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Make the frankly ridiculous prototypes for modpow() and modmul() more sane
[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 }
852 return b;
853}
854
8df7a775 855static int do_ssh_init(unsigned char c) {
856 static char *vsp;
857 static char version[10];
858 static char vstring[80];
859 static char vlog[sizeof(vstring)+20];
860 static int i;
374330e2 861
8df7a775 862 crBegin;
863
864 /* Search for the string "SSH-" in the input. */
374330e2 865 i = 0;
8df7a775 866 while (1) {
867 static const int transS[] = { 1, 2, 2, 1 };
868 static const int transH[] = { 0, 0, 3, 0 };
869 static const int transminus[] = { 0, 0, 0, -1 };
870 if (c == 'S') i = transS[i];
871 else if (c == 'H') i = transH[i];
872 else if (c == '-') i = transminus[i];
374330e2 873 else i = 0;
8df7a775 874 if (i < 0)
875 break;
876 crReturn(1); /* get another character */
374330e2 877 }
8df7a775 878
c5e9c988 879 strcpy(vstring, "SSH-");
880 vsp = vstring+4;
374330e2 881 i = 0;
882 while (1) {
8df7a775 883 crReturn(1); /* get another char */
c5e9c988 884 if (vsp < vstring+sizeof(vstring)-1)
885 *vsp++ = c;
374330e2 886 if (i >= 0) {
887 if (c == '-') {
888 version[i] = '\0';
889 i = -1;
890 } else if (i < sizeof(version)-1)
891 version[i++] = c;
892 }
893 else if (c == '\n')
894 break;
895 }
896
960e736a 897 rdpkt2_state.incoming_sequence = 0;
898
c5e9c988 899 *vsp = 0;
900 sprintf(vlog, "Server version: %s", vstring);
901 vlog[strcspn(vlog, "\r\n")] = '\0';
902 logevent(vlog);
903
adf799dd 904 /*
905 * Server version "1.99" means we can choose whether we use v1
906 * or v2 protocol. Choice is based on cfg.sshprot.
907 */
908 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 909 /*
910 * This is a v2 server. Begin v2 protocol.
911 */
912 char *verstring = "SSH-2.0-PuTTY";
913 SHA_Init(&exhash);
914 /*
915 * Hash our version string and their version string.
916 */
917 sha_string(&exhash, verstring, strlen(verstring));
918 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
919 sprintf(vstring, "%s\n", verstring);
920 sprintf(vlog, "We claim version: %s", verstring);
921 logevent(vlog);
922 logevent("Using SSH protocol version 2");
8df7a775 923 sk_write(s, vstring, strlen(vstring));
e5574168 924 ssh_protocol = ssh2_protocol;
6abbf9e3 925 ssh_version = 2;
e5574168 926 s_rdpkt = ssh2_rdpkt;
927 } else {
928 /*
929 * This is a v1 server. Begin v1 protocol.
930 */
931 sprintf(vstring, "SSH-%s-PuTTY\n",
932 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
933 sprintf(vlog, "We claim version: %s", vstring);
934 vlog[strcspn(vlog, "\r\n")] = '\0';
935 logevent(vlog);
936 logevent("Using SSH protocol version 1");
8df7a775 937 sk_write(s, vstring, strlen(vstring));
e5574168 938 ssh_protocol = ssh1_protocol;
6abbf9e3 939 ssh_version = 1;
e5574168 940 s_rdpkt = ssh1_rdpkt;
941 }
8df7a775 942
943 crFinish(0);
944}
945
946static void ssh_gotdata(unsigned char *data, int datalen)
947{
948 crBegin;
949
950 /*
951 * To begin with, feed the characters one by one to the
952 * protocol initialisation / selection function do_ssh_init().
953 * When that returns 0, we're done with the initial greeting
954 * exchange and can move on to packet discipline.
955 */
956 while (1) {
957 int ret;
958 if (datalen == 0)
959 crReturnV; /* more data please */
960 ret = do_ssh_init(*data);
961 data++; datalen--;
962 if (ret == 0)
963 break;
964 }
965
966 /*
967 * We emerge from that loop when the initial negotiation is
968 * over and we have selected an s_rdpkt function. Now pass
969 * everything to s_rdpkt, and then pass the resulting packets
970 * to the proper protocol handler.
971 */
972 if (datalen == 0)
973 crReturnV;
974 while (1) {
975 while (datalen > 0) {
976 if ( s_rdpkt(&data, &datalen) == 0 ) {
977 ssh_protocol(NULL, 0, 1);
978 if (ssh_state == SSH_STATE_CLOSED) {
979 return;
980 }
981 }
982 }
983 crReturnV;
984 }
985 crFinishV;
986}
987
988static int ssh_receive(Socket s, int urgent, char *data, int len) {
989 if (!len) {
990 /* Connection has closed. */
991 sk_close(s);
992 s = NULL;
993 return 0;
994 }
995 ssh_gotdata (data, len);
fef97f43 996 return 1;
374330e2 997}
998
fb09bf1c 999/*
8df7a775 1000 * Connect to specified host and port.
1001 * Returns an error message, or NULL on success.
1002 * Also places the canonical host name into `realhost'.
1003 */
1004static char *connect_to_host(char *host, int port, char **realhost)
1005{
1006 SockAddr addr;
1007 char *err;
1008#ifdef FWHACK
1009 char *FWhost;
1010 int FWport;
1011#endif
1012
1013 savedhost = malloc(1+strlen(host));
1014 if (!savedhost)
1015 fatalbox("Out of memory");
1016 strcpy(savedhost, host);
1017
1018 if (port < 0)
1019 port = 22; /* default ssh port */
1020 savedport = port;
1021
1022#ifdef FWHACK
1023 FWhost = host;
1024 FWport = port;
1025 host = FWSTR;
1026 port = 23;
1027#endif
1028
1029 /*
1030 * Try to find host.
1031 */
1032 addr = sk_namelookup(host, realhost);
1033 if ( (err = sk_addr_error(addr)) )
1034 return err;
1035
1036#ifdef FWHACK
1037 *realhost = FWhost;
1038#endif
1039
1040 /*
1041 * Open socket.
1042 */
1043 s = sk_new(addr, port, ssh_receive);
1044 if ( (err = sk_socket_error(s)) )
1045 return err;
1046
1047#ifdef FWHACK
1048 sk_write(s, "connect ", 8);
1049 sk_write(s, FWhost, strlen(FWhost));
1050 {
1051 char buf[20];
1052 sprintf(buf, " %d\n", FWport);
1053 sk_write(s, buf, strlen(buf));
1054 }
1055#endif
1056
1057 return NULL;
1058}
1059
1060/*
fb09bf1c 1061 * Handle the key exchange and user authentication phases.
1062 */
e5574168 1063static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1064{
374330e2 1065 int i, j, len;
374330e2 1066 unsigned char *rsabuf, *keystr1, *keystr2;
1067 unsigned char cookie[8];
1068 struct RSAKey servkey, hostkey;
1069 struct MD5Context md5c;
ccbfb941 1070 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1071 static int tried_publickey;
1072 static unsigned char session_id[16];
bea1ef5f 1073 int cipher_type;
b585ec46 1074 static char username[100];
374330e2 1075
374330e2 1076 crBegin;
1077
fb09bf1c 1078 if (!ispkt) crWaitUntil(ispkt);
374330e2 1079
8d5de777 1080 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1081 bombout(("Public key packet not received"));
1082 crReturn(0);
1083 }
374330e2 1084
c5e9c988 1085 logevent("Received public keys");
374330e2 1086
c5e9c988 1087 memcpy(cookie, pktin.body, 8);
374330e2 1088
7cca0d81 1089 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1090 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1091
c5e9c988 1092 /*
1c2a93c4 1093 * Log the host key fingerprint.
c5e9c988 1094 */
c5e9c988 1095 {
1096 char logmsg[80];
1c2a93c4 1097 logevent("Host key fingerprint is:");
c5e9c988 1098 strcpy(logmsg, " ");
1c2a93c4 1099 hostkey.comment = NULL;
1100 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1101 &hostkey);
c5e9c988 1102 logevent(logmsg);
1103 }
1104
fb09bf1c 1105 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1106 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1107
c5e9c988 1108 MD5Init(&md5c);
374330e2 1109 MD5Update(&md5c, keystr2, hostkey.bytes);
1110 MD5Update(&md5c, keystr1, servkey.bytes);
1111 MD5Update(&md5c, pktin.body, 8);
374330e2 1112 MD5Final(session_id, &md5c);
1113
1114 for (i=0; i<32; i++)
1115 session_key[i] = random_byte();
1116
1117 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1118
1119 rsabuf = malloc(len);
1120 if (!rsabuf)
1121 fatalbox("Out of memory");
1122
89ee5268 1123 /*
1124 * Verify the host key.
1125 */
1126 {
1127 /*
1128 * First format the key into a string.
1129 */
1130 int len = rsastr_len(&hostkey);
d5859615 1131 char fingerprint[100];
89ee5268 1132 char *keystr = malloc(len);
1133 if (!keystr)
1134 fatalbox("Out of memory");
1135 rsastr_fmt(keystr, &hostkey);
d5859615 1136 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1137 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
89ee5268 1138 free(keystr);
1139 }
374330e2 1140
1141 for (i=0; i<32; i++) {
1142 rsabuf[i] = session_key[i];
1143 if (i < 16)
1144 rsabuf[i] ^= session_id[i];
1145 }
1146
1147 if (hostkey.bytes > servkey.bytes) {
1148 rsaencrypt(rsabuf, 32, &servkey);
1149 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1150 } else {
1151 rsaencrypt(rsabuf, 32, &hostkey);
1152 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1153 }
1154
c5e9c988 1155 logevent("Encrypted session key");
1156
bea1ef5f 1157 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1158 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1159 SSH_CIPHER_3DES;
1160 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1161 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1162 cipher_type = SSH_CIPHER_3DES;
1163 }
c5e9c988 1164 switch (cipher_type) {
1165 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1166 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1167 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1168 }
bea1ef5f 1169
e5574168 1170 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1171 PKT_CHAR, cipher_type,
1172 PKT_DATA, cookie, 8,
1173 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1174 PKT_DATA, rsabuf, len,
1175 PKT_INT, 0,
1176 PKT_END);
1177
c5e9c988 1178 logevent("Trying to enable encryption...");
374330e2 1179
1180 free(rsabuf);
1181
5e8358ad 1182 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1183 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1184 &ssh_3des;
374330e2 1185 cipher->sesskey(session_key);
1186
fb09bf1c 1187 crWaitUntil(ispkt);
374330e2 1188
8d5de777 1189 if (pktin.type != SSH1_SMSG_SUCCESS) {
1190 bombout(("Encryption not successfully enabled"));
1191 crReturn(0);
1192 }
374330e2 1193
c5e9c988 1194 logevent("Successfully started encryption");
1195
374330e2 1196 fflush(stdout);
1197 {
374330e2 1198 static int pos = 0;
1199 static char c;
67779be7 1200 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1201 c_write("login as: ", 10);
67779be7 1202 ssh_send_ok = 1;
374330e2 1203 while (pos >= 0) {
fb09bf1c 1204 crWaitUntil(!ispkt);
374330e2 1205 while (inlen--) switch (c = *in++) {
1206 case 10: case 13:
1207 username[pos] = 0;
1208 pos = -1;
1209 break;
1210 case 8: case 127:
1211 if (pos > 0) {
1212 c_write("\b \b", 3);
1213 pos--;
1214 }
1215 break;
1216 case 21: case 27:
1217 while (pos > 0) {
1218 c_write("\b \b", 3);
1219 pos--;
1220 }
1221 break;
1222 case 3: case 4:
1223 random_save_seed();
1224 exit(0);
1225 break;
1226 default:
40d24aa6 1227 if (((c >= ' ' && c <= '~') ||
1228 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1229 username[pos++] = c;
1230 c_write(&c, 1);
1231 }
1232 break;
1233 }
1234 }
1235 c_write("\r\n", 2);
1236 username[strcspn(username, "\n\r")] = '\0';
1237 } else {
1238 char stuff[200];
1239 strncpy(username, cfg.username, 99);
1240 username[99] = '\0';
67779be7 1241 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
fb09bf1c 1242 sprintf(stuff, "Sent username \"%s\".\r\n", username);
4017be6d 1243 c_write(stuff, strlen(stuff));
fb09bf1c 1244 }
374330e2 1245 }
fb09bf1c 1246
e5574168 1247 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1248 {
1249 char userlog[20+sizeof(username)];
1250 sprintf(userlog, "Sent username \"%s\"", username);
1251 logevent(userlog);
1252 }
374330e2 1253 }
1254
fb09bf1c 1255 crWaitUntil(ispkt);
374330e2 1256
7cca0d81 1257 tried_publickey = 0;
1258
e5574168 1259 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1260 static char password[100];
a52f067e 1261 static char prompt[200];
374330e2 1262 static int pos;
1263 static char c;
ccbfb941 1264 static int pwpkt_type;
ccbfb941 1265 /*
1266 * Show password prompt, having first obtained it via a TIS
18515c51 1267 * or CryptoCard exchange if we're doing TIS or CryptoCard
1268 * authentication.
ccbfb941 1269 */
e5574168 1270 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1271 if (agent_exists()) {
1272 /*
1273 * Attempt RSA authentication using Pageant.
1274 */
1275 static unsigned char request[5], *response, *p;
1276 static int responselen;
1277 static int i, nkeys;
1278 static int authed = FALSE;
1279 void *r;
1280
1281 logevent("Pageant is running. Requesting keys.");
1282
1283 /* Request the keys held by the agent. */
1284 PUT_32BIT(request, 1);
1285 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1286 agent_query(request, 5, &r, &responselen);
1287 response = (unsigned char *)r;
1288 if (response) {
1289 p = response + 5;
1290 nkeys = GET_32BIT(p); p += 4;
1291 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1292 logevent(buf); }
1293 for (i = 0; i < nkeys; i++) {
1294 static struct RSAKey key;
1295 static Bignum challenge;
b8bb811a 1296 static char *commentp;
1297 static int commentlen;
5c58ad2d 1298
1299 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1300 logevent(buf); }
1301 p += 4;
1302 p += ssh1_read_bignum(p, &key.exponent);
1303 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1304 commentlen = GET_32BIT(p); p += 4;
1305 commentp = p; p += commentlen;
5c58ad2d 1306 send_packet(SSH1_CMSG_AUTH_RSA,
1307 PKT_BIGNUM, key.modulus, PKT_END);
1308 crWaitUntil(ispkt);
1309 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1310 logevent("Key refused");
1311 continue;
1312 }
1313 logevent("Received RSA challenge");
1314 ssh1_read_bignum(pktin.body, &challenge);
1315 {
1316 char *agentreq, *q, *ret;
1317 int len, retlen;
1318 len = 1 + 4; /* message type, bit count */
1319 len += ssh1_bignum_length(key.exponent);
1320 len += ssh1_bignum_length(key.modulus);
1321 len += ssh1_bignum_length(challenge);
1322 len += 16; /* session id */
1323 len += 4; /* response format */
1324 agentreq = malloc(4 + len);
1325 PUT_32BIT(agentreq, len);
1326 q = agentreq + 4;
1327 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1328 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1329 q += 4;
1330 q += ssh1_write_bignum(q, key.exponent);
1331 q += ssh1_write_bignum(q, key.modulus);
1332 q += ssh1_write_bignum(q, challenge);
1333 memcpy(q, session_id, 16); q += 16;
1334 PUT_32BIT(q, 1); /* response format */
1335 agent_query(agentreq, len+4, &ret, &retlen);
1336 free(agentreq);
1337 if (ret) {
1338 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1339 logevent("Sending Pageant's response");
1340 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1341 PKT_DATA, ret+5, 16, PKT_END);
1342 free(ret);
1343 crWaitUntil(ispkt);
1344 if (pktin.type == SSH1_SMSG_SUCCESS) {
1345 logevent("Pageant's response accepted");
c4fa2fce 1346 if (flags & FLAG_VERBOSE) {
1347 c_write("Authenticated using RSA key \"",
1348 29);
1349 c_write(commentp, commentlen);
1350 c_write("\" from agent\r\n", 14);
1351 }
5c58ad2d 1352 authed = TRUE;
1353 } else
1354 logevent("Pageant's response not accepted");
1355 } else {
1356 logevent("Pageant failed to answer challenge");
1357 free(ret);
1358 }
1359 } else {
1360 logevent("No reply received from Pageant");
1361 }
1362 }
1363 freebn(key.exponent);
1364 freebn(key.modulus);
1365 freebn(challenge);
1366 if (authed)
1367 break;
1368 }
1369 }
1370 if (authed)
1371 break;
1372 }
7cca0d81 1373 if (*cfg.keyfile && !tried_publickey)
1374 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1375
a52f067e 1376 if (pktin.type == SSH1_SMSG_FAILURE &&
1377 cfg.try_tis_auth &&
1378 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1379 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1380 logevent("Requested TIS authentication");
1381 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1382 crWaitUntil(ispkt);
1383 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1384 logevent("TIS authentication declined");
1385 if (flags & FLAG_INTERACTIVE)
1386 c_write("TIS authentication refused.\r\n", 29);
1387 } else {
1388 int challengelen = ((pktin.body[0] << 24) |
1389 (pktin.body[1] << 16) |
1390 (pktin.body[2] << 8) |
1391 (pktin.body[3]));
1392 logevent("Received TIS challenge");
1393 if (challengelen > sizeof(prompt)-1)
1394 challengelen = sizeof(prompt)-1; /* prevent overrun */
1395 memcpy(prompt, pktin.body+4, challengelen);
1396 prompt[challengelen] = '\0';
1397 }
1398 }
1399 if (pktin.type == SSH1_SMSG_FAILURE &&
1400 cfg.try_tis_auth &&
1401 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1402 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1403 logevent("Requested CryptoCard authentication");
1404 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1405 crWaitUntil(ispkt);
1406 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1407 logevent("CryptoCard authentication declined");
1408 c_write("CryptoCard authentication refused.\r\n", 29);
1409 } else {
1410 int challengelen = ((pktin.body[0] << 24) |
1411 (pktin.body[1] << 16) |
1412 (pktin.body[2] << 8) |
1413 (pktin.body[3]));
1414 logevent("Received CryptoCard challenge");
1415 if (challengelen > sizeof(prompt)-1)
1416 challengelen = sizeof(prompt)-1; /* prevent overrun */
1417 memcpy(prompt, pktin.body+4, challengelen);
1418 strncpy(prompt + challengelen, "\r\nResponse : ",
1419 sizeof(prompt)-challengelen);
1420 prompt[sizeof(prompt)-1] = '\0';
1421 }
1422 }
1423 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1424 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1425 username, savedhost);
a52f067e 1426 }
1427 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1428 char *comment = NULL;
1429 if (flags & FLAG_VERBOSE)
1430 c_write("Trying public key authentication.\r\n", 35);
1431 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1432 if (flags & FLAG_VERBOSE)
1433 c_write("No passphrase required.\r\n", 25);
1434 goto tryauth;
1435 }
1436 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1437 free(comment);
1438 }
1439
d8426c54 1440 if (ssh_get_password) {
85ee8208 1441 if (!ssh_get_password(prompt, password, sizeof(password))) {
1442 /*
1443 * get_password failed to get a password (for
1444 * example because one was supplied on the command
1445 * line which has already failed to work).
1446 * Terminate.
1447 */
1448 logevent("No more passwords to try");
1449 ssh_state = SSH_STATE_CLOSED;
1450 crReturn(1);
1451 }
fb09bf1c 1452 } else {
a52f067e 1453 c_write(prompt, strlen(prompt));
7cca0d81 1454 pos = 0;
67779be7 1455 ssh_send_ok = 1;
7cca0d81 1456 while (pos >= 0) {
1457 crWaitUntil(!ispkt);
1458 while (inlen--) switch (c = *in++) {
1459 case 10: case 13:
1460 password[pos] = 0;
1461 pos = -1;
1462 break;
1463 case 8: case 127:
1464 if (pos > 0)
1465 pos--;
1466 break;
1467 case 21: case 27:
1468 pos = 0;
1469 break;
1470 case 3: case 4:
1471 random_save_seed();
1472 exit(0);
1473 break;
1474 default:
1475 if (((c >= ' ' && c <= '~') ||
1476 ((unsigned char)c >= 160)) && pos < sizeof(password))
1477 password[pos++] = c;
1478 break;
1479 }
1480 }
1481 c_write("\r\n", 2);
a52f067e 1482 }
fb09bf1c 1483
7cca0d81 1484 tryauth:
1485 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1486 /*
1487 * Try public key authentication with the specified
1488 * key file.
1489 */
1490 static struct RSAKey pubkey;
1491 static Bignum challenge, response;
1492 static int i;
1493 static unsigned char buffer[32];
1494
1495 tried_publickey = 1;
6e522441 1496 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
7cca0d81 1497 if (i == 0) {
1498 c_write("Couldn't load public key from ", 30);
1499 c_write(cfg.keyfile, strlen(cfg.keyfile));
1500 c_write(".\r\n", 3);
1501 continue; /* go and try password */
1502 }
1503 if (i == -1) {
1504 c_write("Wrong passphrase.\r\n", 19);
1505 tried_publickey = 0;
1506 continue; /* try again */
1507 }
1508
1509 /*
1510 * Send a public key attempt.
1511 */
1512 send_packet(SSH1_CMSG_AUTH_RSA,
1513 PKT_BIGNUM, pubkey.modulus, PKT_END);
1514
1515 crWaitUntil(ispkt);
1516 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1517 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1518 continue; /* go and try password */
1519 }
8d5de777 1520 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1521 bombout(("Bizarre response to offer of public key"));
1522 crReturn(0);
1523 }
7cca0d81 1524 ssh1_read_bignum(pktin.body, &challenge);
1525 response = rsadecrypt(challenge, &pubkey);
1526 freebn(pubkey.private_exponent); /* burn the evidence */
1527
1528 for (i = 0; i < 32; i += 2) {
1529 buffer[i] = response[16-i/2] >> 8;
1530 buffer[i+1] = response[16-i/2] & 0xFF;
1531 }
1532
1533 MD5Init(&md5c);
1534 MD5Update(&md5c, buffer, 32);
1535 MD5Update(&md5c, session_id, 16);
1536 MD5Final(buffer, &md5c);
1537
1538 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1539 PKT_DATA, buffer, 16, PKT_END);
1540
1541 crWaitUntil(ispkt);
1542 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1543 if (flags & FLAG_VERBOSE)
1544 c_write("Failed to authenticate with our public key.\r\n",
1545 45);
7cca0d81 1546 continue; /* go and try password */
1547 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1548 bombout(("Bizarre response to RSA authentication response"));
1549 crReturn(0);
7cca0d81 1550 }
1551
1552 break; /* we're through! */
1553 } else {
1554 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1555 }
c5e9c988 1556 logevent("Sent password");
374330e2 1557 memset(password, 0, strlen(password));
fb09bf1c 1558 crWaitUntil(ispkt);
e5574168 1559 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1560 if (flags & FLAG_VERBOSE)
1561 c_write("Access denied\r\n", 15);
c5e9c988 1562 logevent("Authentication refused");
e5574168 1563 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1564 logevent("Received disconnect request");
85ee8208 1565 ssh_state = SSH_STATE_CLOSED;
1566 crReturn(1);
e5574168 1567 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1568 bombout(("Strange packet received, type %d", pktin.type));
1569 crReturn(0);
374330e2 1570 }
1571 }
1572
c5e9c988 1573 logevent("Authentication successful");
1574
fb09bf1c 1575 crFinish(1);
1576}
1577
e5574168 1578static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1579 crBegin;
1580
1581 random_init();
1582
e5574168 1583 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1584 crReturnV;
85ee8208 1585 }
1586 if (ssh_state == SSH_STATE_CLOSED)
1587 crReturnV;
fb09bf1c 1588
979310f1 1589 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1590 logevent("Requesting agent forwarding");
1591 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1592 do { crReturnV; } while (!ispkt);
1593 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1594 bombout(("Protocol confusion"));
1595 crReturnV;
dacbd0e8 1596 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1597 logevent("Agent forwarding refused");
1598 } else
1599 logevent("Agent forwarding enabled");
1600 }
1601
fef97f43 1602 if (!cfg.nopty) {
e5574168 1603 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1604 PKT_STR, cfg.termtype,
1605 PKT_INT, rows, PKT_INT, cols,
1606 PKT_INT, 0, PKT_INT, 0,
1607 PKT_CHAR, 0,
1608 PKT_END);
fef97f43 1609 ssh_state = SSH_STATE_INTERMED;
1610 do { crReturnV; } while (!ispkt);
e5574168 1611 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1612 bombout(("Protocol confusion"));
1613 crReturnV;
e5574168 1614 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1615 c_write("Server refused to allocate pty\r\n", 32);
1616 }
c5e9c988 1617 logevent("Allocated pty");
374330e2 1618 }
1619
6abbf9e3 1620 if (*cfg.remote_cmd)
1621 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1622 else
1623 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1624 logevent("Started session");
374330e2 1625
1626 ssh_state = SSH_STATE_SESSION;
1627 if (size_needed)
1628 ssh_size();
1629
8ccc75b0 1630 ssh_send_ok = 1;
dacbd0e8 1631 ssh_channels = newtree234(ssh_channelcmp);
6f34e365 1632 begin_session();
374330e2 1633 while (1) {
1634 crReturnV;
1635 if (ispkt) {
e5574168 1636 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1637 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1638 long len = GET_32BIT(pktin.body);
fe50e814 1639 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1640 pktin.body+4, len);
e5574168 1641 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1642 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1643 logevent("Received disconnect request");
dacbd0e8 1644 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1645 /* Remote side is trying to open a channel to talk to our
1646 * agent. Give them back a local channel number. */
d211621f 1647 unsigned i = 1;
dacbd0e8 1648 struct ssh_channel *c;
1649 enum234 e;
1650 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1651 if (c->localid > i)
1652 break; /* found a free number */
1653 i = c->localid + 1;
1654 }
1655 c = malloc(sizeof(struct ssh_channel));
1656 c->remoteid = GET_32BIT(pktin.body);
1657 c->localid = i;
b8bb811a 1658 c->closes = 0;
dacbd0e8 1659 c->type = SSH1_SMSG_AGENT_OPEN; /* identify channel type */
bb487ce2 1660 c->u.a.lensofar = 0;
dacbd0e8 1661 add234(ssh_channels, c);
1662 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1663 PKT_INT, c->remoteid, PKT_INT, c->localid,
1664 PKT_END);
1665 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1666 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1667 /* Remote side closes a channel. */
d211621f 1668 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1669 struct ssh_channel *c;
1670 c = find234(ssh_channels, &i, ssh_channelfind);
1671 if (c) {
1672 int closetype;
1673 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1674 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1675 c->closes |= closetype;
1676 if (c->closes == 3) {
1677 del234(ssh_channels, c);
1678 free(c);
1679 }
1680 }
1681 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1682 /* Data sent down one of our channels. */
1683 int i = GET_32BIT(pktin.body);
1684 int len = GET_32BIT(pktin.body+4);
1685 unsigned char *p = pktin.body+8;
1686 struct ssh_channel *c;
1687 c = find234(ssh_channels, &i, ssh_channelfind);
1688 if (c) {
1689 switch(c->type) {
1690 case SSH1_SMSG_AGENT_OPEN:
1691 /* Data for an agent message. Buffer it. */
1692 while (len > 0) {
1693 if (c->u.a.lensofar < 4) {
1694 int l = min(4 - c->u.a.lensofar, len);
1695 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
1696 p += l; len -= l; c->u.a.lensofar += l;
1697 }
1698 if (c->u.a.lensofar == 4) {
1699 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
1700 c->u.a.message = malloc(c->u.a.totallen);
1701 memcpy(c->u.a.message, c->u.a.msglen, 4);
1702 }
1703 if (c->u.a.lensofar >= 4 && len > 0) {
1704 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
1705 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
1706 p += l; len -= l; c->u.a.lensofar += l;
1707 }
1708 if (c->u.a.lensofar == c->u.a.totallen) {
1709 void *reply, *sentreply;
1710 int replylen;
1711 agent_query(c->u.a.message, c->u.a.totallen,
1712 &reply, &replylen);
1713 if (reply)
1714 sentreply = reply;
1715 else {
1716 /* Fake SSH_AGENT_FAILURE. */
1717 sentreply = "\0\0\0\1\5";
1718 replylen = 5;
1719 }
1720 send_packet(SSH1_MSG_CHANNEL_DATA,
1721 PKT_INT, c->remoteid,
1722 PKT_INT, replylen,
1723 PKT_DATA, sentreply, replylen,
1724 PKT_END);
1725 if (reply)
1726 free(reply);
1727 free(c->u.a.message);
1728 c->u.a.lensofar = 0;
1729 }
1730 }
1731 break;
1732 }
1733 }
e5574168 1734 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 1735 /* may be from EXEC_SHELL on some servers */
e5574168 1736 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 1737 /* may be from EXEC_SHELL on some servers
374330e2 1738 * if no pty is available or in other odd cases. Ignore */
e5574168 1739 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1740 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 1741 } else {
8d5de777 1742 bombout(("Strange packet received: type %d", pktin.type));
1743 crReturnV;
374330e2 1744 }
1745 } else {
8df7a775 1746 while (inlen > 0) {
1747 int len = min(inlen, 512);
1748 send_packet(SSH1_CMSG_STDIN_DATA,
1749 PKT_INT, len, PKT_DATA, in, len, PKT_END);
1750 in += len;
1751 inlen -= len;
1752 }
374330e2 1753 }
1754 }
1755
1756 crFinishV;
1757}
1758
1759/*
e5574168 1760 * Utility routine for decoding comma-separated strings in KEXINIT.
1761 */
75cab814 1762static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 1763 int needlen = strlen(needle);
1764 while (1) {
1765 /*
1766 * Is it at the start of the string?
1767 */
1768 if (haylen >= needlen && /* haystack is long enough */
1769 !memcmp(needle, haystack, needlen) && /* initial match */
1770 (haylen == needlen || haystack[needlen] == ',')
1771 /* either , or EOS follows */
1772 )
1773 return 1;
1774 /*
1775 * If not, search for the next comma and resume after that.
1776 * If no comma found, terminate.
1777 */
1778 while (haylen > 0 && *haystack != ',')
1779 haylen--, haystack++;
1780 if (haylen == 0)
1781 return 0;
1782 haylen--, haystack++; /* skip over comma itself */
1783 }
1784}
1785
1786/*
d39f364a 1787 * SSH2 key creation method.
1788 */
75cab814 1789static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
d39f364a 1790 SHA_State s;
1791 /* First 20 bytes. */
1792 SHA_Init(&s);
1793 sha_mpint(&s, K);
1794 SHA_Bytes(&s, H, 20);
1795 SHA_Bytes(&s, &chr, 1);
1796 SHA_Bytes(&s, H, 20);
1797 SHA_Final(&s, keyspace);
1798 /* Next 20 bytes. */
1799 SHA_Init(&s);
1800 sha_mpint(&s, K);
1801 SHA_Bytes(&s, H, 20);
1802 SHA_Bytes(&s, keyspace, 20);
1803 SHA_Final(&s, keyspace+20);
1804}
1805
1806/*
7cca0d81 1807 * Handle the SSH2 transport layer.
e5574168 1808 */
7cca0d81 1809static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 1810{
1811 static int i, len;
1812 static char *str;
1813 static Bignum e, f, K;
7591b9ff 1814 static const struct ssh_mac **maclist;
8b2715b2 1815 static int nmacs;
57476f6b 1816 static const struct ssh_cipher *cscipher_tobe = NULL;
1817 static const struct ssh_cipher *sccipher_tobe = NULL;
1818 static const struct ssh_mac *csmac_tobe = NULL;
1819 static const struct ssh_mac *scmac_tobe = NULL;
1820 static const struct ssh_compress *cscomp_tobe = NULL;
1821 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 1822 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 1823 static int hostkeylen, siglen;
1824 static unsigned char exchange_hash[20];
d39f364a 1825 static unsigned char keyspace[40];
57476f6b 1826 static const struct ssh_cipher *preferred_cipher;
e5574168 1827
1828 crBegin;
7cca0d81 1829 random_init();
e5574168 1830
5e8358ad 1831 /*
1832 * Set up the preferred cipher.
1833 */
1834 if (cfg.cipher == CIPHER_BLOWFISH) {
57476f6b 1835 preferred_cipher = &ssh_blowfish_ssh2;
5e8358ad 1836 } else if (cfg.cipher == CIPHER_DES) {
1837 logevent("Single DES not supported in SSH2; using 3DES");
57476f6b 1838 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1839 } else if (cfg.cipher == CIPHER_3DES) {
57476f6b 1840 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1841 } else {
1842 /* Shouldn't happen, but we do want to initialise to _something_. */
57476f6b 1843 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1844 }
1845
7591b9ff 1846 /*
1847 * Be prepared to work around the buggy MAC problem.
1848 */
1849 if (cfg.buggymac)
8b2715b2 1850 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 1851 else
8b2715b2 1852 maclist = macs, nmacs = lenof(macs);
7591b9ff 1853
7cca0d81 1854 begin_key_exchange:
e5574168 1855 /*
1856 * Construct and send our key exchange packet.
1857 */
1858 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1859 for (i = 0; i < 16; i++)
1860 ssh2_pkt_addbyte((unsigned char)random_byte());
1861 /* List key exchange algorithms. */
1862 ssh2_pkt_addstring_start();
1863 for (i = 0; i < lenof(kex_algs); i++) {
1864 ssh2_pkt_addstring_str(kex_algs[i]->name);
1865 if (i < lenof(kex_algs)-1)
1866 ssh2_pkt_addstring_str(",");
1867 }
1868 /* List server host key algorithms. */
1869 ssh2_pkt_addstring_start();
1870 for (i = 0; i < lenof(hostkey_algs); i++) {
1871 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1872 if (i < lenof(hostkey_algs)-1)
1873 ssh2_pkt_addstring_str(",");
1874 }
1875 /* List client->server encryption algorithms. */
1876 ssh2_pkt_addstring_start();
729e54b4 1877 for (i = 0; i < lenof(ciphers)+1; i++) {
1878 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1879 ssh2_pkt_addstring_str(c->name);
729e54b4 1880 if (i < lenof(ciphers))
e5574168 1881 ssh2_pkt_addstring_str(",");
1882 }
1883 /* List server->client encryption algorithms. */
1884 ssh2_pkt_addstring_start();
729e54b4 1885 for (i = 0; i < lenof(ciphers)+1; i++) {
1886 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1887 ssh2_pkt_addstring_str(c->name);
729e54b4 1888 if (i < lenof(ciphers))
e5574168 1889 ssh2_pkt_addstring_str(",");
1890 }
1891 /* List client->server MAC algorithms. */
1892 ssh2_pkt_addstring_start();
8b2715b2 1893 for (i = 0; i < nmacs; i++) {
7591b9ff 1894 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 1895 if (i < nmacs-1)
e5574168 1896 ssh2_pkt_addstring_str(",");
1897 }
1898 /* List server->client MAC algorithms. */
1899 ssh2_pkt_addstring_start();
8b2715b2 1900 for (i = 0; i < nmacs; i++) {
7591b9ff 1901 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 1902 if (i < nmacs-1)
e5574168 1903 ssh2_pkt_addstring_str(",");
1904 }
1905 /* List client->server compression algorithms. */
1906 ssh2_pkt_addstring_start();
1907 for (i = 0; i < lenof(compressions); i++) {
1908 ssh2_pkt_addstring_str(compressions[i]->name);
1909 if (i < lenof(compressions)-1)
1910 ssh2_pkt_addstring_str(",");
1911 }
1912 /* List server->client compression algorithms. */
1913 ssh2_pkt_addstring_start();
1914 for (i = 0; i < lenof(compressions); i++) {
1915 ssh2_pkt_addstring_str(compressions[i]->name);
1916 if (i < lenof(compressions)-1)
1917 ssh2_pkt_addstring_str(",");
1918 }
1919 /* List client->server languages. Empty list. */
1920 ssh2_pkt_addstring_start();
1921 /* List server->client languages. Empty list. */
1922 ssh2_pkt_addstring_start();
1923 /* First KEX packet does _not_ follow, because we're not that brave. */
1924 ssh2_pkt_addbool(FALSE);
1925 /* Reserved. */
1926 ssh2_pkt_adduint32(0);
1927 sha_string(&exhash, pktout.data+5, pktout.length-5);
1928 ssh2_pkt_send();
1929
1930 if (!ispkt) crWaitUntil(ispkt);
1931 sha_string(&exhash, pktin.data+5, pktin.length-5);
1932
1933 /*
1934 * Now examine the other side's KEXINIT to see what we're up
1935 * to.
1936 */
7cca0d81 1937 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 1938 bombout(("expected key exchange packet from server"));
1939 crReturn(0);
7cca0d81 1940 }
e5574168 1941 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1942 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1943 pktin.savedpos += 16; /* skip garbage cookie */
1944 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1945 for (i = 0; i < lenof(kex_algs); i++) {
1946 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1947 kex = kex_algs[i];
1948 break;
1949 }
1950 }
1951 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1952 for (i = 0; i < lenof(hostkey_algs); i++) {
1953 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1954 hostkey = hostkey_algs[i];
1955 break;
1956 }
1957 }
1958 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 1959 for (i = 0; i < lenof(ciphers)+1; i++) {
1960 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1961 if (in_commasep_string(c->name, str, len)) {
729e54b4 1962 cscipher_tobe = c;
e5574168 1963 break;
1964 }
1965 }
1966 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
729e54b4 1967 for (i = 0; i < lenof(ciphers)+1; i++) {
1968 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1969 if (in_commasep_string(c->name, str, len)) {
729e54b4 1970 sccipher_tobe = c;
e5574168 1971 break;
1972 }
1973 }
1974 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 1975 for (i = 0; i < nmacs; i++) {
7591b9ff 1976 if (in_commasep_string(maclist[i]->name, str, len)) {
1977 csmac_tobe = maclist[i];
e5574168 1978 break;
1979 }
1980 }
1981 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 1982 for (i = 0; i < nmacs; i++) {
7591b9ff 1983 if (in_commasep_string(maclist[i]->name, str, len)) {
1984 scmac_tobe = maclist[i];
e5574168 1985 break;
1986 }
1987 }
1988 ssh2_pkt_getstring(&str, &len); /* client->server compression */
1989 for (i = 0; i < lenof(compressions); i++) {
1990 if (in_commasep_string(compressions[i]->name, str, len)) {
1991 cscomp_tobe = compressions[i];
1992 break;
1993 }
1994 }
1995 ssh2_pkt_getstring(&str, &len); /* server->client compression */
1996 for (i = 0; i < lenof(compressions); i++) {
1997 if (in_commasep_string(compressions[i]->name, str, len)) {
1998 sccomp_tobe = compressions[i];
1999 break;
2000 }
2001 }
e5574168 2002
2003 /*
2004 * Currently we only support Diffie-Hellman and DSS, so let's
2005 * bomb out if those aren't selected.
2006 */
8d5de777 2007 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2008 bombout(("internal fault: chaos in SSH 2 transport layer"));
2009 crReturn(0);
2010 }
e5574168 2011
2012 /*
2013 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2014 */
2015 e = dh_create_e();
e5574168 2016 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2017 ssh2_pkt_addmp(e);
2018 ssh2_pkt_send();
2019
2020 crWaitUntil(ispkt);
7cca0d81 2021 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2022 bombout(("expected key exchange packet from server"));
2023 crReturn(0);
7cca0d81 2024 }
e5574168 2025 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2026 f = ssh2_pkt_getmp();
e5574168 2027 ssh2_pkt_getstring(&sigdata, &siglen);
2028
2029 K = dh_find_K(f);
e5574168 2030
2031 sha_string(&exhash, hostkeydata, hostkeylen);
2032 sha_mpint(&exhash, e);
2033 sha_mpint(&exhash, f);
2034 sha_mpint(&exhash, K);
2035 SHA_Final(&exhash, exchange_hash);
2036
7cca0d81 2037#if 0
e5574168 2038 debug(("Exchange hash is:\r\n"));
2039 for (i = 0; i < 20; i++)
2040 debug((" %02x", exchange_hash[i]));
2041 debug(("\r\n"));
7cca0d81 2042#endif
2043
2044 hostkey->setkey(hostkeydata, hostkeylen);
8d5de777 2045 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20)) {
2046 bombout(("Server failed host key check"));
2047 crReturn(0);
2048 }
e5574168 2049
2050 /*
7cca0d81 2051 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2052 */
7cca0d81 2053 crWaitUntil(ispkt);
8d5de777 2054 if (pktin.type != SSH2_MSG_NEWKEYS) {
2055 bombout(("expected new-keys packet from server"));
2056 crReturn(0);
2057 }
d39f364a 2058
2059 /*
7cca0d81 2060 * Authenticate remote host: verify host key. (We've already
2061 * checked the signature of the exchange hash.)
e5574168 2062 */
7cca0d81 2063 keystr = hostkey->fmtkey();
d5859615 2064 fingerprint = hostkey->fingerprint();
d4857987 2065 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2066 keystr, fingerprint);
d5859615 2067 logevent("Host key fingerprint is:");
2068 logevent(fingerprint);
2069 free(fingerprint);
7cca0d81 2070 free(keystr);
d39f364a 2071
2072 /*
7cca0d81 2073 * Send SSH2_MSG_NEWKEYS.
d39f364a 2074 */
2075 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2076 ssh2_pkt_send();
d39f364a 2077
2078 /*
2079 * Create and initialise session keys.
2080 */
2081 cscipher = cscipher_tobe;
2082 sccipher = sccipher_tobe;
2083 csmac = csmac_tobe;
2084 scmac = scmac_tobe;
2085 cscomp = cscomp_tobe;
2086 sccomp = sccomp_tobe;
2087 /*
2088 * Set IVs after keys.
2089 */
2090 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
2091 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
2092 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2093 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2094 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2095 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2096
033b4cef 2097 /*
7cca0d81 2098 * Now we're encrypting. Begin returning 1 to the protocol main
2099 * function so that other things can run on top of the
2100 * transport. If we ever see a KEXINIT, we must go back to the
2101 * start.
033b4cef 2102 */
7cca0d81 2103 do {
2104 crReturn(1);
2105 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2106 goto begin_key_exchange;
e5574168 2107
2108 crFinish(1);
2109}
2110
7cca0d81 2111/*
2112 * Handle the SSH2 userauth and connection layers.
2113 */
2114static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2115{
7cca0d81 2116 static unsigned long remote_winsize;
2117 static unsigned long remote_maxpkt;
2118
e5574168 2119 crBegin;
2120
7cca0d81 2121 /*
2122 * Request userauth protocol, and await a response to it.
2123 */
2124 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2125 ssh2_pkt_addstring("ssh-userauth");
2126 ssh2_pkt_send();
2127 crWaitUntilV(ispkt);
8d5de777 2128 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2129 bombout(("Server refused user authentication protocol"));
2130 crReturnV;
2131 }
7cca0d81 2132
2133 /*
2134 * FIXME: currently we support only password authentication.
2135 * (This places us technically in violation of the SSH2 spec.
2136 * We must fix this.)
2137 */
2138 while (1) {
2139 /*
2140 * Get a username and a password.
2141 */
2142 static char username[100];
2143 static char password[100];
2144 static int pos = 0;
2145 static char c;
e5574168 2146
67779be7 2147 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2148 c_write("login as: ", 10);
67779be7 2149 ssh_send_ok = 1;
7cca0d81 2150 while (pos >= 0) {
2151 crWaitUntilV(!ispkt);
2152 while (inlen--) switch (c = *in++) {
2153 case 10: case 13:
2154 username[pos] = 0;
2155 pos = -1;
2156 break;
2157 case 8: case 127:
2158 if (pos > 0) {
2159 c_write("\b \b", 3);
2160 pos--;
2161 }
2162 break;
2163 case 21: case 27:
2164 while (pos > 0) {
2165 c_write("\b \b", 3);
2166 pos--;
2167 }
2168 break;
2169 case 3: case 4:
2170 random_save_seed();
2171 exit(0);
2172 break;
2173 default:
2174 if (((c >= ' ' && c <= '~') ||
2175 ((unsigned char)c >= 160)) && pos < 40) {
2176 username[pos++] = c;
2177 c_write(&c, 1);
2178 }
2179 break;
2180 }
2181 }
2182 c_write("\r\n", 2);
2183 username[strcspn(username, "\n\r")] = '\0';
2184 } else {
2185 char stuff[200];
2186 strncpy(username, cfg.username, 99);
2187 username[99] = '\0';
67779be7 2188 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2189 sprintf(stuff, "Using username \"%s\".\r\n", username);
2190 c_write(stuff, strlen(stuff));
2191 }
2192 }
2193
d8426c54 2194 if (ssh_get_password) {
7cca0d81 2195 char prompt[200];
b585ec46 2196 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
7cca0d81 2197 if (!ssh_get_password(prompt, password, sizeof(password))) {
2198 /*
2199 * get_password failed to get a password (for
2200 * example because one was supplied on the command
2201 * line which has already failed to work).
2202 * Terminate.
2203 */
2204 logevent("No more passwords to try");
2205 ssh_state = SSH_STATE_CLOSED;
2206 crReturnV;
2207 }
2208 } else {
2209 c_write("password: ", 10);
67779be7 2210 ssh_send_ok = 1;
7cca0d81 2211
2212 pos = 0;
2213 while (pos >= 0) {
2214 crWaitUntilV(!ispkt);
2215 while (inlen--) switch (c = *in++) {
2216 case 10: case 13:
2217 password[pos] = 0;
2218 pos = -1;
2219 break;
2220 case 8: case 127:
2221 if (pos > 0)
2222 pos--;
2223 break;
2224 case 21: case 27:
2225 pos = 0;
2226 break;
2227 case 3: case 4:
2228 random_save_seed();
2229 exit(0);
2230 break;
2231 default:
2232 if (((c >= ' ' && c <= '~') ||
2233 ((unsigned char)c >= 160)) && pos < 40)
2234 password[pos++] = c;
2235 break;
2236 }
2237 }
2238 c_write("\r\n", 2);
2239 }
2240
2241 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2242 ssh2_pkt_addstring(username);
2243 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2244 ssh2_pkt_addstring("password");
2245 ssh2_pkt_addbool(FALSE);
2246 ssh2_pkt_addstring(password);
2247 ssh2_pkt_send();
2248
2249 crWaitUntilV(ispkt);
2250 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2251 c_write("Access denied\r\n", 15);
2252 logevent("Authentication refused");
2253 } else
2254 break;
2255 }
2256
2257 /*
2258 * Now we're authenticated for the connection protocol. The
2259 * connection protocol will automatically have started at this
2260 * point; there's no need to send SERVICE_REQUEST.
2261 */
2262
2263 /*
2264 * So now create a channel with a session in it.
2265 */
d211621f 2266 mainchan = malloc(sizeof(struct ssh_channel));
2267 mainchan->localid = 100; /* as good as any */
7cca0d81 2268 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2269 ssh2_pkt_addstring("session");
d211621f 2270 ssh2_pkt_adduint32(mainchan->localid);
cf6e59d6 2271 ssh2_pkt_adduint32(0x8000UL); /* our window size */
d211621f 2272 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2273 ssh2_pkt_send();
2274 crWaitUntilV(ispkt);
2275 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2276 bombout(("Server refused to open a session"));
2277 crReturnV;
7cca0d81 2278 /* FIXME: error data comes back in FAILURE packet */
2279 }
d211621f 2280 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2281 bombout(("Server's channel confirmation cited wrong channel"));
2282 crReturnV;
7cca0d81 2283 }
d211621f 2284 mainchan->remoteid = ssh2_pkt_getuint32();
2285 mainchan->u.v2.remwindow = ssh2_pkt_getuint32();
2286 mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32();
2287 mainchan->u.v2.outbuffer = NULL;
2288 mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0;
7cca0d81 2289 logevent("Opened channel for session");
2290
2291 /*
2292 * Now allocate a pty for the session.
2293 */
67779be7 2294 if (!cfg.nopty) {
2295 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2296 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2297 ssh2_pkt_addstring("pty-req");
2298 ssh2_pkt_addbool(1); /* want reply */
2299 ssh2_pkt_addstring(cfg.termtype);
2300 ssh2_pkt_adduint32(cols);
2301 ssh2_pkt_adduint32(rows);
2302 ssh2_pkt_adduint32(0); /* pixel width */
2303 ssh2_pkt_adduint32(0); /* pixel height */
2304 ssh2_pkt_addstring_start();
2305 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2306 ssh2_pkt_send();
7cca0d81 2307
67779be7 2308 do {
2309 crWaitUntilV(ispkt);
2310 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2311 /* FIXME: be able to handle other channels here */
2312 if (ssh2_pkt_getuint32() != mainchan->localid)
2313 continue; /* wrong channel */
2314 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2315 }
2316 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2317
67779be7 2318 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2319 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2320 bombout(("Server got confused by pty request"));
2321 crReturnV;
67779be7 2322 }
2323 c_write("Server refused to allocate pty\r\n", 32);
2324 } else {
2325 logevent("Allocated pty");
7cca0d81 2326 }
7cca0d81 2327 }
2328
2329 /*
67779be7 2330 * Start a shell or a remote command.
7cca0d81 2331 */
2332 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2333 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2334 if (*cfg.remote_cmd) {
2335 ssh2_pkt_addstring("exec");
2336 ssh2_pkt_addbool(1); /* want reply */
2337 ssh2_pkt_addstring(cfg.remote_cmd);
2338 } else {
2339 ssh2_pkt_addstring("shell");
2340 ssh2_pkt_addbool(1); /* want reply */
2341 }
7cca0d81 2342 ssh2_pkt_send();
d211621f 2343 do {
7cca0d81 2344 crWaitUntilV(ispkt);
d211621f 2345 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2346 /* FIXME: be able to handle other channels here */
2347 if (ssh2_pkt_getuint32() != mainchan->localid)
2348 continue; /* wrong channel */
2349 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2350 }
7cca0d81 2351 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2352 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2353 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2354 bombout(("Server got confused by shell/command request"));
2355 crReturnV;
7cca0d81 2356 }
8d5de777 2357 bombout(("Server refused to start a shell/command"));
2358 crReturnV;
7cca0d81 2359 } else {
8d5de777 2360 logevent("Started a shell/command");
7cca0d81 2361 }
2362
2363 /*
2364 * Transfer data!
2365 */
8ccc75b0 2366 ssh_send_ok = 1;
6f34e365 2367 begin_session();
7cca0d81 2368 while (1) {
d211621f 2369 static int try_send;
e5574168 2370 crReturnV;
d211621f 2371 try_send = FALSE;
7cca0d81 2372 if (ispkt) {
2373 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2374 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2375 char *data;
2376 int length;
d211621f 2377 /* FIXME: be able to handle other channels here */
2378 if (ssh2_pkt_getuint32() != mainchan->localid)
7cca0d81 2379 continue; /* wrong channel */
2380 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2381 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2382 continue; /* extended but not stderr */
2383 ssh2_pkt_getstring(&data, &length);
d211621f 2384 if (data) {
fe50e814 2385 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
2386 data, length);
d211621f 2387 /*
2388 * Enlarge the window again at the remote side,
2389 * just in case it ever runs down and they fail
2390 * to send us any more data.
2391 */
2392 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2393 ssh2_pkt_adduint32(mainchan->remoteid);
2394 ssh2_pkt_adduint32(length);
2395 ssh2_pkt_send();
2396 }
7cca0d81 2397 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2398 ssh_state = SSH_STATE_CLOSED;
d211621f 2399 logevent("Received disconnect message");
7cca0d81 2400 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2401 continue; /* exit status et al; ignore (FIXME?) */
d211621f 2402 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2403 continue; /* remote sends EOF; ignore */
2404 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
2405 /* FIXME: be able to handle other channels here */
2406 if (ssh2_pkt_getuint32() != mainchan->localid)
2407 continue; /* wrong channel */
2408 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2409 ssh2_pkt_adduint32(mainchan->remoteid);
2410 ssh2_pkt_send();
2411 /* FIXME: mark the channel as closed */
2412 if (1 /* FIXME: "all channels are closed" */) {
2413 logevent("All channels closed. Disconnecting");
2414 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2415 ssh2_pkt_send();
cf6e59d6 2416 ssh_state = SSH_STATE_CLOSED;
8df7a775 2417 sk_close(s);
2418 s = NULL;
d211621f 2419 }
2420 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2421 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
d211621f 2422 /* FIXME: be able to handle other channels here */
2423 if (ssh2_pkt_getuint32() != mainchan->localid)
2424 continue; /* wrong channel */
2425 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2426 try_send = TRUE;
7cca0d81 2427 } else {
8d5de777 2428 bombout(("Strange packet received: type %d", pktin.type));
2429 crReturnV;
7cca0d81 2430 }
2431 } else {
d211621f 2432 /*
2433 * We have spare data. Add it to the channel buffer.
2434 */
2435 if (mainchan->u.v2.outbufsize <
2436 mainchan->u.v2.outbuflen + inlen) {
2437 mainchan->u.v2.outbufsize =
2438 mainchan->u.v2.outbuflen + inlen + 1024;
2439 mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer,
2440 mainchan->u.v2.outbufsize);
2441 }
2442 memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen,
2443 in, inlen);
2444 mainchan->u.v2.outbuflen += inlen;
2445 try_send = TRUE;
7cca0d81 2446 }
d211621f 2447 if (try_send) {
2448 /*
2449 * Try to send data on the channel if we can. (FIXME:
2450 * on _all_ channels.)
2451 */
2452 while (mainchan->u.v2.remwindow > 0 &&
2453 mainchan->u.v2.outbuflen > 0) {
2454 unsigned len = mainchan->u.v2.remwindow;
2455 if (len > mainchan->u.v2.outbuflen)
2456 len = mainchan->u.v2.outbuflen;
2457 if (len > mainchan->u.v2.remmaxpkt)
2458 len = mainchan->u.v2.remmaxpkt;
2459 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2460 ssh2_pkt_adduint32(mainchan->remoteid);
2461 ssh2_pkt_addstring_start();
2462 ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len);
2463 ssh2_pkt_send();
2464 mainchan->u.v2.outbuflen -= len;
2465 memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len,
2466 mainchan->u.v2.outbuflen);
2467 mainchan->u.v2.remwindow -= len;
2468 }
2469 }
e5574168 2470 }
2471
2472 crFinishV;
2473}
2474
2475/*
7cca0d81 2476 * Handle the top-level SSH2 protocol.
2477 */
2478static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2479{
2480 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2481 return;
2482 do_ssh2_authconn(in, inlen, ispkt);
2483}
2484
2485/*
8df7a775 2486 * Called to set up the connection.
374330e2 2487 *
2488 * Returns an error message, or NULL on success.
374330e2 2489 */
8df7a775 2490static char *ssh_init (char *host, int port, char **realhost) {
fb09bf1c 2491 char *p;
8f203108 2492
2493#ifdef MSCRYPTOAPI
2494 if(crypto_startup() == 0)
2495 return "Microsoft high encryption pack not installed!";
2496#endif
374330e2 2497
8df7a775 2498 ssh_send_ok = 0;
2499
fb09bf1c 2500 p = connect_to_host(host, port, realhost);
2501 if (p != NULL)
2502 return p;
374330e2 2503
374330e2 2504 return NULL;
2505}
2506
2507/*
374330e2 2508 * Called to send data down the Telnet connection.
2509 */
2510static void ssh_send (char *buf, int len) {
8df7a775 2511 if (s == NULL)
374330e2 2512 return;
2513
2514 ssh_protocol(buf, len, 0);
2515}
2516
2517/*
2518 * Called to set the size of the window from Telnet's POV.
2519 */
2520static void ssh_size(void) {
2521 switch (ssh_state) {
2522 case SSH_STATE_BEFORE_SIZE:
21248260 2523 case SSH_STATE_CLOSED:
374330e2 2524 break; /* do nothing */
2525 case SSH_STATE_INTERMED:
2526 size_needed = TRUE; /* buffer for later */
2527 break;
2528 case SSH_STATE_SESSION:
fef97f43 2529 if (!cfg.nopty) {
e5574168 2530 send_packet(SSH1_CMSG_WINDOW_SIZE,
fb09bf1c 2531 PKT_INT, rows, PKT_INT, cols,
2532 PKT_INT, 0, PKT_INT, 0, PKT_END);
fef97f43 2533 }
374330e2 2534 }
2535}
2536
2537/*
6abbf9e3 2538 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2539 * can send an EOF and collect resulting output (e.g. `plink
2540 * hostname sort').
374330e2 2541 */
2542static void ssh_special (Telnet_Special code) {
6abbf9e3 2543 if (code == TS_EOF) {
67779be7 2544 if (ssh_version == 1) {
6abbf9e3 2545 send_packet(SSH1_CMSG_EOF, PKT_END);
2546 } else {
2547 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 2548 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 2549 ssh2_pkt_send();
2550 }
67779be7 2551 logevent("Sent EOF message");
ec55b220 2552 } else if (code == TS_PING) {
2553 if (ssh_version == 1) {
2554 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
2555 } else {
2556 ssh2_pkt_init(SSH2_MSG_IGNORE);
2557 ssh2_pkt_addstring_start();
2558 ssh2_pkt_send();
2559 }
6abbf9e3 2560 } else {
2561 /* do nothing */
2562 }
374330e2 2563}
2564
8df7a775 2565static Socket ssh_socket(void) { return s; }
8ccc75b0 2566
2567static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 2568
374330e2 2569Backend ssh_backend = {
2570 ssh_init,
374330e2 2571 ssh_send,
2572 ssh_size,
4017be6d 2573 ssh_special,
8ccc75b0 2574 ssh_socket,
97db3be4 2575 ssh_sendok,
2576 22
374330e2 2577};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator