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