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