projects / u / mdw / putty / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
Ensure all backends _remember_ the connection has closed after
[u/mdw/putty] / ssh.c
CommitLineData
8df7a775 1#include <windows.h>
374330e2 2#include <stdio.h>
3#include <stdlib.h>
fb09bf1c 4#include <stdarg.h>
5#include <assert.h>
374330e2 6
7#include "putty.h"
dacbd0e8 8#include "tree234.h"
fb09bf1c 9#include "ssh.h"
374330e2 10
11#ifndef FALSE
12#define FALSE 0
13#endif
14#ifndef TRUE
15#define TRUE 1
16#endif
17
fb09bf1c 18#define logevent(s) { logevent(s); \
67779be7 19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
fb09bf1c 20 fprintf(stderr, "%s\n", s); }
21
8df7a775 22#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, sk_close(s), \
23 s = NULL, connection_fatal msg )
8d5de777 24
d211621f 25#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
26#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
27#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
28#define SSH1_CMSG_USER 4 /* 0x4 */
29#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
30#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
31#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
32#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
33#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
34#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
35#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
36#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
37#define SSH1_SMSG_SUCCESS 14 /* 0xe */
38#define SSH1_SMSG_FAILURE 15 /* 0xf */
39#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
40#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
41#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
42#define SSH1_CMSG_EOF 19 /* 0x13 */
43#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
44#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
45#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
46#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
47#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
48#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
9c964e85 49#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
50#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
51#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
d211621f 52#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
53#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
d211621f 54#define SSH1_MSG_IGNORE 32 /* 0x20 */
9c964e85 55#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
56#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
57#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
d211621f 58#define SSH1_MSG_DEBUG 36 /* 0x24 */
4ba9b64b 59#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
d211621f 60#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
61#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
62#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
63#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
64#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
65#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
66
67#define SSH1_AUTH_TIS 5 /* 0x5 */
68#define SSH1_AUTH_CCARD 16 /* 0x10 */
69
70#define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
71#define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
72#define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
73#define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
74#define SSH_AGENT_FAILURE 5 /* 0x5 */
75#define SSH_AGENT_SUCCESS 6 /* 0x6 */
76#define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
77#define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
78
79#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
80#define SSH2_MSG_IGNORE 2 /* 0x2 */
81#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
82#define SSH2_MSG_DEBUG 4 /* 0x4 */
83#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
84#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
85#define SSH2_MSG_KEXINIT 20 /* 0x14 */
86#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
87#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
88#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
89#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
95#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
96#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
97#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
98#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
99#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
100#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
101#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
102#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
103#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
104#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
105#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
106#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
107#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
108#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
109
9005f3ba 110#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
111#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
112#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
113#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
114#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
115#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
116#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
117#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
118#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
119#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
120#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
121
d211621f 122#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
123#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
124#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
125#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
126
127#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 128
129#define GET_32BIT(cp) \
130 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
131 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
132 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
133 ((unsigned long)(unsigned char)(cp)[3]))
134
135#define PUT_32BIT(cp, value) { \
136 (cp)[0] = (unsigned char)((value) >> 24); \
137 (cp)[1] = (unsigned char)((value) >> 16); \
138 (cp)[2] = (unsigned char)((value) >> 8); \
139 (cp)[3] = (unsigned char)(value); }
140
7cca0d81 141enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 142
374330e2 143/* Coroutine mechanics for the sillier bits of the code */
144#define crBegin1 static int crLine = 0;
145#define crBegin2 switch(crLine) { case 0:;
146#define crBegin crBegin1; crBegin2;
147#define crFinish(z) } crLine = 0; return (z)
148#define crFinishV } crLine = 0; return
149#define crReturn(z) \
150 do {\
151 crLine=__LINE__; return (z); case __LINE__:;\
152 } while (0)
153#define crReturnV \
154 do {\
155 crLine=__LINE__; return; case __LINE__:;\
156 } while (0)
157#define crStop(z) do{ crLine = 0; return (z); }while(0)
158#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 159#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 160#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 161
57476f6b 162extern const struct ssh_cipher ssh_3des;
163extern const struct ssh_cipher ssh_3des_ssh2;
164extern const struct ssh_cipher ssh_des;
165extern const struct ssh_cipher ssh_blowfish_ssh1;
166extern const struct ssh_cipher ssh_blowfish_ssh2;
e5574168 167
0c6c9a70 168extern char *x11_init (Socket *, char *, void *);
9c964e85 169extern void x11_close (Socket);
170extern void x11_send (Socket , char *, int);
171extern void x11_invent_auth(char *, int, char *, int);
172
5e8358ad 173/*
174 * Ciphers for SSH2. We miss out single-DES because it isn't
175 * supported; also 3DES and Blowfish are both done differently from
176 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
177 * endianness and different-sized keys.)
5e8358ad 178 */
57476f6b 179const static struct ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 };
e5574168 180
57476f6b 181extern const struct ssh_kex ssh_diffiehellman;
182const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
e5574168 183
e055a386 184extern const struct ssh_signkey ssh_dss;
185const static struct ssh_signkey *hostkey_algs[] = { &ssh_dss };
e5574168 186
8b2715b2 187extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy;
e5574168 188
d39f364a 189static void nullmac_key(unsigned char *key) { }
e5574168 190static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
191static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
57476f6b 192const static struct ssh_mac ssh_mac_none = {
d39f364a 193 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 194};
8b2715b2 195const static struct ssh_mac *macs[] = {
196 &ssh_sha1, &ssh_md5, &ssh_mac_none };
197const static struct ssh_mac *buggymacs[] = {
198 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
e5574168 199
4ba9b64b 200static void ssh_comp_none_init(void) { }
201static int ssh_comp_none_block(unsigned char *block, int len,
202 unsigned char **outblock, int *outlen) {
203 return 0;
204}
57476f6b 205const static struct ssh_compress ssh_comp_none = {
4ba9b64b 206 "none",
207 ssh_comp_none_init, ssh_comp_none_block,
208 ssh_comp_none_init, ssh_comp_none_block
e5574168 209};
4ba9b64b 210extern const struct ssh_compress ssh_zlib;
211const static struct ssh_compress *compressions[] = {
212 &ssh_zlib, &ssh_comp_none };
374330e2 213
783415f8 214enum { /* channel types */
215 CHAN_MAINSESSION,
216 CHAN_X11,
217 CHAN_AGENT,
218};
219
dacbd0e8 220/*
221 * 2-3-4 tree storing channels.
222 */
223struct ssh_channel {
d211621f 224 unsigned remoteid, localid;
dacbd0e8 225 int type;
226 int closes;
783415f8 227 struct ssh2_data_channel {
228 unsigned char *outbuffer;
229 unsigned outbuflen, outbufsize;
230 unsigned remwindow, remmaxpkt;
231 } v2;
dacbd0e8 232 union {
233 struct ssh_agent_channel {
234 unsigned char *message;
235 unsigned char msglen[4];
236 int lensofar, totallen;
237 } a;
9c964e85 238 struct ssh_x11_channel {
239 Socket s;
783415f8 240 } x11;
dacbd0e8 241 } u;
242};
57476f6b 243
244struct Packet {
245 long length;
246 int type;
247 unsigned char *data;
248 unsigned char *body;
249 long savedpos;
250 long maxlen;
251};
252
0db56f73 253static SHA_State exhash, exhashbase;
57476f6b 254
8df7a775 255static Socket s = NULL;
57476f6b 256
257static unsigned char session_key[32];
4ba9b64b 258static int ssh1_compressing;
db7d555c 259static int ssh_agentfwd_enabled;
9c964e85 260static int ssh_X11_fwd_enabled;
57476f6b 261static const struct ssh_cipher *cipher = NULL;
262static const struct ssh_cipher *cscipher = NULL;
263static const struct ssh_cipher *sccipher = NULL;
264static const struct ssh_mac *csmac = NULL;
265static const struct ssh_mac *scmac = NULL;
266static const struct ssh_compress *cscomp = NULL;
267static const struct ssh_compress *sccomp = NULL;
268static const struct ssh_kex *kex = NULL;
e055a386 269static const struct ssh_signkey *hostkey = NULL;
57476f6b 270int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
271
272static char *savedhost;
273static int savedport;
274static int ssh_send_ok;
0965bee0 275static int ssh_echoing, ssh_editing;
57476f6b 276
dacbd0e8 277static tree234 *ssh_channels; /* indexed by local id */
57476f6b 278static struct ssh_channel *mainchan; /* primary session channel */
279
280static enum {
3687d221 281 SSH_STATE_PREPACKET,
57476f6b 282 SSH_STATE_BEFORE_SIZE,
283 SSH_STATE_INTERMED,
284 SSH_STATE_SESSION,
285 SSH_STATE_CLOSED
3687d221 286} ssh_state = SSH_STATE_PREPACKET;
57476f6b 287
3687d221 288static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 289
290static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
291static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
292
293static int ssh_version;
294static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
295static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
296static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
297static void ssh_size(void);
3687d221 298static void ssh_special (Telnet_Special);
783415f8 299static void ssh2_try_send(struct ssh_channel *c);
300static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
57476f6b 301
302static int (*s_rdpkt)(unsigned char **data, int *datalen);
303
304static struct rdpkt1_state_tag {
305 long len, pad, biglen, to_read;
306 unsigned long realcrc, gotcrc;
307 unsigned char *p;
308 int i;
309 int chunk;
310} rdpkt1_state;
311
960e736a 312static struct rdpkt2_state_tag {
313 long len, pad, payload, packetlen, maclen;
314 int i;
315 int cipherblk;
316 unsigned long incoming_sequence;
317} rdpkt2_state;
318
dacbd0e8 319static int ssh_channelcmp(void *av, void *bv) {
320 struct ssh_channel *a = (struct ssh_channel *)av;
321 struct ssh_channel *b = (struct ssh_channel *)bv;
322 if (a->localid < b->localid) return -1;
323 if (a->localid > b->localid) return +1;
324 return 0;
325}
326static int ssh_channelfind(void *av, void *bv) {
d211621f 327 unsigned *a = (unsigned *)av;
dacbd0e8 328 struct ssh_channel *b = (struct ssh_channel *)bv;
329 if (*a < b->localid) return -1;
330 if (*a > b->localid) return +1;
331 return 0;
332}
333
374330e2 334static void c_write (char *buf, int len) {
67779be7 335 if ((flags & FLAG_STDERR)) {
4017be6d 336 int i;
337 for (i = 0; i < len; i++)
338 if (buf[i] != '\r')
339 fputc(buf[i], stderr);
fb09bf1c 340 return;
341 }
fe50e814 342 from_backend(1, buf, len);
3bdaf79d 343}
344
fb09bf1c 345/*
346 * Collect incoming data in the incoming packet buffer.
e5574168 347 * Decipher and verify the packet when it is completely read.
348 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 349 * Update the *data and *datalen variables.
350 * Return the additional nr of bytes needed, or 0 when
351 * a complete packet is available.
352 */
e5574168 353static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 354{
57476f6b 355 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 356
357 crBegin;
374330e2 358
fb09bf1c 359next_packet:
37508af4 360
fb09bf1c 361 pktin.type = 0;
362 pktin.length = 0;
374330e2 363
57476f6b 364 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 365 while ((*datalen) == 0)
57476f6b 366 crReturn(4-st->i);
367 st->len = (st->len << 8) + **data;
fb09bf1c 368 (*data)++, (*datalen)--;
369 }
374330e2 370
fb09bf1c 371#ifdef FWHACK
57476f6b 372 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
373 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 374 }
375#endif
374330e2 376
57476f6b 377 st->pad = 8 - (st->len % 8);
378 st->biglen = st->len + st->pad;
379 pktin.length = st->len - 5;
fb09bf1c 380
57476f6b 381 if (pktin.maxlen < st->biglen) {
382 pktin.maxlen = st->biglen;
dcbde236 383 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
384 srealloc(pktin.data, st->biglen+APIEXTRA));
fb09bf1c 385 if (!pktin.data)
386 fatalbox("Out of memory");
387 }
374330e2 388
57476f6b 389 st->to_read = st->biglen;
390 st->p = pktin.data;
391 while (st->to_read > 0) {
392 st->chunk = st->to_read;
fb09bf1c 393 while ((*datalen) == 0)
57476f6b 394 crReturn(st->to_read);
395 if (st->chunk > (*datalen))
396 st->chunk = (*datalen);
397 memcpy(st->p, *data, st->chunk);
398 *data += st->chunk;
399 *datalen -= st->chunk;
400 st->p += st->chunk;
401 st->to_read -= st->chunk;
fb09bf1c 402 }
374330e2 403
fb09bf1c 404 if (cipher)
57476f6b 405 cipher->decrypt(pktin.data, st->biglen);
698a5108 406#if 0
407 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
408 for (st->i = 0; st->i < st->biglen; st->i++)
409 debug((" %02x", (unsigned char)pktin.data[st->i]));
410 debug(("\r\n"));
411#endif
374330e2 412
57476f6b 413 st->realcrc = crc32(pktin.data, st->biglen-4);
414 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
415 if (st->gotcrc != st->realcrc) {
8d5de777 416 bombout(("Incorrect CRC received on packet"));
417 crReturn(0);
fb09bf1c 418 }
572f871e 419
4ba9b64b 420 pktin.body = pktin.data + st->pad + 1;
421
422 if (ssh1_compressing) {
423 unsigned char *decompblk;
424 int decomplen;
425#if 0
426 int i;
427 debug(("Packet payload pre-decompression:\n"));
428 for (i = -1; i < pktin.length; i++)
429 debug((" %02x", (unsigned char)pktin.body[i]));
430 debug(("\r\n"));
431#endif
432 zlib_decompress_block(pktin.body-1, pktin.length+1,
433 &decompblk, &decomplen);
434
435 if (pktin.maxlen < st->pad + decomplen) {
436 pktin.maxlen = st->pad + decomplen;
dcbde236 437 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
58298665 438 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 439 if (!pktin.data)
440 fatalbox("Out of memory");
441 }
442
443 memcpy(pktin.body-1, decompblk, decomplen);
dcbde236 444 sfree(decompblk);
4ba9b64b 445 pktin.length = decomplen-1;
446#if 0
447 debug(("Packet payload post-decompression:\n"));
448 for (i = -1; i < pktin.length; i++)
449 debug((" %02x", (unsigned char)pktin.body[i]));
450 debug(("\r\n"));
451#endif
452 }
453
e5574168 454 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
455 pktin.type == SSH1_SMSG_STDERR_DATA ||
456 pktin.type == SSH1_MSG_DEBUG ||
18515c51 457 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
458 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 459 long strlen = GET_32BIT(pktin.body);
8d5de777 460 if (strlen + 4 != pktin.length) {
461 bombout(("Received data packet with bogus string length"));
462 crReturn(0);
463 }
fb09bf1c 464 }
465
4ba9b64b 466 pktin.type = pktin.body[-1];
467
e5574168 468 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 469 /* log debug message */
470 char buf[80];
471 int strlen = GET_32BIT(pktin.body);
472 strcpy(buf, "Remote: ");
473 if (strlen > 70) strlen = 70;
474 memcpy(buf+8, pktin.body+4, strlen);
475 buf[8+strlen] = '\0';
476 logevent(buf);
477 goto next_packet;
e5574168 478 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 479 /* do nothing */
480 goto next_packet;
481 }
482
483 crFinish(0);
484}
485
e5574168 486static int ssh2_rdpkt(unsigned char **data, int *datalen)
487{
960e736a 488 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 489
490 crBegin;
491
492next_packet:
e5574168 493 pktin.type = 0;
494 pktin.length = 0;
960e736a 495 if (sccipher)
496 st->cipherblk = sccipher->blksize;
e5574168 497 else
960e736a 498 st->cipherblk = 8;
499 if (st->cipherblk < 8)
500 st->cipherblk = 8;
501
502 if (pktin.maxlen < st->cipherblk) {
503 pktin.maxlen = st->cipherblk;
dcbde236 504 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
505 srealloc(pktin.data, st->cipherblk+APIEXTRA));
e5574168 506 if (!pktin.data)
507 fatalbox("Out of memory");
508 }
509
510 /*
511 * Acquire and decrypt the first block of the packet. This will
512 * contain the length and padding details.
513 */
960e736a 514 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 515 while ((*datalen) == 0)
960e736a 516 crReturn(st->cipherblk-st->i);
517 pktin.data[st->i] = *(*data)++;
e5574168 518 (*datalen)--;
519 }
520#ifdef FWHACK
521 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
522 /* FIXME */
523 }
524#endif
525 if (sccipher)
960e736a 526 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 527
528 /*
529 * Now get the length and padding figures.
530 */
960e736a 531 st->len = GET_32BIT(pktin.data);
532 st->pad = pktin.data[4];
e5574168 533
534 /*
535 * This enables us to deduce the payload length.
536 */
960e736a 537 st->payload = st->len - st->pad - 1;
e5574168 538
960e736a 539 pktin.length = st->payload + 5;
e5574168 540
541 /*
542 * So now we can work out the total packet length.
543 */
960e736a 544 st->packetlen = st->len + 4;
545 st->maclen = scmac ? scmac->len : 0;
e5574168 546
547 /*
548 * Adjust memory allocation if packet is too big.
549 */
960e736a 550 if (pktin.maxlen < st->packetlen+st->maclen) {
551 pktin.maxlen = st->packetlen+st->maclen;
dcbde236 552 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
553 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
e5574168 554 if (!pktin.data)
555 fatalbox("Out of memory");
556 }
557
558 /*
559 * Read and decrypt the remainder of the packet.
560 */
960e736a 561 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
e5574168 562 while ((*datalen) == 0)
960e736a 563 crReturn(st->packetlen + st->maclen - st->i);
564 pktin.data[st->i] = *(*data)++;
e5574168 565 (*datalen)--;
566 }
567 /* Decrypt everything _except_ the MAC. */
568 if (sccipher)
960e736a 569 sccipher->decrypt(pktin.data + st->cipherblk,
570 st->packetlen - st->cipherblk);
e5574168 571
7cca0d81 572#if 0
960e736a 573 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
574 for (st->i = 0; st->i < st->packetlen; st->i++)
575 debug((" %02x", (unsigned char)pktin.data[st->i]));
d39f364a 576 debug(("\r\n"));
7cca0d81 577#endif
d39f364a 578
e5574168 579 /*
580 * Check the MAC.
581 */
960e736a 582 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
8d5de777 583 bombout(("Incorrect MAC received on packet"));
584 crReturn(0);
585 }
960e736a 586 st->incoming_sequence++; /* whether or not we MACed */
e5574168 587
4ba9b64b 588 /*
589 * Decompress packet payload.
590 */
591 {
592 unsigned char *newpayload;
593 int newlen;
594 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
595 &newpayload, &newlen)) {
596 if (pktin.maxlen < newlen+5) {
597 pktin.maxlen = newlen+5;
dcbde236 598 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
599 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
4ba9b64b 600 if (!pktin.data)
601 fatalbox("Out of memory");
602 }
603 pktin.length = 5 + newlen;
604 memcpy(pktin.data+5, newpayload, newlen);
605#if 0
606 debug(("Post-decompression payload:\r\n"));
607 for (st->i = 0; st->i < newlen; st->i++)
608 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
609 debug(("\r\n"));
610#endif
611
dcbde236 612 sfree(newpayload);
4ba9b64b 613 }
614 }
615
e5574168 616 pktin.savedpos = 6;
617 pktin.type = pktin.data[5];
e5574168 618
7cca0d81 619 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
620 goto next_packet; /* FIXME: print DEBUG message */
e5574168 621
622 crFinish(0);
623}
624
4ba9b64b 625static void ssh1_pktout_size(int len) {
374330e2 626 int pad, biglen;
627
628 len += 5; /* type and CRC */
629 pad = 8 - (len%8);
630 biglen = len + pad;
631
632 pktout.length = len-5;
633 if (pktout.maxlen < biglen) {
634 pktout.maxlen = biglen;
8f203108 635#ifdef MSCRYPTOAPI
fb09bf1c 636 /* Allocate enough buffer space for extra block
8f203108 637 * for MS CryptEncrypt() */
dcbde236 638 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
639 srealloc(pktout.data, biglen+12));
8f203108 640#else
dcbde236 641 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
642 srealloc(pktout.data, biglen+4));
8f203108 643#endif
374330e2 644 if (!pktout.data)
645 fatalbox("Out of memory");
646 }
4ba9b64b 647 pktout.body = pktout.data+4+pad+1;
648}
374330e2 649
4ba9b64b 650static void s_wrpkt_start(int type, int len) {
651 ssh1_pktout_size(len);
374330e2 652 pktout.type = type;
374330e2 653}
654
655static void s_wrpkt(void) {
656 int pad, len, biglen, i;
657 unsigned long crc;
658
4ba9b64b 659 pktout.body[-1] = pktout.type;
660
661 if (ssh1_compressing) {
662 unsigned char *compblk;
663 int complen;
664#if 0
665 debug(("Packet payload pre-compression:\n"));
666 for (i = -1; i < pktout.length; i++)
667 debug((" %02x", (unsigned char)pktout.body[i]));
668 debug(("\r\n"));
669#endif
670 zlib_compress_block(pktout.body-1, pktout.length+1,
671 &compblk, &complen);
672 ssh1_pktout_size(complen-1);
673 memcpy(pktout.body-1, compblk, complen);
dcbde236 674 sfree(compblk);
4ba9b64b 675#if 0
676 debug(("Packet payload post-compression:\n"));
677 for (i = -1; i < pktout.length; i++)
678 debug((" %02x", (unsigned char)pktout.body[i]));
679 debug(("\r\n"));
680#endif
681 }
682
374330e2 683 len = pktout.length + 5; /* type and CRC */
684 pad = 8 - (len%8);
685 biglen = len + pad;
686
374330e2 687 for (i=0; i<pad; i++)
688 pktout.data[i+4] = random_byte();
689 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 690 PUT_32BIT(pktout.data+biglen, crc);
691 PUT_32BIT(pktout.data, len);
374330e2 692
698a5108 693#if 0
694 debug(("Sending packet len=%d\r\n", biglen+4));
695 for (i = 0; i < biglen+4; i++)
696 debug((" %02x", (unsigned char)pktout.data[i]));
697 debug(("\r\n"));
698#endif
374330e2 699 if (cipher)
700 cipher->encrypt(pktout.data+4, biglen);
701
8df7a775 702 sk_write(s, pktout.data, biglen+4);
374330e2 703}
704
fb09bf1c 705/*
706 * Construct a packet with the specified contents and
707 * send it to the server.
708 */
709static void send_packet(int pkttype, ...)
710{
711 va_list args;
712 unsigned char *p, *argp, argchar;
713 unsigned long argint;
714 int pktlen, argtype, arglen;
7cca0d81 715 Bignum bn;
fb09bf1c 716
717 pktlen = 0;
718 va_start(args, pkttype);
719 while ((argtype = va_arg(args, int)) != PKT_END) {
720 switch (argtype) {
721 case PKT_INT:
722 (void) va_arg(args, int);
723 pktlen += 4;
724 break;
725 case PKT_CHAR:
726 (void) va_arg(args, char);
727 pktlen++;
728 break;
729 case PKT_DATA:
730 (void) va_arg(args, unsigned char *);
731 arglen = va_arg(args, int);
732 pktlen += arglen;
733 break;
734 case PKT_STR:
735 argp = va_arg(args, unsigned char *);
736 arglen = strlen(argp);
737 pktlen += 4 + arglen;
738 break;
7cca0d81 739 case PKT_BIGNUM:
740 bn = va_arg(args, Bignum);
5c58ad2d 741 pktlen += ssh1_bignum_length(bn);
7cca0d81 742 break;
fb09bf1c 743 default:
744 assert(0);
745 }
746 }
747 va_end(args);
748
749 s_wrpkt_start(pkttype, pktlen);
750 p = pktout.body;
751
752 va_start(args, pkttype);
753 while ((argtype = va_arg(args, int)) != PKT_END) {
754 switch (argtype) {
755 case PKT_INT:
756 argint = va_arg(args, int);
757 PUT_32BIT(p, argint);
758 p += 4;
759 break;
760 case PKT_CHAR:
761 argchar = va_arg(args, unsigned char);
762 *p = argchar;
763 p++;
764 break;
765 case PKT_DATA:
766 argp = va_arg(args, unsigned char *);
767 arglen = va_arg(args, int);
768 memcpy(p, argp, arglen);
769 p += arglen;
770 break;
771 case PKT_STR:
772 argp = va_arg(args, unsigned char *);
773 arglen = strlen(argp);
774 PUT_32BIT(p, arglen);
775 memcpy(p + 4, argp, arglen);
776 p += 4 + arglen;
777 break;
7cca0d81 778 case PKT_BIGNUM:
779 bn = va_arg(args, Bignum);
5c58ad2d 780 p += ssh1_write_bignum(p, bn);
7cca0d81 781 break;
fb09bf1c 782 }
783 }
784 va_end(args);
785
786 s_wrpkt();
787}
788
9697bfd2 789static int ssh_versioncmp(char *a, char *b) {
790 char *ae, *be;
791 unsigned long av, bv;
792
43aa02a7 793 av = strtoul(a, &ae, 10);
794 bv = strtoul(b, &be, 10);
9697bfd2 795 if (av != bv) return (av < bv ? -1 : +1);
796 if (*ae == '.') ae++;
797 if (*be == '.') be++;
43aa02a7 798 av = strtoul(ae, &ae, 10);
799 bv = strtoul(be, &be, 10);
9697bfd2 800 if (av != bv) return (av < bv ? -1 : +1);
801 return 0;
802}
803
e5574168 804
805/*
806 * Utility routine for putting an SSH-protocol `string' into a SHA
807 * state.
808 */
809#include <stdio.h>
75cab814 810static void sha_string(SHA_State *s, void *str, int len) {
e5574168 811 unsigned char lenblk[4];
e5574168 812 PUT_32BIT(lenblk, len);
e5574168 813 SHA_Bytes(s, lenblk, 4);
e5574168 814 SHA_Bytes(s, str, len);
815}
816
7cca0d81 817/*
818 * SSH2 packet construction functions.
819 */
783415f8 820static void ssh2_pkt_ensure(int length) {
821 if (pktout.maxlen < length) {
822 pktout.maxlen = length + 256;
dcbde236 823 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
824 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
7cca0d81 825 if (!pktout.data)
826 fatalbox("Out of memory");
827 }
783415f8 828}
829static void ssh2_pkt_adddata(void *data, int len) {
830 pktout.length += len;
831 ssh2_pkt_ensure(pktout.length);
7cca0d81 832 memcpy(pktout.data+pktout.length-len, data, len);
833}
75cab814 834static void ssh2_pkt_addbyte(unsigned char byte) {
7cca0d81 835 ssh2_pkt_adddata(&byte, 1);
836}
75cab814 837static void ssh2_pkt_init(int pkt_type) {
7cca0d81 838 pktout.length = 5;
839 ssh2_pkt_addbyte((unsigned char)pkt_type);
840}
75cab814 841static void ssh2_pkt_addbool(unsigned char value) {
7cca0d81 842 ssh2_pkt_adddata(&value, 1);
843}
75cab814 844static void ssh2_pkt_adduint32(unsigned long value) {
7cca0d81 845 unsigned char x[4];
846 PUT_32BIT(x, value);
847 ssh2_pkt_adddata(x, 4);
848}
75cab814 849static void ssh2_pkt_addstring_start(void) {
7cca0d81 850 ssh2_pkt_adduint32(0);
851 pktout.savedpos = pktout.length;
852}
75cab814 853static void ssh2_pkt_addstring_str(char *data) {
7cca0d81 854 ssh2_pkt_adddata(data, strlen(data));
855 PUT_32BIT(pktout.data + pktout.savedpos - 4,
856 pktout.length - pktout.savedpos);
857}
75cab814 858static void ssh2_pkt_addstring_data(char *data, int len) {
7cca0d81 859 ssh2_pkt_adddata(data, len);
860 PUT_32BIT(pktout.data + pktout.savedpos - 4,
861 pktout.length - pktout.savedpos);
862}
75cab814 863static void ssh2_pkt_addstring(char *data) {
7cca0d81 864 ssh2_pkt_addstring_start();
865 ssh2_pkt_addstring_str(data);
866}
75cab814 867static char *ssh2_mpint_fmt(Bignum b, int *len) {
7cca0d81 868 unsigned char *p;
869 int i, n = b[0];
dcbde236 870 p = smalloc(n * 2 + 1);
7cca0d81 871 if (!p)
872 fatalbox("out of memory");
873 p[0] = 0;
874 for (i = 0; i < n; i++) {
875 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
876 p[i*2+2] = (b[n-i] ) & 0xFF;
877 }
878 i = 0;
879 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
880 i++;
881 memmove(p, p+i, n*2+1-i);
882 *len = n*2+1-i;
883 return p;
884}
75cab814 885static void ssh2_pkt_addmp(Bignum b) {
7cca0d81 886 unsigned char *p;
887 int len;
888 p = ssh2_mpint_fmt(b, &len);
889 ssh2_pkt_addstring_start();
890 ssh2_pkt_addstring_data(p, len);
dcbde236 891 sfree(p);
7cca0d81 892}
75cab814 893static void ssh2_pkt_send(void) {
7cca0d81 894 int cipherblk, maclen, padding, i;
895 static unsigned long outgoing_sequence = 0;
896
897 /*
4ba9b64b 898 * Compress packet payload.
899 */
900#if 0
901 debug(("Pre-compression payload:\r\n"));
902 for (i = 5; i < pktout.length; i++)
903 debug((" %02x", (unsigned char)pktout.data[i]));
904 debug(("\r\n"));
905#endif
906 {
907 unsigned char *newpayload;
908 int newlen;
909 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
910 &newpayload, &newlen)) {
911 pktout.length = 5;
912 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 913 sfree(newpayload);
4ba9b64b 914 }
915 }
916
917 /*
7cca0d81 918 * Add padding. At least four bytes, and must also bring total
919 * length (minus MAC) up to a multiple of the block size.
920 */
921 cipherblk = cipher ? cipher->blksize : 8; /* block size */
922 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
923 padding = 4;
924 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 925 maclen = csmac ? csmac->len : 0;
926 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 927 pktout.data[4] = padding;
928 for (i = 0; i < padding; i++)
929 pktout.data[pktout.length + i] = random_byte();
930 PUT_32BIT(pktout.data, pktout.length + padding - 4);
931 if (csmac)
932 csmac->generate(pktout.data, pktout.length + padding,
933 outgoing_sequence);
934 outgoing_sequence++; /* whether or not we MACed */
935
936#if 0
937 debug(("Sending packet len=%d\r\n", pktout.length+padding));
938 for (i = 0; i < pktout.length+padding; i++)
939 debug((" %02x", (unsigned char)pktout.data[i]));
940 debug(("\r\n"));
941#endif
942
943 if (cscipher)
944 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 945
8df7a775 946 sk_write(s, pktout.data, pktout.length + padding + maclen);
7cca0d81 947}
948
949#if 0
950void bndebug(char *string, Bignum b) {
951 unsigned char *p;
952 int i, len;
953 p = ssh2_mpint_fmt(b, &len);
954 debug(("%s", string));
955 for (i = 0; i < len; i++)
956 debug((" %02x", p[i]));
957 debug(("\r\n"));
dcbde236 958 sfree(p);
7cca0d81 959}
960#endif
961
75cab814 962static void sha_mpint(SHA_State *s, Bignum b) {
7cca0d81 963 unsigned char *p;
964 int len;
965 p = ssh2_mpint_fmt(b, &len);
966 sha_string(s, p, len);
dcbde236 967 sfree(p);
7cca0d81 968}
969
970/*
971 * SSH2 packet decode functions.
972 */
75cab814 973static unsigned long ssh2_pkt_getuint32(void) {
7cca0d81 974 unsigned long value;
975 if (pktin.length - pktin.savedpos < 4)
976 return 0; /* arrgh, no way to decline (FIXME?) */
977 value = GET_32BIT(pktin.data+pktin.savedpos);
978 pktin.savedpos += 4;
979 return value;
980}
75cab814 981static void ssh2_pkt_getstring(char **p, int *length) {
7cca0d81 982 *p = NULL;
983 if (pktin.length - pktin.savedpos < 4)
984 return;
985 *length = GET_32BIT(pktin.data+pktin.savedpos);
986 pktin.savedpos += 4;
987 if (pktin.length - pktin.savedpos < *length)
988 return;
989 *p = pktin.data+pktin.savedpos;
990 pktin.savedpos += *length;
991}
75cab814 992static Bignum ssh2_pkt_getmp(void) {
7cca0d81 993 char *p;
994 int i, j, length;
995 Bignum b;
996
997 ssh2_pkt_getstring(&p, &length);
998 if (!p)
999 return NULL;
8d5de777 1000 if (p[0] & 0x80) {
1001 bombout(("internal error: Can't handle negative mpints"));
1002 return NULL;
1003 }
7cca0d81 1004 b = newbn((length+1)/2);
1005 for (i = 0; i < length; i++) {
1006 j = length - 1 - i;
1007 if (j & 1)
1008 b[j/2+1] |= ((unsigned char)p[i]) << 8;
1009 else
1010 b[j/2+1] |= ((unsigned char)p[i]);
1011 }
6b4e00ee 1012 while (b[0] > 1 && b[b[0]] == 0) b[0]--;
7cca0d81 1013 return b;
1014}
1015
8df7a775 1016static int do_ssh_init(unsigned char c) {
1017 static char *vsp;
1018 static char version[10];
1019 static char vstring[80];
1020 static char vlog[sizeof(vstring)+20];
1021 static int i;
374330e2 1022
8df7a775 1023 crBegin;
1024
1025 /* Search for the string "SSH-" in the input. */
374330e2 1026 i = 0;
8df7a775 1027 while (1) {
1028 static const int transS[] = { 1, 2, 2, 1 };
1029 static const int transH[] = { 0, 0, 3, 0 };
1030 static const int transminus[] = { 0, 0, 0, -1 };
1031 if (c == 'S') i = transS[i];
1032 else if (c == 'H') i = transH[i];
1033 else if (c == '-') i = transminus[i];
374330e2 1034 else i = 0;
8df7a775 1035 if (i < 0)
1036 break;
1037 crReturn(1); /* get another character */
374330e2 1038 }
8df7a775 1039
c5e9c988 1040 strcpy(vstring, "SSH-");
1041 vsp = vstring+4;
374330e2 1042 i = 0;
1043 while (1) {
8df7a775 1044 crReturn(1); /* get another char */
c5e9c988 1045 if (vsp < vstring+sizeof(vstring)-1)
1046 *vsp++ = c;
374330e2 1047 if (i >= 0) {
1048 if (c == '-') {
1049 version[i] = '\0';
1050 i = -1;
1051 } else if (i < sizeof(version)-1)
1052 version[i++] = c;
1053 }
1054 else if (c == '\n')
1055 break;
1056 }
1057
db7d555c 1058 ssh_agentfwd_enabled = FALSE;
960e736a 1059 rdpkt2_state.incoming_sequence = 0;
1060
c5e9c988 1061 *vsp = 0;
1062 sprintf(vlog, "Server version: %s", vstring);
1063 vlog[strcspn(vlog, "\r\n")] = '\0';
1064 logevent(vlog);
1065
adf799dd 1066 /*
1067 * Server version "1.99" means we can choose whether we use v1
1068 * or v2 protocol. Choice is based on cfg.sshprot.
1069 */
1070 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 1071 /*
1072 * This is a v2 server. Begin v2 protocol.
1073 */
1074 char *verstring = "SSH-2.0-PuTTY";
0db56f73 1075 SHA_Init(&exhashbase);
e5574168 1076 /*
1077 * Hash our version string and their version string.
1078 */
0db56f73 1079 sha_string(&exhashbase, verstring, strlen(verstring));
1080 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
e5574168 1081 sprintf(vstring, "%s\n", verstring);
1082 sprintf(vlog, "We claim version: %s", verstring);
1083 logevent(vlog);
1084 logevent("Using SSH protocol version 2");
8df7a775 1085 sk_write(s, vstring, strlen(vstring));
e5574168 1086 ssh_protocol = ssh2_protocol;
6abbf9e3 1087 ssh_version = 2;
e5574168 1088 s_rdpkt = ssh2_rdpkt;
1089 } else {
1090 /*
1091 * This is a v1 server. Begin v1 protocol.
1092 */
1093 sprintf(vstring, "SSH-%s-PuTTY\n",
1094 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1095 sprintf(vlog, "We claim version: %s", vstring);
1096 vlog[strcspn(vlog, "\r\n")] = '\0';
1097 logevent(vlog);
1098 logevent("Using SSH protocol version 1");
8df7a775 1099 sk_write(s, vstring, strlen(vstring));
e5574168 1100 ssh_protocol = ssh1_protocol;
6abbf9e3 1101 ssh_version = 1;
e5574168 1102 s_rdpkt = ssh1_rdpkt;
1103 }
3687d221 1104 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1105
1106 crFinish(0);
1107}
1108
1109static void ssh_gotdata(unsigned char *data, int datalen)
1110{
1111 crBegin;
1112
1113 /*
1114 * To begin with, feed the characters one by one to the
1115 * protocol initialisation / selection function do_ssh_init().
1116 * When that returns 0, we're done with the initial greeting
1117 * exchange and can move on to packet discipline.
1118 */
1119 while (1) {
1120 int ret;
1121 if (datalen == 0)
1122 crReturnV; /* more data please */
1123 ret = do_ssh_init(*data);
1124 data++; datalen--;
1125 if (ret == 0)
1126 break;
1127 }
1128
1129 /*
1130 * We emerge from that loop when the initial negotiation is
1131 * over and we have selected an s_rdpkt function. Now pass
1132 * everything to s_rdpkt, and then pass the resulting packets
1133 * to the proper protocol handler.
1134 */
1135 if (datalen == 0)
1136 crReturnV;
1137 while (1) {
1138 while (datalen > 0) {
1139 if ( s_rdpkt(&data, &datalen) == 0 ) {
1140 ssh_protocol(NULL, 0, 1);
1141 if (ssh_state == SSH_STATE_CLOSED) {
1142 return;
1143 }
1144 }
1145 }
1146 crReturnV;
1147 }
1148 crFinishV;
1149}
1150
340cf649 1151static int ssh_receive(Socket skt, int urgent, char *data, int len) {
2c94fd1c 1152 if (urgent==3) {
1153 /* A socket error has occurred. */
7dbb9f56 1154 ssh_state = SSH_STATE_CLOSED;
1155 s = NULL;
2c94fd1c 1156 connection_fatal(data);
1157 len = 0;
1158 }
8df7a775 1159 if (!len) {
1160 /* Connection has closed. */
6abb6cd7 1161 ssh_state = SSH_STATE_CLOSED;
8df7a775 1162 sk_close(s);
1163 s = NULL;
1164 return 0;
1165 }
1166 ssh_gotdata (data, len);
3257deae 1167 if (ssh_state == SSH_STATE_CLOSED) {
1168 if (s) {
1169 sk_close(s);
1170 s = NULL;
1171 }
1172 return 0;
1173 }
fef97f43 1174 return 1;
374330e2 1175}
1176
fb09bf1c 1177/*
8df7a775 1178 * Connect to specified host and port.
1179 * Returns an error message, or NULL on success.
1180 * Also places the canonical host name into `realhost'.
1181 */
1182static char *connect_to_host(char *host, int port, char **realhost)
1183{
1184 SockAddr addr;
1185 char *err;
1186#ifdef FWHACK
1187 char *FWhost;
1188 int FWport;
1189#endif
1190
dcbde236 1191 savedhost = smalloc(1+strlen(host));
8df7a775 1192 if (!savedhost)
1193 fatalbox("Out of memory");
1194 strcpy(savedhost, host);
1195
1196 if (port < 0)
1197 port = 22; /* default ssh port */
1198 savedport = port;
1199
1200#ifdef FWHACK
1201 FWhost = host;
1202 FWport = port;
1203 host = FWSTR;
1204 port = 23;
1205#endif
1206
1207 /*
1208 * Try to find host.
1209 */
1210 addr = sk_namelookup(host, realhost);
1211 if ( (err = sk_addr_error(addr)) )
1212 return err;
1213
1214#ifdef FWHACK
1215 *realhost = FWhost;
1216#endif
1217
1218 /*
1219 * Open socket.
1220 */
c91409da 1221 s = sk_new(addr, port, 0, ssh_receive);
8df7a775 1222 if ( (err = sk_socket_error(s)) )
1223 return err;
1224
1225#ifdef FWHACK
1226 sk_write(s, "connect ", 8);
1227 sk_write(s, FWhost, strlen(FWhost));
1228 {
1229 char buf[20];
1230 sprintf(buf, " %d\n", FWport);
1231 sk_write(s, buf, strlen(buf));
1232 }
1233#endif
1234
1235 return NULL;
1236}
1237
1238/*
fb09bf1c 1239 * Handle the key exchange and user authentication phases.
1240 */
e5574168 1241static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1242{
374330e2 1243 int i, j, len;
374330e2 1244 unsigned char *rsabuf, *keystr1, *keystr2;
1245 unsigned char cookie[8];
1246 struct RSAKey servkey, hostkey;
1247 struct MD5Context md5c;
ccbfb941 1248 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1249 static int tried_publickey;
1250 static unsigned char session_id[16];
bea1ef5f 1251 int cipher_type;
b585ec46 1252 static char username[100];
374330e2 1253
374330e2 1254 crBegin;
1255
fb09bf1c 1256 if (!ispkt) crWaitUntil(ispkt);
374330e2 1257
8d5de777 1258 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1259 bombout(("Public key packet not received"));
1260 crReturn(0);
1261 }
374330e2 1262
c5e9c988 1263 logevent("Received public keys");
374330e2 1264
c5e9c988 1265 memcpy(cookie, pktin.body, 8);
374330e2 1266
7cca0d81 1267 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1268 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1269
c5e9c988 1270 /*
1c2a93c4 1271 * Log the host key fingerprint.
c5e9c988 1272 */
c5e9c988 1273 {
1274 char logmsg[80];
1c2a93c4 1275 logevent("Host key fingerprint is:");
c5e9c988 1276 strcpy(logmsg, " ");
1c2a93c4 1277 hostkey.comment = NULL;
1278 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1279 &hostkey);
c5e9c988 1280 logevent(logmsg);
1281 }
1282
fb09bf1c 1283 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1284 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1285
c5e9c988 1286 MD5Init(&md5c);
374330e2 1287 MD5Update(&md5c, keystr2, hostkey.bytes);
1288 MD5Update(&md5c, keystr1, servkey.bytes);
1289 MD5Update(&md5c, pktin.body, 8);
374330e2 1290 MD5Final(session_id, &md5c);
1291
1292 for (i=0; i<32; i++)
1293 session_key[i] = random_byte();
1294
1295 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1296
dcbde236 1297 rsabuf = smalloc(len);
374330e2 1298 if (!rsabuf)
1299 fatalbox("Out of memory");
1300
89ee5268 1301 /*
1302 * Verify the host key.
1303 */
1304 {
1305 /*
1306 * First format the key into a string.
1307 */
1308 int len = rsastr_len(&hostkey);
d5859615 1309 char fingerprint[100];
dcbde236 1310 char *keystr = smalloc(len);
89ee5268 1311 if (!keystr)
1312 fatalbox("Out of memory");
1313 rsastr_fmt(keystr, &hostkey);
d5859615 1314 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1315 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
dcbde236 1316 sfree(keystr);
89ee5268 1317 }
374330e2 1318
1319 for (i=0; i<32; i++) {
1320 rsabuf[i] = session_key[i];
1321 if (i < 16)
1322 rsabuf[i] ^= session_id[i];
1323 }
1324
1325 if (hostkey.bytes > servkey.bytes) {
1326 rsaencrypt(rsabuf, 32, &servkey);
1327 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1328 } else {
1329 rsaencrypt(rsabuf, 32, &hostkey);
1330 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1331 }
1332
c5e9c988 1333 logevent("Encrypted session key");
1334
bea1ef5f 1335 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1336 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1337 SSH_CIPHER_3DES;
1338 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1339 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1340 cipher_type = SSH_CIPHER_3DES;
1341 }
c5e9c988 1342 switch (cipher_type) {
1343 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1344 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1345 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1346 }
bea1ef5f 1347
e5574168 1348 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1349 PKT_CHAR, cipher_type,
1350 PKT_DATA, cookie, 8,
1351 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1352 PKT_DATA, rsabuf, len,
1353 PKT_INT, 0,
1354 PKT_END);
1355
c5e9c988 1356 logevent("Trying to enable encryption...");
374330e2 1357
dcbde236 1358 sfree(rsabuf);
374330e2 1359
5e8358ad 1360 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1361 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1362 &ssh_3des;
374330e2 1363 cipher->sesskey(session_key);
1364
fb09bf1c 1365 crWaitUntil(ispkt);
374330e2 1366
8d5de777 1367 if (pktin.type != SSH1_SMSG_SUCCESS) {
1368 bombout(("Encryption not successfully enabled"));
1369 crReturn(0);
1370 }
374330e2 1371
c5e9c988 1372 logevent("Successfully started encryption");
1373
374330e2 1374 fflush(stdout);
1375 {
374330e2 1376 static int pos = 0;
1377 static char c;
67779be7 1378 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1379 c_write("login as: ", 10);
67779be7 1380 ssh_send_ok = 1;
374330e2 1381 while (pos >= 0) {
fb09bf1c 1382 crWaitUntil(!ispkt);
374330e2 1383 while (inlen--) switch (c = *in++) {
1384 case 10: case 13:
1385 username[pos] = 0;
1386 pos = -1;
1387 break;
1388 case 8: case 127:
1389 if (pos > 0) {
1390 c_write("\b \b", 3);
1391 pos--;
1392 }
1393 break;
1394 case 21: case 27:
1395 while (pos > 0) {
1396 c_write("\b \b", 3);
1397 pos--;
1398 }
1399 break;
1400 case 3: case 4:
1401 random_save_seed();
1402 exit(0);
1403 break;
1404 default:
40d24aa6 1405 if (((c >= ' ' && c <= '~') ||
1406 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1407 username[pos++] = c;
1408 c_write(&c, 1);
1409 }
1410 break;
1411 }
1412 }
1413 c_write("\r\n", 2);
1414 username[strcspn(username, "\n\r")] = '\0';
1415 } else {
374330e2 1416 strncpy(username, cfg.username, 99);
1417 username[99] = '\0';
374330e2 1418 }
fb09bf1c 1419
e5574168 1420 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1421 {
3c8e959b 1422 char userlog[22+sizeof(username)];
c5e9c988 1423 sprintf(userlog, "Sent username \"%s\"", username);
1424 logevent(userlog);
3c8e959b 1425 if (flags & FLAG_INTERACTIVE &&
1426 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1427 strcat(userlog, "\r\n");
1428 c_write(userlog, strlen(userlog));
1429 }
c5e9c988 1430 }
374330e2 1431 }
1432
fb09bf1c 1433 crWaitUntil(ispkt);
374330e2 1434
7cca0d81 1435 tried_publickey = 0;
1436
e5574168 1437 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1438 static char password[100];
a52f067e 1439 static char prompt[200];
374330e2 1440 static int pos;
1441 static char c;
ccbfb941 1442 static int pwpkt_type;
ccbfb941 1443 /*
1444 * Show password prompt, having first obtained it via a TIS
18515c51 1445 * or CryptoCard exchange if we're doing TIS or CryptoCard
1446 * authentication.
ccbfb941 1447 */
e5574168 1448 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1449 if (agent_exists()) {
1450 /*
1451 * Attempt RSA authentication using Pageant.
1452 */
1453 static unsigned char request[5], *response, *p;
1454 static int responselen;
1455 static int i, nkeys;
1456 static int authed = FALSE;
1457 void *r;
1458
1459 logevent("Pageant is running. Requesting keys.");
1460
1461 /* Request the keys held by the agent. */
1462 PUT_32BIT(request, 1);
1463 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1464 agent_query(request, 5, &r, &responselen);
1465 response = (unsigned char *)r;
1466 if (response) {
1467 p = response + 5;
1468 nkeys = GET_32BIT(p); p += 4;
1469 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1470 logevent(buf); }
1471 for (i = 0; i < nkeys; i++) {
1472 static struct RSAKey key;
1473 static Bignum challenge;
b8bb811a 1474 static char *commentp;
1475 static int commentlen;
5c58ad2d 1476
1477 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1478 logevent(buf); }
1479 p += 4;
1480 p += ssh1_read_bignum(p, &key.exponent);
1481 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1482 commentlen = GET_32BIT(p); p += 4;
1483 commentp = p; p += commentlen;
5c58ad2d 1484 send_packet(SSH1_CMSG_AUTH_RSA,
1485 PKT_BIGNUM, key.modulus, PKT_END);
1486 crWaitUntil(ispkt);
1487 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1488 logevent("Key refused");
1489 continue;
1490 }
1491 logevent("Received RSA challenge");
1492 ssh1_read_bignum(pktin.body, &challenge);
1493 {
1494 char *agentreq, *q, *ret;
1495 int len, retlen;
1496 len = 1 + 4; /* message type, bit count */
1497 len += ssh1_bignum_length(key.exponent);
1498 len += ssh1_bignum_length(key.modulus);
1499 len += ssh1_bignum_length(challenge);
1500 len += 16; /* session id */
1501 len += 4; /* response format */
dcbde236 1502 agentreq = smalloc(4 + len);
5c58ad2d 1503 PUT_32BIT(agentreq, len);
1504 q = agentreq + 4;
1505 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1506 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1507 q += 4;
1508 q += ssh1_write_bignum(q, key.exponent);
1509 q += ssh1_write_bignum(q, key.modulus);
1510 q += ssh1_write_bignum(q, challenge);
1511 memcpy(q, session_id, 16); q += 16;
1512 PUT_32BIT(q, 1); /* response format */
1513 agent_query(agentreq, len+4, &ret, &retlen);
dcbde236 1514 sfree(agentreq);
5c58ad2d 1515 if (ret) {
1516 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1517 logevent("Sending Pageant's response");
1518 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1519 PKT_DATA, ret+5, 16, PKT_END);
dcbde236 1520 sfree(ret);
5c58ad2d 1521 crWaitUntil(ispkt);
1522 if (pktin.type == SSH1_SMSG_SUCCESS) {
1523 logevent("Pageant's response accepted");
c4fa2fce 1524 if (flags & FLAG_VERBOSE) {
1525 c_write("Authenticated using RSA key \"",
1526 29);
1527 c_write(commentp, commentlen);
1528 c_write("\" from agent\r\n", 14);
1529 }
5c58ad2d 1530 authed = TRUE;
1531 } else
1532 logevent("Pageant's response not accepted");
1533 } else {
1534 logevent("Pageant failed to answer challenge");
dcbde236 1535 sfree(ret);
5c58ad2d 1536 }
1537 } else {
1538 logevent("No reply received from Pageant");
1539 }
1540 }
1541 freebn(key.exponent);
1542 freebn(key.modulus);
1543 freebn(challenge);
1544 if (authed)
1545 break;
1546 }
1547 }
1548 if (authed)
1549 break;
1550 }
7cca0d81 1551 if (*cfg.keyfile && !tried_publickey)
1552 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1553
a52f067e 1554 if (pktin.type == SSH1_SMSG_FAILURE &&
1555 cfg.try_tis_auth &&
1556 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1557 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1558 logevent("Requested TIS authentication");
1559 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1560 crWaitUntil(ispkt);
1561 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1562 logevent("TIS authentication declined");
1563 if (flags & FLAG_INTERACTIVE)
1564 c_write("TIS authentication refused.\r\n", 29);
1565 } else {
1566 int challengelen = ((pktin.body[0] << 24) |
1567 (pktin.body[1] << 16) |
1568 (pktin.body[2] << 8) |
1569 (pktin.body[3]));
1570 logevent("Received TIS challenge");
1571 if (challengelen > sizeof(prompt)-1)
1572 challengelen = sizeof(prompt)-1; /* prevent overrun */
1573 memcpy(prompt, pktin.body+4, challengelen);
1574 prompt[challengelen] = '\0';
1575 }
1576 }
1577 if (pktin.type == SSH1_SMSG_FAILURE &&
1578 cfg.try_tis_auth &&
1579 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1580 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1581 logevent("Requested CryptoCard authentication");
1582 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1583 crWaitUntil(ispkt);
1584 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1585 logevent("CryptoCard authentication declined");
1586 c_write("CryptoCard authentication refused.\r\n", 29);
1587 } else {
1588 int challengelen = ((pktin.body[0] << 24) |
1589 (pktin.body[1] << 16) |
1590 (pktin.body[2] << 8) |
1591 (pktin.body[3]));
1592 logevent("Received CryptoCard challenge");
1593 if (challengelen > sizeof(prompt)-1)
1594 challengelen = sizeof(prompt)-1; /* prevent overrun */
1595 memcpy(prompt, pktin.body+4, challengelen);
1596 strncpy(prompt + challengelen, "\r\nResponse : ",
1597 sizeof(prompt)-challengelen);
1598 prompt[sizeof(prompt)-1] = '\0';
1599 }
1600 }
1601 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1602 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1603 username, savedhost);
a52f067e 1604 }
1605 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1606 char *comment = NULL;
1607 if (flags & FLAG_VERBOSE)
1608 c_write("Trying public key authentication.\r\n", 35);
1609 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1610 if (flags & FLAG_VERBOSE)
1611 c_write("No passphrase required.\r\n", 25);
1612 goto tryauth;
1613 }
1614 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
dcbde236 1615 sfree(comment);
a52f067e 1616 }
1617
d8426c54 1618 if (ssh_get_password) {
85ee8208 1619 if (!ssh_get_password(prompt, password, sizeof(password))) {
1620 /*
1621 * get_password failed to get a password (for
1622 * example because one was supplied on the command
1623 * line which has already failed to work).
1624 * Terminate.
1625 */
1626 logevent("No more passwords to try");
1627 ssh_state = SSH_STATE_CLOSED;
1628 crReturn(1);
1629 }
fb09bf1c 1630 } else {
a52f067e 1631 c_write(prompt, strlen(prompt));
7cca0d81 1632 pos = 0;
67779be7 1633 ssh_send_ok = 1;
7cca0d81 1634 while (pos >= 0) {
1635 crWaitUntil(!ispkt);
1636 while (inlen--) switch (c = *in++) {
1637 case 10: case 13:
1638 password[pos] = 0;
1639 pos = -1;
1640 break;
1641 case 8: case 127:
1642 if (pos > 0)
1643 pos--;
1644 break;
1645 case 21: case 27:
1646 pos = 0;
1647 break;
1648 case 3: case 4:
1649 random_save_seed();
1650 exit(0);
1651 break;
1652 default:
1653 if (((c >= ' ' && c <= '~') ||
1654 ((unsigned char)c >= 160)) && pos < sizeof(password))
1655 password[pos++] = c;
1656 break;
1657 }
1658 }
1659 c_write("\r\n", 2);
a52f067e 1660 }
fb09bf1c 1661
7cca0d81 1662 tryauth:
1663 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1664 /*
1665 * Try public key authentication with the specified
1666 * key file.
1667 */
1668 static struct RSAKey pubkey;
1669 static Bignum challenge, response;
1670 static int i;
1671 static unsigned char buffer[32];
1672
1673 tried_publickey = 1;
6e522441 1674 i = loadrsakey(cfg.keyfile, &pubkey, NULL, password);
7cca0d81 1675 if (i == 0) {
1676 c_write("Couldn't load public key from ", 30);
1677 c_write(cfg.keyfile, strlen(cfg.keyfile));
1678 c_write(".\r\n", 3);
1679 continue; /* go and try password */
1680 }
1681 if (i == -1) {
1682 c_write("Wrong passphrase.\r\n", 19);
1683 tried_publickey = 0;
1684 continue; /* try again */
1685 }
1686
1687 /*
1688 * Send a public key attempt.
1689 */
1690 send_packet(SSH1_CMSG_AUTH_RSA,
1691 PKT_BIGNUM, pubkey.modulus, PKT_END);
1692
1693 crWaitUntil(ispkt);
1694 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1695 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1696 continue; /* go and try password */
1697 }
8d5de777 1698 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1699 bombout(("Bizarre response to offer of public key"));
1700 crReturn(0);
1701 }
7cca0d81 1702 ssh1_read_bignum(pktin.body, &challenge);
1703 response = rsadecrypt(challenge, &pubkey);
1704 freebn(pubkey.private_exponent); /* burn the evidence */
1705
1706 for (i = 0; i < 32; i += 2) {
1707 buffer[i] = response[16-i/2] >> 8;
1708 buffer[i+1] = response[16-i/2] & 0xFF;
1709 }
1710
1711 MD5Init(&md5c);
1712 MD5Update(&md5c, buffer, 32);
1713 MD5Update(&md5c, session_id, 16);
1714 MD5Final(buffer, &md5c);
1715
1716 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1717 PKT_DATA, buffer, 16, PKT_END);
1718
1719 crWaitUntil(ispkt);
1720 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1721 if (flags & FLAG_VERBOSE)
1722 c_write("Failed to authenticate with our public key.\r\n",
1723 45);
7cca0d81 1724 continue; /* go and try password */
1725 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1726 bombout(("Bizarre response to RSA authentication response"));
1727 crReturn(0);
7cca0d81 1728 }
1729
1730 break; /* we're through! */
1731 } else {
1732 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1733 }
c5e9c988 1734 logevent("Sent password");
374330e2 1735 memset(password, 0, strlen(password));
fb09bf1c 1736 crWaitUntil(ispkt);
e5574168 1737 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1738 if (flags & FLAG_VERBOSE)
1739 c_write("Access denied\r\n", 15);
c5e9c988 1740 logevent("Authentication refused");
e5574168 1741 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1742 logevent("Received disconnect request");
85ee8208 1743 ssh_state = SSH_STATE_CLOSED;
1744 crReturn(1);
e5574168 1745 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1746 bombout(("Strange packet received, type %d", pktin.type));
1747 crReturn(0);
374330e2 1748 }
1749 }
1750
c5e9c988 1751 logevent("Authentication successful");
1752
fb09bf1c 1753 crFinish(1);
1754}
1755
9c964e85 1756void sshfwd_close(struct ssh_channel *c) {
783415f8 1757 if (c) {
1758 if (ssh_version == 1) {
1759 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
1760 } else {
1761 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
1762 ssh2_pkt_adduint32(c->remoteid);
1763 ssh2_pkt_send();
1764 }
1765 c->closes = 1;
1766 if (c->type == CHAN_X11) {
1767 c->u.x11.s = NULL;
1768 logevent("X11 connection terminated");
1769 }
1770 }
9c964e85 1771}
1772
1773void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
783415f8 1774 if (ssh_version == 1) {
1775 send_packet(SSH1_MSG_CHANNEL_DATA,
1776 PKT_INT, c->remoteid,
1777 PKT_INT, len,
1778 PKT_DATA, buf, len,
1779 PKT_END);
1780 } else {
1781 ssh2_add_channel_data(c, buf, len);
1782 ssh2_try_send(c);
1783 }
9c964e85 1784}
1785
e5574168 1786static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1787 crBegin;
1788
1789 random_init();
1790
e5574168 1791 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1792 crReturnV;
85ee8208 1793 }
1794 if (ssh_state == SSH_STATE_CLOSED)
1795 crReturnV;
fb09bf1c 1796
979310f1 1797 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1798 logevent("Requesting agent forwarding");
1799 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1800 do { crReturnV; } while (!ispkt);
1801 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1802 bombout(("Protocol confusion"));
1803 crReturnV;
dacbd0e8 1804 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1805 logevent("Agent forwarding refused");
db7d555c 1806 } else {
dacbd0e8 1807 logevent("Agent forwarding enabled");
db7d555c 1808 ssh_agentfwd_enabled = TRUE;
1809 }
dacbd0e8 1810 }
1811
9c964e85 1812 if (cfg.x11_forward) {
1813 char proto[20], data[64];
1814 logevent("Requesting X11 forwarding");
1815 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
1816 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
1817 PKT_STR, proto, PKT_STR, data,
1818 PKT_INT, 0,
1819 PKT_END);
1820 do { crReturnV; } while (!ispkt);
1821 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1822 bombout(("Protocol confusion"));
1823 crReturnV;
1824 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1825 logevent("X11 forwarding refused");
1826 } else {
1827 logevent("X11 forwarding enabled");
1828 ssh_X11_fwd_enabled = TRUE;
1829 }
1830 }
1831
fef97f43 1832 if (!cfg.nopty) {
e5574168 1833 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1834 PKT_STR, cfg.termtype,
1835 PKT_INT, rows, PKT_INT, cols,
1836 PKT_INT, 0, PKT_INT, 0,
1837 PKT_CHAR, 0,
1838 PKT_END);
fef97f43 1839 ssh_state = SSH_STATE_INTERMED;
1840 do { crReturnV; } while (!ispkt);
e5574168 1841 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1842 bombout(("Protocol confusion"));
1843 crReturnV;
e5574168 1844 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1845 c_write("Server refused to allocate pty\r\n", 32);
0965bee0 1846 ssh_editing = ssh_echoing = 1;
fef97f43 1847 }
c5e9c988 1848 logevent("Allocated pty");
0965bee0 1849 } else {
1850 ssh_editing = ssh_echoing = 1;
374330e2 1851 }
1852
4ba9b64b 1853 if (cfg.compression) {
1854 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
1855 do { crReturnV; } while (!ispkt);
1856 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
1857 bombout(("Protocol confusion"));
1858 crReturnV;
1859 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1860 c_write("Server refused to compress\r\n", 32);
1861 }
1862 logevent("Started compression");
1863 ssh1_compressing = TRUE;
1864 zlib_compress_init();
1865 zlib_decompress_init();
1866 }
1867
6abbf9e3 1868 if (*cfg.remote_cmd)
1869 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1870 else
1871 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1872 logevent("Started session");
374330e2 1873
1874 ssh_state = SSH_STATE_SESSION;
1875 if (size_needed)
1876 ssh_size();
3687d221 1877 if (eof_needed)
1878 ssh_special(TS_EOF);
374330e2 1879
0965bee0 1880 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 1881 ssh_send_ok = 1;
dacbd0e8 1882 ssh_channels = newtree234(ssh_channelcmp);
374330e2 1883 while (1) {
1884 crReturnV;
1885 if (ispkt) {
e5574168 1886 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1887 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1888 long len = GET_32BIT(pktin.body);
fe50e814 1889 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
1890 pktin.body+4, len);
e5574168 1891 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1892 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1893 logevent("Received disconnect request");
3257deae 1894 crReturnV;
9c964e85 1895 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
1896 /* Remote side is trying to open a channel to talk to our
1897 * X-Server. Give them back a local channel number. */
1898 unsigned i;
1899 struct ssh_channel *c, *d;
1900 enum234 e;
1901
1902 logevent("Received X11 connect request");
1903 /* Refuse if X11 forwarding is disabled. */
1904 if (!ssh_X11_fwd_enabled) {
1905 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1906 PKT_INT, GET_32BIT(pktin.body),
1907 PKT_END);
1908 logevent("Rejected X11 connect request");
1909 } else {
9c964e85 1910 c = smalloc(sizeof(struct ssh_channel));
1911
0c6c9a70 1912 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
9c964e85 1913 logevent("opening X11 forward connection failed");
1914 sfree(c);
1915 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1916 PKT_INT, GET_32BIT(pktin.body),
1917 PKT_END);
1918 } else {
1919 logevent("opening X11 forward connection succeeded");
1920 for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) {
783415f8 1921 if (d->localid > i)
1922 break; /* found a free number */
1923 i = d->localid + 1;
9c964e85 1924 }
1925 c->remoteid = GET_32BIT(pktin.body);
1926 c->localid = i;
1927 c->closes = 0;
783415f8 1928 c->type = CHAN_X11; /* identify channel type */
9c964e85 1929 add234(ssh_channels, c);
1930 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1931 PKT_INT, c->remoteid, PKT_INT, c->localid,
1932 PKT_END);
1933 logevent("Opened X11 forward channel");
1934 }
1935 }
dacbd0e8 1936 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1937 /* Remote side is trying to open a channel to talk to our
1938 * agent. Give them back a local channel number. */
db7d555c 1939 unsigned i;
dacbd0e8 1940 struct ssh_channel *c;
1941 enum234 e;
db7d555c 1942
1943 /* Refuse if agent forwarding is disabled. */
1944 if (!ssh_agentfwd_enabled) {
1945 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
1946 PKT_INT, GET_32BIT(pktin.body),
1947 PKT_END);
1948 } else {
1949 i = 1;
1950 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1951 if (c->localid > i)
1952 break; /* found a free number */
1953 i = c->localid + 1;
1954 }
dcbde236 1955 c = smalloc(sizeof(struct ssh_channel));
db7d555c 1956 c->remoteid = GET_32BIT(pktin.body);
1957 c->localid = i;
1958 c->closes = 0;
783415f8 1959 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 1960 c->u.a.lensofar = 0;
1961 add234(ssh_channels, c);
1962 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1963 PKT_INT, c->remoteid, PKT_INT, c->localid,
1964 PKT_END);
1965 }
1966 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1967 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
dacbd0e8 1968 /* Remote side closes a channel. */
d211621f 1969 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1970 struct ssh_channel *c;
1971 c = find234(ssh_channels, &i, ssh_channelfind);
1972 if (c) {
1973 int closetype;
1974 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1975 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
783415f8 1976 if ((c->closes == 0) && (c->type == CHAN_X11)) {
9c964e85 1977 logevent("X11 connection closed");
1978 assert(c->u.x11.s != NULL);
1979 x11_close(c->u.x11.s);
1980 c->u.x11.s = NULL;
1981 }
dacbd0e8 1982 c->closes |= closetype;
1983 if (c->closes == 3) {
1984 del234(ssh_channels, c);
dcbde236 1985 sfree(c);
dacbd0e8 1986 }
1987 }
1988 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1989 /* Data sent down one of our channels. */
1990 int i = GET_32BIT(pktin.body);
1991 int len = GET_32BIT(pktin.body+4);
1992 unsigned char *p = pktin.body+8;
1993 struct ssh_channel *c;
1994 c = find234(ssh_channels, &i, ssh_channelfind);
1995 if (c) {
1996 switch(c->type) {
783415f8 1997 case CHAN_X11:
9c964e85 1998 x11_send(c->u.x11.s, p, len);
1999 break;
783415f8 2000 case CHAN_AGENT:
dacbd0e8 2001 /* Data for an agent message. Buffer it. */
2002 while (len > 0) {
2003 if (c->u.a.lensofar < 4) {
2004 int l = min(4 - c->u.a.lensofar, len);
2005 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2006 p += l; len -= l; c->u.a.lensofar += l;
2007 }
2008 if (c->u.a.lensofar == 4) {
2009 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
dcbde236 2010 c->u.a.message = smalloc(c->u.a.totallen);
dacbd0e8 2011 memcpy(c->u.a.message, c->u.a.msglen, 4);
2012 }
2013 if (c->u.a.lensofar >= 4 && len > 0) {
2014 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2015 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2016 p += l; len -= l; c->u.a.lensofar += l;
2017 }
2018 if (c->u.a.lensofar == c->u.a.totallen) {
2019 void *reply, *sentreply;
2020 int replylen;
2021 agent_query(c->u.a.message, c->u.a.totallen,
2022 &reply, &replylen);
2023 if (reply)
2024 sentreply = reply;
2025 else {
2026 /* Fake SSH_AGENT_FAILURE. */
2027 sentreply = "\0\0\0\1\5";
2028 replylen = 5;
2029 }
2030 send_packet(SSH1_MSG_CHANNEL_DATA,
2031 PKT_INT, c->remoteid,
2032 PKT_INT, replylen,
2033 PKT_DATA, sentreply, replylen,
2034 PKT_END);
2035 if (reply)
dcbde236 2036 sfree(reply);
2037 sfree(c->u.a.message);
dacbd0e8 2038 c->u.a.lensofar = 0;
2039 }
2040 }
2041 break;
2042 }
2043 }
e5574168 2044 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 2045 /* may be from EXEC_SHELL on some servers */
e5574168 2046 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 2047 /* may be from EXEC_SHELL on some servers
374330e2 2048 * if no pty is available or in other odd cases. Ignore */
e5574168 2049 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2050 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 2051 } else {
8d5de777 2052 bombout(("Strange packet received: type %d", pktin.type));
2053 crReturnV;
374330e2 2054 }
2055 } else {
8df7a775 2056 while (inlen > 0) {
2057 int len = min(inlen, 512);
2058 send_packet(SSH1_CMSG_STDIN_DATA,
2059 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2060 in += len;
2061 inlen -= len;
2062 }
374330e2 2063 }
2064 }
2065
2066 crFinishV;
2067}
2068
2069/*
e5574168 2070 * Utility routine for decoding comma-separated strings in KEXINIT.
2071 */
75cab814 2072static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 2073 int needlen = strlen(needle);
2074 while (1) {
2075 /*
2076 * Is it at the start of the string?
2077 */
2078 if (haylen >= needlen && /* haystack is long enough */
2079 !memcmp(needle, haystack, needlen) && /* initial match */
2080 (haylen == needlen || haystack[needlen] == ',')
2081 /* either , or EOS follows */
2082 )
2083 return 1;
2084 /*
2085 * If not, search for the next comma and resume after that.
2086 * If no comma found, terminate.
2087 */
2088 while (haylen > 0 && *haystack != ',')
2089 haylen--, haystack++;
2090 if (haylen == 0)
2091 return 0;
2092 haylen--, haystack++; /* skip over comma itself */
2093 }
2094}
2095
2096/*
d39f364a 2097 * SSH2 key creation method.
2098 */
75cab814 2099static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
d39f364a 2100 SHA_State s;
2101 /* First 20 bytes. */
2102 SHA_Init(&s);
2103 sha_mpint(&s, K);
2104 SHA_Bytes(&s, H, 20);
2105 SHA_Bytes(&s, &chr, 1);
2106 SHA_Bytes(&s, H, 20);
2107 SHA_Final(&s, keyspace);
2108 /* Next 20 bytes. */
2109 SHA_Init(&s);
2110 sha_mpint(&s, K);
2111 SHA_Bytes(&s, H, 20);
2112 SHA_Bytes(&s, keyspace, 20);
2113 SHA_Final(&s, keyspace+20);
2114}
2115
2116/*
7cca0d81 2117 * Handle the SSH2 transport layer.
e5574168 2118 */
7cca0d81 2119static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 2120{
2121 static int i, len;
2122 static char *str;
2123 static Bignum e, f, K;
7591b9ff 2124 static const struct ssh_mac **maclist;
8b2715b2 2125 static int nmacs;
57476f6b 2126 static const struct ssh_cipher *cscipher_tobe = NULL;
2127 static const struct ssh_cipher *sccipher_tobe = NULL;
2128 static const struct ssh_mac *csmac_tobe = NULL;
2129 static const struct ssh_mac *scmac_tobe = NULL;
2130 static const struct ssh_compress *cscomp_tobe = NULL;
2131 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 2132 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 2133 static int hostkeylen, siglen;
e055a386 2134 static void *hkey; /* actual host key */
e5574168 2135 static unsigned char exchange_hash[20];
d39f364a 2136 static unsigned char keyspace[40];
57476f6b 2137 static const struct ssh_cipher *preferred_cipher;
4ba9b64b 2138 static const struct ssh_compress *preferred_comp;
0db56f73 2139 static int first_kex;
e5574168 2140
2141 crBegin;
7cca0d81 2142 random_init();
0db56f73 2143 first_kex = 1;
e5574168 2144
5e8358ad 2145 /*
4ba9b64b 2146 * Set up the preferred cipher and compression.
5e8358ad 2147 */
2148 if (cfg.cipher == CIPHER_BLOWFISH) {
57476f6b 2149 preferred_cipher = &ssh_blowfish_ssh2;
5e8358ad 2150 } else if (cfg.cipher == CIPHER_DES) {
2151 logevent("Single DES not supported in SSH2; using 3DES");
57476f6b 2152 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 2153 } else if (cfg.cipher == CIPHER_3DES) {
57476f6b 2154 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 2155 } else {
2156 /* Shouldn't happen, but we do want to initialise to _something_. */
57476f6b 2157 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 2158 }
4ba9b64b 2159 if (cfg.compression)
2160 preferred_comp = &ssh_zlib;
2161 else
2162 preferred_comp = &ssh_comp_none;
5e8358ad 2163
7591b9ff 2164 /*
2165 * Be prepared to work around the buggy MAC problem.
2166 */
2167 if (cfg.buggymac)
8b2715b2 2168 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 2169 else
8b2715b2 2170 maclist = macs, nmacs = lenof(macs);
7591b9ff 2171
7cca0d81 2172 begin_key_exchange:
e5574168 2173 /*
2174 * Construct and send our key exchange packet.
2175 */
2176 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2177 for (i = 0; i < 16; i++)
2178 ssh2_pkt_addbyte((unsigned char)random_byte());
2179 /* List key exchange algorithms. */
2180 ssh2_pkt_addstring_start();
2181 for (i = 0; i < lenof(kex_algs); i++) {
2182 ssh2_pkt_addstring_str(kex_algs[i]->name);
2183 if (i < lenof(kex_algs)-1)
2184 ssh2_pkt_addstring_str(",");
2185 }
2186 /* List server host key algorithms. */
2187 ssh2_pkt_addstring_start();
2188 for (i = 0; i < lenof(hostkey_algs); i++) {
2189 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2190 if (i < lenof(hostkey_algs)-1)
2191 ssh2_pkt_addstring_str(",");
2192 }
2193 /* List client->server encryption algorithms. */
2194 ssh2_pkt_addstring_start();
729e54b4 2195 for (i = 0; i < lenof(ciphers)+1; i++) {
2196 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2197 ssh2_pkt_addstring_str(c->name);
729e54b4 2198 if (i < lenof(ciphers))
e5574168 2199 ssh2_pkt_addstring_str(",");
2200 }
2201 /* List server->client encryption algorithms. */
2202 ssh2_pkt_addstring_start();
729e54b4 2203 for (i = 0; i < lenof(ciphers)+1; i++) {
2204 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2205 ssh2_pkt_addstring_str(c->name);
729e54b4 2206 if (i < lenof(ciphers))
e5574168 2207 ssh2_pkt_addstring_str(",");
2208 }
2209 /* List client->server MAC algorithms. */
2210 ssh2_pkt_addstring_start();
8b2715b2 2211 for (i = 0; i < nmacs; i++) {
7591b9ff 2212 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2213 if (i < nmacs-1)
e5574168 2214 ssh2_pkt_addstring_str(",");
2215 }
2216 /* List server->client MAC algorithms. */
2217 ssh2_pkt_addstring_start();
8b2715b2 2218 for (i = 0; i < nmacs; i++) {
7591b9ff 2219 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2220 if (i < nmacs-1)
e5574168 2221 ssh2_pkt_addstring_str(",");
2222 }
2223 /* List client->server compression algorithms. */
2224 ssh2_pkt_addstring_start();
4ba9b64b 2225 for (i = 0; i < lenof(compressions)+1; i++) {
2226 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2227 ssh2_pkt_addstring_str(c->name);
2228 if (i < lenof(compressions))
e5574168 2229 ssh2_pkt_addstring_str(",");
2230 }
2231 /* List server->client compression algorithms. */
2232 ssh2_pkt_addstring_start();
4ba9b64b 2233 for (i = 0; i < lenof(compressions)+1; i++) {
2234 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2235 ssh2_pkt_addstring_str(c->name);
2236 if (i < lenof(compressions))
e5574168 2237 ssh2_pkt_addstring_str(",");
2238 }
2239 /* List client->server languages. Empty list. */
2240 ssh2_pkt_addstring_start();
2241 /* List server->client languages. Empty list. */
2242 ssh2_pkt_addstring_start();
2243 /* First KEX packet does _not_ follow, because we're not that brave. */
2244 ssh2_pkt_addbool(FALSE);
2245 /* Reserved. */
2246 ssh2_pkt_adduint32(0);
0db56f73 2247
2248 exhash = exhashbase;
e5574168 2249 sha_string(&exhash, pktout.data+5, pktout.length-5);
0db56f73 2250
e5574168 2251 ssh2_pkt_send();
2252
2253 if (!ispkt) crWaitUntil(ispkt);
2254 sha_string(&exhash, pktin.data+5, pktin.length-5);
2255
2256 /*
2257 * Now examine the other side's KEXINIT to see what we're up
2258 * to.
2259 */
7cca0d81 2260 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 2261 bombout(("expected key exchange packet from server"));
2262 crReturn(0);
7cca0d81 2263 }
e5574168 2264 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2265 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2266 pktin.savedpos += 16; /* skip garbage cookie */
2267 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2268 for (i = 0; i < lenof(kex_algs); i++) {
2269 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2270 kex = kex_algs[i];
2271 break;
2272 }
2273 }
2274 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2275 for (i = 0; i < lenof(hostkey_algs); i++) {
2276 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2277 hostkey = hostkey_algs[i];
2278 break;
2279 }
2280 }
2281 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 2282 for (i = 0; i < lenof(ciphers)+1; i++) {
2283 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2284 if (in_commasep_string(c->name, str, len)) {
729e54b4 2285 cscipher_tobe = c;
e5574168 2286 break;
2287 }
2288 }
2289 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
729e54b4 2290 for (i = 0; i < lenof(ciphers)+1; i++) {
2291 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 2292 if (in_commasep_string(c->name, str, len)) {
729e54b4 2293 sccipher_tobe = c;
e5574168 2294 break;
2295 }
2296 }
2297 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 2298 for (i = 0; i < nmacs; i++) {
7591b9ff 2299 if (in_commasep_string(maclist[i]->name, str, len)) {
2300 csmac_tobe = maclist[i];
e5574168 2301 break;
2302 }
2303 }
2304 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 2305 for (i = 0; i < nmacs; i++) {
7591b9ff 2306 if (in_commasep_string(maclist[i]->name, str, len)) {
2307 scmac_tobe = maclist[i];
e5574168 2308 break;
2309 }
2310 }
2311 ssh2_pkt_getstring(&str, &len); /* client->server compression */
4ba9b64b 2312 for (i = 0; i < lenof(compressions)+1; i++) {
2313 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2314 if (in_commasep_string(c->name, str, len)) {
2315 cscomp_tobe = c;
e5574168 2316 break;
2317 }
2318 }
2319 ssh2_pkt_getstring(&str, &len); /* server->client compression */
4ba9b64b 2320 for (i = 0; i < lenof(compressions)+1; i++) {
2321 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2322 if (in_commasep_string(c->name, str, len)) {
2323 sccomp_tobe = c;
e5574168 2324 break;
2325 }
2326 }
e5574168 2327
2328 /*
2329 * Currently we only support Diffie-Hellman and DSS, so let's
2330 * bomb out if those aren't selected.
2331 */
8d5de777 2332 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2333 bombout(("internal fault: chaos in SSH 2 transport layer"));
2334 crReturn(0);
2335 }
e5574168 2336
2337 /*
2338 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2339 */
2340 e = dh_create_e();
e5574168 2341 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2342 ssh2_pkt_addmp(e);
2343 ssh2_pkt_send();
2344
2345 crWaitUntil(ispkt);
7cca0d81 2346 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2347 bombout(("expected key exchange packet from server"));
2348 crReturn(0);
7cca0d81 2349 }
e5574168 2350 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2351 f = ssh2_pkt_getmp();
e5574168 2352 ssh2_pkt_getstring(&sigdata, &siglen);
2353
2354 K = dh_find_K(f);
e5574168 2355
2356 sha_string(&exhash, hostkeydata, hostkeylen);
2357 sha_mpint(&exhash, e);
2358 sha_mpint(&exhash, f);
2359 sha_mpint(&exhash, K);
2360 SHA_Final(&exhash, exchange_hash);
2361
7cca0d81 2362#if 0
e5574168 2363 debug(("Exchange hash is:\r\n"));
2364 for (i = 0; i < 20; i++)
2365 debug((" %02x", exchange_hash[i]));
2366 debug(("\r\n"));
7cca0d81 2367#endif
2368
e055a386 2369 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2370 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
8d5de777 2371 bombout(("Server failed host key check"));
2372 crReturn(0);
2373 }
e5574168 2374
2375 /*
7cca0d81 2376 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2377 */
7cca0d81 2378 crWaitUntil(ispkt);
8d5de777 2379 if (pktin.type != SSH2_MSG_NEWKEYS) {
2380 bombout(("expected new-keys packet from server"));
2381 crReturn(0);
2382 }
d39f364a 2383
2384 /*
7cca0d81 2385 * Authenticate remote host: verify host key. (We've already
2386 * checked the signature of the exchange hash.)
e5574168 2387 */
e055a386 2388 keystr = hostkey->fmtkey(hkey);
2389 fingerprint = hostkey->fingerprint(hkey);
d4857987 2390 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2391 keystr, fingerprint);
d5859615 2392 logevent("Host key fingerprint is:");
2393 logevent(fingerprint);
dcbde236 2394 sfree(fingerprint);
2395 sfree(keystr);
e055a386 2396 hostkey->freekey(hkey);
d39f364a 2397
2398 /*
7cca0d81 2399 * Send SSH2_MSG_NEWKEYS.
d39f364a 2400 */
2401 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2402 ssh2_pkt_send();
d39f364a 2403
2404 /*
2405 * Create and initialise session keys.
2406 */
2407 cscipher = cscipher_tobe;
2408 sccipher = sccipher_tobe;
2409 csmac = csmac_tobe;
2410 scmac = scmac_tobe;
2411 cscomp = cscomp_tobe;
2412 sccomp = sccomp_tobe;
4ba9b64b 2413 cscomp->compress_init();
2414 sccomp->decompress_init();
d39f364a 2415 /*
2416 * Set IVs after keys.
2417 */
2418 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
21d7754f 2419 ssh2_mkkey(K, exchange_hash, 'D', keyspace); sccipher->setsckey(keyspace);
d39f364a 2420 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2421 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2422 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2423 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2424
033b4cef 2425 /*
0db56f73 2426 * If this is the first key exchange phase, we must pass the
2427 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2428 * wants to see it but because it will need time to initialise
2429 * itself before it sees an actual packet. In subsequent key
2430 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2431 * it would only confuse the layer above.
2432 */
2433 if (!first_kex) {
2434 crReturn(0);
2435 }
2436 first_kex = 0;
2437
2438 /*
7cca0d81 2439 * Now we're encrypting. Begin returning 1 to the protocol main
2440 * function so that other things can run on top of the
2441 * transport. If we ever see a KEXINIT, we must go back to the
2442 * start.
033b4cef 2443 */
7cca0d81 2444 do {
2445 crReturn(1);
2446 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2447 goto begin_key_exchange;
e5574168 2448
2449 crFinish(1);
2450}
2451
7cca0d81 2452/*
783415f8 2453 * Add data to an SSH2 channel output buffer.
2454 */
2455static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2456 if (c->v2.outbufsize <
2457 c->v2.outbuflen + len) {
2458 c->v2.outbufsize =
2459 c->v2.outbuflen + len + 1024;
2460 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2461 c->v2.outbufsize);
2462 }
2463 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2464 buf, len);
2465 c->v2.outbuflen += len;
2466}
2467
2468/*
2469 * Attempt to send data on an SSH2 channel.
2470 */
2471static void ssh2_try_send(struct ssh_channel *c) {
2472 while (c->v2.remwindow > 0 &&
2473 c->v2.outbuflen > 0) {
2474 unsigned len = c->v2.remwindow;
2475 if (len > c->v2.outbuflen)
2476 len = c->v2.outbuflen;
2477 if (len > c->v2.remmaxpkt)
2478 len = c->v2.remmaxpkt;
2479 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2480 ssh2_pkt_adduint32(c->remoteid);
2481 ssh2_pkt_addstring_start();
2482 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2483 ssh2_pkt_send();
2484 c->v2.outbuflen -= len;
2485 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2486 c->v2.outbuflen);
2487 c->v2.remwindow -= len;
2488 }
2489}
2490
2491/*
7cca0d81 2492 * Handle the SSH2 userauth and connection layers.
2493 */
2494static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2495{
7cca0d81 2496 static unsigned long remote_winsize;
2497 static unsigned long remote_maxpkt;
2498
e5574168 2499 crBegin;
2500
7cca0d81 2501 /*
2502 * Request userauth protocol, and await a response to it.
2503 */
2504 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2505 ssh2_pkt_addstring("ssh-userauth");
2506 ssh2_pkt_send();
2507 crWaitUntilV(ispkt);
8d5de777 2508 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2509 bombout(("Server refused user authentication protocol"));
2510 crReturnV;
2511 }
7cca0d81 2512
2513 /*
2514 * FIXME: currently we support only password authentication.
2515 * (This places us technically in violation of the SSH2 spec.
2516 * We must fix this.)
2517 */
2518 while (1) {
2519 /*
2520 * Get a username and a password.
2521 */
2522 static char username[100];
2523 static char password[100];
2524 static int pos = 0;
2525 static char c;
e5574168 2526
67779be7 2527 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2528 c_write("login as: ", 10);
67779be7 2529 ssh_send_ok = 1;
7cca0d81 2530 while (pos >= 0) {
2531 crWaitUntilV(!ispkt);
2532 while (inlen--) switch (c = *in++) {
2533 case 10: case 13:
2534 username[pos] = 0;
2535 pos = -1;
2536 break;
2537 case 8: case 127:
2538 if (pos > 0) {
2539 c_write("\b \b", 3);
2540 pos--;
2541 }
2542 break;
2543 case 21: case 27:
2544 while (pos > 0) {
2545 c_write("\b \b", 3);
2546 pos--;
2547 }
2548 break;
2549 case 3: case 4:
2550 random_save_seed();
2551 exit(0);
2552 break;
2553 default:
2554 if (((c >= ' ' && c <= '~') ||
2555 ((unsigned char)c >= 160)) && pos < 40) {
2556 username[pos++] = c;
2557 c_write(&c, 1);
2558 }
2559 break;
2560 }
2561 }
2562 c_write("\r\n", 2);
2563 username[strcspn(username, "\n\r")] = '\0';
2564 } else {
2565 char stuff[200];
2566 strncpy(username, cfg.username, 99);
2567 username[99] = '\0';
67779be7 2568 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2569 sprintf(stuff, "Using username \"%s\".\r\n", username);
2570 c_write(stuff, strlen(stuff));
2571 }
2572 }
2573
d8426c54 2574 if (ssh_get_password) {
7cca0d81 2575 char prompt[200];
b585ec46 2576 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
7cca0d81 2577 if (!ssh_get_password(prompt, password, sizeof(password))) {
2578 /*
2579 * get_password failed to get a password (for
2580 * example because one was supplied on the command
2581 * line which has already failed to work).
2582 * Terminate.
2583 */
2584 logevent("No more passwords to try");
2585 ssh_state = SSH_STATE_CLOSED;
2586 crReturnV;
2587 }
2588 } else {
2589 c_write("password: ", 10);
67779be7 2590 ssh_send_ok = 1;
7cca0d81 2591
2592 pos = 0;
2593 while (pos >= 0) {
2594 crWaitUntilV(!ispkt);
2595 while (inlen--) switch (c = *in++) {
2596 case 10: case 13:
2597 password[pos] = 0;
2598 pos = -1;
2599 break;
2600 case 8: case 127:
2601 if (pos > 0)
2602 pos--;
2603 break;
2604 case 21: case 27:
2605 pos = 0;
2606 break;
2607 case 3: case 4:
2608 random_save_seed();
2609 exit(0);
2610 break;
2611 default:
2612 if (((c >= ' ' && c <= '~') ||
2613 ((unsigned char)c >= 160)) && pos < 40)
2614 password[pos++] = c;
2615 break;
2616 }
2617 }
2618 c_write("\r\n", 2);
2619 }
2620
2621 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2622 ssh2_pkt_addstring(username);
2623 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2624 ssh2_pkt_addstring("password");
2625 ssh2_pkt_addbool(FALSE);
2626 ssh2_pkt_addstring(password);
2627 ssh2_pkt_send();
2628
2629 crWaitUntilV(ispkt);
2630 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2631 c_write("Access denied\r\n", 15);
2632 logevent("Authentication refused");
2633 } else
2634 break;
2635 }
2636
2637 /*
2638 * Now we're authenticated for the connection protocol. The
2639 * connection protocol will automatically have started at this
2640 * point; there's no need to send SERVICE_REQUEST.
2641 */
2642
2643 /*
2644 * So now create a channel with a session in it.
2645 */
dcbde236 2646 mainchan = smalloc(sizeof(struct ssh_channel));
d211621f 2647 mainchan->localid = 100; /* as good as any */
7cca0d81 2648 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2649 ssh2_pkt_addstring("session");
d211621f 2650 ssh2_pkt_adduint32(mainchan->localid);
cf6e59d6 2651 ssh2_pkt_adduint32(0x8000UL); /* our window size */
d211621f 2652 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2653 ssh2_pkt_send();
2654 crWaitUntilV(ispkt);
2655 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2656 bombout(("Server refused to open a session"));
2657 crReturnV;
7cca0d81 2658 /* FIXME: error data comes back in FAILURE packet */
2659 }
d211621f 2660 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2661 bombout(("Server's channel confirmation cited wrong channel"));
2662 crReturnV;
7cca0d81 2663 }
d211621f 2664 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 2665 mainchan->type = CHAN_MAINSESSION;
2666 mainchan->closes = 0;
2667 mainchan->v2.remwindow = ssh2_pkt_getuint32();
2668 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
2669 mainchan->v2.outbuffer = NULL;
2670 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
2671 ssh_channels = newtree234(ssh_channelcmp);
2672 add234(ssh_channels, mainchan);
7cca0d81 2673 logevent("Opened channel for session");
2674
2675 /*
783415f8 2676 * Potentially enable X11 forwarding.
2677 */
2678 if (cfg.x11_forward) {
2679 char proto[20], data[64];
2680 logevent("Requesting X11 forwarding");
2681 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2682 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2683 ssh2_pkt_adduint32(mainchan->remoteid);
2684 ssh2_pkt_addstring("x11-req");
2685 ssh2_pkt_addbool(1); /* want reply */
2686 ssh2_pkt_addbool(0); /* many connections */
2687 ssh2_pkt_addstring(proto);
2688 ssh2_pkt_addstring(data);
2689 ssh2_pkt_adduint32(0); /* screen number */
2690 ssh2_pkt_send();
2691
2692 do {
2693 crWaitUntilV(ispkt);
2694 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2695 unsigned i = ssh2_pkt_getuint32();
2696 struct ssh_channel *c;
2697 c = find234(ssh_channels, &i, ssh_channelfind);
2698 if (!c)
2699 continue; /* nonexistent channel */
2700 c->v2.remwindow += ssh2_pkt_getuint32();
2701 }
2702 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2703
2704 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2705 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2706 bombout(("Server got confused by X11 forwarding request"));
2707 crReturnV;
2708 }
2709 logevent("X11 forwarding refused");
2710 } else {
2711 logevent("X11 forwarding enabled");
2712 ssh_X11_fwd_enabled = TRUE;
2713 }
2714 }
2715
2716 /*
7cca0d81 2717 * Now allocate a pty for the session.
2718 */
67779be7 2719 if (!cfg.nopty) {
2720 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2721 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2722 ssh2_pkt_addstring("pty-req");
2723 ssh2_pkt_addbool(1); /* want reply */
2724 ssh2_pkt_addstring(cfg.termtype);
2725 ssh2_pkt_adduint32(cols);
2726 ssh2_pkt_adduint32(rows);
2727 ssh2_pkt_adduint32(0); /* pixel width */
2728 ssh2_pkt_adduint32(0); /* pixel height */
2729 ssh2_pkt_addstring_start();
2730 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2731 ssh2_pkt_send();
6e48c3fe 2732 ssh_state = SSH_STATE_INTERMED;
7cca0d81 2733
67779be7 2734 do {
2735 crWaitUntilV(ispkt);
2736 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 2737 unsigned i = ssh2_pkt_getuint32();
2738 struct ssh_channel *c;
2739 c = find234(ssh_channels, &i, ssh_channelfind);
2740 if (!c)
2741 continue; /* nonexistent channel */
2742 c->v2.remwindow += ssh2_pkt_getuint32();
67779be7 2743 }
2744 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2745
67779be7 2746 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2747 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2748 bombout(("Server got confused by pty request"));
2749 crReturnV;
67779be7 2750 }
2751 c_write("Server refused to allocate pty\r\n", 32);
0965bee0 2752 ssh_editing = ssh_echoing = 1;
67779be7 2753 } else {
2754 logevent("Allocated pty");
7cca0d81 2755 }
0965bee0 2756 } else {
2757 ssh_editing = ssh_echoing = 1;
7cca0d81 2758 }
2759
2760 /*
67779be7 2761 * Start a shell or a remote command.
7cca0d81 2762 */
2763 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2764 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2765 if (*cfg.remote_cmd) {
2766 ssh2_pkt_addstring("exec");
2767 ssh2_pkt_addbool(1); /* want reply */
2768 ssh2_pkt_addstring(cfg.remote_cmd);
2769 } else {
2770 ssh2_pkt_addstring("shell");
2771 ssh2_pkt_addbool(1); /* want reply */
2772 }
7cca0d81 2773 ssh2_pkt_send();
d211621f 2774 do {
7cca0d81 2775 crWaitUntilV(ispkt);
d211621f 2776 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 2777 unsigned i = ssh2_pkt_getuint32();
2778 struct ssh_channel *c;
2779 c = find234(ssh_channels, &i, ssh_channelfind);
2780 if (!c)
2781 continue; /* nonexistent channel */
2782 c->v2.remwindow += ssh2_pkt_getuint32();
d211621f 2783 }
7cca0d81 2784 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2785 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2786 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2787 bombout(("Server got confused by shell/command request"));
2788 crReturnV;
7cca0d81 2789 }
8d5de777 2790 bombout(("Server refused to start a shell/command"));
2791 crReturnV;
7cca0d81 2792 } else {
8d5de777 2793 logevent("Started a shell/command");
7cca0d81 2794 }
2795
6e48c3fe 2796 ssh_state = SSH_STATE_SESSION;
2797 if (size_needed)
2798 ssh_size();
3687d221 2799 if (eof_needed)
2800 ssh_special(TS_EOF);
6e48c3fe 2801
7cca0d81 2802 /*
2803 * Transfer data!
2804 */
0965bee0 2805 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 2806 ssh_send_ok = 1;
7cca0d81 2807 while (1) {
d211621f 2808 static int try_send;
e5574168 2809 crReturnV;
d211621f 2810 try_send = FALSE;
7cca0d81 2811 if (ispkt) {
2812 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2813 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2814 char *data;
2815 int length;
783415f8 2816 unsigned i = ssh2_pkt_getuint32();
2817 struct ssh_channel *c;
2818 c = find234(ssh_channels, &i, ssh_channelfind);
2819 if (!c)
2820 continue; /* nonexistent channel */
7cca0d81 2821 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2822 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2823 continue; /* extended but not stderr */
2824 ssh2_pkt_getstring(&data, &length);
d211621f 2825 if (data) {
783415f8 2826 switch (c->type) {
2827 case CHAN_MAINSESSION:
2828 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
2829 data, length);
2830 break;
2831 case CHAN_X11:
2832 x11_send(c->u.x11.s, data, length);
2833 break;
2834 }
d211621f 2835 /*
783415f8 2836 * Enlarge the window again at the remote
2837 * side, just in case it ever runs down and
2838 * they fail to send us any more data.
d211621f 2839 */
2840 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
783415f8 2841 ssh2_pkt_adduint32(c->remoteid);
d211621f 2842 ssh2_pkt_adduint32(length);
2843 ssh2_pkt_send();
2844 }
7cca0d81 2845 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2846 ssh_state = SSH_STATE_CLOSED;
d211621f 2847 logevent("Received disconnect message");
3257deae 2848 crReturnV;
7cca0d81 2849 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2850 continue; /* exit status et al; ignore (FIXME?) */
d211621f 2851 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
783415f8 2852 unsigned i = ssh2_pkt_getuint32();
2853 struct ssh_channel *c;
2854
2855 c = find234(ssh_channels, &i, ssh_channelfind);
2856 if (!c)
2857 continue; /* nonexistent channel */
2858
2859 if (c->type == CHAN_X11) {
2860 /*
2861 * Remote EOF on an X11 channel means we should
2862 * wrap up and close the channel ourselves.
2863 */
2864 x11_close(c->u.x11.s);
2865 sshfwd_close(c);
2866 }
d211621f 2867 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
783415f8 2868 unsigned i = ssh2_pkt_getuint32();
2869 struct ssh_channel *c;
2870 enum234 e;
2871
2872 c = find234(ssh_channels, &i, ssh_channelfind);
2873 if (!c)
2874 continue; /* nonexistent channel */
2875 if (c->closes == 0) {
2876 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2877 ssh2_pkt_adduint32(c->remoteid);
2878 ssh2_pkt_send();
2879 }
2880 /* Do pre-close processing on the channel. */
2881 switch (c->type) {
2882 case CHAN_MAINSESSION:
2883 break; /* nothing to see here, move along */
2884 case CHAN_X11:
2885 break;
2886 }
2887 del234(ssh_channels, c);
2888 sfree(c->v2.outbuffer);
2889 sfree(c);
2890
2891 /*
2892 * See if that was the last channel left open.
2893 */
2894 c = first234(ssh_channels, &e);
2895 if (!c) {
d211621f 2896 logevent("All channels closed. Disconnecting");
2897 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
9005f3ba 2898 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
2899 ssh2_pkt_addstring("All open channels closed");
2900 ssh2_pkt_addstring("en"); /* language tag */
d211621f 2901 ssh2_pkt_send();
cf6e59d6 2902 ssh_state = SSH_STATE_CLOSED;
3257deae 2903 crReturnV;
d211621f 2904 }
2905 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2906 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 2907 unsigned i = ssh2_pkt_getuint32();
2908 struct ssh_channel *c;
2909 c = find234(ssh_channels, &i, ssh_channelfind);
2910 if (!c)
2911 continue; /* nonexistent channel */
2912 mainchan->v2.remwindow += ssh2_pkt_getuint32();
d211621f 2913 try_send = TRUE;
783415f8 2914 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
2915 char *type;
2916 int typelen;
2917 char *error = NULL;
2918 struct ssh_channel *c;
2919 ssh2_pkt_getstring(&type, &typelen);
2920 c = smalloc(sizeof(struct ssh_channel));
2921
2922 if (typelen == 3 && !memcmp(type, "x11", 3)) {
783415f8 2923 if (!ssh_X11_fwd_enabled)
2924 error = "X11 forwarding is not enabled";
0c6c9a70 2925 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
783415f8 2926 error = "Unable to open an X11 connection";
2927 } else {
2928 c->type = CHAN_X11;
2929 }
2930 } else {
2931 error = "Unsupported channel type requested";
2932 }
2933
2934 c->remoteid = ssh2_pkt_getuint32();
2935 if (error) {
2936 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
2937 ssh2_pkt_adduint32(c->remoteid);
2938 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
2939 ssh2_pkt_addstring(error);
2940 ssh2_pkt_addstring("en"); /* language tag */
2941 ssh2_pkt_send();
2942 sfree(c);
2943 } else {
2944 struct ssh_channel *d;
2945 unsigned i;
2946 enum234 e;
2947
2948 for (i=1, d = first234(ssh_channels, &e); d;
2949 d = next234(&e)) {
2950 if (d->localid > i)
2951 break; /* found a free number */
2952 i = d->localid + 1;
2953 }
2954 c->localid = i;
2955 c->closes = 0;
2956 c->v2.remwindow = ssh2_pkt_getuint32();
2957 c->v2.remmaxpkt = ssh2_pkt_getuint32();
2958 c->v2.outbuffer = NULL;
2959 c->v2.outbuflen = c->v2.outbufsize = 0;
2960 add234(ssh_channels, c);
2961 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
2962 ssh2_pkt_adduint32(c->remoteid);
2963 ssh2_pkt_adduint32(c->localid);
2964 ssh2_pkt_adduint32(0x8000UL); /* our window size */
2965 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
2966 ssh2_pkt_send();
2967 }
7cca0d81 2968 } else {
8d5de777 2969 bombout(("Strange packet received: type %d", pktin.type));
2970 crReturnV;
7cca0d81 2971 }
2972 } else {
d211621f 2973 /*
2974 * We have spare data. Add it to the channel buffer.
2975 */
783415f8 2976 ssh2_add_channel_data(mainchan, in, inlen);
d211621f 2977 try_send = TRUE;
7cca0d81 2978 }
d211621f 2979 if (try_send) {
783415f8 2980 enum234 e;
2981 struct ssh_channel *c;
d211621f 2982 /*
783415f8 2983 * Try to send data on all channels if we can.
d211621f 2984 */
783415f8 2985 for (c = first234(ssh_channels, &e); c; c = next234(&e))
2986 ssh2_try_send(c);
d211621f 2987 }
e5574168 2988 }
2989
2990 crFinishV;
2991}
2992
2993/*
7cca0d81 2994 * Handle the top-level SSH2 protocol.
2995 */
2996static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2997{
2998 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2999 return;
3000 do_ssh2_authconn(in, inlen, ispkt);
3001}
3002
3003/*
8df7a775 3004 * Called to set up the connection.
374330e2 3005 *
3006 * Returns an error message, or NULL on success.
374330e2 3007 */
8df7a775 3008static char *ssh_init (char *host, int port, char **realhost) {
fb09bf1c 3009 char *p;
8f203108 3010
3011#ifdef MSCRYPTOAPI
3012 if(crypto_startup() == 0)
3013 return "Microsoft high encryption pack not installed!";
3014#endif
374330e2 3015
8df7a775 3016 ssh_send_ok = 0;
0965bee0 3017 ssh_editing = 0;
3018 ssh_echoing = 0;
8df7a775 3019
fb09bf1c 3020 p = connect_to_host(host, port, realhost);
3021 if (p != NULL)
3022 return p;
374330e2 3023
374330e2 3024 return NULL;
3025}
3026
3027/*
374330e2 3028 * Called to send data down the Telnet connection.
3029 */
3030static void ssh_send (char *buf, int len) {
f78051a1 3031 if (s == NULL || ssh_protocol == NULL)
374330e2 3032 return;
3033
3034 ssh_protocol(buf, len, 0);
3035}
3036
3037/*
6e48c3fe 3038 * Called to set the size of the window from SSH's POV.
374330e2 3039 */
3040static void ssh_size(void) {
3041 switch (ssh_state) {
3042 case SSH_STATE_BEFORE_SIZE:
3687d221 3043 case SSH_STATE_PREPACKET:
21248260 3044 case SSH_STATE_CLOSED:
374330e2 3045 break; /* do nothing */
3046 case SSH_STATE_INTERMED:
3047 size_needed = TRUE; /* buffer for later */
3048 break;
3049 case SSH_STATE_SESSION:
fef97f43 3050 if (!cfg.nopty) {
6e48c3fe 3051 if (ssh_version == 1) {
3052 send_packet(SSH1_CMSG_WINDOW_SIZE,
3053 PKT_INT, rows, PKT_INT, cols,
3054 PKT_INT, 0, PKT_INT, 0, PKT_END);
3055 } else {
3056 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3057 ssh2_pkt_adduint32(mainchan->remoteid);
3058 ssh2_pkt_addstring("window-change");
3059 ssh2_pkt_addbool(0);
3060 ssh2_pkt_adduint32(cols);
3061 ssh2_pkt_adduint32(rows);
3062 ssh2_pkt_adduint32(0);
3063 ssh2_pkt_adduint32(0);
3064 ssh2_pkt_send();
3065 }
fef97f43 3066 }
3687d221 3067 break;
374330e2 3068 }
3069}
3070
3071/*
6abbf9e3 3072 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3073 * can send an EOF and collect resulting output (e.g. `plink
3074 * hostname sort').
374330e2 3075 */
3076static void ssh_special (Telnet_Special code) {
6abbf9e3 3077 if (code == TS_EOF) {
3687d221 3078 if (ssh_state != SSH_STATE_SESSION) {
3079 /*
3080 * Buffer the EOF in case we are pre-SESSION, so we can
3081 * send it as soon as we reach SESSION.
3082 */
3083 if (code == TS_EOF)
3084 eof_needed = TRUE;
3085 return;
3086 }
67779be7 3087 if (ssh_version == 1) {
6abbf9e3 3088 send_packet(SSH1_CMSG_EOF, PKT_END);
3089 } else {
3090 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 3091 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 3092 ssh2_pkt_send();
3093 }
67779be7 3094 logevent("Sent EOF message");
ec55b220 3095 } else if (code == TS_PING) {
3687d221 3096 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
3097 return;
ec55b220 3098 if (ssh_version == 1) {
3099 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
3100 } else {
3101 ssh2_pkt_init(SSH2_MSG_IGNORE);
3102 ssh2_pkt_addstring_start();
3103 ssh2_pkt_send();
3104 }
6abbf9e3 3105 } else {
3106 /* do nothing */
3107 }
374330e2 3108}
3109
8df7a775 3110static Socket ssh_socket(void) { return s; }
8ccc75b0 3111
3112static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 3113
0965bee0 3114static int ssh_ldisc(int option) {
3115 if (option == LD_ECHO) return ssh_echoing;
3116 if (option == LD_EDIT) return ssh_editing;
3117 return FALSE;
3118}
3119
374330e2 3120Backend ssh_backend = {
3121 ssh_init,
374330e2 3122 ssh_send,
3123 ssh_size,
4017be6d 3124 ssh_special,
8ccc75b0 3125 ssh_socket,
97db3be4 3126 ssh_sendok,
0965bee0 3127 ssh_ldisc,
97db3be4 3128 22
374330e2 3129};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator