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[u/mdw/putty] / ssh.c
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374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
4d331a77 5#ifndef AUTO_WINSOCK
6#ifdef WINSOCK_TWO
7#include <winsock2.h>
8#else
374330e2 9#include <winsock.h>
4d331a77 10#endif
11#endif
374330e2 12
13#include "putty.h"
dacbd0e8 14#include "tree234.h"
fb09bf1c 15#include "ssh.h"
374330e2 16
17#ifndef FALSE
18#define FALSE 0
19#endif
20#ifndef TRUE
21#define TRUE 1
22#endif
23
fb09bf1c 24#define logevent(s) { logevent(s); \
67779be7 25 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
fb09bf1c 26 fprintf(stderr, "%s\n", s); }
27
8d5de777 28#define bombout(msg) ( ssh_state == SSH_STATE_CLOSED, closesocket(s), \
29 s = INVALID_SOCKET, connection_fatal msg )
30
d211621f 31#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
32#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
33#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
34#define SSH1_CMSG_USER 4 /* 0x4 */
35#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
36#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
37#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
38#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
39#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
40#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
41#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
42#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
43#define SSH1_SMSG_SUCCESS 14 /* 0xe */
44#define SSH1_SMSG_FAILURE 15 /* 0xf */
45#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
46#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
47#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
48#define SSH1_CMSG_EOF 19 /* 0x13 */
49#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
50#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
51#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
52#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
53#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
54#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
55#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
56#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
57#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
58#define SSH1_MSG_IGNORE 32 /* 0x20 */
59#define SSH1_MSG_DEBUG 36 /* 0x24 */
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
110#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
111#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
112#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
113#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
114
115#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 116
117#define GET_32BIT(cp) \
118 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
119 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
120 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
121 ((unsigned long)(unsigned char)(cp)[3]))
122
123#define PUT_32BIT(cp, value) { \
124 (cp)[0] = (unsigned char)((value) >> 24); \
125 (cp)[1] = (unsigned char)((value) >> 16); \
126 (cp)[2] = (unsigned char)((value) >> 8); \
127 (cp)[3] = (unsigned char)(value); }
128
7cca0d81 129enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 130
374330e2 131/* Coroutine mechanics for the sillier bits of the code */
132#define crBegin1 static int crLine = 0;
133#define crBegin2 switch(crLine) { case 0:;
134#define crBegin crBegin1; crBegin2;
135#define crFinish(z) } crLine = 0; return (z)
136#define crFinishV } crLine = 0; return
137#define crReturn(z) \
138 do {\
139 crLine=__LINE__; return (z); case __LINE__:;\
140 } while (0)
141#define crReturnV \
142 do {\
143 crLine=__LINE__; return; case __LINE__:;\
144 } while (0)
145#define crStop(z) do{ crLine = 0; return (z); }while(0)
146#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 147#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 148#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 149
e5574168 150extern struct ssh_cipher ssh_3des;
033b4cef 151extern struct ssh_cipher ssh_3des_ssh2;
e5574168 152extern struct ssh_cipher ssh_des;
5e8358ad 153extern struct ssh_cipher ssh_blowfish_ssh1;
154extern struct ssh_cipher ssh_blowfish_ssh2;
e5574168 155
5e8358ad 156/*
157 * Ciphers for SSH2. We miss out single-DES because it isn't
158 * supported; also 3DES and Blowfish are both done differently from
159 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
160 * endianness and different-sized keys.)
161 *
162 * The first entry in this array is set up to be whatever the user
163 * asks for as a cipher. Thereafter there is a fixed preference
164 * order of fallback ciphers.
165 */
166struct ssh_cipher *ciphers[] = { NULL, &ssh_blowfish_ssh2, &ssh_3des_ssh2 };
e5574168 167
168extern struct ssh_kex ssh_diffiehellman;
169struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
170
171extern struct ssh_hostkey ssh_dss;
172struct ssh_hostkey *hostkey_algs[] = { &ssh_dss };
173
174extern struct ssh_mac ssh_sha1;
175
dacbd0e8 176static SHA_State exhash;
e5574168 177
d39f364a 178static void nullmac_key(unsigned char *key) { }
e5574168 179static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
180static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
181struct ssh_mac ssh_mac_none = {
d39f364a 182 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 183};
184struct ssh_mac *macs[] = { &ssh_sha1, &ssh_mac_none };
185
186struct ssh_compress ssh_comp_none = {
187 "none"
188};
189struct ssh_compress *compressions[] = { &ssh_comp_none };
190
374330e2 191static SOCKET s = INVALID_SOCKET;
192
193static unsigned char session_key[32];
194static struct ssh_cipher *cipher = NULL;
e5574168 195static struct ssh_cipher *cscipher = NULL;
196static struct ssh_cipher *sccipher = NULL;
197static struct ssh_mac *csmac = NULL;
198static struct ssh_mac *scmac = NULL;
199static struct ssh_compress *cscomp = NULL;
200static struct ssh_compress *sccomp = NULL;
201static struct ssh_kex *kex = NULL;
202static struct ssh_hostkey *hostkey = NULL;
85ee8208 203int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
374330e2 204
205static char *savedhost;
d4857987 206static int savedport;
8ccc75b0 207static int ssh_send_ok;
374330e2 208
dacbd0e8 209/*
210 * 2-3-4 tree storing channels.
211 */
212struct ssh_channel {
d211621f 213 unsigned remoteid, localid;
dacbd0e8 214 int type;
215 int closes;
216 union {
217 struct ssh_agent_channel {
218 unsigned char *message;
219 unsigned char msglen[4];
220 int lensofar, totallen;
221 } a;
d211621f 222 struct ssh2_data_channel {
223 unsigned char *outbuffer;
224 unsigned outbuflen, outbufsize;
225 unsigned remwindow, remmaxpkt;
226 } v2;
dacbd0e8 227 } u;
228};
229static tree234 *ssh_channels; /* indexed by local id */
230static int ssh_channelcmp(void *av, void *bv) {
231 struct ssh_channel *a = (struct ssh_channel *)av;
232 struct ssh_channel *b = (struct ssh_channel *)bv;
233 if (a->localid < b->localid) return -1;
234 if (a->localid > b->localid) return +1;
235 return 0;
236}
237static int ssh_channelfind(void *av, void *bv) {
d211621f 238 unsigned *a = (unsigned *)av;
dacbd0e8 239 struct ssh_channel *b = (struct ssh_channel *)bv;
240 if (*a < b->localid) return -1;
241 if (*a > b->localid) return +1;
242 return 0;
243}
244
d211621f 245static struct ssh_channel *mainchan; /* primary session channel */
246
374330e2 247static enum {
248 SSH_STATE_BEFORE_SIZE,
249 SSH_STATE_INTERMED,
21248260 250 SSH_STATE_SESSION,
251 SSH_STATE_CLOSED
374330e2 252} ssh_state = SSH_STATE_BEFORE_SIZE;
253
254static int size_needed = FALSE;
255
256static void s_write (char *buf, int len) {
257 while (len > 0) {
258 int i = send (s, buf, len, 0);
4017be6d 259 noise_ultralight(i);
8d5de777 260 if (i <= 0) {
261 bombout(("Lost connection while sending"));
262 return;
263 }
374330e2 264 if (i > 0)
265 len -= i, buf += i;
266 }
267}
268
269static int s_read (char *buf, int len) {
270 int ret = 0;
271 while (len > 0) {
272 int i = recv (s, buf, len, 0);
4017be6d 273 noise_ultralight(i);
374330e2 274 if (i > 0)
275 len -= i, buf += i, ret += i;
276 else
277 return i;
278 }
279 return ret;
280}
281
282static void c_write (char *buf, int len) {
67779be7 283 if ((flags & FLAG_STDERR)) {
4017be6d 284 int i;
285 for (i = 0; i < len; i++)
286 if (buf[i] != '\r')
287 fputc(buf[i], stderr);
fb09bf1c 288 return;
289 }
c9def1b8 290 while (len--)
291 c_write1(*buf++);
374330e2 292}
293
3bdaf79d 294static void c_writedata (char *buf, int len) {
295 while (len--)
296 c_write1(*buf++);
297}
298
374330e2 299struct Packet {
300 long length;
301 int type;
374330e2 302 unsigned char *data;
303 unsigned char *body;
e5574168 304 long savedpos;
374330e2 305 long maxlen;
306};
307
fb09bf1c 308static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
309static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
374330e2 310
6abbf9e3 311static int ssh_version;
e5574168 312static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
313static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
314static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
374330e2 315static void ssh_size(void);
316
e5574168 317static int (*s_rdpkt)(unsigned char **data, int *datalen);
fb09bf1c 318
319/*
320 * Collect incoming data in the incoming packet buffer.
e5574168 321 * Decipher and verify the packet when it is completely read.
322 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 323 * Update the *data and *datalen variables.
324 * Return the additional nr of bytes needed, or 0 when
325 * a complete packet is available.
326 */
e5574168 327static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 328{
329 static long len, pad, biglen, to_read;
572f871e 330 static unsigned long realcrc, gotcrc;
fb09bf1c 331 static unsigned char *p;
332 static int i;
374330e2 333
334 crBegin;
374330e2 335
fb09bf1c 336next_packet:
37508af4 337
fb09bf1c 338 pktin.type = 0;
339 pktin.length = 0;
374330e2 340
fb09bf1c 341 for (i = len = 0; i < 4; i++) {
342 while ((*datalen) == 0)
343 crReturn(4-i);
344 len = (len << 8) + **data;
345 (*data)++, (*datalen)--;
346 }
374330e2 347
fb09bf1c 348#ifdef FWHACK
349 if (len == 0x52656d6f) { /* "Remo"te server has closed ... */
350 len = 0x300; /* big enough to carry to end */
351 }
352#endif
374330e2 353
fb09bf1c 354 pad = 8 - (len % 8);
355 biglen = len + pad;
356 pktin.length = len - 5;
357
358 if (pktin.maxlen < biglen) {
359 pktin.maxlen = biglen;
e5574168 360 pktin.data = (pktin.data == NULL ? malloc(biglen+APIEXTRA) :
361 realloc(pktin.data, biglen+APIEXTRA));
fb09bf1c 362 if (!pktin.data)
363 fatalbox("Out of memory");
364 }
374330e2 365
fb09bf1c 366 to_read = biglen;
367 p = pktin.data;
368 while (to_read > 0) {
369 static int chunk;
370 chunk = to_read;
371 while ((*datalen) == 0)
372 crReturn(to_read);
373 if (chunk > (*datalen))
374 chunk = (*datalen);
375 memcpy(p, *data, chunk);
376 *data += chunk;
377 *datalen -= chunk;
378 p += chunk;
379 to_read -= chunk;
380 }
374330e2 381
fb09bf1c 382 if (cipher)
383 cipher->decrypt(pktin.data, biglen);
374330e2 384
fb09bf1c 385 pktin.type = pktin.data[pad];
386 pktin.body = pktin.data + pad + 1;
374330e2 387
fb09bf1c 388 realcrc = crc32(pktin.data, biglen-4);
389 gotcrc = GET_32BIT(pktin.data+biglen-4);
390 if (gotcrc != realcrc) {
8d5de777 391 bombout(("Incorrect CRC received on packet"));
392 crReturn(0);
fb09bf1c 393 }
572f871e 394
e5574168 395 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
396 pktin.type == SSH1_SMSG_STDERR_DATA ||
397 pktin.type == SSH1_MSG_DEBUG ||
18515c51 398 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
399 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 400 long strlen = GET_32BIT(pktin.body);
8d5de777 401 if (strlen + 4 != pktin.length) {
402 bombout(("Received data packet with bogus string length"));
403 crReturn(0);
404 }
fb09bf1c 405 }
406
e5574168 407 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 408 /* log debug message */
409 char buf[80];
410 int strlen = GET_32BIT(pktin.body);
411 strcpy(buf, "Remote: ");
412 if (strlen > 70) strlen = 70;
413 memcpy(buf+8, pktin.body+4, strlen);
414 buf[8+strlen] = '\0';
415 logevent(buf);
416 goto next_packet;
e5574168 417 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 418 /* do nothing */
419 goto next_packet;
420 }
421
422 crFinish(0);
423}
424
e5574168 425static int ssh2_rdpkt(unsigned char **data, int *datalen)
426{
427 static long len, pad, payload, packetlen, maclen;
428 static int i;
429 static int cipherblk;
430 static unsigned long incoming_sequence = 0;
431
432 crBegin;
433
434next_packet:
435
436 pktin.type = 0;
437 pktin.length = 0;
438
439 if (cipher)
440 cipherblk = cipher->blksize;
441 else
442 cipherblk = 8;
443 if (cipherblk < 8)
444 cipherblk = 8;
445
446 if (pktin.maxlen < cipherblk) {
447 pktin.maxlen = cipherblk;
448 pktin.data = (pktin.data == NULL ? malloc(cipherblk+APIEXTRA) :
449 realloc(pktin.data, cipherblk+APIEXTRA));
450 if (!pktin.data)
451 fatalbox("Out of memory");
452 }
453
454 /*
455 * Acquire and decrypt the first block of the packet. This will
456 * contain the length and padding details.
457 */
458 for (i = len = 0; i < cipherblk; i++) {
459 while ((*datalen) == 0)
460 crReturn(cipherblk-i);
461 pktin.data[i] = *(*data)++;
462 (*datalen)--;
463 }
464#ifdef FWHACK
465 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
466 /* FIXME */
467 }
468#endif
469 if (sccipher)
470 sccipher->decrypt(pktin.data, cipherblk);
471
472 /*
473 * Now get the length and padding figures.
474 */
475 len = GET_32BIT(pktin.data);
476 pad = pktin.data[4];
477
478 /*
479 * This enables us to deduce the payload length.
480 */
481 payload = len - pad - 1;
482
483 pktin.length = payload + 5;
484
485 /*
486 * So now we can work out the total packet length.
487 */
488 packetlen = len + 4;
489 maclen = scmac ? scmac->len : 0;
490
491 /*
492 * Adjust memory allocation if packet is too big.
493 */
59dcd2a8 494 if (pktin.maxlen < packetlen+maclen) {
495 pktin.maxlen = packetlen+maclen;
496 pktin.data = (pktin.data == NULL ? malloc(pktin.maxlen+APIEXTRA) :
497 realloc(pktin.data, pktin.maxlen+APIEXTRA));
e5574168 498 if (!pktin.data)
499 fatalbox("Out of memory");
500 }
501
502 /*
503 * Read and decrypt the remainder of the packet.
504 */
505 for (i = cipherblk; i < packetlen + maclen; i++) {
506 while ((*datalen) == 0)
507 crReturn(packetlen + maclen - i);
508 pktin.data[i] = *(*data)++;
509 (*datalen)--;
510 }
511 /* Decrypt everything _except_ the MAC. */
512 if (sccipher)
513 sccipher->decrypt(pktin.data + cipherblk, packetlen - cipherblk);
514
7cca0d81 515#if 0
d39f364a 516 debug(("Got packet len=%d pad=%d\r\n", len, pad));
517 for (i = 0; i < packetlen; i++)
518 debug((" %02x", (unsigned char)pktin.data[i]));
519 debug(("\r\n"));
7cca0d81 520#endif
d39f364a 521
e5574168 522 /*
523 * Check the MAC.
524 */
8d5de777 525 if (scmac && !scmac->verify(pktin.data, len+4, incoming_sequence)) {
526 bombout(("Incorrect MAC received on packet"));
527 crReturn(0);
528 }
033b4cef 529 incoming_sequence++; /* whether or not we MACed */
e5574168 530
531 pktin.savedpos = 6;
532 pktin.type = pktin.data[5];
e5574168 533
7cca0d81 534 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
535 goto next_packet; /* FIXME: print DEBUG message */
e5574168 536
537 crFinish(0);
538}
539
fb09bf1c 540static void ssh_gotdata(unsigned char *data, int datalen)
541{
542 while (datalen > 0) {
85ee8208 543 if ( s_rdpkt(&data, &datalen) == 0 ) {
374330e2 544 ssh_protocol(NULL, 0, 1);
85ee8208 545 if (ssh_state == SSH_STATE_CLOSED) {
546 return;
547 }
548 }
374330e2 549 }
374330e2 550}
551
fb09bf1c 552
374330e2 553static void s_wrpkt_start(int type, int len) {
554 int pad, biglen;
555
556 len += 5; /* type and CRC */
557 pad = 8 - (len%8);
558 biglen = len + pad;
559
560 pktout.length = len-5;
561 if (pktout.maxlen < biglen) {
562 pktout.maxlen = biglen;
8f203108 563#ifdef MSCRYPTOAPI
fb09bf1c 564 /* Allocate enough buffer space for extra block
8f203108 565 * for MS CryptEncrypt() */
fb09bf1c 566 pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
567 realloc(pktout.data, biglen+12));
8f203108 568#else
c1f5f956 569 pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
570 realloc(pktout.data, biglen+4));
8f203108 571#endif
374330e2 572 if (!pktout.data)
573 fatalbox("Out of memory");
574 }
575
576 pktout.type = type;
577 pktout.body = pktout.data+4+pad+1;
578}
579
580static void s_wrpkt(void) {
581 int pad, len, biglen, i;
582 unsigned long crc;
583
584 len = pktout.length + 5; /* type and CRC */
585 pad = 8 - (len%8);
586 biglen = len + pad;
587
588 pktout.body[-1] = pktout.type;
589 for (i=0; i<pad; i++)
590 pktout.data[i+4] = random_byte();
591 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 592 PUT_32BIT(pktout.data+biglen, crc);
593 PUT_32BIT(pktout.data, len);
374330e2 594
595 if (cipher)
596 cipher->encrypt(pktout.data+4, biglen);
597
598 s_write(pktout.data, biglen+4);
599}
600
fb09bf1c 601/*
602 * Construct a packet with the specified contents and
603 * send it to the server.
604 */
605static void send_packet(int pkttype, ...)
606{
607 va_list args;
608 unsigned char *p, *argp, argchar;
609 unsigned long argint;
610 int pktlen, argtype, arglen;
7cca0d81 611 Bignum bn;
fb09bf1c 612
613 pktlen = 0;
614 va_start(args, pkttype);
615 while ((argtype = va_arg(args, int)) != PKT_END) {
616 switch (argtype) {
617 case PKT_INT:
618 (void) va_arg(args, int);
619 pktlen += 4;
620 break;
621 case PKT_CHAR:
622 (void) va_arg(args, char);
623 pktlen++;
624 break;
625 case PKT_DATA:
626 (void) va_arg(args, unsigned char *);
627 arglen = va_arg(args, int);
628 pktlen += arglen;
629 break;
630 case PKT_STR:
631 argp = va_arg(args, unsigned char *);
632 arglen = strlen(argp);
633 pktlen += 4 + arglen;
634 break;
7cca0d81 635 case PKT_BIGNUM:
636 bn = va_arg(args, Bignum);
5c58ad2d 637 pktlen += ssh1_bignum_length(bn);
7cca0d81 638 break;
fb09bf1c 639 default:
640 assert(0);
641 }
642 }
643 va_end(args);
644
645 s_wrpkt_start(pkttype, pktlen);
646 p = pktout.body;
647
648 va_start(args, pkttype);
649 while ((argtype = va_arg(args, int)) != PKT_END) {
650 switch (argtype) {
651 case PKT_INT:
652 argint = va_arg(args, int);
653 PUT_32BIT(p, argint);
654 p += 4;
655 break;
656 case PKT_CHAR:
657 argchar = va_arg(args, unsigned char);
658 *p = argchar;
659 p++;
660 break;
661 case PKT_DATA:
662 argp = va_arg(args, unsigned char *);
663 arglen = va_arg(args, int);
664 memcpy(p, argp, arglen);
665 p += arglen;
666 break;
667 case PKT_STR:
668 argp = va_arg(args, unsigned char *);
669 arglen = strlen(argp);
670 PUT_32BIT(p, arglen);
671 memcpy(p + 4, argp, arglen);
672 p += 4 + arglen;
673 break;
7cca0d81 674 case PKT_BIGNUM:
675 bn = va_arg(args, Bignum);
5c58ad2d 676 p += ssh1_write_bignum(p, bn);
7cca0d81 677 break;
fb09bf1c 678 }
679 }
680 va_end(args);
681
682 s_wrpkt();
683}
684
685
686/*
687 * Connect to specified host and port.
688 * Returns an error message, or NULL on success.
689 * Also places the canonical host name into `realhost'.
690 */
691static char *connect_to_host(char *host, int port, char **realhost)
692{
693 SOCKADDR_IN addr;
694 struct hostent *h;
695 unsigned long a;
696#ifdef FWHACK
697 char *FWhost;
698 int FWport;
699#endif
700
701 savedhost = malloc(1+strlen(host));
702 if (!savedhost)
703 fatalbox("Out of memory");
704 strcpy(savedhost, host);
705
706 if (port < 0)
707 port = 22; /* default ssh port */
d4857987 708 savedport = port;
fb09bf1c 709
710#ifdef FWHACK
711 FWhost = host;
712 FWport = port;
713 host = FWSTR;
714 port = 23;
715#endif
716
717 /*
718 * Try to find host.
719 */
720 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
721 if ( (h = gethostbyname(host)) == NULL)
722 switch (WSAGetLastError()) {
723 case WSAENETDOWN: return "Network is down";
724 case WSAHOST_NOT_FOUND: case WSANO_DATA:
725 return "Host does not exist";
726 case WSATRY_AGAIN: return "Host not found";
727 default: return "gethostbyname: unknown error";
728 }
729 memcpy (&a, h->h_addr, sizeof(a));
730 *realhost = h->h_name;
731 } else
732 *realhost = host;
733#ifdef FWHACK
734 *realhost = FWhost;
735#endif
736 a = ntohl(a);
737
738 /*
739 * Open socket.
740 */
741 s = socket(AF_INET, SOCK_STREAM, 0);
742 if (s == INVALID_SOCKET)
743 switch (WSAGetLastError()) {
744 case WSAENETDOWN: return "Network is down";
745 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
746 default: return "socket(): unknown error";
747 }
748
749 /*
750 * Bind to local address.
751 */
752 addr.sin_family = AF_INET;
753 addr.sin_addr.s_addr = htonl(INADDR_ANY);
754 addr.sin_port = htons(0);
755 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
756 switch (WSAGetLastError()) {
757 case WSAENETDOWN: return "Network is down";
758 default: return "bind(): unknown error";
759 }
760
761 /*
762 * Connect to remote address.
763 */
764 addr.sin_addr.s_addr = htonl(a);
765 addr.sin_port = htons((short)port);
766 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
767 switch (WSAGetLastError()) {
768 case WSAENETDOWN: return "Network is down";
769 case WSAECONNREFUSED: return "Connection refused";
770 case WSAENETUNREACH: return "Network is unreachable";
771 case WSAEHOSTUNREACH: return "No route to host";
772 default: return "connect(): unknown error";
773 }
774
775#ifdef FWHACK
776 send(s, "connect ", 8, 0);
777 send(s, FWhost, strlen(FWhost), 0);
778 {
779 char buf[20];
780 sprintf(buf, " %d\n", FWport);
781 send (s, buf, strlen(buf), 0);
782 }
783#endif
784
785 return NULL;
786}
787
9697bfd2 788static int ssh_versioncmp(char *a, char *b) {
789 char *ae, *be;
790 unsigned long av, bv;
791
43aa02a7 792 av = strtoul(a, &ae, 10);
793 bv = strtoul(b, &be, 10);
9697bfd2 794 if (av != bv) return (av < bv ? -1 : +1);
795 if (*ae == '.') ae++;
796 if (*be == '.') be++;
43aa02a7 797 av = strtoul(ae, &ae, 10);
798 bv = strtoul(be, &be, 10);
9697bfd2 799 if (av != bv) return (av < bv ? -1 : +1);
800 return 0;
801}
802
e5574168 803
804/*
805 * Utility routine for putting an SSH-protocol `string' into a SHA
806 * state.
807 */
808#include <stdio.h>
809void sha_string(SHA_State *s, void *str, int len) {
810 unsigned char lenblk[4];
e5574168 811 PUT_32BIT(lenblk, len);
e5574168 812 SHA_Bytes(s, lenblk, 4);
e5574168 813 SHA_Bytes(s, str, len);
814}
815
7cca0d81 816/*
817 * SSH2 packet construction functions.
818 */
819void ssh2_pkt_adddata(void *data, int len) {
820 pktout.length += len;
821 if (pktout.maxlen < pktout.length) {
822 pktout.maxlen = pktout.length + 256;
823 pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) :
824 realloc(pktout.data, pktout.maxlen+APIEXTRA));
825 if (!pktout.data)
826 fatalbox("Out of memory");
827 }
828 memcpy(pktout.data+pktout.length-len, data, len);
829}
830void ssh2_pkt_addbyte(unsigned char byte) {
831 ssh2_pkt_adddata(&byte, 1);
832}
833void ssh2_pkt_init(int pkt_type) {
834 pktout.length = 5;
835 ssh2_pkt_addbyte((unsigned char)pkt_type);
836}
837void ssh2_pkt_addbool(unsigned char value) {
838 ssh2_pkt_adddata(&value, 1);
839}
840void ssh2_pkt_adduint32(unsigned long value) {
841 unsigned char x[4];
842 PUT_32BIT(x, value);
843 ssh2_pkt_adddata(x, 4);
844}
845void ssh2_pkt_addstring_start(void) {
846 ssh2_pkt_adduint32(0);
847 pktout.savedpos = pktout.length;
848}
849void ssh2_pkt_addstring_str(char *data) {
850 ssh2_pkt_adddata(data, strlen(data));
851 PUT_32BIT(pktout.data + pktout.savedpos - 4,
852 pktout.length - pktout.savedpos);
853}
854void ssh2_pkt_addstring_data(char *data, int len) {
855 ssh2_pkt_adddata(data, len);
856 PUT_32BIT(pktout.data + pktout.savedpos - 4,
857 pktout.length - pktout.savedpos);
858}
859void ssh2_pkt_addstring(char *data) {
860 ssh2_pkt_addstring_start();
861 ssh2_pkt_addstring_str(data);
862}
863char *ssh2_mpint_fmt(Bignum b, int *len) {
864 unsigned char *p;
865 int i, n = b[0];
866 p = malloc(n * 2 + 1);
867 if (!p)
868 fatalbox("out of memory");
869 p[0] = 0;
870 for (i = 0; i < n; i++) {
871 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
872 p[i*2+2] = (b[n-i] ) & 0xFF;
873 }
874 i = 0;
875 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
876 i++;
877 memmove(p, p+i, n*2+1-i);
878 *len = n*2+1-i;
879 return p;
880}
881void ssh2_pkt_addmp(Bignum b) {
882 unsigned char *p;
883 int len;
884 p = ssh2_mpint_fmt(b, &len);
885 ssh2_pkt_addstring_start();
886 ssh2_pkt_addstring_data(p, len);
887 free(p);
888}
889void ssh2_pkt_send(void) {
890 int cipherblk, maclen, padding, i;
891 static unsigned long outgoing_sequence = 0;
892
893 /*
894 * Add padding. At least four bytes, and must also bring total
895 * length (minus MAC) up to a multiple of the block size.
896 */
897 cipherblk = cipher ? cipher->blksize : 8; /* block size */
898 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
899 padding = 4;
900 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
901 pktout.data[4] = padding;
902 for (i = 0; i < padding; i++)
903 pktout.data[pktout.length + i] = random_byte();
904 PUT_32BIT(pktout.data, pktout.length + padding - 4);
905 if (csmac)
906 csmac->generate(pktout.data, pktout.length + padding,
907 outgoing_sequence);
908 outgoing_sequence++; /* whether or not we MACed */
909
910#if 0
911 debug(("Sending packet len=%d\r\n", pktout.length+padding));
912 for (i = 0; i < pktout.length+padding; i++)
913 debug((" %02x", (unsigned char)pktout.data[i]));
914 debug(("\r\n"));
915#endif
916
917 if (cscipher)
918 cscipher->encrypt(pktout.data, pktout.length + padding);
919 maclen = csmac ? csmac->len : 0;
920
921 s_write(pktout.data, pktout.length + padding + maclen);
922}
923
924#if 0
925void bndebug(char *string, Bignum b) {
926 unsigned char *p;
927 int i, len;
928 p = ssh2_mpint_fmt(b, &len);
929 debug(("%s", string));
930 for (i = 0; i < len; i++)
931 debug((" %02x", p[i]));
932 debug(("\r\n"));
933 free(p);
934}
935#endif
936
937void sha_mpint(SHA_State *s, Bignum b) {
938 unsigned char *p;
939 int len;
940 p = ssh2_mpint_fmt(b, &len);
941 sha_string(s, p, len);
942 free(p);
943}
944
945/*
946 * SSH2 packet decode functions.
947 */
948unsigned long ssh2_pkt_getuint32(void) {
949 unsigned long value;
950 if (pktin.length - pktin.savedpos < 4)
951 return 0; /* arrgh, no way to decline (FIXME?) */
952 value = GET_32BIT(pktin.data+pktin.savedpos);
953 pktin.savedpos += 4;
954 return value;
955}
956void ssh2_pkt_getstring(char **p, int *length) {
957 *p = NULL;
958 if (pktin.length - pktin.savedpos < 4)
959 return;
960 *length = GET_32BIT(pktin.data+pktin.savedpos);
961 pktin.savedpos += 4;
962 if (pktin.length - pktin.savedpos < *length)
963 return;
964 *p = pktin.data+pktin.savedpos;
965 pktin.savedpos += *length;
966}
967Bignum ssh2_pkt_getmp(void) {
968 char *p;
969 int i, j, length;
970 Bignum b;
971
972 ssh2_pkt_getstring(&p, &length);
973 if (!p)
974 return NULL;
8d5de777 975 if (p[0] & 0x80) {
976 bombout(("internal error: Can't handle negative mpints"));
977 return NULL;
978 }
7cca0d81 979 b = newbn((length+1)/2);
980 for (i = 0; i < length; i++) {
981 j = length - 1 - i;
982 if (j & 1)
983 b[j/2+1] |= ((unsigned char)p[i]) << 8;
984 else
985 b[j/2+1] |= ((unsigned char)p[i]);
986 }
987 return b;
988}
989
374330e2 990static int do_ssh_init(void) {
c5e9c988 991 char c, *vsp;
374330e2 992 char version[10];
c5e9c988 993 char vstring[80];
994 char vlog[sizeof(vstring)+20];
374330e2 995 int i;
996
997#ifdef FWHACK
998 i = 0;
999 while (s_read(&c, 1) == 1) {
1000 if (c == 'S' && i < 2) i++;
1001 else if (c == 'S' && i == 2) i = 2;
1002 else if (c == 'H' && i == 2) break;
1003 else i = 0;
1004 }
1005#else
1006 if (s_read(&c,1) != 1 || c != 'S') return 0;
1007 if (s_read(&c,1) != 1 || c != 'S') return 0;
1008 if (s_read(&c,1) != 1 || c != 'H') return 0;
1009#endif
c5e9c988 1010 strcpy(vstring, "SSH-");
1011 vsp = vstring+4;
374330e2 1012 if (s_read(&c,1) != 1 || c != '-') return 0;
1013 i = 0;
1014 while (1) {
1015 if (s_read(&c,1) != 1)
1016 return 0;
c5e9c988 1017 if (vsp < vstring+sizeof(vstring)-1)
1018 *vsp++ = c;
374330e2 1019 if (i >= 0) {
1020 if (c == '-') {
1021 version[i] = '\0';
1022 i = -1;
1023 } else if (i < sizeof(version)-1)
1024 version[i++] = c;
1025 }
1026 else if (c == '\n')
1027 break;
1028 }
1029
c5e9c988 1030 *vsp = 0;
1031 sprintf(vlog, "Server version: %s", vstring);
1032 vlog[strcspn(vlog, "\r\n")] = '\0';
1033 logevent(vlog);
1034
adf799dd 1035 /*
1036 * Server version "1.99" means we can choose whether we use v1
1037 * or v2 protocol. Choice is based on cfg.sshprot.
1038 */
1039 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 1040 /*
1041 * This is a v2 server. Begin v2 protocol.
1042 */
1043 char *verstring = "SSH-2.0-PuTTY";
1044 SHA_Init(&exhash);
1045 /*
1046 * Hash our version string and their version string.
1047 */
1048 sha_string(&exhash, verstring, strlen(verstring));
1049 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
1050 sprintf(vstring, "%s\n", verstring);
1051 sprintf(vlog, "We claim version: %s", verstring);
1052 logevent(vlog);
1053 logevent("Using SSH protocol version 2");
1054 s_write(vstring, strlen(vstring));
1055 ssh_protocol = ssh2_protocol;
6abbf9e3 1056 ssh_version = 2;
e5574168 1057 s_rdpkt = ssh2_rdpkt;
1058 } else {
1059 /*
1060 * This is a v1 server. Begin v1 protocol.
1061 */
1062 sprintf(vstring, "SSH-%s-PuTTY\n",
1063 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1064 sprintf(vlog, "We claim version: %s", vstring);
1065 vlog[strcspn(vlog, "\r\n")] = '\0';
1066 logevent(vlog);
1067 logevent("Using SSH protocol version 1");
1068 s_write(vstring, strlen(vstring));
1069 ssh_protocol = ssh1_protocol;
6abbf9e3 1070 ssh_version = 1;
e5574168 1071 s_rdpkt = ssh1_rdpkt;
1072 }
8ccc75b0 1073 ssh_send_ok = 0;
fef97f43 1074 return 1;
374330e2 1075}
1076
fb09bf1c 1077/*
1078 * Handle the key exchange and user authentication phases.
1079 */
e5574168 1080static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1081{
374330e2 1082 int i, j, len;
374330e2 1083 unsigned char *rsabuf, *keystr1, *keystr2;
1084 unsigned char cookie[8];
1085 struct RSAKey servkey, hostkey;
1086 struct MD5Context md5c;
ccbfb941 1087 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1088 static int tried_publickey;
1089 static unsigned char session_id[16];
bea1ef5f 1090 int cipher_type;
374330e2 1091
374330e2 1092 crBegin;
1093
fb09bf1c 1094 if (!ispkt) crWaitUntil(ispkt);
374330e2 1095
8d5de777 1096 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1097 bombout(("Public key packet not received"));
1098 crReturn(0);
1099 }
374330e2 1100
c5e9c988 1101 logevent("Received public keys");
374330e2 1102
c5e9c988 1103 memcpy(cookie, pktin.body, 8);
374330e2 1104
7cca0d81 1105 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1106 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1107
c5e9c988 1108 /*
1c2a93c4 1109 * Log the host key fingerprint.
c5e9c988 1110 */
c5e9c988 1111 {
1112 char logmsg[80];
1c2a93c4 1113 logevent("Host key fingerprint is:");
c5e9c988 1114 strcpy(logmsg, " ");
1c2a93c4 1115 hostkey.comment = NULL;
1116 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1117 &hostkey);
c5e9c988 1118 logevent(logmsg);
1119 }
1120
fb09bf1c 1121 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1122 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1123
c5e9c988 1124 MD5Init(&md5c);
374330e2 1125 MD5Update(&md5c, keystr2, hostkey.bytes);
1126 MD5Update(&md5c, keystr1, servkey.bytes);
1127 MD5Update(&md5c, pktin.body, 8);
374330e2 1128 MD5Final(session_id, &md5c);
1129
1130 for (i=0; i<32; i++)
1131 session_key[i] = random_byte();
1132
1133 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1134
1135 rsabuf = malloc(len);
1136 if (!rsabuf)
1137 fatalbox("Out of memory");
1138
89ee5268 1139 /*
1140 * Verify the host key.
1141 */
1142 {
1143 /*
1144 * First format the key into a string.
1145 */
1146 int len = rsastr_len(&hostkey);
d5859615 1147 char fingerprint[100];
89ee5268 1148 char *keystr = malloc(len);
1149 if (!keystr)
1150 fatalbox("Out of memory");
1151 rsastr_fmt(keystr, &hostkey);
d5859615 1152 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1153 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
89ee5268 1154 free(keystr);
1155 }
374330e2 1156
1157 for (i=0; i<32; i++) {
1158 rsabuf[i] = session_key[i];
1159 if (i < 16)
1160 rsabuf[i] ^= session_id[i];
1161 }
1162
1163 if (hostkey.bytes > servkey.bytes) {
1164 rsaencrypt(rsabuf, 32, &servkey);
1165 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1166 } else {
1167 rsaencrypt(rsabuf, 32, &hostkey);
1168 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1169 }
1170
c5e9c988 1171 logevent("Encrypted session key");
1172
bea1ef5f 1173 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1174 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1175 SSH_CIPHER_3DES;
1176 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1177 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1178 cipher_type = SSH_CIPHER_3DES;
1179 }
c5e9c988 1180 switch (cipher_type) {
1181 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1182 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1183 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1184 }
bea1ef5f 1185
e5574168 1186 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1187 PKT_CHAR, cipher_type,
1188 PKT_DATA, cookie, 8,
1189 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1190 PKT_DATA, rsabuf, len,
1191 PKT_INT, 0,
1192 PKT_END);
1193
c5e9c988 1194 logevent("Trying to enable encryption...");
374330e2 1195
1196 free(rsabuf);
1197
5e8358ad 1198 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1199 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1200 &ssh_3des;
374330e2 1201 cipher->sesskey(session_key);
1202
fb09bf1c 1203 crWaitUntil(ispkt);
374330e2 1204
8d5de777 1205 if (pktin.type != SSH1_SMSG_SUCCESS) {
1206 bombout(("Encryption not successfully enabled"));
1207 crReturn(0);
1208 }
374330e2 1209
c5e9c988 1210 logevent("Successfully started encryption");
1211
374330e2 1212 fflush(stdout);
1213 {
1214 static char username[100];
1215 static int pos = 0;
1216 static char c;
67779be7 1217 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1218 c_write("login as: ", 10);
67779be7 1219 ssh_send_ok = 1;
374330e2 1220 while (pos >= 0) {
fb09bf1c 1221 crWaitUntil(!ispkt);
374330e2 1222 while (inlen--) switch (c = *in++) {
1223 case 10: case 13:
1224 username[pos] = 0;
1225 pos = -1;
1226 break;
1227 case 8: case 127:
1228 if (pos > 0) {
1229 c_write("\b \b", 3);
1230 pos--;
1231 }
1232 break;
1233 case 21: case 27:
1234 while (pos > 0) {
1235 c_write("\b \b", 3);
1236 pos--;
1237 }
1238 break;
1239 case 3: case 4:
1240 random_save_seed();
1241 exit(0);
1242 break;
1243 default:
40d24aa6 1244 if (((c >= ' ' && c <= '~') ||
1245 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1246 username[pos++] = c;
1247 c_write(&c, 1);
1248 }
1249 break;
1250 }
1251 }
1252 c_write("\r\n", 2);
1253 username[strcspn(username, "\n\r")] = '\0';
1254 } else {
1255 char stuff[200];
1256 strncpy(username, cfg.username, 99);
1257 username[99] = '\0';
67779be7 1258 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
fb09bf1c 1259 sprintf(stuff, "Sent username \"%s\".\r\n", username);
4017be6d 1260 c_write(stuff, strlen(stuff));
fb09bf1c 1261 }
374330e2 1262 }
fb09bf1c 1263
e5574168 1264 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1265 {
1266 char userlog[20+sizeof(username)];
1267 sprintf(userlog, "Sent username \"%s\"", username);
1268 logevent(userlog);
1269 }
374330e2 1270 }
1271
fb09bf1c 1272 crWaitUntil(ispkt);
374330e2 1273
7cca0d81 1274 tried_publickey = 0;
1275
e5574168 1276 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1277 static char password[100];
a52f067e 1278 static char prompt[200];
374330e2 1279 static int pos;
1280 static char c;
ccbfb941 1281 static int pwpkt_type;
ccbfb941 1282 /*
1283 * Show password prompt, having first obtained it via a TIS
18515c51 1284 * or CryptoCard exchange if we're doing TIS or CryptoCard
1285 * authentication.
ccbfb941 1286 */
e5574168 1287 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1288 if (agent_exists()) {
1289 /*
1290 * Attempt RSA authentication using Pageant.
1291 */
1292 static unsigned char request[5], *response, *p;
1293 static int responselen;
1294 static int i, nkeys;
1295 static int authed = FALSE;
1296 void *r;
1297
1298 logevent("Pageant is running. Requesting keys.");
1299
1300 /* Request the keys held by the agent. */
1301 PUT_32BIT(request, 1);
1302 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1303 agent_query(request, 5, &r, &responselen);
1304 response = (unsigned char *)r;
1305 if (response) {
1306 p = response + 5;
1307 nkeys = GET_32BIT(p); p += 4;
1308 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1309 logevent(buf); }
1310 for (i = 0; i < nkeys; i++) {
1311 static struct RSAKey key;
1312 static Bignum challenge;
b8bb811a 1313 static char *commentp;
1314 static int commentlen;
5c58ad2d 1315
1316 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1317 logevent(buf); }
1318 p += 4;
1319 p += ssh1_read_bignum(p, &key.exponent);
1320 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1321 commentlen = GET_32BIT(p); p += 4;
1322 commentp = p; p += commentlen;
5c58ad2d 1323 send_packet(SSH1_CMSG_AUTH_RSA,
1324 PKT_BIGNUM, key.modulus, PKT_END);
1325 crWaitUntil(ispkt);
1326 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1327 logevent("Key refused");
1328 continue;
1329 }
1330 logevent("Received RSA challenge");
1331 ssh1_read_bignum(pktin.body, &challenge);
1332 {
1333 char *agentreq, *q, *ret;
1334 int len, retlen;
1335 len = 1 + 4; /* message type, bit count */
1336 len += ssh1_bignum_length(key.exponent);
1337 len += ssh1_bignum_length(key.modulus);
1338 len += ssh1_bignum_length(challenge);
1339 len += 16; /* session id */
1340 len += 4; /* response format */
1341 agentreq = malloc(4 + len);
1342 PUT_32BIT(agentreq, len);
1343 q = agentreq + 4;
1344 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1345 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1346 q += 4;
1347 q += ssh1_write_bignum(q, key.exponent);
1348 q += ssh1_write_bignum(q, key.modulus);
1349 q += ssh1_write_bignum(q, challenge);
1350 memcpy(q, session_id, 16); q += 16;
1351 PUT_32BIT(q, 1); /* response format */
1352 agent_query(agentreq, len+4, &ret, &retlen);
1353 free(agentreq);
1354 if (ret) {
1355 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1356 logevent("Sending Pageant's response");
1357 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1358 PKT_DATA, ret+5, 16, PKT_END);
1359 free(ret);
1360 crWaitUntil(ispkt);
1361 if (pktin.type == SSH1_SMSG_SUCCESS) {
1362 logevent("Pageant's response accepted");
c4fa2fce 1363 if (flags & FLAG_VERBOSE) {
1364 c_write("Authenticated using RSA key \"",
1365 29);
1366 c_write(commentp, commentlen);
1367 c_write("\" from agent\r\n", 14);
1368 }
5c58ad2d 1369 authed = TRUE;
1370 } else
1371 logevent("Pageant's response not accepted");
1372 } else {
1373 logevent("Pageant failed to answer challenge");
1374 free(ret);
1375 }
1376 } else {
1377 logevent("No reply received from Pageant");
1378 }
1379 }
1380 freebn(key.exponent);
1381 freebn(key.modulus);
1382 freebn(challenge);
1383 if (authed)
1384 break;
1385 }
1386 }
1387 if (authed)
1388 break;
1389 }
7cca0d81 1390 if (*cfg.keyfile && !tried_publickey)
1391 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1392
a52f067e 1393 if (pktin.type == SSH1_SMSG_FAILURE &&
1394 cfg.try_tis_auth &&
1395 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1396 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1397 logevent("Requested TIS authentication");
1398 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1399 crWaitUntil(ispkt);
1400 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1401 logevent("TIS authentication declined");
1402 if (flags & FLAG_INTERACTIVE)
1403 c_write("TIS authentication refused.\r\n", 29);
1404 } else {
1405 int challengelen = ((pktin.body[0] << 24) |
1406 (pktin.body[1] << 16) |
1407 (pktin.body[2] << 8) |
1408 (pktin.body[3]));
1409 logevent("Received TIS challenge");
1410 if (challengelen > sizeof(prompt)-1)
1411 challengelen = sizeof(prompt)-1; /* prevent overrun */
1412 memcpy(prompt, pktin.body+4, challengelen);
1413 prompt[challengelen] = '\0';
1414 }
1415 }
1416 if (pktin.type == SSH1_SMSG_FAILURE &&
1417 cfg.try_tis_auth &&
1418 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1419 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1420 logevent("Requested CryptoCard authentication");
1421 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1422 crWaitUntil(ispkt);
1423 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1424 logevent("CryptoCard authentication declined");
1425 c_write("CryptoCard authentication refused.\r\n", 29);
1426 } else {
1427 int challengelen = ((pktin.body[0] << 24) |
1428 (pktin.body[1] << 16) |
1429 (pktin.body[2] << 8) |
1430 (pktin.body[3]));
1431 logevent("Received CryptoCard challenge");
1432 if (challengelen > sizeof(prompt)-1)
1433 challengelen = sizeof(prompt)-1; /* prevent overrun */
1434 memcpy(prompt, pktin.body+4, challengelen);
1435 strncpy(prompt + challengelen, "\r\nResponse : ",
1436 sizeof(prompt)-challengelen);
1437 prompt[sizeof(prompt)-1] = '\0';
1438 }
1439 }
1440 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1441 sprintf(prompt, "%.90s@%.90s's password: ",
1442 cfg.username, savedhost);
1443 }
1444 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1445 char *comment = NULL;
1446 if (flags & FLAG_VERBOSE)
1447 c_write("Trying public key authentication.\r\n", 35);
1448 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1449 if (flags & FLAG_VERBOSE)
1450 c_write("No passphrase required.\r\n", 25);
1451 goto tryauth;
1452 }
1453 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1454 free(comment);
1455 }
1456
1457 if (!(flags & FLAG_INTERACTIVE)) {
85ee8208 1458 if (!ssh_get_password(prompt, password, sizeof(password))) {
1459 /*
1460 * get_password failed to get a password (for
1461 * example because one was supplied on the command
1462 * line which has already failed to work).
1463 * Terminate.
1464 */
1465 logevent("No more passwords to try");
1466 ssh_state = SSH_STATE_CLOSED;
1467 crReturn(1);
1468 }
fb09bf1c 1469 } else {
a52f067e 1470 c_write(prompt, strlen(prompt));
7cca0d81 1471 pos = 0;
67779be7 1472 ssh_send_ok = 1;
7cca0d81 1473 while (pos >= 0) {
1474 crWaitUntil(!ispkt);
1475 while (inlen--) switch (c = *in++) {
1476 case 10: case 13:
1477 password[pos] = 0;
1478 pos = -1;
1479 break;
1480 case 8: case 127:
1481 if (pos > 0)
1482 pos--;
1483 break;
1484 case 21: case 27:
1485 pos = 0;
1486 break;
1487 case 3: case 4:
1488 random_save_seed();
1489 exit(0);
1490 break;
1491 default:
1492 if (((c >= ' ' && c <= '~') ||
1493 ((unsigned char)c >= 160)) && pos < sizeof(password))
1494 password[pos++] = c;
1495 break;
1496 }
1497 }
1498 c_write("\r\n", 2);
a52f067e 1499 }
fb09bf1c 1500
7cca0d81 1501 tryauth:
1502 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1503 /*
1504 * Try public key authentication with the specified
1505 * key file.
1506 */
1507 static struct RSAKey pubkey;
1508 static Bignum challenge, response;
1509 static int i;
1510 static unsigned char buffer[32];
1511
1512 tried_publickey = 1;
1513 i = loadrsakey(cfg.keyfile, &pubkey, password);
1514 if (i == 0) {
1515 c_write("Couldn't load public key from ", 30);
1516 c_write(cfg.keyfile, strlen(cfg.keyfile));
1517 c_write(".\r\n", 3);
1518 continue; /* go and try password */
1519 }
1520 if (i == -1) {
1521 c_write("Wrong passphrase.\r\n", 19);
1522 tried_publickey = 0;
1523 continue; /* try again */
1524 }
1525
1526 /*
1527 * Send a public key attempt.
1528 */
1529 send_packet(SSH1_CMSG_AUTH_RSA,
1530 PKT_BIGNUM, pubkey.modulus, PKT_END);
1531
1532 crWaitUntil(ispkt);
1533 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1534 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1535 continue; /* go and try password */
1536 }
8d5de777 1537 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1538 bombout(("Bizarre response to offer of public key"));
1539 crReturn(0);
1540 }
7cca0d81 1541 ssh1_read_bignum(pktin.body, &challenge);
1542 response = rsadecrypt(challenge, &pubkey);
1543 freebn(pubkey.private_exponent); /* burn the evidence */
1544
1545 for (i = 0; i < 32; i += 2) {
1546 buffer[i] = response[16-i/2] >> 8;
1547 buffer[i+1] = response[16-i/2] & 0xFF;
1548 }
1549
1550 MD5Init(&md5c);
1551 MD5Update(&md5c, buffer, 32);
1552 MD5Update(&md5c, session_id, 16);
1553 MD5Final(buffer, &md5c);
1554
1555 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1556 PKT_DATA, buffer, 16, PKT_END);
1557
1558 crWaitUntil(ispkt);
1559 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1560 if (flags & FLAG_VERBOSE)
1561 c_write("Failed to authenticate with our public key.\r\n",
1562 45);
7cca0d81 1563 continue; /* go and try password */
1564 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1565 bombout(("Bizarre response to RSA authentication response"));
1566 crReturn(0);
7cca0d81 1567 }
1568
1569 break; /* we're through! */
1570 } else {
1571 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1572 }
c5e9c988 1573 logevent("Sent password");
374330e2 1574 memset(password, 0, strlen(password));
fb09bf1c 1575 crWaitUntil(ispkt);
e5574168 1576 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1577 if (flags & FLAG_VERBOSE)
1578 c_write("Access denied\r\n", 15);
c5e9c988 1579 logevent("Authentication refused");
e5574168 1580 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1581 logevent("Received disconnect request");
85ee8208 1582 ssh_state = SSH_STATE_CLOSED;
1583 crReturn(1);
e5574168 1584 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1585 bombout(("Strange packet received, type %d", pktin.type));
1586 crReturn(0);
374330e2 1587 }
1588 }
1589
c5e9c988 1590 logevent("Authentication successful");
1591
fb09bf1c 1592 crFinish(1);
1593}
1594
e5574168 1595static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1596 crBegin;
1597
1598 random_init();
1599
e5574168 1600 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1601 crReturnV;
85ee8208 1602 }
1603 if (ssh_state == SSH_STATE_CLOSED)
1604 crReturnV;
fb09bf1c 1605
979310f1 1606 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1607 logevent("Requesting agent forwarding");
1608 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1609 do { crReturnV; } while (!ispkt);
1610 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1611 bombout(("Protocol confusion"));
1612 crReturnV;
dacbd0e8 1613 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1614 logevent("Agent forwarding refused");
1615 } else
1616 logevent("Agent forwarding enabled");
1617 }
1618
fef97f43 1619 if (!cfg.nopty) {
e5574168 1620 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1621 PKT_STR, cfg.termtype,
1622 PKT_INT, rows, PKT_INT, cols,
1623 PKT_INT, 0, PKT_INT, 0,
1624 PKT_CHAR, 0,
1625 PKT_END);
fef97f43 1626 ssh_state = SSH_STATE_INTERMED;
1627 do { crReturnV; } while (!ispkt);
e5574168 1628 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1629 bombout(("Protocol confusion"));
1630 crReturnV;
e5574168 1631 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1632 c_write("Server refused to allocate pty\r\n", 32);
1633 }
c5e9c988 1634 logevent("Allocated pty");
374330e2 1635 }
1636
6abbf9e3 1637 if (*cfg.remote_cmd)
1638 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1639 else
1640 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1641 logevent("Started session");
374330e2 1642
1643 ssh_state = SSH_STATE_SESSION;
1644 if (size_needed)
1645 ssh_size();
1646
8ccc75b0 1647 ssh_send_ok = 1;
dacbd0e8 1648 ssh_channels = newtree234(ssh_channelcmp);
6f34e365 1649 begin_session();
374330e2 1650 while (1) {
1651 crReturnV;
1652 if (ispkt) {
e5574168 1653 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1654 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1655 long len = GET_32BIT(pktin.body);
3bdaf79d 1656 c_writedata(pktin.body+4, len);
e5574168 1657 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1658 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1659 logevent("Received disconnect request");
dacbd0e8 1660 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1661 /* Remote side is trying to open a channel to talk to our
1662 * agent. Give them back a local channel number. */
d211621f 1663 unsigned i = 1;
dacbd0e8 1664 struct ssh_channel *c;
1665 enum234 e;
1666 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1667 if (c->localid > i)
1668 break; /* found a free number */
1669 i = c->localid + 1;
1670 }
1671 c = malloc(sizeof(struct ssh_channel));
1672 c->remoteid = GET_32BIT(pktin.body);
1673 c->localid = i;
b8bb811a 1674 c->closes = 0;
dacbd0e8 1675 c->type = SSH1_SMSG_AGENT_OPEN; /* identify channel type */
bb487ce2 1676 c->u.a.lensofar = 0;
dacbd0e8 1677 add234(ssh_channels, c);
1678 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1679 PKT_INT, c->remoteid, PKT_INT, c->localid,
1680 PKT_END);
1681 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1682 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1683 /* Remote side closes a channel. */
d211621f 1684 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1685 struct ssh_channel *c;
1686 c = find234(ssh_channels, &i, ssh_channelfind);
1687 if (c) {
1688 int closetype;
1689 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1690 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1691 c->closes |= closetype;
1692 if (c->closes == 3) {
1693 del234(ssh_channels, c);
1694 free(c);
1695 }
1696 }
1697 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1698 /* Data sent down one of our channels. */
1699 int i = GET_32BIT(pktin.body);
1700 int len = GET_32BIT(pktin.body+4);
1701 unsigned char *p = pktin.body+8;
1702 struct ssh_channel *c;
1703 c = find234(ssh_channels, &i, ssh_channelfind);
1704 if (c) {
1705 switch(c->type) {
1706 case SSH1_SMSG_AGENT_OPEN:
1707 /* Data for an agent message. Buffer it. */
1708 while (len > 0) {
1709 if (c->u.a.lensofar < 4) {
1710 int l = min(4 - c->u.a.lensofar, len);
1711 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
1712 p += l; len -= l; c->u.a.lensofar += l;
1713 }
1714 if (c->u.a.lensofar == 4) {
1715 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
1716 c->u.a.message = malloc(c->u.a.totallen);
1717 memcpy(c->u.a.message, c->u.a.msglen, 4);
1718 }
1719 if (c->u.a.lensofar >= 4 && len > 0) {
1720 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
1721 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
1722 p += l; len -= l; c->u.a.lensofar += l;
1723 }
1724 if (c->u.a.lensofar == c->u.a.totallen) {
1725 void *reply, *sentreply;
1726 int replylen;
1727 agent_query(c->u.a.message, c->u.a.totallen,
1728 &reply, &replylen);
1729 if (reply)
1730 sentreply = reply;
1731 else {
1732 /* Fake SSH_AGENT_FAILURE. */
1733 sentreply = "\0\0\0\1\5";
1734 replylen = 5;
1735 }
1736 send_packet(SSH1_MSG_CHANNEL_DATA,
1737 PKT_INT, c->remoteid,
1738 PKT_INT, replylen,
1739 PKT_DATA, sentreply, replylen,
1740 PKT_END);
1741 if (reply)
1742 free(reply);
1743 free(c->u.a.message);
1744 c->u.a.lensofar = 0;
1745 }
1746 }
1747 break;
1748 }
1749 }
e5574168 1750 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 1751 /* may be from EXEC_SHELL on some servers */
e5574168 1752 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 1753 /* may be from EXEC_SHELL on some servers
374330e2 1754 * if no pty is available or in other odd cases. Ignore */
e5574168 1755 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1756 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 1757 } else {
8d5de777 1758 bombout(("Strange packet received: type %d", pktin.type));
1759 crReturnV;
374330e2 1760 }
1761 } else {
e5574168 1762 send_packet(SSH1_CMSG_STDIN_DATA,
fb09bf1c 1763 PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
374330e2 1764 }
1765 }
1766
1767 crFinishV;
1768}
1769
1770/*
e5574168 1771 * Utility routine for decoding comma-separated strings in KEXINIT.
1772 */
1773int in_commasep_string(char *needle, char *haystack, int haylen) {
1774 int needlen = strlen(needle);
1775 while (1) {
1776 /*
1777 * Is it at the start of the string?
1778 */
1779 if (haylen >= needlen && /* haystack is long enough */
1780 !memcmp(needle, haystack, needlen) && /* initial match */
1781 (haylen == needlen || haystack[needlen] == ',')
1782 /* either , or EOS follows */
1783 )
1784 return 1;
1785 /*
1786 * If not, search for the next comma and resume after that.
1787 * If no comma found, terminate.
1788 */
1789 while (haylen > 0 && *haystack != ',')
1790 haylen--, haystack++;
1791 if (haylen == 0)
1792 return 0;
1793 haylen--, haystack++; /* skip over comma itself */
1794 }
1795}
1796
1797/*
d39f364a 1798 * SSH2 key creation method.
1799 */
1800void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
1801 SHA_State s;
1802 /* First 20 bytes. */
1803 SHA_Init(&s);
1804 sha_mpint(&s, K);
1805 SHA_Bytes(&s, H, 20);
1806 SHA_Bytes(&s, &chr, 1);
1807 SHA_Bytes(&s, H, 20);
1808 SHA_Final(&s, keyspace);
1809 /* Next 20 bytes. */
1810 SHA_Init(&s);
1811 sha_mpint(&s, K);
1812 SHA_Bytes(&s, H, 20);
1813 SHA_Bytes(&s, keyspace, 20);
1814 SHA_Final(&s, keyspace+20);
1815}
1816
1817/*
7cca0d81 1818 * Handle the SSH2 transport layer.
e5574168 1819 */
7cca0d81 1820static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 1821{
1822 static int i, len;
1823 static char *str;
1824 static Bignum e, f, K;
1825 static struct ssh_cipher *cscipher_tobe = NULL;
1826 static struct ssh_cipher *sccipher_tobe = NULL;
1827 static struct ssh_mac *csmac_tobe = NULL;
1828 static struct ssh_mac *scmac_tobe = NULL;
1829 static struct ssh_compress *cscomp_tobe = NULL;
1830 static struct ssh_compress *sccomp_tobe = NULL;
d5859615 1831 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 1832 static int hostkeylen, siglen;
1833 static unsigned char exchange_hash[20];
d39f364a 1834 static unsigned char keyspace[40];
e5574168 1835
1836 crBegin;
7cca0d81 1837 random_init();
e5574168 1838
5e8358ad 1839 /*
1840 * Set up the preferred cipher.
1841 */
1842 if (cfg.cipher == CIPHER_BLOWFISH) {
1843 ciphers[0] = &ssh_blowfish_ssh2;
1844 } else if (cfg.cipher == CIPHER_DES) {
1845 logevent("Single DES not supported in SSH2; using 3DES");
1846 ciphers[0] = &ssh_3des_ssh2;
1847 } else if (cfg.cipher == CIPHER_3DES) {
1848 ciphers[0] = &ssh_3des_ssh2;
1849 } else {
1850 /* Shouldn't happen, but we do want to initialise to _something_. */
1851 ciphers[0] = &ssh_3des_ssh2;
1852 }
1853
7cca0d81 1854 begin_key_exchange:
e5574168 1855 /*
1856 * Construct and send our key exchange packet.
1857 */
1858 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1859 for (i = 0; i < 16; i++)
1860 ssh2_pkt_addbyte((unsigned char)random_byte());
1861 /* List key exchange algorithms. */
1862 ssh2_pkt_addstring_start();
1863 for (i = 0; i < lenof(kex_algs); i++) {
1864 ssh2_pkt_addstring_str(kex_algs[i]->name);
1865 if (i < lenof(kex_algs)-1)
1866 ssh2_pkt_addstring_str(",");
1867 }
1868 /* List server host key algorithms. */
1869 ssh2_pkt_addstring_start();
1870 for (i = 0; i < lenof(hostkey_algs); i++) {
1871 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1872 if (i < lenof(hostkey_algs)-1)
1873 ssh2_pkt_addstring_str(",");
1874 }
1875 /* List client->server encryption algorithms. */
1876 ssh2_pkt_addstring_start();
1877 for (i = 0; i < lenof(ciphers); i++) {
1878 ssh2_pkt_addstring_str(ciphers[i]->name);
1879 if (i < lenof(ciphers)-1)
1880 ssh2_pkt_addstring_str(",");
1881 }
1882 /* List server->client encryption algorithms. */
1883 ssh2_pkt_addstring_start();
1884 for (i = 0; i < lenof(ciphers); i++) {
1885 ssh2_pkt_addstring_str(ciphers[i]->name);
1886 if (i < lenof(ciphers)-1)
1887 ssh2_pkt_addstring_str(",");
1888 }
1889 /* List client->server MAC algorithms. */
1890 ssh2_pkt_addstring_start();
1891 for (i = 0; i < lenof(macs); i++) {
1892 ssh2_pkt_addstring_str(macs[i]->name);
1893 if (i < lenof(macs)-1)
1894 ssh2_pkt_addstring_str(",");
1895 }
1896 /* List server->client MAC algorithms. */
1897 ssh2_pkt_addstring_start();
1898 for (i = 0; i < lenof(macs); i++) {
1899 ssh2_pkt_addstring_str(macs[i]->name);
1900 if (i < lenof(macs)-1)
1901 ssh2_pkt_addstring_str(",");
1902 }
1903 /* List client->server compression algorithms. */
1904 ssh2_pkt_addstring_start();
1905 for (i = 0; i < lenof(compressions); i++) {
1906 ssh2_pkt_addstring_str(compressions[i]->name);
1907 if (i < lenof(compressions)-1)
1908 ssh2_pkt_addstring_str(",");
1909 }
1910 /* List server->client compression algorithms. */
1911 ssh2_pkt_addstring_start();
1912 for (i = 0; i < lenof(compressions); i++) {
1913 ssh2_pkt_addstring_str(compressions[i]->name);
1914 if (i < lenof(compressions)-1)
1915 ssh2_pkt_addstring_str(",");
1916 }
1917 /* List client->server languages. Empty list. */
1918 ssh2_pkt_addstring_start();
1919 /* List server->client languages. Empty list. */
1920 ssh2_pkt_addstring_start();
1921 /* First KEX packet does _not_ follow, because we're not that brave. */
1922 ssh2_pkt_addbool(FALSE);
1923 /* Reserved. */
1924 ssh2_pkt_adduint32(0);
1925 sha_string(&exhash, pktout.data+5, pktout.length-5);
1926 ssh2_pkt_send();
1927
1928 if (!ispkt) crWaitUntil(ispkt);
1929 sha_string(&exhash, pktin.data+5, pktin.length-5);
1930
1931 /*
1932 * Now examine the other side's KEXINIT to see what we're up
1933 * to.
1934 */
7cca0d81 1935 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 1936 bombout(("expected key exchange packet from server"));
1937 crReturn(0);
7cca0d81 1938 }
e5574168 1939 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1940 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1941 pktin.savedpos += 16; /* skip garbage cookie */
1942 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1943 for (i = 0; i < lenof(kex_algs); i++) {
1944 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1945 kex = kex_algs[i];
1946 break;
1947 }
1948 }
1949 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1950 for (i = 0; i < lenof(hostkey_algs); i++) {
1951 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1952 hostkey = hostkey_algs[i];
1953 break;
1954 }
1955 }
1956 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
1957 for (i = 0; i < lenof(ciphers); i++) {
1958 if (in_commasep_string(ciphers[i]->name, str, len)) {
1959 cscipher_tobe = ciphers[i];
1960 break;
1961 }
1962 }
1963 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
1964 for (i = 0; i < lenof(ciphers); i++) {
1965 if (in_commasep_string(ciphers[i]->name, str, len)) {
1966 sccipher_tobe = ciphers[i];
1967 break;
1968 }
1969 }
1970 ssh2_pkt_getstring(&str, &len); /* client->server mac */
1971 for (i = 0; i < lenof(macs); i++) {
1972 if (in_commasep_string(macs[i]->name, str, len)) {
1973 csmac_tobe = macs[i];
1974 break;
1975 }
1976 }
1977 ssh2_pkt_getstring(&str, &len); /* server->client mac */
1978 for (i = 0; i < lenof(macs); i++) {
1979 if (in_commasep_string(macs[i]->name, str, len)) {
1980 scmac_tobe = macs[i];
1981 break;
1982 }
1983 }
1984 ssh2_pkt_getstring(&str, &len); /* client->server compression */
1985 for (i = 0; i < lenof(compressions); i++) {
1986 if (in_commasep_string(compressions[i]->name, str, len)) {
1987 cscomp_tobe = compressions[i];
1988 break;
1989 }
1990 }
1991 ssh2_pkt_getstring(&str, &len); /* server->client compression */
1992 for (i = 0; i < lenof(compressions); i++) {
1993 if (in_commasep_string(compressions[i]->name, str, len)) {
1994 sccomp_tobe = compressions[i];
1995 break;
1996 }
1997 }
e5574168 1998
1999 /*
2000 * Currently we only support Diffie-Hellman and DSS, so let's
2001 * bomb out if those aren't selected.
2002 */
8d5de777 2003 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2004 bombout(("internal fault: chaos in SSH 2 transport layer"));
2005 crReturn(0);
2006 }
e5574168 2007
2008 /*
2009 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2010 */
2011 e = dh_create_e();
e5574168 2012 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2013 ssh2_pkt_addmp(e);
2014 ssh2_pkt_send();
2015
2016 crWaitUntil(ispkt);
7cca0d81 2017 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2018 bombout(("expected key exchange packet from server"));
2019 crReturn(0);
7cca0d81 2020 }
e5574168 2021 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2022 f = ssh2_pkt_getmp();
e5574168 2023 ssh2_pkt_getstring(&sigdata, &siglen);
2024
2025 K = dh_find_K(f);
e5574168 2026
2027 sha_string(&exhash, hostkeydata, hostkeylen);
2028 sha_mpint(&exhash, e);
2029 sha_mpint(&exhash, f);
2030 sha_mpint(&exhash, K);
2031 SHA_Final(&exhash, exchange_hash);
2032
7cca0d81 2033#if 0
e5574168 2034 debug(("Exchange hash is:\r\n"));
2035 for (i = 0; i < 20; i++)
2036 debug((" %02x", exchange_hash[i]));
2037 debug(("\r\n"));
7cca0d81 2038#endif
2039
2040 hostkey->setkey(hostkeydata, hostkeylen);
8d5de777 2041 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20)) {
2042 bombout(("Server failed host key check"));
2043 crReturn(0);
2044 }
e5574168 2045
2046 /*
7cca0d81 2047 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2048 */
7cca0d81 2049 crWaitUntil(ispkt);
8d5de777 2050 if (pktin.type != SSH2_MSG_NEWKEYS) {
2051 bombout(("expected new-keys packet from server"));
2052 crReturn(0);
2053 }
d39f364a 2054
2055 /*
7cca0d81 2056 * Authenticate remote host: verify host key. (We've already
2057 * checked the signature of the exchange hash.)
e5574168 2058 */
7cca0d81 2059 keystr = hostkey->fmtkey();
d5859615 2060 fingerprint = hostkey->fingerprint();
d4857987 2061 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2062 keystr, fingerprint);
d5859615 2063 logevent("Host key fingerprint is:");
2064 logevent(fingerprint);
2065 free(fingerprint);
7cca0d81 2066 free(keystr);
d39f364a 2067
2068 /*
7cca0d81 2069 * Send SSH2_MSG_NEWKEYS.
d39f364a 2070 */
2071 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2072 ssh2_pkt_send();
d39f364a 2073
2074 /*
2075 * Create and initialise session keys.
2076 */
2077 cscipher = cscipher_tobe;
2078 sccipher = sccipher_tobe;
2079 csmac = csmac_tobe;
2080 scmac = scmac_tobe;
2081 cscomp = cscomp_tobe;
2082 sccomp = sccomp_tobe;
2083 /*
2084 * Set IVs after keys.
2085 */
2086 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
2087 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
2088 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2089 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2090 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2091 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2092
033b4cef 2093 /*
7cca0d81 2094 * Now we're encrypting. Begin returning 1 to the protocol main
2095 * function so that other things can run on top of the
2096 * transport. If we ever see a KEXINIT, we must go back to the
2097 * start.
033b4cef 2098 */
7cca0d81 2099 do {
2100 crReturn(1);
2101 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2102 goto begin_key_exchange;
e5574168 2103
2104 crFinish(1);
2105}
2106
7cca0d81 2107/*
2108 * Handle the SSH2 userauth and connection layers.
2109 */
2110static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2111{
7cca0d81 2112 static unsigned long remote_winsize;
2113 static unsigned long remote_maxpkt;
2114
e5574168 2115 crBegin;
2116
7cca0d81 2117 /*
2118 * Request userauth protocol, and await a response to it.
2119 */
2120 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2121 ssh2_pkt_addstring("ssh-userauth");
2122 ssh2_pkt_send();
2123 crWaitUntilV(ispkt);
8d5de777 2124 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2125 bombout(("Server refused user authentication protocol"));
2126 crReturnV;
2127 }
7cca0d81 2128
2129 /*
2130 * FIXME: currently we support only password authentication.
2131 * (This places us technically in violation of the SSH2 spec.
2132 * We must fix this.)
2133 */
2134 while (1) {
2135 /*
2136 * Get a username and a password.
2137 */
2138 static char username[100];
2139 static char password[100];
2140 static int pos = 0;
2141 static char c;
e5574168 2142
67779be7 2143 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2144 c_write("login as: ", 10);
67779be7 2145 ssh_send_ok = 1;
7cca0d81 2146 while (pos >= 0) {
2147 crWaitUntilV(!ispkt);
2148 while (inlen--) switch (c = *in++) {
2149 case 10: case 13:
2150 username[pos] = 0;
2151 pos = -1;
2152 break;
2153 case 8: case 127:
2154 if (pos > 0) {
2155 c_write("\b \b", 3);
2156 pos--;
2157 }
2158 break;
2159 case 21: case 27:
2160 while (pos > 0) {
2161 c_write("\b \b", 3);
2162 pos--;
2163 }
2164 break;
2165 case 3: case 4:
2166 random_save_seed();
2167 exit(0);
2168 break;
2169 default:
2170 if (((c >= ' ' && c <= '~') ||
2171 ((unsigned char)c >= 160)) && pos < 40) {
2172 username[pos++] = c;
2173 c_write(&c, 1);
2174 }
2175 break;
2176 }
2177 }
2178 c_write("\r\n", 2);
2179 username[strcspn(username, "\n\r")] = '\0';
2180 } else {
2181 char stuff[200];
2182 strncpy(username, cfg.username, 99);
2183 username[99] = '\0';
67779be7 2184 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2185 sprintf(stuff, "Using username \"%s\".\r\n", username);
2186 c_write(stuff, strlen(stuff));
2187 }
2188 }
2189
67779be7 2190 if (!(flags & FLAG_INTERACTIVE)) {
7cca0d81 2191 char prompt[200];
3bdaf79d 2192 sprintf(prompt, "%.90s@%.90s's password: ", cfg.username, savedhost);
7cca0d81 2193 if (!ssh_get_password(prompt, password, sizeof(password))) {
2194 /*
2195 * get_password failed to get a password (for
2196 * example because one was supplied on the command
2197 * line which has already failed to work).
2198 * Terminate.
2199 */
2200 logevent("No more passwords to try");
2201 ssh_state = SSH_STATE_CLOSED;
2202 crReturnV;
2203 }
2204 } else {
2205 c_write("password: ", 10);
67779be7 2206 ssh_send_ok = 1;
7cca0d81 2207
2208 pos = 0;
2209 while (pos >= 0) {
2210 crWaitUntilV(!ispkt);
2211 while (inlen--) switch (c = *in++) {
2212 case 10: case 13:
2213 password[pos] = 0;
2214 pos = -1;
2215 break;
2216 case 8: case 127:
2217 if (pos > 0)
2218 pos--;
2219 break;
2220 case 21: case 27:
2221 pos = 0;
2222 break;
2223 case 3: case 4:
2224 random_save_seed();
2225 exit(0);
2226 break;
2227 default:
2228 if (((c >= ' ' && c <= '~') ||
2229 ((unsigned char)c >= 160)) && pos < 40)
2230 password[pos++] = c;
2231 break;
2232 }
2233 }
2234 c_write("\r\n", 2);
2235 }
2236
2237 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2238 ssh2_pkt_addstring(username);
2239 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2240 ssh2_pkt_addstring("password");
2241 ssh2_pkt_addbool(FALSE);
2242 ssh2_pkt_addstring(password);
2243 ssh2_pkt_send();
2244
2245 crWaitUntilV(ispkt);
2246 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2247 c_write("Access denied\r\n", 15);
2248 logevent("Authentication refused");
2249 } else
2250 break;
2251 }
2252
2253 /*
2254 * Now we're authenticated for the connection protocol. The
2255 * connection protocol will automatically have started at this
2256 * point; there's no need to send SERVICE_REQUEST.
2257 */
2258
2259 /*
2260 * So now create a channel with a session in it.
2261 */
d211621f 2262 mainchan = malloc(sizeof(struct ssh_channel));
2263 mainchan->localid = 100; /* as good as any */
7cca0d81 2264 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2265 ssh2_pkt_addstring("session");
d211621f 2266 ssh2_pkt_adduint32(mainchan->localid);
2267 ssh2_pkt_adduint32(0x7FFFFFFFUL); /* our window size */
2268 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2269 ssh2_pkt_send();
2270 crWaitUntilV(ispkt);
2271 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2272 bombout(("Server refused to open a session"));
2273 crReturnV;
7cca0d81 2274 /* FIXME: error data comes back in FAILURE packet */
2275 }
d211621f 2276 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2277 bombout(("Server's channel confirmation cited wrong channel"));
2278 crReturnV;
7cca0d81 2279 }
d211621f 2280 mainchan->remoteid = ssh2_pkt_getuint32();
2281 mainchan->u.v2.remwindow = ssh2_pkt_getuint32();
2282 mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32();
2283 mainchan->u.v2.outbuffer = NULL;
2284 mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0;
7cca0d81 2285 logevent("Opened channel for session");
2286
2287 /*
2288 * Now allocate a pty for the session.
2289 */
67779be7 2290 if (!cfg.nopty) {
2291 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2292 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2293 ssh2_pkt_addstring("pty-req");
2294 ssh2_pkt_addbool(1); /* want reply */
2295 ssh2_pkt_addstring(cfg.termtype);
2296 ssh2_pkt_adduint32(cols);
2297 ssh2_pkt_adduint32(rows);
2298 ssh2_pkt_adduint32(0); /* pixel width */
2299 ssh2_pkt_adduint32(0); /* pixel height */
2300 ssh2_pkt_addstring_start();
2301 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2302 ssh2_pkt_send();
7cca0d81 2303
67779be7 2304 do {
2305 crWaitUntilV(ispkt);
2306 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2307 /* FIXME: be able to handle other channels here */
2308 if (ssh2_pkt_getuint32() != mainchan->localid)
2309 continue; /* wrong channel */
2310 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2311 }
2312 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2313
67779be7 2314 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2315 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2316 bombout(("Server got confused by pty request"));
2317 crReturnV;
67779be7 2318 }
2319 c_write("Server refused to allocate pty\r\n", 32);
2320 } else {
2321 logevent("Allocated pty");
7cca0d81 2322 }
7cca0d81 2323 }
2324
2325 /*
67779be7 2326 * Start a shell or a remote command.
7cca0d81 2327 */
2328 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2329 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2330 if (*cfg.remote_cmd) {
2331 ssh2_pkt_addstring("exec");
2332 ssh2_pkt_addbool(1); /* want reply */
2333 ssh2_pkt_addstring(cfg.remote_cmd);
2334 } else {
2335 ssh2_pkt_addstring("shell");
2336 ssh2_pkt_addbool(1); /* want reply */
2337 }
7cca0d81 2338 ssh2_pkt_send();
d211621f 2339 do {
7cca0d81 2340 crWaitUntilV(ispkt);
d211621f 2341 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2342 /* FIXME: be able to handle other channels here */
2343 if (ssh2_pkt_getuint32() != mainchan->localid)
2344 continue; /* wrong channel */
2345 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2346 }
7cca0d81 2347 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2348 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2349 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2350 bombout(("Server got confused by shell/command request"));
2351 crReturnV;
7cca0d81 2352 }
8d5de777 2353 bombout(("Server refused to start a shell/command"));
2354 crReturnV;
7cca0d81 2355 } else {
8d5de777 2356 logevent("Started a shell/command");
7cca0d81 2357 }
2358
2359 /*
2360 * Transfer data!
2361 */
8ccc75b0 2362 ssh_send_ok = 1;
6f34e365 2363 begin_session();
7cca0d81 2364 while (1) {
d211621f 2365 static int try_send;
e5574168 2366 crReturnV;
d211621f 2367 try_send = FALSE;
7cca0d81 2368 if (ispkt) {
2369 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2370 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2371 char *data;
2372 int length;
d211621f 2373 /* FIXME: be able to handle other channels here */
2374 if (ssh2_pkt_getuint32() != mainchan->localid)
7cca0d81 2375 continue; /* wrong channel */
2376 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2377 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2378 continue; /* extended but not stderr */
2379 ssh2_pkt_getstring(&data, &length);
d211621f 2380 if (data) {
3bdaf79d 2381 c_writedata(data, length);
d211621f 2382 /*
2383 * Enlarge the window again at the remote side,
2384 * just in case it ever runs down and they fail
2385 * to send us any more data.
2386 */
2387 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2388 ssh2_pkt_adduint32(mainchan->remoteid);
2389 ssh2_pkt_adduint32(length);
2390 ssh2_pkt_send();
2391 }
7cca0d81 2392 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2393 ssh_state = SSH_STATE_CLOSED;
d211621f 2394 logevent("Received disconnect message");
7cca0d81 2395 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2396 continue; /* exit status et al; ignore (FIXME?) */
d211621f 2397 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2398 continue; /* remote sends EOF; ignore */
2399 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
2400 /* FIXME: be able to handle other channels here */
2401 if (ssh2_pkt_getuint32() != mainchan->localid)
2402 continue; /* wrong channel */
2403 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2404 ssh2_pkt_adduint32(mainchan->remoteid);
2405 ssh2_pkt_send();
2406 /* FIXME: mark the channel as closed */
2407 if (1 /* FIXME: "all channels are closed" */) {
2408 logevent("All channels closed. Disconnecting");
2409 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2410 ssh2_pkt_send();
2411 }
2412 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2413 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
d211621f 2414 /* FIXME: be able to handle other channels here */
2415 if (ssh2_pkt_getuint32() != mainchan->localid)
2416 continue; /* wrong channel */
2417 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2418 try_send = TRUE;
7cca0d81 2419 } else {
8d5de777 2420 bombout(("Strange packet received: type %d", pktin.type));
2421 crReturnV;
7cca0d81 2422 }
2423 } else {
d211621f 2424 /*
2425 * We have spare data. Add it to the channel buffer.
2426 */
2427 if (mainchan->u.v2.outbufsize <
2428 mainchan->u.v2.outbuflen + inlen) {
2429 mainchan->u.v2.outbufsize =
2430 mainchan->u.v2.outbuflen + inlen + 1024;
2431 mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer,
2432 mainchan->u.v2.outbufsize);
2433 }
2434 memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen,
2435 in, inlen);
2436 mainchan->u.v2.outbuflen += inlen;
2437 try_send = TRUE;
7cca0d81 2438 }
d211621f 2439 if (try_send) {
2440 /*
2441 * Try to send data on the channel if we can. (FIXME:
2442 * on _all_ channels.)
2443 */
2444 while (mainchan->u.v2.remwindow > 0 &&
2445 mainchan->u.v2.outbuflen > 0) {
2446 unsigned len = mainchan->u.v2.remwindow;
2447 if (len > mainchan->u.v2.outbuflen)
2448 len = mainchan->u.v2.outbuflen;
2449 if (len > mainchan->u.v2.remmaxpkt)
2450 len = mainchan->u.v2.remmaxpkt;
2451 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2452 ssh2_pkt_adduint32(mainchan->remoteid);
2453 ssh2_pkt_addstring_start();
2454 ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len);
2455 ssh2_pkt_send();
2456 mainchan->u.v2.outbuflen -= len;
2457 memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len,
2458 mainchan->u.v2.outbuflen);
2459 mainchan->u.v2.remwindow -= len;
2460 }
2461 }
e5574168 2462 }
2463
2464 crFinishV;
2465}
2466
2467/*
7cca0d81 2468 * Handle the top-level SSH2 protocol.
2469 */
2470static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2471{
2472 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2473 return;
2474 do_ssh2_authconn(in, inlen, ispkt);
2475}
2476
2477/*
374330e2 2478 * Called to set up the connection. Will arrange for WM_NETEVENT
2479 * messages to be passed to the specified window, whose window
2480 * procedure should then call telnet_msg().
2481 *
2482 * Returns an error message, or NULL on success.
374330e2 2483 */
2484static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
fb09bf1c 2485 char *p;
8f203108 2486
2487#ifdef MSCRYPTOAPI
2488 if(crypto_startup() == 0)
2489 return "Microsoft high encryption pack not installed!";
2490#endif
374330e2 2491
fb09bf1c 2492 p = connect_to_host(host, port, realhost);
2493 if (p != NULL)
2494 return p;
374330e2 2495
2496 if (!do_ssh_init())
2497 return "Protocol initialisation error";
2498
4017be6d 2499 if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
374330e2 2500 switch (WSAGetLastError()) {
2501 case WSAENETDOWN: return "Network is down";
2502 default: return "WSAAsyncSelect(): unknown error";
2503 }
2504
2505 return NULL;
2506}
2507
2508/*
2509 * Process a WM_NETEVENT message. Will return 0 if the connection
2510 * has closed, or <0 for a socket error.
2511 */
2512static int ssh_msg (WPARAM wParam, LPARAM lParam) {
2513 int ret;
2514 char buf[256];
2515
8ce72d2c 2516 /*
2517 * Because reading less than the whole of the available pending
2518 * data can generate an FD_READ event, we need to allow for the
2519 * possibility that FD_READ may arrive with FD_CLOSE already in
2520 * the queue; so it's possible that we can get here even with s
2521 * invalid. If so, we return 1 and don't worry about it.
2522 */
2523 if (s == INVALID_SOCKET)
2524 return 1;
374330e2 2525
8d5de777 2526 if (WSAGETSELECTERROR(lParam) != 0) {
2527 closesocket(s);
2528 s = INVALID_SOCKET;
374330e2 2529 return -WSAGETSELECTERROR(lParam);
8d5de777 2530 }
374330e2 2531
2532 switch (WSAGETSELECTEVENT(lParam)) {
2533 case FD_READ:
8ce72d2c 2534 case FD_CLOSE:
374330e2 2535 ret = recv(s, buf, sizeof(buf), 0);
2536 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
2537 return 1;
8d5de777 2538 if (ret < 0) { /* any _other_ error */
2539 closesocket(s);
2540 s = INVALID_SOCKET;
374330e2 2541 return -10000-WSAGetLastError();
8d5de777 2542 }
374330e2 2543 if (ret == 0) {
2544 s = INVALID_SOCKET;
8ce72d2c 2545 return 0;
374330e2 2546 }
2547 ssh_gotdata (buf, ret);
85ee8208 2548 if (ssh_state == SSH_STATE_CLOSED) {
2549 closesocket(s);
2550 s = INVALID_SOCKET;
2551 return 0;
2552 }
374330e2 2553 return 1;
374330e2 2554 }
2555 return 1; /* shouldn't happen, but WTF */
2556}
2557
2558/*
2559 * Called to send data down the Telnet connection.
2560 */
2561static void ssh_send (char *buf, int len) {
2562 if (s == INVALID_SOCKET)
2563 return;
2564
2565 ssh_protocol(buf, len, 0);
2566}
2567
2568/*
2569 * Called to set the size of the window from Telnet's POV.
2570 */
2571static void ssh_size(void) {
2572 switch (ssh_state) {
2573 case SSH_STATE_BEFORE_SIZE:
21248260 2574 case SSH_STATE_CLOSED:
374330e2 2575 break; /* do nothing */
2576 case SSH_STATE_INTERMED:
2577 size_needed = TRUE; /* buffer for later */
2578 break;
2579 case SSH_STATE_SESSION:
fef97f43 2580 if (!cfg.nopty) {
e5574168 2581 send_packet(SSH1_CMSG_WINDOW_SIZE,
fb09bf1c 2582 PKT_INT, rows, PKT_INT, cols,
2583 PKT_INT, 0, PKT_INT, 0, PKT_END);
fef97f43 2584 }
374330e2 2585 }
2586}
2587
2588/*
6abbf9e3 2589 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2590 * can send an EOF and collect resulting output (e.g. `plink
2591 * hostname sort').
374330e2 2592 */
2593static void ssh_special (Telnet_Special code) {
6abbf9e3 2594 if (code == TS_EOF) {
67779be7 2595 if (ssh_version == 1) {
6abbf9e3 2596 send_packet(SSH1_CMSG_EOF, PKT_END);
2597 } else {
2598 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 2599 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 2600 ssh2_pkt_send();
2601 }
67779be7 2602 logevent("Sent EOF message");
6abbf9e3 2603 } else {
2604 /* do nothing */
2605 }
374330e2 2606}
2607
8ccc75b0 2608static SOCKET ssh_socket(void) { return s; }
2609
2610static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 2611
374330e2 2612Backend ssh_backend = {
2613 ssh_init,
2614 ssh_msg,
2615 ssh_send,
2616 ssh_size,
4017be6d 2617 ssh_special,
8ccc75b0 2618 ssh_socket,
2619 ssh_sendok
374330e2 2620};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator