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Improve socket error handling so that a socket error isn't an
[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
0c6c9a70 168extern char *x11_init (Socket *, char *, void *);
9c964e85 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) {
2c94fd1c 1151 if (urgent==3) {
1152 /* A socket error has occurred. */
1153 connection_fatal(data);
1154 len = 0;
1155 }
8df7a775 1156 if (!len) {
1157 /* Connection has closed. */
6abb6cd7 1158 ssh_state = SSH_STATE_CLOSED;
8df7a775 1159 sk_close(s);
1160 s = NULL;
1161 return 0;
1162 }
1163 ssh_gotdata (data, len);
3257deae 1164 if (ssh_state == SSH_STATE_CLOSED) {
1165 if (s) {
1166 sk_close(s);
1167 s = NULL;
1168 }
1169 return 0;
1170 }
fef97f43 1171 return 1;
374330e2 1172}
1173
fb09bf1c 1174/*
8df7a775 1175 * Connect to specified host and port.
1176 * Returns an error message, or NULL on success.
1177 * Also places the canonical host name into `realhost'.
1178 */
1179static char *connect_to_host(char *host, int port, char **realhost)
1180{
1181 SockAddr addr;
1182 char *err;
1183#ifdef FWHACK
1184 char *FWhost;
1185 int FWport;
1186#endif
1187
dcbde236 1188 savedhost = smalloc(1+strlen(host));
8df7a775 1189 if (!savedhost)
1190 fatalbox("Out of memory");
1191 strcpy(savedhost, host);
1192
1193 if (port < 0)
1194 port = 22; /* default ssh port */
1195 savedport = port;
1196
1197#ifdef FWHACK
1198 FWhost = host;
1199 FWport = port;
1200 host = FWSTR;
1201 port = 23;
1202#endif
1203
1204 /*
1205 * Try to find host.
1206 */
1207 addr = sk_namelookup(host, realhost);
1208 if ( (err = sk_addr_error(addr)) )
1209 return err;
1210
1211#ifdef FWHACK
1212 *realhost = FWhost;
1213#endif
1214
1215 /*
1216 * Open socket.
1217 */
c91409da 1218 s = sk_new(addr, port, 0, ssh_receive);
8df7a775 1219 if ( (err = sk_socket_error(s)) )
1220 return err;
1221
1222#ifdef FWHACK
1223 sk_write(s, "connect ", 8);
1224 sk_write(s, FWhost, strlen(FWhost));
1225 {
1226 char buf[20];
1227 sprintf(buf, " %d\n", FWport);
1228 sk_write(s, buf, strlen(buf));
1229 }
1230#endif
1231
1232 return NULL;
1233}
1234
1235/*
fb09bf1c 1236 * Handle the key exchange and user authentication phases.
1237 */
e5574168 1238static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1239{
374330e2 1240 int i, j, len;
374330e2 1241 unsigned char *rsabuf, *keystr1, *keystr2;
1242 unsigned char cookie[8];
1243 struct RSAKey servkey, hostkey;
1244 struct MD5Context md5c;
ccbfb941 1245 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1246 static int tried_publickey;
1247 static unsigned char session_id[16];
bea1ef5f 1248 int cipher_type;
b585ec46 1249 static char username[100];
374330e2 1250
374330e2 1251 crBegin;
1252
fb09bf1c 1253 if (!ispkt) crWaitUntil(ispkt);
374330e2 1254
8d5de777 1255 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1256 bombout(("Public key packet not received"));
1257 crReturn(0);
1258 }
374330e2 1259
c5e9c988 1260 logevent("Received public keys");
374330e2 1261
c5e9c988 1262 memcpy(cookie, pktin.body, 8);
374330e2 1263
7cca0d81 1264 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1265 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1266
c5e9c988 1267 /*
1c2a93c4 1268 * Log the host key fingerprint.
c5e9c988 1269 */
c5e9c988 1270 {
1271 char logmsg[80];
1c2a93c4 1272 logevent("Host key fingerprint is:");
c5e9c988 1273 strcpy(logmsg, " ");
1c2a93c4 1274 hostkey.comment = NULL;
1275 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1276 &hostkey);
c5e9c988 1277 logevent(logmsg);
1278 }
1279
fb09bf1c 1280 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1281 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1282
c5e9c988 1283 MD5Init(&md5c);
374330e2 1284 MD5Update(&md5c, keystr2, hostkey.bytes);
1285 MD5Update(&md5c, keystr1, servkey.bytes);
1286 MD5Update(&md5c, pktin.body, 8);
374330e2 1287 MD5Final(session_id, &md5c);
1288
1289 for (i=0; i<32; i++)
1290 session_key[i] = random_byte();
1291
1292 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1293
dcbde236 1294 rsabuf = smalloc(len);
374330e2 1295 if (!rsabuf)
1296 fatalbox("Out of memory");
1297
89ee5268 1298 /*
1299 * Verify the host key.
1300 */
1301 {
1302 /*
1303 * First format the key into a string.
1304 */
1305 int len = rsastr_len(&hostkey);
d5859615 1306 char fingerprint[100];
dcbde236 1307 char *keystr = smalloc(len);
89ee5268 1308 if (!keystr)
1309 fatalbox("Out of memory");
1310 rsastr_fmt(keystr, &hostkey);
d5859615 1311 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1312 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
dcbde236 1313 sfree(keystr);
89ee5268 1314 }
374330e2 1315
1316 for (i=0; i<32; i++) {
1317 rsabuf[i] = session_key[i];
1318 if (i < 16)
1319 rsabuf[i] ^= session_id[i];
1320 }
1321
1322 if (hostkey.bytes > servkey.bytes) {
1323 rsaencrypt(rsabuf, 32, &servkey);
1324 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1325 } else {
1326 rsaencrypt(rsabuf, 32, &hostkey);
1327 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1328 }
1329
c5e9c988 1330 logevent("Encrypted session key");
1331
bea1ef5f 1332 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1333 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1334 SSH_CIPHER_3DES;
1335 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1336 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1337 cipher_type = SSH_CIPHER_3DES;
1338 }
c5e9c988 1339 switch (cipher_type) {
1340 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1341 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1342 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1343 }
bea1ef5f 1344
e5574168 1345 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1346 PKT_CHAR, cipher_type,
1347 PKT_DATA, cookie, 8,
1348 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1349 PKT_DATA, rsabuf, len,
1350 PKT_INT, 0,
1351 PKT_END);
1352
c5e9c988 1353 logevent("Trying to enable encryption...");
374330e2 1354
dcbde236 1355 sfree(rsabuf);
374330e2 1356
5e8358ad 1357 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1358 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1359 &ssh_3des;
374330e2 1360 cipher->sesskey(session_key);
1361
fb09bf1c 1362 crWaitUntil(ispkt);
374330e2 1363
8d5de777 1364 if (pktin.type != SSH1_SMSG_SUCCESS) {
1365 bombout(("Encryption not successfully enabled"));
1366 crReturn(0);
1367 }
374330e2 1368
c5e9c988 1369 logevent("Successfully started encryption");
1370
374330e2 1371 fflush(stdout);
1372 {
374330e2 1373 static int pos = 0;
1374 static char c;
67779be7 1375 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1376 c_write("login as: ", 10);
67779be7 1377 ssh_send_ok = 1;
374330e2 1378 while (pos >= 0) {
fb09bf1c 1379 crWaitUntil(!ispkt);
374330e2 1380 while (inlen--) switch (c = *in++) {
1381 case 10: case 13:
1382 username[pos] = 0;
1383 pos = -1;
1384 break;
1385 case 8: case 127:
1386 if (pos > 0) {
1387 c_write("\b \b", 3);
1388 pos--;
1389 }
1390 break;
1391 case 21: case 27:
1392 while (pos > 0) {
1393 c_write("\b \b", 3);
1394 pos--;
1395 }
1396 break;
1397 case 3: case 4:
1398 random_save_seed();
1399 exit(0);
1400 break;
1401 default:
40d24aa6 1402 if (((c >= ' ' && c <= '~') ||
1403 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1404 username[pos++] = c;
1405 c_write(&c, 1);
1406 }
1407 break;
1408 }
1409 }
1410 c_write("\r\n", 2);
1411 username[strcspn(username, "\n\r")] = '\0';
1412 } else {
374330e2 1413 strncpy(username, cfg.username, 99);
1414 username[99] = '\0';
374330e2 1415 }
fb09bf1c 1416
e5574168 1417 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1418 {
3c8e959b 1419 char userlog[22+sizeof(username)];
c5e9c988 1420 sprintf(userlog, "Sent username \"%s\"", username);
1421 logevent(userlog);
3c8e959b 1422 if (flags & FLAG_INTERACTIVE &&
1423 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1424 strcat(userlog, "\r\n");
1425 c_write(userlog, strlen(userlog));
1426 }
c5e9c988 1427 }
374330e2 1428 }
1429
fb09bf1c 1430 crWaitUntil(ispkt);
374330e2 1431
7cca0d81 1432 tried_publickey = 0;
1433
e5574168 1434 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1435 static char password[100];
a52f067e 1436 static char prompt[200];
374330e2 1437 static int pos;
1438 static char c;
ccbfb941 1439 static int pwpkt_type;
ccbfb941 1440 /*
1441 * Show password prompt, having first obtained it via a TIS
18515c51 1442 * or CryptoCard exchange if we're doing TIS or CryptoCard
1443 * authentication.
ccbfb941 1444 */
e5574168 1445 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1446 if (agent_exists()) {
1447 /*
1448 * Attempt RSA authentication using Pageant.
1449 */
1450 static unsigned char request[5], *response, *p;
1451 static int responselen;
1452 static int i, nkeys;
1453 static int authed = FALSE;
1454 void *r;
1455
1456 logevent("Pageant is running. Requesting keys.");
1457
1458 /* Request the keys held by the agent. */
1459 PUT_32BIT(request, 1);
1460 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1461 agent_query(request, 5, &r, &responselen);
1462 response = (unsigned char *)r;
1463 if (response) {
1464 p = response + 5;
1465 nkeys = GET_32BIT(p); p += 4;
1466 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1467 logevent(buf); }
1468 for (i = 0; i < nkeys; i++) {
1469 static struct RSAKey key;
1470 static Bignum challenge;
b8bb811a 1471 static char *commentp;
1472 static int commentlen;
5c58ad2d 1473
1474 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1475 logevent(buf); }
1476 p += 4;
1477 p += ssh1_read_bignum(p, &key.exponent);
1478 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1479 commentlen = GET_32BIT(p); p += 4;
1480 commentp = p; p += commentlen;
5c58ad2d 1481 send_packet(SSH1_CMSG_AUTH_RSA,
1482 PKT_BIGNUM, key.modulus, PKT_END);
1483 crWaitUntil(ispkt);
1484 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1485 logevent("Key refused");
1486 continue;
1487 }
1488 logevent("Received RSA challenge");
1489 ssh1_read_bignum(pktin.body, &challenge);
1490 {
1491 char *agentreq, *q, *ret;
1492 int len, retlen;
1493 len = 1 + 4; /* message type, bit count */
1494 len += ssh1_bignum_length(key.exponent);
1495 len += ssh1_bignum_length(key.modulus);
1496 len += ssh1_bignum_length(challenge);
1497 len += 16; /* session id */
1498 len += 4; /* response format */
dcbde236 1499 agentreq = smalloc(4 + len);
5c58ad2d 1500 PUT_32BIT(agentreq, len);
1501 q = agentreq + 4;
1502 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1503 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1504 q += 4;
1505 q += ssh1_write_bignum(q, key.exponent);
1506 q += ssh1_write_bignum(q, key.modulus);
1507 q += ssh1_write_bignum(q, challenge);
1508 memcpy(q, session_id, 16); q += 16;
1509 PUT_32BIT(q, 1); /* response format */
1510 agent_query(agentreq, len+4, &ret, &retlen);
dcbde236 1511 sfree(agentreq);
5c58ad2d 1512 if (ret) {
1513 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1514 logevent("Sending Pageant's response");
1515 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1516 PKT_DATA, ret+5, 16, PKT_END);
dcbde236 1517 sfree(ret);
5c58ad2d 1518 crWaitUntil(ispkt);
1519 if (pktin.type == SSH1_SMSG_SUCCESS) {
1520 logevent("Pageant's response accepted");
c4fa2fce 1521 if (flags & FLAG_VERBOSE) {
1522 c_write("Authenticated using RSA key \"",
1523 29);
1524 c_write(commentp, commentlen);
1525 c_write("\" from agent\r\n", 14);
1526 }
5c58ad2d 1527 authed = TRUE;
1528 } else
1529 logevent("Pageant's response not accepted");
1530 } else {
1531 logevent("Pageant failed to answer challenge");
dcbde236 1532 sfree(ret);
5c58ad2d 1533 }
1534 } else {
1535 logevent("No reply received from Pageant");
1536 }
1537 }
1538 freebn(key.exponent);
1539 freebn(key.modulus);
1540 freebn(challenge);
1541 if (authed)
1542 break;
1543 }
1544 }
1545 if (authed)
1546 break;
1547 }
7cca0d81 1548 if (*cfg.keyfile && !tried_publickey)
1549 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1550
a52f067e 1551 if (pktin.type == SSH1_SMSG_FAILURE &&
1552 cfg.try_tis_auth &&
1553 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1554 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1555 logevent("Requested TIS authentication");
1556 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1557 crWaitUntil(ispkt);
1558 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1559 logevent("TIS authentication declined");
1560 if (flags & FLAG_INTERACTIVE)
1561 c_write("TIS authentication refused.\r\n", 29);
1562 } else {
1563 int challengelen = ((pktin.body[0] << 24) |
1564 (pktin.body[1] << 16) |
1565 (pktin.body[2] << 8) |
1566 (pktin.body[3]));
1567 logevent("Received TIS challenge");
1568 if (challengelen > sizeof(prompt)-1)
1569 challengelen = sizeof(prompt)-1; /* prevent overrun */
1570 memcpy(prompt, pktin.body+4, challengelen);
1571 prompt[challengelen] = '\0';
1572 }
1573 }
1574 if (pktin.type == SSH1_SMSG_FAILURE &&
1575 cfg.try_tis_auth &&
1576 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1577 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1578 logevent("Requested CryptoCard authentication");
1579 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1580 crWaitUntil(ispkt);
1581 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1582 logevent("CryptoCard authentication declined");
1583 c_write("CryptoCard authentication refused.\r\n", 29);
1584 } else {
1585 int challengelen = ((pktin.body[0] << 24) |
1586 (pktin.body[1] << 16) |
1587 (pktin.body[2] << 8) |
1588 (pktin.body[3]));
1589 logevent("Received CryptoCard challenge");
1590 if (challengelen > sizeof(prompt)-1)
1591 challengelen = sizeof(prompt)-1; /* prevent overrun */
1592 memcpy(prompt, pktin.body+4, challengelen);
1593 strncpy(prompt + challengelen, "\r\nResponse : ",
1594 sizeof(prompt)-challengelen);
1595 prompt[sizeof(prompt)-1] = '\0';
1596 }
1597 }
1598 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1599 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1600 username, savedhost);
a52f067e 1601 }
1602 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1603 char *comment = NULL;
1604 if (flags & FLAG_VERBOSE)
1605 c_write("Trying public key authentication.\r\n", 35);
1606 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1607 if (flags & FLAG_VERBOSE)
1608 c_write("No passphrase required.\r\n", 25);
1609 goto tryauth;
1610 }
1611 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
dcbde236 1612 sfree(comment);
a52f067e 1613 }
1614
d8426c54 1615 if (ssh_get_password) {
85ee8208 1616 if (!ssh_get_password(prompt, password, sizeof(password))) {
1617 /*
1618 * get_password failed to get a password (for
1619 * example because one was supplied on the command
1620 * line which has already failed to work).
1621 * Terminate.
1622 */
1623 logevent("No more passwords to try");
1624 ssh_state = SSH_STATE_CLOSED;
1625 crReturn(1);
1626 }
fb09bf1c 1627 } else {
a52f067e 1628 c_write(prompt, strlen(prompt));
7cca0d81 1629 pos = 0;
67779be7 1630 ssh_send_ok = 1;
7cca0d81 1631 while (pos >= 0) {
1632 crWaitUntil(!ispkt);
1633 while (inlen--) switch (c = *in++) {
1634 case 10: case 13:
1635 password[pos] = 0;
1636 pos = -1;
1637 break;
1638 case 8: case 127:
1639 if (pos > 0)
1640 pos--;
1641 break;
1642 case 21: case 27:
1643 pos = 0;
1644 break;
1645 case 3: case 4:
1646 random_save_seed();
1647 exit(0);
1648 break;
1649 default:
1650 if (((c >= ' ' && c <= '~') ||
1651 ((unsigned char)c >= 160)) && pos < sizeof(password))
1652 password[pos++] = c;
1653 break;
1654 }
1655 }
1656 c_write("\r\n", 2);
a52f067e 1657 }
fb09bf1c 1658
7cca0d81 1659 tryauth:
1660 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1661 /*
1662 * Try public key authentication with the specified
1663 * key file.
1664 */
1665 static struct RSAKey pubkey;
1666 static Bignum challenge, response;
1667 static int i;
1668 static unsigned char buffer[32];
1669
1670 tried_publickey = 1;
6e522441 1671 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
7cca0d81 1672 if (i == 0) {
1673 c_write("Couldn't load public key from ", 30);
1674 c_write(cfg.keyfile, strlen(cfg.keyfile));
1675 c_write(".\r\n", 3);
1676 continue; /* go and try password */
1677 }
1678 if (i == -1) {
1679 c_write("Wrong passphrase.\r\n", 19);
1680 tried_publickey = 0;
1681 continue; /* try again */
1682 }
1683
1684 /*
1685 * Send a public key attempt.
1686 */
1687 send_packet(SSH1_CMSG_AUTH_RSA,
1688 PKT_BIGNUM, pubkey.modulus, PKT_END);
1689
1690 crWaitUntil(ispkt);
1691 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1692 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1693 continue; /* go and try password */
1694 }
8d5de777 1695 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1696 bombout(("Bizarre response to offer of public key"));
1697 crReturn(0);
1698 }
7cca0d81 1699 ssh1_read_bignum(pktin.body, &challenge);
1700 response = rsadecrypt(challenge, &pubkey);
1701 freebn(pubkey.private_exponent); /* burn the evidence */
1702
1703 for (i = 0; i < 32; i += 2) {
1704 buffer[i] = response[16-i/2] >> 8;
1705 buffer[i+1] = response[16-i/2] & 0xFF;
1706 }
1707
1708 MD5Init(&md5c);
1709 MD5Update(&md5c, buffer, 32);
1710 MD5Update(&md5c, session_id, 16);
1711 MD5Final(buffer, &md5c);
1712
1713 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1714 PKT_DATA, buffer, 16, PKT_END);
1715
1716 crWaitUntil(ispkt);
1717 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1718 if (flags & FLAG_VERBOSE)
1719 c_write("Failed to authenticate with our public key.\r\n",
1720 45);
7cca0d81 1721 continue; /* go and try password */
1722 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1723 bombout(("Bizarre response to RSA authentication response"));
1724 crReturn(0);
7cca0d81 1725 }
1726
1727 break; /* we're through! */
1728 } else {
1729 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1730 }
c5e9c988 1731 logevent("Sent password");
374330e2 1732 memset(password, 0, strlen(password));
fb09bf1c 1733 crWaitUntil(ispkt);
e5574168 1734 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1735 if (flags & FLAG_VERBOSE)
1736 c_write("Access denied\r\n", 15);
c5e9c988 1737 logevent("Authentication refused");
e5574168 1738 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1739 logevent("Received disconnect request");
85ee8208 1740 ssh_state = SSH_STATE_CLOSED;
1741 crReturn(1);
e5574168 1742 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1743 bombout(("Strange packet received, type %d", pktin.type));
1744 crReturn(0);
374330e2 1745 }
1746 }
1747
c5e9c988 1748 logevent("Authentication successful");
1749
fb09bf1c 1750 crFinish(1);
1751}
1752
9c964e85 1753void sshfwd_close(struct ssh_channel *c) {
783415f8 1754 if (c) {
1755 if (ssh_version == 1) {
1756 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
1757 } else {
1758 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
1759 ssh2_pkt_adduint32(c->remoteid);
1760 ssh2_pkt_send();
1761 }
1762 c->closes = 1;
1763 if (c->type == CHAN_X11) {
1764 c->u.x11.s = NULL;
1765 logevent("X11 connection terminated");
1766 }
1767 }
9c964e85 1768}
1769
1770void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
783415f8 1771 if (ssh_version == 1) {
1772 send_packet(SSH1_MSG_CHANNEL_DATA,
1773 PKT_INT, c->remoteid,
1774 PKT_INT, len,
1775 PKT_DATA, buf, len,
1776 PKT_END);
1777 } else {
1778 ssh2_add_channel_data(c, buf, len);
1779 ssh2_try_send(c);
1780 }
9c964e85 1781}
1782
e5574168 1783static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1784 crBegin;
1785
1786 random_init();
1787
e5574168 1788 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1789 crReturnV;
85ee8208 1790 }
1791 if (ssh_state == SSH_STATE_CLOSED)
1792 crReturnV;
fb09bf1c 1793
979310f1 1794 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1795 logevent("Requesting agent forwarding");
1796 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1797 do { crReturnV; } while (!ispkt);
1798 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1799 bombout(("Protocol confusion"));
1800 crReturnV;
dacbd0e8 1801 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1802 logevent("Agent forwarding refused");
db7d555c 1803 } else {
dacbd0e8 1804 logevent("Agent forwarding enabled");
db7d555c 1805 ssh_agentfwd_enabled = TRUE;
1806 }
dacbd0e8 1807 }
1808
9c964e85 1809 if (cfg.x11_forward) {
1810 char proto[20], data[64];
1811 logevent("Requesting X11 forwarding");
1812 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
1813 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
1814 PKT_STR, proto, PKT_STR, data,
1815 PKT_INT, 0,
1816 PKT_END);
1817 do { crReturnV; } while (!ispkt);
1818 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1819 bombout(("Protocol confusion"));
1820 crReturnV;
1821 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1822 logevent("X11 forwarding refused");
1823 } else {
1824 logevent("X11 forwarding enabled");
1825 ssh_X11_fwd_enabled = TRUE;
1826 }
1827 }
1828
fef97f43 1829 if (!cfg.nopty) {
e5574168 1830 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1831 PKT_STR, cfg.termtype,
1832 PKT_INT, rows, PKT_INT, cols,
1833 PKT_INT, 0, PKT_INT, 0,
1834 PKT_CHAR, 0,
1835 PKT_END);
fef97f43 1836 ssh_state = SSH_STATE_INTERMED;
1837 do { crReturnV; } while (!ispkt);
e5574168 1838 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1839 bombout(("Protocol confusion"));
1840 crReturnV;
e5574168 1841 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1842 c_write("Server refused to allocate pty\r\n", 32);
1843 }
c5e9c988 1844 logevent("Allocated pty");
374330e2 1845 }
1846
4ba9b64b 1847 if (cfg.compression) {
1848 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
1849 do { crReturnV; } while (!ispkt);
1850 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1851 bombout(("Protocol confusion"));
1852 crReturnV;
1853 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1854 c_write("Server refused to compress\r\n", 32);
1855 }
1856 logevent("Started compression");
1857 ssh1_compressing = TRUE;
1858 zlib_compress_init();
1859 zlib_decompress_init();
1860 }
1861
6abbf9e3 1862 if (*cfg.remote_cmd)
1863 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1864 else
1865 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1866 logevent("Started session");
374330e2 1867
1868 ssh_state = SSH_STATE_SESSION;
1869 if (size_needed)
1870 ssh_size();
3687d221 1871 if (eof_needed)
1872 ssh_special(TS_EOF);
374330e2 1873
8ccc75b0 1874 ssh_send_ok = 1;
dacbd0e8 1875 ssh_channels = newtree234(ssh_channelcmp);
6f34e365 1876 begin_session();
374330e2 1877 while (1) {
1878 crReturnV;
1879 if (ispkt) {
e5574168 1880 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1881 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1882 long len = GET_32BIT(pktin.body);
fe50e814 1883 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1884 pktin.body+4, len);
e5574168 1885 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1886 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1887 logevent("Received disconnect request");
3257deae 1888 crReturnV;
9c964e85 1889 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
1890 /* Remote side is trying to open a channel to talk to our
1891 * X-Server. Give them back a local channel number. */
1892 unsigned i;
1893 struct ssh_channel *c, *d;
1894 enum234 e;
1895
1896 logevent("Received X11 connect request");
1897 /* Refuse if X11 forwarding is disabled. */
1898 if (!ssh_X11_fwd_enabled) {
1899 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1900 PKT_INT, GET_32BIT(pktin.body),
1901 PKT_END);
1902 logevent("Rejected X11 connect request");
1903 } else {
9c964e85 1904 c = smalloc(sizeof(struct ssh_channel));
1905
0c6c9a70 1906 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
9c964e85 1907 logevent("opening X11 forward connection failed");
1908 sfree(c);
1909 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1910 PKT_INT, GET_32BIT(pktin.body),
1911 PKT_END);
1912 } else {
1913 logevent("opening X11 forward connection succeeded");
1914 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
783415f8 1915 if (d->localid > i)
1916 break; /* found a free number */
1917 i = d->localid + 1;
9c964e85 1918 }
1919 c->remoteid = GET_32BIT(pktin.body);
1920 c->localid = i;
1921 c->closes = 0;
783415f8 1922 c->type = CHAN_X11; /* identify channel type */
9c964e85 1923 add234(ssh_channels, c);
1924 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1925 PKT_INT, c->remoteid, PKT_INT, c->localid,
1926 PKT_END);
1927 logevent("Opened X11 forward channel");
1928 }
1929 }
dacbd0e8 1930 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1931 /* Remote side is trying to open a channel to talk to our
1932 * agent. Give them back a local channel number. */
db7d555c 1933 unsigned i;
dacbd0e8 1934 struct ssh_channel *c;
1935 enum234 e;
db7d555c 1936
1937 /* Refuse if agent forwarding is disabled. */
1938 if (!ssh_agentfwd_enabled) {
1939 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1940 PKT_INT, GET_32BIT(pktin.body),
1941 PKT_END);
1942 } else {
1943 i = 1;
1944 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1945 if (c->localid > i)
1946 break; /* found a free number */
1947 i = c->localid + 1;
1948 }
dcbde236 1949 c = smalloc(sizeof(struct ssh_channel));
db7d555c 1950 c->remoteid = GET_32BIT(pktin.body);
1951 c->localid = i;
1952 c->closes = 0;
783415f8 1953 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 1954 c->u.a.lensofar = 0;
1955 add234(ssh_channels, c);
1956 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1957 PKT_INT, c->remoteid, PKT_INT, c->localid,
1958 PKT_END);
1959 }
1960 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1961 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
dacbd0e8 1962 /* Remote side closes a channel. */
d211621f 1963 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1964 struct ssh_channel *c;
1965 c = find234(ssh_channels, &i, ssh_channelfind);
1966 if (c) {
1967 int closetype;
1968 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1969 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
783415f8 1970 if ((c->closes == 0) && (c->type == CHAN_X11)) {
9c964e85 1971 logevent("X11 connection closed");
1972 assert(c->u.x11.s != NULL);
1973 x11_close(c->u.x11.s);
1974 c->u.x11.s = NULL;
1975 }
dacbd0e8 1976 c->closes |= closetype;
1977 if (c->closes == 3) {
1978 del234(ssh_channels, c);
dcbde236 1979 sfree(c);
dacbd0e8 1980 }
1981 }
1982 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1983 /* Data sent down one of our channels. */
1984 int i = GET_32BIT(pktin.body);
1985 int len = GET_32BIT(pktin.body+4);
1986 unsigned char *p = pktin.body+8;
1987 struct ssh_channel *c;
1988 c = find234(ssh_channels, &i, ssh_channelfind);
1989 if (c) {
1990 switch(c->type) {
783415f8 1991 case CHAN_X11:
9c964e85 1992 x11_send(c->u.x11.s, p, len);
1993 break;
783415f8 1994 case CHAN_AGENT:
dacbd0e8 1995 /* Data for an agent message. Buffer it. */
1996 while (len > 0) {
1997 if (c->u.a.lensofar < 4) {
1998 int l = min(4 - c->u.a.lensofar, len);
1999 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2000 p += l; len -= l; c->u.a.lensofar += l;
2001 }
2002 if (c->u.a.lensofar == 4) {
2003 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
dcbde236 2004 c->u.a.message = smalloc(c->u.a.totallen);
dacbd0e8 2005 memcpy(c->u.a.message, c->u.a.msglen, 4);
2006 }
2007 if (c->u.a.lensofar >= 4 && len > 0) {
2008 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2009 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2010 p += l; len -= l; c->u.a.lensofar += l;
2011 }
2012 if (c->u.a.lensofar == c->u.a.totallen) {
2013 void *reply, *sentreply;
2014 int replylen;
2015 agent_query(c->u.a.message, c->u.a.totallen,
2016 &reply, &replylen);
2017 if (reply)
2018 sentreply = reply;
2019 else {
2020 /* Fake SSH_AGENT_FAILURE. */
2021 sentreply = "\0\0\0\1\5";
2022 replylen = 5;
2023 }
2024 send_packet(SSH1_MSG_CHANNEL_DATA,
2025 PKT_INT, c->remoteid,
2026 PKT_INT, replylen,
2027 PKT_DATA, sentreply, replylen,
2028 PKT_END);
2029 if (reply)
dcbde236 2030 sfree(reply);
2031 sfree(c->u.a.message);
dacbd0e8 2032 c->u.a.lensofar = 0;
2033 }
2034 }
2035 break;
2036 }
2037 }
e5574168 2038 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 2039 /* may be from EXEC_SHELL on some servers */
e5574168 2040 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 2041 /* may be from EXEC_SHELL on some servers
374330e2 2042 * if no pty is available or in other odd cases. Ignore */
e5574168 2043 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2044 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 2045 } else {
8d5de777 2046 bombout(("Strange packet received: type %d", pktin.type));
2047 crReturnV;
374330e2 2048 }
2049 } else {
8df7a775 2050 while (inlen > 0) {
2051 int len = min(inlen, 512);
2052 send_packet(SSH1_CMSG_STDIN_DATA,
2053 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2054 in += len;
2055 inlen -= len;
2056 }
374330e2 2057 }
2058 }
2059
2060 crFinishV;
2061}
2062
2063/*
e5574168 2064 * Utility routine for decoding comma-separated strings in KEXINIT.
2065 */
75cab814 2066static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 2067 int needlen = strlen(needle);
2068 while (1) {
2069 /*
2070 * Is it at the start of the string?
2071 */
2072 if (haylen >= needlen && /* haystack is long enough */
2073 !memcmp(needle, haystack, needlen) && /* initial match */
2074 (haylen == needlen || haystack[needlen] == ',')
2075 /* either , or EOS follows */
2076 )
2077 return 1;
2078 /*
2079 * If not, search for the next comma and resume after that.
2080 * If no comma found, terminate.
2081 */
2082 while (haylen > 0 && *haystack != ',')
2083 haylen--, haystack++;
2084 if (haylen == 0)
2085 return 0;
2086 haylen--, haystack++; /* skip over comma itself */
2087 }
2088}
2089
2090/*
d39f364a 2091 * SSH2 key creation method.
2092 */
75cab814 2093static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
d39f364a 2094 SHA_State s;
2095 /* First 20 bytes. */
2096 SHA_Init(&s);
2097 sha_mpint(&s, K);
2098 SHA_Bytes(&s, H, 20);
2099 SHA_Bytes(&s, &chr, 1);
2100 SHA_Bytes(&s, H, 20);
2101 SHA_Final(&s, keyspace);
2102 /* Next 20 bytes. */
2103 SHA_Init(&s);
2104 sha_mpint(&s, K);
2105 SHA_Bytes(&s, H, 20);
2106 SHA_Bytes(&s, keyspace, 20);
2107 SHA_Final(&s, keyspace+20);
2108}
2109
2110/*
7cca0d81 2111 * Handle the SSH2 transport layer.
e5574168 2112 */
7cca0d81 2113static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 2114{
2115 static int i, len;
2116 static char *str;
2117 static Bignum e, f, K;
7591b9ff 2118 static const struct ssh_mac **maclist;
8b2715b2 2119 static int nmacs;
57476f6b 2120 static const struct ssh_cipher *cscipher_tobe = NULL;
2121 static const struct ssh_cipher *sccipher_tobe = NULL;
2122 static const struct ssh_mac *csmac_tobe = NULL;
2123 static const struct ssh_mac *scmac_tobe = NULL;
2124 static const struct ssh_compress *cscomp_tobe = NULL;
2125 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 2126 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 2127 static int hostkeylen, siglen;
e055a386 2128 static void *hkey; /* actual host key */
e5574168 2129 static unsigned char exchange_hash[20];
d39f364a 2130 static unsigned char keyspace[40];
57476f6b 2131 static const struct ssh_cipher *preferred_cipher;
4ba9b64b 2132 static const struct ssh_compress *preferred_comp;
0db56f73 2133 static int first_kex;
e5574168 2134
2135 crBegin;
7cca0d81 2136 random_init();
0db56f73 2137 first_kex = 1;
e5574168 2138
5e8358ad 2139 /*
4ba9b64b 2140 * Set up the preferred cipher and compression.
5e8358ad 2141 */
2142 if (cfg.cipher == CIPHER_BLOWFISH) {
57476f6b 2143 preferred_cipher = &ssh_blowfish_ssh2;
5e8358ad 2144 } else if (cfg.cipher == CIPHER_DES) {
2145 logevent("Single DES not supported in SSH2; using 3DES");
57476f6b 2146 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 2147 } else if (cfg.cipher == CIPHER_3DES) {
57476f6b 2148 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 2149 } else {
2150 /* Shouldn't happen, but we do want to initialise to _something_. */
57476f6b 2151 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 2152 }
4ba9b64b 2153 if (cfg.compression)
2154 preferred_comp = &ssh_zlib;
2155 else
2156 preferred_comp = &ssh_comp_none;
5e8358ad 2157
7591b9ff 2158 /*
2159 * Be prepared to work around the buggy MAC problem.
2160 */
2161 if (cfg.buggymac)
8b2715b2 2162 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 2163 else
8b2715b2 2164 maclist = macs, nmacs = lenof(macs);
7591b9ff 2165
7cca0d81 2166 begin_key_exchange:
e5574168 2167 /*
2168 * Construct and send our key exchange packet.
2169 */
2170 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2171 for (i = 0; i < 16; i++)
2172 ssh2_pkt_addbyte((unsigned char)random_byte());
2173 /* List key exchange algorithms. */
2174 ssh2_pkt_addstring_start();
2175 for (i = 0; i < lenof(kex_algs); i++) {
2176 ssh2_pkt_addstring_str(kex_algs[i]->name);
2177 if (i < lenof(kex_algs)-1)
2178 ssh2_pkt_addstring_str(",");
2179 }
2180 /* List server host key algorithms. */
2181 ssh2_pkt_addstring_start();
2182 for (i = 0; i < lenof(hostkey_algs); i++) {
2183 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2184 if (i < lenof(hostkey_algs)-1)
2185 ssh2_pkt_addstring_str(",");
2186 }
2187 /* List client->server encryption algorithms. */
2188 ssh2_pkt_addstring_start();
729e54b4 2189 for (i = 0; i < lenof(ciphers)+1; i++) {
2190 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2191 ssh2_pkt_addstring_str(c->name);
729e54b4 2192 if (i < lenof(ciphers))
e5574168 2193 ssh2_pkt_addstring_str(",");
2194 }
2195 /* List server->client encryption algorithms. */
2196 ssh2_pkt_addstring_start();
729e54b4 2197 for (i = 0; i < lenof(ciphers)+1; i++) {
2198 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2199 ssh2_pkt_addstring_str(c->name);
729e54b4 2200 if (i < lenof(ciphers))
e5574168 2201 ssh2_pkt_addstring_str(",");
2202 }
2203 /* List client->server MAC algorithms. */
2204 ssh2_pkt_addstring_start();
8b2715b2 2205 for (i = 0; i < nmacs; i++) {
7591b9ff 2206 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2207 if (i < nmacs-1)
e5574168 2208 ssh2_pkt_addstring_str(",");
2209 }
2210 /* List server->client MAC algorithms. */
2211 ssh2_pkt_addstring_start();
8b2715b2 2212 for (i = 0; i < nmacs; i++) {
7591b9ff 2213 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2214 if (i < nmacs-1)
e5574168 2215 ssh2_pkt_addstring_str(",");
2216 }
2217 /* List client->server compression algorithms. */
2218 ssh2_pkt_addstring_start();
4ba9b64b 2219 for (i = 0; i < lenof(compressions)+1; i++) {
2220 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2221 ssh2_pkt_addstring_str(c->name);
2222 if (i < lenof(compressions))
e5574168 2223 ssh2_pkt_addstring_str(",");
2224 }
2225 /* List server->client compression algorithms. */
2226 ssh2_pkt_addstring_start();
4ba9b64b 2227 for (i = 0; i < lenof(compressions)+1; i++) {
2228 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2229 ssh2_pkt_addstring_str(c->name);
2230 if (i < lenof(compressions))
e5574168 2231 ssh2_pkt_addstring_str(",");
2232 }
2233 /* List client->server languages. Empty list. */
2234 ssh2_pkt_addstring_start();
2235 /* List server->client languages. Empty list. */
2236 ssh2_pkt_addstring_start();
2237 /* First KEX packet does _not_ follow, because we're not that brave. */
2238 ssh2_pkt_addbool(FALSE);
2239 /* Reserved. */
2240 ssh2_pkt_adduint32(0);
0db56f73 2241
2242 exhash = exhashbase;
e5574168 2243 sha_string(&exhash, pktout.data+5, pktout.length-5);
0db56f73 2244
e5574168 2245 ssh2_pkt_send();
2246
2247 if (!ispkt) crWaitUntil(ispkt);
2248 sha_string(&exhash, pktin.data+5, pktin.length-5);
2249
2250 /*
2251 * Now examine the other side's KEXINIT to see what we're up
2252 * to.
2253 */
7cca0d81 2254 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 2255 bombout(("expected key exchange packet from server"));
2256 crReturn(0);
7cca0d81 2257 }
e5574168 2258 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2259 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2260 pktin.savedpos += 16; /* skip garbage cookie */
2261 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2262 for (i = 0; i < lenof(kex_algs); i++) {
2263 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2264 kex = kex_algs[i];
2265 break;
2266 }
2267 }
2268 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2269 for (i = 0; i < lenof(hostkey_algs); i++) {
2270 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2271 hostkey = hostkey_algs[i];
2272 break;
2273 }
2274 }
2275 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 2276 for (i = 0; i < lenof(ciphers)+1; i++) {
2277 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2278 if (in_commasep_string(c->name, str, len)) {
729e54b4 2279 cscipher_tobe = c;
e5574168 2280 break;
2281 }
2282 }
2283 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
729e54b4 2284 for (i = 0; i < lenof(ciphers)+1; i++) {
2285 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2286 if (in_commasep_string(c->name, str, len)) {
729e54b4 2287 sccipher_tobe = c;
e5574168 2288 break;
2289 }
2290 }
2291 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 2292 for (i = 0; i < nmacs; i++) {
7591b9ff 2293 if (in_commasep_string(maclist[i]->name, str, len)) {
2294 csmac_tobe = maclist[i];
e5574168 2295 break;
2296 }
2297 }
2298 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 2299 for (i = 0; i < nmacs; i++) {
7591b9ff 2300 if (in_commasep_string(maclist[i]->name, str, len)) {
2301 scmac_tobe = maclist[i];
e5574168 2302 break;
2303 }
2304 }
2305 ssh2_pkt_getstring(&str, &len); /* client->server compression */
4ba9b64b 2306 for (i = 0; i < lenof(compressions)+1; i++) {
2307 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2308 if (in_commasep_string(c->name, str, len)) {
2309 cscomp_tobe = c;
e5574168 2310 break;
2311 }
2312 }
2313 ssh2_pkt_getstring(&str, &len); /* server->client compression */
4ba9b64b 2314 for (i = 0; i < lenof(compressions)+1; i++) {
2315 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2316 if (in_commasep_string(c->name, str, len)) {
2317 sccomp_tobe = c;
e5574168 2318 break;
2319 }
2320 }
e5574168 2321
2322 /*
2323 * Currently we only support Diffie-Hellman and DSS, so let's
2324 * bomb out if those aren't selected.
2325 */
8d5de777 2326 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2327 bombout(("internal fault: chaos in SSH 2 transport layer"));
2328 crReturn(0);
2329 }
e5574168 2330
2331 /*
2332 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2333 */
2334 e = dh_create_e();
e5574168 2335 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2336 ssh2_pkt_addmp(e);
2337 ssh2_pkt_send();
2338
2339 crWaitUntil(ispkt);
7cca0d81 2340 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2341 bombout(("expected key exchange packet from server"));
2342 crReturn(0);
7cca0d81 2343 }
e5574168 2344 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2345 f = ssh2_pkt_getmp();
e5574168 2346 ssh2_pkt_getstring(&sigdata, &siglen);
2347
2348 K = dh_find_K(f);
e5574168 2349
2350 sha_string(&exhash, hostkeydata, hostkeylen);
2351 sha_mpint(&exhash, e);
2352 sha_mpint(&exhash, f);
2353 sha_mpint(&exhash, K);
2354 SHA_Final(&exhash, exchange_hash);
2355
7cca0d81 2356#if 0
e5574168 2357 debug(("Exchange hash is:\r\n"));
2358 for (i = 0; i < 20; i++)
2359 debug((" %02x", exchange_hash[i]));
2360 debug(("\r\n"));
7cca0d81 2361#endif
2362
e055a386 2363 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2364 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
8d5de777 2365 bombout(("Server failed host key check"));
2366 crReturn(0);
2367 }
e5574168 2368
2369 /*
7cca0d81 2370 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2371 */
7cca0d81 2372 crWaitUntil(ispkt);
8d5de777 2373 if (pktin.type != SSH2_MSG_NEWKEYS) {
2374 bombout(("expected new-keys packet from server"));
2375 crReturn(0);
2376 }
d39f364a 2377
2378 /*
7cca0d81 2379 * Authenticate remote host: verify host key. (We've already
2380 * checked the signature of the exchange hash.)
e5574168 2381 */
e055a386 2382 keystr = hostkey->fmtkey(hkey);
2383 fingerprint = hostkey->fingerprint(hkey);
d4857987 2384 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2385 keystr, fingerprint);
d5859615 2386 logevent("Host key fingerprint is:");
2387 logevent(fingerprint);
dcbde236 2388 sfree(fingerprint);
2389 sfree(keystr);
e055a386 2390 hostkey->freekey(hkey);
d39f364a 2391
2392 /*
7cca0d81 2393 * Send SSH2_MSG_NEWKEYS.
d39f364a 2394 */
2395 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2396 ssh2_pkt_send();
d39f364a 2397
2398 /*
2399 * Create and initialise session keys.
2400 */
2401 cscipher = cscipher_tobe;
2402 sccipher = sccipher_tobe;
2403 csmac = csmac_tobe;
2404 scmac = scmac_tobe;
2405 cscomp = cscomp_tobe;
2406 sccomp = sccomp_tobe;
4ba9b64b 2407 cscomp->compress_init();
2408 sccomp->decompress_init();
d39f364a 2409 /*
2410 * Set IVs after keys.
2411 */
2412 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
21d7754f 2413 ssh2_mkkey(K, exchange_hash, 'D', keyspace); sccipher->setsckey(keyspace);
d39f364a 2414 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2415 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2416 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2417 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2418
033b4cef 2419 /*
0db56f73 2420 * If this is the first key exchange phase, we must pass the
2421 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2422 * wants to see it but because it will need time to initialise
2423 * itself before it sees an actual packet. In subsequent key
2424 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2425 * it would only confuse the layer above.
2426 */
2427 if (!first_kex) {
2428 crReturn(0);
2429 }
2430 first_kex = 0;
2431
2432 /*
7cca0d81 2433 * Now we're encrypting. Begin returning 1 to the protocol main
2434 * function so that other things can run on top of the
2435 * transport. If we ever see a KEXINIT, we must go back to the
2436 * start.
033b4cef 2437 */
7cca0d81 2438 do {
2439 crReturn(1);
2440 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2441 goto begin_key_exchange;
e5574168 2442
2443 crFinish(1);
2444}
2445
7cca0d81 2446/*
783415f8 2447 * Add data to an SSH2 channel output buffer.
2448 */
2449static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2450 if (c->v2.outbufsize <
2451 c->v2.outbuflen + len) {
2452 c->v2.outbufsize =
2453 c->v2.outbuflen + len + 1024;
2454 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2455 c->v2.outbufsize);
2456 }
2457 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2458 buf, len);
2459 c->v2.outbuflen += len;
2460}
2461
2462/*
2463 * Attempt to send data on an SSH2 channel.
2464 */
2465static void ssh2_try_send(struct ssh_channel *c) {
2466 while (c->v2.remwindow > 0 &&
2467 c->v2.outbuflen > 0) {
2468 unsigned len = c->v2.remwindow;
2469 if (len > c->v2.outbuflen)
2470 len = c->v2.outbuflen;
2471 if (len > c->v2.remmaxpkt)
2472 len = c->v2.remmaxpkt;
2473 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2474 ssh2_pkt_adduint32(c->remoteid);
2475 ssh2_pkt_addstring_start();
2476 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2477 ssh2_pkt_send();
2478 c->v2.outbuflen -= len;
2479 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2480 c->v2.outbuflen);
2481 c->v2.remwindow -= len;
2482 }
2483}
2484
2485/*
7cca0d81 2486 * Handle the SSH2 userauth and connection layers.
2487 */
2488static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2489{
7cca0d81 2490 static unsigned long remote_winsize;
2491 static unsigned long remote_maxpkt;
2492
e5574168 2493 crBegin;
2494
7cca0d81 2495 /*
2496 * Request userauth protocol, and await a response to it.
2497 */
2498 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2499 ssh2_pkt_addstring("ssh-userauth");
2500 ssh2_pkt_send();
2501 crWaitUntilV(ispkt);
8d5de777 2502 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2503 bombout(("Server refused user authentication protocol"));
2504 crReturnV;
2505 }
7cca0d81 2506
2507 /*
2508 * FIXME: currently we support only password authentication.
2509 * (This places us technically in violation of the SSH2 spec.
2510 * We must fix this.)
2511 */
2512 while (1) {
2513 /*
2514 * Get a username and a password.
2515 */
2516 static char username[100];
2517 static char password[100];
2518 static int pos = 0;
2519 static char c;
e5574168 2520
67779be7 2521 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2522 c_write("login as: ", 10);
67779be7 2523 ssh_send_ok = 1;
7cca0d81 2524 while (pos >= 0) {
2525 crWaitUntilV(!ispkt);
2526 while (inlen--) switch (c = *in++) {
2527 case 10: case 13:
2528 username[pos] = 0;
2529 pos = -1;
2530 break;
2531 case 8: case 127:
2532 if (pos > 0) {
2533 c_write("\b \b", 3);
2534 pos--;
2535 }
2536 break;
2537 case 21: case 27:
2538 while (pos > 0) {
2539 c_write("\b \b", 3);
2540 pos--;
2541 }
2542 break;
2543 case 3: case 4:
2544 random_save_seed();
2545 exit(0);
2546 break;
2547 default:
2548 if (((c >= ' ' && c <= '~') ||
2549 ((unsigned char)c >= 160)) && pos < 40) {
2550 username[pos++] = c;
2551 c_write(&c, 1);
2552 }
2553 break;
2554 }
2555 }
2556 c_write("\r\n", 2);
2557 username[strcspn(username, "\n\r")] = '\0';
2558 } else {
2559 char stuff[200];
2560 strncpy(username, cfg.username, 99);
2561 username[99] = '\0';
67779be7 2562 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2563 sprintf(stuff, "Using username \"%s\".\r\n", username);
2564 c_write(stuff, strlen(stuff));
2565 }
2566 }
2567
d8426c54 2568 if (ssh_get_password) {
7cca0d81 2569 char prompt[200];
b585ec46 2570 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
7cca0d81 2571 if (!ssh_get_password(prompt, password, sizeof(password))) {
2572 /*
2573 * get_password failed to get a password (for
2574 * example because one was supplied on the command
2575 * line which has already failed to work).
2576 * Terminate.
2577 */
2578 logevent("No more passwords to try");
2579 ssh_state = SSH_STATE_CLOSED;
2580 crReturnV;
2581 }
2582 } else {
2583 c_write("password: ", 10);
67779be7 2584 ssh_send_ok = 1;
7cca0d81 2585
2586 pos = 0;
2587 while (pos >= 0) {
2588 crWaitUntilV(!ispkt);
2589 while (inlen--) switch (c = *in++) {
2590 case 10: case 13:
2591 password[pos] = 0;
2592 pos = -1;
2593 break;
2594 case 8: case 127:
2595 if (pos > 0)
2596 pos--;
2597 break;
2598 case 21: case 27:
2599 pos = 0;
2600 break;
2601 case 3: case 4:
2602 random_save_seed();
2603 exit(0);
2604 break;
2605 default:
2606 if (((c >= ' ' && c <= '~') ||
2607 ((unsigned char)c >= 160)) && pos < 40)
2608 password[pos++] = c;
2609 break;
2610 }
2611 }
2612 c_write("\r\n", 2);
2613 }
2614
2615 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2616 ssh2_pkt_addstring(username);
2617 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2618 ssh2_pkt_addstring("password");
2619 ssh2_pkt_addbool(FALSE);
2620 ssh2_pkt_addstring(password);
2621 ssh2_pkt_send();
2622
2623 crWaitUntilV(ispkt);
2624 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2625 c_write("Access denied\r\n", 15);
2626 logevent("Authentication refused");
2627 } else
2628 break;
2629 }
2630
2631 /*
2632 * Now we're authenticated for the connection protocol. The
2633 * connection protocol will automatically have started at this
2634 * point; there's no need to send SERVICE_REQUEST.
2635 */
2636
2637 /*
2638 * So now create a channel with a session in it.
2639 */
dcbde236 2640 mainchan = smalloc(sizeof(struct ssh_channel));
d211621f 2641 mainchan->localid = 100; /* as good as any */
7cca0d81 2642 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2643 ssh2_pkt_addstring("session");
d211621f 2644 ssh2_pkt_adduint32(mainchan->localid);
cf6e59d6 2645 ssh2_pkt_adduint32(0x8000UL); /* our window size */
d211621f 2646 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2647 ssh2_pkt_send();
2648 crWaitUntilV(ispkt);
2649 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2650 bombout(("Server refused to open a session"));
2651 crReturnV;
7cca0d81 2652 /* FIXME: error data comes back in FAILURE packet */
2653 }
d211621f 2654 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2655 bombout(("Server's channel confirmation cited wrong channel"));
2656 crReturnV;
7cca0d81 2657 }
d211621f 2658 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 2659 mainchan->type = CHAN_MAINSESSION;
2660 mainchan->closes = 0;
2661 mainchan->v2.remwindow = ssh2_pkt_getuint32();
2662 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
2663 mainchan->v2.outbuffer = NULL;
2664 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
2665 ssh_channels = newtree234(ssh_channelcmp);
2666 add234(ssh_channels, mainchan);
7cca0d81 2667 logevent("Opened channel for session");
2668
2669 /*
783415f8 2670 * Potentially enable X11 forwarding.
2671 */
2672 if (cfg.x11_forward) {
2673 char proto[20], data[64];
2674 logevent("Requesting X11 forwarding");
2675 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2676 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2677 ssh2_pkt_adduint32(mainchan->remoteid);
2678 ssh2_pkt_addstring("x11-req");
2679 ssh2_pkt_addbool(1); /* want reply */
2680 ssh2_pkt_addbool(0); /* many connections */
2681 ssh2_pkt_addstring(proto);
2682 ssh2_pkt_addstring(data);
2683 ssh2_pkt_adduint32(0); /* screen number */
2684 ssh2_pkt_send();
2685
2686 do {
2687 crWaitUntilV(ispkt);
2688 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2689 unsigned i = ssh2_pkt_getuint32();
2690 struct ssh_channel *c;
2691 c = find234(ssh_channels, &i, ssh_channelfind);
2692 if (!c)
2693 continue; /* nonexistent channel */
2694 c->v2.remwindow += ssh2_pkt_getuint32();
2695 }
2696 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2697
2698 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2699 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2700 bombout(("Server got confused by X11 forwarding request"));
2701 crReturnV;
2702 }
2703 logevent("X11 forwarding refused");
2704 } else {
2705 logevent("X11 forwarding enabled");
2706 ssh_X11_fwd_enabled = TRUE;
2707 }
2708 }
2709
2710 /*
7cca0d81 2711 * Now allocate a pty for the session.
2712 */
67779be7 2713 if (!cfg.nopty) {
2714 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2715 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2716 ssh2_pkt_addstring("pty-req");
2717 ssh2_pkt_addbool(1); /* want reply */
2718 ssh2_pkt_addstring(cfg.termtype);
2719 ssh2_pkt_adduint32(cols);
2720 ssh2_pkt_adduint32(rows);
2721 ssh2_pkt_adduint32(0); /* pixel width */
2722 ssh2_pkt_adduint32(0); /* pixel height */
2723 ssh2_pkt_addstring_start();
2724 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2725 ssh2_pkt_send();
6e48c3fe 2726 ssh_state = SSH_STATE_INTERMED;
7cca0d81 2727
67779be7 2728 do {
2729 crWaitUntilV(ispkt);
2730 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 2731 unsigned i = ssh2_pkt_getuint32();
2732 struct ssh_channel *c;
2733 c = find234(ssh_channels, &i, ssh_channelfind);
2734 if (!c)
2735 continue; /* nonexistent channel */
2736 c->v2.remwindow += ssh2_pkt_getuint32();
67779be7 2737 }
2738 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2739
67779be7 2740 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2741 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2742 bombout(("Server got confused by pty request"));
2743 crReturnV;
67779be7 2744 }
2745 c_write("Server refused to allocate pty\r\n", 32);
2746 } else {
2747 logevent("Allocated pty");
7cca0d81 2748 }
7cca0d81 2749 }
2750
2751 /*
67779be7 2752 * Start a shell or a remote command.
7cca0d81 2753 */
2754 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2755 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2756 if (*cfg.remote_cmd) {
2757 ssh2_pkt_addstring("exec");
2758 ssh2_pkt_addbool(1); /* want reply */
2759 ssh2_pkt_addstring(cfg.remote_cmd);
2760 } else {
2761 ssh2_pkt_addstring("shell");
2762 ssh2_pkt_addbool(1); /* want reply */
2763 }
7cca0d81 2764 ssh2_pkt_send();
d211621f 2765 do {
7cca0d81 2766 crWaitUntilV(ispkt);
d211621f 2767 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 2768 unsigned i = ssh2_pkt_getuint32();
2769 struct ssh_channel *c;
2770 c = find234(ssh_channels, &i, ssh_channelfind);
2771 if (!c)
2772 continue; /* nonexistent channel */
2773 c->v2.remwindow += ssh2_pkt_getuint32();
d211621f 2774 }
7cca0d81 2775 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2776 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2777 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2778 bombout(("Server got confused by shell/command request"));
2779 crReturnV;
7cca0d81 2780 }
8d5de777 2781 bombout(("Server refused to start a shell/command"));
2782 crReturnV;
7cca0d81 2783 } else {
8d5de777 2784 logevent("Started a shell/command");
7cca0d81 2785 }
2786
6e48c3fe 2787 ssh_state = SSH_STATE_SESSION;
2788 if (size_needed)
2789 ssh_size();
3687d221 2790 if (eof_needed)
2791 ssh_special(TS_EOF);
6e48c3fe 2792
7cca0d81 2793 /*
2794 * Transfer data!
2795 */
8ccc75b0 2796 ssh_send_ok = 1;
6f34e365 2797 begin_session();
7cca0d81 2798 while (1) {
d211621f 2799 static int try_send;
e5574168 2800 crReturnV;
d211621f 2801 try_send = FALSE;
7cca0d81 2802 if (ispkt) {
2803 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2804 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2805 char *data;
2806 int length;
783415f8 2807 unsigned i = ssh2_pkt_getuint32();
2808 struct ssh_channel *c;
2809 c = find234(ssh_channels, &i, ssh_channelfind);
2810 if (!c)
2811 continue; /* nonexistent channel */
7cca0d81 2812 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2813 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2814 continue; /* extended but not stderr */
2815 ssh2_pkt_getstring(&data, &length);
d211621f 2816 if (data) {
783415f8 2817 switch (c->type) {
2818 case CHAN_MAINSESSION:
2819 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
2820 data, length);
2821 break;
2822 case CHAN_X11:
2823 x11_send(c->u.x11.s, data, length);
2824 break;
2825 }
d211621f 2826 /*
783415f8 2827 * Enlarge the window again at the remote
2828 * side, just in case it ever runs down and
2829 * they fail to send us any more data.
d211621f 2830 */
2831 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
783415f8 2832 ssh2_pkt_adduint32(c->remoteid);
d211621f 2833 ssh2_pkt_adduint32(length);
2834 ssh2_pkt_send();
2835 }
7cca0d81 2836 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2837 ssh_state = SSH_STATE_CLOSED;
d211621f 2838 logevent("Received disconnect message");
3257deae 2839 crReturnV;
7cca0d81 2840 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2841 continue; /* exit status et al; ignore (FIXME?) */
d211621f 2842 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
783415f8 2843 unsigned i = ssh2_pkt_getuint32();
2844 struct ssh_channel *c;
2845
2846 c = find234(ssh_channels, &i, ssh_channelfind);
2847 if (!c)
2848 continue; /* nonexistent channel */
2849
2850 if (c->type == CHAN_X11) {
2851 /*
2852 * Remote EOF on an X11 channel means we should
2853 * wrap up and close the channel ourselves.
2854 */
2855 x11_close(c->u.x11.s);
2856 sshfwd_close(c);
2857 }
d211621f 2858 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
783415f8 2859 unsigned i = ssh2_pkt_getuint32();
2860 struct ssh_channel *c;
2861 enum234 e;
2862
2863 c = find234(ssh_channels, &i, ssh_channelfind);
2864 if (!c)
2865 continue; /* nonexistent channel */
2866 if (c->closes == 0) {
2867 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2868 ssh2_pkt_adduint32(c->remoteid);
2869 ssh2_pkt_send();
2870 }
2871 /* Do pre-close processing on the channel. */
2872 switch (c->type) {
2873 case CHAN_MAINSESSION:
2874 break; /* nothing to see here, move along */
2875 case CHAN_X11:
2876 break;
2877 }
2878 del234(ssh_channels, c);
2879 sfree(c->v2.outbuffer);
2880 sfree(c);
2881
2882 /*
2883 * See if that was the last channel left open.
2884 */
2885 c = first234(ssh_channels, &e);
2886 if (!c) {
d211621f 2887 logevent("All channels closed. Disconnecting");
2888 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
9005f3ba 2889 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
2890 ssh2_pkt_addstring("All open channels closed");
2891 ssh2_pkt_addstring("en"); /* language tag */
d211621f 2892 ssh2_pkt_send();
cf6e59d6 2893 ssh_state = SSH_STATE_CLOSED;
3257deae 2894 crReturnV;
d211621f 2895 }
2896 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2897 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 2898 unsigned i = ssh2_pkt_getuint32();
2899 struct ssh_channel *c;
2900 c = find234(ssh_channels, &i, ssh_channelfind);
2901 if (!c)
2902 continue; /* nonexistent channel */
2903 mainchan->v2.remwindow += ssh2_pkt_getuint32();
d211621f 2904 try_send = TRUE;
783415f8 2905 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
2906 char *type;
2907 int typelen;
2908 char *error = NULL;
2909 struct ssh_channel *c;
2910 ssh2_pkt_getstring(&type, &typelen);
2911 c = smalloc(sizeof(struct ssh_channel));
2912
2913 if (typelen == 3 && !memcmp(type, "x11", 3)) {
783415f8 2914 if (!ssh_X11_fwd_enabled)
2915 error = "X11 forwarding is not enabled";
0c6c9a70 2916 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
783415f8 2917 error = "Unable to open an X11 connection";
2918 } else {
2919 c->type = CHAN_X11;
2920 }
2921 } else {
2922 error = "Unsupported channel type requested";
2923 }
2924
2925 c->remoteid = ssh2_pkt_getuint32();
2926 if (error) {
2927 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
2928 ssh2_pkt_adduint32(c->remoteid);
2929 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
2930 ssh2_pkt_addstring(error);
2931 ssh2_pkt_addstring("en"); /* language tag */
2932 ssh2_pkt_send();
2933 sfree(c);
2934 } else {
2935 struct ssh_channel *d;
2936 unsigned i;
2937 enum234 e;
2938
2939 for (i=1, d = first234(ssh_channels, &e); d;
2940 d = next234(&e)) {
2941 if (d->localid > i)
2942 break; /* found a free number */
2943 i = d->localid + 1;
2944 }
2945 c->localid = i;
2946 c->closes = 0;
2947 c->v2.remwindow = ssh2_pkt_getuint32();
2948 c->v2.remmaxpkt = ssh2_pkt_getuint32();
2949 c->v2.outbuffer = NULL;
2950 c->v2.outbuflen = c->v2.outbufsize = 0;
2951 add234(ssh_channels, c);
2952 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
2953 ssh2_pkt_adduint32(c->remoteid);
2954 ssh2_pkt_adduint32(c->localid);
2955 ssh2_pkt_adduint32(0x8000UL); /* our window size */
2956 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
2957 ssh2_pkt_send();
2958 }
7cca0d81 2959 } else {
8d5de777 2960 bombout(("Strange packet received: type %d", pktin.type));
2961 crReturnV;
7cca0d81 2962 }
2963 } else {
d211621f 2964 /*
2965 * We have spare data. Add it to the channel buffer.
2966 */
783415f8 2967 ssh2_add_channel_data(mainchan, in, inlen);
d211621f 2968 try_send = TRUE;
7cca0d81 2969 }
d211621f 2970 if (try_send) {
783415f8 2971 enum234 e;
2972 struct ssh_channel *c;
d211621f 2973 /*
783415f8 2974 * Try to send data on all channels if we can.
d211621f 2975 */
783415f8 2976 for (c = first234(ssh_channels, &e); c; c = next234(&e))
2977 ssh2_try_send(c);
d211621f 2978 }
e5574168 2979 }
2980
2981 crFinishV;
2982}
2983
2984/*
7cca0d81 2985 * Handle the top-level SSH2 protocol.
2986 */
2987static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2988{
2989 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2990 return;
2991 do_ssh2_authconn(in, inlen, ispkt);
2992}
2993
2994/*
8df7a775 2995 * Called to set up the connection.
374330e2 2996 *
2997 * Returns an error message, or NULL on success.
374330e2 2998 */
8df7a775 2999static char *ssh_init (char *host, int port, char **realhost) {
fb09bf1c 3000 char *p;
8f203108 3001
3002#ifdef MSCRYPTOAPI
3003 if(crypto_startup() == 0)
3004 return "Microsoft high encryption pack not installed!";
3005#endif
374330e2 3006
8df7a775 3007 ssh_send_ok = 0;
3008
fb09bf1c 3009 p = connect_to_host(host, port, realhost);
3010 if (p != NULL)
3011 return p;
374330e2 3012
374330e2 3013 return NULL;
3014}
3015
3016/*
374330e2 3017 * Called to send data down the Telnet connection.
3018 */
3019static void ssh_send (char *buf, int len) {
f78051a1 3020 if (s == NULL || ssh_protocol == NULL)
374330e2 3021 return;
3022
3023 ssh_protocol(buf, len, 0);
3024}
3025
3026/*
6e48c3fe 3027 * Called to set the size of the window from SSH's POV.
374330e2 3028 */
3029static void ssh_size(void) {
3030 switch (ssh_state) {
3031 case SSH_STATE_BEFORE_SIZE:
3687d221 3032 case SSH_STATE_PREPACKET:
21248260 3033 case SSH_STATE_CLOSED:
374330e2 3034 break; /* do nothing */
3035 case SSH_STATE_INTERMED:
3036 size_needed = TRUE; /* buffer for later */
3037 break;
3038 case SSH_STATE_SESSION:
fef97f43 3039 if (!cfg.nopty) {
6e48c3fe 3040 if (ssh_version == 1) {
3041 send_packet(SSH1_CMSG_WINDOW_SIZE,
3042 PKT_INT, rows, PKT_INT, cols,
3043 PKT_INT, 0, PKT_INT, 0, PKT_END);
3044 } else {
3045 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3046 ssh2_pkt_adduint32(mainchan->remoteid);
3047 ssh2_pkt_addstring("window-change");
3048 ssh2_pkt_addbool(0);
3049 ssh2_pkt_adduint32(cols);
3050 ssh2_pkt_adduint32(rows);
3051 ssh2_pkt_adduint32(0);
3052 ssh2_pkt_adduint32(0);
3053 ssh2_pkt_send();
3054 }
fef97f43 3055 }
3687d221 3056 break;
374330e2 3057 }
3058}
3059
3060/*
6abbf9e3 3061 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3062 * can send an EOF and collect resulting output (e.g. `plink
3063 * hostname sort').
374330e2 3064 */
3065static void ssh_special (Telnet_Special code) {
6abbf9e3 3066 if (code == TS_EOF) {
3687d221 3067 if (ssh_state != SSH_STATE_SESSION) {
3068 /*
3069 * Buffer the EOF in case we are pre-SESSION, so we can
3070 * send it as soon as we reach SESSION.
3071 */
3072 if (code == TS_EOF)
3073 eof_needed = TRUE;
3074 return;
3075 }
67779be7 3076 if (ssh_version == 1) {
6abbf9e3 3077 send_packet(SSH1_CMSG_EOF, PKT_END);
3078 } else {
3079 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 3080 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 3081 ssh2_pkt_send();
3082 }
67779be7 3083 logevent("Sent EOF message");
ec55b220 3084 } else if (code == TS_PING) {
3687d221 3085 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3086 return;
ec55b220 3087 if (ssh_version == 1) {
3088 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3089 } else {
3090 ssh2_pkt_init(SSH2_MSG_IGNORE);
3091 ssh2_pkt_addstring_start();
3092 ssh2_pkt_send();
3093 }
6abbf9e3 3094 } else {
3095 /* do nothing */
3096 }
374330e2 3097}
3098
8df7a775 3099static Socket ssh_socket(void) { return s; }
8ccc75b0 3100
3101static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 3102
374330e2 3103Backend ssh_backend = {
3104 ssh_init,
374330e2 3105 ssh_send,
3106 ssh_size,
4017be6d 3107 ssh_special,
8ccc75b0 3108 ssh_socket,
97db3be4 3109 ssh_sendok,
3110 22
374330e2 3111};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator