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From RDB: telnet can now start up in passive mode, in which it
[u/mdw/putty] / ssh.c
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8df7a775 1#include <windows.h>
374330e2 2#include <stdio.h>
3#include <stdlib.h>
fb09bf1c 4#include <stdarg.h>
5#include <assert.h>
374330e2 6
7#include "putty.h"
dacbd0e8 8#include "tree234.h"
fb09bf1c 9#include "ssh.h"
374330e2 10
11#ifndef FALSE
12#define FALSE 0
13#endif
14#ifndef TRUE
15#define TRUE 1
16#endif
17
765c4200 18/* uncomment this for packet level debugging */
19/* #define DUMP_PACKETS */
20
fb09bf1c 21#define logevent(s) { logevent(s); \
67779be7 22 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
b4453f49 23 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
fb09bf1c 24
3cd52910 25#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
4a8fc3c4 26 (s ? sk_close(s), s = NULL : 0), \
3cd52910 27 connection_fatal msg )
8d5de777 28
32874aea 29#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
30#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
31#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
32#define SSH1_CMSG_USER 4 /* 0x4 */
33#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
34#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
35#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
36#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
37#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
38#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
39#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
40#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
41#define SSH1_SMSG_SUCCESS 14 /* 0xe */
42#define SSH1_SMSG_FAILURE 15 /* 0xf */
43#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
44#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
45#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
46#define SSH1_CMSG_EOF 19 /* 0x13 */
47#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
48#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
49#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
50#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
51#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
52#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
53#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
54#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
55#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
56#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
57#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
58#define SSH1_MSG_IGNORE 32 /* 0x20 */
59#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
60#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
61#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
62#define SSH1_MSG_DEBUG 36 /* 0x24 */
63#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
64#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
65#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
66#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
67#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
68#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
69#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
70
71#define SSH1_AUTH_TIS 5 /* 0x5 */
72#define SSH1_AUTH_CCARD 16 /* 0x10 */
73
74#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 75/* Mask for protoflags we will echo back to server if seen */
32874aea 76#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
77
78#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
79#define SSH2_MSG_IGNORE 2 /* 0x2 */
80#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
81#define SSH2_MSG_DEBUG 4 /* 0x4 */
82#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
83#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
84#define SSH2_MSG_KEXINIT 20 /* 0x14 */
85#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
86#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
87#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
88#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
89#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
90#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
91#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
92#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
93#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
94#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
95#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
96#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
97#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
98#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
99#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
100#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
101#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
102#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
103#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
104#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
105#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
106#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
107#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
108#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
109#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
110#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
111#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
112
113#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
114#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
115#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
116#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
117#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
118#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
119#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
120#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
121#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
122#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
123#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
124#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
125#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
126#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
127#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 128
129static const char *const ssh2_disconnect_reasons[] = {
130 NULL,
131 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
132 "SSH_DISCONNECT_PROTOCOL_ERROR",
133 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
134 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
135 "SSH_DISCONNECT_MAC_ERROR",
136 "SSH_DISCONNECT_COMPRESSION_ERROR",
137 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
138 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
139 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
140 "SSH_DISCONNECT_CONNECTION_LOST",
141 "SSH_DISCONNECT_BY_APPLICATION",
142 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
143 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
144 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
145 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
146};
9005f3ba 147
32874aea 148#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
149#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
150#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
151#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 152
32874aea 153#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 154
7d503c31 155/*
156 * Various remote-bug flags.
157 */
158#define BUG_CHOKES_ON_SSH1_IGNORE 1
159#define BUG_SSH2_HMAC 2
160
fb09bf1c 161#define GET_32BIT(cp) \
162 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
163 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
164 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
165 ((unsigned long)(unsigned char)(cp)[3]))
166
167#define PUT_32BIT(cp, value) { \
168 (cp)[0] = (unsigned char)((value) >> 24); \
169 (cp)[1] = (unsigned char)((value) >> 16); \
170 (cp)[2] = (unsigned char)((value) >> 8); \
171 (cp)[3] = (unsigned char)(value); }
172
7cca0d81 173enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 174
374330e2 175/* Coroutine mechanics for the sillier bits of the code */
176#define crBegin1 static int crLine = 0;
177#define crBegin2 switch(crLine) { case 0:;
178#define crBegin crBegin1; crBegin2;
179#define crFinish(z) } crLine = 0; return (z)
180#define crFinishV } crLine = 0; return
181#define crReturn(z) \
182 do {\
183 crLine=__LINE__; return (z); case __LINE__:;\
184 } while (0)
185#define crReturnV \
186 do {\
187 crLine=__LINE__; return; case __LINE__:;\
188 } while (0)
189#define crStop(z) do{ crLine = 0; return (z); }while(0)
190#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 191#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 192#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 193
32874aea 194extern char *x11_init(Socket *, char *, void *);
195extern void x11_close(Socket);
196extern void x11_send(Socket, char *, int);
9c964e85 197extern void x11_invent_auth(char *, int, char *, int);
198
5e8358ad 199/*
200 * Ciphers for SSH2. We miss out single-DES because it isn't
201 * supported; also 3DES and Blowfish are both done differently from
202 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
203 * endianness and different-sized keys.)
5e8358ad 204 */
0a3f1d48 205const static struct ssh2_ciphers *ciphers[] = {
206 &ssh2_aes,
207 &ssh2_blowfish,
208 &ssh2_3des,
8479e33c 209};
e5574168 210
a92dd380 211const static struct ssh_kex *kex_algs[] = {
a92dd380 212 &ssh_diffiehellman_gex,
32874aea 213 &ssh_diffiehellman
214};
e5574168 215
85cc02bb 216const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 217
32874aea 218static void nullmac_key(unsigned char *key)
219{
220}
221static void nullmac_generate(unsigned char *blk, int len,
222 unsigned long seq)
223{
224}
225static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
226{
227 return 1;
228}
57476f6b 229const static struct ssh_mac ssh_mac_none = {
d39f364a 230 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 231};
8b2715b2 232const static struct ssh_mac *macs[] = {
32874aea 233 &ssh_sha1, &ssh_md5, &ssh_mac_none
234};
8b2715b2 235const static struct ssh_mac *buggymacs[] = {
32874aea 236 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
237};
e5574168 238
32874aea 239static void ssh_comp_none_init(void)
240{
241}
4ba9b64b 242static int ssh_comp_none_block(unsigned char *block, int len,
32874aea 243 unsigned char **outblock, int *outlen)
244{
245 return 0;
246}
247static int ssh_comp_none_disable(void)
248{
4ba9b64b 249 return 0;
250}
57476f6b 251const static struct ssh_compress ssh_comp_none = {
4ba9b64b 252 "none",
253 ssh_comp_none_init, ssh_comp_none_block,
63b00c83 254 ssh_comp_none_init, ssh_comp_none_block,
255 ssh_comp_none_disable
e5574168 256};
4ba9b64b 257extern const struct ssh_compress ssh_zlib;
258const static struct ssh_compress *compressions[] = {
32874aea 259 &ssh_zlib, &ssh_comp_none
260};
374330e2 261
32874aea 262enum { /* channel types */
783415f8 263 CHAN_MAINSESSION,
264 CHAN_X11,
265 CHAN_AGENT,
266};
267
dacbd0e8 268/*
269 * 2-3-4 tree storing channels.
270 */
271struct ssh_channel {
d211621f 272 unsigned remoteid, localid;
dacbd0e8 273 int type;
274 int closes;
783415f8 275 struct ssh2_data_channel {
32874aea 276 unsigned char *outbuffer;
277 unsigned outbuflen, outbufsize;
278 unsigned remwindow, remmaxpkt;
783415f8 279 } v2;
dacbd0e8 280 union {
32874aea 281 struct ssh_agent_channel {
282 unsigned char *message;
283 unsigned char msglen[4];
284 int lensofar, totallen;
285 } a;
286 struct ssh_x11_channel {
287 Socket s;
288 } x11;
dacbd0e8 289 } u;
290};
57476f6b 291
292struct Packet {
293 long length;
294 int type;
295 unsigned char *data;
296 unsigned char *body;
297 long savedpos;
298 long maxlen;
299};
300
0db56f73 301static SHA_State exhash, exhashbase;
57476f6b 302
8df7a775 303static Socket s = NULL;
57476f6b 304
305static unsigned char session_key[32];
4ba9b64b 306static int ssh1_compressing;
b96dc54c 307static int ssh1_remote_protoflags;
308static int ssh1_local_protoflags;
db7d555c 309static int ssh_agentfwd_enabled;
9c964e85 310static int ssh_X11_fwd_enabled;
7d503c31 311static int ssh_remote_bugs;
57476f6b 312static const struct ssh_cipher *cipher = NULL;
0a3f1d48 313static const struct ssh2_cipher *cscipher = NULL;
314static const struct ssh2_cipher *sccipher = NULL;
57476f6b 315static const struct ssh_mac *csmac = NULL;
316static const struct ssh_mac *scmac = NULL;
317static const struct ssh_compress *cscomp = NULL;
318static const struct ssh_compress *sccomp = NULL;
319static const struct ssh_kex *kex = NULL;
e055a386 320static const struct ssh_signkey *hostkey = NULL;
65a22376 321static unsigned char ssh2_session_id[20];
32874aea 322int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
323 int is_pw) = NULL;
57476f6b 324
325static char *savedhost;
326static int savedport;
327static int ssh_send_ok;
0965bee0 328static int ssh_echoing, ssh_editing;
57476f6b 329
32874aea 330static tree234 *ssh_channels; /* indexed by local id */
57476f6b 331static struct ssh_channel *mainchan; /* primary session channel */
332
333static enum {
3687d221 334 SSH_STATE_PREPACKET,
57476f6b 335 SSH_STATE_BEFORE_SIZE,
336 SSH_STATE_INTERMED,
337 SSH_STATE_SESSION,
338 SSH_STATE_CLOSED
3687d221 339} ssh_state = SSH_STATE_PREPACKET;
57476f6b 340
3687d221 341static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 342
343static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
344static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
b185170a 345static unsigned char *deferred_send_data = NULL;
346static int deferred_len = 0, deferred_size = 0;
57476f6b 347
348static int ssh_version;
32874aea 349static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
57476f6b 350static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
351static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
352static void ssh_size(void);
32874aea 353static void ssh_special(Telnet_Special);
783415f8 354static void ssh2_try_send(struct ssh_channel *c);
32874aea 355static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
356 int len);
57476f6b 357
32874aea 358static int (*s_rdpkt) (unsigned char **data, int *datalen);
57476f6b 359
360static struct rdpkt1_state_tag {
361 long len, pad, biglen, to_read;
362 unsigned long realcrc, gotcrc;
363 unsigned char *p;
364 int i;
365 int chunk;
366} rdpkt1_state;
367
960e736a 368static struct rdpkt2_state_tag {
369 long len, pad, payload, packetlen, maclen;
370 int i;
371 int cipherblk;
372 unsigned long incoming_sequence;
373} rdpkt2_state;
374
32874aea 375static int ssh_channelcmp(void *av, void *bv)
376{
377 struct ssh_channel *a = (struct ssh_channel *) av;
378 struct ssh_channel *b = (struct ssh_channel *) bv;
379 if (a->localid < b->localid)
380 return -1;
381 if (a->localid > b->localid)
382 return +1;
dacbd0e8 383 return 0;
384}
32874aea 385static int ssh_channelfind(void *av, void *bv)
386{
387 unsigned *a = (unsigned *) av;
388 struct ssh_channel *b = (struct ssh_channel *) bv;
389 if (*a < b->localid)
390 return -1;
391 if (*a > b->localid)
392 return +1;
dacbd0e8 393 return 0;
394}
395
32874aea 396static int alloc_channel_id(void)
397{
260f3dec 398 const unsigned CHANNEL_NUMBER_OFFSET = 256;
399 unsigned low, high, mid;
d2371c81 400 int tsize;
401 struct ssh_channel *c;
402
403 /*
404 * First-fit allocation of channel numbers: always pick the
405 * lowest unused one. To do this, binary-search using the
406 * counted B-tree to find the largest channel ID which is in a
407 * contiguous sequence from the beginning. (Precisely
408 * everything in that sequence must have ID equal to its tree
409 * index plus CHANNEL_NUMBER_OFFSET.)
410 */
411 tsize = count234(ssh_channels);
412
32874aea 413 low = -1;
414 high = tsize;
d2371c81 415 while (high - low > 1) {
416 mid = (high + low) / 2;
417 c = index234(ssh_channels, mid);
418 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
419 low = mid; /* this one is fine */
420 else
421 high = mid; /* this one is past it */
422 }
423 /*
424 * Now low points to either -1, or the tree index of the
425 * largest ID in the initial sequence.
426 */
427 {
428 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
429 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
430 }
431 return low + 1 + CHANNEL_NUMBER_OFFSET;
432}
433
32874aea 434static void c_write(char *buf, int len)
435{
67779be7 436 if ((flags & FLAG_STDERR)) {
32874aea 437 int i;
438 for (i = 0; i < len; i++)
439 if (buf[i] != '\r')
440 fputc(buf[i], stderr);
fb09bf1c 441 return;
442 }
fe50e814 443 from_backend(1, buf, len);
3bdaf79d 444}
445
32874aea 446static void c_write_untrusted(char *buf, int len)
447{
a209e957 448 int i;
449 for (i = 0; i < len; i++) {
32874aea 450 if (buf[i] == '\n')
451 c_write("\r\n", 2);
452 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
453 c_write(buf + i, 1);
a209e957 454 }
455}
456
32874aea 457static void c_write_str(char *buf)
458{
1408a877 459 c_write(buf, strlen(buf));
460}
461
fb09bf1c 462/*
463 * Collect incoming data in the incoming packet buffer.
e5574168 464 * Decipher and verify the packet when it is completely read.
465 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 466 * Update the *data and *datalen variables.
467 * Return the additional nr of bytes needed, or 0 when
468 * a complete packet is available.
469 */
e5574168 470static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 471{
57476f6b 472 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 473
474 crBegin;
374330e2 475
32874aea 476 next_packet:
37508af4 477
fb09bf1c 478 pktin.type = 0;
479 pktin.length = 0;
374330e2 480
57476f6b 481 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 482 while ((*datalen) == 0)
32874aea 483 crReturn(4 - st->i);
57476f6b 484 st->len = (st->len << 8) + **data;
fb09bf1c 485 (*data)++, (*datalen)--;
486 }
374330e2 487
fb09bf1c 488#ifdef FWHACK
32874aea 489 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
490 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 491 }
492#endif
374330e2 493
57476f6b 494 st->pad = 8 - (st->len % 8);
495 st->biglen = st->len + st->pad;
496 pktin.length = st->len - 5;
fb09bf1c 497
57476f6b 498 if (pktin.maxlen < st->biglen) {
499 pktin.maxlen = st->biglen;
32874aea 500 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
501 srealloc(pktin.data, st->biglen + APIEXTRA));
fb09bf1c 502 if (!pktin.data)
503 fatalbox("Out of memory");
504 }
374330e2 505
57476f6b 506 st->to_read = st->biglen;
507 st->p = pktin.data;
508 while (st->to_read > 0) {
32874aea 509 st->chunk = st->to_read;
fb09bf1c 510 while ((*datalen) == 0)
57476f6b 511 crReturn(st->to_read);
512 if (st->chunk > (*datalen))
513 st->chunk = (*datalen);
514 memcpy(st->p, *data, st->chunk);
515 *data += st->chunk;
516 *datalen -= st->chunk;
517 st->p += st->chunk;
518 st->to_read -= st->chunk;
fb09bf1c 519 }
374330e2 520
fb09bf1c 521 if (cipher)
57476f6b 522 cipher->decrypt(pktin.data, st->biglen);
765c4200 523#ifdef DUMP_PACKETS
524 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
525 dmemdump(pktin.data, st->biglen);
698a5108 526#endif
374330e2 527
32874aea 528 st->realcrc = crc32(pktin.data, st->biglen - 4);
529 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
57476f6b 530 if (st->gotcrc != st->realcrc) {
8d5de777 531 bombout(("Incorrect CRC received on packet"));
32874aea 532 crReturn(0);
fb09bf1c 533 }
572f871e 534
4ba9b64b 535 pktin.body = pktin.data + st->pad + 1;
536
537 if (ssh1_compressing) {
538 unsigned char *decompblk;
539 int decomplen;
765c4200 540#ifdef DUMP_PACKETS
541 debug(("Packet payload pre-decompression:\n"));
32874aea 542 dmemdump(pktin.body - 1, pktin.length + 1);
4ba9b64b 543#endif
32874aea 544 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
4ba9b64b 545 &decompblk, &decomplen);
546
547 if (pktin.maxlen < st->pad + decomplen) {
548 pktin.maxlen = st->pad + decomplen;
32874aea 549 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
550 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 551 if (!pktin.data)
552 fatalbox("Out of memory");
553 }
554
32874aea 555 memcpy(pktin.body - 1, decompblk, decomplen);
dcbde236 556 sfree(decompblk);
32874aea 557 pktin.length = decomplen - 1;
765c4200 558#ifdef DUMP_PACKETS
559 debug(("Packet payload post-decompression:\n"));
32874aea 560 dmemdump(pktin.body - 1, pktin.length + 1);
4ba9b64b 561#endif
562 }
563
e5574168 564 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 565 pktin.type == SSH1_SMSG_STDERR_DATA ||
566 pktin.type == SSH1_MSG_DEBUG ||
567 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
568 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 569 long strlen = GET_32BIT(pktin.body);
8d5de777 570 if (strlen + 4 != pktin.length) {
571 bombout(("Received data packet with bogus string length"));
32874aea 572 crReturn(0);
573 }
fb09bf1c 574 }
575
4ba9b64b 576 pktin.type = pktin.body[-1];
577
e5574168 578 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 579 /* log debug message */
580 char buf[80];
581 int strlen = GET_32BIT(pktin.body);
582 strcpy(buf, "Remote: ");
32874aea 583 if (strlen > 70)
584 strlen = 70;
585 memcpy(buf + 8, pktin.body + 4, strlen);
586 buf[8 + strlen] = '\0';
fb09bf1c 587 logevent(buf);
588 goto next_packet;
e5574168 589 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 590 /* do nothing */
591 goto next_packet;
592 }
593
38c4a8da 594 if (pktin.type == SSH1_MSG_DISCONNECT) {
595 /* log reason code in disconnect message */
596 char buf[256];
260f3dec 597 unsigned msglen = GET_32BIT(pktin.body);
598 unsigned nowlen;
38c4a8da 599 strcpy(buf, "Remote sent disconnect: ");
600 nowlen = strlen(buf);
32874aea 601 if (msglen > sizeof(buf) - nowlen - 1)
602 msglen = sizeof(buf) - nowlen - 1;
603 memcpy(buf + nowlen, pktin.body + 4, msglen);
604 buf[nowlen + msglen] = '\0';
38c4a8da 605 logevent(buf);
606 }
607
fb09bf1c 608 crFinish(0);
609}
610
e5574168 611static int ssh2_rdpkt(unsigned char **data, int *datalen)
612{
960e736a 613 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 614
615 crBegin;
616
32874aea 617 next_packet:
e5574168 618 pktin.type = 0;
619 pktin.length = 0;
960e736a 620 if (sccipher)
32874aea 621 st->cipherblk = sccipher->blksize;
e5574168 622 else
32874aea 623 st->cipherblk = 8;
960e736a 624 if (st->cipherblk < 8)
32874aea 625 st->cipherblk = 8;
960e736a 626
627 if (pktin.maxlen < st->cipherblk) {
628 pktin.maxlen = st->cipherblk;
32874aea 629 pktin.data =
630 (pktin.data ==
631 NULL ? smalloc(st->cipherblk +
632 APIEXTRA) : srealloc(pktin.data,
633 st->cipherblk +
634 APIEXTRA));
e5574168 635 if (!pktin.data)
636 fatalbox("Out of memory");
637 }
638
639 /*
640 * Acquire and decrypt the first block of the packet. This will
641 * contain the length and padding details.
642 */
32874aea 643 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 644 while ((*datalen) == 0)
32874aea 645 crReturn(st->cipherblk - st->i);
960e736a 646 pktin.data[st->i] = *(*data)++;
32874aea 647 (*datalen)--;
e5574168 648 }
649#ifdef FWHACK
32874aea 650 if (!memcmp(pktin.data, "Remo", 4)) { /* "Remo"te server has closed ... */
651 /* FIXME */
e5574168 652 }
653#endif
654 if (sccipher)
32874aea 655 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 656
657 /*
658 * Now get the length and padding figures.
659 */
960e736a 660 st->len = GET_32BIT(pktin.data);
661 st->pad = pktin.data[4];
e5574168 662
663 /*
664 * This enables us to deduce the payload length.
665 */
960e736a 666 st->payload = st->len - st->pad - 1;
e5574168 667
960e736a 668 pktin.length = st->payload + 5;
e5574168 669
670 /*
671 * So now we can work out the total packet length.
672 */
960e736a 673 st->packetlen = st->len + 4;
674 st->maclen = scmac ? scmac->len : 0;
e5574168 675
676 /*
677 * Adjust memory allocation if packet is too big.
678 */
32874aea 679 if (pktin.maxlen < st->packetlen + st->maclen) {
680 pktin.maxlen = st->packetlen + st->maclen;
681 pktin.data =
682 (pktin.data ==
683 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
684 pktin.maxlen
685 +
686 APIEXTRA));
e5574168 687 if (!pktin.data)
688 fatalbox("Out of memory");
689 }
690
691 /*
692 * Read and decrypt the remainder of the packet.
693 */
32874aea 694 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
695 st->i++) {
e5574168 696 while ((*datalen) == 0)
960e736a 697 crReturn(st->packetlen + st->maclen - st->i);
698 pktin.data[st->i] = *(*data)++;
32874aea 699 (*datalen)--;
e5574168 700 }
701 /* Decrypt everything _except_ the MAC. */
702 if (sccipher)
32874aea 703 sccipher->decrypt(pktin.data + st->cipherblk,
704 st->packetlen - st->cipherblk);
e5574168 705
765c4200 706#ifdef DUMP_PACKETS
707 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
708 dmemdump(pktin.data, st->packetlen);
7cca0d81 709#endif
d39f364a 710
e5574168 711 /*
712 * Check the MAC.
713 */
32874aea 714 if (scmac
715 && !scmac->verify(pktin.data, st->len + 4,
716 st->incoming_sequence)) {
8d5de777 717 bombout(("Incorrect MAC received on packet"));
32874aea 718 crReturn(0);
8d5de777 719 }
32874aea 720 st->incoming_sequence++; /* whether or not we MACed */
e5574168 721
4ba9b64b 722 /*
723 * Decompress packet payload.
724 */
725 {
726 unsigned char *newpayload;
727 int newlen;
32874aea 728 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
4ba9b64b 729 &newpayload, &newlen)) {
32874aea 730 if (pktin.maxlen < newlen + 5) {
731 pktin.maxlen = newlen + 5;
732 pktin.data =
733 (pktin.data ==
734 NULL ? smalloc(pktin.maxlen +
735 APIEXTRA) : srealloc(pktin.data,
736 pktin.maxlen +
737 APIEXTRA));
4ba9b64b 738 if (!pktin.data)
739 fatalbox("Out of memory");
740 }
741 pktin.length = 5 + newlen;
32874aea 742 memcpy(pktin.data + 5, newpayload, newlen);
765c4200 743#ifdef DUMP_PACKETS
744 debug(("Post-decompression payload:\n"));
32874aea 745 dmemdump(pktin.data + 5, newlen);
4ba9b64b 746#endif
747
dcbde236 748 sfree(newpayload);
4ba9b64b 749 }
750 }
751
e5574168 752 pktin.savedpos = 6;
753 pktin.type = pktin.data[5];
e5574168 754
7cca0d81 755 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
32874aea 756 goto next_packet; /* FIXME: print DEBUG message */
e5574168 757
38c4a8da 758 if (pktin.type == SSH2_MSG_DISCONNECT) {
759 /* log reason code in disconnect message */
760 char buf[256];
32874aea 761 int reason = GET_32BIT(pktin.data + 6);
762 unsigned msglen = GET_32BIT(pktin.data + 10);
260f3dec 763 unsigned nowlen;
38c4a8da 764 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
765 sprintf(buf, "Received disconnect message (%s)",
766 ssh2_disconnect_reasons[reason]);
767 } else {
32874aea 768 sprintf(buf, "Received disconnect message (unknown type %d)",
769 reason);
38c4a8da 770 }
771 logevent(buf);
772 strcpy(buf, "Disconnection message text: ");
773 nowlen = strlen(buf);
32874aea 774 if (msglen > sizeof(buf) - nowlen - 1)
775 msglen = sizeof(buf) - nowlen - 1;
776 memcpy(buf + nowlen, pktin.data + 14, msglen);
777 buf[nowlen + msglen] = '\0';
38c4a8da 778 logevent(buf);
779 }
780
e5574168 781 crFinish(0);
782}
783
32874aea 784static void ssh1_pktout_size(int len)
785{
374330e2 786 int pad, biglen;
787
788 len += 5; /* type and CRC */
32874aea 789 pad = 8 - (len % 8);
374330e2 790 biglen = len + pad;
791
32874aea 792 pktout.length = len - 5;
374330e2 793 if (pktout.maxlen < biglen) {
794 pktout.maxlen = biglen;
8f203108 795#ifdef MSCRYPTOAPI
fb09bf1c 796 /* Allocate enough buffer space for extra block
8f203108 797 * for MS CryptEncrypt() */
32874aea 798 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
799 srealloc(pktout.data, biglen + 12));
8f203108 800#else
32874aea 801 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
802 srealloc(pktout.data, biglen + 4));
8f203108 803#endif
374330e2 804 if (!pktout.data)
805 fatalbox("Out of memory");
806 }
32874aea 807 pktout.body = pktout.data + 4 + pad + 1;
4ba9b64b 808}
374330e2 809
32874aea 810static void s_wrpkt_start(int type, int len)
811{
4ba9b64b 812 ssh1_pktout_size(len);
374330e2 813 pktout.type = type;
374330e2 814}
815
32874aea 816static int s_wrpkt_prepare(void)
817{
374330e2 818 int pad, len, biglen, i;
819 unsigned long crc;
820
4ba9b64b 821 pktout.body[-1] = pktout.type;
822
765c4200 823#ifdef DUMP_PACKETS
7d503c31 824 debug(("Packet payload pre-compression:\n"));
32874aea 825 dmemdump(pktout.body - 1, pktout.length + 1);
7d503c31 826#endif
827
4ba9b64b 828 if (ssh1_compressing) {
829 unsigned char *compblk;
830 int complen;
32874aea 831 zlib_compress_block(pktout.body - 1, pktout.length + 1,
4ba9b64b 832 &compblk, &complen);
32874aea 833 ssh1_pktout_size(complen - 1);
834 memcpy(pktout.body - 1, compblk, complen);
dcbde236 835 sfree(compblk);
765c4200 836#ifdef DUMP_PACKETS
4ba9b64b 837 debug(("Packet payload post-compression:\n"));
32874aea 838 dmemdump(pktout.body - 1, pktout.length + 1);
4ba9b64b 839#endif
840 }
841
374330e2 842 len = pktout.length + 5; /* type and CRC */
32874aea 843 pad = 8 - (len % 8);
374330e2 844 biglen = len + pad;
845
32874aea 846 for (i = 0; i < pad; i++)
847 pktout.data[i + 4] = random_byte();
848 crc = crc32(pktout.data + 4, biglen - 4);
849 PUT_32BIT(pktout.data + biglen, crc);
fb09bf1c 850 PUT_32BIT(pktout.data, len);
374330e2 851
765c4200 852#ifdef DUMP_PACKETS
32874aea 853 debug(("Sending packet len=%d\n", biglen + 4));
854 dmemdump(pktout.data, biglen + 4);
698a5108 855#endif
374330e2 856 if (cipher)
32874aea 857 cipher->encrypt(pktout.data + 4, biglen);
374330e2 858
32874aea 859 return biglen + 4;
39065bed 860}
861
32874aea 862static void s_wrpkt(void)
863{
39065bed 864 int len;
865 len = s_wrpkt_prepare();
866 sk_write(s, pktout.data, len);
867}
868
32874aea 869static void s_wrpkt_defer(void)
870{
39065bed 871 int len;
872 len = s_wrpkt_prepare();
873 if (deferred_len + len > deferred_size) {
32874aea 874 deferred_size = deferred_len + len + 128;
875 deferred_send_data = srealloc(deferred_send_data, deferred_size);
39065bed 876 }
32874aea 877 memcpy(deferred_send_data + deferred_len, pktout.data, len);
39065bed 878 deferred_len += len;
374330e2 879}
880
fb09bf1c 881/*
39065bed 882 * Construct a packet with the specified contents.
fb09bf1c 883 */
39065bed 884static void construct_packet(int pkttype, va_list ap1, va_list ap2)
fb09bf1c 885{
fb09bf1c 886 unsigned char *p, *argp, argchar;
887 unsigned long argint;
888 int pktlen, argtype, arglen;
7cca0d81 889 Bignum bn;
fb09bf1c 890
891 pktlen = 0;
39065bed 892 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 893 switch (argtype) {
894 case PKT_INT:
39065bed 895 (void) va_arg(ap1, int);
fb09bf1c 896 pktlen += 4;
897 break;
898 case PKT_CHAR:
39065bed 899 (void) va_arg(ap1, char);
fb09bf1c 900 pktlen++;
901 break;
902 case PKT_DATA:
39065bed 903 (void) va_arg(ap1, unsigned char *);
904 arglen = va_arg(ap1, int);
fb09bf1c 905 pktlen += arglen;
906 break;
907 case PKT_STR:
39065bed 908 argp = va_arg(ap1, unsigned char *);
fb09bf1c 909 arglen = strlen(argp);
910 pktlen += 4 + arglen;
911 break;
7cca0d81 912 case PKT_BIGNUM:
39065bed 913 bn = va_arg(ap1, Bignum);
32874aea 914 pktlen += ssh1_bignum_length(bn);
7cca0d81 915 break;
fb09bf1c 916 default:
917 assert(0);
918 }
919 }
fb09bf1c 920
921 s_wrpkt_start(pkttype, pktlen);
922 p = pktout.body;
923
39065bed 924 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 925 switch (argtype) {
926 case PKT_INT:
39065bed 927 argint = va_arg(ap2, int);
fb09bf1c 928 PUT_32BIT(p, argint);
929 p += 4;
930 break;
931 case PKT_CHAR:
39065bed 932 argchar = va_arg(ap2, unsigned char);
fb09bf1c 933 *p = argchar;
934 p++;
935 break;
936 case PKT_DATA:
39065bed 937 argp = va_arg(ap2, unsigned char *);
938 arglen = va_arg(ap2, int);
fb09bf1c 939 memcpy(p, argp, arglen);
940 p += arglen;
941 break;
942 case PKT_STR:
39065bed 943 argp = va_arg(ap2, unsigned char *);
fb09bf1c 944 arglen = strlen(argp);
945 PUT_32BIT(p, arglen);
946 memcpy(p + 4, argp, arglen);
947 p += 4 + arglen;
948 break;
7cca0d81 949 case PKT_BIGNUM:
39065bed 950 bn = va_arg(ap2, Bignum);
32874aea 951 p += ssh1_write_bignum(p, bn);
7cca0d81 952 break;
fb09bf1c 953 }
954 }
39065bed 955}
fb09bf1c 956
32874aea 957static void send_packet(int pkttype, ...)
958{
39065bed 959 va_list ap1, ap2;
960 va_start(ap1, pkttype);
961 va_start(ap2, pkttype);
962 construct_packet(pkttype, ap1, ap2);
fb09bf1c 963 s_wrpkt();
964}
965
32874aea 966static void defer_packet(int pkttype, ...)
967{
39065bed 968 va_list ap1, ap2;
969 va_start(ap1, pkttype);
970 va_start(ap2, pkttype);
971 construct_packet(pkttype, ap1, ap2);
972 s_wrpkt_defer();
973}
974
32874aea 975static int ssh_versioncmp(char *a, char *b)
976{
9697bfd2 977 char *ae, *be;
978 unsigned long av, bv;
979
43aa02a7 980 av = strtoul(a, &ae, 10);
981 bv = strtoul(b, &be, 10);
32874aea 982 if (av != bv)
983 return (av < bv ? -1 : +1);
984 if (*ae == '.')
985 ae++;
986 if (*be == '.')
987 be++;
43aa02a7 988 av = strtoul(ae, &ae, 10);
989 bv = strtoul(be, &be, 10);
32874aea 990 if (av != bv)
991 return (av < bv ? -1 : +1);
9697bfd2 992 return 0;
993}
994
e5574168 995
996/*
a92dd380 997 * Utility routines for putting an SSH-protocol `string' and
998 * `uint32' into a SHA state.
e5574168 999 */
1000#include <stdio.h>
32874aea 1001static void sha_string(SHA_State * s, void *str, int len)
1002{
e5574168 1003 unsigned char lenblk[4];
e5574168 1004 PUT_32BIT(lenblk, len);
e5574168 1005 SHA_Bytes(s, lenblk, 4);
e5574168 1006 SHA_Bytes(s, str, len);
1007}
1008
32874aea 1009static void sha_uint32(SHA_State * s, unsigned i)
1010{
a92dd380 1011 unsigned char intblk[4];
1012 PUT_32BIT(intblk, i);
1013 SHA_Bytes(s, intblk, 4);
1014}
1015
7cca0d81 1016/*
1017 * SSH2 packet construction functions.
1018 */
32874aea 1019static void ssh2_pkt_ensure(int length)
1020{
783415f8 1021 if (pktout.maxlen < length) {
32874aea 1022 pktout.maxlen = length + 256;
1023 pktout.data =
1024 (pktout.data ==
1025 NULL ? smalloc(pktout.maxlen +
1026 APIEXTRA) : srealloc(pktout.data,
1027 pktout.maxlen +
1028 APIEXTRA));
1029 if (!pktout.data)
1030 fatalbox("Out of memory");
7cca0d81 1031 }
783415f8 1032}
32874aea 1033static void ssh2_pkt_adddata(void *data, int len)
1034{
783415f8 1035 pktout.length += len;
1036 ssh2_pkt_ensure(pktout.length);
32874aea 1037 memcpy(pktout.data + pktout.length - len, data, len);
7cca0d81 1038}
32874aea 1039static void ssh2_pkt_addbyte(unsigned char byte)
1040{
7cca0d81 1041 ssh2_pkt_adddata(&byte, 1);
1042}
32874aea 1043static void ssh2_pkt_init(int pkt_type)
1044{
7cca0d81 1045 pktout.length = 5;
32874aea 1046 ssh2_pkt_addbyte((unsigned char) pkt_type);
7cca0d81 1047}
32874aea 1048static void ssh2_pkt_addbool(unsigned char value)
1049{
7cca0d81 1050 ssh2_pkt_adddata(&value, 1);
1051}
32874aea 1052static void ssh2_pkt_adduint32(unsigned long value)
1053{
7cca0d81 1054 unsigned char x[4];
1055 PUT_32BIT(x, value);
1056 ssh2_pkt_adddata(x, 4);
1057}
32874aea 1058static void ssh2_pkt_addstring_start(void)
1059{
7cca0d81 1060 ssh2_pkt_adduint32(0);
1061 pktout.savedpos = pktout.length;
1062}
32874aea 1063static void ssh2_pkt_addstring_str(char *data)
1064{
7cca0d81 1065 ssh2_pkt_adddata(data, strlen(data));
1066 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1067 pktout.length - pktout.savedpos);
7cca0d81 1068}
32874aea 1069static void ssh2_pkt_addstring_data(char *data, int len)
1070{
7cca0d81 1071 ssh2_pkt_adddata(data, len);
1072 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1073 pktout.length - pktout.savedpos);
7cca0d81 1074}
32874aea 1075static void ssh2_pkt_addstring(char *data)
1076{
7cca0d81 1077 ssh2_pkt_addstring_start();
1078 ssh2_pkt_addstring_str(data);
1079}
32874aea 1080static char *ssh2_mpint_fmt(Bignum b, int *len)
1081{
7cca0d81 1082 unsigned char *p;
32874aea 1083 int i, n = (bignum_bitcount(b) + 7) / 8;
3709bfe9 1084 p = smalloc(n + 1);
7cca0d81 1085 if (!p)
32874aea 1086 fatalbox("out of memory");
7cca0d81 1087 p[0] = 0;
3709bfe9 1088 for (i = 1; i <= n; i++)
32874aea 1089 p[i] = bignum_byte(b, n - i);
7cca0d81 1090 i = 0;
32874aea 1091 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1092 i++;
1093 memmove(p, p + i, n + 1 - i);
1094 *len = n + 1 - i;
7cca0d81 1095 return p;
1096}
32874aea 1097static void ssh2_pkt_addmp(Bignum b)
1098{
7cca0d81 1099 unsigned char *p;
1100 int len;
1101 p = ssh2_mpint_fmt(b, &len);
1102 ssh2_pkt_addstring_start();
1103 ssh2_pkt_addstring_data(p, len);
dcbde236 1104 sfree(p);
7cca0d81 1105}
b185170a 1106
1107/*
1108 * Construct an SSH2 final-form packet: compress it, encrypt it,
1109 * put the MAC on it. Final packet, ready to be sent, is stored in
1110 * pktout.data. Total length is returned.
1111 */
32874aea 1112static int ssh2_pkt_construct(void)
1113{
7cca0d81 1114 int cipherblk, maclen, padding, i;
1115 static unsigned long outgoing_sequence = 0;
1116
1117 /*
4ba9b64b 1118 * Compress packet payload.
1119 */
765c4200 1120#ifdef DUMP_PACKETS
1121 debug(("Pre-compression payload:\n"));
32874aea 1122 dmemdump(pktout.data + 5, pktout.length - 5);
4ba9b64b 1123#endif
1124 {
1125 unsigned char *newpayload;
1126 int newlen;
32874aea 1127 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
4ba9b64b 1128 &newpayload, &newlen)) {
1129 pktout.length = 5;
1130 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 1131 sfree(newpayload);
4ba9b64b 1132 }
1133 }
1134
1135 /*
7cca0d81 1136 * Add padding. At least four bytes, and must also bring total
1137 * length (minus MAC) up to a multiple of the block size.
1138 */
32874aea 1139 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1140 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1141 padding = 4;
32874aea 1142 padding +=
1143 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 1144 maclen = csmac ? csmac->len : 0;
1145 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 1146 pktout.data[4] = padding;
1147 for (i = 0; i < padding; i++)
32874aea 1148 pktout.data[pktout.length + i] = random_byte();
7cca0d81 1149 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1150 if (csmac)
32874aea 1151 csmac->generate(pktout.data, pktout.length + padding,
1152 outgoing_sequence);
1153 outgoing_sequence++; /* whether or not we MACed */
7cca0d81 1154
765c4200 1155#ifdef DUMP_PACKETS
32874aea 1156 debug(("Sending packet len=%d\n", pktout.length + padding));
1157 dmemdump(pktout.data, pktout.length + padding);
7cca0d81 1158#endif
1159
1160 if (cscipher)
32874aea 1161 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 1162
b185170a 1163 /* Ready-to-send packet starts at pktout.data. We return length. */
1164 return pktout.length + padding + maclen;
1165}
1166
1167/*
1168 * Construct and send an SSH2 packet immediately.
1169 */
32874aea 1170static void ssh2_pkt_send(void)
1171{
b185170a 1172 int len = ssh2_pkt_construct();
1173 sk_write(s, pktout.data, len);
1174}
1175
1176/*
1177 * Construct an SSH2 packet and add it to a deferred data block.
1178 * Useful for sending multiple packets in a single sk_write() call,
1179 * to prevent a traffic-analysing listener from being able to work
1180 * out the length of any particular packet (such as the password
1181 * packet).
1182 *
1183 * Note that because SSH2 sequence-numbers its packets, this can
1184 * NOT be used as an m4-style `defer' allowing packets to be
1185 * constructed in one order and sent in another.
1186 */
32874aea 1187static void ssh2_pkt_defer(void)
1188{
b185170a 1189 int len = ssh2_pkt_construct();
1190 if (deferred_len + len > deferred_size) {
32874aea 1191 deferred_size = deferred_len + len + 128;
1192 deferred_send_data = srealloc(deferred_send_data, deferred_size);
b185170a 1193 }
32874aea 1194 memcpy(deferred_send_data + deferred_len, pktout.data, len);
b185170a 1195 deferred_len += len;
1196}
1197
1198/*
1199 * Send the whole deferred data block constructed by
39065bed 1200 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1201 */
32874aea 1202static void ssh_pkt_defersend(void)
1203{
b185170a 1204 sk_write(s, deferred_send_data, deferred_len);
1205 deferred_len = deferred_size = 0;
1206 sfree(deferred_send_data);
1207 deferred_send_data = NULL;
7cca0d81 1208}
1209
1210#if 0
32874aea 1211void bndebug(char *string, Bignum b)
1212{
7cca0d81 1213 unsigned char *p;
1214 int i, len;
1215 p = ssh2_mpint_fmt(b, &len);
1216 debug(("%s", string));
1217 for (i = 0; i < len; i++)
32874aea 1218 debug((" %02x", p[i]));
765c4200 1219 debug(("\n"));
dcbde236 1220 sfree(p);
7cca0d81 1221}
1222#endif
1223
32874aea 1224static void sha_mpint(SHA_State * s, Bignum b)
1225{
7cca0d81 1226 unsigned char *p;
1227 int len;
1228 p = ssh2_mpint_fmt(b, &len);
1229 sha_string(s, p, len);
dcbde236 1230 sfree(p);
7cca0d81 1231}
1232
1233/*
1234 * SSH2 packet decode functions.
1235 */
32874aea 1236static unsigned long ssh2_pkt_getuint32(void)
1237{
7cca0d81 1238 unsigned long value;
1239 if (pktin.length - pktin.savedpos < 4)
32874aea 1240 return 0; /* arrgh, no way to decline (FIXME?) */
1241 value = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1242 pktin.savedpos += 4;
1243 return value;
1244}
32874aea 1245static int ssh2_pkt_getbool(void)
1246{
65a22376 1247 unsigned long value;
1248 if (pktin.length - pktin.savedpos < 1)
32874aea 1249 return 0; /* arrgh, no way to decline (FIXME?) */
65a22376 1250 value = pktin.data[pktin.savedpos] != 0;
1251 pktin.savedpos++;
1252 return value;
1253}
32874aea 1254static void ssh2_pkt_getstring(char **p, int *length)
1255{
7cca0d81 1256 *p = NULL;
1257 if (pktin.length - pktin.savedpos < 4)
32874aea 1258 return;
1259 *length = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1260 pktin.savedpos += 4;
1261 if (pktin.length - pktin.savedpos < *length)
32874aea 1262 return;
1263 *p = pktin.data + pktin.savedpos;
7cca0d81 1264 pktin.savedpos += *length;
1265}
32874aea 1266static Bignum ssh2_pkt_getmp(void)
1267{
7cca0d81 1268 char *p;
3709bfe9 1269 int length;
7cca0d81 1270 Bignum b;
1271
1272 ssh2_pkt_getstring(&p, &length);
1273 if (!p)
32874aea 1274 return NULL;
8d5de777 1275 if (p[0] & 0x80) {
32874aea 1276 bombout(("internal error: Can't handle negative mpints"));
1277 return NULL;
8d5de777 1278 }
3709bfe9 1279 b = bignum_from_bytes(p, length);
7cca0d81 1280 return b;
1281}
1282
7d503c31 1283/*
1284 * Examine the remote side's version string and compare it against
1285 * a list of known buggy implementations.
1286 */
32874aea 1287static void ssh_detect_bugs(char *vstring)
1288{
1289 char *imp; /* pointer to implementation part */
7d503c31 1290 imp = vstring;
1291 imp += strcspn(imp, "-");
32874aea 1292 if (*imp)
1293 imp++;
7d503c31 1294 imp += strcspn(imp, "-");
32874aea 1295 if (*imp)
1296 imp++;
7d503c31 1297
1298 ssh_remote_bugs = 0;
1299
1300 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
32874aea 1301 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1302 !strcmp(imp, "1.2.22")) {
1303 /*
1304 * These versions don't support SSH1_MSG_IGNORE, so we have
1305 * to use a different defence against password length
1306 * sniffing.
1307 */
1308 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1309 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1310 }
1311
1312 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
32874aea 1313 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1314 !strncmp(imp, "2.1 ", 4)) {
1315 /*
1316 * These versions have the HMAC bug.
1317 */
1318 ssh_remote_bugs |= BUG_SSH2_HMAC;
1319 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1320 }
1321}
1322
32874aea 1323static int do_ssh_init(unsigned char c)
1324{
50526e47 1325 static char vslen;
8df7a775 1326 static char version[10];
50526e47 1327 static char *vstring;
1328 static int vstrsize;
1329 static char *vlog;
8df7a775 1330 static int i;
374330e2 1331
8df7a775 1332 crBegin;
1333
1334 /* Search for the string "SSH-" in the input. */
374330e2 1335 i = 0;
8df7a775 1336 while (1) {
1337 static const int transS[] = { 1, 2, 2, 1 };
1338 static const int transH[] = { 0, 0, 3, 0 };
1339 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1340 if (c == 'S')
1341 i = transS[i];
1342 else if (c == 'H')
1343 i = transH[i];
1344 else if (c == '-')
1345 i = transminus[i];
1346 else
1347 i = 0;
8df7a775 1348 if (i < 0)
1349 break;
1350 crReturn(1); /* get another character */
374330e2 1351 }
8df7a775 1352
50526e47 1353 vstring = smalloc(16);
1354 vstrsize = 16;
c5e9c988 1355 strcpy(vstring, "SSH-");
50526e47 1356 vslen = 4;
374330e2 1357 i = 0;
1358 while (1) {
8df7a775 1359 crReturn(1); /* get another char */
32874aea 1360 if (vslen >= vstrsize - 1) {
1361 vstrsize += 16;
1362 vstring = srealloc(vstring, vstrsize);
1363 }
1364 vstring[vslen++] = c;
374330e2 1365 if (i >= 0) {
1366 if (c == '-') {
1367 version[i] = '\0';
1368 i = -1;
32874aea 1369 } else if (i < sizeof(version) - 1)
374330e2 1370 version[i++] = c;
32874aea 1371 } else if (c == '\n')
374330e2 1372 break;
1373 }
1374
db7d555c 1375 ssh_agentfwd_enabled = FALSE;
960e736a 1376 rdpkt2_state.incoming_sequence = 0;
1377
50526e47 1378 vstring[vslen] = 0;
9275ca8a 1379 vlog = smalloc(20 + vslen);
c5e9c988 1380 sprintf(vlog, "Server version: %s", vstring);
7d503c31 1381 ssh_detect_bugs(vstring);
c5e9c988 1382 vlog[strcspn(vlog, "\r\n")] = '\0';
1383 logevent(vlog);
9275ca8a 1384 sfree(vlog);
c5e9c988 1385
adf799dd 1386 /*
1387 * Server version "1.99" means we can choose whether we use v1
1388 * or v2 protocol. Choice is based on cfg.sshprot.
1389 */
1390 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
32874aea 1391 /*
1392 * This is a v2 server. Begin v2 protocol.
1393 */
1394 char verstring[80], vlog[100];
1395 sprintf(verstring, "SSH-2.0-%s", sshver);
1396 SHA_Init(&exhashbase);
1397 /*
1398 * Hash our version string and their version string.
1399 */
1400 sha_string(&exhashbase, verstring, strlen(verstring));
1401 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1402 sprintf(vlog, "We claim version: %s", verstring);
1403 logevent(vlog);
1404 strcat(verstring, "\n");
1405 logevent("Using SSH protocol version 2");
1406 sk_write(s, verstring, strlen(verstring));
1407 ssh_protocol = ssh2_protocol;
1408 ssh_version = 2;
1409 s_rdpkt = ssh2_rdpkt;
e5574168 1410 } else {
32874aea 1411 /*
1412 * This is a v1 server. Begin v1 protocol.
1413 */
1414 char verstring[80], vlog[100];
1415 sprintf(verstring, "SSH-%s-%s",
1416 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1417 sshver);
1418 sprintf(vlog, "We claim version: %s", verstring);
1419 logevent(vlog);
1420 strcat(verstring, "\n");
1421 logevent("Using SSH protocol version 1");
1422 sk_write(s, verstring, strlen(verstring));
1423 ssh_protocol = ssh1_protocol;
1424 ssh_version = 1;
1425 s_rdpkt = ssh1_rdpkt;
e5574168 1426 }
3687d221 1427 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1428
50526e47 1429 sfree(vstring);
50526e47 1430
8df7a775 1431 crFinish(0);
1432}
1433
1434static void ssh_gotdata(unsigned char *data, int datalen)
1435{
1436 crBegin;
1437
1438 /*
1439 * To begin with, feed the characters one by one to the
1440 * protocol initialisation / selection function do_ssh_init().
1441 * When that returns 0, we're done with the initial greeting
1442 * exchange and can move on to packet discipline.
1443 */
1444 while (1) {
1445 int ret;
1446 if (datalen == 0)
1447 crReturnV; /* more data please */
1448 ret = do_ssh_init(*data);
32874aea 1449 data++;
1450 datalen--;
8df7a775 1451 if (ret == 0)
1452 break;
1453 }
1454
1455 /*
1456 * We emerge from that loop when the initial negotiation is
1457 * over and we have selected an s_rdpkt function. Now pass
1458 * everything to s_rdpkt, and then pass the resulting packets
1459 * to the proper protocol handler.
1460 */
1461 if (datalen == 0)
1462 crReturnV;
1463 while (1) {
1464 while (datalen > 0) {
32874aea 1465 if (s_rdpkt(&data, &datalen) == 0) {
8df7a775 1466 ssh_protocol(NULL, 0, 1);
1467 if (ssh_state == SSH_STATE_CLOSED) {
1468 return;
1469 }
1470 }
1471 }
1472 crReturnV;
1473 }
1474 crFinishV;
1475}
1476
32874aea 1477static int ssh_closing(Plug plug, char *error_msg, int error_code,
1478 int calling_back)
1479{
7e78000d 1480 ssh_state = SSH_STATE_CLOSED;
1481 sk_close(s);
1482 s = NULL;
1483 if (error_msg) {
32874aea 1484 /* A socket error has occurred. */
1485 connection_fatal(error_msg);
7e78000d 1486 } else {
1487 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1488 }
7e78000d 1489 return 0;
1490}
1491
32874aea 1492static int ssh_receive(Plug plug, int urgent, char *data, int len)
1493{
1494 ssh_gotdata(data, len);
3257deae 1495 if (ssh_state == SSH_STATE_CLOSED) {
32874aea 1496 if (s) {
1497 sk_close(s);
1498 s = NULL;
1499 }
1500 return 0;
3257deae 1501 }
fef97f43 1502 return 1;
374330e2 1503}
1504
fb09bf1c 1505/*
8df7a775 1506 * Connect to specified host and port.
1507 * Returns an error message, or NULL on success.
1508 * Also places the canonical host name into `realhost'.
1509 */
1510static char *connect_to_host(char *host, int port, char **realhost)
1511{
7e78000d 1512 static struct plug_function_table fn_table = {
1513 ssh_closing,
1514 ssh_receive
1515 }, *fn_table_ptr = &fn_table;
1516
8df7a775 1517 SockAddr addr;
1518 char *err;
1519#ifdef FWHACK
1520 char *FWhost;
1521 int FWport;
1522#endif
1523
32874aea 1524 savedhost = smalloc(1 + strlen(host));
8df7a775 1525 if (!savedhost)
1526 fatalbox("Out of memory");
1527 strcpy(savedhost, host);
1528
1529 if (port < 0)
1530 port = 22; /* default ssh port */
1531 savedport = port;
1532
1533#ifdef FWHACK
1534 FWhost = host;
1535 FWport = port;
1536 host = FWSTR;
1537 port = 23;
1538#endif
1539
1540 /*
1541 * Try to find host.
1542 */
1543 addr = sk_namelookup(host, realhost);
32874aea 1544 if ((err = sk_addr_error(addr)))
8df7a775 1545 return err;
1546
1547#ifdef FWHACK
1548 *realhost = FWhost;
1549#endif
1550
1551 /*
1552 * Open socket.
1553 */
7e78000d 1554 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
32874aea 1555 if ((err = sk_socket_error(s)))
8df7a775 1556 return err;
1557
1558#ifdef FWHACK
1559 sk_write(s, "connect ", 8);
1560 sk_write(s, FWhost, strlen(FWhost));
1561 {
1562 char buf[20];
1563 sprintf(buf, " %d\n", FWport);
1564 sk_write(s, buf, strlen(buf));
1565 }
1566#endif
1567
1568 return NULL;
1569}
1570
1571/*
fb09bf1c 1572 * Handle the key exchange and user authentication phases.
1573 */
e5574168 1574static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1575{
374330e2 1576 int i, j, len;
374330e2 1577 unsigned char *rsabuf, *keystr1, *keystr2;
1578 unsigned char cookie[8];
1579 struct RSAKey servkey, hostkey;
1580 struct MD5Context md5c;
ccbfb941 1581 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1582 static int tried_publickey;
1583 static unsigned char session_id[16];
bea1ef5f 1584 int cipher_type;
b585ec46 1585 static char username[100];
374330e2 1586
374330e2 1587 crBegin;
1588
32874aea 1589 if (!ispkt)
1590 crWaitUntil(ispkt);
374330e2 1591
8d5de777 1592 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1593 bombout(("Public key packet not received"));
32874aea 1594 crReturn(0);
8d5de777 1595 }
374330e2 1596
c5e9c988 1597 logevent("Received public keys");
374330e2 1598
c5e9c988 1599 memcpy(cookie, pktin.body, 8);
374330e2 1600
32874aea 1601 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1602 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
374330e2 1603
c5e9c988 1604 /*
1c2a93c4 1605 * Log the host key fingerprint.
c5e9c988 1606 */
c5e9c988 1607 {
1608 char logmsg[80];
1c2a93c4 1609 logevent("Host key fingerprint is:");
c5e9c988 1610 strcpy(logmsg, " ");
32874aea 1611 hostkey.comment = NULL;
1612 rsa_fingerprint(logmsg + strlen(logmsg),
1613 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 1614 logevent(logmsg);
1615 }
1616
32874aea 1617 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1618 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1619 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
bea1ef5f 1620
32874aea 1621 ssh1_local_protoflags =
1622 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
b96dc54c 1623 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1624
c5e9c988 1625 MD5Init(&md5c);
374330e2 1626 MD5Update(&md5c, keystr2, hostkey.bytes);
1627 MD5Update(&md5c, keystr1, servkey.bytes);
1628 MD5Update(&md5c, pktin.body, 8);
374330e2 1629 MD5Final(session_id, &md5c);
1630
32874aea 1631 for (i = 0; i < 32; i++)
374330e2 1632 session_key[i] = random_byte();
1633
1634 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1635
dcbde236 1636 rsabuf = smalloc(len);
374330e2 1637 if (!rsabuf)
1638 fatalbox("Out of memory");
1639
89ee5268 1640 /*
1641 * Verify the host key.
1642 */
1643 {
32874aea 1644 /*
1645 * First format the key into a string.
1646 */
1647 int len = rsastr_len(&hostkey);
1648 char fingerprint[100];
1649 char *keystr = smalloc(len);
1650 if (!keystr)
1651 fatalbox("Out of memory");
1652 rsastr_fmt(keystr, &hostkey);
1653 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1654 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1655 fingerprint);
1656 sfree(keystr);
1657 }
1658
1659 for (i = 0; i < 32; i++) {
374330e2 1660 rsabuf[i] = session_key[i];
1661 if (i < 16)
1662 rsabuf[i] ^= session_id[i];
1663 }
1664
1665 if (hostkey.bytes > servkey.bytes) {
1666 rsaencrypt(rsabuf, 32, &servkey);
1667 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1668 } else {
1669 rsaencrypt(rsabuf, 32, &hostkey);
1670 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1671 }
1672
c5e9c988 1673 logevent("Encrypted session key");
1674
0a3f1d48 1675 switch (cfg.cipher) {
32874aea 1676 case CIPHER_BLOWFISH:
1677 cipher_type = SSH_CIPHER_BLOWFISH;
1678 break;
1679 case CIPHER_DES:
1680 cipher_type = SSH_CIPHER_DES;
1681 break;
1682 case CIPHER_3DES:
1683 cipher_type = SSH_CIPHER_3DES;
1684 break;
0a3f1d48 1685 case CIPHER_AES:
32874aea 1686 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1687 cipher_type = SSH_CIPHER_3DES;
1688 break;
0a3f1d48 1689 }
bea1ef5f 1690 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
32874aea 1691 c_write_str
1692 ("Selected cipher not supported, falling back to 3DES\r\n");
bea1ef5f 1693 cipher_type = SSH_CIPHER_3DES;
a99a05c0 1694 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1695 bombout(("Server violates SSH 1 protocol by "
1696 "not supporting 3DES encryption"));
1697 crReturn(0);
1698 }
bea1ef5f 1699 }
c5e9c988 1700 switch (cipher_type) {
32874aea 1701 case SSH_CIPHER_3DES:
1702 logevent("Using 3DES encryption");
1703 break;
1704 case SSH_CIPHER_DES:
1705 logevent("Using single-DES encryption");
1706 break;
1707 case SSH_CIPHER_BLOWFISH:
1708 logevent("Using Blowfish encryption");
1709 break;
c5e9c988 1710 }
bea1ef5f 1711
e5574168 1712 send_packet(SSH1_CMSG_SESSION_KEY,
32874aea 1713 PKT_CHAR, cipher_type,
1714 PKT_DATA, cookie, 8,
1715 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
1716 PKT_DATA, rsabuf, len,
1717 PKT_INT, ssh1_local_protoflags, PKT_END);
fb09bf1c 1718
c5e9c988 1719 logevent("Trying to enable encryption...");
374330e2 1720
dcbde236 1721 sfree(rsabuf);
374330e2 1722
5e8358ad 1723 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
32874aea 1724 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
374330e2 1725 cipher->sesskey(session_key);
1726
fb09bf1c 1727 crWaitUntil(ispkt);
374330e2 1728
8d5de777 1729 if (pktin.type != SSH1_SMSG_SUCCESS) {
1730 bombout(("Encryption not successfully enabled"));
32874aea 1731 crReturn(0);
8d5de777 1732 }
374330e2 1733
c5e9c988 1734 logevent("Successfully started encryption");
1735
374330e2 1736 fflush(stdout);
1737 {
374330e2 1738 static int pos = 0;
1739 static char c;
67779be7 1740 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
32874aea 1741 if (ssh_get_line) {
1742 if (!ssh_get_line("login as: ",
1743 username, sizeof(username), FALSE)) {
1744 /*
1745 * get_line failed to get a username.
1746 * Terminate.
1747 */
1748 logevent("No username provided. Abandoning session.");
1749 ssh_state = SSH_STATE_CLOSED;
1750 crReturn(1);
1751 }
1752 } else {
1753 c_write_str("login as: ");
1754 ssh_send_ok = 1;
1755 while (pos >= 0) {
1756 crWaitUntil(!ispkt);
1757 while (inlen--)
1758 switch (c = *in++) {
1759 case 10:
1760 case 13:
1761 username[pos] = 0;
1762 pos = -1;
1763 break;
1764 case 8:
1765 case 127:
1766 if (pos > 0) {
1767 c_write_str("\b \b");
1768 pos--;
1769 }
1770 break;
1771 case 21:
1772 case 27:
1773 while (pos > 0) {
1774 c_write_str("\b \b");
1775 pos--;
1776 }
1777 break;
1778 case 3:
1779 case 4:
1780 random_save_seed();
1781 exit(0);
1782 break;
1783 default:
1784 if (((c >= ' ' && c <= '~') ||
1785 ((unsigned char) c >= 160)) && pos < 40) {
1786 username[pos++] = c;
1787 c_write(&c, 1);
1788 }
1789 break;
1790 }
1791 }
1792 c_write_str("\r\n");
1793 username[strcspn(username, "\n\r")] = '\0';
1794 }
1795 } else {
374330e2 1796 strncpy(username, cfg.username, 99);
1797 username[99] = '\0';
374330e2 1798 }
fb09bf1c 1799
e5574168 1800 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1801 {
32874aea 1802 char userlog[22 + sizeof(username)];
c5e9c988 1803 sprintf(userlog, "Sent username \"%s\"", username);
1804 logevent(userlog);
32874aea 1805 if (flags & FLAG_INTERACTIVE &&
1806 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 1807 strcat(userlog, "\r\n");
32874aea 1808 c_write_str(userlog);
3c8e959b 1809 }
c5e9c988 1810 }
374330e2 1811 }
1812
fb09bf1c 1813 crWaitUntil(ispkt);
374330e2 1814
7cca0d81 1815 tried_publickey = 0;
1816
e5574168 1817 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1818 static char password[100];
a52f067e 1819 static char prompt[200];
374330e2 1820 static int pos;
1821 static char c;
32874aea 1822 static int pwpkt_type;
1823 /*
1824 * Show password prompt, having first obtained it via a TIS
1825 * or CryptoCard exchange if we're doing TIS or CryptoCard
1826 * authentication.
1827 */
1828 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1829 if (agent_exists()) {
1830 /*
1831 * Attempt RSA authentication using Pageant.
1832 */
1833 static unsigned char request[5], *response, *p;
1834 static int responselen;
1835 static int i, nkeys;
1836 static int authed = FALSE;
1837 void *r;
1838
1839 logevent("Pageant is running. Requesting keys.");
1840
1841 /* Request the keys held by the agent. */
1842 PUT_32BIT(request, 1);
1843 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
1844 agent_query(request, 5, &r, &responselen);
1845 response = (unsigned char *) r;
1846 if (response && responselen >= 5 &&
1847 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
1848 p = response + 5;
1849 nkeys = GET_32BIT(p);
1850 p += 4;
1851 {
1852 char buf[64];
1853 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
1854 logevent(buf);
1855 }
1856 for (i = 0; i < nkeys; i++) {
1857 static struct RSAKey key;
1858 static Bignum challenge;
1859 static char *commentp;
1860 static int commentlen;
1861
1862 {
1863 char buf[64];
1864 sprintf(buf, "Trying Pageant key #%d", i);
1865 logevent(buf);
1866 }
1867 p += 4;
1868 p += ssh1_read_bignum(p, &key.exponent);
1869 p += ssh1_read_bignum(p, &key.modulus);
1870 commentlen = GET_32BIT(p);
1871 p += 4;
1872 commentp = p;
1873 p += commentlen;
1874 send_packet(SSH1_CMSG_AUTH_RSA,
1875 PKT_BIGNUM, key.modulus, PKT_END);
1876 crWaitUntil(ispkt);
1877 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1878 logevent("Key refused");
1879 continue;
1880 }
1881 logevent("Received RSA challenge");
1882 ssh1_read_bignum(pktin.body, &challenge);
1883 {
1884 char *agentreq, *q, *ret;
1885 int len, retlen;
1886 len = 1 + 4; /* message type, bit count */
1887 len += ssh1_bignum_length(key.exponent);
1888 len += ssh1_bignum_length(key.modulus);
1889 len += ssh1_bignum_length(challenge);
1890 len += 16; /* session id */
1891 len += 4; /* response format */
1892 agentreq = smalloc(4 + len);
1893 PUT_32BIT(agentreq, len);
1894 q = agentreq + 4;
1895 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
1896 PUT_32BIT(q, bignum_bitcount(key.modulus));
1897 q += 4;
1898 q += ssh1_write_bignum(q, key.exponent);
1899 q += ssh1_write_bignum(q, key.modulus);
1900 q += ssh1_write_bignum(q, challenge);
1901 memcpy(q, session_id, 16);
1902 q += 16;
1903 PUT_32BIT(q, 1); /* response format */
1904 agent_query(agentreq, len + 4, &ret, &retlen);
1905 sfree(agentreq);
1906 if (ret) {
1907 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
1908 logevent("Sending Pageant's response");
1909 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1910 PKT_DATA, ret + 5, 16,
1911 PKT_END);
1912 sfree(ret);
1913 crWaitUntil(ispkt);
1914 if (pktin.type == SSH1_SMSG_SUCCESS) {
1915 logevent
1916 ("Pageant's response accepted");
1917 if (flags & FLAG_VERBOSE) {
1918 c_write_str
1919 ("Authenticated using RSA key \"");
1920 c_write(commentp, commentlen);
1921 c_write_str("\" from agent\r\n");
1922 }
1923 authed = TRUE;
1924 } else
1925 logevent
1926 ("Pageant's response not accepted");
1927 } else {
1928 logevent
1929 ("Pageant failed to answer challenge");
1930 sfree(ret);
1931 }
1932 } else {
1933 logevent("No reply received from Pageant");
1934 }
1935 }
1936 freebn(key.exponent);
1937 freebn(key.modulus);
1938 freebn(challenge);
1939 if (authed)
1940 break;
1941 }
1942 }
1943 if (authed)
1944 break;
1945 }
1946 if (*cfg.keyfile && !tried_publickey)
1947 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1948
1949 if (pktin.type == SSH1_SMSG_FAILURE &&
1950 cfg.try_tis_auth &&
1951 (supported_auths_mask & (1 << SSH1_AUTH_TIS))) {
1952 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1953 logevent("Requested TIS authentication");
1954 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1955 crWaitUntil(ispkt);
1956 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1957 logevent("TIS authentication declined");
1958 if (flags & FLAG_INTERACTIVE)
1959 c_write_str("TIS authentication refused.\r\n");
1960 } else {
1961 int challengelen = ((pktin.body[0] << 24) |
1962 (pktin.body[1] << 16) |
1963 (pktin.body[2] << 8) |
1964 (pktin.body[3]));
1965 logevent("Received TIS challenge");
1966 if (challengelen > sizeof(prompt) - 1)
1967 challengelen = sizeof(prompt) - 1; /* prevent overrun */
1968 memcpy(prompt, pktin.body + 4, challengelen);
1969 prompt[challengelen] = '\0';
1970 }
1971 }
1972 if (pktin.type == SSH1_SMSG_FAILURE &&
1973 cfg.try_tis_auth &&
1974 (supported_auths_mask & (1 << SSH1_AUTH_CCARD))) {
1975 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1976 logevent("Requested CryptoCard authentication");
1977 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1978 crWaitUntil(ispkt);
1979 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1980 logevent("CryptoCard authentication declined");
1981 c_write_str("CryptoCard authentication refused.\r\n");
1982 } else {
1983 int challengelen = ((pktin.body[0] << 24) |
1984 (pktin.body[1] << 16) |
1985 (pktin.body[2] << 8) |
1986 (pktin.body[3]));
1987 logevent("Received CryptoCard challenge");
1988 if (challengelen > sizeof(prompt) - 1)
1989 challengelen = sizeof(prompt) - 1; /* prevent overrun */
1990 memcpy(prompt, pktin.body + 4, challengelen);
1991 strncpy(prompt + challengelen, "\r\nResponse : ",
1992 sizeof(prompt) - challengelen);
1993 prompt[sizeof(prompt) - 1] = '\0';
1994 }
1995 }
1996 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1997 sprintf(prompt, "%.90s@%.90s's password: ",
1998 username, savedhost);
1999 }
2000 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2001 char *comment = NULL;
2002 if (flags & FLAG_VERBOSE)
2003 c_write_str("Trying public key authentication.\r\n");
2004 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2005 if (flags & FLAG_VERBOSE)
2006 c_write_str("No passphrase required.\r\n");
2007 goto tryauth;
2008 }
2009 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2010 sfree(comment);
2011 }
a52f067e 2012
fa17a66e 2013 if (ssh_get_line) {
2014 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
32874aea 2015 /*
2016 * get_line failed to get a password (for example
2017 * because one was supplied on the command line
2018 * which has already failed to work). Terminate.
2019 */
2020 logevent("No more passwords to try");
2021 ssh_state = SSH_STATE_CLOSED;
2022 crReturn(1);
2023 }
fb09bf1c 2024 } else {
32874aea 2025 c_write_str(prompt);
2026 pos = 0;
2027 ssh_send_ok = 1;
2028 while (pos >= 0) {
2029 crWaitUntil(!ispkt);
2030 while (inlen--)
2031 switch (c = *in++) {
2032 case 10:
2033 case 13:
2034 password[pos] = 0;
2035 pos = -1;
2036 break;
2037 case 8:
2038 case 127:
2039 if (pos > 0)
2040 pos--;
2041 break;
2042 case 21:
2043 case 27:
2044 pos = 0;
2045 break;
2046 case 3:
2047 case 4:
2048 random_save_seed();
2049 exit(0);
2050 break;
2051 default:
2052 if (((c >= ' ' && c <= '~') ||
2053 ((unsigned char) c >= 160))
2054 && pos < sizeof(password))
2055 password[pos++] = c;
2056 break;
2057 }
2058 }
2059 c_write_str("\r\n");
2060 }
2061
2062 tryauth:
7cca0d81 2063 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2064 /*
2065 * Try public key authentication with the specified
2066 * key file.
2067 */
2068 static struct RSAKey pubkey;
2069 static Bignum challenge, response;
2070 static int i;
2071 static unsigned char buffer[32];
2072
2073 tried_publickey = 1;
2074 i = loadrsakey(cfg.keyfile, &pubkey, password);
2075 if (i == 0) {
2076 c_write_str("Couldn't load public key from ");
2077 c_write_str(cfg.keyfile);
2078 c_write_str(".\r\n");
2079 continue; /* go and try password */
2080 }
2081 if (i == -1) {
2082 c_write_str("Wrong passphrase.\r\n");
2083 tried_publickey = 0;
2084 continue; /* try again */
2085 }
2086
2087 /*
2088 * Send a public key attempt.
2089 */
2090 send_packet(SSH1_CMSG_AUTH_RSA,
2091 PKT_BIGNUM, pubkey.modulus, PKT_END);
2092
2093 crWaitUntil(ispkt);
2094 if (pktin.type == SSH1_SMSG_FAILURE) {
2095 c_write_str("Server refused our public key.\r\n");
2096 continue; /* go and try password */
2097 }
2098 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2099 bombout(("Bizarre response to offer of public key"));
2100 crReturn(0);
2101 }
2102 ssh1_read_bignum(pktin.body, &challenge);
2103 response = rsadecrypt(challenge, &pubkey);
2104 freebn(pubkey.private_exponent); /* burn the evidence */
2105
2106 for (i = 0; i < 32; i++) {
2107 buffer[i] = bignum_byte(response, 31 - i);
2108 }
2109
2110 MD5Init(&md5c);
2111 MD5Update(&md5c, buffer, 32);
2112 MD5Update(&md5c, session_id, 16);
2113 MD5Final(buffer, &md5c);
2114
2115 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2116 PKT_DATA, buffer, 16, PKT_END);
2117
2118 crWaitUntil(ispkt);
2119 if (pktin.type == SSH1_SMSG_FAILURE) {
2120 if (flags & FLAG_VERBOSE)
2121 c_write_str
2122 ("Failed to authenticate with our public key.\r\n");
2123 continue; /* go and try password */
2124 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2125 bombout(
2126 ("Bizarre response to RSA authentication response"));
2127 crReturn(0);
2128 }
2129
2130 break; /* we're through! */
2131 } else {
2132 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2133 /*
2134 * Defence against traffic analysis: we send a
2135 * whole bunch of packets containing strings of
2136 * different lengths. One of these strings is the
2137 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2138 * The others are all random data in
2139 * SSH1_MSG_IGNORE packets. This way a passive
2140 * listener can't tell which is the password, and
2141 * hence can't deduce the password length.
2142 *
2143 * Anybody with a password length greater than 16
2144 * bytes is going to have enough entropy in their
2145 * password that a listener won't find it _that_
2146 * much help to know how long it is. So what we'll
2147 * do is:
2148 *
2149 * - if password length < 16, we send 15 packets
2150 * containing string lengths 1 through 15
2151 *
2152 * - otherwise, we let N be the nearest multiple
2153 * of 8 below the password length, and send 8
2154 * packets containing string lengths N through
2155 * N+7. This won't obscure the order of
2156 * magnitude of the password length, but it will
2157 * introduce a bit of extra uncertainty.
2158 *
2159 * A few servers (the old 1.2.18 through 1.2.22)
2160 * can't deal with SSH1_MSG_IGNORE. For these
2161 * servers, we need an alternative defence. We make
2162 * use of the fact that the password is interpreted
2163 * as a C string: so we can append a NUL, then some
2164 * random data.
2165 */
2166 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
2167 char string[64];
2168 char *s;
2169 int len;
2170
2171 len = strlen(password);
2172 if (len < sizeof(string)) {
2173 s = string;
2174 strcpy(string, password);
2175 len++; /* cover the zero byte */
2176 while (len < sizeof(string)) {
2177 string[len++] = (char) random_byte();
2178 }
2179 } else {
2180 s = password;
2181 }
2182 send_packet(pwpkt_type, PKT_INT, len,
2183 PKT_DATA, s, len, PKT_END);
2184 } else {
2185 int bottom, top, pwlen, i;
2186 char *randomstr;
2187
2188 pwlen = strlen(password);
2189 if (pwlen < 16) {
2190 bottom = 0; /* zero length passwords are OK! :-) */
2191 top = 15;
2192 } else {
2193 bottom = pwlen & ~7;
2194 top = bottom + 7;
2195 }
2196
2197 assert(pwlen >= bottom && pwlen <= top);
2198
2199 randomstr = smalloc(top + 1);
2200
2201 for (i = bottom; i <= top; i++) {
2202 if (i == pwlen)
2203 defer_packet(pwpkt_type, PKT_STR, password,
2204 PKT_END);
2205 else {
2206 for (j = 0; j < i; j++) {
2207 do {
2208 randomstr[j] = random_byte();
2209 } while (randomstr[j] == '\0');
2210 }
2211 randomstr[i] = '\0';
2212 defer_packet(SSH1_MSG_IGNORE,
2213 PKT_STR, randomstr, PKT_END);
2214 }
2215 }
2216 ssh_pkt_defersend();
2217 }
2218 } else {
2219 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2220 }
2221 }
c5e9c988 2222 logevent("Sent password");
374330e2 2223 memset(password, 0, strlen(password));
fb09bf1c 2224 crWaitUntil(ispkt);
e5574168 2225 if (pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2226 if (flags & FLAG_VERBOSE)
2227 c_write_str("Access denied\r\n");
c5e9c988 2228 logevent("Authentication refused");
e5574168 2229 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 2230 logevent("Received disconnect request");
32874aea 2231 ssh_state = SSH_STATE_CLOSED;
85ee8208 2232 crReturn(1);
e5574168 2233 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2234 bombout(("Strange packet received, type %d", pktin.type));
32874aea 2235 crReturn(0);
374330e2 2236 }
2237 }
2238
c5e9c988 2239 logevent("Authentication successful");
2240
fb09bf1c 2241 crFinish(1);
2242}
2243
32874aea 2244void sshfwd_close(struct ssh_channel *c)
2245{
80e48603 2246 if (c && !c->closes) {
32874aea 2247 if (ssh_version == 1) {
2248 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2249 PKT_END);
2250 } else {
2251 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2252 ssh2_pkt_adduint32(c->remoteid);
2253 ssh2_pkt_send();
2254 }
2255 c->closes = 1;
2256 if (c->type == CHAN_X11) {
2257 c->u.x11.s = NULL;
2258 logevent("X11 connection terminated");
2259 }
2260 }
2261}
2262
2263void sshfwd_write(struct ssh_channel *c, char *buf, int len)
2264{
783415f8 2265 if (ssh_version == 1) {
32874aea 2266 send_packet(SSH1_MSG_CHANNEL_DATA,
2267 PKT_INT, c->remoteid,
2268 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
783415f8 2269 } else {
32874aea 2270 ssh2_add_channel_data(c, buf, len);
2271 ssh2_try_send(c);
783415f8 2272 }
9c964e85 2273}
2274
32874aea 2275static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2276{
fb09bf1c 2277 crBegin;
2278
2279 random_init();
2280
e5574168 2281 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 2282 crReturnV;
85ee8208 2283 }
2284 if (ssh_state == SSH_STATE_CLOSED)
32874aea 2285 crReturnV;
fb09bf1c 2286
979310f1 2287 if (cfg.agentfwd && agent_exists()) {
32874aea 2288 logevent("Requesting agent forwarding");
2289 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2290 do {
2291 crReturnV;
2292 } while (!ispkt);
2293 if (pktin.type != SSH1_SMSG_SUCCESS
2294 && pktin.type != SSH1_SMSG_FAILURE) {
2295 bombout(("Protocol confusion"));
2296 crReturnV;
2297 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2298 logevent("Agent forwarding refused");
2299 } else {
2300 logevent("Agent forwarding enabled");
db7d555c 2301 ssh_agentfwd_enabled = TRUE;
2302 }
dacbd0e8 2303 }
2304
9c964e85 2305 if (cfg.x11_forward) {
32874aea 2306 char proto[20], data[64];
2307 logevent("Requesting X11 forwarding");
2308 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2309 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2310 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2311 PKT_STR, proto, PKT_STR, data,
2312 PKT_INT, 0, PKT_END);
2313 } else {
2314 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2315 PKT_STR, proto, PKT_STR, data, PKT_END);
2316 }
2317 do {
2318 crReturnV;
2319 } while (!ispkt);
2320 if (pktin.type != SSH1_SMSG_SUCCESS
2321 && pktin.type != SSH1_SMSG_FAILURE) {
2322 bombout(("Protocol confusion"));
2323 crReturnV;
2324 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2325 logevent("X11 forwarding refused");
2326 } else {
2327 logevent("X11 forwarding enabled");
9c964e85 2328 ssh_X11_fwd_enabled = TRUE;
2329 }
2330 }
2331
fef97f43 2332 if (!cfg.nopty) {
e5574168 2333 send_packet(SSH1_CMSG_REQUEST_PTY,
32874aea 2334 PKT_STR, cfg.termtype,
2335 PKT_INT, rows, PKT_INT, cols,
2336 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2337 ssh_state = SSH_STATE_INTERMED;
2338 do {
2339 crReturnV;
2340 } while (!ispkt);
2341 if (pktin.type != SSH1_SMSG_SUCCESS
2342 && pktin.type != SSH1_SMSG_FAILURE) {
2343 bombout(("Protocol confusion"));
2344 crReturnV;
2345 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2346 c_write_str("Server refused to allocate pty\r\n");
2347 ssh_editing = ssh_echoing = 1;
2348 }
c5e9c988 2349 logevent("Allocated pty");
0965bee0 2350 } else {
32874aea 2351 ssh_editing = ssh_echoing = 1;
374330e2 2352 }
2353
4ba9b64b 2354 if (cfg.compression) {
32874aea 2355 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2356 do {
2357 crReturnV;
2358 } while (!ispkt);
2359 if (pktin.type != SSH1_SMSG_SUCCESS
2360 && pktin.type != SSH1_SMSG_FAILURE) {
2361 bombout(("Protocol confusion"));
2362 crReturnV;
2363 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2364 c_write_str("Server refused to compress\r\n");
2365 }
4ba9b64b 2366 logevent("Started compression");
2367 ssh1_compressing = TRUE;
2368 zlib_compress_init();
2369 zlib_decompress_init();
2370 }
2371
96621a84 2372 if (*cfg.remote_cmd_ptr)
32874aea 2373 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd_ptr,
2374 PKT_END);
6abbf9e3 2375 else
32874aea 2376 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 2377 logevent("Started session");
374330e2 2378
2379 ssh_state = SSH_STATE_SESSION;
2380 if (size_needed)
2381 ssh_size();
3687d221 2382 if (eof_needed)
32874aea 2383 ssh_special(TS_EOF);
374330e2 2384
32874aea 2385 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 2386 ssh_send_ok = 1;
dacbd0e8 2387 ssh_channels = newtree234(ssh_channelcmp);
374330e2 2388 while (1) {
2389 crReturnV;
2390 if (ispkt) {
e5574168 2391 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 2392 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 2393 long len = GET_32BIT(pktin.body);
fe50e814 2394 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
32874aea 2395 pktin.body + 4, len);
e5574168 2396 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
32874aea 2397 ssh_state = SSH_STATE_CLOSED;
c5e9c988 2398 logevent("Received disconnect request");
32874aea 2399 crReturnV;
2400 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2401 /* Remote side is trying to open a channel to talk to our
2402 * X-Server. Give them back a local channel number. */
2403 struct ssh_channel *c;
9c964e85 2404
2405 logevent("Received X11 connect request");
2406 /* Refuse if X11 forwarding is disabled. */
2407 if (!ssh_X11_fwd_enabled) {
2408 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 2409 PKT_INT, GET_32BIT(pktin.body), PKT_END);
9c964e85 2410 logevent("Rejected X11 connect request");
2411 } else {
9c964e85 2412 c = smalloc(sizeof(struct ssh_channel));
2413
32874aea 2414 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2415 logevent("opening X11 forward connection failed");
2416 sfree(c);
2417 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2418 PKT_INT, GET_32BIT(pktin.body),
2419 PKT_END);
9c964e85 2420 } else {
32874aea 2421 logevent
2422 ("opening X11 forward connection succeeded");
2423 c->remoteid = GET_32BIT(pktin.body);
2424 c->localid = alloc_channel_id();
2425 c->closes = 0;
2426 c->type = CHAN_X11; /* identify channel type */
2427 add234(ssh_channels, c);
2428 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2429 PKT_INT, c->remoteid, PKT_INT,
2430 c->localid, PKT_END);
2431 logevent("Opened X11 forward channel");
9c964e85 2432 }
2433 }
32874aea 2434 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2435 /* Remote side is trying to open a channel to talk to our
2436 * agent. Give them back a local channel number. */
2437 struct ssh_channel *c;
db7d555c 2438
2439 /* Refuse if agent forwarding is disabled. */
2440 if (!ssh_agentfwd_enabled) {
2441 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 2442 PKT_INT, GET_32BIT(pktin.body), PKT_END);
db7d555c 2443 } else {
dcbde236 2444 c = smalloc(sizeof(struct ssh_channel));
db7d555c 2445 c->remoteid = GET_32BIT(pktin.body);
d2371c81 2446 c->localid = alloc_channel_id();
db7d555c 2447 c->closes = 0;
32874aea 2448 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 2449 c->u.a.lensofar = 0;
2450 add234(ssh_channels, c);
2451 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2452 PKT_INT, c->remoteid, PKT_INT, c->localid,
2453 PKT_END);
2454 }
2455 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2456 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 2457 /* Remote side closes a channel. */
2458 unsigned i = GET_32BIT(pktin.body);
2459 struct ssh_channel *c;
2460 c = find234(ssh_channels, &i, ssh_channelfind);
2461 if (c) {
2462 int closetype;
2463 closetype =
2464 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2465 if (!(c->closes & closetype))
2466 send_packet(pktin.type, PKT_INT, c->remoteid,
2467 PKT_END);
783415f8 2468 if ((c->closes == 0) && (c->type == CHAN_X11)) {
32874aea 2469 logevent("X11 connection closed");
9c964e85 2470 assert(c->u.x11.s != NULL);
2471 x11_close(c->u.x11.s);
2472 c->u.x11.s = NULL;
2473 }
32874aea 2474 c->closes |= closetype;
2475 if (c->closes == 3) {
2476 del234(ssh_channels, c);
2477 sfree(c);
2478 }
2479 }
2480 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2481 /* Data sent down one of our channels. */
2482 int i = GET_32BIT(pktin.body);
2483 int len = GET_32BIT(pktin.body + 4);
2484 unsigned char *p = pktin.body + 8;
2485 struct ssh_channel *c;
2486 c = find234(ssh_channels, &i, ssh_channelfind);
2487 if (c) {
2488 switch (c->type) {
2489 case CHAN_X11:
9c964e85 2490 x11_send(c->u.x11.s, p, len);
2491 break;
32874aea 2492 case CHAN_AGENT:
2493 /* Data for an agent message. Buffer it. */
2494 while (len > 0) {
2495 if (c->u.a.lensofar < 4) {
2496 int l = min(4 - c->u.a.lensofar, len);
2497 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
2498 l);
2499 p += l;
2500 len -= l;
2501 c->u.a.lensofar += l;
2502 }
2503 if (c->u.a.lensofar == 4) {
2504 c->u.a.totallen =
2505 4 + GET_32BIT(c->u.a.msglen);
2506 c->u.a.message = smalloc(c->u.a.totallen);
2507 memcpy(c->u.a.message, c->u.a.msglen, 4);
2508 }
2509 if (c->u.a.lensofar >= 4 && len > 0) {
2510 int l =
2511 min(c->u.a.totallen - c->u.a.lensofar,
2512 len);
2513 memcpy(c->u.a.message + c->u.a.lensofar, p,
2514 l);
2515 p += l;
2516 len -= l;
2517 c->u.a.lensofar += l;
2518 }
2519 if (c->u.a.lensofar == c->u.a.totallen) {
2520 void *reply, *sentreply;
2521 int replylen;
2522 agent_query(c->u.a.message,
2523 c->u.a.totallen, &reply,
2524 &replylen);
2525 if (reply)
2526 sentreply = reply;
2527 else {
2528 /* Fake SSH_AGENT_FAILURE. */
2529 sentreply = "\0\0\0\1\5";
2530 replylen = 5;
2531 }
2532 send_packet(SSH1_MSG_CHANNEL_DATA,
2533 PKT_INT, c->remoteid,
2534 PKT_INT, replylen,
2535 PKT_DATA, sentreply, replylen,
2536 PKT_END);
2537 if (reply)
2538 sfree(reply);
2539 sfree(c->u.a.message);
2540 c->u.a.lensofar = 0;
2541 }
2542 }
2543 break;
2544 }
2545 }
e5574168 2546 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 2547 /* may be from EXEC_SHELL on some servers */
e5574168 2548 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 2549 /* may be from EXEC_SHELL on some servers
374330e2 2550 * if no pty is available or in other odd cases. Ignore */
e5574168 2551 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2552 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 2553 } else {
8d5de777 2554 bombout(("Strange packet received: type %d", pktin.type));
32874aea 2555 crReturnV;
374330e2 2556 }
2557 } else {
8df7a775 2558 while (inlen > 0) {
2559 int len = min(inlen, 512);
2560 send_packet(SSH1_CMSG_STDIN_DATA,
2561 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2562 in += len;
2563 inlen -= len;
2564 }
374330e2 2565 }
2566 }
2567
2568 crFinishV;
2569}
2570
2571/*
e5574168 2572 * Utility routine for decoding comma-separated strings in KEXINIT.
2573 */
32874aea 2574static int in_commasep_string(char *needle, char *haystack, int haylen)
2575{
e5574168 2576 int needlen = strlen(needle);
2577 while (1) {
32874aea 2578 /*
2579 * Is it at the start of the string?
2580 */
2581 if (haylen >= needlen && /* haystack is long enough */
2582 !memcmp(needle, haystack, needlen) && /* initial match */
2583 (haylen == needlen || haystack[needlen] == ',')
2584 /* either , or EOS follows */
2585 )
2586 return 1;
2587 /*
2588 * If not, search for the next comma and resume after that.
2589 * If no comma found, terminate.
2590 */
2591 while (haylen > 0 && *haystack != ',')
2592 haylen--, haystack++;
2593 if (haylen == 0)
2594 return 0;
2595 haylen--, haystack++; /* skip over comma itself */
e5574168 2596 }
2597}
2598
2599/*
d39f364a 2600 * SSH2 key creation method.
2601 */
32874aea 2602static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
2603 char *keyspace)
2604{
d39f364a 2605 SHA_State s;
2606 /* First 20 bytes. */
2607 SHA_Init(&s);
2608 sha_mpint(&s, K);
2609 SHA_Bytes(&s, H, 20);
2610 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 2611 SHA_Bytes(&s, sessid, 20);
d39f364a 2612 SHA_Final(&s, keyspace);
2613 /* Next 20 bytes. */
2614 SHA_Init(&s);
2615 sha_mpint(&s, K);
2616 SHA_Bytes(&s, H, 20);
2617 SHA_Bytes(&s, keyspace, 20);
32874aea 2618 SHA_Final(&s, keyspace + 20);
d39f364a 2619}
2620
2621/*
7cca0d81 2622 * Handle the SSH2 transport layer.
e5574168 2623 */
7cca0d81 2624static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 2625{
7bd5a860 2626 static int i, j, len, nbits, pbits;
e5574168 2627 static char *str;
a92dd380 2628 static Bignum p, g, e, f, K;
2629 static int kex_init_value, kex_reply_value;
7591b9ff 2630 static const struct ssh_mac **maclist;
8b2715b2 2631 static int nmacs;
0a3f1d48 2632 static const struct ssh2_cipher *cscipher_tobe = NULL;
2633 static const struct ssh2_cipher *sccipher_tobe = NULL;
57476f6b 2634 static const struct ssh_mac *csmac_tobe = NULL;
2635 static const struct ssh_mac *scmac_tobe = NULL;
2636 static const struct ssh_compress *cscomp_tobe = NULL;
2637 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 2638 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 2639 static int hostkeylen, siglen;
e055a386 2640 static void *hkey; /* actual host key */
e5574168 2641 static unsigned char exchange_hash[20];
d39f364a 2642 static unsigned char keyspace[40];
0a3f1d48 2643 static const struct ssh2_ciphers *preferred_cipher;
4ba9b64b 2644 static const struct ssh_compress *preferred_comp;
0db56f73 2645 static int first_kex;
e5574168 2646
2647 crBegin;
7cca0d81 2648 random_init();
0db56f73 2649 first_kex = 1;
e5574168 2650
5e8358ad 2651 /*
4ba9b64b 2652 * Set up the preferred cipher and compression.
5e8358ad 2653 */
2654 if (cfg.cipher == CIPHER_BLOWFISH) {
32874aea 2655 preferred_cipher = &ssh2_blowfish;
5e8358ad 2656 } else if (cfg.cipher == CIPHER_DES) {
32874aea 2657 logevent("Single DES not supported in SSH2; using 3DES");
2658 preferred_cipher = &ssh2_3des;
5e8358ad 2659 } else if (cfg.cipher == CIPHER_3DES) {
32874aea 2660 preferred_cipher = &ssh2_3des;
0a3f1d48 2661 } else if (cfg.cipher == CIPHER_AES) {
32874aea 2662 preferred_cipher = &ssh2_aes;
5e8358ad 2663 } else {
32874aea 2664 /* Shouldn't happen, but we do want to initialise to _something_. */
2665 preferred_cipher = &ssh2_3des;
5e8358ad 2666 }
4ba9b64b 2667 if (cfg.compression)
2668 preferred_comp = &ssh_zlib;
2669 else
2670 preferred_comp = &ssh_comp_none;
5e8358ad 2671
7591b9ff 2672 /*
2673 * Be prepared to work around the buggy MAC problem.
2674 */
7d503c31 2675 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
32874aea 2676 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 2677 else
32874aea 2678 maclist = macs, nmacs = lenof(macs);
7591b9ff 2679
32874aea 2680 begin_key_exchange:
e5574168 2681 /*
2682 * Construct and send our key exchange packet.
2683 */
2684 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2685 for (i = 0; i < 16; i++)
32874aea 2686 ssh2_pkt_addbyte((unsigned char) random_byte());
e5574168 2687 /* List key exchange algorithms. */
2688 ssh2_pkt_addstring_start();
2689 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 2690 ssh2_pkt_addstring_str(kex_algs[i]->name);
2691 if (i < lenof(kex_algs) - 1)
2692 ssh2_pkt_addstring_str(",");
e5574168 2693 }
2694 /* List server host key algorithms. */
2695 ssh2_pkt_addstring_start();
2696 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 2697 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2698 if (i < lenof(hostkey_algs) - 1)
2699 ssh2_pkt_addstring_str(",");
e5574168 2700 }
2701 /* List client->server encryption algorithms. */
2702 ssh2_pkt_addstring_start();
32874aea 2703 for (i = 0; i < lenof(ciphers) + 1; i++) {
2704 const struct ssh2_ciphers *c =
2705 i == 0 ? preferred_cipher : ciphers[i - 1];
2706 for (j = 0; j < c->nciphers; j++) {
2707 ssh2_pkt_addstring_str(c->list[j]->name);
2708 if (i < lenof(ciphers) || j < c->nciphers - 1)
2709 ssh2_pkt_addstring_str(",");
2710 }
e5574168 2711 }
2712 /* List server->client encryption algorithms. */
2713 ssh2_pkt_addstring_start();
32874aea 2714 for (i = 0; i < lenof(ciphers) + 1; i++) {
2715 const struct ssh2_ciphers *c =
2716 i == 0 ? preferred_cipher : ciphers[i - 1];
2717 for (j = 0; j < c->nciphers; j++) {
2718 ssh2_pkt_addstring_str(c->list[j]->name);
2719 if (i < lenof(ciphers) || j < c->nciphers - 1)
2720 ssh2_pkt_addstring_str(",");
2721 }
e5574168 2722 }
2723 /* List client->server MAC algorithms. */
2724 ssh2_pkt_addstring_start();
8b2715b2 2725 for (i = 0; i < nmacs; i++) {
32874aea 2726 ssh2_pkt_addstring_str(maclist[i]->name);
2727 if (i < nmacs - 1)
2728 ssh2_pkt_addstring_str(",");
e5574168 2729 }
2730 /* List server->client MAC algorithms. */
2731 ssh2_pkt_addstring_start();
8b2715b2 2732 for (i = 0; i < nmacs; i++) {
32874aea 2733 ssh2_pkt_addstring_str(maclist[i]->name);
2734 if (i < nmacs - 1)
2735 ssh2_pkt_addstring_str(",");
e5574168 2736 }
2737 /* List client->server compression algorithms. */
2738 ssh2_pkt_addstring_start();
32874aea 2739 for (i = 0; i < lenof(compressions) + 1; i++) {
2740 const struct ssh_compress *c =
2741 i == 0 ? preferred_comp : compressions[i - 1];
2742 ssh2_pkt_addstring_str(c->name);
2743 if (i < lenof(compressions))
2744 ssh2_pkt_addstring_str(",");
e5574168 2745 }
2746 /* List server->client compression algorithms. */
2747 ssh2_pkt_addstring_start();
32874aea 2748 for (i = 0; i < lenof(compressions) + 1; i++) {
2749 const struct ssh_compress *c =
2750 i == 0 ? preferred_comp : compressions[i - 1];
2751 ssh2_pkt_addstring_str(c->name);
2752 if (i < lenof(compressions))
2753 ssh2_pkt_addstring_str(",");
e5574168 2754 }
2755 /* List client->server languages. Empty list. */
2756 ssh2_pkt_addstring_start();
2757 /* List server->client languages. Empty list. */
2758 ssh2_pkt_addstring_start();
2759 /* First KEX packet does _not_ follow, because we're not that brave. */
2760 ssh2_pkt_addbool(FALSE);
2761 /* Reserved. */
2762 ssh2_pkt_adduint32(0);
0db56f73 2763
2764 exhash = exhashbase;
32874aea 2765 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
0db56f73 2766
e5574168 2767 ssh2_pkt_send();
2768
32874aea 2769 if (!ispkt)
2770 crWaitUntil(ispkt);
2771 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
e5574168 2772
2773 /*
2774 * Now examine the other side's KEXINIT to see what we're up
2775 * to.
2776 */
7cca0d81 2777 if (pktin.type != SSH2_MSG_KEXINIT) {
32874aea 2778 bombout(("expected key exchange packet from server"));
2779 crReturn(0);
7cca0d81 2780 }
32874aea 2781 kex = NULL;
2782 hostkey = NULL;
2783 cscipher_tobe = NULL;
2784 sccipher_tobe = NULL;
2785 csmac_tobe = NULL;
2786 scmac_tobe = NULL;
2787 cscomp_tobe = NULL;
2788 sccomp_tobe = NULL;
2789 pktin.savedpos += 16; /* skip garbage cookie */
e5574168 2790 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2791 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 2792 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2793 kex = kex_algs[i];
2794 break;
2795 }
e5574168 2796 }
2797 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2798 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 2799 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2800 hostkey = hostkey_algs[i];
2801 break;
2802 }
e5574168 2803 }
2804 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
32874aea 2805 for (i = 0; i < lenof(ciphers) + 1; i++) {
2806 const struct ssh2_ciphers *c =
2807 i == 0 ? preferred_cipher : ciphers[i - 1];
2808 for (j = 0; j < c->nciphers; j++) {
2809 if (in_commasep_string(c->list[j]->name, str, len)) {
2810 cscipher_tobe = c->list[j];
2811 break;
2812 }
2813 }
2814 if (cscipher_tobe)
2815 break;
e5574168 2816 }
2817 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
32874aea 2818 for (i = 0; i < lenof(ciphers) + 1; i++) {
2819 const struct ssh2_ciphers *c =
2820 i == 0 ? preferred_cipher : ciphers[i - 1];
2821 for (j = 0; j < c->nciphers; j++) {
2822 if (in_commasep_string(c->list[j]->name, str, len)) {
2823 sccipher_tobe = c->list[j];
2824 break;
2825 }
2826 }
2827 if (sccipher_tobe)
2828 break;
e5574168 2829 }
2830 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 2831 for (i = 0; i < nmacs; i++) {
32874aea 2832 if (in_commasep_string(maclist[i]->name, str, len)) {
2833 csmac_tobe = maclist[i];
2834 break;
2835 }
e5574168 2836 }
2837 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 2838 for (i = 0; i < nmacs; i++) {
32874aea 2839 if (in_commasep_string(maclist[i]->name, str, len)) {
2840 scmac_tobe = maclist[i];
2841 break;
2842 }
e5574168 2843 }
2844 ssh2_pkt_getstring(&str, &len); /* client->server compression */
32874aea 2845 for (i = 0; i < lenof(compressions) + 1; i++) {
2846 const struct ssh_compress *c =
2847 i == 0 ? preferred_comp : compressions[i - 1];
2848 if (in_commasep_string(c->name, str, len)) {
2849 cscomp_tobe = c;
2850 break;
2851 }
e5574168 2852 }
2853 ssh2_pkt_getstring(&str, &len); /* server->client compression */
32874aea 2854 for (i = 0; i < lenof(compressions) + 1; i++) {
2855 const struct ssh_compress *c =
2856 i == 0 ? preferred_comp : compressions[i - 1];
2857 if (in_commasep_string(c->name, str, len)) {
2858 sccomp_tobe = c;
2859 break;
2860 }
e5574168 2861 }
e5574168 2862
2863 /*
7bd5a860 2864 * Work out the number of bits of key we will need from the key
2865 * exchange. We start with the maximum key length of either
2866 * cipher...
2867 */
2868 {
32874aea 2869 int csbits, scbits;
7bd5a860 2870
2871 csbits = cscipher_tobe->keylen;
2872 scbits = sccipher_tobe->keylen;
2873 nbits = (csbits > scbits ? csbits : scbits);
2874 }
2875 /* The keys only have 160-bit entropy, since they're based on
2876 * a SHA-1 hash. So cap the key size at 160 bits. */
32874aea 2877 if (nbits > 160)
2878 nbits = 160;
7bd5a860 2879
2880 /*
a92dd380 2881 * If we're doing Diffie-Hellman group exchange, start by
2882 * requesting a group.
e5574168 2883 */
a92dd380 2884 if (kex == &ssh_diffiehellman_gex) {
32874aea 2885 logevent("Doing Diffie-Hellman group exchange");
2886 /*
2887 * Work out how big a DH group we will need to allow that
2888 * much data.
7bd5a860 2889 */
32874aea 2890 pbits = 512 << ((nbits - 1) / 64);
2891 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
2892 ssh2_pkt_adduint32(pbits);
2893 ssh2_pkt_send();
2894
2895 crWaitUntil(ispkt);
2896 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
2897 bombout(("expected key exchange group packet from server"));
2898 crReturn(0);
2899 }
2900 p = ssh2_pkt_getmp();
2901 g = ssh2_pkt_getmp();
2902 dh_setup_group(p, g);
2903 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
2904 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 2905 } else {
32874aea 2906 dh_setup_group1();
2907 kex_init_value = SSH2_MSG_KEXDH_INIT;
2908 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 2909 }
e5574168 2910
a92dd380 2911 logevent("Doing Diffie-Hellman key exchange");
e5574168 2912 /*
a92dd380 2913 * Now generate and send e for Diffie-Hellman.
e5574168 2914 */
32874aea 2915 e = dh_create_e(nbits * 2);
a92dd380 2916 ssh2_pkt_init(kex_init_value);
e5574168 2917 ssh2_pkt_addmp(e);
2918 ssh2_pkt_send();
2919
2920 crWaitUntil(ispkt);
a92dd380 2921 if (pktin.type != kex_reply_value) {
32874aea 2922 bombout(("expected key exchange reply packet from server"));
2923 crReturn(0);
7cca0d81 2924 }
e5574168 2925 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2926 f = ssh2_pkt_getmp();
e5574168 2927 ssh2_pkt_getstring(&sigdata, &siglen);
2928
2929 K = dh_find_K(f);
e5574168 2930
2931 sha_string(&exhash, hostkeydata, hostkeylen);
a92dd380 2932 if (kex == &ssh_diffiehellman_gex) {
32874aea 2933 sha_uint32(&exhash, pbits);
2934 sha_mpint(&exhash, p);
2935 sha_mpint(&exhash, g);
a92dd380 2936 }
e5574168 2937 sha_mpint(&exhash, e);
2938 sha_mpint(&exhash, f);
2939 sha_mpint(&exhash, K);
2940 SHA_Final(&exhash, exchange_hash);
2941
3709bfe9 2942 dh_cleanup();
2943
7cca0d81 2944#if 0
765c4200 2945 debug(("Exchange hash is:\n"));
2946 dmemdump(exchange_hash, 20);
7cca0d81 2947#endif
2948
e055a386 2949 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2950 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
32874aea 2951 bombout(("Server failed host key check"));
2952 crReturn(0);
8d5de777 2953 }
e5574168 2954
2955 /*
7cca0d81 2956 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2957 */
7cca0d81 2958 crWaitUntil(ispkt);
8d5de777 2959 if (pktin.type != SSH2_MSG_NEWKEYS) {
32874aea 2960 bombout(("expected new-keys packet from server"));
2961 crReturn(0);
8d5de777 2962 }
d39f364a 2963
2964 /*
7cca0d81 2965 * Authenticate remote host: verify host key. (We've already
2966 * checked the signature of the exchange hash.)
e5574168 2967 */
e055a386 2968 keystr = hostkey->fmtkey(hkey);
2969 fingerprint = hostkey->fingerprint(hkey);
d4857987 2970 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
32874aea 2971 keystr, fingerprint);
2972 if (first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 2973 logevent("Host key fingerprint is:");
2974 logevent(fingerprint);
2975 }
dcbde236 2976 sfree(fingerprint);
2977 sfree(keystr);
e055a386 2978 hostkey->freekey(hkey);
d39f364a 2979
2980 /*
7cca0d81 2981 * Send SSH2_MSG_NEWKEYS.
d39f364a 2982 */
2983 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2984 ssh2_pkt_send();
d39f364a 2985
2986 /*
2987 * Create and initialise session keys.
2988 */
2989 cscipher = cscipher_tobe;
2990 sccipher = sccipher_tobe;
2991 csmac = csmac_tobe;
2992 scmac = scmac_tobe;
2993 cscomp = cscomp_tobe;
2994 sccomp = sccomp_tobe;
4ba9b64b 2995 cscomp->compress_init();
2996 sccomp->decompress_init();
d39f364a 2997 /*
5e0d7cb8 2998 * Set IVs after keys. Here we use the exchange hash from the
2999 * _first_ key exchange.
d39f364a 3000 */
5e0d7cb8 3001 if (first_kex)
65a22376 3002 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3003 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
5e0d7cb8 3004 cscipher->setcskey(keyspace);
65a22376 3005 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
5e0d7cb8 3006 sccipher->setsckey(keyspace);
65a22376 3007 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
5e0d7cb8 3008 cscipher->setcsiv(keyspace);
65a22376 3009 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
5e0d7cb8 3010 sccipher->setsciv(keyspace);
65a22376 3011 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
5e0d7cb8 3012 csmac->setcskey(keyspace);
65a22376 3013 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
5e0d7cb8 3014 scmac->setsckey(keyspace);
d39f364a 3015
033b4cef 3016 /*
0db56f73 3017 * If this is the first key exchange phase, we must pass the
3018 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3019 * wants to see it but because it will need time to initialise
3020 * itself before it sees an actual packet. In subsequent key
3021 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3022 * it would only confuse the layer above.
3023 */
3024 if (!first_kex) {
32874aea 3025 crReturn(0);
0db56f73 3026 }
3027 first_kex = 0;
3028
3029 /*
7cca0d81 3030 * Now we're encrypting. Begin returning 1 to the protocol main
3031 * function so that other things can run on top of the
3032 * transport. If we ever see a KEXINIT, we must go back to the
3033 * start.
033b4cef 3034 */
e96adf72 3035 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 3036 crReturn(1);
e96adf72 3037 }
5e0d7cb8 3038 logevent("Server initiated key re-exchange");
7cca0d81 3039 goto begin_key_exchange;
e5574168 3040
3041 crFinish(1);
3042}
3043
7cca0d81 3044/*
783415f8 3045 * Add data to an SSH2 channel output buffer.
3046 */
32874aea 3047static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3048 int len)
3049{
3050 if (c->v2.outbufsize < c->v2.outbuflen + len) {
3051 c->v2.outbufsize = c->v2.outbuflen + len + 1024;
3052 c->v2.outbuffer = srealloc(c->v2.outbuffer, c->v2.outbufsize);
3053 }
3054 memcpy(c->v2.outbuffer + c->v2.outbuflen, buf, len);
783415f8 3055 c->v2.outbuflen += len;
3056}
3057
3058/*
3059 * Attempt to send data on an SSH2 channel.
3060 */
32874aea 3061static void ssh2_try_send(struct ssh_channel *c)
3062{
3063 while (c->v2.remwindow > 0 && c->v2.outbuflen > 0) {
3064 unsigned len = c->v2.remwindow;
3065 if (len > c->v2.outbuflen)
3066 len = c->v2.outbuflen;
3067 if (len > c->v2.remmaxpkt)
3068 len = c->v2.remmaxpkt;
3069 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3070 ssh2_pkt_adduint32(c->remoteid);
3071 ssh2_pkt_addstring_start();
3072 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
3073 ssh2_pkt_send();
3074 c->v2.outbuflen -= len;
3075 memmove(c->v2.outbuffer, c->v2.outbuffer + len, c->v2.outbuflen);
3076 c->v2.remwindow -= len;
783415f8 3077 }
3078}
3079
3080/*
7cca0d81 3081 * Handle the SSH2 userauth and connection layers.
3082 */
3083static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3084{
7cca0d81 3085 static unsigned long remote_winsize;
3086 static unsigned long remote_maxpkt;
65a22376 3087 static enum {
32874aea 3088 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
3089 AUTH_PASSWORD
65a22376 3090 } method;
1408a877 3091 static enum {
32874aea 3092 AUTH_TYPE_NONE,
3093 AUTH_TYPE_PUBLICKEY,
3094 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3095 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
3096 AUTH_TYPE_PASSWORD
1408a877 3097 } type;
1983e559 3098 static int gotit, need_pw, can_pubkey, can_passwd;
3099 static int tried_pubkey_config, tried_agent;
1408a877 3100 static int we_are_in;
65a22376 3101 static char username[100];
3102 static char pwprompt[200];
3103 static char password[100];
7cca0d81 3104
e5574168 3105 crBegin;
3106
7cca0d81 3107 /*
3108 * Request userauth protocol, and await a response to it.
3109 */
3110 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3111 ssh2_pkt_addstring("ssh-userauth");
3112 ssh2_pkt_send();
3113 crWaitUntilV(ispkt);
8d5de777 3114 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
32874aea 3115 bombout(("Server refused user authentication protocol"));
3116 crReturnV;
8d5de777 3117 }
7cca0d81 3118
3119 /*
1408a877 3120 * We repeat this whole loop, including the username prompt,
3121 * until we manage a successful authentication. If the user
3122 * types the wrong _password_, they are sent back to the
3123 * beginning to try another username. (If they specify a
3124 * username in the config, they are never asked, even if they
3125 * do give a wrong password.)
3126 *
3127 * I think this best serves the needs of
3128 *
3129 * - the people who have no configuration, no keys, and just
3130 * want to try repeated (username,password) pairs until they
3131 * type both correctly
3132 *
3133 * - people who have keys and configuration but occasionally
3134 * need to fall back to passwords
3135 *
3136 * - people with a key held in Pageant, who might not have
3137 * logged in to a particular machine before; so they want to
3138 * type a username, and then _either_ their key will be
3139 * accepted, _or_ they will type a password. If they mistype
3140 * the username they will want to be able to get back and
3141 * retype it!
7cca0d81 3142 */
1408a877 3143 do {
3144 static int pos;
7cca0d81 3145 static char c;
e5574168 3146
1408a877 3147 /*
3148 * Get a username.
3149 */
3150 pos = 0;
67779be7 3151 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
32874aea 3152 if (ssh_get_line) {
3153 if (!ssh_get_line("login as: ",
3154 username, sizeof(username), FALSE)) {
3155 /*
3156 * get_line failed to get a username.
3157 * Terminate.
3158 */
3159 logevent("No username provided. Abandoning session.");
3160 ssh_state = SSH_STATE_CLOSED;
3161 crReturnV;
3162 }
3163 } else {
3164 c_write_str("login as: ");
3165 ssh_send_ok = 1;
3166 while (pos >= 0) {
3167 crWaitUntilV(!ispkt);
3168 while (inlen--)
3169 switch (c = *in++) {
3170 case 10:
3171 case 13:
3172 username[pos] = 0;
3173 pos = -1;
3174 break;
3175 case 8:
3176 case 127:
3177 if (pos > 0) {
3178 c_write_str("\b \b");
3179 pos--;
3180 }
3181 break;
3182 case 21:
3183 case 27:
3184 while (pos > 0) {
3185 c_write_str("\b \b");
3186 pos--;
3187 }
3188 break;
3189 case 3:
3190 case 4:
3191 random_save_seed();
3192 exit(0);
3193 break;
3194 default:
3195 if (((c >= ' ' && c <= '~') ||
3196 ((unsigned char) c >= 160)) && pos < 40) {
3197 username[pos++] = c;
3198 c_write(&c, 1);
3199 }
3200 break;
3201 }
3202 }
3203 }
1408a877 3204 c_write_str("\r\n");
7cca0d81 3205 username[strcspn(username, "\n\r")] = '\0';
3206 } else {
3207 char stuff[200];
3208 strncpy(username, cfg.username, 99);
3209 username[99] = '\0';
65a22376 3210 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 3211 sprintf(stuff, "Using username \"%s\".\r\n", username);
1408a877 3212 c_write_str(stuff);
7cca0d81 3213 }
3214 }
3215
65a22376 3216 /*
1408a877 3217 * Send an authentication request using method "none": (a)
3218 * just in case it succeeds, and (b) so that we know what
3219 * authentication methods we can usefully try next.
65a22376 3220 */
1408a877 3221 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3222 ssh2_pkt_addstring(username);
32874aea 3223 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 3224 ssh2_pkt_addstring("none"); /* method */
3225 ssh2_pkt_send();
3226 type = AUTH_TYPE_NONE;
3227 gotit = FALSE;
3228 we_are_in = FALSE;
7cca0d81 3229
1408a877 3230 tried_pubkey_config = FALSE;
1983e559 3231 tried_agent = FALSE;
65a22376 3232
1408a877 3233 while (1) {
3234 /*
3235 * Wait for the result of the last authentication request.
3236 */
3237 if (!gotit)
3238 crWaitUntilV(ispkt);
3239 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 3240 char *banner;
3241 int size;
3242 /*
3243 * Don't show the banner if we're operating in
3244 * non-verbose non-interactive mode. (It's probably
3245 * a script, which means nobody will read the
3246 * banner _anyway_, and moreover the printing of
3247 * the banner will screw up processing on the
3248 * output of (say) plink.)
3249 */
3250 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3251 ssh2_pkt_getstring(&banner, &size);
3252 if (banner)
3253 c_write_untrusted(banner, size);
3254 }
1408a877 3255 crWaitUntilV(ispkt);
3256 }
3257 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3258 logevent("Access granted");
3259 we_are_in = TRUE;
3260 break;
3261 }
65a22376 3262
1408a877 3263 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
32874aea 3264 bombout(
3265 ("Strange packet received during authentication: type %d",
1408a877 3266 pktin.type));
38c4a8da 3267 crReturnV;
65a22376 3268 }
3269
1408a877 3270 gotit = FALSE;
65a22376 3271
1408a877 3272 /*
3273 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3274 * we can look at the string in it and know what we can
3275 * helpfully try next.
3276 */
3277 {
3278 char *methods;
3279 int methlen;
3280 ssh2_pkt_getstring(&methods, &methlen);
3281 if (!ssh2_pkt_getbool()) {
3282 /*
3283 * We have received an unequivocal Access
3284 * Denied. This can translate to a variety of
3285 * messages:
3286 *
3287 * - if we'd just tried "none" authentication,
3288 * it's not worth printing anything at all
3289 *
3290 * - if we'd just tried a public key _offer_,
3291 * the message should be "Server refused our
3292 * key" (or no message at all if the key
3293 * came from Pageant)
3294 *
3295 * - if we'd just tried anything else, the
3296 * message really should be "Access denied".
3297 *
3298 * Additionally, if we'd just tried password
3299 * authentication, we should break out of this
3300 * whole loop so as to go back to the username
3301 * prompt.
3302 */
3303 if (type == AUTH_TYPE_NONE) {
3304 /* do nothing */
3305 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3306 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3307 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3308 c_write_str("Server refused our key\r\n");
3309 logevent("Server refused public key");
3310 } else {
3311 c_write_str("Access denied\r\n");
3312 logevent("Access denied");
3313 if (type == AUTH_TYPE_PASSWORD) {
3314 we_are_in = FALSE;
3315 break;
3316 }
3317 }
3318 } else {
3319 c_write_str("Further authentication required\r\n");
3320 logevent("Further authentication required");
3321 }
65a22376 3322
32874aea 3323 can_pubkey =
3324 in_commasep_string("publickey", methods, methlen);
3325 can_passwd =
3326 in_commasep_string("password", methods, methlen);
1408a877 3327 }
65a22376 3328
1408a877 3329 method = 0;
65a22376 3330
78afa559 3331 if (!method && can_pubkey && agent_exists() && !tried_agent) {
1983e559 3332 /*
3333 * Attempt public-key authentication using Pageant.
3334 */
3335 static unsigned char request[5], *response, *p;
3336 static int responselen;
3337 static int i, nkeys;
3338 static int authed = FALSE;
3339 void *r;
3340
3341 tried_agent = TRUE;
3342
3343 logevent("Pageant is running. Requesting keys.");
3344
3345 /* Request the keys held by the agent. */
3346 PUT_32BIT(request, 1);
3347 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3348 agent_query(request, 5, &r, &responselen);
32874aea 3349 response = (unsigned char *) r;
95797139 3350 if (response && responselen >= 5 &&
32874aea 3351 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
1983e559 3352 p = response + 5;
32874aea 3353 nkeys = GET_32BIT(p);
3354 p += 4;
3355 {
3356 char buf[64];
3357 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3358 logevent(buf);
3359 }
1983e559 3360 for (i = 0; i < nkeys; i++) {
3361 static char *pkblob, *alg, *commentp;
3362 static int pklen, alglen, commentlen;
3363 static int siglen, retlen, len;
3364 static char *q, *agentreq, *ret;
3365
32874aea 3366 {
3367 char buf[64];
3368 sprintf(buf, "Trying Pageant key #%d", i);
3369 logevent(buf);
3370 }
3371 pklen = GET_32BIT(p);
3372 p += 4;
3373 pkblob = p;
3374 p += pklen;
1983e559 3375 alglen = GET_32BIT(pkblob);
3376 alg = pkblob + 4;
32874aea 3377 commentlen = GET_32BIT(p);
3378 p += 4;
3379 commentp = p;
3380 p += commentlen;
1983e559 3381 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3382 ssh2_pkt_addstring(username);
32874aea 3383 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3384 ssh2_pkt_addstring("publickey"); /* method */
3385 ssh2_pkt_addbool(FALSE); /* no signature included */
1983e559 3386 ssh2_pkt_addstring_start();
3387 ssh2_pkt_addstring_data(alg, alglen);
3388 ssh2_pkt_addstring_start();
3389 ssh2_pkt_addstring_data(pkblob, pklen);
3390 ssh2_pkt_send();
3391
3392 crWaitUntilV(ispkt);
3393 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3394 logevent("Key refused");
3395 continue;
3396 }
3397
32874aea 3398 if (flags & FLAG_VERBOSE) {
3399 c_write_str
3400 ("Authenticating with public key \"");
3401 c_write(commentp, commentlen);
3402 c_write_str("\" from agent\r\n");
3403 }
1983e559 3404
3405 /*
3406 * Server is willing to accept the key.
3407 * Construct a SIGN_REQUEST.
3408 */
3409 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3410 ssh2_pkt_addstring(username);
32874aea 3411 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3412 ssh2_pkt_addstring("publickey"); /* method */
1983e559 3413 ssh2_pkt_addbool(TRUE);
3414 ssh2_pkt_addstring_start();
3415 ssh2_pkt_addstring_data(alg, alglen);
3416 ssh2_pkt_addstring_start();
3417 ssh2_pkt_addstring_data(pkblob, pklen);
3418
3419 siglen = pktout.length - 5 + 4 + 20;
32874aea 3420 len = 1; /* message type */
3421 len += 4 + pklen; /* key blob */
3422 len += 4 + siglen; /* data to sign */
3423 len += 4; /* flags */
1983e559 3424 agentreq = smalloc(4 + len);
3425 PUT_32BIT(agentreq, len);
3426 q = agentreq + 4;
3427 *q++ = SSH2_AGENTC_SIGN_REQUEST;
32874aea 3428 PUT_32BIT(q, pklen);
3429 q += 4;
3430 memcpy(q, pkblob, pklen);
3431 q += pklen;
3432 PUT_32BIT(q, siglen);
3433 q += 4;
1983e559 3434 /* Now the data to be signed... */
32874aea 3435 PUT_32BIT(q, 20);
3436 q += 4;
3437 memcpy(q, ssh2_session_id, 20);
3438 q += 20;
3439 memcpy(q, pktout.data + 5, pktout.length - 5);
3440 q += pktout.length - 5;
1983e559 3441 /* And finally the (zero) flags word. */
3442 PUT_32BIT(q, 0);
32874aea 3443 agent_query(agentreq, len + 4, &ret, &retlen);
1983e559 3444 sfree(agentreq);
3445 if (ret) {
3446 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3447 logevent("Sending Pageant's response");
3448 ssh2_pkt_addstring_start();
32874aea 3449 ssh2_pkt_addstring_data(ret + 9,
3450 GET_32BIT(ret +
3451 5));
1983e559 3452 ssh2_pkt_send();
3453 authed = TRUE;
3454 break;
3455 } else {
32874aea 3456 logevent
3457 ("Pageant failed to answer challenge");
1983e559 3458 sfree(ret);
3459 }
3460 }
3461 }
3462 if (authed)
3463 continue;
3464 }
3465 }
3466
32874aea 3467 if (!method && can_pubkey && *cfg.keyfile
3468 && !tried_pubkey_config) {
1408a877 3469 unsigned char *pub_blob;
3470 char *algorithm, *comment;
3471 int pub_blob_len;
65a22376 3472
1408a877 3473 tried_pubkey_config = TRUE;
65a22376 3474
65a22376 3475 /*
1408a877 3476 * Try the public key supplied in the configuration.
3477 *
3478 * First, offer the public blob to see if the server is
3479 * willing to accept it.
65a22376 3480 */
1408a877 3481 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3482 &pub_blob_len);
3483 if (pub_blob) {
3484 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3485 ssh2_pkt_addstring(username);
32874aea 3486 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3487 ssh2_pkt_addstring("publickey"); /* method */
3488 ssh2_pkt_addbool(FALSE); /* no signature included */
1408a877 3489 ssh2_pkt_addstring(algorithm);
3490 ssh2_pkt_addstring_start();
3491 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3492 ssh2_pkt_send();
32874aea 3493 logevent("Offered public key"); /* FIXME */
1408a877 3494
3495 crWaitUntilV(ispkt);
3496 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3497 gotit = TRUE;
3498 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 3499 continue; /* key refused; give up on it */
1408a877 3500 }
65a22376 3501
1408a877 3502 logevent("Offer of public key accepted");
65a22376 3503 /*
1408a877 3504 * Actually attempt a serious authentication using
3505 * the key.
65a22376 3506 */
1408a877 3507 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
32874aea 3508 sprintf(pwprompt,
3509 "Passphrase for key \"%.100s\": ",
3510 comment);
1408a877 3511 need_pw = TRUE;
3512 } else {
3513 need_pw = FALSE;
3514 }
3515 c_write_str("Authenticating with public key \"");
3516 c_write_str(comment);
3517 c_write_str("\"\r\n");
3518 method = AUTH_PUBLICKEY_FILE;
65a22376 3519 }
1408a877 3520 }
3521
3522 if (!method && can_passwd) {
3523 method = AUTH_PASSWORD;
32874aea 3524 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
3525 savedhost);
1408a877 3526 need_pw = TRUE;
3527 }
3528
3529 if (need_pw) {
fa17a66e 3530 if (ssh_get_line) {
3531 if (!ssh_get_line(pwprompt, password,
32874aea 3532 sizeof(password), TRUE)) {
1408a877 3533 /*
fa17a66e 3534 * get_line failed to get a password (for
3535 * example because one was supplied on the
3536 * command line which has already failed to
3537 * work). Terminate.
1408a877 3538 */
3539 logevent("No more passwords to try");
3540 ssh_state = SSH_STATE_CLOSED;
3541 crReturnV;
3542 }
3543 } else {
3544 static int pos = 0;
3545 static char c;
3546
3547 c_write_str(pwprompt);
3548 ssh_send_ok = 1;
3549
3550 pos = 0;
3551 while (pos >= 0) {
3552 crWaitUntilV(!ispkt);
32874aea 3553 while (inlen--)
3554 switch (c = *in++) {
3555 case 10:
3556 case 13:
3557 password[pos] = 0;
3558 pos = -1;
3559 break;
3560 case 8:
3561 case 127:
3562 if (pos > 0)
3563 pos--;
3564 break;
3565 case 21:
3566 case 27:
3567 pos = 0;
3568 break;
3569 case 3:
3570 case 4:
3571 random_save_seed();
3572 exit(0);
3573 break;
3574 default:
3575 if (((c >= ' ' && c <= '~') ||
3576 ((unsigned char) c >= 160))
3577 && pos < 40)
3578 password[pos++] = c;
3579 break;
3580 }
65a22376 3581 }
1408a877 3582 c_write_str("\r\n");
65a22376 3583 }
65a22376 3584 }
65a22376 3585
1408a877 3586 if (method == AUTH_PUBLICKEY_FILE) {
3587 /*
3588 * We have our passphrase. Now try the actual authentication.
3589 */
3590 struct ssh2_userkey *key;
65a22376 3591
1408a877 3592 key = ssh2_load_userkey(cfg.keyfile, password);
3593 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3594 if (key == SSH2_WRONG_PASSPHRASE) {
3595 c_write_str("Wrong passphrase\r\n");
3596 tried_pubkey_config = FALSE;
3597 } else {
3598 c_write_str("Unable to load private key\r\n");
3599 tried_pubkey_config = TRUE;
3600 }
3601 /* Send a spurious AUTH_NONE to return to the top. */
3602 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3603 ssh2_pkt_addstring(username);
32874aea 3604 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3605 ssh2_pkt_addstring("none"); /* method */
1408a877 3606 ssh2_pkt_send();
3607 type = AUTH_TYPE_NONE;
3608 } else {
3609 unsigned char *blob, *sigdata;
3610 int blob_len, sigdata_len;
65a22376 3611
1408a877 3612 /*
3613 * We have loaded the private key and the server
3614 * has announced that it's willing to accept it.
3615 * Hallelujah. Generate a signature and send it.
3616 */
3617 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3618 ssh2_pkt_addstring(username);
32874aea 3619 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3620 ssh2_pkt_addstring("publickey"); /* method */
1408a877 3621 ssh2_pkt_addbool(TRUE);
3622 ssh2_pkt_addstring(key->alg->name);
3623 blob = key->alg->public_blob(key->data, &blob_len);
3624 ssh2_pkt_addstring_start();
3625 ssh2_pkt_addstring_data(blob, blob_len);
3626 sfree(blob);
3627
3628 /*
3629 * The data to be signed is:
3630 *
3631 * string session-id
3632 *
3633 * followed by everything so far placed in the
3634 * outgoing packet.
3635 */
3636 sigdata_len = pktout.length - 5 + 4 + 20;
3637 sigdata = smalloc(sigdata_len);
3638 PUT_32BIT(sigdata, 20);
32874aea 3639 memcpy(sigdata + 4, ssh2_session_id, 20);
3640 memcpy(sigdata + 24, pktout.data + 5,
3641 pktout.length - 5);
3642 blob =
3643 key->alg->sign(key->data, sigdata, sigdata_len,
3644 &blob_len);
1408a877 3645 ssh2_pkt_addstring_start();
3646 ssh2_pkt_addstring_data(blob, blob_len);
3647 sfree(blob);
3648 sfree(sigdata);
3649
3650 ssh2_pkt_send();
3651 type = AUTH_TYPE_PUBLICKEY;
3652 }
3653 } else if (method == AUTH_PASSWORD) {
65a22376 3654 /*
1408a877 3655 * We send the password packet lumped tightly together with
3656 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3657 * string long enough to make the total length of the two
3658 * packets constant. This should ensure that a passive
3659 * listener doing traffic analyis can't work out the length
3660 * of the password.
3661 *
3662 * For this to work, we need an assumption about the
3663 * maximum length of the password packet. I think 256 is
3664 * pretty conservative. Anyone using a password longer than
3665 * that probably doesn't have much to worry about from
3666 * people who find out how long their password is!
65a22376 3667 */
3668 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3669 ssh2_pkt_addstring(username);
32874aea 3670 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 3671 ssh2_pkt_addstring("password");
3672 ssh2_pkt_addbool(FALSE);
3673 ssh2_pkt_addstring(password);
3674 ssh2_pkt_defer();
65a22376 3675 /*
1408a877 3676 * We'll include a string that's an exact multiple of the
3677 * cipher block size. If the cipher is NULL for some
3678 * reason, we don't do this trick at all because we gain
3679 * nothing by it.
65a22376 3680 */
32874aea 3681 if (cscipher) {
3682 int stringlen, i;
3683
3684 stringlen = (256 - deferred_len);
3685 stringlen += cscipher->blksize - 1;
3686 stringlen -= (stringlen % cscipher->blksize);
3687 if (cscomp) {
3688 /*
3689 * Temporarily disable actual compression,
3690 * so we can guarantee to get this string
3691 * exactly the length we want it. The
3692 * compression-disabling routine should
3693 * return an integer indicating how many
3694 * bytes we should adjust our string length
3695 * by.
3696 */
3697 stringlen -= cscomp->disable_compression();
3698 }
1408a877 3699 ssh2_pkt_init(SSH2_MSG_IGNORE);
3700 ssh2_pkt_addstring_start();
6e9e9520 3701 for (i = 0; i < stringlen; i++) {
32874aea 3702 char c = (char) random_byte();
3703 ssh2_pkt_addstring_data(&c, 1);
65a22376 3704 }
1408a877 3705 ssh2_pkt_defer();
65a22376 3706 }
39065bed 3707 ssh_pkt_defersend();
0d43337a 3708 logevent("Sent password");
1408a877 3709 type = AUTH_TYPE_PASSWORD;
3710 } else {
32874aea 3711 c_write_str
3712 ("No supported authentication methods left to try!\r\n");
3713 logevent
3714 ("No supported authentications offered. Disconnecting");
1408a877 3715 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3716 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
32874aea 3717 ssh2_pkt_addstring
3718 ("No supported authentication methods available");
3719 ssh2_pkt_addstring("en"); /* language tag */
1408a877 3720 ssh2_pkt_send();
3721 ssh_state = SSH_STATE_CLOSED;
3722 crReturnV;
65a22376 3723 }
65a22376 3724 }
1408a877 3725 } while (!we_are_in);
7cca0d81 3726
3727 /*
3728 * Now we're authenticated for the connection protocol. The
3729 * connection protocol will automatically have started at this
3730 * point; there's no need to send SERVICE_REQUEST.
3731 */
3732
3733 /*
3734 * So now create a channel with a session in it.
3735 */
d2371c81 3736 ssh_channels = newtree234(ssh_channelcmp);
dcbde236 3737 mainchan = smalloc(sizeof(struct ssh_channel));
d2371c81 3738 mainchan->localid = alloc_channel_id();
7cca0d81 3739 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3740 ssh2_pkt_addstring("session");
d211621f 3741 ssh2_pkt_adduint32(mainchan->localid);
32874aea 3742 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3743 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 3744 ssh2_pkt_send();
3745 crWaitUntilV(ispkt);
3746 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
32874aea 3747 bombout(("Server refused to open a session"));
3748 crReturnV;
3749 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 3750 }
d211621f 3751 if (ssh2_pkt_getuint32() != mainchan->localid) {
32874aea 3752 bombout(("Server's channel confirmation cited wrong channel"));
3753 crReturnV;
7cca0d81 3754 }
d211621f 3755 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 3756 mainchan->type = CHAN_MAINSESSION;
3757 mainchan->closes = 0;
3758 mainchan->v2.remwindow = ssh2_pkt_getuint32();
3759 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
3760 mainchan->v2.outbuffer = NULL;
3761 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
783415f8 3762 add234(ssh_channels, mainchan);
7cca0d81 3763 logevent("Opened channel for session");
3764
3765 /*
783415f8 3766 * Potentially enable X11 forwarding.
3767 */
3768 if (cfg.x11_forward) {
32874aea 3769 char proto[20], data[64];
3770 logevent("Requesting X11 forwarding");
3771 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3772 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3773 ssh2_pkt_adduint32(mainchan->remoteid);
3774 ssh2_pkt_addstring("x11-req");
3775 ssh2_pkt_addbool(1); /* want reply */
3776 ssh2_pkt_addbool(0); /* many connections */
3777 ssh2_pkt_addstring(proto);
3778 ssh2_pkt_addstring(data);
3779 ssh2_pkt_adduint32(0); /* screen number */
3780 ssh2_pkt_send();
3781
3782 do {
3783 crWaitUntilV(ispkt);
3784 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3785 unsigned i = ssh2_pkt_getuint32();
3786 struct ssh_channel *c;
3787 c = find234(ssh_channels, &i, ssh_channelfind);
3788 if (!c)
3789 continue; /* nonexistent channel */
3790 c->v2.remwindow += ssh2_pkt_getuint32();
3791 }
3792 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3793
3794 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3795 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3796 bombout(("Server got confused by X11 forwarding request"));
3797 crReturnV;
3798 }
3799 logevent("X11 forwarding refused");
3800 } else {
3801 logevent("X11 forwarding enabled");
783415f8 3802 ssh_X11_fwd_enabled = TRUE;
32874aea 3803 }
783415f8 3804 }
3805
3806 /*
36c2a3e9 3807 * Potentially enable agent forwarding.
3808 */
3809 if (cfg.agentfwd && agent_exists()) {
32874aea 3810 logevent("Requesting OpenSSH-style agent forwarding");
3811 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3812 ssh2_pkt_adduint32(mainchan->remoteid);
3813 ssh2_pkt_addstring("auth-agent-req@openssh.com");
3814 ssh2_pkt_addbool(1); /* want reply */
3815 ssh2_pkt_send();
3816
3817 do {
3818 crWaitUntilV(ispkt);
3819 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3820 unsigned i = ssh2_pkt_getuint32();
3821 struct ssh_channel *c;
3822 c = find234(ssh_channels, &i, ssh_channelfind);
3823 if (!c)
3824 continue; /* nonexistent channel */
3825 c->v2.remwindow += ssh2_pkt_getuint32();
3826 }
3827 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3828
3829 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3830 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3831 bombout(
3832 ("Server got confused by agent forwarding request"));
3833 crReturnV;
3834 }
3835 logevent("Agent forwarding refused");
3836 } else {
3837 logevent("Agent forwarding enabled");
36c2a3e9 3838 ssh_agentfwd_enabled = TRUE;
32874aea 3839 }
36c2a3e9 3840 }
3841
3842 /*
7cca0d81 3843 * Now allocate a pty for the session.
3844 */
67779be7 3845 if (!cfg.nopty) {
32874aea 3846 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3847 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3848 ssh2_pkt_addstring("pty-req");
3849 ssh2_pkt_addbool(1); /* want reply */
3850 ssh2_pkt_addstring(cfg.termtype);
3851 ssh2_pkt_adduint32(cols);
3852 ssh2_pkt_adduint32(rows);
3853 ssh2_pkt_adduint32(0); /* pixel width */
3854 ssh2_pkt_adduint32(0); /* pixel height */
3855 ssh2_pkt_addstring_start();
3856 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
3857 ssh2_pkt_send();
3858 ssh_state = SSH_STATE_INTERMED;
3859
3860 do {
3861 crWaitUntilV(ispkt);
3862 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3863 unsigned i = ssh2_pkt_getuint32();
3864 struct ssh_channel *c;
3865 c = find234(ssh_channels, &i, ssh_channelfind);
3866 if (!c)
3867 continue; /* nonexistent channel */
3868 c->v2.remwindow += ssh2_pkt_getuint32();
3869 }
3870 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3871
3872 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3873 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3874 bombout(("Server got confused by pty request"));
3875 crReturnV;
3876 }
3877 c_write_str("Server refused to allocate pty\r\n");
3878 ssh_editing = ssh_echoing = 1;
3879 } else {
3880 logevent("Allocated pty");
3881 }
0965bee0 3882 } else {
32874aea 3883 ssh_editing = ssh_echoing = 1;
7cca0d81 3884 }
3885
3886 /*
67779be7 3887 * Start a shell or a remote command.
7cca0d81 3888 */
3889 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
32874aea 3890 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4a8fc3c4 3891 if (cfg.ssh_subsys) {
32874aea 3892 ssh2_pkt_addstring("subsystem");
3893 ssh2_pkt_addbool(1); /* want reply */
3894 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
96621a84 3895 } else if (*cfg.remote_cmd_ptr) {
32874aea 3896 ssh2_pkt_addstring("exec");
3897 ssh2_pkt_addbool(1); /* want reply */
3898 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
67779be7 3899 } else {
32874aea 3900 ssh2_pkt_addstring("shell");
3901 ssh2_pkt_addbool(1); /* want reply */
67779be7 3902 }
7cca0d81 3903 ssh2_pkt_send();
d211621f 3904 do {
32874aea 3905 crWaitUntilV(ispkt);
3906 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3907 unsigned i = ssh2_pkt_getuint32();
3908 struct ssh_channel *c;
3909 c = find234(ssh_channels, &i, ssh_channelfind);
3910 if (!c)
3911 continue; /* nonexistent channel */
3912 c->v2.remwindow += ssh2_pkt_getuint32();
3913 }
7cca0d81 3914 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3915 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
32874aea 3916 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3917 bombout(("Server got confused by shell/command request"));
3918 crReturnV;
3919 }
3920 bombout(("Server refused to start a shell/command"));
3921 crReturnV;
7cca0d81 3922 } else {
32874aea 3923 logevent("Started a shell/command");
7cca0d81 3924 }
3925
6e48c3fe 3926 ssh_state = SSH_STATE_SESSION;
3927 if (size_needed)
3928 ssh_size();
3687d221 3929 if (eof_needed)
32874aea 3930 ssh_special(TS_EOF);
6e48c3fe 3931
7cca0d81 3932 /*
3933 * Transfer data!
3934 */
32874aea 3935 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 3936 ssh_send_ok = 1;
7cca0d81 3937 while (1) {
32874aea 3938 static int try_send;
e5574168 3939 crReturnV;
32874aea 3940 try_send = FALSE;
7cca0d81 3941 if (ispkt) {
3942 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
32874aea 3943 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
3944 char *data;
3945 int length;
3946 unsigned i = ssh2_pkt_getuint32();
3947 struct ssh_channel *c;
3948 c = find234(ssh_channels, &i, ssh_channelfind);
3949 if (!c)
3950 continue; /* nonexistent channel */
3951 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
3952 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
3953 continue; /* extended but not stderr */
3954 ssh2_pkt_getstring(&data, &length);
3955 if (data) {
3956 switch (c->type) {
3957 case CHAN_MAINSESSION:
3958 from_backend(pktin.type ==
3959 SSH2_MSG_CHANNEL_EXTENDED_DATA, data,
3960 length);
3961 break;
3962 case CHAN_X11:
3963 x11_send(c->u.x11.s, data, length);
3964 break;
36c2a3e9 3965 case CHAN_AGENT:
32874aea 3966 while (length > 0) {
3967 if (c->u.a.lensofar < 4) {
3968 int l = min(4 - c->u.a.lensofar, length);
3969 memcpy(c->u.a.msglen + c->u.a.lensofar,
3970 data, l);
3971 data += l;
3972 length -= l;
3973 c->u.a.lensofar += l;
3974 }
3975 if (c->u.a.lensofar == 4) {
3976 c->u.a.totallen =
3977 4 + GET_32BIT(c->u.a.msglen);
3978 c->u.a.message = smalloc(c->u.a.totallen);
3979 memcpy(c->u.a.message, c->u.a.msglen, 4);
3980 }
3981 if (c->u.a.lensofar >= 4 && length > 0) {
3982 int l =
3983 min(c->u.a.totallen - c->u.a.lensofar,
3984 length);
3985 memcpy(c->u.a.message + c->u.a.lensofar,
3986 data, l);
3987 data += l;
3988 length -= l;
3989 c->u.a.lensofar += l;
3990 }
3991 if (c->u.a.lensofar == c->u.a.totallen) {
3992 void *reply, *sentreply;
3993 int replylen;
3994 agent_query(c->u.a.message,
3995 c->u.a.totallen, &reply,
3996 &replylen);
3997 if (reply)
3998 sentreply = reply;
3999 else {
4000 /* Fake SSH_AGENT_FAILURE. */
4001 sentreply = "\0\0\0\1\5";
4002 replylen = 5;
4003 }
4004 ssh2_add_channel_data(c, sentreply,
4005 replylen);
36c2a3e9 4006 try_send = TRUE;
32874aea 4007 if (reply)
4008 sfree(reply);
4009 sfree(c->u.a.message);
4010 c->u.a.lensofar = 0;
4011 }
4012 }
4013 break;
4014 }
4015 /*
4016 * Enlarge the window again at the remote
4017 * side, just in case it ever runs down and
4018 * they fail to send us any more data.
4019 */
4020 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4021 ssh2_pkt_adduint32(c->remoteid);
4022 ssh2_pkt_adduint32(length);
4023 ssh2_pkt_send();
4024 }
7cca0d81 4025 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
32874aea 4026 ssh_state = SSH_STATE_CLOSED;
d211621f 4027 logevent("Received disconnect message");
32874aea 4028 crReturnV;
7cca0d81 4029 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
32874aea 4030 continue; /* exit status et al; ignore (FIXME?) */
d211621f 4031 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
32874aea 4032 unsigned i = ssh2_pkt_getuint32();
4033 struct ssh_channel *c;
4034
4035 c = find234(ssh_channels, &i, ssh_channelfind);
4036 if (!c)
4037 continue; /* nonexistent channel */
4038
4039 if (c->type == CHAN_X11) {
4040 /*
4041 * Remote EOF on an X11 channel means we should
4042 * wrap up and close the channel ourselves.
4043 */
4044 x11_close(c->u.x11.s);
4045 sshfwd_close(c);
4046 } else if (c->type == CHAN_AGENT) {
36c2a3e9 4047 sshfwd_close(c);
4048 }
d211621f 4049 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
32874aea 4050 unsigned i = ssh2_pkt_getuint32();
4051 struct ssh_channel *c;
4052
4053 c = find234(ssh_channels, &i, ssh_channelfind);
4054 if (!c)
4055 continue; /* nonexistent channel */
4056 if (c->closes == 0) {
4057 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4058 ssh2_pkt_adduint32(c->remoteid);
4059 ssh2_pkt_send();
4060 }
4061 /* Do pre-close processing on the channel. */
4062 switch (c->type) {
4063 case CHAN_MAINSESSION:
4064 break; /* nothing to see here, move along */
4065 case CHAN_X11:
4066 break;
4067 case CHAN_AGENT:
4068 break;
4069 }
4070 del234(ssh_channels, c);
4071 sfree(c->v2.outbuffer);
4072 sfree(c);
4073
4074 /*
4075 * See if that was the last channel left open.
4076 */
4077 if (count234(ssh_channels) == 0) {
4078 logevent("All channels closed. Disconnecting");
4079 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4080 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4081 ssh2_pkt_addstring("All open channels closed");
4082 ssh2_pkt_addstring("en"); /* language tag */
4083 ssh2_pkt_send();
4084 ssh_state = SSH_STATE_CLOSED;
4085 crReturnV;
4086 }
4087 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 4088 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
32874aea 4089 unsigned i = ssh2_pkt_getuint32();
4090 struct ssh_channel *c;
4091 c = find234(ssh_channels, &i, ssh_channelfind);
4092 if (!c)
4093 continue; /* nonexistent channel */
4094 c->v2.remwindow += ssh2_pkt_getuint32();
4095 try_send = TRUE;
783415f8 4096 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 4097 char *type;
4098 int typelen;
4099 char *error = NULL;
4100 struct ssh_channel *c;
4101 ssh2_pkt_getstring(&type, &typelen);
4102 c = smalloc(sizeof(struct ssh_channel));
4103
4104 if (typelen == 3 && !memcmp(type, "x11", 3)) {
4105 if (!ssh_X11_fwd_enabled)
4106 error = "X11 forwarding is not enabled";
4107 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
4108 NULL) {
4109 error = "Unable to open an X11 connection";
4110 } else {
4111 c->type = CHAN_X11;
4112 }
4113 } else if (typelen == 22 &&
36c2a3e9 4114 !memcmp(type, "auth-agent@openssh.com", 3)) {
32874aea 4115 if (!ssh_agentfwd_enabled)
4116 error = "Agent forwarding is not enabled";
36c2a3e9 4117 else {
32874aea 4118 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 4119 c->u.a.lensofar = 0;
32874aea 4120 }
4121 } else {
4122 error = "Unsupported channel type requested";
4123 }
4124
4125 c->remoteid = ssh2_pkt_getuint32();
4126 if (error) {
4127 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
4128 ssh2_pkt_adduint32(c->remoteid);
4129 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
4130 ssh2_pkt_addstring(error);
4131 ssh2_pkt_addstring("en"); /* language tag */
4132 ssh2_pkt_send();
4133 sfree(c);
4134 } else {
4135 c->localid = alloc_channel_id();
4136 c->closes = 0;
4137 c->v2.remwindow = ssh2_pkt_getuint32();
4138 c->v2.remmaxpkt = ssh2_pkt_getuint32();
4139 c->v2.outbuffer = NULL;
4140 c->v2.outbuflen = c->v2.outbufsize = 0;
4141 add234(ssh_channels, c);
4142 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
4143 ssh2_pkt_adduint32(c->remoteid);
4144 ssh2_pkt_adduint32(c->localid);
4145 ssh2_pkt_adduint32(0x8000UL); /* our window size */
4146 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4147 ssh2_pkt_send();
4148 }
7cca0d81 4149 } else {
8d5de777 4150 bombout(("Strange packet received: type %d", pktin.type));
32874aea 4151 crReturnV;
7cca0d81 4152 }
4153 } else {
32874aea 4154 /*
4155 * We have spare data. Add it to the channel buffer.
4156 */
4157 ssh2_add_channel_data(mainchan, in, inlen);
4158 try_send = TRUE;
4159 }
4160 if (try_send) {
4161 int i;
4162 struct ssh_channel *c;
4163 /*
4164 * Try to send data on all channels if we can.
4165 */
4166 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++)
4167 ssh2_try_send(c);
7cca0d81 4168 }
e5574168 4169 }
4170
4171 crFinishV;
4172}
4173
4174/*
7cca0d81 4175 * Handle the top-level SSH2 protocol.
4176 */
4177static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
4178{
4179 if (do_ssh2_transport(in, inlen, ispkt) == 0)
32874aea 4180 return;
7cca0d81 4181 do_ssh2_authconn(in, inlen, ispkt);
4182}
4183
4184/*
8df7a775 4185 * Called to set up the connection.
374330e2 4186 *
4187 * Returns an error message, or NULL on success.
374330e2 4188 */
32874aea 4189static char *ssh_init(char *host, int port, char **realhost)
4190{
fb09bf1c 4191 char *p;
32874aea 4192
8f203108 4193#ifdef MSCRYPTOAPI
32874aea 4194 if (crypto_startup() == 0)
8f203108 4195 return "Microsoft high encryption pack not installed!";
4196#endif
374330e2 4197
8df7a775 4198 ssh_send_ok = 0;
0965bee0 4199 ssh_editing = 0;
4200 ssh_echoing = 0;
8df7a775 4201
fb09bf1c 4202 p = connect_to_host(host, port, realhost);
4203 if (p != NULL)
4204 return p;
374330e2 4205
374330e2 4206 return NULL;
4207}
4208
4209/*
374330e2 4210 * Called to send data down the Telnet connection.
4211 */
32874aea 4212static void ssh_send(char *buf, int len)
4213{
f78051a1 4214 if (s == NULL || ssh_protocol == NULL)
374330e2 4215 return;
4216
4217 ssh_protocol(buf, len, 0);
4218}
4219
4220/*
6e48c3fe 4221 * Called to set the size of the window from SSH's POV.
374330e2 4222 */
32874aea 4223static void ssh_size(void)
4224{
374330e2 4225 switch (ssh_state) {
4226 case SSH_STATE_BEFORE_SIZE:
3687d221 4227 case SSH_STATE_PREPACKET:
21248260 4228 case SSH_STATE_CLOSED:
374330e2 4229 break; /* do nothing */
4230 case SSH_STATE_INTERMED:
4231 size_needed = TRUE; /* buffer for later */
4232 break;
4233 case SSH_STATE_SESSION:
32874aea 4234 if (!cfg.nopty) {
4235 if (ssh_version == 1) {
4236 send_packet(SSH1_CMSG_WINDOW_SIZE,
4237 PKT_INT, rows, PKT_INT, cols,
4238 PKT_INT, 0, PKT_INT, 0, PKT_END);
4239 } else {
4240 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4241 ssh2_pkt_adduint32(mainchan->remoteid);
4242 ssh2_pkt_addstring("window-change");
4243 ssh2_pkt_addbool(0);
4244 ssh2_pkt_adduint32(cols);
4245 ssh2_pkt_adduint32(rows);
4246 ssh2_pkt_adduint32(0);
4247 ssh2_pkt_adduint32(0);
4248 ssh2_pkt_send();
4249 }
4250 }
4251 break;
374330e2 4252 }
4253}
4254
4255/*
6abbf9e3 4256 * Send Telnet special codes. TS_EOF is useful for `plink', so you
4257 * can send an EOF and collect resulting output (e.g. `plink
4258 * hostname sort').
374330e2 4259 */
32874aea 4260static void ssh_special(Telnet_Special code)
4261{
6abbf9e3 4262 if (code == TS_EOF) {
32874aea 4263 if (ssh_state != SSH_STATE_SESSION) {
4264 /*
4265 * Buffer the EOF in case we are pre-SESSION, so we can
4266 * send it as soon as we reach SESSION.
4267 */
4268 if (code == TS_EOF)
4269 eof_needed = TRUE;
4270 return;
4271 }
4272 if (ssh_version == 1) {
4273 send_packet(SSH1_CMSG_EOF, PKT_END);
4274 } else {
4275 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4276 ssh2_pkt_adduint32(mainchan->remoteid);
4277 ssh2_pkt_send();
4278 }
4279 logevent("Sent EOF message");
ec55b220 4280 } else if (code == TS_PING) {
32874aea 4281 if (ssh_state == SSH_STATE_CLOSED
4282 || ssh_state == SSH_STATE_PREPACKET) return;
4283 if (ssh_version == 1) {
4284 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
4285 } else {
4286 ssh2_pkt_init(SSH2_MSG_IGNORE);
4287 ssh2_pkt_addstring_start();
4288 ssh2_pkt_send();
4289 }
6abbf9e3 4290 } else {
32874aea 4291 /* do nothing */
6abbf9e3 4292 }
374330e2 4293}
4294
32874aea 4295static Socket ssh_socket(void)
4296{
4297 return s;
4298}
8ccc75b0 4299
32874aea 4300static int ssh_sendok(void)
4301{
4302 return ssh_send_ok;
4303}
fb09bf1c 4304
32874aea 4305static int ssh_ldisc(int option)
4306{
4307 if (option == LD_ECHO)
4308 return ssh_echoing;
4309 if (option == LD_EDIT)
4310 return ssh_editing;
0965bee0 4311 return FALSE;
4312}
4313
374330e2 4314Backend ssh_backend = {
4315 ssh_init,
374330e2 4316 ssh_send,
4317 ssh_size,
4017be6d 4318 ssh_special,
8ccc75b0 4319 ssh_socket,
97db3be4 4320 ssh_sendok,
0965bee0 4321 ssh_ldisc,
97db3be4 4322 22
374330e2 4323};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator