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Misc bugfixes
[u/mdw/putty] / ssh.c
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8df7a775 1#include <windows.h>
374330e2 2#include <stdio.h>
3#include <stdlib.h>
fb09bf1c 4#include <stdarg.h>
5#include <assert.h>
374330e2 6
7#include "putty.h"
dacbd0e8 8#include "tree234.h"
fb09bf1c 9#include "ssh.h"
374330e2 10
11#ifndef FALSE
12#define FALSE 0
13#endif
14#ifndef TRUE
15#define TRUE 1
16#endif
17
fb09bf1c 18#define logevent(s) { logevent(s); \
67779be7 19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
fb09bf1c 20 fprintf(stderr, "%s\n", s); }
21
8df7a775 22#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, sk_close(s), \
23 s = NULL, connection_fatal msg )
8d5de777 24
d211621f 25#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
26#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
27#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
28#define SSH1_CMSG_USER 4 /* 0x4 */
29#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
30#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
31#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
32#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
33#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
34#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
35#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
36#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
37#define SSH1_SMSG_SUCCESS 14 /* 0xe */
38#define SSH1_SMSG_FAILURE 15 /* 0xf */
39#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
40#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
41#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
42#define SSH1_CMSG_EOF 19 /* 0x13 */
43#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
44#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
45#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
46#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
47#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
48#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
49#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
50#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
51#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
52#define SSH1_MSG_IGNORE 32 /* 0x20 */
53#define SSH1_MSG_DEBUG 36 /* 0x24 */
54#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
55#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
56#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
57#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
58#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
59#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
60
61#define SSH1_AUTH_TIS 5 /* 0x5 */
62#define SSH1_AUTH_CCARD 16 /* 0x10 */
63
64#define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
65#define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
66#define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
67#define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
68#define SSH_AGENT_FAILURE 5 /* 0x5 */
69#define SSH_AGENT_SUCCESS 6 /* 0x6 */
70#define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
71#define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
72
73#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
74#define SSH2_MSG_IGNORE 2 /* 0x2 */
75#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
76#define SSH2_MSG_DEBUG 4 /* 0x4 */
77#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
78#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
79#define SSH2_MSG_KEXINIT 20 /* 0x14 */
80#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
81#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
82#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
83#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
84#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
85#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
86#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
87#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
88#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
89#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
90#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
91#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
92#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
93#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
94#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
95#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
96#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
97#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
98#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
99#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
100#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
101#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
102#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
103
9005f3ba 104#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
105#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
106#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
107#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
108#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
109#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
110#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
111#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
112#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
113#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
114#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
115
d211621f 116#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
117#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
118#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
119#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
120
121#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 122
123#define GET_32BIT(cp) \
124 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
125 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
126 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
127 ((unsigned long)(unsigned char)(cp)[3]))
128
129#define PUT_32BIT(cp, value) { \
130 (cp)[0] = (unsigned char)((value) >> 24); \
131 (cp)[1] = (unsigned char)((value) >> 16); \
132 (cp)[2] = (unsigned char)((value) >> 8); \
133 (cp)[3] = (unsigned char)(value); }
134
7cca0d81 135enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 136
374330e2 137/* Coroutine mechanics for the sillier bits of the code */
138#define crBegin1 static int crLine = 0;
139#define crBegin2 switch(crLine) { case 0:;
140#define crBegin crBegin1; crBegin2;
141#define crFinish(z) } crLine = 0; return (z)
142#define crFinishV } crLine = 0; return
143#define crReturn(z) \
144 do {\
145 crLine=__LINE__; return (z); case __LINE__:;\
146 } while (0)
147#define crReturnV \
148 do {\
149 crLine=__LINE__; return; case __LINE__:;\
150 } while (0)
151#define crStop(z) do{ crLine = 0; return (z); }while(0)
152#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 153#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 154#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 155
57476f6b 156extern const struct ssh_cipher ssh_3des;
157extern const struct ssh_cipher ssh_3des_ssh2;
158extern const struct ssh_cipher ssh_des;
159extern const struct ssh_cipher ssh_blowfish_ssh1;
160extern const struct ssh_cipher ssh_blowfish_ssh2;
e5574168 161
5e8358ad 162/*
163 * Ciphers for SSH2. We miss out single-DES because it isn't
164 * supported; also 3DES and Blowfish are both done differently from
165 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
166 * endianness and different-sized keys.)
5e8358ad 167 */
57476f6b 168const static struct ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 };
e5574168 169
57476f6b 170extern const struct ssh_kex ssh_diffiehellman;
171const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
e5574168 172
57476f6b 173extern const struct ssh_hostkey ssh_dss;
174const static struct ssh_hostkey *hostkey_algs[] = { &ssh_dss };
e5574168 175
8b2715b2 176extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy;
e5574168 177
d39f364a 178static void nullmac_key(unsigned char *key) { }
e5574168 179static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
180static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
57476f6b 181const static struct ssh_mac ssh_mac_none = {
d39f364a 182 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 183};
8b2715b2 184const static struct ssh_mac *macs[] = {
185 &ssh_sha1, &ssh_md5, &ssh_mac_none };
186const static struct ssh_mac *buggymacs[] = {
187 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
e5574168 188
57476f6b 189const static struct ssh_compress ssh_comp_none = {
e5574168 190 "none"
191};
57476f6b 192const static struct ssh_compress *compressions[] = { &ssh_comp_none };
374330e2 193
dacbd0e8 194/*
195 * 2-3-4 tree storing channels.
196 */
197struct ssh_channel {
d211621f 198 unsigned remoteid, localid;
dacbd0e8 199 int type;
200 int closes;
201 union {
202 struct ssh_agent_channel {
203 unsigned char *message;
204 unsigned char msglen[4];
205 int lensofar, totallen;
206 } a;
d211621f 207 struct ssh2_data_channel {
208 unsigned char *outbuffer;
209 unsigned outbuflen, outbufsize;
210 unsigned remwindow, remmaxpkt;
211 } v2;
dacbd0e8 212 } u;
213};
57476f6b 214
215struct Packet {
216 long length;
217 int type;
218 unsigned char *data;
219 unsigned char *body;
220 long savedpos;
221 long maxlen;
222};
223
224static SHA_State exhash;
225
8df7a775 226static Socket s = NULL;
57476f6b 227
228static unsigned char session_key[32];
229static const struct ssh_cipher *cipher = NULL;
230static const struct ssh_cipher *cscipher = NULL;
231static const struct ssh_cipher *sccipher = NULL;
232static const struct ssh_mac *csmac = NULL;
233static const struct ssh_mac *scmac = NULL;
234static const struct ssh_compress *cscomp = NULL;
235static const struct ssh_compress *sccomp = NULL;
236static const struct ssh_kex *kex = NULL;
237static const struct ssh_hostkey *hostkey = NULL;
238int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
239
240static char *savedhost;
241static int savedport;
242static int ssh_send_ok;
243
dacbd0e8 244static tree234 *ssh_channels; /* indexed by local id */
57476f6b 245static struct ssh_channel *mainchan; /* primary session channel */
246
247static enum {
248 SSH_STATE_BEFORE_SIZE,
249 SSH_STATE_INTERMED,
250 SSH_STATE_SESSION,
251 SSH_STATE_CLOSED
252} ssh_state = SSH_STATE_BEFORE_SIZE;
253
254static int size_needed = FALSE;
255
256static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
257static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
258
259static int ssh_version;
260static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
261static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
262static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
263static void ssh_size(void);
264
265static int (*s_rdpkt)(unsigned char **data, int *datalen);
266
267static struct rdpkt1_state_tag {
268 long len, pad, biglen, to_read;
269 unsigned long realcrc, gotcrc;
270 unsigned char *p;
271 int i;
272 int chunk;
273} rdpkt1_state;
274
960e736a 275static struct rdpkt2_state_tag {
276 long len, pad, payload, packetlen, maclen;
277 int i;
278 int cipherblk;
279 unsigned long incoming_sequence;
280} rdpkt2_state;
281
dacbd0e8 282static int ssh_channelcmp(void *av, void *bv) {
283 struct ssh_channel *a = (struct ssh_channel *)av;
284 struct ssh_channel *b = (struct ssh_channel *)bv;
285 if (a->localid < b->localid) return -1;
286 if (a->localid > b->localid) return +1;
287 return 0;
288}
289static int ssh_channelfind(void *av, void *bv) {
d211621f 290 unsigned *a = (unsigned *)av;
dacbd0e8 291 struct ssh_channel *b = (struct ssh_channel *)bv;
292 if (*a < b->localid) return -1;
293 if (*a > b->localid) return +1;
294 return 0;
295}
296
374330e2 297static void c_write (char *buf, int len) {
67779be7 298 if ((flags & FLAG_STDERR)) {
4017be6d 299 int i;
300 for (i = 0; i < len; i++)
301 if (buf[i] != '\r')
302 fputc(buf[i], stderr);
fb09bf1c 303 return;
304 }
fe50e814 305 from_backend(1, buf, len);
3bdaf79d 306}
307
fb09bf1c 308/*
309 * Collect incoming data in the incoming packet buffer.
e5574168 310 * Decipher and verify the packet when it is completely read.
311 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 312 * Update the *data and *datalen variables.
313 * Return the additional nr of bytes needed, or 0 when
314 * a complete packet is available.
315 */
e5574168 316static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 317{
57476f6b 318 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 319
320 crBegin;
374330e2 321
fb09bf1c 322next_packet:
37508af4 323
fb09bf1c 324 pktin.type = 0;
325 pktin.length = 0;
374330e2 326
57476f6b 327 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 328 while ((*datalen) == 0)
57476f6b 329 crReturn(4-st->i);
330 st->len = (st->len << 8) + **data;
fb09bf1c 331 (*data)++, (*datalen)--;
332 }
374330e2 333
fb09bf1c 334#ifdef FWHACK
57476f6b 335 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
336 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 337 }
338#endif
374330e2 339
57476f6b 340 st->pad = 8 - (st->len % 8);
341 st->biglen = st->len + st->pad;
342 pktin.length = st->len - 5;
fb09bf1c 343
57476f6b 344 if (pktin.maxlen < st->biglen) {
345 pktin.maxlen = st->biglen;
346 pktin.data = (pktin.data == NULL ? malloc(st->biglen+APIEXTRA) :
347 realloc(pktin.data, st->biglen+APIEXTRA));
fb09bf1c 348 if (!pktin.data)
349 fatalbox("Out of memory");
350 }
374330e2 351
57476f6b 352 st->to_read = st->biglen;
353 st->p = pktin.data;
354 while (st->to_read > 0) {
355 st->chunk = st->to_read;
fb09bf1c 356 while ((*datalen) == 0)
57476f6b 357 crReturn(st->to_read);
358 if (st->chunk > (*datalen))
359 st->chunk = (*datalen);
360 memcpy(st->p, *data, st->chunk);
361 *data += st->chunk;
362 *datalen -= st->chunk;
363 st->p += st->chunk;
364 st->to_read -= st->chunk;
fb09bf1c 365 }
374330e2 366
fb09bf1c 367 if (cipher)
57476f6b 368 cipher->decrypt(pktin.data, st->biglen);
698a5108 369#if 0
370 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
371 for (st->i = 0; st->i < st->biglen; st->i++)
372 debug((" %02x", (unsigned char)pktin.data[st->i]));
373 debug(("\r\n"));
374#endif
374330e2 375
57476f6b 376 pktin.type = pktin.data[st->pad];
377 pktin.body = pktin.data + st->pad + 1;
374330e2 378
57476f6b 379 st->realcrc = crc32(pktin.data, st->biglen-4);
380 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
381 if (st->gotcrc != st->realcrc) {
8d5de777 382 bombout(("Incorrect CRC received on packet"));
383 crReturn(0);
fb09bf1c 384 }
572f871e 385
e5574168 386 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
387 pktin.type == SSH1_SMSG_STDERR_DATA ||
388 pktin.type == SSH1_MSG_DEBUG ||
18515c51 389 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
390 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 391 long strlen = GET_32BIT(pktin.body);
8d5de777 392 if (strlen + 4 != pktin.length) {
393 bombout(("Received data packet with bogus string length"));
394 crReturn(0);
395 }
fb09bf1c 396 }
397
e5574168 398 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 399 /* log debug message */
400 char buf[80];
401 int strlen = GET_32BIT(pktin.body);
402 strcpy(buf, "Remote: ");
403 if (strlen > 70) strlen = 70;
404 memcpy(buf+8, pktin.body+4, strlen);
405 buf[8+strlen] = '\0';
406 logevent(buf);
407 goto next_packet;
e5574168 408 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 409 /* do nothing */
410 goto next_packet;
411 }
412
413 crFinish(0);
414}
415
e5574168 416static int ssh2_rdpkt(unsigned char **data, int *datalen)
417{
960e736a 418 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 419
420 crBegin;
421
422next_packet:
e5574168 423 pktin.type = 0;
424 pktin.length = 0;
960e736a 425 if (sccipher)
426 st->cipherblk = sccipher->blksize;
e5574168 427 else
960e736a 428 st->cipherblk = 8;
429 if (st->cipherblk < 8)
430 st->cipherblk = 8;
431
432 if (pktin.maxlen < st->cipherblk) {
433 pktin.maxlen = st->cipherblk;
434 pktin.data = (pktin.data == NULL ? malloc(st->cipherblk+APIEXTRA) :
435 realloc(pktin.data, st->cipherblk+APIEXTRA));
e5574168 436 if (!pktin.data)
437 fatalbox("Out of memory");
438 }
439
440 /*
441 * Acquire and decrypt the first block of the packet. This will
442 * contain the length and padding details.
443 */
960e736a 444 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 445 while ((*datalen) == 0)
960e736a 446 crReturn(st->cipherblk-st->i);
447 pktin.data[st->i] = *(*data)++;
e5574168 448 (*datalen)--;
449 }
450#ifdef FWHACK
451 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
452 /* FIXME */
453 }
454#endif
455 if (sccipher)
960e736a 456 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 457
458 /*
459 * Now get the length and padding figures.
460 */
960e736a 461 st->len = GET_32BIT(pktin.data);
462 st->pad = pktin.data[4];
e5574168 463
464 /*
465 * This enables us to deduce the payload length.
466 */
960e736a 467 st->payload = st->len - st->pad - 1;
e5574168 468
960e736a 469 pktin.length = st->payload + 5;
e5574168 470
471 /*
472 * So now we can work out the total packet length.
473 */
960e736a 474 st->packetlen = st->len + 4;
475 st->maclen = scmac ? scmac->len : 0;
e5574168 476
477 /*
478 * Adjust memory allocation if packet is too big.
479 */
960e736a 480 if (pktin.maxlen < st->packetlen+st->maclen) {
481 pktin.maxlen = st->packetlen+st->maclen;
59dcd2a8 482 pktin.data = (pktin.data == NULL ? malloc(pktin.maxlen+APIEXTRA) :
483 realloc(pktin.data, pktin.maxlen+APIEXTRA));
e5574168 484 if (!pktin.data)
485 fatalbox("Out of memory");
486 }
487
488 /*
489 * Read and decrypt the remainder of the packet.
490 */
960e736a 491 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
e5574168 492 while ((*datalen) == 0)
960e736a 493 crReturn(st->packetlen + st->maclen - st->i);
494 pktin.data[st->i] = *(*data)++;
e5574168 495 (*datalen)--;
496 }
497 /* Decrypt everything _except_ the MAC. */
498 if (sccipher)
960e736a 499 sccipher->decrypt(pktin.data + st->cipherblk,
500 st->packetlen - st->cipherblk);
e5574168 501
7cca0d81 502#if 0
960e736a 503 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
504 for (st->i = 0; st->i < st->packetlen; st->i++)
505 debug((" %02x", (unsigned char)pktin.data[st->i]));
d39f364a 506 debug(("\r\n"));
7cca0d81 507#endif
d39f364a 508
e5574168 509 /*
510 * Check the MAC.
511 */
960e736a 512 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
8d5de777 513 bombout(("Incorrect MAC received on packet"));
514 crReturn(0);
515 }
960e736a 516 st->incoming_sequence++; /* whether or not we MACed */
e5574168 517
518 pktin.savedpos = 6;
519 pktin.type = pktin.data[5];
e5574168 520
7cca0d81 521 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
522 goto next_packet; /* FIXME: print DEBUG message */
e5574168 523
524 crFinish(0);
525}
526
374330e2 527static void s_wrpkt_start(int type, int len) {
528 int pad, biglen;
529
530 len += 5; /* type and CRC */
531 pad = 8 - (len%8);
532 biglen = len + pad;
533
534 pktout.length = len-5;
535 if (pktout.maxlen < biglen) {
536 pktout.maxlen = biglen;
8f203108 537#ifdef MSCRYPTOAPI
fb09bf1c 538 /* Allocate enough buffer space for extra block
8f203108 539 * for MS CryptEncrypt() */
fb09bf1c 540 pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
541 realloc(pktout.data, biglen+12));
8f203108 542#else
c1f5f956 543 pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
544 realloc(pktout.data, biglen+4));
8f203108 545#endif
374330e2 546 if (!pktout.data)
547 fatalbox("Out of memory");
548 }
549
550 pktout.type = type;
551 pktout.body = pktout.data+4+pad+1;
552}
553
554static void s_wrpkt(void) {
555 int pad, len, biglen, i;
556 unsigned long crc;
557
558 len = pktout.length + 5; /* type and CRC */
559 pad = 8 - (len%8);
560 biglen = len + pad;
561
562 pktout.body[-1] = pktout.type;
563 for (i=0; i<pad; i++)
564 pktout.data[i+4] = random_byte();
565 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 566 PUT_32BIT(pktout.data+biglen, crc);
567 PUT_32BIT(pktout.data, len);
374330e2 568
698a5108 569#if 0
570 debug(("Sending packet len=%d\r\n", biglen+4));
571 for (i = 0; i < biglen+4; i++)
572 debug((" %02x", (unsigned char)pktout.data[i]));
573 debug(("\r\n"));
574#endif
374330e2 575 if (cipher)
576 cipher->encrypt(pktout.data+4, biglen);
577
8df7a775 578 sk_write(s, pktout.data, biglen+4);
374330e2 579}
580
fb09bf1c 581/*
582 * Construct a packet with the specified contents and
583 * send it to the server.
584 */
585static void send_packet(int pkttype, ...)
586{
587 va_list args;
588 unsigned char *p, *argp, argchar;
589 unsigned long argint;
590 int pktlen, argtype, arglen;
7cca0d81 591 Bignum bn;
fb09bf1c 592
593 pktlen = 0;
594 va_start(args, pkttype);
595 while ((argtype = va_arg(args, int)) != PKT_END) {
596 switch (argtype) {
597 case PKT_INT:
598 (void) va_arg(args, int);
599 pktlen += 4;
600 break;
601 case PKT_CHAR:
602 (void) va_arg(args, char);
603 pktlen++;
604 break;
605 case PKT_DATA:
606 (void) va_arg(args, unsigned char *);
607 arglen = va_arg(args, int);
608 pktlen += arglen;
609 break;
610 case PKT_STR:
611 argp = va_arg(args, unsigned char *);
612 arglen = strlen(argp);
613 pktlen += 4 + arglen;
614 break;
7cca0d81 615 case PKT_BIGNUM:
616 bn = va_arg(args, Bignum);
5c58ad2d 617 pktlen += ssh1_bignum_length(bn);
7cca0d81 618 break;
fb09bf1c 619 default:
620 assert(0);
621 }
622 }
623 va_end(args);
624
625 s_wrpkt_start(pkttype, pktlen);
626 p = pktout.body;
627
628 va_start(args, pkttype);
629 while ((argtype = va_arg(args, int)) != PKT_END) {
630 switch (argtype) {
631 case PKT_INT:
632 argint = va_arg(args, int);
633 PUT_32BIT(p, argint);
634 p += 4;
635 break;
636 case PKT_CHAR:
637 argchar = va_arg(args, unsigned char);
638 *p = argchar;
639 p++;
640 break;
641 case PKT_DATA:
642 argp = va_arg(args, unsigned char *);
643 arglen = va_arg(args, int);
644 memcpy(p, argp, arglen);
645 p += arglen;
646 break;
647 case PKT_STR:
648 argp = va_arg(args, unsigned char *);
649 arglen = strlen(argp);
650 PUT_32BIT(p, arglen);
651 memcpy(p + 4, argp, arglen);
652 p += 4 + arglen;
653 break;
7cca0d81 654 case PKT_BIGNUM:
655 bn = va_arg(args, Bignum);
5c58ad2d 656 p += ssh1_write_bignum(p, bn);
7cca0d81 657 break;
fb09bf1c 658 }
659 }
660 va_end(args);
661
662 s_wrpkt();
663}
664
9697bfd2 665static int ssh_versioncmp(char *a, char *b) {
666 char *ae, *be;
667 unsigned long av, bv;
668
43aa02a7 669 av = strtoul(a, &ae, 10);
670 bv = strtoul(b, &be, 10);
9697bfd2 671 if (av != bv) return (av < bv ? -1 : +1);
672 if (*ae == '.') ae++;
673 if (*be == '.') be++;
43aa02a7 674 av = strtoul(ae, &ae, 10);
675 bv = strtoul(be, &be, 10);
9697bfd2 676 if (av != bv) return (av < bv ? -1 : +1);
677 return 0;
678}
679
e5574168 680
681/*
682 * Utility routine for putting an SSH-protocol `string' into a SHA
683 * state.
684 */
685#include <stdio.h>
75cab814 686static void sha_string(SHA_State *s, void *str, int len) {
e5574168 687 unsigned char lenblk[4];
e5574168 688 PUT_32BIT(lenblk, len);
e5574168 689 SHA_Bytes(s, lenblk, 4);
e5574168 690 SHA_Bytes(s, str, len);
691}
692
7cca0d81 693/*
694 * SSH2 packet construction functions.
695 */
75cab814 696static void ssh2_pkt_adddata(void *data, int len) {
7cca0d81 697 pktout.length += len;
698 if (pktout.maxlen < pktout.length) {
699 pktout.maxlen = pktout.length + 256;
700 pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) :
701 realloc(pktout.data, pktout.maxlen+APIEXTRA));
702 if (!pktout.data)
703 fatalbox("Out of memory");
704 }
705 memcpy(pktout.data+pktout.length-len, data, len);
706}
75cab814 707static void ssh2_pkt_addbyte(unsigned char byte) {
7cca0d81 708 ssh2_pkt_adddata(&byte, 1);
709}
75cab814 710static void ssh2_pkt_init(int pkt_type) {
7cca0d81 711 pktout.length = 5;
712 ssh2_pkt_addbyte((unsigned char)pkt_type);
713}
75cab814 714static void ssh2_pkt_addbool(unsigned char value) {
7cca0d81 715 ssh2_pkt_adddata(&value, 1);
716}
75cab814 717static void ssh2_pkt_adduint32(unsigned long value) {
7cca0d81 718 unsigned char x[4];
719 PUT_32BIT(x, value);
720 ssh2_pkt_adddata(x, 4);
721}
75cab814 722static void ssh2_pkt_addstring_start(void) {
7cca0d81 723 ssh2_pkt_adduint32(0);
724 pktout.savedpos = pktout.length;
725}
75cab814 726static void ssh2_pkt_addstring_str(char *data) {
7cca0d81 727 ssh2_pkt_adddata(data, strlen(data));
728 PUT_32BIT(pktout.data + pktout.savedpos - 4,
729 pktout.length - pktout.savedpos);
730}
75cab814 731static void ssh2_pkt_addstring_data(char *data, int len) {
7cca0d81 732 ssh2_pkt_adddata(data, len);
733 PUT_32BIT(pktout.data + pktout.savedpos - 4,
734 pktout.length - pktout.savedpos);
735}
75cab814 736static void ssh2_pkt_addstring(char *data) {
7cca0d81 737 ssh2_pkt_addstring_start();
738 ssh2_pkt_addstring_str(data);
739}
75cab814 740static char *ssh2_mpint_fmt(Bignum b, int *len) {
7cca0d81 741 unsigned char *p;
742 int i, n = b[0];
743 p = malloc(n * 2 + 1);
744 if (!p)
745 fatalbox("out of memory");
746 p[0] = 0;
747 for (i = 0; i < n; i++) {
748 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
749 p[i*2+2] = (b[n-i] ) & 0xFF;
750 }
751 i = 0;
752 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
753 i++;
754 memmove(p, p+i, n*2+1-i);
755 *len = n*2+1-i;
756 return p;
757}
75cab814 758static void ssh2_pkt_addmp(Bignum b) {
7cca0d81 759 unsigned char *p;
760 int len;
761 p = ssh2_mpint_fmt(b, &len);
762 ssh2_pkt_addstring_start();
763 ssh2_pkt_addstring_data(p, len);
764 free(p);
765}
75cab814 766static void ssh2_pkt_send(void) {
7cca0d81 767 int cipherblk, maclen, padding, i;
768 static unsigned long outgoing_sequence = 0;
769
770 /*
771 * Add padding. At least four bytes, and must also bring total
772 * length (minus MAC) up to a multiple of the block size.
773 */
774 cipherblk = cipher ? cipher->blksize : 8; /* block size */
775 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
776 padding = 4;
777 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
778 pktout.data[4] = padding;
779 for (i = 0; i < padding; i++)
780 pktout.data[pktout.length + i] = random_byte();
781 PUT_32BIT(pktout.data, pktout.length + padding - 4);
782 if (csmac)
783 csmac->generate(pktout.data, pktout.length + padding,
784 outgoing_sequence);
785 outgoing_sequence++; /* whether or not we MACed */
786
787#if 0
788 debug(("Sending packet len=%d\r\n", pktout.length+padding));
789 for (i = 0; i < pktout.length+padding; i++)
790 debug((" %02x", (unsigned char)pktout.data[i]));
791 debug(("\r\n"));
792#endif
793
794 if (cscipher)
795 cscipher->encrypt(pktout.data, pktout.length + padding);
796 maclen = csmac ? csmac->len : 0;
797
8df7a775 798 sk_write(s, pktout.data, pktout.length + padding + maclen);
7cca0d81 799}
800
801#if 0
802void bndebug(char *string, Bignum b) {
803 unsigned char *p;
804 int i, len;
805 p = ssh2_mpint_fmt(b, &len);
806 debug(("%s", string));
807 for (i = 0; i < len; i++)
808 debug((" %02x", p[i]));
809 debug(("\r\n"));
810 free(p);
811}
812#endif
813
75cab814 814static void sha_mpint(SHA_State *s, Bignum b) {
7cca0d81 815 unsigned char *p;
816 int len;
817 p = ssh2_mpint_fmt(b, &len);
818 sha_string(s, p, len);
819 free(p);
820}
821
822/*
823 * SSH2 packet decode functions.
824 */
75cab814 825static unsigned long ssh2_pkt_getuint32(void) {
7cca0d81 826 unsigned long value;
827 if (pktin.length - pktin.savedpos < 4)
828 return 0; /* arrgh, no way to decline (FIXME?) */
829 value = GET_32BIT(pktin.data+pktin.savedpos);
830 pktin.savedpos += 4;
831 return value;
832}
75cab814 833static void ssh2_pkt_getstring(char **p, int *length) {
7cca0d81 834 *p = NULL;
835 if (pktin.length - pktin.savedpos < 4)
836 return;
837 *length = GET_32BIT(pktin.data+pktin.savedpos);
838 pktin.savedpos += 4;
839 if (pktin.length - pktin.savedpos < *length)
840 return;
841 *p = pktin.data+pktin.savedpos;
842 pktin.savedpos += *length;
843}
75cab814 844static Bignum ssh2_pkt_getmp(void) {
7cca0d81 845 char *p;
846 int i, j, length;
847 Bignum b;
848
849 ssh2_pkt_getstring(&p, &length);
850 if (!p)
851 return NULL;
8d5de777 852 if (p[0] & 0x80) {
853 bombout(("internal error: Can't handle negative mpints"));
854 return NULL;
855 }
7cca0d81 856 b = newbn((length+1)/2);
857 for (i = 0; i < length; i++) {
858 j = length - 1 - i;
859 if (j & 1)
860 b[j/2+1] |= ((unsigned char)p[i]) << 8;
861 else
862 b[j/2+1] |= ((unsigned char)p[i]);
863 }
6b4e00ee 864 while (b[0] > 1 && b[b[0]] == 0) b[0]--;
7cca0d81 865 return b;
866}
867
8df7a775 868static int do_ssh_init(unsigned char c) {
869 static char *vsp;
870 static char version[10];
871 static char vstring[80];
872 static char vlog[sizeof(vstring)+20];
873 static int i;
374330e2 874
8df7a775 875 crBegin;
876
877 /* Search for the string "SSH-" in the input. */
374330e2 878 i = 0;
8df7a775 879 while (1) {
880 static const int transS[] = { 1, 2, 2, 1 };
881 static const int transH[] = { 0, 0, 3, 0 };
882 static const int transminus[] = { 0, 0, 0, -1 };
883 if (c == 'S') i = transS[i];
884 else if (c == 'H') i = transH[i];
885 else if (c == '-') i = transminus[i];
374330e2 886 else i = 0;
8df7a775 887 if (i < 0)
888 break;
889 crReturn(1); /* get another character */
374330e2 890 }
8df7a775 891
c5e9c988 892 strcpy(vstring, "SSH-");
893 vsp = vstring+4;
374330e2 894 i = 0;
895 while (1) {
8df7a775 896 crReturn(1); /* get another char */
c5e9c988 897 if (vsp < vstring+sizeof(vstring)-1)
898 *vsp++ = c;
374330e2 899 if (i >= 0) {
900 if (c == '-') {
901 version[i] = '\0';
902 i = -1;
903 } else if (i < sizeof(version)-1)
904 version[i++] = c;
905 }
906 else if (c == '\n')
907 break;
908 }
909
960e736a 910 rdpkt2_state.incoming_sequence = 0;
911
c5e9c988 912 *vsp = 0;
913 sprintf(vlog, "Server version: %s", vstring);
914 vlog[strcspn(vlog, "\r\n")] = '\0';
915 logevent(vlog);
916
adf799dd 917 /*
918 * Server version "1.99" means we can choose whether we use v1
919 * or v2 protocol. Choice is based on cfg.sshprot.
920 */
921 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 922 /*
923 * This is a v2 server. Begin v2 protocol.
924 */
925 char *verstring = "SSH-2.0-PuTTY";
926 SHA_Init(&exhash);
927 /*
928 * Hash our version string and their version string.
929 */
930 sha_string(&exhash, verstring, strlen(verstring));
931 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
932 sprintf(vstring, "%s\n", verstring);
933 sprintf(vlog, "We claim version: %s", verstring);
934 logevent(vlog);
935 logevent("Using SSH protocol version 2");
8df7a775 936 sk_write(s, vstring, strlen(vstring));
e5574168 937 ssh_protocol = ssh2_protocol;
6abbf9e3 938 ssh_version = 2;
e5574168 939 s_rdpkt = ssh2_rdpkt;
940 } else {
941 /*
942 * This is a v1 server. Begin v1 protocol.
943 */
944 sprintf(vstring, "SSH-%s-PuTTY\n",
945 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
946 sprintf(vlog, "We claim version: %s", vstring);
947 vlog[strcspn(vlog, "\r\n")] = '\0';
948 logevent(vlog);
949 logevent("Using SSH protocol version 1");
8df7a775 950 sk_write(s, vstring, strlen(vstring));
e5574168 951 ssh_protocol = ssh1_protocol;
6abbf9e3 952 ssh_version = 1;
e5574168 953 s_rdpkt = ssh1_rdpkt;
954 }
8df7a775 955
956 crFinish(0);
957}
958
959static void ssh_gotdata(unsigned char *data, int datalen)
960{
961 crBegin;
962
963 /*
964 * To begin with, feed the characters one by one to the
965 * protocol initialisation / selection function do_ssh_init().
966 * When that returns 0, we're done with the initial greeting
967 * exchange and can move on to packet discipline.
968 */
969 while (1) {
970 int ret;
971 if (datalen == 0)
972 crReturnV; /* more data please */
973 ret = do_ssh_init(*data);
974 data++; datalen--;
975 if (ret == 0)
976 break;
977 }
978
979 /*
980 * We emerge from that loop when the initial negotiation is
981 * over and we have selected an s_rdpkt function. Now pass
982 * everything to s_rdpkt, and then pass the resulting packets
983 * to the proper protocol handler.
984 */
985 if (datalen == 0)
986 crReturnV;
987 while (1) {
988 while (datalen > 0) {
989 if ( s_rdpkt(&data, &datalen) == 0 ) {
990 ssh_protocol(NULL, 0, 1);
991 if (ssh_state == SSH_STATE_CLOSED) {
992 return;
993 }
994 }
995 }
996 crReturnV;
997 }
998 crFinishV;
999}
1000
340cf649 1001static int ssh_receive(Socket skt, int urgent, char *data, int len) {
8df7a775 1002 if (!len) {
1003 /* Connection has closed. */
1004 sk_close(s);
1005 s = NULL;
1006 return 0;
1007 }
1008 ssh_gotdata (data, len);
3257deae 1009 if (ssh_state == SSH_STATE_CLOSED) {
1010 if (s) {
1011 sk_close(s);
1012 s = NULL;
1013 }
1014 return 0;
1015 }
fef97f43 1016 return 1;
374330e2 1017}
1018
fb09bf1c 1019/*
8df7a775 1020 * Connect to specified host and port.
1021 * Returns an error message, or NULL on success.
1022 * Also places the canonical host name into `realhost'.
1023 */
1024static char *connect_to_host(char *host, int port, char **realhost)
1025{
1026 SockAddr addr;
1027 char *err;
1028#ifdef FWHACK
1029 char *FWhost;
1030 int FWport;
1031#endif
1032
1033 savedhost = malloc(1+strlen(host));
1034 if (!savedhost)
1035 fatalbox("Out of memory");
1036 strcpy(savedhost, host);
1037
1038 if (port < 0)
1039 port = 22; /* default ssh port */
1040 savedport = port;
1041
1042#ifdef FWHACK
1043 FWhost = host;
1044 FWport = port;
1045 host = FWSTR;
1046 port = 23;
1047#endif
1048
1049 /*
1050 * Try to find host.
1051 */
1052 addr = sk_namelookup(host, realhost);
1053 if ( (err = sk_addr_error(addr)) )
1054 return err;
1055
1056#ifdef FWHACK
1057 *realhost = FWhost;
1058#endif
1059
1060 /*
1061 * Open socket.
1062 */
1063 s = sk_new(addr, port, ssh_receive);
1064 if ( (err = sk_socket_error(s)) )
1065 return err;
1066
1067#ifdef FWHACK
1068 sk_write(s, "connect ", 8);
1069 sk_write(s, FWhost, strlen(FWhost));
1070 {
1071 char buf[20];
1072 sprintf(buf, " %d\n", FWport);
1073 sk_write(s, buf, strlen(buf));
1074 }
1075#endif
1076
1077 return NULL;
1078}
1079
1080/*
fb09bf1c 1081 * Handle the key exchange and user authentication phases.
1082 */
e5574168 1083static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1084{
374330e2 1085 int i, j, len;
374330e2 1086 unsigned char *rsabuf, *keystr1, *keystr2;
1087 unsigned char cookie[8];
1088 struct RSAKey servkey, hostkey;
1089 struct MD5Context md5c;
ccbfb941 1090 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1091 static int tried_publickey;
1092 static unsigned char session_id[16];
bea1ef5f 1093 int cipher_type;
b585ec46 1094 static char username[100];
374330e2 1095
374330e2 1096 crBegin;
1097
fb09bf1c 1098 if (!ispkt) crWaitUntil(ispkt);
374330e2 1099
8d5de777 1100 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1101 bombout(("Public key packet not received"));
1102 crReturn(0);
1103 }
374330e2 1104
c5e9c988 1105 logevent("Received public keys");
374330e2 1106
c5e9c988 1107 memcpy(cookie, pktin.body, 8);
374330e2 1108
7cca0d81 1109 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1110 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1111
c5e9c988 1112 /*
1c2a93c4 1113 * Log the host key fingerprint.
c5e9c988 1114 */
c5e9c988 1115 {
1116 char logmsg[80];
1c2a93c4 1117 logevent("Host key fingerprint is:");
c5e9c988 1118 strcpy(logmsg, " ");
1c2a93c4 1119 hostkey.comment = NULL;
1120 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1121 &hostkey);
c5e9c988 1122 logevent(logmsg);
1123 }
1124
fb09bf1c 1125 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1126 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1127
c5e9c988 1128 MD5Init(&md5c);
374330e2 1129 MD5Update(&md5c, keystr2, hostkey.bytes);
1130 MD5Update(&md5c, keystr1, servkey.bytes);
1131 MD5Update(&md5c, pktin.body, 8);
374330e2 1132 MD5Final(session_id, &md5c);
1133
1134 for (i=0; i<32; i++)
1135 session_key[i] = random_byte();
1136
1137 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1138
1139 rsabuf = malloc(len);
1140 if (!rsabuf)
1141 fatalbox("Out of memory");
1142
89ee5268 1143 /*
1144 * Verify the host key.
1145 */
1146 {
1147 /*
1148 * First format the key into a string.
1149 */
1150 int len = rsastr_len(&hostkey);
d5859615 1151 char fingerprint[100];
89ee5268 1152 char *keystr = malloc(len);
1153 if (!keystr)
1154 fatalbox("Out of memory");
1155 rsastr_fmt(keystr, &hostkey);
d5859615 1156 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1157 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
89ee5268 1158 free(keystr);
1159 }
374330e2 1160
1161 for (i=0; i<32; i++) {
1162 rsabuf[i] = session_key[i];
1163 if (i < 16)
1164 rsabuf[i] ^= session_id[i];
1165 }
1166
1167 if (hostkey.bytes > servkey.bytes) {
1168 rsaencrypt(rsabuf, 32, &servkey);
1169 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1170 } else {
1171 rsaencrypt(rsabuf, 32, &hostkey);
1172 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1173 }
1174
c5e9c988 1175 logevent("Encrypted session key");
1176
bea1ef5f 1177 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1178 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1179 SSH_CIPHER_3DES;
1180 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1181 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1182 cipher_type = SSH_CIPHER_3DES;
1183 }
c5e9c988 1184 switch (cipher_type) {
1185 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1186 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1187 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1188 }
bea1ef5f 1189
e5574168 1190 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1191 PKT_CHAR, cipher_type,
1192 PKT_DATA, cookie, 8,
1193 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1194 PKT_DATA, rsabuf, len,
1195 PKT_INT, 0,
1196 PKT_END);
1197
c5e9c988 1198 logevent("Trying to enable encryption...");
374330e2 1199
1200 free(rsabuf);
1201
5e8358ad 1202 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1203 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1204 &ssh_3des;
374330e2 1205 cipher->sesskey(session_key);
1206
fb09bf1c 1207 crWaitUntil(ispkt);
374330e2 1208
8d5de777 1209 if (pktin.type != SSH1_SMSG_SUCCESS) {
1210 bombout(("Encryption not successfully enabled"));
1211 crReturn(0);
1212 }
374330e2 1213
c5e9c988 1214 logevent("Successfully started encryption");
1215
374330e2 1216 fflush(stdout);
1217 {
374330e2 1218 static int pos = 0;
1219 static char c;
67779be7 1220 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1221 c_write("login as: ", 10);
67779be7 1222 ssh_send_ok = 1;
374330e2 1223 while (pos >= 0) {
fb09bf1c 1224 crWaitUntil(!ispkt);
374330e2 1225 while (inlen--) switch (c = *in++) {
1226 case 10: case 13:
1227 username[pos] = 0;
1228 pos = -1;
1229 break;
1230 case 8: case 127:
1231 if (pos > 0) {
1232 c_write("\b \b", 3);
1233 pos--;
1234 }
1235 break;
1236 case 21: case 27:
1237 while (pos > 0) {
1238 c_write("\b \b", 3);
1239 pos--;
1240 }
1241 break;
1242 case 3: case 4:
1243 random_save_seed();
1244 exit(0);
1245 break;
1246 default:
40d24aa6 1247 if (((c >= ' ' && c <= '~') ||
1248 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1249 username[pos++] = c;
1250 c_write(&c, 1);
1251 }
1252 break;
1253 }
1254 }
1255 c_write("\r\n", 2);
1256 username[strcspn(username, "\n\r")] = '\0';
1257 } else {
1258 char stuff[200];
1259 strncpy(username, cfg.username, 99);
1260 username[99] = '\0';
67779be7 1261 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
fb09bf1c 1262 sprintf(stuff, "Sent username \"%s\".\r\n", username);
4017be6d 1263 c_write(stuff, strlen(stuff));
fb09bf1c 1264 }
374330e2 1265 }
fb09bf1c 1266
e5574168 1267 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1268 {
1269 char userlog[20+sizeof(username)];
1270 sprintf(userlog, "Sent username \"%s\"", username);
1271 logevent(userlog);
1272 }
374330e2 1273 }
1274
fb09bf1c 1275 crWaitUntil(ispkt);
374330e2 1276
7cca0d81 1277 tried_publickey = 0;
1278
e5574168 1279 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1280 static char password[100];
a52f067e 1281 static char prompt[200];
374330e2 1282 static int pos;
1283 static char c;
ccbfb941 1284 static int pwpkt_type;
ccbfb941 1285 /*
1286 * Show password prompt, having first obtained it via a TIS
18515c51 1287 * or CryptoCard exchange if we're doing TIS or CryptoCard
1288 * authentication.
ccbfb941 1289 */
e5574168 1290 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1291 if (agent_exists()) {
1292 /*
1293 * Attempt RSA authentication using Pageant.
1294 */
1295 static unsigned char request[5], *response, *p;
1296 static int responselen;
1297 static int i, nkeys;
1298 static int authed = FALSE;
1299 void *r;
1300
1301 logevent("Pageant is running. Requesting keys.");
1302
1303 /* Request the keys held by the agent. */
1304 PUT_32BIT(request, 1);
1305 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1306 agent_query(request, 5, &r, &responselen);
1307 response = (unsigned char *)r;
1308 if (response) {
1309 p = response + 5;
1310 nkeys = GET_32BIT(p); p += 4;
1311 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1312 logevent(buf); }
1313 for (i = 0; i < nkeys; i++) {
1314 static struct RSAKey key;
1315 static Bignum challenge;
b8bb811a 1316 static char *commentp;
1317 static int commentlen;
5c58ad2d 1318
1319 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1320 logevent(buf); }
1321 p += 4;
1322 p += ssh1_read_bignum(p, &key.exponent);
1323 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1324 commentlen = GET_32BIT(p); p += 4;
1325 commentp = p; p += commentlen;
5c58ad2d 1326 send_packet(SSH1_CMSG_AUTH_RSA,
1327 PKT_BIGNUM, key.modulus, PKT_END);
1328 crWaitUntil(ispkt);
1329 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1330 logevent("Key refused");
1331 continue;
1332 }
1333 logevent("Received RSA challenge");
1334 ssh1_read_bignum(pktin.body, &challenge);
1335 {
1336 char *agentreq, *q, *ret;
1337 int len, retlen;
1338 len = 1 + 4; /* message type, bit count */
1339 len += ssh1_bignum_length(key.exponent);
1340 len += ssh1_bignum_length(key.modulus);
1341 len += ssh1_bignum_length(challenge);
1342 len += 16; /* session id */
1343 len += 4; /* response format */
1344 agentreq = malloc(4 + len);
1345 PUT_32BIT(agentreq, len);
1346 q = agentreq + 4;
1347 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1348 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1349 q += 4;
1350 q += ssh1_write_bignum(q, key.exponent);
1351 q += ssh1_write_bignum(q, key.modulus);
1352 q += ssh1_write_bignum(q, challenge);
1353 memcpy(q, session_id, 16); q += 16;
1354 PUT_32BIT(q, 1); /* response format */
1355 agent_query(agentreq, len+4, &ret, &retlen);
1356 free(agentreq);
1357 if (ret) {
1358 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1359 logevent("Sending Pageant's response");
1360 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1361 PKT_DATA, ret+5, 16, PKT_END);
1362 free(ret);
1363 crWaitUntil(ispkt);
1364 if (pktin.type == SSH1_SMSG_SUCCESS) {
1365 logevent("Pageant's response accepted");
c4fa2fce 1366 if (flags & FLAG_VERBOSE) {
1367 c_write("Authenticated using RSA key \"",
1368 29);
1369 c_write(commentp, commentlen);
1370 c_write("\" from agent\r\n", 14);
1371 }
5c58ad2d 1372 authed = TRUE;
1373 } else
1374 logevent("Pageant's response not accepted");
1375 } else {
1376 logevent("Pageant failed to answer challenge");
1377 free(ret);
1378 }
1379 } else {
1380 logevent("No reply received from Pageant");
1381 }
1382 }
1383 freebn(key.exponent);
1384 freebn(key.modulus);
1385 freebn(challenge);
1386 if (authed)
1387 break;
1388 }
1389 }
1390 if (authed)
1391 break;
1392 }
7cca0d81 1393 if (*cfg.keyfile && !tried_publickey)
1394 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1395
a52f067e 1396 if (pktin.type == SSH1_SMSG_FAILURE &&
1397 cfg.try_tis_auth &&
1398 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1399 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1400 logevent("Requested TIS authentication");
1401 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1402 crWaitUntil(ispkt);
1403 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1404 logevent("TIS authentication declined");
1405 if (flags & FLAG_INTERACTIVE)
1406 c_write("TIS authentication refused.\r\n", 29);
1407 } else {
1408 int challengelen = ((pktin.body[0] << 24) |
1409 (pktin.body[1] << 16) |
1410 (pktin.body[2] << 8) |
1411 (pktin.body[3]));
1412 logevent("Received TIS challenge");
1413 if (challengelen > sizeof(prompt)-1)
1414 challengelen = sizeof(prompt)-1; /* prevent overrun */
1415 memcpy(prompt, pktin.body+4, challengelen);
1416 prompt[challengelen] = '\0';
1417 }
1418 }
1419 if (pktin.type == SSH1_SMSG_FAILURE &&
1420 cfg.try_tis_auth &&
1421 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1422 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1423 logevent("Requested CryptoCard authentication");
1424 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1425 crWaitUntil(ispkt);
1426 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1427 logevent("CryptoCard authentication declined");
1428 c_write("CryptoCard authentication refused.\r\n", 29);
1429 } else {
1430 int challengelen = ((pktin.body[0] << 24) |
1431 (pktin.body[1] << 16) |
1432 (pktin.body[2] << 8) |
1433 (pktin.body[3]));
1434 logevent("Received CryptoCard challenge");
1435 if (challengelen > sizeof(prompt)-1)
1436 challengelen = sizeof(prompt)-1; /* prevent overrun */
1437 memcpy(prompt, pktin.body+4, challengelen);
1438 strncpy(prompt + challengelen, "\r\nResponse : ",
1439 sizeof(prompt)-challengelen);
1440 prompt[sizeof(prompt)-1] = '\0';
1441 }
1442 }
1443 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1444 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1445 username, savedhost);
a52f067e 1446 }
1447 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1448 char *comment = NULL;
1449 if (flags & FLAG_VERBOSE)
1450 c_write("Trying public key authentication.\r\n", 35);
1451 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1452 if (flags & FLAG_VERBOSE)
1453 c_write("No passphrase required.\r\n", 25);
1454 goto tryauth;
1455 }
1456 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1457 free(comment);
1458 }
1459
d8426c54 1460 if (ssh_get_password) {
85ee8208 1461 if (!ssh_get_password(prompt, password, sizeof(password))) {
1462 /*
1463 * get_password failed to get a password (for
1464 * example because one was supplied on the command
1465 * line which has already failed to work).
1466 * Terminate.
1467 */
1468 logevent("No more passwords to try");
1469 ssh_state = SSH_STATE_CLOSED;
1470 crReturn(1);
1471 }
fb09bf1c 1472 } else {
a52f067e 1473 c_write(prompt, strlen(prompt));
7cca0d81 1474 pos = 0;
67779be7 1475 ssh_send_ok = 1;
7cca0d81 1476 while (pos >= 0) {
1477 crWaitUntil(!ispkt);
1478 while (inlen--) switch (c = *in++) {
1479 case 10: case 13:
1480 password[pos] = 0;
1481 pos = -1;
1482 break;
1483 case 8: case 127:
1484 if (pos > 0)
1485 pos--;
1486 break;
1487 case 21: case 27:
1488 pos = 0;
1489 break;
1490 case 3: case 4:
1491 random_save_seed();
1492 exit(0);
1493 break;
1494 default:
1495 if (((c >= ' ' && c <= '~') ||
1496 ((unsigned char)c >= 160)) && pos < sizeof(password))
1497 password[pos++] = c;
1498 break;
1499 }
1500 }
1501 c_write("\r\n", 2);
a52f067e 1502 }
fb09bf1c 1503
7cca0d81 1504 tryauth:
1505 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1506 /*
1507 * Try public key authentication with the specified
1508 * key file.
1509 */
1510 static struct RSAKey pubkey;
1511 static Bignum challenge, response;
1512 static int i;
1513 static unsigned char buffer[32];
1514
1515 tried_publickey = 1;
6e522441 1516 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
7cca0d81 1517 if (i == 0) {
1518 c_write("Couldn't load public key from ", 30);
1519 c_write(cfg.keyfile, strlen(cfg.keyfile));
1520 c_write(".\r\n", 3);
1521 continue; /* go and try password */
1522 }
1523 if (i == -1) {
1524 c_write("Wrong passphrase.\r\n", 19);
1525 tried_publickey = 0;
1526 continue; /* try again */
1527 }
1528
1529 /*
1530 * Send a public key attempt.
1531 */
1532 send_packet(SSH1_CMSG_AUTH_RSA,
1533 PKT_BIGNUM, pubkey.modulus, PKT_END);
1534
1535 crWaitUntil(ispkt);
1536 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1537 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1538 continue; /* go and try password */
1539 }
8d5de777 1540 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1541 bombout(("Bizarre response to offer of public key"));
1542 crReturn(0);
1543 }
7cca0d81 1544 ssh1_read_bignum(pktin.body, &challenge);
1545 response = rsadecrypt(challenge, &pubkey);
1546 freebn(pubkey.private_exponent); /* burn the evidence */
1547
1548 for (i = 0; i < 32; i += 2) {
1549 buffer[i] = response[16-i/2] >> 8;
1550 buffer[i+1] = response[16-i/2] & 0xFF;
1551 }
1552
1553 MD5Init(&md5c);
1554 MD5Update(&md5c, buffer, 32);
1555 MD5Update(&md5c, session_id, 16);
1556 MD5Final(buffer, &md5c);
1557
1558 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1559 PKT_DATA, buffer, 16, PKT_END);
1560
1561 crWaitUntil(ispkt);
1562 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1563 if (flags & FLAG_VERBOSE)
1564 c_write("Failed to authenticate with our public key.\r\n",
1565 45);
7cca0d81 1566 continue; /* go and try password */
1567 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1568 bombout(("Bizarre response to RSA authentication response"));
1569 crReturn(0);
7cca0d81 1570 }
1571
1572 break; /* we're through! */
1573 } else {
1574 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1575 }
c5e9c988 1576 logevent("Sent password");
374330e2 1577 memset(password, 0, strlen(password));
fb09bf1c 1578 crWaitUntil(ispkt);
e5574168 1579 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1580 if (flags & FLAG_VERBOSE)
1581 c_write("Access denied\r\n", 15);
c5e9c988 1582 logevent("Authentication refused");
e5574168 1583 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1584 logevent("Received disconnect request");
85ee8208 1585 ssh_state = SSH_STATE_CLOSED;
1586 crReturn(1);
e5574168 1587 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1588 bombout(("Strange packet received, type %d", pktin.type));
1589 crReturn(0);
374330e2 1590 }
1591 }
1592
c5e9c988 1593 logevent("Authentication successful");
1594
fb09bf1c 1595 crFinish(1);
1596}
1597
e5574168 1598static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1599 crBegin;
1600
1601 random_init();
1602
e5574168 1603 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1604 crReturnV;
85ee8208 1605 }
1606 if (ssh_state == SSH_STATE_CLOSED)
1607 crReturnV;
fb09bf1c 1608
979310f1 1609 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1610 logevent("Requesting agent forwarding");
1611 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1612 do { crReturnV; } while (!ispkt);
1613 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1614 bombout(("Protocol confusion"));
1615 crReturnV;
dacbd0e8 1616 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1617 logevent("Agent forwarding refused");
1618 } else
1619 logevent("Agent forwarding enabled");
1620 }
1621
fef97f43 1622 if (!cfg.nopty) {
e5574168 1623 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1624 PKT_STR, cfg.termtype,
1625 PKT_INT, rows, PKT_INT, cols,
1626 PKT_INT, 0, PKT_INT, 0,
1627 PKT_CHAR, 0,
1628 PKT_END);
fef97f43 1629 ssh_state = SSH_STATE_INTERMED;
1630 do { crReturnV; } while (!ispkt);
e5574168 1631 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1632 bombout(("Protocol confusion"));
1633 crReturnV;
e5574168 1634 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1635 c_write("Server refused to allocate pty\r\n", 32);
1636 }
c5e9c988 1637 logevent("Allocated pty");
374330e2 1638 }
1639
6abbf9e3 1640 if (*cfg.remote_cmd)
1641 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1642 else
1643 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1644 logevent("Started session");
374330e2 1645
1646 ssh_state = SSH_STATE_SESSION;
1647 if (size_needed)
1648 ssh_size();
1649
8ccc75b0 1650 ssh_send_ok = 1;
dacbd0e8 1651 ssh_channels = newtree234(ssh_channelcmp);
6f34e365 1652 begin_session();
374330e2 1653 while (1) {
1654 crReturnV;
1655 if (ispkt) {
e5574168 1656 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1657 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1658 long len = GET_32BIT(pktin.body);
fe50e814 1659 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1660 pktin.body+4, len);
e5574168 1661 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1662 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1663 logevent("Received disconnect request");
3257deae 1664 crReturnV;
dacbd0e8 1665 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1666 /* Remote side is trying to open a channel to talk to our
1667 * agent. Give them back a local channel number. */
d211621f 1668 unsigned i = 1;
dacbd0e8 1669 struct ssh_channel *c;
1670 enum234 e;
1671 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1672 if (c->localid > i)
1673 break; /* found a free number */
1674 i = c->localid + 1;
1675 }
1676 c = malloc(sizeof(struct ssh_channel));
1677 c->remoteid = GET_32BIT(pktin.body);
1678 c->localid = i;
b8bb811a 1679 c->closes = 0;
dacbd0e8 1680 c->type = SSH1_SMSG_AGENT_OPEN; /* identify channel type */
bb487ce2 1681 c->u.a.lensofar = 0;
dacbd0e8 1682 add234(ssh_channels, c);
1683 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1684 PKT_INT, c->remoteid, PKT_INT, c->localid,
1685 PKT_END);
1686 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1687 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1688 /* Remote side closes a channel. */
d211621f 1689 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1690 struct ssh_channel *c;
1691 c = find234(ssh_channels, &i, ssh_channelfind);
1692 if (c) {
1693 int closetype;
1694 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1695 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1696 c->closes |= closetype;
1697 if (c->closes == 3) {
1698 del234(ssh_channels, c);
1699 free(c);
1700 }
1701 }
1702 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1703 /* Data sent down one of our channels. */
1704 int i = GET_32BIT(pktin.body);
1705 int len = GET_32BIT(pktin.body+4);
1706 unsigned char *p = pktin.body+8;
1707 struct ssh_channel *c;
1708 c = find234(ssh_channels, &i, ssh_channelfind);
1709 if (c) {
1710 switch(c->type) {
1711 case SSH1_SMSG_AGENT_OPEN:
1712 /* Data for an agent message. Buffer it. */
1713 while (len > 0) {
1714 if (c->u.a.lensofar < 4) {
1715 int l = min(4 - c->u.a.lensofar, len);
1716 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
1717 p += l; len -= l; c->u.a.lensofar += l;
1718 }
1719 if (c->u.a.lensofar == 4) {
1720 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
1721 c->u.a.message = malloc(c->u.a.totallen);
1722 memcpy(c->u.a.message, c->u.a.msglen, 4);
1723 }
1724 if (c->u.a.lensofar >= 4 && len > 0) {
1725 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
1726 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
1727 p += l; len -= l; c->u.a.lensofar += l;
1728 }
1729 if (c->u.a.lensofar == c->u.a.totallen) {
1730 void *reply, *sentreply;
1731 int replylen;
1732 agent_query(c->u.a.message, c->u.a.totallen,
1733 &reply, &replylen);
1734 if (reply)
1735 sentreply = reply;
1736 else {
1737 /* Fake SSH_AGENT_FAILURE. */
1738 sentreply = "\0\0\0\1\5";
1739 replylen = 5;
1740 }
1741 send_packet(SSH1_MSG_CHANNEL_DATA,
1742 PKT_INT, c->remoteid,
1743 PKT_INT, replylen,
1744 PKT_DATA, sentreply, replylen,
1745 PKT_END);
1746 if (reply)
1747 free(reply);
1748 free(c->u.a.message);
1749 c->u.a.lensofar = 0;
1750 }
1751 }
1752 break;
1753 }
1754 }
e5574168 1755 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 1756 /* may be from EXEC_SHELL on some servers */
e5574168 1757 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 1758 /* may be from EXEC_SHELL on some servers
374330e2 1759 * if no pty is available or in other odd cases. Ignore */
e5574168 1760 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1761 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 1762 } else {
8d5de777 1763 bombout(("Strange packet received: type %d", pktin.type));
1764 crReturnV;
374330e2 1765 }
1766 } else {
8df7a775 1767 while (inlen > 0) {
1768 int len = min(inlen, 512);
1769 send_packet(SSH1_CMSG_STDIN_DATA,
1770 PKT_INT, len, PKT_DATA, in, len, PKT_END);
1771 in += len;
1772 inlen -= len;
1773 }
374330e2 1774 }
1775 }
1776
1777 crFinishV;
1778}
1779
1780/*
e5574168 1781 * Utility routine for decoding comma-separated strings in KEXINIT.
1782 */
75cab814 1783static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 1784 int needlen = strlen(needle);
1785 while (1) {
1786 /*
1787 * Is it at the start of the string?
1788 */
1789 if (haylen >= needlen && /* haystack is long enough */
1790 !memcmp(needle, haystack, needlen) && /* initial match */
1791 (haylen == needlen || haystack[needlen] == ',')
1792 /* either , or EOS follows */
1793 )
1794 return 1;
1795 /*
1796 * If not, search for the next comma and resume after that.
1797 * If no comma found, terminate.
1798 */
1799 while (haylen > 0 && *haystack != ',')
1800 haylen--, haystack++;
1801 if (haylen == 0)
1802 return 0;
1803 haylen--, haystack++; /* skip over comma itself */
1804 }
1805}
1806
1807/*
d39f364a 1808 * SSH2 key creation method.
1809 */
75cab814 1810static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
d39f364a 1811 SHA_State s;
1812 /* First 20 bytes. */
1813 SHA_Init(&s);
1814 sha_mpint(&s, K);
1815 SHA_Bytes(&s, H, 20);
1816 SHA_Bytes(&s, &chr, 1);
1817 SHA_Bytes(&s, H, 20);
1818 SHA_Final(&s, keyspace);
1819 /* Next 20 bytes. */
1820 SHA_Init(&s);
1821 sha_mpint(&s, K);
1822 SHA_Bytes(&s, H, 20);
1823 SHA_Bytes(&s, keyspace, 20);
1824 SHA_Final(&s, keyspace+20);
1825}
1826
1827/*
7cca0d81 1828 * Handle the SSH2 transport layer.
e5574168 1829 */
7cca0d81 1830static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 1831{
1832 static int i, len;
1833 static char *str;
1834 static Bignum e, f, K;
7591b9ff 1835 static const struct ssh_mac **maclist;
8b2715b2 1836 static int nmacs;
57476f6b 1837 static const struct ssh_cipher *cscipher_tobe = NULL;
1838 static const struct ssh_cipher *sccipher_tobe = NULL;
1839 static const struct ssh_mac *csmac_tobe = NULL;
1840 static const struct ssh_mac *scmac_tobe = NULL;
1841 static const struct ssh_compress *cscomp_tobe = NULL;
1842 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 1843 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 1844 static int hostkeylen, siglen;
1845 static unsigned char exchange_hash[20];
d39f364a 1846 static unsigned char keyspace[40];
57476f6b 1847 static const struct ssh_cipher *preferred_cipher;
e5574168 1848
1849 crBegin;
7cca0d81 1850 random_init();
e5574168 1851
5e8358ad 1852 /*
1853 * Set up the preferred cipher.
1854 */
1855 if (cfg.cipher == CIPHER_BLOWFISH) {
57476f6b 1856 preferred_cipher = &ssh_blowfish_ssh2;
5e8358ad 1857 } else if (cfg.cipher == CIPHER_DES) {
1858 logevent("Single DES not supported in SSH2; using 3DES");
57476f6b 1859 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1860 } else if (cfg.cipher == CIPHER_3DES) {
57476f6b 1861 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1862 } else {
1863 /* Shouldn't happen, but we do want to initialise to _something_. */
57476f6b 1864 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1865 }
1866
7591b9ff 1867 /*
1868 * Be prepared to work around the buggy MAC problem.
1869 */
1870 if (cfg.buggymac)
8b2715b2 1871 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 1872 else
8b2715b2 1873 maclist = macs, nmacs = lenof(macs);
7591b9ff 1874
7cca0d81 1875 begin_key_exchange:
e5574168 1876 /*
1877 * Construct and send our key exchange packet.
1878 */
1879 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1880 for (i = 0; i < 16; i++)
1881 ssh2_pkt_addbyte((unsigned char)random_byte());
1882 /* List key exchange algorithms. */
1883 ssh2_pkt_addstring_start();
1884 for (i = 0; i < lenof(kex_algs); i++) {
1885 ssh2_pkt_addstring_str(kex_algs[i]->name);
1886 if (i < lenof(kex_algs)-1)
1887 ssh2_pkt_addstring_str(",");
1888 }
1889 /* List server host key algorithms. */
1890 ssh2_pkt_addstring_start();
1891 for (i = 0; i < lenof(hostkey_algs); i++) {
1892 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1893 if (i < lenof(hostkey_algs)-1)
1894 ssh2_pkt_addstring_str(",");
1895 }
1896 /* List client->server encryption algorithms. */
1897 ssh2_pkt_addstring_start();
729e54b4 1898 for (i = 0; i < lenof(ciphers)+1; i++) {
1899 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1900 ssh2_pkt_addstring_str(c->name);
729e54b4 1901 if (i < lenof(ciphers))
e5574168 1902 ssh2_pkt_addstring_str(",");
1903 }
1904 /* List server->client encryption algorithms. */
1905 ssh2_pkt_addstring_start();
729e54b4 1906 for (i = 0; i < lenof(ciphers)+1; i++) {
1907 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1908 ssh2_pkt_addstring_str(c->name);
729e54b4 1909 if (i < lenof(ciphers))
e5574168 1910 ssh2_pkt_addstring_str(",");
1911 }
1912 /* List client->server MAC algorithms. */
1913 ssh2_pkt_addstring_start();
8b2715b2 1914 for (i = 0; i < nmacs; i++) {
7591b9ff 1915 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 1916 if (i < nmacs-1)
e5574168 1917 ssh2_pkt_addstring_str(",");
1918 }
1919 /* List server->client MAC algorithms. */
1920 ssh2_pkt_addstring_start();
8b2715b2 1921 for (i = 0; i < nmacs; i++) {
7591b9ff 1922 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 1923 if (i < nmacs-1)
e5574168 1924 ssh2_pkt_addstring_str(",");
1925 }
1926 /* List client->server compression algorithms. */
1927 ssh2_pkt_addstring_start();
1928 for (i = 0; i < lenof(compressions); i++) {
1929 ssh2_pkt_addstring_str(compressions[i]->name);
1930 if (i < lenof(compressions)-1)
1931 ssh2_pkt_addstring_str(",");
1932 }
1933 /* List server->client compression algorithms. */
1934 ssh2_pkt_addstring_start();
1935 for (i = 0; i < lenof(compressions); i++) {
1936 ssh2_pkt_addstring_str(compressions[i]->name);
1937 if (i < lenof(compressions)-1)
1938 ssh2_pkt_addstring_str(",");
1939 }
1940 /* List client->server languages. Empty list. */
1941 ssh2_pkt_addstring_start();
1942 /* List server->client languages. Empty list. */
1943 ssh2_pkt_addstring_start();
1944 /* First KEX packet does _not_ follow, because we're not that brave. */
1945 ssh2_pkt_addbool(FALSE);
1946 /* Reserved. */
1947 ssh2_pkt_adduint32(0);
1948 sha_string(&exhash, pktout.data+5, pktout.length-5);
1949 ssh2_pkt_send();
1950
1951 if (!ispkt) crWaitUntil(ispkt);
1952 sha_string(&exhash, pktin.data+5, pktin.length-5);
1953
1954 /*
1955 * Now examine the other side's KEXINIT to see what we're up
1956 * to.
1957 */
7cca0d81 1958 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 1959 bombout(("expected key exchange packet from server"));
1960 crReturn(0);
7cca0d81 1961 }
e5574168 1962 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1963 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1964 pktin.savedpos += 16; /* skip garbage cookie */
1965 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1966 for (i = 0; i < lenof(kex_algs); i++) {
1967 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1968 kex = kex_algs[i];
1969 break;
1970 }
1971 }
1972 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1973 for (i = 0; i < lenof(hostkey_algs); i++) {
1974 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1975 hostkey = hostkey_algs[i];
1976 break;
1977 }
1978 }
1979 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 1980 for (i = 0; i < lenof(ciphers)+1; i++) {
1981 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1982 if (in_commasep_string(c->name, str, len)) {
729e54b4 1983 cscipher_tobe = c;
e5574168 1984 break;
1985 }
1986 }
1987 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
729e54b4 1988 for (i = 0; i < lenof(ciphers)+1; i++) {
1989 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1990 if (in_commasep_string(c->name, str, len)) {
729e54b4 1991 sccipher_tobe = c;
e5574168 1992 break;
1993 }
1994 }
1995 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 1996 for (i = 0; i < nmacs; i++) {
7591b9ff 1997 if (in_commasep_string(maclist[i]->name, str, len)) {
1998 csmac_tobe = maclist[i];
e5574168 1999 break;
2000 }
2001 }
2002 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 2003 for (i = 0; i < nmacs; i++) {
7591b9ff 2004 if (in_commasep_string(maclist[i]->name, str, len)) {
2005 scmac_tobe = maclist[i];
e5574168 2006 break;
2007 }
2008 }
2009 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2010 for (i = 0; i < lenof(compressions); i++) {
2011 if (in_commasep_string(compressions[i]->name, str, len)) {
2012 cscomp_tobe = compressions[i];
2013 break;
2014 }
2015 }
2016 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2017 for (i = 0; i < lenof(compressions); i++) {
2018 if (in_commasep_string(compressions[i]->name, str, len)) {
2019 sccomp_tobe = compressions[i];
2020 break;
2021 }
2022 }
e5574168 2023
2024 /*
2025 * Currently we only support Diffie-Hellman and DSS, so let's
2026 * bomb out if those aren't selected.
2027 */
8d5de777 2028 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2029 bombout(("internal fault: chaos in SSH 2 transport layer"));
2030 crReturn(0);
2031 }
e5574168 2032
2033 /*
2034 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2035 */
2036 e = dh_create_e();
e5574168 2037 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2038 ssh2_pkt_addmp(e);
2039 ssh2_pkt_send();
2040
2041 crWaitUntil(ispkt);
7cca0d81 2042 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2043 bombout(("expected key exchange packet from server"));
2044 crReturn(0);
7cca0d81 2045 }
e5574168 2046 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2047 f = ssh2_pkt_getmp();
e5574168 2048 ssh2_pkt_getstring(&sigdata, &siglen);
2049
2050 K = dh_find_K(f);
e5574168 2051
2052 sha_string(&exhash, hostkeydata, hostkeylen);
2053 sha_mpint(&exhash, e);
2054 sha_mpint(&exhash, f);
2055 sha_mpint(&exhash, K);
2056 SHA_Final(&exhash, exchange_hash);
2057
7cca0d81 2058#if 0
e5574168 2059 debug(("Exchange hash is:\r\n"));
2060 for (i = 0; i < 20; i++)
2061 debug((" %02x", exchange_hash[i]));
2062 debug(("\r\n"));
7cca0d81 2063#endif
2064
2065 hostkey->setkey(hostkeydata, hostkeylen);
8d5de777 2066 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20)) {
2067 bombout(("Server failed host key check"));
2068 crReturn(0);
2069 }
e5574168 2070
2071 /*
7cca0d81 2072 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2073 */
7cca0d81 2074 crWaitUntil(ispkt);
8d5de777 2075 if (pktin.type != SSH2_MSG_NEWKEYS) {
2076 bombout(("expected new-keys packet from server"));
2077 crReturn(0);
2078 }
d39f364a 2079
2080 /*
7cca0d81 2081 * Authenticate remote host: verify host key. (We've already
2082 * checked the signature of the exchange hash.)
e5574168 2083 */
7cca0d81 2084 keystr = hostkey->fmtkey();
d5859615 2085 fingerprint = hostkey->fingerprint();
d4857987 2086 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2087 keystr, fingerprint);
d5859615 2088 logevent("Host key fingerprint is:");
2089 logevent(fingerprint);
2090 free(fingerprint);
7cca0d81 2091 free(keystr);
d39f364a 2092
2093 /*
7cca0d81 2094 * Send SSH2_MSG_NEWKEYS.
d39f364a 2095 */
2096 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2097 ssh2_pkt_send();
d39f364a 2098
2099 /*
2100 * Create and initialise session keys.
2101 */
2102 cscipher = cscipher_tobe;
2103 sccipher = sccipher_tobe;
2104 csmac = csmac_tobe;
2105 scmac = scmac_tobe;
2106 cscomp = cscomp_tobe;
2107 sccomp = sccomp_tobe;
2108 /*
2109 * Set IVs after keys.
2110 */
2111 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
2112 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
2113 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2114 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2115 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2116 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2117
033b4cef 2118 /*
7cca0d81 2119 * Now we're encrypting. Begin returning 1 to the protocol main
2120 * function so that other things can run on top of the
2121 * transport. If we ever see a KEXINIT, we must go back to the
2122 * start.
033b4cef 2123 */
7cca0d81 2124 do {
2125 crReturn(1);
2126 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2127 goto begin_key_exchange;
e5574168 2128
2129 crFinish(1);
2130}
2131
7cca0d81 2132/*
2133 * Handle the SSH2 userauth and connection layers.
2134 */
2135static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2136{
7cca0d81 2137 static unsigned long remote_winsize;
2138 static unsigned long remote_maxpkt;
2139
e5574168 2140 crBegin;
2141
7cca0d81 2142 /*
2143 * Request userauth protocol, and await a response to it.
2144 */
2145 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2146 ssh2_pkt_addstring("ssh-userauth");
2147 ssh2_pkt_send();
2148 crWaitUntilV(ispkt);
8d5de777 2149 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2150 bombout(("Server refused user authentication protocol"));
2151 crReturnV;
2152 }
7cca0d81 2153
2154 /*
2155 * FIXME: currently we support only password authentication.
2156 * (This places us technically in violation of the SSH2 spec.
2157 * We must fix this.)
2158 */
2159 while (1) {
2160 /*
2161 * Get a username and a password.
2162 */
2163 static char username[100];
2164 static char password[100];
2165 static int pos = 0;
2166 static char c;
e5574168 2167
67779be7 2168 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2169 c_write("login as: ", 10);
67779be7 2170 ssh_send_ok = 1;
7cca0d81 2171 while (pos >= 0) {
2172 crWaitUntilV(!ispkt);
2173 while (inlen--) switch (c = *in++) {
2174 case 10: case 13:
2175 username[pos] = 0;
2176 pos = -1;
2177 break;
2178 case 8: case 127:
2179 if (pos > 0) {
2180 c_write("\b \b", 3);
2181 pos--;
2182 }
2183 break;
2184 case 21: case 27:
2185 while (pos > 0) {
2186 c_write("\b \b", 3);
2187 pos--;
2188 }
2189 break;
2190 case 3: case 4:
2191 random_save_seed();
2192 exit(0);
2193 break;
2194 default:
2195 if (((c >= ' ' && c <= '~') ||
2196 ((unsigned char)c >= 160)) && pos < 40) {
2197 username[pos++] = c;
2198 c_write(&c, 1);
2199 }
2200 break;
2201 }
2202 }
2203 c_write("\r\n", 2);
2204 username[strcspn(username, "\n\r")] = '\0';
2205 } else {
2206 char stuff[200];
2207 strncpy(username, cfg.username, 99);
2208 username[99] = '\0';
67779be7 2209 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2210 sprintf(stuff, "Using username \"%s\".\r\n", username);
2211 c_write(stuff, strlen(stuff));
2212 }
2213 }
2214
d8426c54 2215 if (ssh_get_password) {
7cca0d81 2216 char prompt[200];
b585ec46 2217 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
7cca0d81 2218 if (!ssh_get_password(prompt, password, sizeof(password))) {
2219 /*
2220 * get_password failed to get a password (for
2221 * example because one was supplied on the command
2222 * line which has already failed to work).
2223 * Terminate.
2224 */
2225 logevent("No more passwords to try");
2226 ssh_state = SSH_STATE_CLOSED;
2227 crReturnV;
2228 }
2229 } else {
2230 c_write("password: ", 10);
67779be7 2231 ssh_send_ok = 1;
7cca0d81 2232
2233 pos = 0;
2234 while (pos >= 0) {
2235 crWaitUntilV(!ispkt);
2236 while (inlen--) switch (c = *in++) {
2237 case 10: case 13:
2238 password[pos] = 0;
2239 pos = -1;
2240 break;
2241 case 8: case 127:
2242 if (pos > 0)
2243 pos--;
2244 break;
2245 case 21: case 27:
2246 pos = 0;
2247 break;
2248 case 3: case 4:
2249 random_save_seed();
2250 exit(0);
2251 break;
2252 default:
2253 if (((c >= ' ' && c <= '~') ||
2254 ((unsigned char)c >= 160)) && pos < 40)
2255 password[pos++] = c;
2256 break;
2257 }
2258 }
2259 c_write("\r\n", 2);
2260 }
2261
2262 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2263 ssh2_pkt_addstring(username);
2264 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2265 ssh2_pkt_addstring("password");
2266 ssh2_pkt_addbool(FALSE);
2267 ssh2_pkt_addstring(password);
2268 ssh2_pkt_send();
2269
2270 crWaitUntilV(ispkt);
2271 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2272 c_write("Access denied\r\n", 15);
2273 logevent("Authentication refused");
2274 } else
2275 break;
2276 }
2277
2278 /*
2279 * Now we're authenticated for the connection protocol. The
2280 * connection protocol will automatically have started at this
2281 * point; there's no need to send SERVICE_REQUEST.
2282 */
2283
2284 /*
2285 * So now create a channel with a session in it.
2286 */
d211621f 2287 mainchan = malloc(sizeof(struct ssh_channel));
2288 mainchan->localid = 100; /* as good as any */
7cca0d81 2289 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2290 ssh2_pkt_addstring("session");
d211621f 2291 ssh2_pkt_adduint32(mainchan->localid);
cf6e59d6 2292 ssh2_pkt_adduint32(0x8000UL); /* our window size */
d211621f 2293 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2294 ssh2_pkt_send();
2295 crWaitUntilV(ispkt);
2296 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2297 bombout(("Server refused to open a session"));
2298 crReturnV;
7cca0d81 2299 /* FIXME: error data comes back in FAILURE packet */
2300 }
d211621f 2301 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2302 bombout(("Server's channel confirmation cited wrong channel"));
2303 crReturnV;
7cca0d81 2304 }
d211621f 2305 mainchan->remoteid = ssh2_pkt_getuint32();
2306 mainchan->u.v2.remwindow = ssh2_pkt_getuint32();
2307 mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32();
2308 mainchan->u.v2.outbuffer = NULL;
2309 mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0;
7cca0d81 2310 logevent("Opened channel for session");
2311
2312 /*
2313 * Now allocate a pty for the session.
2314 */
67779be7 2315 if (!cfg.nopty) {
2316 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2317 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2318 ssh2_pkt_addstring("pty-req");
2319 ssh2_pkt_addbool(1); /* want reply */
2320 ssh2_pkt_addstring(cfg.termtype);
2321 ssh2_pkt_adduint32(cols);
2322 ssh2_pkt_adduint32(rows);
2323 ssh2_pkt_adduint32(0); /* pixel width */
2324 ssh2_pkt_adduint32(0); /* pixel height */
2325 ssh2_pkt_addstring_start();
2326 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2327 ssh2_pkt_send();
6e48c3fe 2328 ssh_state = SSH_STATE_INTERMED;
7cca0d81 2329
67779be7 2330 do {
2331 crWaitUntilV(ispkt);
2332 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2333 /* FIXME: be able to handle other channels here */
2334 if (ssh2_pkt_getuint32() != mainchan->localid)
2335 continue; /* wrong channel */
2336 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2337 }
2338 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2339
67779be7 2340 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2341 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2342 bombout(("Server got confused by pty request"));
2343 crReturnV;
67779be7 2344 }
2345 c_write("Server refused to allocate pty\r\n", 32);
2346 } else {
2347 logevent("Allocated pty");
7cca0d81 2348 }
7cca0d81 2349 }
2350
2351 /*
67779be7 2352 * Start a shell or a remote command.
7cca0d81 2353 */
2354 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2355 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2356 if (*cfg.remote_cmd) {
2357 ssh2_pkt_addstring("exec");
2358 ssh2_pkt_addbool(1); /* want reply */
2359 ssh2_pkt_addstring(cfg.remote_cmd);
2360 } else {
2361 ssh2_pkt_addstring("shell");
2362 ssh2_pkt_addbool(1); /* want reply */
2363 }
7cca0d81 2364 ssh2_pkt_send();
d211621f 2365 do {
7cca0d81 2366 crWaitUntilV(ispkt);
d211621f 2367 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2368 /* FIXME: be able to handle other channels here */
2369 if (ssh2_pkt_getuint32() != mainchan->localid)
2370 continue; /* wrong channel */
2371 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2372 }
7cca0d81 2373 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2374 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2375 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2376 bombout(("Server got confused by shell/command request"));
2377 crReturnV;
7cca0d81 2378 }
8d5de777 2379 bombout(("Server refused to start a shell/command"));
2380 crReturnV;
7cca0d81 2381 } else {
8d5de777 2382 logevent("Started a shell/command");
7cca0d81 2383 }
2384
6e48c3fe 2385 ssh_state = SSH_STATE_SESSION;
2386 if (size_needed)
2387 ssh_size();
2388
7cca0d81 2389 /*
2390 * Transfer data!
2391 */
8ccc75b0 2392 ssh_send_ok = 1;
6f34e365 2393 begin_session();
7cca0d81 2394 while (1) {
d211621f 2395 static int try_send;
e5574168 2396 crReturnV;
d211621f 2397 try_send = FALSE;
7cca0d81 2398 if (ispkt) {
2399 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2400 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2401 char *data;
2402 int length;
d211621f 2403 /* FIXME: be able to handle other channels here */
2404 if (ssh2_pkt_getuint32() != mainchan->localid)
7cca0d81 2405 continue; /* wrong channel */
2406 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2407 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2408 continue; /* extended but not stderr */
2409 ssh2_pkt_getstring(&data, &length);
d211621f 2410 if (data) {
fe50e814 2411 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
2412 data, length);
d211621f 2413 /*
2414 * Enlarge the window again at the remote side,
2415 * just in case it ever runs down and they fail
2416 * to send us any more data.
2417 */
2418 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2419 ssh2_pkt_adduint32(mainchan->remoteid);
2420 ssh2_pkt_adduint32(length);
2421 ssh2_pkt_send();
2422 }
7cca0d81 2423 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2424 ssh_state = SSH_STATE_CLOSED;
d211621f 2425 logevent("Received disconnect message");
3257deae 2426 crReturnV;
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);
9005f3ba 2442 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
2443 ssh2_pkt_addstring("All open channels closed");
2444 ssh2_pkt_addstring("en"); /* language tag */
d211621f 2445 ssh2_pkt_send();
cf6e59d6 2446 ssh_state = SSH_STATE_CLOSED;
3257deae 2447 crReturnV;
d211621f 2448 }
2449 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2450 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
d211621f 2451 /* FIXME: be able to handle other channels here */
2452 if (ssh2_pkt_getuint32() != mainchan->localid)
2453 continue; /* wrong channel */
2454 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2455 try_send = TRUE;
7cca0d81 2456 } else {
8d5de777 2457 bombout(("Strange packet received: type %d", pktin.type));
2458 crReturnV;
7cca0d81 2459 }
2460 } else {
d211621f 2461 /*
2462 * We have spare data. Add it to the channel buffer.
2463 */
2464 if (mainchan->u.v2.outbufsize <
2465 mainchan->u.v2.outbuflen + inlen) {
2466 mainchan->u.v2.outbufsize =
2467 mainchan->u.v2.outbuflen + inlen + 1024;
2468 mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer,
2469 mainchan->u.v2.outbufsize);
2470 }
2471 memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen,
2472 in, inlen);
2473 mainchan->u.v2.outbuflen += inlen;
2474 try_send = TRUE;
7cca0d81 2475 }
d211621f 2476 if (try_send) {
2477 /*
2478 * Try to send data on the channel if we can. (FIXME:
2479 * on _all_ channels.)
2480 */
2481 while (mainchan->u.v2.remwindow > 0 &&
2482 mainchan->u.v2.outbuflen > 0) {
2483 unsigned len = mainchan->u.v2.remwindow;
2484 if (len > mainchan->u.v2.outbuflen)
2485 len = mainchan->u.v2.outbuflen;
2486 if (len > mainchan->u.v2.remmaxpkt)
2487 len = mainchan->u.v2.remmaxpkt;
2488 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2489 ssh2_pkt_adduint32(mainchan->remoteid);
2490 ssh2_pkt_addstring_start();
2491 ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len);
2492 ssh2_pkt_send();
2493 mainchan->u.v2.outbuflen -= len;
2494 memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len,
2495 mainchan->u.v2.outbuflen);
2496 mainchan->u.v2.remwindow -= len;
2497 }
2498 }
e5574168 2499 }
2500
2501 crFinishV;
2502}
2503
2504/*
7cca0d81 2505 * Handle the top-level SSH2 protocol.
2506 */
2507static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2508{
2509 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2510 return;
2511 do_ssh2_authconn(in, inlen, ispkt);
2512}
2513
2514/*
8df7a775 2515 * Called to set up the connection.
374330e2 2516 *
2517 * Returns an error message, or NULL on success.
374330e2 2518 */
8df7a775 2519static char *ssh_init (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
8df7a775 2527 ssh_send_ok = 0;
2528
fb09bf1c 2529 p = connect_to_host(host, port, realhost);
2530 if (p != NULL)
2531 return p;
374330e2 2532
374330e2 2533 return NULL;
2534}
2535
2536/*
374330e2 2537 * Called to send data down the Telnet connection.
2538 */
2539static void ssh_send (char *buf, int len) {
8df7a775 2540 if (s == NULL)
374330e2 2541 return;
2542
2543 ssh_protocol(buf, len, 0);
2544}
2545
2546/*
6e48c3fe 2547 * Called to set the size of the window from SSH's POV.
374330e2 2548 */
2549static void ssh_size(void) {
2550 switch (ssh_state) {
2551 case SSH_STATE_BEFORE_SIZE:
21248260 2552 case SSH_STATE_CLOSED:
374330e2 2553 break; /* do nothing */
2554 case SSH_STATE_INTERMED:
2555 size_needed = TRUE; /* buffer for later */
2556 break;
2557 case SSH_STATE_SESSION:
fef97f43 2558 if (!cfg.nopty) {
6e48c3fe 2559 if (ssh_version == 1) {
2560 send_packet(SSH1_CMSG_WINDOW_SIZE,
2561 PKT_INT, rows, PKT_INT, cols,
2562 PKT_INT, 0, PKT_INT, 0, PKT_END);
2563 } else {
2564 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2565 ssh2_pkt_adduint32(mainchan->remoteid);
2566 ssh2_pkt_addstring("window-change");
2567 ssh2_pkt_addbool(0);
2568 ssh2_pkt_adduint32(cols);
2569 ssh2_pkt_adduint32(rows);
2570 ssh2_pkt_adduint32(0);
2571 ssh2_pkt_adduint32(0);
2572 ssh2_pkt_send();
2573 }
fef97f43 2574 }
374330e2 2575 }
2576}
2577
2578/*
6abbf9e3 2579 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2580 * can send an EOF and collect resulting output (e.g. `plink
2581 * hostname sort').
374330e2 2582 */
2583static void ssh_special (Telnet_Special code) {
6abbf9e3 2584 if (code == TS_EOF) {
67779be7 2585 if (ssh_version == 1) {
6abbf9e3 2586 send_packet(SSH1_CMSG_EOF, PKT_END);
2587 } else {
2588 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 2589 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 2590 ssh2_pkt_send();
2591 }
67779be7 2592 logevent("Sent EOF message");
ec55b220 2593 } else if (code == TS_PING) {
2594 if (ssh_version == 1) {
2595 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
2596 } else {
2597 ssh2_pkt_init(SSH2_MSG_IGNORE);
2598 ssh2_pkt_addstring_start();
2599 ssh2_pkt_send();
2600 }
6abbf9e3 2601 } else {
2602 /* do nothing */
2603 }
374330e2 2604}
2605
8df7a775 2606static Socket ssh_socket(void) { return s; }
8ccc75b0 2607
2608static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 2609
374330e2 2610Backend ssh_backend = {
2611 ssh_init,
374330e2 2612 ssh_send,
2613 ssh_size,
4017be6d 2614 ssh_special,
8ccc75b0 2615 ssh_socket,
97db3be4 2616 ssh_sendok,
2617 22
374330e2 2618};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator