 */
2547static int ssh_msg (WPARAM wParam, LPARAM lParam) {
2548 int ret;
2549 char buf[256];
2550
8ce72d2c 2551 /*
2552 * Because reading less than the whole of the available pending
2553 * data can generate an FD_READ event, we need to allow for the
2554 * possibility that FD_READ may arrive with FD_CLOSE already in
2555 * the queue; so it's possible that we can get here even with s
2556 * invalid. If so, we return 1 and don't worry about it.
2557 */
2558 if (s == INVALID_SOCKET)
2559 return 1;
374330e2 2560
8d5de777 2561 if (WSAGETSELECTERROR(lParam) != 0) {
2562 closesocket(s);
2563 s = INVALID_SOCKET;
374330e2 2564 return -WSAGETSELECTERROR(lParam);
8d5de777 2565 }
374330e2 2566
2567 switch (WSAGETSELECTEVENT(lParam)) {
2568 case FD_READ:
8ce72d2c 2569 case FD_CLOSE:
374330e2 2570 ret = recv(s, buf, sizeof(buf), 0);
2571 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
2572 return 1;
8d5de777 2573 if (ret < 0) { /* any _other_ error */
2574 closesocket(s);
2575 s = INVALID_SOCKET;
374330e2 2576 return -10000-WSAGetLastError();
8d5de777 2577 }
374330e2 2578 if (ret == 0) {
2579 s = INVALID_SOCKET;
8ce72d2c 2580 return 0;
374330e2 2581 }
2582 ssh_gotdata (buf, ret);
85ee8208 2583 if (ssh_state == SSH_STATE_CLOSED) {
2584 closesocket(s);
2585 s = INVALID_SOCKET;
2586 return 0;
2587 }
374330e2 2588 return 1;
374330e2 2589 }
2590 return 1; /* shouldn't happen, but WTF */
2591}
2592
2593/*
2594 * Called to send data down the Telnet connection.
2595 */
2596static void ssh_send (char *buf, int len) {
2597 if (s == INVALID_SOCKET)
2598 return;
2599
2600 ssh_protocol(buf, len, 0);
2601}
2602
2603/*
2604 * Called to set the size of the window from Telnet's POV.
2605 */
2606static void ssh_size(void) {
2607 switch (ssh_state) {
2608 case SSH_STATE_BEFORE_SIZE:
21248260 2609 case SSH_STATE_CLOSED:
374330e2 2610 break; /* do nothing */
2611 case SSH_STATE_INTERMED:
2612 size_needed = TRUE; /* buffer for later */
2613 break;
2614 case SSH_STATE_SESSION:
fef97f43 2615 if (!cfg.nopty) {
e5574168 2616 send_packet(SSH1_CMSG_WINDOW_SIZE,
fb09bf1c 2617 PKT_INT, rows, PKT_INT, cols,
2618 PKT_INT, 0, PKT_INT, 0, PKT_END);
fef97f43 2619 }
374330e2 2620 }
2621}
2622
2623/*
6abbf9e3 2624 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2625 * can send an EOF and collect resulting output (e.g. `plink
2626 * hostname sort').
374330e2 2627 */
2628static void ssh_special (Telnet_Special code) {
6abbf9e3 2629 if (code == TS_EOF) {
67779be7 2630 if (ssh_version == 1) {
6abbf9e3 2631 send_packet(SSH1_CMSG_EOF, PKT_END);
2632 } else {
2633 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 2634 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 2635 ssh2_pkt_send();
2636 }
67779be7 2637 logevent("Sent EOF message");
ec55b220 2638 } else if (code == TS_PING) {
2639 if (ssh_version == 1) {
2640 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
2641 } else {
2642 ssh2_pkt_init(SSH2_MSG_IGNORE);
2643 ssh2_pkt_addstring_start();
2644 ssh2_pkt_send();
2645 }
6abbf9e3 2646 } else {
2647 /* do nothing */
2648 }
374330e2 2649}
2650
8ccc75b0 2651static SOCKET ssh_socket(void) { return s; }
2652
2653static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 2654
374330e2 2655Backend ssh_backend = {
2656 ssh_init,
2657 ssh_msg,
2658 ssh_send,
2659 ssh_size,
4017be6d 2660 ssh_special,
8ccc75b0 2661 ssh_socket,
97db3be4 2662 ssh_sendok,
2663 22
374330e2 2664};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator