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Source form of win_res.rc
[u/mdw/putty] / ssh.c
CommitLineData
374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
374330e2 5#include <winsock.h>
6
7#include "putty.h"
fb09bf1c 8#include "ssh.h"
9#include "scp.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); \
4017be6d 19 if (!(flags & FLAG_CONNECTION) && (flags & FLAG_VERBOSE)) \
fb09bf1c 20 fprintf(stderr, "%s\n", s); }
21
e5574168 22#define SSH1_MSG_DISCONNECT 1
23#define SSH1_SMSG_PUBLIC_KEY 2
24#define SSH1_CMSG_SESSION_KEY 3
25#define SSH1_CMSG_USER 4
7cca0d81 26#define SSH1_CMSG_AUTH_RSA 6
27#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7
28#define SSH1_CMSG_AUTH_RSA_RESPONSE 8
e5574168 29#define SSH1_CMSG_AUTH_PASSWORD 9
30#define SSH1_CMSG_REQUEST_PTY 10
31#define SSH1_CMSG_WINDOW_SIZE 11
32#define SSH1_CMSG_EXEC_SHELL 12
33#define SSH1_CMSG_EXEC_CMD 13
34#define SSH1_SMSG_SUCCESS 14
35#define SSH1_SMSG_FAILURE 15
36#define SSH1_CMSG_STDIN_DATA 16
37#define SSH1_SMSG_STDOUT_DATA 17
38#define SSH1_SMSG_STDERR_DATA 18
39#define SSH1_CMSG_EOF 19
40#define SSH1_SMSG_EXIT_STATUS 20
41#define SSH1_CMSG_EXIT_CONFIRMATION 33
42#define SSH1_MSG_IGNORE 32
43#define SSH1_MSG_DEBUG 36
44#define SSH1_CMSG_AUTH_TIS 39
45#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40
46#define SSH1_CMSG_AUTH_TIS_RESPONSE 41
18515c51 47#define SSH1_CMSG_AUTH_CCARD 70
48#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71
49#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72
e5574168 50
51#define SSH1_AUTH_TIS 5
18515c51 52#define SSH1_AUTH_CCARD 16
e5574168 53
5c58ad2d 54#define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1
55#define SSH_AGENT_RSA_IDENTITIES_ANSWER 2
56#define SSH_AGENTC_RSA_CHALLENGE 3
57#define SSH_AGENT_RSA_RESPONSE 4
58#define SSH_AGENT_FAILURE 5
59#define SSH_AGENT_SUCCESS 6
60#define SSH_AGENTC_ADD_RSA_IDENTITY 7
61#define SSH_AGENTC_REMOVE_RSA_IDENTITY 8
62
e5574168 63#define SSH2_MSG_DISCONNECT 1
64#define SSH2_MSG_IGNORE 2
65#define SSH2_MSG_UNIMPLEMENTED 3
66#define SSH2_MSG_DEBUG 4
67#define SSH2_MSG_SERVICE_REQUEST 5
68#define SSH2_MSG_SERVICE_ACCEPT 6
69#define SSH2_MSG_KEXINIT 20
70#define SSH2_MSG_NEWKEYS 21
71#define SSH2_MSG_KEXDH_INIT 30
72#define SSH2_MSG_KEXDH_REPLY 31
7cca0d81 73#define SSH2_MSG_USERAUTH_REQUEST 50
74#define SSH2_MSG_USERAUTH_FAILURE 51
75#define SSH2_MSG_USERAUTH_SUCCESS 52
76#define SSH2_MSG_USERAUTH_BANNER 53
77#define SSH2_MSG_USERAUTH_PK_OK 60
78#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60
79#define SSH2_MSG_GLOBAL_REQUEST 80
80#define SSH2_MSG_REQUEST_SUCCESS 81
81#define SSH2_MSG_REQUEST_FAILURE 82
82#define SSH2_MSG_CHANNEL_OPEN 90
83#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91
84#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92
85#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93
86#define SSH2_MSG_CHANNEL_DATA 94
87#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95
88#define SSH2_MSG_CHANNEL_EOF 96
89#define SSH2_MSG_CHANNEL_CLOSE 97
90#define SSH2_MSG_CHANNEL_REQUEST 98
91#define SSH2_MSG_CHANNEL_SUCCESS 99
92#define SSH2_MSG_CHANNEL_FAILURE 100
93
94#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1
95#define SSH2_OPEN_CONNECT_FAILED 2
96#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3
97#define SSH2_OPEN_RESOURCE_SHORTAGE 4
98#define SSH2_EXTENDED_DATA_STDERR 1
fb09bf1c 99
100#define GET_32BIT(cp) \
101 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
102 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
103 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
104 ((unsigned long)(unsigned char)(cp)[3]))
105
106#define PUT_32BIT(cp, value) { \
107 (cp)[0] = (unsigned char)((value) >> 24); \
108 (cp)[1] = (unsigned char)((value) >> 16); \
109 (cp)[2] = (unsigned char)((value) >> 8); \
110 (cp)[3] = (unsigned char)(value); }
111
7cca0d81 112enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 113
374330e2 114/* Coroutine mechanics for the sillier bits of the code */
115#define crBegin1 static int crLine = 0;
116#define crBegin2 switch(crLine) { case 0:;
117#define crBegin crBegin1; crBegin2;
118#define crFinish(z) } crLine = 0; return (z)
119#define crFinishV } crLine = 0; return
120#define crReturn(z) \
121 do {\
122 crLine=__LINE__; return (z); case __LINE__:;\
123 } while (0)
124#define crReturnV \
125 do {\
126 crLine=__LINE__; return; case __LINE__:;\
127 } while (0)
128#define crStop(z) do{ crLine = 0; return (z); }while(0)
129#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 130#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 131#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 132
e5574168 133extern struct ssh_cipher ssh_3des;
033b4cef 134extern struct ssh_cipher ssh_3des_ssh2;
e5574168 135extern struct ssh_cipher ssh_des;
136extern struct ssh_cipher ssh_blowfish;
137
138/* for ssh 2; we miss out single-DES because it isn't supported */
033b4cef 139struct ssh_cipher *ciphers[] = { &ssh_3des_ssh2, &ssh_blowfish };
e5574168 140
141extern struct ssh_kex ssh_diffiehellman;
142struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
143
144extern struct ssh_hostkey ssh_dss;
145struct ssh_hostkey *hostkey_algs[] = { &ssh_dss };
146
147extern struct ssh_mac ssh_sha1;
148
149SHA_State exhash;
150
d39f364a 151static void nullmac_key(unsigned char *key) { }
e5574168 152static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
153static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
154struct ssh_mac ssh_mac_none = {
d39f364a 155 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 156};
157struct ssh_mac *macs[] = { &ssh_sha1, &ssh_mac_none };
158
159struct ssh_compress ssh_comp_none = {
160 "none"
161};
162struct ssh_compress *compressions[] = { &ssh_comp_none };
163
374330e2 164static SOCKET s = INVALID_SOCKET;
165
166static unsigned char session_key[32];
167static struct ssh_cipher *cipher = NULL;
e5574168 168static struct ssh_cipher *cscipher = NULL;
169static struct ssh_cipher *sccipher = NULL;
170static struct ssh_mac *csmac = NULL;
171static struct ssh_mac *scmac = NULL;
172static struct ssh_compress *cscomp = NULL;
173static struct ssh_compress *sccomp = NULL;
174static struct ssh_kex *kex = NULL;
175static struct ssh_hostkey *hostkey = NULL;
85ee8208 176int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
374330e2 177
178static char *savedhost;
8ccc75b0 179static int ssh_send_ok;
374330e2 180
181static enum {
182 SSH_STATE_BEFORE_SIZE,
183 SSH_STATE_INTERMED,
21248260 184 SSH_STATE_SESSION,
185 SSH_STATE_CLOSED
374330e2 186} ssh_state = SSH_STATE_BEFORE_SIZE;
187
188static int size_needed = FALSE;
189
190static void s_write (char *buf, int len) {
191 while (len > 0) {
192 int i = send (s, buf, len, 0);
4017be6d 193 noise_ultralight(i);
194 if (i <= 0)
195 fatalbox("Lost connection while sending");
374330e2 196 if (i > 0)
197 len -= i, buf += i;
198 }
199}
200
201static int s_read (char *buf, int len) {
202 int ret = 0;
203 while (len > 0) {
204 int i = recv (s, buf, len, 0);
4017be6d 205 noise_ultralight(i);
374330e2 206 if (i > 0)
207 len -= i, buf += i, ret += i;
208 else
209 return i;
210 }
211 return ret;
212}
213
214static void c_write (char *buf, int len) {
4017be6d 215 if (!(flags & FLAG_CONNECTION)) {
216 int i;
217 for (i = 0; i < len; i++)
218 if (buf[i] != '\r')
219 fputc(buf[i], stderr);
fb09bf1c 220 return;
221 }
c9def1b8 222 while (len--)
223 c_write1(*buf++);
374330e2 224}
225
226struct Packet {
227 long length;
228 int type;
374330e2 229 unsigned char *data;
230 unsigned char *body;
e5574168 231 long savedpos;
374330e2 232 long maxlen;
233};
234
fb09bf1c 235static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
236static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
374330e2 237
6abbf9e3 238static int ssh_version;
e5574168 239static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
240static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
241static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
374330e2 242static void ssh_size(void);
243
e5574168 244static int (*s_rdpkt)(unsigned char **data, int *datalen);
fb09bf1c 245
246/*
247 * Collect incoming data in the incoming packet buffer.
e5574168 248 * Decipher and verify the packet when it is completely read.
249 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 250 * Update the *data and *datalen variables.
251 * Return the additional nr of bytes needed, or 0 when
252 * a complete packet is available.
253 */
e5574168 254static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 255{
256 static long len, pad, biglen, to_read;
572f871e 257 static unsigned long realcrc, gotcrc;
fb09bf1c 258 static unsigned char *p;
259 static int i;
374330e2 260
261 crBegin;
374330e2 262
fb09bf1c 263next_packet:
37508af4 264
fb09bf1c 265 pktin.type = 0;
266 pktin.length = 0;
374330e2 267
fb09bf1c 268 for (i = len = 0; i < 4; i++) {
269 while ((*datalen) == 0)
270 crReturn(4-i);
271 len = (len << 8) + **data;
272 (*data)++, (*datalen)--;
273 }
374330e2 274
fb09bf1c 275#ifdef FWHACK
276 if (len == 0x52656d6f) { /* "Remo"te server has closed ... */
277 len = 0x300; /* big enough to carry to end */
278 }
279#endif
374330e2 280
fb09bf1c 281 pad = 8 - (len % 8);
282 biglen = len + pad;
283 pktin.length = len - 5;
284
285 if (pktin.maxlen < biglen) {
286 pktin.maxlen = biglen;
e5574168 287 pktin.data = (pktin.data == NULL ? malloc(biglen+APIEXTRA) :
288 realloc(pktin.data, biglen+APIEXTRA));
fb09bf1c 289 if (!pktin.data)
290 fatalbox("Out of memory");
291 }
374330e2 292
fb09bf1c 293 to_read = biglen;
294 p = pktin.data;
295 while (to_read > 0) {
296 static int chunk;
297 chunk = to_read;
298 while ((*datalen) == 0)
299 crReturn(to_read);
300 if (chunk > (*datalen))
301 chunk = (*datalen);
302 memcpy(p, *data, chunk);
303 *data += chunk;
304 *datalen -= chunk;
305 p += chunk;
306 to_read -= chunk;
307 }
374330e2 308
fb09bf1c 309 if (cipher)
310 cipher->decrypt(pktin.data, biglen);
374330e2 311
fb09bf1c 312 pktin.type = pktin.data[pad];
313 pktin.body = pktin.data + pad + 1;
374330e2 314
fb09bf1c 315 realcrc = crc32(pktin.data, biglen-4);
316 gotcrc = GET_32BIT(pktin.data+biglen-4);
317 if (gotcrc != realcrc) {
318 fatalbox("Incorrect CRC received on packet");
319 }
572f871e 320
e5574168 321 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
322 pktin.type == SSH1_SMSG_STDERR_DATA ||
323 pktin.type == SSH1_MSG_DEBUG ||
18515c51 324 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
325 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 326 long strlen = GET_32BIT(pktin.body);
327 if (strlen + 4 != pktin.length)
328 fatalbox("Received data packet with bogus string length");
329 }
330
e5574168 331 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 332 /* log debug message */
333 char buf[80];
334 int strlen = GET_32BIT(pktin.body);
335 strcpy(buf, "Remote: ");
336 if (strlen > 70) strlen = 70;
337 memcpy(buf+8, pktin.body+4, strlen);
338 buf[8+strlen] = '\0';
339 logevent(buf);
340 goto next_packet;
e5574168 341 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 342 /* do nothing */
343 goto next_packet;
344 }
345
346 crFinish(0);
347}
348
e5574168 349static int ssh2_rdpkt(unsigned char **data, int *datalen)
350{
351 static long len, pad, payload, packetlen, maclen;
352 static int i;
353 static int cipherblk;
354 static unsigned long incoming_sequence = 0;
355
356 crBegin;
357
358next_packet:
359
360 pktin.type = 0;
361 pktin.length = 0;
362
363 if (cipher)
364 cipherblk = cipher->blksize;
365 else
366 cipherblk = 8;
367 if (cipherblk < 8)
368 cipherblk = 8;
369
370 if (pktin.maxlen < cipherblk) {
371 pktin.maxlen = cipherblk;
372 pktin.data = (pktin.data == NULL ? malloc(cipherblk+APIEXTRA) :
373 realloc(pktin.data, cipherblk+APIEXTRA));
374 if (!pktin.data)
375 fatalbox("Out of memory");
376 }
377
378 /*
379 * Acquire and decrypt the first block of the packet. This will
380 * contain the length and padding details.
381 */
382 for (i = len = 0; i < cipherblk; i++) {
383 while ((*datalen) == 0)
384 crReturn(cipherblk-i);
385 pktin.data[i] = *(*data)++;
386 (*datalen)--;
387 }
388#ifdef FWHACK
389 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
390 /* FIXME */
391 }
392#endif
393 if (sccipher)
394 sccipher->decrypt(pktin.data, cipherblk);
395
396 /*
397 * Now get the length and padding figures.
398 */
399 len = GET_32BIT(pktin.data);
400 pad = pktin.data[4];
401
402 /*
403 * This enables us to deduce the payload length.
404 */
405 payload = len - pad - 1;
406
407 pktin.length = payload + 5;
408
409 /*
410 * So now we can work out the total packet length.
411 */
412 packetlen = len + 4;
413 maclen = scmac ? scmac->len : 0;
414
415 /*
416 * Adjust memory allocation if packet is too big.
417 */
418 if (pktin.maxlen < packetlen) {
419 pktin.maxlen = packetlen;
420 pktin.data = (pktin.data == NULL ? malloc(packetlen+APIEXTRA) :
421 realloc(pktin.data, packetlen+APIEXTRA));
422 if (!pktin.data)
423 fatalbox("Out of memory");
424 }
425
426 /*
427 * Read and decrypt the remainder of the packet.
428 */
429 for (i = cipherblk; i < packetlen + maclen; i++) {
430 while ((*datalen) == 0)
431 crReturn(packetlen + maclen - i);
432 pktin.data[i] = *(*data)++;
433 (*datalen)--;
434 }
435 /* Decrypt everything _except_ the MAC. */
436 if (sccipher)
437 sccipher->decrypt(pktin.data + cipherblk, packetlen - cipherblk);
438
7cca0d81 439#if 0
d39f364a 440 debug(("Got packet len=%d pad=%d\r\n", len, pad));
441 for (i = 0; i < packetlen; i++)
442 debug((" %02x", (unsigned char)pktin.data[i]));
443 debug(("\r\n"));
7cca0d81 444#endif
d39f364a 445
e5574168 446 /*
447 * Check the MAC.
448 */
033b4cef 449 if (scmac && !scmac->verify(pktin.data, len+4, incoming_sequence))
e5574168 450 fatalbox("Incorrect MAC received on packet");
033b4cef 451 incoming_sequence++; /* whether or not we MACed */
e5574168 452
453 pktin.savedpos = 6;
454 pktin.type = pktin.data[5];
e5574168 455
7cca0d81 456 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
457 goto next_packet; /* FIXME: print DEBUG message */
e5574168 458
459 crFinish(0);
460}
461
fb09bf1c 462static void ssh_gotdata(unsigned char *data, int datalen)
463{
464 while (datalen > 0) {
85ee8208 465 if ( s_rdpkt(&data, &datalen) == 0 ) {
374330e2 466 ssh_protocol(NULL, 0, 1);
85ee8208 467 if (ssh_state == SSH_STATE_CLOSED) {
468 return;
469 }
470 }
374330e2 471 }
374330e2 472}
473
fb09bf1c 474
374330e2 475static void s_wrpkt_start(int type, int len) {
476 int pad, biglen;
477
478 len += 5; /* type and CRC */
479 pad = 8 - (len%8);
480 biglen = len + pad;
481
482 pktout.length = len-5;
483 if (pktout.maxlen < biglen) {
484 pktout.maxlen = biglen;
8f203108 485#ifdef MSCRYPTOAPI
fb09bf1c 486 /* Allocate enough buffer space for extra block
8f203108 487 * for MS CryptEncrypt() */
fb09bf1c 488 pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
489 realloc(pktout.data, biglen+12));
8f203108 490#else
c1f5f956 491 pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
492 realloc(pktout.data, biglen+4));
8f203108 493#endif
374330e2 494 if (!pktout.data)
495 fatalbox("Out of memory");
496 }
497
498 pktout.type = type;
499 pktout.body = pktout.data+4+pad+1;
500}
501
502static void s_wrpkt(void) {
503 int pad, len, biglen, i;
504 unsigned long crc;
505
506 len = pktout.length + 5; /* type and CRC */
507 pad = 8 - (len%8);
508 biglen = len + pad;
509
510 pktout.body[-1] = pktout.type;
511 for (i=0; i<pad; i++)
512 pktout.data[i+4] = random_byte();
513 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 514 PUT_32BIT(pktout.data+biglen, crc);
515 PUT_32BIT(pktout.data, len);
374330e2 516
517 if (cipher)
518 cipher->encrypt(pktout.data+4, biglen);
519
520 s_write(pktout.data, biglen+4);
521}
522
fb09bf1c 523/*
524 * Construct a packet with the specified contents and
525 * send it to the server.
526 */
527static void send_packet(int pkttype, ...)
528{
529 va_list args;
530 unsigned char *p, *argp, argchar;
531 unsigned long argint;
532 int pktlen, argtype, arglen;
7cca0d81 533 Bignum bn;
fb09bf1c 534
535 pktlen = 0;
536 va_start(args, pkttype);
537 while ((argtype = va_arg(args, int)) != PKT_END) {
538 switch (argtype) {
539 case PKT_INT:
540 (void) va_arg(args, int);
541 pktlen += 4;
542 break;
543 case PKT_CHAR:
544 (void) va_arg(args, char);
545 pktlen++;
546 break;
547 case PKT_DATA:
548 (void) va_arg(args, unsigned char *);
549 arglen = va_arg(args, int);
550 pktlen += arglen;
551 break;
552 case PKT_STR:
553 argp = va_arg(args, unsigned char *);
554 arglen = strlen(argp);
555 pktlen += 4 + arglen;
556 break;
7cca0d81 557 case PKT_BIGNUM:
558 bn = va_arg(args, Bignum);
5c58ad2d 559 pktlen += ssh1_bignum_length(bn);
7cca0d81 560 break;
fb09bf1c 561 default:
562 assert(0);
563 }
564 }
565 va_end(args);
566
567 s_wrpkt_start(pkttype, pktlen);
568 p = pktout.body;
569
570 va_start(args, pkttype);
571 while ((argtype = va_arg(args, int)) != PKT_END) {
572 switch (argtype) {
573 case PKT_INT:
574 argint = va_arg(args, int);
575 PUT_32BIT(p, argint);
576 p += 4;
577 break;
578 case PKT_CHAR:
579 argchar = va_arg(args, unsigned char);
580 *p = argchar;
581 p++;
582 break;
583 case PKT_DATA:
584 argp = va_arg(args, unsigned char *);
585 arglen = va_arg(args, int);
586 memcpy(p, argp, arglen);
587 p += arglen;
588 break;
589 case PKT_STR:
590 argp = va_arg(args, unsigned char *);
591 arglen = strlen(argp);
592 PUT_32BIT(p, arglen);
593 memcpy(p + 4, argp, arglen);
594 p += 4 + arglen;
595 break;
7cca0d81 596 case PKT_BIGNUM:
597 bn = va_arg(args, Bignum);
5c58ad2d 598 p += ssh1_write_bignum(p, bn);
7cca0d81 599 break;
fb09bf1c 600 }
601 }
602 va_end(args);
603
604 s_wrpkt();
605}
606
607
608/*
609 * Connect to specified host and port.
610 * Returns an error message, or NULL on success.
611 * Also places the canonical host name into `realhost'.
612 */
613static char *connect_to_host(char *host, int port, char **realhost)
614{
615 SOCKADDR_IN addr;
616 struct hostent *h;
617 unsigned long a;
618#ifdef FWHACK
619 char *FWhost;
620 int FWport;
621#endif
622
623 savedhost = malloc(1+strlen(host));
624 if (!savedhost)
625 fatalbox("Out of memory");
626 strcpy(savedhost, host);
627
628 if (port < 0)
629 port = 22; /* default ssh port */
630
631#ifdef FWHACK
632 FWhost = host;
633 FWport = port;
634 host = FWSTR;
635 port = 23;
636#endif
637
638 /*
639 * Try to find host.
640 */
641 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
642 if ( (h = gethostbyname(host)) == NULL)
643 switch (WSAGetLastError()) {
644 case WSAENETDOWN: return "Network is down";
645 case WSAHOST_NOT_FOUND: case WSANO_DATA:
646 return "Host does not exist";
647 case WSATRY_AGAIN: return "Host not found";
648 default: return "gethostbyname: unknown error";
649 }
650 memcpy (&a, h->h_addr, sizeof(a));
651 *realhost = h->h_name;
652 } else
653 *realhost = host;
654#ifdef FWHACK
655 *realhost = FWhost;
656#endif
657 a = ntohl(a);
658
659 /*
660 * Open socket.
661 */
662 s = socket(AF_INET, SOCK_STREAM, 0);
663 if (s == INVALID_SOCKET)
664 switch (WSAGetLastError()) {
665 case WSAENETDOWN: return "Network is down";
666 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
667 default: return "socket(): unknown error";
668 }
669
670 /*
671 * Bind to local address.
672 */
673 addr.sin_family = AF_INET;
674 addr.sin_addr.s_addr = htonl(INADDR_ANY);
675 addr.sin_port = htons(0);
676 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
677 switch (WSAGetLastError()) {
678 case WSAENETDOWN: return "Network is down";
679 default: return "bind(): unknown error";
680 }
681
682 /*
683 * Connect to remote address.
684 */
685 addr.sin_addr.s_addr = htonl(a);
686 addr.sin_port = htons((short)port);
687 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
688 switch (WSAGetLastError()) {
689 case WSAENETDOWN: return "Network is down";
690 case WSAECONNREFUSED: return "Connection refused";
691 case WSAENETUNREACH: return "Network is unreachable";
692 case WSAEHOSTUNREACH: return "No route to host";
693 default: return "connect(): unknown error";
694 }
695
696#ifdef FWHACK
697 send(s, "connect ", 8, 0);
698 send(s, FWhost, strlen(FWhost), 0);
699 {
700 char buf[20];
701 sprintf(buf, " %d\n", FWport);
702 send (s, buf, strlen(buf), 0);
703 }
704#endif
705
706 return NULL;
707}
708
9697bfd2 709static int ssh_versioncmp(char *a, char *b) {
710 char *ae, *be;
711 unsigned long av, bv;
712
43aa02a7 713 av = strtoul(a, &ae, 10);
714 bv = strtoul(b, &be, 10);
9697bfd2 715 if (av != bv) return (av < bv ? -1 : +1);
716 if (*ae == '.') ae++;
717 if (*be == '.') be++;
43aa02a7 718 av = strtoul(ae, &ae, 10);
719 bv = strtoul(be, &be, 10);
9697bfd2 720 if (av != bv) return (av < bv ? -1 : +1);
721 return 0;
722}
723
e5574168 724
725/*
726 * Utility routine for putting an SSH-protocol `string' into a SHA
727 * state.
728 */
729#include <stdio.h>
730void sha_string(SHA_State *s, void *str, int len) {
731 unsigned char lenblk[4];
e5574168 732 PUT_32BIT(lenblk, len);
e5574168 733 SHA_Bytes(s, lenblk, 4);
e5574168 734 SHA_Bytes(s, str, len);
735}
736
7cca0d81 737/*
738 * SSH2 packet construction functions.
739 */
740void ssh2_pkt_adddata(void *data, int len) {
741 pktout.length += len;
742 if (pktout.maxlen < pktout.length) {
743 pktout.maxlen = pktout.length + 256;
744 pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) :
745 realloc(pktout.data, pktout.maxlen+APIEXTRA));
746 if (!pktout.data)
747 fatalbox("Out of memory");
748 }
749 memcpy(pktout.data+pktout.length-len, data, len);
750}
751void ssh2_pkt_addbyte(unsigned char byte) {
752 ssh2_pkt_adddata(&byte, 1);
753}
754void ssh2_pkt_init(int pkt_type) {
755 pktout.length = 5;
756 ssh2_pkt_addbyte((unsigned char)pkt_type);
757}
758void ssh2_pkt_addbool(unsigned char value) {
759 ssh2_pkt_adddata(&value, 1);
760}
761void ssh2_pkt_adduint32(unsigned long value) {
762 unsigned char x[4];
763 PUT_32BIT(x, value);
764 ssh2_pkt_adddata(x, 4);
765}
766void ssh2_pkt_addstring_start(void) {
767 ssh2_pkt_adduint32(0);
768 pktout.savedpos = pktout.length;
769}
770void ssh2_pkt_addstring_str(char *data) {
771 ssh2_pkt_adddata(data, strlen(data));
772 PUT_32BIT(pktout.data + pktout.savedpos - 4,
773 pktout.length - pktout.savedpos);
774}
775void ssh2_pkt_addstring_data(char *data, int len) {
776 ssh2_pkt_adddata(data, len);
777 PUT_32BIT(pktout.data + pktout.savedpos - 4,
778 pktout.length - pktout.savedpos);
779}
780void ssh2_pkt_addstring(char *data) {
781 ssh2_pkt_addstring_start();
782 ssh2_pkt_addstring_str(data);
783}
784char *ssh2_mpint_fmt(Bignum b, int *len) {
785 unsigned char *p;
786 int i, n = b[0];
787 p = malloc(n * 2 + 1);
788 if (!p)
789 fatalbox("out of memory");
790 p[0] = 0;
791 for (i = 0; i < n; i++) {
792 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
793 p[i*2+2] = (b[n-i] ) & 0xFF;
794 }
795 i = 0;
796 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
797 i++;
798 memmove(p, p+i, n*2+1-i);
799 *len = n*2+1-i;
800 return p;
801}
802void ssh2_pkt_addmp(Bignum b) {
803 unsigned char *p;
804 int len;
805 p = ssh2_mpint_fmt(b, &len);
806 ssh2_pkt_addstring_start();
807 ssh2_pkt_addstring_data(p, len);
808 free(p);
809}
810void ssh2_pkt_send(void) {
811 int cipherblk, maclen, padding, i;
812 static unsigned long outgoing_sequence = 0;
813
814 /*
815 * Add padding. At least four bytes, and must also bring total
816 * length (minus MAC) up to a multiple of the block size.
817 */
818 cipherblk = cipher ? cipher->blksize : 8; /* block size */
819 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
820 padding = 4;
821 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
822 pktout.data[4] = padding;
823 for (i = 0; i < padding; i++)
824 pktout.data[pktout.length + i] = random_byte();
825 PUT_32BIT(pktout.data, pktout.length + padding - 4);
826 if (csmac)
827 csmac->generate(pktout.data, pktout.length + padding,
828 outgoing_sequence);
829 outgoing_sequence++; /* whether or not we MACed */
830
831#if 0
832 debug(("Sending packet len=%d\r\n", pktout.length+padding));
833 for (i = 0; i < pktout.length+padding; i++)
834 debug((" %02x", (unsigned char)pktout.data[i]));
835 debug(("\r\n"));
836#endif
837
838 if (cscipher)
839 cscipher->encrypt(pktout.data, pktout.length + padding);
840 maclen = csmac ? csmac->len : 0;
841
842 s_write(pktout.data, pktout.length + padding + maclen);
843}
844
845#if 0
846void bndebug(char *string, Bignum b) {
847 unsigned char *p;
848 int i, len;
849 p = ssh2_mpint_fmt(b, &len);
850 debug(("%s", string));
851 for (i = 0; i < len; i++)
852 debug((" %02x", p[i]));
853 debug(("\r\n"));
854 free(p);
855}
856#endif
857
858void sha_mpint(SHA_State *s, Bignum b) {
859 unsigned char *p;
860 int len;
861 p = ssh2_mpint_fmt(b, &len);
862 sha_string(s, p, len);
863 free(p);
864}
865
866/*
867 * SSH2 packet decode functions.
868 */
869unsigned long ssh2_pkt_getuint32(void) {
870 unsigned long value;
871 if (pktin.length - pktin.savedpos < 4)
872 return 0; /* arrgh, no way to decline (FIXME?) */
873 value = GET_32BIT(pktin.data+pktin.savedpos);
874 pktin.savedpos += 4;
875 return value;
876}
877void ssh2_pkt_getstring(char **p, int *length) {
878 *p = NULL;
879 if (pktin.length - pktin.savedpos < 4)
880 return;
881 *length = GET_32BIT(pktin.data+pktin.savedpos);
882 pktin.savedpos += 4;
883 if (pktin.length - pktin.savedpos < *length)
884 return;
885 *p = pktin.data+pktin.savedpos;
886 pktin.savedpos += *length;
887}
888Bignum ssh2_pkt_getmp(void) {
889 char *p;
890 int i, j, length;
891 Bignum b;
892
893 ssh2_pkt_getstring(&p, &length);
894 if (!p)
895 return NULL;
896 if (p[0] & 0x80)
897 fatalbox("internal error: Can't handle negative mpints");
898 b = newbn((length+1)/2);
899 for (i = 0; i < length; i++) {
900 j = length - 1 - i;
901 if (j & 1)
902 b[j/2+1] |= ((unsigned char)p[i]) << 8;
903 else
904 b[j/2+1] |= ((unsigned char)p[i]);
905 }
906 return b;
907}
908
374330e2 909static int do_ssh_init(void) {
c5e9c988 910 char c, *vsp;
374330e2 911 char version[10];
c5e9c988 912 char vstring[80];
913 char vlog[sizeof(vstring)+20];
374330e2 914 int i;
915
916#ifdef FWHACK
917 i = 0;
918 while (s_read(&c, 1) == 1) {
919 if (c == 'S' && i < 2) i++;
920 else if (c == 'S' && i == 2) i = 2;
921 else if (c == 'H' && i == 2) break;
922 else i = 0;
923 }
924#else
925 if (s_read(&c,1) != 1 || c != 'S') return 0;
926 if (s_read(&c,1) != 1 || c != 'S') return 0;
927 if (s_read(&c,1) != 1 || c != 'H') return 0;
928#endif
c5e9c988 929 strcpy(vstring, "SSH-");
930 vsp = vstring+4;
374330e2 931 if (s_read(&c,1) != 1 || c != '-') return 0;
932 i = 0;
933 while (1) {
934 if (s_read(&c,1) != 1)
935 return 0;
c5e9c988 936 if (vsp < vstring+sizeof(vstring)-1)
937 *vsp++ = c;
374330e2 938 if (i >= 0) {
939 if (c == '-') {
940 version[i] = '\0';
941 i = -1;
942 } else if (i < sizeof(version)-1)
943 version[i++] = c;
944 }
945 else if (c == '\n')
946 break;
947 }
948
c5e9c988 949 *vsp = 0;
950 sprintf(vlog, "Server version: %s", vstring);
951 vlog[strcspn(vlog, "\r\n")] = '\0';
952 logevent(vlog);
953
adf799dd 954 /*
955 * Server version "1.99" means we can choose whether we use v1
956 * or v2 protocol. Choice is based on cfg.sshprot.
957 */
958 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 959 /*
960 * This is a v2 server. Begin v2 protocol.
961 */
962 char *verstring = "SSH-2.0-PuTTY";
963 SHA_Init(&exhash);
964 /*
965 * Hash our version string and their version string.
966 */
967 sha_string(&exhash, verstring, strlen(verstring));
968 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
969 sprintf(vstring, "%s\n", verstring);
970 sprintf(vlog, "We claim version: %s", verstring);
971 logevent(vlog);
972 logevent("Using SSH protocol version 2");
973 s_write(vstring, strlen(vstring));
974 ssh_protocol = ssh2_protocol;
6abbf9e3 975 ssh_version = 2;
e5574168 976 s_rdpkt = ssh2_rdpkt;
977 } else {
978 /*
979 * This is a v1 server. Begin v1 protocol.
980 */
981 sprintf(vstring, "SSH-%s-PuTTY\n",
982 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
983 sprintf(vlog, "We claim version: %s", vstring);
984 vlog[strcspn(vlog, "\r\n")] = '\0';
985 logevent(vlog);
986 logevent("Using SSH protocol version 1");
987 s_write(vstring, strlen(vstring));
988 ssh_protocol = ssh1_protocol;
6abbf9e3 989 ssh_version = 1;
e5574168 990 s_rdpkt = ssh1_rdpkt;
991 }
8ccc75b0 992 ssh_send_ok = 0;
fef97f43 993 return 1;
374330e2 994}
995
fb09bf1c 996/*
997 * Handle the key exchange and user authentication phases.
998 */
e5574168 999static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1000{
374330e2 1001 int i, j, len;
374330e2 1002 unsigned char *rsabuf, *keystr1, *keystr2;
1003 unsigned char cookie[8];
1004 struct RSAKey servkey, hostkey;
1005 struct MD5Context md5c;
ccbfb941 1006 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1007 static int tried_publickey;
1008 static unsigned char session_id[16];
bea1ef5f 1009 int cipher_type;
374330e2 1010
374330e2 1011 crBegin;
1012
fb09bf1c 1013 if (!ispkt) crWaitUntil(ispkt);
374330e2 1014
e5574168 1015 if (pktin.type != SSH1_SMSG_PUBLIC_KEY)
374330e2 1016 fatalbox("Public key packet not received");
1017
c5e9c988 1018 logevent("Received public keys");
374330e2 1019
c5e9c988 1020 memcpy(cookie, pktin.body, 8);
374330e2 1021
7cca0d81 1022 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1023 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1024
c5e9c988 1025 /*
1026 * Hash the host key and print the hash in the log box. Just as
1027 * a last resort in case the registry's host key checking is
1028 * compromised, we'll allow the user some ability to verify
1029 * host keys by eye.
1030 */
1031 MD5Init(&md5c);
1032 MD5Update(&md5c, keystr2, hostkey.bytes);
1033 MD5Final(session_id, &md5c);
1034 {
1035 char logmsg[80];
1036 int i;
1037 logevent("Host key MD5 is:");
1038 strcpy(logmsg, " ");
1039 for (i = 0; i < 16; i++)
1040 sprintf(logmsg+strlen(logmsg), "%02x", session_id[i]);
1041 logevent(logmsg);
1042 }
1043
fb09bf1c 1044 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1045 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1046
c5e9c988 1047 MD5Init(&md5c);
374330e2 1048 MD5Update(&md5c, keystr2, hostkey.bytes);
1049 MD5Update(&md5c, keystr1, servkey.bytes);
1050 MD5Update(&md5c, pktin.body, 8);
374330e2 1051 MD5Final(session_id, &md5c);
1052
1053 for (i=0; i<32; i++)
1054 session_key[i] = random_byte();
1055
1056 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1057
1058 rsabuf = malloc(len);
1059 if (!rsabuf)
1060 fatalbox("Out of memory");
1061
89ee5268 1062 /*
1063 * Verify the host key.
1064 */
1065 {
1066 /*
1067 * First format the key into a string.
1068 */
1069 int len = rsastr_len(&hostkey);
1070 char *keystr = malloc(len);
1071 if (!keystr)
1072 fatalbox("Out of memory");
1073 rsastr_fmt(keystr, &hostkey);
1074 verify_ssh_host_key(savedhost, keystr);
1075 free(keystr);
1076 }
374330e2 1077
1078 for (i=0; i<32; i++) {
1079 rsabuf[i] = session_key[i];
1080 if (i < 16)
1081 rsabuf[i] ^= session_id[i];
1082 }
1083
1084 if (hostkey.bytes > servkey.bytes) {
1085 rsaencrypt(rsabuf, 32, &servkey);
1086 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1087 } else {
1088 rsaencrypt(rsabuf, 32, &hostkey);
1089 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1090 }
1091
c5e9c988 1092 logevent("Encrypted session key");
1093
bea1ef5f 1094 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1095 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1096 SSH_CIPHER_3DES;
1097 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1098 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1099 cipher_type = SSH_CIPHER_3DES;
1100 }
c5e9c988 1101 switch (cipher_type) {
1102 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1103 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1104 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1105 }
bea1ef5f 1106
e5574168 1107 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1108 PKT_CHAR, cipher_type,
1109 PKT_DATA, cookie, 8,
1110 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1111 PKT_DATA, rsabuf, len,
1112 PKT_INT, 0,
1113 PKT_END);
1114
c5e9c988 1115 logevent("Trying to enable encryption...");
374330e2 1116
1117 free(rsabuf);
1118
bea1ef5f 1119 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish :
9697bfd2 1120 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1121 &ssh_3des;
374330e2 1122 cipher->sesskey(session_key);
1123
fb09bf1c 1124 crWaitUntil(ispkt);
374330e2 1125
e5574168 1126 if (pktin.type != SSH1_SMSG_SUCCESS)
374330e2 1127 fatalbox("Encryption not successfully enabled");
1128
c5e9c988 1129 logevent("Successfully started encryption");
1130
374330e2 1131 fflush(stdout);
1132 {
1133 static char username[100];
1134 static int pos = 0;
1135 static char c;
5c58ad2d 1136 if ((flags & FLAG_CONNECTION) && !*cfg.username) {
374330e2 1137 c_write("login as: ", 10);
1138 while (pos >= 0) {
fb09bf1c 1139 crWaitUntil(!ispkt);
374330e2 1140 while (inlen--) switch (c = *in++) {
1141 case 10: case 13:
1142 username[pos] = 0;
1143 pos = -1;
1144 break;
1145 case 8: case 127:
1146 if (pos > 0) {
1147 c_write("\b \b", 3);
1148 pos--;
1149 }
1150 break;
1151 case 21: case 27:
1152 while (pos > 0) {
1153 c_write("\b \b", 3);
1154 pos--;
1155 }
1156 break;
1157 case 3: case 4:
1158 random_save_seed();
1159 exit(0);
1160 break;
1161 default:
40d24aa6 1162 if (((c >= ' ' && c <= '~') ||
1163 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1164 username[pos++] = c;
1165 c_write(&c, 1);
1166 }
1167 break;
1168 }
1169 }
1170 c_write("\r\n", 2);
1171 username[strcspn(username, "\n\r")] = '\0';
1172 } else {
1173 char stuff[200];
1174 strncpy(username, cfg.username, 99);
1175 username[99] = '\0';
4017be6d 1176 if (flags & FLAG_VERBOSE) {
fb09bf1c 1177 sprintf(stuff, "Sent username \"%s\".\r\n", username);
4017be6d 1178 c_write(stuff, strlen(stuff));
fb09bf1c 1179 }
374330e2 1180 }
fb09bf1c 1181
e5574168 1182 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1183 {
1184 char userlog[20+sizeof(username)];
1185 sprintf(userlog, "Sent username \"%s\"", username);
1186 logevent(userlog);
1187 }
374330e2 1188 }
1189
fb09bf1c 1190 crWaitUntil(ispkt);
374330e2 1191
7cca0d81 1192 tried_publickey = 0;
1193
e5574168 1194 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1195 static char password[100];
1196 static int pos;
1197 static char c;
ccbfb941 1198 static int pwpkt_type;
ccbfb941 1199 /*
1200 * Show password prompt, having first obtained it via a TIS
18515c51 1201 * or CryptoCard exchange if we're doing TIS or CryptoCard
1202 * authentication.
ccbfb941 1203 */
e5574168 1204 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1205 if (agent_exists()) {
1206 /*
1207 * Attempt RSA authentication using Pageant.
1208 */
1209 static unsigned char request[5], *response, *p;
1210 static int responselen;
1211 static int i, nkeys;
1212 static int authed = FALSE;
1213 void *r;
1214
1215 logevent("Pageant is running. Requesting keys.");
1216
1217 /* Request the keys held by the agent. */
1218 PUT_32BIT(request, 1);
1219 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1220 agent_query(request, 5, &r, &responselen);
1221 response = (unsigned char *)r;
1222 if (response) {
1223 p = response + 5;
1224 nkeys = GET_32BIT(p); p += 4;
1225 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1226 logevent(buf); }
1227 for (i = 0; i < nkeys; i++) {
1228 static struct RSAKey key;
1229 static Bignum challenge;
1230
1231 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1232 logevent(buf); }
1233 p += 4;
1234 p += ssh1_read_bignum(p, &key.exponent);
1235 p += ssh1_read_bignum(p, &key.modulus);
1236 send_packet(SSH1_CMSG_AUTH_RSA,
1237 PKT_BIGNUM, key.modulus, PKT_END);
1238 crWaitUntil(ispkt);
1239 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1240 logevent("Key refused");
1241 continue;
1242 }
1243 logevent("Received RSA challenge");
1244 ssh1_read_bignum(pktin.body, &challenge);
1245 {
1246 char *agentreq, *q, *ret;
1247 int len, retlen;
1248 len = 1 + 4; /* message type, bit count */
1249 len += ssh1_bignum_length(key.exponent);
1250 len += ssh1_bignum_length(key.modulus);
1251 len += ssh1_bignum_length(challenge);
1252 len += 16; /* session id */
1253 len += 4; /* response format */
1254 agentreq = malloc(4 + len);
1255 PUT_32BIT(agentreq, len);
1256 q = agentreq + 4;
1257 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1258 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1259 q += 4;
1260 q += ssh1_write_bignum(q, key.exponent);
1261 q += ssh1_write_bignum(q, key.modulus);
1262 q += ssh1_write_bignum(q, challenge);
1263 memcpy(q, session_id, 16); q += 16;
1264 PUT_32BIT(q, 1); /* response format */
1265 agent_query(agentreq, len+4, &ret, &retlen);
1266 free(agentreq);
1267 if (ret) {
1268 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1269 logevent("Sending Pageant's response");
1270 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1271 PKT_DATA, ret+5, 16, PKT_END);
1272 free(ret);
1273 crWaitUntil(ispkt);
1274 if (pktin.type == SSH1_SMSG_SUCCESS) {
1275 logevent("Pageant's response accepted");
1276 authed = TRUE;
1277 } else
1278 logevent("Pageant's response not accepted");
1279 } else {
1280 logevent("Pageant failed to answer challenge");
1281 free(ret);
1282 }
1283 } else {
1284 logevent("No reply received from Pageant");
1285 }
1286 }
1287 freebn(key.exponent);
1288 freebn(key.modulus);
1289 freebn(challenge);
1290 if (authed)
1291 break;
1292 }
1293 }
1294 if (authed)
1295 break;
1296 }
7cca0d81 1297 if (*cfg.keyfile && !tried_publickey)
1298 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1299
4017be6d 1300 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD && !FLAG_WINDOWED) {
fb09bf1c 1301 char prompt[200];
1302 sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
85ee8208 1303 if (!ssh_get_password(prompt, password, sizeof(password))) {
1304 /*
1305 * get_password failed to get a password (for
1306 * example because one was supplied on the command
1307 * line which has already failed to work).
1308 * Terminate.
1309 */
1310 logevent("No more passwords to try");
1311 ssh_state = SSH_STATE_CLOSED;
1312 crReturn(1);
1313 }
fb09bf1c 1314 } else {
1315
7cca0d81 1316 if (pktin.type == SSH1_SMSG_FAILURE &&
1317 cfg.try_tis_auth &&
1318 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1319 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1320 logevent("Requested TIS authentication");
1321 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1322 crWaitUntil(ispkt);
1323 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1324 logevent("TIS authentication declined");
1325 c_write("TIS authentication refused.\r\n", 29);
1326 } else {
1327 int challengelen = ((pktin.body[0] << 24) |
1328 (pktin.body[1] << 16) |
1329 (pktin.body[2] << 8) |
1330 (pktin.body[3]));
1331 logevent("Received TIS challenge");
1332 c_write(pktin.body+4, challengelen);
1333 }
1334 }
18515c51 1335 if (pktin.type == SSH1_SMSG_FAILURE &&
1336 cfg.try_tis_auth &&
1337 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1338 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1339 logevent("Requested CryptoCard authentication");
1340 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1341 crWaitUntil(ispkt);
1342 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1343 logevent("CryptoCard authentication declined");
1344 c_write("CryptoCard authentication refused.\r\n", 29);
1345 } else {
1346 int challengelen = ((pktin.body[0] << 24) |
1347 (pktin.body[1] << 16) |
1348 (pktin.body[2] << 8) |
1349 (pktin.body[3]));
1350 logevent("Received CryptoCard challenge");
1351 c_write(pktin.body+4, challengelen);
1352 c_write("\r\nResponse : ", 13);
1353 }
1354 }
7cca0d81 1355 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD)
1356 c_write("password: ", 10);
1357 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
4017be6d 1358 if (flags & FLAG_VERBOSE)
1359 c_write("Trying public key authentication.\r\n", 35);
7cca0d81 1360 if (!rsakey_encrypted(cfg.keyfile)) {
4017be6d 1361 if (flags & FLAG_VERBOSE)
1362 c_write("No passphrase required.\r\n", 25);
7cca0d81 1363 goto tryauth;
1364 }
1365 c_write("passphrase: ", 12);
ccbfb941 1366 }
ccbfb941 1367
7cca0d81 1368 pos = 0;
1369 while (pos >= 0) {
1370 crWaitUntil(!ispkt);
1371 while (inlen--) switch (c = *in++) {
1372 case 10: case 13:
1373 password[pos] = 0;
1374 pos = -1;
1375 break;
1376 case 8: case 127:
1377 if (pos > 0)
1378 pos--;
1379 break;
1380 case 21: case 27:
1381 pos = 0;
1382 break;
1383 case 3: case 4:
1384 random_save_seed();
1385 exit(0);
1386 break;
1387 default:
1388 if (((c >= ' ' && c <= '~') ||
1389 ((unsigned char)c >= 160)) && pos < sizeof(password))
1390 password[pos++] = c;
1391 break;
1392 }
1393 }
1394 c_write("\r\n", 2);
fb09bf1c 1395
1396 }
1397
7cca0d81 1398 tryauth:
1399 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1400 /*
1401 * Try public key authentication with the specified
1402 * key file.
1403 */
1404 static struct RSAKey pubkey;
1405 static Bignum challenge, response;
1406 static int i;
1407 static unsigned char buffer[32];
1408
1409 tried_publickey = 1;
1410 i = loadrsakey(cfg.keyfile, &pubkey, password);
1411 if (i == 0) {
1412 c_write("Couldn't load public key from ", 30);
1413 c_write(cfg.keyfile, strlen(cfg.keyfile));
1414 c_write(".\r\n", 3);
1415 continue; /* go and try password */
1416 }
1417 if (i == -1) {
1418 c_write("Wrong passphrase.\r\n", 19);
1419 tried_publickey = 0;
1420 continue; /* try again */
1421 }
1422
1423 /*
1424 * Send a public key attempt.
1425 */
1426 send_packet(SSH1_CMSG_AUTH_RSA,
1427 PKT_BIGNUM, pubkey.modulus, PKT_END);
1428
1429 crWaitUntil(ispkt);
1430 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1431 if (flags & FLAG_VERBOSE)
1432 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1433 continue; /* go and try password */
1434 }
1435 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE)
1436 fatalbox("Bizarre response to offer of public key");
1437 ssh1_read_bignum(pktin.body, &challenge);
1438 response = rsadecrypt(challenge, &pubkey);
1439 freebn(pubkey.private_exponent); /* burn the evidence */
1440
1441 for (i = 0; i < 32; i += 2) {
1442 buffer[i] = response[16-i/2] >> 8;
1443 buffer[i+1] = response[16-i/2] & 0xFF;
1444 }
1445
1446 MD5Init(&md5c);
1447 MD5Update(&md5c, buffer, 32);
1448 MD5Update(&md5c, session_id, 16);
1449 MD5Final(buffer, &md5c);
1450
1451 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1452 PKT_DATA, buffer, 16, PKT_END);
1453
1454 crWaitUntil(ispkt);
1455 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1456 if (flags & FLAG_VERBOSE)
1457 c_write("Failed to authenticate with our public key.\r\n",
1458 45);
7cca0d81 1459 continue; /* go and try password */
1460 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
1461 fatalbox("Bizarre response to RSA authentication response");
1462 }
1463
1464 break; /* we're through! */
1465 } else {
1466 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1467 }
c5e9c988 1468 logevent("Sent password");
374330e2 1469 memset(password, 0, strlen(password));
fb09bf1c 1470 crWaitUntil(ispkt);
e5574168 1471 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1472 if (flags & FLAG_VERBOSE)
1473 c_write("Access denied\r\n", 15);
c5e9c988 1474 logevent("Authentication refused");
e5574168 1475 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1476 logevent("Received disconnect request");
85ee8208 1477 ssh_state = SSH_STATE_CLOSED;
1478 crReturn(1);
e5574168 1479 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
374330e2 1480 fatalbox("Strange packet received, type %d", pktin.type);
1481 }
1482 }
1483
c5e9c988 1484 logevent("Authentication successful");
1485
fb09bf1c 1486 crFinish(1);
1487}
1488
e5574168 1489static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1490 crBegin;
1491
1492 random_init();
1493
e5574168 1494 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1495 crReturnV;
85ee8208 1496 }
1497 if (ssh_state == SSH_STATE_CLOSED)
1498 crReturnV;
fb09bf1c 1499
fef97f43 1500 if (!cfg.nopty) {
e5574168 1501 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1502 PKT_STR, cfg.termtype,
1503 PKT_INT, rows, PKT_INT, cols,
1504 PKT_INT, 0, PKT_INT, 0,
1505 PKT_CHAR, 0,
1506 PKT_END);
fef97f43 1507 ssh_state = SSH_STATE_INTERMED;
1508 do { crReturnV; } while (!ispkt);
e5574168 1509 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
fef97f43 1510 fatalbox("Protocol confusion");
e5574168 1511 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1512 c_write("Server refused to allocate pty\r\n", 32);
1513 }
c5e9c988 1514 logevent("Allocated pty");
374330e2 1515 }
1516
6abbf9e3 1517 if (*cfg.remote_cmd)
1518 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1519 else
1520 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1521 logevent("Started session");
374330e2 1522
1523 ssh_state = SSH_STATE_SESSION;
1524 if (size_needed)
1525 ssh_size();
1526
8ccc75b0 1527 ssh_send_ok = 1;
374330e2 1528 while (1) {
1529 crReturnV;
1530 if (ispkt) {
e5574168 1531 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1532 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1533 long len = GET_32BIT(pktin.body);
1534 c_write(pktin.body+4, len);
e5574168 1535 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1536 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1537 logevent("Received disconnect request");
e5574168 1538 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 1539 /* may be from EXEC_SHELL on some servers */
e5574168 1540 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 1541 /* may be from EXEC_SHELL on some servers
374330e2 1542 * if no pty is available or in other odd cases. Ignore */
e5574168 1543 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1544 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 1545 } else {
1546 fatalbox("Strange packet received: type %d", pktin.type);
1547 }
1548 } else {
e5574168 1549 send_packet(SSH1_CMSG_STDIN_DATA,
fb09bf1c 1550 PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
374330e2 1551 }
1552 }
1553
1554 crFinishV;
1555}
1556
1557/*
e5574168 1558 * Utility routine for decoding comma-separated strings in KEXINIT.
1559 */
1560int in_commasep_string(char *needle, char *haystack, int haylen) {
1561 int needlen = strlen(needle);
1562 while (1) {
1563 /*
1564 * Is it at the start of the string?
1565 */
1566 if (haylen >= needlen && /* haystack is long enough */
1567 !memcmp(needle, haystack, needlen) && /* initial match */
1568 (haylen == needlen || haystack[needlen] == ',')
1569 /* either , or EOS follows */
1570 )
1571 return 1;
1572 /*
1573 * If not, search for the next comma and resume after that.
1574 * If no comma found, terminate.
1575 */
1576 while (haylen > 0 && *haystack != ',')
1577 haylen--, haystack++;
1578 if (haylen == 0)
1579 return 0;
1580 haylen--, haystack++; /* skip over comma itself */
1581 }
1582}
1583
1584/*
d39f364a 1585 * SSH2 key creation method.
1586 */
1587void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
1588 SHA_State s;
1589 /* First 20 bytes. */
1590 SHA_Init(&s);
1591 sha_mpint(&s, K);
1592 SHA_Bytes(&s, H, 20);
1593 SHA_Bytes(&s, &chr, 1);
1594 SHA_Bytes(&s, H, 20);
1595 SHA_Final(&s, keyspace);
1596 /* Next 20 bytes. */
1597 SHA_Init(&s);
1598 sha_mpint(&s, K);
1599 SHA_Bytes(&s, H, 20);
1600 SHA_Bytes(&s, keyspace, 20);
1601 SHA_Final(&s, keyspace+20);
1602}
1603
1604/*
7cca0d81 1605 * Handle the SSH2 transport layer.
e5574168 1606 */
7cca0d81 1607static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 1608{
1609 static int i, len;
1610 static char *str;
1611 static Bignum e, f, K;
1612 static struct ssh_cipher *cscipher_tobe = NULL;
1613 static struct ssh_cipher *sccipher_tobe = NULL;
1614 static struct ssh_mac *csmac_tobe = NULL;
1615 static struct ssh_mac *scmac_tobe = NULL;
1616 static struct ssh_compress *cscomp_tobe = NULL;
1617 static struct ssh_compress *sccomp_tobe = NULL;
7cca0d81 1618 static char *hostkeydata, *sigdata, *keystr;
e5574168 1619 static int hostkeylen, siglen;
1620 static unsigned char exchange_hash[20];
d39f364a 1621 static unsigned char keyspace[40];
e5574168 1622
1623 crBegin;
7cca0d81 1624 random_init();
e5574168 1625
7cca0d81 1626 begin_key_exchange:
e5574168 1627 /*
1628 * Construct and send our key exchange packet.
1629 */
1630 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1631 for (i = 0; i < 16; i++)
1632 ssh2_pkt_addbyte((unsigned char)random_byte());
1633 /* List key exchange algorithms. */
1634 ssh2_pkt_addstring_start();
1635 for (i = 0; i < lenof(kex_algs); i++) {
1636 ssh2_pkt_addstring_str(kex_algs[i]->name);
1637 if (i < lenof(kex_algs)-1)
1638 ssh2_pkt_addstring_str(",");
1639 }
1640 /* List server host key algorithms. */
1641 ssh2_pkt_addstring_start();
1642 for (i = 0; i < lenof(hostkey_algs); i++) {
1643 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1644 if (i < lenof(hostkey_algs)-1)
1645 ssh2_pkt_addstring_str(",");
1646 }
1647 /* List client->server encryption algorithms. */
1648 ssh2_pkt_addstring_start();
1649 for (i = 0; i < lenof(ciphers); i++) {
1650 ssh2_pkt_addstring_str(ciphers[i]->name);
1651 if (i < lenof(ciphers)-1)
1652 ssh2_pkt_addstring_str(",");
1653 }
1654 /* List server->client encryption algorithms. */
1655 ssh2_pkt_addstring_start();
1656 for (i = 0; i < lenof(ciphers); i++) {
1657 ssh2_pkt_addstring_str(ciphers[i]->name);
1658 if (i < lenof(ciphers)-1)
1659 ssh2_pkt_addstring_str(",");
1660 }
1661 /* List client->server MAC algorithms. */
1662 ssh2_pkt_addstring_start();
1663 for (i = 0; i < lenof(macs); i++) {
1664 ssh2_pkt_addstring_str(macs[i]->name);
1665 if (i < lenof(macs)-1)
1666 ssh2_pkt_addstring_str(",");
1667 }
1668 /* List server->client MAC algorithms. */
1669 ssh2_pkt_addstring_start();
1670 for (i = 0; i < lenof(macs); i++) {
1671 ssh2_pkt_addstring_str(macs[i]->name);
1672 if (i < lenof(macs)-1)
1673 ssh2_pkt_addstring_str(",");
1674 }
1675 /* List client->server compression algorithms. */
1676 ssh2_pkt_addstring_start();
1677 for (i = 0; i < lenof(compressions); i++) {
1678 ssh2_pkt_addstring_str(compressions[i]->name);
1679 if (i < lenof(compressions)-1)
1680 ssh2_pkt_addstring_str(",");
1681 }
1682 /* List server->client compression algorithms. */
1683 ssh2_pkt_addstring_start();
1684 for (i = 0; i < lenof(compressions); i++) {
1685 ssh2_pkt_addstring_str(compressions[i]->name);
1686 if (i < lenof(compressions)-1)
1687 ssh2_pkt_addstring_str(",");
1688 }
1689 /* List client->server languages. Empty list. */
1690 ssh2_pkt_addstring_start();
1691 /* List server->client languages. Empty list. */
1692 ssh2_pkt_addstring_start();
1693 /* First KEX packet does _not_ follow, because we're not that brave. */
1694 ssh2_pkt_addbool(FALSE);
1695 /* Reserved. */
1696 ssh2_pkt_adduint32(0);
1697 sha_string(&exhash, pktout.data+5, pktout.length-5);
1698 ssh2_pkt_send();
1699
1700 if (!ispkt) crWaitUntil(ispkt);
1701 sha_string(&exhash, pktin.data+5, pktin.length-5);
1702
1703 /*
1704 * Now examine the other side's KEXINIT to see what we're up
1705 * to.
1706 */
7cca0d81 1707 if (pktin.type != SSH2_MSG_KEXINIT) {
e5574168 1708 fatalbox("expected key exchange packet from server");
7cca0d81 1709 }
e5574168 1710 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1711 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1712 pktin.savedpos += 16; /* skip garbage cookie */
1713 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1714 for (i = 0; i < lenof(kex_algs); i++) {
1715 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1716 kex = kex_algs[i];
1717 break;
1718 }
1719 }
1720 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1721 for (i = 0; i < lenof(hostkey_algs); i++) {
1722 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1723 hostkey = hostkey_algs[i];
1724 break;
1725 }
1726 }
1727 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
1728 for (i = 0; i < lenof(ciphers); i++) {
1729 if (in_commasep_string(ciphers[i]->name, str, len)) {
1730 cscipher_tobe = ciphers[i];
1731 break;
1732 }
1733 }
1734 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
1735 for (i = 0; i < lenof(ciphers); i++) {
1736 if (in_commasep_string(ciphers[i]->name, str, len)) {
1737 sccipher_tobe = ciphers[i];
1738 break;
1739 }
1740 }
1741 ssh2_pkt_getstring(&str, &len); /* client->server mac */
1742 for (i = 0; i < lenof(macs); i++) {
1743 if (in_commasep_string(macs[i]->name, str, len)) {
1744 csmac_tobe = macs[i];
1745 break;
1746 }
1747 }
1748 ssh2_pkt_getstring(&str, &len); /* server->client mac */
1749 for (i = 0; i < lenof(macs); i++) {
1750 if (in_commasep_string(macs[i]->name, str, len)) {
1751 scmac_tobe = macs[i];
1752 break;
1753 }
1754 }
1755 ssh2_pkt_getstring(&str, &len); /* client->server compression */
1756 for (i = 0; i < lenof(compressions); i++) {
1757 if (in_commasep_string(compressions[i]->name, str, len)) {
1758 cscomp_tobe = compressions[i];
1759 break;
1760 }
1761 }
1762 ssh2_pkt_getstring(&str, &len); /* server->client compression */
1763 for (i = 0; i < lenof(compressions); i++) {
1764 if (in_commasep_string(compressions[i]->name, str, len)) {
1765 sccomp_tobe = compressions[i];
1766 break;
1767 }
1768 }
e5574168 1769
1770 /*
1771 * Currently we only support Diffie-Hellman and DSS, so let's
1772 * bomb out if those aren't selected.
1773 */
1774 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss)
1775 fatalbox("internal fault: chaos in SSH 2 transport layer");
1776
1777 /*
1778 * Now we begin the fun. Generate and send e for Diffie-Hellman.
1779 */
1780 e = dh_create_e();
e5574168 1781 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
1782 ssh2_pkt_addmp(e);
1783 ssh2_pkt_send();
1784
1785 crWaitUntil(ispkt);
7cca0d81 1786 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
e5574168 1787 fatalbox("expected key exchange packet from server");
7cca0d81 1788 }
e5574168 1789 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
1790 f = ssh2_pkt_getmp();
e5574168 1791 ssh2_pkt_getstring(&sigdata, &siglen);
1792
1793 K = dh_find_K(f);
e5574168 1794
1795 sha_string(&exhash, hostkeydata, hostkeylen);
1796 sha_mpint(&exhash, e);
1797 sha_mpint(&exhash, f);
1798 sha_mpint(&exhash, K);
1799 SHA_Final(&exhash, exchange_hash);
1800
7cca0d81 1801#if 0
e5574168 1802 debug(("Exchange hash is:\r\n"));
1803 for (i = 0; i < 20; i++)
1804 debug((" %02x", exchange_hash[i]));
1805 debug(("\r\n"));
7cca0d81 1806#endif
1807
1808 hostkey->setkey(hostkeydata, hostkeylen);
1809 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20))
1810 fatalbox("Server failed host key check");
e5574168 1811
1812 /*
7cca0d81 1813 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 1814 */
7cca0d81 1815 crWaitUntil(ispkt);
1816 if (pktin.type != SSH2_MSG_NEWKEYS)
1817 fatalbox("expected new-keys packet from server");
d39f364a 1818
1819 /*
7cca0d81 1820 * Authenticate remote host: verify host key. (We've already
1821 * checked the signature of the exchange hash.)
e5574168 1822 */
7cca0d81 1823 keystr = hostkey->fmtkey();
1824 verify_ssh_host_key(savedhost, keystr);
1825 free(keystr);
d39f364a 1826
1827 /*
7cca0d81 1828 * Send SSH2_MSG_NEWKEYS.
d39f364a 1829 */
1830 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
1831 ssh2_pkt_send();
d39f364a 1832
1833 /*
1834 * Create and initialise session keys.
1835 */
1836 cscipher = cscipher_tobe;
1837 sccipher = sccipher_tobe;
1838 csmac = csmac_tobe;
1839 scmac = scmac_tobe;
1840 cscomp = cscomp_tobe;
1841 sccomp = sccomp_tobe;
1842 /*
1843 * Set IVs after keys.
1844 */
1845 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
1846 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
1847 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
1848 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
1849 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
1850 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
1851
033b4cef 1852 /*
7cca0d81 1853 * Now we're encrypting. Begin returning 1 to the protocol main
1854 * function so that other things can run on top of the
1855 * transport. If we ever see a KEXINIT, we must go back to the
1856 * start.
033b4cef 1857 */
7cca0d81 1858 do {
1859 crReturn(1);
1860 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
1861 goto begin_key_exchange;
e5574168 1862
1863 crFinish(1);
1864}
1865
7cca0d81 1866/*
6abbf9e3 1867 * SSH2: remote identifier for the main session channel.
1868 */
1869static unsigned long ssh_remote_channel;
1870
1871/*
7cca0d81 1872 * Handle the SSH2 userauth and connection layers.
1873 */
1874static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
1875{
7cca0d81 1876 static unsigned long remote_winsize;
1877 static unsigned long remote_maxpkt;
1878
e5574168 1879 crBegin;
1880
7cca0d81 1881 /*
1882 * Request userauth protocol, and await a response to it.
1883 */
1884 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
1885 ssh2_pkt_addstring("ssh-userauth");
1886 ssh2_pkt_send();
1887 crWaitUntilV(ispkt);
1888 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT)
1889 fatalbox("Server refused user authentication protocol");
1890
1891 /*
1892 * FIXME: currently we support only password authentication.
1893 * (This places us technically in violation of the SSH2 spec.
1894 * We must fix this.)
1895 */
1896 while (1) {
1897 /*
1898 * Get a username and a password.
1899 */
1900 static char username[100];
1901 static char password[100];
1902 static int pos = 0;
1903 static char c;
e5574168 1904
4017be6d 1905 if ((flags & FLAG_CONNECTION) && !*cfg.username) {
7cca0d81 1906 c_write("login as: ", 10);
1907 while (pos >= 0) {
1908 crWaitUntilV(!ispkt);
1909 while (inlen--) switch (c = *in++) {
1910 case 10: case 13:
1911 username[pos] = 0;
1912 pos = -1;
1913 break;
1914 case 8: case 127:
1915 if (pos > 0) {
1916 c_write("\b \b", 3);
1917 pos--;
1918 }
1919 break;
1920 case 21: case 27:
1921 while (pos > 0) {
1922 c_write("\b \b", 3);
1923 pos--;
1924 }
1925 break;
1926 case 3: case 4:
1927 random_save_seed();
1928 exit(0);
1929 break;
1930 default:
1931 if (((c >= ' ' && c <= '~') ||
1932 ((unsigned char)c >= 160)) && pos < 40) {
1933 username[pos++] = c;
1934 c_write(&c, 1);
1935 }
1936 break;
1937 }
1938 }
1939 c_write("\r\n", 2);
1940 username[strcspn(username, "\n\r")] = '\0';
1941 } else {
1942 char stuff[200];
1943 strncpy(username, cfg.username, 99);
1944 username[99] = '\0';
4017be6d 1945 if (flags & FLAG_VERBOSE) {
7cca0d81 1946 sprintf(stuff, "Using username \"%s\".\r\n", username);
1947 c_write(stuff, strlen(stuff));
1948 }
1949 }
1950
4017be6d 1951 if (!(flags & FLAG_WINDOWED)) {
7cca0d81 1952 char prompt[200];
1953 sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
1954 if (!ssh_get_password(prompt, password, sizeof(password))) {
1955 /*
1956 * get_password failed to get a password (for
1957 * example because one was supplied on the command
1958 * line which has already failed to work).
1959 * Terminate.
1960 */
1961 logevent("No more passwords to try");
1962 ssh_state = SSH_STATE_CLOSED;
1963 crReturnV;
1964 }
1965 } else {
1966 c_write("password: ", 10);
1967
1968 pos = 0;
1969 while (pos >= 0) {
1970 crWaitUntilV(!ispkt);
1971 while (inlen--) switch (c = *in++) {
1972 case 10: case 13:
1973 password[pos] = 0;
1974 pos = -1;
1975 break;
1976 case 8: case 127:
1977 if (pos > 0)
1978 pos--;
1979 break;
1980 case 21: case 27:
1981 pos = 0;
1982 break;
1983 case 3: case 4:
1984 random_save_seed();
1985 exit(0);
1986 break;
1987 default:
1988 if (((c >= ' ' && c <= '~') ||
1989 ((unsigned char)c >= 160)) && pos < 40)
1990 password[pos++] = c;
1991 break;
1992 }
1993 }
1994 c_write("\r\n", 2);
1995 }
1996
1997 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
1998 ssh2_pkt_addstring(username);
1999 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2000 ssh2_pkt_addstring("password");
2001 ssh2_pkt_addbool(FALSE);
2002 ssh2_pkt_addstring(password);
2003 ssh2_pkt_send();
2004
2005 crWaitUntilV(ispkt);
2006 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2007 c_write("Access denied\r\n", 15);
2008 logevent("Authentication refused");
2009 } else
2010 break;
2011 }
2012
2013 /*
2014 * Now we're authenticated for the connection protocol. The
2015 * connection protocol will automatically have started at this
2016 * point; there's no need to send SERVICE_REQUEST.
2017 */
2018
2019 /*
2020 * So now create a channel with a session in it.
2021 */
2022 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2023 ssh2_pkt_addstring("session");
2024 ssh2_pkt_adduint32(100); /* as good as any */
2025 ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big window which we ignore */
2026 ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big max pkt size */
2027 ssh2_pkt_send();
2028 crWaitUntilV(ispkt);
2029 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
2030 fatalbox("Server refused to open a session");
2031 /* FIXME: error data comes back in FAILURE packet */
2032 }
2033 if (ssh2_pkt_getuint32() != 100) {
2034 fatalbox("Server's channel confirmation cited wrong channel");
2035 }
6abbf9e3 2036 ssh_remote_channel = ssh2_pkt_getuint32();
7cca0d81 2037 remote_winsize = ssh2_pkt_getuint32();
2038 remote_maxpkt = ssh2_pkt_getuint32();
2039 logevent("Opened channel for session");
2040
2041 /*
2042 * Now allocate a pty for the session.
2043 */
2044 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6abbf9e3 2045 ssh2_pkt_adduint32(ssh_remote_channel); /* recipient channel */
7cca0d81 2046 ssh2_pkt_addstring("pty-req");
2047 ssh2_pkt_addbool(1); /* want reply */
2048 ssh2_pkt_addstring(cfg.termtype);
2049 ssh2_pkt_adduint32(cols);
2050 ssh2_pkt_adduint32(rows);
2051 ssh2_pkt_adduint32(0); /* pixel width */
2052 ssh2_pkt_adduint32(0); /* pixel height */
2053 ssh2_pkt_addstring_start();
2054 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
2055 ssh2_pkt_send();
2056
2057 do { /* FIXME: pay attention to these */
2058 crWaitUntilV(ispkt);
2059 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2060
2061 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2062 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2063 fatalbox("Server got confused by pty request");
2064 }
2065 c_write("Server refused to allocate pty\r\n", 32);
2066 } else {
2067 logevent("Allocated pty");
2068 }
2069
2070 /*
2071 * Start a shell.
2072 */
2073 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6abbf9e3 2074 ssh2_pkt_adduint32(ssh_remote_channel); /* recipient channel */
7cca0d81 2075 ssh2_pkt_addstring("shell");
2076 ssh2_pkt_addbool(1); /* want reply */
2077 ssh2_pkt_send();
2078 do { /* FIXME: pay attention to these */
2079 crWaitUntilV(ispkt);
2080 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2081 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2082 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
2083 fatalbox("Server got confused by shell request");
2084 }
2085 fatalbox("Server refused to start a shell");
2086 } else {
2087 logevent("Started a shell");
2088 }
2089
2090 /*
2091 * Transfer data!
2092 */
8ccc75b0 2093 ssh_send_ok = 1;
7cca0d81 2094 while (1) {
e5574168 2095 crReturnV;
7cca0d81 2096 if (ispkt) {
2097 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2098 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2099 char *data;
2100 int length;
2101 if (ssh2_pkt_getuint32() != 100)
2102 continue; /* wrong channel */
2103 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2104 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2105 continue; /* extended but not stderr */
2106 ssh2_pkt_getstring(&data, &length);
2107 if (data)
2108 c_write(data, length);
2109 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2110 ssh_state = SSH_STATE_CLOSED;
2111 logevent("Received disconnect request");
2112 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2113 continue; /* exit status et al; ignore (FIXME?) */
2114 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2115 continue; /* ignore for now (FIXME!) */
2116 } else {
2117 fatalbox("Strange packet received: type %d", pktin.type);
2118 }
2119 } else {
2120 /* FIXME: for now, ignore window size */
2121 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6abbf9e3 2122 ssh2_pkt_adduint32(ssh_remote_channel);
7cca0d81 2123 ssh2_pkt_addstring_start();
2124 ssh2_pkt_addstring_data(in, inlen);
2125 ssh2_pkt_send();
2126 }
e5574168 2127 }
2128
2129 crFinishV;
2130}
2131
2132/*
7cca0d81 2133 * Handle the top-level SSH2 protocol.
2134 */
2135static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2136{
2137 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2138 return;
2139 do_ssh2_authconn(in, inlen, ispkt);
2140}
2141
2142/*
374330e2 2143 * Called to set up the connection. Will arrange for WM_NETEVENT
2144 * messages to be passed to the specified window, whose window
2145 * procedure should then call telnet_msg().
2146 *
2147 * Returns an error message, or NULL on success.
374330e2 2148 */
2149static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
fb09bf1c 2150 char *p;
8f203108 2151
2152#ifdef MSCRYPTOAPI
2153 if(crypto_startup() == 0)
2154 return "Microsoft high encryption pack not installed!";
2155#endif
374330e2 2156
fb09bf1c 2157 p = connect_to_host(host, port, realhost);
2158 if (p != NULL)
2159 return p;
374330e2 2160
2161 if (!do_ssh_init())
2162 return "Protocol initialisation error";
2163
4017be6d 2164 if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
374330e2 2165 switch (WSAGetLastError()) {
2166 case WSAENETDOWN: return "Network is down";
2167 default: return "WSAAsyncSelect(): unknown error";
2168 }
2169
2170 return NULL;
2171}
2172
2173/*
2174 * Process a WM_NETEVENT message. Will return 0 if the connection
2175 * has closed, or <0 for a socket error.
2176 */
2177static int ssh_msg (WPARAM wParam, LPARAM lParam) {
2178 int ret;
2179 char buf[256];
2180
8ce72d2c 2181 /*
2182 * Because reading less than the whole of the available pending
2183 * data can generate an FD_READ event, we need to allow for the
2184 * possibility that FD_READ may arrive with FD_CLOSE already in
2185 * the queue; so it's possible that we can get here even with s
2186 * invalid. If so, we return 1 and don't worry about it.
2187 */
2188 if (s == INVALID_SOCKET)
2189 return 1;
374330e2 2190
2191 if (WSAGETSELECTERROR(lParam) != 0)
2192 return -WSAGETSELECTERROR(lParam);
2193
2194 switch (WSAGETSELECTEVENT(lParam)) {
2195 case FD_READ:
8ce72d2c 2196 case FD_CLOSE:
374330e2 2197 ret = recv(s, buf, sizeof(buf), 0);
2198 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
2199 return 1;
2200 if (ret < 0) /* any _other_ error */
2201 return -10000-WSAGetLastError();
2202 if (ret == 0) {
2203 s = INVALID_SOCKET;
8ce72d2c 2204 return 0;
374330e2 2205 }
2206 ssh_gotdata (buf, ret);
85ee8208 2207 if (ssh_state == SSH_STATE_CLOSED) {
2208 closesocket(s);
2209 s = INVALID_SOCKET;
2210 return 0;
2211 }
374330e2 2212 return 1;
374330e2 2213 }
2214 return 1; /* shouldn't happen, but WTF */
2215}
2216
2217/*
2218 * Called to send data down the Telnet connection.
2219 */
2220static void ssh_send (char *buf, int len) {
2221 if (s == INVALID_SOCKET)
2222 return;
2223
2224 ssh_protocol(buf, len, 0);
2225}
2226
2227/*
2228 * Called to set the size of the window from Telnet's POV.
2229 */
2230static void ssh_size(void) {
2231 switch (ssh_state) {
2232 case SSH_STATE_BEFORE_SIZE:
21248260 2233 case SSH_STATE_CLOSED:
374330e2 2234 break; /* do nothing */
2235 case SSH_STATE_INTERMED:
2236 size_needed = TRUE; /* buffer for later */
2237 break;
2238 case SSH_STATE_SESSION:
fef97f43 2239 if (!cfg.nopty) {
e5574168 2240 send_packet(SSH1_CMSG_WINDOW_SIZE,
fb09bf1c 2241 PKT_INT, rows, PKT_INT, cols,
2242 PKT_INT, 0, PKT_INT, 0, PKT_END);
fef97f43 2243 }
374330e2 2244 }
2245}
2246
2247/*
6abbf9e3 2248 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2249 * can send an EOF and collect resulting output (e.g. `plink
2250 * hostname sort').
374330e2 2251 */
2252static void ssh_special (Telnet_Special code) {
6abbf9e3 2253 if (code == TS_EOF) {
2254 if (ssh_version = 1) {
2255 send_packet(SSH1_CMSG_EOF, PKT_END);
2256 } else {
2257 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
2258 ssh2_pkt_adduint32(ssh_remote_channel);
2259 ssh2_pkt_send();
2260 }
2261 } else {
2262 /* do nothing */
2263 }
374330e2 2264}
2265
fb09bf1c 2266
2267/*
2268 * Read and decrypt one incoming SSH packet.
2269 * (only used by pSCP)
2270 */
2271static void get_packet(void)
2272{
2273 unsigned char buf[4096], *p;
2274 long to_read;
2275 int len;
2276
fb09bf1c 2277 p = NULL;
2278 len = 0;
2279
2280 while ((to_read = s_rdpkt(&p, &len)) > 0) {
2281 if (to_read > sizeof(buf)) to_read = sizeof(buf);
2282 len = s_read(buf, to_read);
2283 if (len != to_read) {
2284 closesocket(s);
2285 s = INVALID_SOCKET;
2286 return;
2287 }
2288 p = buf;
2289 }
2290
2291 assert(len == 0);
2292}
2293
2294/*
2295 * Receive a block of data over the SSH link. Block until
2296 * all data is available. Return nr of bytes read (0 if lost connection).
2297 * (only used by pSCP)
2298 */
2299int ssh_scp_recv(unsigned char *buf, int len)
2300{
2301 static int pending_input_len = 0;
2302 static unsigned char *pending_input_ptr;
2303 int to_read = len;
2304
fb09bf1c 2305 if (pending_input_len >= to_read) {
2306 memcpy(buf, pending_input_ptr, to_read);
2307 pending_input_ptr += to_read;
2308 pending_input_len -= to_read;
2309 return len;
2310 }
2311
2312 if (pending_input_len > 0) {
2313 memcpy(buf, pending_input_ptr, pending_input_len);
2314 buf += pending_input_len;
2315 to_read -= pending_input_len;
2316 pending_input_len = 0;
2317 }
2318
2319 if (s == INVALID_SOCKET)
2320 return 0;
2321 while (to_read > 0) {
2322 get_packet();
2323 if (s == INVALID_SOCKET)
2324 return 0;
e5574168 2325 if (pktin.type == SSH1_SMSG_STDOUT_DATA) {
fb09bf1c 2326 int plen = GET_32BIT(pktin.body);
2327 if (plen <= to_read) {
2328 memcpy(buf, pktin.body + 4, plen);
2329 buf += plen;
2330 to_read -= plen;
2331 } else {
2332 memcpy(buf, pktin.body + 4, to_read);
2333 pending_input_len = plen - to_read;
2334 pending_input_ptr = pktin.body + 4 + to_read;
2335 to_read = 0;
2336 }
e5574168 2337 } else if (pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 2338 int plen = GET_32BIT(pktin.body);
2339 fwrite(pktin.body + 4, plen, 1, stderr);
e5574168 2340 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 2341 logevent("Received disconnect request");
e5574168 2342 } else if (pktin.type == SSH1_SMSG_SUCCESS ||
2343 pktin.type == SSH1_SMSG_FAILURE) {
fb09bf1c 2344 /* ignore */
e5574168 2345 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
fb09bf1c 2346 char logbuf[100];
2347 sprintf(logbuf, "Remote exit status: %d", GET_32BIT(pktin.body));
2348 logevent(logbuf);
e5574168 2349 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
fb09bf1c 2350 logevent("Closing connection");
2351 closesocket(s);
2352 s = INVALID_SOCKET;
2353 } else {
2354 fatalbox("Strange packet received: type %d", pktin.type);
2355 }
2356 }
2357
2358 return len;
2359}
2360
2361/*
2362 * Send a block of data over the SSH link.
2363 * Block until all data is sent.
2364 * (only used by pSCP)
2365 */
2366void ssh_scp_send(unsigned char *buf, int len)
2367{
fb09bf1c 2368 if (s == INVALID_SOCKET)
2369 return;
e5574168 2370 send_packet(SSH1_CMSG_STDIN_DATA,
fb09bf1c 2371 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2372}
2373
2374/*
2375 * Send an EOF notification to the server.
2376 * (only used by pSCP)
2377 */
2378void ssh_scp_send_eof(void)
2379{
fb09bf1c 2380 if (s == INVALID_SOCKET)
2381 return;
e5574168 2382 send_packet(SSH1_CMSG_EOF, PKT_END);
fb09bf1c 2383}
2384
2385/*
2386 * Set up the connection, login on the remote host and
2387 * start execution of a command.
2388 * Returns an error message, or NULL on success.
2389 * (only used by pSCP)
2390 */
2391char *ssh_scp_init(char *host, int port, char *cmd, char **realhost)
2392{
2393 char buf[160], *p;
2394
fb09bf1c 2395#ifdef MSCRYPTOAPI
2396 if (crypto_startup() == 0)
2397 return "Microsoft high encryption pack not installed!";
2398#endif
2399
2400 p = connect_to_host(host, port, realhost);
2401 if (p != NULL)
2402 return p;
2403
2404 random_init();
2405
2406 if (!do_ssh_init())
2407 return "Protocol initialisation error";
2408
2409 /* Exchange keys and login */
2410 do {
2411 get_packet();
2412 if (s == INVALID_SOCKET)
2413 return "Connection closed by remote host";
e5574168 2414 } while (!do_ssh1_login(NULL, 0, 1));
85ee8208 2415
2416 if (ssh_state == SSH_STATE_CLOSED) {
2417 closesocket(s);
2418 s = INVALID_SOCKET;
2419 return "Session initialisation error";
2420 }
fb09bf1c 2421
2422 /* Execute command */
2423 sprintf(buf, "Sending command: %.100s", cmd);
2424 logevent(buf);
e5574168 2425 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fb09bf1c 2426
2427 return NULL;
2428}
2429
8ccc75b0 2430static SOCKET ssh_socket(void) { return s; }
2431
2432static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 2433
374330e2 2434Backend ssh_backend = {
2435 ssh_init,
2436 ssh_msg,
2437 ssh_send,
2438 ssh_size,
4017be6d 2439 ssh_special,
8ccc75b0 2440 ssh_socket,
2441 ssh_sendok
374330e2 2442};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator