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