projects / u / mdw / putty / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
Oops - free the key after removing it!
[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 /*
1103 * Hash the host key and print the hash in the log box. Just as
1104 * a last resort in case the registry's host key checking is
1105 * compromised, we'll allow the user some ability to verify
1106 * host keys by eye.
1107 */
1108 MD5Init(&md5c);
1109 MD5Update(&md5c, keystr2, hostkey.bytes);
1110 MD5Final(session_id, &md5c);
1111 {
1112 char logmsg[80];
1113 int i;
1114 logevent("Host key MD5 is:");
1115 strcpy(logmsg, " ");
1116 for (i = 0; i < 16; i++)
1117 sprintf(logmsg+strlen(logmsg), "%02x", session_id[i]);
1118 logevent(logmsg);
1119 }
1120
fb09bf1c 1121 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1122 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1123
c5e9c988 1124 MD5Init(&md5c);
374330e2 1125 MD5Update(&md5c, keystr2, hostkey.bytes);
1126 MD5Update(&md5c, keystr1, servkey.bytes);
1127 MD5Update(&md5c, pktin.body, 8);
374330e2 1128 MD5Final(session_id, &md5c);
1129
1130 for (i=0; i<32; i++)
1131 session_key[i] = random_byte();
1132
1133 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1134
1135 rsabuf = malloc(len);
1136 if (!rsabuf)
1137 fatalbox("Out of memory");
1138
89ee5268 1139 /*
1140 * Verify the host key.
1141 */
1142 {
1143 /*
1144 * First format the key into a string.
1145 */
1146 int len = rsastr_len(&hostkey);
1147 char *keystr = malloc(len);
1148 if (!keystr)
1149 fatalbox("Out of memory");
1150 rsastr_fmt(keystr, &hostkey);
1151 verify_ssh_host_key(savedhost, keystr);
1152 free(keystr);
1153 }
374330e2 1154
1155 for (i=0; i<32; i++) {
1156 rsabuf[i] = session_key[i];
1157 if (i < 16)
1158 rsabuf[i] ^= session_id[i];
1159 }
1160
1161 if (hostkey.bytes > servkey.bytes) {
1162 rsaencrypt(rsabuf, 32, &servkey);
1163 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1164 } else {
1165 rsaencrypt(rsabuf, 32, &hostkey);
1166 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1167 }
1168
c5e9c988 1169 logevent("Encrypted session key");
1170
bea1ef5f 1171 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1172 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1173 SSH_CIPHER_3DES;
1174 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1175 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1176 cipher_type = SSH_CIPHER_3DES;
1177 }
c5e9c988 1178 switch (cipher_type) {
1179 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1180 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1181 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1182 }
bea1ef5f 1183
e5574168 1184 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1185 PKT_CHAR, cipher_type,
1186 PKT_DATA, cookie, 8,
1187 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1188 PKT_DATA, rsabuf, len,
1189 PKT_INT, 0,
1190 PKT_END);
1191
c5e9c988 1192 logevent("Trying to enable encryption...");
374330e2 1193
1194 free(rsabuf);
1195
5e8358ad 1196 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1197 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1198 &ssh_3des;
374330e2 1199 cipher->sesskey(session_key);
1200
fb09bf1c 1201 crWaitUntil(ispkt);
374330e2 1202
8d5de777 1203 if (pktin.type != SSH1_SMSG_SUCCESS) {
1204 bombout(("Encryption not successfully enabled"));
1205 crReturn(0);
1206 }
374330e2 1207
c5e9c988 1208 logevent("Successfully started encryption");
1209
374330e2 1210 fflush(stdout);
1211 {
1212 static char username[100];
1213 static int pos = 0;
1214 static char c;
67779be7 1215 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1216 c_write("login as: ", 10);
67779be7 1217 ssh_send_ok = 1;
374330e2 1218 while (pos >= 0) {
fb09bf1c 1219 crWaitUntil(!ispkt);
374330e2 1220 while (inlen--) switch (c = *in++) {
1221 case 10: case 13:
1222 username[pos] = 0;
1223 pos = -1;
1224 break;
1225 case 8: case 127:
1226 if (pos > 0) {
1227 c_write("\b \b", 3);
1228 pos--;
1229 }
1230 break;
1231 case 21: case 27:
1232 while (pos > 0) {
1233 c_write("\b \b", 3);
1234 pos--;
1235 }
1236 break;
1237 case 3: case 4:
1238 random_save_seed();
1239 exit(0);
1240 break;
1241 default:
40d24aa6 1242 if (((c >= ' ' && c <= '~') ||
1243 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1244 username[pos++] = c;
1245 c_write(&c, 1);
1246 }
1247 break;
1248 }
1249 }
1250 c_write("\r\n", 2);
1251 username[strcspn(username, "\n\r")] = '\0';
1252 } else {
1253 char stuff[200];
1254 strncpy(username, cfg.username, 99);
1255 username[99] = '\0';
67779be7 1256 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
fb09bf1c 1257 sprintf(stuff, "Sent username \"%s\".\r\n", username);
4017be6d 1258 c_write(stuff, strlen(stuff));
fb09bf1c 1259 }
374330e2 1260 }
fb09bf1c 1261
e5574168 1262 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1263 {
1264 char userlog[20+sizeof(username)];
1265 sprintf(userlog, "Sent username \"%s\"", username);
1266 logevent(userlog);
1267 }
374330e2 1268 }
1269
fb09bf1c 1270 crWaitUntil(ispkt);
374330e2 1271
7cca0d81 1272 tried_publickey = 0;
1273
e5574168 1274 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1275 static char password[100];
a52f067e 1276 static char prompt[200];
374330e2 1277 static int pos;
1278 static char c;
ccbfb941 1279 static int pwpkt_type;
ccbfb941 1280 /*
1281 * Show password prompt, having first obtained it via a TIS
18515c51 1282 * or CryptoCard exchange if we're doing TIS or CryptoCard
1283 * authentication.
ccbfb941 1284 */
e5574168 1285 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1286 if (agent_exists()) {
1287 /*
1288 * Attempt RSA authentication using Pageant.
1289 */
1290 static unsigned char request[5], *response, *p;
1291 static int responselen;
1292 static int i, nkeys;
1293 static int authed = FALSE;
1294 void *r;
1295
1296 logevent("Pageant is running. Requesting keys.");
1297
1298 /* Request the keys held by the agent. */
1299 PUT_32BIT(request, 1);
1300 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1301 agent_query(request, 5, &r, &responselen);
1302 response = (unsigned char *)r;
1303 if (response) {
1304 p = response + 5;
1305 nkeys = GET_32BIT(p); p += 4;
1306 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1307 logevent(buf); }
1308 for (i = 0; i < nkeys; i++) {
1309 static struct RSAKey key;
1310 static Bignum challenge;
b8bb811a 1311 static char *commentp;
1312 static int commentlen;
5c58ad2d 1313
1314 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1315 logevent(buf); }
1316 p += 4;
1317 p += ssh1_read_bignum(p, &key.exponent);
1318 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1319 commentlen = GET_32BIT(p); p += 4;
1320 commentp = p; p += commentlen;
5c58ad2d 1321 send_packet(SSH1_CMSG_AUTH_RSA,
1322 PKT_BIGNUM, key.modulus, PKT_END);
1323 crWaitUntil(ispkt);
1324 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1325 logevent("Key refused");
1326 continue;
1327 }
1328 logevent("Received RSA challenge");
1329 ssh1_read_bignum(pktin.body, &challenge);
1330 {
1331 char *agentreq, *q, *ret;
1332 int len, retlen;
1333 len = 1 + 4; /* message type, bit count */
1334 len += ssh1_bignum_length(key.exponent);
1335 len += ssh1_bignum_length(key.modulus);
1336 len += ssh1_bignum_length(challenge);
1337 len += 16; /* session id */
1338 len += 4; /* response format */
1339 agentreq = malloc(4 + len);
1340 PUT_32BIT(agentreq, len);
1341 q = agentreq + 4;
1342 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1343 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1344 q += 4;
1345 q += ssh1_write_bignum(q, key.exponent);
1346 q += ssh1_write_bignum(q, key.modulus);
1347 q += ssh1_write_bignum(q, challenge);
1348 memcpy(q, session_id, 16); q += 16;
1349 PUT_32BIT(q, 1); /* response format */
1350 agent_query(agentreq, len+4, &ret, &retlen);
1351 free(agentreq);
1352 if (ret) {
1353 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1354 logevent("Sending Pageant's response");
1355 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1356 PKT_DATA, ret+5, 16, PKT_END);
1357 free(ret);
1358 crWaitUntil(ispkt);
1359 if (pktin.type == SSH1_SMSG_SUCCESS) {
1360 logevent("Pageant's response accepted");
c4fa2fce 1361 if (flags & FLAG_VERBOSE) {
1362 c_write("Authenticated using RSA key \"",
1363 29);
1364 c_write(commentp, commentlen);
1365 c_write("\" from agent\r\n", 14);
1366 }
5c58ad2d 1367 authed = TRUE;
1368 } else
1369 logevent("Pageant's response not accepted");
1370 } else {
1371 logevent("Pageant failed to answer challenge");
1372 free(ret);
1373 }
1374 } else {
1375 logevent("No reply received from Pageant");
1376 }
1377 }
1378 freebn(key.exponent);
1379 freebn(key.modulus);
1380 freebn(challenge);
1381 if (authed)
1382 break;
1383 }
1384 }
1385 if (authed)
1386 break;
1387 }
7cca0d81 1388 if (*cfg.keyfile && !tried_publickey)
1389 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1390
a52f067e 1391 if (pktin.type == SSH1_SMSG_FAILURE &&
1392 cfg.try_tis_auth &&
1393 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1394 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1395 logevent("Requested TIS authentication");
1396 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1397 crWaitUntil(ispkt);
1398 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1399 logevent("TIS authentication declined");
1400 if (flags & FLAG_INTERACTIVE)
1401 c_write("TIS authentication refused.\r\n", 29);
1402 } else {
1403 int challengelen = ((pktin.body[0] << 24) |
1404 (pktin.body[1] << 16) |
1405 (pktin.body[2] << 8) |
1406 (pktin.body[3]));
1407 logevent("Received TIS challenge");
1408 if (challengelen > sizeof(prompt)-1)
1409 challengelen = sizeof(prompt)-1; /* prevent overrun */
1410 memcpy(prompt, pktin.body+4, challengelen);
1411 prompt[challengelen] = '\0';
1412 }
1413 }
1414 if (pktin.type == SSH1_SMSG_FAILURE &&
1415 cfg.try_tis_auth &&
1416 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1417 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1418 logevent("Requested CryptoCard authentication");
1419 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1420 crWaitUntil(ispkt);
1421 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1422 logevent("CryptoCard authentication declined");
1423 c_write("CryptoCard authentication refused.\r\n", 29);
1424 } else {
1425 int challengelen = ((pktin.body[0] << 24) |
1426 (pktin.body[1] << 16) |
1427 (pktin.body[2] << 8) |
1428 (pktin.body[3]));
1429 logevent("Received CryptoCard challenge");
1430 if (challengelen > sizeof(prompt)-1)
1431 challengelen = sizeof(prompt)-1; /* prevent overrun */
1432 memcpy(prompt, pktin.body+4, challengelen);
1433 strncpy(prompt + challengelen, "\r\nResponse : ",
1434 sizeof(prompt)-challengelen);
1435 prompt[sizeof(prompt)-1] = '\0';
1436 }
1437 }
1438 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1439 sprintf(prompt, "%.90s@%.90s's password: ",
1440 cfg.username, savedhost);
1441 }
1442 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1443 char *comment = NULL;
1444 if (flags & FLAG_VERBOSE)
1445 c_write("Trying public key authentication.\r\n", 35);
1446 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1447 if (flags & FLAG_VERBOSE)
1448 c_write("No passphrase required.\r\n", 25);
1449 goto tryauth;
1450 }
1451 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1452 free(comment);
1453 }
1454
1455 if (!(flags & FLAG_INTERACTIVE)) {
85ee8208 1456 if (!ssh_get_password(prompt, password, sizeof(password))) {
1457 /*
1458 * get_password failed to get a password (for
1459 * example because one was supplied on the command
1460 * line which has already failed to work).
1461 * Terminate.
1462 */
1463 logevent("No more passwords to try");
1464 ssh_state = SSH_STATE_CLOSED;
1465 crReturn(1);
1466 }
fb09bf1c 1467 } else {
a52f067e 1468 c_write(prompt, strlen(prompt));
7cca0d81 1469 pos = 0;
67779be7 1470 ssh_send_ok = 1;
7cca0d81 1471 while (pos >= 0) {
1472 crWaitUntil(!ispkt);
1473 while (inlen--) switch (c = *in++) {
1474 case 10: case 13:
1475 password[pos] = 0;
1476 pos = -1;
1477 break;
1478 case 8: case 127:
1479 if (pos > 0)
1480 pos--;
1481 break;
1482 case 21: case 27:
1483 pos = 0;
1484 break;
1485 case 3: case 4:
1486 random_save_seed();
1487 exit(0);
1488 break;
1489 default:
1490 if (((c >= ' ' && c <= '~') ||
1491 ((unsigned char)c >= 160)) && pos < sizeof(password))
1492 password[pos++] = c;
1493 break;
1494 }
1495 }
1496 c_write("\r\n", 2);
a52f067e 1497 }
fb09bf1c 1498
7cca0d81 1499 tryauth:
1500 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1501 /*
1502 * Try public key authentication with the specified
1503 * key file.
1504 */
1505 static struct RSAKey pubkey;
1506 static Bignum challenge, response;
1507 static int i;
1508 static unsigned char buffer[32];
1509
1510 tried_publickey = 1;
1511 i = loadrsakey(cfg.keyfile, &pubkey, password);
1512 if (i == 0) {
1513 c_write("Couldn't load public key from ", 30);
1514 c_write(cfg.keyfile, strlen(cfg.keyfile));
1515 c_write(".\r\n", 3);
1516 continue; /* go and try password */
1517 }
1518 if (i == -1) {
1519 c_write("Wrong passphrase.\r\n", 19);
1520 tried_publickey = 0;
1521 continue; /* try again */
1522 }
1523
1524 /*
1525 * Send a public key attempt.
1526 */
1527 send_packet(SSH1_CMSG_AUTH_RSA,
1528 PKT_BIGNUM, pubkey.modulus, PKT_END);
1529
1530 crWaitUntil(ispkt);
1531 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1532 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1533 continue; /* go and try password */
1534 }
8d5de777 1535 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1536 bombout(("Bizarre response to offer of public key"));
1537 crReturn(0);
1538 }
7cca0d81 1539 ssh1_read_bignum(pktin.body, &challenge);
1540 response = rsadecrypt(challenge, &pubkey);
1541 freebn(pubkey.private_exponent); /* burn the evidence */
1542
1543 for (i = 0; i < 32; i += 2) {
1544 buffer[i] = response[16-i/2] >> 8;
1545 buffer[i+1] = response[16-i/2] & 0xFF;
1546 }
1547
1548 MD5Init(&md5c);
1549 MD5Update(&md5c, buffer, 32);
1550 MD5Update(&md5c, session_id, 16);
1551 MD5Final(buffer, &md5c);
1552
1553 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1554 PKT_DATA, buffer, 16, PKT_END);
1555
1556 crWaitUntil(ispkt);
1557 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1558 if (flags & FLAG_VERBOSE)
1559 c_write("Failed to authenticate with our public key.\r\n",
1560 45);
7cca0d81 1561 continue; /* go and try password */
1562 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1563 bombout(("Bizarre response to RSA authentication response"));
1564 crReturn(0);
7cca0d81 1565 }
1566
1567 break; /* we're through! */
1568 } else {
1569 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1570 }
c5e9c988 1571 logevent("Sent password");
374330e2 1572 memset(password, 0, strlen(password));
fb09bf1c 1573 crWaitUntil(ispkt);
e5574168 1574 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1575 if (flags & FLAG_VERBOSE)
1576 c_write("Access denied\r\n", 15);
c5e9c988 1577 logevent("Authentication refused");
e5574168 1578 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1579 logevent("Received disconnect request");
85ee8208 1580 ssh_state = SSH_STATE_CLOSED;
1581 crReturn(1);
e5574168 1582 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1583 bombout(("Strange packet received, type %d", pktin.type));
1584 crReturn(0);
374330e2 1585 }
1586 }
1587
c5e9c988 1588 logevent("Authentication successful");
1589
fb09bf1c 1590 crFinish(1);
1591}
1592
e5574168 1593static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1594 crBegin;
1595
1596 random_init();
1597
e5574168 1598 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1599 crReturnV;
85ee8208 1600 }
1601 if (ssh_state == SSH_STATE_CLOSED)
1602 crReturnV;
fb09bf1c 1603
979310f1 1604 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1605 logevent("Requesting agent forwarding");
1606 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1607 do { crReturnV; } while (!ispkt);
1608 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1609 bombout(("Protocol confusion"));
1610 crReturnV;
dacbd0e8 1611 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1612 logevent("Agent forwarding refused");
1613 } else
1614 logevent("Agent forwarding enabled");
1615 }
1616
fef97f43 1617 if (!cfg.nopty) {
e5574168 1618 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1619 PKT_STR, cfg.termtype,
1620 PKT_INT, rows, PKT_INT, cols,
1621 PKT_INT, 0, PKT_INT, 0,
1622 PKT_CHAR, 0,
1623 PKT_END);
fef97f43 1624 ssh_state = SSH_STATE_INTERMED;
1625 do { crReturnV; } while (!ispkt);
e5574168 1626 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1627 bombout(("Protocol confusion"));
1628 crReturnV;
e5574168 1629 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1630 c_write("Server refused to allocate pty\r\n", 32);
1631 }
c5e9c988 1632 logevent("Allocated pty");
374330e2 1633 }
1634
6abbf9e3 1635 if (*cfg.remote_cmd)
1636 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1637 else
1638 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1639 logevent("Started session");
374330e2 1640
1641 ssh_state = SSH_STATE_SESSION;
1642 if (size_needed)
1643 ssh_size();
1644
8ccc75b0 1645 ssh_send_ok = 1;
dacbd0e8 1646 ssh_channels = newtree234(ssh_channelcmp);
6f34e365 1647 begin_session();
374330e2 1648 while (1) {
1649 crReturnV;
1650 if (ispkt) {
e5574168 1651 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1652 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1653 long len = GET_32BIT(pktin.body);
1654 c_write(pktin.body+4, len);
e5574168 1655 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1656 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1657 logevent("Received disconnect request");
dacbd0e8 1658 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1659 /* Remote side is trying to open a channel to talk to our
1660 * agent. Give them back a local channel number. */
d211621f 1661 unsigned i = 1;
dacbd0e8 1662 struct ssh_channel *c;
1663 enum234 e;
1664 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1665 if (c->localid > i)
1666 break; /* found a free number */
1667 i = c->localid + 1;
1668 }
1669 c = malloc(sizeof(struct ssh_channel));
1670 c->remoteid = GET_32BIT(pktin.body);
1671 c->localid = i;
b8bb811a 1672 c->closes = 0;
dacbd0e8 1673 c->type = SSH1_SMSG_AGENT_OPEN; /* identify channel type */
bb487ce2 1674 c->u.a.lensofar = 0;
dacbd0e8 1675 add234(ssh_channels, c);
1676 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1677 PKT_INT, c->remoteid, PKT_INT, c->localid,
1678 PKT_END);
1679 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1680 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1681 /* Remote side closes a channel. */
d211621f 1682 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1683 struct ssh_channel *c;
1684 c = find234(ssh_channels, &i, ssh_channelfind);
1685 if (c) {
1686 int closetype;
1687 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1688 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1689 c->closes |= closetype;
1690 if (c->closes == 3) {
1691 del234(ssh_channels, c);
1692 free(c);
1693 }
1694 }
1695 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1696 /* Data sent down one of our channels. */
1697 int i = GET_32BIT(pktin.body);
1698 int len = GET_32BIT(pktin.body+4);
1699 unsigned char *p = pktin.body+8;
1700 struct ssh_channel *c;
1701 c = find234(ssh_channels, &i, ssh_channelfind);
1702 if (c) {
1703 switch(c->type) {
1704 case SSH1_SMSG_AGENT_OPEN:
1705 /* Data for an agent message. Buffer it. */
1706 while (len > 0) {
1707 if (c->u.a.lensofar < 4) {
1708 int l = min(4 - c->u.a.lensofar, len);
1709 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
1710 p += l; len -= l; c->u.a.lensofar += l;
1711 }
1712 if (c->u.a.lensofar == 4) {
1713 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
1714 c->u.a.message = malloc(c->u.a.totallen);
1715 memcpy(c->u.a.message, c->u.a.msglen, 4);
1716 }
1717 if (c->u.a.lensofar >= 4 && len > 0) {
1718 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
1719 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
1720 p += l; len -= l; c->u.a.lensofar += l;
1721 }
1722 if (c->u.a.lensofar == c->u.a.totallen) {
1723 void *reply, *sentreply;
1724 int replylen;
1725 agent_query(c->u.a.message, c->u.a.totallen,
1726 &reply, &replylen);
1727 if (reply)
1728 sentreply = reply;
1729 else {
1730 /* Fake SSH_AGENT_FAILURE. */
1731 sentreply = "\0\0\0\1\5";
1732 replylen = 5;
1733 }
1734 send_packet(SSH1_MSG_CHANNEL_DATA,
1735 PKT_INT, c->remoteid,
1736 PKT_INT, replylen,
1737 PKT_DATA, sentreply, replylen,
1738 PKT_END);
1739 if (reply)
1740 free(reply);
1741 free(c->u.a.message);
1742 c->u.a.lensofar = 0;
1743 }
1744 }
1745 break;
1746 }
1747 }
e5574168 1748 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 1749 /* may be from EXEC_SHELL on some servers */
e5574168 1750 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 1751 /* may be from EXEC_SHELL on some servers
374330e2 1752 * if no pty is available or in other odd cases. Ignore */
e5574168 1753 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1754 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 1755 } else {
8d5de777 1756 bombout(("Strange packet received: type %d", pktin.type));
1757 crReturnV;
374330e2 1758 }
1759 } else {
e5574168 1760 send_packet(SSH1_CMSG_STDIN_DATA,
fb09bf1c 1761 PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
374330e2 1762 }
1763 }
1764
1765 crFinishV;
1766}
1767
1768/*
e5574168 1769 * Utility routine for decoding comma-separated strings in KEXINIT.
1770 */
1771int in_commasep_string(char *needle, char *haystack, int haylen) {
1772 int needlen = strlen(needle);
1773 while (1) {
1774 /*
1775 * Is it at the start of the string?
1776 */
1777 if (haylen >= needlen && /* haystack is long enough */
1778 !memcmp(needle, haystack, needlen) && /* initial match */
1779 (haylen == needlen || haystack[needlen] == ',')
1780 /* either , or EOS follows */
1781 )
1782 return 1;
1783 /*
1784 * If not, search for the next comma and resume after that.
1785 * If no comma found, terminate.
1786 */
1787 while (haylen > 0 && *haystack != ',')
1788 haylen--, haystack++;
1789 if (haylen == 0)
1790 return 0;
1791 haylen--, haystack++; /* skip over comma itself */
1792 }
1793}
1794
1795/*
d39f364a 1796 * SSH2 key creation method.
1797 */
1798void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
1799 SHA_State s;
1800 /* First 20 bytes. */
1801 SHA_Init(&s);
1802 sha_mpint(&s, K);
1803 SHA_Bytes(&s, H, 20);
1804 SHA_Bytes(&s, &chr, 1);
1805 SHA_Bytes(&s, H, 20);
1806 SHA_Final(&s, keyspace);
1807 /* Next 20 bytes. */
1808 SHA_Init(&s);
1809 sha_mpint(&s, K);
1810 SHA_Bytes(&s, H, 20);
1811 SHA_Bytes(&s, keyspace, 20);
1812 SHA_Final(&s, keyspace+20);
1813}
1814
1815/*
7cca0d81 1816 * Handle the SSH2 transport layer.
e5574168 1817 */
7cca0d81 1818static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 1819{
1820 static int i, len;
1821 static char *str;
1822 static Bignum e, f, K;
1823 static struct ssh_cipher *cscipher_tobe = NULL;
1824 static struct ssh_cipher *sccipher_tobe = NULL;
1825 static struct ssh_mac *csmac_tobe = NULL;
1826 static struct ssh_mac *scmac_tobe = NULL;
1827 static struct ssh_compress *cscomp_tobe = NULL;
1828 static struct ssh_compress *sccomp_tobe = NULL;
7cca0d81 1829 static char *hostkeydata, *sigdata, *keystr;
e5574168 1830 static int hostkeylen, siglen;
1831 static unsigned char exchange_hash[20];
d39f364a 1832 static unsigned char keyspace[40];
e5574168 1833
1834 crBegin;
7cca0d81 1835 random_init();
e5574168 1836
5e8358ad 1837 /*
1838 * Set up the preferred cipher.
1839 */
1840 if (cfg.cipher == CIPHER_BLOWFISH) {
1841 ciphers[0] = &ssh_blowfish_ssh2;
1842 } else if (cfg.cipher == CIPHER_DES) {
1843 logevent("Single DES not supported in SSH2; using 3DES");
1844 ciphers[0] = &ssh_3des_ssh2;
1845 } else if (cfg.cipher == CIPHER_3DES) {
1846 ciphers[0] = &ssh_3des_ssh2;
1847 } else {
1848 /* Shouldn't happen, but we do want to initialise to _something_. */
1849 ciphers[0] = &ssh_3des_ssh2;
1850 }
1851
7cca0d81 1852 begin_key_exchange:
e5574168 1853 /*
1854 * Construct and send our key exchange packet.
1855 */
1856 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1857 for (i = 0; i < 16; i++)
1858 ssh2_pkt_addbyte((unsigned char)random_byte());
1859 /* List key exchange algorithms. */
1860 ssh2_pkt_addstring_start();
1861 for (i = 0; i < lenof(kex_algs); i++) {
1862 ssh2_pkt_addstring_str(kex_algs[i]->name);
1863 if (i < lenof(kex_algs)-1)
1864 ssh2_pkt_addstring_str(",");
1865 }
1866 /* List server host key algorithms. */
1867 ssh2_pkt_addstring_start();
1868 for (i = 0; i < lenof(hostkey_algs); i++) {
1869 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1870 if (i < lenof(hostkey_algs)-1)
1871 ssh2_pkt_addstring_str(",");
1872 }
1873 /* List client->server encryption algorithms. */
1874 ssh2_pkt_addstring_start();
1875 for (i = 0; i < lenof(ciphers); i++) {
1876 ssh2_pkt_addstring_str(ciphers[i]->name);
1877 if (i < lenof(ciphers)-1)
1878 ssh2_pkt_addstring_str(",");
1879 }
1880 /* List server->client encryption algorithms. */
1881 ssh2_pkt_addstring_start();
1882 for (i = 0; i < lenof(ciphers); i++) {
1883 ssh2_pkt_addstring_str(ciphers[i]->name);
1884 if (i < lenof(ciphers)-1)
1885 ssh2_pkt_addstring_str(",");
1886 }
1887 /* List client->server MAC algorithms. */
1888 ssh2_pkt_addstring_start();
1889 for (i = 0; i < lenof(macs); i++) {
1890 ssh2_pkt_addstring_str(macs[i]->name);
1891 if (i < lenof(macs)-1)
1892 ssh2_pkt_addstring_str(",");
1893 }
1894 /* List server->client MAC algorithms. */
1895 ssh2_pkt_addstring_start();
1896 for (i = 0; i < lenof(macs); i++) {
1897 ssh2_pkt_addstring_str(macs[i]->name);
1898 if (i < lenof(macs)-1)
1899 ssh2_pkt_addstring_str(",");
1900 }
1901 /* List client->server compression algorithms. */
1902 ssh2_pkt_addstring_start();
1903 for (i = 0; i < lenof(compressions); i++) {
1904 ssh2_pkt_addstring_str(compressions[i]->name);
1905 if (i < lenof(compressions)-1)
1906 ssh2_pkt_addstring_str(",");
1907 }
1908 /* List server->client compression algorithms. */
1909 ssh2_pkt_addstring_start();
1910 for (i = 0; i < lenof(compressions); i++) {
1911 ssh2_pkt_addstring_str(compressions[i]->name);
1912 if (i < lenof(compressions)-1)
1913 ssh2_pkt_addstring_str(",");
1914 }
1915 /* List client->server languages. Empty list. */
1916 ssh2_pkt_addstring_start();
1917 /* List server->client languages. Empty list. */
1918 ssh2_pkt_addstring_start();
1919 /* First KEX packet does _not_ follow, because we're not that brave. */
1920 ssh2_pkt_addbool(FALSE);
1921 /* Reserved. */
1922 ssh2_pkt_adduint32(0);
1923 sha_string(&exhash, pktout.data+5, pktout.length-5);
1924 ssh2_pkt_send();
1925
1926 if (!ispkt) crWaitUntil(ispkt);
1927 sha_string(&exhash, pktin.data+5, pktin.length-5);
1928
1929 /*
1930 * Now examine the other side's KEXINIT to see what we're up
1931 * to.
1932 */
7cca0d81 1933 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 1934 bombout(("expected key exchange packet from server"));
1935 crReturn(0);
7cca0d81 1936 }
e5574168 1937 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1938 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1939 pktin.savedpos += 16; /* skip garbage cookie */
1940 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1941 for (i = 0; i < lenof(kex_algs); i++) {
1942 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1943 kex = kex_algs[i];
1944 break;
1945 }
1946 }
1947 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1948 for (i = 0; i < lenof(hostkey_algs); i++) {
1949 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1950 hostkey = hostkey_algs[i];
1951 break;
1952 }
1953 }
1954 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
1955 for (i = 0; i < lenof(ciphers); i++) {
1956 if (in_commasep_string(ciphers[i]->name, str, len)) {
1957 cscipher_tobe = ciphers[i];
1958 break;
1959 }
1960 }
1961 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
1962 for (i = 0; i < lenof(ciphers); i++) {
1963 if (in_commasep_string(ciphers[i]->name, str, len)) {
1964 sccipher_tobe = ciphers[i];
1965 break;
1966 }
1967 }
1968 ssh2_pkt_getstring(&str, &len); /* client->server mac */
1969 for (i = 0; i < lenof(macs); i++) {
1970 if (in_commasep_string(macs[i]->name, str, len)) {
1971 csmac_tobe = macs[i];
1972 break;
1973 }
1974 }
1975 ssh2_pkt_getstring(&str, &len); /* server->client mac */
1976 for (i = 0; i < lenof(macs); i++) {
1977 if (in_commasep_string(macs[i]->name, str, len)) {
1978 scmac_tobe = macs[i];
1979 break;
1980 }
1981 }
1982 ssh2_pkt_getstring(&str, &len); /* client->server compression */
1983 for (i = 0; i < lenof(compressions); i++) {
1984 if (in_commasep_string(compressions[i]->name, str, len)) {
1985 cscomp_tobe = compressions[i];
1986 break;
1987 }
1988 }
1989 ssh2_pkt_getstring(&str, &len); /* server->client compression */
1990 for (i = 0; i < lenof(compressions); i++) {
1991 if (in_commasep_string(compressions[i]->name, str, len)) {
1992 sccomp_tobe = compressions[i];
1993 break;
1994 }
1995 }
e5574168 1996
1997 /*
1998 * Currently we only support Diffie-Hellman and DSS, so let's
1999 * bomb out if those aren't selected.
2000 */
8d5de777 2001 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2002 bombout(("internal fault: chaos in SSH 2 transport layer"));
2003 crReturn(0);
2004 }
e5574168 2005
2006 /*
2007 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2008 */
2009 e = dh_create_e();
e5574168 2010 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2011 ssh2_pkt_addmp(e);
2012 ssh2_pkt_send();
2013
2014 crWaitUntil(ispkt);
7cca0d81 2015 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2016 bombout(("expected key exchange packet from server"));
2017 crReturn(0);
7cca0d81 2018 }
e5574168 2019 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2020 f = ssh2_pkt_getmp();
e5574168 2021 ssh2_pkt_getstring(&sigdata, &siglen);
2022
2023 K = dh_find_K(f);
e5574168 2024
2025 sha_string(&exhash, hostkeydata, hostkeylen);
2026 sha_mpint(&exhash, e);
2027 sha_mpint(&exhash, f);
2028 sha_mpint(&exhash, K);
2029 SHA_Final(&exhash, exchange_hash);
2030
7cca0d81 2031#if 0
e5574168 2032 debug(("Exchange hash is:\r\n"));
2033 for (i = 0; i < 20; i++)
2034 debug((" %02x", exchange_hash[i]));
2035 debug(("\r\n"));
7cca0d81 2036#endif
2037
2038 hostkey->setkey(hostkeydata, hostkeylen);
8d5de777 2039 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20)) {
2040 bombout(("Server failed host key check"));
2041 crReturn(0);
2042 }
e5574168 2043
2044 /*
7cca0d81 2045 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2046 */
7cca0d81 2047 crWaitUntil(ispkt);
8d5de777 2048 if (pktin.type != SSH2_MSG_NEWKEYS) {
2049 bombout(("expected new-keys packet from server"));
2050 crReturn(0);
2051 }
d39f364a 2052
2053 /*
7cca0d81 2054 * Authenticate remote host: verify host key. (We've already
2055 * checked the signature of the exchange hash.)
e5574168 2056 */
7cca0d81 2057 keystr = hostkey->fmtkey();
2058 verify_ssh_host_key(savedhost, keystr);
2059 free(keystr);
d39f364a 2060
2061 /*
7cca0d81 2062 * Send SSH2_MSG_NEWKEYS.
d39f364a 2063 */
2064 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2065 ssh2_pkt_send();
d39f364a 2066
2067 /*
2068 * Create and initialise session keys.
2069 */
2070 cscipher = cscipher_tobe;
2071 sccipher = sccipher_tobe;
2072 csmac = csmac_tobe;
2073 scmac = scmac_tobe;
2074 cscomp = cscomp_tobe;
2075 sccomp = sccomp_tobe;
2076 /*
2077 * Set IVs after keys.
2078 */
2079 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
2080 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
2081 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2082 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2083 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2084 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2085
033b4cef 2086 /*
7cca0d81 2087 * Now we're encrypting. Begin returning 1 to the protocol main
2088 * function so that other things can run on top of the
2089 * transport. If we ever see a KEXINIT, we must go back to the
2090 * start.
033b4cef 2091 */
7cca0d81 2092 do {
2093 crReturn(1);
2094 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2095 goto begin_key_exchange;
e5574168 2096
2097 crFinish(1);
2098}
2099
7cca0d81 2100/*
2101 * Handle the SSH2 userauth and connection layers.
2102 */
2103static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2104{
7cca0d81 2105 static unsigned long remote_winsize;
2106 static unsigned long remote_maxpkt;
2107
e5574168 2108 crBegin;
2109
7cca0d81 2110 /*
2111 * Request userauth protocol, and await a response to it.
2112 */
2113 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2114 ssh2_pkt_addstring("ssh-userauth");
2115 ssh2_pkt_send();
2116 crWaitUntilV(ispkt);
8d5de777 2117 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2118 bombout(("Server refused user authentication protocol"));
2119 crReturnV;
2120 }
7cca0d81 2121
2122 /*
2123 * FIXME: currently we support only password authentication.
2124 * (This places us technically in violation of the SSH2 spec.
2125 * We must fix this.)
2126 */
2127 while (1) {
2128 /*
2129 * Get a username and a password.
2130 */
2131 static char username[100];
2132 static char password[100];
2133 static int pos = 0;
2134 static char c;
e5574168 2135
67779be7 2136 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2137 c_write("login as: ", 10);
67779be7 2138 ssh_send_ok = 1;
7cca0d81 2139 while (pos >= 0) {
2140 crWaitUntilV(!ispkt);
2141 while (inlen--) switch (c = *in++) {
2142 case 10: case 13:
2143 username[pos] = 0;
2144 pos = -1;
2145 break;
2146 case 8: case 127:
2147 if (pos > 0) {
2148 c_write("\b \b", 3);
2149 pos--;
2150 }
2151 break;
2152 case 21: case 27:
2153 while (pos > 0) {
2154 c_write("\b \b", 3);
2155 pos--;
2156 }
2157 break;
2158 case 3: case 4:
2159 random_save_seed();
2160 exit(0);
2161 break;
2162 default:
2163 if (((c >= ' ' && c <= '~') ||
2164 ((unsigned char)c >= 160)) && pos < 40) {
2165 username[pos++] = c;
2166 c_write(&c, 1);
2167 }
2168 break;
2169 }
2170 }
2171 c_write("\r\n", 2);
2172 username[strcspn(username, "\n\r")] = '\0';
2173 } else {
2174 char stuff[200];
2175 strncpy(username, cfg.username, 99);
2176 username[99] = '\0';
67779be7 2177 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2178 sprintf(stuff, "Using username \"%s\".\r\n", username);
2179 c_write(stuff, strlen(stuff));
2180 }
2181 }
2182
67779be7 2183 if (!(flags & FLAG_INTERACTIVE)) {
7cca0d81 2184 char prompt[200];
2185 sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
2186 if (!ssh_get_password(prompt, password, sizeof(password))) {
2187 /*
2188 * get_password failed to get a password (for
2189 * example because one was supplied on the command
2190 * line which has already failed to work).
2191 * Terminate.
2192 */
2193 logevent("No more passwords to try");
2194 ssh_state = SSH_STATE_CLOSED;
2195 crReturnV;
2196 }
2197 } else {
2198 c_write("password: ", 10);
67779be7 2199 ssh_send_ok = 1;
7cca0d81 2200
2201 pos = 0;
2202 while (pos >= 0) {
2203 crWaitUntilV(!ispkt);
2204 while (inlen--) switch (c = *in++) {
2205 case 10: case 13:
2206 password[pos] = 0;
2207 pos = -1;
2208 break;
2209 case 8: case 127:
2210 if (pos > 0)
2211 pos--;
2212 break;
2213 case 21: case 27:
2214 pos = 0;
2215 break;
2216 case 3: case 4:
2217 random_save_seed();
2218 exit(0);
2219 break;
2220 default:
2221 if (((c >= ' ' && c <= '~') ||
2222 ((unsigned char)c >= 160)) && pos < 40)
2223 password[pos++] = c;
2224 break;
2225 }
2226 }
2227 c_write("\r\n", 2);
2228 }
2229
2230 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2231 ssh2_pkt_addstring(username);
2232 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2233 ssh2_pkt_addstring("password");
2234 ssh2_pkt_addbool(FALSE);
2235 ssh2_pkt_addstring(password);
2236 ssh2_pkt_send();
2237
2238 crWaitUntilV(ispkt);
2239 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2240 c_write("Access denied\r\n", 15);
2241 logevent("Authentication refused");
2242 } else
2243 break;
2244 }
2245
2246 /*
2247 * Now we're authenticated for the connection protocol. The
2248 * connection protocol will automatically have started at this
2249 * point; there's no need to send SERVICE_REQUEST.
2250 */
2251
2252 /*
2253 * So now create a channel with a session in it.
2254 */
d211621f 2255 mainchan = malloc(sizeof(struct ssh_channel));
2256 mainchan->localid = 100; /* as good as any */
7cca0d81 2257 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2258 ssh2_pkt_addstring("session");
d211621f 2259 ssh2_pkt_adduint32(mainchan->localid);
2260 ssh2_pkt_adduint32(0x7FFFFFFFUL); /* our window size */
2261 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2262 ssh2_pkt_send();
2263 crWaitUntilV(ispkt);
2264 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2265 bombout(("Server refused to open a session"));
2266 crReturnV;
7cca0d81 2267 /* FIXME: error data comes back in FAILURE packet */
2268 }
d211621f 2269 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2270 bombout(("Server's channel confirmation cited wrong channel"));
2271 crReturnV;
7cca0d81 2272 }
d211621f 2273 mainchan->remoteid = ssh2_pkt_getuint32();
2274 mainchan->u.v2.remwindow = ssh2_pkt_getuint32();
2275 mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32();
2276 mainchan->u.v2.outbuffer = NULL;
2277 mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0;
7cca0d81 2278 logevent("Opened channel for session");
2279
2280 /*
2281 * Now allocate a pty for the session.
2282 */
67779be7 2283 if (!cfg.nopty) {
2284 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2285 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2286 ssh2_pkt_addstring("pty-req");
2287 ssh2_pkt_addbool(1); /* want reply */
2288 ssh2_pkt_addstring(cfg.termtype);
2289 ssh2_pkt_adduint32(cols);
2290 ssh2_pkt_adduint32(rows);
2291 ssh2_pkt_adduint32(0); /* pixel width */
2292 ssh2_pkt_adduint32(0); /* pixel height */
2293 ssh2_pkt_addstring_start();
2294 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2295 ssh2_pkt_send();
7cca0d81 2296
67779be7 2297 do {
2298 crWaitUntilV(ispkt);
2299 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2300 /* FIXME: be able to handle other channels here */
2301 if (ssh2_pkt_getuint32() != mainchan->localid)
2302 continue; /* wrong channel */
2303 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2304 }
2305 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2306
67779be7 2307 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2308 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2309 bombout(("Server got confused by pty request"));
2310 crReturnV;
67779be7 2311 }
2312 c_write("Server refused to allocate pty\r\n", 32);
2313 } else {
2314 logevent("Allocated pty");
7cca0d81 2315 }
7cca0d81 2316 }
2317
2318 /*
67779be7 2319 * Start a shell or a remote command.
7cca0d81 2320 */
2321 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2322 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2323 if (*cfg.remote_cmd) {
2324 ssh2_pkt_addstring("exec");
2325 ssh2_pkt_addbool(1); /* want reply */
2326 ssh2_pkt_addstring(cfg.remote_cmd);
2327 } else {
2328 ssh2_pkt_addstring("shell");
2329 ssh2_pkt_addbool(1); /* want reply */
2330 }
7cca0d81 2331 ssh2_pkt_send();
d211621f 2332 do {
7cca0d81 2333 crWaitUntilV(ispkt);
d211621f 2334 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2335 /* FIXME: be able to handle other channels here */
2336 if (ssh2_pkt_getuint32() != mainchan->localid)
2337 continue; /* wrong channel */
2338 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2339 }
7cca0d81 2340 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2341 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2342 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2343 bombout(("Server got confused by shell/command request"));
2344 crReturnV;
7cca0d81 2345 }
8d5de777 2346 bombout(("Server refused to start a shell/command"));
2347 crReturnV;
7cca0d81 2348 } else {
8d5de777 2349 logevent("Started a shell/command");
7cca0d81 2350 }
2351
2352 /*
2353 * Transfer data!
2354 */
8ccc75b0 2355 ssh_send_ok = 1;
6f34e365 2356 begin_session();
7cca0d81 2357 while (1) {
d211621f 2358 static int try_send;
e5574168 2359 crReturnV;
d211621f 2360 try_send = FALSE;
7cca0d81 2361 if (ispkt) {
2362 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2363 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2364 char *data;
2365 int length;
d211621f 2366 /* FIXME: be able to handle other channels here */
2367 if (ssh2_pkt_getuint32() != mainchan->localid)
7cca0d81 2368 continue; /* wrong channel */
2369 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2370 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2371 continue; /* extended but not stderr */
2372 ssh2_pkt_getstring(&data, &length);
d211621f 2373 if (data) {
7cca0d81 2374 c_write(data, length);
d211621f 2375 /*
2376 * Enlarge the window again at the remote side,
2377 * just in case it ever runs down and they fail
2378 * to send us any more data.
2379 */
2380 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2381 ssh2_pkt_adduint32(mainchan->remoteid);
2382 ssh2_pkt_adduint32(length);
2383 ssh2_pkt_send();
2384 }
7cca0d81 2385 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2386 ssh_state = SSH_STATE_CLOSED;
d211621f 2387 logevent("Received disconnect message");
7cca0d81 2388 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2389 continue; /* exit status et al; ignore (FIXME?) */
d211621f 2390 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2391 continue; /* remote sends EOF; ignore */
2392 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
2393 /* FIXME: be able to handle other channels here */
2394 if (ssh2_pkt_getuint32() != mainchan->localid)
2395 continue; /* wrong channel */
2396 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2397 ssh2_pkt_adduint32(mainchan->remoteid);
2398 ssh2_pkt_send();
2399 /* FIXME: mark the channel as closed */
2400 if (1 /* FIXME: "all channels are closed" */) {
2401 logevent("All channels closed. Disconnecting");
2402 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2403 ssh2_pkt_send();
2404 }
2405 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2406 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
d211621f 2407 /* FIXME: be able to handle other channels here */
2408 if (ssh2_pkt_getuint32() != mainchan->localid)
2409 continue; /* wrong channel */
2410 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2411 try_send = TRUE;
7cca0d81 2412 } else {
8d5de777 2413 bombout(("Strange packet received: type %d", pktin.type));
2414 crReturnV;
7cca0d81 2415 }
2416 } else {
d211621f 2417 /*
2418 * We have spare data. Add it to the channel buffer.
2419 */
2420 if (mainchan->u.v2.outbufsize <
2421 mainchan->u.v2.outbuflen + inlen) {
2422 mainchan->u.v2.outbufsize =
2423 mainchan->u.v2.outbuflen + inlen + 1024;
2424 mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer,
2425 mainchan->u.v2.outbufsize);
2426 }
2427 memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen,
2428 in, inlen);
2429 mainchan->u.v2.outbuflen += inlen;
2430 try_send = TRUE;
7cca0d81 2431 }
d211621f 2432 if (try_send) {
2433 /*
2434 * Try to send data on the channel if we can. (FIXME:
2435 * on _all_ channels.)
2436 */
2437 while (mainchan->u.v2.remwindow > 0 &&
2438 mainchan->u.v2.outbuflen > 0) {
2439 unsigned len = mainchan->u.v2.remwindow;
2440 if (len > mainchan->u.v2.outbuflen)
2441 len = mainchan->u.v2.outbuflen;
2442 if (len > mainchan->u.v2.remmaxpkt)
2443 len = mainchan->u.v2.remmaxpkt;
2444 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2445 ssh2_pkt_adduint32(mainchan->remoteid);
2446 ssh2_pkt_addstring_start();
2447 ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len);
2448 ssh2_pkt_send();
2449 mainchan->u.v2.outbuflen -= len;
2450 memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len,
2451 mainchan->u.v2.outbuflen);
2452 mainchan->u.v2.remwindow -= len;
2453 }
2454 }
e5574168 2455 }
2456
2457 crFinishV;
2458}
2459
2460/*
7cca0d81 2461 * Handle the top-level SSH2 protocol.
2462 */
2463static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2464{
2465 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2466 return;
2467 do_ssh2_authconn(in, inlen, ispkt);
2468}
2469
2470/*
374330e2 2471 * Called to set up the connection. Will arrange for WM_NETEVENT
2472 * messages to be passed to the specified window, whose window
2473 * procedure should then call telnet_msg().
2474 *
2475 * Returns an error message, or NULL on success.
374330e2 2476 */
2477static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
fb09bf1c 2478 char *p;
8f203108 2479
2480#ifdef MSCRYPTOAPI
2481 if(crypto_startup() == 0)
2482 return "Microsoft high encryption pack not installed!";
2483#endif
374330e2 2484
fb09bf1c 2485 p = connect_to_host(host, port, realhost);
2486 if (p != NULL)
2487 return p;
374330e2 2488
2489 if (!do_ssh_init())
2490 return "Protocol initialisation error";
2491
4017be6d 2492 if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
374330e2 2493 switch (WSAGetLastError()) {
2494 case WSAENETDOWN: return "Network is down";
2495 default: return "WSAAsyncSelect(): unknown error";
2496 }
2497
2498 return NULL;
2499}
2500
2501/*
2502 * Process a WM_NETEVENT message. Will return 0 if the connection
2503 * has closed, or <0 for a socket error.
2504 */
2505static int ssh_msg (WPARAM wParam, LPARAM lParam) {
2506 int ret;
2507 char buf[256];
2508
8ce72d2c 2509 /*
2510 * Because reading less than the whole of the available pending
2511 * data can generate an FD_READ event, we need to allow for the
2512 * possibility that FD_READ may arrive with FD_CLOSE already in
2513 * the queue; so it's possible that we can get here even with s
2514 * invalid. If so, we return 1 and don't worry about it.
2515 */
2516 if (s == INVALID_SOCKET)
2517 return 1;
374330e2 2518
8d5de777 2519 if (WSAGETSELECTERROR(lParam) != 0) {
2520 closesocket(s);
2521 s = INVALID_SOCKET;
374330e2 2522 return -WSAGETSELECTERROR(lParam);
8d5de777 2523 }
374330e2 2524
2525 switch (WSAGETSELECTEVENT(lParam)) {
2526 case FD_READ:
8ce72d2c 2527 case FD_CLOSE:
374330e2 2528 ret = recv(s, buf, sizeof(buf), 0);
2529 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
2530 return 1;
8d5de777 2531 if (ret < 0) { /* any _other_ error */
2532 closesocket(s);
2533 s = INVALID_SOCKET;
374330e2 2534 return -10000-WSAGetLastError();
8d5de777 2535 }
374330e2 2536 if (ret == 0) {
2537 s = INVALID_SOCKET;
8ce72d2c 2538 return 0;
374330e2 2539 }
2540 ssh_gotdata (buf, ret);
85ee8208 2541 if (ssh_state == SSH_STATE_CLOSED) {
2542 closesocket(s);
2543 s = INVALID_SOCKET;
2544 return 0;
2545 }
374330e2 2546 return 1;
374330e2 2547 }
2548 return 1; /* shouldn't happen, but WTF */
2549}
2550
2551/*
2552 * Called to send data down the Telnet connection.
2553 */
2554static void ssh_send (char *buf, int len) {
2555 if (s == INVALID_SOCKET)
2556 return;
2557
2558 ssh_protocol(buf, len, 0);
2559}
2560
2561/*
2562 * Called to set the size of the window from Telnet's POV.
2563 */
2564static void ssh_size(void) {
2565 switch (ssh_state) {
2566 case SSH_STATE_BEFORE_SIZE:
21248260 2567 case SSH_STATE_CLOSED:
374330e2 2568 break; /* do nothing */
2569 case SSH_STATE_INTERMED:
2570 size_needed = TRUE; /* buffer for later */
2571 break;
2572 case SSH_STATE_SESSION:
fef97f43 2573 if (!cfg.nopty) {
e5574168 2574 send_packet(SSH1_CMSG_WINDOW_SIZE,
fb09bf1c 2575 PKT_INT, rows, PKT_INT, cols,
2576 PKT_INT, 0, PKT_INT, 0, PKT_END);
fef97f43 2577 }
374330e2 2578 }
2579}
2580
2581/*
6abbf9e3 2582 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2583 * can send an EOF and collect resulting output (e.g. `plink
2584 * hostname sort').
374330e2 2585 */
2586static void ssh_special (Telnet_Special code) {
6abbf9e3 2587 if (code == TS_EOF) {
67779be7 2588 if (ssh_version == 1) {
6abbf9e3 2589 send_packet(SSH1_CMSG_EOF, PKT_END);
2590 } else {
2591 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 2592 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 2593 ssh2_pkt_send();
2594 }
67779be7 2595 logevent("Sent EOF message");
6abbf9e3 2596 } else {
2597 /* do nothing */
2598 }
374330e2 2599}
2600
fb09bf1c 2601
2602/*
2603 * Read and decrypt one incoming SSH packet.
2604 * (only used by pSCP)
2605 */
2606static void get_packet(void)
2607{
2608 unsigned char buf[4096], *p;
2609 long to_read;
2610 int len;
2611
fb09bf1c 2612 p = NULL;
2613 len = 0;
2614
2615 while ((to_read = s_rdpkt(&p, &len)) > 0) {
2616 if (to_read > sizeof(buf)) to_read = sizeof(buf);
2617 len = s_read(buf, to_read);
2618 if (len != to_read) {
2619 closesocket(s);
2620 s = INVALID_SOCKET;
2621 return;
2622 }
2623 p = buf;
2624 }
2625
2626 assert(len == 0);
2627}
2628
2629/*
2630 * Receive a block of data over the SSH link. Block until
2631 * all data is available. Return nr of bytes read (0 if lost connection).
2632 * (only used by pSCP)
2633 */
2634int ssh_scp_recv(unsigned char *buf, int len)
2635{
2636 static int pending_input_len = 0;
2637 static unsigned char *pending_input_ptr;
2638 int to_read = len;
2639
fb09bf1c 2640 if (pending_input_len >= to_read) {
2641 memcpy(buf, pending_input_ptr, to_read);
2642 pending_input_ptr += to_read;
2643 pending_input_len -= to_read;
2644 return len;
2645 }
2646
2647 if (pending_input_len > 0) {
2648 memcpy(buf, pending_input_ptr, pending_input_len);
2649 buf += pending_input_len;
2650 to_read -= pending_input_len;
2651 pending_input_len = 0;
2652 }
2653
2654 if (s == INVALID_SOCKET)
2655 return 0;
2656 while (to_read > 0) {
2657 get_packet();
2658 if (s == INVALID_SOCKET)
2659 return 0;
e5574168 2660 if (pktin.type == SSH1_SMSG_STDOUT_DATA) {
fb09bf1c 2661 int plen = GET_32BIT(pktin.body);
2662 if (plen <= to_read) {
2663 memcpy(buf, pktin.body + 4, plen);
2664 buf += plen;
2665 to_read -= plen;
2666 } else {
2667 memcpy(buf, pktin.body + 4, to_read);
2668 pending_input_len = plen - to_read;
2669 pending_input_ptr = pktin.body + 4 + to_read;
2670 to_read = 0;
2671 }
e5574168 2672 } else if (pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 2673 int plen = GET_32BIT(pktin.body);
2674 fwrite(pktin.body + 4, plen, 1, stderr);
e5574168 2675 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 2676 logevent("Received disconnect request");
e5574168 2677 } else if (pktin.type == SSH1_SMSG_SUCCESS ||
2678 pktin.type == SSH1_SMSG_FAILURE) {
fb09bf1c 2679 /* ignore */
e5574168 2680 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
fb09bf1c 2681 char logbuf[100];
2682 sprintf(logbuf, "Remote exit status: %d", GET_32BIT(pktin.body));
2683 logevent(logbuf);
e5574168 2684 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
fb09bf1c 2685 logevent("Closing connection");
2686 closesocket(s);
2687 s = INVALID_SOCKET;
2688 } else {
8d5de777 2689 bombout(("Strange packet received: type %d", pktin.type));
2690 return 0;
fb09bf1c 2691 }
2692 }
2693
2694 return len;
2695}
2696
2697/*
2698 * Send a block of data over the SSH link.
2699 * Block until all data is sent.
2700 * (only used by pSCP)
2701 */
2702void ssh_scp_send(unsigned char *buf, int len)
2703{
fb09bf1c 2704 if (s == INVALID_SOCKET)
2705 return;
e5574168 2706 send_packet(SSH1_CMSG_STDIN_DATA,
fb09bf1c 2707 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2708}
2709
2710/*
2711 * Send an EOF notification to the server.
2712 * (only used by pSCP)
2713 */
2714void ssh_scp_send_eof(void)
2715{
fb09bf1c 2716 if (s == INVALID_SOCKET)
2717 return;
e5574168 2718 send_packet(SSH1_CMSG_EOF, PKT_END);
fb09bf1c 2719}
2720
2721/*
2722 * Set up the connection, login on the remote host and
2723 * start execution of a command.
2724 * Returns an error message, or NULL on success.
2725 * (only used by pSCP)
2726 */
2727char *ssh_scp_init(char *host, int port, char *cmd, char **realhost)
2728{
2729 char buf[160], *p;
2730
fb09bf1c 2731#ifdef MSCRYPTOAPI
2732 if (crypto_startup() == 0)
2733 return "Microsoft high encryption pack not installed!";
2734#endif
2735
2736 p = connect_to_host(host, port, realhost);
2737 if (p != NULL)
2738 return p;
2739
2740 random_init();
2741
2742 if (!do_ssh_init())
2743 return "Protocol initialisation error";
2744
2745 /* Exchange keys and login */
2746 do {
2747 get_packet();
2748 if (s == INVALID_SOCKET)
2749 return "Connection closed by remote host";
e5574168 2750 } while (!do_ssh1_login(NULL, 0, 1));
85ee8208 2751
2752 if (ssh_state == SSH_STATE_CLOSED) {
2753 closesocket(s);
2754 s = INVALID_SOCKET;
2755 return "Session initialisation error";
2756 }
fb09bf1c 2757
2758 /* Execute command */
2759 sprintf(buf, "Sending command: %.100s", cmd);
2760 logevent(buf);
e5574168 2761 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fb09bf1c 2762
2763 return NULL;
2764}
2765
8ccc75b0 2766static SOCKET ssh_socket(void) { return s; }
2767
2768static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 2769
374330e2 2770Backend ssh_backend = {
2771 ssh_init,
2772 ssh_msg,
2773 ssh_send,
2774 ssh_size,
4017be6d 2775 ssh_special,
8ccc75b0 2776 ssh_socket,
2777 ssh_sendok
374330e2 2778};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator