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[u/mdw/putty] / ssh.c
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8df7a775 1#include <windows.h>
374330e2 2#include <stdio.h>
3#include <stdlib.h>
fb09bf1c 4#include <stdarg.h>
5#include <assert.h>
374330e2 6
7#include "putty.h"
dacbd0e8 8#include "tree234.h"
fb09bf1c 9#include "ssh.h"
374330e2 10
11#ifndef FALSE
12#define FALSE 0
13#endif
14#ifndef TRUE
15#define TRUE 1
16#endif
17
fb09bf1c 18#define logevent(s) { logevent(s); \
67779be7 19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
fb09bf1c 20 fprintf(stderr, "%s\n", s); }
21
3cd52910 22#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
23 (s ? sk_close(s), s = NULL : (void)0), \
24 connection_fatal msg )
8d5de777 25
d211621f 26#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
27#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
28#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
29#define SSH1_CMSG_USER 4 /* 0x4 */
30#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
31#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
32#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
33#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
34#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
35#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
36#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
37#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
38#define SSH1_SMSG_SUCCESS 14 /* 0xe */
39#define SSH1_SMSG_FAILURE 15 /* 0xf */
40#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
41#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
42#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
43#define SSH1_CMSG_EOF 19 /* 0x13 */
44#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
45#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
46#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
47#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
48#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
49#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
9c964e85 50#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
51#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
52#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
d211621f 53#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
54#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
d211621f 55#define SSH1_MSG_IGNORE 32 /* 0x20 */
9c964e85 56#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
57#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
58#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
d211621f 59#define SSH1_MSG_DEBUG 36 /* 0x24 */
4ba9b64b 60#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
d211621f 61#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
62#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
63#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
64#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
65#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
66#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
67
68#define SSH1_AUTH_TIS 5 /* 0x5 */
69#define SSH1_AUTH_CCARD 16 /* 0x10 */
70
71#define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
72#define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
73#define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
74#define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
75#define SSH_AGENT_FAILURE 5 /* 0x5 */
76#define SSH_AGENT_SUCCESS 6 /* 0x6 */
77#define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
78#define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
79
80#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
81#define SSH2_MSG_IGNORE 2 /* 0x2 */
82#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
83#define SSH2_MSG_DEBUG 4 /* 0x4 */
84#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
85#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
86#define SSH2_MSG_KEXINIT 20 /* 0x14 */
87#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
88#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
89#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
90#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
91#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
92#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
93#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
94#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
95#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
96#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
97#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
98#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
99#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
100#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
101#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
102#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
103#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
104#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
105#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
106#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
107#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
108#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
109#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
110
9005f3ba 111#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
112#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
113#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
114#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
115#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
116#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
117#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
118#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
119#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
120#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
121#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
122
d211621f 123#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
124#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
125#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
126#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
127
128#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 129
130#define GET_32BIT(cp) \
131 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
132 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
133 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
134 ((unsigned long)(unsigned char)(cp)[3]))
135
136#define PUT_32BIT(cp, value) { \
137 (cp)[0] = (unsigned char)((value) >> 24); \
138 (cp)[1] = (unsigned char)((value) >> 16); \
139 (cp)[2] = (unsigned char)((value) >> 8); \
140 (cp)[3] = (unsigned char)(value); }
141
7cca0d81 142enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 143
374330e2 144/* Coroutine mechanics for the sillier bits of the code */
145#define crBegin1 static int crLine = 0;
146#define crBegin2 switch(crLine) { case 0:;
147#define crBegin crBegin1; crBegin2;
148#define crFinish(z) } crLine = 0; return (z)
149#define crFinishV } crLine = 0; return
150#define crReturn(z) \
151 do {\
152 crLine=__LINE__; return (z); case __LINE__:;\
153 } while (0)
154#define crReturnV \
155 do {\
156 crLine=__LINE__; return; case __LINE__:;\
157 } while (0)
158#define crStop(z) do{ crLine = 0; return (z); }while(0)
159#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 160#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 161#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 162
57476f6b 163extern const struct ssh_cipher ssh_3des;
164extern const struct ssh_cipher ssh_3des_ssh2;
165extern const struct ssh_cipher ssh_des;
166extern const struct ssh_cipher ssh_blowfish_ssh1;
167extern const struct ssh_cipher ssh_blowfish_ssh2;
e5574168 168
0c6c9a70 169extern char *x11_init (Socket *, char *, void *);
9c964e85 170extern void x11_close (Socket);
171extern void x11_send (Socket , char *, int);
172extern void x11_invent_auth(char *, int, char *, int);
173
5e8358ad 174/*
175 * Ciphers for SSH2. We miss out single-DES because it isn't
176 * supported; also 3DES and Blowfish are both done differently from
177 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
178 * endianness and different-sized keys.)
5e8358ad 179 */
57476f6b 180const static struct ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 };
e5574168 181
57476f6b 182extern const struct ssh_kex ssh_diffiehellman;
183const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
e5574168 184
e055a386 185extern const struct ssh_signkey ssh_dss;
186const static struct ssh_signkey *hostkey_algs[] = { &ssh_dss };
e5574168 187
8b2715b2 188extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy;
e5574168 189
d39f364a 190static void nullmac_key(unsigned char *key) { }
e5574168 191static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
192static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
57476f6b 193const static struct ssh_mac ssh_mac_none = {
d39f364a 194 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 195};
8b2715b2 196const static struct ssh_mac *macs[] = {
197 &ssh_sha1, &ssh_md5, &ssh_mac_none };
198const static struct ssh_mac *buggymacs[] = {
199 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
e5574168 200
4ba9b64b 201static void ssh_comp_none_init(void) { }
202static int ssh_comp_none_block(unsigned char *block, int len,
203 unsigned char **outblock, int *outlen) {
204 return 0;
205}
57476f6b 206const static struct ssh_compress ssh_comp_none = {
4ba9b64b 207 "none",
208 ssh_comp_none_init, ssh_comp_none_block,
209 ssh_comp_none_init, ssh_comp_none_block
e5574168 210};
4ba9b64b 211extern const struct ssh_compress ssh_zlib;
212const static struct ssh_compress *compressions[] = {
213 &ssh_zlib, &ssh_comp_none };
374330e2 214
783415f8 215enum { /* channel types */
216 CHAN_MAINSESSION,
217 CHAN_X11,
218 CHAN_AGENT,
219};
220
dacbd0e8 221/*
222 * 2-3-4 tree storing channels.
223 */
224struct ssh_channel {
d211621f 225 unsigned remoteid, localid;
dacbd0e8 226 int type;
227 int closes;
783415f8 228 struct ssh2_data_channel {
229 unsigned char *outbuffer;
230 unsigned outbuflen, outbufsize;
231 unsigned remwindow, remmaxpkt;
232 } v2;
dacbd0e8 233 union {
234 struct ssh_agent_channel {
235 unsigned char *message;
236 unsigned char msglen[4];
237 int lensofar, totallen;
238 } a;
9c964e85 239 struct ssh_x11_channel {
240 Socket s;
783415f8 241 } x11;
dacbd0e8 242 } u;
243};
57476f6b 244
245struct Packet {
246 long length;
247 int type;
248 unsigned char *data;
249 unsigned char *body;
250 long savedpos;
251 long maxlen;
252};
253
0db56f73 254static SHA_State exhash, exhashbase;
57476f6b 255
8df7a775 256static Socket s = NULL;
57476f6b 257
258static unsigned char session_key[32];
4ba9b64b 259static int ssh1_compressing;
db7d555c 260static int ssh_agentfwd_enabled;
9c964e85 261static int ssh_X11_fwd_enabled;
57476f6b 262static const struct ssh_cipher *cipher = NULL;
263static const struct ssh_cipher *cscipher = NULL;
264static const struct ssh_cipher *sccipher = NULL;
265static const struct ssh_mac *csmac = NULL;
266static const struct ssh_mac *scmac = NULL;
267static const struct ssh_compress *cscomp = NULL;
268static const struct ssh_compress *sccomp = NULL;
269static const struct ssh_kex *kex = NULL;
e055a386 270static const struct ssh_signkey *hostkey = NULL;
57476f6b 271int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
272
273static char *savedhost;
274static int savedport;
275static int ssh_send_ok;
0965bee0 276static int ssh_echoing, ssh_editing;
57476f6b 277
dacbd0e8 278static tree234 *ssh_channels; /* indexed by local id */
57476f6b 279static struct ssh_channel *mainchan; /* primary session channel */
280
281static enum {
3687d221 282 SSH_STATE_PREPACKET,
57476f6b 283 SSH_STATE_BEFORE_SIZE,
284 SSH_STATE_INTERMED,
285 SSH_STATE_SESSION,
286 SSH_STATE_CLOSED
3687d221 287} ssh_state = SSH_STATE_PREPACKET;
57476f6b 288
3687d221 289static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 290
291static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
292static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
293
294static int ssh_version;
295static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
296static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
297static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
298static void ssh_size(void);
3687d221 299static void ssh_special (Telnet_Special);
783415f8 300static void ssh2_try_send(struct ssh_channel *c);
301static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
57476f6b 302
303static int (*s_rdpkt)(unsigned char **data, int *datalen);
304
305static struct rdpkt1_state_tag {
306 long len, pad, biglen, to_read;
307 unsigned long realcrc, gotcrc;
308 unsigned char *p;
309 int i;
310 int chunk;
311} rdpkt1_state;
312
960e736a 313static struct rdpkt2_state_tag {
314 long len, pad, payload, packetlen, maclen;
315 int i;
316 int cipherblk;
317 unsigned long incoming_sequence;
318} rdpkt2_state;
319
dacbd0e8 320static int ssh_channelcmp(void *av, void *bv) {
321 struct ssh_channel *a = (struct ssh_channel *)av;
322 struct ssh_channel *b = (struct ssh_channel *)bv;
323 if (a->localid < b->localid) return -1;
324 if (a->localid > b->localid) return +1;
325 return 0;
326}
327static int ssh_channelfind(void *av, void *bv) {
d211621f 328 unsigned *a = (unsigned *)av;
dacbd0e8 329 struct ssh_channel *b = (struct ssh_channel *)bv;
330 if (*a < b->localid) return -1;
331 if (*a > b->localid) return +1;
332 return 0;
333}
334
374330e2 335static void c_write (char *buf, int len) {
67779be7 336 if ((flags & FLAG_STDERR)) {
4017be6d 337 int i;
338 for (i = 0; i < len; i++)
339 if (buf[i] != '\r')
340 fputc(buf[i], stderr);
fb09bf1c 341 return;
342 }
fe50e814 343 from_backend(1, buf, len);
3bdaf79d 344}
345
fb09bf1c 346/*
347 * Collect incoming data in the incoming packet buffer.
e5574168 348 * Decipher and verify the packet when it is completely read.
349 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 350 * Update the *data and *datalen variables.
351 * Return the additional nr of bytes needed, or 0 when
352 * a complete packet is available.
353 */
e5574168 354static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 355{
57476f6b 356 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 357
358 crBegin;
374330e2 359
fb09bf1c 360next_packet:
37508af4 361
fb09bf1c 362 pktin.type = 0;
363 pktin.length = 0;
374330e2 364
57476f6b 365 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 366 while ((*datalen) == 0)
57476f6b 367 crReturn(4-st->i);
368 st->len = (st->len << 8) + **data;
fb09bf1c 369 (*data)++, (*datalen)--;
370 }
374330e2 371
fb09bf1c 372#ifdef FWHACK
57476f6b 373 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
374 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 375 }
376#endif
374330e2 377
57476f6b 378 st->pad = 8 - (st->len % 8);
379 st->biglen = st->len + st->pad;
380 pktin.length = st->len - 5;
fb09bf1c 381
57476f6b 382 if (pktin.maxlen < st->biglen) {
383 pktin.maxlen = st->biglen;
dcbde236 384 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
385 srealloc(pktin.data, st->biglen+APIEXTRA));
fb09bf1c 386 if (!pktin.data)
387 fatalbox("Out of memory");
388 }
374330e2 389
57476f6b 390 st->to_read = st->biglen;
391 st->p = pktin.data;
392 while (st->to_read > 0) {
393 st->chunk = st->to_read;
fb09bf1c 394 while ((*datalen) == 0)
57476f6b 395 crReturn(st->to_read);
396 if (st->chunk > (*datalen))
397 st->chunk = (*datalen);
398 memcpy(st->p, *data, st->chunk);
399 *data += st->chunk;
400 *datalen -= st->chunk;
401 st->p += st->chunk;
402 st->to_read -= st->chunk;
fb09bf1c 403 }
374330e2 404
fb09bf1c 405 if (cipher)
57476f6b 406 cipher->decrypt(pktin.data, st->biglen);
698a5108 407#if 0
408 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
409 for (st->i = 0; st->i < st->biglen; st->i++)
410 debug((" %02x", (unsigned char)pktin.data[st->i]));
411 debug(("\r\n"));
412#endif
374330e2 413
57476f6b 414 st->realcrc = crc32(pktin.data, st->biglen-4);
415 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
416 if (st->gotcrc != st->realcrc) {
8d5de777 417 bombout(("Incorrect CRC received on packet"));
418 crReturn(0);
fb09bf1c 419 }
572f871e 420
4ba9b64b 421 pktin.body = pktin.data + st->pad + 1;
422
423 if (ssh1_compressing) {
424 unsigned char *decompblk;
425 int decomplen;
426#if 0
427 int i;
428 debug(("Packet payload pre-decompression:\n"));
429 for (i = -1; i < pktin.length; i++)
430 debug((" %02x", (unsigned char)pktin.body[i]));
431 debug(("\r\n"));
432#endif
433 zlib_decompress_block(pktin.body-1, pktin.length+1,
434 &decompblk, &decomplen);
435
436 if (pktin.maxlen < st->pad + decomplen) {
437 pktin.maxlen = st->pad + decomplen;
dcbde236 438 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
58298665 439 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 440 if (!pktin.data)
441 fatalbox("Out of memory");
442 }
443
444 memcpy(pktin.body-1, decompblk, decomplen);
dcbde236 445 sfree(decompblk);
4ba9b64b 446 pktin.length = decomplen-1;
447#if 0
448 debug(("Packet payload post-decompression:\n"));
449 for (i = -1; i < pktin.length; i++)
450 debug((" %02x", (unsigned char)pktin.body[i]));
451 debug(("\r\n"));
452#endif
453 }
454
e5574168 455 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
456 pktin.type == SSH1_SMSG_STDERR_DATA ||
457 pktin.type == SSH1_MSG_DEBUG ||
18515c51 458 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
459 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 460 long strlen = GET_32BIT(pktin.body);
8d5de777 461 if (strlen + 4 != pktin.length) {
462 bombout(("Received data packet with bogus string length"));
463 crReturn(0);
464 }
fb09bf1c 465 }
466
4ba9b64b 467 pktin.type = pktin.body[-1];
468
e5574168 469 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 470 /* log debug message */
471 char buf[80];
472 int strlen = GET_32BIT(pktin.body);
473 strcpy(buf, "Remote: ");
474 if (strlen > 70) strlen = 70;
475 memcpy(buf+8, pktin.body+4, strlen);
476 buf[8+strlen] = '\0';
477 logevent(buf);
478 goto next_packet;
e5574168 479 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 480 /* do nothing */
481 goto next_packet;
482 }
483
484 crFinish(0);
485}
486
e5574168 487static int ssh2_rdpkt(unsigned char **data, int *datalen)
488{
960e736a 489 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 490
491 crBegin;
492
493next_packet:
e5574168 494 pktin.type = 0;
495 pktin.length = 0;
960e736a 496 if (sccipher)
497 st->cipherblk = sccipher->blksize;
e5574168 498 else
960e736a 499 st->cipherblk = 8;
500 if (st->cipherblk < 8)
501 st->cipherblk = 8;
502
503 if (pktin.maxlen < st->cipherblk) {
504 pktin.maxlen = st->cipherblk;
dcbde236 505 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
506 srealloc(pktin.data, st->cipherblk+APIEXTRA));
e5574168 507 if (!pktin.data)
508 fatalbox("Out of memory");
509 }
510
511 /*
512 * Acquire and decrypt the first block of the packet. This will
513 * contain the length and padding details.
514 */
960e736a 515 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 516 while ((*datalen) == 0)
960e736a 517 crReturn(st->cipherblk-st->i);
518 pktin.data[st->i] = *(*data)++;
e5574168 519 (*datalen)--;
520 }
521#ifdef FWHACK
522 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
523 /* FIXME */
524 }
525#endif
526 if (sccipher)
960e736a 527 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 528
529 /*
530 * Now get the length and padding figures.
531 */
960e736a 532 st->len = GET_32BIT(pktin.data);
533 st->pad = pktin.data[4];
e5574168 534
535 /*
536 * This enables us to deduce the payload length.
537 */
960e736a 538 st->payload = st->len - st->pad - 1;
e5574168 539
960e736a 540 pktin.length = st->payload + 5;
e5574168 541
542 /*
543 * So now we can work out the total packet length.
544 */
960e736a 545 st->packetlen = st->len + 4;
546 st->maclen = scmac ? scmac->len : 0;
e5574168 547
548 /*
549 * Adjust memory allocation if packet is too big.
550 */
960e736a 551 if (pktin.maxlen < st->packetlen+st->maclen) {
552 pktin.maxlen = st->packetlen+st->maclen;
dcbde236 553 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
554 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
e5574168 555 if (!pktin.data)
556 fatalbox("Out of memory");
557 }
558
559 /*
560 * Read and decrypt the remainder of the packet.
561 */
960e736a 562 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
e5574168 563 while ((*datalen) == 0)
960e736a 564 crReturn(st->packetlen + st->maclen - st->i);
565 pktin.data[st->i] = *(*data)++;
e5574168 566 (*datalen)--;
567 }
568 /* Decrypt everything _except_ the MAC. */
569 if (sccipher)
960e736a 570 sccipher->decrypt(pktin.data + st->cipherblk,
571 st->packetlen - st->cipherblk);
e5574168 572
7cca0d81 573#if 0
960e736a 574 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
575 for (st->i = 0; st->i < st->packetlen; st->i++)
576 debug((" %02x", (unsigned char)pktin.data[st->i]));
d39f364a 577 debug(("\r\n"));
7cca0d81 578#endif
d39f364a 579
e5574168 580 /*
581 * Check the MAC.
582 */
960e736a 583 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
8d5de777 584 bombout(("Incorrect MAC received on packet"));
585 crReturn(0);
586 }
960e736a 587 st->incoming_sequence++; /* whether or not we MACed */
e5574168 588
4ba9b64b 589 /*
590 * Decompress packet payload.
591 */
592 {
593 unsigned char *newpayload;
594 int newlen;
595 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
596 &newpayload, &newlen)) {
597 if (pktin.maxlen < newlen+5) {
598 pktin.maxlen = newlen+5;
dcbde236 599 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
600 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
4ba9b64b 601 if (!pktin.data)
602 fatalbox("Out of memory");
603 }
604 pktin.length = 5 + newlen;
605 memcpy(pktin.data+5, newpayload, newlen);
606#if 0
607 debug(("Post-decompression payload:\r\n"));
608 for (st->i = 0; st->i < newlen; st->i++)
609 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
610 debug(("\r\n"));
611#endif
612
dcbde236 613 sfree(newpayload);
4ba9b64b 614 }
615 }
616
e5574168 617 pktin.savedpos = 6;
618 pktin.type = pktin.data[5];
e5574168 619
7cca0d81 620 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
621 goto next_packet; /* FIXME: print DEBUG message */
e5574168 622
623 crFinish(0);
624}
625
4ba9b64b 626static void ssh1_pktout_size(int len) {
374330e2 627 int pad, biglen;
628
629 len += 5; /* type and CRC */
630 pad = 8 - (len%8);
631 biglen = len + pad;
632
633 pktout.length = len-5;
634 if (pktout.maxlen < biglen) {
635 pktout.maxlen = biglen;
8f203108 636#ifdef MSCRYPTOAPI
fb09bf1c 637 /* Allocate enough buffer space for extra block
8f203108 638 * for MS CryptEncrypt() */
dcbde236 639 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
640 srealloc(pktout.data, biglen+12));
8f203108 641#else
dcbde236 642 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
643 srealloc(pktout.data, biglen+4));
8f203108 644#endif
374330e2 645 if (!pktout.data)
646 fatalbox("Out of memory");
647 }
4ba9b64b 648 pktout.body = pktout.data+4+pad+1;
649}
374330e2 650
4ba9b64b 651static void s_wrpkt_start(int type, int len) {
652 ssh1_pktout_size(len);
374330e2 653 pktout.type = type;
374330e2 654}
655
656static void s_wrpkt(void) {
657 int pad, len, biglen, i;
658 unsigned long crc;
659
4ba9b64b 660 pktout.body[-1] = pktout.type;
661
662 if (ssh1_compressing) {
663 unsigned char *compblk;
664 int complen;
665#if 0
666 debug(("Packet payload pre-compression:\n"));
667 for (i = -1; i < pktout.length; i++)
668 debug((" %02x", (unsigned char)pktout.body[i]));
669 debug(("\r\n"));
670#endif
671 zlib_compress_block(pktout.body-1, pktout.length+1,
672 &compblk, &complen);
673 ssh1_pktout_size(complen-1);
674 memcpy(pktout.body-1, compblk, complen);
dcbde236 675 sfree(compblk);
4ba9b64b 676#if 0
677 debug(("Packet payload post-compression:\n"));
678 for (i = -1; i < pktout.length; i++)
679 debug((" %02x", (unsigned char)pktout.body[i]));
680 debug(("\r\n"));
681#endif
682 }
683
374330e2 684 len = pktout.length + 5; /* type and CRC */
685 pad = 8 - (len%8);
686 biglen = len + pad;
687
374330e2 688 for (i=0; i<pad; i++)
689 pktout.data[i+4] = random_byte();
690 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 691 PUT_32BIT(pktout.data+biglen, crc);
692 PUT_32BIT(pktout.data, len);
374330e2 693
698a5108 694#if 0
695 debug(("Sending packet len=%d\r\n", biglen+4));
696 for (i = 0; i < biglen+4; i++)
697 debug((" %02x", (unsigned char)pktout.data[i]));
698 debug(("\r\n"));
699#endif
374330e2 700 if (cipher)
701 cipher->encrypt(pktout.data+4, biglen);
702
8df7a775 703 sk_write(s, pktout.data, biglen+4);
374330e2 704}
705
fb09bf1c 706/*
707 * Construct a packet with the specified contents and
708 * send it to the server.
709 */
710static void send_packet(int pkttype, ...)
711{
712 va_list args;
713 unsigned char *p, *argp, argchar;
714 unsigned long argint;
715 int pktlen, argtype, arglen;
7cca0d81 716 Bignum bn;
fb09bf1c 717
718 pktlen = 0;
719 va_start(args, pkttype);
720 while ((argtype = va_arg(args, int)) != PKT_END) {
721 switch (argtype) {
722 case PKT_INT:
723 (void) va_arg(args, int);
724 pktlen += 4;
725 break;
726 case PKT_CHAR:
727 (void) va_arg(args, char);
728 pktlen++;
729 break;
730 case PKT_DATA:
731 (void) va_arg(args, unsigned char *);
732 arglen = va_arg(args, int);
733 pktlen += arglen;
734 break;
735 case PKT_STR:
736 argp = va_arg(args, unsigned char *);
737 arglen = strlen(argp);
738 pktlen += 4 + arglen;
739 break;
7cca0d81 740 case PKT_BIGNUM:
741 bn = va_arg(args, Bignum);
5c58ad2d 742 pktlen += ssh1_bignum_length(bn);
7cca0d81 743 break;
fb09bf1c 744 default:
745 assert(0);
746 }
747 }
748 va_end(args);
749
750 s_wrpkt_start(pkttype, pktlen);
751 p = pktout.body;
752
753 va_start(args, pkttype);
754 while ((argtype = va_arg(args, int)) != PKT_END) {
755 switch (argtype) {
756 case PKT_INT:
757 argint = va_arg(args, int);
758 PUT_32BIT(p, argint);
759 p += 4;
760 break;
761 case PKT_CHAR:
762 argchar = va_arg(args, unsigned char);
763 *p = argchar;
764 p++;
765 break;
766 case PKT_DATA:
767 argp = va_arg(args, unsigned char *);
768 arglen = va_arg(args, int);
769 memcpy(p, argp, arglen);
770 p += arglen;
771 break;
772 case PKT_STR:
773 argp = va_arg(args, unsigned char *);
774 arglen = strlen(argp);
775 PUT_32BIT(p, arglen);
776 memcpy(p + 4, argp, arglen);
777 p += 4 + arglen;
778 break;
7cca0d81 779 case PKT_BIGNUM:
780 bn = va_arg(args, Bignum);
5c58ad2d 781 p += ssh1_write_bignum(p, bn);
7cca0d81 782 break;
fb09bf1c 783 }
784 }
785 va_end(args);
786
787 s_wrpkt();
788}
789
9697bfd2 790static int ssh_versioncmp(char *a, char *b) {
791 char *ae, *be;
792 unsigned long av, bv;
793
43aa02a7 794 av = strtoul(a, &ae, 10);
795 bv = strtoul(b, &be, 10);
9697bfd2 796 if (av != bv) return (av < bv ? -1 : +1);
797 if (*ae == '.') ae++;
798 if (*be == '.') be++;
43aa02a7 799 av = strtoul(ae, &ae, 10);
800 bv = strtoul(be, &be, 10);
9697bfd2 801 if (av != bv) return (av < bv ? -1 : +1);
802 return 0;
803}
804
e5574168 805
806/*
807 * Utility routine for putting an SSH-protocol `string' into a SHA
808 * state.
809 */
810#include <stdio.h>
75cab814 811static void sha_string(SHA_State *s, void *str, int len) {
e5574168 812 unsigned char lenblk[4];
e5574168 813 PUT_32BIT(lenblk, len);
e5574168 814 SHA_Bytes(s, lenblk, 4);
e5574168 815 SHA_Bytes(s, str, len);
816}
817
7cca0d81 818/*
819 * SSH2 packet construction functions.
820 */
783415f8 821static void ssh2_pkt_ensure(int length) {
822 if (pktout.maxlen < length) {
823 pktout.maxlen = length + 256;
dcbde236 824 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
825 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
7cca0d81 826 if (!pktout.data)
827 fatalbox("Out of memory");
828 }
783415f8 829}
830static void ssh2_pkt_adddata(void *data, int len) {
831 pktout.length += len;
832 ssh2_pkt_ensure(pktout.length);
7cca0d81 833 memcpy(pktout.data+pktout.length-len, data, len);
834}
75cab814 835static void ssh2_pkt_addbyte(unsigned char byte) {
7cca0d81 836 ssh2_pkt_adddata(&byte, 1);
837}
75cab814 838static void ssh2_pkt_init(int pkt_type) {
7cca0d81 839 pktout.length = 5;
840 ssh2_pkt_addbyte((unsigned char)pkt_type);
841}
75cab814 842static void ssh2_pkt_addbool(unsigned char value) {
7cca0d81 843 ssh2_pkt_adddata(&value, 1);
844}
75cab814 845static void ssh2_pkt_adduint32(unsigned long value) {
7cca0d81 846 unsigned char x[4];
847 PUT_32BIT(x, value);
848 ssh2_pkt_adddata(x, 4);
849}
75cab814 850static void ssh2_pkt_addstring_start(void) {
7cca0d81 851 ssh2_pkt_adduint32(0);
852 pktout.savedpos = pktout.length;
853}
75cab814 854static void ssh2_pkt_addstring_str(char *data) {
7cca0d81 855 ssh2_pkt_adddata(data, strlen(data));
856 PUT_32BIT(pktout.data + pktout.savedpos - 4,
857 pktout.length - pktout.savedpos);
858}
75cab814 859static void ssh2_pkt_addstring_data(char *data, int len) {
7cca0d81 860 ssh2_pkt_adddata(data, len);
861 PUT_32BIT(pktout.data + pktout.savedpos - 4,
862 pktout.length - pktout.savedpos);
863}
75cab814 864static void ssh2_pkt_addstring(char *data) {
7cca0d81 865 ssh2_pkt_addstring_start();
866 ssh2_pkt_addstring_str(data);
867}
75cab814 868static char *ssh2_mpint_fmt(Bignum b, int *len) {
7cca0d81 869 unsigned char *p;
870 int i, n = b[0];
dcbde236 871 p = smalloc(n * 2 + 1);
7cca0d81 872 if (!p)
873 fatalbox("out of memory");
874 p[0] = 0;
875 for (i = 0; i < n; i++) {
876 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
877 p[i*2+2] = (b[n-i] ) & 0xFF;
878 }
879 i = 0;
880 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
881 i++;
882 memmove(p, p+i, n*2+1-i);
883 *len = n*2+1-i;
884 return p;
885}
75cab814 886static void ssh2_pkt_addmp(Bignum b) {
7cca0d81 887 unsigned char *p;
888 int len;
889 p = ssh2_mpint_fmt(b, &len);
890 ssh2_pkt_addstring_start();
891 ssh2_pkt_addstring_data(p, len);
dcbde236 892 sfree(p);
7cca0d81 893}
75cab814 894static void ssh2_pkt_send(void) {
7cca0d81 895 int cipherblk, maclen, padding, i;
896 static unsigned long outgoing_sequence = 0;
897
898 /*
4ba9b64b 899 * Compress packet payload.
900 */
901#if 0
902 debug(("Pre-compression payload:\r\n"));
903 for (i = 5; i < pktout.length; i++)
904 debug((" %02x", (unsigned char)pktout.data[i]));
905 debug(("\r\n"));
906#endif
907 {
908 unsigned char *newpayload;
909 int newlen;
910 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
911 &newpayload, &newlen)) {
912 pktout.length = 5;
913 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 914 sfree(newpayload);
4ba9b64b 915 }
916 }
917
918 /*
7cca0d81 919 * Add padding. At least four bytes, and must also bring total
920 * length (minus MAC) up to a multiple of the block size.
921 */
922 cipherblk = cipher ? cipher->blksize : 8; /* block size */
923 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
924 padding = 4;
925 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 926 maclen = csmac ? csmac->len : 0;
927 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 928 pktout.data[4] = padding;
929 for (i = 0; i < padding; i++)
930 pktout.data[pktout.length + i] = random_byte();
931 PUT_32BIT(pktout.data, pktout.length + padding - 4);
932 if (csmac)
933 csmac->generate(pktout.data, pktout.length + padding,
934 outgoing_sequence);
935 outgoing_sequence++; /* whether or not we MACed */
936
937#if 0
938 debug(("Sending packet len=%d\r\n", pktout.length+padding));
939 for (i = 0; i < pktout.length+padding; i++)
940 debug((" %02x", (unsigned char)pktout.data[i]));
941 debug(("\r\n"));
942#endif
943
944 if (cscipher)
945 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 946
8df7a775 947 sk_write(s, pktout.data, pktout.length + padding + maclen);
7cca0d81 948}
949
950#if 0
951void bndebug(char *string, Bignum b) {
952 unsigned char *p;
953 int i, len;
954 p = ssh2_mpint_fmt(b, &len);
955 debug(("%s", string));
956 for (i = 0; i < len; i++)
957 debug((" %02x", p[i]));
958 debug(("\r\n"));
dcbde236 959 sfree(p);
7cca0d81 960}
961#endif
962
75cab814 963static void sha_mpint(SHA_State *s, Bignum b) {
7cca0d81 964 unsigned char *p;
965 int len;
966 p = ssh2_mpint_fmt(b, &len);
967 sha_string(s, p, len);
dcbde236 968 sfree(p);
7cca0d81 969}
970
971/*
972 * SSH2 packet decode functions.
973 */
75cab814 974static unsigned long ssh2_pkt_getuint32(void) {
7cca0d81 975 unsigned long value;
976 if (pktin.length - pktin.savedpos < 4)
977 return 0; /* arrgh, no way to decline (FIXME?) */
978 value = GET_32BIT(pktin.data+pktin.savedpos);
979 pktin.savedpos += 4;
980 return value;
981}
75cab814 982static void ssh2_pkt_getstring(char **p, int *length) {
7cca0d81 983 *p = NULL;
984 if (pktin.length - pktin.savedpos < 4)
985 return;
986 *length = GET_32BIT(pktin.data+pktin.savedpos);
987 pktin.savedpos += 4;
988 if (pktin.length - pktin.savedpos < *length)
989 return;
990 *p = pktin.data+pktin.savedpos;
991 pktin.savedpos += *length;
992}
75cab814 993static Bignum ssh2_pkt_getmp(void) {
7cca0d81 994 char *p;
995 int i, j, length;
996 Bignum b;
997
998 ssh2_pkt_getstring(&p, &length);
999 if (!p)
1000 return NULL;
8d5de777 1001 if (p[0] & 0x80) {
1002 bombout(("internal error: Can't handle negative mpints"));
1003 return NULL;
1004 }
7cca0d81 1005 b = newbn((length+1)/2);
1006 for (i = 0; i < length; i++) {
1007 j = length - 1 - i;
1008 if (j & 1)
1009 b[j/2+1] |= ((unsigned char)p[i]) << 8;
1010 else
1011 b[j/2+1] |= ((unsigned char)p[i]);
1012 }
6b4e00ee 1013 while (b[0] > 1 && b[b[0]] == 0) b[0]--;
7cca0d81 1014 return b;
1015}
1016
8df7a775 1017static int do_ssh_init(unsigned char c) {
1018 static char *vsp;
1019 static char version[10];
1020 static char vstring[80];
1021 static char vlog[sizeof(vstring)+20];
1022 static int i;
374330e2 1023
8df7a775 1024 crBegin;
1025
1026 /* Search for the string "SSH-" in the input. */
374330e2 1027 i = 0;
8df7a775 1028 while (1) {
1029 static const int transS[] = { 1, 2, 2, 1 };
1030 static const int transH[] = { 0, 0, 3, 0 };
1031 static const int transminus[] = { 0, 0, 0, -1 };
1032 if (c == 'S') i = transS[i];
1033 else if (c == 'H') i = transH[i];
1034 else if (c == '-') i = transminus[i];
374330e2 1035 else i = 0;
8df7a775 1036 if (i < 0)
1037 break;
1038 crReturn(1); /* get another character */
374330e2 1039 }
8df7a775 1040
c5e9c988 1041 strcpy(vstring, "SSH-");
1042 vsp = vstring+4;
374330e2 1043 i = 0;
1044 while (1) {
8df7a775 1045 crReturn(1); /* get another char */
c5e9c988 1046 if (vsp < vstring+sizeof(vstring)-1)
1047 *vsp++ = c;
374330e2 1048 if (i >= 0) {
1049 if (c == '-') {
1050 version[i] = '\0';
1051 i = -1;
1052 } else if (i < sizeof(version)-1)
1053 version[i++] = c;
1054 }
1055 else if (c == '\n')
1056 break;
1057 }
1058
db7d555c 1059 ssh_agentfwd_enabled = FALSE;
960e736a 1060 rdpkt2_state.incoming_sequence = 0;
1061
c5e9c988 1062 *vsp = 0;
1063 sprintf(vlog, "Server version: %s", vstring);
1064 vlog[strcspn(vlog, "\r\n")] = '\0';
1065 logevent(vlog);
1066
adf799dd 1067 /*
1068 * Server version "1.99" means we can choose whether we use v1
1069 * or v2 protocol. Choice is based on cfg.sshprot.
1070 */
1071 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 1072 /*
1073 * This is a v2 server. Begin v2 protocol.
1074 */
1075 char *verstring = "SSH-2.0-PuTTY";
0db56f73 1076 SHA_Init(&exhashbase);
e5574168 1077 /*
1078 * Hash our version string and their version string.
1079 */
0db56f73 1080 sha_string(&exhashbase, verstring, strlen(verstring));
1081 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
e5574168 1082 sprintf(vstring, "%s\n", verstring);
1083 sprintf(vlog, "We claim version: %s", verstring);
1084 logevent(vlog);
1085 logevent("Using SSH protocol version 2");
8df7a775 1086 sk_write(s, vstring, strlen(vstring));
e5574168 1087 ssh_protocol = ssh2_protocol;
6abbf9e3 1088 ssh_version = 2;
e5574168 1089 s_rdpkt = ssh2_rdpkt;
1090 } else {
1091 /*
1092 * This is a v1 server. Begin v1 protocol.
1093 */
1094 sprintf(vstring, "SSH-%s-PuTTY\n",
1095 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1096 sprintf(vlog, "We claim version: %s", vstring);
1097 vlog[strcspn(vlog, "\r\n")] = '\0';
1098 logevent(vlog);
1099 logevent("Using SSH protocol version 1");
8df7a775 1100 sk_write(s, vstring, strlen(vstring));
e5574168 1101 ssh_protocol = ssh1_protocol;
6abbf9e3 1102 ssh_version = 1;
e5574168 1103 s_rdpkt = ssh1_rdpkt;
1104 }
3687d221 1105 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1106
1107 crFinish(0);
1108}
1109
1110static void ssh_gotdata(unsigned char *data, int datalen)
1111{
1112 crBegin;
1113
1114 /*
1115 * To begin with, feed the characters one by one to the
1116 * protocol initialisation / selection function do_ssh_init().
1117 * When that returns 0, we're done with the initial greeting
1118 * exchange and can move on to packet discipline.
1119 */
1120 while (1) {
1121 int ret;
1122 if (datalen == 0)
1123 crReturnV; /* more data please */
1124 ret = do_ssh_init(*data);
1125 data++; datalen--;
1126 if (ret == 0)
1127 break;
1128 }
1129
1130 /*
1131 * We emerge from that loop when the initial negotiation is
1132 * over and we have selected an s_rdpkt function. Now pass
1133 * everything to s_rdpkt, and then pass the resulting packets
1134 * to the proper protocol handler.
1135 */
1136 if (datalen == 0)
1137 crReturnV;
1138 while (1) {
1139 while (datalen > 0) {
1140 if ( s_rdpkt(&data, &datalen) == 0 ) {
1141 ssh_protocol(NULL, 0, 1);
1142 if (ssh_state == SSH_STATE_CLOSED) {
1143 return;
1144 }
1145 }
1146 }
1147 crReturnV;
1148 }
1149 crFinishV;
1150}
1151
340cf649 1152static int ssh_receive(Socket skt, int urgent, char *data, int len) {
2c94fd1c 1153 if (urgent==3) {
1154 /* A socket error has occurred. */
7dbb9f56 1155 ssh_state = SSH_STATE_CLOSED;
b47b2198 1156 sk_close(s);
7dbb9f56 1157 s = NULL;
2c94fd1c 1158 connection_fatal(data);
b47b2198 1159 return 0;
1160 } else if (!len) {
8df7a775 1161 /* Connection has closed. */
6abb6cd7 1162 ssh_state = SSH_STATE_CLOSED;
8df7a775 1163 sk_close(s);
1164 s = NULL;
1165 return 0;
1166 }
1167 ssh_gotdata (data, len);
3257deae 1168 if (ssh_state == SSH_STATE_CLOSED) {
1169 if (s) {
1170 sk_close(s);
1171 s = NULL;
1172 }
1173 return 0;
1174 }
fef97f43 1175 return 1;
374330e2 1176}
1177
fb09bf1c 1178/*
8df7a775 1179 * Connect to specified host and port.
1180 * Returns an error message, or NULL on success.
1181 * Also places the canonical host name into `realhost'.
1182 */
1183static char *connect_to_host(char *host, int port, char **realhost)
1184{
1185 SockAddr addr;
1186 char *err;
1187#ifdef FWHACK
1188 char *FWhost;
1189 int FWport;
1190#endif
1191
dcbde236 1192 savedhost = smalloc(1+strlen(host));
8df7a775 1193 if (!savedhost)
1194 fatalbox("Out of memory");
1195 strcpy(savedhost, host);
1196
1197 if (port < 0)
1198 port = 22; /* default ssh port */
1199 savedport = port;
1200
1201#ifdef FWHACK
1202 FWhost = host;
1203 FWport = port;
1204 host = FWSTR;
1205 port = 23;
1206#endif
1207
1208 /*
1209 * Try to find host.
1210 */
1211 addr = sk_namelookup(host, realhost);
1212 if ( (err = sk_addr_error(addr)) )
1213 return err;
1214
1215#ifdef FWHACK
1216 *realhost = FWhost;
1217#endif
1218
1219 /*
1220 * Open socket.
1221 */
4b1e8acc 1222 s = sk_new(addr, port, 0, 1, ssh_receive);
8df7a775 1223 if ( (err = sk_socket_error(s)) )
1224 return err;
1225
1226#ifdef FWHACK
1227 sk_write(s, "connect ", 8);
1228 sk_write(s, FWhost, strlen(FWhost));
1229 {
1230 char buf[20];
1231 sprintf(buf, " %d\n", FWport);
1232 sk_write(s, buf, strlen(buf));
1233 }
1234#endif
1235
1236 return NULL;
1237}
1238
1239/*
fb09bf1c 1240 * Handle the key exchange and user authentication phases.
1241 */
e5574168 1242static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1243{
374330e2 1244 int i, j, len;
374330e2 1245 unsigned char *rsabuf, *keystr1, *keystr2;
1246 unsigned char cookie[8];
1247 struct RSAKey servkey, hostkey;
1248 struct MD5Context md5c;
ccbfb941 1249 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1250 static int tried_publickey;
1251 static unsigned char session_id[16];
bea1ef5f 1252 int cipher_type;
b585ec46 1253 static char username[100];
374330e2 1254
374330e2 1255 crBegin;
1256
fb09bf1c 1257 if (!ispkt) crWaitUntil(ispkt);
374330e2 1258
8d5de777 1259 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1260 bombout(("Public key packet not received"));
1261 crReturn(0);
1262 }
374330e2 1263
c5e9c988 1264 logevent("Received public keys");
374330e2 1265
c5e9c988 1266 memcpy(cookie, pktin.body, 8);
374330e2 1267
7cca0d81 1268 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1269 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1270
c5e9c988 1271 /*
1c2a93c4 1272 * Log the host key fingerprint.
c5e9c988 1273 */
c5e9c988 1274 {
1275 char logmsg[80];
1c2a93c4 1276 logevent("Host key fingerprint is:");
c5e9c988 1277 strcpy(logmsg, " ");
1c2a93c4 1278 hostkey.comment = NULL;
1279 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1280 &hostkey);
c5e9c988 1281 logevent(logmsg);
1282 }
1283
fb09bf1c 1284 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1285 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1286
c5e9c988 1287 MD5Init(&md5c);
374330e2 1288 MD5Update(&md5c, keystr2, hostkey.bytes);
1289 MD5Update(&md5c, keystr1, servkey.bytes);
1290 MD5Update(&md5c, pktin.body, 8);
374330e2 1291 MD5Final(session_id, &md5c);
1292
1293 for (i=0; i<32; i++)
1294 session_key[i] = random_byte();
1295
1296 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1297
dcbde236 1298 rsabuf = smalloc(len);
374330e2 1299 if (!rsabuf)
1300 fatalbox("Out of memory");
1301
89ee5268 1302 /*
1303 * Verify the host key.
1304 */
1305 {
1306 /*
1307 * First format the key into a string.
1308 */
1309 int len = rsastr_len(&hostkey);
d5859615 1310 char fingerprint[100];
dcbde236 1311 char *keystr = smalloc(len);
89ee5268 1312 if (!keystr)
1313 fatalbox("Out of memory");
1314 rsastr_fmt(keystr, &hostkey);
d5859615 1315 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1316 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
dcbde236 1317 sfree(keystr);
89ee5268 1318 }
374330e2 1319
1320 for (i=0; i<32; i++) {
1321 rsabuf[i] = session_key[i];
1322 if (i < 16)
1323 rsabuf[i] ^= session_id[i];
1324 }
1325
1326 if (hostkey.bytes > servkey.bytes) {
1327 rsaencrypt(rsabuf, 32, &servkey);
1328 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1329 } else {
1330 rsaencrypt(rsabuf, 32, &hostkey);
1331 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1332 }
1333
c5e9c988 1334 logevent("Encrypted session key");
1335
bea1ef5f 1336 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1337 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1338 SSH_CIPHER_3DES;
1339 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1340 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1341 cipher_type = SSH_CIPHER_3DES;
1342 }
c5e9c988 1343 switch (cipher_type) {
1344 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1345 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1346 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1347 }
bea1ef5f 1348
e5574168 1349 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1350 PKT_CHAR, cipher_type,
1351 PKT_DATA, cookie, 8,
1352 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1353 PKT_DATA, rsabuf, len,
1354 PKT_INT, 0,
1355 PKT_END);
1356
c5e9c988 1357 logevent("Trying to enable encryption...");
374330e2 1358
dcbde236 1359 sfree(rsabuf);
374330e2 1360
5e8358ad 1361 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1362 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1363 &ssh_3des;
374330e2 1364 cipher->sesskey(session_key);
1365
fb09bf1c 1366 crWaitUntil(ispkt);
374330e2 1367
8d5de777 1368 if (pktin.type != SSH1_SMSG_SUCCESS) {
1369 bombout(("Encryption not successfully enabled"));
1370 crReturn(0);
1371 }
374330e2 1372
c5e9c988 1373 logevent("Successfully started encryption");
1374
374330e2 1375 fflush(stdout);
1376 {
374330e2 1377 static int pos = 0;
1378 static char c;
67779be7 1379 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1380 c_write("login as: ", 10);
67779be7 1381 ssh_send_ok = 1;
374330e2 1382 while (pos >= 0) {
fb09bf1c 1383 crWaitUntil(!ispkt);
374330e2 1384 while (inlen--) switch (c = *in++) {
1385 case 10: case 13:
1386 username[pos] = 0;
1387 pos = -1;
1388 break;
1389 case 8: case 127:
1390 if (pos > 0) {
1391 c_write("\b \b", 3);
1392 pos--;
1393 }
1394 break;
1395 case 21: case 27:
1396 while (pos > 0) {
1397 c_write("\b \b", 3);
1398 pos--;
1399 }
1400 break;
1401 case 3: case 4:
1402 random_save_seed();
1403 exit(0);
1404 break;
1405 default:
40d24aa6 1406 if (((c >= ' ' && c <= '~') ||
1407 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1408 username[pos++] = c;
1409 c_write(&c, 1);
1410 }
1411 break;
1412 }
1413 }
1414 c_write("\r\n", 2);
1415 username[strcspn(username, "\n\r")] = '\0';
1416 } else {
374330e2 1417 strncpy(username, cfg.username, 99);
1418 username[99] = '\0';
374330e2 1419 }
fb09bf1c 1420
e5574168 1421 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1422 {
3c8e959b 1423 char userlog[22+sizeof(username)];
c5e9c988 1424 sprintf(userlog, "Sent username \"%s\"", username);
1425 logevent(userlog);
3c8e959b 1426 if (flags & FLAG_INTERACTIVE &&
1427 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1428 strcat(userlog, "\r\n");
1429 c_write(userlog, strlen(userlog));
1430 }
c5e9c988 1431 }
374330e2 1432 }
1433
fb09bf1c 1434 crWaitUntil(ispkt);
374330e2 1435
7cca0d81 1436 tried_publickey = 0;
1437
e5574168 1438 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1439 static char password[100];
a52f067e 1440 static char prompt[200];
374330e2 1441 static int pos;
1442 static char c;
ccbfb941 1443 static int pwpkt_type;
ccbfb941 1444 /*
1445 * Show password prompt, having first obtained it via a TIS
18515c51 1446 * or CryptoCard exchange if we're doing TIS or CryptoCard
1447 * authentication.
ccbfb941 1448 */
e5574168 1449 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1450 if (agent_exists()) {
1451 /*
1452 * Attempt RSA authentication using Pageant.
1453 */
1454 static unsigned char request[5], *response, *p;
1455 static int responselen;
1456 static int i, nkeys;
1457 static int authed = FALSE;
1458 void *r;
1459
1460 logevent("Pageant is running. Requesting keys.");
1461
1462 /* Request the keys held by the agent. */
1463 PUT_32BIT(request, 1);
1464 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1465 agent_query(request, 5, &r, &responselen);
1466 response = (unsigned char *)r;
1467 if (response) {
1468 p = response + 5;
1469 nkeys = GET_32BIT(p); p += 4;
1470 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1471 logevent(buf); }
1472 for (i = 0; i < nkeys; i++) {
1473 static struct RSAKey key;
1474 static Bignum challenge;
b8bb811a 1475 static char *commentp;
1476 static int commentlen;
5c58ad2d 1477
1478 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1479 logevent(buf); }
1480 p += 4;
1481 p += ssh1_read_bignum(p, &key.exponent);
1482 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1483 commentlen = GET_32BIT(p); p += 4;
1484 commentp = p; p += commentlen;
5c58ad2d 1485 send_packet(SSH1_CMSG_AUTH_RSA,
1486 PKT_BIGNUM, key.modulus, PKT_END);
1487 crWaitUntil(ispkt);
1488 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1489 logevent("Key refused");
1490 continue;
1491 }
1492 logevent("Received RSA challenge");
1493 ssh1_read_bignum(pktin.body, &challenge);
1494 {
1495 char *agentreq, *q, *ret;
1496 int len, retlen;
1497 len = 1 + 4; /* message type, bit count */
1498 len += ssh1_bignum_length(key.exponent);
1499 len += ssh1_bignum_length(key.modulus);
1500 len += ssh1_bignum_length(challenge);
1501 len += 16; /* session id */
1502 len += 4; /* response format */
dcbde236 1503 agentreq = smalloc(4 + len);
5c58ad2d 1504 PUT_32BIT(agentreq, len);
1505 q = agentreq + 4;
1506 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1507 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1508 q += 4;
1509 q += ssh1_write_bignum(q, key.exponent);
1510 q += ssh1_write_bignum(q, key.modulus);
1511 q += ssh1_write_bignum(q, challenge);
1512 memcpy(q, session_id, 16); q += 16;
1513 PUT_32BIT(q, 1); /* response format */
1514 agent_query(agentreq, len+4, &ret, &retlen);
dcbde236 1515 sfree(agentreq);
5c58ad2d 1516 if (ret) {
1517 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1518 logevent("Sending Pageant's response");
1519 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1520 PKT_DATA, ret+5, 16, PKT_END);
dcbde236 1521 sfree(ret);
5c58ad2d 1522 crWaitUntil(ispkt);
1523 if (pktin.type == SSH1_SMSG_SUCCESS) {
1524 logevent("Pageant's response accepted");
c4fa2fce 1525 if (flags & FLAG_VERBOSE) {
1526 c_write("Authenticated using RSA key \"",
1527 29);
1528 c_write(commentp, commentlen);
1529 c_write("\" from agent\r\n", 14);
1530 }
5c58ad2d 1531 authed = TRUE;
1532 } else
1533 logevent("Pageant's response not accepted");
1534 } else {
1535 logevent("Pageant failed to answer challenge");
dcbde236 1536 sfree(ret);
5c58ad2d 1537 }
1538 } else {
1539 logevent("No reply received from Pageant");
1540 }
1541 }
1542 freebn(key.exponent);
1543 freebn(key.modulus);
1544 freebn(challenge);
1545 if (authed)
1546 break;
1547 }
1548 }
1549 if (authed)
1550 break;
1551 }
7cca0d81 1552 if (*cfg.keyfile && !tried_publickey)
1553 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1554
a52f067e 1555 if (pktin.type == SSH1_SMSG_FAILURE &&
1556 cfg.try_tis_auth &&
1557 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1558 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1559 logevent("Requested TIS authentication");
1560 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1561 crWaitUntil(ispkt);
1562 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1563 logevent("TIS authentication declined");
1564 if (flags & FLAG_INTERACTIVE)
1565 c_write("TIS authentication refused.\r\n", 29);
1566 } else {
1567 int challengelen = ((pktin.body[0] << 24) |
1568 (pktin.body[1] << 16) |
1569 (pktin.body[2] << 8) |
1570 (pktin.body[3]));
1571 logevent("Received TIS challenge");
1572 if (challengelen > sizeof(prompt)-1)
1573 challengelen = sizeof(prompt)-1; /* prevent overrun */
1574 memcpy(prompt, pktin.body+4, challengelen);
1575 prompt[challengelen] = '\0';
1576 }
1577 }
1578 if (pktin.type == SSH1_SMSG_FAILURE &&
1579 cfg.try_tis_auth &&
1580 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1581 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1582 logevent("Requested CryptoCard authentication");
1583 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1584 crWaitUntil(ispkt);
1585 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1586 logevent("CryptoCard authentication declined");
1587 c_write("CryptoCard authentication refused.\r\n", 29);
1588 } else {
1589 int challengelen = ((pktin.body[0] << 24) |
1590 (pktin.body[1] << 16) |
1591 (pktin.body[2] << 8) |
1592 (pktin.body[3]));
1593 logevent("Received CryptoCard challenge");
1594 if (challengelen > sizeof(prompt)-1)
1595 challengelen = sizeof(prompt)-1; /* prevent overrun */
1596 memcpy(prompt, pktin.body+4, challengelen);
1597 strncpy(prompt + challengelen, "\r\nResponse : ",
1598 sizeof(prompt)-challengelen);
1599 prompt[sizeof(prompt)-1] = '\0';
1600 }
1601 }
1602 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1603 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1604 username, savedhost);
a52f067e 1605 }
1606 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1607 char *comment = NULL;
1608 if (flags & FLAG_VERBOSE)
1609 c_write("Trying public key authentication.\r\n", 35);
1610 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1611 if (flags & FLAG_VERBOSE)
1612 c_write("No passphrase required.\r\n", 25);
1613 goto tryauth;
1614 }
1615 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
dcbde236 1616 sfree(comment);
a52f067e 1617 }
1618
d8426c54 1619 if (ssh_get_password) {
85ee8208 1620 if (!ssh_get_password(prompt, password, sizeof(password))) {
1621 /*
1622 * get_password failed to get a password (for
1623 * example because one was supplied on the command
1624 * line which has already failed to work).
1625 * Terminate.
1626 */
1627 logevent("No more passwords to try");
1628 ssh_state = SSH_STATE_CLOSED;
1629 crReturn(1);
1630 }
fb09bf1c 1631 } else {
a52f067e 1632 c_write(prompt, strlen(prompt));
7cca0d81 1633 pos = 0;
67779be7 1634 ssh_send_ok = 1;
7cca0d81 1635 while (pos >= 0) {
1636 crWaitUntil(!ispkt);
1637 while (inlen--) switch (c = *in++) {
1638 case 10: case 13:
1639 password[pos] = 0;
1640 pos = -1;
1641 break;
1642 case 8: case 127:
1643 if (pos > 0)
1644 pos--;
1645 break;
1646 case 21: case 27:
1647 pos = 0;
1648 break;
1649 case 3: case 4:
1650 random_save_seed();
1651 exit(0);
1652 break;
1653 default:
1654 if (((c >= ' ' && c <= '~') ||
1655 ((unsigned char)c >= 160)) && pos < sizeof(password))
1656 password[pos++] = c;
1657 break;
1658 }
1659 }
1660 c_write("\r\n", 2);
a52f067e 1661 }
fb09bf1c 1662
7cca0d81 1663 tryauth:
1664 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1665 /*
1666 * Try public key authentication with the specified
1667 * key file.
1668 */
1669 static struct RSAKey pubkey;
1670 static Bignum challenge, response;
1671 static int i;
1672 static unsigned char buffer[32];
1673
1674 tried_publickey = 1;
6e522441 1675 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
7cca0d81 1676 if (i == 0) {
1677 c_write("Couldn't load public key from ", 30);
1678 c_write(cfg.keyfile, strlen(cfg.keyfile));
1679 c_write(".\r\n", 3);
1680 continue; /* go and try password */
1681 }
1682 if (i == -1) {
1683 c_write("Wrong passphrase.\r\n", 19);
1684 tried_publickey = 0;
1685 continue; /* try again */
1686 }
1687
1688 /*
1689 * Send a public key attempt.
1690 */
1691 send_packet(SSH1_CMSG_AUTH_RSA,
1692 PKT_BIGNUM, pubkey.modulus, PKT_END);
1693
1694 crWaitUntil(ispkt);
1695 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1696 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1697 continue; /* go and try password */
1698 }
8d5de777 1699 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1700 bombout(("Bizarre response to offer of public key"));
1701 crReturn(0);
1702 }
7cca0d81 1703 ssh1_read_bignum(pktin.body, &challenge);
1704 response = rsadecrypt(challenge, &pubkey);
1705 freebn(pubkey.private_exponent); /* burn the evidence */
1706
1707 for (i = 0; i < 32; i += 2) {
1708 buffer[i] = response[16-i/2] >> 8;
1709 buffer[i+1] = response[16-i/2] & 0xFF;
1710 }
1711
1712 MD5Init(&md5c);
1713 MD5Update(&md5c, buffer, 32);
1714 MD5Update(&md5c, session_id, 16);
1715 MD5Final(buffer, &md5c);
1716
1717 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1718 PKT_DATA, buffer, 16, PKT_END);
1719
1720 crWaitUntil(ispkt);
1721 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1722 if (flags & FLAG_VERBOSE)
1723 c_write("Failed to authenticate with our public key.\r\n",
1724 45);
7cca0d81 1725 continue; /* go and try password */
1726 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1727 bombout(("Bizarre response to RSA authentication response"));
1728 crReturn(0);
7cca0d81 1729 }
1730
1731 break; /* we're through! */
1732 } else {
1733 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1734 }
c5e9c988 1735 logevent("Sent password");
374330e2 1736 memset(password, 0, strlen(password));
fb09bf1c 1737 crWaitUntil(ispkt);
e5574168 1738 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1739 if (flags & FLAG_VERBOSE)
1740 c_write("Access denied\r\n", 15);
c5e9c988 1741 logevent("Authentication refused");
e5574168 1742 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1743 logevent("Received disconnect request");
85ee8208 1744 ssh_state = SSH_STATE_CLOSED;
1745 crReturn(1);
e5574168 1746 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1747 bombout(("Strange packet received, type %d", pktin.type));
1748 crReturn(0);
374330e2 1749 }
1750 }
1751
c5e9c988 1752 logevent("Authentication successful");
1753
fb09bf1c 1754 crFinish(1);
1755}
1756
9c964e85 1757void sshfwd_close(struct ssh_channel *c) {
783415f8 1758 if (c) {
1759 if (ssh_version == 1) {
1760 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
1761 } else {
1762 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
1763 ssh2_pkt_adduint32(c->remoteid);
1764 ssh2_pkt_send();
1765 }
1766 c->closes = 1;
1767 if (c->type == CHAN_X11) {
1768 c->u.x11.s = NULL;
1769 logevent("X11 connection terminated");
1770 }
1771 }
9c964e85 1772}
1773
1774void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
783415f8 1775 if (ssh_version == 1) {
1776 send_packet(SSH1_MSG_CHANNEL_DATA,
1777 PKT_INT, c->remoteid,
1778 PKT_INT, len,
1779 PKT_DATA, buf, len,
1780 PKT_END);
1781 } else {
1782 ssh2_add_channel_data(c, buf, len);
1783 ssh2_try_send(c);
1784 }
9c964e85 1785}
1786
e5574168 1787static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1788 crBegin;
1789
1790 random_init();
1791
e5574168 1792 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1793 crReturnV;
85ee8208 1794 }
1795 if (ssh_state == SSH_STATE_CLOSED)
1796 crReturnV;
fb09bf1c 1797
979310f1 1798 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1799 logevent("Requesting agent forwarding");
1800 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1801 do { crReturnV; } while (!ispkt);
1802 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1803 bombout(("Protocol confusion"));
1804 crReturnV;
dacbd0e8 1805 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1806 logevent("Agent forwarding refused");
db7d555c 1807 } else {
dacbd0e8 1808 logevent("Agent forwarding enabled");
db7d555c 1809 ssh_agentfwd_enabled = TRUE;
1810 }
dacbd0e8 1811 }
1812
9c964e85 1813 if (cfg.x11_forward) {
1814 char proto[20], data[64];
1815 logevent("Requesting X11 forwarding");
1816 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
1817 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
1818 PKT_STR, proto, PKT_STR, data,
1819 PKT_INT, 0,
1820 PKT_END);
1821 do { crReturnV; } while (!ispkt);
1822 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1823 bombout(("Protocol confusion"));
1824 crReturnV;
1825 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1826 logevent("X11 forwarding refused");
1827 } else {
1828 logevent("X11 forwarding enabled");
1829 ssh_X11_fwd_enabled = TRUE;
1830 }
1831 }
1832
fef97f43 1833 if (!cfg.nopty) {
e5574168 1834 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1835 PKT_STR, cfg.termtype,
1836 PKT_INT, rows, PKT_INT, cols,
1837 PKT_INT, 0, PKT_INT, 0,
1838 PKT_CHAR, 0,
1839 PKT_END);
fef97f43 1840 ssh_state = SSH_STATE_INTERMED;
1841 do { crReturnV; } while (!ispkt);
e5574168 1842 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1843 bombout(("Protocol confusion"));
1844 crReturnV;
e5574168 1845 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1846 c_write("Server refused to allocate pty\r\n", 32);
0965bee0 1847 ssh_editing = ssh_echoing = 1;
fef97f43 1848 }
c5e9c988 1849 logevent("Allocated pty");
0965bee0 1850 } else {
1851 ssh_editing = ssh_echoing = 1;
374330e2 1852 }
1853
4ba9b64b 1854 if (cfg.compression) {
1855 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
1856 do { crReturnV; } while (!ispkt);
1857 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1858 bombout(("Protocol confusion"));
1859 crReturnV;
1860 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1861 c_write("Server refused to compress\r\n", 32);
1862 }
1863 logevent("Started compression");
1864 ssh1_compressing = TRUE;
1865 zlib_compress_init();
1866 zlib_decompress_init();
1867 }
1868
6abbf9e3 1869 if (*cfg.remote_cmd)
1870 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1871 else
1872 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1873 logevent("Started session");
374330e2 1874
1875 ssh_state = SSH_STATE_SESSION;
1876 if (size_needed)
1877 ssh_size();
3687d221 1878 if (eof_needed)
1879 ssh_special(TS_EOF);
374330e2 1880
0965bee0 1881 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 1882 ssh_send_ok = 1;
dacbd0e8 1883 ssh_channels = newtree234(ssh_channelcmp);
374330e2 1884 while (1) {
1885 crReturnV;
1886 if (ispkt) {
e5574168 1887 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1888 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1889 long len = GET_32BIT(pktin.body);
fe50e814 1890 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1891 pktin.body+4, len);
e5574168 1892 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1893 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1894 logevent("Received disconnect request");
3257deae 1895 crReturnV;
9c964e85 1896 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
1897 /* Remote side is trying to open a channel to talk to our
1898 * X-Server. Give them back a local channel number. */
1899 unsigned i;
1900 struct ssh_channel *c, *d;
1901 enum234 e;
1902
1903 logevent("Received X11 connect request");
1904 /* Refuse if X11 forwarding is disabled. */
1905 if (!ssh_X11_fwd_enabled) {
1906 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1907 PKT_INT, GET_32BIT(pktin.body),
1908 PKT_END);
1909 logevent("Rejected X11 connect request");
1910 } else {
9c964e85 1911 c = smalloc(sizeof(struct ssh_channel));
1912
0c6c9a70 1913 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
9c964e85 1914 logevent("opening X11 forward connection failed");
1915 sfree(c);
1916 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1917 PKT_INT, GET_32BIT(pktin.body),
1918 PKT_END);
1919 } else {
1920 logevent("opening X11 forward connection succeeded");
1921 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
783415f8 1922 if (d->localid > i)
1923 break; /* found a free number */
1924 i = d->localid + 1;
9c964e85 1925 }
1926 c->remoteid = GET_32BIT(pktin.body);
1927 c->localid = i;
1928 c->closes = 0;
783415f8 1929 c->type = CHAN_X11; /* identify channel type */
9c964e85 1930 add234(ssh_channels, c);
1931 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1932 PKT_INT, c->remoteid, PKT_INT, c->localid,
1933 PKT_END);
1934 logevent("Opened X11 forward channel");
1935 }
1936 }
dacbd0e8 1937 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1938 /* Remote side is trying to open a channel to talk to our
1939 * agent. Give them back a local channel number. */
db7d555c 1940 unsigned i;
dacbd0e8 1941 struct ssh_channel *c;
1942 enum234 e;
db7d555c 1943
1944 /* Refuse if agent forwarding is disabled. */
1945 if (!ssh_agentfwd_enabled) {
1946 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1947 PKT_INT, GET_32BIT(pktin.body),
1948 PKT_END);
1949 } else {
1950 i = 1;
1951 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1952 if (c->localid > i)
1953 break; /* found a free number */
1954 i = c->localid + 1;
1955 }
dcbde236 1956 c = smalloc(sizeof(struct ssh_channel));
db7d555c 1957 c->remoteid = GET_32BIT(pktin.body);
1958 c->localid = i;
1959 c->closes = 0;
783415f8 1960 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 1961 c->u.a.lensofar = 0;
1962 add234(ssh_channels, c);
1963 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1964 PKT_INT, c->remoteid, PKT_INT, c->localid,
1965 PKT_END);
1966 }
1967 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1968 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
dacbd0e8 1969 /* Remote side closes a channel. */
d211621f 1970 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1971 struct ssh_channel *c;
1972 c = find234(ssh_channels, &i, ssh_channelfind);
1973 if (c) {
1974 int closetype;
1975 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1976 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
783415f8 1977 if ((c->closes == 0) && (c->type == CHAN_X11)) {
9c964e85 1978 logevent("X11 connection closed");
1979 assert(c->u.x11.s != NULL);
1980 x11_close(c->u.x11.s);
1981 c->u.x11.s = NULL;
1982 }
dacbd0e8 1983 c->closes |= closetype;
1984 if (c->closes == 3) {
1985 del234(ssh_channels, c);
dcbde236 1986 sfree(c);
dacbd0e8 1987 }
1988 }
1989 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1990 /* Data sent down one of our channels. */
1991 int i = GET_32BIT(pktin.body);
1992 int len = GET_32BIT(pktin.body+4);
1993 unsigned char *p = pktin.body+8;
1994 struct ssh_channel *c;
1995 c = find234(ssh_channels, &i, ssh_channelfind);
1996 if (c) {
1997 switch(c->type) {
783415f8 1998 case CHAN_X11:
9c964e85 1999 x11_send(c->u.x11.s, p, len);
2000 break;
783415f8 2001 case CHAN_AGENT:
dacbd0e8 2002 /* Data for an agent message. Buffer it. */
2003 while (len > 0) {
2004 if (c->u.a.lensofar < 4) {
2005 int l = min(4 - c->u.a.lensofar, len);
2006 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2007 p += l; len -= l; c->u.a.lensofar += l;
2008 }
2009 if (c->u.a.lensofar == 4) {
2010 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
dcbde236 2011 c->u.a.message = smalloc(c->u.a.totallen);
dacbd0e8 2012 memcpy(c->u.a.message, c->u.a.msglen, 4);
2013 }
2014 if (c->u.a.lensofar >= 4 && len > 0) {
2015 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2016 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2017 p += l; len -= l; c->u.a.lensofar += l;
2018 }
2019 if (c->u.a.lensofar == c->u.a.totallen) {
2020 void *reply, *sentreply;
2021 int replylen;
2022 agent_query(c->u.a.message, c->u.a.totallen,
2023 &reply, &replylen);
2024 if (reply)
2025 sentreply = reply;
2026 else {
2027 /* Fake SSH_AGENT_FAILURE. */
2028 sentreply = "\0\0\0\1\5";
2029 replylen = 5;
2030 }
2031 send_packet(SSH1_MSG_CHANNEL_DATA,
2032 PKT_INT, c->remoteid,
2033 PKT_INT, replylen,
2034 PKT_DATA, sentreply, replylen,
2035 PKT_END);
2036 if (reply)
dcbde236 2037 sfree(reply);
2038 sfree(c->u.a.message);
dacbd0e8 2039 c->u.a.lensofar = 0;
2040 }
2041 }
2042 break;
2043 }
2044 }
e5574168 2045 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 2046 /* may be from EXEC_SHELL on some servers */
e5574168 2047 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 2048 /* may be from EXEC_SHELL on some servers
374330e2 2049 * if no pty is available or in other odd cases. Ignore */
e5574168 2050 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2051 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 2052 } else {
8d5de777 2053 bombout(("Strange packet received: type %d", pktin.type));
2054 crReturnV;
374330e2 2055 }
2056 } else {
8df7a775 2057 while (inlen > 0) {
2058 int len = min(inlen, 512);
2059 send_packet(SSH1_CMSG_STDIN_DATA,
2060 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2061 in += len;
2062 inlen -= len;
2063 }
374330e2 2064 }
2065 }
2066
2067 crFinishV;
2068}
2069
2070/*
e5574168 2071 * Utility routine for decoding comma-separated strings in KEXINIT.
2072 */
75cab814 2073static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 2074 int needlen = strlen(needle);
2075 while (1) {
2076 /*
2077 * Is it at the start of the string?
2078 */
2079 if (haylen >= needlen && /* haystack is long enough */
2080 !memcmp(needle, haystack, needlen) && /* initial match */
2081 (haylen == needlen || haystack[needlen] == ',')
2082 /* either , or EOS follows */
2083 )
2084 return 1;
2085 /*
2086 * If not, search for the next comma and resume after that.
2087 * If no comma found, terminate.
2088 */
2089 while (haylen > 0 && *haystack != ',')
2090 haylen--, haystack++;
2091 if (haylen == 0)
2092 return 0;
2093 haylen--, haystack++; /* skip over comma itself */
2094 }
2095}
2096
2097/*
d39f364a 2098 * SSH2 key creation method.
2099 */
5e0d7cb8 2100static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) {
d39f364a 2101 SHA_State s;
2102 /* First 20 bytes. */
2103 SHA_Init(&s);
2104 sha_mpint(&s, K);
2105 SHA_Bytes(&s, H, 20);
2106 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 2107 SHA_Bytes(&s, sessid, 20);
d39f364a 2108 SHA_Final(&s, keyspace);
2109 /* Next 20 bytes. */
2110 SHA_Init(&s);
2111 sha_mpint(&s, K);
2112 SHA_Bytes(&s, H, 20);
2113 SHA_Bytes(&s, keyspace, 20);
2114 SHA_Final(&s, keyspace+20);
2115}
2116
2117/*
7cca0d81 2118 * Handle the SSH2 transport layer.
e5574168 2119 */
7cca0d81 2120static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 2121{
2122 static int i, len;
2123 static char *str;
2124 static Bignum e, f, K;
7591b9ff 2125 static const struct ssh_mac **maclist;
8b2715b2 2126 static int nmacs;
57476f6b 2127 static const struct ssh_cipher *cscipher_tobe = NULL;
2128 static const struct ssh_cipher *sccipher_tobe = NULL;
2129 static const struct ssh_mac *csmac_tobe = NULL;
2130 static const struct ssh_mac *scmac_tobe = NULL;
2131 static const struct ssh_compress *cscomp_tobe = NULL;
2132 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 2133 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 2134 static int hostkeylen, siglen;
e055a386 2135 static void *hkey; /* actual host key */
e5574168 2136 static unsigned char exchange_hash[20];
5e0d7cb8 2137 static unsigned char first_exchange_hash[20];
d39f364a 2138 static unsigned char keyspace[40];
57476f6b 2139 static const struct ssh_cipher *preferred_cipher;
4ba9b64b 2140 static const struct ssh_compress *preferred_comp;
0db56f73 2141 static int first_kex;
e5574168 2142
2143 crBegin;
7cca0d81 2144 random_init();
0db56f73 2145 first_kex = 1;
e5574168 2146
5e8358ad 2147 /*
4ba9b64b 2148 * Set up the preferred cipher and compression.
5e8358ad 2149 */
2150 if (cfg.cipher == CIPHER_BLOWFISH) {
57476f6b 2151 preferred_cipher = &ssh_blowfish_ssh2;
5e8358ad 2152 } else if (cfg.cipher == CIPHER_DES) {
2153 logevent("Single DES not supported in SSH2; using 3DES");
57476f6b 2154 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 2155 } else if (cfg.cipher == CIPHER_3DES) {
57476f6b 2156 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 2157 } else {
2158 /* Shouldn't happen, but we do want to initialise to _something_. */
57476f6b 2159 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 2160 }
4ba9b64b 2161 if (cfg.compression)
2162 preferred_comp = &ssh_zlib;
2163 else
2164 preferred_comp = &ssh_comp_none;
5e8358ad 2165
7591b9ff 2166 /*
2167 * Be prepared to work around the buggy MAC problem.
2168 */
2169 if (cfg.buggymac)
8b2715b2 2170 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 2171 else
8b2715b2 2172 maclist = macs, nmacs = lenof(macs);
7591b9ff 2173
7cca0d81 2174 begin_key_exchange:
e5574168 2175 /*
2176 * Construct and send our key exchange packet.
2177 */
2178 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2179 for (i = 0; i < 16; i++)
2180 ssh2_pkt_addbyte((unsigned char)random_byte());
2181 /* List key exchange algorithms. */
2182 ssh2_pkt_addstring_start();
2183 for (i = 0; i < lenof(kex_algs); i++) {
2184 ssh2_pkt_addstring_str(kex_algs[i]->name);
2185 if (i < lenof(kex_algs)-1)
2186 ssh2_pkt_addstring_str(",");
2187 }
2188 /* List server host key algorithms. */
2189 ssh2_pkt_addstring_start();
2190 for (i = 0; i < lenof(hostkey_algs); i++) {
2191 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2192 if (i < lenof(hostkey_algs)-1)
2193 ssh2_pkt_addstring_str(",");
2194 }
2195 /* List client->server encryption algorithms. */
2196 ssh2_pkt_addstring_start();
729e54b4 2197 for (i = 0; i < lenof(ciphers)+1; i++) {
2198 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2199 ssh2_pkt_addstring_str(c->name);
729e54b4 2200 if (i < lenof(ciphers))
e5574168 2201 ssh2_pkt_addstring_str(",");
2202 }
2203 /* List server->client encryption algorithms. */
2204 ssh2_pkt_addstring_start();
729e54b4 2205 for (i = 0; i < lenof(ciphers)+1; i++) {
2206 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2207 ssh2_pkt_addstring_str(c->name);
729e54b4 2208 if (i < lenof(ciphers))
e5574168 2209 ssh2_pkt_addstring_str(",");
2210 }
2211 /* List client->server MAC algorithms. */
2212 ssh2_pkt_addstring_start();
8b2715b2 2213 for (i = 0; i < nmacs; i++) {
7591b9ff 2214 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2215 if (i < nmacs-1)
e5574168 2216 ssh2_pkt_addstring_str(",");
2217 }
2218 /* List server->client MAC algorithms. */
2219 ssh2_pkt_addstring_start();
8b2715b2 2220 for (i = 0; i < nmacs; i++) {
7591b9ff 2221 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2222 if (i < nmacs-1)
e5574168 2223 ssh2_pkt_addstring_str(",");
2224 }
2225 /* List client->server compression algorithms. */
2226 ssh2_pkt_addstring_start();
4ba9b64b 2227 for (i = 0; i < lenof(compressions)+1; i++) {
2228 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2229 ssh2_pkt_addstring_str(c->name);
2230 if (i < lenof(compressions))
e5574168 2231 ssh2_pkt_addstring_str(",");
2232 }
2233 /* List server->client compression algorithms. */
2234 ssh2_pkt_addstring_start();
4ba9b64b 2235 for (i = 0; i < lenof(compressions)+1; i++) {
2236 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2237 ssh2_pkt_addstring_str(c->name);
2238 if (i < lenof(compressions))
e5574168 2239 ssh2_pkt_addstring_str(",");
2240 }
2241 /* List client->server languages. Empty list. */
2242 ssh2_pkt_addstring_start();
2243 /* List server->client languages. Empty list. */
2244 ssh2_pkt_addstring_start();
2245 /* First KEX packet does _not_ follow, because we're not that brave. */
2246 ssh2_pkt_addbool(FALSE);
2247 /* Reserved. */
2248 ssh2_pkt_adduint32(0);
0db56f73 2249
2250 exhash = exhashbase;
e5574168 2251 sha_string(&exhash, pktout.data+5, pktout.length-5);
0db56f73 2252
e5574168 2253 ssh2_pkt_send();
2254
2255 if (!ispkt) crWaitUntil(ispkt);
2256 sha_string(&exhash, pktin.data+5, pktin.length-5);
2257
2258 /*
2259 * Now examine the other side's KEXINIT to see what we're up
2260 * to.
2261 */
7cca0d81 2262 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 2263 bombout(("expected key exchange packet from server"));
2264 crReturn(0);
7cca0d81 2265 }
e5574168 2266 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2267 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2268 pktin.savedpos += 16; /* skip garbage cookie */
2269 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2270 for (i = 0; i < lenof(kex_algs); i++) {
2271 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2272 kex = kex_algs[i];
2273 break;
2274 }
2275 }
2276 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2277 for (i = 0; i < lenof(hostkey_algs); i++) {
2278 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2279 hostkey = hostkey_algs[i];
2280 break;
2281 }
2282 }
2283 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 2284 for (i = 0; i < lenof(ciphers)+1; i++) {
2285 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2286 if (in_commasep_string(c->name, str, len)) {
729e54b4 2287 cscipher_tobe = c;
e5574168 2288 break;
2289 }
2290 }
2291 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
729e54b4 2292 for (i = 0; i < lenof(ciphers)+1; i++) {
2293 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2294 if (in_commasep_string(c->name, str, len)) {
729e54b4 2295 sccipher_tobe = c;
e5574168 2296 break;
2297 }
2298 }
2299 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 2300 for (i = 0; i < nmacs; i++) {
7591b9ff 2301 if (in_commasep_string(maclist[i]->name, str, len)) {
2302 csmac_tobe = maclist[i];
e5574168 2303 break;
2304 }
2305 }
2306 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 2307 for (i = 0; i < nmacs; i++) {
7591b9ff 2308 if (in_commasep_string(maclist[i]->name, str, len)) {
2309 scmac_tobe = maclist[i];
e5574168 2310 break;
2311 }
2312 }
2313 ssh2_pkt_getstring(&str, &len); /* client->server compression */
4ba9b64b 2314 for (i = 0; i < lenof(compressions)+1; i++) {
2315 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2316 if (in_commasep_string(c->name, str, len)) {
2317 cscomp_tobe = c;
e5574168 2318 break;
2319 }
2320 }
2321 ssh2_pkt_getstring(&str, &len); /* server->client compression */
4ba9b64b 2322 for (i = 0; i < lenof(compressions)+1; i++) {
2323 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2324 if (in_commasep_string(c->name, str, len)) {
2325 sccomp_tobe = c;
e5574168 2326 break;
2327 }
2328 }
e5574168 2329
2330 /*
2331 * Currently we only support Diffie-Hellman and DSS, so let's
2332 * bomb out if those aren't selected.
2333 */
8d5de777 2334 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2335 bombout(("internal fault: chaos in SSH 2 transport layer"));
2336 crReturn(0);
2337 }
e5574168 2338
2339 /*
2340 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2341 */
2342 e = dh_create_e();
e5574168 2343 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2344 ssh2_pkt_addmp(e);
2345 ssh2_pkt_send();
2346
2347 crWaitUntil(ispkt);
7cca0d81 2348 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2349 bombout(("expected key exchange packet from server"));
2350 crReturn(0);
7cca0d81 2351 }
e5574168 2352 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2353 f = ssh2_pkt_getmp();
e5574168 2354 ssh2_pkt_getstring(&sigdata, &siglen);
2355
2356 K = dh_find_K(f);
e5574168 2357
2358 sha_string(&exhash, hostkeydata, hostkeylen);
2359 sha_mpint(&exhash, e);
2360 sha_mpint(&exhash, f);
2361 sha_mpint(&exhash, K);
2362 SHA_Final(&exhash, exchange_hash);
2363
7cca0d81 2364#if 0
e5574168 2365 debug(("Exchange hash is:\r\n"));
2366 for (i = 0; i < 20; i++)
2367 debug((" %02x", exchange_hash[i]));
2368 debug(("\r\n"));
7cca0d81 2369#endif
2370
e055a386 2371 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2372 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
8d5de777 2373 bombout(("Server failed host key check"));
2374 crReturn(0);
2375 }
e5574168 2376
2377 /*
7cca0d81 2378 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2379 */
7cca0d81 2380 crWaitUntil(ispkt);
8d5de777 2381 if (pktin.type != SSH2_MSG_NEWKEYS) {
2382 bombout(("expected new-keys packet from server"));
2383 crReturn(0);
2384 }
d39f364a 2385
2386 /*
7cca0d81 2387 * Authenticate remote host: verify host key. (We've already
2388 * checked the signature of the exchange hash.)
e5574168 2389 */
e055a386 2390 keystr = hostkey->fmtkey(hkey);
2391 fingerprint = hostkey->fingerprint(hkey);
d4857987 2392 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2393 keystr, fingerprint);
5e0d7cb8 2394 if (first_kex) { /* don't bother logging this in rekeys */
2395 logevent("Host key fingerprint is:");
2396 logevent(fingerprint);
2397 }
dcbde236 2398 sfree(fingerprint);
2399 sfree(keystr);
e055a386 2400 hostkey->freekey(hkey);
d39f364a 2401
2402 /*
7cca0d81 2403 * Send SSH2_MSG_NEWKEYS.
d39f364a 2404 */
2405 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2406 ssh2_pkt_send();
d39f364a 2407
2408 /*
2409 * Create and initialise session keys.
2410 */
2411 cscipher = cscipher_tobe;
2412 sccipher = sccipher_tobe;
2413 csmac = csmac_tobe;
2414 scmac = scmac_tobe;
2415 cscomp = cscomp_tobe;
2416 sccomp = sccomp_tobe;
4ba9b64b 2417 cscomp->compress_init();
2418 sccomp->decompress_init();
d39f364a 2419 /*
5e0d7cb8 2420 * Set IVs after keys. Here we use the exchange hash from the
2421 * _first_ key exchange.
d39f364a 2422 */
5e0d7cb8 2423 if (first_kex)
2424 memcpy(first_exchange_hash, exchange_hash, sizeof(exchange_hash));
2425 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'C', keyspace);
2426 cscipher->setcskey(keyspace);
2427 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'D', keyspace);
2428 sccipher->setsckey(keyspace);
2429 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'A', keyspace);
2430 cscipher->setcsiv(keyspace);
2431 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'B', keyspace);
2432 sccipher->setsciv(keyspace);
2433 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'E', keyspace);
2434 csmac->setcskey(keyspace);
2435 ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'F', keyspace);
2436 scmac->setsckey(keyspace);
d39f364a 2437
033b4cef 2438 /*
0db56f73 2439 * If this is the first key exchange phase, we must pass the
2440 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2441 * wants to see it but because it will need time to initialise
2442 * itself before it sees an actual packet. In subsequent key
2443 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2444 * it would only confuse the layer above.
2445 */
2446 if (!first_kex) {
2447 crReturn(0);
2448 }
2449 first_kex = 0;
2450
2451 /*
7cca0d81 2452 * Now we're encrypting. Begin returning 1 to the protocol main
2453 * function so that other things can run on top of the
2454 * transport. If we ever see a KEXINIT, we must go back to the
2455 * start.
033b4cef 2456 */
7cca0d81 2457 do {
2458 crReturn(1);
2459 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
5e0d7cb8 2460 logevent("Server initiated key re-exchange");
7cca0d81 2461 goto begin_key_exchange;
e5574168 2462
2463 crFinish(1);
2464}
2465
7cca0d81 2466/*
783415f8 2467 * Add data to an SSH2 channel output buffer.
2468 */
2469static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2470 if (c->v2.outbufsize <
2471 c->v2.outbuflen + len) {
2472 c->v2.outbufsize =
2473 c->v2.outbuflen + len + 1024;
2474 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2475 c->v2.outbufsize);
2476 }
2477 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2478 buf, len);
2479 c->v2.outbuflen += len;
2480}
2481
2482/*
2483 * Attempt to send data on an SSH2 channel.
2484 */
2485static void ssh2_try_send(struct ssh_channel *c) {
2486 while (c->v2.remwindow > 0 &&
2487 c->v2.outbuflen > 0) {
2488 unsigned len = c->v2.remwindow;
2489 if (len > c->v2.outbuflen)
2490 len = c->v2.outbuflen;
2491 if (len > c->v2.remmaxpkt)
2492 len = c->v2.remmaxpkt;
2493 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2494 ssh2_pkt_adduint32(c->remoteid);
2495 ssh2_pkt_addstring_start();
2496 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2497 ssh2_pkt_send();
2498 c->v2.outbuflen -= len;
2499 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2500 c->v2.outbuflen);
2501 c->v2.remwindow -= len;
2502 }
2503}
2504
2505/*
7cca0d81 2506 * Handle the SSH2 userauth and connection layers.
2507 */
2508static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2509{
7cca0d81 2510 static unsigned long remote_winsize;
2511 static unsigned long remote_maxpkt;
2512
e5574168 2513 crBegin;
2514
7cca0d81 2515 /*
2516 * Request userauth protocol, and await a response to it.
2517 */
2518 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2519 ssh2_pkt_addstring("ssh-userauth");
2520 ssh2_pkt_send();
2521 crWaitUntilV(ispkt);
8d5de777 2522 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2523 bombout(("Server refused user authentication protocol"));
2524 crReturnV;
2525 }
7cca0d81 2526
2527 /*
2528 * FIXME: currently we support only password authentication.
2529 * (This places us technically in violation of the SSH2 spec.
2530 * We must fix this.)
2531 */
2532 while (1) {
2533 /*
2534 * Get a username and a password.
2535 */
2536 static char username[100];
2537 static char password[100];
2538 static int pos = 0;
2539 static char c;
e5574168 2540
67779be7 2541 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2542 c_write("login as: ", 10);
67779be7 2543 ssh_send_ok = 1;
7cca0d81 2544 while (pos >= 0) {
2545 crWaitUntilV(!ispkt);
2546 while (inlen--) switch (c = *in++) {
2547 case 10: case 13:
2548 username[pos] = 0;
2549 pos = -1;
2550 break;
2551 case 8: case 127:
2552 if (pos > 0) {
2553 c_write("\b \b", 3);
2554 pos--;
2555 }
2556 break;
2557 case 21: case 27:
2558 while (pos > 0) {
2559 c_write("\b \b", 3);
2560 pos--;
2561 }
2562 break;
2563 case 3: case 4:
2564 random_save_seed();
2565 exit(0);
2566 break;
2567 default:
2568 if (((c >= ' ' && c <= '~') ||
2569 ((unsigned char)c >= 160)) && pos < 40) {
2570 username[pos++] = c;
2571 c_write(&c, 1);
2572 }
2573 break;
2574 }
2575 }
2576 c_write("\r\n", 2);
2577 username[strcspn(username, "\n\r")] = '\0';
2578 } else {
2579 char stuff[200];
2580 strncpy(username, cfg.username, 99);
2581 username[99] = '\0';
67779be7 2582 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2583 sprintf(stuff, "Using username \"%s\".\r\n", username);
2584 c_write(stuff, strlen(stuff));
2585 }
2586 }
2587
d8426c54 2588 if (ssh_get_password) {
7cca0d81 2589 char prompt[200];
b585ec46 2590 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
7cca0d81 2591 if (!ssh_get_password(prompt, password, sizeof(password))) {
2592 /*
2593 * get_password failed to get a password (for
2594 * example because one was supplied on the command
2595 * line which has already failed to work).
2596 * Terminate.
2597 */
2598 logevent("No more passwords to try");
2599 ssh_state = SSH_STATE_CLOSED;
2600 crReturnV;
2601 }
2602 } else {
2603 c_write("password: ", 10);
67779be7 2604 ssh_send_ok = 1;
7cca0d81 2605
2606 pos = 0;
2607 while (pos >= 0) {
2608 crWaitUntilV(!ispkt);
2609 while (inlen--) switch (c = *in++) {
2610 case 10: case 13:
2611 password[pos] = 0;
2612 pos = -1;
2613 break;
2614 case 8: case 127:
2615 if (pos > 0)
2616 pos--;
2617 break;
2618 case 21: case 27:
2619 pos = 0;
2620 break;
2621 case 3: case 4:
2622 random_save_seed();
2623 exit(0);
2624 break;
2625 default:
2626 if (((c >= ' ' && c <= '~') ||
2627 ((unsigned char)c >= 160)) && pos < 40)
2628 password[pos++] = c;
2629 break;
2630 }
2631 }
2632 c_write("\r\n", 2);
2633 }
2634
2635 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2636 ssh2_pkt_addstring(username);
2637 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2638 ssh2_pkt_addstring("password");
2639 ssh2_pkt_addbool(FALSE);
2640 ssh2_pkt_addstring(password);
2641 ssh2_pkt_send();
2642
2643 crWaitUntilV(ispkt);
2644 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2645 c_write("Access denied\r\n", 15);
2646 logevent("Authentication refused");
2647 } else
2648 break;
2649 }
2650
2651 /*
2652 * Now we're authenticated for the connection protocol. The
2653 * connection protocol will automatically have started at this
2654 * point; there's no need to send SERVICE_REQUEST.
2655 */
2656
2657 /*
2658 * So now create a channel with a session in it.
2659 */
dcbde236 2660 mainchan = smalloc(sizeof(struct ssh_channel));
d211621f 2661 mainchan->localid = 100; /* as good as any */
7cca0d81 2662 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2663 ssh2_pkt_addstring("session");
d211621f 2664 ssh2_pkt_adduint32(mainchan->localid);
cf6e59d6 2665 ssh2_pkt_adduint32(0x8000UL); /* our window size */
d211621f 2666 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2667 ssh2_pkt_send();
2668 crWaitUntilV(ispkt);
2669 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2670 bombout(("Server refused to open a session"));
2671 crReturnV;
7cca0d81 2672 /* FIXME: error data comes back in FAILURE packet */
2673 }
d211621f 2674 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2675 bombout(("Server's channel confirmation cited wrong channel"));
2676 crReturnV;
7cca0d81 2677 }
d211621f 2678 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 2679 mainchan->type = CHAN_MAINSESSION;
2680 mainchan->closes = 0;
2681 mainchan->v2.remwindow = ssh2_pkt_getuint32();
2682 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
2683 mainchan->v2.outbuffer = NULL;
2684 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
2685 ssh_channels = newtree234(ssh_channelcmp);
2686 add234(ssh_channels, mainchan);
7cca0d81 2687 logevent("Opened channel for session");
2688
2689 /*
783415f8 2690 * Potentially enable X11 forwarding.
2691 */
2692 if (cfg.x11_forward) {
2693 char proto[20], data[64];
2694 logevent("Requesting X11 forwarding");
2695 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2696 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2697 ssh2_pkt_adduint32(mainchan->remoteid);
2698 ssh2_pkt_addstring("x11-req");
2699 ssh2_pkt_addbool(1); /* want reply */
2700 ssh2_pkt_addbool(0); /* many connections */
2701 ssh2_pkt_addstring(proto);
2702 ssh2_pkt_addstring(data);
2703 ssh2_pkt_adduint32(0); /* screen number */
2704 ssh2_pkt_send();
2705
2706 do {
2707 crWaitUntilV(ispkt);
2708 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2709 unsigned i = ssh2_pkt_getuint32();
2710 struct ssh_channel *c;
2711 c = find234(ssh_channels, &i, ssh_channelfind);
2712 if (!c)
2713 continue; /* nonexistent channel */
2714 c->v2.remwindow += ssh2_pkt_getuint32();
2715 }
2716 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2717
2718 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2719 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2720 bombout(("Server got confused by X11 forwarding request"));
2721 crReturnV;
2722 }
2723 logevent("X11 forwarding refused");
2724 } else {
2725 logevent("X11 forwarding enabled");
2726 ssh_X11_fwd_enabled = TRUE;
2727 }
2728 }
2729
2730 /*
7cca0d81 2731 * Now allocate a pty for the session.
2732 */
67779be7 2733 if (!cfg.nopty) {
2734 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2735 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2736 ssh2_pkt_addstring("pty-req");
2737 ssh2_pkt_addbool(1); /* want reply */
2738 ssh2_pkt_addstring(cfg.termtype);
2739 ssh2_pkt_adduint32(cols);
2740 ssh2_pkt_adduint32(rows);
2741 ssh2_pkt_adduint32(0); /* pixel width */
2742 ssh2_pkt_adduint32(0); /* pixel height */
2743 ssh2_pkt_addstring_start();
2744 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2745 ssh2_pkt_send();
6e48c3fe 2746 ssh_state = SSH_STATE_INTERMED;
7cca0d81 2747
67779be7 2748 do {
2749 crWaitUntilV(ispkt);
2750 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 2751 unsigned i = ssh2_pkt_getuint32();
2752 struct ssh_channel *c;
2753 c = find234(ssh_channels, &i, ssh_channelfind);
2754 if (!c)
2755 continue; /* nonexistent channel */
2756 c->v2.remwindow += ssh2_pkt_getuint32();
67779be7 2757 }
2758 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2759
67779be7 2760 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2761 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2762 bombout(("Server got confused by pty request"));
2763 crReturnV;
67779be7 2764 }
2765 c_write("Server refused to allocate pty\r\n", 32);
0965bee0 2766 ssh_editing = ssh_echoing = 1;
67779be7 2767 } else {
2768 logevent("Allocated pty");
7cca0d81 2769 }
0965bee0 2770 } else {
2771 ssh_editing = ssh_echoing = 1;
7cca0d81 2772 }
2773
2774 /*
67779be7 2775 * Start a shell or a remote command.
7cca0d81 2776 */
2777 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2778 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2779 if (*cfg.remote_cmd) {
2780 ssh2_pkt_addstring("exec");
2781 ssh2_pkt_addbool(1); /* want reply */
2782 ssh2_pkt_addstring(cfg.remote_cmd);
2783 } else {
2784 ssh2_pkt_addstring("shell");
2785 ssh2_pkt_addbool(1); /* want reply */
2786 }
7cca0d81 2787 ssh2_pkt_send();
d211621f 2788 do {
7cca0d81 2789 crWaitUntilV(ispkt);
d211621f 2790 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 2791 unsigned i = ssh2_pkt_getuint32();
2792 struct ssh_channel *c;
2793 c = find234(ssh_channels, &i, ssh_channelfind);
2794 if (!c)
2795 continue; /* nonexistent channel */
2796 c->v2.remwindow += ssh2_pkt_getuint32();
d211621f 2797 }
7cca0d81 2798 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2799 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2800 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2801 bombout(("Server got confused by shell/command request"));
2802 crReturnV;
7cca0d81 2803 }
8d5de777 2804 bombout(("Server refused to start a shell/command"));
2805 crReturnV;
7cca0d81 2806 } else {
8d5de777 2807 logevent("Started a shell/command");
7cca0d81 2808 }
2809
6e48c3fe 2810 ssh_state = SSH_STATE_SESSION;
2811 if (size_needed)
2812 ssh_size();
3687d221 2813 if (eof_needed)
2814 ssh_special(TS_EOF);
6e48c3fe 2815
7cca0d81 2816 /*
2817 * Transfer data!
2818 */
0965bee0 2819 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 2820 ssh_send_ok = 1;
7cca0d81 2821 while (1) {
d211621f 2822 static int try_send;
e5574168 2823 crReturnV;
d211621f 2824 try_send = FALSE;
7cca0d81 2825 if (ispkt) {
2826 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2827 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2828 char *data;
2829 int length;
783415f8 2830 unsigned i = ssh2_pkt_getuint32();
2831 struct ssh_channel *c;
2832 c = find234(ssh_channels, &i, ssh_channelfind);
2833 if (!c)
2834 continue; /* nonexistent channel */
7cca0d81 2835 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2836 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2837 continue; /* extended but not stderr */
2838 ssh2_pkt_getstring(&data, &length);
d211621f 2839 if (data) {
783415f8 2840 switch (c->type) {
2841 case CHAN_MAINSESSION:
2842 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
2843 data, length);
2844 break;
2845 case CHAN_X11:
2846 x11_send(c->u.x11.s, data, length);
2847 break;
2848 }
d211621f 2849 /*
783415f8 2850 * Enlarge the window again at the remote
2851 * side, just in case it ever runs down and
2852 * they fail to send us any more data.
d211621f 2853 */
2854 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
783415f8 2855 ssh2_pkt_adduint32(c->remoteid);
d211621f 2856 ssh2_pkt_adduint32(length);
2857 ssh2_pkt_send();
2858 }
7cca0d81 2859 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2860 ssh_state = SSH_STATE_CLOSED;
d211621f 2861 logevent("Received disconnect message");
3257deae 2862 crReturnV;
7cca0d81 2863 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2864 continue; /* exit status et al; ignore (FIXME?) */
d211621f 2865 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
783415f8 2866 unsigned i = ssh2_pkt_getuint32();
2867 struct ssh_channel *c;
2868
2869 c = find234(ssh_channels, &i, ssh_channelfind);
2870 if (!c)
2871 continue; /* nonexistent channel */
2872
2873 if (c->type == CHAN_X11) {
2874 /*
2875 * Remote EOF on an X11 channel means we should
2876 * wrap up and close the channel ourselves.
2877 */
2878 x11_close(c->u.x11.s);
2879 sshfwd_close(c);
2880 }
d211621f 2881 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
783415f8 2882 unsigned i = ssh2_pkt_getuint32();
2883 struct ssh_channel *c;
2884 enum234 e;
2885
2886 c = find234(ssh_channels, &i, ssh_channelfind);
2887 if (!c)
2888 continue; /* nonexistent channel */
2889 if (c->closes == 0) {
2890 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2891 ssh2_pkt_adduint32(c->remoteid);
2892 ssh2_pkt_send();
2893 }
2894 /* Do pre-close processing on the channel. */
2895 switch (c->type) {
2896 case CHAN_MAINSESSION:
2897 break; /* nothing to see here, move along */
2898 case CHAN_X11:
2899 break;
2900 }
2901 del234(ssh_channels, c);
2902 sfree(c->v2.outbuffer);
2903 sfree(c);
2904
2905 /*
2906 * See if that was the last channel left open.
2907 */
2908 c = first234(ssh_channels, &e);
2909 if (!c) {
d211621f 2910 logevent("All channels closed. Disconnecting");
2911 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
9005f3ba 2912 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
2913 ssh2_pkt_addstring("All open channels closed");
2914 ssh2_pkt_addstring("en"); /* language tag */
d211621f 2915 ssh2_pkt_send();
cf6e59d6 2916 ssh_state = SSH_STATE_CLOSED;
3257deae 2917 crReturnV;
d211621f 2918 }
2919 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2920 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 2921 unsigned i = ssh2_pkt_getuint32();
2922 struct ssh_channel *c;
2923 c = find234(ssh_channels, &i, ssh_channelfind);
2924 if (!c)
2925 continue; /* nonexistent channel */
2926 mainchan->v2.remwindow += ssh2_pkt_getuint32();
d211621f 2927 try_send = TRUE;
783415f8 2928 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
2929 char *type;
2930 int typelen;
2931 char *error = NULL;
2932 struct ssh_channel *c;
2933 ssh2_pkt_getstring(&type, &typelen);
2934 c = smalloc(sizeof(struct ssh_channel));
2935
2936 if (typelen == 3 && !memcmp(type, "x11", 3)) {
783415f8 2937 if (!ssh_X11_fwd_enabled)
2938 error = "X11 forwarding is not enabled";
0c6c9a70 2939 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
783415f8 2940 error = "Unable to open an X11 connection";
2941 } else {
2942 c->type = CHAN_X11;
2943 }
2944 } else {
2945 error = "Unsupported channel type requested";
2946 }
2947
2948 c->remoteid = ssh2_pkt_getuint32();
2949 if (error) {
2950 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
2951 ssh2_pkt_adduint32(c->remoteid);
2952 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
2953 ssh2_pkt_addstring(error);
2954 ssh2_pkt_addstring("en"); /* language tag */
2955 ssh2_pkt_send();
2956 sfree(c);
2957 } else {
2958 struct ssh_channel *d;
2959 unsigned i;
2960 enum234 e;
2961
2962 for (i=1, d = first234(ssh_channels, &e); d;
2963 d = next234(&e)) {
2964 if (d->localid > i)
2965 break; /* found a free number */
2966 i = d->localid + 1;
2967 }
2968 c->localid = i;
2969 c->closes = 0;
2970 c->v2.remwindow = ssh2_pkt_getuint32();
2971 c->v2.remmaxpkt = ssh2_pkt_getuint32();
2972 c->v2.outbuffer = NULL;
2973 c->v2.outbuflen = c->v2.outbufsize = 0;
2974 add234(ssh_channels, c);
2975 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
2976 ssh2_pkt_adduint32(c->remoteid);
2977 ssh2_pkt_adduint32(c->localid);
2978 ssh2_pkt_adduint32(0x8000UL); /* our window size */
2979 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
2980 ssh2_pkt_send();
2981 }
7cca0d81 2982 } else {
8d5de777 2983 bombout(("Strange packet received: type %d", pktin.type));
2984 crReturnV;
7cca0d81 2985 }
2986 } else {
d211621f 2987 /*
2988 * We have spare data. Add it to the channel buffer.
2989 */
783415f8 2990 ssh2_add_channel_data(mainchan, in, inlen);
d211621f 2991 try_send = TRUE;
7cca0d81 2992 }
d211621f 2993 if (try_send) {
783415f8 2994 enum234 e;
2995 struct ssh_channel *c;
d211621f 2996 /*
783415f8 2997 * Try to send data on all channels if we can.
d211621f 2998 */
783415f8 2999 for (c = first234(ssh_channels, &e); c; c = next234(&e))
3000 ssh2_try_send(c);
d211621f 3001 }
e5574168 3002 }
3003
3004 crFinishV;
3005}
3006
3007/*
7cca0d81 3008 * Handle the top-level SSH2 protocol.
3009 */
3010static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
3011{
3012 if (do_ssh2_transport(in, inlen, ispkt) == 0)
3013 return;
3014 do_ssh2_authconn(in, inlen, ispkt);
3015}
3016
3017/*
8df7a775 3018 * Called to set up the connection.
374330e2 3019 *
3020 * Returns an error message, or NULL on success.
374330e2 3021 */
8df7a775 3022static char *ssh_init (char *host, int port, char **realhost) {
fb09bf1c 3023 char *p;
8f203108 3024
3025#ifdef MSCRYPTOAPI
3026 if(crypto_startup() == 0)
3027 return "Microsoft high encryption pack not installed!";
3028#endif
374330e2 3029
8df7a775 3030 ssh_send_ok = 0;
0965bee0 3031 ssh_editing = 0;
3032 ssh_echoing = 0;
8df7a775 3033
fb09bf1c 3034 p = connect_to_host(host, port, realhost);
3035 if (p != NULL)
3036 return p;
374330e2 3037
374330e2 3038 return NULL;
3039}
3040
3041/*
374330e2 3042 * Called to send data down the Telnet connection.
3043 */
3044static void ssh_send (char *buf, int len) {
f78051a1 3045 if (s == NULL || ssh_protocol == NULL)
374330e2 3046 return;
3047
3048 ssh_protocol(buf, len, 0);
3049}
3050
3051/*
6e48c3fe 3052 * Called to set the size of the window from SSH's POV.
374330e2 3053 */
3054static void ssh_size(void) {
3055 switch (ssh_state) {
3056 case SSH_STATE_BEFORE_SIZE:
3687d221 3057 case SSH_STATE_PREPACKET:
21248260 3058 case SSH_STATE_CLOSED:
374330e2 3059 break; /* do nothing */
3060 case SSH_STATE_INTERMED:
3061 size_needed = TRUE; /* buffer for later */
3062 break;
3063 case SSH_STATE_SESSION:
fef97f43 3064 if (!cfg.nopty) {
6e48c3fe 3065 if (ssh_version == 1) {
3066 send_packet(SSH1_CMSG_WINDOW_SIZE,
3067 PKT_INT, rows, PKT_INT, cols,
3068 PKT_INT, 0, PKT_INT, 0, PKT_END);
3069 } else {
3070 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3071 ssh2_pkt_adduint32(mainchan->remoteid);
3072 ssh2_pkt_addstring("window-change");
3073 ssh2_pkt_addbool(0);
3074 ssh2_pkt_adduint32(cols);
3075 ssh2_pkt_adduint32(rows);
3076 ssh2_pkt_adduint32(0);
3077 ssh2_pkt_adduint32(0);
3078 ssh2_pkt_send();
3079 }
fef97f43 3080 }
3687d221 3081 break;
374330e2 3082 }
3083}
3084
3085/*
6abbf9e3 3086 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3087 * can send an EOF and collect resulting output (e.g. `plink
3088 * hostname sort').
374330e2 3089 */
3090static void ssh_special (Telnet_Special code) {
6abbf9e3 3091 if (code == TS_EOF) {
3687d221 3092 if (ssh_state != SSH_STATE_SESSION) {
3093 /*
3094 * Buffer the EOF in case we are pre-SESSION, so we can
3095 * send it as soon as we reach SESSION.
3096 */
3097 if (code == TS_EOF)
3098 eof_needed = TRUE;
3099 return;
3100 }
67779be7 3101 if (ssh_version == 1) {
6abbf9e3 3102 send_packet(SSH1_CMSG_EOF, PKT_END);
3103 } else {
3104 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 3105 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 3106 ssh2_pkt_send();
3107 }
67779be7 3108 logevent("Sent EOF message");
ec55b220 3109 } else if (code == TS_PING) {
3687d221 3110 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3111 return;
ec55b220 3112 if (ssh_version == 1) {
3113 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3114 } else {
3115 ssh2_pkt_init(SSH2_MSG_IGNORE);
3116 ssh2_pkt_addstring_start();
3117 ssh2_pkt_send();
3118 }
6abbf9e3 3119 } else {
3120 /* do nothing */
3121 }
374330e2 3122}
3123
8df7a775 3124static Socket ssh_socket(void) { return s; }
8ccc75b0 3125
3126static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 3127
0965bee0 3128static int ssh_ldisc(int option) {
3129 if (option == LD_ECHO) return ssh_echoing;
3130 if (option == LD_EDIT) return ssh_editing;
3131 return FALSE;
3132}
3133
374330e2 3134Backend ssh_backend = {
3135 ssh_init,
374330e2 3136 ssh_send,
3137 ssh_size,
4017be6d 3138 ssh_special,
8ccc75b0 3139 ssh_socket,
97db3be4 3140 ssh_sendok,
0965bee0 3141 ssh_ldisc,
97db3be4 3142 22
374330e2 3143};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator