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Implement OpenSSH-compatible RSA key fingerprints and use them throughout
[u/mdw/putty] / ssh.c
CommitLineData
374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
4d331a77 5#ifndef AUTO_WINSOCK
6#ifdef WINSOCK_TWO
7#include <winsock2.h>
8#else
374330e2 9#include <winsock.h>
4d331a77 10#endif
11#endif
374330e2 12
13#include "putty.h"
dacbd0e8 14#include "tree234.h"
fb09bf1c 15#include "ssh.h"
16#include "scp.h"
374330e2 17
18#ifndef FALSE
19#define FALSE 0
20#endif
21#ifndef TRUE
22#define TRUE 1
23#endif
24
fb09bf1c 25#define logevent(s) { logevent(s); \
67779be7 26 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
fb09bf1c 27 fprintf(stderr, "%s\n", s); }
28
8d5de777 29#define bombout(msg) ( ssh_state == SSH_STATE_CLOSED, closesocket(s), \
30 s = INVALID_SOCKET, connection_fatal msg )
31
d211621f 32#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
33#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
34#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
35#define SSH1_CMSG_USER 4 /* 0x4 */
36#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
37#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
38#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
39#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
40#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
41#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
42#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
43#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
44#define SSH1_SMSG_SUCCESS 14 /* 0xe */
45#define SSH1_SMSG_FAILURE 15 /* 0xf */
46#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
47#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
48#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
49#define SSH1_CMSG_EOF 19 /* 0x13 */
50#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
51#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
52#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
53#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
54#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
55#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
56#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
57#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
58#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
59#define SSH1_MSG_IGNORE 32 /* 0x20 */
60#define SSH1_MSG_DEBUG 36 /* 0x24 */
61#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
62#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
63#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
64#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
65#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
66#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
67
68#define SSH1_AUTH_TIS 5 /* 0x5 */
69#define SSH1_AUTH_CCARD 16 /* 0x10 */
70
71#define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
72#define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
73#define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
74#define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
75#define SSH_AGENT_FAILURE 5 /* 0x5 */
76#define SSH_AGENT_SUCCESS 6 /* 0x6 */
77#define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
78#define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
79
80#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
81#define SSH2_MSG_IGNORE 2 /* 0x2 */
82#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
83#define SSH2_MSG_DEBUG 4 /* 0x4 */
84#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
85#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
86#define SSH2_MSG_KEXINIT 20 /* 0x14 */
87#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
88#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
89#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
90#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
91#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
92#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
93#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
94#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
95#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
96#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
97#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
98#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
99#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
100#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
101#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
102#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
103#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
104#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
105#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
106#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
107#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
108#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
109#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
110
111#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
112#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
113#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
114#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
115
116#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 117
118#define GET_32BIT(cp) \
119 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
120 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
121 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
122 ((unsigned long)(unsigned char)(cp)[3]))
123
124#define PUT_32BIT(cp, value) { \
125 (cp)[0] = (unsigned char)((value) >> 24); \
126 (cp)[1] = (unsigned char)((value) >> 16); \
127 (cp)[2] = (unsigned char)((value) >> 8); \
128 (cp)[3] = (unsigned char)(value); }
129
7cca0d81 130enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 131
374330e2 132/* Coroutine mechanics for the sillier bits of the code */
133#define crBegin1 static int crLine = 0;
134#define crBegin2 switch(crLine) { case 0:;
135#define crBegin crBegin1; crBegin2;
136#define crFinish(z) } crLine = 0; return (z)
137#define crFinishV } crLine = 0; return
138#define crReturn(z) \
139 do {\
140 crLine=__LINE__; return (z); case __LINE__:;\
141 } while (0)
142#define crReturnV \
143 do {\
144 crLine=__LINE__; return; case __LINE__:;\
145 } while (0)
146#define crStop(z) do{ crLine = 0; return (z); }while(0)
147#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 148#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 149#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 150
e5574168 151extern struct ssh_cipher ssh_3des;
033b4cef 152extern struct ssh_cipher ssh_3des_ssh2;
e5574168 153extern struct ssh_cipher ssh_des;
5e8358ad 154extern struct ssh_cipher ssh_blowfish_ssh1;
155extern struct ssh_cipher ssh_blowfish_ssh2;
e5574168 156
5e8358ad 157/*
158 * Ciphers for SSH2. We miss out single-DES because it isn't
159 * supported; also 3DES and Blowfish are both done differently from
160 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
161 * endianness and different-sized keys.)
162 *
163 * The first entry in this array is set up to be whatever the user
164 * asks for as a cipher. Thereafter there is a fixed preference
165 * order of fallback ciphers.
166 */
167struct ssh_cipher *ciphers[] = { NULL, &ssh_blowfish_ssh2, &ssh_3des_ssh2 };
e5574168 168
169extern struct ssh_kex ssh_diffiehellman;
170struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
171
172extern struct ssh_hostkey ssh_dss;
173struct ssh_hostkey *hostkey_algs[] = { &ssh_dss };
174
175extern struct ssh_mac ssh_sha1;
176
dacbd0e8 177static SHA_State exhash;
e5574168 178
d39f364a 179static void nullmac_key(unsigned char *key) { }
e5574168 180static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
181static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
182struct ssh_mac ssh_mac_none = {
d39f364a 183 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 184};
185struct ssh_mac *macs[] = { &ssh_sha1, &ssh_mac_none };
186
187struct ssh_compress ssh_comp_none = {
188 "none"
189};
190struct ssh_compress *compressions[] = { &ssh_comp_none };
191
374330e2 192static SOCKET s = INVALID_SOCKET;
193
194static unsigned char session_key[32];
195static struct ssh_cipher *cipher = NULL;
e5574168 196static struct ssh_cipher *cscipher = NULL;
197static struct ssh_cipher *sccipher = NULL;
198static struct ssh_mac *csmac = NULL;
199static struct ssh_mac *scmac = NULL;
200static struct ssh_compress *cscomp = NULL;
201static struct ssh_compress *sccomp = NULL;
202static struct ssh_kex *kex = NULL;
203static struct ssh_hostkey *hostkey = NULL;
85ee8208 204int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
374330e2 205
206static char *savedhost;
8ccc75b0 207static int ssh_send_ok;
374330e2 208
dacbd0e8 209/*
210 * 2-3-4 tree storing channels.
211 */
212struct ssh_channel {
d211621f 213 unsigned remoteid, localid;
dacbd0e8 214 int type;
215 int closes;
216 union {
217 struct ssh_agent_channel {
218 unsigned char *message;
219 unsigned char msglen[4];
220 int lensofar, totallen;
221 } a;
d211621f 222 struct ssh2_data_channel {
223 unsigned char *outbuffer;
224 unsigned outbuflen, outbufsize;
225 unsigned remwindow, remmaxpkt;
226 } v2;
dacbd0e8 227 } u;
228};
229static tree234 *ssh_channels; /* indexed by local id */
230static int ssh_channelcmp(void *av, void *bv) {
231 struct ssh_channel *a = (struct ssh_channel *)av;
232 struct ssh_channel *b = (struct ssh_channel *)bv;
233 if (a->localid < b->localid) return -1;
234 if (a->localid > b->localid) return +1;
235 return 0;
236}
237static int ssh_channelfind(void *av, void *bv) {
d211621f 238 unsigned *a = (unsigned *)av;
dacbd0e8 239 struct ssh_channel *b = (struct ssh_channel *)bv;
240 if (*a < b->localid) return -1;
241 if (*a > b->localid) return +1;
242 return 0;
243}
244
d211621f 245static struct ssh_channel *mainchan; /* primary session channel */
246
374330e2 247static enum {
248 SSH_STATE_BEFORE_SIZE,
249 SSH_STATE_INTERMED,
21248260 250 SSH_STATE_SESSION,
251 SSH_STATE_CLOSED
374330e2 252} ssh_state = SSH_STATE_BEFORE_SIZE;
253
254static int size_needed = FALSE;
255
256static void s_write (char *buf, int len) {
257 while (len > 0) {
258 int i = send (s, buf, len, 0);
4017be6d 259 noise_ultralight(i);
8d5de777 260 if (i <= 0) {
261 bombout(("Lost connection while sending"));
262 return;
263 }
374330e2 264 if (i > 0)
265 len -= i, buf += i;
266 }
267}
268
269static int s_read (char *buf, int len) {
270 int ret = 0;
271 while (len > 0) {
272 int i = recv (s, buf, len, 0);
4017be6d 273 noise_ultralight(i);
374330e2 274 if (i > 0)
275 len -= i, buf += i, ret += i;
276 else
277 return i;
278 }
279 return ret;
280}
281
282static void c_write (char *buf, int len) {
67779be7 283 if ((flags & FLAG_STDERR)) {
4017be6d 284 int i;
285 for (i = 0; i < len; i++)
286 if (buf[i] != '\r')
287 fputc(buf[i], stderr);
fb09bf1c 288 return;
289 }
c9def1b8 290 while (len--)
291 c_write1(*buf++);
374330e2 292}
293
294struct Packet {
295 long length;
296 int type;
374330e2 297 unsigned char *data;
298 unsigned char *body;
e5574168 299 long savedpos;
374330e2 300 long maxlen;
301};
302
fb09bf1c 303static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
304static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
374330e2 305
6abbf9e3 306static int ssh_version;
e5574168 307static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
308static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
309static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
374330e2 310static void ssh_size(void);
311
e5574168 312static int (*s_rdpkt)(unsigned char **data, int *datalen);
fb09bf1c 313
314/*
315 * Collect incoming data in the incoming packet buffer.
e5574168 316 * Decipher and verify the packet when it is completely read.
317 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 318 * Update the *data and *datalen variables.
319 * Return the additional nr of bytes needed, or 0 when
320 * a complete packet is available.
321 */
e5574168 322static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 323{
324 static long len, pad, biglen, to_read;
572f871e 325 static unsigned long realcrc, gotcrc;
fb09bf1c 326 static unsigned char *p;
327 static int i;
374330e2 328
329 crBegin;
374330e2 330
fb09bf1c 331next_packet:
37508af4 332
fb09bf1c 333 pktin.type = 0;
334 pktin.length = 0;
374330e2 335
fb09bf1c 336 for (i = len = 0; i < 4; i++) {
337 while ((*datalen) == 0)
338 crReturn(4-i);
339 len = (len << 8) + **data;
340 (*data)++, (*datalen)--;
341 }
374330e2 342
fb09bf1c 343#ifdef FWHACK
344 if (len == 0x52656d6f) { /* "Remo"te server has closed ... */
345 len = 0x300; /* big enough to carry to end */
346 }
347#endif
374330e2 348
fb09bf1c 349 pad = 8 - (len % 8);
350 biglen = len + pad;
351 pktin.length = len - 5;
352
353 if (pktin.maxlen < biglen) {
354 pktin.maxlen = biglen;
e5574168 355 pktin.data = (pktin.data == NULL ? malloc(biglen+APIEXTRA) :
356 realloc(pktin.data, biglen+APIEXTRA));
fb09bf1c 357 if (!pktin.data)
358 fatalbox("Out of memory");
359 }
374330e2 360
fb09bf1c 361 to_read = biglen;
362 p = pktin.data;
363 while (to_read > 0) {
364 static int chunk;
365 chunk = to_read;
366 while ((*datalen) == 0)
367 crReturn(to_read);
368 if (chunk > (*datalen))
369 chunk = (*datalen);
370 memcpy(p, *data, chunk);
371 *data += chunk;
372 *datalen -= chunk;
373 p += chunk;
374 to_read -= chunk;
375 }
374330e2 376
fb09bf1c 377 if (cipher)
378 cipher->decrypt(pktin.data, biglen);
374330e2 379
fb09bf1c 380 pktin.type = pktin.data[pad];
381 pktin.body = pktin.data + pad + 1;
374330e2 382
fb09bf1c 383 realcrc = crc32(pktin.data, biglen-4);
384 gotcrc = GET_32BIT(pktin.data+biglen-4);
385 if (gotcrc != realcrc) {
8d5de777 386 bombout(("Incorrect CRC received on packet"));
387 crReturn(0);
fb09bf1c 388 }
572f871e 389
e5574168 390 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
391 pktin.type == SSH1_SMSG_STDERR_DATA ||
392 pktin.type == SSH1_MSG_DEBUG ||
18515c51 393 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
394 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 395 long strlen = GET_32BIT(pktin.body);
8d5de777 396 if (strlen + 4 != pktin.length) {
397 bombout(("Received data packet with bogus string length"));
398 crReturn(0);
399 }
fb09bf1c 400 }
401
e5574168 402 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 403 /* log debug message */
404 char buf[80];
405 int strlen = GET_32BIT(pktin.body);
406 strcpy(buf, "Remote: ");
407 if (strlen > 70) strlen = 70;
408 memcpy(buf+8, pktin.body+4, strlen);
409 buf[8+strlen] = '\0';
410 logevent(buf);
411 goto next_packet;
e5574168 412 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 413 /* do nothing */
414 goto next_packet;
415 }
416
417 crFinish(0);
418}
419
e5574168 420static int ssh2_rdpkt(unsigned char **data, int *datalen)
421{
422 static long len, pad, payload, packetlen, maclen;
423 static int i;
424 static int cipherblk;
425 static unsigned long incoming_sequence = 0;
426
427 crBegin;
428
429next_packet:
430
431 pktin.type = 0;
432 pktin.length = 0;
433
434 if (cipher)
435 cipherblk = cipher->blksize;
436 else
437 cipherblk = 8;
438 if (cipherblk < 8)
439 cipherblk = 8;
440
441 if (pktin.maxlen < cipherblk) {
442 pktin.maxlen = cipherblk;
443 pktin.data = (pktin.data == NULL ? malloc(cipherblk+APIEXTRA) :
444 realloc(pktin.data, cipherblk+APIEXTRA));
445 if (!pktin.data)
446 fatalbox("Out of memory");
447 }
448
449 /*
450 * Acquire and decrypt the first block of the packet. This will
451 * contain the length and padding details.
452 */
453 for (i = len = 0; i < cipherblk; i++) {
454 while ((*datalen) == 0)
455 crReturn(cipherblk-i);
456 pktin.data[i] = *(*data)++;
457 (*datalen)--;
458 }
459#ifdef FWHACK
460 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
461 /* FIXME */
462 }
463#endif
464 if (sccipher)
465 sccipher->decrypt(pktin.data, cipherblk);
466
467 /*
468 * Now get the length and padding figures.
469 */
470 len = GET_32BIT(pktin.data);
471 pad = pktin.data[4];
472
473 /*
474 * This enables us to deduce the payload length.
475 */
476 payload = len - pad - 1;
477
478 pktin.length = payload + 5;
479
480 /*
481 * So now we can work out the total packet length.
482 */
483 packetlen = len + 4;
484 maclen = scmac ? scmac->len : 0;
485
486 /*
487 * Adjust memory allocation if packet is too big.
488 */
59dcd2a8 489 if (pktin.maxlen < packetlen+maclen) {
490 pktin.maxlen = packetlen+maclen;
491 pktin.data = (pktin.data == NULL ? malloc(pktin.maxlen+APIEXTRA) :
492 realloc(pktin.data, pktin.maxlen+APIEXTRA));
e5574168 493 if (!pktin.data)
494 fatalbox("Out of memory");
495 }
496
497 /*
498 * Read and decrypt the remainder of the packet.
499 */
500 for (i = cipherblk; i < packetlen + maclen; i++) {
501 while ((*datalen) == 0)
502 crReturn(packetlen + maclen - i);
503 pktin.data[i] = *(*data)++;
504 (*datalen)--;
505 }
506 /* Decrypt everything _except_ the MAC. */
507 if (sccipher)
508 sccipher->decrypt(pktin.data + cipherblk, packetlen - cipherblk);
509
7cca0d81 510#if 0
d39f364a 511 debug(("Got packet len=%d pad=%d\r\n", len, pad));
512 for (i = 0; i < packetlen; i++)
513 debug((" %02x", (unsigned char)pktin.data[i]));
514 debug(("\r\n"));
7cca0d81 515#endif
d39f364a 516
e5574168 517 /*
518 * Check the MAC.
519 */
8d5de777 520 if (scmac && !scmac->verify(pktin.data, len+4, incoming_sequence)) {
521 bombout(("Incorrect MAC received on packet"));
522 crReturn(0);
523 }
033b4cef 524 incoming_sequence++; /* whether or not we MACed */
e5574168 525
526 pktin.savedpos = 6;
527 pktin.type = pktin.data[5];
e5574168 528
7cca0d81 529 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
530 goto next_packet; /* FIXME: print DEBUG message */
e5574168 531
532 crFinish(0);
533}
534
fb09bf1c 535static void ssh_gotdata(unsigned char *data, int datalen)
536{
537 while (datalen > 0) {
85ee8208 538 if ( s_rdpkt(&data, &datalen) == 0 ) {
374330e2 539 ssh_protocol(NULL, 0, 1);
85ee8208 540 if (ssh_state == SSH_STATE_CLOSED) {
541 return;
542 }
543 }
374330e2 544 }
374330e2 545}
546
fb09bf1c 547
374330e2 548static void s_wrpkt_start(int type, int len) {
549 int pad, biglen;
550
551 len += 5; /* type and CRC */
552 pad = 8 - (len%8);
553 biglen = len + pad;
554
555 pktout.length = len-5;
556 if (pktout.maxlen < biglen) {
557 pktout.maxlen = biglen;
8f203108 558#ifdef MSCRYPTOAPI
fb09bf1c 559 /* Allocate enough buffer space for extra block
8f203108 560 * for MS CryptEncrypt() */
fb09bf1c 561 pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
562 realloc(pktout.data, biglen+12));
8f203108 563#else
c1f5f956 564 pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
565 realloc(pktout.data, biglen+4));
8f203108 566#endif
374330e2 567 if (!pktout.data)
568 fatalbox("Out of memory");
569 }
570
571 pktout.type = type;
572 pktout.body = pktout.data+4+pad+1;
573}
574
575static void s_wrpkt(void) {
576 int pad, len, biglen, i;
577 unsigned long crc;
578
579 len = pktout.length + 5; /* type and CRC */
580 pad = 8 - (len%8);
581 biglen = len + pad;
582
583 pktout.body[-1] = pktout.type;
584 for (i=0; i<pad; i++)
585 pktout.data[i+4] = random_byte();
586 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 587 PUT_32BIT(pktout.data+biglen, crc);
588 PUT_32BIT(pktout.data, len);
374330e2 589
590 if (cipher)
591 cipher->encrypt(pktout.data+4, biglen);
592
593 s_write(pktout.data, biglen+4);
594}
595
fb09bf1c 596/*
597 * Construct a packet with the specified contents and
598 * send it to the server.
599 */
600static void send_packet(int pkttype, ...)
601{
602 va_list args;
603 unsigned char *p, *argp, argchar;
604 unsigned long argint;
605 int pktlen, argtype, arglen;
7cca0d81 606 Bignum bn;
fb09bf1c 607
608 pktlen = 0;
609 va_start(args, pkttype);
610 while ((argtype = va_arg(args, int)) != PKT_END) {
611 switch (argtype) {
612 case PKT_INT:
613 (void) va_arg(args, int);
614 pktlen += 4;
615 break;
616 case PKT_CHAR:
617 (void) va_arg(args, char);
618 pktlen++;
619 break;
620 case PKT_DATA:
621 (void) va_arg(args, unsigned char *);
622 arglen = va_arg(args, int);
623 pktlen += arglen;
624 break;
625 case PKT_STR:
626 argp = va_arg(args, unsigned char *);
627 arglen = strlen(argp);
628 pktlen += 4 + arglen;
629 break;
7cca0d81 630 case PKT_BIGNUM:
631 bn = va_arg(args, Bignum);
5c58ad2d 632 pktlen += ssh1_bignum_length(bn);
7cca0d81 633 break;
fb09bf1c 634 default:
635 assert(0);
636 }
637 }
638 va_end(args);
639
640 s_wrpkt_start(pkttype, pktlen);
641 p = pktout.body;
642
643 va_start(args, pkttype);
644 while ((argtype = va_arg(args, int)) != PKT_END) {
645 switch (argtype) {
646 case PKT_INT:
647 argint = va_arg(args, int);
648 PUT_32BIT(p, argint);
649 p += 4;
650 break;
651 case PKT_CHAR:
652 argchar = va_arg(args, unsigned char);
653 *p = argchar;
654 p++;
655 break;
656 case PKT_DATA:
657 argp = va_arg(args, unsigned char *);
658 arglen = va_arg(args, int);
659 memcpy(p, argp, arglen);
660 p += arglen;
661 break;
662 case PKT_STR:
663 argp = va_arg(args, unsigned char *);
664 arglen = strlen(argp);
665 PUT_32BIT(p, arglen);
666 memcpy(p + 4, argp, arglen);
667 p += 4 + arglen;
668 break;
7cca0d81 669 case PKT_BIGNUM:
670 bn = va_arg(args, Bignum);
5c58ad2d 671 p += ssh1_write_bignum(p, bn);
7cca0d81 672 break;
fb09bf1c 673 }
674 }
675 va_end(args);
676
677 s_wrpkt();
678}
679
680
681/*
682 * Connect to specified host and port.
683 * Returns an error message, or NULL on success.
684 * Also places the canonical host name into `realhost'.
685 */
686static char *connect_to_host(char *host, int port, char **realhost)
687{
688 SOCKADDR_IN addr;
689 struct hostent *h;
690 unsigned long a;
691#ifdef FWHACK
692 char *FWhost;
693 int FWport;
694#endif
695
696 savedhost = malloc(1+strlen(host));
697 if (!savedhost)
698 fatalbox("Out of memory");
699 strcpy(savedhost, host);
700
701 if (port < 0)
702 port = 22; /* default ssh port */
703
704#ifdef FWHACK
705 FWhost = host;
706 FWport = port;
707 host = FWSTR;
708 port = 23;
709#endif
710
711 /*
712 * Try to find host.
713 */
714 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
715 if ( (h = gethostbyname(host)) == NULL)
716 switch (WSAGetLastError()) {
717 case WSAENETDOWN: return "Network is down";
718 case WSAHOST_NOT_FOUND: case WSANO_DATA:
719 return "Host does not exist";
720 case WSATRY_AGAIN: return "Host not found";
721 default: return "gethostbyname: unknown error";
722 }
723 memcpy (&a, h->h_addr, sizeof(a));
724 *realhost = h->h_name;
725 } else
726 *realhost = host;
727#ifdef FWHACK
728 *realhost = FWhost;
729#endif
730 a = ntohl(a);
731
732 /*
733 * Open socket.
734 */
735 s = socket(AF_INET, SOCK_STREAM, 0);
736 if (s == INVALID_SOCKET)
737 switch (WSAGetLastError()) {
738 case WSAENETDOWN: return "Network is down";
739 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
740 default: return "socket(): unknown error";
741 }
742
743 /*
744 * Bind to local address.
745 */
746 addr.sin_family = AF_INET;
747 addr.sin_addr.s_addr = htonl(INADDR_ANY);
748 addr.sin_port = htons(0);
749 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
750 switch (WSAGetLastError()) {
751 case WSAENETDOWN: return "Network is down";
752 default: return "bind(): unknown error";
753 }
754
755 /*
756 * Connect to remote address.
757 */
758 addr.sin_addr.s_addr = htonl(a);
759 addr.sin_port = htons((short)port);
760 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
761 switch (WSAGetLastError()) {
762 case WSAENETDOWN: return "Network is down";
763 case WSAECONNREFUSED: return "Connection refused";
764 case WSAENETUNREACH: return "Network is unreachable";
765 case WSAEHOSTUNREACH: return "No route to host";
766 default: return "connect(): unknown error";
767 }
768
769#ifdef FWHACK
770 send(s, "connect ", 8, 0);
771 send(s, FWhost, strlen(FWhost), 0);
772 {
773 char buf[20];
774 sprintf(buf, " %d\n", FWport);
775 send (s, buf, strlen(buf), 0);
776 }
777#endif
778
779 return NULL;
780}
781
9697bfd2 782static int ssh_versioncmp(char *a, char *b) {
783 char *ae, *be;
784 unsigned long av, bv;
785
43aa02a7 786 av = strtoul(a, &ae, 10);
787 bv = strtoul(b, &be, 10);
9697bfd2 788 if (av != bv) return (av < bv ? -1 : +1);
789 if (*ae == '.') ae++;
790 if (*be == '.') be++;
43aa02a7 791 av = strtoul(ae, &ae, 10);
792 bv = strtoul(be, &be, 10);
9697bfd2 793 if (av != bv) return (av < bv ? -1 : +1);
794 return 0;
795}
796
e5574168 797
798/*
799 * Utility routine for putting an SSH-protocol `string' into a SHA
800 * state.
801 */
802#include <stdio.h>
803void sha_string(SHA_State *s, void *str, int len) {
804 unsigned char lenblk[4];
e5574168 805 PUT_32BIT(lenblk, len);
e5574168 806 SHA_Bytes(s, lenblk, 4);
e5574168 807 SHA_Bytes(s, str, len);
808}
809
7cca0d81 810/*
811 * SSH2 packet construction functions.
812 */
813void ssh2_pkt_adddata(void *data, int len) {
814 pktout.length += len;
815 if (pktout.maxlen < pktout.length) {
816 pktout.maxlen = pktout.length + 256;
817 pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) :
818 realloc(pktout.data, pktout.maxlen+APIEXTRA));
819 if (!pktout.data)
820 fatalbox("Out of memory");
821 }
822 memcpy(pktout.data+pktout.length-len, data, len);
823}
824void ssh2_pkt_addbyte(unsigned char byte) {
825 ssh2_pkt_adddata(&byte, 1);
826}
827void ssh2_pkt_init(int pkt_type) {
828 pktout.length = 5;
829 ssh2_pkt_addbyte((unsigned char)pkt_type);
830}
831void ssh2_pkt_addbool(unsigned char value) {
832 ssh2_pkt_adddata(&value, 1);
833}
834void ssh2_pkt_adduint32(unsigned long value) {
835 unsigned char x[4];
836 PUT_32BIT(x, value);
837 ssh2_pkt_adddata(x, 4);
838}
839void ssh2_pkt_addstring_start(void) {
840 ssh2_pkt_adduint32(0);
841 pktout.savedpos = pktout.length;
842}
843void ssh2_pkt_addstring_str(char *data) {
844 ssh2_pkt_adddata(data, strlen(data));
845 PUT_32BIT(pktout.data + pktout.savedpos - 4,
846 pktout.length - pktout.savedpos);
847}
848void ssh2_pkt_addstring_data(char *data, int len) {
849 ssh2_pkt_adddata(data, len);
850 PUT_32BIT(pktout.data + pktout.savedpos - 4,
851 pktout.length - pktout.savedpos);
852}
853void ssh2_pkt_addstring(char *data) {
854 ssh2_pkt_addstring_start();
855 ssh2_pkt_addstring_str(data);
856}
857char *ssh2_mpint_fmt(Bignum b, int *len) {
858 unsigned char *p;
859 int i, n = b[0];
860 p = malloc(n * 2 + 1);
861 if (!p)
862 fatalbox("out of memory");
863 p[0] = 0;
864 for (i = 0; i < n; i++) {
865 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
866 p[i*2+2] = (b[n-i] ) & 0xFF;
867 }
868 i = 0;
869 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
870 i++;
871 memmove(p, p+i, n*2+1-i);
872 *len = n*2+1-i;
873 return p;
874}
875void ssh2_pkt_addmp(Bignum b) {
876 unsigned char *p;
877 int len;
878 p = ssh2_mpint_fmt(b, &len);
879 ssh2_pkt_addstring_start();
880 ssh2_pkt_addstring_data(p, len);
881 free(p);
882}
883void ssh2_pkt_send(void) {
884 int cipherblk, maclen, padding, i;
885 static unsigned long outgoing_sequence = 0;
886
887 /*
888 * Add padding. At least four bytes, and must also bring total
889 * length (minus MAC) up to a multiple of the block size.
890 */
891 cipherblk = cipher ? cipher->blksize : 8; /* block size */
892 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
893 padding = 4;
894 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
895 pktout.data[4] = padding;
896 for (i = 0; i < padding; i++)
897 pktout.data[pktout.length + i] = random_byte();
898 PUT_32BIT(pktout.data, pktout.length + padding - 4);
899 if (csmac)
900 csmac->generate(pktout.data, pktout.length + padding,
901 outgoing_sequence);
902 outgoing_sequence++; /* whether or not we MACed */
903
904#if 0
905 debug(("Sending packet len=%d\r\n", pktout.length+padding));
906 for (i = 0; i < pktout.length+padding; i++)
907 debug((" %02x", (unsigned char)pktout.data[i]));
908 debug(("\r\n"));
909#endif
910
911 if (cscipher)
912 cscipher->encrypt(pktout.data, pktout.length + padding);
913 maclen = csmac ? csmac->len : 0;
914
915 s_write(pktout.data, pktout.length + padding + maclen);
916}
917
918#if 0
919void bndebug(char *string, Bignum b) {
920 unsigned char *p;
921 int i, len;
922 p = ssh2_mpint_fmt(b, &len);
923 debug(("%s", string));
924 for (i = 0; i < len; i++)
925 debug((" %02x", p[i]));
926 debug(("\r\n"));
927 free(p);
928}
929#endif
930
931void sha_mpint(SHA_State *s, Bignum b) {
932 unsigned char *p;
933 int len;
934 p = ssh2_mpint_fmt(b, &len);
935 sha_string(s, p, len);
936 free(p);
937}
938
939/*
940 * SSH2 packet decode functions.
941 */
942unsigned long ssh2_pkt_getuint32(void) {
943 unsigned long value;
944 if (pktin.length - pktin.savedpos < 4)
945 return 0; /* arrgh, no way to decline (FIXME?) */
946 value = GET_32BIT(pktin.data+pktin.savedpos);
947 pktin.savedpos += 4;
948 return value;
949}
950void ssh2_pkt_getstring(char **p, int *length) {
951 *p = NULL;
952 if (pktin.length - pktin.savedpos < 4)
953 return;
954 *length = GET_32BIT(pktin.data+pktin.savedpos);
955 pktin.savedpos += 4;
956 if (pktin.length - pktin.savedpos < *length)
957 return;
958 *p = pktin.data+pktin.savedpos;
959 pktin.savedpos += *length;
960}
961Bignum ssh2_pkt_getmp(void) {
962 char *p;
963 int i, j, length;
964 Bignum b;
965
966 ssh2_pkt_getstring(&p, &length);
967 if (!p)
968 return NULL;
8d5de777 969 if (p[0] & 0x80) {
970 bombout(("internal error: Can't handle negative mpints"));
971 return NULL;
972 }
7cca0d81 973 b = newbn((length+1)/2);
974 for (i = 0; i < length; i++) {
975 j = length - 1 - i;
976 if (j & 1)
977 b[j/2+1] |= ((unsigned char)p[i]) << 8;
978 else
979 b[j/2+1] |= ((unsigned char)p[i]);
980 }
981 return b;
982}
983
374330e2 984static int do_ssh_init(void) {
c5e9c988 985 char c, *vsp;
374330e2 986 char version[10];
c5e9c988 987 char vstring[80];
988 char vlog[sizeof(vstring)+20];
374330e2 989 int i;
990
991#ifdef FWHACK
992 i = 0;
993 while (s_read(&c, 1) == 1) {
994 if (c == 'S' && i < 2) i++;
995 else if (c == 'S' && i == 2) i = 2;
996 else if (c == 'H' && i == 2) break;
997 else i = 0;
998 }
999#else
1000 if (s_read(&c,1) != 1 || c != 'S') return 0;
1001 if (s_read(&c,1) != 1 || c != 'S') return 0;
1002 if (s_read(&c,1) != 1 || c != 'H') return 0;
1003#endif
c5e9c988 1004 strcpy(vstring, "SSH-");
1005 vsp = vstring+4;
374330e2 1006 if (s_read(&c,1) != 1 || c != '-') return 0;
1007 i = 0;
1008 while (1) {
1009 if (s_read(&c,1) != 1)
1010 return 0;
c5e9c988 1011 if (vsp < vstring+sizeof(vstring)-1)
1012 *vsp++ = c;
374330e2 1013 if (i >= 0) {
1014 if (c == '-') {
1015 version[i] = '\0';
1016 i = -1;
1017 } else if (i < sizeof(version)-1)
1018 version[i++] = c;
1019 }
1020 else if (c == '\n')
1021 break;
1022 }
1023
c5e9c988 1024 *vsp = 0;
1025 sprintf(vlog, "Server version: %s", vstring);
1026 vlog[strcspn(vlog, "\r\n")] = '\0';
1027 logevent(vlog);
1028
adf799dd 1029 /*
1030 * Server version "1.99" means we can choose whether we use v1
1031 * or v2 protocol. Choice is based on cfg.sshprot.
1032 */
1033 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 1034 /*
1035 * This is a v2 server. Begin v2 protocol.
1036 */
1037 char *verstring = "SSH-2.0-PuTTY";
1038 SHA_Init(&exhash);
1039 /*
1040 * Hash our version string and their version string.
1041 */
1042 sha_string(&exhash, verstring, strlen(verstring));
1043 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
1044 sprintf(vstring, "%s\n", verstring);
1045 sprintf(vlog, "We claim version: %s", verstring);
1046 logevent(vlog);
1047 logevent("Using SSH protocol version 2");
1048 s_write(vstring, strlen(vstring));
1049 ssh_protocol = ssh2_protocol;
6abbf9e3 1050 ssh_version = 2;
e5574168 1051 s_rdpkt = ssh2_rdpkt;
1052 } else {
1053 /*
1054 * This is a v1 server. Begin v1 protocol.
1055 */
1056 sprintf(vstring, "SSH-%s-PuTTY\n",
1057 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1058 sprintf(vlog, "We claim version: %s", vstring);
1059 vlog[strcspn(vlog, "\r\n")] = '\0';
1060 logevent(vlog);
1061 logevent("Using SSH protocol version 1");
1062 s_write(vstring, strlen(vstring));
1063 ssh_protocol = ssh1_protocol;
6abbf9e3 1064 ssh_version = 1;
e5574168 1065 s_rdpkt = ssh1_rdpkt;
1066 }
8ccc75b0 1067 ssh_send_ok = 0;
fef97f43 1068 return 1;
374330e2 1069}
1070
fb09bf1c 1071/*
1072 * Handle the key exchange and user authentication phases.
1073 */
e5574168 1074static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1075{
374330e2 1076 int i, j, len;
374330e2 1077 unsigned char *rsabuf, *keystr1, *keystr2;
1078 unsigned char cookie[8];
1079 struct RSAKey servkey, hostkey;
1080 struct MD5Context md5c;
ccbfb941 1081 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1082 static int tried_publickey;
1083 static unsigned char session_id[16];
bea1ef5f 1084 int cipher_type;
374330e2 1085
374330e2 1086 crBegin;
1087
fb09bf1c 1088 if (!ispkt) crWaitUntil(ispkt);
374330e2 1089
8d5de777 1090 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1091 bombout(("Public key packet not received"));
1092 crReturn(0);
1093 }
374330e2 1094
c5e9c988 1095 logevent("Received public keys");
374330e2 1096
c5e9c988 1097 memcpy(cookie, pktin.body, 8);
374330e2 1098
7cca0d81 1099 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1100 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1101
c5e9c988 1102 /*
1c2a93c4 1103 * Log the host key fingerprint.
c5e9c988 1104 */
c5e9c988 1105 {
1106 char logmsg[80];
1c2a93c4 1107 logevent("Host key fingerprint is:");
c5e9c988 1108 strcpy(logmsg, " ");
1c2a93c4 1109 hostkey.comment = NULL;
1110 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1111 &hostkey);
c5e9c988 1112 logevent(logmsg);
1113 }
1114
fb09bf1c 1115 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1116 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1117
c5e9c988 1118 MD5Init(&md5c);
374330e2 1119 MD5Update(&md5c, keystr2, hostkey.bytes);
1120 MD5Update(&md5c, keystr1, servkey.bytes);
1121 MD5Update(&md5c, pktin.body, 8);
374330e2 1122 MD5Final(session_id, &md5c);
1123
1124 for (i=0; i<32; i++)
1125 session_key[i] = random_byte();
1126
1127 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1128
1129 rsabuf = malloc(len);
1130 if (!rsabuf)
1131 fatalbox("Out of memory");
1132
89ee5268 1133 /*
1134 * Verify the host key.
1135 */
1136 {
1137 /*
1138 * First format the key into a string.
1139 */
1140 int len = rsastr_len(&hostkey);
1141 char *keystr = malloc(len);
1142 if (!keystr)
1143 fatalbox("Out of memory");
1144 rsastr_fmt(keystr, &hostkey);
1145 verify_ssh_host_key(savedhost, keystr);
1146 free(keystr);
1147 }
374330e2 1148
1149 for (i=0; i<32; i++) {
1150 rsabuf[i] = session_key[i];
1151 if (i < 16)
1152 rsabuf[i] ^= session_id[i];
1153 }
1154
1155 if (hostkey.bytes > servkey.bytes) {
1156 rsaencrypt(rsabuf, 32, &servkey);
1157 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1158 } else {
1159 rsaencrypt(rsabuf, 32, &hostkey);
1160 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1161 }
1162
c5e9c988 1163 logevent("Encrypted session key");
1164
bea1ef5f 1165 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1166 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1167 SSH_CIPHER_3DES;
1168 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1169 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1170 cipher_type = SSH_CIPHER_3DES;
1171 }
c5e9c988 1172 switch (cipher_type) {
1173 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1174 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1175 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1176 }
bea1ef5f 1177
e5574168 1178 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1179 PKT_CHAR, cipher_type,
1180 PKT_DATA, cookie, 8,
1181 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1182 PKT_DATA, rsabuf, len,
1183 PKT_INT, 0,
1184 PKT_END);
1185
c5e9c988 1186 logevent("Trying to enable encryption...");
374330e2 1187
1188 free(rsabuf);
1189
5e8358ad 1190 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1191 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1192 &ssh_3des;
374330e2 1193 cipher->sesskey(session_key);
1194
fb09bf1c 1195 crWaitUntil(ispkt);
374330e2 1196
8d5de777 1197 if (pktin.type != SSH1_SMSG_SUCCESS) {
1198 bombout(("Encryption not successfully enabled"));
1199 crReturn(0);
1200 }
374330e2 1201
c5e9c988 1202 logevent("Successfully started encryption");
1203
374330e2 1204 fflush(stdout);
1205 {
1206 static char username[100];
1207 static int pos = 0;
1208 static char c;
67779be7 1209 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1210 c_write("login as: ", 10);
67779be7 1211 ssh_send_ok = 1;
374330e2 1212 while (pos >= 0) {
fb09bf1c 1213 crWaitUntil(!ispkt);
374330e2 1214 while (inlen--) switch (c = *in++) {
1215 case 10: case 13:
1216 username[pos] = 0;
1217 pos = -1;
1218 break;
1219 case 8: case 127:
1220 if (pos > 0) {
1221 c_write("\b \b", 3);
1222 pos--;
1223 }
1224 break;
1225 case 21: case 27:
1226 while (pos > 0) {
1227 c_write("\b \b", 3);
1228 pos--;
1229 }
1230 break;
1231 case 3: case 4:
1232 random_save_seed();
1233 exit(0);
1234 break;
1235 default:
40d24aa6 1236 if (((c >= ' ' && c <= '~') ||
1237 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1238 username[pos++] = c;
1239 c_write(&c, 1);
1240 }
1241 break;
1242 }
1243 }
1244 c_write("\r\n", 2);
1245 username[strcspn(username, "\n\r")] = '\0';
1246 } else {
1247 char stuff[200];
1248 strncpy(username, cfg.username, 99);
1249 username[99] = '\0';
67779be7 1250 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
fb09bf1c 1251 sprintf(stuff, "Sent username \"%s\".\r\n", username);
4017be6d 1252 c_write(stuff, strlen(stuff));
fb09bf1c 1253 }
374330e2 1254 }
fb09bf1c 1255
e5574168 1256 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1257 {
1258 char userlog[20+sizeof(username)];
1259 sprintf(userlog, "Sent username \"%s\"", username);
1260 logevent(userlog);
1261 }
374330e2 1262 }
1263
fb09bf1c 1264 crWaitUntil(ispkt);
374330e2 1265
7cca0d81 1266 tried_publickey = 0;
1267
e5574168 1268 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1269 static char password[100];
a52f067e 1270 static char prompt[200];
374330e2 1271 static int pos;
1272 static char c;
ccbfb941 1273 static int pwpkt_type;
ccbfb941 1274 /*
1275 * Show password prompt, having first obtained it via a TIS
18515c51 1276 * or CryptoCard exchange if we're doing TIS or CryptoCard
1277 * authentication.
ccbfb941 1278 */
e5574168 1279 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1280 if (agent_exists()) {
1281 /*
1282 * Attempt RSA authentication using Pageant.
1283 */
1284 static unsigned char request[5], *response, *p;
1285 static int responselen;
1286 static int i, nkeys;
1287 static int authed = FALSE;
1288 void *r;
1289
1290 logevent("Pageant is running. Requesting keys.");
1291
1292 /* Request the keys held by the agent. */
1293 PUT_32BIT(request, 1);
1294 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1295 agent_query(request, 5, &r, &responselen);
1296 response = (unsigned char *)r;
1297 if (response) {
1298 p = response + 5;
1299 nkeys = GET_32BIT(p); p += 4;
1300 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1301 logevent(buf); }
1302 for (i = 0; i < nkeys; i++) {
1303 static struct RSAKey key;
1304 static Bignum challenge;
b8bb811a 1305 static char *commentp;
1306 static int commentlen;
5c58ad2d 1307
1308 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1309 logevent(buf); }
1310 p += 4;
1311 p += ssh1_read_bignum(p, &key.exponent);
1312 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1313 commentlen = GET_32BIT(p); p += 4;
1314 commentp = p; p += commentlen;
5c58ad2d 1315 send_packet(SSH1_CMSG_AUTH_RSA,
1316 PKT_BIGNUM, key.modulus, PKT_END);
1317 crWaitUntil(ispkt);
1318 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1319 logevent("Key refused");
1320 continue;
1321 }
1322 logevent("Received RSA challenge");
1323 ssh1_read_bignum(pktin.body, &challenge);
1324 {
1325 char *agentreq, *q, *ret;
1326 int len, retlen;
1327 len = 1 + 4; /* message type, bit count */
1328 len += ssh1_bignum_length(key.exponent);
1329 len += ssh1_bignum_length(key.modulus);
1330 len += ssh1_bignum_length(challenge);
1331 len += 16; /* session id */
1332 len += 4; /* response format */
1333 agentreq = malloc(4 + len);
1334 PUT_32BIT(agentreq, len);
1335 q = agentreq + 4;
1336 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1337 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1338 q += 4;
1339 q += ssh1_write_bignum(q, key.exponent);
1340 q += ssh1_write_bignum(q, key.modulus);
1341 q += ssh1_write_bignum(q, challenge);
1342 memcpy(q, session_id, 16); q += 16;
1343 PUT_32BIT(q, 1); /* response format */
1344 agent_query(agentreq, len+4, &ret, &retlen);
1345 free(agentreq);
1346 if (ret) {
1347 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1348 logevent("Sending Pageant's response");
1349 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1350 PKT_DATA, ret+5, 16, PKT_END);
1351 free(ret);
1352 crWaitUntil(ispkt);
1353 if (pktin.type == SSH1_SMSG_SUCCESS) {
1354 logevent("Pageant's response accepted");
c4fa2fce 1355 if (flags & FLAG_VERBOSE) {
1356 c_write("Authenticated using RSA key \"",
1357 29);
1358 c_write(commentp, commentlen);
1359 c_write("\" from agent\r\n", 14);
1360 }
5c58ad2d 1361 authed = TRUE;
1362 } else
1363 logevent("Pageant's response not accepted");
1364 } else {
1365 logevent("Pageant failed to answer challenge");
1366 free(ret);
1367 }
1368 } else {
1369 logevent("No reply received from Pageant");
1370 }
1371 }
1372 freebn(key.exponent);
1373 freebn(key.modulus);
1374 freebn(challenge);
1375 if (authed)
1376 break;
1377 }
1378 }
1379 if (authed)
1380 break;
1381 }
7cca0d81 1382 if (*cfg.keyfile && !tried_publickey)
1383 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1384
a52f067e 1385 if (pktin.type == SSH1_SMSG_FAILURE &&
1386 cfg.try_tis_auth &&
1387 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1388 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1389 logevent("Requested TIS authentication");
1390 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1391 crWaitUntil(ispkt);
1392 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1393 logevent("TIS authentication declined");
1394 if (flags & FLAG_INTERACTIVE)
1395 c_write("TIS authentication refused.\r\n", 29);
1396 } else {
1397 int challengelen = ((pktin.body[0] << 24) |
1398 (pktin.body[1] << 16) |
1399 (pktin.body[2] << 8) |
1400 (pktin.body[3]));
1401 logevent("Received TIS challenge");
1402 if (challengelen > sizeof(prompt)-1)
1403 challengelen = sizeof(prompt)-1; /* prevent overrun */
1404 memcpy(prompt, pktin.body+4, challengelen);
1405 prompt[challengelen] = '\0';
1406 }
1407 }
1408 if (pktin.type == SSH1_SMSG_FAILURE &&
1409 cfg.try_tis_auth &&
1410 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1411 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1412 logevent("Requested CryptoCard authentication");
1413 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1414 crWaitUntil(ispkt);
1415 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1416 logevent("CryptoCard authentication declined");
1417 c_write("CryptoCard authentication refused.\r\n", 29);
1418 } else {
1419 int challengelen = ((pktin.body[0] << 24) |
1420 (pktin.body[1] << 16) |
1421 (pktin.body[2] << 8) |
1422 (pktin.body[3]));
1423 logevent("Received CryptoCard challenge");
1424 if (challengelen > sizeof(prompt)-1)
1425 challengelen = sizeof(prompt)-1; /* prevent overrun */
1426 memcpy(prompt, pktin.body+4, challengelen);
1427 strncpy(prompt + challengelen, "\r\nResponse : ",
1428 sizeof(prompt)-challengelen);
1429 prompt[sizeof(prompt)-1] = '\0';
1430 }
1431 }
1432 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1433 sprintf(prompt, "%.90s@%.90s's password: ",
1434 cfg.username, savedhost);
1435 }
1436 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1437 char *comment = NULL;
1438 if (flags & FLAG_VERBOSE)
1439 c_write("Trying public key authentication.\r\n", 35);
1440 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1441 if (flags & FLAG_VERBOSE)
1442 c_write("No passphrase required.\r\n", 25);
1443 goto tryauth;
1444 }
1445 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1446 free(comment);
1447 }
1448
1449 if (!(flags & FLAG_INTERACTIVE)) {
85ee8208 1450 if (!ssh_get_password(prompt, password, sizeof(password))) {
1451 /*
1452 * get_password failed to get a password (for
1453 * example because one was supplied on the command
1454 * line which has already failed to work).
1455 * Terminate.
1456 */
1457 logevent("No more passwords to try");
1458 ssh_state = SSH_STATE_CLOSED;
1459 crReturn(1);
1460 }
fb09bf1c 1461 } else {
a52f067e 1462 c_write(prompt, strlen(prompt));
7cca0d81 1463 pos = 0;
67779be7 1464 ssh_send_ok = 1;
7cca0d81 1465 while (pos >= 0) {
1466 crWaitUntil(!ispkt);
1467 while (inlen--) switch (c = *in++) {
1468 case 10: case 13:
1469 password[pos] = 0;
1470 pos = -1;
1471 break;
1472 case 8: case 127:
1473 if (pos > 0)
1474 pos--;
1475 break;
1476 case 21: case 27:
1477 pos = 0;
1478 break;
1479 case 3: case 4:
1480 random_save_seed();
1481 exit(0);
1482 break;
1483 default:
1484 if (((c >= ' ' && c <= '~') ||
1485 ((unsigned char)c >= 160)) && pos < sizeof(password))
1486 password[pos++] = c;
1487 break;
1488 }
1489 }
1490 c_write("\r\n", 2);
a52f067e 1491 }
fb09bf1c 1492
7cca0d81 1493 tryauth:
1494 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1495 /*
1496 * Try public key authentication with the specified
1497 * key file.
1498 */
1499 static struct RSAKey pubkey;
1500 static Bignum challenge, response;
1501 static int i;
1502 static unsigned char buffer[32];
1503
1504 tried_publickey = 1;
1505 i = loadrsakey(cfg.keyfile, &pubkey, password);
1506 if (i == 0) {
1507 c_write("Couldn't load public key from ", 30);
1508 c_write(cfg.keyfile, strlen(cfg.keyfile));
1509 c_write(".\r\n", 3);
1510 continue; /* go and try password */
1511 }
1512 if (i == -1) {
1513 c_write("Wrong passphrase.\r\n", 19);
1514 tried_publickey = 0;
1515 continue; /* try again */
1516 }
1517
1518 /*
1519 * Send a public key attempt.
1520 */
1521 send_packet(SSH1_CMSG_AUTH_RSA,
1522 PKT_BIGNUM, pubkey.modulus, PKT_END);
1523
1524 crWaitUntil(ispkt);
1525 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1526 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1527 continue; /* go and try password */
1528 }
8d5de777 1529 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1530 bombout(("Bizarre response to offer of public key"));
1531 crReturn(0);
1532 }
7cca0d81 1533 ssh1_read_bignum(pktin.body, &challenge);
1534 response = rsadecrypt(challenge, &pubkey);
1535 freebn(pubkey.private_exponent); /* burn the evidence */
1536
1537 for (i = 0; i < 32; i += 2) {
1538 buffer[i] = response[16-i/2] >> 8;
1539 buffer[i+1] = response[16-i/2] & 0xFF;
1540 }
1541
1542 MD5Init(&md5c);
1543 MD5Update(&md5c, buffer, 32);
1544 MD5Update(&md5c, session_id, 16);
1545 MD5Final(buffer, &md5c);
1546
1547 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1548 PKT_DATA, buffer, 16, PKT_END);
1549
1550 crWaitUntil(ispkt);
1551 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1552 if (flags & FLAG_VERBOSE)
1553 c_write("Failed to authenticate with our public key.\r\n",
1554 45);
7cca0d81 1555 continue; /* go and try password */
1556 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1557 bombout(("Bizarre response to RSA authentication response"));
1558 crReturn(0);
7cca0d81 1559 }
1560
1561 break; /* we're through! */
1562 } else {
1563 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1564 }
c5e9c988 1565 logevent("Sent password");
374330e2 1566 memset(password, 0, strlen(password));
fb09bf1c 1567 crWaitUntil(ispkt);
e5574168 1568 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1569 if (flags & FLAG_VERBOSE)
1570 c_write("Access denied\r\n", 15);
c5e9c988 1571 logevent("Authentication refused");
e5574168 1572 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1573 logevent("Received disconnect request");
85ee8208 1574 ssh_state = SSH_STATE_CLOSED;
1575 crReturn(1);
e5574168 1576 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1577 bombout(("Strange packet received, type %d", pktin.type));
1578 crReturn(0);
374330e2 1579 }
1580 }
1581
c5e9c988 1582 logevent("Authentication successful");
1583
fb09bf1c 1584 crFinish(1);
1585}
1586
e5574168 1587static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1588 crBegin;
1589
1590 random_init();
1591
e5574168 1592 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1593 crReturnV;
85ee8208 1594 }
1595 if (ssh_state == SSH_STATE_CLOSED)
1596 crReturnV;
fb09bf1c 1597
979310f1 1598 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1599 logevent("Requesting agent forwarding");
1600 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1601 do { crReturnV; } while (!ispkt);
1602 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1603 bombout(("Protocol confusion"));
1604 crReturnV;
dacbd0e8 1605 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1606 logevent("Agent forwarding refused");
1607 } else
1608 logevent("Agent forwarding enabled");
1609 }
1610
fef97f43 1611 if (!cfg.nopty) {
e5574168 1612 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1613 PKT_STR, cfg.termtype,
1614 PKT_INT, rows, PKT_INT, cols,
1615 PKT_INT, 0, PKT_INT, 0,
1616 PKT_CHAR, 0,
1617 PKT_END);
fef97f43 1618 ssh_state = SSH_STATE_INTERMED;
1619 do { crReturnV; } while (!ispkt);
e5574168 1620 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1621 bombout(("Protocol confusion"));
1622 crReturnV;
e5574168 1623 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1624 c_write("Server refused to allocate pty\r\n", 32);
1625 }
c5e9c988 1626 logevent("Allocated pty");
374330e2 1627 }
1628
6abbf9e3 1629 if (*cfg.remote_cmd)
1630 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1631 else
1632 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1633 logevent("Started session");
374330e2 1634
1635 ssh_state = SSH_STATE_SESSION;
1636 if (size_needed)
1637 ssh_size();
1638
8ccc75b0 1639 ssh_send_ok = 1;
dacbd0e8 1640 ssh_channels = newtree234(ssh_channelcmp);
6f34e365 1641 begin_session();
374330e2 1642 while (1) {
1643 crReturnV;
1644 if (ispkt) {
e5574168 1645 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1646 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1647 long len = GET_32BIT(pktin.body);
1648 c_write(pktin.body+4, len);
e5574168 1649 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1650 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1651 logevent("Received disconnect request");
dacbd0e8 1652 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1653 /* Remote side is trying to open a channel to talk to our
1654 * agent. Give them back a local channel number. */
d211621f 1655 unsigned i = 1;
dacbd0e8 1656 struct ssh_channel *c;
1657 enum234 e;
1658 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1659 if (c->localid > i)
1660 break; /* found a free number */
1661 i = c->localid + 1;
1662 }
1663 c = malloc(sizeof(struct ssh_channel));
1664 c->remoteid = GET_32BIT(pktin.body);
1665 c->localid = i;
b8bb811a 1666 c->closes = 0;
dacbd0e8 1667 c->type = SSH1_SMSG_AGENT_OPEN; /* identify channel type */
bb487ce2 1668 c->u.a.lensofar = 0;
dacbd0e8 1669 add234(ssh_channels, c);
1670 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1671 PKT_INT, c->remoteid, PKT_INT, c->localid,
1672 PKT_END);
1673 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1674 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1675 /* Remote side closes a channel. */
d211621f 1676 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1677 struct ssh_channel *c;
1678 c = find234(ssh_channels, &i, ssh_channelfind);
1679 if (c) {
1680 int closetype;
1681 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1682 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1683 c->closes |= closetype;
1684 if (c->closes == 3) {
1685 del234(ssh_channels, c);
1686 free(c);
1687 }
1688 }
1689 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1690 /* Data sent down one of our channels. */
1691 int i = GET_32BIT(pktin.body);
1692 int len = GET_32BIT(pktin.body+4);
1693 unsigned char *p = pktin.body+8;
1694 struct ssh_channel *c;
1695 c = find234(ssh_channels, &i, ssh_channelfind);
1696 if (c) {
1697 switch(c->type) {
1698 case SSH1_SMSG_AGENT_OPEN:
1699 /* Data for an agent message. Buffer it. */
1700 while (len > 0) {
1701 if (c->u.a.lensofar < 4) {
1702 int l = min(4 - c->u.a.lensofar, len);
1703 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
1704 p += l; len -= l; c->u.a.lensofar += l;
1705 }
1706 if (c->u.a.lensofar == 4) {
1707 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
1708 c->u.a.message = malloc(c->u.a.totallen);
1709 memcpy(c->u.a.message, c->u.a.msglen, 4);
1710 }
1711 if (c->u.a.lensofar >= 4 && len > 0) {
1712 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
1713 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
1714 p += l; len -= l; c->u.a.lensofar += l;
1715 }
1716 if (c->u.a.lensofar == c->u.a.totallen) {
1717 void *reply, *sentreply;
1718 int replylen;
1719 agent_query(c->u.a.message, c->u.a.totallen,
1720 &reply, &replylen);
1721 if (reply)
1722 sentreply = reply;
1723 else {
1724 /* Fake SSH_AGENT_FAILURE. */
1725 sentreply = "\0\0\0\1\5";
1726 replylen = 5;
1727 }
1728 send_packet(SSH1_MSG_CHANNEL_DATA,
1729 PKT_INT, c->remoteid,
1730 PKT_INT, replylen,
1731 PKT_DATA, sentreply, replylen,
1732 PKT_END);
1733 if (reply)
1734 free(reply);
1735 free(c->u.a.message);
1736 c->u.a.lensofar = 0;
1737 }
1738 }
1739 break;
1740 }
1741 }
e5574168 1742 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 1743 /* may be from EXEC_SHELL on some servers */
e5574168 1744 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 1745 /* may be from EXEC_SHELL on some servers
374330e2 1746 * if no pty is available or in other odd cases. Ignore */
e5574168 1747 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1748 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 1749 } else {
8d5de777 1750 bombout(("Strange packet received: type %d", pktin.type));
1751 crReturnV;
374330e2 1752 }
1753 } else {
e5574168 1754 send_packet(SSH1_CMSG_STDIN_DATA,
fb09bf1c 1755 PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
374330e2 1756 }
1757 }
1758
1759 crFinishV;
1760}
1761
1762/*
e5574168 1763 * Utility routine for decoding comma-separated strings in KEXINIT.
1764 */
1765int in_commasep_string(char *needle, char *haystack, int haylen) {
1766 int needlen = strlen(needle);
1767 while (1) {
1768 /*
1769 * Is it at the start of the string?
1770 */
1771 if (haylen >= needlen && /* haystack is long enough */
1772 !memcmp(needle, haystack, needlen) && /* initial match */
1773 (haylen == needlen || haystack[needlen] == ',')
1774 /* either , or EOS follows */
1775 )
1776 return 1;
1777 /*
1778 * If not, search for the next comma and resume after that.
1779 * If no comma found, terminate.
1780 */
1781 while (haylen > 0 && *haystack != ',')
1782 haylen--, haystack++;
1783 if (haylen == 0)
1784 return 0;
1785 haylen--, haystack++; /* skip over comma itself */
1786 }
1787}
1788
1789/*
d39f364a 1790 * SSH2 key creation method.
1791 */
1792void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
1793 SHA_State s;
1794 /* First 20 bytes. */
1795 SHA_Init(&s);
1796 sha_mpint(&s, K);
1797 SHA_Bytes(&s, H, 20);
1798 SHA_Bytes(&s, &chr, 1);
1799 SHA_Bytes(&s, H, 20);
1800 SHA_Final(&s, keyspace);
1801 /* Next 20 bytes. */
1802 SHA_Init(&s);
1803 sha_mpint(&s, K);
1804 SHA_Bytes(&s, H, 20);
1805 SHA_Bytes(&s, keyspace, 20);
1806 SHA_Final(&s, keyspace+20);
1807}
1808
1809/*
7cca0d81 1810 * Handle the SSH2 transport layer.
e5574168 1811 */
7cca0d81 1812static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 1813{
1814 static int i, len;
1815 static char *str;
1816 static Bignum e, f, K;
1817 static struct ssh_cipher *cscipher_tobe = NULL;
1818 static struct ssh_cipher *sccipher_tobe = NULL;
1819 static struct ssh_mac *csmac_tobe = NULL;
1820 static struct ssh_mac *scmac_tobe = NULL;
1821 static struct ssh_compress *cscomp_tobe = NULL;
1822 static struct ssh_compress *sccomp_tobe = NULL;
7cca0d81 1823 static char *hostkeydata, *sigdata, *keystr;
e5574168 1824 static int hostkeylen, siglen;
1825 static unsigned char exchange_hash[20];
d39f364a 1826 static unsigned char keyspace[40];
e5574168 1827
1828 crBegin;
7cca0d81 1829 random_init();
e5574168 1830
5e8358ad 1831 /*
1832 * Set up the preferred cipher.
1833 */
1834 if (cfg.cipher == CIPHER_BLOWFISH) {
1835 ciphers[0] = &ssh_blowfish_ssh2;
1836 } else if (cfg.cipher == CIPHER_DES) {
1837 logevent("Single DES not supported in SSH2; using 3DES");
1838 ciphers[0] = &ssh_3des_ssh2;
1839 } else if (cfg.cipher == CIPHER_3DES) {
1840 ciphers[0] = &ssh_3des_ssh2;
1841 } else {
1842 /* Shouldn't happen, but we do want to initialise to _something_. */
1843 ciphers[0] = &ssh_3des_ssh2;
1844 }
1845
7cca0d81 1846 begin_key_exchange:
e5574168 1847 /*
1848 * Construct and send our key exchange packet.
1849 */
1850 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1851 for (i = 0; i < 16; i++)
1852 ssh2_pkt_addbyte((unsigned char)random_byte());
1853 /* List key exchange algorithms. */
1854 ssh2_pkt_addstring_start();
1855 for (i = 0; i < lenof(kex_algs); i++) {
1856 ssh2_pkt_addstring_str(kex_algs[i]->name);
1857 if (i < lenof(kex_algs)-1)
1858 ssh2_pkt_addstring_str(",");
1859 }
1860 /* List server host key algorithms. */
1861 ssh2_pkt_addstring_start();
1862 for (i = 0; i < lenof(hostkey_algs); i++) {
1863 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1864 if (i < lenof(hostkey_algs)-1)
1865 ssh2_pkt_addstring_str(",");
1866 }
1867 /* List client->server encryption algorithms. */
1868 ssh2_pkt_addstring_start();
1869 for (i = 0; i < lenof(ciphers); i++) {
1870 ssh2_pkt_addstring_str(ciphers[i]->name);
1871 if (i < lenof(ciphers)-1)
1872 ssh2_pkt_addstring_str(",");
1873 }
1874 /* List server->client encryption algorithms. */
1875 ssh2_pkt_addstring_start();
1876 for (i = 0; i < lenof(ciphers); i++) {
1877 ssh2_pkt_addstring_str(ciphers[i]->name);
1878 if (i < lenof(ciphers)-1)
1879 ssh2_pkt_addstring_str(",");
1880 }
1881 /* List client->server MAC algorithms. */
1882 ssh2_pkt_addstring_start();
1883 for (i = 0; i < lenof(macs); i++) {
1884 ssh2_pkt_addstring_str(macs[i]->name);
1885 if (i < lenof(macs)-1)
1886 ssh2_pkt_addstring_str(",");
1887 }
1888 /* List server->client MAC algorithms. */
1889 ssh2_pkt_addstring_start();
1890 for (i = 0; i < lenof(macs); i++) {
1891 ssh2_pkt_addstring_str(macs[i]->name);
1892 if (i < lenof(macs)-1)
1893 ssh2_pkt_addstring_str(",");
1894 }
1895 /* List client->server compression algorithms. */
1896 ssh2_pkt_addstring_start();
1897 for (i = 0; i < lenof(compressions); i++) {
1898 ssh2_pkt_addstring_str(compressions[i]->name);
1899 if (i < lenof(compressions)-1)
1900 ssh2_pkt_addstring_str(",");
1901 }
1902 /* List server->client compression algorithms. */
1903 ssh2_pkt_addstring_start();
1904 for (i = 0; i < lenof(compressions); i++) {
1905 ssh2_pkt_addstring_str(compressions[i]->name);
1906 if (i < lenof(compressions)-1)
1907 ssh2_pkt_addstring_str(",");
1908 }
1909 /* List client->server languages. Empty list. */
1910 ssh2_pkt_addstring_start();
1911 /* List server->client languages. Empty list. */
1912 ssh2_pkt_addstring_start();
1913 /* First KEX packet does _not_ follow, because we're not that brave. */
1914 ssh2_pkt_addbool(FALSE);
1915 /* Reserved. */
1916 ssh2_pkt_adduint32(0);
1917 sha_string(&exhash, pktout.data+5, pktout.length-5);
1918 ssh2_pkt_send();
1919
1920 if (!ispkt) crWaitUntil(ispkt);
1921 sha_string(&exhash, pktin.data+5, pktin.length-5);
1922
1923 /*
1924 * Now examine the other side's KEXINIT to see what we're up
1925 * to.
1926 */
7cca0d81 1927 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 1928 bombout(("expected key exchange packet from server"));
1929 crReturn(0);
7cca0d81 1930 }
e5574168 1931 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1932 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1933 pktin.savedpos += 16; /* skip garbage cookie */
1934 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1935 for (i = 0; i < lenof(kex_algs); i++) {
1936 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1937 kex = kex_algs[i];
1938 break;
1939 }
1940 }
1941 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1942 for (i = 0; i < lenof(hostkey_algs); i++) {
1943 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1944 hostkey = hostkey_algs[i];
1945 break;
1946 }
1947 }
1948 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
1949 for (i = 0; i < lenof(ciphers); i++) {
1950 if (in_commasep_string(ciphers[i]->name, str, len)) {
1951 cscipher_tobe = ciphers[i];
1952 break;
1953 }
1954 }
1955 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
1956 for (i = 0; i < lenof(ciphers); i++) {
1957 if (in_commasep_string(ciphers[i]->name, str, len)) {
1958 sccipher_tobe = ciphers[i];
1959 break;
1960 }
1961 }
1962 ssh2_pkt_getstring(&str, &len); /* client->server mac */
1963 for (i = 0; i < lenof(macs); i++) {
1964 if (in_commasep_string(macs[i]->name, str, len)) {
1965 csmac_tobe = macs[i];
1966 break;
1967 }
1968 }
1969 ssh2_pkt_getstring(&str, &len); /* server->client mac */
1970 for (i = 0; i < lenof(macs); i++) {
1971 if (in_commasep_string(macs[i]->name, str, len)) {
1972 scmac_tobe = macs[i];
1973 break;
1974 }
1975 }
1976 ssh2_pkt_getstring(&str, &len); /* client->server compression */
1977 for (i = 0; i < lenof(compressions); i++) {
1978 if (in_commasep_string(compressions[i]->name, str, len)) {
1979 cscomp_tobe = compressions[i];
1980 break;
1981 }
1982 }
1983 ssh2_pkt_getstring(&str, &len); /* server->client compression */
1984 for (i = 0; i < lenof(compressions); i++) {
1985 if (in_commasep_string(compressions[i]->name, str, len)) {
1986 sccomp_tobe = compressions[i];
1987 break;
1988 }
1989 }
e5574168 1990
1991 /*
1992 * Currently we only support Diffie-Hellman and DSS, so let's
1993 * bomb out if those aren't selected.
1994 */
8d5de777 1995 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
1996 bombout(("internal fault: chaos in SSH 2 transport layer"));
1997 crReturn(0);
1998 }
e5574168 1999
2000 /*
2001 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2002 */
2003 e = dh_create_e();
e5574168 2004 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2005 ssh2_pkt_addmp(e);
2006 ssh2_pkt_send();
2007
2008 crWaitUntil(ispkt);
7cca0d81 2009 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2010 bombout(("expected key exchange packet from server"));
2011 crReturn(0);
7cca0d81 2012 }
e5574168 2013 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2014 f = ssh2_pkt_getmp();
e5574168 2015 ssh2_pkt_getstring(&sigdata, &siglen);
2016
2017 K = dh_find_K(f);
e5574168 2018
2019 sha_string(&exhash, hostkeydata, hostkeylen);
2020 sha_mpint(&exhash, e);
2021 sha_mpint(&exhash, f);
2022 sha_mpint(&exhash, K);
2023 SHA_Final(&exhash, exchange_hash);
2024
7cca0d81 2025#if 0
e5574168 2026 debug(("Exchange hash is:\r\n"));
2027 for (i = 0; i < 20; i++)
2028 debug((" %02x", exchange_hash[i]));
2029 debug(("\r\n"));
7cca0d81 2030#endif
2031
2032 hostkey->setkey(hostkeydata, hostkeylen);
8d5de777 2033 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20)) {
2034 bombout(("Server failed host key check"));
2035 crReturn(0);
2036 }
e5574168 2037
2038 /*
7cca0d81 2039 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2040 */
7cca0d81 2041 crWaitUntil(ispkt);
8d5de777 2042 if (pktin.type != SSH2_MSG_NEWKEYS) {
2043 bombout(("expected new-keys packet from server"));
2044 crReturn(0);
2045 }
d39f364a 2046
2047 /*
7cca0d81 2048 * Authenticate remote host: verify host key. (We've already
2049 * checked the signature of the exchange hash.)
e5574168 2050 */
7cca0d81 2051 keystr = hostkey->fmtkey();
2052 verify_ssh_host_key(savedhost, keystr);
2053 free(keystr);
d39f364a 2054
2055 /*
7cca0d81 2056 * Send SSH2_MSG_NEWKEYS.
d39f364a 2057 */
2058 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2059 ssh2_pkt_send();
d39f364a 2060
2061 /*
2062 * Create and initialise session keys.
2063 */
2064 cscipher = cscipher_tobe;
2065 sccipher = sccipher_tobe;
2066 csmac = csmac_tobe;
2067 scmac = scmac_tobe;
2068 cscomp = cscomp_tobe;
2069 sccomp = sccomp_tobe;
2070 /*
2071 * Set IVs after keys.
2072 */
2073 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
2074 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
2075 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2076 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2077 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2078 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2079
033b4cef 2080 /*
7cca0d81 2081 * Now we're encrypting. Begin returning 1 to the protocol main
2082 * function so that other things can run on top of the
2083 * transport. If we ever see a KEXINIT, we must go back to the
2084 * start.
033b4cef 2085 */
7cca0d81 2086 do {
2087 crReturn(1);
2088 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2089 goto begin_key_exchange;
e5574168 2090
2091 crFinish(1);
2092}
2093
7cca0d81 2094/*
2095 * Handle the SSH2 userauth and connection layers.
2096 */
2097static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2098{
7cca0d81 2099 static unsigned long remote_winsize;
2100 static unsigned long remote_maxpkt;
2101
e5574168 2102 crBegin;
2103
7cca0d81 2104 /*
2105 * Request userauth protocol, and await a response to it.
2106 */
2107 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2108 ssh2_pkt_addstring("ssh-userauth");
2109 ssh2_pkt_send();
2110 crWaitUntilV(ispkt);
8d5de777 2111 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2112 bombout(("Server refused user authentication protocol"));
2113 crReturnV;
2114 }
7cca0d81 2115
2116 /*
2117 * FIXME: currently we support only password authentication.
2118 * (This places us technically in violation of the SSH2 spec.
2119 * We must fix this.)
2120 */
2121 while (1) {
2122 /*
2123 * Get a username and a password.
2124 */
2125 static char username[100];
2126 static char password[100];
2127 static int pos = 0;
2128 static char c;
e5574168 2129
67779be7 2130 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2131 c_write("login as: ", 10);
67779be7 2132 ssh_send_ok = 1;
7cca0d81 2133 while (pos >= 0) {
2134 crWaitUntilV(!ispkt);
2135 while (inlen--) switch (c = *in++) {
2136 case 10: case 13:
2137 username[pos] = 0;
2138 pos = -1;
2139 break;
2140 case 8: case 127:
2141 if (pos > 0) {
2142 c_write("\b \b", 3);
2143 pos--;
2144 }
2145 break;
2146 case 21: case 27:
2147 while (pos > 0) {
2148 c_write("\b \b", 3);
2149 pos--;
2150 }
2151 break;
2152 case 3: case 4:
2153 random_save_seed();
2154 exit(0);
2155 break;
2156 default:
2157 if (((c >= ' ' && c <= '~') ||
2158 ((unsigned char)c >= 160)) && pos < 40) {
2159 username[pos++] = c;
2160 c_write(&c, 1);
2161 }
2162 break;
2163 }
2164 }
2165 c_write("\r\n", 2);
2166 username[strcspn(username, "\n\r")] = '\0';
2167 } else {
2168 char stuff[200];
2169 strncpy(username, cfg.username, 99);
2170 username[99] = '\0';
67779be7 2171 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2172 sprintf(stuff, "Using username \"%s\".\r\n", username);
2173 c_write(stuff, strlen(stuff));
2174 }
2175 }
2176
67779be7 2177 if (!(flags & FLAG_INTERACTIVE)) {
7cca0d81 2178 char prompt[200];
2179 sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
2180 if (!ssh_get_password(prompt, password, sizeof(password))) {
2181 /*
2182 * get_password failed to get a password (for
2183 * example because one was supplied on the command
2184 * line which has already failed to work).
2185 * Terminate.
2186 */
2187 logevent("No more passwords to try");
2188 ssh_state = SSH_STATE_CLOSED;
2189 crReturnV;
2190 }
2191 } else {
2192 c_write("password: ", 10);
67779be7 2193 ssh_send_ok = 1;
7cca0d81 2194
2195 pos = 0;
2196 while (pos >= 0) {
2197 crWaitUntilV(!ispkt);
2198 while (inlen--) switch (c = *in++) {
2199 case 10: case 13:
2200 password[pos] = 0;
2201 pos = -1;
2202 break;
2203 case 8: case 127:
2204 if (pos > 0)
2205 pos--;
2206 break;
2207 case 21: case 27:
2208 pos = 0;
2209 break;
2210 case 3: case 4:
2211 random_save_seed();
2212 exit(0);
2213 break;
2214 default:
2215 if (((c >= ' ' && c <= '~') ||
2216 ((unsigned char)c >= 160)) && pos < 40)
2217 password[pos++] = c;
2218 break;
2219 }
2220 }
2221 c_write("\r\n", 2);
2222 }
2223
2224 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2225 ssh2_pkt_addstring(username);
2226 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2227 ssh2_pkt_addstring("password");
2228 ssh2_pkt_addbool(FALSE);
2229 ssh2_pkt_addstring(password);
2230 ssh2_pkt_send();
2231
2232 crWaitUntilV(ispkt);
2233 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2234 c_write("Access denied\r\n", 15);
2235 logevent("Authentication refused");
2236 } else
2237 break;
2238 }
2239
2240 /*
2241 * Now we're authenticated for the connection protocol. The
2242 * connection protocol will automatically have started at this
2243 * point; there's no need to send SERVICE_REQUEST.
2244 */
2245
2246 /*
2247 * So now create a channel with a session in it.
2248 */
d211621f 2249 mainchan = malloc(sizeof(struct ssh_channel));
2250 mainchan->localid = 100; /* as good as any */
7cca0d81 2251 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2252 ssh2_pkt_addstring("session");
d211621f 2253 ssh2_pkt_adduint32(mainchan->localid);
2254 ssh2_pkt_adduint32(0x7FFFFFFFUL); /* our window size */
2255 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2256 ssh2_pkt_send();
2257 crWaitUntilV(ispkt);
2258 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2259 bombout(("Server refused to open a session"));
2260 crReturnV;
7cca0d81 2261 /* FIXME: error data comes back in FAILURE packet */
2262 }
d211621f 2263 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2264 bombout(("Server's channel confirmation cited wrong channel"));
2265 crReturnV;
7cca0d81 2266 }
d211621f 2267 mainchan->remoteid = ssh2_pkt_getuint32();
2268 mainchan->u.v2.remwindow = ssh2_pkt_getuint32();
2269 mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32();
2270 mainchan->u.v2.outbuffer = NULL;
2271 mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0;
7cca0d81 2272 logevent("Opened channel for session");
2273
2274 /*
2275 * Now allocate a pty for the session.
2276 */
67779be7 2277 if (!cfg.nopty) {
2278 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2279 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2280 ssh2_pkt_addstring("pty-req");
2281 ssh2_pkt_addbool(1); /* want reply */
2282 ssh2_pkt_addstring(cfg.termtype);
2283 ssh2_pkt_adduint32(cols);
2284 ssh2_pkt_adduint32(rows);
2285 ssh2_pkt_adduint32(0); /* pixel width */
2286 ssh2_pkt_adduint32(0); /* pixel height */
2287 ssh2_pkt_addstring_start();
2288 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2289 ssh2_pkt_send();
7cca0d81 2290
67779be7 2291 do {
2292 crWaitUntilV(ispkt);
2293 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2294 /* FIXME: be able to handle other channels here */
2295 if (ssh2_pkt_getuint32() != mainchan->localid)
2296 continue; /* wrong channel */
2297 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2298 }
2299 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2300
67779be7 2301 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2302 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2303 bombout(("Server got confused by pty request"));
2304 crReturnV;
67779be7 2305 }
2306 c_write("Server refused to allocate pty\r\n", 32);
2307 } else {
2308 logevent("Allocated pty");
7cca0d81 2309 }
7cca0d81 2310 }
2311
2312 /*
67779be7 2313 * Start a shell or a remote command.
7cca0d81 2314 */
2315 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2316 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2317 if (*cfg.remote_cmd) {
2318 ssh2_pkt_addstring("exec");
2319 ssh2_pkt_addbool(1); /* want reply */
2320 ssh2_pkt_addstring(cfg.remote_cmd);
2321 } else {
2322 ssh2_pkt_addstring("shell");
2323 ssh2_pkt_addbool(1); /* want reply */
2324 }
7cca0d81 2325 ssh2_pkt_send();
d211621f 2326 do {
7cca0d81 2327 crWaitUntilV(ispkt);
d211621f 2328 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2329 /* FIXME: be able to handle other channels here */
2330 if (ssh2_pkt_getuint32() != mainchan->localid)
2331 continue; /* wrong channel */
2332 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2333 }
7cca0d81 2334 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2335 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2336 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2337 bombout(("Server got confused by shell/command request"));
2338 crReturnV;
7cca0d81 2339 }
8d5de777 2340 bombout(("Server refused to start a shell/command"));
2341 crReturnV;
7cca0d81 2342 } else {
8d5de777 2343 logevent("Started a shell/command");
7cca0d81 2344 }
2345
2346 /*
2347 * Transfer data!
2348 */
8ccc75b0 2349 ssh_send_ok = 1;
6f34e365 2350 begin_session();
7cca0d81 2351 while (1) {
d211621f 2352 static int try_send;
e5574168 2353 crReturnV;
d211621f 2354 try_send = FALSE;
7cca0d81 2355 if (ispkt) {
2356 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2357 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2358 char *data;
2359 int length;
d211621f 2360 /* FIXME: be able to handle other channels here */
2361 if (ssh2_pkt_getuint32() != mainchan->localid)
7cca0d81 2362 continue; /* wrong channel */
2363 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2364 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2365 continue; /* extended but not stderr */
2366 ssh2_pkt_getstring(&data, &length);
d211621f 2367 if (data) {
7cca0d81 2368 c_write(data, length);
d211621f 2369 /*
2370 * Enlarge the window again at the remote side,
2371 * just in case it ever runs down and they fail
2372 * to send us any more data.
2373 */
2374 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2375 ssh2_pkt_adduint32(mainchan->remoteid);
2376 ssh2_pkt_adduint32(length);
2377 ssh2_pkt_send();
2378 }
7cca0d81 2379 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2380 ssh_state = SSH_STATE_CLOSED;
d211621f 2381 logevent("Received disconnect message");
7cca0d81 2382 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2383 continue; /* exit status et al; ignore (FIXME?) */
d211621f 2384 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2385 continue; /* remote sends EOF; ignore */
2386 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
2387 /* FIXME: be able to handle other channels here */
2388 if (ssh2_pkt_getuint32() != mainchan->localid)
2389 continue; /* wrong channel */
2390 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2391 ssh2_pkt_adduint32(mainchan->remoteid);
2392 ssh2_pkt_send();
2393 /* FIXME: mark the channel as closed */
2394 if (1 /* FIXME: "all channels are closed" */) {
2395 logevent("All channels closed. Disconnecting");
2396 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2397 ssh2_pkt_send();
2398 }
2399 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2400 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
d211621f 2401 /* FIXME: be able to handle other channels here */
2402 if (ssh2_pkt_getuint32() != mainchan->localid)
2403 continue; /* wrong channel */
2404 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2405 try_send = TRUE;
7cca0d81 2406 } else {
8d5de777 2407 bombout(("Strange packet received: type %d", pktin.type));
2408 crReturnV;
7cca0d81 2409 }
2410 } else {
d211621f 2411 /*
2412 * We have spare data. Add it to the channel buffer.
2413 */
2414 if (mainchan->u.v2.outbufsize <
2415 mainchan->u.v2.outbuflen + inlen) {
2416 mainchan->u.v2.outbufsize =
2417 mainchan->u.v2.outbuflen + inlen + 1024;
2418 mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer,
2419 mainchan->u.v2.outbufsize);
2420 }
2421 memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen,
2422 in, inlen);
2423 mainchan->u.v2.outbuflen += inlen;
2424 try_send = TRUE;
7cca0d81 2425 }
d211621f 2426 if (try_send) {
2427 /*
2428 * Try to send data on the channel if we can. (FIXME:
2429 * on _all_ channels.)
2430 */
2431 while (mainchan->u.v2.remwindow > 0 &&
2432 mainchan->u.v2.outbuflen > 0) {
2433 unsigned len = mainchan->u.v2.remwindow;
2434 if (len > mainchan->u.v2.outbuflen)
2435 len = mainchan->u.v2.outbuflen;
2436 if (len > mainchan->u.v2.remmaxpkt)
2437 len = mainchan->u.v2.remmaxpkt;
2438 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2439 ssh2_pkt_adduint32(mainchan->remoteid);
2440 ssh2_pkt_addstring_start();
2441 ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len);
2442 ssh2_pkt_send();
2443 mainchan->u.v2.outbuflen -= len;
2444 memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len,
2445 mainchan->u.v2.outbuflen);
2446 mainchan->u.v2.remwindow -= len;
2447 }
2448 }
e5574168 2449 }
2450
2451 crFinishV;
2452}
2453
2454/*
7cca0d81 2455 * Handle the top-level SSH2 protocol.
2456 */
2457static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2458{
2459 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2460 return;
2461 do_ssh2_authconn(in, inlen, ispkt);
2462}
2463
2464/*
374330e2 2465 * Called to set up the connection. Will arrange for WM_NETEVENT
2466 * messages to be passed to the specified window, whose window
2467 * procedure should then call telnet_msg().
2468 *
2469 * Returns an error message, or NULL on success.
374330e2 2470 */
2471static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
fb09bf1c 2472 char *p;
8f203108 2473
2474#ifdef MSCRYPTOAPI
2475 if(crypto_startup() == 0)
2476 return "Microsoft high encryption pack not installed!";
2477#endif
374330e2 2478
fb09bf1c 2479 p = connect_to_host(host, port, realhost);
2480 if (p != NULL)
2481 return p;
374330e2 2482
2483 if (!do_ssh_init())
2484 return "Protocol initialisation error";
2485
4017be6d 2486 if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
374330e2 2487 switch (WSAGetLastError()) {
2488 case WSAENETDOWN: return "Network is down";
2489 default: return "WSAAsyncSelect(): unknown error";
2490 }
2491
2492 return NULL;
2493}
2494
2495/*
2496 * Process a WM_NETEVENT message. Will return 0 if the connection
2497 * has closed, or <0 for a socket error.
2498 */
2499static int ssh_msg (WPARAM wParam, LPARAM lParam) {
2500 int ret;
2501 char buf[256];
2502
8ce72d2c 2503 /*
2504 * Because reading less than the whole of the available pending
2505 * data can generate an FD_READ event, we need to allow for the
2506 * possibility that FD_READ may arrive with FD_CLOSE already in
2507 * the queue; so it's possible that we can get here even with s
2508 * invalid. If so, we return 1 and don't worry about it.
2509 */
2510 if (s == INVALID_SOCKET)
2511 return 1;
374330e2 2512
8d5de777 2513 if (WSAGETSELECTERROR(lParam) != 0) {
2514 closesocket(s);
2515 s = INVALID_SOCKET;
374330e2 2516 return -WSAGETSELECTERROR(lParam);
8d5de777 2517 }
374330e2 2518
2519 switch (WSAGETSELECTEVENT(lParam)) {
2520 case FD_READ:
8ce72d2c 2521 case FD_CLOSE:
374330e2 2522 ret = recv(s, buf, sizeof(buf), 0);
2523 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
2524 return 1;
8d5de777 2525 if (ret < 0) { /* any _other_ error */
2526 closesocket(s);
2527 s = INVALID_SOCKET;
374330e2 2528 return -10000-WSAGetLastError();
8d5de777 2529 }
374330e2 2530 if (ret == 0) {
2531 s = INVALID_SOCKET;
8ce72d2c 2532 return 0;
374330e2 2533 }
2534 ssh_gotdata (buf, ret);
85ee8208 2535 if (ssh_state == SSH_STATE_CLOSED) {
2536 closesocket(s);
2537 s = INVALID_SOCKET;
2538 return 0;
2539 }
374330e2 2540 return 1;
374330e2 2541 }
2542 return 1; /* shouldn't happen, but WTF */
2543}
2544
2545/*
2546 * Called to send data down the Telnet connection.
2547 */
2548static void ssh_send (char *buf, int len) {
2549 if (s == INVALID_SOCKET)
2550 return;
2551
2552 ssh_protocol(buf, len, 0);
2553}
2554
2555/*
2556 * Called to set the size of the window from Telnet's POV.
2557 */
2558static void ssh_size(void) {
2559 switch (ssh_state) {
2560 case SSH_STATE_BEFORE_SIZE:
21248260 2561 case SSH_STATE_CLOSED:
374330e2 2562 break; /* do nothing */
2563 case SSH_STATE_INTERMED:
2564 size_needed = TRUE; /* buffer for later */
2565 break;
2566 case SSH_STATE_SESSION:
fef97f43 2567 if (!cfg.nopty) {
e5574168 2568 send_packet(SSH1_CMSG_WINDOW_SIZE,
fb09bf1c 2569 PKT_INT, rows, PKT_INT, cols,
2570 PKT_INT, 0, PKT_INT, 0, PKT_END);
fef97f43 2571 }
374330e2 2572 }
2573}
2574
2575/*
6abbf9e3 2576 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2577 * can send an EOF and collect resulting output (e.g. `plink
2578 * hostname sort').
374330e2 2579 */
2580static void ssh_special (Telnet_Special code) {
6abbf9e3 2581 if (code == TS_EOF) {
67779be7 2582 if (ssh_version == 1) {
6abbf9e3 2583 send_packet(SSH1_CMSG_EOF, PKT_END);
2584 } else {
2585 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 2586 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 2587 ssh2_pkt_send();
2588 }
67779be7 2589 logevent("Sent EOF message");
6abbf9e3 2590 } else {
2591 /* do nothing */
2592 }
374330e2 2593}
2594
fb09bf1c 2595
2596/*
2597 * Read and decrypt one incoming SSH packet.
2598 * (only used by pSCP)
2599 */
2600static void get_packet(void)
2601{
2602 unsigned char buf[4096], *p;
2603 long to_read;
2604 int len;
2605
fb09bf1c 2606 p = NULL;
2607 len = 0;
2608
2609 while ((to_read = s_rdpkt(&p, &len)) > 0) {
2610 if (to_read > sizeof(buf)) to_read = sizeof(buf);
2611 len = s_read(buf, to_read);
2612 if (len != to_read) {
2613 closesocket(s);
2614 s = INVALID_SOCKET;
2615 return;
2616 }
2617 p = buf;
2618 }
2619
2620 assert(len == 0);
2621}
2622
2623/*
2624 * Receive a block of data over the SSH link. Block until
2625 * all data is available. Return nr of bytes read (0 if lost connection).
2626 * (only used by pSCP)
2627 */
2628int ssh_scp_recv(unsigned char *buf, int len)
2629{
2630 static int pending_input_len = 0;
2631 static unsigned char *pending_input_ptr;
2632 int to_read = len;
2633
fb09bf1c 2634 if (pending_input_len >= to_read) {
2635 memcpy(buf, pending_input_ptr, to_read);
2636 pending_input_ptr += to_read;
2637 pending_input_len -= to_read;
2638 return len;
2639 }
2640
2641 if (pending_input_len > 0) {
2642 memcpy(buf, pending_input_ptr, pending_input_len);
2643 buf += pending_input_len;
2644 to_read -= pending_input_len;
2645 pending_input_len = 0;
2646 }
2647
2648 if (s == INVALID_SOCKET)
2649 return 0;
2650 while (to_read > 0) {
2651 get_packet();
2652 if (s == INVALID_SOCKET)
2653 return 0;
e5574168 2654 if (pktin.type == SSH1_SMSG_STDOUT_DATA) {
fb09bf1c 2655 int plen = GET_32BIT(pktin.body);
2656 if (plen <= to_read) {
2657 memcpy(buf, pktin.body + 4, plen);
2658 buf += plen;
2659 to_read -= plen;
2660 } else {
2661 memcpy(buf, pktin.body + 4, to_read);
2662 pending_input_len = plen - to_read;
2663 pending_input_ptr = pktin.body + 4 + to_read;
2664 to_read = 0;
2665 }
e5574168 2666 } else if (pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 2667 int plen = GET_32BIT(pktin.body);
2668 fwrite(pktin.body + 4, plen, 1, stderr);
e5574168 2669 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 2670 logevent("Received disconnect request");
e5574168 2671 } else if (pktin.type == SSH1_SMSG_SUCCESS ||
2672 pktin.type == SSH1_SMSG_FAILURE) {
fb09bf1c 2673 /* ignore */
e5574168 2674 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
fb09bf1c 2675 char logbuf[100];
2676 sprintf(logbuf, "Remote exit status: %d", GET_32BIT(pktin.body));
2677 logevent(logbuf);
e5574168 2678 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
fb09bf1c 2679 logevent("Closing connection");
2680 closesocket(s);
2681 s = INVALID_SOCKET;
2682 } else {
8d5de777 2683 bombout(("Strange packet received: type %d", pktin.type));
2684 return 0;
fb09bf1c 2685 }
2686 }
2687
2688 return len;
2689}
2690
2691/*
2692 * Send a block of data over the SSH link.
2693 * Block until all data is sent.
2694 * (only used by pSCP)
2695 */
2696void ssh_scp_send(unsigned char *buf, int len)
2697{
fb09bf1c 2698 if (s == INVALID_SOCKET)
2699 return;
e5574168 2700 send_packet(SSH1_CMSG_STDIN_DATA,
fb09bf1c 2701 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2702}
2703
2704/*
2705 * Send an EOF notification to the server.
2706 * (only used by pSCP)
2707 */
2708void ssh_scp_send_eof(void)
2709{
fb09bf1c 2710 if (s == INVALID_SOCKET)
2711 return;
e5574168 2712 send_packet(SSH1_CMSG_EOF, PKT_END);
fb09bf1c 2713}
2714
2715/*
2716 * Set up the connection, login on the remote host and
2717 * start execution of a command.
2718 * Returns an error message, or NULL on success.
2719 * (only used by pSCP)
2720 */
2721char *ssh_scp_init(char *host, int port, char *cmd, char **realhost)
2722{
2723 char buf[160], *p;
2724
fb09bf1c 2725#ifdef MSCRYPTOAPI
2726 if (crypto_startup() == 0)
2727 return "Microsoft high encryption pack not installed!";
2728#endif
2729
2730 p = connect_to_host(host, port, realhost);
2731 if (p != NULL)
2732 return p;
2733
2734 random_init();
2735
2736 if (!do_ssh_init())
2737 return "Protocol initialisation error";
2738
2739 /* Exchange keys and login */
2740 do {
2741 get_packet();
2742 if (s == INVALID_SOCKET)
2743 return "Connection closed by remote host";
e5574168 2744 } while (!do_ssh1_login(NULL, 0, 1));
85ee8208 2745
2746 if (ssh_state == SSH_STATE_CLOSED) {
2747 closesocket(s);
2748 s = INVALID_SOCKET;
2749 return "Session initialisation error";
2750 }
fb09bf1c 2751
2752 /* Execute command */
2753 sprintf(buf, "Sending command: %.100s", cmd);
2754 logevent(buf);
e5574168 2755 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fb09bf1c 2756
2757 return NULL;
2758}
2759
8ccc75b0 2760static SOCKET ssh_socket(void) { return s; }
2761
2762static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 2763
374330e2 2764Backend ssh_backend = {
2765 ssh_init,
2766 ssh_msg,
2767 ssh_send,
2768 ssh_size,
4017be6d 2769 ssh_special,
8ccc75b0 2770 ssh_socket,
2771 ssh_sendok
374330e2 2772};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator