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Miscellaneous fixes for better interoperation with commercial SSH 2
[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
7591b9ff 170extern const struct ssh_mac 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};
57476f6b 178const static struct ssh_mac *macs[] = { &ssh_sha1, &ssh_mac_none };
7591b9ff 179const static struct ssh_mac *buggymacs[] = { &ssh_sha1_buggy, &ssh_mac_none };
e5574168 180
57476f6b 181const static struct ssh_compress ssh_comp_none = {
e5574168 182 "none"
183};
57476f6b 184const static struct ssh_compress *compressions[] = { &ssh_comp_none };
374330e2 185
dacbd0e8 186/*
187 * 2-3-4 tree storing channels.
188 */
189struct ssh_channel {
d211621f 190 unsigned remoteid, localid;
dacbd0e8 191 int type;
192 int closes;
193 union {
194 struct ssh_agent_channel {
195 unsigned char *message;
196 unsigned char msglen[4];
197 int lensofar, totallen;
198 } a;
d211621f 199 struct ssh2_data_channel {
200 unsigned char *outbuffer;
201 unsigned outbuflen, outbufsize;
202 unsigned remwindow, remmaxpkt;
203 } v2;
dacbd0e8 204 } u;
205};
57476f6b 206
207struct Packet {
208 long length;
209 int type;
210 unsigned char *data;
211 unsigned char *body;
212 long savedpos;
213 long maxlen;
214};
215
216static SHA_State exhash;
217
218static SOCKET s = INVALID_SOCKET;
219
220static unsigned char session_key[32];
221static const struct ssh_cipher *cipher = NULL;
222static const struct ssh_cipher *cscipher = NULL;
223static const struct ssh_cipher *sccipher = NULL;
224static const struct ssh_mac *csmac = NULL;
225static const struct ssh_mac *scmac = NULL;
226static const struct ssh_compress *cscomp = NULL;
227static const struct ssh_compress *sccomp = NULL;
228static const struct ssh_kex *kex = NULL;
229static const struct ssh_hostkey *hostkey = NULL;
230int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
231
232static char *savedhost;
233static int savedport;
234static int ssh_send_ok;
235
dacbd0e8 236static tree234 *ssh_channels; /* indexed by local id */
57476f6b 237static struct ssh_channel *mainchan; /* primary session channel */
238
239static enum {
240 SSH_STATE_BEFORE_SIZE,
241 SSH_STATE_INTERMED,
242 SSH_STATE_SESSION,
243 SSH_STATE_CLOSED
244} ssh_state = SSH_STATE_BEFORE_SIZE;
245
246static int size_needed = FALSE;
247
248static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
249static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
250
251static int ssh_version;
252static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
253static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
254static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
255static void ssh_size(void);
256
257static int (*s_rdpkt)(unsigned char **data, int *datalen);
258
259static struct rdpkt1_state_tag {
260 long len, pad, biglen, to_read;
261 unsigned long realcrc, gotcrc;
262 unsigned char *p;
263 int i;
264 int chunk;
265} rdpkt1_state;
266
960e736a 267static struct rdpkt2_state_tag {
268 long len, pad, payload, packetlen, maclen;
269 int i;
270 int cipherblk;
271 unsigned long incoming_sequence;
272} rdpkt2_state;
273
dacbd0e8 274static int ssh_channelcmp(void *av, void *bv) {
275 struct ssh_channel *a = (struct ssh_channel *)av;
276 struct ssh_channel *b = (struct ssh_channel *)bv;
277 if (a->localid < b->localid) return -1;
278 if (a->localid > b->localid) return +1;
279 return 0;
280}
281static int ssh_channelfind(void *av, void *bv) {
d211621f 282 unsigned *a = (unsigned *)av;
dacbd0e8 283 struct ssh_channel *b = (struct ssh_channel *)bv;
284 if (*a < b->localid) return -1;
285 if (*a > b->localid) return +1;
286 return 0;
287}
288
374330e2 289static void s_write (char *buf, int len) {
290 while (len > 0) {
291 int i = send (s, buf, len, 0);
4017be6d 292 noise_ultralight(i);
8d5de777 293 if (i <= 0) {
294 bombout(("Lost connection while sending"));
295 return;
296 }
374330e2 297 if (i > 0)
298 len -= i, buf += i;
299 }
300}
301
302static int s_read (char *buf, int len) {
303 int ret = 0;
304 while (len > 0) {
305 int i = recv (s, buf, len, 0);
4017be6d 306 noise_ultralight(i);
374330e2 307 if (i > 0)
308 len -= i, buf += i, ret += i;
309 else
310 return i;
311 }
312 return ret;
313}
314
315static void c_write (char *buf, int len) {
67779be7 316 if ((flags & FLAG_STDERR)) {
4017be6d 317 int i;
318 for (i = 0; i < len; i++)
319 if (buf[i] != '\r')
320 fputc(buf[i], stderr);
fb09bf1c 321 return;
322 }
c9def1b8 323 while (len--)
324 c_write1(*buf++);
374330e2 325}
326
3bdaf79d 327static void c_writedata (char *buf, int len) {
328 while (len--)
329 c_write1(*buf++);
330}
331
fb09bf1c 332/*
333 * Collect incoming data in the incoming packet buffer.
e5574168 334 * Decipher and verify the packet when it is completely read.
335 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 336 * Update the *data and *datalen variables.
337 * Return the additional nr of bytes needed, or 0 when
338 * a complete packet is available.
339 */
e5574168 340static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 341{
57476f6b 342 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 343
344 crBegin;
374330e2 345
fb09bf1c 346next_packet:
37508af4 347
fb09bf1c 348 pktin.type = 0;
349 pktin.length = 0;
374330e2 350
57476f6b 351 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 352 while ((*datalen) == 0)
57476f6b 353 crReturn(4-st->i);
354 st->len = (st->len << 8) + **data;
fb09bf1c 355 (*data)++, (*datalen)--;
356 }
374330e2 357
fb09bf1c 358#ifdef FWHACK
57476f6b 359 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
360 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 361 }
362#endif
374330e2 363
57476f6b 364 st->pad = 8 - (st->len % 8);
365 st->biglen = st->len + st->pad;
366 pktin.length = st->len - 5;
fb09bf1c 367
57476f6b 368 if (pktin.maxlen < st->biglen) {
369 pktin.maxlen = st->biglen;
370 pktin.data = (pktin.data == NULL ? malloc(st->biglen+APIEXTRA) :
371 realloc(pktin.data, st->biglen+APIEXTRA));
fb09bf1c 372 if (!pktin.data)
373 fatalbox("Out of memory");
374 }
374330e2 375
57476f6b 376 st->to_read = st->biglen;
377 st->p = pktin.data;
378 while (st->to_read > 0) {
379 st->chunk = st->to_read;
fb09bf1c 380 while ((*datalen) == 0)
57476f6b 381 crReturn(st->to_read);
382 if (st->chunk > (*datalen))
383 st->chunk = (*datalen);
384 memcpy(st->p, *data, st->chunk);
385 *data += st->chunk;
386 *datalen -= st->chunk;
387 st->p += st->chunk;
388 st->to_read -= st->chunk;
fb09bf1c 389 }
374330e2 390
fb09bf1c 391 if (cipher)
57476f6b 392 cipher->decrypt(pktin.data, st->biglen);
374330e2 393
57476f6b 394 pktin.type = pktin.data[st->pad];
395 pktin.body = pktin.data + st->pad + 1;
374330e2 396
57476f6b 397 st->realcrc = crc32(pktin.data, st->biglen-4);
398 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
399 if (st->gotcrc != st->realcrc) {
8d5de777 400 bombout(("Incorrect CRC received on packet"));
401 crReturn(0);
fb09bf1c 402 }
572f871e 403
e5574168 404 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
405 pktin.type == SSH1_SMSG_STDERR_DATA ||
406 pktin.type == SSH1_MSG_DEBUG ||
18515c51 407 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
408 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 409 long strlen = GET_32BIT(pktin.body);
8d5de777 410 if (strlen + 4 != pktin.length) {
411 bombout(("Received data packet with bogus string length"));
412 crReturn(0);
413 }
fb09bf1c 414 }
415
e5574168 416 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 417 /* log debug message */
418 char buf[80];
419 int strlen = GET_32BIT(pktin.body);
420 strcpy(buf, "Remote: ");
421 if (strlen > 70) strlen = 70;
422 memcpy(buf+8, pktin.body+4, strlen);
423 buf[8+strlen] = '\0';
424 logevent(buf);
425 goto next_packet;
e5574168 426 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 427 /* do nothing */
428 goto next_packet;
429 }
430
431 crFinish(0);
432}
433
e5574168 434static int ssh2_rdpkt(unsigned char **data, int *datalen)
435{
960e736a 436 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 437
438 crBegin;
439
440next_packet:
e5574168 441 pktin.type = 0;
442 pktin.length = 0;
960e736a 443 if (sccipher)
444 st->cipherblk = sccipher->blksize;
e5574168 445 else
960e736a 446 st->cipherblk = 8;
447 if (st->cipherblk < 8)
448 st->cipherblk = 8;
449
450 if (pktin.maxlen < st->cipherblk) {
451 pktin.maxlen = st->cipherblk;
452 pktin.data = (pktin.data == NULL ? malloc(st->cipherblk+APIEXTRA) :
453 realloc(pktin.data, st->cipherblk+APIEXTRA));
e5574168 454 if (!pktin.data)
455 fatalbox("Out of memory");
456 }
457
458 /*
459 * Acquire and decrypt the first block of the packet. This will
460 * contain the length and padding details.
461 */
960e736a 462 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 463 while ((*datalen) == 0)
960e736a 464 crReturn(st->cipherblk-st->i);
465 pktin.data[st->i] = *(*data)++;
e5574168 466 (*datalen)--;
467 }
468#ifdef FWHACK
469 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
470 /* FIXME */
471 }
472#endif
473 if (sccipher)
960e736a 474 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 475
476 /*
477 * Now get the length and padding figures.
478 */
960e736a 479 st->len = GET_32BIT(pktin.data);
480 st->pad = pktin.data[4];
e5574168 481
482 /*
483 * This enables us to deduce the payload length.
484 */
960e736a 485 st->payload = st->len - st->pad - 1;
e5574168 486
960e736a 487 pktin.length = st->payload + 5;
e5574168 488
489 /*
490 * So now we can work out the total packet length.
491 */
960e736a 492 st->packetlen = st->len + 4;
493 st->maclen = scmac ? scmac->len : 0;
e5574168 494
495 /*
496 * Adjust memory allocation if packet is too big.
497 */
960e736a 498 if (pktin.maxlen < st->packetlen+st->maclen) {
499 pktin.maxlen = st->packetlen+st->maclen;
59dcd2a8 500 pktin.data = (pktin.data == NULL ? malloc(pktin.maxlen+APIEXTRA) :
501 realloc(pktin.data, pktin.maxlen+APIEXTRA));
e5574168 502 if (!pktin.data)
503 fatalbox("Out of memory");
504 }
505
506 /*
507 * Read and decrypt the remainder of the packet.
508 */
960e736a 509 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
e5574168 510 while ((*datalen) == 0)
960e736a 511 crReturn(st->packetlen + st->maclen - st->i);
512 pktin.data[st->i] = *(*data)++;
e5574168 513 (*datalen)--;
514 }
515 /* Decrypt everything _except_ the MAC. */
516 if (sccipher)
960e736a 517 sccipher->decrypt(pktin.data + st->cipherblk,
518 st->packetlen - st->cipherblk);
e5574168 519
7cca0d81 520#if 0
960e736a 521 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
522 for (st->i = 0; st->i < st->packetlen; st->i++)
523 debug((" %02x", (unsigned char)pktin.data[st->i]));
d39f364a 524 debug(("\r\n"));
7cca0d81 525#endif
d39f364a 526
e5574168 527 /*
528 * Check the MAC.
529 */
960e736a 530 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
8d5de777 531 bombout(("Incorrect MAC received on packet"));
532 crReturn(0);
533 }
960e736a 534 st->incoming_sequence++; /* whether or not we MACed */
e5574168 535
536 pktin.savedpos = 6;
537 pktin.type = pktin.data[5];
e5574168 538
7cca0d81 539 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
540 goto next_packet; /* FIXME: print DEBUG message */
e5574168 541
542 crFinish(0);
543}
544
fb09bf1c 545static void ssh_gotdata(unsigned char *data, int datalen)
546{
547 while (datalen > 0) {
85ee8208 548 if ( s_rdpkt(&data, &datalen) == 0 ) {
374330e2 549 ssh_protocol(NULL, 0, 1);
85ee8208 550 if (ssh_state == SSH_STATE_CLOSED) {
551 return;
552 }
553 }
374330e2 554 }
374330e2 555}
556
fb09bf1c 557
374330e2 558static void s_wrpkt_start(int type, int len) {
559 int pad, biglen;
560
561 len += 5; /* type and CRC */
562 pad = 8 - (len%8);
563 biglen = len + pad;
564
565 pktout.length = len-5;
566 if (pktout.maxlen < biglen) {
567 pktout.maxlen = biglen;
8f203108 568#ifdef MSCRYPTOAPI
fb09bf1c 569 /* Allocate enough buffer space for extra block
8f203108 570 * for MS CryptEncrypt() */
fb09bf1c 571 pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
572 realloc(pktout.data, biglen+12));
8f203108 573#else
c1f5f956 574 pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
575 realloc(pktout.data, biglen+4));
8f203108 576#endif
374330e2 577 if (!pktout.data)
578 fatalbox("Out of memory");
579 }
580
581 pktout.type = type;
582 pktout.body = pktout.data+4+pad+1;
583}
584
585static void s_wrpkt(void) {
586 int pad, len, biglen, i;
587 unsigned long crc;
588
589 len = pktout.length + 5; /* type and CRC */
590 pad = 8 - (len%8);
591 biglen = len + pad;
592
593 pktout.body[-1] = pktout.type;
594 for (i=0; i<pad; i++)
595 pktout.data[i+4] = random_byte();
596 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 597 PUT_32BIT(pktout.data+biglen, crc);
598 PUT_32BIT(pktout.data, len);
374330e2 599
600 if (cipher)
601 cipher->encrypt(pktout.data+4, biglen);
602
603 s_write(pktout.data, biglen+4);
604}
605
fb09bf1c 606/*
607 * Construct a packet with the specified contents and
608 * send it to the server.
609 */
610static void send_packet(int pkttype, ...)
611{
612 va_list args;
613 unsigned char *p, *argp, argchar;
614 unsigned long argint;
615 int pktlen, argtype, arglen;
7cca0d81 616 Bignum bn;
fb09bf1c 617
618 pktlen = 0;
619 va_start(args, pkttype);
620 while ((argtype = va_arg(args, int)) != PKT_END) {
621 switch (argtype) {
622 case PKT_INT:
623 (void) va_arg(args, int);
624 pktlen += 4;
625 break;
626 case PKT_CHAR:
627 (void) va_arg(args, char);
628 pktlen++;
629 break;
630 case PKT_DATA:
631 (void) va_arg(args, unsigned char *);
632 arglen = va_arg(args, int);
633 pktlen += arglen;
634 break;
635 case PKT_STR:
636 argp = va_arg(args, unsigned char *);
637 arglen = strlen(argp);
638 pktlen += 4 + arglen;
639 break;
7cca0d81 640 case PKT_BIGNUM:
641 bn = va_arg(args, Bignum);
5c58ad2d 642 pktlen += ssh1_bignum_length(bn);
7cca0d81 643 break;
fb09bf1c 644 default:
645 assert(0);
646 }
647 }
648 va_end(args);
649
650 s_wrpkt_start(pkttype, pktlen);
651 p = pktout.body;
652
653 va_start(args, pkttype);
654 while ((argtype = va_arg(args, int)) != PKT_END) {
655 switch (argtype) {
656 case PKT_INT:
657 argint = va_arg(args, int);
658 PUT_32BIT(p, argint);
659 p += 4;
660 break;
661 case PKT_CHAR:
662 argchar = va_arg(args, unsigned char);
663 *p = argchar;
664 p++;
665 break;
666 case PKT_DATA:
667 argp = va_arg(args, unsigned char *);
668 arglen = va_arg(args, int);
669 memcpy(p, argp, arglen);
670 p += arglen;
671 break;
672 case PKT_STR:
673 argp = va_arg(args, unsigned char *);
674 arglen = strlen(argp);
675 PUT_32BIT(p, arglen);
676 memcpy(p + 4, argp, arglen);
677 p += 4 + arglen;
678 break;
7cca0d81 679 case PKT_BIGNUM:
680 bn = va_arg(args, Bignum);
5c58ad2d 681 p += ssh1_write_bignum(p, bn);
7cca0d81 682 break;
fb09bf1c 683 }
684 }
685 va_end(args);
686
687 s_wrpkt();
688}
689
690
691/*
692 * Connect to specified host and port.
693 * Returns an error message, or NULL on success.
694 * Also places the canonical host name into `realhost'.
695 */
696static char *connect_to_host(char *host, int port, char **realhost)
697{
698 SOCKADDR_IN addr;
699 struct hostent *h;
700 unsigned long a;
701#ifdef FWHACK
702 char *FWhost;
703 int FWport;
704#endif
705
706 savedhost = malloc(1+strlen(host));
707 if (!savedhost)
708 fatalbox("Out of memory");
709 strcpy(savedhost, host);
710
711 if (port < 0)
712 port = 22; /* default ssh port */
d4857987 713 savedport = port;
fb09bf1c 714
715#ifdef FWHACK
716 FWhost = host;
717 FWport = port;
718 host = FWSTR;
719 port = 23;
720#endif
721
722 /*
723 * Try to find host.
724 */
725 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
726 if ( (h = gethostbyname(host)) == NULL)
727 switch (WSAGetLastError()) {
728 case WSAENETDOWN: return "Network is down";
729 case WSAHOST_NOT_FOUND: case WSANO_DATA:
730 return "Host does not exist";
731 case WSATRY_AGAIN: return "Host not found";
732 default: return "gethostbyname: unknown error";
733 }
734 memcpy (&a, h->h_addr, sizeof(a));
735 *realhost = h->h_name;
736 } else
737 *realhost = host;
738#ifdef FWHACK
739 *realhost = FWhost;
740#endif
741 a = ntohl(a);
742
743 /*
744 * Open socket.
745 */
746 s = socket(AF_INET, SOCK_STREAM, 0);
747 if (s == INVALID_SOCKET)
748 switch (WSAGetLastError()) {
749 case WSAENETDOWN: return "Network is down";
750 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
751 default: return "socket(): unknown error";
752 }
753
754 /*
755 * Bind to local address.
756 */
757 addr.sin_family = AF_INET;
758 addr.sin_addr.s_addr = htonl(INADDR_ANY);
759 addr.sin_port = htons(0);
760 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
761 switch (WSAGetLastError()) {
762 case WSAENETDOWN: return "Network is down";
763 default: return "bind(): unknown error";
764 }
765
766 /*
767 * Connect to remote address.
768 */
769 addr.sin_addr.s_addr = htonl(a);
770 addr.sin_port = htons((short)port);
771 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
772 switch (WSAGetLastError()) {
773 case WSAENETDOWN: return "Network is down";
774 case WSAECONNREFUSED: return "Connection refused";
775 case WSAENETUNREACH: return "Network is unreachable";
776 case WSAEHOSTUNREACH: return "No route to host";
777 default: return "connect(): unknown error";
778 }
779
780#ifdef FWHACK
781 send(s, "connect ", 8, 0);
782 send(s, FWhost, strlen(FWhost), 0);
783 {
784 char buf[20];
785 sprintf(buf, " %d\n", FWport);
786 send (s, buf, strlen(buf), 0);
787 }
788#endif
789
790 return NULL;
791}
792
9697bfd2 793static int ssh_versioncmp(char *a, char *b) {
794 char *ae, *be;
795 unsigned long av, bv;
796
43aa02a7 797 av = strtoul(a, &ae, 10);
798 bv = strtoul(b, &be, 10);
9697bfd2 799 if (av != bv) return (av < bv ? -1 : +1);
800 if (*ae == '.') ae++;
801 if (*be == '.') be++;
43aa02a7 802 av = strtoul(ae, &ae, 10);
803 bv = strtoul(be, &be, 10);
9697bfd2 804 if (av != bv) return (av < bv ? -1 : +1);
805 return 0;
806}
807
e5574168 808
809/*
810 * Utility routine for putting an SSH-protocol `string' into a SHA
811 * state.
812 */
813#include <stdio.h>
75cab814 814static void sha_string(SHA_State *s, void *str, int len) {
e5574168 815 unsigned char lenblk[4];
e5574168 816 PUT_32BIT(lenblk, len);
e5574168 817 SHA_Bytes(s, lenblk, 4);
e5574168 818 SHA_Bytes(s, str, len);
819}
820
7cca0d81 821/*
822 * SSH2 packet construction functions.
823 */
75cab814 824static void ssh2_pkt_adddata(void *data, int len) {
7cca0d81 825 pktout.length += len;
826 if (pktout.maxlen < pktout.length) {
827 pktout.maxlen = pktout.length + 256;
828 pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) :
829 realloc(pktout.data, pktout.maxlen+APIEXTRA));
830 if (!pktout.data)
831 fatalbox("Out of memory");
832 }
833 memcpy(pktout.data+pktout.length-len, data, len);
834}
75cab814 835static void ssh2_pkt_addbyte(unsigned char byte) {
7cca0d81 836 ssh2_pkt_adddata(&byte, 1);
837}
75cab814 838static void ssh2_pkt_init(int pkt_type) {
7cca0d81 839 pktout.length = 5;
840 ssh2_pkt_addbyte((unsigned char)pkt_type);
841}
75cab814 842static void ssh2_pkt_addbool(unsigned char value) {
7cca0d81 843 ssh2_pkt_adddata(&value, 1);
844}
75cab814 845static void ssh2_pkt_adduint32(unsigned long value) {
7cca0d81 846 unsigned char x[4];
847 PUT_32BIT(x, value);
848 ssh2_pkt_adddata(x, 4);
849}
75cab814 850static void ssh2_pkt_addstring_start(void) {
7cca0d81 851 ssh2_pkt_adduint32(0);
852 pktout.savedpos = pktout.length;
853}
75cab814 854static void ssh2_pkt_addstring_str(char *data) {
7cca0d81 855 ssh2_pkt_adddata(data, strlen(data));
856 PUT_32BIT(pktout.data + pktout.savedpos - 4,
857 pktout.length - pktout.savedpos);
858}
75cab814 859static void ssh2_pkt_addstring_data(char *data, int len) {
7cca0d81 860 ssh2_pkt_adddata(data, len);
861 PUT_32BIT(pktout.data + pktout.savedpos - 4,
862 pktout.length - pktout.savedpos);
863}
75cab814 864static void ssh2_pkt_addstring(char *data) {
7cca0d81 865 ssh2_pkt_addstring_start();
866 ssh2_pkt_addstring_str(data);
867}
75cab814 868static char *ssh2_mpint_fmt(Bignum b, int *len) {
7cca0d81 869 unsigned char *p;
870 int i, n = b[0];
871 p = malloc(n * 2 + 1);
872 if (!p)
873 fatalbox("out of memory");
874 p[0] = 0;
875 for (i = 0; i < n; i++) {
876 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
877 p[i*2+2] = (b[n-i] ) & 0xFF;
878 }
879 i = 0;
880 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
881 i++;
882 memmove(p, p+i, n*2+1-i);
883 *len = n*2+1-i;
884 return p;
885}
75cab814 886static void ssh2_pkt_addmp(Bignum b) {
7cca0d81 887 unsigned char *p;
888 int len;
889 p = ssh2_mpint_fmt(b, &len);
890 ssh2_pkt_addstring_start();
891 ssh2_pkt_addstring_data(p, len);
892 free(p);
893}
75cab814 894static void ssh2_pkt_send(void) {
7cca0d81 895 int cipherblk, maclen, padding, i;
896 static unsigned long outgoing_sequence = 0;
897
898 /*
899 * Add padding. At least four bytes, and must also bring total
900 * length (minus MAC) up to a multiple of the block size.
901 */
902 cipherblk = cipher ? cipher->blksize : 8; /* block size */
903 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
904 padding = 4;
905 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
906 pktout.data[4] = padding;
907 for (i = 0; i < padding; i++)
908 pktout.data[pktout.length + i] = random_byte();
909 PUT_32BIT(pktout.data, pktout.length + padding - 4);
910 if (csmac)
911 csmac->generate(pktout.data, pktout.length + padding,
912 outgoing_sequence);
913 outgoing_sequence++; /* whether or not we MACed */
914
915#if 0
916 debug(("Sending packet len=%d\r\n", pktout.length+padding));
917 for (i = 0; i < pktout.length+padding; i++)
918 debug((" %02x", (unsigned char)pktout.data[i]));
919 debug(("\r\n"));
920#endif
921
922 if (cscipher)
923 cscipher->encrypt(pktout.data, pktout.length + padding);
924 maclen = csmac ? csmac->len : 0;
925
926 s_write(pktout.data, pktout.length + padding + maclen);
927}
928
929#if 0
930void bndebug(char *string, Bignum b) {
931 unsigned char *p;
932 int i, len;
933 p = ssh2_mpint_fmt(b, &len);
934 debug(("%s", string));
935 for (i = 0; i < len; i++)
936 debug((" %02x", p[i]));
937 debug(("\r\n"));
938 free(p);
939}
940#endif
941
75cab814 942static void sha_mpint(SHA_State *s, Bignum b) {
7cca0d81 943 unsigned char *p;
944 int len;
945 p = ssh2_mpint_fmt(b, &len);
946 sha_string(s, p, len);
947 free(p);
948}
949
950/*
951 * SSH2 packet decode functions.
952 */
75cab814 953static unsigned long ssh2_pkt_getuint32(void) {
7cca0d81 954 unsigned long value;
955 if (pktin.length - pktin.savedpos < 4)
956 return 0; /* arrgh, no way to decline (FIXME?) */
957 value = GET_32BIT(pktin.data+pktin.savedpos);
958 pktin.savedpos += 4;
959 return value;
960}
75cab814 961static void ssh2_pkt_getstring(char **p, int *length) {
7cca0d81 962 *p = NULL;
963 if (pktin.length - pktin.savedpos < 4)
964 return;
965 *length = GET_32BIT(pktin.data+pktin.savedpos);
966 pktin.savedpos += 4;
967 if (pktin.length - pktin.savedpos < *length)
968 return;
969 *p = pktin.data+pktin.savedpos;
970 pktin.savedpos += *length;
971}
75cab814 972static Bignum ssh2_pkt_getmp(void) {
7cca0d81 973 char *p;
974 int i, j, length;
975 Bignum b;
976
977 ssh2_pkt_getstring(&p, &length);
978 if (!p)
979 return NULL;
8d5de777 980 if (p[0] & 0x80) {
981 bombout(("internal error: Can't handle negative mpints"));
982 return NULL;
983 }
7cca0d81 984 b = newbn((length+1)/2);
985 for (i = 0; i < length; i++) {
986 j = length - 1 - i;
987 if (j & 1)
988 b[j/2+1] |= ((unsigned char)p[i]) << 8;
989 else
990 b[j/2+1] |= ((unsigned char)p[i]);
991 }
992 return b;
993}
994
374330e2 995static int do_ssh_init(void) {
c5e9c988 996 char c, *vsp;
374330e2 997 char version[10];
c5e9c988 998 char vstring[80];
999 char vlog[sizeof(vstring)+20];
374330e2 1000 int i;
1001
1002#ifdef FWHACK
1003 i = 0;
1004 while (s_read(&c, 1) == 1) {
1005 if (c == 'S' && i < 2) i++;
1006 else if (c == 'S' && i == 2) i = 2;
1007 else if (c == 'H' && i == 2) break;
1008 else i = 0;
1009 }
1010#else
1011 if (s_read(&c,1) != 1 || c != 'S') return 0;
1012 if (s_read(&c,1) != 1 || c != 'S') return 0;
1013 if (s_read(&c,1) != 1 || c != 'H') return 0;
1014#endif
c5e9c988 1015 strcpy(vstring, "SSH-");
1016 vsp = vstring+4;
374330e2 1017 if (s_read(&c,1) != 1 || c != '-') return 0;
1018 i = 0;
1019 while (1) {
1020 if (s_read(&c,1) != 1)
1021 return 0;
c5e9c988 1022 if (vsp < vstring+sizeof(vstring)-1)
1023 *vsp++ = c;
374330e2 1024 if (i >= 0) {
1025 if (c == '-') {
1026 version[i] = '\0';
1027 i = -1;
1028 } else if (i < sizeof(version)-1)
1029 version[i++] = c;
1030 }
1031 else if (c == '\n')
1032 break;
1033 }
1034
960e736a 1035 rdpkt2_state.incoming_sequence = 0;
1036
c5e9c988 1037 *vsp = 0;
1038 sprintf(vlog, "Server version: %s", vstring);
1039 vlog[strcspn(vlog, "\r\n")] = '\0';
1040 logevent(vlog);
1041
adf799dd 1042 /*
1043 * Server version "1.99" means we can choose whether we use v1
1044 * or v2 protocol. Choice is based on cfg.sshprot.
1045 */
1046 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 1047 /*
1048 * This is a v2 server. Begin v2 protocol.
1049 */
1050 char *verstring = "SSH-2.0-PuTTY";
1051 SHA_Init(&exhash);
1052 /*
1053 * Hash our version string and their version string.
1054 */
1055 sha_string(&exhash, verstring, strlen(verstring));
1056 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
1057 sprintf(vstring, "%s\n", verstring);
1058 sprintf(vlog, "We claim version: %s", verstring);
1059 logevent(vlog);
1060 logevent("Using SSH protocol version 2");
1061 s_write(vstring, strlen(vstring));
1062 ssh_protocol = ssh2_protocol;
6abbf9e3 1063 ssh_version = 2;
e5574168 1064 s_rdpkt = ssh2_rdpkt;
1065 } else {
1066 /*
1067 * This is a v1 server. Begin v1 protocol.
1068 */
1069 sprintf(vstring, "SSH-%s-PuTTY\n",
1070 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1071 sprintf(vlog, "We claim version: %s", vstring);
1072 vlog[strcspn(vlog, "\r\n")] = '\0';
1073 logevent(vlog);
1074 logevent("Using SSH protocol version 1");
1075 s_write(vstring, strlen(vstring));
1076 ssh_protocol = ssh1_protocol;
6abbf9e3 1077 ssh_version = 1;
e5574168 1078 s_rdpkt = ssh1_rdpkt;
1079 }
8ccc75b0 1080 ssh_send_ok = 0;
fef97f43 1081 return 1;
374330e2 1082}
1083
fb09bf1c 1084/*
1085 * Handle the key exchange and user authentication phases.
1086 */
e5574168 1087static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1088{
374330e2 1089 int i, j, len;
374330e2 1090 unsigned char *rsabuf, *keystr1, *keystr2;
1091 unsigned char cookie[8];
1092 struct RSAKey servkey, hostkey;
1093 struct MD5Context md5c;
ccbfb941 1094 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1095 static int tried_publickey;
1096 static unsigned char session_id[16];
bea1ef5f 1097 int cipher_type;
b585ec46 1098 static char username[100];
374330e2 1099
374330e2 1100 crBegin;
1101
fb09bf1c 1102 if (!ispkt) crWaitUntil(ispkt);
374330e2 1103
8d5de777 1104 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1105 bombout(("Public key packet not received"));
1106 crReturn(0);
1107 }
374330e2 1108
c5e9c988 1109 logevent("Received public keys");
374330e2 1110
c5e9c988 1111 memcpy(cookie, pktin.body, 8);
374330e2 1112
7cca0d81 1113 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1114 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1115
c5e9c988 1116 /*
1c2a93c4 1117 * Log the host key fingerprint.
c5e9c988 1118 */
c5e9c988 1119 {
1120 char logmsg[80];
1c2a93c4 1121 logevent("Host key fingerprint is:");
c5e9c988 1122 strcpy(logmsg, " ");
1c2a93c4 1123 hostkey.comment = NULL;
1124 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1125 &hostkey);
c5e9c988 1126 logevent(logmsg);
1127 }
1128
fb09bf1c 1129 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1130 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1131
c5e9c988 1132 MD5Init(&md5c);
374330e2 1133 MD5Update(&md5c, keystr2, hostkey.bytes);
1134 MD5Update(&md5c, keystr1, servkey.bytes);
1135 MD5Update(&md5c, pktin.body, 8);
374330e2 1136 MD5Final(session_id, &md5c);
1137
1138 for (i=0; i<32; i++)
1139 session_key[i] = random_byte();
1140
1141 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1142
1143 rsabuf = malloc(len);
1144 if (!rsabuf)
1145 fatalbox("Out of memory");
1146
89ee5268 1147 /*
1148 * Verify the host key.
1149 */
1150 {
1151 /*
1152 * First format the key into a string.
1153 */
1154 int len = rsastr_len(&hostkey);
d5859615 1155 char fingerprint[100];
89ee5268 1156 char *keystr = malloc(len);
1157 if (!keystr)
1158 fatalbox("Out of memory");
1159 rsastr_fmt(keystr, &hostkey);
d5859615 1160 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1161 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
89ee5268 1162 free(keystr);
1163 }
374330e2 1164
1165 for (i=0; i<32; i++) {
1166 rsabuf[i] = session_key[i];
1167 if (i < 16)
1168 rsabuf[i] ^= session_id[i];
1169 }
1170
1171 if (hostkey.bytes > servkey.bytes) {
1172 rsaencrypt(rsabuf, 32, &servkey);
1173 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1174 } else {
1175 rsaencrypt(rsabuf, 32, &hostkey);
1176 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1177 }
1178
c5e9c988 1179 logevent("Encrypted session key");
1180
bea1ef5f 1181 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1182 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1183 SSH_CIPHER_3DES;
1184 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1185 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1186 cipher_type = SSH_CIPHER_3DES;
1187 }
c5e9c988 1188 switch (cipher_type) {
1189 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1190 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1191 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1192 }
bea1ef5f 1193
e5574168 1194 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1195 PKT_CHAR, cipher_type,
1196 PKT_DATA, cookie, 8,
1197 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1198 PKT_DATA, rsabuf, len,
1199 PKT_INT, 0,
1200 PKT_END);
1201
c5e9c988 1202 logevent("Trying to enable encryption...");
374330e2 1203
1204 free(rsabuf);
1205
5e8358ad 1206 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1207 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1208 &ssh_3des;
374330e2 1209 cipher->sesskey(session_key);
1210
fb09bf1c 1211 crWaitUntil(ispkt);
374330e2 1212
8d5de777 1213 if (pktin.type != SSH1_SMSG_SUCCESS) {
1214 bombout(("Encryption not successfully enabled"));
1215 crReturn(0);
1216 }
374330e2 1217
c5e9c988 1218 logevent("Successfully started encryption");
1219
374330e2 1220 fflush(stdout);
1221 {
374330e2 1222 static int pos = 0;
1223 static char c;
67779be7 1224 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1225 c_write("login as: ", 10);
67779be7 1226 ssh_send_ok = 1;
374330e2 1227 while (pos >= 0) {
fb09bf1c 1228 crWaitUntil(!ispkt);
374330e2 1229 while (inlen--) switch (c = *in++) {
1230 case 10: case 13:
1231 username[pos] = 0;
1232 pos = -1;
1233 break;
1234 case 8: case 127:
1235 if (pos > 0) {
1236 c_write("\b \b", 3);
1237 pos--;
1238 }
1239 break;
1240 case 21: case 27:
1241 while (pos > 0) {
1242 c_write("\b \b", 3);
1243 pos--;
1244 }
1245 break;
1246 case 3: case 4:
1247 random_save_seed();
1248 exit(0);
1249 break;
1250 default:
40d24aa6 1251 if (((c >= ' ' && c <= '~') ||
1252 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1253 username[pos++] = c;
1254 c_write(&c, 1);
1255 }
1256 break;
1257 }
1258 }
1259 c_write("\r\n", 2);
1260 username[strcspn(username, "\n\r")] = '\0';
1261 } else {
1262 char stuff[200];
1263 strncpy(username, cfg.username, 99);
1264 username[99] = '\0';
67779be7 1265 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
fb09bf1c 1266 sprintf(stuff, "Sent username \"%s\".\r\n", username);
4017be6d 1267 c_write(stuff, strlen(stuff));
fb09bf1c 1268 }
374330e2 1269 }
fb09bf1c 1270
e5574168 1271 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1272 {
1273 char userlog[20+sizeof(username)];
1274 sprintf(userlog, "Sent username \"%s\"", username);
1275 logevent(userlog);
1276 }
374330e2 1277 }
1278
fb09bf1c 1279 crWaitUntil(ispkt);
374330e2 1280
7cca0d81 1281 tried_publickey = 0;
1282
e5574168 1283 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1284 static char password[100];
a52f067e 1285 static char prompt[200];
374330e2 1286 static int pos;
1287 static char c;
ccbfb941 1288 static int pwpkt_type;
ccbfb941 1289 /*
1290 * Show password prompt, having first obtained it via a TIS
18515c51 1291 * or CryptoCard exchange if we're doing TIS or CryptoCard
1292 * authentication.
ccbfb941 1293 */
e5574168 1294 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1295 if (agent_exists()) {
1296 /*
1297 * Attempt RSA authentication using Pageant.
1298 */
1299 static unsigned char request[5], *response, *p;
1300 static int responselen;
1301 static int i, nkeys;
1302 static int authed = FALSE;
1303 void *r;
1304
1305 logevent("Pageant is running. Requesting keys.");
1306
1307 /* Request the keys held by the agent. */
1308 PUT_32BIT(request, 1);
1309 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1310 agent_query(request, 5, &r, &responselen);
1311 response = (unsigned char *)r;
1312 if (response) {
1313 p = response + 5;
1314 nkeys = GET_32BIT(p); p += 4;
1315 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1316 logevent(buf); }
1317 for (i = 0; i < nkeys; i++) {
1318 static struct RSAKey key;
1319 static Bignum challenge;
b8bb811a 1320 static char *commentp;
1321 static int commentlen;
5c58ad2d 1322
1323 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1324 logevent(buf); }
1325 p += 4;
1326 p += ssh1_read_bignum(p, &key.exponent);
1327 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1328 commentlen = GET_32BIT(p); p += 4;
1329 commentp = p; p += commentlen;
5c58ad2d 1330 send_packet(SSH1_CMSG_AUTH_RSA,
1331 PKT_BIGNUM, key.modulus, PKT_END);
1332 crWaitUntil(ispkt);
1333 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1334 logevent("Key refused");
1335 continue;
1336 }
1337 logevent("Received RSA challenge");
1338 ssh1_read_bignum(pktin.body, &challenge);
1339 {
1340 char *agentreq, *q, *ret;
1341 int len, retlen;
1342 len = 1 + 4; /* message type, bit count */
1343 len += ssh1_bignum_length(key.exponent);
1344 len += ssh1_bignum_length(key.modulus);
1345 len += ssh1_bignum_length(challenge);
1346 len += 16; /* session id */
1347 len += 4; /* response format */
1348 agentreq = malloc(4 + len);
1349 PUT_32BIT(agentreq, len);
1350 q = agentreq + 4;
1351 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1352 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1353 q += 4;
1354 q += ssh1_write_bignum(q, key.exponent);
1355 q += ssh1_write_bignum(q, key.modulus);
1356 q += ssh1_write_bignum(q, challenge);
1357 memcpy(q, session_id, 16); q += 16;
1358 PUT_32BIT(q, 1); /* response format */
1359 agent_query(agentreq, len+4, &ret, &retlen);
1360 free(agentreq);
1361 if (ret) {
1362 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1363 logevent("Sending Pageant's response");
1364 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1365 PKT_DATA, ret+5, 16, PKT_END);
1366 free(ret);
1367 crWaitUntil(ispkt);
1368 if (pktin.type == SSH1_SMSG_SUCCESS) {
1369 logevent("Pageant's response accepted");
c4fa2fce 1370 if (flags & FLAG_VERBOSE) {
1371 c_write("Authenticated using RSA key \"",
1372 29);
1373 c_write(commentp, commentlen);
1374 c_write("\" from agent\r\n", 14);
1375 }
5c58ad2d 1376 authed = TRUE;
1377 } else
1378 logevent("Pageant's response not accepted");
1379 } else {
1380 logevent("Pageant failed to answer challenge");
1381 free(ret);
1382 }
1383 } else {
1384 logevent("No reply received from Pageant");
1385 }
1386 }
1387 freebn(key.exponent);
1388 freebn(key.modulus);
1389 freebn(challenge);
1390 if (authed)
1391 break;
1392 }
1393 }
1394 if (authed)
1395 break;
1396 }
7cca0d81 1397 if (*cfg.keyfile && !tried_publickey)
1398 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1399
a52f067e 1400 if (pktin.type == SSH1_SMSG_FAILURE &&
1401 cfg.try_tis_auth &&
1402 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1403 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1404 logevent("Requested TIS authentication");
1405 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1406 crWaitUntil(ispkt);
1407 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1408 logevent("TIS authentication declined");
1409 if (flags & FLAG_INTERACTIVE)
1410 c_write("TIS authentication refused.\r\n", 29);
1411 } else {
1412 int challengelen = ((pktin.body[0] << 24) |
1413 (pktin.body[1] << 16) |
1414 (pktin.body[2] << 8) |
1415 (pktin.body[3]));
1416 logevent("Received TIS challenge");
1417 if (challengelen > sizeof(prompt)-1)
1418 challengelen = sizeof(prompt)-1; /* prevent overrun */
1419 memcpy(prompt, pktin.body+4, challengelen);
1420 prompt[challengelen] = '\0';
1421 }
1422 }
1423 if (pktin.type == SSH1_SMSG_FAILURE &&
1424 cfg.try_tis_auth &&
1425 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1426 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1427 logevent("Requested CryptoCard authentication");
1428 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1429 crWaitUntil(ispkt);
1430 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1431 logevent("CryptoCard authentication declined");
1432 c_write("CryptoCard authentication refused.\r\n", 29);
1433 } else {
1434 int challengelen = ((pktin.body[0] << 24) |
1435 (pktin.body[1] << 16) |
1436 (pktin.body[2] << 8) |
1437 (pktin.body[3]));
1438 logevent("Received CryptoCard challenge");
1439 if (challengelen > sizeof(prompt)-1)
1440 challengelen = sizeof(prompt)-1; /* prevent overrun */
1441 memcpy(prompt, pktin.body+4, challengelen);
1442 strncpy(prompt + challengelen, "\r\nResponse : ",
1443 sizeof(prompt)-challengelen);
1444 prompt[sizeof(prompt)-1] = '\0';
1445 }
1446 }
1447 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1448 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1449 username, savedhost);
a52f067e 1450 }
1451 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1452 char *comment = NULL;
1453 if (flags & FLAG_VERBOSE)
1454 c_write("Trying public key authentication.\r\n", 35);
1455 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1456 if (flags & FLAG_VERBOSE)
1457 c_write("No passphrase required.\r\n", 25);
1458 goto tryauth;
1459 }
1460 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1461 free(comment);
1462 }
1463
d8426c54 1464 if (ssh_get_password) {
85ee8208 1465 if (!ssh_get_password(prompt, password, sizeof(password))) {
1466 /*
1467 * get_password failed to get a password (for
1468 * example because one was supplied on the command
1469 * line which has already failed to work).
1470 * Terminate.
1471 */
1472 logevent("No more passwords to try");
1473 ssh_state = SSH_STATE_CLOSED;
1474 crReturn(1);
1475 }
fb09bf1c 1476 } else {
a52f067e 1477 c_write(prompt, strlen(prompt));
7cca0d81 1478 pos = 0;
67779be7 1479 ssh_send_ok = 1;
7cca0d81 1480 while (pos >= 0) {
1481 crWaitUntil(!ispkt);
1482 while (inlen--) switch (c = *in++) {
1483 case 10: case 13:
1484 password[pos] = 0;
1485 pos = -1;
1486 break;
1487 case 8: case 127:
1488 if (pos > 0)
1489 pos--;
1490 break;
1491 case 21: case 27:
1492 pos = 0;
1493 break;
1494 case 3: case 4:
1495 random_save_seed();
1496 exit(0);
1497 break;
1498 default:
1499 if (((c >= ' ' && c <= '~') ||
1500 ((unsigned char)c >= 160)) && pos < sizeof(password))
1501 password[pos++] = c;
1502 break;
1503 }
1504 }
1505 c_write("\r\n", 2);
a52f067e 1506 }
fb09bf1c 1507
7cca0d81 1508 tryauth:
1509 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1510 /*
1511 * Try public key authentication with the specified
1512 * key file.
1513 */
1514 static struct RSAKey pubkey;
1515 static Bignum challenge, response;
1516 static int i;
1517 static unsigned char buffer[32];
1518
1519 tried_publickey = 1;
1520 i = loadrsakey(cfg.keyfile, &pubkey, password);
1521 if (i == 0) {
1522 c_write("Couldn't load public key from ", 30);
1523 c_write(cfg.keyfile, strlen(cfg.keyfile));
1524 c_write(".\r\n", 3);
1525 continue; /* go and try password */
1526 }
1527 if (i == -1) {
1528 c_write("Wrong passphrase.\r\n", 19);
1529 tried_publickey = 0;
1530 continue; /* try again */
1531 }
1532
1533 /*
1534 * Send a public key attempt.
1535 */
1536 send_packet(SSH1_CMSG_AUTH_RSA,
1537 PKT_BIGNUM, pubkey.modulus, PKT_END);
1538
1539 crWaitUntil(ispkt);
1540 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1541 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1542 continue; /* go and try password */
1543 }
8d5de777 1544 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1545 bombout(("Bizarre response to offer of public key"));
1546 crReturn(0);
1547 }
7cca0d81 1548 ssh1_read_bignum(pktin.body, &challenge);
1549 response = rsadecrypt(challenge, &pubkey);
1550 freebn(pubkey.private_exponent); /* burn the evidence */
1551
1552 for (i = 0; i < 32; i += 2) {
1553 buffer[i] = response[16-i/2] >> 8;
1554 buffer[i+1] = response[16-i/2] & 0xFF;
1555 }
1556
1557 MD5Init(&md5c);
1558 MD5Update(&md5c, buffer, 32);
1559 MD5Update(&md5c, session_id, 16);
1560 MD5Final(buffer, &md5c);
1561
1562 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1563 PKT_DATA, buffer, 16, PKT_END);
1564
1565 crWaitUntil(ispkt);
1566 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1567 if (flags & FLAG_VERBOSE)
1568 c_write("Failed to authenticate with our public key.\r\n",
1569 45);
7cca0d81 1570 continue; /* go and try password */
1571 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1572 bombout(("Bizarre response to RSA authentication response"));
1573 crReturn(0);
7cca0d81 1574 }
1575
1576 break; /* we're through! */
1577 } else {
1578 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1579 }
c5e9c988 1580 logevent("Sent password");
374330e2 1581 memset(password, 0, strlen(password));
fb09bf1c 1582 crWaitUntil(ispkt);
e5574168 1583 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1584 if (flags & FLAG_VERBOSE)
1585 c_write("Access denied\r\n", 15);
c5e9c988 1586 logevent("Authentication refused");
e5574168 1587 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1588 logevent("Received disconnect request");
85ee8208 1589 ssh_state = SSH_STATE_CLOSED;
1590 crReturn(1);
e5574168 1591 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1592 bombout(("Strange packet received, type %d", pktin.type));
1593 crReturn(0);
374330e2 1594 }
1595 }
1596
c5e9c988 1597 logevent("Authentication successful");
1598
fb09bf1c 1599 crFinish(1);
1600}
1601
e5574168 1602static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1603 crBegin;
1604
1605 random_init();
1606
e5574168 1607 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1608 crReturnV;
85ee8208 1609 }
1610 if (ssh_state == SSH_STATE_CLOSED)
1611 crReturnV;
fb09bf1c 1612
979310f1 1613 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1614 logevent("Requesting agent forwarding");
1615 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1616 do { crReturnV; } while (!ispkt);
1617 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1618 bombout(("Protocol confusion"));
1619 crReturnV;
dacbd0e8 1620 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1621 logevent("Agent forwarding refused");
1622 } else
1623 logevent("Agent forwarding enabled");
1624 }
1625
fef97f43 1626 if (!cfg.nopty) {
e5574168 1627 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1628 PKT_STR, cfg.termtype,
1629 PKT_INT, rows, PKT_INT, cols,
1630 PKT_INT, 0, PKT_INT, 0,
1631 PKT_CHAR, 0,
1632 PKT_END);
fef97f43 1633 ssh_state = SSH_STATE_INTERMED;
1634 do { crReturnV; } while (!ispkt);
e5574168 1635 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1636 bombout(("Protocol confusion"));
1637 crReturnV;
e5574168 1638 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1639 c_write("Server refused to allocate pty\r\n", 32);
1640 }
c5e9c988 1641 logevent("Allocated pty");
374330e2 1642 }
1643
6abbf9e3 1644 if (*cfg.remote_cmd)
1645 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1646 else
1647 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1648 logevent("Started session");
374330e2 1649
1650 ssh_state = SSH_STATE_SESSION;
1651 if (size_needed)
1652 ssh_size();
1653
8ccc75b0 1654 ssh_send_ok = 1;
dacbd0e8 1655 ssh_channels = newtree234(ssh_channelcmp);
6f34e365 1656 begin_session();
374330e2 1657 while (1) {
1658 crReturnV;
1659 if (ispkt) {
e5574168 1660 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1661 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1662 long len = GET_32BIT(pktin.body);
3bdaf79d 1663 c_writedata(pktin.body+4, len);
e5574168 1664 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1665 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1666 logevent("Received disconnect request");
dacbd0e8 1667 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1668 /* Remote side is trying to open a channel to talk to our
1669 * agent. Give them back a local channel number. */
d211621f 1670 unsigned i = 1;
dacbd0e8 1671 struct ssh_channel *c;
1672 enum234 e;
1673 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1674 if (c->localid > i)
1675 break; /* found a free number */
1676 i = c->localid + 1;
1677 }
1678 c = malloc(sizeof(struct ssh_channel));
1679 c->remoteid = GET_32BIT(pktin.body);
1680 c->localid = i;
b8bb811a 1681 c->closes = 0;
dacbd0e8 1682 c->type = SSH1_SMSG_AGENT_OPEN; /* identify channel type */
bb487ce2 1683 c->u.a.lensofar = 0;
dacbd0e8 1684 add234(ssh_channels, c);
1685 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1686 PKT_INT, c->remoteid, PKT_INT, c->localid,
1687 PKT_END);
1688 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1689 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1690 /* Remote side closes a channel. */
d211621f 1691 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1692 struct ssh_channel *c;
1693 c = find234(ssh_channels, &i, ssh_channelfind);
1694 if (c) {
1695 int closetype;
1696 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1697 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1698 c->closes |= closetype;
1699 if (c->closes == 3) {
1700 del234(ssh_channels, c);
1701 free(c);
1702 }
1703 }
1704 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1705 /* Data sent down one of our channels. */
1706 int i = GET_32BIT(pktin.body);
1707 int len = GET_32BIT(pktin.body+4);
1708 unsigned char *p = pktin.body+8;
1709 struct ssh_channel *c;
1710 c = find234(ssh_channels, &i, ssh_channelfind);
1711 if (c) {
1712 switch(c->type) {
1713 case SSH1_SMSG_AGENT_OPEN:
1714 /* Data for an agent message. Buffer it. */
1715 while (len > 0) {
1716 if (c->u.a.lensofar < 4) {
1717 int l = min(4 - c->u.a.lensofar, len);
1718 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
1719 p += l; len -= l; c->u.a.lensofar += l;
1720 }
1721 if (c->u.a.lensofar == 4) {
1722 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
1723 c->u.a.message = malloc(c->u.a.totallen);
1724 memcpy(c->u.a.message, c->u.a.msglen, 4);
1725 }
1726 if (c->u.a.lensofar >= 4 && len > 0) {
1727 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
1728 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
1729 p += l; len -= l; c->u.a.lensofar += l;
1730 }
1731 if (c->u.a.lensofar == c->u.a.totallen) {
1732 void *reply, *sentreply;
1733 int replylen;
1734 agent_query(c->u.a.message, c->u.a.totallen,
1735 &reply, &replylen);
1736 if (reply)
1737 sentreply = reply;
1738 else {
1739 /* Fake SSH_AGENT_FAILURE. */
1740 sentreply = "\0\0\0\1\5";
1741 replylen = 5;
1742 }
1743 send_packet(SSH1_MSG_CHANNEL_DATA,
1744 PKT_INT, c->remoteid,
1745 PKT_INT, replylen,
1746 PKT_DATA, sentreply, replylen,
1747 PKT_END);
1748 if (reply)
1749 free(reply);
1750 free(c->u.a.message);
1751 c->u.a.lensofar = 0;
1752 }
1753 }
1754 break;
1755 }
1756 }
e5574168 1757 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 1758 /* may be from EXEC_SHELL on some servers */
e5574168 1759 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 1760 /* may be from EXEC_SHELL on some servers
374330e2 1761 * if no pty is available or in other odd cases. Ignore */
e5574168 1762 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1763 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 1764 } else {
8d5de777 1765 bombout(("Strange packet received: type %d", pktin.type));
1766 crReturnV;
374330e2 1767 }
1768 } else {
e5574168 1769 send_packet(SSH1_CMSG_STDIN_DATA,
fb09bf1c 1770 PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
374330e2 1771 }
1772 }
1773
1774 crFinishV;
1775}
1776
1777/*
e5574168 1778 * Utility routine for decoding comma-separated strings in KEXINIT.
1779 */
75cab814 1780static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 1781 int needlen = strlen(needle);
1782 while (1) {
1783 /*
1784 * Is it at the start of the string?
1785 */
1786 if (haylen >= needlen && /* haystack is long enough */
1787 !memcmp(needle, haystack, needlen) && /* initial match */
1788 (haylen == needlen || haystack[needlen] == ',')
1789 /* either , or EOS follows */
1790 )
1791 return 1;
1792 /*
1793 * If not, search for the next comma and resume after that.
1794 * If no comma found, terminate.
1795 */
1796 while (haylen > 0 && *haystack != ',')
1797 haylen--, haystack++;
1798 if (haylen == 0)
1799 return 0;
1800 haylen--, haystack++; /* skip over comma itself */
1801 }
1802}
1803
1804/*
d39f364a 1805 * SSH2 key creation method.
1806 */
75cab814 1807static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
d39f364a 1808 SHA_State s;
1809 /* First 20 bytes. */
1810 SHA_Init(&s);
1811 sha_mpint(&s, K);
1812 SHA_Bytes(&s, H, 20);
1813 SHA_Bytes(&s, &chr, 1);
1814 SHA_Bytes(&s, H, 20);
1815 SHA_Final(&s, keyspace);
1816 /* Next 20 bytes. */
1817 SHA_Init(&s);
1818 sha_mpint(&s, K);
1819 SHA_Bytes(&s, H, 20);
1820 SHA_Bytes(&s, keyspace, 20);
1821 SHA_Final(&s, keyspace+20);
1822}
1823
1824/*
7cca0d81 1825 * Handle the SSH2 transport layer.
e5574168 1826 */
7cca0d81 1827static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 1828{
1829 static int i, len;
1830 static char *str;
1831 static Bignum e, f, K;
7591b9ff 1832 static const struct ssh_mac **maclist;
57476f6b 1833 static const struct ssh_cipher *cscipher_tobe = NULL;
1834 static const struct ssh_cipher *sccipher_tobe = NULL;
1835 static const struct ssh_mac *csmac_tobe = NULL;
1836 static const struct ssh_mac *scmac_tobe = NULL;
1837 static const struct ssh_compress *cscomp_tobe = NULL;
1838 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 1839 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 1840 static int hostkeylen, siglen;
1841 static unsigned char exchange_hash[20];
d39f364a 1842 static unsigned char keyspace[40];
57476f6b 1843 static const struct ssh_cipher *preferred_cipher;
e5574168 1844
1845 crBegin;
7cca0d81 1846 random_init();
e5574168 1847
5e8358ad 1848 /*
1849 * Set up the preferred cipher.
1850 */
1851 if (cfg.cipher == CIPHER_BLOWFISH) {
57476f6b 1852 preferred_cipher = &ssh_blowfish_ssh2;
5e8358ad 1853 } else if (cfg.cipher == CIPHER_DES) {
1854 logevent("Single DES not supported in SSH2; using 3DES");
57476f6b 1855 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1856 } else if (cfg.cipher == CIPHER_3DES) {
57476f6b 1857 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1858 } else {
1859 /* Shouldn't happen, but we do want to initialise to _something_. */
57476f6b 1860 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1861 }
1862
7591b9ff 1863 /*
1864 * Be prepared to work around the buggy MAC problem.
1865 */
1866 if (cfg.buggymac)
1867 maclist = buggymacs;
1868 else
1869 maclist = macs;
1870
7cca0d81 1871 begin_key_exchange:
e5574168 1872 /*
1873 * Construct and send our key exchange packet.
1874 */
1875 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1876 for (i = 0; i < 16; i++)
1877 ssh2_pkt_addbyte((unsigned char)random_byte());
1878 /* List key exchange algorithms. */
1879 ssh2_pkt_addstring_start();
1880 for (i = 0; i < lenof(kex_algs); i++) {
1881 ssh2_pkt_addstring_str(kex_algs[i]->name);
1882 if (i < lenof(kex_algs)-1)
1883 ssh2_pkt_addstring_str(",");
1884 }
1885 /* List server host key algorithms. */
1886 ssh2_pkt_addstring_start();
1887 for (i = 0; i < lenof(hostkey_algs); i++) {
1888 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1889 if (i < lenof(hostkey_algs)-1)
1890 ssh2_pkt_addstring_str(",");
1891 }
1892 /* List client->server encryption algorithms. */
1893 ssh2_pkt_addstring_start();
729e54b4 1894 for (i = 0; i < lenof(ciphers)+1; i++) {
1895 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1896 ssh2_pkt_addstring_str(c->name);
729e54b4 1897 if (i < lenof(ciphers))
e5574168 1898 ssh2_pkt_addstring_str(",");
1899 }
1900 /* List server->client encryption algorithms. */
1901 ssh2_pkt_addstring_start();
729e54b4 1902 for (i = 0; i < lenof(ciphers)+1; i++) {
1903 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1904 ssh2_pkt_addstring_str(c->name);
729e54b4 1905 if (i < lenof(ciphers))
e5574168 1906 ssh2_pkt_addstring_str(",");
1907 }
1908 /* List client->server MAC algorithms. */
1909 ssh2_pkt_addstring_start();
7591b9ff 1910 for (i = 0; i < lenof(maclist); i++) {
1911 ssh2_pkt_addstring_str(maclist[i]->name);
1912 if (i < lenof(maclist)-1)
e5574168 1913 ssh2_pkt_addstring_str(",");
1914 }
1915 /* List server->client MAC algorithms. */
1916 ssh2_pkt_addstring_start();
7591b9ff 1917 for (i = 0; i < lenof(maclist); i++) {
1918 ssh2_pkt_addstring_str(maclist[i]->name);
1919 if (i < lenof(maclist)-1)
e5574168 1920 ssh2_pkt_addstring_str(",");
1921 }
1922 /* List client->server compression algorithms. */
1923 ssh2_pkt_addstring_start();
1924 for (i = 0; i < lenof(compressions); i++) {
1925 ssh2_pkt_addstring_str(compressions[i]->name);
1926 if (i < lenof(compressions)-1)
1927 ssh2_pkt_addstring_str(",");
1928 }
1929 /* List server->client compression algorithms. */
1930 ssh2_pkt_addstring_start();
1931 for (i = 0; i < lenof(compressions); i++) {
1932 ssh2_pkt_addstring_str(compressions[i]->name);
1933 if (i < lenof(compressions)-1)
1934 ssh2_pkt_addstring_str(",");
1935 }
1936 /* List client->server languages. Empty list. */
1937 ssh2_pkt_addstring_start();
1938 /* List server->client languages. Empty list. */
1939 ssh2_pkt_addstring_start();
1940 /* First KEX packet does _not_ follow, because we're not that brave. */
1941 ssh2_pkt_addbool(FALSE);
1942 /* Reserved. */
1943 ssh2_pkt_adduint32(0);
1944 sha_string(&exhash, pktout.data+5, pktout.length-5);
1945 ssh2_pkt_send();
1946
1947 if (!ispkt) crWaitUntil(ispkt);
1948 sha_string(&exhash, pktin.data+5, pktin.length-5);
1949
1950 /*
1951 * Now examine the other side's KEXINIT to see what we're up
1952 * to.
1953 */
7cca0d81 1954 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 1955 bombout(("expected key exchange packet from server"));
1956 crReturn(0);
7cca0d81 1957 }
e5574168 1958 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1959 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1960 pktin.savedpos += 16; /* skip garbage cookie */
1961 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1962 for (i = 0; i < lenof(kex_algs); i++) {
1963 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1964 kex = kex_algs[i];
1965 break;
1966 }
1967 }
1968 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1969 for (i = 0; i < lenof(hostkey_algs); i++) {
1970 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1971 hostkey = hostkey_algs[i];
1972 break;
1973 }
1974 }
1975 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 1976 for (i = 0; i < lenof(ciphers)+1; i++) {
1977 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1978 if (in_commasep_string(c->name, str, len)) {
729e54b4 1979 cscipher_tobe = c;
e5574168 1980 break;
1981 }
1982 }
1983 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
729e54b4 1984 for (i = 0; i < lenof(ciphers)+1; i++) {
1985 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1986 if (in_commasep_string(c->name, str, len)) {
729e54b4 1987 sccipher_tobe = c;
e5574168 1988 break;
1989 }
1990 }
1991 ssh2_pkt_getstring(&str, &len); /* client->server mac */
7591b9ff 1992 for (i = 0; i < lenof(maclist); i++) {
1993 if (in_commasep_string(maclist[i]->name, str, len)) {
1994 csmac_tobe = maclist[i];
e5574168 1995 break;
1996 }
1997 }
1998 ssh2_pkt_getstring(&str, &len); /* server->client mac */
7591b9ff 1999 for (i = 0; i < lenof(maclist); i++) {
2000 if (in_commasep_string(maclist[i]->name, str, len)) {
2001 scmac_tobe = maclist[i];
e5574168 2002 break;
2003 }
2004 }
2005 ssh2_pkt_getstring(&str, &len); /* client->server compression */
2006 for (i = 0; i < lenof(compressions); i++) {
2007 if (in_commasep_string(compressions[i]->name, str, len)) {
2008 cscomp_tobe = compressions[i];
2009 break;
2010 }
2011 }
2012 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2013 for (i = 0; i < lenof(compressions); i++) {
2014 if (in_commasep_string(compressions[i]->name, str, len)) {
2015 sccomp_tobe = compressions[i];
2016 break;
2017 }
2018 }
e5574168 2019
2020 /*
2021 * Currently we only support Diffie-Hellman and DSS, so let's
2022 * bomb out if those aren't selected.
2023 */
8d5de777 2024 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2025 bombout(("internal fault: chaos in SSH 2 transport layer"));
2026 crReturn(0);
2027 }
e5574168 2028
2029 /*
2030 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2031 */
2032 e = dh_create_e();
e5574168 2033 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2034 ssh2_pkt_addmp(e);
2035 ssh2_pkt_send();
2036
2037 crWaitUntil(ispkt);
7cca0d81 2038 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2039 bombout(("expected key exchange packet from server"));
2040 crReturn(0);
7cca0d81 2041 }
e5574168 2042 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2043 f = ssh2_pkt_getmp();
e5574168 2044 ssh2_pkt_getstring(&sigdata, &siglen);
2045
2046 K = dh_find_K(f);
e5574168 2047
2048 sha_string(&exhash, hostkeydata, hostkeylen);
2049 sha_mpint(&exhash, e);
2050 sha_mpint(&exhash, f);
2051 sha_mpint(&exhash, K);
2052 SHA_Final(&exhash, exchange_hash);
2053
7cca0d81 2054#if 0
e5574168 2055 debug(("Exchange hash is:\r\n"));
2056 for (i = 0; i < 20; i++)
2057 debug((" %02x", exchange_hash[i]));
2058 debug(("\r\n"));
7cca0d81 2059#endif
2060
2061 hostkey->setkey(hostkeydata, hostkeylen);
8d5de777 2062 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20)) {
2063 bombout(("Server failed host key check"));
2064 crReturn(0);
2065 }
e5574168 2066
2067 /*
7cca0d81 2068 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2069 */
7cca0d81 2070 crWaitUntil(ispkt);
8d5de777 2071 if (pktin.type != SSH2_MSG_NEWKEYS) {
2072 bombout(("expected new-keys packet from server"));
2073 crReturn(0);
2074 }
d39f364a 2075
2076 /*
7cca0d81 2077 * Authenticate remote host: verify host key. (We've already
2078 * checked the signature of the exchange hash.)
e5574168 2079 */
7cca0d81 2080 keystr = hostkey->fmtkey();
d5859615 2081 fingerprint = hostkey->fingerprint();
d4857987 2082 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2083 keystr, fingerprint);
d5859615 2084 logevent("Host key fingerprint is:");
2085 logevent(fingerprint);
2086 free(fingerprint);
7cca0d81 2087 free(keystr);
d39f364a 2088
2089 /*
7cca0d81 2090 * Send SSH2_MSG_NEWKEYS.
d39f364a 2091 */
2092 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2093 ssh2_pkt_send();
d39f364a 2094
2095 /*
2096 * Create and initialise session keys.
2097 */
2098 cscipher = cscipher_tobe;
2099 sccipher = sccipher_tobe;
2100 csmac = csmac_tobe;
2101 scmac = scmac_tobe;
2102 cscomp = cscomp_tobe;
2103 sccomp = sccomp_tobe;
2104 /*
2105 * Set IVs after keys.
2106 */
2107 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
2108 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
2109 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2110 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2111 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2112 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2113
033b4cef 2114 /*
7cca0d81 2115 * Now we're encrypting. Begin returning 1 to the protocol main
2116 * function so that other things can run on top of the
2117 * transport. If we ever see a KEXINIT, we must go back to the
2118 * start.
033b4cef 2119 */
7cca0d81 2120 do {
2121 crReturn(1);
2122 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2123 goto begin_key_exchange;
e5574168 2124
2125 crFinish(1);
2126}
2127
7cca0d81 2128/*
2129 * Handle the SSH2 userauth and connection layers.
2130 */
2131static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2132{
7cca0d81 2133 static unsigned long remote_winsize;
2134 static unsigned long remote_maxpkt;
2135
e5574168 2136 crBegin;
2137
7cca0d81 2138 /*
2139 * Request userauth protocol, and await a response to it.
2140 */
2141 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2142 ssh2_pkt_addstring("ssh-userauth");
2143 ssh2_pkt_send();
2144 crWaitUntilV(ispkt);
8d5de777 2145 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2146 bombout(("Server refused user authentication protocol"));
2147 crReturnV;
2148 }
7cca0d81 2149
2150 /*
2151 * FIXME: currently we support only password authentication.
2152 * (This places us technically in violation of the SSH2 spec.
2153 * We must fix this.)
2154 */
2155 while (1) {
2156 /*
2157 * Get a username and a password.
2158 */
2159 static char username[100];
2160 static char password[100];
2161 static int pos = 0;
2162 static char c;
e5574168 2163
67779be7 2164 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2165 c_write("login as: ", 10);
67779be7 2166 ssh_send_ok = 1;
7cca0d81 2167 while (pos >= 0) {
2168 crWaitUntilV(!ispkt);
2169 while (inlen--) switch (c = *in++) {
2170 case 10: case 13:
2171 username[pos] = 0;
2172 pos = -1;
2173 break;
2174 case 8: case 127:
2175 if (pos > 0) {
2176 c_write("\b \b", 3);
2177 pos--;
2178 }
2179 break;
2180 case 21: case 27:
2181 while (pos > 0) {
2182 c_write("\b \b", 3);
2183 pos--;
2184 }
2185 break;
2186 case 3: case 4:
2187 random_save_seed();
2188 exit(0);
2189 break;
2190 default:
2191 if (((c >= ' ' && c <= '~') ||
2192 ((unsigned char)c >= 160)) && pos < 40) {
2193 username[pos++] = c;
2194 c_write(&c, 1);
2195 }
2196 break;
2197 }
2198 }
2199 c_write("\r\n", 2);
2200 username[strcspn(username, "\n\r")] = '\0';
2201 } else {
2202 char stuff[200];
2203 strncpy(username, cfg.username, 99);
2204 username[99] = '\0';
67779be7 2205 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2206 sprintf(stuff, "Using username \"%s\".\r\n", username);
2207 c_write(stuff, strlen(stuff));
2208 }
2209 }
2210
d8426c54 2211 if (ssh_get_password) {
7cca0d81 2212 char prompt[200];
b585ec46 2213 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
7cca0d81 2214 if (!ssh_get_password(prompt, password, sizeof(password))) {
2215 /*
2216 * get_password failed to get a password (for
2217 * example because one was supplied on the command
2218 * line which has already failed to work).
2219 * Terminate.
2220 */
2221 logevent("No more passwords to try");
2222 ssh_state = SSH_STATE_CLOSED;
2223 crReturnV;
2224 }
2225 } else {
2226 c_write("password: ", 10);
67779be7 2227 ssh_send_ok = 1;
7cca0d81 2228
2229 pos = 0;
2230 while (pos >= 0) {
2231 crWaitUntilV(!ispkt);
2232 while (inlen--) switch (c = *in++) {
2233 case 10: case 13:
2234 password[pos] = 0;
2235 pos = -1;
2236 break;
2237 case 8: case 127:
2238 if (pos > 0)
2239 pos--;
2240 break;
2241 case 21: case 27:
2242 pos = 0;
2243 break;
2244 case 3: case 4:
2245 random_save_seed();
2246 exit(0);
2247 break;
2248 default:
2249 if (((c >= ' ' && c <= '~') ||
2250 ((unsigned char)c >= 160)) && pos < 40)
2251 password[pos++] = c;
2252 break;
2253 }
2254 }
2255 c_write("\r\n", 2);
2256 }
2257
2258 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2259 ssh2_pkt_addstring(username);
2260 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2261 ssh2_pkt_addstring("password");
2262 ssh2_pkt_addbool(FALSE);
2263 ssh2_pkt_addstring(password);
2264 ssh2_pkt_send();
2265
2266 crWaitUntilV(ispkt);
2267 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2268 c_write("Access denied\r\n", 15);
2269 logevent("Authentication refused");
2270 } else
2271 break;
2272 }
2273
2274 /*
2275 * Now we're authenticated for the connection protocol. The
2276 * connection protocol will automatically have started at this
2277 * point; there's no need to send SERVICE_REQUEST.
2278 */
2279
2280 /*
2281 * So now create a channel with a session in it.
2282 */
d211621f 2283 mainchan = malloc(sizeof(struct ssh_channel));
2284 mainchan->localid = 100; /* as good as any */
7cca0d81 2285 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2286 ssh2_pkt_addstring("session");
d211621f 2287 ssh2_pkt_adduint32(mainchan->localid);
cf6e59d6 2288 ssh2_pkt_adduint32(0x8000UL); /* our window size */
d211621f 2289 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2290 ssh2_pkt_send();
2291 crWaitUntilV(ispkt);
2292 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2293 bombout(("Server refused to open a session"));
2294 crReturnV;
7cca0d81 2295 /* FIXME: error data comes back in FAILURE packet */
2296 }
d211621f 2297 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2298 bombout(("Server's channel confirmation cited wrong channel"));
2299 crReturnV;
7cca0d81 2300 }
d211621f 2301 mainchan->remoteid = ssh2_pkt_getuint32();
2302 mainchan->u.v2.remwindow = ssh2_pkt_getuint32();
2303 mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32();
2304 mainchan->u.v2.outbuffer = NULL;
2305 mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0;
7cca0d81 2306 logevent("Opened channel for session");
2307
2308 /*
2309 * Now allocate a pty for the session.
2310 */
67779be7 2311 if (!cfg.nopty) {
2312 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2313 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2314 ssh2_pkt_addstring("pty-req");
2315 ssh2_pkt_addbool(1); /* want reply */
2316 ssh2_pkt_addstring(cfg.termtype);
2317 ssh2_pkt_adduint32(cols);
2318 ssh2_pkt_adduint32(rows);
2319 ssh2_pkt_adduint32(0); /* pixel width */
2320 ssh2_pkt_adduint32(0); /* pixel height */
2321 ssh2_pkt_addstring_start();
2322 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2323 ssh2_pkt_send();
7cca0d81 2324
67779be7 2325 do {
2326 crWaitUntilV(ispkt);
2327 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2328 /* FIXME: be able to handle other channels here */
2329 if (ssh2_pkt_getuint32() != mainchan->localid)
2330 continue; /* wrong channel */
2331 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2332 }
2333 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2334
67779be7 2335 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2336 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2337 bombout(("Server got confused by pty request"));
2338 crReturnV;
67779be7 2339 }
2340 c_write("Server refused to allocate pty\r\n", 32);
2341 } else {
2342 logevent("Allocated pty");
7cca0d81 2343 }
7cca0d81 2344 }
2345
2346 /*
67779be7 2347 * Start a shell or a remote command.
7cca0d81 2348 */
2349 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2350 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2351 if (*cfg.remote_cmd) {
2352 ssh2_pkt_addstring("exec");
2353 ssh2_pkt_addbool(1); /* want reply */
2354 ssh2_pkt_addstring(cfg.remote_cmd);
2355 } else {
2356 ssh2_pkt_addstring("shell");
2357 ssh2_pkt_addbool(1); /* want reply */
2358 }
7cca0d81 2359 ssh2_pkt_send();
d211621f 2360 do {
7cca0d81 2361 crWaitUntilV(ispkt);
d211621f 2362 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2363 /* FIXME: be able to handle other channels here */
2364 if (ssh2_pkt_getuint32() != mainchan->localid)
2365 continue; /* wrong channel */
2366 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2367 }
7cca0d81 2368 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2369 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2370 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2371 bombout(("Server got confused by shell/command request"));
2372 crReturnV;
7cca0d81 2373 }
8d5de777 2374 bombout(("Server refused to start a shell/command"));
2375 crReturnV;
7cca0d81 2376 } else {
8d5de777 2377 logevent("Started a shell/command");
7cca0d81 2378 }
2379
2380 /*
2381 * Transfer data!
2382 */
8ccc75b0 2383 ssh_send_ok = 1;
6f34e365 2384 begin_session();
7cca0d81 2385 while (1) {
d211621f 2386 static int try_send;
e5574168 2387 crReturnV;
d211621f 2388 try_send = FALSE;
7cca0d81 2389 if (ispkt) {
2390 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2391 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2392 char *data;
2393 int length;
d211621f 2394 /* FIXME: be able to handle other channels here */
2395 if (ssh2_pkt_getuint32() != mainchan->localid)
7cca0d81 2396 continue; /* wrong channel */
2397 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2398 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2399 continue; /* extended but not stderr */
2400 ssh2_pkt_getstring(&data, &length);
d211621f 2401 if (data) {
3bdaf79d 2402 c_writedata(data, length);
d211621f 2403 /*
2404 * Enlarge the window again at the remote side,
2405 * just in case it ever runs down and they fail
2406 * to send us any more data.
2407 */
2408 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2409 ssh2_pkt_adduint32(mainchan->remoteid);
2410 ssh2_pkt_adduint32(length);
2411 ssh2_pkt_send();
2412 }
7cca0d81 2413 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2414 ssh_state = SSH_STATE_CLOSED;
d211621f 2415 logevent("Received disconnect message");
7cca0d81 2416 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2417 continue; /* exit status et al; ignore (FIXME?) */
d211621f 2418 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2419 continue; /* remote sends EOF; ignore */
2420 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
2421 /* FIXME: be able to handle other channels here */
2422 if (ssh2_pkt_getuint32() != mainchan->localid)
2423 continue; /* wrong channel */
2424 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2425 ssh2_pkt_adduint32(mainchan->remoteid);
2426 ssh2_pkt_send();
2427 /* FIXME: mark the channel as closed */
2428 if (1 /* FIXME: "all channels are closed" */) {
2429 logevent("All channels closed. Disconnecting");
2430 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2431 ssh2_pkt_send();
cf6e59d6 2432 ssh_state = SSH_STATE_CLOSED;
2433 closesocket(s);
2434 s = INVALID_SOCKET;
d211621f 2435 }
2436 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2437 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
d211621f 2438 /* FIXME: be able to handle other channels here */
2439 if (ssh2_pkt_getuint32() != mainchan->localid)
2440 continue; /* wrong channel */
2441 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2442 try_send = TRUE;
7cca0d81 2443 } else {
8d5de777 2444 bombout(("Strange packet received: type %d", pktin.type));
2445 crReturnV;
7cca0d81 2446 }
2447 } else {
d211621f 2448 /*
2449 * We have spare data. Add it to the channel buffer.
2450 */
2451 if (mainchan->u.v2.outbufsize <
2452 mainchan->u.v2.outbuflen + inlen) {
2453 mainchan->u.v2.outbufsize =
2454 mainchan->u.v2.outbuflen + inlen + 1024;
2455 mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer,
2456 mainchan->u.v2.outbufsize);
2457 }
2458 memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen,
2459 in, inlen);
2460 mainchan->u.v2.outbuflen += inlen;
2461 try_send = TRUE;
7cca0d81 2462 }
d211621f 2463 if (try_send) {
2464 /*
2465 * Try to send data on the channel if we can. (FIXME:
2466 * on _all_ channels.)
2467 */
2468 while (mainchan->u.v2.remwindow > 0 &&
2469 mainchan->u.v2.outbuflen > 0) {
2470 unsigned len = mainchan->u.v2.remwindow;
2471 if (len > mainchan->u.v2.outbuflen)
2472 len = mainchan->u.v2.outbuflen;
2473 if (len > mainchan->u.v2.remmaxpkt)
2474 len = mainchan->u.v2.remmaxpkt;
2475 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2476 ssh2_pkt_adduint32(mainchan->remoteid);
2477 ssh2_pkt_addstring_start();
2478 ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len);
2479 ssh2_pkt_send();
2480 mainchan->u.v2.outbuflen -= len;
2481 memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len,
2482 mainchan->u.v2.outbuflen);
2483 mainchan->u.v2.remwindow -= len;
2484 }
2485 }
e5574168 2486 }
2487
2488 crFinishV;
2489}
2490
2491/*
7cca0d81 2492 * Handle the top-level SSH2 protocol.
2493 */
2494static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2495{
2496 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2497 return;
2498 do_ssh2_authconn(in, inlen, ispkt);
2499}
2500
2501/*
374330e2 2502 * Called to set up the connection. Will arrange for WM_NETEVENT
2503 * messages to be passed to the specified window, whose window
2504 * procedure should then call telnet_msg().
2505 *
2506 * Returns an error message, or NULL on success.
374330e2 2507 */
2508static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
fb09bf1c 2509 char *p;
8f203108 2510
2511#ifdef MSCRYPTOAPI
2512 if(crypto_startup() == 0)
2513 return "Microsoft high encryption pack not installed!";
2514#endif
374330e2 2515
fb09bf1c 2516 p = connect_to_host(host, port, realhost);
2517 if (p != NULL)
2518 return p;
374330e2 2519
2520 if (!do_ssh_init())
2521 return "Protocol initialisation error";
2522
4017be6d 2523 if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
374330e2 2524 switch (WSAGetLastError()) {
2525 case WSAENETDOWN: return "Network is down";
2526 default: return "WSAAsyncSelect(): unknown error";
2527 }
2528
2529 return NULL;
2530}
2531
2532/*
2533 * Process a WM_NETEVENT message. Will return 0 if the connection
2534 * has closed, or <0 for a socket error.
2535 */
2536static int ssh_msg (WPARAM wParam, LPARAM lParam) {
2537 int ret;
2538 char buf[256];
2539
8ce72d2c 2540 /*
2541 * Because reading less than the whole of the available pending
2542 * data can generate an FD_READ event, we need to allow for the
2543 * possibility that FD_READ may arrive with FD_CLOSE already in
2544 * the queue; so it's possible that we can get here even with s
2545 * invalid. If so, we return 1 and don't worry about it.
2546 */
2547 if (s == INVALID_SOCKET)
2548 return 1;
374330e2 2549
8d5de777 2550 if (WSAGETSELECTERROR(lParam) != 0) {
2551 closesocket(s);
2552 s = INVALID_SOCKET;
374330e2 2553 return -WSAGETSELECTERROR(lParam);
8d5de777 2554 }
374330e2 2555
2556 switch (WSAGETSELECTEVENT(lParam)) {
2557 case FD_READ:
8ce72d2c 2558 case FD_CLOSE:
374330e2 2559 ret = recv(s, buf, sizeof(buf), 0);
2560 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
2561 return 1;
8d5de777 2562 if (ret < 0) { /* any _other_ error */
2563 closesocket(s);
2564 s = INVALID_SOCKET;
374330e2 2565 return -10000-WSAGetLastError();
8d5de777 2566 }
374330e2 2567 if (ret == 0) {
2568 s = INVALID_SOCKET;
8ce72d2c 2569 return 0;
374330e2 2570 }
2571 ssh_gotdata (buf, ret);
85ee8208 2572 if (ssh_state == SSH_STATE_CLOSED) {
2573 closesocket(s);
2574 s = INVALID_SOCKET;
2575 return 0;
2576 }
374330e2 2577 return 1;
374330e2 2578 }
2579 return 1; /* shouldn't happen, but WTF */
2580}
2581
2582/*
2583 * Called to send data down the Telnet connection.
2584 */
2585static void ssh_send (char *buf, int len) {
2586 if (s == INVALID_SOCKET)
2587 return;
2588
2589 ssh_protocol(buf, len, 0);
2590}
2591
2592/*
2593 * Called to set the size of the window from Telnet's POV.
2594 */
2595static void ssh_size(void) {
2596 switch (ssh_state) {
2597 case SSH_STATE_BEFORE_SIZE:
21248260 2598 case SSH_STATE_CLOSED:
374330e2 2599 break; /* do nothing */
2600 case SSH_STATE_INTERMED:
2601 size_needed = TRUE; /* buffer for later */
2602 break;
2603 case SSH_STATE_SESSION:
fef97f43 2604 if (!cfg.nopty) {
e5574168 2605 send_packet(SSH1_CMSG_WINDOW_SIZE,
fb09bf1c 2606 PKT_INT, rows, PKT_INT, cols,
2607 PKT_INT, 0, PKT_INT, 0, PKT_END);
fef97f43 2608 }
374330e2 2609 }
2610}
2611
2612/*
6abbf9e3 2613 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2614 * can send an EOF and collect resulting output (e.g. `plink
2615 * hostname sort').
374330e2 2616 */
2617static void ssh_special (Telnet_Special code) {
6abbf9e3 2618 if (code == TS_EOF) {
67779be7 2619 if (ssh_version == 1) {
6abbf9e3 2620 send_packet(SSH1_CMSG_EOF, PKT_END);
2621 } else {
2622 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 2623 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 2624 ssh2_pkt_send();
2625 }
67779be7 2626 logevent("Sent EOF message");
ec55b220 2627 } else if (code == TS_PING) {
2628 if (ssh_version == 1) {
2629 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
2630 } else {
2631 ssh2_pkt_init(SSH2_MSG_IGNORE);
2632 ssh2_pkt_addstring_start();
2633 ssh2_pkt_send();
2634 }
6abbf9e3 2635 } else {
2636 /* do nothing */
2637 }
374330e2 2638}
2639
8ccc75b0 2640static SOCKET ssh_socket(void) { return s; }
2641
2642static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 2643
374330e2 2644Backend ssh_backend = {
2645 ssh_init,
2646 ssh_msg,
2647 ssh_send,
2648 ssh_size,
4017be6d 2649 ssh_special,
8ccc75b0 2650 ssh_socket,
97db3be4 2651 ssh_sendok,
2652 22
374330e2 2653};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator