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David Brinegar's workaround for an error reporting problem in some
[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
3cd52910 22#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
4a8fc3c4 23 (s ? sk_close(s), s = NULL : 0), \
3cd52910 24 connection_fatal msg )
8d5de777 25
d211621f 26#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
27#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
28#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
29#define SSH1_CMSG_USER 4 /* 0x4 */
30#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
31#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
32#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
33#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
34#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
35#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
36#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
37#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
38#define SSH1_SMSG_SUCCESS 14 /* 0xe */
39#define SSH1_SMSG_FAILURE 15 /* 0xf */
40#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
41#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
42#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
43#define SSH1_CMSG_EOF 19 /* 0x13 */
44#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
45#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
46#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
47#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
48#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
49#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
9c964e85 50#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
51#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
52#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
d211621f 53#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
54#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
d211621f 55#define SSH1_MSG_IGNORE 32 /* 0x20 */
9c964e85 56#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
57#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
58#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
d211621f 59#define SSH1_MSG_DEBUG 36 /* 0x24 */
4ba9b64b 60#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
d211621f 61#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
62#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
63#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
64#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
65#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
66#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
67
68#define SSH1_AUTH_TIS 5 /* 0x5 */
69#define SSH1_AUTH_CCARD 16 /* 0x10 */
70
d211621f 71#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
72#define SSH2_MSG_IGNORE 2 /* 0x2 */
73#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
74#define SSH2_MSG_DEBUG 4 /* 0x4 */
75#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
76#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
77#define SSH2_MSG_KEXINIT 20 /* 0x14 */
78#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
79#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
80#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
a92dd380 81#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
82#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
83#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
84#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
d211621f 85#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
86#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
87#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
88#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
89#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
90#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
91#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
92#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
93#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
94#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
95#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
96#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
97#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
98#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
99#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
100#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
101#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
102#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
103#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
104#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
105
9005f3ba 106#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
107#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
108#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
109#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
110#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
111#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
112#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
113#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
114#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
115#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
116#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
117
d211621f 118#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
119#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
120#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
121#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
122
123#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 124
7d503c31 125/*
126 * Various remote-bug flags.
127 */
128#define BUG_CHOKES_ON_SSH1_IGNORE 1
129#define BUG_SSH2_HMAC 2
130
fb09bf1c 131#define GET_32BIT(cp) \
132 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
133 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
134 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
135 ((unsigned long)(unsigned char)(cp)[3]))
136
137#define PUT_32BIT(cp, value) { \
138 (cp)[0] = (unsigned char)((value) >> 24); \
139 (cp)[1] = (unsigned char)((value) >> 16); \
140 (cp)[2] = (unsigned char)((value) >> 8); \
141 (cp)[3] = (unsigned char)(value); }
142
7cca0d81 143enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 144
374330e2 145/* Coroutine mechanics for the sillier bits of the code */
146#define crBegin1 static int crLine = 0;
147#define crBegin2 switch(crLine) { case 0:;
148#define crBegin crBegin1; crBegin2;
149#define crFinish(z) } crLine = 0; return (z)
150#define crFinishV } crLine = 0; return
151#define crReturn(z) \
152 do {\
153 crLine=__LINE__; return (z); case __LINE__:;\
154 } while (0)
155#define crReturnV \
156 do {\
157 crLine=__LINE__; return; case __LINE__:;\
158 } while (0)
159#define crStop(z) do{ crLine = 0; return (z); }while(0)
160#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 161#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 162#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 163
0c6c9a70 164extern char *x11_init (Socket *, char *, void *);
9c964e85 165extern void x11_close (Socket);
166extern void x11_send (Socket , char *, int);
167extern void x11_invent_auth(char *, int, char *, int);
168
5e8358ad 169/*
170 * Ciphers for SSH2. We miss out single-DES because it isn't
171 * supported; also 3DES and Blowfish are both done differently from
172 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
173 * endianness and different-sized keys.)
5e8358ad 174 */
0a3f1d48 175const static struct ssh2_ciphers *ciphers[] = {
176 &ssh2_aes,
177 &ssh2_blowfish,
178 &ssh2_3des,
8479e33c 179};
e5574168 180
a92dd380 181const static struct ssh_kex *kex_algs[] = {
a92dd380 182 &ssh_diffiehellman_gex,
a92dd380 183 &ssh_diffiehellman };
e5574168 184
85cc02bb 185const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 186
d39f364a 187static void nullmac_key(unsigned char *key) { }
e5574168 188static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
189static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
57476f6b 190const static struct ssh_mac ssh_mac_none = {
d39f364a 191 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 192};
8b2715b2 193const static struct ssh_mac *macs[] = {
194 &ssh_sha1, &ssh_md5, &ssh_mac_none };
195const static struct ssh_mac *buggymacs[] = {
196 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
e5574168 197
4ba9b64b 198static void ssh_comp_none_init(void) { }
199static int ssh_comp_none_block(unsigned char *block, int len,
200 unsigned char **outblock, int *outlen) {
201 return 0;
202}
63b00c83 203static int ssh_comp_none_disable(void) { return 0; }
57476f6b 204const static struct ssh_compress ssh_comp_none = {
4ba9b64b 205 "none",
206 ssh_comp_none_init, ssh_comp_none_block,
63b00c83 207 ssh_comp_none_init, ssh_comp_none_block,
208 ssh_comp_none_disable
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;
7d503c31 261static int ssh_remote_bugs;
57476f6b 262static const struct ssh_cipher *cipher = NULL;
0a3f1d48 263static const struct ssh2_cipher *cscipher = NULL;
264static const struct ssh2_cipher *sccipher = NULL;
57476f6b 265static const struct ssh_mac *csmac = NULL;
266static const struct ssh_mac *scmac = NULL;
267static const struct ssh_compress *cscomp = NULL;
268static const struct ssh_compress *sccomp = NULL;
269static const struct ssh_kex *kex = NULL;
e055a386 270static const struct ssh_signkey *hostkey = NULL;
65a22376 271static unsigned char ssh2_session_id[20];
fa17a66e 272int (*ssh_get_line)(const char *prompt, char *str, int maxlen,
273 int is_pw) = NULL;
57476f6b 274
275static char *savedhost;
276static int savedport;
277static int ssh_send_ok;
0965bee0 278static int ssh_echoing, ssh_editing;
57476f6b 279
dacbd0e8 280static tree234 *ssh_channels; /* indexed by local id */
57476f6b 281static struct ssh_channel *mainchan; /* primary session channel */
282
283static enum {
3687d221 284 SSH_STATE_PREPACKET,
57476f6b 285 SSH_STATE_BEFORE_SIZE,
286 SSH_STATE_INTERMED,
287 SSH_STATE_SESSION,
288 SSH_STATE_CLOSED
3687d221 289} ssh_state = SSH_STATE_PREPACKET;
57476f6b 290
3687d221 291static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 292
293static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
294static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
b185170a 295static unsigned char *deferred_send_data = NULL;
296static int deferred_len = 0, deferred_size = 0;
57476f6b 297
298static int ssh_version;
299static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
300static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
301static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
302static void ssh_size(void);
3687d221 303static void ssh_special (Telnet_Special);
783415f8 304static void ssh2_try_send(struct ssh_channel *c);
305static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
57476f6b 306
307static int (*s_rdpkt)(unsigned char **data, int *datalen);
308
309static struct rdpkt1_state_tag {
310 long len, pad, biglen, to_read;
311 unsigned long realcrc, gotcrc;
312 unsigned char *p;
313 int i;
314 int chunk;
315} rdpkt1_state;
316
960e736a 317static struct rdpkt2_state_tag {
318 long len, pad, payload, packetlen, maclen;
319 int i;
320 int cipherblk;
321 unsigned long incoming_sequence;
322} rdpkt2_state;
323
dacbd0e8 324static int ssh_channelcmp(void *av, void *bv) {
325 struct ssh_channel *a = (struct ssh_channel *)av;
326 struct ssh_channel *b = (struct ssh_channel *)bv;
327 if (a->localid < b->localid) return -1;
328 if (a->localid > b->localid) return +1;
329 return 0;
330}
331static int ssh_channelfind(void *av, void *bv) {
d211621f 332 unsigned *a = (unsigned *)av;
dacbd0e8 333 struct ssh_channel *b = (struct ssh_channel *)bv;
334 if (*a < b->localid) return -1;
335 if (*a > b->localid) return +1;
336 return 0;
337}
338
374330e2 339static void c_write (char *buf, int len) {
67779be7 340 if ((flags & FLAG_STDERR)) {
4017be6d 341 int i;
342 for (i = 0; i < len; i++)
343 if (buf[i] != '\r')
344 fputc(buf[i], stderr);
fb09bf1c 345 return;
346 }
fe50e814 347 from_backend(1, buf, len);
3bdaf79d 348}
349
1408a877 350static void c_write_str (char *buf) {
351 c_write(buf, strlen(buf));
352}
353
fb09bf1c 354/*
355 * Collect incoming data in the incoming packet buffer.
e5574168 356 * Decipher and verify the packet when it is completely read.
357 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 358 * Update the *data and *datalen variables.
359 * Return the additional nr of bytes needed, or 0 when
360 * a complete packet is available.
361 */
e5574168 362static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 363{
57476f6b 364 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 365
366 crBegin;
374330e2 367
fb09bf1c 368next_packet:
37508af4 369
fb09bf1c 370 pktin.type = 0;
371 pktin.length = 0;
374330e2 372
57476f6b 373 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 374 while ((*datalen) == 0)
57476f6b 375 crReturn(4-st->i);
376 st->len = (st->len << 8) + **data;
fb09bf1c 377 (*data)++, (*datalen)--;
378 }
374330e2 379
fb09bf1c 380#ifdef FWHACK
57476f6b 381 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
382 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 383 }
384#endif
374330e2 385
57476f6b 386 st->pad = 8 - (st->len % 8);
387 st->biglen = st->len + st->pad;
388 pktin.length = st->len - 5;
fb09bf1c 389
57476f6b 390 if (pktin.maxlen < st->biglen) {
391 pktin.maxlen = st->biglen;
dcbde236 392 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
393 srealloc(pktin.data, st->biglen+APIEXTRA));
fb09bf1c 394 if (!pktin.data)
395 fatalbox("Out of memory");
396 }
374330e2 397
57476f6b 398 st->to_read = st->biglen;
399 st->p = pktin.data;
400 while (st->to_read > 0) {
401 st->chunk = st->to_read;
fb09bf1c 402 while ((*datalen) == 0)
57476f6b 403 crReturn(st->to_read);
404 if (st->chunk > (*datalen))
405 st->chunk = (*datalen);
406 memcpy(st->p, *data, st->chunk);
407 *data += st->chunk;
408 *datalen -= st->chunk;
409 st->p += st->chunk;
410 st->to_read -= st->chunk;
fb09bf1c 411 }
374330e2 412
fb09bf1c 413 if (cipher)
57476f6b 414 cipher->decrypt(pktin.data, st->biglen);
698a5108 415#if 0
416 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
417 for (st->i = 0; st->i < st->biglen; st->i++)
418 debug((" %02x", (unsigned char)pktin.data[st->i]));
419 debug(("\r\n"));
420#endif
374330e2 421
57476f6b 422 st->realcrc = crc32(pktin.data, st->biglen-4);
423 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
424 if (st->gotcrc != st->realcrc) {
8d5de777 425 bombout(("Incorrect CRC received on packet"));
426 crReturn(0);
fb09bf1c 427 }
572f871e 428
4ba9b64b 429 pktin.body = pktin.data + st->pad + 1;
430
431 if (ssh1_compressing) {
432 unsigned char *decompblk;
433 int decomplen;
434#if 0
435 int i;
436 debug(("Packet payload pre-decompression:\n"));
437 for (i = -1; i < pktin.length; i++)
438 debug((" %02x", (unsigned char)pktin.body[i]));
439 debug(("\r\n"));
440#endif
441 zlib_decompress_block(pktin.body-1, pktin.length+1,
442 &decompblk, &decomplen);
443
444 if (pktin.maxlen < st->pad + decomplen) {
445 pktin.maxlen = st->pad + decomplen;
dcbde236 446 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
58298665 447 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 448 if (!pktin.data)
449 fatalbox("Out of memory");
450 }
451
452 memcpy(pktin.body-1, decompblk, decomplen);
dcbde236 453 sfree(decompblk);
4ba9b64b 454 pktin.length = decomplen-1;
455#if 0
456 debug(("Packet payload post-decompression:\n"));
457 for (i = -1; i < pktin.length; i++)
458 debug((" %02x", (unsigned char)pktin.body[i]));
459 debug(("\r\n"));
460#endif
461 }
462
e5574168 463 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
464 pktin.type == SSH1_SMSG_STDERR_DATA ||
465 pktin.type == SSH1_MSG_DEBUG ||
18515c51 466 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
467 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 468 long strlen = GET_32BIT(pktin.body);
8d5de777 469 if (strlen + 4 != pktin.length) {
470 bombout(("Received data packet with bogus string length"));
471 crReturn(0);
472 }
fb09bf1c 473 }
474
4ba9b64b 475 pktin.type = pktin.body[-1];
476
e5574168 477 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 478 /* log debug message */
479 char buf[80];
480 int strlen = GET_32BIT(pktin.body);
481 strcpy(buf, "Remote: ");
482 if (strlen > 70) strlen = 70;
483 memcpy(buf+8, pktin.body+4, strlen);
484 buf[8+strlen] = '\0';
485 logevent(buf);
486 goto next_packet;
e5574168 487 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 488 /* do nothing */
489 goto next_packet;
490 }
491
492 crFinish(0);
493}
494
e5574168 495static int ssh2_rdpkt(unsigned char **data, int *datalen)
496{
960e736a 497 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 498
499 crBegin;
500
501next_packet:
e5574168 502 pktin.type = 0;
503 pktin.length = 0;
960e736a 504 if (sccipher)
505 st->cipherblk = sccipher->blksize;
e5574168 506 else
960e736a 507 st->cipherblk = 8;
508 if (st->cipherblk < 8)
509 st->cipherblk = 8;
510
511 if (pktin.maxlen < st->cipherblk) {
512 pktin.maxlen = st->cipherblk;
dcbde236 513 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
514 srealloc(pktin.data, st->cipherblk+APIEXTRA));
e5574168 515 if (!pktin.data)
516 fatalbox("Out of memory");
517 }
518
519 /*
520 * Acquire and decrypt the first block of the packet. This will
521 * contain the length and padding details.
522 */
960e736a 523 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 524 while ((*datalen) == 0)
960e736a 525 crReturn(st->cipherblk-st->i);
526 pktin.data[st->i] = *(*data)++;
e5574168 527 (*datalen)--;
528 }
529#ifdef FWHACK
530 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
531 /* FIXME */
532 }
533#endif
534 if (sccipher)
960e736a 535 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 536
537 /*
538 * Now get the length and padding figures.
539 */
960e736a 540 st->len = GET_32BIT(pktin.data);
541 st->pad = pktin.data[4];
e5574168 542
543 /*
544 * This enables us to deduce the payload length.
545 */
960e736a 546 st->payload = st->len - st->pad - 1;
e5574168 547
960e736a 548 pktin.length = st->payload + 5;
e5574168 549
550 /*
551 * So now we can work out the total packet length.
552 */
960e736a 553 st->packetlen = st->len + 4;
554 st->maclen = scmac ? scmac->len : 0;
e5574168 555
556 /*
557 * Adjust memory allocation if packet is too big.
558 */
960e736a 559 if (pktin.maxlen < st->packetlen+st->maclen) {
560 pktin.maxlen = st->packetlen+st->maclen;
dcbde236 561 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
562 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
e5574168 563 if (!pktin.data)
564 fatalbox("Out of memory");
565 }
566
567 /*
568 * Read and decrypt the remainder of the packet.
569 */
960e736a 570 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
e5574168 571 while ((*datalen) == 0)
960e736a 572 crReturn(st->packetlen + st->maclen - st->i);
573 pktin.data[st->i] = *(*data)++;
e5574168 574 (*datalen)--;
575 }
576 /* Decrypt everything _except_ the MAC. */
577 if (sccipher)
960e736a 578 sccipher->decrypt(pktin.data + st->cipherblk,
579 st->packetlen - st->cipherblk);
e5574168 580
7cca0d81 581#if 0
960e736a 582 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
583 for (st->i = 0; st->i < st->packetlen; st->i++)
584 debug((" %02x", (unsigned char)pktin.data[st->i]));
d39f364a 585 debug(("\r\n"));
7cca0d81 586#endif
d39f364a 587
e5574168 588 /*
589 * Check the MAC.
590 */
960e736a 591 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
8d5de777 592 bombout(("Incorrect MAC received on packet"));
593 crReturn(0);
594 }
960e736a 595 st->incoming_sequence++; /* whether or not we MACed */
e5574168 596
4ba9b64b 597 /*
598 * Decompress packet payload.
599 */
600 {
601 unsigned char *newpayload;
602 int newlen;
603 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
604 &newpayload, &newlen)) {
605 if (pktin.maxlen < newlen+5) {
606 pktin.maxlen = newlen+5;
dcbde236 607 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
608 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
4ba9b64b 609 if (!pktin.data)
610 fatalbox("Out of memory");
611 }
612 pktin.length = 5 + newlen;
613 memcpy(pktin.data+5, newpayload, newlen);
614#if 0
615 debug(("Post-decompression payload:\r\n"));
616 for (st->i = 0; st->i < newlen; st->i++)
617 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
618 debug(("\r\n"));
619#endif
620
dcbde236 621 sfree(newpayload);
4ba9b64b 622 }
623 }
624
e5574168 625 pktin.savedpos = 6;
626 pktin.type = pktin.data[5];
e5574168 627
7cca0d81 628 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
629 goto next_packet; /* FIXME: print DEBUG message */
e5574168 630
631 crFinish(0);
632}
633
4ba9b64b 634static void ssh1_pktout_size(int len) {
374330e2 635 int pad, biglen;
636
637 len += 5; /* type and CRC */
638 pad = 8 - (len%8);
639 biglen = len + pad;
640
641 pktout.length = len-5;
642 if (pktout.maxlen < biglen) {
643 pktout.maxlen = biglen;
8f203108 644#ifdef MSCRYPTOAPI
fb09bf1c 645 /* Allocate enough buffer space for extra block
8f203108 646 * for MS CryptEncrypt() */
dcbde236 647 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
648 srealloc(pktout.data, biglen+12));
8f203108 649#else
dcbde236 650 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
651 srealloc(pktout.data, biglen+4));
8f203108 652#endif
374330e2 653 if (!pktout.data)
654 fatalbox("Out of memory");
655 }
4ba9b64b 656 pktout.body = pktout.data+4+pad+1;
657}
374330e2 658
4ba9b64b 659static void s_wrpkt_start(int type, int len) {
660 ssh1_pktout_size(len);
374330e2 661 pktout.type = type;
374330e2 662}
663
39065bed 664static int s_wrpkt_prepare(void) {
374330e2 665 int pad, len, biglen, i;
666 unsigned long crc;
667
4ba9b64b 668 pktout.body[-1] = pktout.type;
669
7d503c31 670#if 0
671 debug(("Packet payload pre-compression:\n"));
672 for (i = -1; i < pktout.length; i++)
673 debug((" %02x", (unsigned char)pktout.body[i]));
674 debug(("\r\n"));
675#endif
676
4ba9b64b 677 if (ssh1_compressing) {
678 unsigned char *compblk;
679 int complen;
4ba9b64b 680 zlib_compress_block(pktout.body-1, pktout.length+1,
681 &compblk, &complen);
682 ssh1_pktout_size(complen-1);
683 memcpy(pktout.body-1, compblk, complen);
dcbde236 684 sfree(compblk);
4ba9b64b 685#if 0
686 debug(("Packet payload post-compression:\n"));
687 for (i = -1; i < pktout.length; i++)
688 debug((" %02x", (unsigned char)pktout.body[i]));
689 debug(("\r\n"));
690#endif
691 }
692
374330e2 693 len = pktout.length + 5; /* type and CRC */
694 pad = 8 - (len%8);
695 biglen = len + pad;
696
374330e2 697 for (i=0; i<pad; i++)
698 pktout.data[i+4] = random_byte();
699 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 700 PUT_32BIT(pktout.data+biglen, crc);
701 PUT_32BIT(pktout.data, len);
374330e2 702
698a5108 703#if 0
704 debug(("Sending packet len=%d\r\n", biglen+4));
705 for (i = 0; i < biglen+4; i++)
706 debug((" %02x", (unsigned char)pktout.data[i]));
707 debug(("\r\n"));
708#endif
374330e2 709 if (cipher)
710 cipher->encrypt(pktout.data+4, biglen);
711
39065bed 712 return biglen+4;
713}
714
715static void s_wrpkt(void) {
716 int len;
717 len = s_wrpkt_prepare();
718 sk_write(s, pktout.data, len);
719}
720
721static void s_wrpkt_defer(void) {
722 int len;
723 len = s_wrpkt_prepare();
724 if (deferred_len + len > deferred_size) {
725 deferred_size = deferred_len + len + 128;
726 deferred_send_data = srealloc(deferred_send_data, deferred_size);
727 }
728 memcpy(deferred_send_data+deferred_len, pktout.data, len);
729 deferred_len += len;
374330e2 730}
731
fb09bf1c 732/*
39065bed 733 * Construct a packet with the specified contents.
fb09bf1c 734 */
39065bed 735static void construct_packet(int pkttype, va_list ap1, va_list ap2)
fb09bf1c 736{
fb09bf1c 737 unsigned char *p, *argp, argchar;
738 unsigned long argint;
739 int pktlen, argtype, arglen;
7cca0d81 740 Bignum bn;
fb09bf1c 741
742 pktlen = 0;
39065bed 743 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 744 switch (argtype) {
745 case PKT_INT:
39065bed 746 (void) va_arg(ap1, int);
fb09bf1c 747 pktlen += 4;
748 break;
749 case PKT_CHAR:
39065bed 750 (void) va_arg(ap1, char);
fb09bf1c 751 pktlen++;
752 break;
753 case PKT_DATA:
39065bed 754 (void) va_arg(ap1, unsigned char *);
755 arglen = va_arg(ap1, int);
fb09bf1c 756 pktlen += arglen;
757 break;
758 case PKT_STR:
39065bed 759 argp = va_arg(ap1, unsigned char *);
fb09bf1c 760 arglen = strlen(argp);
761 pktlen += 4 + arglen;
762 break;
7cca0d81 763 case PKT_BIGNUM:
39065bed 764 bn = va_arg(ap1, Bignum);
5c58ad2d 765 pktlen += ssh1_bignum_length(bn);
7cca0d81 766 break;
fb09bf1c 767 default:
768 assert(0);
769 }
770 }
fb09bf1c 771
772 s_wrpkt_start(pkttype, pktlen);
773 p = pktout.body;
774
39065bed 775 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 776 switch (argtype) {
777 case PKT_INT:
39065bed 778 argint = va_arg(ap2, int);
fb09bf1c 779 PUT_32BIT(p, argint);
780 p += 4;
781 break;
782 case PKT_CHAR:
39065bed 783 argchar = va_arg(ap2, unsigned char);
fb09bf1c 784 *p = argchar;
785 p++;
786 break;
787 case PKT_DATA:
39065bed 788 argp = va_arg(ap2, unsigned char *);
789 arglen = va_arg(ap2, int);
fb09bf1c 790 memcpy(p, argp, arglen);
791 p += arglen;
792 break;
793 case PKT_STR:
39065bed 794 argp = va_arg(ap2, unsigned char *);
fb09bf1c 795 arglen = strlen(argp);
796 PUT_32BIT(p, arglen);
797 memcpy(p + 4, argp, arglen);
798 p += 4 + arglen;
799 break;
7cca0d81 800 case PKT_BIGNUM:
39065bed 801 bn = va_arg(ap2, Bignum);
5c58ad2d 802 p += ssh1_write_bignum(p, bn);
7cca0d81 803 break;
fb09bf1c 804 }
805 }
39065bed 806}
fb09bf1c 807
39065bed 808static void send_packet(int pkttype, ...) {
809 va_list ap1, ap2;
810 va_start(ap1, pkttype);
811 va_start(ap2, pkttype);
812 construct_packet(pkttype, ap1, ap2);
fb09bf1c 813 s_wrpkt();
814}
815
39065bed 816static void defer_packet(int pkttype, ...) {
817 va_list ap1, ap2;
818 va_start(ap1, pkttype);
819 va_start(ap2, pkttype);
820 construct_packet(pkttype, ap1, ap2);
821 s_wrpkt_defer();
822}
823
9697bfd2 824static int ssh_versioncmp(char *a, char *b) {
825 char *ae, *be;
826 unsigned long av, bv;
827
43aa02a7 828 av = strtoul(a, &ae, 10);
829 bv = strtoul(b, &be, 10);
9697bfd2 830 if (av != bv) return (av < bv ? -1 : +1);
831 if (*ae == '.') ae++;
832 if (*be == '.') be++;
43aa02a7 833 av = strtoul(ae, &ae, 10);
834 bv = strtoul(be, &be, 10);
9697bfd2 835 if (av != bv) return (av < bv ? -1 : +1);
836 return 0;
837}
838
e5574168 839
840/*
a92dd380 841 * Utility routines for putting an SSH-protocol `string' and
842 * `uint32' into a SHA state.
e5574168 843 */
844#include <stdio.h>
75cab814 845static void sha_string(SHA_State *s, void *str, int len) {
e5574168 846 unsigned char lenblk[4];
e5574168 847 PUT_32BIT(lenblk, len);
e5574168 848 SHA_Bytes(s, lenblk, 4);
e5574168 849 SHA_Bytes(s, str, len);
850}
851
a92dd380 852static void sha_uint32(SHA_State *s, unsigned i) {
853 unsigned char intblk[4];
854 PUT_32BIT(intblk, i);
855 SHA_Bytes(s, intblk, 4);
856}
857
7cca0d81 858/*
859 * SSH2 packet construction functions.
860 */
783415f8 861static void ssh2_pkt_ensure(int length) {
862 if (pktout.maxlen < length) {
863 pktout.maxlen = length + 256;
dcbde236 864 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
865 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
7cca0d81 866 if (!pktout.data)
867 fatalbox("Out of memory");
868 }
783415f8 869}
870static void ssh2_pkt_adddata(void *data, int len) {
871 pktout.length += len;
872 ssh2_pkt_ensure(pktout.length);
7cca0d81 873 memcpy(pktout.data+pktout.length-len, data, len);
874}
75cab814 875static void ssh2_pkt_addbyte(unsigned char byte) {
7cca0d81 876 ssh2_pkt_adddata(&byte, 1);
877}
75cab814 878static void ssh2_pkt_init(int pkt_type) {
7cca0d81 879 pktout.length = 5;
880 ssh2_pkt_addbyte((unsigned char)pkt_type);
881}
75cab814 882static void ssh2_pkt_addbool(unsigned char value) {
7cca0d81 883 ssh2_pkt_adddata(&value, 1);
884}
75cab814 885static void ssh2_pkt_adduint32(unsigned long value) {
7cca0d81 886 unsigned char x[4];
887 PUT_32BIT(x, value);
888 ssh2_pkt_adddata(x, 4);
889}
75cab814 890static void ssh2_pkt_addstring_start(void) {
7cca0d81 891 ssh2_pkt_adduint32(0);
892 pktout.savedpos = pktout.length;
893}
75cab814 894static void ssh2_pkt_addstring_str(char *data) {
7cca0d81 895 ssh2_pkt_adddata(data, strlen(data));
896 PUT_32BIT(pktout.data + pktout.savedpos - 4,
897 pktout.length - pktout.savedpos);
898}
75cab814 899static void ssh2_pkt_addstring_data(char *data, int len) {
7cca0d81 900 ssh2_pkt_adddata(data, len);
901 PUT_32BIT(pktout.data + pktout.savedpos - 4,
902 pktout.length - pktout.savedpos);
903}
75cab814 904static void ssh2_pkt_addstring(char *data) {
7cca0d81 905 ssh2_pkt_addstring_start();
906 ssh2_pkt_addstring_str(data);
907}
75cab814 908static char *ssh2_mpint_fmt(Bignum b, int *len) {
7cca0d81 909 unsigned char *p;
3709bfe9 910 int i, n = (ssh1_bignum_bitcount(b)+7)/8;
911 p = smalloc(n + 1);
7cca0d81 912 if (!p)
913 fatalbox("out of memory");
914 p[0] = 0;
3709bfe9 915 for (i = 1; i <= n; i++)
916 p[i] = bignum_byte(b, n-i);
7cca0d81 917 i = 0;
3709bfe9 918 while (i <= n && p[i] == 0 && (p[i+1] & 0x80) == 0)
7cca0d81 919 i++;
3709bfe9 920 memmove(p, p+i, n+1-i);
921 *len = n+1-i;
7cca0d81 922 return p;
923}
75cab814 924static void ssh2_pkt_addmp(Bignum b) {
7cca0d81 925 unsigned char *p;
926 int len;
927 p = ssh2_mpint_fmt(b, &len);
928 ssh2_pkt_addstring_start();
929 ssh2_pkt_addstring_data(p, len);
dcbde236 930 sfree(p);
7cca0d81 931}
b185170a 932
933/*
934 * Construct an SSH2 final-form packet: compress it, encrypt it,
935 * put the MAC on it. Final packet, ready to be sent, is stored in
936 * pktout.data. Total length is returned.
937 */
938static int ssh2_pkt_construct(void) {
7cca0d81 939 int cipherblk, maclen, padding, i;
940 static unsigned long outgoing_sequence = 0;
941
942 /*
4ba9b64b 943 * Compress packet payload.
944 */
945#if 0
946 debug(("Pre-compression payload:\r\n"));
947 for (i = 5; i < pktout.length; i++)
948 debug((" %02x", (unsigned char)pktout.data[i]));
949 debug(("\r\n"));
950#endif
951 {
952 unsigned char *newpayload;
953 int newlen;
954 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
955 &newpayload, &newlen)) {
956 pktout.length = 5;
957 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 958 sfree(newpayload);
4ba9b64b 959 }
960 }
961
962 /*
7cca0d81 963 * Add padding. At least four bytes, and must also bring total
964 * length (minus MAC) up to a multiple of the block size.
965 */
8479e33c 966 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
7cca0d81 967 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
968 padding = 4;
969 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 970 maclen = csmac ? csmac->len : 0;
971 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 972 pktout.data[4] = padding;
973 for (i = 0; i < padding; i++)
974 pktout.data[pktout.length + i] = random_byte();
975 PUT_32BIT(pktout.data, pktout.length + padding - 4);
976 if (csmac)
977 csmac->generate(pktout.data, pktout.length + padding,
978 outgoing_sequence);
979 outgoing_sequence++; /* whether or not we MACed */
980
981#if 0
982 debug(("Sending packet len=%d\r\n", pktout.length+padding));
983 for (i = 0; i < pktout.length+padding; i++)
984 debug((" %02x", (unsigned char)pktout.data[i]));
985 debug(("\r\n"));
986#endif
987
988 if (cscipher)
989 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 990
b185170a 991 /* Ready-to-send packet starts at pktout.data. We return length. */
992 return pktout.length + padding + maclen;
993}
994
995/*
996 * Construct and send an SSH2 packet immediately.
997 */
998static void ssh2_pkt_send(void) {
999 int len = ssh2_pkt_construct();
1000 sk_write(s, pktout.data, len);
1001}
1002
1003/*
1004 * Construct an SSH2 packet and add it to a deferred data block.
1005 * Useful for sending multiple packets in a single sk_write() call,
1006 * to prevent a traffic-analysing listener from being able to work
1007 * out the length of any particular packet (such as the password
1008 * packet).
1009 *
1010 * Note that because SSH2 sequence-numbers its packets, this can
1011 * NOT be used as an m4-style `defer' allowing packets to be
1012 * constructed in one order and sent in another.
1013 */
1014static void ssh2_pkt_defer(void) {
1015 int len = ssh2_pkt_construct();
1016 if (deferred_len + len > deferred_size) {
1017 deferred_size = deferred_len + len + 128;
1018 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1019 }
1020 memcpy(deferred_send_data+deferred_len, pktout.data, len);
1021 deferred_len += len;
1022}
1023
1024/*
1025 * Send the whole deferred data block constructed by
39065bed 1026 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1027 */
39065bed 1028static void ssh_pkt_defersend(void) {
b185170a 1029 sk_write(s, deferred_send_data, deferred_len);
1030 deferred_len = deferred_size = 0;
1031 sfree(deferred_send_data);
1032 deferred_send_data = NULL;
7cca0d81 1033}
1034
1035#if 0
1036void bndebug(char *string, Bignum b) {
1037 unsigned char *p;
1038 int i, len;
1039 p = ssh2_mpint_fmt(b, &len);
1040 debug(("%s", string));
1041 for (i = 0; i < len; i++)
1042 debug((" %02x", p[i]));
1043 debug(("\r\n"));
dcbde236 1044 sfree(p);
7cca0d81 1045}
1046#endif
1047
75cab814 1048static void sha_mpint(SHA_State *s, Bignum b) {
7cca0d81 1049 unsigned char *p;
1050 int len;
1051 p = ssh2_mpint_fmt(b, &len);
1052 sha_string(s, p, len);
dcbde236 1053 sfree(p);
7cca0d81 1054}
1055
1056/*
1057 * SSH2 packet decode functions.
1058 */
75cab814 1059static unsigned long ssh2_pkt_getuint32(void) {
7cca0d81 1060 unsigned long value;
1061 if (pktin.length - pktin.savedpos < 4)
1062 return 0; /* arrgh, no way to decline (FIXME?) */
1063 value = GET_32BIT(pktin.data+pktin.savedpos);
1064 pktin.savedpos += 4;
1065 return value;
1066}
65a22376 1067static int ssh2_pkt_getbool(void) {
1068 unsigned long value;
1069 if (pktin.length - pktin.savedpos < 1)
1070 return 0; /* arrgh, no way to decline (FIXME?) */
1071 value = pktin.data[pktin.savedpos] != 0;
1072 pktin.savedpos++;
1073 return value;
1074}
75cab814 1075static void ssh2_pkt_getstring(char **p, int *length) {
7cca0d81 1076 *p = NULL;
1077 if (pktin.length - pktin.savedpos < 4)
1078 return;
1079 *length = GET_32BIT(pktin.data+pktin.savedpos);
1080 pktin.savedpos += 4;
1081 if (pktin.length - pktin.savedpos < *length)
1082 return;
1083 *p = pktin.data+pktin.savedpos;
1084 pktin.savedpos += *length;
1085}
75cab814 1086static Bignum ssh2_pkt_getmp(void) {
7cca0d81 1087 char *p;
3709bfe9 1088 int length;
7cca0d81 1089 Bignum b;
1090
1091 ssh2_pkt_getstring(&p, &length);
1092 if (!p)
1093 return NULL;
8d5de777 1094 if (p[0] & 0x80) {
1095 bombout(("internal error: Can't handle negative mpints"));
1096 return NULL;
1097 }
3709bfe9 1098 b = bignum_from_bytes(p, length);
7cca0d81 1099 return b;
1100}
1101
7d503c31 1102/*
1103 * Examine the remote side's version string and compare it against
1104 * a list of known buggy implementations.
1105 */
1106static void ssh_detect_bugs(char *vstring) {
1107 char *imp; /* pointer to implementation part */
1108 imp = vstring;
1109 imp += strcspn(imp, "-");
1110 imp += strcspn(imp, "-");
1111
1112 ssh_remote_bugs = 0;
1113
1114 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1115 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1116 !strcmp(imp, "1.2.22")) {
1117 /*
1118 * These versions don't support SSH1_MSG_IGNORE, so we have
1119 * to use a different defence against password length
1120 * sniffing.
1121 */
1122 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1123 logevent("We believe remote version has SSH1 ignore bug");
1124 }
1125
1126 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1127 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1128 !strncmp(imp, "2.1 ", 4)) {
1129 /*
1130 * These versions have the HMAC bug.
1131 */
1132 ssh_remote_bugs |= BUG_SSH2_HMAC;
1133 logevent("We believe remote version has SSH2 HMAC bug");
1134 }
1135}
1136
8df7a775 1137static int do_ssh_init(unsigned char c) {
1138 static char *vsp;
1139 static char version[10];
1140 static char vstring[80];
1141 static char vlog[sizeof(vstring)+20];
1142 static int i;
374330e2 1143
8df7a775 1144 crBegin;
1145
1146 /* Search for the string "SSH-" in the input. */
374330e2 1147 i = 0;
8df7a775 1148 while (1) {
1149 static const int transS[] = { 1, 2, 2, 1 };
1150 static const int transH[] = { 0, 0, 3, 0 };
1151 static const int transminus[] = { 0, 0, 0, -1 };
1152 if (c == 'S') i = transS[i];
1153 else if (c == 'H') i = transH[i];
1154 else if (c == '-') i = transminus[i];
374330e2 1155 else i = 0;
8df7a775 1156 if (i < 0)
1157 break;
1158 crReturn(1); /* get another character */
374330e2 1159 }
8df7a775 1160
c5e9c988 1161 strcpy(vstring, "SSH-");
1162 vsp = vstring+4;
374330e2 1163 i = 0;
1164 while (1) {
8df7a775 1165 crReturn(1); /* get another char */
c5e9c988 1166 if (vsp < vstring+sizeof(vstring)-1)
1167 *vsp++ = c;
374330e2 1168 if (i >= 0) {
1169 if (c == '-') {
1170 version[i] = '\0';
1171 i = -1;
1172 } else if (i < sizeof(version)-1)
1173 version[i++] = c;
1174 }
1175 else if (c == '\n')
1176 break;
1177 }
1178
db7d555c 1179 ssh_agentfwd_enabled = FALSE;
960e736a 1180 rdpkt2_state.incoming_sequence = 0;
1181
c5e9c988 1182 *vsp = 0;
1183 sprintf(vlog, "Server version: %s", vstring);
7d503c31 1184 ssh_detect_bugs(vstring);
c5e9c988 1185 vlog[strcspn(vlog, "\r\n")] = '\0';
1186 logevent(vlog);
1187
adf799dd 1188 /*
1189 * Server version "1.99" means we can choose whether we use v1
1190 * or v2 protocol. Choice is based on cfg.sshprot.
1191 */
1192 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 1193 /*
1194 * This is a v2 server. Begin v2 protocol.
1195 */
900a4ee6 1196 char verstring[80];
1197 sprintf(verstring, "SSH-2.0-%s", sshver);
0db56f73 1198 SHA_Init(&exhashbase);
e5574168 1199 /*
1200 * Hash our version string and their version string.
1201 */
0db56f73 1202 sha_string(&exhashbase, verstring, strlen(verstring));
1203 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
e5574168 1204 sprintf(vstring, "%s\n", verstring);
1205 sprintf(vlog, "We claim version: %s", verstring);
1206 logevent(vlog);
1207 logevent("Using SSH protocol version 2");
8df7a775 1208 sk_write(s, vstring, strlen(vstring));
e5574168 1209 ssh_protocol = ssh2_protocol;
6abbf9e3 1210 ssh_version = 2;
e5574168 1211 s_rdpkt = ssh2_rdpkt;
1212 } else {
1213 /*
1214 * This is a v1 server. Begin v1 protocol.
1215 */
900a4ee6 1216 sprintf(vstring, "SSH-%s-%s\n",
1217 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1218 sshver);
e5574168 1219 sprintf(vlog, "We claim version: %s", vstring);
1220 vlog[strcspn(vlog, "\r\n")] = '\0';
1221 logevent(vlog);
1222 logevent("Using SSH protocol version 1");
8df7a775 1223 sk_write(s, vstring, strlen(vstring));
e5574168 1224 ssh_protocol = ssh1_protocol;
6abbf9e3 1225 ssh_version = 1;
e5574168 1226 s_rdpkt = ssh1_rdpkt;
1227 }
3687d221 1228 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1229
1230 crFinish(0);
1231}
1232
1233static void ssh_gotdata(unsigned char *data, int datalen)
1234{
1235 crBegin;
1236
1237 /*
1238 * To begin with, feed the characters one by one to the
1239 * protocol initialisation / selection function do_ssh_init().
1240 * When that returns 0, we're done with the initial greeting
1241 * exchange and can move on to packet discipline.
1242 */
1243 while (1) {
1244 int ret;
1245 if (datalen == 0)
1246 crReturnV; /* more data please */
1247 ret = do_ssh_init(*data);
1248 data++; datalen--;
1249 if (ret == 0)
1250 break;
1251 }
1252
1253 /*
1254 * We emerge from that loop when the initial negotiation is
1255 * over and we have selected an s_rdpkt function. Now pass
1256 * everything to s_rdpkt, and then pass the resulting packets
1257 * to the proper protocol handler.
1258 */
1259 if (datalen == 0)
1260 crReturnV;
1261 while (1) {
1262 while (datalen > 0) {
1263 if ( s_rdpkt(&data, &datalen) == 0 ) {
1264 ssh_protocol(NULL, 0, 1);
1265 if (ssh_state == SSH_STATE_CLOSED) {
1266 return;
1267 }
1268 }
1269 }
1270 crReturnV;
1271 }
1272 crFinishV;
1273}
1274
7e78000d 1275static int ssh_closing (Plug plug, char *error_msg, int error_code, int calling_back) {
1276 ssh_state = SSH_STATE_CLOSED;
1277 sk_close(s);
1278 s = NULL;
1279 if (error_msg) {
2c94fd1c 1280 /* A socket error has occurred. */
7e78000d 1281 connection_fatal (error_msg);
1282 } else {
1283 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1284 }
7e78000d 1285 return 0;
1286}
1287
1288static int ssh_receive(Plug plug, int urgent, char *data, int len) {
8df7a775 1289 ssh_gotdata (data, len);
3257deae 1290 if (ssh_state == SSH_STATE_CLOSED) {
1291 if (s) {
1292 sk_close(s);
1293 s = NULL;
1294 }
1295 return 0;
1296 }
fef97f43 1297 return 1;
374330e2 1298}
1299
fb09bf1c 1300/*
8df7a775 1301 * Connect to specified host and port.
1302 * Returns an error message, or NULL on success.
1303 * Also places the canonical host name into `realhost'.
1304 */
1305static char *connect_to_host(char *host, int port, char **realhost)
1306{
7e78000d 1307 static struct plug_function_table fn_table = {
1308 ssh_closing,
1309 ssh_receive
1310 }, *fn_table_ptr = &fn_table;
1311
8df7a775 1312 SockAddr addr;
1313 char *err;
1314#ifdef FWHACK
1315 char *FWhost;
1316 int FWport;
1317#endif
1318
dcbde236 1319 savedhost = smalloc(1+strlen(host));
8df7a775 1320 if (!savedhost)
1321 fatalbox("Out of memory");
1322 strcpy(savedhost, host);
1323
1324 if (port < 0)
1325 port = 22; /* default ssh port */
1326 savedport = port;
1327
1328#ifdef FWHACK
1329 FWhost = host;
1330 FWport = port;
1331 host = FWSTR;
1332 port = 23;
1333#endif
1334
1335 /*
1336 * Try to find host.
1337 */
1338 addr = sk_namelookup(host, realhost);
1339 if ( (err = sk_addr_error(addr)) )
1340 return err;
1341
1342#ifdef FWHACK
1343 *realhost = FWhost;
1344#endif
1345
1346 /*
1347 * Open socket.
1348 */
7e78000d 1349 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
8df7a775 1350 if ( (err = sk_socket_error(s)) )
1351 return err;
1352
1353#ifdef FWHACK
1354 sk_write(s, "connect ", 8);
1355 sk_write(s, FWhost, strlen(FWhost));
1356 {
1357 char buf[20];
1358 sprintf(buf, " %d\n", FWport);
1359 sk_write(s, buf, strlen(buf));
1360 }
1361#endif
1362
1363 return NULL;
1364}
1365
1366/*
fb09bf1c 1367 * Handle the key exchange and user authentication phases.
1368 */
e5574168 1369static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1370{
374330e2 1371 int i, j, len;
374330e2 1372 unsigned char *rsabuf, *keystr1, *keystr2;
1373 unsigned char cookie[8];
1374 struct RSAKey servkey, hostkey;
1375 struct MD5Context md5c;
ccbfb941 1376 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1377 static int tried_publickey;
1378 static unsigned char session_id[16];
bea1ef5f 1379 int cipher_type;
b585ec46 1380 static char username[100];
374330e2 1381
374330e2 1382 crBegin;
1383
fb09bf1c 1384 if (!ispkt) crWaitUntil(ispkt);
374330e2 1385
8d5de777 1386 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1387 bombout(("Public key packet not received"));
1388 crReturn(0);
1389 }
374330e2 1390
c5e9c988 1391 logevent("Received public keys");
374330e2 1392
c5e9c988 1393 memcpy(cookie, pktin.body, 8);
374330e2 1394
7cca0d81 1395 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1396 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1397
c5e9c988 1398 /*
1c2a93c4 1399 * Log the host key fingerprint.
c5e9c988 1400 */
c5e9c988 1401 {
1402 char logmsg[80];
1c2a93c4 1403 logevent("Host key fingerprint is:");
c5e9c988 1404 strcpy(logmsg, " ");
1c2a93c4 1405 hostkey.comment = NULL;
1406 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1407 &hostkey);
c5e9c988 1408 logevent(logmsg);
1409 }
1410
fb09bf1c 1411 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1412 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1413
c5e9c988 1414 MD5Init(&md5c);
374330e2 1415 MD5Update(&md5c, keystr2, hostkey.bytes);
1416 MD5Update(&md5c, keystr1, servkey.bytes);
1417 MD5Update(&md5c, pktin.body, 8);
374330e2 1418 MD5Final(session_id, &md5c);
1419
1420 for (i=0; i<32; i++)
1421 session_key[i] = random_byte();
1422
1423 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1424
dcbde236 1425 rsabuf = smalloc(len);
374330e2 1426 if (!rsabuf)
1427 fatalbox("Out of memory");
1428
89ee5268 1429 /*
1430 * Verify the host key.
1431 */
1432 {
1433 /*
1434 * First format the key into a string.
1435 */
1436 int len = rsastr_len(&hostkey);
d5859615 1437 char fingerprint[100];
dcbde236 1438 char *keystr = smalloc(len);
89ee5268 1439 if (!keystr)
1440 fatalbox("Out of memory");
1441 rsastr_fmt(keystr, &hostkey);
d5859615 1442 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1443 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
dcbde236 1444 sfree(keystr);
89ee5268 1445 }
374330e2 1446
1447 for (i=0; i<32; i++) {
1448 rsabuf[i] = session_key[i];
1449 if (i < 16)
1450 rsabuf[i] ^= session_id[i];
1451 }
1452
1453 if (hostkey.bytes > servkey.bytes) {
1454 rsaencrypt(rsabuf, 32, &servkey);
1455 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1456 } else {
1457 rsaencrypt(rsabuf, 32, &hostkey);
1458 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1459 }
1460
c5e9c988 1461 logevent("Encrypted session key");
1462
0a3f1d48 1463 switch (cfg.cipher) {
1464 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; break;
1465 case CIPHER_DES: cipher_type = SSH_CIPHER_DES; break;
1466 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; break;
1467 case CIPHER_AES:
1408a877 1468 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
0a3f1d48 1469 cipher_type = SSH_CIPHER_3DES;
1470 break;
1471 }
bea1ef5f 1472 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1408a877 1473 c_write_str("Selected cipher not supported, falling back to 3DES\r\n");
bea1ef5f 1474 cipher_type = SSH_CIPHER_3DES;
1475 }
c5e9c988 1476 switch (cipher_type) {
1477 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1478 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1479 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1480 }
bea1ef5f 1481
e5574168 1482 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1483 PKT_CHAR, cipher_type,
1484 PKT_DATA, cookie, 8,
1485 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1486 PKT_DATA, rsabuf, len,
1487 PKT_INT, 0,
1488 PKT_END);
1489
c5e9c988 1490 logevent("Trying to enable encryption...");
374330e2 1491
dcbde236 1492 sfree(rsabuf);
374330e2 1493
5e8358ad 1494 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1495 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1496 &ssh_3des;
374330e2 1497 cipher->sesskey(session_key);
1498
fb09bf1c 1499 crWaitUntil(ispkt);
374330e2 1500
8d5de777 1501 if (pktin.type != SSH1_SMSG_SUCCESS) {
1502 bombout(("Encryption not successfully enabled"));
1503 crReturn(0);
1504 }
374330e2 1505
c5e9c988 1506 logevent("Successfully started encryption");
1507
374330e2 1508 fflush(stdout);
1509 {
374330e2 1510 static int pos = 0;
1511 static char c;
67779be7 1512 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
fa17a66e 1513 if (ssh_get_line) {
1514 if (!ssh_get_line("login as: ",
1515 username, sizeof(username), FALSE)) {
1516 /*
1517 * get_line failed to get a username.
1518 * Terminate.
1519 */
1520 logevent("No username provided. Abandoning session.");
1521 ssh_state = SSH_STATE_CLOSED;
1522 crReturn(1);
1523 }
1524 } else {
1525 c_write_str("login as: ");
1526 ssh_send_ok = 1;
1527 while (pos >= 0) {
1528 crWaitUntil(!ispkt);
1529 while (inlen--) switch (c = *in++) {
1530 case 10: case 13:
1531 username[pos] = 0;
1532 pos = -1;
1533 break;
1534 case 8: case 127:
1535 if (pos > 0) {
1536 c_write_str("\b \b");
1537 pos--;
1538 }
1539 break;
1540 case 21: case 27:
1541 while (pos > 0) {
1542 c_write_str("\b \b");
1543 pos--;
1544 }
1545 break;
1546 case 3: case 4:
1547 random_save_seed();
1548 exit(0);
1549 break;
1550 default:
1551 if (((c >= ' ' && c <= '~') ||
1552 ((unsigned char)c >= 160)) && pos < 40) {
1553 username[pos++] = c;
1554 c_write(&c, 1);
1555 }
1556 break;
1557 }
1558 }
1559 c_write_str("\r\n");
1560 username[strcspn(username, "\n\r")] = '\0';
1561 }
1562 } else {
374330e2 1563 strncpy(username, cfg.username, 99);
1564 username[99] = '\0';
374330e2 1565 }
fb09bf1c 1566
e5574168 1567 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1568 {
3c8e959b 1569 char userlog[22+sizeof(username)];
c5e9c988 1570 sprintf(userlog, "Sent username \"%s\"", username);
1571 logevent(userlog);
3c8e959b 1572 if (flags & FLAG_INTERACTIVE &&
1573 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1574 strcat(userlog, "\r\n");
1408a877 1575 c_write_str(userlog);
3c8e959b 1576 }
c5e9c988 1577 }
374330e2 1578 }
1579
fb09bf1c 1580 crWaitUntil(ispkt);
374330e2 1581
7cca0d81 1582 tried_publickey = 0;
1583
e5574168 1584 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1585 static char password[100];
a52f067e 1586 static char prompt[200];
374330e2 1587 static int pos;
1588 static char c;
ccbfb941 1589 static int pwpkt_type;
ccbfb941 1590 /*
1591 * Show password prompt, having first obtained it via a TIS
18515c51 1592 * or CryptoCard exchange if we're doing TIS or CryptoCard
1593 * authentication.
ccbfb941 1594 */
e5574168 1595 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1596 if (agent_exists()) {
1597 /*
1598 * Attempt RSA authentication using Pageant.
1599 */
1600 static unsigned char request[5], *response, *p;
1601 static int responselen;
1602 static int i, nkeys;
1603 static int authed = FALSE;
1604 void *r;
1605
1606 logevent("Pageant is running. Requesting keys.");
1607
1608 /* Request the keys held by the agent. */
1609 PUT_32BIT(request, 1);
1983e559 1610 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
5c58ad2d 1611 agent_query(request, 5, &r, &responselen);
1612 response = (unsigned char *)r;
95797139 1613 if (response && responselen >= 5 &&
1614 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
5c58ad2d 1615 p = response + 5;
1616 nkeys = GET_32BIT(p); p += 4;
6328ea7a 1617 { char buf[64]; sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
5c58ad2d 1618 logevent(buf); }
1619 for (i = 0; i < nkeys; i++) {
1620 static struct RSAKey key;
1621 static Bignum challenge;
b8bb811a 1622 static char *commentp;
1623 static int commentlen;
5c58ad2d 1624
1625 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1626 logevent(buf); }
1627 p += 4;
1628 p += ssh1_read_bignum(p, &key.exponent);
1629 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1630 commentlen = GET_32BIT(p); p += 4;
1631 commentp = p; p += commentlen;
5c58ad2d 1632 send_packet(SSH1_CMSG_AUTH_RSA,
1633 PKT_BIGNUM, key.modulus, PKT_END);
1634 crWaitUntil(ispkt);
1635 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1636 logevent("Key refused");
1637 continue;
1638 }
1639 logevent("Received RSA challenge");
1640 ssh1_read_bignum(pktin.body, &challenge);
1641 {
1642 char *agentreq, *q, *ret;
1643 int len, retlen;
1644 len = 1 + 4; /* message type, bit count */
1645 len += ssh1_bignum_length(key.exponent);
1646 len += ssh1_bignum_length(key.modulus);
1647 len += ssh1_bignum_length(challenge);
1648 len += 16; /* session id */
1649 len += 4; /* response format */
dcbde236 1650 agentreq = smalloc(4 + len);
5c58ad2d 1651 PUT_32BIT(agentreq, len);
1652 q = agentreq + 4;
1983e559 1653 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
5c58ad2d 1654 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1655 q += 4;
1656 q += ssh1_write_bignum(q, key.exponent);
1657 q += ssh1_write_bignum(q, key.modulus);
1658 q += ssh1_write_bignum(q, challenge);
1659 memcpy(q, session_id, 16); q += 16;
1660 PUT_32BIT(q, 1); /* response format */
1661 agent_query(agentreq, len+4, &ret, &retlen);
dcbde236 1662 sfree(agentreq);
5c58ad2d 1663 if (ret) {
1983e559 1664 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
5c58ad2d 1665 logevent("Sending Pageant's response");
1666 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1667 PKT_DATA, ret+5, 16, PKT_END);
dcbde236 1668 sfree(ret);
5c58ad2d 1669 crWaitUntil(ispkt);
1670 if (pktin.type == SSH1_SMSG_SUCCESS) {
1671 logevent("Pageant's response accepted");
c4fa2fce 1672 if (flags & FLAG_VERBOSE) {
1408a877 1673 c_write_str("Authenticated using RSA key \"");
c4fa2fce 1674 c_write(commentp, commentlen);
1408a877 1675 c_write_str("\" from agent\r\n");
c4fa2fce 1676 }
5c58ad2d 1677 authed = TRUE;
1678 } else
1679 logevent("Pageant's response not accepted");
1680 } else {
1681 logevent("Pageant failed to answer challenge");
dcbde236 1682 sfree(ret);
5c58ad2d 1683 }
1684 } else {
1685 logevent("No reply received from Pageant");
1686 }
1687 }
1688 freebn(key.exponent);
1689 freebn(key.modulus);
1690 freebn(challenge);
1691 if (authed)
1692 break;
1693 }
1694 }
1695 if (authed)
1696 break;
1697 }
7cca0d81 1698 if (*cfg.keyfile && !tried_publickey)
1699 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1700
a52f067e 1701 if (pktin.type == SSH1_SMSG_FAILURE &&
1702 cfg.try_tis_auth &&
1703 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1704 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1705 logevent("Requested TIS authentication");
1706 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1707 crWaitUntil(ispkt);
1708 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1709 logevent("TIS authentication declined");
1710 if (flags & FLAG_INTERACTIVE)
1408a877 1711 c_write_str("TIS authentication refused.\r\n");
a52f067e 1712 } else {
1713 int challengelen = ((pktin.body[0] << 24) |
1714 (pktin.body[1] << 16) |
1715 (pktin.body[2] << 8) |
1716 (pktin.body[3]));
1717 logevent("Received TIS challenge");
1718 if (challengelen > sizeof(prompt)-1)
1719 challengelen = sizeof(prompt)-1; /* prevent overrun */
1720 memcpy(prompt, pktin.body+4, challengelen);
1721 prompt[challengelen] = '\0';
1722 }
1723 }
1724 if (pktin.type == SSH1_SMSG_FAILURE &&
1725 cfg.try_tis_auth &&
1726 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1727 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1728 logevent("Requested CryptoCard authentication");
1729 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1730 crWaitUntil(ispkt);
1731 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1732 logevent("CryptoCard authentication declined");
1408a877 1733 c_write_str("CryptoCard authentication refused.\r\n");
a52f067e 1734 } else {
1735 int challengelen = ((pktin.body[0] << 24) |
1736 (pktin.body[1] << 16) |
1737 (pktin.body[2] << 8) |
1738 (pktin.body[3]));
1739 logevent("Received CryptoCard challenge");
1740 if (challengelen > sizeof(prompt)-1)
1741 challengelen = sizeof(prompt)-1; /* prevent overrun */
1742 memcpy(prompt, pktin.body+4, challengelen);
1743 strncpy(prompt + challengelen, "\r\nResponse : ",
1744 sizeof(prompt)-challengelen);
1745 prompt[sizeof(prompt)-1] = '\0';
1746 }
1747 }
1748 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1749 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1750 username, savedhost);
a52f067e 1751 }
1752 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1753 char *comment = NULL;
1754 if (flags & FLAG_VERBOSE)
1408a877 1755 c_write_str("Trying public key authentication.\r\n");
a52f067e 1756 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1757 if (flags & FLAG_VERBOSE)
1408a877 1758 c_write_str("No passphrase required.\r\n");
a52f067e 1759 goto tryauth;
1760 }
1761 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
dcbde236 1762 sfree(comment);
a52f067e 1763 }
1764
fa17a66e 1765 if (ssh_get_line) {
1766 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
85ee8208 1767 /*
fa17a66e 1768 * get_line failed to get a password (for example
1769 * because one was supplied on the command line
1770 * which has already failed to work). Terminate.
85ee8208 1771 */
1772 logevent("No more passwords to try");
1773 ssh_state = SSH_STATE_CLOSED;
1774 crReturn(1);
1775 }
fb09bf1c 1776 } else {
1408a877 1777 c_write_str(prompt);
7cca0d81 1778 pos = 0;
67779be7 1779 ssh_send_ok = 1;
7cca0d81 1780 while (pos >= 0) {
1781 crWaitUntil(!ispkt);
1782 while (inlen--) switch (c = *in++) {
1783 case 10: case 13:
1784 password[pos] = 0;
1785 pos = -1;
1786 break;
1787 case 8: case 127:
1788 if (pos > 0)
1789 pos--;
1790 break;
1791 case 21: case 27:
1792 pos = 0;
1793 break;
1794 case 3: case 4:
1795 random_save_seed();
1796 exit(0);
1797 break;
1798 default:
1799 if (((c >= ' ' && c <= '~') ||
1800 ((unsigned char)c >= 160)) && pos < sizeof(password))
1801 password[pos++] = c;
1802 break;
1803 }
1804 }
1408a877 1805 c_write_str("\r\n");
a52f067e 1806 }
fb09bf1c 1807
7cca0d81 1808 tryauth:
1809 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1810 /*
1811 * Try public key authentication with the specified
1812 * key file.
1813 */
1814 static struct RSAKey pubkey;
1815 static Bignum challenge, response;
1816 static int i;
1817 static unsigned char buffer[32];
1818
1819 tried_publickey = 1;
65a22376 1820 i = loadrsakey(cfg.keyfile, &pubkey, password);
7cca0d81 1821 if (i == 0) {
1408a877 1822 c_write_str("Couldn't load public key from ");
1823 c_write_str(cfg.keyfile);
1824 c_write_str(".\r\n");
7cca0d81 1825 continue; /* go and try password */
1826 }
1827 if (i == -1) {
1408a877 1828 c_write_str("Wrong passphrase.\r\n");
7cca0d81 1829 tried_publickey = 0;
1830 continue; /* try again */
1831 }
1832
1833 /*
1834 * Send a public key attempt.
1835 */
1836 send_packet(SSH1_CMSG_AUTH_RSA,
1837 PKT_BIGNUM, pubkey.modulus, PKT_END);
1838
1839 crWaitUntil(ispkt);
1840 if (pktin.type == SSH1_SMSG_FAILURE) {
1408a877 1841 c_write_str("Server refused our public key.\r\n");
7cca0d81 1842 continue; /* go and try password */
1843 }
8d5de777 1844 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1845 bombout(("Bizarre response to offer of public key"));
1846 crReturn(0);
1847 }
7cca0d81 1848 ssh1_read_bignum(pktin.body, &challenge);
1849 response = rsadecrypt(challenge, &pubkey);
1850 freebn(pubkey.private_exponent); /* burn the evidence */
1851
3709bfe9 1852 for (i = 0; i < 32; i++) {
1853 buffer[i] = bignum_byte(response, 31-i);
7cca0d81 1854 }
1855
1856 MD5Init(&md5c);
1857 MD5Update(&md5c, buffer, 32);
1858 MD5Update(&md5c, session_id, 16);
1859 MD5Final(buffer, &md5c);
1860
1861 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1862 PKT_DATA, buffer, 16, PKT_END);
1863
1864 crWaitUntil(ispkt);
1865 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1866 if (flags & FLAG_VERBOSE)
1408a877 1867 c_write_str("Failed to authenticate with our public key.\r\n");
7cca0d81 1868 continue; /* go and try password */
1869 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1870 bombout(("Bizarre response to RSA authentication response"));
1871 crReturn(0);
7cca0d81 1872 }
1873
1874 break; /* we're through! */
1875 } else {
39065bed 1876 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1877 /*
1878 * Defence against traffic analysis: we send a
1879 * whole bunch of packets containing strings of
1880 * different lengths. One of these strings is the
1881 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
1882 * The others are all random data in
1883 * SSH1_MSG_IGNORE packets. This way a passive
1884 * listener can't tell which is the password, and
1885 * hence can't deduce the password length.
1886 *
1887 * Anybody with a password length greater than 16
1888 * bytes is going to have enough entropy in their
1889 * password that a listener won't find it _that_
1890 * much help to know how long it is. So what we'll
1891 * do is:
1892 *
1893 * - if password length < 16, we send 15 packets
1894 * containing string lengths 1 through 15
1895 *
1896 * - otherwise, we let N be the nearest multiple
1897 * of 8 below the password length, and send 8
1898 * packets containing string lengths N through
1899 * N+7. This won't obscure the order of
1900 * magnitude of the password length, but it will
1901 * introduce a bit of extra uncertainty.
7d503c31 1902 *
1903 * A few servers (the old 1.2.18 through 1.2.22)
1904 * can't deal with SSH1_MSG_IGNORE. For these
1905 * servers, we need an alternative defence. We make
1906 * use of the fact that the password is interpreted
1907 * as a C string: so we can append a NUL, then some
1908 * random data.
39065bed 1909 */
7d503c31 1910 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
1911 char string[64];
1912 char *s;
1913 int len;
1914
1915 len = strlen(password);
1916 if (len < sizeof(string)) {
1917 s = string;
1918 strcpy(string, password);
1919 len++; /* cover the zero byte */
1920 while (len < sizeof(string)) {
1921 string[len++] = (char)random_byte();
1922 }
1923 } else {
1924 s = password;
1925 }
1926 send_packet(pwpkt_type, PKT_INT, len,
1927 PKT_DATA, s, len, PKT_END);
39065bed 1928 } else {
7d503c31 1929 int bottom, top, pwlen, i;
1930 char *randomstr;
1931
1932 pwlen = strlen(password);
1933 if (pwlen < 16) {
98c84eb4 1934 bottom = 0; /* zero length passwords are OK! :-) */
7d503c31 1935 top = 15;
1936 } else {
1937 bottom = pwlen &~ 7;
1938 top = bottom + 7;
1939 }
39065bed 1940
7d503c31 1941 assert(pwlen >= bottom && pwlen <= top);
39065bed 1942
7d503c31 1943 randomstr = smalloc(top+1);
39065bed 1944
7d503c31 1945 for (i = bottom; i <= top; i++) {
1946 if (i == pwlen)
1947 defer_packet(pwpkt_type, PKT_STR, password, PKT_END);
1948 else {
1949 for (j = 0; j < i; j++) {
1950 do {
1951 randomstr[j] = random_byte();
1952 } while (randomstr[j] == '\0');
1953 }
1954 randomstr[i] = '\0';
1955 defer_packet(SSH1_MSG_IGNORE,
1956 PKT_STR, randomstr, PKT_END);
39065bed 1957 }
39065bed 1958 }
7d503c31 1959 ssh_pkt_defersend();
39065bed 1960 }
39065bed 1961 } else {
1962 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1963 }
7cca0d81 1964 }
c5e9c988 1965 logevent("Sent password");
374330e2 1966 memset(password, 0, strlen(password));
fb09bf1c 1967 crWaitUntil(ispkt);
e5574168 1968 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1969 if (flags & FLAG_VERBOSE)
1408a877 1970 c_write_str("Access denied\r\n");
c5e9c988 1971 logevent("Authentication refused");
e5574168 1972 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1973 logevent("Received disconnect request");
85ee8208 1974 ssh_state = SSH_STATE_CLOSED;
1975 crReturn(1);
e5574168 1976 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1977 bombout(("Strange packet received, type %d", pktin.type));
1978 crReturn(0);
374330e2 1979 }
1980 }
1981
c5e9c988 1982 logevent("Authentication successful");
1983
fb09bf1c 1984 crFinish(1);
1985}
1986
9c964e85 1987void sshfwd_close(struct ssh_channel *c) {
80e48603 1988 if (c && !c->closes) {
783415f8 1989 if (ssh_version == 1) {
1990 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
1991 } else {
1992 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
1993 ssh2_pkt_adduint32(c->remoteid);
1994 ssh2_pkt_send();
1995 }
1996 c->closes = 1;
1997 if (c->type == CHAN_X11) {
1998 c->u.x11.s = NULL;
1999 logevent("X11 connection terminated");
2000 }
2001 }
9c964e85 2002}
2003
2004void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
783415f8 2005 if (ssh_version == 1) {
2006 send_packet(SSH1_MSG_CHANNEL_DATA,
2007 PKT_INT, c->remoteid,
2008 PKT_INT, len,
2009 PKT_DATA, buf, len,
2010 PKT_END);
2011 } else {
2012 ssh2_add_channel_data(c, buf, len);
2013 ssh2_try_send(c);
2014 }
9c964e85 2015}
2016
e5574168 2017static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 2018 crBegin;
2019
2020 random_init();
2021
e5574168 2022 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 2023 crReturnV;
85ee8208 2024 }
2025 if (ssh_state == SSH_STATE_CLOSED)
2026 crReturnV;
fb09bf1c 2027
979310f1 2028 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 2029 logevent("Requesting agent forwarding");
2030 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2031 do { crReturnV; } while (!ispkt);
2032 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 2033 bombout(("Protocol confusion"));
2034 crReturnV;
dacbd0e8 2035 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2036 logevent("Agent forwarding refused");
db7d555c 2037 } else {
dacbd0e8 2038 logevent("Agent forwarding enabled");
db7d555c 2039 ssh_agentfwd_enabled = TRUE;
2040 }
dacbd0e8 2041 }
2042
9c964e85 2043 if (cfg.x11_forward) {
2044 char proto[20], data[64];
2045 logevent("Requesting X11 forwarding");
2046 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2047 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2048 PKT_STR, proto, PKT_STR, data,
2049 PKT_INT, 0,
2050 PKT_END);
2051 do { crReturnV; } while (!ispkt);
2052 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2053 bombout(("Protocol confusion"));
2054 crReturnV;
2055 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2056 logevent("X11 forwarding refused");
2057 } else {
2058 logevent("X11 forwarding enabled");
2059 ssh_X11_fwd_enabled = TRUE;
2060 }
2061 }
2062
fef97f43 2063 if (!cfg.nopty) {
e5574168 2064 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 2065 PKT_STR, cfg.termtype,
2066 PKT_INT, rows, PKT_INT, cols,
2067 PKT_INT, 0, PKT_INT, 0,
2068 PKT_CHAR, 0,
2069 PKT_END);
fef97f43 2070 ssh_state = SSH_STATE_INTERMED;
2071 do { crReturnV; } while (!ispkt);
e5574168 2072 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 2073 bombout(("Protocol confusion"));
2074 crReturnV;
e5574168 2075 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1408a877 2076 c_write_str("Server refused to allocate pty\r\n");
0965bee0 2077 ssh_editing = ssh_echoing = 1;
fef97f43 2078 }
c5e9c988 2079 logevent("Allocated pty");
0965bee0 2080 } else {
2081 ssh_editing = ssh_echoing = 1;
374330e2 2082 }
2083
4ba9b64b 2084 if (cfg.compression) {
2085 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2086 do { crReturnV; } while (!ispkt);
2087 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2088 bombout(("Protocol confusion"));
2089 crReturnV;
2090 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1408a877 2091 c_write_str("Server refused to compress\r\n");
4ba9b64b 2092 }
2093 logevent("Started compression");
2094 ssh1_compressing = TRUE;
2095 zlib_compress_init();
2096 zlib_decompress_init();
2097 }
2098
6abbf9e3 2099 if (*cfg.remote_cmd)
2100 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
2101 else
2102 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 2103 logevent("Started session");
374330e2 2104
2105 ssh_state = SSH_STATE_SESSION;
2106 if (size_needed)
2107 ssh_size();
3687d221 2108 if (eof_needed)
2109 ssh_special(TS_EOF);
374330e2 2110
0965bee0 2111 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 2112 ssh_send_ok = 1;
dacbd0e8 2113 ssh_channels = newtree234(ssh_channelcmp);
374330e2 2114 while (1) {
2115 crReturnV;
2116 if (ispkt) {
e5574168 2117 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2118 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 2119 long len = GET_32BIT(pktin.body);
fe50e814 2120 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2121 pktin.body+4, len);
e5574168 2122 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 2123 ssh_state = SSH_STATE_CLOSED;
c5e9c988 2124 logevent("Received disconnect request");
3257deae 2125 crReturnV;
9c964e85 2126 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2127 /* Remote side is trying to open a channel to talk to our
2128 * X-Server. Give them back a local channel number. */
2129 unsigned i;
2130 struct ssh_channel *c, *d;
2131 enum234 e;
2132
2133 logevent("Received X11 connect request");
2134 /* Refuse if X11 forwarding is disabled. */
2135 if (!ssh_X11_fwd_enabled) {
2136 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2137 PKT_INT, GET_32BIT(pktin.body),
2138 PKT_END);
2139 logevent("Rejected X11 connect request");
2140 } else {
9c964e85 2141 c = smalloc(sizeof(struct ssh_channel));
2142
0c6c9a70 2143 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
9c964e85 2144 logevent("opening X11 forward connection failed");
2145 sfree(c);
2146 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2147 PKT_INT, GET_32BIT(pktin.body),
2148 PKT_END);
2149 } else {
2150 logevent("opening X11 forward connection succeeded");
2151 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
783415f8 2152 if (d->localid > i)
2153 break; /* found a free number */
2154 i = d->localid + 1;
9c964e85 2155 }
2156 c->remoteid = GET_32BIT(pktin.body);
2157 c->localid = i;
2158 c->closes = 0;
783415f8 2159 c->type = CHAN_X11; /* identify channel type */
9c964e85 2160 add234(ssh_channels, c);
2161 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2162 PKT_INT, c->remoteid, PKT_INT, c->localid,
2163 PKT_END);
2164 logevent("Opened X11 forward channel");
2165 }
2166 }
dacbd0e8 2167 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2168 /* Remote side is trying to open a channel to talk to our
2169 * agent. Give them back a local channel number. */
db7d555c 2170 unsigned i;
dacbd0e8 2171 struct ssh_channel *c;
2172 enum234 e;
db7d555c 2173
2174 /* Refuse if agent forwarding is disabled. */
2175 if (!ssh_agentfwd_enabled) {
2176 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2177 PKT_INT, GET_32BIT(pktin.body),
2178 PKT_END);
2179 } else {
2180 i = 1;
2181 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
2182 if (c->localid > i)
2183 break; /* found a free number */
2184 i = c->localid + 1;
2185 }
dcbde236 2186 c = smalloc(sizeof(struct ssh_channel));
db7d555c 2187 c->remoteid = GET_32BIT(pktin.body);
2188 c->localid = i;
2189 c->closes = 0;
783415f8 2190 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 2191 c->u.a.lensofar = 0;
2192 add234(ssh_channels, c);
2193 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2194 PKT_INT, c->remoteid, PKT_INT, c->localid,
2195 PKT_END);
2196 }
2197 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2198 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
dacbd0e8 2199 /* Remote side closes a channel. */
d211621f 2200 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 2201 struct ssh_channel *c;
2202 c = find234(ssh_channels, &i, ssh_channelfind);
2203 if (c) {
2204 int closetype;
2205 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2206 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
783415f8 2207 if ((c->closes == 0) && (c->type == CHAN_X11)) {
9c964e85 2208 logevent("X11 connection closed");
2209 assert(c->u.x11.s != NULL);
2210 x11_close(c->u.x11.s);
2211 c->u.x11.s = NULL;
2212 }
dacbd0e8 2213 c->closes |= closetype;
2214 if (c->closes == 3) {
2215 del234(ssh_channels, c);
dcbde236 2216 sfree(c);
dacbd0e8 2217 }
2218 }
2219 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2220 /* Data sent down one of our channels. */
2221 int i = GET_32BIT(pktin.body);
2222 int len = GET_32BIT(pktin.body+4);
2223 unsigned char *p = pktin.body+8;
2224 struct ssh_channel *c;
2225 c = find234(ssh_channels, &i, ssh_channelfind);
2226 if (c) {
2227 switch(c->type) {
783415f8 2228 case CHAN_X11:
9c964e85 2229 x11_send(c->u.x11.s, p, len);
2230 break;
783415f8 2231 case CHAN_AGENT:
dacbd0e8 2232 /* Data for an agent message. Buffer it. */
2233 while (len > 0) {
2234 if (c->u.a.lensofar < 4) {
2235 int l = min(4 - c->u.a.lensofar, len);
2236 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2237 p += l; len -= l; c->u.a.lensofar += l;
2238 }
2239 if (c->u.a.lensofar == 4) {
2240 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
dcbde236 2241 c->u.a.message = smalloc(c->u.a.totallen);
dacbd0e8 2242 memcpy(c->u.a.message, c->u.a.msglen, 4);
2243 }
2244 if (c->u.a.lensofar >= 4 && len > 0) {
2245 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2246 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2247 p += l; len -= l; c->u.a.lensofar += l;
2248 }
2249 if (c->u.a.lensofar == c->u.a.totallen) {
2250 void *reply, *sentreply;
2251 int replylen;
2252 agent_query(c->u.a.message, c->u.a.totallen,
2253 &reply, &replylen);
2254 if (reply)
2255 sentreply = reply;
2256 else {
2257 /* Fake SSH_AGENT_FAILURE. */
2258 sentreply = "\0\0\0\1\5";
2259 replylen = 5;
2260 }
2261 send_packet(SSH1_MSG_CHANNEL_DATA,
2262 PKT_INT, c->remoteid,
2263 PKT_INT, replylen,
2264 PKT_DATA, sentreply, replylen,
2265 PKT_END);
2266 if (reply)
dcbde236 2267 sfree(reply);
2268 sfree(c->u.a.message);
dacbd0e8 2269 c->u.a.lensofar = 0;
2270 }
2271 }
2272 break;
2273 }
2274 }
e5574168 2275 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 2276 /* may be from EXEC_SHELL on some servers */
e5574168 2277 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 2278 /* may be from EXEC_SHELL on some servers
374330e2 2279 * if no pty is available or in other odd cases. Ignore */
e5574168 2280 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2281 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 2282 } else {
8d5de777 2283 bombout(("Strange packet received: type %d", pktin.type));
2284 crReturnV;
374330e2 2285 }
2286 } else {
8df7a775 2287 while (inlen > 0) {
2288 int len = min(inlen, 512);
2289 send_packet(SSH1_CMSG_STDIN_DATA,
2290 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2291 in += len;
2292 inlen -= len;
2293 }
374330e2 2294 }
2295 }
2296
2297 crFinishV;
2298}
2299
2300/*
e5574168 2301 * Utility routine for decoding comma-separated strings in KEXINIT.
2302 */
75cab814 2303static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 2304 int needlen = strlen(needle);
2305 while (1) {
2306 /*
2307 * Is it at the start of the string?
2308 */
2309 if (haylen >= needlen && /* haystack is long enough */
2310 !memcmp(needle, haystack, needlen) && /* initial match */
2311 (haylen == needlen || haystack[needlen] == ',')
2312 /* either , or EOS follows */
2313 )
2314 return 1;
2315 /*
2316 * If not, search for the next comma and resume after that.
2317 * If no comma found, terminate.
2318 */
2319 while (haylen > 0 && *haystack != ',')
2320 haylen--, haystack++;
2321 if (haylen == 0)
2322 return 0;
2323 haylen--, haystack++; /* skip over comma itself */
2324 }
2325}
2326
2327/*
d39f364a 2328 * SSH2 key creation method.
2329 */
5e0d7cb8 2330static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) {
d39f364a 2331 SHA_State s;
2332 /* First 20 bytes. */
2333 SHA_Init(&s);
2334 sha_mpint(&s, K);
2335 SHA_Bytes(&s, H, 20);
2336 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 2337 SHA_Bytes(&s, sessid, 20);
d39f364a 2338 SHA_Final(&s, keyspace);
2339 /* Next 20 bytes. */
2340 SHA_Init(&s);
2341 sha_mpint(&s, K);
2342 SHA_Bytes(&s, H, 20);
2343 SHA_Bytes(&s, keyspace, 20);
2344 SHA_Final(&s, keyspace+20);
2345}
2346
2347/*
7cca0d81 2348 * Handle the SSH2 transport layer.
e5574168 2349 */
7cca0d81 2350static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 2351{
7bd5a860 2352 static int i, j, len, nbits, pbits;
e5574168 2353 static char *str;
a92dd380 2354 static Bignum p, g, e, f, K;
2355 static int kex_init_value, kex_reply_value;
7591b9ff 2356 static const struct ssh_mac **maclist;
8b2715b2 2357 static int nmacs;
0a3f1d48 2358 static const struct ssh2_cipher *cscipher_tobe = NULL;
2359 static const struct ssh2_cipher *sccipher_tobe = NULL;
57476f6b 2360 static const struct ssh_mac *csmac_tobe = NULL;
2361 static const struct ssh_mac *scmac_tobe = NULL;
2362 static const struct ssh_compress *cscomp_tobe = NULL;
2363 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 2364 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 2365 static int hostkeylen, siglen;
e055a386 2366 static void *hkey; /* actual host key */
e5574168 2367 static unsigned char exchange_hash[20];
d39f364a 2368 static unsigned char keyspace[40];
0a3f1d48 2369 static const struct ssh2_ciphers *preferred_cipher;
4ba9b64b 2370 static const struct ssh_compress *preferred_comp;
0db56f73 2371 static int first_kex;
e5574168 2372
2373 crBegin;
7cca0d81 2374 random_init();
0db56f73 2375 first_kex = 1;
e5574168 2376
5e8358ad 2377 /*
4ba9b64b 2378 * Set up the preferred cipher and compression.
5e8358ad 2379 */
2380 if (cfg.cipher == CIPHER_BLOWFISH) {
0a3f1d48 2381 preferred_cipher = &ssh2_blowfish;
5e8358ad 2382 } else if (cfg.cipher == CIPHER_DES) {
2383 logevent("Single DES not supported in SSH2; using 3DES");
0a3f1d48 2384 preferred_cipher = &ssh2_3des;
5e8358ad 2385 } else if (cfg.cipher == CIPHER_3DES) {
0a3f1d48 2386 preferred_cipher = &ssh2_3des;
2387 } else if (cfg.cipher == CIPHER_AES) {
2388 preferred_cipher = &ssh2_aes;
5e8358ad 2389 } else {
2390 /* Shouldn't happen, but we do want to initialise to _something_. */
0a3f1d48 2391 preferred_cipher = &ssh2_3des;
5e8358ad 2392 }
4ba9b64b 2393 if (cfg.compression)
2394 preferred_comp = &ssh_zlib;
2395 else
2396 preferred_comp = &ssh_comp_none;
5e8358ad 2397
7591b9ff 2398 /*
2399 * Be prepared to work around the buggy MAC problem.
2400 */
7d503c31 2401 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
8b2715b2 2402 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 2403 else
8b2715b2 2404 maclist = macs, nmacs = lenof(macs);
7591b9ff 2405
7cca0d81 2406 begin_key_exchange:
e5574168 2407 /*
2408 * Construct and send our key exchange packet.
2409 */
2410 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2411 for (i = 0; i < 16; i++)
2412 ssh2_pkt_addbyte((unsigned char)random_byte());
2413 /* List key exchange algorithms. */
2414 ssh2_pkt_addstring_start();
2415 for (i = 0; i < lenof(kex_algs); i++) {
2416 ssh2_pkt_addstring_str(kex_algs[i]->name);
2417 if (i < lenof(kex_algs)-1)
2418 ssh2_pkt_addstring_str(",");
2419 }
2420 /* List server host key algorithms. */
2421 ssh2_pkt_addstring_start();
2422 for (i = 0; i < lenof(hostkey_algs); i++) {
2423 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2424 if (i < lenof(hostkey_algs)-1)
2425 ssh2_pkt_addstring_str(",");
2426 }
2427 /* List client->server encryption algorithms. */
2428 ssh2_pkt_addstring_start();
729e54b4 2429 for (i = 0; i < lenof(ciphers)+1; i++) {
0a3f1d48 2430 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2431 for (j = 0; j < c->nciphers; j++) {
2432 ssh2_pkt_addstring_str(c->list[j]->name);
2433 if (i < lenof(ciphers) || j < c->nciphers-1)
2434 ssh2_pkt_addstring_str(",");
2435 }
e5574168 2436 }
2437 /* List server->client encryption algorithms. */
2438 ssh2_pkt_addstring_start();
729e54b4 2439 for (i = 0; i < lenof(ciphers)+1; i++) {
0a3f1d48 2440 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2441 for (j = 0; j < c->nciphers; j++) {
2442 ssh2_pkt_addstring_str(c->list[j]->name);
2443 if (i < lenof(ciphers) || j < c->nciphers-1)
2444 ssh2_pkt_addstring_str(",");
2445 }
e5574168 2446 }
2447 /* List client->server MAC algorithms. */
2448 ssh2_pkt_addstring_start();
8b2715b2 2449 for (i = 0; i < nmacs; i++) {
7591b9ff 2450 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2451 if (i < nmacs-1)
e5574168 2452 ssh2_pkt_addstring_str(",");
2453 }
2454 /* List server->client MAC algorithms. */
2455 ssh2_pkt_addstring_start();
8b2715b2 2456 for (i = 0; i < nmacs; i++) {
7591b9ff 2457 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2458 if (i < nmacs-1)
e5574168 2459 ssh2_pkt_addstring_str(",");
2460 }
2461 /* List client->server compression algorithms. */
2462 ssh2_pkt_addstring_start();
4ba9b64b 2463 for (i = 0; i < lenof(compressions)+1; i++) {
2464 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2465 ssh2_pkt_addstring_str(c->name);
2466 if (i < lenof(compressions))
e5574168 2467 ssh2_pkt_addstring_str(",");
2468 }
2469 /* List server->client compression algorithms. */
2470 ssh2_pkt_addstring_start();
4ba9b64b 2471 for (i = 0; i < lenof(compressions)+1; i++) {
2472 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2473 ssh2_pkt_addstring_str(c->name);
2474 if (i < lenof(compressions))
e5574168 2475 ssh2_pkt_addstring_str(",");
2476 }
2477 /* List client->server languages. Empty list. */
2478 ssh2_pkt_addstring_start();
2479 /* List server->client languages. Empty list. */
2480 ssh2_pkt_addstring_start();
2481 /* First KEX packet does _not_ follow, because we're not that brave. */
2482 ssh2_pkt_addbool(FALSE);
2483 /* Reserved. */
2484 ssh2_pkt_adduint32(0);
0db56f73 2485
2486 exhash = exhashbase;
e5574168 2487 sha_string(&exhash, pktout.data+5, pktout.length-5);
0db56f73 2488
e5574168 2489 ssh2_pkt_send();
2490
2491 if (!ispkt) crWaitUntil(ispkt);
2492 sha_string(&exhash, pktin.data+5, pktin.length-5);
2493
2494 /*
2495 * Now examine the other side's KEXINIT to see what we're up
2496 * to.
2497 */
7cca0d81 2498 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 2499 bombout(("expected key exchange packet from server"));
2500 crReturn(0);
7cca0d81 2501 }
e5574168 2502 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2503 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2504 pktin.savedpos += 16; /* skip garbage cookie */
2505 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2506 for (i = 0; i < lenof(kex_algs); i++) {
2507 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2508 kex = kex_algs[i];
2509 break;
2510 }
2511 }
2512 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2513 for (i = 0; i < lenof(hostkey_algs); i++) {
2514 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2515 hostkey = hostkey_algs[i];
2516 break;
2517 }
2518 }
2519 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 2520 for (i = 0; i < lenof(ciphers)+1; i++) {
0a3f1d48 2521 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2522 for (j = 0; j < c->nciphers; j++) {
2523 if (in_commasep_string(c->list[j]->name, str, len)) {
2524 cscipher_tobe = c->list[j];
2525 break;
2526 }
e5574168 2527 }
0a3f1d48 2528 if (cscipher_tobe)
2529 break;
e5574168 2530 }
2531 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
729e54b4 2532 for (i = 0; i < lenof(ciphers)+1; i++) {
0a3f1d48 2533 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2534 for (j = 0; j < c->nciphers; j++) {
2535 if (in_commasep_string(c->list[j]->name, str, len)) {
2536 sccipher_tobe = c->list[j];
2537 break;
2538 }
e5574168 2539 }
0a3f1d48 2540 if (sccipher_tobe)
2541 break;
e5574168 2542 }
2543 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 2544 for (i = 0; i < nmacs; i++) {
7591b9ff 2545 if (in_commasep_string(maclist[i]->name, str, len)) {
2546 csmac_tobe = maclist[i];
e5574168 2547 break;
2548 }
2549 }
2550 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 2551 for (i = 0; i < nmacs; i++) {
7591b9ff 2552 if (in_commasep_string(maclist[i]->name, str, len)) {
2553 scmac_tobe = maclist[i];
e5574168 2554 break;
2555 }
2556 }
2557 ssh2_pkt_getstring(&str, &len); /* client->server compression */
4ba9b64b 2558 for (i = 0; i < lenof(compressions)+1; i++) {
2559 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2560 if (in_commasep_string(c->name, str, len)) {
2561 cscomp_tobe = c;
e5574168 2562 break;
2563 }
2564 }
2565 ssh2_pkt_getstring(&str, &len); /* server->client compression */
4ba9b64b 2566 for (i = 0; i < lenof(compressions)+1; i++) {
2567 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2568 if (in_commasep_string(c->name, str, len)) {
2569 sccomp_tobe = c;
e5574168 2570 break;
2571 }
2572 }
e5574168 2573
2574 /*
7bd5a860 2575 * Work out the number of bits of key we will need from the key
2576 * exchange. We start with the maximum key length of either
2577 * cipher...
2578 */
2579 {
2580 int csbits, scbits;
2581
2582 csbits = cscipher_tobe->keylen;
2583 scbits = sccipher_tobe->keylen;
2584 nbits = (csbits > scbits ? csbits : scbits);
2585 }
2586 /* The keys only have 160-bit entropy, since they're based on
2587 * a SHA-1 hash. So cap the key size at 160 bits. */
2588 if (nbits > 160) nbits = 160;
2589
2590 /*
a92dd380 2591 * If we're doing Diffie-Hellman group exchange, start by
2592 * requesting a group.
e5574168 2593 */
a92dd380 2594 if (kex == &ssh_diffiehellman_gex) {
a92dd380 2595 logevent("Doing Diffie-Hellman group exchange");
2596 /*
7bd5a860 2597 * Work out how big a DH group we will need to allow that
2598 * much data.
2599 */
2600 pbits = 512 << ((nbits-1) / 64);
a92dd380 2601 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
7bd5a860 2602 ssh2_pkt_adduint32(pbits);
a92dd380 2603 ssh2_pkt_send();
2604
2605 crWaitUntil(ispkt);
2606 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
2607 bombout(("expected key exchange group packet from server"));
2608 crReturn(0);
2609 }
2610 p = ssh2_pkt_getmp();
2611 g = ssh2_pkt_getmp();
2612 dh_setup_group(p, g);
2613 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
2614 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
2615 } else {
2616 dh_setup_group1();
2617 kex_init_value = SSH2_MSG_KEXDH_INIT;
2618 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 2619 }
e5574168 2620
a92dd380 2621 logevent("Doing Diffie-Hellman key exchange");
e5574168 2622 /*
a92dd380 2623 * Now generate and send e for Diffie-Hellman.
e5574168 2624 */
7bd5a860 2625 e = dh_create_e(nbits*2);
a92dd380 2626 ssh2_pkt_init(kex_init_value);
e5574168 2627 ssh2_pkt_addmp(e);
2628 ssh2_pkt_send();
2629
2630 crWaitUntil(ispkt);
a92dd380 2631 if (pktin.type != kex_reply_value) {
2632 bombout(("expected key exchange reply packet from server"));
8d5de777 2633 crReturn(0);
7cca0d81 2634 }
e5574168 2635 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2636 f = ssh2_pkt_getmp();
e5574168 2637 ssh2_pkt_getstring(&sigdata, &siglen);
2638
2639 K = dh_find_K(f);
e5574168 2640
2641 sha_string(&exhash, hostkeydata, hostkeylen);
a92dd380 2642 if (kex == &ssh_diffiehellman_gex) {
7bd5a860 2643 sha_uint32(&exhash, pbits);
a92dd380 2644 sha_mpint(&exhash, p);
2645 sha_mpint(&exhash, g);
2646 }
e5574168 2647 sha_mpint(&exhash, e);
2648 sha_mpint(&exhash, f);
2649 sha_mpint(&exhash, K);
2650 SHA_Final(&exhash, exchange_hash);
2651
3709bfe9 2652 dh_cleanup();
2653
7cca0d81 2654#if 0
e5574168 2655 debug(("Exchange hash is:\r\n"));
2656 for (i = 0; i < 20; i++)
2657 debug((" %02x", exchange_hash[i]));
2658 debug(("\r\n"));
7cca0d81 2659#endif
2660
e055a386 2661 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2662 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
8d5de777 2663 bombout(("Server failed host key check"));
2664 crReturn(0);
2665 }
e5574168 2666
2667 /*
7cca0d81 2668 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2669 */
7cca0d81 2670 crWaitUntil(ispkt);
8d5de777 2671 if (pktin.type != SSH2_MSG_NEWKEYS) {
2672 bombout(("expected new-keys packet from server"));
2673 crReturn(0);
2674 }
d39f364a 2675
2676 /*
7cca0d81 2677 * Authenticate remote host: verify host key. (We've already
2678 * checked the signature of the exchange hash.)
e5574168 2679 */
e055a386 2680 keystr = hostkey->fmtkey(hkey);
2681 fingerprint = hostkey->fingerprint(hkey);
d4857987 2682 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2683 keystr, fingerprint);
a92dd380 2684 if (first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 2685 logevent("Host key fingerprint is:");
2686 logevent(fingerprint);
2687 }
dcbde236 2688 sfree(fingerprint);
2689 sfree(keystr);
e055a386 2690 hostkey->freekey(hkey);
d39f364a 2691
2692 /*
7cca0d81 2693 * Send SSH2_MSG_NEWKEYS.
d39f364a 2694 */
2695 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2696 ssh2_pkt_send();
d39f364a 2697
2698 /*
2699 * Create and initialise session keys.
2700 */
2701 cscipher = cscipher_tobe;
2702 sccipher = sccipher_tobe;
2703 csmac = csmac_tobe;
2704 scmac = scmac_tobe;
2705 cscomp = cscomp_tobe;
2706 sccomp = sccomp_tobe;
4ba9b64b 2707 cscomp->compress_init();
2708 sccomp->decompress_init();
d39f364a 2709 /*
5e0d7cb8 2710 * Set IVs after keys. Here we use the exchange hash from the
2711 * _first_ key exchange.
d39f364a 2712 */
5e0d7cb8 2713 if (first_kex)
65a22376 2714 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
2715 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
5e0d7cb8 2716 cscipher->setcskey(keyspace);
65a22376 2717 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
5e0d7cb8 2718 sccipher->setsckey(keyspace);
65a22376 2719 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
5e0d7cb8 2720 cscipher->setcsiv(keyspace);
65a22376 2721 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
5e0d7cb8 2722 sccipher->setsciv(keyspace);
65a22376 2723 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
5e0d7cb8 2724 csmac->setcskey(keyspace);
65a22376 2725 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
5e0d7cb8 2726 scmac->setsckey(keyspace);
d39f364a 2727
033b4cef 2728 /*
0db56f73 2729 * If this is the first key exchange phase, we must pass the
2730 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2731 * wants to see it but because it will need time to initialise
2732 * itself before it sees an actual packet. In subsequent key
2733 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2734 * it would only confuse the layer above.
2735 */
2736 if (!first_kex) {
2737 crReturn(0);
2738 }
2739 first_kex = 0;
2740
2741 /*
7cca0d81 2742 * Now we're encrypting. Begin returning 1 to the protocol main
2743 * function so that other things can run on top of the
2744 * transport. If we ever see a KEXINIT, we must go back to the
2745 * start.
033b4cef 2746 */
e96adf72 2747 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
7cca0d81 2748 crReturn(1);
e96adf72 2749 }
5e0d7cb8 2750 logevent("Server initiated key re-exchange");
7cca0d81 2751 goto begin_key_exchange;
e5574168 2752
2753 crFinish(1);
2754}
2755
7cca0d81 2756/*
783415f8 2757 * Add data to an SSH2 channel output buffer.
2758 */
2759static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2760 if (c->v2.outbufsize <
2761 c->v2.outbuflen + len) {
2762 c->v2.outbufsize =
2763 c->v2.outbuflen + len + 1024;
2764 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2765 c->v2.outbufsize);
2766 }
2767 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2768 buf, len);
2769 c->v2.outbuflen += len;
2770}
2771
2772/*
2773 * Attempt to send data on an SSH2 channel.
2774 */
2775static void ssh2_try_send(struct ssh_channel *c) {
2776 while (c->v2.remwindow > 0 &&
2777 c->v2.outbuflen > 0) {
2778 unsigned len = c->v2.remwindow;
2779 if (len > c->v2.outbuflen)
2780 len = c->v2.outbuflen;
2781 if (len > c->v2.remmaxpkt)
2782 len = c->v2.remmaxpkt;
2783 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2784 ssh2_pkt_adduint32(c->remoteid);
2785 ssh2_pkt_addstring_start();
2786 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2787 ssh2_pkt_send();
2788 c->v2.outbuflen -= len;
2789 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2790 c->v2.outbuflen);
2791 c->v2.remwindow -= len;
2792 }
2793}
2794
2795/*
7cca0d81 2796 * Handle the SSH2 userauth and connection layers.
2797 */
2798static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2799{
7cca0d81 2800 static unsigned long remote_winsize;
2801 static unsigned long remote_maxpkt;
65a22376 2802 static enum {
2803 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, AUTH_PASSWORD
2804 } method;
1408a877 2805 static enum {
2806 AUTH_TYPE_NONE,
2807 AUTH_TYPE_PUBLICKEY,
2808 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
2809 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
2810 AUTH_TYPE_PASSWORD
2811 } type;
1983e559 2812 static int gotit, need_pw, can_pubkey, can_passwd;
2813 static int tried_pubkey_config, tried_agent;
1408a877 2814 static int we_are_in;
65a22376 2815 static char username[100];
2816 static char pwprompt[200];
2817 static char password[100];
7cca0d81 2818
e5574168 2819 crBegin;
2820
7cca0d81 2821 /*
2822 * Request userauth protocol, and await a response to it.
2823 */
2824 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2825 ssh2_pkt_addstring("ssh-userauth");
2826 ssh2_pkt_send();
2827 crWaitUntilV(ispkt);
8d5de777 2828 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2829 bombout(("Server refused user authentication protocol"));
2830 crReturnV;
2831 }
7cca0d81 2832
2833 /*
1408a877 2834 * We repeat this whole loop, including the username prompt,
2835 * until we manage a successful authentication. If the user
2836 * types the wrong _password_, they are sent back to the
2837 * beginning to try another username. (If they specify a
2838 * username in the config, they are never asked, even if they
2839 * do give a wrong password.)
2840 *
2841 * I think this best serves the needs of
2842 *
2843 * - the people who have no configuration, no keys, and just
2844 * want to try repeated (username,password) pairs until they
2845 * type both correctly
2846 *
2847 * - people who have keys and configuration but occasionally
2848 * need to fall back to passwords
2849 *
2850 * - people with a key held in Pageant, who might not have
2851 * logged in to a particular machine before; so they want to
2852 * type a username, and then _either_ their key will be
2853 * accepted, _or_ they will type a password. If they mistype
2854 * the username they will want to be able to get back and
2855 * retype it!
7cca0d81 2856 */
1408a877 2857 do {
2858 static int pos;
7cca0d81 2859 static char c;
e5574168 2860
1408a877 2861 /*
2862 * Get a username.
2863 */
2864 pos = 0;
67779be7 2865 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
fa17a66e 2866 if (ssh_get_line) {
2867 if (!ssh_get_line("login as: ",
2868 username, sizeof(username), FALSE)) {
2869 /*
2870 * get_line failed to get a username.
2871 * Terminate.
2872 */
2873 logevent("No username provided. Abandoning session.");
2874 ssh_state = SSH_STATE_CLOSED;
dae2b91f 2875 crReturnV;
fa17a66e 2876 }
2877 } else {
2878 c_write_str("login as: ");
2879 ssh_send_ok = 1;
2880 while (pos >= 0) {
2881 crWaitUntilV(!ispkt);
2882 while (inlen--) switch (c = *in++) {
2883 case 10: case 13:
2884 username[pos] = 0;
2885 pos = -1;
2886 break;
2887 case 8: case 127:
2888 if (pos > 0) {
2889 c_write_str("\b \b");
2890 pos--;
2891 }
2892 break;
2893 case 21: case 27:
2894 while (pos > 0) {
2895 c_write_str("\b \b");
2896 pos--;
2897 }
2898 break;
2899 case 3: case 4:
2900 random_save_seed();
2901 exit(0);
2902 break;
2903 default:
2904 if (((c >= ' ' && c <= '~') ||
2905 ((unsigned char)c >= 160)) && pos < 40) {
2906 username[pos++] = c;
2907 c_write(&c, 1);
2908 }
2909 break;
2910 }
2911 }
2912 }
1408a877 2913 c_write_str("\r\n");
7cca0d81 2914 username[strcspn(username, "\n\r")] = '\0';
2915 } else {
2916 char stuff[200];
2917 strncpy(username, cfg.username, 99);
2918 username[99] = '\0';
65a22376 2919 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2920 sprintf(stuff, "Using username \"%s\".\r\n", username);
1408a877 2921 c_write_str(stuff);
7cca0d81 2922 }
2923 }
2924
65a22376 2925 /*
1408a877 2926 * Send an authentication request using method "none": (a)
2927 * just in case it succeeds, and (b) so that we know what
2928 * authentication methods we can usefully try next.
65a22376 2929 */
1408a877 2930 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2931 ssh2_pkt_addstring(username);
2932 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2933 ssh2_pkt_addstring("none"); /* method */
2934 ssh2_pkt_send();
2935 type = AUTH_TYPE_NONE;
2936 gotit = FALSE;
2937 we_are_in = FALSE;
7cca0d81 2938
1408a877 2939 tried_pubkey_config = FALSE;
1983e559 2940 tried_agent = FALSE;
65a22376 2941
1408a877 2942 while (1) {
2943 /*
2944 * Wait for the result of the last authentication request.
2945 */
2946 if (!gotit)
2947 crWaitUntilV(ispkt);
2948 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
2949 /* FIXME: should support this */
2950 crWaitUntilV(ispkt);
2951 }
2952 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
2953 logevent("Access granted");
2954 we_are_in = TRUE;
2955 break;
2956 }
65a22376 2957
1408a877 2958 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
2959 bombout(("Strange packet received during authentication: type %d",
2960 pktin.type));
65a22376 2961 }
2962
1408a877 2963 gotit = FALSE;
65a22376 2964
1408a877 2965 /*
2966 * OK, we're now sitting on a USERAUTH_FAILURE message, so
2967 * we can look at the string in it and know what we can
2968 * helpfully try next.
2969 */
2970 {
2971 char *methods;
2972 int methlen;
2973 ssh2_pkt_getstring(&methods, &methlen);
2974 if (!ssh2_pkt_getbool()) {
2975 /*
2976 * We have received an unequivocal Access
2977 * Denied. This can translate to a variety of
2978 * messages:
2979 *
2980 * - if we'd just tried "none" authentication,
2981 * it's not worth printing anything at all
2982 *
2983 * - if we'd just tried a public key _offer_,
2984 * the message should be "Server refused our
2985 * key" (or no message at all if the key
2986 * came from Pageant)
2987 *
2988 * - if we'd just tried anything else, the
2989 * message really should be "Access denied".
2990 *
2991 * Additionally, if we'd just tried password
2992 * authentication, we should break out of this
2993 * whole loop so as to go back to the username
2994 * prompt.
2995 */
2996 if (type == AUTH_TYPE_NONE) {
2997 /* do nothing */
2998 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
2999 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3000 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3001 c_write_str("Server refused our key\r\n");
3002 logevent("Server refused public key");
3003 } else {
3004 c_write_str("Access denied\r\n");
3005 logevent("Access denied");
3006 if (type == AUTH_TYPE_PASSWORD) {
3007 we_are_in = FALSE;
3008 break;
3009 }
3010 }
3011 } else {
3012 c_write_str("Further authentication required\r\n");
3013 logevent("Further authentication required");
3014 }
65a22376 3015
1408a877 3016 can_pubkey = in_commasep_string("publickey", methods, methlen);
3017 can_passwd = in_commasep_string("password", methods, methlen);
3018 }
65a22376 3019
1408a877 3020 method = 0;
65a22376 3021
1983e559 3022 if (!method && can_pubkey && agent_exists && !tried_agent) {
3023 /*
3024 * Attempt public-key authentication using Pageant.
3025 */
3026 static unsigned char request[5], *response, *p;
3027 static int responselen;
3028 static int i, nkeys;
3029 static int authed = FALSE;
3030 void *r;
3031
3032 tried_agent = TRUE;
3033
3034 logevent("Pageant is running. Requesting keys.");
3035
3036 /* Request the keys held by the agent. */
3037 PUT_32BIT(request, 1);
3038 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3039 agent_query(request, 5, &r, &responselen);
3040 response = (unsigned char *)r;
95797139 3041 if (response && responselen >= 5 &&
3042 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
1983e559 3043 p = response + 5;
3044 nkeys = GET_32BIT(p); p += 4;
6328ea7a 3045 { char buf[64]; sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
1983e559 3046 logevent(buf); }
3047 for (i = 0; i < nkeys; i++) {
3048 static char *pkblob, *alg, *commentp;
3049 static int pklen, alglen, commentlen;
3050 static int siglen, retlen, len;
3051 static char *q, *agentreq, *ret;
3052
3053 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
3054 logevent(buf); }
3055 pklen = GET_32BIT(p); p += 4;
3056 pkblob = p; p += pklen;
3057 alglen = GET_32BIT(pkblob);
3058 alg = pkblob + 4;
3059 commentlen = GET_32BIT(p); p += 4;
3060 commentp = p; p += commentlen;
3061 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3062 ssh2_pkt_addstring(username);
3063 ssh2_pkt_addstring("ssh-connection");/* service requested */
3064 ssh2_pkt_addstring("publickey");/* method */
3065 ssh2_pkt_addbool(FALSE); /* no signature included */
3066 ssh2_pkt_addstring_start();
3067 ssh2_pkt_addstring_data(alg, alglen);
3068 ssh2_pkt_addstring_start();
3069 ssh2_pkt_addstring_data(pkblob, pklen);
3070 ssh2_pkt_send();
3071
3072 crWaitUntilV(ispkt);
3073 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3074 logevent("Key refused");
3075 continue;
3076 }
3077
3078 c_write_str("Authenticating with public key \"");
3079 c_write(commentp, commentlen);
3080 c_write_str("\" from agent\r\n");
3081
3082 /*
3083 * Server is willing to accept the key.
3084 * Construct a SIGN_REQUEST.
3085 */
3086 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3087 ssh2_pkt_addstring(username);
3088 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3089 ssh2_pkt_addstring("publickey"); /* method */
3090 ssh2_pkt_addbool(TRUE);
3091 ssh2_pkt_addstring_start();
3092 ssh2_pkt_addstring_data(alg, alglen);
3093 ssh2_pkt_addstring_start();
3094 ssh2_pkt_addstring_data(pkblob, pklen);
3095
3096 siglen = pktout.length - 5 + 4 + 20;
3097 len = 1; /* message type */
3098 len += 4 + pklen; /* key blob */
3099 len += 4 + siglen; /* data to sign */
3100 len += 4; /* flags */
3101 agentreq = smalloc(4 + len);
3102 PUT_32BIT(agentreq, len);
3103 q = agentreq + 4;
3104 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3105 PUT_32BIT(q, pklen); q += 4;
3106 memcpy(q, pkblob, pklen); q += pklen;
3107 PUT_32BIT(q, siglen); q += 4;
3108 /* Now the data to be signed... */
3109 PUT_32BIT(q, 20); q += 4;
3110 memcpy(q, ssh2_session_id, 20); q += 20;
3111 memcpy(q, pktout.data+5, pktout.length-5);
3112 q += pktout.length-5;
3113 /* And finally the (zero) flags word. */
3114 PUT_32BIT(q, 0);
3115 agent_query(agentreq, len+4, &ret, &retlen);
3116 sfree(agentreq);
3117 if (ret) {
3118 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3119 logevent("Sending Pageant's response");
3120 ssh2_pkt_addstring_start();
3121 ssh2_pkt_addstring_data(ret+9, GET_32BIT(ret+5));
3122 ssh2_pkt_send();
3123 authed = TRUE;
3124 break;
3125 } else {
3126 logevent("Pageant failed to answer challenge");
3127 sfree(ret);
3128 }
3129 }
3130 }
3131 if (authed)
3132 continue;
3133 }
3134 }
3135
1408a877 3136 if (!method && can_pubkey && *cfg.keyfile && !tried_pubkey_config) {
3137 unsigned char *pub_blob;
3138 char *algorithm, *comment;
3139 int pub_blob_len;
65a22376 3140
1408a877 3141 tried_pubkey_config = TRUE;
65a22376 3142
65a22376 3143 /*
1408a877 3144 * Try the public key supplied in the configuration.
3145 *
3146 * First, offer the public blob to see if the server is
3147 * willing to accept it.
65a22376 3148 */
1408a877 3149 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3150 &pub_blob_len);
3151 if (pub_blob) {
3152 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3153 ssh2_pkt_addstring(username);
3154 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3155 ssh2_pkt_addstring("publickey");/* method */
3156 ssh2_pkt_addbool(FALSE); /* no signature included */
3157 ssh2_pkt_addstring(algorithm);
3158 ssh2_pkt_addstring_start();
3159 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3160 ssh2_pkt_send();
3161 logevent("Offered public key"); /* FIXME */
3162
3163 crWaitUntilV(ispkt);
3164 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3165 gotit = TRUE;
3166 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
3167 continue; /* key refused; give up on it */
3168 }
65a22376 3169
1408a877 3170 logevent("Offer of public key accepted");
65a22376 3171 /*
1408a877 3172 * Actually attempt a serious authentication using
3173 * the key.
65a22376 3174 */
1408a877 3175 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
3176 sprintf(pwprompt, "Passphrase for key \"%.100s\": ", comment);
3177 need_pw = TRUE;
3178 } else {
3179 need_pw = FALSE;
3180 }
3181 c_write_str("Authenticating with public key \"");
3182 c_write_str(comment);
3183 c_write_str("\"\r\n");
3184 method = AUTH_PUBLICKEY_FILE;
65a22376 3185 }
1408a877 3186 }
3187
3188 if (!method && can_passwd) {
3189 method = AUTH_PASSWORD;
3190 sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost);
3191 need_pw = TRUE;
3192 }
3193
3194 if (need_pw) {
fa17a66e 3195 if (ssh_get_line) {
3196 if (!ssh_get_line(pwprompt, password,
3197 sizeof(password), TRUE)) {
1408a877 3198 /*
fa17a66e 3199 * get_line failed to get a password (for
3200 * example because one was supplied on the
3201 * command line which has already failed to
3202 * work). Terminate.
1408a877 3203 */
3204 logevent("No more passwords to try");
3205 ssh_state = SSH_STATE_CLOSED;
3206 crReturnV;
3207 }
3208 } else {
3209 static int pos = 0;
3210 static char c;
3211
3212 c_write_str(pwprompt);
3213 ssh_send_ok = 1;
3214
3215 pos = 0;
3216 while (pos >= 0) {
3217 crWaitUntilV(!ispkt);
3218 while (inlen--) switch (c = *in++) {
3219 case 10: case 13:
3220 password[pos] = 0;
3221 pos = -1;
3222 break;
3223 case 8: case 127:
3224 if (pos > 0)
3225 pos--;
3226 break;
3227 case 21: case 27:
3228 pos = 0;
3229 break;
3230 case 3: case 4:
3231 random_save_seed();
3232 exit(0);
3233 break;
3234 default:
3235 if (((c >= ' ' && c <= '~') ||
3236 ((unsigned char)c >= 160)) && pos < 40)
3237 password[pos++] = c;
3238 break;
3239 }
65a22376 3240 }
1408a877 3241 c_write_str("\r\n");
65a22376 3242 }
65a22376 3243 }
65a22376 3244
1408a877 3245 if (method == AUTH_PUBLICKEY_FILE) {
3246 /*
3247 * We have our passphrase. Now try the actual authentication.
3248 */
3249 struct ssh2_userkey *key;
65a22376 3250
1408a877 3251 key = ssh2_load_userkey(cfg.keyfile, password);
3252 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3253 if (key == SSH2_WRONG_PASSPHRASE) {
3254 c_write_str("Wrong passphrase\r\n");
3255 tried_pubkey_config = FALSE;
3256 } else {
3257 c_write_str("Unable to load private key\r\n");
3258 tried_pubkey_config = TRUE;
3259 }
3260 /* Send a spurious AUTH_NONE to return to the top. */
3261 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3262 ssh2_pkt_addstring(username);
3263 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3264 ssh2_pkt_addstring("none"); /* method */
3265 ssh2_pkt_send();
3266 type = AUTH_TYPE_NONE;
3267 } else {
3268 unsigned char *blob, *sigdata;
3269 int blob_len, sigdata_len;
65a22376 3270
1408a877 3271 /*
3272 * We have loaded the private key and the server
3273 * has announced that it's willing to accept it.
3274 * Hallelujah. Generate a signature and send it.
3275 */
3276 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3277 ssh2_pkt_addstring(username);
3278 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3279 ssh2_pkt_addstring("publickey"); /* method */
3280 ssh2_pkt_addbool(TRUE);
3281 ssh2_pkt_addstring(key->alg->name);
3282 blob = key->alg->public_blob(key->data, &blob_len);
3283 ssh2_pkt_addstring_start();
3284 ssh2_pkt_addstring_data(blob, blob_len);
3285 sfree(blob);
3286
3287 /*
3288 * The data to be signed is:
3289 *
3290 * string session-id
3291 *
3292 * followed by everything so far placed in the
3293 * outgoing packet.
3294 */
3295 sigdata_len = pktout.length - 5 + 4 + 20;
3296 sigdata = smalloc(sigdata_len);
3297 PUT_32BIT(sigdata, 20);
3298 memcpy(sigdata+4, ssh2_session_id, 20);
3299 memcpy(sigdata+24, pktout.data+5, pktout.length-5);
3300 blob = key->alg->sign(key->data, sigdata, sigdata_len, &blob_len);
3301 ssh2_pkt_addstring_start();
3302 ssh2_pkt_addstring_data(blob, blob_len);
3303 sfree(blob);
3304 sfree(sigdata);
3305
3306 ssh2_pkt_send();
3307 type = AUTH_TYPE_PUBLICKEY;
3308 }
3309 } else if (method == AUTH_PASSWORD) {
65a22376 3310 /*
1408a877 3311 * We send the password packet lumped tightly together with
3312 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3313 * string long enough to make the total length of the two
3314 * packets constant. This should ensure that a passive
3315 * listener doing traffic analyis can't work out the length
3316 * of the password.
3317 *
3318 * For this to work, we need an assumption about the
3319 * maximum length of the password packet. I think 256 is
3320 * pretty conservative. Anyone using a password longer than
3321 * that probably doesn't have much to worry about from
3322 * people who find out how long their password is!
65a22376 3323 */
3324 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3325 ssh2_pkt_addstring(username);
3326 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 3327 ssh2_pkt_addstring("password");
3328 ssh2_pkt_addbool(FALSE);
3329 ssh2_pkt_addstring(password);
3330 ssh2_pkt_defer();
65a22376 3331 /*
1408a877 3332 * We'll include a string that's an exact multiple of the
3333 * cipher block size. If the cipher is NULL for some
3334 * reason, we don't do this trick at all because we gain
3335 * nothing by it.
65a22376 3336 */
6e9e9520 3337 if (cscipher) {
3338 int stringlen, i;
3339
3340 stringlen = (256 - deferred_len);
3341 stringlen += cscipher->blksize - 1;
3342 stringlen -= (stringlen % cscipher->blksize);
3343 if (cscomp) {
3344 /*
3345 * Temporarily disable actual compression,
3346 * so we can guarantee to get this string
3347 * exactly the length we want it. The
3348 * compression-disabling routine should
3349 * return an integer indicating how many
3350 * bytes we should adjust our string length
3351 * by.
3352 */
3353 stringlen -= cscomp->disable_compression();
3354 }
1408a877 3355 ssh2_pkt_init(SSH2_MSG_IGNORE);
3356 ssh2_pkt_addstring_start();
6e9e9520 3357 for (i = 0; i < stringlen; i++) {
3358 char c = (char)random_byte();
3359 ssh2_pkt_addstring_data(&c, 1);
65a22376 3360 }
1408a877 3361 ssh2_pkt_defer();
65a22376 3362 }
39065bed 3363 ssh_pkt_defersend();
0d43337a 3364 logevent("Sent password");
1408a877 3365 type = AUTH_TYPE_PASSWORD;
3366 } else {
3367 c_write_str("No supported authentication methods left to try!\r\n");
3368 logevent("No supported authentications offered. Disconnecting");
3369 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3370 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3371 ssh2_pkt_addstring("No supported authentication methods available");
3372 ssh2_pkt_addstring("en"); /* language tag */
3373 ssh2_pkt_send();
3374 ssh_state = SSH_STATE_CLOSED;
3375 crReturnV;
65a22376 3376 }
65a22376 3377 }
1408a877 3378 } while (!we_are_in);
7cca0d81 3379
3380 /*
3381 * Now we're authenticated for the connection protocol. The
3382 * connection protocol will automatically have started at this
3383 * point; there's no need to send SERVICE_REQUEST.
3384 */
3385
3386 /*
3387 * So now create a channel with a session in it.
3388 */
dcbde236 3389 mainchan = smalloc(sizeof(struct ssh_channel));
d211621f 3390 mainchan->localid = 100; /* as good as any */
7cca0d81 3391 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3392 ssh2_pkt_addstring("session");
d211621f 3393 ssh2_pkt_adduint32(mainchan->localid);
cf6e59d6 3394 ssh2_pkt_adduint32(0x8000UL); /* our window size */
d211621f 3395 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 3396 ssh2_pkt_send();
3397 crWaitUntilV(ispkt);
3398 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 3399 bombout(("Server refused to open a session"));
3400 crReturnV;
7cca0d81 3401 /* FIXME: error data comes back in FAILURE packet */
3402 }
d211621f 3403 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 3404 bombout(("Server's channel confirmation cited wrong channel"));
3405 crReturnV;
7cca0d81 3406 }
d211621f 3407 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 3408 mainchan->type = CHAN_MAINSESSION;
3409 mainchan->closes = 0;
3410 mainchan->v2.remwindow = ssh2_pkt_getuint32();
3411 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
3412 mainchan->v2.outbuffer = NULL;
3413 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
3414 ssh_channels = newtree234(ssh_channelcmp);
3415 add234(ssh_channels, mainchan);
7cca0d81 3416 logevent("Opened channel for session");
3417
3418 /*
783415f8 3419 * Potentially enable X11 forwarding.
3420 */
3421 if (cfg.x11_forward) {
3422 char proto[20], data[64];
3423 logevent("Requesting X11 forwarding");
3424 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3425 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3426 ssh2_pkt_adduint32(mainchan->remoteid);
3427 ssh2_pkt_addstring("x11-req");
3428 ssh2_pkt_addbool(1); /* want reply */
3429 ssh2_pkt_addbool(0); /* many connections */
3430 ssh2_pkt_addstring(proto);
3431 ssh2_pkt_addstring(data);
3432 ssh2_pkt_adduint32(0); /* screen number */
3433 ssh2_pkt_send();
3434
3435 do {
3436 crWaitUntilV(ispkt);
3437 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3438 unsigned i = ssh2_pkt_getuint32();
3439 struct ssh_channel *c;
3440 c = find234(ssh_channels, &i, ssh_channelfind);
3441 if (!c)
3442 continue; /* nonexistent channel */
3443 c->v2.remwindow += ssh2_pkt_getuint32();
3444 }
3445 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3446
3447 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3448 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3449 bombout(("Server got confused by X11 forwarding request"));
3450 crReturnV;
3451 }
3452 logevent("X11 forwarding refused");
3453 } else {
3454 logevent("X11 forwarding enabled");
3455 ssh_X11_fwd_enabled = TRUE;
3456 }
3457 }
3458
3459 /*
36c2a3e9 3460 * Potentially enable agent forwarding.
3461 */
3462 if (cfg.agentfwd && agent_exists()) {
36c2a3e9 3463 logevent("Requesting OpenSSH-style agent forwarding");
36c2a3e9 3464 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3465 ssh2_pkt_adduint32(mainchan->remoteid);
3466 ssh2_pkt_addstring("auth-agent-req@openssh.com");
3467 ssh2_pkt_addbool(1); /* want reply */
3468 ssh2_pkt_send();
3469
3470 do {
3471 crWaitUntilV(ispkt);
3472 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3473 unsigned i = ssh2_pkt_getuint32();
3474 struct ssh_channel *c;
3475 c = find234(ssh_channels, &i, ssh_channelfind);
3476 if (!c)
3477 continue; /* nonexistent channel */
3478 c->v2.remwindow += ssh2_pkt_getuint32();
3479 }
3480 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3481
3482 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3483 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3484 bombout(("Server got confused by agent forwarding request"));
3485 crReturnV;
3486 }
3487 logevent("Agent forwarding refused");
3488 } else {
3489 logevent("Agent forwarding enabled");
3490 ssh_agentfwd_enabled = TRUE;
3491 }
3492 }
3493
3494 /*
7cca0d81 3495 * Now allocate a pty for the session.
3496 */
67779be7 3497 if (!cfg.nopty) {
3498 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3499 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3500 ssh2_pkt_addstring("pty-req");
3501 ssh2_pkt_addbool(1); /* want reply */
3502 ssh2_pkt_addstring(cfg.termtype);
3503 ssh2_pkt_adduint32(cols);
3504 ssh2_pkt_adduint32(rows);
3505 ssh2_pkt_adduint32(0); /* pixel width */
3506 ssh2_pkt_adduint32(0); /* pixel height */
3507 ssh2_pkt_addstring_start();
3508 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
3509 ssh2_pkt_send();
6e48c3fe 3510 ssh_state = SSH_STATE_INTERMED;
7cca0d81 3511
67779be7 3512 do {
3513 crWaitUntilV(ispkt);
3514 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 3515 unsigned i = ssh2_pkt_getuint32();
3516 struct ssh_channel *c;
3517 c = find234(ssh_channels, &i, ssh_channelfind);
3518 if (!c)
3519 continue; /* nonexistent channel */
3520 c->v2.remwindow += ssh2_pkt_getuint32();
67779be7 3521 }
3522 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 3523
67779be7 3524 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3525 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 3526 bombout(("Server got confused by pty request"));
3527 crReturnV;
67779be7 3528 }
1408a877 3529 c_write_str("Server refused to allocate pty\r\n");
0965bee0 3530 ssh_editing = ssh_echoing = 1;
67779be7 3531 } else {
3532 logevent("Allocated pty");
7cca0d81 3533 }
0965bee0 3534 } else {
3535 ssh_editing = ssh_echoing = 1;
7cca0d81 3536 }
3537
3538 /*
67779be7 3539 * Start a shell or a remote command.
7cca0d81 3540 */
3541 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 3542 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4a8fc3c4 3543 if (cfg.ssh_subsys) {
3544 ssh2_pkt_addstring("subsystem");
3545 ssh2_pkt_addbool(1); /* want reply */
3546 ssh2_pkt_addstring(cfg.remote_cmd);
3547 } else if (*cfg.remote_cmd) {
67779be7 3548 ssh2_pkt_addstring("exec");
3549 ssh2_pkt_addbool(1); /* want reply */
3550 ssh2_pkt_addstring(cfg.remote_cmd);
3551 } else {
3552 ssh2_pkt_addstring("shell");
3553 ssh2_pkt_addbool(1); /* want reply */
3554 }
7cca0d81 3555 ssh2_pkt_send();
d211621f 3556 do {
7cca0d81 3557 crWaitUntilV(ispkt);
d211621f 3558 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 3559 unsigned i = ssh2_pkt_getuint32();
3560 struct ssh_channel *c;
3561 c = find234(ssh_channels, &i, ssh_channelfind);
3562 if (!c)
3563 continue; /* nonexistent channel */
3564 c->v2.remwindow += ssh2_pkt_getuint32();
d211621f 3565 }
7cca0d81 3566 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3567 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3568 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 3569 bombout(("Server got confused by shell/command request"));
3570 crReturnV;
7cca0d81 3571 }
8d5de777 3572 bombout(("Server refused to start a shell/command"));
3573 crReturnV;
7cca0d81 3574 } else {
8d5de777 3575 logevent("Started a shell/command");
7cca0d81 3576 }
3577
6e48c3fe 3578 ssh_state = SSH_STATE_SESSION;
3579 if (size_needed)
3580 ssh_size();
3687d221 3581 if (eof_needed)
3582 ssh_special(TS_EOF);
6e48c3fe 3583
7cca0d81 3584 /*
3585 * Transfer data!
3586 */
0965bee0 3587 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 3588 ssh_send_ok = 1;
7cca0d81 3589 while (1) {
d211621f 3590 static int try_send;
e5574168 3591 crReturnV;
d211621f 3592 try_send = FALSE;
7cca0d81 3593 if (ispkt) {
3594 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
3595 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
3596 char *data;
3597 int length;
783415f8 3598 unsigned i = ssh2_pkt_getuint32();
3599 struct ssh_channel *c;
3600 c = find234(ssh_channels, &i, ssh_channelfind);
3601 if (!c)
3602 continue; /* nonexistent channel */
7cca0d81 3603 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
3604 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
3605 continue; /* extended but not stderr */
3606 ssh2_pkt_getstring(&data, &length);
d211621f 3607 if (data) {
783415f8 3608 switch (c->type) {
3609 case CHAN_MAINSESSION:
3610 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
3611 data, length);
3612 break;
3613 case CHAN_X11:
3614 x11_send(c->u.x11.s, data, length);
3615 break;
36c2a3e9 3616 case CHAN_AGENT:
3617 while (length > 0) {
3618 if (c->u.a.lensofar < 4) {
3619 int l = min(4 - c->u.a.lensofar, length);
3620 memcpy(c->u.a.msglen + c->u.a.lensofar, data, l);
3621 data += l; length -= l; c->u.a.lensofar += l;
3622 }
3623 if (c->u.a.lensofar == 4) {
3624 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
3625 c->u.a.message = smalloc(c->u.a.totallen);
3626 memcpy(c->u.a.message, c->u.a.msglen, 4);
3627 }
3628 if (c->u.a.lensofar >= 4 && length > 0) {
3629 int l = min(c->u.a.totallen - c->u.a.lensofar,
3630 length);
3631 memcpy(c->u.a.message + c->u.a.lensofar, data, l);
3632 data += l; length -= l; c->u.a.lensofar += l;
3633 }
3634 if (c->u.a.lensofar == c->u.a.totallen) {
3635 void *reply, *sentreply;
3636 int replylen;
3637 agent_query(c->u.a.message, c->u.a.totallen,
3638 &reply, &replylen);
3639 if (reply)
3640 sentreply = reply;
3641 else {
3642 /* Fake SSH_AGENT_FAILURE. */
3643 sentreply = "\0\0\0\1\5";
3644 replylen = 5;
3645 }
3646 ssh2_add_channel_data(c, sentreply, replylen);
3647 try_send = TRUE;
3648 if (reply)
3649 sfree(reply);
3650 sfree(c->u.a.message);
3651 c->u.a.lensofar = 0;
3652 }
3653 }
3654 break;
783415f8 3655 }
d211621f 3656 /*
783415f8 3657 * Enlarge the window again at the remote
3658 * side, just in case it ever runs down and
3659 * they fail to send us any more data.
d211621f 3660 */
3661 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
783415f8 3662 ssh2_pkt_adduint32(c->remoteid);
d211621f 3663 ssh2_pkt_adduint32(length);
3664 ssh2_pkt_send();
3665 }
7cca0d81 3666 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
3667 ssh_state = SSH_STATE_CLOSED;
d211621f 3668 logevent("Received disconnect message");
3257deae 3669 crReturnV;
7cca0d81 3670 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
3671 continue; /* exit status et al; ignore (FIXME?) */
d211621f 3672 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
783415f8 3673 unsigned i = ssh2_pkt_getuint32();
3674 struct ssh_channel *c;
3675
3676 c = find234(ssh_channels, &i, ssh_channelfind);
3677 if (!c)
3678 continue; /* nonexistent channel */
3679
3680 if (c->type == CHAN_X11) {
3681 /*
3682 * Remote EOF on an X11 channel means we should
3683 * wrap up and close the channel ourselves.
3684 */
3685 x11_close(c->u.x11.s);
3686 sshfwd_close(c);
36c2a3e9 3687 } else if (c->type == CHAN_AGENT) {
3688 sshfwd_close(c);
3689 }
d211621f 3690 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
783415f8 3691 unsigned i = ssh2_pkt_getuint32();
3692 struct ssh_channel *c;
3693 enum234 e;
3694
3695 c = find234(ssh_channels, &i, ssh_channelfind);
3696 if (!c)
3697 continue; /* nonexistent channel */
3698 if (c->closes == 0) {
3699 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3700 ssh2_pkt_adduint32(c->remoteid);
3701 ssh2_pkt_send();
3702 }
3703 /* Do pre-close processing on the channel. */
3704 switch (c->type) {
3705 case CHAN_MAINSESSION:
3706 break; /* nothing to see here, move along */
3707 case CHAN_X11:
3708 break;
36c2a3e9 3709 case CHAN_AGENT:
3710 break;
783415f8 3711 }
3712 del234(ssh_channels, c);
3713 sfree(c->v2.outbuffer);
3714 sfree(c);
3715
3716 /*
3717 * See if that was the last channel left open.
3718 */
3719 c = first234(ssh_channels, &e);
3720 if (!c) {
d211621f 3721 logevent("All channels closed. Disconnecting");
3722 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
9005f3ba 3723 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3724 ssh2_pkt_addstring("All open channels closed");
3725 ssh2_pkt_addstring("en"); /* language tag */
d211621f 3726 ssh2_pkt_send();
cf6e59d6 3727 ssh_state = SSH_STATE_CLOSED;
3257deae 3728 crReturnV;
d211621f 3729 }
3730 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 3731 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 3732 unsigned i = ssh2_pkt_getuint32();
3733 struct ssh_channel *c;
3734 c = find234(ssh_channels, &i, ssh_channelfind);
3735 if (!c)
3736 continue; /* nonexistent channel */
3737 mainchan->v2.remwindow += ssh2_pkt_getuint32();
d211621f 3738 try_send = TRUE;
783415f8 3739 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
3740 char *type;
3741 int typelen;
3742 char *error = NULL;
3743 struct ssh_channel *c;
3744 ssh2_pkt_getstring(&type, &typelen);
3745 c = smalloc(sizeof(struct ssh_channel));
3746
3747 if (typelen == 3 && !memcmp(type, "x11", 3)) {
783415f8 3748 if (!ssh_X11_fwd_enabled)
3749 error = "X11 forwarding is not enabled";
0c6c9a70 3750 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
783415f8 3751 error = "Unable to open an X11 connection";
3752 } else {
3753 c->type = CHAN_X11;
3754 }
36c2a3e9 3755 } else if (typelen == 22 &&
3756 !memcmp(type, "auth-agent@openssh.com", 3)) {
3757 if (!ssh_agentfwd_enabled)
3758 error = "Agent forwarding is not enabled";
3759 else {
3760 c->type = CHAN_AGENT; /* identify channel type */
3761 c->u.a.lensofar = 0;
3762 }
783415f8 3763 } else {
3764 error = "Unsupported channel type requested";
3765 }
3766
3767 c->remoteid = ssh2_pkt_getuint32();
3768 if (error) {
3769 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
3770 ssh2_pkt_adduint32(c->remoteid);
3771 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
3772 ssh2_pkt_addstring(error);
3773 ssh2_pkt_addstring("en"); /* language tag */
3774 ssh2_pkt_send();
3775 sfree(c);
3776 } else {
3777 struct ssh_channel *d;
3778 unsigned i;
3779 enum234 e;
3780
3781 for (i=1, d = first234(ssh_channels, &e); d;
3782 d = next234(&e)) {
3783 if (d->localid > i)
3784 break; /* found a free number */
3785 i = d->localid + 1;
3786 }
3787 c->localid = i;
3788 c->closes = 0;
3789 c->v2.remwindow = ssh2_pkt_getuint32();
3790 c->v2.remmaxpkt = ssh2_pkt_getuint32();
3791 c->v2.outbuffer = NULL;
3792 c->v2.outbuflen = c->v2.outbufsize = 0;
3793 add234(ssh_channels, c);
3794 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
3795 ssh2_pkt_adduint32(c->remoteid);
3796 ssh2_pkt_adduint32(c->localid);
3797 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3798 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3799 ssh2_pkt_send();
3800 }
7cca0d81 3801 } else {
8d5de777 3802 bombout(("Strange packet received: type %d", pktin.type));
3803 crReturnV;
7cca0d81 3804 }
3805 } else {
d211621f 3806 /*
3807 * We have spare data. Add it to the channel buffer.
3808 */
783415f8 3809 ssh2_add_channel_data(mainchan, in, inlen);
d211621f 3810 try_send = TRUE;
7cca0d81 3811 }
d211621f 3812 if (try_send) {
783415f8 3813 enum234 e;
3814 struct ssh_channel *c;
d211621f 3815 /*
783415f8 3816 * Try to send data on all channels if we can.
d211621f 3817 */
783415f8 3818 for (c = first234(ssh_channels, &e); c; c = next234(&e))
3819 ssh2_try_send(c);
d211621f 3820 }
e5574168 3821 }
3822
3823 crFinishV;
3824}
3825
3826/*
7cca0d81 3827 * Handle the top-level SSH2 protocol.
3828 */
3829static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
3830{
3831 if (do_ssh2_transport(in, inlen, ispkt) == 0)
3832 return;
3833 do_ssh2_authconn(in, inlen, ispkt);
3834}
3835
3836/*
8df7a775 3837 * Called to set up the connection.
374330e2 3838 *
3839 * Returns an error message, or NULL on success.
374330e2 3840 */
8df7a775 3841static char *ssh_init (char *host, int port, char **realhost) {
fb09bf1c 3842 char *p;
8f203108 3843
3844#ifdef MSCRYPTOAPI
3845 if(crypto_startup() == 0)
3846 return "Microsoft high encryption pack not installed!";
3847#endif
374330e2 3848
8df7a775 3849 ssh_send_ok = 0;
0965bee0 3850 ssh_editing = 0;
3851 ssh_echoing = 0;
8df7a775 3852
fb09bf1c 3853 p = connect_to_host(host, port, realhost);
3854 if (p != NULL)
3855 return p;
374330e2 3856
374330e2 3857 return NULL;
3858}
3859
3860/*
374330e2 3861 * Called to send data down the Telnet connection.
3862 */
3863static void ssh_send (char *buf, int len) {
f78051a1 3864 if (s == NULL || ssh_protocol == NULL)
374330e2 3865 return;
3866
3867 ssh_protocol(buf, len, 0);
3868}
3869
3870/*
6e48c3fe 3871 * Called to set the size of the window from SSH's POV.
374330e2 3872 */
3873static void ssh_size(void) {
3874 switch (ssh_state) {
3875 case SSH_STATE_BEFORE_SIZE:
3687d221 3876 case SSH_STATE_PREPACKET:
21248260 3877 case SSH_STATE_CLOSED:
374330e2 3878 break; /* do nothing */
3879 case SSH_STATE_INTERMED:
3880 size_needed = TRUE; /* buffer for later */
3881 break;
3882 case SSH_STATE_SESSION:
fef97f43 3883 if (!cfg.nopty) {
6e48c3fe 3884 if (ssh_version == 1) {
3885 send_packet(SSH1_CMSG_WINDOW_SIZE,
3886 PKT_INT, rows, PKT_INT, cols,
3887 PKT_INT, 0, PKT_INT, 0, PKT_END);
3888 } else {
3889 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3890 ssh2_pkt_adduint32(mainchan->remoteid);
3891 ssh2_pkt_addstring("window-change");
3892 ssh2_pkt_addbool(0);
3893 ssh2_pkt_adduint32(cols);
3894 ssh2_pkt_adduint32(rows);
3895 ssh2_pkt_adduint32(0);
3896 ssh2_pkt_adduint32(0);
3897 ssh2_pkt_send();
3898 }
fef97f43 3899 }
3687d221 3900 break;
374330e2 3901 }
3902}
3903
3904/*
6abbf9e3 3905 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3906 * can send an EOF and collect resulting output (e.g. `plink
3907 * hostname sort').
374330e2 3908 */
3909static void ssh_special (Telnet_Special code) {
6abbf9e3 3910 if (code == TS_EOF) {
3687d221 3911 if (ssh_state != SSH_STATE_SESSION) {
3912 /*
3913 * Buffer the EOF in case we are pre-SESSION, so we can
3914 * send it as soon as we reach SESSION.
3915 */
3916 if (code == TS_EOF)
3917 eof_needed = TRUE;
3918 return;
3919 }
67779be7 3920 if (ssh_version == 1) {
6abbf9e3 3921 send_packet(SSH1_CMSG_EOF, PKT_END);
3922 } else {
3923 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 3924 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 3925 ssh2_pkt_send();
3926 }
67779be7 3927 logevent("Sent EOF message");
ec55b220 3928 } else if (code == TS_PING) {
3687d221 3929 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3930 return;
ec55b220 3931 if (ssh_version == 1) {
3932 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3933 } else {
3934 ssh2_pkt_init(SSH2_MSG_IGNORE);
3935 ssh2_pkt_addstring_start();
3936 ssh2_pkt_send();
3937 }
6abbf9e3 3938 } else {
3939 /* do nothing */
3940 }
374330e2 3941}
3942
8df7a775 3943static Socket ssh_socket(void) { return s; }
8ccc75b0 3944
3945static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 3946
0965bee0 3947static int ssh_ldisc(int option) {
3948 if (option == LD_ECHO) return ssh_echoing;
3949 if (option == LD_EDIT) return ssh_editing;
3950 return FALSE;
3951}
3952
374330e2 3953Backend ssh_backend = {
3954 ssh_init,
374330e2 3955 ssh_send,
3956 ssh_size,
4017be6d 3957 ssh_special,
8ccc75b0 3958 ssh_socket,
97db3be4 3959 ssh_sendok,
0965bee0 3960 ssh_ldisc,
97db3be4 3961 22
374330e2 3962};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator