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Bring the SSH2 channel architecture up to scratch, enabling X
[u/mdw/putty] / ssh.c
CommitLineData
8df7a775 1#include <windows.h>
374330e2 2#include <stdio.h>
3#include <stdlib.h>
fb09bf1c 4#include <stdarg.h>
5#include <assert.h>
374330e2 6
7#include "putty.h"
dacbd0e8 8#include "tree234.h"
fb09bf1c 9#include "ssh.h"
374330e2 10
11#ifndef FALSE
12#define FALSE 0
13#endif
14#ifndef TRUE
15#define TRUE 1
16#endif
17
fb09bf1c 18#define logevent(s) { logevent(s); \
67779be7 19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
fb09bf1c 20 fprintf(stderr, "%s\n", s); }
21
8df7a775 22#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, sk_close(s), \
23 s = NULL, connection_fatal msg )
8d5de777 24
d211621f 25#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
26#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
27#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
28#define SSH1_CMSG_USER 4 /* 0x4 */
29#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
30#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
31#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
32#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
33#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
34#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
35#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
36#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
37#define SSH1_SMSG_SUCCESS 14 /* 0xe */
38#define SSH1_SMSG_FAILURE 15 /* 0xf */
39#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
40#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
41#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
42#define SSH1_CMSG_EOF 19 /* 0x13 */
43#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
44#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
45#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
46#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
47#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
48#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
9c964e85 49#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
50#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
51#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
d211621f 52#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
53#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
d211621f 54#define SSH1_MSG_IGNORE 32 /* 0x20 */
9c964e85 55#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
56#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
57#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
d211621f 58#define SSH1_MSG_DEBUG 36 /* 0x24 */
4ba9b64b 59#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
d211621f 60#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
61#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
62#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
63#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
64#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
65#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
66
67#define SSH1_AUTH_TIS 5 /* 0x5 */
68#define SSH1_AUTH_CCARD 16 /* 0x10 */
69
70#define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
71#define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
72#define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
73#define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
74#define SSH_AGENT_FAILURE 5 /* 0x5 */
75#define SSH_AGENT_SUCCESS 6 /* 0x6 */
76#define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
77#define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
78
79#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
80#define SSH2_MSG_IGNORE 2 /* 0x2 */
81#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
82#define SSH2_MSG_DEBUG 4 /* 0x4 */
83#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
84#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
85#define SSH2_MSG_KEXINIT 20 /* 0x14 */
86#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
87#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
88#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
89#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
95#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
96#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
97#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
98#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
99#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
100#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
101#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
102#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
103#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
104#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
105#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
106#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
107#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
108#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
109
9005f3ba 110#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
111#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
112#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
113#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
114#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
115#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
116#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
117#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
118#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
119#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
120#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
121
d211621f 122#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
123#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
124#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
125#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
126
127#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 128
129#define GET_32BIT(cp) \
130 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
131 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
132 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
133 ((unsigned long)(unsigned char)(cp)[3]))
134
135#define PUT_32BIT(cp, value) { \
136 (cp)[0] = (unsigned char)((value) >> 24); \
137 (cp)[1] = (unsigned char)((value) >> 16); \
138 (cp)[2] = (unsigned char)((value) >> 8); \
139 (cp)[3] = (unsigned char)(value); }
140
7cca0d81 141enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 142
374330e2 143/* Coroutine mechanics for the sillier bits of the code */
144#define crBegin1 static int crLine = 0;
145#define crBegin2 switch(crLine) { case 0:;
146#define crBegin crBegin1; crBegin2;
147#define crFinish(z) } crLine = 0; return (z)
148#define crFinishV } crLine = 0; return
149#define crReturn(z) \
150 do {\
151 crLine=__LINE__; return (z); case __LINE__:;\
152 } while (0)
153#define crReturnV \
154 do {\
155 crLine=__LINE__; return; case __LINE__:;\
156 } while (0)
157#define crStop(z) do{ crLine = 0; return (z); }while(0)
158#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 159#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 160#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 161
57476f6b 162extern const struct ssh_cipher ssh_3des;
163extern const struct ssh_cipher ssh_3des_ssh2;
164extern const struct ssh_cipher ssh_des;
165extern const struct ssh_cipher ssh_blowfish_ssh1;
166extern const struct ssh_cipher ssh_blowfish_ssh2;
e5574168 167
9c964e85 168extern char *x11_init (Socket *, char *, void *, char **);
169extern void x11_close (Socket);
170extern void x11_send (Socket , char *, int);
171extern void x11_invent_auth(char *, int, char *, int);
172
5e8358ad 173/*
174 * Ciphers for SSH2. We miss out single-DES because it isn't
175 * supported; also 3DES and Blowfish are both done differently from
176 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
177 * endianness and different-sized keys.)
5e8358ad 178 */
57476f6b 179const static struct ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 };
e5574168 180
57476f6b 181extern const struct ssh_kex ssh_diffiehellman;
182const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
e5574168 183
e055a386 184extern const struct ssh_signkey ssh_dss;
185const static struct ssh_signkey *hostkey_algs[] = { &ssh_dss };
e5574168 186
8b2715b2 187extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy;
e5574168 188
d39f364a 189static void nullmac_key(unsigned char *key) { }
e5574168 190static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
191static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
57476f6b 192const static struct ssh_mac ssh_mac_none = {
d39f364a 193 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 194};
8b2715b2 195const static struct ssh_mac *macs[] = {
196 &ssh_sha1, &ssh_md5, &ssh_mac_none };
197const static struct ssh_mac *buggymacs[] = {
198 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
e5574168 199
4ba9b64b 200static void ssh_comp_none_init(void) { }
201static int ssh_comp_none_block(unsigned char *block, int len,
202 unsigned char **outblock, int *outlen) {
203 return 0;
204}
57476f6b 205const static struct ssh_compress ssh_comp_none = {
4ba9b64b 206 "none",
207 ssh_comp_none_init, ssh_comp_none_block,
208 ssh_comp_none_init, ssh_comp_none_block
e5574168 209};
4ba9b64b 210extern const struct ssh_compress ssh_zlib;
211const static struct ssh_compress *compressions[] = {
212 &ssh_zlib, &ssh_comp_none };
374330e2 213
783415f8 214enum { /* channel types */
215 CHAN_MAINSESSION,
216 CHAN_X11,
217 CHAN_AGENT,
218};
219
dacbd0e8 220/*
221 * 2-3-4 tree storing channels.
222 */
223struct ssh_channel {
d211621f 224 unsigned remoteid, localid;
dacbd0e8 225 int type;
226 int closes;
783415f8 227 struct ssh2_data_channel {
228 unsigned char *outbuffer;
229 unsigned outbuflen, outbufsize;
230 unsigned remwindow, remmaxpkt;
231 } v2;
dacbd0e8 232 union {
233 struct ssh_agent_channel {
234 unsigned char *message;
235 unsigned char msglen[4];
236 int lensofar, totallen;
237 } a;
9c964e85 238 struct ssh_x11_channel {
239 Socket s;
783415f8 240 } x11;
dacbd0e8 241 } u;
242};
57476f6b 243
244struct Packet {
245 long length;
246 int type;
247 unsigned char *data;
248 unsigned char *body;
249 long savedpos;
250 long maxlen;
251};
252
0db56f73 253static SHA_State exhash, exhashbase;
57476f6b 254
8df7a775 255static Socket s = NULL;
57476f6b 256
257static unsigned char session_key[32];
4ba9b64b 258static int ssh1_compressing;
db7d555c 259static int ssh_agentfwd_enabled;
9c964e85 260static int ssh_X11_fwd_enabled;
57476f6b 261static const struct ssh_cipher *cipher = NULL;
262static const struct ssh_cipher *cscipher = NULL;
263static const struct ssh_cipher *sccipher = NULL;
264static const struct ssh_mac *csmac = NULL;
265static const struct ssh_mac *scmac = NULL;
266static const struct ssh_compress *cscomp = NULL;
267static const struct ssh_compress *sccomp = NULL;
268static const struct ssh_kex *kex = NULL;
e055a386 269static const struct ssh_signkey *hostkey = NULL;
57476f6b 270int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
271
272static char *savedhost;
273static int savedport;
274static int ssh_send_ok;
275
dacbd0e8 276static tree234 *ssh_channels; /* indexed by local id */
57476f6b 277static struct ssh_channel *mainchan; /* primary session channel */
278
279static enum {
3687d221 280 SSH_STATE_PREPACKET,
57476f6b 281 SSH_STATE_BEFORE_SIZE,
282 SSH_STATE_INTERMED,
283 SSH_STATE_SESSION,
284 SSH_STATE_CLOSED
3687d221 285} ssh_state = SSH_STATE_PREPACKET;
57476f6b 286
3687d221 287static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 288
289static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
290static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
291
292static int ssh_version;
293static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
294static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
295static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
296static void ssh_size(void);
3687d221 297static void ssh_special (Telnet_Special);
783415f8 298static void ssh2_try_send(struct ssh_channel *c);
299static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
57476f6b 300
301static int (*s_rdpkt)(unsigned char **data, int *datalen);
302
303static struct rdpkt1_state_tag {
304 long len, pad, biglen, to_read;
305 unsigned long realcrc, gotcrc;
306 unsigned char *p;
307 int i;
308 int chunk;
309} rdpkt1_state;
310
960e736a 311static struct rdpkt2_state_tag {
312 long len, pad, payload, packetlen, maclen;
313 int i;
314 int cipherblk;
315 unsigned long incoming_sequence;
316} rdpkt2_state;
317
dacbd0e8 318static int ssh_channelcmp(void *av, void *bv) {
319 struct ssh_channel *a = (struct ssh_channel *)av;
320 struct ssh_channel *b = (struct ssh_channel *)bv;
321 if (a->localid < b->localid) return -1;
322 if (a->localid > b->localid) return +1;
323 return 0;
324}
325static int ssh_channelfind(void *av, void *bv) {
d211621f 326 unsigned *a = (unsigned *)av;
dacbd0e8 327 struct ssh_channel *b = (struct ssh_channel *)bv;
328 if (*a < b->localid) return -1;
329 if (*a > b->localid) return +1;
330 return 0;
331}
332
374330e2 333static void c_write (char *buf, int len) {
67779be7 334 if ((flags & FLAG_STDERR)) {
4017be6d 335 int i;
336 for (i = 0; i < len; i++)
337 if (buf[i] != '\r')
338 fputc(buf[i], stderr);
fb09bf1c 339 return;
340 }
fe50e814 341 from_backend(1, buf, len);
3bdaf79d 342}
343
fb09bf1c 344/*
345 * Collect incoming data in the incoming packet buffer.
e5574168 346 * Decipher and verify the packet when it is completely read.
347 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 348 * Update the *data and *datalen variables.
349 * Return the additional nr of bytes needed, or 0 when
350 * a complete packet is available.
351 */
e5574168 352static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 353{
57476f6b 354 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 355
356 crBegin;
374330e2 357
fb09bf1c 358next_packet:
37508af4 359
fb09bf1c 360 pktin.type = 0;
361 pktin.length = 0;
374330e2 362
57476f6b 363 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 364 while ((*datalen) == 0)
57476f6b 365 crReturn(4-st->i);
366 st->len = (st->len << 8) + **data;
fb09bf1c 367 (*data)++, (*datalen)--;
368 }
374330e2 369
fb09bf1c 370#ifdef FWHACK
57476f6b 371 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
372 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 373 }
374#endif
374330e2 375
57476f6b 376 st->pad = 8 - (st->len % 8);
377 st->biglen = st->len + st->pad;
378 pktin.length = st->len - 5;
fb09bf1c 379
57476f6b 380 if (pktin.maxlen < st->biglen) {
381 pktin.maxlen = st->biglen;
dcbde236 382 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
383 srealloc(pktin.data, st->biglen+APIEXTRA));
fb09bf1c 384 if (!pktin.data)
385 fatalbox("Out of memory");
386 }
374330e2 387
57476f6b 388 st->to_read = st->biglen;
389 st->p = pktin.data;
390 while (st->to_read > 0) {
391 st->chunk = st->to_read;
fb09bf1c 392 while ((*datalen) == 0)
57476f6b 393 crReturn(st->to_read);
394 if (st->chunk > (*datalen))
395 st->chunk = (*datalen);
396 memcpy(st->p, *data, st->chunk);
397 *data += st->chunk;
398 *datalen -= st->chunk;
399 st->p += st->chunk;
400 st->to_read -= st->chunk;
fb09bf1c 401 }
374330e2 402
fb09bf1c 403 if (cipher)
57476f6b 404 cipher->decrypt(pktin.data, st->biglen);
698a5108 405#if 0
406 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
407 for (st->i = 0; st->i < st->biglen; st->i++)
408 debug((" %02x", (unsigned char)pktin.data[st->i]));
409 debug(("\r\n"));
410#endif
374330e2 411
57476f6b 412 st->realcrc = crc32(pktin.data, st->biglen-4);
413 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
414 if (st->gotcrc != st->realcrc) {
8d5de777 415 bombout(("Incorrect CRC received on packet"));
416 crReturn(0);
fb09bf1c 417 }
572f871e 418
4ba9b64b 419 pktin.body = pktin.data + st->pad + 1;
420
421 if (ssh1_compressing) {
422 unsigned char *decompblk;
423 int decomplen;
424#if 0
425 int i;
426 debug(("Packet payload pre-decompression:\n"));
427 for (i = -1; i < pktin.length; i++)
428 debug((" %02x", (unsigned char)pktin.body[i]));
429 debug(("\r\n"));
430#endif
431 zlib_decompress_block(pktin.body-1, pktin.length+1,
432 &decompblk, &decomplen);
433
434 if (pktin.maxlen < st->pad + decomplen) {
435 pktin.maxlen = st->pad + decomplen;
dcbde236 436 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
58298665 437 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 438 if (!pktin.data)
439 fatalbox("Out of memory");
440 }
441
442 memcpy(pktin.body-1, decompblk, decomplen);
dcbde236 443 sfree(decompblk);
4ba9b64b 444 pktin.length = decomplen-1;
445#if 0
446 debug(("Packet payload post-decompression:\n"));
447 for (i = -1; i < pktin.length; i++)
448 debug((" %02x", (unsigned char)pktin.body[i]));
449 debug(("\r\n"));
450#endif
451 }
452
e5574168 453 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
454 pktin.type == SSH1_SMSG_STDERR_DATA ||
455 pktin.type == SSH1_MSG_DEBUG ||
18515c51 456 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
457 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 458 long strlen = GET_32BIT(pktin.body);
8d5de777 459 if (strlen + 4 != pktin.length) {
460 bombout(("Received data packet with bogus string length"));
461 crReturn(0);
462 }
fb09bf1c 463 }
464
4ba9b64b 465 pktin.type = pktin.body[-1];
466
e5574168 467 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 468 /* log debug message */
469 char buf[80];
470 int strlen = GET_32BIT(pktin.body);
471 strcpy(buf, "Remote: ");
472 if (strlen > 70) strlen = 70;
473 memcpy(buf+8, pktin.body+4, strlen);
474 buf[8+strlen] = '\0';
475 logevent(buf);
476 goto next_packet;
e5574168 477 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 478 /* do nothing */
479 goto next_packet;
480 }
481
482 crFinish(0);
483}
484
e5574168 485static int ssh2_rdpkt(unsigned char **data, int *datalen)
486{
960e736a 487 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 488
489 crBegin;
490
491next_packet:
e5574168 492 pktin.type = 0;
493 pktin.length = 0;
960e736a 494 if (sccipher)
495 st->cipherblk = sccipher->blksize;
e5574168 496 else
960e736a 497 st->cipherblk = 8;
498 if (st->cipherblk < 8)
499 st->cipherblk = 8;
500
501 if (pktin.maxlen < st->cipherblk) {
502 pktin.maxlen = st->cipherblk;
dcbde236 503 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
504 srealloc(pktin.data, st->cipherblk+APIEXTRA));
e5574168 505 if (!pktin.data)
506 fatalbox("Out of memory");
507 }
508
509 /*
510 * Acquire and decrypt the first block of the packet. This will
511 * contain the length and padding details.
512 */
960e736a 513 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 514 while ((*datalen) == 0)
960e736a 515 crReturn(st->cipherblk-st->i);
516 pktin.data[st->i] = *(*data)++;
e5574168 517 (*datalen)--;
518 }
519#ifdef FWHACK
520 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
521 /* FIXME */
522 }
523#endif
524 if (sccipher)
960e736a 525 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 526
527 /*
528 * Now get the length and padding figures.
529 */
960e736a 530 st->len = GET_32BIT(pktin.data);
531 st->pad = pktin.data[4];
e5574168 532
533 /*
534 * This enables us to deduce the payload length.
535 */
960e736a 536 st->payload = st->len - st->pad - 1;
e5574168 537
960e736a 538 pktin.length = st->payload + 5;
e5574168 539
540 /*
541 * So now we can work out the total packet length.
542 */
960e736a 543 st->packetlen = st->len + 4;
544 st->maclen = scmac ? scmac->len : 0;
e5574168 545
546 /*
547 * Adjust memory allocation if packet is too big.
548 */
960e736a 549 if (pktin.maxlen < st->packetlen+st->maclen) {
550 pktin.maxlen = st->packetlen+st->maclen;
dcbde236 551 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
552 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
e5574168 553 if (!pktin.data)
554 fatalbox("Out of memory");
555 }
556
557 /*
558 * Read and decrypt the remainder of the packet.
559 */
960e736a 560 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
e5574168 561 while ((*datalen) == 0)
960e736a 562 crReturn(st->packetlen + st->maclen - st->i);
563 pktin.data[st->i] = *(*data)++;
e5574168 564 (*datalen)--;
565 }
566 /* Decrypt everything _except_ the MAC. */
567 if (sccipher)
960e736a 568 sccipher->decrypt(pktin.data + st->cipherblk,
569 st->packetlen - st->cipherblk);
e5574168 570
7cca0d81 571#if 0
960e736a 572 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
573 for (st->i = 0; st->i < st->packetlen; st->i++)
574 debug((" %02x", (unsigned char)pktin.data[st->i]));
d39f364a 575 debug(("\r\n"));
7cca0d81 576#endif
d39f364a 577
e5574168 578 /*
579 * Check the MAC.
580 */
960e736a 581 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
8d5de777 582 bombout(("Incorrect MAC received on packet"));
583 crReturn(0);
584 }
960e736a 585 st->incoming_sequence++; /* whether or not we MACed */
e5574168 586
4ba9b64b 587 /*
588 * Decompress packet payload.
589 */
590 {
591 unsigned char *newpayload;
592 int newlen;
593 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
594 &newpayload, &newlen)) {
595 if (pktin.maxlen < newlen+5) {
596 pktin.maxlen = newlen+5;
dcbde236 597 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
598 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
4ba9b64b 599 if (!pktin.data)
600 fatalbox("Out of memory");
601 }
602 pktin.length = 5 + newlen;
603 memcpy(pktin.data+5, newpayload, newlen);
604#if 0
605 debug(("Post-decompression payload:\r\n"));
606 for (st->i = 0; st->i < newlen; st->i++)
607 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
608 debug(("\r\n"));
609#endif
610
dcbde236 611 sfree(newpayload);
4ba9b64b 612 }
613 }
614
e5574168 615 pktin.savedpos = 6;
616 pktin.type = pktin.data[5];
e5574168 617
7cca0d81 618 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
619 goto next_packet; /* FIXME: print DEBUG message */
e5574168 620
621 crFinish(0);
622}
623
4ba9b64b 624static void ssh1_pktout_size(int len) {
374330e2 625 int pad, biglen;
626
627 len += 5; /* type and CRC */
628 pad = 8 - (len%8);
629 biglen = len + pad;
630
631 pktout.length = len-5;
632 if (pktout.maxlen < biglen) {
633 pktout.maxlen = biglen;
8f203108 634#ifdef MSCRYPTOAPI
fb09bf1c 635 /* Allocate enough buffer space for extra block
8f203108 636 * for MS CryptEncrypt() */
dcbde236 637 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
638 srealloc(pktout.data, biglen+12));
8f203108 639#else
dcbde236 640 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
641 srealloc(pktout.data, biglen+4));
8f203108 642#endif
374330e2 643 if (!pktout.data)
644 fatalbox("Out of memory");
645 }
4ba9b64b 646 pktout.body = pktout.data+4+pad+1;
647}
374330e2 648
4ba9b64b 649static void s_wrpkt_start(int type, int len) {
650 ssh1_pktout_size(len);
374330e2 651 pktout.type = type;
374330e2 652}
653
654static void s_wrpkt(void) {
655 int pad, len, biglen, i;
656 unsigned long crc;
657
4ba9b64b 658 pktout.body[-1] = pktout.type;
659
660 if (ssh1_compressing) {
661 unsigned char *compblk;
662 int complen;
663#if 0
664 debug(("Packet payload pre-compression:\n"));
665 for (i = -1; i < pktout.length; i++)
666 debug((" %02x", (unsigned char)pktout.body[i]));
667 debug(("\r\n"));
668#endif
669 zlib_compress_block(pktout.body-1, pktout.length+1,
670 &compblk, &complen);
671 ssh1_pktout_size(complen-1);
672 memcpy(pktout.body-1, compblk, complen);
dcbde236 673 sfree(compblk);
4ba9b64b 674#if 0
675 debug(("Packet payload post-compression:\n"));
676 for (i = -1; i < pktout.length; i++)
677 debug((" %02x", (unsigned char)pktout.body[i]));
678 debug(("\r\n"));
679#endif
680 }
681
374330e2 682 len = pktout.length + 5; /* type and CRC */
683 pad = 8 - (len%8);
684 biglen = len + pad;
685
374330e2 686 for (i=0; i<pad; i++)
687 pktout.data[i+4] = random_byte();
688 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 689 PUT_32BIT(pktout.data+biglen, crc);
690 PUT_32BIT(pktout.data, len);
374330e2 691
698a5108 692#if 0
693 debug(("Sending packet len=%d\r\n", biglen+4));
694 for (i = 0; i < biglen+4; i++)
695 debug((" %02x", (unsigned char)pktout.data[i]));
696 debug(("\r\n"));
697#endif
374330e2 698 if (cipher)
699 cipher->encrypt(pktout.data+4, biglen);
700
8df7a775 701 sk_write(s, pktout.data, biglen+4);
374330e2 702}
703
fb09bf1c 704/*
705 * Construct a packet with the specified contents and
706 * send it to the server.
707 */
708static void send_packet(int pkttype, ...)
709{
710 va_list args;
711 unsigned char *p, *argp, argchar;
712 unsigned long argint;
713 int pktlen, argtype, arglen;
7cca0d81 714 Bignum bn;
fb09bf1c 715
716 pktlen = 0;
717 va_start(args, pkttype);
718 while ((argtype = va_arg(args, int)) != PKT_END) {
719 switch (argtype) {
720 case PKT_INT:
721 (void) va_arg(args, int);
722 pktlen += 4;
723 break;
724 case PKT_CHAR:
725 (void) va_arg(args, char);
726 pktlen++;
727 break;
728 case PKT_DATA:
729 (void) va_arg(args, unsigned char *);
730 arglen = va_arg(args, int);
731 pktlen += arglen;
732 break;
733 case PKT_STR:
734 argp = va_arg(args, unsigned char *);
735 arglen = strlen(argp);
736 pktlen += 4 + arglen;
737 break;
7cca0d81 738 case PKT_BIGNUM:
739 bn = va_arg(args, Bignum);
5c58ad2d 740 pktlen += ssh1_bignum_length(bn);
7cca0d81 741 break;
fb09bf1c 742 default:
743 assert(0);
744 }
745 }
746 va_end(args);
747
748 s_wrpkt_start(pkttype, pktlen);
749 p = pktout.body;
750
751 va_start(args, pkttype);
752 while ((argtype = va_arg(args, int)) != PKT_END) {
753 switch (argtype) {
754 case PKT_INT:
755 argint = va_arg(args, int);
756 PUT_32BIT(p, argint);
757 p += 4;
758 break;
759 case PKT_CHAR:
760 argchar = va_arg(args, unsigned char);
761 *p = argchar;
762 p++;
763 break;
764 case PKT_DATA:
765 argp = va_arg(args, unsigned char *);
766 arglen = va_arg(args, int);
767 memcpy(p, argp, arglen);
768 p += arglen;
769 break;
770 case PKT_STR:
771 argp = va_arg(args, unsigned char *);
772 arglen = strlen(argp);
773 PUT_32BIT(p, arglen);
774 memcpy(p + 4, argp, arglen);
775 p += 4 + arglen;
776 break;
7cca0d81 777 case PKT_BIGNUM:
778 bn = va_arg(args, Bignum);
5c58ad2d 779 p += ssh1_write_bignum(p, bn);
7cca0d81 780 break;
fb09bf1c 781 }
782 }
783 va_end(args);
784
785 s_wrpkt();
786}
787
9697bfd2 788static int ssh_versioncmp(char *a, char *b) {
789 char *ae, *be;
790 unsigned long av, bv;
791
43aa02a7 792 av = strtoul(a, &ae, 10);
793 bv = strtoul(b, &be, 10);
9697bfd2 794 if (av != bv) return (av < bv ? -1 : +1);
795 if (*ae == '.') ae++;
796 if (*be == '.') be++;
43aa02a7 797 av = strtoul(ae, &ae, 10);
798 bv = strtoul(be, &be, 10);
9697bfd2 799 if (av != bv) return (av < bv ? -1 : +1);
800 return 0;
801}
802
e5574168 803
804/*
805 * Utility routine for putting an SSH-protocol `string' into a SHA
806 * state.
807 */
808#include <stdio.h>
75cab814 809static void sha_string(SHA_State *s, void *str, int len) {
e5574168 810 unsigned char lenblk[4];
e5574168 811 PUT_32BIT(lenblk, len);
e5574168 812 SHA_Bytes(s, lenblk, 4);
e5574168 813 SHA_Bytes(s, str, len);
814}
815
7cca0d81 816/*
817 * SSH2 packet construction functions.
818 */
783415f8 819static void ssh2_pkt_ensure(int length) {
820 if (pktout.maxlen < length) {
821 pktout.maxlen = length + 256;
dcbde236 822 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
823 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
7cca0d81 824 if (!pktout.data)
825 fatalbox("Out of memory");
826 }
783415f8 827}
828static void ssh2_pkt_adddata(void *data, int len) {
829 pktout.length += len;
830 ssh2_pkt_ensure(pktout.length);
7cca0d81 831 memcpy(pktout.data+pktout.length-len, data, len);
832}
75cab814 833static void ssh2_pkt_addbyte(unsigned char byte) {
7cca0d81 834 ssh2_pkt_adddata(&byte, 1);
835}
75cab814 836static void ssh2_pkt_init(int pkt_type) {
7cca0d81 837 pktout.length = 5;
838 ssh2_pkt_addbyte((unsigned char)pkt_type);
839}
75cab814 840static void ssh2_pkt_addbool(unsigned char value) {
7cca0d81 841 ssh2_pkt_adddata(&value, 1);
842}
75cab814 843static void ssh2_pkt_adduint32(unsigned long value) {
7cca0d81 844 unsigned char x[4];
845 PUT_32BIT(x, value);
846 ssh2_pkt_adddata(x, 4);
847}
75cab814 848static void ssh2_pkt_addstring_start(void) {
7cca0d81 849 ssh2_pkt_adduint32(0);
850 pktout.savedpos = pktout.length;
851}
75cab814 852static void ssh2_pkt_addstring_str(char *data) {
7cca0d81 853 ssh2_pkt_adddata(data, strlen(data));
854 PUT_32BIT(pktout.data + pktout.savedpos - 4,
855 pktout.length - pktout.savedpos);
856}
75cab814 857static void ssh2_pkt_addstring_data(char *data, int len) {
7cca0d81 858 ssh2_pkt_adddata(data, len);
859 PUT_32BIT(pktout.data + pktout.savedpos - 4,
860 pktout.length - pktout.savedpos);
861}
75cab814 862static void ssh2_pkt_addstring(char *data) {
7cca0d81 863 ssh2_pkt_addstring_start();
864 ssh2_pkt_addstring_str(data);
865}
75cab814 866static char *ssh2_mpint_fmt(Bignum b, int *len) {
7cca0d81 867 unsigned char *p;
868 int i, n = b[0];
dcbde236 869 p = smalloc(n * 2 + 1);
7cca0d81 870 if (!p)
871 fatalbox("out of memory");
872 p[0] = 0;
873 for (i = 0; i < n; i++) {
874 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
875 p[i*2+2] = (b[n-i] ) & 0xFF;
876 }
877 i = 0;
878 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
879 i++;
880 memmove(p, p+i, n*2+1-i);
881 *len = n*2+1-i;
882 return p;
883}
75cab814 884static void ssh2_pkt_addmp(Bignum b) {
7cca0d81 885 unsigned char *p;
886 int len;
887 p = ssh2_mpint_fmt(b, &len);
888 ssh2_pkt_addstring_start();
889 ssh2_pkt_addstring_data(p, len);
dcbde236 890 sfree(p);
7cca0d81 891}
75cab814 892static void ssh2_pkt_send(void) {
7cca0d81 893 int cipherblk, maclen, padding, i;
894 static unsigned long outgoing_sequence = 0;
895
896 /*
4ba9b64b 897 * Compress packet payload.
898 */
899#if 0
900 debug(("Pre-compression payload:\r\n"));
901 for (i = 5; i < pktout.length; i++)
902 debug((" %02x", (unsigned char)pktout.data[i]));
903 debug(("\r\n"));
904#endif
905 {
906 unsigned char *newpayload;
907 int newlen;
908 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
909 &newpayload, &newlen)) {
910 pktout.length = 5;
911 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 912 sfree(newpayload);
4ba9b64b 913 }
914 }
915
916 /*
7cca0d81 917 * Add padding. At least four bytes, and must also bring total
918 * length (minus MAC) up to a multiple of the block size.
919 */
920 cipherblk = cipher ? cipher->blksize : 8; /* block size */
921 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
922 padding = 4;
923 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 924 maclen = csmac ? csmac->len : 0;
925 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 926 pktout.data[4] = padding;
927 for (i = 0; i < padding; i++)
928 pktout.data[pktout.length + i] = random_byte();
929 PUT_32BIT(pktout.data, pktout.length + padding - 4);
930 if (csmac)
931 csmac->generate(pktout.data, pktout.length + padding,
932 outgoing_sequence);
933 outgoing_sequence++; /* whether or not we MACed */
934
935#if 0
936 debug(("Sending packet len=%d\r\n", pktout.length+padding));
937 for (i = 0; i < pktout.length+padding; i++)
938 debug((" %02x", (unsigned char)pktout.data[i]));
939 debug(("\r\n"));
940#endif
941
942 if (cscipher)
943 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 944
8df7a775 945 sk_write(s, pktout.data, pktout.length + padding + maclen);
7cca0d81 946}
947
948#if 0
949void bndebug(char *string, Bignum b) {
950 unsigned char *p;
951 int i, len;
952 p = ssh2_mpint_fmt(b, &len);
953 debug(("%s", string));
954 for (i = 0; i < len; i++)
955 debug((" %02x", p[i]));
956 debug(("\r\n"));
dcbde236 957 sfree(p);
7cca0d81 958}
959#endif
960
75cab814 961static void sha_mpint(SHA_State *s, Bignum b) {
7cca0d81 962 unsigned char *p;
963 int len;
964 p = ssh2_mpint_fmt(b, &len);
965 sha_string(s, p, len);
dcbde236 966 sfree(p);
7cca0d81 967}
968
969/*
970 * SSH2 packet decode functions.
971 */
75cab814 972static unsigned long ssh2_pkt_getuint32(void) {
7cca0d81 973 unsigned long value;
974 if (pktin.length - pktin.savedpos < 4)
975 return 0; /* arrgh, no way to decline (FIXME?) */
976 value = GET_32BIT(pktin.data+pktin.savedpos);
977 pktin.savedpos += 4;
978 return value;
979}
75cab814 980static void ssh2_pkt_getstring(char **p, int *length) {
7cca0d81 981 *p = NULL;
982 if (pktin.length - pktin.savedpos < 4)
983 return;
984 *length = GET_32BIT(pktin.data+pktin.savedpos);
985 pktin.savedpos += 4;
986 if (pktin.length - pktin.savedpos < *length)
987 return;
988 *p = pktin.data+pktin.savedpos;
989 pktin.savedpos += *length;
990}
75cab814 991static Bignum ssh2_pkt_getmp(void) {
7cca0d81 992 char *p;
993 int i, j, length;
994 Bignum b;
995
996 ssh2_pkt_getstring(&p, &length);
997 if (!p)
998 return NULL;
8d5de777 999 if (p[0] & 0x80) {
1000 bombout(("internal error: Can't handle negative mpints"));
1001 return NULL;
1002 }
7cca0d81 1003 b = newbn((length+1)/2);
1004 for (i = 0; i < length; i++) {
1005 j = length - 1 - i;
1006 if (j & 1)
1007 b[j/2+1] |= ((unsigned char)p[i]) << 8;
1008 else
1009 b[j/2+1] |= ((unsigned char)p[i]);
1010 }
6b4e00ee 1011 while (b[0] > 1 && b[b[0]] == 0) b[0]--;
7cca0d81 1012 return b;
1013}
1014
8df7a775 1015static int do_ssh_init(unsigned char c) {
1016 static char *vsp;
1017 static char version[10];
1018 static char vstring[80];
1019 static char vlog[sizeof(vstring)+20];
1020 static int i;
374330e2 1021
8df7a775 1022 crBegin;
1023
1024 /* Search for the string "SSH-" in the input. */
374330e2 1025 i = 0;
8df7a775 1026 while (1) {
1027 static const int transS[] = { 1, 2, 2, 1 };
1028 static const int transH[] = { 0, 0, 3, 0 };
1029 static const int transminus[] = { 0, 0, 0, -1 };
1030 if (c == 'S') i = transS[i];
1031 else if (c == 'H') i = transH[i];
1032 else if (c == '-') i = transminus[i];
374330e2 1033 else i = 0;
8df7a775 1034 if (i < 0)
1035 break;
1036 crReturn(1); /* get another character */
374330e2 1037 }
8df7a775 1038
c5e9c988 1039 strcpy(vstring, "SSH-");
1040 vsp = vstring+4;
374330e2 1041 i = 0;
1042 while (1) {
8df7a775 1043 crReturn(1); /* get another char */
c5e9c988 1044 if (vsp < vstring+sizeof(vstring)-1)
1045 *vsp++ = c;
374330e2 1046 if (i >= 0) {
1047 if (c == '-') {
1048 version[i] = '\0';
1049 i = -1;
1050 } else if (i < sizeof(version)-1)
1051 version[i++] = c;
1052 }
1053 else if (c == '\n')
1054 break;
1055 }
1056
db7d555c 1057 ssh_agentfwd_enabled = FALSE;
960e736a 1058 rdpkt2_state.incoming_sequence = 0;
1059
c5e9c988 1060 *vsp = 0;
1061 sprintf(vlog, "Server version: %s", vstring);
1062 vlog[strcspn(vlog, "\r\n")] = '\0';
1063 logevent(vlog);
1064
adf799dd 1065 /*
1066 * Server version "1.99" means we can choose whether we use v1
1067 * or v2 protocol. Choice is based on cfg.sshprot.
1068 */
1069 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 1070 /*
1071 * This is a v2 server. Begin v2 protocol.
1072 */
1073 char *verstring = "SSH-2.0-PuTTY";
0db56f73 1074 SHA_Init(&exhashbase);
e5574168 1075 /*
1076 * Hash our version string and their version string.
1077 */
0db56f73 1078 sha_string(&exhashbase, verstring, strlen(verstring));
1079 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
e5574168 1080 sprintf(vstring, "%s\n", verstring);
1081 sprintf(vlog, "We claim version: %s", verstring);
1082 logevent(vlog);
1083 logevent("Using SSH protocol version 2");
8df7a775 1084 sk_write(s, vstring, strlen(vstring));
e5574168 1085 ssh_protocol = ssh2_protocol;
6abbf9e3 1086 ssh_version = 2;
e5574168 1087 s_rdpkt = ssh2_rdpkt;
1088 } else {
1089 /*
1090 * This is a v1 server. Begin v1 protocol.
1091 */
1092 sprintf(vstring, "SSH-%s-PuTTY\n",
1093 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1094 sprintf(vlog, "We claim version: %s", vstring);
1095 vlog[strcspn(vlog, "\r\n")] = '\0';
1096 logevent(vlog);
1097 logevent("Using SSH protocol version 1");
8df7a775 1098 sk_write(s, vstring, strlen(vstring));
e5574168 1099 ssh_protocol = ssh1_protocol;
6abbf9e3 1100 ssh_version = 1;
e5574168 1101 s_rdpkt = ssh1_rdpkt;
1102 }
3687d221 1103 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1104
1105 crFinish(0);
1106}
1107
1108static void ssh_gotdata(unsigned char *data, int datalen)
1109{
1110 crBegin;
1111
1112 /*
1113 * To begin with, feed the characters one by one to the
1114 * protocol initialisation / selection function do_ssh_init().
1115 * When that returns 0, we're done with the initial greeting
1116 * exchange and can move on to packet discipline.
1117 */
1118 while (1) {
1119 int ret;
1120 if (datalen == 0)
1121 crReturnV; /* more data please */
1122 ret = do_ssh_init(*data);
1123 data++; datalen--;
1124 if (ret == 0)
1125 break;
1126 }
1127
1128 /*
1129 * We emerge from that loop when the initial negotiation is
1130 * over and we have selected an s_rdpkt function. Now pass
1131 * everything to s_rdpkt, and then pass the resulting packets
1132 * to the proper protocol handler.
1133 */
1134 if (datalen == 0)
1135 crReturnV;
1136 while (1) {
1137 while (datalen > 0) {
1138 if ( s_rdpkt(&data, &datalen) == 0 ) {
1139 ssh_protocol(NULL, 0, 1);
1140 if (ssh_state == SSH_STATE_CLOSED) {
1141 return;
1142 }
1143 }
1144 }
1145 crReturnV;
1146 }
1147 crFinishV;
1148}
1149
340cf649 1150static int ssh_receive(Socket skt, int urgent, char *data, int len) {
8df7a775 1151 if (!len) {
1152 /* Connection has closed. */
6abb6cd7 1153 ssh_state = SSH_STATE_CLOSED;
8df7a775 1154 sk_close(s);
1155 s = NULL;
1156 return 0;
1157 }
1158 ssh_gotdata (data, len);
3257deae 1159 if (ssh_state == SSH_STATE_CLOSED) {
1160 if (s) {
1161 sk_close(s);
1162 s = NULL;
1163 }
1164 return 0;
1165 }
fef97f43 1166 return 1;
374330e2 1167}
1168
fb09bf1c 1169/*
8df7a775 1170 * Connect to specified host and port.
1171 * Returns an error message, or NULL on success.
1172 * Also places the canonical host name into `realhost'.
1173 */
1174static char *connect_to_host(char *host, int port, char **realhost)
1175{
1176 SockAddr addr;
1177 char *err;
1178#ifdef FWHACK
1179 char *FWhost;
1180 int FWport;
1181#endif
1182
dcbde236 1183 savedhost = smalloc(1+strlen(host));
8df7a775 1184 if (!savedhost)
1185 fatalbox("Out of memory");
1186 strcpy(savedhost, host);
1187
1188 if (port < 0)
1189 port = 22; /* default ssh port */
1190 savedport = port;
1191
1192#ifdef FWHACK
1193 FWhost = host;
1194 FWport = port;
1195 host = FWSTR;
1196 port = 23;
1197#endif
1198
1199 /*
1200 * Try to find host.
1201 */
1202 addr = sk_namelookup(host, realhost);
1203 if ( (err = sk_addr_error(addr)) )
1204 return err;
1205
1206#ifdef FWHACK
1207 *realhost = FWhost;
1208#endif
1209
1210 /*
1211 * Open socket.
1212 */
c91409da 1213 s = sk_new(addr, port, 0, ssh_receive);
8df7a775 1214 if ( (err = sk_socket_error(s)) )
1215 return err;
1216
1217#ifdef FWHACK
1218 sk_write(s, "connect ", 8);
1219 sk_write(s, FWhost, strlen(FWhost));
1220 {
1221 char buf[20];
1222 sprintf(buf, " %d\n", FWport);
1223 sk_write(s, buf, strlen(buf));
1224 }
1225#endif
1226
1227 return NULL;
1228}
1229
1230/*
fb09bf1c 1231 * Handle the key exchange and user authentication phases.
1232 */
e5574168 1233static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1234{
374330e2 1235 int i, j, len;
374330e2 1236 unsigned char *rsabuf, *keystr1, *keystr2;
1237 unsigned char cookie[8];
1238 struct RSAKey servkey, hostkey;
1239 struct MD5Context md5c;
ccbfb941 1240 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1241 static int tried_publickey;
1242 static unsigned char session_id[16];
bea1ef5f 1243 int cipher_type;
b585ec46 1244 static char username[100];
374330e2 1245
374330e2 1246 crBegin;
1247
fb09bf1c 1248 if (!ispkt) crWaitUntil(ispkt);
374330e2 1249
8d5de777 1250 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1251 bombout(("Public key packet not received"));
1252 crReturn(0);
1253 }
374330e2 1254
c5e9c988 1255 logevent("Received public keys");
374330e2 1256
c5e9c988 1257 memcpy(cookie, pktin.body, 8);
374330e2 1258
7cca0d81 1259 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1260 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1261
c5e9c988 1262 /*
1c2a93c4 1263 * Log the host key fingerprint.
c5e9c988 1264 */
c5e9c988 1265 {
1266 char logmsg[80];
1c2a93c4 1267 logevent("Host key fingerprint is:");
c5e9c988 1268 strcpy(logmsg, " ");
1c2a93c4 1269 hostkey.comment = NULL;
1270 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1271 &hostkey);
c5e9c988 1272 logevent(logmsg);
1273 }
1274
fb09bf1c 1275 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1276 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1277
c5e9c988 1278 MD5Init(&md5c);
374330e2 1279 MD5Update(&md5c, keystr2, hostkey.bytes);
1280 MD5Update(&md5c, keystr1, servkey.bytes);
1281 MD5Update(&md5c, pktin.body, 8);
374330e2 1282 MD5Final(session_id, &md5c);
1283
1284 for (i=0; i<32; i++)
1285 session_key[i] = random_byte();
1286
1287 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1288
dcbde236 1289 rsabuf = smalloc(len);
374330e2 1290 if (!rsabuf)
1291 fatalbox("Out of memory");
1292
89ee5268 1293 /*
1294 * Verify the host key.
1295 */
1296 {
1297 /*
1298 * First format the key into a string.
1299 */
1300 int len = rsastr_len(&hostkey);
d5859615 1301 char fingerprint[100];
dcbde236 1302 char *keystr = smalloc(len);
89ee5268 1303 if (!keystr)
1304 fatalbox("Out of memory");
1305 rsastr_fmt(keystr, &hostkey);
d5859615 1306 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1307 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
dcbde236 1308 sfree(keystr);
89ee5268 1309 }
374330e2 1310
1311 for (i=0; i<32; i++) {
1312 rsabuf[i] = session_key[i];
1313 if (i < 16)
1314 rsabuf[i] ^= session_id[i];
1315 }
1316
1317 if (hostkey.bytes > servkey.bytes) {
1318 rsaencrypt(rsabuf, 32, &servkey);
1319 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1320 } else {
1321 rsaencrypt(rsabuf, 32, &hostkey);
1322 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1323 }
1324
c5e9c988 1325 logevent("Encrypted session key");
1326
bea1ef5f 1327 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1328 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1329 SSH_CIPHER_3DES;
1330 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1331 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1332 cipher_type = SSH_CIPHER_3DES;
1333 }
c5e9c988 1334 switch (cipher_type) {
1335 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1336 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1337 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1338 }
bea1ef5f 1339
e5574168 1340 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1341 PKT_CHAR, cipher_type,
1342 PKT_DATA, cookie, 8,
1343 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1344 PKT_DATA, rsabuf, len,
1345 PKT_INT, 0,
1346 PKT_END);
1347
c5e9c988 1348 logevent("Trying to enable encryption...");
374330e2 1349
dcbde236 1350 sfree(rsabuf);
374330e2 1351
5e8358ad 1352 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1353 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1354 &ssh_3des;
374330e2 1355 cipher->sesskey(session_key);
1356
fb09bf1c 1357 crWaitUntil(ispkt);
374330e2 1358
8d5de777 1359 if (pktin.type != SSH1_SMSG_SUCCESS) {
1360 bombout(("Encryption not successfully enabled"));
1361 crReturn(0);
1362 }
374330e2 1363
c5e9c988 1364 logevent("Successfully started encryption");
1365
374330e2 1366 fflush(stdout);
1367 {
374330e2 1368 static int pos = 0;
1369 static char c;
67779be7 1370 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1371 c_write("login as: ", 10);
67779be7 1372 ssh_send_ok = 1;
374330e2 1373 while (pos >= 0) {
fb09bf1c 1374 crWaitUntil(!ispkt);
374330e2 1375 while (inlen--) switch (c = *in++) {
1376 case 10: case 13:
1377 username[pos] = 0;
1378 pos = -1;
1379 break;
1380 case 8: case 127:
1381 if (pos > 0) {
1382 c_write("\b \b", 3);
1383 pos--;
1384 }
1385 break;
1386 case 21: case 27:
1387 while (pos > 0) {
1388 c_write("\b \b", 3);
1389 pos--;
1390 }
1391 break;
1392 case 3: case 4:
1393 random_save_seed();
1394 exit(0);
1395 break;
1396 default:
40d24aa6 1397 if (((c >= ' ' && c <= '~') ||
1398 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1399 username[pos++] = c;
1400 c_write(&c, 1);
1401 }
1402 break;
1403 }
1404 }
1405 c_write("\r\n", 2);
1406 username[strcspn(username, "\n\r")] = '\0';
1407 } else {
374330e2 1408 strncpy(username, cfg.username, 99);
1409 username[99] = '\0';
374330e2 1410 }
fb09bf1c 1411
e5574168 1412 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1413 {
3c8e959b 1414 char userlog[22+sizeof(username)];
c5e9c988 1415 sprintf(userlog, "Sent username \"%s\"", username);
1416 logevent(userlog);
3c8e959b 1417 if (flags & FLAG_INTERACTIVE &&
1418 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1419 strcat(userlog, "\r\n");
1420 c_write(userlog, strlen(userlog));
1421 }
c5e9c988 1422 }
374330e2 1423 }
1424
fb09bf1c 1425 crWaitUntil(ispkt);
374330e2 1426
7cca0d81 1427 tried_publickey = 0;
1428
e5574168 1429 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1430 static char password[100];
a52f067e 1431 static char prompt[200];
374330e2 1432 static int pos;
1433 static char c;
ccbfb941 1434 static int pwpkt_type;
ccbfb941 1435 /*
1436 * Show password prompt, having first obtained it via a TIS
18515c51 1437 * or CryptoCard exchange if we're doing TIS or CryptoCard
1438 * authentication.
ccbfb941 1439 */
e5574168 1440 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1441 if (agent_exists()) {
1442 /*
1443 * Attempt RSA authentication using Pageant.
1444 */
1445 static unsigned char request[5], *response, *p;
1446 static int responselen;
1447 static int i, nkeys;
1448 static int authed = FALSE;
1449 void *r;
1450
1451 logevent("Pageant is running. Requesting keys.");
1452
1453 /* Request the keys held by the agent. */
1454 PUT_32BIT(request, 1);
1455 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1456 agent_query(request, 5, &r, &responselen);
1457 response = (unsigned char *)r;
1458 if (response) {
1459 p = response + 5;
1460 nkeys = GET_32BIT(p); p += 4;
1461 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1462 logevent(buf); }
1463 for (i = 0; i < nkeys; i++) {
1464 static struct RSAKey key;
1465 static Bignum challenge;
b8bb811a 1466 static char *commentp;
1467 static int commentlen;
5c58ad2d 1468
1469 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1470 logevent(buf); }
1471 p += 4;
1472 p += ssh1_read_bignum(p, &key.exponent);
1473 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1474 commentlen = GET_32BIT(p); p += 4;
1475 commentp = p; p += commentlen;
5c58ad2d 1476 send_packet(SSH1_CMSG_AUTH_RSA,
1477 PKT_BIGNUM, key.modulus, PKT_END);
1478 crWaitUntil(ispkt);
1479 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1480 logevent("Key refused");
1481 continue;
1482 }
1483 logevent("Received RSA challenge");
1484 ssh1_read_bignum(pktin.body, &challenge);
1485 {
1486 char *agentreq, *q, *ret;
1487 int len, retlen;
1488 len = 1 + 4; /* message type, bit count */
1489 len += ssh1_bignum_length(key.exponent);
1490 len += ssh1_bignum_length(key.modulus);
1491 len += ssh1_bignum_length(challenge);
1492 len += 16; /* session id */
1493 len += 4; /* response format */
dcbde236 1494 agentreq = smalloc(4 + len);
5c58ad2d 1495 PUT_32BIT(agentreq, len);
1496 q = agentreq + 4;
1497 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1498 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1499 q += 4;
1500 q += ssh1_write_bignum(q, key.exponent);
1501 q += ssh1_write_bignum(q, key.modulus);
1502 q += ssh1_write_bignum(q, challenge);
1503 memcpy(q, session_id, 16); q += 16;
1504 PUT_32BIT(q, 1); /* response format */
1505 agent_query(agentreq, len+4, &ret, &retlen);
dcbde236 1506 sfree(agentreq);
5c58ad2d 1507 if (ret) {
1508 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1509 logevent("Sending Pageant's response");
1510 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1511 PKT_DATA, ret+5, 16, PKT_END);
dcbde236 1512 sfree(ret);
5c58ad2d 1513 crWaitUntil(ispkt);
1514 if (pktin.type == SSH1_SMSG_SUCCESS) {
1515 logevent("Pageant's response accepted");
c4fa2fce 1516 if (flags & FLAG_VERBOSE) {
1517 c_write("Authenticated using RSA key \"",
1518 29);
1519 c_write(commentp, commentlen);
1520 c_write("\" from agent\r\n", 14);
1521 }
5c58ad2d 1522 authed = TRUE;
1523 } else
1524 logevent("Pageant's response not accepted");
1525 } else {
1526 logevent("Pageant failed to answer challenge");
dcbde236 1527 sfree(ret);
5c58ad2d 1528 }
1529 } else {
1530 logevent("No reply received from Pageant");
1531 }
1532 }
1533 freebn(key.exponent);
1534 freebn(key.modulus);
1535 freebn(challenge);
1536 if (authed)
1537 break;
1538 }
1539 }
1540 if (authed)
1541 break;
1542 }
7cca0d81 1543 if (*cfg.keyfile && !tried_publickey)
1544 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1545
a52f067e 1546 if (pktin.type == SSH1_SMSG_FAILURE &&
1547 cfg.try_tis_auth &&
1548 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1549 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1550 logevent("Requested TIS authentication");
1551 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1552 crWaitUntil(ispkt);
1553 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1554 logevent("TIS authentication declined");
1555 if (flags & FLAG_INTERACTIVE)
1556 c_write("TIS authentication refused.\r\n", 29);
1557 } else {
1558 int challengelen = ((pktin.body[0] << 24) |
1559 (pktin.body[1] << 16) |
1560 (pktin.body[2] << 8) |
1561 (pktin.body[3]));
1562 logevent("Received TIS challenge");
1563 if (challengelen > sizeof(prompt)-1)
1564 challengelen = sizeof(prompt)-1; /* prevent overrun */
1565 memcpy(prompt, pktin.body+4, challengelen);
1566 prompt[challengelen] = '\0';
1567 }
1568 }
1569 if (pktin.type == SSH1_SMSG_FAILURE &&
1570 cfg.try_tis_auth &&
1571 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1572 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1573 logevent("Requested CryptoCard authentication");
1574 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1575 crWaitUntil(ispkt);
1576 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1577 logevent("CryptoCard authentication declined");
1578 c_write("CryptoCard authentication refused.\r\n", 29);
1579 } else {
1580 int challengelen = ((pktin.body[0] << 24) |
1581 (pktin.body[1] << 16) |
1582 (pktin.body[2] << 8) |
1583 (pktin.body[3]));
1584 logevent("Received CryptoCard challenge");
1585 if (challengelen > sizeof(prompt)-1)
1586 challengelen = sizeof(prompt)-1; /* prevent overrun */
1587 memcpy(prompt, pktin.body+4, challengelen);
1588 strncpy(prompt + challengelen, "\r\nResponse : ",
1589 sizeof(prompt)-challengelen);
1590 prompt[sizeof(prompt)-1] = '\0';
1591 }
1592 }
1593 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1594 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1595 username, savedhost);
a52f067e 1596 }
1597 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1598 char *comment = NULL;
1599 if (flags & FLAG_VERBOSE)
1600 c_write("Trying public key authentication.\r\n", 35);
1601 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1602 if (flags & FLAG_VERBOSE)
1603 c_write("No passphrase required.\r\n", 25);
1604 goto tryauth;
1605 }
1606 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
dcbde236 1607 sfree(comment);
a52f067e 1608 }
1609
d8426c54 1610 if (ssh_get_password) {
85ee8208 1611 if (!ssh_get_password(prompt, password, sizeof(password))) {
1612 /*
1613 * get_password failed to get a password (for
1614 * example because one was supplied on the command
1615 * line which has already failed to work).
1616 * Terminate.
1617 */
1618 logevent("No more passwords to try");
1619 ssh_state = SSH_STATE_CLOSED;
1620 crReturn(1);
1621 }
fb09bf1c 1622 } else {
a52f067e 1623 c_write(prompt, strlen(prompt));
7cca0d81 1624 pos = 0;
67779be7 1625 ssh_send_ok = 1;
7cca0d81 1626 while (pos >= 0) {
1627 crWaitUntil(!ispkt);
1628 while (inlen--) switch (c = *in++) {
1629 case 10: case 13:
1630 password[pos] = 0;
1631 pos = -1;
1632 break;
1633 case 8: case 127:
1634 if (pos > 0)
1635 pos--;
1636 break;
1637 case 21: case 27:
1638 pos = 0;
1639 break;
1640 case 3: case 4:
1641 random_save_seed();
1642 exit(0);
1643 break;
1644 default:
1645 if (((c >= ' ' && c <= '~') ||
1646 ((unsigned char)c >= 160)) && pos < sizeof(password))
1647 password[pos++] = c;
1648 break;
1649 }
1650 }
1651 c_write("\r\n", 2);
a52f067e 1652 }
fb09bf1c 1653
7cca0d81 1654 tryauth:
1655 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1656 /*
1657 * Try public key authentication with the specified
1658 * key file.
1659 */
1660 static struct RSAKey pubkey;
1661 static Bignum challenge, response;
1662 static int i;
1663 static unsigned char buffer[32];
1664
1665 tried_publickey = 1;
6e522441 1666 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
7cca0d81 1667 if (i == 0) {
1668 c_write("Couldn't load public key from ", 30);
1669 c_write(cfg.keyfile, strlen(cfg.keyfile));
1670 c_write(".\r\n", 3);
1671 continue; /* go and try password */
1672 }
1673 if (i == -1) {
1674 c_write("Wrong passphrase.\r\n", 19);
1675 tried_publickey = 0;
1676 continue; /* try again */
1677 }
1678
1679 /*
1680 * Send a public key attempt.
1681 */
1682 send_packet(SSH1_CMSG_AUTH_RSA,
1683 PKT_BIGNUM, pubkey.modulus, PKT_END);
1684
1685 crWaitUntil(ispkt);
1686 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1687 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1688 continue; /* go and try password */
1689 }
8d5de777 1690 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1691 bombout(("Bizarre response to offer of public key"));
1692 crReturn(0);
1693 }
7cca0d81 1694 ssh1_read_bignum(pktin.body, &challenge);
1695 response = rsadecrypt(challenge, &pubkey);
1696 freebn(pubkey.private_exponent); /* burn the evidence */
1697
1698 for (i = 0; i < 32; i += 2) {
1699 buffer[i] = response[16-i/2] >> 8;
1700 buffer[i+1] = response[16-i/2] & 0xFF;
1701 }
1702
1703 MD5Init(&md5c);
1704 MD5Update(&md5c, buffer, 32);
1705 MD5Update(&md5c, session_id, 16);
1706 MD5Final(buffer, &md5c);
1707
1708 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1709 PKT_DATA, buffer, 16, PKT_END);
1710
1711 crWaitUntil(ispkt);
1712 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1713 if (flags & FLAG_VERBOSE)
1714 c_write("Failed to authenticate with our public key.\r\n",
1715 45);
7cca0d81 1716 continue; /* go and try password */
1717 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1718 bombout(("Bizarre response to RSA authentication response"));
1719 crReturn(0);
7cca0d81 1720 }
1721
1722 break; /* we're through! */
1723 } else {
1724 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1725 }
c5e9c988 1726 logevent("Sent password");
374330e2 1727 memset(password, 0, strlen(password));
fb09bf1c 1728 crWaitUntil(ispkt);
e5574168 1729 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1730 if (flags & FLAG_VERBOSE)
1731 c_write("Access denied\r\n", 15);
c5e9c988 1732 logevent("Authentication refused");
e5574168 1733 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1734 logevent("Received disconnect request");
85ee8208 1735 ssh_state = SSH_STATE_CLOSED;
1736 crReturn(1);
e5574168 1737 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1738 bombout(("Strange packet received, type %d", pktin.type));
1739 crReturn(0);
374330e2 1740 }
1741 }
1742
c5e9c988 1743 logevent("Authentication successful");
1744
fb09bf1c 1745 crFinish(1);
1746}
1747
9c964e85 1748void sshfwd_close(struct ssh_channel *c) {
783415f8 1749 if (c) {
1750 if (ssh_version == 1) {
1751 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
1752 } else {
1753 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
1754 ssh2_pkt_adduint32(c->remoteid);
1755 ssh2_pkt_send();
1756 }
1757 c->closes = 1;
1758 if (c->type == CHAN_X11) {
1759 c->u.x11.s = NULL;
1760 logevent("X11 connection terminated");
1761 }
1762 }
9c964e85 1763}
1764
1765void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
783415f8 1766 if (ssh_version == 1) {
1767 send_packet(SSH1_MSG_CHANNEL_DATA,
1768 PKT_INT, c->remoteid,
1769 PKT_INT, len,
1770 PKT_DATA, buf, len,
1771 PKT_END);
1772 } else {
1773 ssh2_add_channel_data(c, buf, len);
1774 ssh2_try_send(c);
1775 }
9c964e85 1776}
1777
e5574168 1778static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1779 crBegin;
1780
1781 random_init();
1782
e5574168 1783 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1784 crReturnV;
85ee8208 1785 }
1786 if (ssh_state == SSH_STATE_CLOSED)
1787 crReturnV;
fb09bf1c 1788
979310f1 1789 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1790 logevent("Requesting agent forwarding");
1791 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1792 do { crReturnV; } while (!ispkt);
1793 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1794 bombout(("Protocol confusion"));
1795 crReturnV;
dacbd0e8 1796 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1797 logevent("Agent forwarding refused");
db7d555c 1798 } else {
dacbd0e8 1799 logevent("Agent forwarding enabled");
db7d555c 1800 ssh_agentfwd_enabled = TRUE;
1801 }
dacbd0e8 1802 }
1803
9c964e85 1804 if (cfg.x11_forward) {
1805 char proto[20], data[64];
1806 logevent("Requesting X11 forwarding");
1807 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
1808 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
1809 PKT_STR, proto, PKT_STR, data,
1810 PKT_INT, 0,
1811 PKT_END);
1812 do { crReturnV; } while (!ispkt);
1813 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1814 bombout(("Protocol confusion"));
1815 crReturnV;
1816 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1817 logevent("X11 forwarding refused");
1818 } else {
1819 logevent("X11 forwarding enabled");
1820 ssh_X11_fwd_enabled = TRUE;
1821 }
1822 }
1823
fef97f43 1824 if (!cfg.nopty) {
e5574168 1825 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1826 PKT_STR, cfg.termtype,
1827 PKT_INT, rows, PKT_INT, cols,
1828 PKT_INT, 0, PKT_INT, 0,
1829 PKT_CHAR, 0,
1830 PKT_END);
fef97f43 1831 ssh_state = SSH_STATE_INTERMED;
1832 do { crReturnV; } while (!ispkt);
e5574168 1833 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1834 bombout(("Protocol confusion"));
1835 crReturnV;
e5574168 1836 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1837 c_write("Server refused to allocate pty\r\n", 32);
1838 }
c5e9c988 1839 logevent("Allocated pty");
374330e2 1840 }
1841
4ba9b64b 1842 if (cfg.compression) {
1843 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
1844 do { crReturnV; } while (!ispkt);
1845 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1846 bombout(("Protocol confusion"));
1847 crReturnV;
1848 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1849 c_write("Server refused to compress\r\n", 32);
1850 }
1851 logevent("Started compression");
1852 ssh1_compressing = TRUE;
1853 zlib_compress_init();
1854 zlib_decompress_init();
1855 }
1856
6abbf9e3 1857 if (*cfg.remote_cmd)
1858 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1859 else
1860 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1861 logevent("Started session");
374330e2 1862
1863 ssh_state = SSH_STATE_SESSION;
1864 if (size_needed)
1865 ssh_size();
3687d221 1866 if (eof_needed)
1867 ssh_special(TS_EOF);
374330e2 1868
8ccc75b0 1869 ssh_send_ok = 1;
dacbd0e8 1870 ssh_channels = newtree234(ssh_channelcmp);
6f34e365 1871 begin_session();
374330e2 1872 while (1) {
1873 crReturnV;
1874 if (ispkt) {
e5574168 1875 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1876 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1877 long len = GET_32BIT(pktin.body);
fe50e814 1878 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1879 pktin.body+4, len);
e5574168 1880 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1881 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1882 logevent("Received disconnect request");
3257deae 1883 crReturnV;
9c964e85 1884 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
1885 /* Remote side is trying to open a channel to talk to our
1886 * X-Server. Give them back a local channel number. */
1887 unsigned i;
1888 struct ssh_channel *c, *d;
1889 enum234 e;
1890
1891 logevent("Received X11 connect request");
1892 /* Refuse if X11 forwarding is disabled. */
1893 if (!ssh_X11_fwd_enabled) {
1894 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1895 PKT_INT, GET_32BIT(pktin.body),
1896 PKT_END);
1897 logevent("Rejected X11 connect request");
1898 } else {
1899 char *rh;
1900
1901 c = smalloc(sizeof(struct ssh_channel));
1902
1903 if ( x11_init(&c->u.x11.s, cfg.x11_display, c, &rh) != NULL ) {
1904 logevent("opening X11 forward connection failed");
1905 sfree(c);
1906 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1907 PKT_INT, GET_32BIT(pktin.body),
1908 PKT_END);
1909 } else {
1910 logevent("opening X11 forward connection succeeded");
1911 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
783415f8 1912 if (d->localid > i)
1913 break; /* found a free number */
1914 i = d->localid + 1;
9c964e85 1915 }
1916 c->remoteid = GET_32BIT(pktin.body);
1917 c->localid = i;
1918 c->closes = 0;
783415f8 1919 c->type = CHAN_X11; /* identify channel type */
9c964e85 1920 add234(ssh_channels, c);
1921 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1922 PKT_INT, c->remoteid, PKT_INT, c->localid,
1923 PKT_END);
1924 logevent("Opened X11 forward channel");
1925 }
1926 }
dacbd0e8 1927 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1928 /* Remote side is trying to open a channel to talk to our
1929 * agent. Give them back a local channel number. */
db7d555c 1930 unsigned i;
dacbd0e8 1931 struct ssh_channel *c;
1932 enum234 e;
db7d555c 1933
1934 /* Refuse if agent forwarding is disabled. */
1935 if (!ssh_agentfwd_enabled) {
1936 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1937 PKT_INT, GET_32BIT(pktin.body),
1938 PKT_END);
1939 } else {
1940 i = 1;
1941 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1942 if (c->localid > i)
1943 break; /* found a free number */
1944 i = c->localid + 1;
1945 }
dcbde236 1946 c = smalloc(sizeof(struct ssh_channel));
db7d555c 1947 c->remoteid = GET_32BIT(pktin.body);
1948 c->localid = i;
1949 c->closes = 0;
783415f8 1950 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 1951 c->u.a.lensofar = 0;
1952 add234(ssh_channels, c);
1953 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1954 PKT_INT, c->remoteid, PKT_INT, c->localid,
1955 PKT_END);
1956 }
1957 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1958 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
dacbd0e8 1959 /* Remote side closes a channel. */
d211621f 1960 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1961 struct ssh_channel *c;
1962 c = find234(ssh_channels, &i, ssh_channelfind);
1963 if (c) {
1964 int closetype;
1965 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1966 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
783415f8 1967 if ((c->closes == 0) && (c->type == CHAN_X11)) {
9c964e85 1968 logevent("X11 connection closed");
1969 assert(c->u.x11.s != NULL);
1970 x11_close(c->u.x11.s);
1971 c->u.x11.s = NULL;
1972 }
dacbd0e8 1973 c->closes |= closetype;
1974 if (c->closes == 3) {
1975 del234(ssh_channels, c);
dcbde236 1976 sfree(c);
dacbd0e8 1977 }
1978 }
1979 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1980 /* Data sent down one of our channels. */
1981 int i = GET_32BIT(pktin.body);
1982 int len = GET_32BIT(pktin.body+4);
1983 unsigned char *p = pktin.body+8;
1984 struct ssh_channel *c;
1985 c = find234(ssh_channels, &i, ssh_channelfind);
1986 if (c) {
1987 switch(c->type) {
783415f8 1988 case CHAN_X11:
9c964e85 1989 x11_send(c->u.x11.s, p, len);
1990 break;
783415f8 1991 case CHAN_AGENT:
dacbd0e8 1992 /* Data for an agent message. Buffer it. */
1993 while (len > 0) {
1994 if (c->u.a.lensofar < 4) {
1995 int l = min(4 - c->u.a.lensofar, len);
1996 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
1997 p += l; len -= l; c->u.a.lensofar += l;
1998 }
1999 if (c->u.a.lensofar == 4) {
2000 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
dcbde236 2001 c->u.a.message = smalloc(c->u.a.totallen);
dacbd0e8 2002 memcpy(c->u.a.message, c->u.a.msglen, 4);
2003 }
2004 if (c->u.a.lensofar >= 4 && len > 0) {
2005 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2006 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2007 p += l; len -= l; c->u.a.lensofar += l;
2008 }
2009 if (c->u.a.lensofar == c->u.a.totallen) {
2010 void *reply, *sentreply;
2011 int replylen;
2012 agent_query(c->u.a.message, c->u.a.totallen,
2013 &reply, &replylen);
2014 if (reply)
2015 sentreply = reply;
2016 else {
2017 /* Fake SSH_AGENT_FAILURE. */
2018 sentreply = "\0\0\0\1\5";
2019 replylen = 5;
2020 }
2021 send_packet(SSH1_MSG_CHANNEL_DATA,
2022 PKT_INT, c->remoteid,
2023 PKT_INT, replylen,
2024 PKT_DATA, sentreply, replylen,
2025 PKT_END);
2026 if (reply)
dcbde236 2027 sfree(reply);
2028 sfree(c->u.a.message);
dacbd0e8 2029 c->u.a.lensofar = 0;
2030 }
2031 }
2032 break;
2033 }
2034 }
e5574168 2035 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 2036 /* may be from EXEC_SHELL on some servers */
e5574168 2037 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 2038 /* may be from EXEC_SHELL on some servers
374330e2 2039 * if no pty is available or in other odd cases. Ignore */
e5574168 2040 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2041 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 2042 } else {
8d5de777 2043 bombout(("Strange packet received: type %d", pktin.type));
2044 crReturnV;
374330e2 2045 }
2046 } else {
8df7a775 2047 while (inlen > 0) {
2048 int len = min(inlen, 512);
2049 send_packet(SSH1_CMSG_STDIN_DATA,
2050 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2051 in += len;
2052 inlen -= len;
2053 }
374330e2 2054 }
2055 }
2056
2057 crFinishV;
2058}
2059
2060/*
e5574168 2061 * Utility routine for decoding comma-separated strings in KEXINIT.
2062 */
75cab814 2063static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 2064 int needlen = strlen(needle);
2065 while (1) {
2066 /*
2067 * Is it at the start of the string?
2068 */
2069 if (haylen >= needlen && /* haystack is long enough */
2070 !memcmp(needle, haystack, needlen) && /* initial match */
2071 (haylen == needlen || haystack[needlen] == ',')
2072 /* either , or EOS follows */
2073 )
2074 return 1;
2075 /*
2076 * If not, search for the next comma and resume after that.
2077 * If no comma found, terminate.
2078 */
2079 while (haylen > 0 && *haystack != ',')
2080 haylen--, haystack++;
2081 if (haylen == 0)
2082 return 0;
2083 haylen--, haystack++; /* skip over comma itself */
2084 }
2085}
2086
2087/*
d39f364a 2088 * SSH2 key creation method.
2089 */
75cab814 2090static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
d39f364a 2091 SHA_State s;
2092 /* First 20 bytes. */
2093 SHA_Init(&s);
2094 sha_mpint(&s, K);
2095 SHA_Bytes(&s, H, 20);
2096 SHA_Bytes(&s, &chr, 1);
2097 SHA_Bytes(&s, H, 20);
2098 SHA_Final(&s, keyspace);
2099 /* Next 20 bytes. */
2100 SHA_Init(&s);
2101 sha_mpint(&s, K);
2102 SHA_Bytes(&s, H, 20);
2103 SHA_Bytes(&s, keyspace, 20);
2104 SHA_Final(&s, keyspace+20);
2105}
2106
2107/*
7cca0d81 2108 * Handle the SSH2 transport layer.
e5574168 2109 */
7cca0d81 2110static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 2111{
2112 static int i, len;
2113 static char *str;
2114 static Bignum e, f, K;
7591b9ff 2115 static const struct ssh_mac **maclist;
8b2715b2 2116 static int nmacs;
57476f6b 2117 static const struct ssh_cipher *cscipher_tobe = NULL;
2118 static const struct ssh_cipher *sccipher_tobe = NULL;
2119 static const struct ssh_mac *csmac_tobe = NULL;
2120 static const struct ssh_mac *scmac_tobe = NULL;
2121 static const struct ssh_compress *cscomp_tobe = NULL;
2122 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 2123 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 2124 static int hostkeylen, siglen;
e055a386 2125 static void *hkey; /* actual host key */
e5574168 2126 static unsigned char exchange_hash[20];
d39f364a 2127 static unsigned char keyspace[40];
57476f6b 2128 static const struct ssh_cipher *preferred_cipher;
4ba9b64b 2129 static const struct ssh_compress *preferred_comp;
0db56f73 2130 static int first_kex;
e5574168 2131
2132 crBegin;
7cca0d81 2133 random_init();
0db56f73 2134 first_kex = 1;
e5574168 2135
5e8358ad 2136 /*
4ba9b64b 2137 * Set up the preferred cipher and compression.
5e8358ad 2138 */
2139 if (cfg.cipher == CIPHER_BLOWFISH) {
57476f6b 2140 preferred_cipher = &ssh_blowfish_ssh2;
5e8358ad 2141 } else if (cfg.cipher == CIPHER_DES) {
2142 logevent("Single DES not supported in SSH2; using 3DES");
57476f6b 2143 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 2144 } else if (cfg.cipher == CIPHER_3DES) {
57476f6b 2145 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 2146 } else {
2147 /* Shouldn't happen, but we do want to initialise to _something_. */
57476f6b 2148 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 2149 }
4ba9b64b 2150 if (cfg.compression)
2151 preferred_comp = &ssh_zlib;
2152 else
2153 preferred_comp = &ssh_comp_none;
5e8358ad 2154
7591b9ff 2155 /*
2156 * Be prepared to work around the buggy MAC problem.
2157 */
2158 if (cfg.buggymac)
8b2715b2 2159 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 2160 else
8b2715b2 2161 maclist = macs, nmacs = lenof(macs);
7591b9ff 2162
7cca0d81 2163 begin_key_exchange:
e5574168 2164 /*
2165 * Construct and send our key exchange packet.
2166 */
2167 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2168 for (i = 0; i < 16; i++)
2169 ssh2_pkt_addbyte((unsigned char)random_byte());
2170 /* List key exchange algorithms. */
2171 ssh2_pkt_addstring_start();
2172 for (i = 0; i < lenof(kex_algs); i++) {
2173 ssh2_pkt_addstring_str(kex_algs[i]->name);
2174 if (i < lenof(kex_algs)-1)
2175 ssh2_pkt_addstring_str(",");
2176 }
2177 /* List server host key algorithms. */
2178 ssh2_pkt_addstring_start();
2179 for (i = 0; i < lenof(hostkey_algs); i++) {
2180 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2181 if (i < lenof(hostkey_algs)-1)
2182 ssh2_pkt_addstring_str(",");
2183 }
2184 /* List client->server encryption algorithms. */
2185 ssh2_pkt_addstring_start();
729e54b4 2186 for (i = 0; i < lenof(ciphers)+1; i++) {
2187 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2188 ssh2_pkt_addstring_str(c->name);
729e54b4 2189 if (i < lenof(ciphers))
e5574168 2190 ssh2_pkt_addstring_str(",");
2191 }
2192 /* List server->client encryption algorithms. */
2193 ssh2_pkt_addstring_start();
729e54b4 2194 for (i = 0; i < lenof(ciphers)+1; i++) {
2195 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2196 ssh2_pkt_addstring_str(c->name);
729e54b4 2197 if (i < lenof(ciphers))
e5574168 2198 ssh2_pkt_addstring_str(",");
2199 }
2200 /* List client->server MAC algorithms. */
2201 ssh2_pkt_addstring_start();
8b2715b2 2202 for (i = 0; i < nmacs; i++) {
7591b9ff 2203 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2204 if (i < nmacs-1)
e5574168 2205 ssh2_pkt_addstring_str(",");
2206 }
2207 /* List server->client MAC algorithms. */
2208 ssh2_pkt_addstring_start();
8b2715b2 2209 for (i = 0; i < nmacs; i++) {
7591b9ff 2210 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2211 if (i < nmacs-1)
e5574168 2212 ssh2_pkt_addstring_str(",");
2213 }
2214 /* List client->server compression algorithms. */
2215 ssh2_pkt_addstring_start();
4ba9b64b 2216 for (i = 0; i < lenof(compressions)+1; i++) {
2217 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2218 ssh2_pkt_addstring_str(c->name);
2219 if (i < lenof(compressions))
e5574168 2220 ssh2_pkt_addstring_str(",");
2221 }
2222 /* List server->client compression algorithms. */
2223 ssh2_pkt_addstring_start();
4ba9b64b 2224 for (i = 0; i < lenof(compressions)+1; i++) {
2225 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2226 ssh2_pkt_addstring_str(c->name);
2227 if (i < lenof(compressions))
e5574168 2228 ssh2_pkt_addstring_str(",");
2229 }
2230 /* List client->server languages. Empty list. */
2231 ssh2_pkt_addstring_start();
2232 /* List server->client languages. Empty list. */
2233 ssh2_pkt_addstring_start();
2234 /* First KEX packet does _not_ follow, because we're not that brave. */
2235 ssh2_pkt_addbool(FALSE);
2236 /* Reserved. */
2237 ssh2_pkt_adduint32(0);
0db56f73 2238
2239 exhash = exhashbase;
e5574168 2240 sha_string(&exhash, pktout.data+5, pktout.length-5);
0db56f73 2241
e5574168 2242 ssh2_pkt_send();
2243
2244 if (!ispkt) crWaitUntil(ispkt);
2245 sha_string(&exhash, pktin.data+5, pktin.length-5);
2246
2247 /*
2248 * Now examine the other side's KEXINIT to see what we're up
2249 * to.
2250 */
7cca0d81 2251 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 2252 bombout(("expected key exchange packet from server"));
2253 crReturn(0);
7cca0d81 2254 }
e5574168 2255 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2256 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2257 pktin.savedpos += 16; /* skip garbage cookie */
2258 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2259 for (i = 0; i < lenof(kex_algs); i++) {
2260 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2261 kex = kex_algs[i];
2262 break;
2263 }
2264 }
2265 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2266 for (i = 0; i < lenof(hostkey_algs); i++) {
2267 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2268 hostkey = hostkey_algs[i];
2269 break;
2270 }
2271 }
2272 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 2273 for (i = 0; i < lenof(ciphers)+1; i++) {
2274 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2275 if (in_commasep_string(c->name, str, len)) {
729e54b4 2276 cscipher_tobe = c;
e5574168 2277 break;
2278 }
2279 }
2280 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
729e54b4 2281 for (i = 0; i < lenof(ciphers)+1; i++) {
2282 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2283 if (in_commasep_string(c->name, str, len)) {
729e54b4 2284 sccipher_tobe = c;
e5574168 2285 break;
2286 }
2287 }
2288 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 2289 for (i = 0; i < nmacs; i++) {
7591b9ff 2290 if (in_commasep_string(maclist[i]->name, str, len)) {
2291 csmac_tobe = maclist[i];
e5574168 2292 break;
2293 }
2294 }
2295 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 2296 for (i = 0; i < nmacs; i++) {
7591b9ff 2297 if (in_commasep_string(maclist[i]->name, str, len)) {
2298 scmac_tobe = maclist[i];
e5574168 2299 break;
2300 }
2301 }
2302 ssh2_pkt_getstring(&str, &len); /* client->server compression */
4ba9b64b 2303 for (i = 0; i < lenof(compressions)+1; i++) {
2304 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2305 if (in_commasep_string(c->name, str, len)) {
2306 cscomp_tobe = c;
e5574168 2307 break;
2308 }
2309 }
2310 ssh2_pkt_getstring(&str, &len); /* server->client compression */
4ba9b64b 2311 for (i = 0; i < lenof(compressions)+1; i++) {
2312 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2313 if (in_commasep_string(c->name, str, len)) {
2314 sccomp_tobe = c;
e5574168 2315 break;
2316 }
2317 }
e5574168 2318
2319 /*
2320 * Currently we only support Diffie-Hellman and DSS, so let's
2321 * bomb out if those aren't selected.
2322 */
8d5de777 2323 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2324 bombout(("internal fault: chaos in SSH 2 transport layer"));
2325 crReturn(0);
2326 }
e5574168 2327
2328 /*
2329 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2330 */
2331 e = dh_create_e();
e5574168 2332 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2333 ssh2_pkt_addmp(e);
2334 ssh2_pkt_send();
2335
2336 crWaitUntil(ispkt);
7cca0d81 2337 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2338 bombout(("expected key exchange packet from server"));
2339 crReturn(0);
7cca0d81 2340 }
e5574168 2341 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2342 f = ssh2_pkt_getmp();
e5574168 2343 ssh2_pkt_getstring(&sigdata, &siglen);
2344
2345 K = dh_find_K(f);
e5574168 2346
2347 sha_string(&exhash, hostkeydata, hostkeylen);
2348 sha_mpint(&exhash, e);
2349 sha_mpint(&exhash, f);
2350 sha_mpint(&exhash, K);
2351 SHA_Final(&exhash, exchange_hash);
2352
7cca0d81 2353#if 0
e5574168 2354 debug(("Exchange hash is:\r\n"));
2355 for (i = 0; i < 20; i++)
2356 debug((" %02x", exchange_hash[i]));
2357 debug(("\r\n"));
7cca0d81 2358#endif
2359
e055a386 2360 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2361 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
8d5de777 2362 bombout(("Server failed host key check"));
2363 crReturn(0);
2364 }
e5574168 2365
2366 /*
7cca0d81 2367 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2368 */
7cca0d81 2369 crWaitUntil(ispkt);
8d5de777 2370 if (pktin.type != SSH2_MSG_NEWKEYS) {
2371 bombout(("expected new-keys packet from server"));
2372 crReturn(0);
2373 }
d39f364a 2374
2375 /*
7cca0d81 2376 * Authenticate remote host: verify host key. (We've already
2377 * checked the signature of the exchange hash.)
e5574168 2378 */
e055a386 2379 keystr = hostkey->fmtkey(hkey);
2380 fingerprint = hostkey->fingerprint(hkey);
d4857987 2381 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2382 keystr, fingerprint);
d5859615 2383 logevent("Host key fingerprint is:");
2384 logevent(fingerprint);
dcbde236 2385 sfree(fingerprint);
2386 sfree(keystr);
e055a386 2387 hostkey->freekey(hkey);
d39f364a 2388
2389 /*
7cca0d81 2390 * Send SSH2_MSG_NEWKEYS.
d39f364a 2391 */
2392 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2393 ssh2_pkt_send();
d39f364a 2394
2395 /*
2396 * Create and initialise session keys.
2397 */
2398 cscipher = cscipher_tobe;
2399 sccipher = sccipher_tobe;
2400 csmac = csmac_tobe;
2401 scmac = scmac_tobe;
2402 cscomp = cscomp_tobe;
2403 sccomp = sccomp_tobe;
4ba9b64b 2404 cscomp->compress_init();
2405 sccomp->decompress_init();
d39f364a 2406 /*
2407 * Set IVs after keys.
2408 */
2409 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
21d7754f 2410 ssh2_mkkey(K, exchange_hash, 'D', keyspace); sccipher->setsckey(keyspace);
d39f364a 2411 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2412 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2413 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2414 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2415
033b4cef 2416 /*
0db56f73 2417 * If this is the first key exchange phase, we must pass the
2418 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2419 * wants to see it but because it will need time to initialise
2420 * itself before it sees an actual packet. In subsequent key
2421 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2422 * it would only confuse the layer above.
2423 */
2424 if (!first_kex) {
2425 crReturn(0);
2426 }
2427 first_kex = 0;
2428
2429 /*
7cca0d81 2430 * Now we're encrypting. Begin returning 1 to the protocol main
2431 * function so that other things can run on top of the
2432 * transport. If we ever see a KEXINIT, we must go back to the
2433 * start.
033b4cef 2434 */
7cca0d81 2435 do {
2436 crReturn(1);
2437 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2438 goto begin_key_exchange;
e5574168 2439
2440 crFinish(1);
2441}
2442
7cca0d81 2443/*
783415f8 2444 * Add data to an SSH2 channel output buffer.
2445 */
2446static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2447 if (c->v2.outbufsize <
2448 c->v2.outbuflen + len) {
2449 c->v2.outbufsize =
2450 c->v2.outbuflen + len + 1024;
2451 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2452 c->v2.outbufsize);
2453 }
2454 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2455 buf, len);
2456 c->v2.outbuflen += len;
2457}
2458
2459/*
2460 * Attempt to send data on an SSH2 channel.
2461 */
2462static void ssh2_try_send(struct ssh_channel *c) {
2463 while (c->v2.remwindow > 0 &&
2464 c->v2.outbuflen > 0) {
2465 unsigned len = c->v2.remwindow;
2466 if (len > c->v2.outbuflen)
2467 len = c->v2.outbuflen;
2468 if (len > c->v2.remmaxpkt)
2469 len = c->v2.remmaxpkt;
2470 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2471 ssh2_pkt_adduint32(c->remoteid);
2472 ssh2_pkt_addstring_start();
2473 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2474 ssh2_pkt_send();
2475 c->v2.outbuflen -= len;
2476 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2477 c->v2.outbuflen);
2478 c->v2.remwindow -= len;
2479 }
2480}
2481
2482/*
7cca0d81 2483 * Handle the SSH2 userauth and connection layers.
2484 */
2485static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2486{
7cca0d81 2487 static unsigned long remote_winsize;
2488 static unsigned long remote_maxpkt;
2489
e5574168 2490 crBegin;
2491
7cca0d81 2492 /*
2493 * Request userauth protocol, and await a response to it.
2494 */
2495 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2496 ssh2_pkt_addstring("ssh-userauth");
2497 ssh2_pkt_send();
2498 crWaitUntilV(ispkt);
8d5de777 2499 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2500 bombout(("Server refused user authentication protocol"));
2501 crReturnV;
2502 }
7cca0d81 2503
2504 /*
2505 * FIXME: currently we support only password authentication.
2506 * (This places us technically in violation of the SSH2 spec.
2507 * We must fix this.)
2508 */
2509 while (1) {
2510 /*
2511 * Get a username and a password.
2512 */
2513 static char username[100];
2514 static char password[100];
2515 static int pos = 0;
2516 static char c;
e5574168 2517
67779be7 2518 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2519 c_write("login as: ", 10);
67779be7 2520 ssh_send_ok = 1;
7cca0d81 2521 while (pos >= 0) {
2522 crWaitUntilV(!ispkt);
2523 while (inlen--) switch (c = *in++) {
2524 case 10: case 13:
2525 username[pos] = 0;
2526 pos = -1;
2527 break;
2528 case 8: case 127:
2529 if (pos > 0) {
2530 c_write("\b \b", 3);
2531 pos--;
2532 }
2533 break;
2534 case 21: case 27:
2535 while (pos > 0) {
2536 c_write("\b \b", 3);
2537 pos--;
2538 }
2539 break;
2540 case 3: case 4:
2541 random_save_seed();
2542 exit(0);
2543 break;
2544 default:
2545 if (((c >= ' ' && c <= '~') ||
2546 ((unsigned char)c >= 160)) && pos < 40) {
2547 username[pos++] = c;
2548 c_write(&c, 1);
2549 }
2550 break;
2551 }
2552 }
2553 c_write("\r\n", 2);
2554 username[strcspn(username, "\n\r")] = '\0';
2555 } else {
2556 char stuff[200];
2557 strncpy(username, cfg.username, 99);
2558 username[99] = '\0';
67779be7 2559 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2560 sprintf(stuff, "Using username \"%s\".\r\n", username);
2561 c_write(stuff, strlen(stuff));
2562 }
2563 }
2564
d8426c54 2565 if (ssh_get_password) {
7cca0d81 2566 char prompt[200];
b585ec46 2567 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
7cca0d81 2568 if (!ssh_get_password(prompt, password, sizeof(password))) {
2569 /*
2570 * get_password failed to get a password (for
2571 * example because one was supplied on the command
2572 * line which has already failed to work).
2573 * Terminate.
2574 */
2575 logevent("No more passwords to try");
2576 ssh_state = SSH_STATE_CLOSED;
2577 crReturnV;
2578 }
2579 } else {
2580 c_write("password: ", 10);
67779be7 2581 ssh_send_ok = 1;
7cca0d81 2582
2583 pos = 0;
2584 while (pos >= 0) {
2585 crWaitUntilV(!ispkt);
2586 while (inlen--) switch (c = *in++) {
2587 case 10: case 13:
2588 password[pos] = 0;
2589 pos = -1;
2590 break;
2591 case 8: case 127:
2592 if (pos > 0)
2593 pos--;
2594 break;
2595 case 21: case 27:
2596 pos = 0;
2597 break;
2598 case 3: case 4:
2599 random_save_seed();
2600 exit(0);
2601 break;
2602 default:
2603 if (((c >= ' ' && c <= '~') ||
2604 ((unsigned char)c >= 160)) && pos < 40)
2605 password[pos++] = c;
2606 break;
2607 }
2608 }
2609 c_write("\r\n", 2);
2610 }
2611
2612 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2613 ssh2_pkt_addstring(username);
2614 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2615 ssh2_pkt_addstring("password");
2616 ssh2_pkt_addbool(FALSE);
2617 ssh2_pkt_addstring(password);
2618 ssh2_pkt_send();
2619
2620 crWaitUntilV(ispkt);
2621 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2622 c_write("Access denied\r\n", 15);
2623 logevent("Authentication refused");
2624 } else
2625 break;
2626 }
2627
2628 /*
2629 * Now we're authenticated for the connection protocol. The
2630 * connection protocol will automatically have started at this
2631 * point; there's no need to send SERVICE_REQUEST.
2632 */
2633
2634 /*
2635 * So now create a channel with a session in it.
2636 */
dcbde236 2637 mainchan = smalloc(sizeof(struct ssh_channel));
d211621f 2638 mainchan->localid = 100; /* as good as any */
7cca0d81 2639 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2640 ssh2_pkt_addstring("session");
d211621f 2641 ssh2_pkt_adduint32(mainchan->localid);
cf6e59d6 2642 ssh2_pkt_adduint32(0x8000UL); /* our window size */
d211621f 2643 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2644 ssh2_pkt_send();
2645 crWaitUntilV(ispkt);
2646 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2647 bombout(("Server refused to open a session"));
2648 crReturnV;
7cca0d81 2649 /* FIXME: error data comes back in FAILURE packet */
2650 }
d211621f 2651 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2652 bombout(("Server's channel confirmation cited wrong channel"));
2653 crReturnV;
7cca0d81 2654 }
d211621f 2655 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 2656 mainchan->type = CHAN_MAINSESSION;
2657 mainchan->closes = 0;
2658 mainchan->v2.remwindow = ssh2_pkt_getuint32();
2659 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
2660 mainchan->v2.outbuffer = NULL;
2661 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
2662 ssh_channels = newtree234(ssh_channelcmp);
2663 add234(ssh_channels, mainchan);
7cca0d81 2664 logevent("Opened channel for session");
2665
2666 /*
783415f8 2667 * Potentially enable X11 forwarding.
2668 */
2669 if (cfg.x11_forward) {
2670 char proto[20], data[64];
2671 logevent("Requesting X11 forwarding");
2672 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2673 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2674 ssh2_pkt_adduint32(mainchan->remoteid);
2675 ssh2_pkt_addstring("x11-req");
2676 ssh2_pkt_addbool(1); /* want reply */
2677 ssh2_pkt_addbool(0); /* many connections */
2678 ssh2_pkt_addstring(proto);
2679 ssh2_pkt_addstring(data);
2680 ssh2_pkt_adduint32(0); /* screen number */
2681 ssh2_pkt_send();
2682
2683 do {
2684 crWaitUntilV(ispkt);
2685 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2686 unsigned i = ssh2_pkt_getuint32();
2687 struct ssh_channel *c;
2688 c = find234(ssh_channels, &i, ssh_channelfind);
2689 if (!c)
2690 continue; /* nonexistent channel */
2691 c->v2.remwindow += ssh2_pkt_getuint32();
2692 }
2693 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2694
2695 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2696 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2697 bombout(("Server got confused by X11 forwarding request"));
2698 crReturnV;
2699 }
2700 logevent("X11 forwarding refused");
2701 } else {
2702 logevent("X11 forwarding enabled");
2703 ssh_X11_fwd_enabled = TRUE;
2704 }
2705 }
2706
2707 /*
7cca0d81 2708 * Now allocate a pty for the session.
2709 */
67779be7 2710 if (!cfg.nopty) {
2711 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2712 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2713 ssh2_pkt_addstring("pty-req");
2714 ssh2_pkt_addbool(1); /* want reply */
2715 ssh2_pkt_addstring(cfg.termtype);
2716 ssh2_pkt_adduint32(cols);
2717 ssh2_pkt_adduint32(rows);
2718 ssh2_pkt_adduint32(0); /* pixel width */
2719 ssh2_pkt_adduint32(0); /* pixel height */
2720 ssh2_pkt_addstring_start();
2721 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2722 ssh2_pkt_send();
6e48c3fe 2723 ssh_state = SSH_STATE_INTERMED;
7cca0d81 2724
67779be7 2725 do {
2726 crWaitUntilV(ispkt);
2727 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 2728 unsigned i = ssh2_pkt_getuint32();
2729 struct ssh_channel *c;
2730 c = find234(ssh_channels, &i, ssh_channelfind);
2731 if (!c)
2732 continue; /* nonexistent channel */
2733 c->v2.remwindow += ssh2_pkt_getuint32();
67779be7 2734 }
2735 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2736
67779be7 2737 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2738 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2739 bombout(("Server got confused by pty request"));
2740 crReturnV;
67779be7 2741 }
2742 c_write("Server refused to allocate pty\r\n", 32);
2743 } else {
2744 logevent("Allocated pty");
7cca0d81 2745 }
7cca0d81 2746 }
2747
2748 /*
67779be7 2749 * Start a shell or a remote command.
7cca0d81 2750 */
2751 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2752 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2753 if (*cfg.remote_cmd) {
2754 ssh2_pkt_addstring("exec");
2755 ssh2_pkt_addbool(1); /* want reply */
2756 ssh2_pkt_addstring(cfg.remote_cmd);
2757 } else {
2758 ssh2_pkt_addstring("shell");
2759 ssh2_pkt_addbool(1); /* want reply */
2760 }
7cca0d81 2761 ssh2_pkt_send();
d211621f 2762 do {
7cca0d81 2763 crWaitUntilV(ispkt);
d211621f 2764 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 2765 unsigned i = ssh2_pkt_getuint32();
2766 struct ssh_channel *c;
2767 c = find234(ssh_channels, &i, ssh_channelfind);
2768 if (!c)
2769 continue; /* nonexistent channel */
2770 c->v2.remwindow += ssh2_pkt_getuint32();
d211621f 2771 }
7cca0d81 2772 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2773 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2774 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2775 bombout(("Server got confused by shell/command request"));
2776 crReturnV;
7cca0d81 2777 }
8d5de777 2778 bombout(("Server refused to start a shell/command"));
2779 crReturnV;
7cca0d81 2780 } else {
8d5de777 2781 logevent("Started a shell/command");
7cca0d81 2782 }
2783
6e48c3fe 2784 ssh_state = SSH_STATE_SESSION;
2785 if (size_needed)
2786 ssh_size();
3687d221 2787 if (eof_needed)
2788 ssh_special(TS_EOF);
6e48c3fe 2789
7cca0d81 2790 /*
2791 * Transfer data!
2792 */
8ccc75b0 2793 ssh_send_ok = 1;
6f34e365 2794 begin_session();
7cca0d81 2795 while (1) {
d211621f 2796 static int try_send;
e5574168 2797 crReturnV;
d211621f 2798 try_send = FALSE;
7cca0d81 2799 if (ispkt) {
2800 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2801 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2802 char *data;
2803 int length;
783415f8 2804 unsigned i = ssh2_pkt_getuint32();
2805 struct ssh_channel *c;
2806 c = find234(ssh_channels, &i, ssh_channelfind);
2807 if (!c)
2808 continue; /* nonexistent channel */
7cca0d81 2809 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2810 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2811 continue; /* extended but not stderr */
2812 ssh2_pkt_getstring(&data, &length);
d211621f 2813 if (data) {
783415f8 2814 switch (c->type) {
2815 case CHAN_MAINSESSION:
2816 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
2817 data, length);
2818 break;
2819 case CHAN_X11:
2820 x11_send(c->u.x11.s, data, length);
2821 break;
2822 }
d211621f 2823 /*
783415f8 2824 * Enlarge the window again at the remote
2825 * side, just in case it ever runs down and
2826 * they fail to send us any more data.
d211621f 2827 */
2828 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
783415f8 2829 ssh2_pkt_adduint32(c->remoteid);
d211621f 2830 ssh2_pkt_adduint32(length);
2831 ssh2_pkt_send();
2832 }
7cca0d81 2833 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2834 ssh_state = SSH_STATE_CLOSED;
d211621f 2835 logevent("Received disconnect message");
3257deae 2836 crReturnV;
7cca0d81 2837 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2838 continue; /* exit status et al; ignore (FIXME?) */
d211621f 2839 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
783415f8 2840 unsigned i = ssh2_pkt_getuint32();
2841 struct ssh_channel *c;
2842
2843 c = find234(ssh_channels, &i, ssh_channelfind);
2844 if (!c)
2845 continue; /* nonexistent channel */
2846
2847 if (c->type == CHAN_X11) {
2848 /*
2849 * Remote EOF on an X11 channel means we should
2850 * wrap up and close the channel ourselves.
2851 */
2852 x11_close(c->u.x11.s);
2853 sshfwd_close(c);
2854 }
d211621f 2855 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
783415f8 2856 unsigned i = ssh2_pkt_getuint32();
2857 struct ssh_channel *c;
2858 enum234 e;
2859
2860 c = find234(ssh_channels, &i, ssh_channelfind);
2861 if (!c)
2862 continue; /* nonexistent channel */
2863 if (c->closes == 0) {
2864 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2865 ssh2_pkt_adduint32(c->remoteid);
2866 ssh2_pkt_send();
2867 }
2868 /* Do pre-close processing on the channel. */
2869 switch (c->type) {
2870 case CHAN_MAINSESSION:
2871 break; /* nothing to see here, move along */
2872 case CHAN_X11:
2873 break;
2874 }
2875 del234(ssh_channels, c);
2876 sfree(c->v2.outbuffer);
2877 sfree(c);
2878
2879 /*
2880 * See if that was the last channel left open.
2881 */
2882 c = first234(ssh_channels, &e);
2883 if (!c) {
d211621f 2884 logevent("All channels closed. Disconnecting");
2885 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
9005f3ba 2886 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
2887 ssh2_pkt_addstring("All open channels closed");
2888 ssh2_pkt_addstring("en"); /* language tag */
d211621f 2889 ssh2_pkt_send();
cf6e59d6 2890 ssh_state = SSH_STATE_CLOSED;
3257deae 2891 crReturnV;
d211621f 2892 }
2893 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2894 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 2895 unsigned i = ssh2_pkt_getuint32();
2896 struct ssh_channel *c;
2897 c = find234(ssh_channels, &i, ssh_channelfind);
2898 if (!c)
2899 continue; /* nonexistent channel */
2900 mainchan->v2.remwindow += ssh2_pkt_getuint32();
d211621f 2901 try_send = TRUE;
783415f8 2902 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
2903 char *type;
2904 int typelen;
2905 char *error = NULL;
2906 struct ssh_channel *c;
2907 ssh2_pkt_getstring(&type, &typelen);
2908 c = smalloc(sizeof(struct ssh_channel));
2909
2910 if (typelen == 3 && !memcmp(type, "x11", 3)) {
2911 char *rh;
2912 if (!ssh_X11_fwd_enabled)
2913 error = "X11 forwarding is not enabled";
2914 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c, &rh) != NULL ) {
2915 error = "Unable to open an X11 connection";
2916 } else {
2917 c->type = CHAN_X11;
2918 }
2919 } else {
2920 error = "Unsupported channel type requested";
2921 }
2922
2923 c->remoteid = ssh2_pkt_getuint32();
2924 if (error) {
2925 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
2926 ssh2_pkt_adduint32(c->remoteid);
2927 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
2928 ssh2_pkt_addstring(error);
2929 ssh2_pkt_addstring("en"); /* language tag */
2930 ssh2_pkt_send();
2931 sfree(c);
2932 } else {
2933 struct ssh_channel *d;
2934 unsigned i;
2935 enum234 e;
2936
2937 for (i=1, d = first234(ssh_channels, &e); d;
2938 d = next234(&e)) {
2939 if (d->localid > i)
2940 break; /* found a free number */
2941 i = d->localid + 1;
2942 }
2943 c->localid = i;
2944 c->closes = 0;
2945 c->v2.remwindow = ssh2_pkt_getuint32();
2946 c->v2.remmaxpkt = ssh2_pkt_getuint32();
2947 c->v2.outbuffer = NULL;
2948 c->v2.outbuflen = c->v2.outbufsize = 0;
2949 add234(ssh_channels, c);
2950 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
2951 ssh2_pkt_adduint32(c->remoteid);
2952 ssh2_pkt_adduint32(c->localid);
2953 ssh2_pkt_adduint32(0x8000UL); /* our window size */
2954 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
2955 ssh2_pkt_send();
2956 }
7cca0d81 2957 } else {
8d5de777 2958 bombout(("Strange packet received: type %d", pktin.type));
2959 crReturnV;
7cca0d81 2960 }
2961 } else {
d211621f 2962 /*
2963 * We have spare data. Add it to the channel buffer.
2964 */
783415f8 2965 ssh2_add_channel_data(mainchan, in, inlen);
d211621f 2966 try_send = TRUE;
7cca0d81 2967 }
d211621f 2968 if (try_send) {
783415f8 2969 enum234 e;
2970 struct ssh_channel *c;
d211621f 2971 /*
783415f8 2972 * Try to send data on all channels if we can.
d211621f 2973 */
783415f8 2974 for (c = first234(ssh_channels, &e); c; c = next234(&e))
2975 ssh2_try_send(c);
d211621f 2976 }
e5574168 2977 }
2978
2979 crFinishV;
2980}
2981
2982/*
7cca0d81 2983 * Handle the top-level SSH2 protocol.
2984 */
2985static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2986{
2987 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2988 return;
2989 do_ssh2_authconn(in, inlen, ispkt);
2990}
2991
2992/*
8df7a775 2993 * Called to set up the connection.
374330e2 2994 *
2995 * Returns an error message, or NULL on success.
374330e2 2996 */
8df7a775 2997static char *ssh_init (char *host, int port, char **realhost) {
fb09bf1c 2998 char *p;
8f203108 2999
3000#ifdef MSCRYPTOAPI
3001 if(crypto_startup() == 0)
3002 return "Microsoft high encryption pack not installed!";
3003#endif
374330e2 3004
8df7a775 3005 ssh_send_ok = 0;
3006
fb09bf1c 3007 p = connect_to_host(host, port, realhost);
3008 if (p != NULL)
3009 return p;
374330e2 3010
374330e2 3011 return NULL;
3012}
3013
3014/*
374330e2 3015 * Called to send data down the Telnet connection.
3016 */
3017static void ssh_send (char *buf, int len) {
f78051a1 3018 if (s == NULL || ssh_protocol == NULL)
374330e2 3019 return;
3020
3021 ssh_protocol(buf, len, 0);
3022}
3023
3024/*
6e48c3fe 3025 * Called to set the size of the window from SSH's POV.
374330e2 3026 */
3027static void ssh_size(void) {
3028 switch (ssh_state) {
3029 case SSH_STATE_BEFORE_SIZE:
3687d221 3030 case SSH_STATE_PREPACKET:
21248260 3031 case SSH_STATE_CLOSED:
374330e2 3032 break; /* do nothing */
3033 case SSH_STATE_INTERMED:
3034 size_needed = TRUE; /* buffer for later */
3035 break;
3036 case SSH_STATE_SESSION:
fef97f43 3037 if (!cfg.nopty) {
6e48c3fe 3038 if (ssh_version == 1) {
3039 send_packet(SSH1_CMSG_WINDOW_SIZE,
3040 PKT_INT, rows, PKT_INT, cols,
3041 PKT_INT, 0, PKT_INT, 0, PKT_END);
3042 } else {
3043 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3044 ssh2_pkt_adduint32(mainchan->remoteid);
3045 ssh2_pkt_addstring("window-change");
3046 ssh2_pkt_addbool(0);
3047 ssh2_pkt_adduint32(cols);
3048 ssh2_pkt_adduint32(rows);
3049 ssh2_pkt_adduint32(0);
3050 ssh2_pkt_adduint32(0);
3051 ssh2_pkt_send();
3052 }
fef97f43 3053 }
3687d221 3054 break;
374330e2 3055 }
3056}
3057
3058/*
6abbf9e3 3059 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3060 * can send an EOF and collect resulting output (e.g. `plink
3061 * hostname sort').
374330e2 3062 */
3063static void ssh_special (Telnet_Special code) {
6abbf9e3 3064 if (code == TS_EOF) {
3687d221 3065 if (ssh_state != SSH_STATE_SESSION) {
3066 /*
3067 * Buffer the EOF in case we are pre-SESSION, so we can
3068 * send it as soon as we reach SESSION.
3069 */
3070 if (code == TS_EOF)
3071 eof_needed = TRUE;
3072 return;
3073 }
67779be7 3074 if (ssh_version == 1) {
6abbf9e3 3075 send_packet(SSH1_CMSG_EOF, PKT_END);
3076 } else {
3077 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 3078 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 3079 ssh2_pkt_send();
3080 }
67779be7 3081 logevent("Sent EOF message");
ec55b220 3082 } else if (code == TS_PING) {
3687d221 3083 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3084 return;
ec55b220 3085 if (ssh_version == 1) {
3086 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3087 } else {
3088 ssh2_pkt_init(SSH2_MSG_IGNORE);
3089 ssh2_pkt_addstring_start();
3090 ssh2_pkt_send();
3091 }
6abbf9e3 3092 } else {
3093 /* do nothing */
3094 }
374330e2 3095}
3096
8df7a775 3097static Socket ssh_socket(void) { return s; }
8ccc75b0 3098
3099static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 3100
374330e2 3101Backend ssh_backend = {
3102 ssh_init,
374330e2 3103 ssh_send,
3104 ssh_size,
4017be6d 3105 ssh_special,
8ccc75b0 3106 ssh_socket,
97db3be4 3107 ssh_sendok,
3108 22
374330e2 3109};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator