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RSA key generation routines, and the bignum enhancements required to
[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 }
c9def1b8 325 while (len--)
326 c_write1(*buf++);
374330e2 327}
328
3bdaf79d 329static void c_writedata (char *buf, int len) {
330 while (len--)
331 c_write1(*buf++);
332}
333
fb09bf1c 334/*
335 * Collect incoming data in the incoming packet buffer.
e5574168 336 * Decipher and verify the packet when it is completely read.
337 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 338 * Update the *data and *datalen variables.
339 * Return the additional nr of bytes needed, or 0 when
340 * a complete packet is available.
341 */
e5574168 342static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 343{
57476f6b 344 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 345
346 crBegin;
374330e2 347
fb09bf1c 348next_packet:
37508af4 349
fb09bf1c 350 pktin.type = 0;
351 pktin.length = 0;
374330e2 352
57476f6b 353 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 354 while ((*datalen) == 0)
57476f6b 355 crReturn(4-st->i);
356 st->len = (st->len << 8) + **data;
fb09bf1c 357 (*data)++, (*datalen)--;
358 }
374330e2 359
fb09bf1c 360#ifdef FWHACK
57476f6b 361 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
362 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 363 }
364#endif
374330e2 365
57476f6b 366 st->pad = 8 - (st->len % 8);
367 st->biglen = st->len + st->pad;
368 pktin.length = st->len - 5;
fb09bf1c 369
57476f6b 370 if (pktin.maxlen < st->biglen) {
371 pktin.maxlen = st->biglen;
372 pktin.data = (pktin.data == NULL ? malloc(st->biglen+APIEXTRA) :
373 realloc(pktin.data, st->biglen+APIEXTRA));
fb09bf1c 374 if (!pktin.data)
375 fatalbox("Out of memory");
376 }
374330e2 377
57476f6b 378 st->to_read = st->biglen;
379 st->p = pktin.data;
380 while (st->to_read > 0) {
381 st->chunk = st->to_read;
fb09bf1c 382 while ((*datalen) == 0)
57476f6b 383 crReturn(st->to_read);
384 if (st->chunk > (*datalen))
385 st->chunk = (*datalen);
386 memcpy(st->p, *data, st->chunk);
387 *data += st->chunk;
388 *datalen -= st->chunk;
389 st->p += st->chunk;
390 st->to_read -= st->chunk;
fb09bf1c 391 }
374330e2 392
fb09bf1c 393 if (cipher)
57476f6b 394 cipher->decrypt(pktin.data, st->biglen);
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
602 if (cipher)
603 cipher->encrypt(pktout.data+4, biglen);
604
605 s_write(pktout.data, biglen+4);
606}
607
fb09bf1c 608/*
609 * Construct a packet with the specified contents and
610 * send it to the server.
611 */
612static void send_packet(int pkttype, ...)
613{
614 va_list args;
615 unsigned char *p, *argp, argchar;
616 unsigned long argint;
617 int pktlen, argtype, arglen;
7cca0d81 618 Bignum bn;
fb09bf1c 619
620 pktlen = 0;
621 va_start(args, pkttype);
622 while ((argtype = va_arg(args, int)) != PKT_END) {
623 switch (argtype) {
624 case PKT_INT:
625 (void) va_arg(args, int);
626 pktlen += 4;
627 break;
628 case PKT_CHAR:
629 (void) va_arg(args, char);
630 pktlen++;
631 break;
632 case PKT_DATA:
633 (void) va_arg(args, unsigned char *);
634 arglen = va_arg(args, int);
635 pktlen += arglen;
636 break;
637 case PKT_STR:
638 argp = va_arg(args, unsigned char *);
639 arglen = strlen(argp);
640 pktlen += 4 + arglen;
641 break;
7cca0d81 642 case PKT_BIGNUM:
643 bn = va_arg(args, Bignum);
5c58ad2d 644 pktlen += ssh1_bignum_length(bn);
7cca0d81 645 break;
fb09bf1c 646 default:
647 assert(0);
648 }
649 }
650 va_end(args);
651
652 s_wrpkt_start(pkttype, pktlen);
653 p = pktout.body;
654
655 va_start(args, pkttype);
656 while ((argtype = va_arg(args, int)) != PKT_END) {
657 switch (argtype) {
658 case PKT_INT:
659 argint = va_arg(args, int);
660 PUT_32BIT(p, argint);
661 p += 4;
662 break;
663 case PKT_CHAR:
664 argchar = va_arg(args, unsigned char);
665 *p = argchar;
666 p++;
667 break;
668 case PKT_DATA:
669 argp = va_arg(args, unsigned char *);
670 arglen = va_arg(args, int);
671 memcpy(p, argp, arglen);
672 p += arglen;
673 break;
674 case PKT_STR:
675 argp = va_arg(args, unsigned char *);
676 arglen = strlen(argp);
677 PUT_32BIT(p, arglen);
678 memcpy(p + 4, argp, arglen);
679 p += 4 + arglen;
680 break;
7cca0d81 681 case PKT_BIGNUM:
682 bn = va_arg(args, Bignum);
5c58ad2d 683 p += ssh1_write_bignum(p, bn);
7cca0d81 684 break;
fb09bf1c 685 }
686 }
687 va_end(args);
688
689 s_wrpkt();
690}
691
692
693/*
694 * Connect to specified host and port.
695 * Returns an error message, or NULL on success.
696 * Also places the canonical host name into `realhost'.
697 */
698static char *connect_to_host(char *host, int port, char **realhost)
699{
700 SOCKADDR_IN addr;
701 struct hostent *h;
702 unsigned long a;
703#ifdef FWHACK
704 char *FWhost;
705 int FWport;
706#endif
707
708 savedhost = malloc(1+strlen(host));
709 if (!savedhost)
710 fatalbox("Out of memory");
711 strcpy(savedhost, host);
712
713 if (port < 0)
714 port = 22; /* default ssh port */
d4857987 715 savedport = port;
fb09bf1c 716
717#ifdef FWHACK
718 FWhost = host;
719 FWport = port;
720 host = FWSTR;
721 port = 23;
722#endif
723
724 /*
725 * Try to find host.
726 */
727 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
728 if ( (h = gethostbyname(host)) == NULL)
729 switch (WSAGetLastError()) {
730 case WSAENETDOWN: return "Network is down";
731 case WSAHOST_NOT_FOUND: case WSANO_DATA:
732 return "Host does not exist";
733 case WSATRY_AGAIN: return "Host not found";
734 default: return "gethostbyname: unknown error";
735 }
736 memcpy (&a, h->h_addr, sizeof(a));
737 *realhost = h->h_name;
738 } else
739 *realhost = host;
740#ifdef FWHACK
741 *realhost = FWhost;
742#endif
743 a = ntohl(a);
744
745 /*
746 * Open socket.
747 */
748 s = socket(AF_INET, SOCK_STREAM, 0);
749 if (s == INVALID_SOCKET)
750 switch (WSAGetLastError()) {
751 case WSAENETDOWN: return "Network is down";
752 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
753 default: return "socket(): unknown error";
754 }
755
756 /*
757 * Bind to local address.
758 */
759 addr.sin_family = AF_INET;
760 addr.sin_addr.s_addr = htonl(INADDR_ANY);
761 addr.sin_port = htons(0);
762 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
763 switch (WSAGetLastError()) {
764 case WSAENETDOWN: return "Network is down";
765 default: return "bind(): unknown error";
766 }
767
768 /*
769 * Connect to remote address.
770 */
771 addr.sin_addr.s_addr = htonl(a);
772 addr.sin_port = htons((short)port);
773 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
774 switch (WSAGetLastError()) {
775 case WSAENETDOWN: return "Network is down";
776 case WSAECONNREFUSED: return "Connection refused";
777 case WSAENETUNREACH: return "Network is unreachable";
778 case WSAEHOSTUNREACH: return "No route to host";
779 default: return "connect(): unknown error";
780 }
781
782#ifdef FWHACK
783 send(s, "connect ", 8, 0);
784 send(s, FWhost, strlen(FWhost), 0);
785 {
786 char buf[20];
787 sprintf(buf, " %d\n", FWport);
788 send (s, buf, strlen(buf), 0);
789 }
790#endif
791
792 return NULL;
793}
794
9697bfd2 795static int ssh_versioncmp(char *a, char *b) {
796 char *ae, *be;
797 unsigned long av, bv;
798
43aa02a7 799 av = strtoul(a, &ae, 10);
800 bv = strtoul(b, &be, 10);
9697bfd2 801 if (av != bv) return (av < bv ? -1 : +1);
802 if (*ae == '.') ae++;
803 if (*be == '.') be++;
43aa02a7 804 av = strtoul(ae, &ae, 10);
805 bv = strtoul(be, &be, 10);
9697bfd2 806 if (av != bv) return (av < bv ? -1 : +1);
807 return 0;
808}
809
e5574168 810
811/*
812 * Utility routine for putting an SSH-protocol `string' into a SHA
813 * state.
814 */
815#include <stdio.h>
75cab814 816static void sha_string(SHA_State *s, void *str, int len) {
e5574168 817 unsigned char lenblk[4];
e5574168 818 PUT_32BIT(lenblk, len);
e5574168 819 SHA_Bytes(s, lenblk, 4);
e5574168 820 SHA_Bytes(s, str, len);
821}
822
7cca0d81 823/*
824 * SSH2 packet construction functions.
825 */
75cab814 826static void ssh2_pkt_adddata(void *data, int len) {
7cca0d81 827 pktout.length += len;
828 if (pktout.maxlen < pktout.length) {
829 pktout.maxlen = pktout.length + 256;
830 pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) :
831 realloc(pktout.data, pktout.maxlen+APIEXTRA));
832 if (!pktout.data)
833 fatalbox("Out of memory");
834 }
835 memcpy(pktout.data+pktout.length-len, data, len);
836}
75cab814 837static void ssh2_pkt_addbyte(unsigned char byte) {
7cca0d81 838 ssh2_pkt_adddata(&byte, 1);
839}
75cab814 840static void ssh2_pkt_init(int pkt_type) {
7cca0d81 841 pktout.length = 5;
842 ssh2_pkt_addbyte((unsigned char)pkt_type);
843}
75cab814 844static void ssh2_pkt_addbool(unsigned char value) {
7cca0d81 845 ssh2_pkt_adddata(&value, 1);
846}
75cab814 847static void ssh2_pkt_adduint32(unsigned long value) {
7cca0d81 848 unsigned char x[4];
849 PUT_32BIT(x, value);
850 ssh2_pkt_adddata(x, 4);
851}
75cab814 852static void ssh2_pkt_addstring_start(void) {
7cca0d81 853 ssh2_pkt_adduint32(0);
854 pktout.savedpos = pktout.length;
855}
75cab814 856static void ssh2_pkt_addstring_str(char *data) {
7cca0d81 857 ssh2_pkt_adddata(data, strlen(data));
858 PUT_32BIT(pktout.data + pktout.savedpos - 4,
859 pktout.length - pktout.savedpos);
860}
75cab814 861static void ssh2_pkt_addstring_data(char *data, int len) {
7cca0d81 862 ssh2_pkt_adddata(data, len);
863 PUT_32BIT(pktout.data + pktout.savedpos - 4,
864 pktout.length - pktout.savedpos);
865}
75cab814 866static void ssh2_pkt_addstring(char *data) {
7cca0d81 867 ssh2_pkt_addstring_start();
868 ssh2_pkt_addstring_str(data);
869}
75cab814 870static char *ssh2_mpint_fmt(Bignum b, int *len) {
7cca0d81 871 unsigned char *p;
872 int i, n = b[0];
873 p = malloc(n * 2 + 1);
874 if (!p)
875 fatalbox("out of memory");
876 p[0] = 0;
877 for (i = 0; i < n; i++) {
878 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
879 p[i*2+2] = (b[n-i] ) & 0xFF;
880 }
881 i = 0;
882 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
883 i++;
884 memmove(p, p+i, n*2+1-i);
885 *len = n*2+1-i;
886 return p;
887}
75cab814 888static void ssh2_pkt_addmp(Bignum b) {
7cca0d81 889 unsigned char *p;
890 int len;
891 p = ssh2_mpint_fmt(b, &len);
892 ssh2_pkt_addstring_start();
893 ssh2_pkt_addstring_data(p, len);
894 free(p);
895}
75cab814 896static void ssh2_pkt_send(void) {
7cca0d81 897 int cipherblk, maclen, padding, i;
898 static unsigned long outgoing_sequence = 0;
899
900 /*
901 * Add padding. At least four bytes, and must also bring total
902 * length (minus MAC) up to a multiple of the block size.
903 */
904 cipherblk = cipher ? cipher->blksize : 8; /* block size */
905 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
906 padding = 4;
907 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
908 pktout.data[4] = padding;
909 for (i = 0; i < padding; i++)
910 pktout.data[pktout.length + i] = random_byte();
911 PUT_32BIT(pktout.data, pktout.length + padding - 4);
912 if (csmac)
913 csmac->generate(pktout.data, pktout.length + padding,
914 outgoing_sequence);
915 outgoing_sequence++; /* whether or not we MACed */
916
917#if 0
918 debug(("Sending packet len=%d\r\n", pktout.length+padding));
919 for (i = 0; i < pktout.length+padding; i++)
920 debug((" %02x", (unsigned char)pktout.data[i]));
921 debug(("\r\n"));
922#endif
923
924 if (cscipher)
925 cscipher->encrypt(pktout.data, pktout.length + padding);
926 maclen = csmac ? csmac->len : 0;
927
928 s_write(pktout.data, pktout.length + padding + maclen);
929}
930
931#if 0
932void bndebug(char *string, Bignum b) {
933 unsigned char *p;
934 int i, len;
935 p = ssh2_mpint_fmt(b, &len);
936 debug(("%s", string));
937 for (i = 0; i < len; i++)
938 debug((" %02x", p[i]));
939 debug(("\r\n"));
940 free(p);
941}
942#endif
943
75cab814 944static void sha_mpint(SHA_State *s, Bignum b) {
7cca0d81 945 unsigned char *p;
946 int len;
947 p = ssh2_mpint_fmt(b, &len);
948 sha_string(s, p, len);
949 free(p);
950}
951
952/*
953 * SSH2 packet decode functions.
954 */
75cab814 955static unsigned long ssh2_pkt_getuint32(void) {
7cca0d81 956 unsigned long value;
957 if (pktin.length - pktin.savedpos < 4)
958 return 0; /* arrgh, no way to decline (FIXME?) */
959 value = GET_32BIT(pktin.data+pktin.savedpos);
960 pktin.savedpos += 4;
961 return value;
962}
75cab814 963static void ssh2_pkt_getstring(char **p, int *length) {
7cca0d81 964 *p = NULL;
965 if (pktin.length - pktin.savedpos < 4)
966 return;
967 *length = GET_32BIT(pktin.data+pktin.savedpos);
968 pktin.savedpos += 4;
969 if (pktin.length - pktin.savedpos < *length)
970 return;
971 *p = pktin.data+pktin.savedpos;
972 pktin.savedpos += *length;
973}
75cab814 974static Bignum ssh2_pkt_getmp(void) {
7cca0d81 975 char *p;
976 int i, j, length;
977 Bignum b;
978
979 ssh2_pkt_getstring(&p, &length);
980 if (!p)
981 return NULL;
8d5de777 982 if (p[0] & 0x80) {
983 bombout(("internal error: Can't handle negative mpints"));
984 return NULL;
985 }
7cca0d81 986 b = newbn((length+1)/2);
987 for (i = 0; i < length; i++) {
988 j = length - 1 - i;
989 if (j & 1)
990 b[j/2+1] |= ((unsigned char)p[i]) << 8;
991 else
992 b[j/2+1] |= ((unsigned char)p[i]);
993 }
994 return b;
995}
996
374330e2 997static int do_ssh_init(void) {
c5e9c988 998 char c, *vsp;
374330e2 999 char version[10];
c5e9c988 1000 char vstring[80];
1001 char vlog[sizeof(vstring)+20];
374330e2 1002 int i;
1003
1004#ifdef FWHACK
1005 i = 0;
1006 while (s_read(&c, 1) == 1) {
1007 if (c == 'S' && i < 2) i++;
1008 else if (c == 'S' && i == 2) i = 2;
1009 else if (c == 'H' && i == 2) break;
1010 else i = 0;
1011 }
1012#else
1013 if (s_read(&c,1) != 1 || c != 'S') return 0;
1014 if (s_read(&c,1) != 1 || c != 'S') return 0;
1015 if (s_read(&c,1) != 1 || c != 'H') return 0;
1016#endif
c5e9c988 1017 strcpy(vstring, "SSH-");
1018 vsp = vstring+4;
374330e2 1019 if (s_read(&c,1) != 1 || c != '-') return 0;
1020 i = 0;
1021 while (1) {
1022 if (s_read(&c,1) != 1)
1023 return 0;
c5e9c988 1024 if (vsp < vstring+sizeof(vstring)-1)
1025 *vsp++ = c;
374330e2 1026 if (i >= 0) {
1027 if (c == '-') {
1028 version[i] = '\0';
1029 i = -1;
1030 } else if (i < sizeof(version)-1)
1031 version[i++] = c;
1032 }
1033 else if (c == '\n')
1034 break;
1035 }
1036
960e736a 1037 rdpkt2_state.incoming_sequence = 0;
1038
c5e9c988 1039 *vsp = 0;
1040 sprintf(vlog, "Server version: %s", vstring);
1041 vlog[strcspn(vlog, "\r\n")] = '\0';
1042 logevent(vlog);
1043
adf799dd 1044 /*
1045 * Server version "1.99" means we can choose whether we use v1
1046 * or v2 protocol. Choice is based on cfg.sshprot.
1047 */
1048 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 1049 /*
1050 * This is a v2 server. Begin v2 protocol.
1051 */
1052 char *verstring = "SSH-2.0-PuTTY";
1053 SHA_Init(&exhash);
1054 /*
1055 * Hash our version string and their version string.
1056 */
1057 sha_string(&exhash, verstring, strlen(verstring));
1058 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
1059 sprintf(vstring, "%s\n", verstring);
1060 sprintf(vlog, "We claim version: %s", verstring);
1061 logevent(vlog);
1062 logevent("Using SSH protocol version 2");
1063 s_write(vstring, strlen(vstring));
1064 ssh_protocol = ssh2_protocol;
6abbf9e3 1065 ssh_version = 2;
e5574168 1066 s_rdpkt = ssh2_rdpkt;
1067 } else {
1068 /*
1069 * This is a v1 server. Begin v1 protocol.
1070 */
1071 sprintf(vstring, "SSH-%s-PuTTY\n",
1072 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1073 sprintf(vlog, "We claim version: %s", vstring);
1074 vlog[strcspn(vlog, "\r\n")] = '\0';
1075 logevent(vlog);
1076 logevent("Using SSH protocol version 1");
1077 s_write(vstring, strlen(vstring));
1078 ssh_protocol = ssh1_protocol;
6abbf9e3 1079 ssh_version = 1;
e5574168 1080 s_rdpkt = ssh1_rdpkt;
1081 }
8ccc75b0 1082 ssh_send_ok = 0;
fef97f43 1083 return 1;
374330e2 1084}
1085
fb09bf1c 1086/*
1087 * Handle the key exchange and user authentication phases.
1088 */
e5574168 1089static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1090{
374330e2 1091 int i, j, len;
374330e2 1092 unsigned char *rsabuf, *keystr1, *keystr2;
1093 unsigned char cookie[8];
1094 struct RSAKey servkey, hostkey;
1095 struct MD5Context md5c;
ccbfb941 1096 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1097 static int tried_publickey;
1098 static unsigned char session_id[16];
bea1ef5f 1099 int cipher_type;
b585ec46 1100 static char username[100];
374330e2 1101
374330e2 1102 crBegin;
1103
fb09bf1c 1104 if (!ispkt) crWaitUntil(ispkt);
374330e2 1105
8d5de777 1106 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1107 bombout(("Public key packet not received"));
1108 crReturn(0);
1109 }
374330e2 1110
c5e9c988 1111 logevent("Received public keys");
374330e2 1112
c5e9c988 1113 memcpy(cookie, pktin.body, 8);
374330e2 1114
7cca0d81 1115 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1116 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1117
c5e9c988 1118 /*
1c2a93c4 1119 * Log the host key fingerprint.
c5e9c988 1120 */
c5e9c988 1121 {
1122 char logmsg[80];
1c2a93c4 1123 logevent("Host key fingerprint is:");
c5e9c988 1124 strcpy(logmsg, " ");
1c2a93c4 1125 hostkey.comment = NULL;
1126 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1127 &hostkey);
c5e9c988 1128 logevent(logmsg);
1129 }
1130
fb09bf1c 1131 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1132 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1133
c5e9c988 1134 MD5Init(&md5c);
374330e2 1135 MD5Update(&md5c, keystr2, hostkey.bytes);
1136 MD5Update(&md5c, keystr1, servkey.bytes);
1137 MD5Update(&md5c, pktin.body, 8);
374330e2 1138 MD5Final(session_id, &md5c);
1139
1140 for (i=0; i<32; i++)
1141 session_key[i] = random_byte();
1142
1143 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1144
1145 rsabuf = malloc(len);
1146 if (!rsabuf)
1147 fatalbox("Out of memory");
1148
89ee5268 1149 /*
1150 * Verify the host key.
1151 */
1152 {
1153 /*
1154 * First format the key into a string.
1155 */
1156 int len = rsastr_len(&hostkey);
d5859615 1157 char fingerprint[100];
89ee5268 1158 char *keystr = malloc(len);
1159 if (!keystr)
1160 fatalbox("Out of memory");
1161 rsastr_fmt(keystr, &hostkey);
d5859615 1162 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1163 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
89ee5268 1164 free(keystr);
1165 }
374330e2 1166
1167 for (i=0; i<32; i++) {
1168 rsabuf[i] = session_key[i];
1169 if (i < 16)
1170 rsabuf[i] ^= session_id[i];
1171 }
1172
1173 if (hostkey.bytes > servkey.bytes) {
1174 rsaencrypt(rsabuf, 32, &servkey);
1175 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1176 } else {
1177 rsaencrypt(rsabuf, 32, &hostkey);
1178 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1179 }
1180
c5e9c988 1181 logevent("Encrypted session key");
1182
bea1ef5f 1183 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1184 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1185 SSH_CIPHER_3DES;
1186 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1187 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1188 cipher_type = SSH_CIPHER_3DES;
1189 }
c5e9c988 1190 switch (cipher_type) {
1191 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1192 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1193 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1194 }
bea1ef5f 1195
e5574168 1196 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1197 PKT_CHAR, cipher_type,
1198 PKT_DATA, cookie, 8,
1199 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1200 PKT_DATA, rsabuf, len,
1201 PKT_INT, 0,
1202 PKT_END);
1203
c5e9c988 1204 logevent("Trying to enable encryption...");
374330e2 1205
1206 free(rsabuf);
1207
5e8358ad 1208 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1209 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1210 &ssh_3des;
374330e2 1211 cipher->sesskey(session_key);
1212
fb09bf1c 1213 crWaitUntil(ispkt);
374330e2 1214
8d5de777 1215 if (pktin.type != SSH1_SMSG_SUCCESS) {
1216 bombout(("Encryption not successfully enabled"));
1217 crReturn(0);
1218 }
374330e2 1219
c5e9c988 1220 logevent("Successfully started encryption");
1221
374330e2 1222 fflush(stdout);
1223 {
374330e2 1224 static int pos = 0;
1225 static char c;
67779be7 1226 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1227 c_write("login as: ", 10);
67779be7 1228 ssh_send_ok = 1;
374330e2 1229 while (pos >= 0) {
fb09bf1c 1230 crWaitUntil(!ispkt);
374330e2 1231 while (inlen--) switch (c = *in++) {
1232 case 10: case 13:
1233 username[pos] = 0;
1234 pos = -1;
1235 break;
1236 case 8: case 127:
1237 if (pos > 0) {
1238 c_write("\b \b", 3);
1239 pos--;
1240 }
1241 break;
1242 case 21: case 27:
1243 while (pos > 0) {
1244 c_write("\b \b", 3);
1245 pos--;
1246 }
1247 break;
1248 case 3: case 4:
1249 random_save_seed();
1250 exit(0);
1251 break;
1252 default:
40d24aa6 1253 if (((c >= ' ' && c <= '~') ||
1254 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1255 username[pos++] = c;
1256 c_write(&c, 1);
1257 }
1258 break;
1259 }
1260 }
1261 c_write("\r\n", 2);
1262 username[strcspn(username, "\n\r")] = '\0';
1263 } else {
1264 char stuff[200];
1265 strncpy(username, cfg.username, 99);
1266 username[99] = '\0';
67779be7 1267 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
fb09bf1c 1268 sprintf(stuff, "Sent username \"%s\".\r\n", username);
4017be6d 1269 c_write(stuff, strlen(stuff));
fb09bf1c 1270 }
374330e2 1271 }
fb09bf1c 1272
e5574168 1273 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1274 {
1275 char userlog[20+sizeof(username)];
1276 sprintf(userlog, "Sent username \"%s\"", username);
1277 logevent(userlog);
1278 }
374330e2 1279 }
1280
fb09bf1c 1281 crWaitUntil(ispkt);
374330e2 1282
7cca0d81 1283 tried_publickey = 0;
1284
e5574168 1285 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1286 static char password[100];
a52f067e 1287 static char prompt[200];
374330e2 1288 static int pos;
1289 static char c;
ccbfb941 1290 static int pwpkt_type;
ccbfb941 1291 /*
1292 * Show password prompt, having first obtained it via a TIS
18515c51 1293 * or CryptoCard exchange if we're doing TIS or CryptoCard
1294 * authentication.
ccbfb941 1295 */
e5574168 1296 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1297 if (agent_exists()) {
1298 /*
1299 * Attempt RSA authentication using Pageant.
1300 */
1301 static unsigned char request[5], *response, *p;
1302 static int responselen;
1303 static int i, nkeys;
1304 static int authed = FALSE;
1305 void *r;
1306
1307 logevent("Pageant is running. Requesting keys.");
1308
1309 /* Request the keys held by the agent. */
1310 PUT_32BIT(request, 1);
1311 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1312 agent_query(request, 5, &r, &responselen);
1313 response = (unsigned char *)r;
1314 if (response) {
1315 p = response + 5;
1316 nkeys = GET_32BIT(p); p += 4;
1317 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1318 logevent(buf); }
1319 for (i = 0; i < nkeys; i++) {
1320 static struct RSAKey key;
1321 static Bignum challenge;
b8bb811a 1322 static char *commentp;
1323 static int commentlen;
5c58ad2d 1324
1325 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1326 logevent(buf); }
1327 p += 4;
1328 p += ssh1_read_bignum(p, &key.exponent);
1329 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1330 commentlen = GET_32BIT(p); p += 4;
1331 commentp = p; p += commentlen;
5c58ad2d 1332 send_packet(SSH1_CMSG_AUTH_RSA,
1333 PKT_BIGNUM, key.modulus, PKT_END);
1334 crWaitUntil(ispkt);
1335 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1336 logevent("Key refused");
1337 continue;
1338 }
1339 logevent("Received RSA challenge");
1340 ssh1_read_bignum(pktin.body, &challenge);
1341 {
1342 char *agentreq, *q, *ret;
1343 int len, retlen;
1344 len = 1 + 4; /* message type, bit count */
1345 len += ssh1_bignum_length(key.exponent);
1346 len += ssh1_bignum_length(key.modulus);
1347 len += ssh1_bignum_length(challenge);
1348 len += 16; /* session id */
1349 len += 4; /* response format */
1350 agentreq = malloc(4 + len);
1351 PUT_32BIT(agentreq, len);
1352 q = agentreq + 4;
1353 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1354 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1355 q += 4;
1356 q += ssh1_write_bignum(q, key.exponent);
1357 q += ssh1_write_bignum(q, key.modulus);
1358 q += ssh1_write_bignum(q, challenge);
1359 memcpy(q, session_id, 16); q += 16;
1360 PUT_32BIT(q, 1); /* response format */
1361 agent_query(agentreq, len+4, &ret, &retlen);
1362 free(agentreq);
1363 if (ret) {
1364 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1365 logevent("Sending Pageant's response");
1366 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1367 PKT_DATA, ret+5, 16, PKT_END);
1368 free(ret);
1369 crWaitUntil(ispkt);
1370 if (pktin.type == SSH1_SMSG_SUCCESS) {
1371 logevent("Pageant's response accepted");
c4fa2fce 1372 if (flags & FLAG_VERBOSE) {
1373 c_write("Authenticated using RSA key \"",
1374 29);
1375 c_write(commentp, commentlen);
1376 c_write("\" from agent\r\n", 14);
1377 }
5c58ad2d 1378 authed = TRUE;
1379 } else
1380 logevent("Pageant's response not accepted");
1381 } else {
1382 logevent("Pageant failed to answer challenge");
1383 free(ret);
1384 }
1385 } else {
1386 logevent("No reply received from Pageant");
1387 }
1388 }
1389 freebn(key.exponent);
1390 freebn(key.modulus);
1391 freebn(challenge);
1392 if (authed)
1393 break;
1394 }
1395 }
1396 if (authed)
1397 break;
1398 }
7cca0d81 1399 if (*cfg.keyfile && !tried_publickey)
1400 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1401
a52f067e 1402 if (pktin.type == SSH1_SMSG_FAILURE &&
1403 cfg.try_tis_auth &&
1404 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1405 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1406 logevent("Requested TIS authentication");
1407 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1408 crWaitUntil(ispkt);
1409 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1410 logevent("TIS authentication declined");
1411 if (flags & FLAG_INTERACTIVE)
1412 c_write("TIS authentication refused.\r\n", 29);
1413 } else {
1414 int challengelen = ((pktin.body[0] << 24) |
1415 (pktin.body[1] << 16) |
1416 (pktin.body[2] << 8) |
1417 (pktin.body[3]));
1418 logevent("Received TIS challenge");
1419 if (challengelen > sizeof(prompt)-1)
1420 challengelen = sizeof(prompt)-1; /* prevent overrun */
1421 memcpy(prompt, pktin.body+4, challengelen);
1422 prompt[challengelen] = '\0';
1423 }
1424 }
1425 if (pktin.type == SSH1_SMSG_FAILURE &&
1426 cfg.try_tis_auth &&
1427 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1428 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1429 logevent("Requested CryptoCard authentication");
1430 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1431 crWaitUntil(ispkt);
1432 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1433 logevent("CryptoCard authentication declined");
1434 c_write("CryptoCard authentication refused.\r\n", 29);
1435 } else {
1436 int challengelen = ((pktin.body[0] << 24) |
1437 (pktin.body[1] << 16) |
1438 (pktin.body[2] << 8) |
1439 (pktin.body[3]));
1440 logevent("Received CryptoCard challenge");
1441 if (challengelen > sizeof(prompt)-1)
1442 challengelen = sizeof(prompt)-1; /* prevent overrun */
1443 memcpy(prompt, pktin.body+4, challengelen);
1444 strncpy(prompt + challengelen, "\r\nResponse : ",
1445 sizeof(prompt)-challengelen);
1446 prompt[sizeof(prompt)-1] = '\0';
1447 }
1448 }
1449 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1450 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1451 username, savedhost);
a52f067e 1452 }
1453 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1454 char *comment = NULL;
1455 if (flags & FLAG_VERBOSE)
1456 c_write("Trying public key authentication.\r\n", 35);
1457 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1458 if (flags & FLAG_VERBOSE)
1459 c_write("No passphrase required.\r\n", 25);
1460 goto tryauth;
1461 }
1462 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1463 free(comment);
1464 }
1465
d8426c54 1466 if (ssh_get_password) {
85ee8208 1467 if (!ssh_get_password(prompt, password, sizeof(password))) {
1468 /*
1469 * get_password failed to get a password (for
1470 * example because one was supplied on the command
1471 * line which has already failed to work).
1472 * Terminate.
1473 */
1474 logevent("No more passwords to try");
1475 ssh_state = SSH_STATE_CLOSED;
1476 crReturn(1);
1477 }
fb09bf1c 1478 } else {
a52f067e 1479 c_write(prompt, strlen(prompt));
7cca0d81 1480 pos = 0;
67779be7 1481 ssh_send_ok = 1;
7cca0d81 1482 while (pos >= 0) {
1483 crWaitUntil(!ispkt);
1484 while (inlen--) switch (c = *in++) {
1485 case 10: case 13:
1486 password[pos] = 0;
1487 pos = -1;
1488 break;
1489 case 8: case 127:
1490 if (pos > 0)
1491 pos--;
1492 break;
1493 case 21: case 27:
1494 pos = 0;
1495 break;
1496 case 3: case 4:
1497 random_save_seed();
1498 exit(0);
1499 break;
1500 default:
1501 if (((c >= ' ' && c <= '~') ||
1502 ((unsigned char)c >= 160)) && pos < sizeof(password))
1503 password[pos++] = c;
1504 break;
1505 }
1506 }
1507 c_write("\r\n", 2);
a52f067e 1508 }
fb09bf1c 1509
7cca0d81 1510 tryauth:
1511 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1512 /*
1513 * Try public key authentication with the specified
1514 * key file.
1515 */
1516 static struct RSAKey pubkey;
1517 static Bignum challenge, response;
1518 static int i;
1519 static unsigned char buffer[32];
1520
1521 tried_publickey = 1;
1522 i = loadrsakey(cfg.keyfile, &pubkey, password);
1523 if (i == 0) {
1524 c_write("Couldn't load public key from ", 30);
1525 c_write(cfg.keyfile, strlen(cfg.keyfile));
1526 c_write(".\r\n", 3);
1527 continue; /* go and try password */
1528 }
1529 if (i == -1) {
1530 c_write("Wrong passphrase.\r\n", 19);
1531 tried_publickey = 0;
1532 continue; /* try again */
1533 }
1534
1535 /*
1536 * Send a public key attempt.
1537 */
1538 send_packet(SSH1_CMSG_AUTH_RSA,
1539 PKT_BIGNUM, pubkey.modulus, PKT_END);
1540
1541 crWaitUntil(ispkt);
1542 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1543 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1544 continue; /* go and try password */
1545 }
8d5de777 1546 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1547 bombout(("Bizarre response to offer of public key"));
1548 crReturn(0);
1549 }
7cca0d81 1550 ssh1_read_bignum(pktin.body, &challenge);
1551 response = rsadecrypt(challenge, &pubkey);
1552 freebn(pubkey.private_exponent); /* burn the evidence */
1553
1554 for (i = 0; i < 32; i += 2) {
1555 buffer[i] = response[16-i/2] >> 8;
1556 buffer[i+1] = response[16-i/2] & 0xFF;
1557 }
1558
1559 MD5Init(&md5c);
1560 MD5Update(&md5c, buffer, 32);
1561 MD5Update(&md5c, session_id, 16);
1562 MD5Final(buffer, &md5c);
1563
1564 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1565 PKT_DATA, buffer, 16, PKT_END);
1566
1567 crWaitUntil(ispkt);
1568 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1569 if (flags & FLAG_VERBOSE)
1570 c_write("Failed to authenticate with our public key.\r\n",
1571 45);
7cca0d81 1572 continue; /* go and try password */
1573 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1574 bombout(("Bizarre response to RSA authentication response"));
1575 crReturn(0);
7cca0d81 1576 }
1577
1578 break; /* we're through! */
1579 } else {
1580 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1581 }
c5e9c988 1582 logevent("Sent password");
374330e2 1583 memset(password, 0, strlen(password));
fb09bf1c 1584 crWaitUntil(ispkt);
e5574168 1585 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1586 if (flags & FLAG_VERBOSE)
1587 c_write("Access denied\r\n", 15);
c5e9c988 1588 logevent("Authentication refused");
e5574168 1589 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1590 logevent("Received disconnect request");
85ee8208 1591 ssh_state = SSH_STATE_CLOSED;
1592 crReturn(1);
e5574168 1593 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1594 bombout(("Strange packet received, type %d", pktin.type));
1595 crReturn(0);
374330e2 1596 }
1597 }
1598
c5e9c988 1599 logevent("Authentication successful");
1600
fb09bf1c 1601 crFinish(1);
1602}
1603
e5574168 1604static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1605 crBegin;
1606
1607 random_init();
1608
e5574168 1609 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1610 crReturnV;
85ee8208 1611 }
1612 if (ssh_state == SSH_STATE_CLOSED)
1613 crReturnV;
fb09bf1c 1614
979310f1 1615 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1616 logevent("Requesting agent forwarding");
1617 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1618 do { crReturnV; } while (!ispkt);
1619 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1620 bombout(("Protocol confusion"));
1621 crReturnV;
dacbd0e8 1622 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1623 logevent("Agent forwarding refused");
1624 } else
1625 logevent("Agent forwarding enabled");
1626 }
1627
fef97f43 1628 if (!cfg.nopty) {
e5574168 1629 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1630 PKT_STR, cfg.termtype,
1631 PKT_INT, rows, PKT_INT, cols,
1632 PKT_INT, 0, PKT_INT, 0,
1633 PKT_CHAR, 0,
1634 PKT_END);
fef97f43 1635 ssh_state = SSH_STATE_INTERMED;
1636 do { crReturnV; } while (!ispkt);
e5574168 1637 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1638 bombout(("Protocol confusion"));
1639 crReturnV;
e5574168 1640 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1641 c_write("Server refused to allocate pty\r\n", 32);
1642 }
c5e9c988 1643 logevent("Allocated pty");
374330e2 1644 }
1645
6abbf9e3 1646 if (*cfg.remote_cmd)
1647 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1648 else
1649 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1650 logevent("Started session");
374330e2 1651
1652 ssh_state = SSH_STATE_SESSION;
1653 if (size_needed)
1654 ssh_size();
1655
8ccc75b0 1656 ssh_send_ok = 1;
dacbd0e8 1657 ssh_channels = newtree234(ssh_channelcmp);
6f34e365 1658 begin_session();
374330e2 1659 while (1) {
1660 crReturnV;
1661 if (ispkt) {
e5574168 1662 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1663 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1664 long len = GET_32BIT(pktin.body);
3bdaf79d 1665 c_writedata(pktin.body+4, len);
e5574168 1666 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1667 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1668 logevent("Received disconnect request");
dacbd0e8 1669 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1670 /* Remote side is trying to open a channel to talk to our
1671 * agent. Give them back a local channel number. */
d211621f 1672 unsigned i = 1;
dacbd0e8 1673 struct ssh_channel *c;
1674 enum234 e;
1675 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1676 if (c->localid > i)
1677 break; /* found a free number */
1678 i = c->localid + 1;
1679 }
1680 c = malloc(sizeof(struct ssh_channel));
1681 c->remoteid = GET_32BIT(pktin.body);
1682 c->localid = i;
b8bb811a 1683 c->closes = 0;
dacbd0e8 1684 c->type = SSH1_SMSG_AGENT_OPEN; /* identify channel type */
bb487ce2 1685 c->u.a.lensofar = 0;
dacbd0e8 1686 add234(ssh_channels, c);
1687 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1688 PKT_INT, c->remoteid, PKT_INT, c->localid,
1689 PKT_END);
1690 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1691 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1692 /* Remote side closes a channel. */
d211621f 1693 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1694 struct ssh_channel *c;
1695 c = find234(ssh_channels, &i, ssh_channelfind);
1696 if (c) {
1697 int closetype;
1698 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1699 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1700 c->closes |= closetype;
1701 if (c->closes == 3) {
1702 del234(ssh_channels, c);
1703 free(c);
1704 }
1705 }
1706 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1707 /* Data sent down one of our channels. */
1708 int i = GET_32BIT(pktin.body);
1709 int len = GET_32BIT(pktin.body+4);
1710 unsigned char *p = pktin.body+8;
1711 struct ssh_channel *c;
1712 c = find234(ssh_channels, &i, ssh_channelfind);
1713 if (c) {
1714 switch(c->type) {
1715 case SSH1_SMSG_AGENT_OPEN:
1716 /* Data for an agent message. Buffer it. */
1717 while (len > 0) {
1718 if (c->u.a.lensofar < 4) {
1719 int l = min(4 - c->u.a.lensofar, len);
1720 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
1721 p += l; len -= l; c->u.a.lensofar += l;
1722 }
1723 if (c->u.a.lensofar == 4) {
1724 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
1725 c->u.a.message = malloc(c->u.a.totallen);
1726 memcpy(c->u.a.message, c->u.a.msglen, 4);
1727 }
1728 if (c->u.a.lensofar >= 4 && len > 0) {
1729 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
1730 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
1731 p += l; len -= l; c->u.a.lensofar += l;
1732 }
1733 if (c->u.a.lensofar == c->u.a.totallen) {
1734 void *reply, *sentreply;
1735 int replylen;
1736 agent_query(c->u.a.message, c->u.a.totallen,
1737 &reply, &replylen);
1738 if (reply)
1739 sentreply = reply;
1740 else {
1741 /* Fake SSH_AGENT_FAILURE. */
1742 sentreply = "\0\0\0\1\5";
1743 replylen = 5;
1744 }
1745 send_packet(SSH1_MSG_CHANNEL_DATA,
1746 PKT_INT, c->remoteid,
1747 PKT_INT, replylen,
1748 PKT_DATA, sentreply, replylen,
1749 PKT_END);
1750 if (reply)
1751 free(reply);
1752 free(c->u.a.message);
1753 c->u.a.lensofar = 0;
1754 }
1755 }
1756 break;
1757 }
1758 }
e5574168 1759 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 1760 /* may be from EXEC_SHELL on some servers */
e5574168 1761 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 1762 /* may be from EXEC_SHELL on some servers
374330e2 1763 * if no pty is available or in other odd cases. Ignore */
e5574168 1764 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1765 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 1766 } else {
8d5de777 1767 bombout(("Strange packet received: type %d", pktin.type));
1768 crReturnV;
374330e2 1769 }
1770 } else {
e5574168 1771 send_packet(SSH1_CMSG_STDIN_DATA,
fb09bf1c 1772 PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
374330e2 1773 }
1774 }
1775
1776 crFinishV;
1777}
1778
1779/*
e5574168 1780 * Utility routine for decoding comma-separated strings in KEXINIT.
1781 */
75cab814 1782static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 1783 int needlen = strlen(needle);
1784 while (1) {
1785 /*
1786 * Is it at the start of the string?
1787 */
1788 if (haylen >= needlen && /* haystack is long enough */
1789 !memcmp(needle, haystack, needlen) && /* initial match */
1790 (haylen == needlen || haystack[needlen] == ',')
1791 /* either , or EOS follows */
1792 )
1793 return 1;
1794 /*
1795 * If not, search for the next comma and resume after that.
1796 * If no comma found, terminate.
1797 */
1798 while (haylen > 0 && *haystack != ',')
1799 haylen--, haystack++;
1800 if (haylen == 0)
1801 return 0;
1802 haylen--, haystack++; /* skip over comma itself */
1803 }
1804}
1805
1806/*
d39f364a 1807 * SSH2 key creation method.
1808 */
75cab814 1809static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
d39f364a 1810 SHA_State s;
1811 /* First 20 bytes. */
1812 SHA_Init(&s);
1813 sha_mpint(&s, K);
1814 SHA_Bytes(&s, H, 20);
1815 SHA_Bytes(&s, &chr, 1);
1816 SHA_Bytes(&s, H, 20);
1817 SHA_Final(&s, keyspace);
1818 /* Next 20 bytes. */
1819 SHA_Init(&s);
1820 sha_mpint(&s, K);
1821 SHA_Bytes(&s, H, 20);
1822 SHA_Bytes(&s, keyspace, 20);
1823 SHA_Final(&s, keyspace+20);
1824}
1825
1826/*
7cca0d81 1827 * Handle the SSH2 transport layer.
e5574168 1828 */
7cca0d81 1829static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 1830{
1831 static int i, len;
1832 static char *str;
1833 static Bignum e, f, K;
7591b9ff 1834 static const struct ssh_mac **maclist;
8b2715b2 1835 static int nmacs;
57476f6b 1836 static const struct ssh_cipher *cscipher_tobe = NULL;
1837 static const struct ssh_cipher *sccipher_tobe = NULL;
1838 static const struct ssh_mac *csmac_tobe = NULL;
1839 static const struct ssh_mac *scmac_tobe = NULL;
1840 static const struct ssh_compress *cscomp_tobe = NULL;
1841 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 1842 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 1843 static int hostkeylen, siglen;
1844 static unsigned char exchange_hash[20];
d39f364a 1845 static unsigned char keyspace[40];
57476f6b 1846 static const struct ssh_cipher *preferred_cipher;
e5574168 1847
1848 crBegin;
7cca0d81 1849 random_init();
e5574168 1850
5e8358ad 1851 /*
1852 * Set up the preferred cipher.
1853 */
1854 if (cfg.cipher == CIPHER_BLOWFISH) {
57476f6b 1855 preferred_cipher = &ssh_blowfish_ssh2;
5e8358ad 1856 } else if (cfg.cipher == CIPHER_DES) {
1857 logevent("Single DES not supported in SSH2; using 3DES");
57476f6b 1858 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1859 } else if (cfg.cipher == CIPHER_3DES) {
57476f6b 1860 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1861 } else {
1862 /* Shouldn't happen, but we do want to initialise to _something_. */
57476f6b 1863 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1864 }
1865
7591b9ff 1866 /*
1867 * Be prepared to work around the buggy MAC problem.
1868 */
1869 if (cfg.buggymac)
8b2715b2 1870 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 1871 else
8b2715b2 1872 maclist = macs, nmacs = lenof(macs);
7591b9ff 1873
7cca0d81 1874 begin_key_exchange:
e5574168 1875 /*
1876 * Construct and send our key exchange packet.
1877 */
1878 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1879 for (i = 0; i < 16; i++)
1880 ssh2_pkt_addbyte((unsigned char)random_byte());
1881 /* List key exchange algorithms. */
1882 ssh2_pkt_addstring_start();
1883 for (i = 0; i < lenof(kex_algs); i++) {
1884 ssh2_pkt_addstring_str(kex_algs[i]->name);
1885 if (i < lenof(kex_algs)-1)
1886 ssh2_pkt_addstring_str(",");
1887 }
1888 /* List server host key algorithms. */
1889 ssh2_pkt_addstring_start();
1890 for (i = 0; i < lenof(hostkey_algs); i++) {
1891 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1892 if (i < lenof(hostkey_algs)-1)
1893 ssh2_pkt_addstring_str(",");
1894 }
1895 /* List client->server encryption algorithms. */
1896 ssh2_pkt_addstring_start();
729e54b4 1897 for (i = 0; i < lenof(ciphers)+1; i++) {
1898 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1899 ssh2_pkt_addstring_str(c->name);
729e54b4 1900 if (i < lenof(ciphers))
e5574168 1901 ssh2_pkt_addstring_str(",");
1902 }
1903 /* List server->client encryption algorithms. */
1904 ssh2_pkt_addstring_start();
729e54b4 1905 for (i = 0; i < lenof(ciphers)+1; i++) {
1906 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1907 ssh2_pkt_addstring_str(c->name);
729e54b4 1908 if (i < lenof(ciphers))
e5574168 1909 ssh2_pkt_addstring_str(",");
1910 }
1911 /* List client->server MAC algorithms. */
1912 ssh2_pkt_addstring_start();
8b2715b2 1913 for (i = 0; i < nmacs; i++) {
7591b9ff 1914 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 1915 if (i < nmacs-1)
e5574168 1916 ssh2_pkt_addstring_str(",");
1917 }
1918 /* List server->client 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 client->server compression algorithms. */
1926 ssh2_pkt_addstring_start();
1927 for (i = 0; i < lenof(compressions); i++) {
1928 ssh2_pkt_addstring_str(compressions[i]->name);
1929 if (i < lenof(compressions)-1)
1930 ssh2_pkt_addstring_str(",");
1931 }
1932 /* List server->client 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 client->server languages. Empty list. */
1940 ssh2_pkt_addstring_start();
1941 /* List server->client languages. Empty list. */
1942 ssh2_pkt_addstring_start();
1943 /* First KEX packet does _not_ follow, because we're not that brave. */
1944 ssh2_pkt_addbool(FALSE);
1945 /* Reserved. */
1946 ssh2_pkt_adduint32(0);
1947 sha_string(&exhash, pktout.data+5, pktout.length-5);
1948 ssh2_pkt_send();
1949
1950 if (!ispkt) crWaitUntil(ispkt);
1951 sha_string(&exhash, pktin.data+5, pktin.length-5);
1952
1953 /*
1954 * Now examine the other side's KEXINIT to see what we're up
1955 * to.
1956 */
7cca0d81 1957 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 1958 bombout(("expected key exchange packet from server"));
1959 crReturn(0);
7cca0d81 1960 }
e5574168 1961 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1962 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1963 pktin.savedpos += 16; /* skip garbage cookie */
1964 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1965 for (i = 0; i < lenof(kex_algs); i++) {
1966 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1967 kex = kex_algs[i];
1968 break;
1969 }
1970 }
1971 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1972 for (i = 0; i < lenof(hostkey_algs); i++) {
1973 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1974 hostkey = hostkey_algs[i];
1975 break;
1976 }
1977 }
1978 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 1979 for (i = 0; i < lenof(ciphers)+1; i++) {
1980 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1981 if (in_commasep_string(c->name, str, len)) {
729e54b4 1982 cscipher_tobe = c;
e5574168 1983 break;
1984 }
1985 }
1986 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
729e54b4 1987 for (i = 0; i < lenof(ciphers)+1; i++) {
1988 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1989 if (in_commasep_string(c->name, str, len)) {
729e54b4 1990 sccipher_tobe = c;
e5574168 1991 break;
1992 }
1993 }
1994 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 1995 for (i = 0; i < nmacs; i++) {
7591b9ff 1996 if (in_commasep_string(maclist[i]->name, str, len)) {
1997 csmac_tobe = maclist[i];
e5574168 1998 break;
1999 }
2000 }
2001 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 2002 for (i = 0; i < nmacs; i++) {
7591b9ff 2003 if (in_commasep_string(maclist[i]->name, str, len)) {
2004 scmac_tobe = maclist[i];
e5574168 2005 break;
2006 }
2007 }
2008 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2009 for (i = 0; i < lenof(compressions); i++) {
2010 if (in_commasep_string(compressions[i]->name, str, len)) {
2011 cscomp_tobe = compressions[i];
2012 break;
2013 }
2014 }
2015 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2016 for (i = 0; i < lenof(compressions); i++) {
2017 if (in_commasep_string(compressions[i]->name, str, len)) {
2018 sccomp_tobe = compressions[i];
2019 break;
2020 }
2021 }
e5574168 2022
2023 /*
2024 * Currently we only support Diffie-Hellman and DSS, so let's
2025 * bomb out if those aren't selected.
2026 */
8d5de777 2027 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2028 bombout(("internal fault: chaos in SSH 2 transport layer"));
2029 crReturn(0);
2030 }
e5574168 2031
2032 /*
2033 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2034 */
2035 e = dh_create_e();
e5574168 2036 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2037 ssh2_pkt_addmp(e);
2038 ssh2_pkt_send();
2039
2040 crWaitUntil(ispkt);
7cca0d81 2041 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2042 bombout(("expected key exchange packet from server"));
2043 crReturn(0);
7cca0d81 2044 }
e5574168 2045 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2046 f = ssh2_pkt_getmp();
e5574168 2047 ssh2_pkt_getstring(&sigdata, &siglen);
2048
2049 K = dh_find_K(f);
e5574168 2050
2051 sha_string(&exhash, hostkeydata, hostkeylen);
2052 sha_mpint(&exhash, e);
2053 sha_mpint(&exhash, f);
2054 sha_mpint(&exhash, K);
2055 SHA_Final(&exhash, exchange_hash);
2056
7cca0d81 2057#if 0
e5574168 2058 debug(("Exchange hash is:\r\n"));
2059 for (i = 0; i < 20; i++)
2060 debug((" %02x", exchange_hash[i]));
2061 debug(("\r\n"));
7cca0d81 2062#endif
2063
2064 hostkey->setkey(hostkeydata, hostkeylen);
8d5de777 2065 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20)) {
2066 bombout(("Server failed host key check"));
2067 crReturn(0);
2068 }
e5574168 2069
2070 /*
7cca0d81 2071 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2072 */
7cca0d81 2073 crWaitUntil(ispkt);
8d5de777 2074 if (pktin.type != SSH2_MSG_NEWKEYS) {
2075 bombout(("expected new-keys packet from server"));
2076 crReturn(0);
2077 }
d39f364a 2078
2079 /*
7cca0d81 2080 * Authenticate remote host: verify host key. (We've already
2081 * checked the signature of the exchange hash.)
e5574168 2082 */
7cca0d81 2083 keystr = hostkey->fmtkey();
d5859615 2084 fingerprint = hostkey->fingerprint();
d4857987 2085 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2086 keystr, fingerprint);
d5859615 2087 logevent("Host key fingerprint is:");
2088 logevent(fingerprint);
2089 free(fingerprint);
7cca0d81 2090 free(keystr);
d39f364a 2091
2092 /*
7cca0d81 2093 * Send SSH2_MSG_NEWKEYS.
d39f364a 2094 */
2095 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2096 ssh2_pkt_send();
d39f364a 2097
2098 /*
2099 * Create and initialise session keys.
2100 */
2101 cscipher = cscipher_tobe;
2102 sccipher = sccipher_tobe;
2103 csmac = csmac_tobe;
2104 scmac = scmac_tobe;
2105 cscomp = cscomp_tobe;
2106 sccomp = sccomp_tobe;
2107 /*
2108 * Set IVs after keys.
2109 */
2110 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
2111 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
2112 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2113 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2114 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2115 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2116
033b4cef 2117 /*
7cca0d81 2118 * Now we're encrypting. Begin returning 1 to the protocol main
2119 * function so that other things can run on top of the
2120 * transport. If we ever see a KEXINIT, we must go back to the
2121 * start.
033b4cef 2122 */
7cca0d81 2123 do {
2124 crReturn(1);
2125 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2126 goto begin_key_exchange;
e5574168 2127
2128 crFinish(1);
2129}
2130
7cca0d81 2131/*
2132 * Handle the SSH2 userauth and connection layers.
2133 */
2134static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2135{
7cca0d81 2136 static unsigned long remote_winsize;
2137 static unsigned long remote_maxpkt;
2138
e5574168 2139 crBegin;
2140
7cca0d81 2141 /*
2142 * Request userauth protocol, and await a response to it.
2143 */
2144 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2145 ssh2_pkt_addstring("ssh-userauth");
2146 ssh2_pkt_send();
2147 crWaitUntilV(ispkt);
8d5de777 2148 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2149 bombout(("Server refused user authentication protocol"));
2150 crReturnV;
2151 }
7cca0d81 2152
2153 /*
2154 * FIXME: currently we support only password authentication.
2155 * (This places us technically in violation of the SSH2 spec.
2156 * We must fix this.)
2157 */
2158 while (1) {
2159 /*
2160 * Get a username and a password.
2161 */
2162 static char username[100];
2163 static char password[100];
2164 static int pos = 0;
2165 static char c;
e5574168 2166
67779be7 2167 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2168 c_write("login as: ", 10);
67779be7 2169 ssh_send_ok = 1;
7cca0d81 2170 while (pos >= 0) {
2171 crWaitUntilV(!ispkt);
2172 while (inlen--) switch (c = *in++) {
2173 case 10: case 13:
2174 username[pos] = 0;
2175 pos = -1;
2176 break;
2177 case 8: case 127:
2178 if (pos > 0) {
2179 c_write("\b \b", 3);
2180 pos--;
2181 }
2182 break;
2183 case 21: case 27:
2184 while (pos > 0) {
2185 c_write("\b \b", 3);
2186 pos--;
2187 }
2188 break;
2189 case 3: case 4:
2190 random_save_seed();
2191 exit(0);
2192 break;
2193 default:
2194 if (((c >= ' ' && c <= '~') ||
2195 ((unsigned char)c >= 160)) && pos < 40) {
2196 username[pos++] = c;
2197 c_write(&c, 1);
2198 }
2199 break;
2200 }
2201 }
2202 c_write("\r\n", 2);
2203 username[strcspn(username, "\n\r")] = '\0';
2204 } else {
2205 char stuff[200];
2206 strncpy(username, cfg.username, 99);
2207 username[99] = '\0';
67779be7 2208 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2209 sprintf(stuff, "Using username \"%s\".\r\n", username);
2210 c_write(stuff, strlen(stuff));
2211 }
2212 }
2213
d8426c54 2214 if (ssh_get_password) {
7cca0d81 2215 char prompt[200];
b585ec46 2216 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
7cca0d81 2217 if (!ssh_get_password(prompt, password, sizeof(password))) {
2218 /*
2219 * get_password failed to get a password (for
2220 * example because one was supplied on the command
2221 * line which has already failed to work).
2222 * Terminate.
2223 */
2224 logevent("No more passwords to try");
2225 ssh_state = SSH_STATE_CLOSED;
2226 crReturnV;
2227 }
2228 } else {
2229 c_write("password: ", 10);
67779be7 2230 ssh_send_ok = 1;
7cca0d81 2231
2232 pos = 0;
2233 while (pos >= 0) {
2234 crWaitUntilV(!ispkt);
2235 while (inlen--) switch (c = *in++) {
2236 case 10: case 13:
2237 password[pos] = 0;
2238 pos = -1;
2239 break;
2240 case 8: case 127:
2241 if (pos > 0)
2242 pos--;
2243 break;
2244 case 21: case 27:
2245 pos = 0;
2246 break;
2247 case 3: case 4:
2248 random_save_seed();
2249 exit(0);
2250 break;
2251 default:
2252 if (((c >= ' ' && c <= '~') ||
2253 ((unsigned char)c >= 160)) && pos < 40)
2254 password[pos++] = c;
2255 break;
2256 }
2257 }
2258 c_write("\r\n", 2);
2259 }
2260
2261 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2262 ssh2_pkt_addstring(username);
2263 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2264 ssh2_pkt_addstring("password");
2265 ssh2_pkt_addbool(FALSE);
2266 ssh2_pkt_addstring(password);
2267 ssh2_pkt_send();
2268
2269 crWaitUntilV(ispkt);
2270 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2271 c_write("Access denied\r\n", 15);
2272 logevent("Authentication refused");
2273 } else
2274 break;
2275 }
2276
2277 /*
2278 * Now we're authenticated for the connection protocol. The
2279 * connection protocol will automatically have started at this
2280 * point; there's no need to send SERVICE_REQUEST.
2281 */
2282
2283 /*
2284 * So now create a channel with a session in it.
2285 */
d211621f 2286 mainchan = malloc(sizeof(struct ssh_channel));
2287 mainchan->localid = 100; /* as good as any */
7cca0d81 2288 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2289 ssh2_pkt_addstring("session");
d211621f 2290 ssh2_pkt_adduint32(mainchan->localid);
cf6e59d6 2291 ssh2_pkt_adduint32(0x8000UL); /* our window size */
d211621f 2292 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2293 ssh2_pkt_send();
2294 crWaitUntilV(ispkt);
2295 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2296 bombout(("Server refused to open a session"));
2297 crReturnV;
7cca0d81 2298 /* FIXME: error data comes back in FAILURE packet */
2299 }
d211621f 2300 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2301 bombout(("Server's channel confirmation cited wrong channel"));
2302 crReturnV;
7cca0d81 2303 }
d211621f 2304 mainchan->remoteid = ssh2_pkt_getuint32();
2305 mainchan->u.v2.remwindow = ssh2_pkt_getuint32();
2306 mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32();
2307 mainchan->u.v2.outbuffer = NULL;
2308 mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0;
7cca0d81 2309 logevent("Opened channel for session");
2310
2311 /*
2312 * Now allocate a pty for the session.
2313 */
67779be7 2314 if (!cfg.nopty) {
2315 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2316 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2317 ssh2_pkt_addstring("pty-req");
2318 ssh2_pkt_addbool(1); /* want reply */
2319 ssh2_pkt_addstring(cfg.termtype);
2320 ssh2_pkt_adduint32(cols);
2321 ssh2_pkt_adduint32(rows);
2322 ssh2_pkt_adduint32(0); /* pixel width */
2323 ssh2_pkt_adduint32(0); /* pixel height */
2324 ssh2_pkt_addstring_start();
2325 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2326 ssh2_pkt_send();
7cca0d81 2327
67779be7 2328 do {
2329 crWaitUntilV(ispkt);
2330 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2331 /* FIXME: be able to handle other channels here */
2332 if (ssh2_pkt_getuint32() != mainchan->localid)
2333 continue; /* wrong channel */
2334 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2335 }
2336 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2337
67779be7 2338 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2339 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2340 bombout(("Server got confused by pty request"));
2341 crReturnV;
67779be7 2342 }
2343 c_write("Server refused to allocate pty\r\n", 32);
2344 } else {
2345 logevent("Allocated pty");
7cca0d81 2346 }
7cca0d81 2347 }
2348
2349 /*
67779be7 2350 * Start a shell or a remote command.
7cca0d81 2351 */
2352 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2353 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2354 if (*cfg.remote_cmd) {
2355 ssh2_pkt_addstring("exec");
2356 ssh2_pkt_addbool(1); /* want reply */
2357 ssh2_pkt_addstring(cfg.remote_cmd);
2358 } else {
2359 ssh2_pkt_addstring("shell");
2360 ssh2_pkt_addbool(1); /* want reply */
2361 }
7cca0d81 2362 ssh2_pkt_send();
d211621f 2363 do {
7cca0d81 2364 crWaitUntilV(ispkt);
d211621f 2365 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2366 /* FIXME: be able to handle other channels here */
2367 if (ssh2_pkt_getuint32() != mainchan->localid)
2368 continue; /* wrong channel */
2369 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2370 }
7cca0d81 2371 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2372 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2373 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2374 bombout(("Server got confused by shell/command request"));
2375 crReturnV;
7cca0d81 2376 }
8d5de777 2377 bombout(("Server refused to start a shell/command"));
2378 crReturnV;
7cca0d81 2379 } else {
8d5de777 2380 logevent("Started a shell/command");
7cca0d81 2381 }
2382
2383 /*
2384 * Transfer data!
2385 */
8ccc75b0 2386 ssh_send_ok = 1;
6f34e365 2387 begin_session();
7cca0d81 2388 while (1) {
d211621f 2389 static int try_send;
e5574168 2390 crReturnV;
d211621f 2391 try_send = FALSE;
7cca0d81 2392 if (ispkt) {
2393 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2394 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2395 char *data;
2396 int length;
d211621f 2397 /* FIXME: be able to handle other channels here */
2398 if (ssh2_pkt_getuint32() != mainchan->localid)
7cca0d81 2399 continue; /* wrong channel */
2400 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2401 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2402 continue; /* extended but not stderr */
2403 ssh2_pkt_getstring(&data, &length);
d211621f 2404 if (data) {
3bdaf79d 2405 c_writedata(data, length);
d211621f 2406 /*
2407 * Enlarge the window again at the remote side,
2408 * just in case it ever runs down and they fail
2409 * to send us any more data.
2410 */
2411 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2412 ssh2_pkt_adduint32(mainchan->remoteid);
2413 ssh2_pkt_adduint32(length);
2414 ssh2_pkt_send();
2415 }
7cca0d81 2416 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2417 ssh_state = SSH_STATE_CLOSED;
d211621f 2418 logevent("Received disconnect message");
7cca0d81 2419 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2420 continue; /* exit status et al; ignore (FIXME?) */
d211621f 2421 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2422 continue; /* remote sends EOF; ignore */
2423 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
2424 /* FIXME: be able to handle other channels here */
2425 if (ssh2_pkt_getuint32() != mainchan->localid)
2426 continue; /* wrong channel */
2427 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2428 ssh2_pkt_adduint32(mainchan->remoteid);
2429 ssh2_pkt_send();
2430 /* FIXME: mark the channel as closed */
2431 if (1 /* FIXME: "all channels are closed" */) {
2432 logevent("All channels closed. Disconnecting");
2433 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2434 ssh2_pkt_send();
cf6e59d6 2435 ssh_state = SSH_STATE_CLOSED;
2436 closesocket(s);
2437 s = INVALID_SOCKET;
d211621f 2438 }
2439 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2440 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
d211621f 2441 /* FIXME: be able to handle other channels here */
2442 if (ssh2_pkt_getuint32() != mainchan->localid)
2443 continue; /* wrong channel */
2444 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2445 try_send = TRUE;
7cca0d81 2446 } else {
8d5de777 2447 bombout(("Strange packet received: type %d", pktin.type));
2448 crReturnV;
7cca0d81 2449 }
2450 } else {
d211621f 2451 /*
2452 * We have spare data. Add it to the channel buffer.
2453 */
2454 if (mainchan->u.v2.outbufsize <
2455 mainchan->u.v2.outbuflen + inlen) {
2456 mainchan->u.v2.outbufsize =
2457 mainchan->u.v2.outbuflen + inlen + 1024;
2458 mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer,
2459 mainchan->u.v2.outbufsize);
2460 }
2461 memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen,
2462 in, inlen);
2463 mainchan->u.v2.outbuflen += inlen;
2464 try_send = TRUE;
7cca0d81 2465 }
d211621f 2466 if (try_send) {
2467 /*
2468 * Try to send data on the channel if we can. (FIXME:
2469 * on _all_ channels.)
2470 */
2471 while (mainchan->u.v2.remwindow > 0 &&
2472 mainchan->u.v2.outbuflen > 0) {
2473 unsigned len = mainchan->u.v2.remwindow;
2474 if (len > mainchan->u.v2.outbuflen)
2475 len = mainchan->u.v2.outbuflen;
2476 if (len > mainchan->u.v2.remmaxpkt)
2477 len = mainchan->u.v2.remmaxpkt;
2478 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2479 ssh2_pkt_adduint32(mainchan->remoteid);
2480 ssh2_pkt_addstring_start();
2481 ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len);
2482 ssh2_pkt_send();
2483 mainchan->u.v2.outbuflen -= len;
2484 memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len,
2485 mainchan->u.v2.outbuflen);
2486 mainchan->u.v2.remwindow -= len;
2487 }
2488 }
e5574168 2489 }
2490
2491 crFinishV;
2492}
2493
2494/*
7cca0d81 2495 * Handle the top-level SSH2 protocol.
2496 */
2497static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2498{
2499 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2500 return;
2501 do_ssh2_authconn(in, inlen, ispkt);
2502}
2503
2504/*
374330e2 2505 * Called to set up the connection. Will arrange for WM_NETEVENT
2506 * messages to be passed to the specified window, whose window
2507 * procedure should then call telnet_msg().
2508 *
2509 * Returns an error message, or NULL on success.
374330e2 2510 */
2511static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
fb09bf1c 2512 char *p;
8f203108 2513
2514#ifdef MSCRYPTOAPI
2515 if(crypto_startup() == 0)
2516 return "Microsoft high encryption pack not installed!";
2517#endif
374330e2 2518
fb09bf1c 2519 p = connect_to_host(host, port, realhost);
2520 if (p != NULL)
2521 return p;
374330e2 2522
2523 if (!do_ssh_init())
2524 return "Protocol initialisation error";
2525
4017be6d 2526 if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
374330e2 2527 switch (WSAGetLastError()) {
2528 case WSAENETDOWN: return "Network is down";
2529 default: return "WSAAsyncSelect(): unknown error";
2530 }
2531
2532 return NULL;
2533}
2534
2535/*
2536 * Process a WM_NETEVENT message. Will return 0 if the connection
2537 * has closed, or <0 for a socket error.
2538 */
2539static int ssh_msg (WPARAM wParam, LPARAM lParam) {
2540 int ret;
2541 char buf[256];
2542
8ce72d2c 2543 /*
2544 * Because reading less than the whole of the available pending
2545 * data can generate an FD_READ event, we need to allow for the
2546 * possibility that FD_READ may arrive with FD_CLOSE already in
2547 * the queue; so it's possible that we can get here even with s
2548 * invalid. If so, we return 1 and don't worry about it.
2549 */
2550 if (s == INVALID_SOCKET)
2551 return 1;
374330e2 2552
8d5de777 2553 if (WSAGETSELECTERROR(lParam) != 0) {
2554 closesocket(s);
2555 s = INVALID_SOCKET;
374330e2 2556 return -WSAGETSELECTERROR(lParam);
8d5de777 2557 }
374330e2 2558
2559 switch (WSAGETSELECTEVENT(lParam)) {
2560 case FD_READ:
8ce72d2c 2561 case FD_CLOSE:
374330e2 2562 ret = recv(s, buf, sizeof(buf), 0);
2563 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
2564 return 1;
8d5de777 2565 if (ret < 0) { /* any _other_ error */
2566 closesocket(s);
2567 s = INVALID_SOCKET;
374330e2 2568 return -10000-WSAGetLastError();
8d5de777 2569 }
374330e2 2570 if (ret == 0) {
2571 s = INVALID_SOCKET;
8ce72d2c 2572 return 0;
374330e2 2573 }
2574 ssh_gotdata (buf, ret);
85ee8208 2575 if (ssh_state == SSH_STATE_CLOSED) {
2576 closesocket(s);
2577 s = INVALID_SOCKET;
2578 return 0;
2579 }
374330e2 2580 return 1;
374330e2 2581 }
2582 return 1; /* shouldn't happen, but WTF */
2583}
2584
2585/*
2586 * Called to send data down the Telnet connection.
2587 */
2588static void ssh_send (char *buf, int len) {
2589 if (s == INVALID_SOCKET)
2590 return;
2591
2592 ssh_protocol(buf, len, 0);
2593}
2594
2595/*
2596 * Called to set the size of the window from Telnet's POV.
2597 */
2598static void ssh_size(void) {
2599 switch (ssh_state) {
2600 case SSH_STATE_BEFORE_SIZE:
21248260 2601 case SSH_STATE_CLOSED:
374330e2 2602 break; /* do nothing */
2603 case SSH_STATE_INTERMED:
2604 size_needed = TRUE; /* buffer for later */
2605 break;
2606 case SSH_STATE_SESSION:
fef97f43 2607 if (!cfg.nopty) {
e5574168 2608 send_packet(SSH1_CMSG_WINDOW_SIZE,
fb09bf1c 2609 PKT_INT, rows, PKT_INT, cols,
2610 PKT_INT, 0, PKT_INT, 0, PKT_END);
fef97f43 2611 }
374330e2 2612 }
2613}
2614
2615/*
6abbf9e3 2616 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2617 * can send an EOF and collect resulting output (e.g. `plink
2618 * hostname sort').
374330e2 2619 */
2620static void ssh_special (Telnet_Special code) {
6abbf9e3 2621 if (code == TS_EOF) {
67779be7 2622 if (ssh_version == 1) {
6abbf9e3 2623 send_packet(SSH1_CMSG_EOF, PKT_END);
2624 } else {
2625 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 2626 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 2627 ssh2_pkt_send();
2628 }
67779be7 2629 logevent("Sent EOF message");
ec55b220 2630 } else if (code == TS_PING) {
2631 if (ssh_version == 1) {
2632 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
2633 } else {
2634 ssh2_pkt_init(SSH2_MSG_IGNORE);
2635 ssh2_pkt_addstring_start();
2636 ssh2_pkt_send();
2637 }
6abbf9e3 2638 } else {
2639 /* do nothing */
2640 }
374330e2 2641}
2642
8ccc75b0 2643static SOCKET ssh_socket(void) { return s; }
2644
2645static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 2646
374330e2 2647Backend ssh_backend = {
2648 ssh_init,
2649 ssh_msg,
2650 ssh_send,
2651 ssh_size,
4017be6d 2652 ssh_special,
8ccc75b0 2653 ssh_socket,
97db3be4 2654 ssh_sendok,
2655 22
374330e2 2656};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator