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Fix a segfault (addr->error was unpredictable following a dotted-dec lookup)
[u/mdw/putty] / ssh.c
CommitLineData
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
104#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
105#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
106#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
107#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
108
109#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 110
111#define GET_32BIT(cp) \
112 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
113 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
114 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
115 ((unsigned long)(unsigned char)(cp)[3]))
116
117#define PUT_32BIT(cp, value) { \
118 (cp)[0] = (unsigned char)((value) >> 24); \
119 (cp)[1] = (unsigned char)((value) >> 16); \
120 (cp)[2] = (unsigned char)((value) >> 8); \
121 (cp)[3] = (unsigned char)(value); }
122
7cca0d81 123enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 124
374330e2 125/* Coroutine mechanics for the sillier bits of the code */
126#define crBegin1 static int crLine = 0;
127#define crBegin2 switch(crLine) { case 0:;
128#define crBegin crBegin1; crBegin2;
129#define crFinish(z) } crLine = 0; return (z)
130#define crFinishV } crLine = 0; return
131#define crReturn(z) \
132 do {\
133 crLine=__LINE__; return (z); case __LINE__:;\
134 } while (0)
135#define crReturnV \
136 do {\
137 crLine=__LINE__; return; case __LINE__:;\
138 } while (0)
139#define crStop(z) do{ crLine = 0; return (z); }while(0)
140#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 141#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 142#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 143
57476f6b 144extern const struct ssh_cipher ssh_3des;
145extern const struct ssh_cipher ssh_3des_ssh2;
146extern const struct ssh_cipher ssh_des;
147extern const struct ssh_cipher ssh_blowfish_ssh1;
148extern const struct ssh_cipher ssh_blowfish_ssh2;
e5574168 149
5e8358ad 150/*
151 * Ciphers for SSH2. We miss out single-DES because it isn't
152 * supported; also 3DES and Blowfish are both done differently from
153 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
154 * endianness and different-sized keys.)
5e8358ad 155 */
57476f6b 156const static struct ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 };
e5574168 157
57476f6b 158extern const struct ssh_kex ssh_diffiehellman;
159const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
e5574168 160
57476f6b 161extern const struct ssh_hostkey ssh_dss;
162const static struct ssh_hostkey *hostkey_algs[] = { &ssh_dss };
e5574168 163
8b2715b2 164extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy;
e5574168 165
d39f364a 166static void nullmac_key(unsigned char *key) { }
e5574168 167static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
168static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
57476f6b 169const static struct ssh_mac ssh_mac_none = {
d39f364a 170 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 171};
8b2715b2 172const static struct ssh_mac *macs[] = {
173 &ssh_sha1, &ssh_md5, &ssh_mac_none };
174const static struct ssh_mac *buggymacs[] = {
175 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
e5574168 176
57476f6b 177const static struct ssh_compress ssh_comp_none = {
e5574168 178 "none"
179};
57476f6b 180const static struct ssh_compress *compressions[] = { &ssh_comp_none };
374330e2 181
dacbd0e8 182/*
183 * 2-3-4 tree storing channels.
184 */
185struct ssh_channel {
d211621f 186 unsigned remoteid, localid;
dacbd0e8 187 int type;
188 int closes;
189 union {
190 struct ssh_agent_channel {
191 unsigned char *message;
192 unsigned char msglen[4];
193 int lensofar, totallen;
194 } a;
d211621f 195 struct ssh2_data_channel {
196 unsigned char *outbuffer;
197 unsigned outbuflen, outbufsize;
198 unsigned remwindow, remmaxpkt;
199 } v2;
dacbd0e8 200 } u;
201};
57476f6b 202
203struct Packet {
204 long length;
205 int type;
206 unsigned char *data;
207 unsigned char *body;
208 long savedpos;
209 long maxlen;
210};
211
212static SHA_State exhash;
213
8df7a775 214static Socket s = NULL;
57476f6b 215
216static unsigned char session_key[32];
217static const struct ssh_cipher *cipher = NULL;
218static const struct ssh_cipher *cscipher = NULL;
219static const struct ssh_cipher *sccipher = NULL;
220static const struct ssh_mac *csmac = NULL;
221static const struct ssh_mac *scmac = NULL;
222static const struct ssh_compress *cscomp = NULL;
223static const struct ssh_compress *sccomp = NULL;
224static const struct ssh_kex *kex = NULL;
225static const struct ssh_hostkey *hostkey = NULL;
226int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
227
228static char *savedhost;
229static int savedport;
230static int ssh_send_ok;
231
dacbd0e8 232static tree234 *ssh_channels; /* indexed by local id */
57476f6b 233static struct ssh_channel *mainchan; /* primary session channel */
234
235static enum {
236 SSH_STATE_BEFORE_SIZE,
237 SSH_STATE_INTERMED,
238 SSH_STATE_SESSION,
239 SSH_STATE_CLOSED
240} ssh_state = SSH_STATE_BEFORE_SIZE;
241
242static int size_needed = FALSE;
243
244static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
245static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
246
247static int ssh_version;
248static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
249static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
250static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
251static void ssh_size(void);
252
253static int (*s_rdpkt)(unsigned char **data, int *datalen);
254
255static struct rdpkt1_state_tag {
256 long len, pad, biglen, to_read;
257 unsigned long realcrc, gotcrc;
258 unsigned char *p;
259 int i;
260 int chunk;
261} rdpkt1_state;
262
960e736a 263static struct rdpkt2_state_tag {
264 long len, pad, payload, packetlen, maclen;
265 int i;
266 int cipherblk;
267 unsigned long incoming_sequence;
268} rdpkt2_state;
269
dacbd0e8 270static int ssh_channelcmp(void *av, void *bv) {
271 struct ssh_channel *a = (struct ssh_channel *)av;
272 struct ssh_channel *b = (struct ssh_channel *)bv;
273 if (a->localid < b->localid) return -1;
274 if (a->localid > b->localid) return +1;
275 return 0;
276}
277static int ssh_channelfind(void *av, void *bv) {
d211621f 278 unsigned *a = (unsigned *)av;
dacbd0e8 279 struct ssh_channel *b = (struct ssh_channel *)bv;
280 if (*a < b->localid) return -1;
281 if (*a > b->localid) return +1;
282 return 0;
283}
284
374330e2 285static void c_write (char *buf, int len) {
67779be7 286 if ((flags & FLAG_STDERR)) {
4017be6d 287 int i;
288 for (i = 0; i < len; i++)
289 if (buf[i] != '\r')
290 fputc(buf[i], stderr);
fb09bf1c 291 return;
292 }
fe50e814 293 from_backend(1, buf, len);
3bdaf79d 294}
295
fb09bf1c 296/*
297 * Collect incoming data in the incoming packet buffer.
e5574168 298 * Decipher and verify the packet when it is completely read.
299 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 300 * Update the *data and *datalen variables.
301 * Return the additional nr of bytes needed, or 0 when
302 * a complete packet is available.
303 */
e5574168 304static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 305{
57476f6b 306 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 307
308 crBegin;
374330e2 309
fb09bf1c 310next_packet:
37508af4 311
fb09bf1c 312 pktin.type = 0;
313 pktin.length = 0;
374330e2 314
57476f6b 315 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 316 while ((*datalen) == 0)
57476f6b 317 crReturn(4-st->i);
318 st->len = (st->len << 8) + **data;
fb09bf1c 319 (*data)++, (*datalen)--;
320 }
374330e2 321
fb09bf1c 322#ifdef FWHACK
57476f6b 323 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
324 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 325 }
326#endif
374330e2 327
57476f6b 328 st->pad = 8 - (st->len % 8);
329 st->biglen = st->len + st->pad;
330 pktin.length = st->len - 5;
fb09bf1c 331
57476f6b 332 if (pktin.maxlen < st->biglen) {
333 pktin.maxlen = st->biglen;
334 pktin.data = (pktin.data == NULL ? malloc(st->biglen+APIEXTRA) :
335 realloc(pktin.data, st->biglen+APIEXTRA));
fb09bf1c 336 if (!pktin.data)
337 fatalbox("Out of memory");
338 }
374330e2 339
57476f6b 340 st->to_read = st->biglen;
341 st->p = pktin.data;
342 while (st->to_read > 0) {
343 st->chunk = st->to_read;
fb09bf1c 344 while ((*datalen) == 0)
57476f6b 345 crReturn(st->to_read);
346 if (st->chunk > (*datalen))
347 st->chunk = (*datalen);
348 memcpy(st->p, *data, st->chunk);
349 *data += st->chunk;
350 *datalen -= st->chunk;
351 st->p += st->chunk;
352 st->to_read -= st->chunk;
fb09bf1c 353 }
374330e2 354
fb09bf1c 355 if (cipher)
57476f6b 356 cipher->decrypt(pktin.data, st->biglen);
698a5108 357#if 0
358 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
359 for (st->i = 0; st->i < st->biglen; st->i++)
360 debug((" %02x", (unsigned char)pktin.data[st->i]));
361 debug(("\r\n"));
362#endif
374330e2 363
57476f6b 364 pktin.type = pktin.data[st->pad];
365 pktin.body = pktin.data + st->pad + 1;
374330e2 366
57476f6b 367 st->realcrc = crc32(pktin.data, st->biglen-4);
368 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
369 if (st->gotcrc != st->realcrc) {
8d5de777 370 bombout(("Incorrect CRC received on packet"));
371 crReturn(0);
fb09bf1c 372 }
572f871e 373
e5574168 374 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
375 pktin.type == SSH1_SMSG_STDERR_DATA ||
376 pktin.type == SSH1_MSG_DEBUG ||
18515c51 377 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
378 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 379 long strlen = GET_32BIT(pktin.body);
8d5de777 380 if (strlen + 4 != pktin.length) {
381 bombout(("Received data packet with bogus string length"));
382 crReturn(0);
383 }
fb09bf1c 384 }
385
e5574168 386 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 387 /* log debug message */
388 char buf[80];
389 int strlen = GET_32BIT(pktin.body);
390 strcpy(buf, "Remote: ");
391 if (strlen > 70) strlen = 70;
392 memcpy(buf+8, pktin.body+4, strlen);
393 buf[8+strlen] = '\0';
394 logevent(buf);
395 goto next_packet;
e5574168 396 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 397 /* do nothing */
398 goto next_packet;
399 }
400
401 crFinish(0);
402}
403
e5574168 404static int ssh2_rdpkt(unsigned char **data, int *datalen)
405{
960e736a 406 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 407
408 crBegin;
409
410next_packet:
e5574168 411 pktin.type = 0;
412 pktin.length = 0;
960e736a 413 if (sccipher)
414 st->cipherblk = sccipher->blksize;
e5574168 415 else
960e736a 416 st->cipherblk = 8;
417 if (st->cipherblk < 8)
418 st->cipherblk = 8;
419
420 if (pktin.maxlen < st->cipherblk) {
421 pktin.maxlen = st->cipherblk;
422 pktin.data = (pktin.data == NULL ? malloc(st->cipherblk+APIEXTRA) :
423 realloc(pktin.data, st->cipherblk+APIEXTRA));
e5574168 424 if (!pktin.data)
425 fatalbox("Out of memory");
426 }
427
428 /*
429 * Acquire and decrypt the first block of the packet. This will
430 * contain the length and padding details.
431 */
960e736a 432 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 433 while ((*datalen) == 0)
960e736a 434 crReturn(st->cipherblk-st->i);
435 pktin.data[st->i] = *(*data)++;
e5574168 436 (*datalen)--;
437 }
438#ifdef FWHACK
439 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
440 /* FIXME */
441 }
442#endif
443 if (sccipher)
960e736a 444 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 445
446 /*
447 * Now get the length and padding figures.
448 */
960e736a 449 st->len = GET_32BIT(pktin.data);
450 st->pad = pktin.data[4];
e5574168 451
452 /*
453 * This enables us to deduce the payload length.
454 */
960e736a 455 st->payload = st->len - st->pad - 1;
e5574168 456
960e736a 457 pktin.length = st->payload + 5;
e5574168 458
459 /*
460 * So now we can work out the total packet length.
461 */
960e736a 462 st->packetlen = st->len + 4;
463 st->maclen = scmac ? scmac->len : 0;
e5574168 464
465 /*
466 * Adjust memory allocation if packet is too big.
467 */
960e736a 468 if (pktin.maxlen < st->packetlen+st->maclen) {
469 pktin.maxlen = st->packetlen+st->maclen;
59dcd2a8 470 pktin.data = (pktin.data == NULL ? malloc(pktin.maxlen+APIEXTRA) :
471 realloc(pktin.data, pktin.maxlen+APIEXTRA));
e5574168 472 if (!pktin.data)
473 fatalbox("Out of memory");
474 }
475
476 /*
477 * Read and decrypt the remainder of the packet.
478 */
960e736a 479 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
e5574168 480 while ((*datalen) == 0)
960e736a 481 crReturn(st->packetlen + st->maclen - st->i);
482 pktin.data[st->i] = *(*data)++;
e5574168 483 (*datalen)--;
484 }
485 /* Decrypt everything _except_ the MAC. */
486 if (sccipher)
960e736a 487 sccipher->decrypt(pktin.data + st->cipherblk,
488 st->packetlen - st->cipherblk);
e5574168 489
7cca0d81 490#if 0
960e736a 491 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
492 for (st->i = 0; st->i < st->packetlen; st->i++)
493 debug((" %02x", (unsigned char)pktin.data[st->i]));
d39f364a 494 debug(("\r\n"));
7cca0d81 495#endif
d39f364a 496
e5574168 497 /*
498 * Check the MAC.
499 */
960e736a 500 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
8d5de777 501 bombout(("Incorrect MAC received on packet"));
502 crReturn(0);
503 }
960e736a 504 st->incoming_sequence++; /* whether or not we MACed */
e5574168 505
506 pktin.savedpos = 6;
507 pktin.type = pktin.data[5];
e5574168 508
7cca0d81 509 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
510 goto next_packet; /* FIXME: print DEBUG message */
e5574168 511
512 crFinish(0);
513}
514
374330e2 515static void s_wrpkt_start(int type, int len) {
516 int pad, biglen;
517
518 len += 5; /* type and CRC */
519 pad = 8 - (len%8);
520 biglen = len + pad;
521
522 pktout.length = len-5;
523 if (pktout.maxlen < biglen) {
524 pktout.maxlen = biglen;
8f203108 525#ifdef MSCRYPTOAPI
fb09bf1c 526 /* Allocate enough buffer space for extra block
8f203108 527 * for MS CryptEncrypt() */
fb09bf1c 528 pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
529 realloc(pktout.data, biglen+12));
8f203108 530#else
c1f5f956 531 pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
532 realloc(pktout.data, biglen+4));
8f203108 533#endif
374330e2 534 if (!pktout.data)
535 fatalbox("Out of memory");
536 }
537
538 pktout.type = type;
539 pktout.body = pktout.data+4+pad+1;
540}
541
542static void s_wrpkt(void) {
543 int pad, len, biglen, i;
544 unsigned long crc;
545
546 len = pktout.length + 5; /* type and CRC */
547 pad = 8 - (len%8);
548 biglen = len + pad;
549
550 pktout.body[-1] = pktout.type;
551 for (i=0; i<pad; i++)
552 pktout.data[i+4] = random_byte();
553 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 554 PUT_32BIT(pktout.data+biglen, crc);
555 PUT_32BIT(pktout.data, len);
374330e2 556
698a5108 557#if 0
558 debug(("Sending packet len=%d\r\n", biglen+4));
559 for (i = 0; i < biglen+4; i++)
560 debug((" %02x", (unsigned char)pktout.data[i]));
561 debug(("\r\n"));
562#endif
374330e2 563 if (cipher)
564 cipher->encrypt(pktout.data+4, biglen);
565
8df7a775 566 sk_write(s, pktout.data, biglen+4);
374330e2 567}
568
fb09bf1c 569/*
570 * Construct a packet with the specified contents and
571 * send it to the server.
572 */
573static void send_packet(int pkttype, ...)
574{
575 va_list args;
576 unsigned char *p, *argp, argchar;
577 unsigned long argint;
578 int pktlen, argtype, arglen;
7cca0d81 579 Bignum bn;
fb09bf1c 580
581 pktlen = 0;
582 va_start(args, pkttype);
583 while ((argtype = va_arg(args, int)) != PKT_END) {
584 switch (argtype) {
585 case PKT_INT:
586 (void) va_arg(args, int);
587 pktlen += 4;
588 break;
589 case PKT_CHAR:
590 (void) va_arg(args, char);
591 pktlen++;
592 break;
593 case PKT_DATA:
594 (void) va_arg(args, unsigned char *);
595 arglen = va_arg(args, int);
596 pktlen += arglen;
597 break;
598 case PKT_STR:
599 argp = va_arg(args, unsigned char *);
600 arglen = strlen(argp);
601 pktlen += 4 + arglen;
602 break;
7cca0d81 603 case PKT_BIGNUM:
604 bn = va_arg(args, Bignum);
5c58ad2d 605 pktlen += ssh1_bignum_length(bn);
7cca0d81 606 break;
fb09bf1c 607 default:
608 assert(0);
609 }
610 }
611 va_end(args);
612
613 s_wrpkt_start(pkttype, pktlen);
614 p = pktout.body;
615
616 va_start(args, pkttype);
617 while ((argtype = va_arg(args, int)) != PKT_END) {
618 switch (argtype) {
619 case PKT_INT:
620 argint = va_arg(args, int);
621 PUT_32BIT(p, argint);
622 p += 4;
623 break;
624 case PKT_CHAR:
625 argchar = va_arg(args, unsigned char);
626 *p = argchar;
627 p++;
628 break;
629 case PKT_DATA:
630 argp = va_arg(args, unsigned char *);
631 arglen = va_arg(args, int);
632 memcpy(p, argp, arglen);
633 p += arglen;
634 break;
635 case PKT_STR:
636 argp = va_arg(args, unsigned char *);
637 arglen = strlen(argp);
638 PUT_32BIT(p, arglen);
639 memcpy(p + 4, argp, arglen);
640 p += 4 + arglen;
641 break;
7cca0d81 642 case PKT_BIGNUM:
643 bn = va_arg(args, Bignum);
5c58ad2d 644 p += ssh1_write_bignum(p, bn);
7cca0d81 645 break;
fb09bf1c 646 }
647 }
648 va_end(args);
649
650 s_wrpkt();
651}
652
9697bfd2 653static int ssh_versioncmp(char *a, char *b) {
654 char *ae, *be;
655 unsigned long av, bv;
656
43aa02a7 657 av = strtoul(a, &ae, 10);
658 bv = strtoul(b, &be, 10);
9697bfd2 659 if (av != bv) return (av < bv ? -1 : +1);
660 if (*ae == '.') ae++;
661 if (*be == '.') be++;
43aa02a7 662 av = strtoul(ae, &ae, 10);
663 bv = strtoul(be, &be, 10);
9697bfd2 664 if (av != bv) return (av < bv ? -1 : +1);
665 return 0;
666}
667
e5574168 668
669/*
670 * Utility routine for putting an SSH-protocol `string' into a SHA
671 * state.
672 */
673#include <stdio.h>
75cab814 674static void sha_string(SHA_State *s, void *str, int len) {
e5574168 675 unsigned char lenblk[4];
e5574168 676 PUT_32BIT(lenblk, len);
e5574168 677 SHA_Bytes(s, lenblk, 4);
e5574168 678 SHA_Bytes(s, str, len);
679}
680
7cca0d81 681/*
682 * SSH2 packet construction functions.
683 */
75cab814 684static void ssh2_pkt_adddata(void *data, int len) {
7cca0d81 685 pktout.length += len;
686 if (pktout.maxlen < pktout.length) {
687 pktout.maxlen = pktout.length + 256;
688 pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) :
689 realloc(pktout.data, pktout.maxlen+APIEXTRA));
690 if (!pktout.data)
691 fatalbox("Out of memory");
692 }
693 memcpy(pktout.data+pktout.length-len, data, len);
694}
75cab814 695static void ssh2_pkt_addbyte(unsigned char byte) {
7cca0d81 696 ssh2_pkt_adddata(&byte, 1);
697}
75cab814 698static void ssh2_pkt_init(int pkt_type) {
7cca0d81 699 pktout.length = 5;
700 ssh2_pkt_addbyte((unsigned char)pkt_type);
701}
75cab814 702static void ssh2_pkt_addbool(unsigned char value) {
7cca0d81 703 ssh2_pkt_adddata(&value, 1);
704}
75cab814 705static void ssh2_pkt_adduint32(unsigned long value) {
7cca0d81 706 unsigned char x[4];
707 PUT_32BIT(x, value);
708 ssh2_pkt_adddata(x, 4);
709}
75cab814 710static void ssh2_pkt_addstring_start(void) {
7cca0d81 711 ssh2_pkt_adduint32(0);
712 pktout.savedpos = pktout.length;
713}
75cab814 714static void ssh2_pkt_addstring_str(char *data) {
7cca0d81 715 ssh2_pkt_adddata(data, strlen(data));
716 PUT_32BIT(pktout.data + pktout.savedpos - 4,
717 pktout.length - pktout.savedpos);
718}
75cab814 719static void ssh2_pkt_addstring_data(char *data, int len) {
7cca0d81 720 ssh2_pkt_adddata(data, len);
721 PUT_32BIT(pktout.data + pktout.savedpos - 4,
722 pktout.length - pktout.savedpos);
723}
75cab814 724static void ssh2_pkt_addstring(char *data) {
7cca0d81 725 ssh2_pkt_addstring_start();
726 ssh2_pkt_addstring_str(data);
727}
75cab814 728static char *ssh2_mpint_fmt(Bignum b, int *len) {
7cca0d81 729 unsigned char *p;
730 int i, n = b[0];
731 p = malloc(n * 2 + 1);
732 if (!p)
733 fatalbox("out of memory");
734 p[0] = 0;
735 for (i = 0; i < n; i++) {
736 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
737 p[i*2+2] = (b[n-i] ) & 0xFF;
738 }
739 i = 0;
740 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
741 i++;
742 memmove(p, p+i, n*2+1-i);
743 *len = n*2+1-i;
744 return p;
745}
75cab814 746static void ssh2_pkt_addmp(Bignum b) {
7cca0d81 747 unsigned char *p;
748 int len;
749 p = ssh2_mpint_fmt(b, &len);
750 ssh2_pkt_addstring_start();
751 ssh2_pkt_addstring_data(p, len);
752 free(p);
753}
75cab814 754static void ssh2_pkt_send(void) {
7cca0d81 755 int cipherblk, maclen, padding, i;
756 static unsigned long outgoing_sequence = 0;
757
758 /*
759 * Add padding. At least four bytes, and must also bring total
760 * length (minus MAC) up to a multiple of the block size.
761 */
762 cipherblk = cipher ? cipher->blksize : 8; /* block size */
763 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
764 padding = 4;
765 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
766 pktout.data[4] = padding;
767 for (i = 0; i < padding; i++)
768 pktout.data[pktout.length + i] = random_byte();
769 PUT_32BIT(pktout.data, pktout.length + padding - 4);
770 if (csmac)
771 csmac->generate(pktout.data, pktout.length + padding,
772 outgoing_sequence);
773 outgoing_sequence++; /* whether or not we MACed */
774
775#if 0
776 debug(("Sending packet len=%d\r\n", pktout.length+padding));
777 for (i = 0; i < pktout.length+padding; i++)
778 debug((" %02x", (unsigned char)pktout.data[i]));
779 debug(("\r\n"));
780#endif
781
782 if (cscipher)
783 cscipher->encrypt(pktout.data, pktout.length + padding);
784 maclen = csmac ? csmac->len : 0;
785
8df7a775 786 sk_write(s, pktout.data, pktout.length + padding + maclen);
7cca0d81 787}
788
789#if 0
790void bndebug(char *string, Bignum b) {
791 unsigned char *p;
792 int i, len;
793 p = ssh2_mpint_fmt(b, &len);
794 debug(("%s", string));
795 for (i = 0; i < len; i++)
796 debug((" %02x", p[i]));
797 debug(("\r\n"));
798 free(p);
799}
800#endif
801
75cab814 802static void sha_mpint(SHA_State *s, Bignum b) {
7cca0d81 803 unsigned char *p;
804 int len;
805 p = ssh2_mpint_fmt(b, &len);
806 sha_string(s, p, len);
807 free(p);
808}
809
810/*
811 * SSH2 packet decode functions.
812 */
75cab814 813static unsigned long ssh2_pkt_getuint32(void) {
7cca0d81 814 unsigned long value;
815 if (pktin.length - pktin.savedpos < 4)
816 return 0; /* arrgh, no way to decline (FIXME?) */
817 value = GET_32BIT(pktin.data+pktin.savedpos);
818 pktin.savedpos += 4;
819 return value;
820}
75cab814 821static void ssh2_pkt_getstring(char **p, int *length) {
7cca0d81 822 *p = NULL;
823 if (pktin.length - pktin.savedpos < 4)
824 return;
825 *length = GET_32BIT(pktin.data+pktin.savedpos);
826 pktin.savedpos += 4;
827 if (pktin.length - pktin.savedpos < *length)
828 return;
829 *p = pktin.data+pktin.savedpos;
830 pktin.savedpos += *length;
831}
75cab814 832static Bignum ssh2_pkt_getmp(void) {
7cca0d81 833 char *p;
834 int i, j, length;
835 Bignum b;
836
837 ssh2_pkt_getstring(&p, &length);
838 if (!p)
839 return NULL;
8d5de777 840 if (p[0] & 0x80) {
841 bombout(("internal error: Can't handle negative mpints"));
842 return NULL;
843 }
7cca0d81 844 b = newbn((length+1)/2);
845 for (i = 0; i < length; i++) {
846 j = length - 1 - i;
847 if (j & 1)
848 b[j/2+1] |= ((unsigned char)p[i]) << 8;
849 else
850 b[j/2+1] |= ((unsigned char)p[i]);
851 }
6b4e00ee 852 while (b[0] > 1 && b[b[0]] == 0) b[0]--;
7cca0d81 853 return b;
854}
855
8df7a775 856static int do_ssh_init(unsigned char c) {
857 static char *vsp;
858 static char version[10];
859 static char vstring[80];
860 static char vlog[sizeof(vstring)+20];
861 static int i;
374330e2 862
8df7a775 863 crBegin;
864
865 /* Search for the string "SSH-" in the input. */
374330e2 866 i = 0;
8df7a775 867 while (1) {
868 static const int transS[] = { 1, 2, 2, 1 };
869 static const int transH[] = { 0, 0, 3, 0 };
870 static const int transminus[] = { 0, 0, 0, -1 };
871 if (c == 'S') i = transS[i];
872 else if (c == 'H') i = transH[i];
873 else if (c == '-') i = transminus[i];
374330e2 874 else i = 0;
8df7a775 875 if (i < 0)
876 break;
877 crReturn(1); /* get another character */
374330e2 878 }
8df7a775 879
c5e9c988 880 strcpy(vstring, "SSH-");
881 vsp = vstring+4;
374330e2 882 i = 0;
883 while (1) {
8df7a775 884 crReturn(1); /* get another char */
c5e9c988 885 if (vsp < vstring+sizeof(vstring)-1)
886 *vsp++ = c;
374330e2 887 if (i >= 0) {
888 if (c == '-') {
889 version[i] = '\0';
890 i = -1;
891 } else if (i < sizeof(version)-1)
892 version[i++] = c;
893 }
894 else if (c == '\n')
895 break;
896 }
897
960e736a 898 rdpkt2_state.incoming_sequence = 0;
899
c5e9c988 900 *vsp = 0;
901 sprintf(vlog, "Server version: %s", vstring);
902 vlog[strcspn(vlog, "\r\n")] = '\0';
903 logevent(vlog);
904
adf799dd 905 /*
906 * Server version "1.99" means we can choose whether we use v1
907 * or v2 protocol. Choice is based on cfg.sshprot.
908 */
909 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 910 /*
911 * This is a v2 server. Begin v2 protocol.
912 */
913 char *verstring = "SSH-2.0-PuTTY";
914 SHA_Init(&exhash);
915 /*
916 * Hash our version string and their version string.
917 */
918 sha_string(&exhash, verstring, strlen(verstring));
919 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
920 sprintf(vstring, "%s\n", verstring);
921 sprintf(vlog, "We claim version: %s", verstring);
922 logevent(vlog);
923 logevent("Using SSH protocol version 2");
8df7a775 924 sk_write(s, vstring, strlen(vstring));
e5574168 925 ssh_protocol = ssh2_protocol;
6abbf9e3 926 ssh_version = 2;
e5574168 927 s_rdpkt = ssh2_rdpkt;
928 } else {
929 /*
930 * This is a v1 server. Begin v1 protocol.
931 */
932 sprintf(vstring, "SSH-%s-PuTTY\n",
933 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
934 sprintf(vlog, "We claim version: %s", vstring);
935 vlog[strcspn(vlog, "\r\n")] = '\0';
936 logevent(vlog);
937 logevent("Using SSH protocol version 1");
8df7a775 938 sk_write(s, vstring, strlen(vstring));
e5574168 939 ssh_protocol = ssh1_protocol;
6abbf9e3 940 ssh_version = 1;
e5574168 941 s_rdpkt = ssh1_rdpkt;
942 }
8df7a775 943
944 crFinish(0);
945}
946
947static void ssh_gotdata(unsigned char *data, int datalen)
948{
949 crBegin;
950
951 /*
952 * To begin with, feed the characters one by one to the
953 * protocol initialisation / selection function do_ssh_init().
954 * When that returns 0, we're done with the initial greeting
955 * exchange and can move on to packet discipline.
956 */
957 while (1) {
958 int ret;
959 if (datalen == 0)
960 crReturnV; /* more data please */
961 ret = do_ssh_init(*data);
962 data++; datalen--;
963 if (ret == 0)
964 break;
965 }
966
967 /*
968 * We emerge from that loop when the initial negotiation is
969 * over and we have selected an s_rdpkt function. Now pass
970 * everything to s_rdpkt, and then pass the resulting packets
971 * to the proper protocol handler.
972 */
973 if (datalen == 0)
974 crReturnV;
975 while (1) {
976 while (datalen > 0) {
977 if ( s_rdpkt(&data, &datalen) == 0 ) {
978 ssh_protocol(NULL, 0, 1);
979 if (ssh_state == SSH_STATE_CLOSED) {
980 return;
981 }
982 }
983 }
984 crReturnV;
985 }
986 crFinishV;
987}
988
989static int ssh_receive(Socket s, int urgent, char *data, int len) {
990 if (!len) {
991 /* Connection has closed. */
992 sk_close(s);
993 s = NULL;
994 return 0;
995 }
996 ssh_gotdata (data, len);
3257deae 997 if (ssh_state == SSH_STATE_CLOSED) {
998 if (s) {
999 sk_close(s);
1000 s = NULL;
1001 }
1002 return 0;
1003 }
fef97f43 1004 return 1;
374330e2 1005}
1006
fb09bf1c 1007/*
8df7a775 1008 * Connect to specified host and port.
1009 * Returns an error message, or NULL on success.
1010 * Also places the canonical host name into `realhost'.
1011 */
1012static char *connect_to_host(char *host, int port, char **realhost)
1013{
1014 SockAddr addr;
1015 char *err;
1016#ifdef FWHACK
1017 char *FWhost;
1018 int FWport;
1019#endif
1020
1021 savedhost = malloc(1+strlen(host));
1022 if (!savedhost)
1023 fatalbox("Out of memory");
1024 strcpy(savedhost, host);
1025
1026 if (port < 0)
1027 port = 22; /* default ssh port */
1028 savedport = port;
1029
1030#ifdef FWHACK
1031 FWhost = host;
1032 FWport = port;
1033 host = FWSTR;
1034 port = 23;
1035#endif
1036
1037 /*
1038 * Try to find host.
1039 */
1040 addr = sk_namelookup(host, realhost);
1041 if ( (err = sk_addr_error(addr)) )
1042 return err;
1043
1044#ifdef FWHACK
1045 *realhost = FWhost;
1046#endif
1047
1048 /*
1049 * Open socket.
1050 */
1051 s = sk_new(addr, port, ssh_receive);
1052 if ( (err = sk_socket_error(s)) )
1053 return err;
1054
1055#ifdef FWHACK
1056 sk_write(s, "connect ", 8);
1057 sk_write(s, FWhost, strlen(FWhost));
1058 {
1059 char buf[20];
1060 sprintf(buf, " %d\n", FWport);
1061 sk_write(s, buf, strlen(buf));
1062 }
1063#endif
1064
1065 return NULL;
1066}
1067
1068/*
fb09bf1c 1069 * Handle the key exchange and user authentication phases.
1070 */
e5574168 1071static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1072{
374330e2 1073 int i, j, len;
374330e2 1074 unsigned char *rsabuf, *keystr1, *keystr2;
1075 unsigned char cookie[8];
1076 struct RSAKey servkey, hostkey;
1077 struct MD5Context md5c;
ccbfb941 1078 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1079 static int tried_publickey;
1080 static unsigned char session_id[16];
bea1ef5f 1081 int cipher_type;
b585ec46 1082 static char username[100];
374330e2 1083
374330e2 1084 crBegin;
1085
fb09bf1c 1086 if (!ispkt) crWaitUntil(ispkt);
374330e2 1087
8d5de777 1088 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1089 bombout(("Public key packet not received"));
1090 crReturn(0);
1091 }
374330e2 1092
c5e9c988 1093 logevent("Received public keys");
374330e2 1094
c5e9c988 1095 memcpy(cookie, pktin.body, 8);
374330e2 1096
7cca0d81 1097 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1098 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1099
c5e9c988 1100 /*
1c2a93c4 1101 * Log the host key fingerprint.
c5e9c988 1102 */
c5e9c988 1103 {
1104 char logmsg[80];
1c2a93c4 1105 logevent("Host key fingerprint is:");
c5e9c988 1106 strcpy(logmsg, " ");
1c2a93c4 1107 hostkey.comment = NULL;
1108 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1109 &hostkey);
c5e9c988 1110 logevent(logmsg);
1111 }
1112
fb09bf1c 1113 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1114 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1115
c5e9c988 1116 MD5Init(&md5c);
374330e2 1117 MD5Update(&md5c, keystr2, hostkey.bytes);
1118 MD5Update(&md5c, keystr1, servkey.bytes);
1119 MD5Update(&md5c, pktin.body, 8);
374330e2 1120 MD5Final(session_id, &md5c);
1121
1122 for (i=0; i<32; i++)
1123 session_key[i] = random_byte();
1124
1125 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1126
1127 rsabuf = malloc(len);
1128 if (!rsabuf)
1129 fatalbox("Out of memory");
1130
89ee5268 1131 /*
1132 * Verify the host key.
1133 */
1134 {
1135 /*
1136 * First format the key into a string.
1137 */
1138 int len = rsastr_len(&hostkey);
d5859615 1139 char fingerprint[100];
89ee5268 1140 char *keystr = malloc(len);
1141 if (!keystr)
1142 fatalbox("Out of memory");
1143 rsastr_fmt(keystr, &hostkey);
d5859615 1144 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1145 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
89ee5268 1146 free(keystr);
1147 }
374330e2 1148
1149 for (i=0; i<32; i++) {
1150 rsabuf[i] = session_key[i];
1151 if (i < 16)
1152 rsabuf[i] ^= session_id[i];
1153 }
1154
1155 if (hostkey.bytes > servkey.bytes) {
1156 rsaencrypt(rsabuf, 32, &servkey);
1157 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1158 } else {
1159 rsaencrypt(rsabuf, 32, &hostkey);
1160 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1161 }
1162
c5e9c988 1163 logevent("Encrypted session key");
1164
bea1ef5f 1165 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1166 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1167 SSH_CIPHER_3DES;
1168 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1169 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1170 cipher_type = SSH_CIPHER_3DES;
1171 }
c5e9c988 1172 switch (cipher_type) {
1173 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1174 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1175 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1176 }
bea1ef5f 1177
e5574168 1178 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1179 PKT_CHAR, cipher_type,
1180 PKT_DATA, cookie, 8,
1181 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1182 PKT_DATA, rsabuf, len,
1183 PKT_INT, 0,
1184 PKT_END);
1185
c5e9c988 1186 logevent("Trying to enable encryption...");
374330e2 1187
1188 free(rsabuf);
1189
5e8358ad 1190 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1191 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1192 &ssh_3des;
374330e2 1193 cipher->sesskey(session_key);
1194
fb09bf1c 1195 crWaitUntil(ispkt);
374330e2 1196
8d5de777 1197 if (pktin.type != SSH1_SMSG_SUCCESS) {
1198 bombout(("Encryption not successfully enabled"));
1199 crReturn(0);
1200 }
374330e2 1201
c5e9c988 1202 logevent("Successfully started encryption");
1203
374330e2 1204 fflush(stdout);
1205 {
374330e2 1206 static int pos = 0;
1207 static char c;
67779be7 1208 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1209 c_write("login as: ", 10);
67779be7 1210 ssh_send_ok = 1;
374330e2 1211 while (pos >= 0) {
fb09bf1c 1212 crWaitUntil(!ispkt);
374330e2 1213 while (inlen--) switch (c = *in++) {
1214 case 10: case 13:
1215 username[pos] = 0;
1216 pos = -1;
1217 break;
1218 case 8: case 127:
1219 if (pos > 0) {
1220 c_write("\b \b", 3);
1221 pos--;
1222 }
1223 break;
1224 case 21: case 27:
1225 while (pos > 0) {
1226 c_write("\b \b", 3);
1227 pos--;
1228 }
1229 break;
1230 case 3: case 4:
1231 random_save_seed();
1232 exit(0);
1233 break;
1234 default:
40d24aa6 1235 if (((c >= ' ' && c <= '~') ||
1236 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1237 username[pos++] = c;
1238 c_write(&c, 1);
1239 }
1240 break;
1241 }
1242 }
1243 c_write("\r\n", 2);
1244 username[strcspn(username, "\n\r")] = '\0';
1245 } else {
1246 char stuff[200];
1247 strncpy(username, cfg.username, 99);
1248 username[99] = '\0';
67779be7 1249 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
fb09bf1c 1250 sprintf(stuff, "Sent username \"%s\".\r\n", username);
4017be6d 1251 c_write(stuff, strlen(stuff));
fb09bf1c 1252 }
374330e2 1253 }
fb09bf1c 1254
e5574168 1255 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1256 {
1257 char userlog[20+sizeof(username)];
1258 sprintf(userlog, "Sent username \"%s\"", username);
1259 logevent(userlog);
1260 }
374330e2 1261 }
1262
fb09bf1c 1263 crWaitUntil(ispkt);
374330e2 1264
7cca0d81 1265 tried_publickey = 0;
1266
e5574168 1267 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1268 static char password[100];
a52f067e 1269 static char prompt[200];
374330e2 1270 static int pos;
1271 static char c;
ccbfb941 1272 static int pwpkt_type;
ccbfb941 1273 /*
1274 * Show password prompt, having first obtained it via a TIS
18515c51 1275 * or CryptoCard exchange if we're doing TIS or CryptoCard
1276 * authentication.
ccbfb941 1277 */
e5574168 1278 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1279 if (agent_exists()) {
1280 /*
1281 * Attempt RSA authentication using Pageant.
1282 */
1283 static unsigned char request[5], *response, *p;
1284 static int responselen;
1285 static int i, nkeys;
1286 static int authed = FALSE;
1287 void *r;
1288
1289 logevent("Pageant is running. Requesting keys.");
1290
1291 /* Request the keys held by the agent. */
1292 PUT_32BIT(request, 1);
1293 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1294 agent_query(request, 5, &r, &responselen);
1295 response = (unsigned char *)r;
1296 if (response) {
1297 p = response + 5;
1298 nkeys = GET_32BIT(p); p += 4;
1299 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1300 logevent(buf); }
1301 for (i = 0; i < nkeys; i++) {
1302 static struct RSAKey key;
1303 static Bignum challenge;
b8bb811a 1304 static char *commentp;
1305 static int commentlen;
5c58ad2d 1306
1307 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1308 logevent(buf); }
1309 p += 4;
1310 p += ssh1_read_bignum(p, &key.exponent);
1311 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1312 commentlen = GET_32BIT(p); p += 4;
1313 commentp = p; p += commentlen;
5c58ad2d 1314 send_packet(SSH1_CMSG_AUTH_RSA,
1315 PKT_BIGNUM, key.modulus, PKT_END);
1316 crWaitUntil(ispkt);
1317 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1318 logevent("Key refused");
1319 continue;
1320 }
1321 logevent("Received RSA challenge");
1322 ssh1_read_bignum(pktin.body, &challenge);
1323 {
1324 char *agentreq, *q, *ret;
1325 int len, retlen;
1326 len = 1 + 4; /* message type, bit count */
1327 len += ssh1_bignum_length(key.exponent);
1328 len += ssh1_bignum_length(key.modulus);
1329 len += ssh1_bignum_length(challenge);
1330 len += 16; /* session id */
1331 len += 4; /* response format */
1332 agentreq = malloc(4 + len);
1333 PUT_32BIT(agentreq, len);
1334 q = agentreq + 4;
1335 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1336 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1337 q += 4;
1338 q += ssh1_write_bignum(q, key.exponent);
1339 q += ssh1_write_bignum(q, key.modulus);
1340 q += ssh1_write_bignum(q, challenge);
1341 memcpy(q, session_id, 16); q += 16;
1342 PUT_32BIT(q, 1); /* response format */
1343 agent_query(agentreq, len+4, &ret, &retlen);
1344 free(agentreq);
1345 if (ret) {
1346 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1347 logevent("Sending Pageant's response");
1348 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1349 PKT_DATA, ret+5, 16, PKT_END);
1350 free(ret);
1351 crWaitUntil(ispkt);
1352 if (pktin.type == SSH1_SMSG_SUCCESS) {
1353 logevent("Pageant's response accepted");
c4fa2fce 1354 if (flags & FLAG_VERBOSE) {
1355 c_write("Authenticated using RSA key \"",
1356 29);
1357 c_write(commentp, commentlen);
1358 c_write("\" from agent\r\n", 14);
1359 }
5c58ad2d 1360 authed = TRUE;
1361 } else
1362 logevent("Pageant's response not accepted");
1363 } else {
1364 logevent("Pageant failed to answer challenge");
1365 free(ret);
1366 }
1367 } else {
1368 logevent("No reply received from Pageant");
1369 }
1370 }
1371 freebn(key.exponent);
1372 freebn(key.modulus);
1373 freebn(challenge);
1374 if (authed)
1375 break;
1376 }
1377 }
1378 if (authed)
1379 break;
1380 }
7cca0d81 1381 if (*cfg.keyfile && !tried_publickey)
1382 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1383
a52f067e 1384 if (pktin.type == SSH1_SMSG_FAILURE &&
1385 cfg.try_tis_auth &&
1386 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1387 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1388 logevent("Requested TIS authentication");
1389 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1390 crWaitUntil(ispkt);
1391 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1392 logevent("TIS authentication declined");
1393 if (flags & FLAG_INTERACTIVE)
1394 c_write("TIS authentication refused.\r\n", 29);
1395 } else {
1396 int challengelen = ((pktin.body[0] << 24) |
1397 (pktin.body[1] << 16) |
1398 (pktin.body[2] << 8) |
1399 (pktin.body[3]));
1400 logevent("Received TIS challenge");
1401 if (challengelen > sizeof(prompt)-1)
1402 challengelen = sizeof(prompt)-1; /* prevent overrun */
1403 memcpy(prompt, pktin.body+4, challengelen);
1404 prompt[challengelen] = '\0';
1405 }
1406 }
1407 if (pktin.type == SSH1_SMSG_FAILURE &&
1408 cfg.try_tis_auth &&
1409 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1410 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1411 logevent("Requested CryptoCard authentication");
1412 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1413 crWaitUntil(ispkt);
1414 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1415 logevent("CryptoCard authentication declined");
1416 c_write("CryptoCard authentication refused.\r\n", 29);
1417 } else {
1418 int challengelen = ((pktin.body[0] << 24) |
1419 (pktin.body[1] << 16) |
1420 (pktin.body[2] << 8) |
1421 (pktin.body[3]));
1422 logevent("Received CryptoCard challenge");
1423 if (challengelen > sizeof(prompt)-1)
1424 challengelen = sizeof(prompt)-1; /* prevent overrun */
1425 memcpy(prompt, pktin.body+4, challengelen);
1426 strncpy(prompt + challengelen, "\r\nResponse : ",
1427 sizeof(prompt)-challengelen);
1428 prompt[sizeof(prompt)-1] = '\0';
1429 }
1430 }
1431 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1432 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1433 username, savedhost);
a52f067e 1434 }
1435 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1436 char *comment = NULL;
1437 if (flags & FLAG_VERBOSE)
1438 c_write("Trying public key authentication.\r\n", 35);
1439 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1440 if (flags & FLAG_VERBOSE)
1441 c_write("No passphrase required.\r\n", 25);
1442 goto tryauth;
1443 }
1444 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1445 free(comment);
1446 }
1447
d8426c54 1448 if (ssh_get_password) {
85ee8208 1449 if (!ssh_get_password(prompt, password, sizeof(password))) {
1450 /*
1451 * get_password failed to get a password (for
1452 * example because one was supplied on the command
1453 * line which has already failed to work).
1454 * Terminate.
1455 */
1456 logevent("No more passwords to try");
1457 ssh_state = SSH_STATE_CLOSED;
1458 crReturn(1);
1459 }
fb09bf1c 1460 } else {
a52f067e 1461 c_write(prompt, strlen(prompt));
7cca0d81 1462 pos = 0;
67779be7 1463 ssh_send_ok = 1;
7cca0d81 1464 while (pos >= 0) {
1465 crWaitUntil(!ispkt);
1466 while (inlen--) switch (c = *in++) {
1467 case 10: case 13:
1468 password[pos] = 0;
1469 pos = -1;
1470 break;
1471 case 8: case 127:
1472 if (pos > 0)
1473 pos--;
1474 break;
1475 case 21: case 27:
1476 pos = 0;
1477 break;
1478 case 3: case 4:
1479 random_save_seed();
1480 exit(0);
1481 break;
1482 default:
1483 if (((c >= ' ' && c <= '~') ||
1484 ((unsigned char)c >= 160)) && pos < sizeof(password))
1485 password[pos++] = c;
1486 break;
1487 }
1488 }
1489 c_write("\r\n", 2);
a52f067e 1490 }
fb09bf1c 1491
7cca0d81 1492 tryauth:
1493 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1494 /*
1495 * Try public key authentication with the specified
1496 * key file.
1497 */
1498 static struct RSAKey pubkey;
1499 static Bignum challenge, response;
1500 static int i;
1501 static unsigned char buffer[32];
1502
1503 tried_publickey = 1;
6e522441 1504 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
7cca0d81 1505 if (i == 0) {
1506 c_write("Couldn't load public key from ", 30);
1507 c_write(cfg.keyfile, strlen(cfg.keyfile));
1508 c_write(".\r\n", 3);
1509 continue; /* go and try password */
1510 }
1511 if (i == -1) {
1512 c_write("Wrong passphrase.\r\n", 19);
1513 tried_publickey = 0;
1514 continue; /* try again */
1515 }
1516
1517 /*
1518 * Send a public key attempt.
1519 */
1520 send_packet(SSH1_CMSG_AUTH_RSA,
1521 PKT_BIGNUM, pubkey.modulus, PKT_END);
1522
1523 crWaitUntil(ispkt);
1524 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1525 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1526 continue; /* go and try password */
1527 }
8d5de777 1528 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1529 bombout(("Bizarre response to offer of public key"));
1530 crReturn(0);
1531 }
7cca0d81 1532 ssh1_read_bignum(pktin.body, &challenge);
1533 response = rsadecrypt(challenge, &pubkey);
1534 freebn(pubkey.private_exponent); /* burn the evidence */
1535
1536 for (i = 0; i < 32; i += 2) {
1537 buffer[i] = response[16-i/2] >> 8;
1538 buffer[i+1] = response[16-i/2] & 0xFF;
1539 }
1540
1541 MD5Init(&md5c);
1542 MD5Update(&md5c, buffer, 32);
1543 MD5Update(&md5c, session_id, 16);
1544 MD5Final(buffer, &md5c);
1545
1546 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1547 PKT_DATA, buffer, 16, PKT_END);
1548
1549 crWaitUntil(ispkt);
1550 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1551 if (flags & FLAG_VERBOSE)
1552 c_write("Failed to authenticate with our public key.\r\n",
1553 45);
7cca0d81 1554 continue; /* go and try password */
1555 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1556 bombout(("Bizarre response to RSA authentication response"));
1557 crReturn(0);
7cca0d81 1558 }
1559
1560 break; /* we're through! */
1561 } else {
1562 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1563 }
c5e9c988 1564 logevent("Sent password");
374330e2 1565 memset(password, 0, strlen(password));
fb09bf1c 1566 crWaitUntil(ispkt);
e5574168 1567 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1568 if (flags & FLAG_VERBOSE)
1569 c_write("Access denied\r\n", 15);
c5e9c988 1570 logevent("Authentication refused");
e5574168 1571 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1572 logevent("Received disconnect request");
85ee8208 1573 ssh_state = SSH_STATE_CLOSED;
1574 crReturn(1);
e5574168 1575 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1576 bombout(("Strange packet received, type %d", pktin.type));
1577 crReturn(0);
374330e2 1578 }
1579 }
1580
c5e9c988 1581 logevent("Authentication successful");
1582
fb09bf1c 1583 crFinish(1);
1584}
1585
e5574168 1586static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1587 crBegin;
1588
1589 random_init();
1590
e5574168 1591 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1592 crReturnV;
85ee8208 1593 }
1594 if (ssh_state == SSH_STATE_CLOSED)
1595 crReturnV;
fb09bf1c 1596
979310f1 1597 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1598 logevent("Requesting agent forwarding");
1599 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1600 do { crReturnV; } while (!ispkt);
1601 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1602 bombout(("Protocol confusion"));
1603 crReturnV;
dacbd0e8 1604 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1605 logevent("Agent forwarding refused");
1606 } else
1607 logevent("Agent forwarding enabled");
1608 }
1609
fef97f43 1610 if (!cfg.nopty) {
e5574168 1611 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1612 PKT_STR, cfg.termtype,
1613 PKT_INT, rows, PKT_INT, cols,
1614 PKT_INT, 0, PKT_INT, 0,
1615 PKT_CHAR, 0,
1616 PKT_END);
fef97f43 1617 ssh_state = SSH_STATE_INTERMED;
1618 do { crReturnV; } while (!ispkt);
e5574168 1619 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1620 bombout(("Protocol confusion"));
1621 crReturnV;
e5574168 1622 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1623 c_write("Server refused to allocate pty\r\n", 32);
1624 }
c5e9c988 1625 logevent("Allocated pty");
374330e2 1626 }
1627
6abbf9e3 1628 if (*cfg.remote_cmd)
1629 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1630 else
1631 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1632 logevent("Started session");
374330e2 1633
1634 ssh_state = SSH_STATE_SESSION;
1635 if (size_needed)
1636 ssh_size();
1637
8ccc75b0 1638 ssh_send_ok = 1;
dacbd0e8 1639 ssh_channels = newtree234(ssh_channelcmp);
6f34e365 1640 begin_session();
374330e2 1641 while (1) {
1642 crReturnV;
1643 if (ispkt) {
e5574168 1644 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1645 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1646 long len = GET_32BIT(pktin.body);
fe50e814 1647 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1648 pktin.body+4, len);
e5574168 1649 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1650 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1651 logevent("Received disconnect request");
3257deae 1652 crReturnV;
dacbd0e8 1653 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1654 /* Remote side is trying to open a channel to talk to our
1655 * agent. Give them back a local channel number. */
d211621f 1656 unsigned i = 1;
dacbd0e8 1657 struct ssh_channel *c;
1658 enum234 e;
1659 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1660 if (c->localid > i)
1661 break; /* found a free number */
1662 i = c->localid + 1;
1663 }
1664 c = malloc(sizeof(struct ssh_channel));
1665 c->remoteid = GET_32BIT(pktin.body);
1666 c->localid = i;
b8bb811a 1667 c->closes = 0;
dacbd0e8 1668 c->type = SSH1_SMSG_AGENT_OPEN; /* identify channel type */
bb487ce2 1669 c->u.a.lensofar = 0;
dacbd0e8 1670 add234(ssh_channels, c);
1671 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1672 PKT_INT, c->remoteid, PKT_INT, c->localid,
1673 PKT_END);
1674 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1675 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1676 /* Remote side closes a channel. */
d211621f 1677 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1678 struct ssh_channel *c;
1679 c = find234(ssh_channels, &i, ssh_channelfind);
1680 if (c) {
1681 int closetype;
1682 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1683 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1684 c->closes |= closetype;
1685 if (c->closes == 3) {
1686 del234(ssh_channels, c);
1687 free(c);
1688 }
1689 }
1690 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1691 /* Data sent down one of our channels. */
1692 int i = GET_32BIT(pktin.body);
1693 int len = GET_32BIT(pktin.body+4);
1694 unsigned char *p = pktin.body+8;
1695 struct ssh_channel *c;
1696 c = find234(ssh_channels, &i, ssh_channelfind);
1697 if (c) {
1698 switch(c->type) {
1699 case SSH1_SMSG_AGENT_OPEN:
1700 /* Data for an agent message. Buffer it. */
1701 while (len > 0) {
1702 if (c->u.a.lensofar < 4) {
1703 int l = min(4 - c->u.a.lensofar, len);
1704 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
1705 p += l; len -= l; c->u.a.lensofar += l;
1706 }
1707 if (c->u.a.lensofar == 4) {
1708 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
1709 c->u.a.message = malloc(c->u.a.totallen);
1710 memcpy(c->u.a.message, c->u.a.msglen, 4);
1711 }
1712 if (c->u.a.lensofar >= 4 && len > 0) {
1713 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
1714 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
1715 p += l; len -= l; c->u.a.lensofar += l;
1716 }
1717 if (c->u.a.lensofar == c->u.a.totallen) {
1718 void *reply, *sentreply;
1719 int replylen;
1720 agent_query(c->u.a.message, c->u.a.totallen,
1721 &reply, &replylen);
1722 if (reply)
1723 sentreply = reply;
1724 else {
1725 /* Fake SSH_AGENT_FAILURE. */
1726 sentreply = "\0\0\0\1\5";
1727 replylen = 5;
1728 }
1729 send_packet(SSH1_MSG_CHANNEL_DATA,
1730 PKT_INT, c->remoteid,
1731 PKT_INT, replylen,
1732 PKT_DATA, sentreply, replylen,
1733 PKT_END);
1734 if (reply)
1735 free(reply);
1736 free(c->u.a.message);
1737 c->u.a.lensofar = 0;
1738 }
1739 }
1740 break;
1741 }
1742 }
e5574168 1743 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 1744 /* may be from EXEC_SHELL on some servers */
e5574168 1745 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 1746 /* may be from EXEC_SHELL on some servers
374330e2 1747 * if no pty is available or in other odd cases. Ignore */
e5574168 1748 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1749 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 1750 } else {
8d5de777 1751 bombout(("Strange packet received: type %d", pktin.type));
1752 crReturnV;
374330e2 1753 }
1754 } else {
8df7a775 1755 while (inlen > 0) {
1756 int len = min(inlen, 512);
1757 send_packet(SSH1_CMSG_STDIN_DATA,
1758 PKT_INT, len, PKT_DATA, in, len, PKT_END);
1759 in += len;
1760 inlen -= len;
1761 }
374330e2 1762 }
1763 }
1764
1765 crFinishV;
1766}
1767
1768/*
e5574168 1769 * Utility routine for decoding comma-separated strings in KEXINIT.
1770 */
75cab814 1771static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 1772 int needlen = strlen(needle);
1773 while (1) {
1774 /*
1775 * Is it at the start of the string?
1776 */
1777 if (haylen >= needlen && /* haystack is long enough */
1778 !memcmp(needle, haystack, needlen) && /* initial match */
1779 (haylen == needlen || haystack[needlen] == ',')
1780 /* either , or EOS follows */
1781 )
1782 return 1;
1783 /*
1784 * If not, search for the next comma and resume after that.
1785 * If no comma found, terminate.
1786 */
1787 while (haylen > 0 && *haystack != ',')
1788 haylen--, haystack++;
1789 if (haylen == 0)
1790 return 0;
1791 haylen--, haystack++; /* skip over comma itself */
1792 }
1793}
1794
1795/*
d39f364a 1796 * SSH2 key creation method.
1797 */
75cab814 1798static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
d39f364a 1799 SHA_State s;
1800 /* First 20 bytes. */
1801 SHA_Init(&s);
1802 sha_mpint(&s, K);
1803 SHA_Bytes(&s, H, 20);
1804 SHA_Bytes(&s, &chr, 1);
1805 SHA_Bytes(&s, H, 20);
1806 SHA_Final(&s, keyspace);
1807 /* Next 20 bytes. */
1808 SHA_Init(&s);
1809 sha_mpint(&s, K);
1810 SHA_Bytes(&s, H, 20);
1811 SHA_Bytes(&s, keyspace, 20);
1812 SHA_Final(&s, keyspace+20);
1813}
1814
1815/*
7cca0d81 1816 * Handle the SSH2 transport layer.
e5574168 1817 */
7cca0d81 1818static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 1819{
1820 static int i, len;
1821 static char *str;
1822 static Bignum e, f, K;
7591b9ff 1823 static const struct ssh_mac **maclist;
8b2715b2 1824 static int nmacs;
57476f6b 1825 static const struct ssh_cipher *cscipher_tobe = NULL;
1826 static const struct ssh_cipher *sccipher_tobe = NULL;
1827 static const struct ssh_mac *csmac_tobe = NULL;
1828 static const struct ssh_mac *scmac_tobe = NULL;
1829 static const struct ssh_compress *cscomp_tobe = NULL;
1830 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 1831 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 1832 static int hostkeylen, siglen;
1833 static unsigned char exchange_hash[20];
d39f364a 1834 static unsigned char keyspace[40];
57476f6b 1835 static const struct ssh_cipher *preferred_cipher;
e5574168 1836
1837 crBegin;
7cca0d81 1838 random_init();
e5574168 1839
5e8358ad 1840 /*
1841 * Set up the preferred cipher.
1842 */
1843 if (cfg.cipher == CIPHER_BLOWFISH) {
57476f6b 1844 preferred_cipher = &ssh_blowfish_ssh2;
5e8358ad 1845 } else if (cfg.cipher == CIPHER_DES) {
1846 logevent("Single DES not supported in SSH2; using 3DES");
57476f6b 1847 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1848 } else if (cfg.cipher == CIPHER_3DES) {
57476f6b 1849 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1850 } else {
1851 /* Shouldn't happen, but we do want to initialise to _something_. */
57476f6b 1852 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1853 }
1854
7591b9ff 1855 /*
1856 * Be prepared to work around the buggy MAC problem.
1857 */
1858 if (cfg.buggymac)
8b2715b2 1859 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 1860 else
8b2715b2 1861 maclist = macs, nmacs = lenof(macs);
7591b9ff 1862
7cca0d81 1863 begin_key_exchange:
e5574168 1864 /*
1865 * Construct and send our key exchange packet.
1866 */
1867 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1868 for (i = 0; i < 16; i++)
1869 ssh2_pkt_addbyte((unsigned char)random_byte());
1870 /* List key exchange algorithms. */
1871 ssh2_pkt_addstring_start();
1872 for (i = 0; i < lenof(kex_algs); i++) {
1873 ssh2_pkt_addstring_str(kex_algs[i]->name);
1874 if (i < lenof(kex_algs)-1)
1875 ssh2_pkt_addstring_str(",");
1876 }
1877 /* List server host key algorithms. */
1878 ssh2_pkt_addstring_start();
1879 for (i = 0; i < lenof(hostkey_algs); i++) {
1880 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1881 if (i < lenof(hostkey_algs)-1)
1882 ssh2_pkt_addstring_str(",");
1883 }
1884 /* List client->server encryption algorithms. */
1885 ssh2_pkt_addstring_start();
729e54b4 1886 for (i = 0; i < lenof(ciphers)+1; i++) {
1887 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1888 ssh2_pkt_addstring_str(c->name);
729e54b4 1889 if (i < lenof(ciphers))
e5574168 1890 ssh2_pkt_addstring_str(",");
1891 }
1892 /* List server->client 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 client->server MAC algorithms. */
1901 ssh2_pkt_addstring_start();
8b2715b2 1902 for (i = 0; i < nmacs; i++) {
7591b9ff 1903 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 1904 if (i < nmacs-1)
e5574168 1905 ssh2_pkt_addstring_str(",");
1906 }
1907 /* List server->client MAC algorithms. */
1908 ssh2_pkt_addstring_start();
8b2715b2 1909 for (i = 0; i < nmacs; i++) {
7591b9ff 1910 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 1911 if (i < nmacs-1)
e5574168 1912 ssh2_pkt_addstring_str(",");
1913 }
1914 /* List client->server compression algorithms. */
1915 ssh2_pkt_addstring_start();
1916 for (i = 0; i < lenof(compressions); i++) {
1917 ssh2_pkt_addstring_str(compressions[i]->name);
1918 if (i < lenof(compressions)-1)
1919 ssh2_pkt_addstring_str(",");
1920 }
1921 /* List server->client compression algorithms. */
1922 ssh2_pkt_addstring_start();
1923 for (i = 0; i < lenof(compressions); i++) {
1924 ssh2_pkt_addstring_str(compressions[i]->name);
1925 if (i < lenof(compressions)-1)
1926 ssh2_pkt_addstring_str(",");
1927 }
1928 /* List client->server languages. Empty list. */
1929 ssh2_pkt_addstring_start();
1930 /* List server->client languages. Empty list. */
1931 ssh2_pkt_addstring_start();
1932 /* First KEX packet does _not_ follow, because we're not that brave. */
1933 ssh2_pkt_addbool(FALSE);
1934 /* Reserved. */
1935 ssh2_pkt_adduint32(0);
1936 sha_string(&exhash, pktout.data+5, pktout.length-5);
1937 ssh2_pkt_send();
1938
1939 if (!ispkt) crWaitUntil(ispkt);
1940 sha_string(&exhash, pktin.data+5, pktin.length-5);
1941
1942 /*
1943 * Now examine the other side's KEXINIT to see what we're up
1944 * to.
1945 */
7cca0d81 1946 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 1947 bombout(("expected key exchange packet from server"));
1948 crReturn(0);
7cca0d81 1949 }
e5574168 1950 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1951 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1952 pktin.savedpos += 16; /* skip garbage cookie */
1953 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1954 for (i = 0; i < lenof(kex_algs); i++) {
1955 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1956 kex = kex_algs[i];
1957 break;
1958 }
1959 }
1960 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1961 for (i = 0; i < lenof(hostkey_algs); i++) {
1962 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1963 hostkey = hostkey_algs[i];
1964 break;
1965 }
1966 }
1967 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 1968 for (i = 0; i < lenof(ciphers)+1; i++) {
1969 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1970 if (in_commasep_string(c->name, str, len)) {
729e54b4 1971 cscipher_tobe = c;
e5574168 1972 break;
1973 }
1974 }
1975 ssh2_pkt_getstring(&str, &len); /* server->client 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 sccipher_tobe = c;
e5574168 1980 break;
1981 }
1982 }
1983 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 1984 for (i = 0; i < nmacs; i++) {
7591b9ff 1985 if (in_commasep_string(maclist[i]->name, str, len)) {
1986 csmac_tobe = maclist[i];
e5574168 1987 break;
1988 }
1989 }
1990 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 1991 for (i = 0; i < nmacs; i++) {
7591b9ff 1992 if (in_commasep_string(maclist[i]->name, str, len)) {
1993 scmac_tobe = maclist[i];
e5574168 1994 break;
1995 }
1996 }
1997 ssh2_pkt_getstring(&str, &len); /* client->server compression */
1998 for (i = 0; i < lenof(compressions); i++) {
1999 if (in_commasep_string(compressions[i]->name, str, len)) {
2000 cscomp_tobe = compressions[i];
2001 break;
2002 }
2003 }
2004 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2005 for (i = 0; i < lenof(compressions); i++) {
2006 if (in_commasep_string(compressions[i]->name, str, len)) {
2007 sccomp_tobe = compressions[i];
2008 break;
2009 }
2010 }
e5574168 2011
2012 /*
2013 * Currently we only support Diffie-Hellman and DSS, so let's
2014 * bomb out if those aren't selected.
2015 */
8d5de777 2016 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2017 bombout(("internal fault: chaos in SSH 2 transport layer"));
2018 crReturn(0);
2019 }
e5574168 2020
2021 /*
2022 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2023 */
2024 e = dh_create_e();
e5574168 2025 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2026 ssh2_pkt_addmp(e);
2027 ssh2_pkt_send();
2028
2029 crWaitUntil(ispkt);
7cca0d81 2030 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2031 bombout(("expected key exchange packet from server"));
2032 crReturn(0);
7cca0d81 2033 }
e5574168 2034 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2035 f = ssh2_pkt_getmp();
e5574168 2036 ssh2_pkt_getstring(&sigdata, &siglen);
2037
2038 K = dh_find_K(f);
e5574168 2039
2040 sha_string(&exhash, hostkeydata, hostkeylen);
2041 sha_mpint(&exhash, e);
2042 sha_mpint(&exhash, f);
2043 sha_mpint(&exhash, K);
2044 SHA_Final(&exhash, exchange_hash);
2045
7cca0d81 2046#if 0
e5574168 2047 debug(("Exchange hash is:\r\n"));
2048 for (i = 0; i < 20; i++)
2049 debug((" %02x", exchange_hash[i]));
2050 debug(("\r\n"));
7cca0d81 2051#endif
2052
2053 hostkey->setkey(hostkeydata, hostkeylen);
8d5de777 2054 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20)) {
2055 bombout(("Server failed host key check"));
2056 crReturn(0);
2057 }
e5574168 2058
2059 /*
7cca0d81 2060 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2061 */
7cca0d81 2062 crWaitUntil(ispkt);
8d5de777 2063 if (pktin.type != SSH2_MSG_NEWKEYS) {
2064 bombout(("expected new-keys packet from server"));
2065 crReturn(0);
2066 }
d39f364a 2067
2068 /*
7cca0d81 2069 * Authenticate remote host: verify host key. (We've already
2070 * checked the signature of the exchange hash.)
e5574168 2071 */
7cca0d81 2072 keystr = hostkey->fmtkey();
d5859615 2073 fingerprint = hostkey->fingerprint();
d4857987 2074 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2075 keystr, fingerprint);
d5859615 2076 logevent("Host key fingerprint is:");
2077 logevent(fingerprint);
2078 free(fingerprint);
7cca0d81 2079 free(keystr);
d39f364a 2080
2081 /*
7cca0d81 2082 * Send SSH2_MSG_NEWKEYS.
d39f364a 2083 */
2084 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2085 ssh2_pkt_send();
d39f364a 2086
2087 /*
2088 * Create and initialise session keys.
2089 */
2090 cscipher = cscipher_tobe;
2091 sccipher = sccipher_tobe;
2092 csmac = csmac_tobe;
2093 scmac = scmac_tobe;
2094 cscomp = cscomp_tobe;
2095 sccomp = sccomp_tobe;
2096 /*
2097 * Set IVs after keys.
2098 */
2099 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
2100 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
2101 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2102 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2103 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2104 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2105
033b4cef 2106 /*
7cca0d81 2107 * Now we're encrypting. Begin returning 1 to the protocol main
2108 * function so that other things can run on top of the
2109 * transport. If we ever see a KEXINIT, we must go back to the
2110 * start.
033b4cef 2111 */
7cca0d81 2112 do {
2113 crReturn(1);
2114 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2115 goto begin_key_exchange;
e5574168 2116
2117 crFinish(1);
2118}
2119
7cca0d81 2120/*
2121 * Handle the SSH2 userauth and connection layers.
2122 */
2123static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2124{
7cca0d81 2125 static unsigned long remote_winsize;
2126 static unsigned long remote_maxpkt;
2127
e5574168 2128 crBegin;
2129
7cca0d81 2130 /*
2131 * Request userauth protocol, and await a response to it.
2132 */
2133 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2134 ssh2_pkt_addstring("ssh-userauth");
2135 ssh2_pkt_send();
2136 crWaitUntilV(ispkt);
8d5de777 2137 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2138 bombout(("Server refused user authentication protocol"));
2139 crReturnV;
2140 }
7cca0d81 2141
2142 /*
2143 * FIXME: currently we support only password authentication.
2144 * (This places us technically in violation of the SSH2 spec.
2145 * We must fix this.)
2146 */
2147 while (1) {
2148 /*
2149 * Get a username and a password.
2150 */
2151 static char username[100];
2152 static char password[100];
2153 static int pos = 0;
2154 static char c;
e5574168 2155
67779be7 2156 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2157 c_write("login as: ", 10);
67779be7 2158 ssh_send_ok = 1;
7cca0d81 2159 while (pos >= 0) {
2160 crWaitUntilV(!ispkt);
2161 while (inlen--) switch (c = *in++) {
2162 case 10: case 13:
2163 username[pos] = 0;
2164 pos = -1;
2165 break;
2166 case 8: case 127:
2167 if (pos > 0) {
2168 c_write("\b \b", 3);
2169 pos--;
2170 }
2171 break;
2172 case 21: case 27:
2173 while (pos > 0) {
2174 c_write("\b \b", 3);
2175 pos--;
2176 }
2177 break;
2178 case 3: case 4:
2179 random_save_seed();
2180 exit(0);
2181 break;
2182 default:
2183 if (((c >= ' ' && c <= '~') ||
2184 ((unsigned char)c >= 160)) && pos < 40) {
2185 username[pos++] = c;
2186 c_write(&c, 1);
2187 }
2188 break;
2189 }
2190 }
2191 c_write("\r\n", 2);
2192 username[strcspn(username, "\n\r")] = '\0';
2193 } else {
2194 char stuff[200];
2195 strncpy(username, cfg.username, 99);
2196 username[99] = '\0';
67779be7 2197 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2198 sprintf(stuff, "Using username \"%s\".\r\n", username);
2199 c_write(stuff, strlen(stuff));
2200 }
2201 }
2202
d8426c54 2203 if (ssh_get_password) {
7cca0d81 2204 char prompt[200];
b585ec46 2205 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
7cca0d81 2206 if (!ssh_get_password(prompt, password, sizeof(password))) {
2207 /*
2208 * get_password failed to get a password (for
2209 * example because one was supplied on the command
2210 * line which has already failed to work).
2211 * Terminate.
2212 */
2213 logevent("No more passwords to try");
2214 ssh_state = SSH_STATE_CLOSED;
2215 crReturnV;
2216 }
2217 } else {
2218 c_write("password: ", 10);
67779be7 2219 ssh_send_ok = 1;
7cca0d81 2220
2221 pos = 0;
2222 while (pos >= 0) {
2223 crWaitUntilV(!ispkt);
2224 while (inlen--) switch (c = *in++) {
2225 case 10: case 13:
2226 password[pos] = 0;
2227 pos = -1;
2228 break;
2229 case 8: case 127:
2230 if (pos > 0)
2231 pos--;
2232 break;
2233 case 21: case 27:
2234 pos = 0;
2235 break;
2236 case 3: case 4:
2237 random_save_seed();
2238 exit(0);
2239 break;
2240 default:
2241 if (((c >= ' ' && c <= '~') ||
2242 ((unsigned char)c >= 160)) && pos < 40)
2243 password[pos++] = c;
2244 break;
2245 }
2246 }
2247 c_write("\r\n", 2);
2248 }
2249
2250 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2251 ssh2_pkt_addstring(username);
2252 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2253 ssh2_pkt_addstring("password");
2254 ssh2_pkt_addbool(FALSE);
2255 ssh2_pkt_addstring(password);
2256 ssh2_pkt_send();
2257
2258 crWaitUntilV(ispkt);
2259 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2260 c_write("Access denied\r\n", 15);
2261 logevent("Authentication refused");
2262 } else
2263 break;
2264 }
2265
2266 /*
2267 * Now we're authenticated for the connection protocol. The
2268 * connection protocol will automatically have started at this
2269 * point; there's no need to send SERVICE_REQUEST.
2270 */
2271
2272 /*
2273 * So now create a channel with a session in it.
2274 */
d211621f 2275 mainchan = malloc(sizeof(struct ssh_channel));
2276 mainchan->localid = 100; /* as good as any */
7cca0d81 2277 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2278 ssh2_pkt_addstring("session");
d211621f 2279 ssh2_pkt_adduint32(mainchan->localid);
cf6e59d6 2280 ssh2_pkt_adduint32(0x8000UL); /* our window size */
d211621f 2281 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2282 ssh2_pkt_send();
2283 crWaitUntilV(ispkt);
2284 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2285 bombout(("Server refused to open a session"));
2286 crReturnV;
7cca0d81 2287 /* FIXME: error data comes back in FAILURE packet */
2288 }
d211621f 2289 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2290 bombout(("Server's channel confirmation cited wrong channel"));
2291 crReturnV;
7cca0d81 2292 }
d211621f 2293 mainchan->remoteid = ssh2_pkt_getuint32();
2294 mainchan->u.v2.remwindow = ssh2_pkt_getuint32();
2295 mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32();
2296 mainchan->u.v2.outbuffer = NULL;
2297 mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0;
7cca0d81 2298 logevent("Opened channel for session");
2299
2300 /*
2301 * Now allocate a pty for the session.
2302 */
67779be7 2303 if (!cfg.nopty) {
2304 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2305 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2306 ssh2_pkt_addstring("pty-req");
2307 ssh2_pkt_addbool(1); /* want reply */
2308 ssh2_pkt_addstring(cfg.termtype);
2309 ssh2_pkt_adduint32(cols);
2310 ssh2_pkt_adduint32(rows);
2311 ssh2_pkt_adduint32(0); /* pixel width */
2312 ssh2_pkt_adduint32(0); /* pixel height */
2313 ssh2_pkt_addstring_start();
2314 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2315 ssh2_pkt_send();
6e48c3fe 2316 ssh_state = SSH_STATE_INTERMED;
7cca0d81 2317
67779be7 2318 do {
2319 crWaitUntilV(ispkt);
2320 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2321 /* FIXME: be able to handle other channels here */
2322 if (ssh2_pkt_getuint32() != mainchan->localid)
2323 continue; /* wrong channel */
2324 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2325 }
2326 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2327
67779be7 2328 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2329 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2330 bombout(("Server got confused by pty request"));
2331 crReturnV;
67779be7 2332 }
2333 c_write("Server refused to allocate pty\r\n", 32);
2334 } else {
2335 logevent("Allocated pty");
7cca0d81 2336 }
7cca0d81 2337 }
2338
2339 /*
67779be7 2340 * Start a shell or a remote command.
7cca0d81 2341 */
2342 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2343 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2344 if (*cfg.remote_cmd) {
2345 ssh2_pkt_addstring("exec");
2346 ssh2_pkt_addbool(1); /* want reply */
2347 ssh2_pkt_addstring(cfg.remote_cmd);
2348 } else {
2349 ssh2_pkt_addstring("shell");
2350 ssh2_pkt_addbool(1); /* want reply */
2351 }
7cca0d81 2352 ssh2_pkt_send();
d211621f 2353 do {
7cca0d81 2354 crWaitUntilV(ispkt);
d211621f 2355 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2356 /* FIXME: be able to handle other channels here */
2357 if (ssh2_pkt_getuint32() != mainchan->localid)
2358 continue; /* wrong channel */
2359 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2360 }
7cca0d81 2361 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2362 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2363 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2364 bombout(("Server got confused by shell/command request"));
2365 crReturnV;
7cca0d81 2366 }
8d5de777 2367 bombout(("Server refused to start a shell/command"));
2368 crReturnV;
7cca0d81 2369 } else {
8d5de777 2370 logevent("Started a shell/command");
7cca0d81 2371 }
2372
6e48c3fe 2373 ssh_state = SSH_STATE_SESSION;
2374 if (size_needed)
2375 ssh_size();
2376
7cca0d81 2377 /*
2378 * Transfer data!
2379 */
8ccc75b0 2380 ssh_send_ok = 1;
6f34e365 2381 begin_session();
7cca0d81 2382 while (1) {
d211621f 2383 static int try_send;
e5574168 2384 crReturnV;
d211621f 2385 try_send = FALSE;
7cca0d81 2386 if (ispkt) {
2387 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2388 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2389 char *data;
2390 int length;
d211621f 2391 /* FIXME: be able to handle other channels here */
2392 if (ssh2_pkt_getuint32() != mainchan->localid)
7cca0d81 2393 continue; /* wrong channel */
2394 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2395 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2396 continue; /* extended but not stderr */
2397 ssh2_pkt_getstring(&data, &length);
d211621f 2398 if (data) {
fe50e814 2399 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
2400 data, length);
d211621f 2401 /*
2402 * Enlarge the window again at the remote side,
2403 * just in case it ever runs down and they fail
2404 * to send us any more data.
2405 */
2406 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2407 ssh2_pkt_adduint32(mainchan->remoteid);
2408 ssh2_pkt_adduint32(length);
2409 ssh2_pkt_send();
2410 }
7cca0d81 2411 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2412 ssh_state = SSH_STATE_CLOSED;
d211621f 2413 logevent("Received disconnect message");
3257deae 2414 crReturnV;
7cca0d81 2415 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2416 continue; /* exit status et al; ignore (FIXME?) */
d211621f 2417 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2418 continue; /* remote sends EOF; ignore */
2419 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
2420 /* FIXME: be able to handle other channels here */
2421 if (ssh2_pkt_getuint32() != mainchan->localid)
2422 continue; /* wrong channel */
2423 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2424 ssh2_pkt_adduint32(mainchan->remoteid);
2425 ssh2_pkt_send();
2426 /* FIXME: mark the channel as closed */
2427 if (1 /* FIXME: "all channels are closed" */) {
2428 logevent("All channels closed. Disconnecting");
2429 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2430 ssh2_pkt_send();
cf6e59d6 2431 ssh_state = SSH_STATE_CLOSED;
3257deae 2432 crReturnV;
d211621f 2433 }
2434 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2435 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
d211621f 2436 /* FIXME: be able to handle other channels here */
2437 if (ssh2_pkt_getuint32() != mainchan->localid)
2438 continue; /* wrong channel */
2439 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2440 try_send = TRUE;
7cca0d81 2441 } else {
8d5de777 2442 bombout(("Strange packet received: type %d", pktin.type));
2443 crReturnV;
7cca0d81 2444 }
2445 } else {
d211621f 2446 /*
2447 * We have spare data. Add it to the channel buffer.
2448 */
2449 if (mainchan->u.v2.outbufsize <
2450 mainchan->u.v2.outbuflen + inlen) {
2451 mainchan->u.v2.outbufsize =
2452 mainchan->u.v2.outbuflen + inlen + 1024;
2453 mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer,
2454 mainchan->u.v2.outbufsize);
2455 }
2456 memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen,
2457 in, inlen);
2458 mainchan->u.v2.outbuflen += inlen;
2459 try_send = TRUE;
7cca0d81 2460 }
d211621f 2461 if (try_send) {
2462 /*
2463 * Try to send data on the channel if we can. (FIXME:
2464 * on _all_ channels.)
2465 */
2466 while (mainchan->u.v2.remwindow > 0 &&
2467 mainchan->u.v2.outbuflen > 0) {
2468 unsigned len = mainchan->u.v2.remwindow;
2469 if (len > mainchan->u.v2.outbuflen)
2470 len = mainchan->u.v2.outbuflen;
2471 if (len > mainchan->u.v2.remmaxpkt)
2472 len = mainchan->u.v2.remmaxpkt;
2473 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2474 ssh2_pkt_adduint32(mainchan->remoteid);
2475 ssh2_pkt_addstring_start();
2476 ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len);
2477 ssh2_pkt_send();
2478 mainchan->u.v2.outbuflen -= len;
2479 memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len,
2480 mainchan->u.v2.outbuflen);
2481 mainchan->u.v2.remwindow -= len;
2482 }
2483 }
e5574168 2484 }
2485
2486 crFinishV;
2487}
2488
2489/*
7cca0d81 2490 * Handle the top-level SSH2 protocol.
2491 */
2492static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2493{
2494 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2495 return;
2496 do_ssh2_authconn(in, inlen, ispkt);
2497}
2498
2499/*
8df7a775 2500 * Called to set up the connection.
374330e2 2501 *
2502 * Returns an error message, or NULL on success.
374330e2 2503 */
8df7a775 2504static char *ssh_init (char *host, int port, char **realhost) {
fb09bf1c 2505 char *p;
8f203108 2506
2507#ifdef MSCRYPTOAPI
2508 if(crypto_startup() == 0)
2509 return "Microsoft high encryption pack not installed!";
2510#endif
374330e2 2511
8df7a775 2512 ssh_send_ok = 0;
2513
fb09bf1c 2514 p = connect_to_host(host, port, realhost);
2515 if (p != NULL)
2516 return p;
374330e2 2517
374330e2 2518 return NULL;
2519}
2520
2521/*
374330e2 2522 * Called to send data down the Telnet connection.
2523 */
2524static void ssh_send (char *buf, int len) {
8df7a775 2525 if (s == NULL)
374330e2 2526 return;
2527
2528 ssh_protocol(buf, len, 0);
2529}
2530
2531/*
6e48c3fe 2532 * Called to set the size of the window from SSH's POV.
374330e2 2533 */
2534static void ssh_size(void) {
2535 switch (ssh_state) {
2536 case SSH_STATE_BEFORE_SIZE:
21248260 2537 case SSH_STATE_CLOSED:
374330e2 2538 break; /* do nothing */
2539 case SSH_STATE_INTERMED:
2540 size_needed = TRUE; /* buffer for later */
2541 break;
2542 case SSH_STATE_SESSION:
fef97f43 2543 if (!cfg.nopty) {
6e48c3fe 2544 if (ssh_version == 1) {
2545 send_packet(SSH1_CMSG_WINDOW_SIZE,
2546 PKT_INT, rows, PKT_INT, cols,
2547 PKT_INT, 0, PKT_INT, 0, PKT_END);
2548 } else {
2549 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2550 ssh2_pkt_adduint32(mainchan->remoteid);
2551 ssh2_pkt_addstring("window-change");
2552 ssh2_pkt_addbool(0);
2553 ssh2_pkt_adduint32(cols);
2554 ssh2_pkt_adduint32(rows);
2555 ssh2_pkt_adduint32(0);
2556 ssh2_pkt_adduint32(0);
2557 ssh2_pkt_send();
2558 }
fef97f43 2559 }
374330e2 2560 }
2561}
2562
2563/*
6abbf9e3 2564 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2565 * can send an EOF and collect resulting output (e.g. `plink
2566 * hostname sort').
374330e2 2567 */
2568static void ssh_special (Telnet_Special code) {
6abbf9e3 2569 if (code == TS_EOF) {
67779be7 2570 if (ssh_version == 1) {
6abbf9e3 2571 send_packet(SSH1_CMSG_EOF, PKT_END);
2572 } else {
2573 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 2574 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 2575 ssh2_pkt_send();
2576 }
67779be7 2577 logevent("Sent EOF message");
ec55b220 2578 } else if (code == TS_PING) {
2579 if (ssh_version == 1) {
2580 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
2581 } else {
2582 ssh2_pkt_init(SSH2_MSG_IGNORE);
2583 ssh2_pkt_addstring_start();
2584 ssh2_pkt_send();
2585 }
6abbf9e3 2586 } else {
2587 /* do nothing */
2588 }
374330e2 2589}
2590
8df7a775 2591static Socket ssh_socket(void) { return s; }
8ccc75b0 2592
2593static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 2594
374330e2 2595Backend ssh_backend = {
2596 ssh_init,
374330e2 2597 ssh_send,
2598 ssh_size,
4017be6d 2599 ssh_special,
8ccc75b0 2600 ssh_socket,
97db3be4 2601 ssh_sendok,
2602 22
374330e2 2603};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator