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