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Include <mmsystem.h> and winmm.lib for PlaySound.
[u/mdw/putty] / ssh.c
CommitLineData
8df7a775 1#include <windows.h>
374330e2 2#include <stdio.h>
3#include <stdlib.h>
fb09bf1c 4#include <stdarg.h>
5#include <assert.h>
374330e2 6
7#include "putty.h"
dacbd0e8 8#include "tree234.h"
fb09bf1c 9#include "ssh.h"
374330e2 10
11#ifndef FALSE
12#define FALSE 0
13#endif
14#ifndef TRUE
15#define TRUE 1
16#endif
17
fb09bf1c 18#define logevent(s) { logevent(s); \
67779be7 19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
fb09bf1c 20 fprintf(stderr, "%s\n", s); }
21
3cd52910 22#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
4a8fc3c4 23 (s ? sk_close(s), s = NULL : 0), \
3cd52910 24 connection_fatal msg )
8d5de777 25
d211621f 26#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
27#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
28#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
29#define SSH1_CMSG_USER 4 /* 0x4 */
30#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
31#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
32#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
33#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
34#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
35#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
36#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
37#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
38#define SSH1_SMSG_SUCCESS 14 /* 0xe */
39#define SSH1_SMSG_FAILURE 15 /* 0xf */
40#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
41#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
42#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
43#define SSH1_CMSG_EOF 19 /* 0x13 */
44#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
45#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
46#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
47#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
48#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
49#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
9c964e85 50#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
51#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
52#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
d211621f 53#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
54#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
d211621f 55#define SSH1_MSG_IGNORE 32 /* 0x20 */
9c964e85 56#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
57#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
58#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
d211621f 59#define SSH1_MSG_DEBUG 36 /* 0x24 */
4ba9b64b 60#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
d211621f 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
b96dc54c 71#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
72/* Mask for protoflags we will echo back to server if seen */
73#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
74
d211621f 75#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
76#define SSH2_MSG_IGNORE 2 /* 0x2 */
77#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
78#define SSH2_MSG_DEBUG 4 /* 0x4 */
79#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
80#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
81#define SSH2_MSG_KEXINIT 20 /* 0x14 */
82#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
83#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
84#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
a92dd380 85#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
86#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
87#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
88#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
d211621f 89#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
95#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
96#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
97#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
98#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
99#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
100#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
101#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
102#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
103#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
104#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
105#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
106#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
107#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
108#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
109
9005f3ba 110#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
111#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
112#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
113#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
114#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
115#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
116#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
117#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
118#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
119#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
120#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
38c4a8da 121#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
122#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
123#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
124#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
125
126static const char *const ssh2_disconnect_reasons[] = {
127 NULL,
128 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
129 "SSH_DISCONNECT_PROTOCOL_ERROR",
130 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
131 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
132 "SSH_DISCONNECT_MAC_ERROR",
133 "SSH_DISCONNECT_COMPRESSION_ERROR",
134 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
135 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
136 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
137 "SSH_DISCONNECT_CONNECTION_LOST",
138 "SSH_DISCONNECT_BY_APPLICATION",
139 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
140 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
141 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
142 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
143};
9005f3ba 144
d211621f 145#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
146#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
147#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
148#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
149
150#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 151
7d503c31 152/*
153 * Various remote-bug flags.
154 */
155#define BUG_CHOKES_ON_SSH1_IGNORE 1
156#define BUG_SSH2_HMAC 2
157
fb09bf1c 158#define GET_32BIT(cp) \
159 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
160 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
161 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
162 ((unsigned long)(unsigned char)(cp)[3]))
163
164#define PUT_32BIT(cp, value) { \
165 (cp)[0] = (unsigned char)((value) >> 24); \
166 (cp)[1] = (unsigned char)((value) >> 16); \
167 (cp)[2] = (unsigned char)((value) >> 8); \
168 (cp)[3] = (unsigned char)(value); }
169
7cca0d81 170enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 171
374330e2 172/* Coroutine mechanics for the sillier bits of the code */
173#define crBegin1 static int crLine = 0;
174#define crBegin2 switch(crLine) { case 0:;
175#define crBegin crBegin1; crBegin2;
176#define crFinish(z) } crLine = 0; return (z)
177#define crFinishV } crLine = 0; return
178#define crReturn(z) \
179 do {\
180 crLine=__LINE__; return (z); case __LINE__:;\
181 } while (0)
182#define crReturnV \
183 do {\
184 crLine=__LINE__; return; case __LINE__:;\
185 } while (0)
186#define crStop(z) do{ crLine = 0; return (z); }while(0)
187#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 188#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 189#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 190
0c6c9a70 191extern char *x11_init (Socket *, char *, void *);
9c964e85 192extern void x11_close (Socket);
193extern void x11_send (Socket , char *, int);
194extern void x11_invent_auth(char *, int, char *, int);
195
5e8358ad 196/*
197 * Ciphers for SSH2. We miss out single-DES because it isn't
198 * supported; also 3DES and Blowfish are both done differently from
199 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
200 * endianness and different-sized keys.)
5e8358ad 201 */
0a3f1d48 202const static struct ssh2_ciphers *ciphers[] = {
203 &ssh2_aes,
204 &ssh2_blowfish,
205 &ssh2_3des,
8479e33c 206};
e5574168 207
a92dd380 208const static struct ssh_kex *kex_algs[] = {
a92dd380 209 &ssh_diffiehellman_gex,
a92dd380 210 &ssh_diffiehellman };
e5574168 211
85cc02bb 212const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 213
d39f364a 214static void nullmac_key(unsigned char *key) { }
e5574168 215static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
216static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
57476f6b 217const static struct ssh_mac ssh_mac_none = {
d39f364a 218 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 219};
8b2715b2 220const static struct ssh_mac *macs[] = {
221 &ssh_sha1, &ssh_md5, &ssh_mac_none };
222const static struct ssh_mac *buggymacs[] = {
223 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none };
e5574168 224
4ba9b64b 225static void ssh_comp_none_init(void) { }
226static int ssh_comp_none_block(unsigned char *block, int len,
227 unsigned char **outblock, int *outlen) {
228 return 0;
229}
63b00c83 230static int ssh_comp_none_disable(void) { return 0; }
57476f6b 231const static struct ssh_compress ssh_comp_none = {
4ba9b64b 232 "none",
233 ssh_comp_none_init, ssh_comp_none_block,
63b00c83 234 ssh_comp_none_init, ssh_comp_none_block,
235 ssh_comp_none_disable
e5574168 236};
4ba9b64b 237extern const struct ssh_compress ssh_zlib;
238const static struct ssh_compress *compressions[] = {
239 &ssh_zlib, &ssh_comp_none };
374330e2 240
783415f8 241enum { /* channel types */
242 CHAN_MAINSESSION,
243 CHAN_X11,
244 CHAN_AGENT,
245};
246
dacbd0e8 247/*
248 * 2-3-4 tree storing channels.
249 */
250struct ssh_channel {
d211621f 251 unsigned remoteid, localid;
dacbd0e8 252 int type;
253 int closes;
783415f8 254 struct ssh2_data_channel {
255 unsigned char *outbuffer;
256 unsigned outbuflen, outbufsize;
257 unsigned remwindow, remmaxpkt;
258 } v2;
dacbd0e8 259 union {
260 struct ssh_agent_channel {
261 unsigned char *message;
262 unsigned char msglen[4];
263 int lensofar, totallen;
264 } a;
9c964e85 265 struct ssh_x11_channel {
266 Socket s;
783415f8 267 } x11;
dacbd0e8 268 } u;
269};
57476f6b 270
271struct Packet {
272 long length;
273 int type;
274 unsigned char *data;
275 unsigned char *body;
276 long savedpos;
277 long maxlen;
278};
279
0db56f73 280static SHA_State exhash, exhashbase;
57476f6b 281
8df7a775 282static Socket s = NULL;
57476f6b 283
284static unsigned char session_key[32];
4ba9b64b 285static int ssh1_compressing;
b96dc54c 286static int ssh1_remote_protoflags;
287static int ssh1_local_protoflags;
db7d555c 288static int ssh_agentfwd_enabled;
9c964e85 289static int ssh_X11_fwd_enabled;
7d503c31 290static int ssh_remote_bugs;
57476f6b 291static const struct ssh_cipher *cipher = NULL;
0a3f1d48 292static const struct ssh2_cipher *cscipher = NULL;
293static const struct ssh2_cipher *sccipher = NULL;
57476f6b 294static const struct ssh_mac *csmac = NULL;
295static const struct ssh_mac *scmac = NULL;
296static const struct ssh_compress *cscomp = NULL;
297static const struct ssh_compress *sccomp = NULL;
298static const struct ssh_kex *kex = NULL;
e055a386 299static const struct ssh_signkey *hostkey = NULL;
65a22376 300static unsigned char ssh2_session_id[20];
fa17a66e 301int (*ssh_get_line)(const char *prompt, char *str, int maxlen,
302 int is_pw) = NULL;
57476f6b 303
304static char *savedhost;
305static int savedport;
306static int ssh_send_ok;
0965bee0 307static int ssh_echoing, ssh_editing;
57476f6b 308
dacbd0e8 309static tree234 *ssh_channels; /* indexed by local id */
57476f6b 310static struct ssh_channel *mainchan; /* primary session channel */
311
312static enum {
3687d221 313 SSH_STATE_PREPACKET,
57476f6b 314 SSH_STATE_BEFORE_SIZE,
315 SSH_STATE_INTERMED,
316 SSH_STATE_SESSION,
317 SSH_STATE_CLOSED
3687d221 318} ssh_state = SSH_STATE_PREPACKET;
57476f6b 319
3687d221 320static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 321
322static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
323static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
b185170a 324static unsigned char *deferred_send_data = NULL;
325static int deferred_len = 0, deferred_size = 0;
57476f6b 326
327static int ssh_version;
328static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
329static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
330static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
331static void ssh_size(void);
3687d221 332static void ssh_special (Telnet_Special);
783415f8 333static void ssh2_try_send(struct ssh_channel *c);
334static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
57476f6b 335
336static int (*s_rdpkt)(unsigned char **data, int *datalen);
337
338static struct rdpkt1_state_tag {
339 long len, pad, biglen, to_read;
340 unsigned long realcrc, gotcrc;
341 unsigned char *p;
342 int i;
343 int chunk;
344} rdpkt1_state;
345
960e736a 346static struct rdpkt2_state_tag {
347 long len, pad, payload, packetlen, maclen;
348 int i;
349 int cipherblk;
350 unsigned long incoming_sequence;
351} rdpkt2_state;
352
dacbd0e8 353static int ssh_channelcmp(void *av, void *bv) {
354 struct ssh_channel *a = (struct ssh_channel *)av;
355 struct ssh_channel *b = (struct ssh_channel *)bv;
356 if (a->localid < b->localid) return -1;
357 if (a->localid > b->localid) return +1;
358 return 0;
359}
360static int ssh_channelfind(void *av, void *bv) {
d211621f 361 unsigned *a = (unsigned *)av;
dacbd0e8 362 struct ssh_channel *b = (struct ssh_channel *)bv;
363 if (*a < b->localid) return -1;
364 if (*a > b->localid) return +1;
365 return 0;
366}
367
d2371c81 368static int alloc_channel_id(void) {
369 const int CHANNEL_NUMBER_OFFSET = 256;
370 int low, high, mid;
371 int tsize;
372 struct ssh_channel *c;
373
374 /*
375 * First-fit allocation of channel numbers: always pick the
376 * lowest unused one. To do this, binary-search using the
377 * counted B-tree to find the largest channel ID which is in a
378 * contiguous sequence from the beginning. (Precisely
379 * everything in that sequence must have ID equal to its tree
380 * index plus CHANNEL_NUMBER_OFFSET.)
381 */
382 tsize = count234(ssh_channels);
383
384 low = -1; high = tsize;
385 while (high - low > 1) {
386 mid = (high + low) / 2;
387 c = index234(ssh_channels, mid);
388 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
389 low = mid; /* this one is fine */
390 else
391 high = mid; /* this one is past it */
392 }
393 /*
394 * Now low points to either -1, or the tree index of the
395 * largest ID in the initial sequence.
396 */
397 {
398 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
399 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
400 }
401 return low + 1 + CHANNEL_NUMBER_OFFSET;
402}
403
374330e2 404static void c_write (char *buf, int len) {
67779be7 405 if ((flags & FLAG_STDERR)) {
4017be6d 406 int i;
407 for (i = 0; i < len; i++)
408 if (buf[i] != '\r')
409 fputc(buf[i], stderr);
fb09bf1c 410 return;
411 }
fe50e814 412 from_backend(1, buf, len);
3bdaf79d 413}
414
a209e957 415static void c_write_untrusted(char *buf, int len) {
416 int i;
417 for (i = 0; i < len; i++) {
418 if (buf[i] == '\n')
419 c_write("\r\n", 2);
420 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
421 c_write(buf+i, 1);
422 }
423}
424
1408a877 425static void c_write_str (char *buf) {
426 c_write(buf, strlen(buf));
427}
428
fb09bf1c 429/*
430 * Collect incoming data in the incoming packet buffer.
e5574168 431 * Decipher and verify the packet when it is completely read.
432 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 433 * Update the *data and *datalen variables.
434 * Return the additional nr of bytes needed, or 0 when
435 * a complete packet is available.
436 */
e5574168 437static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 438{
57476f6b 439 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 440
441 crBegin;
374330e2 442
fb09bf1c 443next_packet:
37508af4 444
fb09bf1c 445 pktin.type = 0;
446 pktin.length = 0;
374330e2 447
57476f6b 448 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 449 while ((*datalen) == 0)
57476f6b 450 crReturn(4-st->i);
451 st->len = (st->len << 8) + **data;
fb09bf1c 452 (*data)++, (*datalen)--;
453 }
374330e2 454
fb09bf1c 455#ifdef FWHACK
57476f6b 456 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
457 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 458 }
459#endif
374330e2 460
57476f6b 461 st->pad = 8 - (st->len % 8);
462 st->biglen = st->len + st->pad;
463 pktin.length = st->len - 5;
fb09bf1c 464
57476f6b 465 if (pktin.maxlen < st->biglen) {
466 pktin.maxlen = st->biglen;
dcbde236 467 pktin.data = (pktin.data == NULL ? smalloc(st->biglen+APIEXTRA) :
468 srealloc(pktin.data, st->biglen+APIEXTRA));
fb09bf1c 469 if (!pktin.data)
470 fatalbox("Out of memory");
471 }
374330e2 472
57476f6b 473 st->to_read = st->biglen;
474 st->p = pktin.data;
475 while (st->to_read > 0) {
476 st->chunk = st->to_read;
fb09bf1c 477 while ((*datalen) == 0)
57476f6b 478 crReturn(st->to_read);
479 if (st->chunk > (*datalen))
480 st->chunk = (*datalen);
481 memcpy(st->p, *data, st->chunk);
482 *data += st->chunk;
483 *datalen -= st->chunk;
484 st->p += st->chunk;
485 st->to_read -= st->chunk;
fb09bf1c 486 }
374330e2 487
fb09bf1c 488 if (cipher)
57476f6b 489 cipher->decrypt(pktin.data, st->biglen);
698a5108 490#if 0
491 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
492 for (st->i = 0; st->i < st->biglen; st->i++)
493 debug((" %02x", (unsigned char)pktin.data[st->i]));
494 debug(("\r\n"));
495#endif
374330e2 496
57476f6b 497 st->realcrc = crc32(pktin.data, st->biglen-4);
498 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
499 if (st->gotcrc != st->realcrc) {
8d5de777 500 bombout(("Incorrect CRC received on packet"));
501 crReturn(0);
fb09bf1c 502 }
572f871e 503
4ba9b64b 504 pktin.body = pktin.data + st->pad + 1;
505
506 if (ssh1_compressing) {
507 unsigned char *decompblk;
508 int decomplen;
509#if 0
b96dc54c 510 {
511 int i;
512 debug(("Packet payload pre-decompression:\n"));
513 for (i = -1; i < pktin.length; i++)
514 debug((" %02x", (unsigned char)pktin.body[i]));
515 debug(("\r\n"));
516 }
4ba9b64b 517#endif
518 zlib_decompress_block(pktin.body-1, pktin.length+1,
519 &decompblk, &decomplen);
520
521 if (pktin.maxlen < st->pad + decomplen) {
522 pktin.maxlen = st->pad + decomplen;
dcbde236 523 pktin.data = srealloc(pktin.data, pktin.maxlen+APIEXTRA);
58298665 524 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 525 if (!pktin.data)
526 fatalbox("Out of memory");
527 }
528
529 memcpy(pktin.body-1, decompblk, decomplen);
dcbde236 530 sfree(decompblk);
4ba9b64b 531 pktin.length = decomplen-1;
532#if 0
b96dc54c 533 {
534 int i;
535 debug(("Packet payload post-decompression:\n"));
536 for (i = -1; i < pktin.length; i++)
537 debug((" %02x", (unsigned char)pktin.body[i]));
538 debug(("\r\n"));
539 }
4ba9b64b 540#endif
541 }
542
e5574168 543 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
544 pktin.type == SSH1_SMSG_STDERR_DATA ||
545 pktin.type == SSH1_MSG_DEBUG ||
18515c51 546 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
547 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 548 long strlen = GET_32BIT(pktin.body);
8d5de777 549 if (strlen + 4 != pktin.length) {
550 bombout(("Received data packet with bogus string length"));
551 crReturn(0);
552 }
fb09bf1c 553 }
554
4ba9b64b 555 pktin.type = pktin.body[-1];
556
e5574168 557 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 558 /* log debug message */
559 char buf[80];
560 int strlen = GET_32BIT(pktin.body);
561 strcpy(buf, "Remote: ");
562 if (strlen > 70) strlen = 70;
563 memcpy(buf+8, pktin.body+4, strlen);
564 buf[8+strlen] = '\0';
565 logevent(buf);
566 goto next_packet;
e5574168 567 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 568 /* do nothing */
569 goto next_packet;
570 }
571
38c4a8da 572 if (pktin.type == SSH1_MSG_DISCONNECT) {
573 /* log reason code in disconnect message */
574 char buf[256];
575 int msglen = GET_32BIT(pktin.body);
576 int nowlen;
577 strcpy(buf, "Remote sent disconnect: ");
578 nowlen = strlen(buf);
579 if (msglen > sizeof(buf)-nowlen-1)
580 msglen = sizeof(buf)-nowlen-1;
581 memcpy(buf+nowlen, pktin.body+4, msglen);
582 buf[nowlen+msglen] = '\0';
583 logevent(buf);
584 }
585
fb09bf1c 586 crFinish(0);
587}
588
e5574168 589static int ssh2_rdpkt(unsigned char **data, int *datalen)
590{
960e736a 591 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 592
593 crBegin;
594
595next_packet:
e5574168 596 pktin.type = 0;
597 pktin.length = 0;
960e736a 598 if (sccipher)
599 st->cipherblk = sccipher->blksize;
e5574168 600 else
960e736a 601 st->cipherblk = 8;
602 if (st->cipherblk < 8)
603 st->cipherblk = 8;
604
605 if (pktin.maxlen < st->cipherblk) {
606 pktin.maxlen = st->cipherblk;
dcbde236 607 pktin.data = (pktin.data == NULL ? smalloc(st->cipherblk+APIEXTRA) :
608 srealloc(pktin.data, st->cipherblk+APIEXTRA));
e5574168 609 if (!pktin.data)
610 fatalbox("Out of memory");
611 }
612
613 /*
614 * Acquire and decrypt the first block of the packet. This will
615 * contain the length and padding details.
616 */
960e736a 617 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 618 while ((*datalen) == 0)
960e736a 619 crReturn(st->cipherblk-st->i);
620 pktin.data[st->i] = *(*data)++;
e5574168 621 (*datalen)--;
622 }
623#ifdef FWHACK
624 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
625 /* FIXME */
626 }
627#endif
628 if (sccipher)
960e736a 629 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 630
631 /*
632 * Now get the length and padding figures.
633 */
960e736a 634 st->len = GET_32BIT(pktin.data);
635 st->pad = pktin.data[4];
e5574168 636
637 /*
638 * This enables us to deduce the payload length.
639 */
960e736a 640 st->payload = st->len - st->pad - 1;
e5574168 641
960e736a 642 pktin.length = st->payload + 5;
e5574168 643
644 /*
645 * So now we can work out the total packet length.
646 */
960e736a 647 st->packetlen = st->len + 4;
648 st->maclen = scmac ? scmac->len : 0;
e5574168 649
650 /*
651 * Adjust memory allocation if packet is too big.
652 */
960e736a 653 if (pktin.maxlen < st->packetlen+st->maclen) {
654 pktin.maxlen = st->packetlen+st->maclen;
dcbde236 655 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
656 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
e5574168 657 if (!pktin.data)
658 fatalbox("Out of memory");
659 }
660
661 /*
662 * Read and decrypt the remainder of the packet.
663 */
960e736a 664 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
e5574168 665 while ((*datalen) == 0)
960e736a 666 crReturn(st->packetlen + st->maclen - st->i);
667 pktin.data[st->i] = *(*data)++;
e5574168 668 (*datalen)--;
669 }
670 /* Decrypt everything _except_ the MAC. */
671 if (sccipher)
960e736a 672 sccipher->decrypt(pktin.data + st->cipherblk,
673 st->packetlen - st->cipherblk);
e5574168 674
7cca0d81 675#if 0
960e736a 676 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
677 for (st->i = 0; st->i < st->packetlen; st->i++)
678 debug((" %02x", (unsigned char)pktin.data[st->i]));
d39f364a 679 debug(("\r\n"));
7cca0d81 680#endif
d39f364a 681
e5574168 682 /*
683 * Check the MAC.
684 */
960e736a 685 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
8d5de777 686 bombout(("Incorrect MAC received on packet"));
687 crReturn(0);
688 }
960e736a 689 st->incoming_sequence++; /* whether or not we MACed */
e5574168 690
4ba9b64b 691 /*
692 * Decompress packet payload.
693 */
694 {
695 unsigned char *newpayload;
696 int newlen;
697 if (sccomp && sccomp->decompress(pktin.data+5, pktin.length-5,
698 &newpayload, &newlen)) {
699 if (pktin.maxlen < newlen+5) {
700 pktin.maxlen = newlen+5;
dcbde236 701 pktin.data = (pktin.data == NULL ? smalloc(pktin.maxlen+APIEXTRA) :
702 srealloc(pktin.data, pktin.maxlen+APIEXTRA));
4ba9b64b 703 if (!pktin.data)
704 fatalbox("Out of memory");
705 }
706 pktin.length = 5 + newlen;
707 memcpy(pktin.data+5, newpayload, newlen);
708#if 0
709 debug(("Post-decompression payload:\r\n"));
710 for (st->i = 0; st->i < newlen; st->i++)
711 debug((" %02x", (unsigned char)pktin.data[5+st->i]));
712 debug(("\r\n"));
713#endif
714
dcbde236 715 sfree(newpayload);
4ba9b64b 716 }
717 }
718
e5574168 719 pktin.savedpos = 6;
720 pktin.type = pktin.data[5];
e5574168 721
7cca0d81 722 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
723 goto next_packet; /* FIXME: print DEBUG message */
e5574168 724
38c4a8da 725 if (pktin.type == SSH2_MSG_DISCONNECT) {
726 /* log reason code in disconnect message */
727 char buf[256];
728 int reason = GET_32BIT(pktin.data+6);
729 int msglen = GET_32BIT(pktin.data+10);
730 int nowlen;
731 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
732 sprintf(buf, "Received disconnect message (%s)",
733 ssh2_disconnect_reasons[reason]);
734 } else {
735 sprintf(buf, "Received disconnect message (unknown type %d)", reason);
736 }
737 logevent(buf);
738 strcpy(buf, "Disconnection message text: ");
739 nowlen = strlen(buf);
740 if (msglen > sizeof(buf)-nowlen-1)
741 msglen = sizeof(buf)-nowlen-1;
742 memcpy(buf+nowlen, pktin.data+14, msglen);
743 buf[nowlen+msglen] = '\0';
744 logevent(buf);
745 }
746
e5574168 747 crFinish(0);
748}
749
4ba9b64b 750static void ssh1_pktout_size(int len) {
374330e2 751 int pad, biglen;
752
753 len += 5; /* type and CRC */
754 pad = 8 - (len%8);
755 biglen = len + pad;
756
757 pktout.length = len-5;
758 if (pktout.maxlen < biglen) {
759 pktout.maxlen = biglen;
8f203108 760#ifdef MSCRYPTOAPI
fb09bf1c 761 /* Allocate enough buffer space for extra block
8f203108 762 * for MS CryptEncrypt() */
dcbde236 763 pktout.data = (pktout.data == NULL ? smalloc(biglen+12) :
764 srealloc(pktout.data, biglen+12));
8f203108 765#else
dcbde236 766 pktout.data = (pktout.data == NULL ? smalloc(biglen+4) :
767 srealloc(pktout.data, biglen+4));
8f203108 768#endif
374330e2 769 if (!pktout.data)
770 fatalbox("Out of memory");
771 }
4ba9b64b 772 pktout.body = pktout.data+4+pad+1;
773}
374330e2 774
4ba9b64b 775static void s_wrpkt_start(int type, int len) {
776 ssh1_pktout_size(len);
374330e2 777 pktout.type = type;
374330e2 778}
779
39065bed 780static int s_wrpkt_prepare(void) {
374330e2 781 int pad, len, biglen, i;
782 unsigned long crc;
783
4ba9b64b 784 pktout.body[-1] = pktout.type;
785
7d503c31 786#if 0
787 debug(("Packet payload pre-compression:\n"));
788 for (i = -1; i < pktout.length; i++)
789 debug((" %02x", (unsigned char)pktout.body[i]));
790 debug(("\r\n"));
791#endif
792
4ba9b64b 793 if (ssh1_compressing) {
794 unsigned char *compblk;
795 int complen;
4ba9b64b 796 zlib_compress_block(pktout.body-1, pktout.length+1,
797 &compblk, &complen);
798 ssh1_pktout_size(complen-1);
799 memcpy(pktout.body-1, compblk, complen);
dcbde236 800 sfree(compblk);
4ba9b64b 801#if 0
802 debug(("Packet payload post-compression:\n"));
803 for (i = -1; i < pktout.length; i++)
804 debug((" %02x", (unsigned char)pktout.body[i]));
805 debug(("\r\n"));
806#endif
807 }
808
374330e2 809 len = pktout.length + 5; /* type and CRC */
810 pad = 8 - (len%8);
811 biglen = len + pad;
812
374330e2 813 for (i=0; i<pad; i++)
814 pktout.data[i+4] = random_byte();
815 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 816 PUT_32BIT(pktout.data+biglen, crc);
817 PUT_32BIT(pktout.data, len);
374330e2 818
698a5108 819#if 0
820 debug(("Sending packet len=%d\r\n", biglen+4));
821 for (i = 0; i < biglen+4; i++)
822 debug((" %02x", (unsigned char)pktout.data[i]));
823 debug(("\r\n"));
824#endif
374330e2 825 if (cipher)
826 cipher->encrypt(pktout.data+4, biglen);
827
39065bed 828 return biglen+4;
829}
830
831static void s_wrpkt(void) {
832 int len;
833 len = s_wrpkt_prepare();
834 sk_write(s, pktout.data, len);
835}
836
837static void s_wrpkt_defer(void) {
838 int len;
839 len = s_wrpkt_prepare();
840 if (deferred_len + len > deferred_size) {
841 deferred_size = deferred_len + len + 128;
842 deferred_send_data = srealloc(deferred_send_data, deferred_size);
843 }
844 memcpy(deferred_send_data+deferred_len, pktout.data, len);
845 deferred_len += len;
374330e2 846}
847
fb09bf1c 848/*
39065bed 849 * Construct a packet with the specified contents.
fb09bf1c 850 */
39065bed 851static void construct_packet(int pkttype, va_list ap1, va_list ap2)
fb09bf1c 852{
fb09bf1c 853 unsigned char *p, *argp, argchar;
854 unsigned long argint;
855 int pktlen, argtype, arglen;
7cca0d81 856 Bignum bn;
fb09bf1c 857
858 pktlen = 0;
39065bed 859 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 860 switch (argtype) {
861 case PKT_INT:
39065bed 862 (void) va_arg(ap1, int);
fb09bf1c 863 pktlen += 4;
864 break;
865 case PKT_CHAR:
39065bed 866 (void) va_arg(ap1, char);
fb09bf1c 867 pktlen++;
868 break;
869 case PKT_DATA:
39065bed 870 (void) va_arg(ap1, unsigned char *);
871 arglen = va_arg(ap1, int);
fb09bf1c 872 pktlen += arglen;
873 break;
874 case PKT_STR:
39065bed 875 argp = va_arg(ap1, unsigned char *);
fb09bf1c 876 arglen = strlen(argp);
877 pktlen += 4 + arglen;
878 break;
7cca0d81 879 case PKT_BIGNUM:
39065bed 880 bn = va_arg(ap1, Bignum);
5c58ad2d 881 pktlen += ssh1_bignum_length(bn);
7cca0d81 882 break;
fb09bf1c 883 default:
884 assert(0);
885 }
886 }
fb09bf1c 887
888 s_wrpkt_start(pkttype, pktlen);
889 p = pktout.body;
890
39065bed 891 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 892 switch (argtype) {
893 case PKT_INT:
39065bed 894 argint = va_arg(ap2, int);
fb09bf1c 895 PUT_32BIT(p, argint);
896 p += 4;
897 break;
898 case PKT_CHAR:
39065bed 899 argchar = va_arg(ap2, unsigned char);
fb09bf1c 900 *p = argchar;
901 p++;
902 break;
903 case PKT_DATA:
39065bed 904 argp = va_arg(ap2, unsigned char *);
905 arglen = va_arg(ap2, int);
fb09bf1c 906 memcpy(p, argp, arglen);
907 p += arglen;
908 break;
909 case PKT_STR:
39065bed 910 argp = va_arg(ap2, unsigned char *);
fb09bf1c 911 arglen = strlen(argp);
912 PUT_32BIT(p, arglen);
913 memcpy(p + 4, argp, arglen);
914 p += 4 + arglen;
915 break;
7cca0d81 916 case PKT_BIGNUM:
39065bed 917 bn = va_arg(ap2, Bignum);
5c58ad2d 918 p += ssh1_write_bignum(p, bn);
7cca0d81 919 break;
fb09bf1c 920 }
921 }
39065bed 922}
fb09bf1c 923
39065bed 924static void send_packet(int pkttype, ...) {
925 va_list ap1, ap2;
926 va_start(ap1, pkttype);
927 va_start(ap2, pkttype);
928 construct_packet(pkttype, ap1, ap2);
fb09bf1c 929 s_wrpkt();
930}
931
39065bed 932static void defer_packet(int pkttype, ...) {
933 va_list ap1, ap2;
934 va_start(ap1, pkttype);
935 va_start(ap2, pkttype);
936 construct_packet(pkttype, ap1, ap2);
937 s_wrpkt_defer();
938}
939
9697bfd2 940static int ssh_versioncmp(char *a, char *b) {
941 char *ae, *be;
942 unsigned long av, bv;
943
43aa02a7 944 av = strtoul(a, &ae, 10);
945 bv = strtoul(b, &be, 10);
9697bfd2 946 if (av != bv) return (av < bv ? -1 : +1);
947 if (*ae == '.') ae++;
948 if (*be == '.') be++;
43aa02a7 949 av = strtoul(ae, &ae, 10);
950 bv = strtoul(be, &be, 10);
9697bfd2 951 if (av != bv) return (av < bv ? -1 : +1);
952 return 0;
953}
954
e5574168 955
956/*
a92dd380 957 * Utility routines for putting an SSH-protocol `string' and
958 * `uint32' into a SHA state.
e5574168 959 */
960#include <stdio.h>
75cab814 961static void sha_string(SHA_State *s, void *str, int len) {
e5574168 962 unsigned char lenblk[4];
e5574168 963 PUT_32BIT(lenblk, len);
e5574168 964 SHA_Bytes(s, lenblk, 4);
e5574168 965 SHA_Bytes(s, str, len);
966}
967
a92dd380 968static void sha_uint32(SHA_State *s, unsigned i) {
969 unsigned char intblk[4];
970 PUT_32BIT(intblk, i);
971 SHA_Bytes(s, intblk, 4);
972}
973
7cca0d81 974/*
975 * SSH2 packet construction functions.
976 */
783415f8 977static void ssh2_pkt_ensure(int length) {
978 if (pktout.maxlen < length) {
979 pktout.maxlen = length + 256;
dcbde236 980 pktout.data = (pktout.data == NULL ? smalloc(pktout.maxlen+APIEXTRA) :
981 srealloc(pktout.data, pktout.maxlen+APIEXTRA));
7cca0d81 982 if (!pktout.data)
983 fatalbox("Out of memory");
984 }
783415f8 985}
986static void ssh2_pkt_adddata(void *data, int len) {
987 pktout.length += len;
988 ssh2_pkt_ensure(pktout.length);
7cca0d81 989 memcpy(pktout.data+pktout.length-len, data, len);
990}
75cab814 991static void ssh2_pkt_addbyte(unsigned char byte) {
7cca0d81 992 ssh2_pkt_adddata(&byte, 1);
993}
75cab814 994static void ssh2_pkt_init(int pkt_type) {
7cca0d81 995 pktout.length = 5;
996 ssh2_pkt_addbyte((unsigned char)pkt_type);
997}
75cab814 998static void ssh2_pkt_addbool(unsigned char value) {
7cca0d81 999 ssh2_pkt_adddata(&value, 1);
1000}
75cab814 1001static void ssh2_pkt_adduint32(unsigned long value) {
7cca0d81 1002 unsigned char x[4];
1003 PUT_32BIT(x, value);
1004 ssh2_pkt_adddata(x, 4);
1005}
75cab814 1006static void ssh2_pkt_addstring_start(void) {
7cca0d81 1007 ssh2_pkt_adduint32(0);
1008 pktout.savedpos = pktout.length;
1009}
75cab814 1010static void ssh2_pkt_addstring_str(char *data) {
7cca0d81 1011 ssh2_pkt_adddata(data, strlen(data));
1012 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1013 pktout.length - pktout.savedpos);
1014}
75cab814 1015static void ssh2_pkt_addstring_data(char *data, int len) {
7cca0d81 1016 ssh2_pkt_adddata(data, len);
1017 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1018 pktout.length - pktout.savedpos);
1019}
75cab814 1020static void ssh2_pkt_addstring(char *data) {
7cca0d81 1021 ssh2_pkt_addstring_start();
1022 ssh2_pkt_addstring_str(data);
1023}
75cab814 1024static char *ssh2_mpint_fmt(Bignum b, int *len) {
7cca0d81 1025 unsigned char *p;
ddecd643 1026 int i, n = (bignum_bitcount(b)+7)/8;
3709bfe9 1027 p = smalloc(n + 1);
7cca0d81 1028 if (!p)
1029 fatalbox("out of memory");
1030 p[0] = 0;
3709bfe9 1031 for (i = 1; i <= n; i++)
1032 p[i] = bignum_byte(b, n-i);
7cca0d81 1033 i = 0;
3709bfe9 1034 while (i <= n && p[i] == 0 && (p[i+1] & 0x80) == 0)
7cca0d81 1035 i++;
3709bfe9 1036 memmove(p, p+i, n+1-i);
1037 *len = n+1-i;
7cca0d81 1038 return p;
1039}
75cab814 1040static void ssh2_pkt_addmp(Bignum b) {
7cca0d81 1041 unsigned char *p;
1042 int len;
1043 p = ssh2_mpint_fmt(b, &len);
1044 ssh2_pkt_addstring_start();
1045 ssh2_pkt_addstring_data(p, len);
dcbde236 1046 sfree(p);
7cca0d81 1047}
b185170a 1048
1049/*
1050 * Construct an SSH2 final-form packet: compress it, encrypt it,
1051 * put the MAC on it. Final packet, ready to be sent, is stored in
1052 * pktout.data. Total length is returned.
1053 */
1054static int ssh2_pkt_construct(void) {
7cca0d81 1055 int cipherblk, maclen, padding, i;
1056 static unsigned long outgoing_sequence = 0;
1057
1058 /*
4ba9b64b 1059 * Compress packet payload.
1060 */
1061#if 0
1062 debug(("Pre-compression payload:\r\n"));
1063 for (i = 5; i < pktout.length; i++)
1064 debug((" %02x", (unsigned char)pktout.data[i]));
1065 debug(("\r\n"));
1066#endif
1067 {
1068 unsigned char *newpayload;
1069 int newlen;
1070 if (cscomp && cscomp->compress(pktout.data+5, pktout.length-5,
1071 &newpayload, &newlen)) {
1072 pktout.length = 5;
1073 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 1074 sfree(newpayload);
4ba9b64b 1075 }
1076 }
1077
1078 /*
7cca0d81 1079 * Add padding. At least four bytes, and must also bring total
1080 * length (minus MAC) up to a multiple of the block size.
1081 */
8479e33c 1082 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
7cca0d81 1083 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1084 padding = 4;
1085 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 1086 maclen = csmac ? csmac->len : 0;
1087 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 1088 pktout.data[4] = padding;
1089 for (i = 0; i < padding; i++)
1090 pktout.data[pktout.length + i] = random_byte();
1091 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1092 if (csmac)
1093 csmac->generate(pktout.data, pktout.length + padding,
1094 outgoing_sequence);
1095 outgoing_sequence++; /* whether or not we MACed */
1096
1097#if 0
1098 debug(("Sending packet len=%d\r\n", pktout.length+padding));
1099 for (i = 0; i < pktout.length+padding; i++)
1100 debug((" %02x", (unsigned char)pktout.data[i]));
1101 debug(("\r\n"));
1102#endif
1103
1104 if (cscipher)
1105 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 1106
b185170a 1107 /* Ready-to-send packet starts at pktout.data. We return length. */
1108 return pktout.length + padding + maclen;
1109}
1110
1111/*
1112 * Construct and send an SSH2 packet immediately.
1113 */
1114static void ssh2_pkt_send(void) {
1115 int len = ssh2_pkt_construct();
1116 sk_write(s, pktout.data, len);
1117}
1118
1119/*
1120 * Construct an SSH2 packet and add it to a deferred data block.
1121 * Useful for sending multiple packets in a single sk_write() call,
1122 * to prevent a traffic-analysing listener from being able to work
1123 * out the length of any particular packet (such as the password
1124 * packet).
1125 *
1126 * Note that because SSH2 sequence-numbers its packets, this can
1127 * NOT be used as an m4-style `defer' allowing packets to be
1128 * constructed in one order and sent in another.
1129 */
1130static void ssh2_pkt_defer(void) {
1131 int len = ssh2_pkt_construct();
1132 if (deferred_len + len > deferred_size) {
1133 deferred_size = deferred_len + len + 128;
1134 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1135 }
1136 memcpy(deferred_send_data+deferred_len, pktout.data, len);
1137 deferred_len += len;
1138}
1139
1140/*
1141 * Send the whole deferred data block constructed by
39065bed 1142 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1143 */
39065bed 1144static void ssh_pkt_defersend(void) {
b185170a 1145 sk_write(s, deferred_send_data, deferred_len);
1146 deferred_len = deferred_size = 0;
1147 sfree(deferred_send_data);
1148 deferred_send_data = NULL;
7cca0d81 1149}
1150
1151#if 0
1152void bndebug(char *string, Bignum b) {
1153 unsigned char *p;
1154 int i, len;
1155 p = ssh2_mpint_fmt(b, &len);
1156 debug(("%s", string));
1157 for (i = 0; i < len; i++)
1158 debug((" %02x", p[i]));
1159 debug(("\r\n"));
dcbde236 1160 sfree(p);
7cca0d81 1161}
1162#endif
1163
75cab814 1164static void sha_mpint(SHA_State *s, Bignum b) {
7cca0d81 1165 unsigned char *p;
1166 int len;
1167 p = ssh2_mpint_fmt(b, &len);
1168 sha_string(s, p, len);
dcbde236 1169 sfree(p);
7cca0d81 1170}
1171
1172/*
1173 * SSH2 packet decode functions.
1174 */
75cab814 1175static unsigned long ssh2_pkt_getuint32(void) {
7cca0d81 1176 unsigned long value;
1177 if (pktin.length - pktin.savedpos < 4)
1178 return 0; /* arrgh, no way to decline (FIXME?) */
1179 value = GET_32BIT(pktin.data+pktin.savedpos);
1180 pktin.savedpos += 4;
1181 return value;
1182}
65a22376 1183static int ssh2_pkt_getbool(void) {
1184 unsigned long value;
1185 if (pktin.length - pktin.savedpos < 1)
1186 return 0; /* arrgh, no way to decline (FIXME?) */
1187 value = pktin.data[pktin.savedpos] != 0;
1188 pktin.savedpos++;
1189 return value;
1190}
75cab814 1191static void ssh2_pkt_getstring(char **p, int *length) {
7cca0d81 1192 *p = NULL;
1193 if (pktin.length - pktin.savedpos < 4)
1194 return;
1195 *length = GET_32BIT(pktin.data+pktin.savedpos);
1196 pktin.savedpos += 4;
1197 if (pktin.length - pktin.savedpos < *length)
1198 return;
1199 *p = pktin.data+pktin.savedpos;
1200 pktin.savedpos += *length;
1201}
75cab814 1202static Bignum ssh2_pkt_getmp(void) {
7cca0d81 1203 char *p;
3709bfe9 1204 int length;
7cca0d81 1205 Bignum b;
1206
1207 ssh2_pkt_getstring(&p, &length);
1208 if (!p)
1209 return NULL;
8d5de777 1210 if (p[0] & 0x80) {
1211 bombout(("internal error: Can't handle negative mpints"));
1212 return NULL;
1213 }
3709bfe9 1214 b = bignum_from_bytes(p, length);
7cca0d81 1215 return b;
1216}
1217
7d503c31 1218/*
1219 * Examine the remote side's version string and compare it against
1220 * a list of known buggy implementations.
1221 */
1222static void ssh_detect_bugs(char *vstring) {
1223 char *imp; /* pointer to implementation part */
1224 imp = vstring;
1225 imp += strcspn(imp, "-");
620f0caf 1226 if (*imp) imp++;
7d503c31 1227 imp += strcspn(imp, "-");
620f0caf 1228 if (*imp) imp++;
7d503c31 1229
1230 ssh_remote_bugs = 0;
1231
1232 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1233 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1234 !strcmp(imp, "1.2.22")) {
1235 /*
1236 * These versions don't support SSH1_MSG_IGNORE, so we have
1237 * to use a different defence against password length
1238 * sniffing.
1239 */
1240 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1241 logevent("We believe remote version has SSH1 ignore bug");
1242 }
1243
1244 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1245 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1246 !strncmp(imp, "2.1 ", 4)) {
1247 /*
1248 * These versions have the HMAC bug.
1249 */
1250 ssh_remote_bugs |= BUG_SSH2_HMAC;
1251 logevent("We believe remote version has SSH2 HMAC bug");
1252 }
1253}
1254
8df7a775 1255static int do_ssh_init(unsigned char c) {
50526e47 1256 static char vslen;
8df7a775 1257 static char version[10];
50526e47 1258 static char *vstring;
1259 static int vstrsize;
1260 static char *vlog;
8df7a775 1261 static int i;
374330e2 1262
8df7a775 1263 crBegin;
1264
1265 /* Search for the string "SSH-" in the input. */
374330e2 1266 i = 0;
8df7a775 1267 while (1) {
1268 static const int transS[] = { 1, 2, 2, 1 };
1269 static const int transH[] = { 0, 0, 3, 0 };
1270 static const int transminus[] = { 0, 0, 0, -1 };
1271 if (c == 'S') i = transS[i];
1272 else if (c == 'H') i = transH[i];
1273 else if (c == '-') i = transminus[i];
374330e2 1274 else i = 0;
8df7a775 1275 if (i < 0)
1276 break;
1277 crReturn(1); /* get another character */
374330e2 1278 }
8df7a775 1279
50526e47 1280 vstring = smalloc(16);
1281 vstrsize = 16;
c5e9c988 1282 strcpy(vstring, "SSH-");
50526e47 1283 vslen = 4;
374330e2 1284 i = 0;
1285 while (1) {
8df7a775 1286 crReturn(1); /* get another char */
50526e47 1287 if (vslen >= vstrsize-1) {
1288 vstrsize += 16;
1289 vstring = srealloc(vstring, vstrsize);
1290 }
1291 vstring[vslen++] = c;
374330e2 1292 if (i >= 0) {
1293 if (c == '-') {
1294 version[i] = '\0';
1295 i = -1;
1296 } else if (i < sizeof(version)-1)
1297 version[i++] = c;
1298 }
1299 else if (c == '\n')
1300 break;
1301 }
1302
db7d555c 1303 ssh_agentfwd_enabled = FALSE;
960e736a 1304 rdpkt2_state.incoming_sequence = 0;
1305
50526e47 1306 vstring[vslen] = 0;
9275ca8a 1307 vlog = smalloc(20 + vslen);
c5e9c988 1308 sprintf(vlog, "Server version: %s", vstring);
7d503c31 1309 ssh_detect_bugs(vstring);
c5e9c988 1310 vlog[strcspn(vlog, "\r\n")] = '\0';
1311 logevent(vlog);
9275ca8a 1312 sfree(vlog);
c5e9c988 1313
adf799dd 1314 /*
1315 * Server version "1.99" means we can choose whether we use v1
1316 * or v2 protocol. Choice is based on cfg.sshprot.
1317 */
1318 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 1319 /*
1320 * This is a v2 server. Begin v2 protocol.
1321 */
9275ca8a 1322 char verstring[80], vlog[100];
900a4ee6 1323 sprintf(verstring, "SSH-2.0-%s", sshver);
0db56f73 1324 SHA_Init(&exhashbase);
e5574168 1325 /*
1326 * Hash our version string and their version string.
1327 */
0db56f73 1328 sha_string(&exhashbase, verstring, strlen(verstring));
1329 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
e5574168 1330 sprintf(vlog, "We claim version: %s", verstring);
1331 logevent(vlog);
9275ca8a 1332 strcat(verstring, "\n");
e5574168 1333 logevent("Using SSH protocol version 2");
9275ca8a 1334 sk_write(s, verstring, strlen(verstring));
e5574168 1335 ssh_protocol = ssh2_protocol;
6abbf9e3 1336 ssh_version = 2;
e5574168 1337 s_rdpkt = ssh2_rdpkt;
1338 } else {
1339 /*
1340 * This is a v1 server. Begin v1 protocol.
1341 */
9275ca8a 1342 char verstring[80], vlog[100];
1343 sprintf(verstring, "SSH-%s-%s",
900a4ee6 1344 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1345 sshver);
9275ca8a 1346 sprintf(vlog, "We claim version: %s", verstring);
e5574168 1347 logevent(vlog);
9275ca8a 1348 strcat(verstring, "\n");
e5574168 1349 logevent("Using SSH protocol version 1");
9275ca8a 1350 sk_write(s, verstring, strlen(verstring));
e5574168 1351 ssh_protocol = ssh1_protocol;
6abbf9e3 1352 ssh_version = 1;
e5574168 1353 s_rdpkt = ssh1_rdpkt;
1354 }
3687d221 1355 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1356
50526e47 1357 sfree(vstring);
50526e47 1358
8df7a775 1359 crFinish(0);
1360}
1361
1362static void ssh_gotdata(unsigned char *data, int datalen)
1363{
1364 crBegin;
1365
1366 /*
1367 * To begin with, feed the characters one by one to the
1368 * protocol initialisation / selection function do_ssh_init().
1369 * When that returns 0, we're done with the initial greeting
1370 * exchange and can move on to packet discipline.
1371 */
1372 while (1) {
1373 int ret;
1374 if (datalen == 0)
1375 crReturnV; /* more data please */
1376 ret = do_ssh_init(*data);
1377 data++; datalen--;
1378 if (ret == 0)
1379 break;
1380 }
1381
1382 /*
1383 * We emerge from that loop when the initial negotiation is
1384 * over and we have selected an s_rdpkt function. Now pass
1385 * everything to s_rdpkt, and then pass the resulting packets
1386 * to the proper protocol handler.
1387 */
1388 if (datalen == 0)
1389 crReturnV;
1390 while (1) {
1391 while (datalen > 0) {
1392 if ( s_rdpkt(&data, &datalen) == 0 ) {
1393 ssh_protocol(NULL, 0, 1);
1394 if (ssh_state == SSH_STATE_CLOSED) {
1395 return;
1396 }
1397 }
1398 }
1399 crReturnV;
1400 }
1401 crFinishV;
1402}
1403
7e78000d 1404static int ssh_closing (Plug plug, char *error_msg, int error_code, int calling_back) {
1405 ssh_state = SSH_STATE_CLOSED;
1406 sk_close(s);
1407 s = NULL;
1408 if (error_msg) {
2c94fd1c 1409 /* A socket error has occurred. */
7e78000d 1410 connection_fatal (error_msg);
1411 } else {
1412 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1413 }
7e78000d 1414 return 0;
1415}
1416
1417static int ssh_receive(Plug plug, int urgent, char *data, int len) {
8df7a775 1418 ssh_gotdata (data, len);
3257deae 1419 if (ssh_state == SSH_STATE_CLOSED) {
1420 if (s) {
1421 sk_close(s);
1422 s = NULL;
1423 }
1424 return 0;
1425 }
fef97f43 1426 return 1;
374330e2 1427}
1428
fb09bf1c 1429/*
8df7a775 1430 * Connect to specified host and port.
1431 * Returns an error message, or NULL on success.
1432 * Also places the canonical host name into `realhost'.
1433 */
1434static char *connect_to_host(char *host, int port, char **realhost)
1435{
7e78000d 1436 static struct plug_function_table fn_table = {
1437 ssh_closing,
1438 ssh_receive
1439 }, *fn_table_ptr = &fn_table;
1440
8df7a775 1441 SockAddr addr;
1442 char *err;
1443#ifdef FWHACK
1444 char *FWhost;
1445 int FWport;
1446#endif
1447
dcbde236 1448 savedhost = smalloc(1+strlen(host));
8df7a775 1449 if (!savedhost)
1450 fatalbox("Out of memory");
1451 strcpy(savedhost, host);
1452
1453 if (port < 0)
1454 port = 22; /* default ssh port */
1455 savedport = port;
1456
1457#ifdef FWHACK
1458 FWhost = host;
1459 FWport = port;
1460 host = FWSTR;
1461 port = 23;
1462#endif
1463
1464 /*
1465 * Try to find host.
1466 */
1467 addr = sk_namelookup(host, realhost);
1468 if ( (err = sk_addr_error(addr)) )
1469 return err;
1470
1471#ifdef FWHACK
1472 *realhost = FWhost;
1473#endif
1474
1475 /*
1476 * Open socket.
1477 */
7e78000d 1478 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
8df7a775 1479 if ( (err = sk_socket_error(s)) )
1480 return err;
1481
1482#ifdef FWHACK
1483 sk_write(s, "connect ", 8);
1484 sk_write(s, FWhost, strlen(FWhost));
1485 {
1486 char buf[20];
1487 sprintf(buf, " %d\n", FWport);
1488 sk_write(s, buf, strlen(buf));
1489 }
1490#endif
1491
1492 return NULL;
1493}
1494
1495/*
fb09bf1c 1496 * Handle the key exchange and user authentication phases.
1497 */
e5574168 1498static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1499{
374330e2 1500 int i, j, len;
374330e2 1501 unsigned char *rsabuf, *keystr1, *keystr2;
1502 unsigned char cookie[8];
1503 struct RSAKey servkey, hostkey;
1504 struct MD5Context md5c;
ccbfb941 1505 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1506 static int tried_publickey;
1507 static unsigned char session_id[16];
bea1ef5f 1508 int cipher_type;
b585ec46 1509 static char username[100];
374330e2 1510
374330e2 1511 crBegin;
1512
fb09bf1c 1513 if (!ispkt) crWaitUntil(ispkt);
374330e2 1514
8d5de777 1515 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1516 bombout(("Public key packet not received"));
1517 crReturn(0);
1518 }
374330e2 1519
c5e9c988 1520 logevent("Received public keys");
374330e2 1521
c5e9c988 1522 memcpy(cookie, pktin.body, 8);
374330e2 1523
7cca0d81 1524 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1525 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1526
c5e9c988 1527 /*
1c2a93c4 1528 * Log the host key fingerprint.
c5e9c988 1529 */
c5e9c988 1530 {
1531 char logmsg[80];
1c2a93c4 1532 logevent("Host key fingerprint is:");
c5e9c988 1533 strcpy(logmsg, " ");
1c2a93c4 1534 hostkey.comment = NULL;
1535 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1536 &hostkey);
c5e9c988 1537 logevent(logmsg);
1538 }
1539
b96dc54c 1540 ssh1_remote_protoflags = GET_32BIT(pktin.body+8+i+j);
fb09bf1c 1541 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1542 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1543
b96dc54c 1544 ssh1_local_protoflags = ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1545 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1546
c5e9c988 1547 MD5Init(&md5c);
374330e2 1548 MD5Update(&md5c, keystr2, hostkey.bytes);
1549 MD5Update(&md5c, keystr1, servkey.bytes);
1550 MD5Update(&md5c, pktin.body, 8);
374330e2 1551 MD5Final(session_id, &md5c);
1552
1553 for (i=0; i<32; i++)
1554 session_key[i] = random_byte();
1555
1556 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1557
dcbde236 1558 rsabuf = smalloc(len);
374330e2 1559 if (!rsabuf)
1560 fatalbox("Out of memory");
1561
89ee5268 1562 /*
1563 * Verify the host key.
1564 */
1565 {
1566 /*
1567 * First format the key into a string.
1568 */
1569 int len = rsastr_len(&hostkey);
d5859615 1570 char fingerprint[100];
dcbde236 1571 char *keystr = smalloc(len);
89ee5268 1572 if (!keystr)
1573 fatalbox("Out of memory");
1574 rsastr_fmt(keystr, &hostkey);
d5859615 1575 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1576 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
dcbde236 1577 sfree(keystr);
89ee5268 1578 }
374330e2 1579
1580 for (i=0; i<32; i++) {
1581 rsabuf[i] = session_key[i];
1582 if (i < 16)
1583 rsabuf[i] ^= session_id[i];
1584 }
1585
1586 if (hostkey.bytes > servkey.bytes) {
1587 rsaencrypt(rsabuf, 32, &servkey);
1588 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1589 } else {
1590 rsaencrypt(rsabuf, 32, &hostkey);
1591 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1592 }
1593
c5e9c988 1594 logevent("Encrypted session key");
1595
0a3f1d48 1596 switch (cfg.cipher) {
1597 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH; break;
1598 case CIPHER_DES: cipher_type = SSH_CIPHER_DES; break;
1599 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES; break;
1600 case CIPHER_AES:
1408a877 1601 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
0a3f1d48 1602 cipher_type = SSH_CIPHER_3DES;
1603 break;
1604 }
bea1ef5f 1605 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1408a877 1606 c_write_str("Selected cipher not supported, falling back to 3DES\r\n");
bea1ef5f 1607 cipher_type = SSH_CIPHER_3DES;
a99a05c0 1608 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1609 bombout(("Server violates SSH 1 protocol by "
1610 "not supporting 3DES encryption"));
1611 crReturn(0);
1612 }
bea1ef5f 1613 }
c5e9c988 1614 switch (cipher_type) {
1615 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1616 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1617 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1618 }
bea1ef5f 1619
e5574168 1620 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1621 PKT_CHAR, cipher_type,
1622 PKT_DATA, cookie, 8,
1623 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1624 PKT_DATA, rsabuf, len,
b96dc54c 1625 PKT_INT, ssh1_local_protoflags,
fb09bf1c 1626 PKT_END);
1627
c5e9c988 1628 logevent("Trying to enable encryption...");
374330e2 1629
dcbde236 1630 sfree(rsabuf);
374330e2 1631
5e8358ad 1632 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1633 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1634 &ssh_3des;
374330e2 1635 cipher->sesskey(session_key);
1636
fb09bf1c 1637 crWaitUntil(ispkt);
374330e2 1638
8d5de777 1639 if (pktin.type != SSH1_SMSG_SUCCESS) {
1640 bombout(("Encryption not successfully enabled"));
1641 crReturn(0);
1642 }
374330e2 1643
c5e9c988 1644 logevent("Successfully started encryption");
1645
374330e2 1646 fflush(stdout);
1647 {
374330e2 1648 static int pos = 0;
1649 static char c;
67779be7 1650 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
fa17a66e 1651 if (ssh_get_line) {
1652 if (!ssh_get_line("login as: ",
1653 username, sizeof(username), FALSE)) {
1654 /*
1655 * get_line failed to get a username.
1656 * Terminate.
1657 */
1658 logevent("No username provided. Abandoning session.");
1659 ssh_state = SSH_STATE_CLOSED;
1660 crReturn(1);
1661 }
1662 } else {
1663 c_write_str("login as: ");
1664 ssh_send_ok = 1;
1665 while (pos >= 0) {
1666 crWaitUntil(!ispkt);
1667 while (inlen--) switch (c = *in++) {
1668 case 10: case 13:
1669 username[pos] = 0;
1670 pos = -1;
1671 break;
1672 case 8: case 127:
1673 if (pos > 0) {
1674 c_write_str("\b \b");
1675 pos--;
1676 }
1677 break;
1678 case 21: case 27:
1679 while (pos > 0) {
1680 c_write_str("\b \b");
1681 pos--;
1682 }
1683 break;
1684 case 3: case 4:
1685 random_save_seed();
1686 exit(0);
1687 break;
1688 default:
1689 if (((c >= ' ' && c <= '~') ||
1690 ((unsigned char)c >= 160)) && pos < 40) {
1691 username[pos++] = c;
1692 c_write(&c, 1);
1693 }
1694 break;
1695 }
1696 }
1697 c_write_str("\r\n");
1698 username[strcspn(username, "\n\r")] = '\0';
1699 }
1700 } else {
374330e2 1701 strncpy(username, cfg.username, 99);
1702 username[99] = '\0';
374330e2 1703 }
fb09bf1c 1704
e5574168 1705 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1706 {
3c8e959b 1707 char userlog[22+sizeof(username)];
c5e9c988 1708 sprintf(userlog, "Sent username \"%s\"", username);
1709 logevent(userlog);
3c8e959b 1710 if (flags & FLAG_INTERACTIVE &&
1711 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
1712 strcat(userlog, "\r\n");
1408a877 1713 c_write_str(userlog);
3c8e959b 1714 }
c5e9c988 1715 }
374330e2 1716 }
1717
fb09bf1c 1718 crWaitUntil(ispkt);
374330e2 1719
7cca0d81 1720 tried_publickey = 0;
1721
e5574168 1722 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1723 static char password[100];
a52f067e 1724 static char prompt[200];
374330e2 1725 static int pos;
1726 static char c;
ccbfb941 1727 static int pwpkt_type;
ccbfb941 1728 /*
1729 * Show password prompt, having first obtained it via a TIS
18515c51 1730 * or CryptoCard exchange if we're doing TIS or CryptoCard
1731 * authentication.
ccbfb941 1732 */
e5574168 1733 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1734 if (agent_exists()) {
1735 /*
1736 * Attempt RSA authentication using Pageant.
1737 */
1738 static unsigned char request[5], *response, *p;
1739 static int responselen;
1740 static int i, nkeys;
1741 static int authed = FALSE;
1742 void *r;
1743
1744 logevent("Pageant is running. Requesting keys.");
1745
1746 /* Request the keys held by the agent. */
1747 PUT_32BIT(request, 1);
1983e559 1748 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
5c58ad2d 1749 agent_query(request, 5, &r, &responselen);
1750 response = (unsigned char *)r;
95797139 1751 if (response && responselen >= 5 &&
1752 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
5c58ad2d 1753 p = response + 5;
1754 nkeys = GET_32BIT(p); p += 4;
6328ea7a 1755 { char buf[64]; sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
5c58ad2d 1756 logevent(buf); }
1757 for (i = 0; i < nkeys; i++) {
1758 static struct RSAKey key;
1759 static Bignum challenge;
b8bb811a 1760 static char *commentp;
1761 static int commentlen;
5c58ad2d 1762
1763 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1764 logevent(buf); }
1765 p += 4;
1766 p += ssh1_read_bignum(p, &key.exponent);
1767 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1768 commentlen = GET_32BIT(p); p += 4;
1769 commentp = p; p += commentlen;
5c58ad2d 1770 send_packet(SSH1_CMSG_AUTH_RSA,
1771 PKT_BIGNUM, key.modulus, PKT_END);
1772 crWaitUntil(ispkt);
1773 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1774 logevent("Key refused");
1775 continue;
1776 }
1777 logevent("Received RSA challenge");
1778 ssh1_read_bignum(pktin.body, &challenge);
1779 {
1780 char *agentreq, *q, *ret;
1781 int len, retlen;
1782 len = 1 + 4; /* message type, bit count */
1783 len += ssh1_bignum_length(key.exponent);
1784 len += ssh1_bignum_length(key.modulus);
1785 len += ssh1_bignum_length(challenge);
1786 len += 16; /* session id */
1787 len += 4; /* response format */
dcbde236 1788 agentreq = smalloc(4 + len);
5c58ad2d 1789 PUT_32BIT(agentreq, len);
1790 q = agentreq + 4;
1983e559 1791 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
ddecd643 1792 PUT_32BIT(q, bignum_bitcount(key.modulus));
5c58ad2d 1793 q += 4;
1794 q += ssh1_write_bignum(q, key.exponent);
1795 q += ssh1_write_bignum(q, key.modulus);
1796 q += ssh1_write_bignum(q, challenge);
1797 memcpy(q, session_id, 16); q += 16;
1798 PUT_32BIT(q, 1); /* response format */
1799 agent_query(agentreq, len+4, &ret, &retlen);
dcbde236 1800 sfree(agentreq);
5c58ad2d 1801 if (ret) {
1983e559 1802 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
5c58ad2d 1803 logevent("Sending Pageant's response");
1804 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1805 PKT_DATA, ret+5, 16, PKT_END);
dcbde236 1806 sfree(ret);
5c58ad2d 1807 crWaitUntil(ispkt);
1808 if (pktin.type == SSH1_SMSG_SUCCESS) {
1809 logevent("Pageant's response accepted");
c4fa2fce 1810 if (flags & FLAG_VERBOSE) {
1408a877 1811 c_write_str("Authenticated using RSA key \"");
c4fa2fce 1812 c_write(commentp, commentlen);
1408a877 1813 c_write_str("\" from agent\r\n");
c4fa2fce 1814 }
5c58ad2d 1815 authed = TRUE;
1816 } else
1817 logevent("Pageant's response not accepted");
1818 } else {
1819 logevent("Pageant failed to answer challenge");
dcbde236 1820 sfree(ret);
5c58ad2d 1821 }
1822 } else {
1823 logevent("No reply received from Pageant");
1824 }
1825 }
1826 freebn(key.exponent);
1827 freebn(key.modulus);
1828 freebn(challenge);
1829 if (authed)
1830 break;
1831 }
1832 }
1833 if (authed)
1834 break;
1835 }
7cca0d81 1836 if (*cfg.keyfile && !tried_publickey)
1837 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1838
a52f067e 1839 if (pktin.type == SSH1_SMSG_FAILURE &&
1840 cfg.try_tis_auth &&
1841 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1842 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1843 logevent("Requested TIS authentication");
1844 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1845 crWaitUntil(ispkt);
1846 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1847 logevent("TIS authentication declined");
1848 if (flags & FLAG_INTERACTIVE)
1408a877 1849 c_write_str("TIS authentication refused.\r\n");
a52f067e 1850 } else {
1851 int challengelen = ((pktin.body[0] << 24) |
1852 (pktin.body[1] << 16) |
1853 (pktin.body[2] << 8) |
1854 (pktin.body[3]));
1855 logevent("Received TIS challenge");
1856 if (challengelen > sizeof(prompt)-1)
1857 challengelen = sizeof(prompt)-1; /* prevent overrun */
1858 memcpy(prompt, pktin.body+4, challengelen);
1859 prompt[challengelen] = '\0';
1860 }
1861 }
1862 if (pktin.type == SSH1_SMSG_FAILURE &&
1863 cfg.try_tis_auth &&
1864 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1865 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1866 logevent("Requested CryptoCard authentication");
1867 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1868 crWaitUntil(ispkt);
1869 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1870 logevent("CryptoCard authentication declined");
1408a877 1871 c_write_str("CryptoCard authentication refused.\r\n");
a52f067e 1872 } else {
1873 int challengelen = ((pktin.body[0] << 24) |
1874 (pktin.body[1] << 16) |
1875 (pktin.body[2] << 8) |
1876 (pktin.body[3]));
1877 logevent("Received CryptoCard challenge");
1878 if (challengelen > sizeof(prompt)-1)
1879 challengelen = sizeof(prompt)-1; /* prevent overrun */
1880 memcpy(prompt, pktin.body+4, challengelen);
1881 strncpy(prompt + challengelen, "\r\nResponse : ",
1882 sizeof(prompt)-challengelen);
1883 prompt[sizeof(prompt)-1] = '\0';
1884 }
1885 }
1886 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1887 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1888 username, savedhost);
a52f067e 1889 }
1890 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1891 char *comment = NULL;
1892 if (flags & FLAG_VERBOSE)
1408a877 1893 c_write_str("Trying public key authentication.\r\n");
a52f067e 1894 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1895 if (flags & FLAG_VERBOSE)
1408a877 1896 c_write_str("No passphrase required.\r\n");
a52f067e 1897 goto tryauth;
1898 }
1899 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
dcbde236 1900 sfree(comment);
a52f067e 1901 }
1902
fa17a66e 1903 if (ssh_get_line) {
1904 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
85ee8208 1905 /*
fa17a66e 1906 * get_line failed to get a password (for example
1907 * because one was supplied on the command line
1908 * which has already failed to work). Terminate.
85ee8208 1909 */
1910 logevent("No more passwords to try");
1911 ssh_state = SSH_STATE_CLOSED;
1912 crReturn(1);
1913 }
fb09bf1c 1914 } else {
1408a877 1915 c_write_str(prompt);
7cca0d81 1916 pos = 0;
67779be7 1917 ssh_send_ok = 1;
7cca0d81 1918 while (pos >= 0) {
1919 crWaitUntil(!ispkt);
1920 while (inlen--) switch (c = *in++) {
1921 case 10: case 13:
1922 password[pos] = 0;
1923 pos = -1;
1924 break;
1925 case 8: case 127:
1926 if (pos > 0)
1927 pos--;
1928 break;
1929 case 21: case 27:
1930 pos = 0;
1931 break;
1932 case 3: case 4:
1933 random_save_seed();
1934 exit(0);
1935 break;
1936 default:
1937 if (((c >= ' ' && c <= '~') ||
1938 ((unsigned char)c >= 160)) && pos < sizeof(password))
1939 password[pos++] = c;
1940 break;
1941 }
1942 }
1408a877 1943 c_write_str("\r\n");
a52f067e 1944 }
fb09bf1c 1945
7cca0d81 1946 tryauth:
1947 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1948 /*
1949 * Try public key authentication with the specified
1950 * key file.
1951 */
1952 static struct RSAKey pubkey;
1953 static Bignum challenge, response;
1954 static int i;
1955 static unsigned char buffer[32];
1956
1957 tried_publickey = 1;
65a22376 1958 i = loadrsakey(cfg.keyfile, &pubkey, password);
7cca0d81 1959 if (i == 0) {
1408a877 1960 c_write_str("Couldn't load public key from ");
1961 c_write_str(cfg.keyfile);
1962 c_write_str(".\r\n");
7cca0d81 1963 continue; /* go and try password */
1964 }
1965 if (i == -1) {
1408a877 1966 c_write_str("Wrong passphrase.\r\n");
7cca0d81 1967 tried_publickey = 0;
1968 continue; /* try again */
1969 }
1970
1971 /*
1972 * Send a public key attempt.
1973 */
1974 send_packet(SSH1_CMSG_AUTH_RSA,
1975 PKT_BIGNUM, pubkey.modulus, PKT_END);
1976
1977 crWaitUntil(ispkt);
1978 if (pktin.type == SSH1_SMSG_FAILURE) {
1408a877 1979 c_write_str("Server refused our public key.\r\n");
7cca0d81 1980 continue; /* go and try password */
1981 }
8d5de777 1982 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1983 bombout(("Bizarre response to offer of public key"));
1984 crReturn(0);
1985 }
7cca0d81 1986 ssh1_read_bignum(pktin.body, &challenge);
1987 response = rsadecrypt(challenge, &pubkey);
1988 freebn(pubkey.private_exponent); /* burn the evidence */
1989
3709bfe9 1990 for (i = 0; i < 32; i++) {
1991 buffer[i] = bignum_byte(response, 31-i);
7cca0d81 1992 }
1993
1994 MD5Init(&md5c);
1995 MD5Update(&md5c, buffer, 32);
1996 MD5Update(&md5c, session_id, 16);
1997 MD5Final(buffer, &md5c);
1998
1999 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2000 PKT_DATA, buffer, 16, PKT_END);
2001
2002 crWaitUntil(ispkt);
2003 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 2004 if (flags & FLAG_VERBOSE)
1408a877 2005 c_write_str("Failed to authenticate with our public key.\r\n");
7cca0d81 2006 continue; /* go and try password */
2007 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2008 bombout(("Bizarre response to RSA authentication response"));
2009 crReturn(0);
7cca0d81 2010 }
2011
2012 break; /* we're through! */
2013 } else {
39065bed 2014 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2015 /*
2016 * Defence against traffic analysis: we send a
2017 * whole bunch of packets containing strings of
2018 * different lengths. One of these strings is the
2019 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2020 * The others are all random data in
2021 * SSH1_MSG_IGNORE packets. This way a passive
2022 * listener can't tell which is the password, and
2023 * hence can't deduce the password length.
2024 *
2025 * Anybody with a password length greater than 16
2026 * bytes is going to have enough entropy in their
2027 * password that a listener won't find it _that_
2028 * much help to know how long it is. So what we'll
2029 * do is:
2030 *
2031 * - if password length < 16, we send 15 packets
2032 * containing string lengths 1 through 15
2033 *
2034 * - otherwise, we let N be the nearest multiple
2035 * of 8 below the password length, and send 8
2036 * packets containing string lengths N through
2037 * N+7. This won't obscure the order of
2038 * magnitude of the password length, but it will
2039 * introduce a bit of extra uncertainty.
7d503c31 2040 *
2041 * A few servers (the old 1.2.18 through 1.2.22)
2042 * can't deal with SSH1_MSG_IGNORE. For these
2043 * servers, we need an alternative defence. We make
2044 * use of the fact that the password is interpreted
2045 * as a C string: so we can append a NUL, then some
2046 * random data.
39065bed 2047 */
7d503c31 2048 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
2049 char string[64];
2050 char *s;
2051 int len;
2052
2053 len = strlen(password);
2054 if (len < sizeof(string)) {
2055 s = string;
2056 strcpy(string, password);
2057 len++; /* cover the zero byte */
2058 while (len < sizeof(string)) {
2059 string[len++] = (char)random_byte();
2060 }
2061 } else {
2062 s = password;
2063 }
2064 send_packet(pwpkt_type, PKT_INT, len,
2065 PKT_DATA, s, len, PKT_END);
39065bed 2066 } else {
7d503c31 2067 int bottom, top, pwlen, i;
2068 char *randomstr;
2069
2070 pwlen = strlen(password);
2071 if (pwlen < 16) {
98c84eb4 2072 bottom = 0; /* zero length passwords are OK! :-) */
7d503c31 2073 top = 15;
2074 } else {
2075 bottom = pwlen &~ 7;
2076 top = bottom + 7;
2077 }
39065bed 2078
7d503c31 2079 assert(pwlen >= bottom && pwlen <= top);
39065bed 2080
7d503c31 2081 randomstr = smalloc(top+1);
39065bed 2082
7d503c31 2083 for (i = bottom; i <= top; i++) {
2084 if (i == pwlen)
2085 defer_packet(pwpkt_type, PKT_STR, password, PKT_END);
2086 else {
2087 for (j = 0; j < i; j++) {
2088 do {
2089 randomstr[j] = random_byte();
2090 } while (randomstr[j] == '\0');
2091 }
2092 randomstr[i] = '\0';
2093 defer_packet(SSH1_MSG_IGNORE,
2094 PKT_STR, randomstr, PKT_END);
39065bed 2095 }
39065bed 2096 }
7d503c31 2097 ssh_pkt_defersend();
39065bed 2098 }
39065bed 2099 } else {
2100 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2101 }
7cca0d81 2102 }
c5e9c988 2103 logevent("Sent password");
374330e2 2104 memset(password, 0, strlen(password));
fb09bf1c 2105 crWaitUntil(ispkt);
e5574168 2106 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 2107 if (flags & FLAG_VERBOSE)
1408a877 2108 c_write_str("Access denied\r\n");
c5e9c988 2109 logevent("Authentication refused");
e5574168 2110 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 2111 logevent("Received disconnect request");
85ee8208 2112 ssh_state = SSH_STATE_CLOSED;
2113 crReturn(1);
e5574168 2114 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2115 bombout(("Strange packet received, type %d", pktin.type));
2116 crReturn(0);
374330e2 2117 }
2118 }
2119
c5e9c988 2120 logevent("Authentication successful");
2121
fb09bf1c 2122 crFinish(1);
2123}
2124
9c964e85 2125void sshfwd_close(struct ssh_channel *c) {
80e48603 2126 if (c && !c->closes) {
783415f8 2127 if (ssh_version == 1) {
2128 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END);
2129 } else {
2130 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2131 ssh2_pkt_adduint32(c->remoteid);
2132 ssh2_pkt_send();
2133 }
2134 c->closes = 1;
2135 if (c->type == CHAN_X11) {
2136 c->u.x11.s = NULL;
2137 logevent("X11 connection terminated");
2138 }
2139 }
9c964e85 2140}
2141
2142void sshfwd_write(struct ssh_channel *c, char *buf, int len) {
783415f8 2143 if (ssh_version == 1) {
2144 send_packet(SSH1_MSG_CHANNEL_DATA,
2145 PKT_INT, c->remoteid,
2146 PKT_INT, len,
2147 PKT_DATA, buf, len,
2148 PKT_END);
2149 } else {
2150 ssh2_add_channel_data(c, buf, len);
2151 ssh2_try_send(c);
2152 }
9c964e85 2153}
2154
e5574168 2155static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 2156 crBegin;
2157
2158 random_init();
2159
e5574168 2160 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 2161 crReturnV;
85ee8208 2162 }
2163 if (ssh_state == SSH_STATE_CLOSED)
2164 crReturnV;
fb09bf1c 2165
979310f1 2166 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 2167 logevent("Requesting agent forwarding");
2168 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2169 do { crReturnV; } while (!ispkt);
2170 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 2171 bombout(("Protocol confusion"));
2172 crReturnV;
dacbd0e8 2173 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2174 logevent("Agent forwarding refused");
db7d555c 2175 } else {
dacbd0e8 2176 logevent("Agent forwarding enabled");
db7d555c 2177 ssh_agentfwd_enabled = TRUE;
2178 }
dacbd0e8 2179 }
2180
9c964e85 2181 if (cfg.x11_forward) {
2182 char proto[20], data[64];
2183 logevent("Requesting X11 forwarding");
2184 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
b96dc54c 2185 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2186 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2187 PKT_STR, proto, PKT_STR, data,
2188 PKT_INT, 0,
2189 PKT_END);
2190 } else {
2191 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2192 PKT_STR, proto, PKT_STR, data,
2193 PKT_END);
2194 }
9c964e85 2195 do { crReturnV; } while (!ispkt);
2196 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2197 bombout(("Protocol confusion"));
2198 crReturnV;
2199 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2200 logevent("X11 forwarding refused");
2201 } else {
2202 logevent("X11 forwarding enabled");
2203 ssh_X11_fwd_enabled = TRUE;
2204 }
2205 }
2206
fef97f43 2207 if (!cfg.nopty) {
e5574168 2208 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 2209 PKT_STR, cfg.termtype,
2210 PKT_INT, rows, PKT_INT, cols,
2211 PKT_INT, 0, PKT_INT, 0,
2212 PKT_CHAR, 0,
2213 PKT_END);
fef97f43 2214 ssh_state = SSH_STATE_INTERMED;
2215 do { crReturnV; } while (!ispkt);
e5574168 2216 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 2217 bombout(("Protocol confusion"));
2218 crReturnV;
e5574168 2219 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1408a877 2220 c_write_str("Server refused to allocate pty\r\n");
0965bee0 2221 ssh_editing = ssh_echoing = 1;
fef97f43 2222 }
c5e9c988 2223 logevent("Allocated pty");
0965bee0 2224 } else {
2225 ssh_editing = ssh_echoing = 1;
374330e2 2226 }
2227
4ba9b64b 2228 if (cfg.compression) {
2229 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2230 do { crReturnV; } while (!ispkt);
2231 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
2232 bombout(("Protocol confusion"));
2233 crReturnV;
2234 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1408a877 2235 c_write_str("Server refused to compress\r\n");
4ba9b64b 2236 }
2237 logevent("Started compression");
2238 ssh1_compressing = TRUE;
2239 zlib_compress_init();
2240 zlib_decompress_init();
2241 }
2242
96621a84 2243 if (*cfg.remote_cmd_ptr)
2244 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd_ptr, PKT_END);
6abbf9e3 2245 else
2246 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 2247 logevent("Started session");
374330e2 2248
2249 ssh_state = SSH_STATE_SESSION;
2250 if (size_needed)
2251 ssh_size();
3687d221 2252 if (eof_needed)
2253 ssh_special(TS_EOF);
374330e2 2254
0965bee0 2255 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 2256 ssh_send_ok = 1;
dacbd0e8 2257 ssh_channels = newtree234(ssh_channelcmp);
374330e2 2258 while (1) {
2259 crReturnV;
2260 if (ispkt) {
e5574168 2261 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2262 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 2263 long len = GET_32BIT(pktin.body);
fe50e814 2264 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2265 pktin.body+4, len);
e5574168 2266 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 2267 ssh_state = SSH_STATE_CLOSED;
c5e9c988 2268 logevent("Received disconnect request");
3257deae 2269 crReturnV;
9c964e85 2270 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2271 /* Remote side is trying to open a channel to talk to our
2272 * X-Server. Give them back a local channel number. */
9c964e85 2273 struct ssh_channel *c, *d;
9c964e85 2274
2275 logevent("Received X11 connect request");
2276 /* Refuse if X11 forwarding is disabled. */
2277 if (!ssh_X11_fwd_enabled) {
2278 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2279 PKT_INT, GET_32BIT(pktin.body),
2280 PKT_END);
2281 logevent("Rejected X11 connect request");
2282 } else {
9c964e85 2283 c = smalloc(sizeof(struct ssh_channel));
2284
0c6c9a70 2285 if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
9c964e85 2286 logevent("opening X11 forward connection failed");
2287 sfree(c);
2288 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2289 PKT_INT, GET_32BIT(pktin.body),
2290 PKT_END);
2291 } else {
2292 logevent("opening X11 forward connection succeeded");
9c964e85 2293 c->remoteid = GET_32BIT(pktin.body);
d2371c81 2294 c->localid = alloc_channel_id();
9c964e85 2295 c->closes = 0;
783415f8 2296 c->type = CHAN_X11; /* identify channel type */
9c964e85 2297 add234(ssh_channels, c);
2298 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2299 PKT_INT, c->remoteid, PKT_INT, c->localid,
2300 PKT_END);
2301 logevent("Opened X11 forward channel");
2302 }
2303 }
dacbd0e8 2304 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2305 /* Remote side is trying to open a channel to talk to our
2306 * agent. Give them back a local channel number. */
db7d555c 2307 unsigned i;
dacbd0e8 2308 struct ssh_channel *c;
db7d555c 2309
2310 /* Refuse if agent forwarding is disabled. */
2311 if (!ssh_agentfwd_enabled) {
2312 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2313 PKT_INT, GET_32BIT(pktin.body),
2314 PKT_END);
2315 } else {
dcbde236 2316 c = smalloc(sizeof(struct ssh_channel));
db7d555c 2317 c->remoteid = GET_32BIT(pktin.body);
d2371c81 2318 c->localid = alloc_channel_id();
db7d555c 2319 c->closes = 0;
783415f8 2320 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 2321 c->u.a.lensofar = 0;
2322 add234(ssh_channels, c);
2323 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2324 PKT_INT, c->remoteid, PKT_INT, c->localid,
2325 PKT_END);
2326 }
2327 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2328 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
dacbd0e8 2329 /* Remote side closes a channel. */
d211621f 2330 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 2331 struct ssh_channel *c;
2332 c = find234(ssh_channels, &i, ssh_channelfind);
2333 if (c) {
2334 int closetype;
2335 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
824e9f94 2336 if (!(c->closes & closetype))
2337 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
783415f8 2338 if ((c->closes == 0) && (c->type == CHAN_X11)) {
9c964e85 2339 logevent("X11 connection closed");
2340 assert(c->u.x11.s != NULL);
2341 x11_close(c->u.x11.s);
2342 c->u.x11.s = NULL;
2343 }
dacbd0e8 2344 c->closes |= closetype;
2345 if (c->closes == 3) {
2346 del234(ssh_channels, c);
dcbde236 2347 sfree(c);
dacbd0e8 2348 }
2349 }
2350 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2351 /* Data sent down one of our channels. */
2352 int i = GET_32BIT(pktin.body);
2353 int len = GET_32BIT(pktin.body+4);
2354 unsigned char *p = pktin.body+8;
2355 struct ssh_channel *c;
2356 c = find234(ssh_channels, &i, ssh_channelfind);
2357 if (c) {
2358 switch(c->type) {
783415f8 2359 case CHAN_X11:
9c964e85 2360 x11_send(c->u.x11.s, p, len);
2361 break;
783415f8 2362 case CHAN_AGENT:
dacbd0e8 2363 /* Data for an agent message. Buffer it. */
2364 while (len > 0) {
2365 if (c->u.a.lensofar < 4) {
2366 int l = min(4 - c->u.a.lensofar, len);
2367 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
2368 p += l; len -= l; c->u.a.lensofar += l;
2369 }
2370 if (c->u.a.lensofar == 4) {
2371 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
dcbde236 2372 c->u.a.message = smalloc(c->u.a.totallen);
dacbd0e8 2373 memcpy(c->u.a.message, c->u.a.msglen, 4);
2374 }
2375 if (c->u.a.lensofar >= 4 && len > 0) {
2376 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
2377 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
2378 p += l; len -= l; c->u.a.lensofar += l;
2379 }
2380 if (c->u.a.lensofar == c->u.a.totallen) {
2381 void *reply, *sentreply;
2382 int replylen;
2383 agent_query(c->u.a.message, c->u.a.totallen,
2384 &reply, &replylen);
2385 if (reply)
2386 sentreply = reply;
2387 else {
2388 /* Fake SSH_AGENT_FAILURE. */
2389 sentreply = "\0\0\0\1\5";
2390 replylen = 5;
2391 }
2392 send_packet(SSH1_MSG_CHANNEL_DATA,
2393 PKT_INT, c->remoteid,
2394 PKT_INT, replylen,
2395 PKT_DATA, sentreply, replylen,
2396 PKT_END);
2397 if (reply)
dcbde236 2398 sfree(reply);
2399 sfree(c->u.a.message);
dacbd0e8 2400 c->u.a.lensofar = 0;
2401 }
2402 }
2403 break;
2404 }
2405 }
e5574168 2406 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 2407 /* may be from EXEC_SHELL on some servers */
e5574168 2408 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 2409 /* may be from EXEC_SHELL on some servers
374330e2 2410 * if no pty is available or in other odd cases. Ignore */
e5574168 2411 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2412 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 2413 } else {
8d5de777 2414 bombout(("Strange packet received: type %d", pktin.type));
2415 crReturnV;
374330e2 2416 }
2417 } else {
8df7a775 2418 while (inlen > 0) {
2419 int len = min(inlen, 512);
2420 send_packet(SSH1_CMSG_STDIN_DATA,
2421 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2422 in += len;
2423 inlen -= len;
2424 }
374330e2 2425 }
2426 }
2427
2428 crFinishV;
2429}
2430
2431/*
e5574168 2432 * Utility routine for decoding comma-separated strings in KEXINIT.
2433 */
75cab814 2434static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 2435 int needlen = strlen(needle);
2436 while (1) {
2437 /*
2438 * Is it at the start of the string?
2439 */
2440 if (haylen >= needlen && /* haystack is long enough */
2441 !memcmp(needle, haystack, needlen) && /* initial match */
2442 (haylen == needlen || haystack[needlen] == ',')
2443 /* either , or EOS follows */
2444 )
2445 return 1;
2446 /*
2447 * If not, search for the next comma and resume after that.
2448 * If no comma found, terminate.
2449 */
2450 while (haylen > 0 && *haystack != ',')
2451 haylen--, haystack++;
2452 if (haylen == 0)
2453 return 0;
2454 haylen--, haystack++; /* skip over comma itself */
2455 }
2456}
2457
2458/*
d39f364a 2459 * SSH2 key creation method.
2460 */
5e0d7cb8 2461static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr, char *keyspace) {
d39f364a 2462 SHA_State s;
2463 /* First 20 bytes. */
2464 SHA_Init(&s);
2465 sha_mpint(&s, K);
2466 SHA_Bytes(&s, H, 20);
2467 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 2468 SHA_Bytes(&s, sessid, 20);
d39f364a 2469 SHA_Final(&s, keyspace);
2470 /* Next 20 bytes. */
2471 SHA_Init(&s);
2472 sha_mpint(&s, K);
2473 SHA_Bytes(&s, H, 20);
2474 SHA_Bytes(&s, keyspace, 20);
2475 SHA_Final(&s, keyspace+20);
2476}
2477
2478/*
7cca0d81 2479 * Handle the SSH2 transport layer.
e5574168 2480 */
7cca0d81 2481static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 2482{
7bd5a860 2483 static int i, j, len, nbits, pbits;
e5574168 2484 static char *str;
a92dd380 2485 static Bignum p, g, e, f, K;
2486 static int kex_init_value, kex_reply_value;
7591b9ff 2487 static const struct ssh_mac **maclist;
8b2715b2 2488 static int nmacs;
0a3f1d48 2489 static const struct ssh2_cipher *cscipher_tobe = NULL;
2490 static const struct ssh2_cipher *sccipher_tobe = NULL;
57476f6b 2491 static const struct ssh_mac *csmac_tobe = NULL;
2492 static const struct ssh_mac *scmac_tobe = NULL;
2493 static const struct ssh_compress *cscomp_tobe = NULL;
2494 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 2495 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 2496 static int hostkeylen, siglen;
e055a386 2497 static void *hkey; /* actual host key */
e5574168 2498 static unsigned char exchange_hash[20];
d39f364a 2499 static unsigned char keyspace[40];
0a3f1d48 2500 static const struct ssh2_ciphers *preferred_cipher;
4ba9b64b 2501 static const struct ssh_compress *preferred_comp;
0db56f73 2502 static int first_kex;
e5574168 2503
2504 crBegin;
7cca0d81 2505 random_init();
0db56f73 2506 first_kex = 1;
e5574168 2507
5e8358ad 2508 /*
4ba9b64b 2509 * Set up the preferred cipher and compression.
5e8358ad 2510 */
2511 if (cfg.cipher == CIPHER_BLOWFISH) {
0a3f1d48 2512 preferred_cipher = &ssh2_blowfish;
5e8358ad 2513 } else if (cfg.cipher == CIPHER_DES) {
2514 logevent("Single DES not supported in SSH2; using 3DES");
0a3f1d48 2515 preferred_cipher = &ssh2_3des;
5e8358ad 2516 } else if (cfg.cipher == CIPHER_3DES) {
0a3f1d48 2517 preferred_cipher = &ssh2_3des;
2518 } else if (cfg.cipher == CIPHER_AES) {
2519 preferred_cipher = &ssh2_aes;
5e8358ad 2520 } else {
2521 /* Shouldn't happen, but we do want to initialise to _something_. */
0a3f1d48 2522 preferred_cipher = &ssh2_3des;
5e8358ad 2523 }
4ba9b64b 2524 if (cfg.compression)
2525 preferred_comp = &ssh_zlib;
2526 else
2527 preferred_comp = &ssh_comp_none;
5e8358ad 2528
7591b9ff 2529 /*
2530 * Be prepared to work around the buggy MAC problem.
2531 */
7d503c31 2532 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
8b2715b2 2533 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 2534 else
8b2715b2 2535 maclist = macs, nmacs = lenof(macs);
7591b9ff 2536
7cca0d81 2537 begin_key_exchange:
e5574168 2538 /*
2539 * Construct and send our key exchange packet.
2540 */
2541 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2542 for (i = 0; i < 16; i++)
2543 ssh2_pkt_addbyte((unsigned char)random_byte());
2544 /* List key exchange algorithms. */
2545 ssh2_pkt_addstring_start();
2546 for (i = 0; i < lenof(kex_algs); i++) {
2547 ssh2_pkt_addstring_str(kex_algs[i]->name);
2548 if (i < lenof(kex_algs)-1)
2549 ssh2_pkt_addstring_str(",");
2550 }
2551 /* List server host key algorithms. */
2552 ssh2_pkt_addstring_start();
2553 for (i = 0; i < lenof(hostkey_algs); i++) {
2554 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2555 if (i < lenof(hostkey_algs)-1)
2556 ssh2_pkt_addstring_str(",");
2557 }
2558 /* List client->server encryption algorithms. */
2559 ssh2_pkt_addstring_start();
729e54b4 2560 for (i = 0; i < lenof(ciphers)+1; i++) {
0a3f1d48 2561 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2562 for (j = 0; j < c->nciphers; j++) {
2563 ssh2_pkt_addstring_str(c->list[j]->name);
2564 if (i < lenof(ciphers) || j < c->nciphers-1)
2565 ssh2_pkt_addstring_str(",");
2566 }
e5574168 2567 }
2568 /* List server->client encryption algorithms. */
2569 ssh2_pkt_addstring_start();
729e54b4 2570 for (i = 0; i < lenof(ciphers)+1; i++) {
0a3f1d48 2571 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2572 for (j = 0; j < c->nciphers; j++) {
2573 ssh2_pkt_addstring_str(c->list[j]->name);
2574 if (i < lenof(ciphers) || j < c->nciphers-1)
2575 ssh2_pkt_addstring_str(",");
2576 }
e5574168 2577 }
2578 /* List client->server MAC algorithms. */
2579 ssh2_pkt_addstring_start();
8b2715b2 2580 for (i = 0; i < nmacs; i++) {
7591b9ff 2581 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2582 if (i < nmacs-1)
e5574168 2583 ssh2_pkt_addstring_str(",");
2584 }
2585 /* List server->client MAC algorithms. */
2586 ssh2_pkt_addstring_start();
8b2715b2 2587 for (i = 0; i < nmacs; i++) {
7591b9ff 2588 ssh2_pkt_addstring_str(maclist[i]->name);
8b2715b2 2589 if (i < nmacs-1)
e5574168 2590 ssh2_pkt_addstring_str(",");
2591 }
2592 /* List client->server compression algorithms. */
2593 ssh2_pkt_addstring_start();
4ba9b64b 2594 for (i = 0; i < lenof(compressions)+1; i++) {
2595 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2596 ssh2_pkt_addstring_str(c->name);
2597 if (i < lenof(compressions))
e5574168 2598 ssh2_pkt_addstring_str(",");
2599 }
2600 /* List server->client compression algorithms. */
2601 ssh2_pkt_addstring_start();
4ba9b64b 2602 for (i = 0; i < lenof(compressions)+1; i++) {
2603 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2604 ssh2_pkt_addstring_str(c->name);
2605 if (i < lenof(compressions))
e5574168 2606 ssh2_pkt_addstring_str(",");
2607 }
2608 /* List client->server languages. Empty list. */
2609 ssh2_pkt_addstring_start();
2610 /* List server->client languages. Empty list. */
2611 ssh2_pkt_addstring_start();
2612 /* First KEX packet does _not_ follow, because we're not that brave. */
2613 ssh2_pkt_addbool(FALSE);
2614 /* Reserved. */
2615 ssh2_pkt_adduint32(0);
0db56f73 2616
2617 exhash = exhashbase;
e5574168 2618 sha_string(&exhash, pktout.data+5, pktout.length-5);
0db56f73 2619
e5574168 2620 ssh2_pkt_send();
2621
2622 if (!ispkt) crWaitUntil(ispkt);
2623 sha_string(&exhash, pktin.data+5, pktin.length-5);
2624
2625 /*
2626 * Now examine the other side's KEXINIT to see what we're up
2627 * to.
2628 */
7cca0d81 2629 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 2630 bombout(("expected key exchange packet from server"));
2631 crReturn(0);
7cca0d81 2632 }
e5574168 2633 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
2634 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
2635 pktin.savedpos += 16; /* skip garbage cookie */
2636 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2637 for (i = 0; i < lenof(kex_algs); i++) {
2638 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2639 kex = kex_algs[i];
2640 break;
2641 }
2642 }
2643 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2644 for (i = 0; i < lenof(hostkey_algs); i++) {
2645 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2646 hostkey = hostkey_algs[i];
2647 break;
2648 }
2649 }
2650 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 2651 for (i = 0; i < lenof(ciphers)+1; i++) {
0a3f1d48 2652 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2653 for (j = 0; j < c->nciphers; j++) {
2654 if (in_commasep_string(c->list[j]->name, str, len)) {
2655 cscipher_tobe = c->list[j];
2656 break;
2657 }
e5574168 2658 }
0a3f1d48 2659 if (cscipher_tobe)
2660 break;
e5574168 2661 }
2662 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
729e54b4 2663 for (i = 0; i < lenof(ciphers)+1; i++) {
0a3f1d48 2664 const struct ssh2_ciphers *c = i==0 ? preferred_cipher : ciphers[i-1];
2665 for (j = 0; j < c->nciphers; j++) {
2666 if (in_commasep_string(c->list[j]->name, str, len)) {
2667 sccipher_tobe = c->list[j];
2668 break;
2669 }
e5574168 2670 }
0a3f1d48 2671 if (sccipher_tobe)
2672 break;
e5574168 2673 }
2674 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 2675 for (i = 0; i < nmacs; i++) {
7591b9ff 2676 if (in_commasep_string(maclist[i]->name, str, len)) {
2677 csmac_tobe = maclist[i];
e5574168 2678 break;
2679 }
2680 }
2681 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 2682 for (i = 0; i < nmacs; i++) {
7591b9ff 2683 if (in_commasep_string(maclist[i]->name, str, len)) {
2684 scmac_tobe = maclist[i];
e5574168 2685 break;
2686 }
2687 }
2688 ssh2_pkt_getstring(&str, &len); /* client->server compression */
4ba9b64b 2689 for (i = 0; i < lenof(compressions)+1; i++) {
2690 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2691 if (in_commasep_string(c->name, str, len)) {
2692 cscomp_tobe = c;
e5574168 2693 break;
2694 }
2695 }
2696 ssh2_pkt_getstring(&str, &len); /* server->client compression */
4ba9b64b 2697 for (i = 0; i < lenof(compressions)+1; i++) {
2698 const struct ssh_compress *c = i==0 ? preferred_comp : compressions[i-1];
2699 if (in_commasep_string(c->name, str, len)) {
2700 sccomp_tobe = c;
e5574168 2701 break;
2702 }
2703 }
e5574168 2704
2705 /*
7bd5a860 2706 * Work out the number of bits of key we will need from the key
2707 * exchange. We start with the maximum key length of either
2708 * cipher...
2709 */
2710 {
2711 int csbits, scbits;
2712
2713 csbits = cscipher_tobe->keylen;
2714 scbits = sccipher_tobe->keylen;
2715 nbits = (csbits > scbits ? csbits : scbits);
2716 }
2717 /* The keys only have 160-bit entropy, since they're based on
2718 * a SHA-1 hash. So cap the key size at 160 bits. */
2719 if (nbits > 160) nbits = 160;
2720
2721 /*
a92dd380 2722 * If we're doing Diffie-Hellman group exchange, start by
2723 * requesting a group.
e5574168 2724 */
a92dd380 2725 if (kex == &ssh_diffiehellman_gex) {
a92dd380 2726 logevent("Doing Diffie-Hellman group exchange");
2727 /*
7bd5a860 2728 * Work out how big a DH group we will need to allow that
2729 * much data.
2730 */
2731 pbits = 512 << ((nbits-1) / 64);
a92dd380 2732 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
7bd5a860 2733 ssh2_pkt_adduint32(pbits);
a92dd380 2734 ssh2_pkt_send();
2735
2736 crWaitUntil(ispkt);
2737 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
2738 bombout(("expected key exchange group packet from server"));
2739 crReturn(0);
2740 }
2741 p = ssh2_pkt_getmp();
2742 g = ssh2_pkt_getmp();
2743 dh_setup_group(p, g);
2744 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
2745 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
2746 } else {
2747 dh_setup_group1();
2748 kex_init_value = SSH2_MSG_KEXDH_INIT;
2749 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 2750 }
e5574168 2751
a92dd380 2752 logevent("Doing Diffie-Hellman key exchange");
e5574168 2753 /*
a92dd380 2754 * Now generate and send e for Diffie-Hellman.
e5574168 2755 */
7bd5a860 2756 e = dh_create_e(nbits*2);
a92dd380 2757 ssh2_pkt_init(kex_init_value);
e5574168 2758 ssh2_pkt_addmp(e);
2759 ssh2_pkt_send();
2760
2761 crWaitUntil(ispkt);
a92dd380 2762 if (pktin.type != kex_reply_value) {
2763 bombout(("expected key exchange reply packet from server"));
8d5de777 2764 crReturn(0);
7cca0d81 2765 }
e5574168 2766 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2767 f = ssh2_pkt_getmp();
e5574168 2768 ssh2_pkt_getstring(&sigdata, &siglen);
2769
2770 K = dh_find_K(f);
e5574168 2771
2772 sha_string(&exhash, hostkeydata, hostkeylen);
a92dd380 2773 if (kex == &ssh_diffiehellman_gex) {
7bd5a860 2774 sha_uint32(&exhash, pbits);
a92dd380 2775 sha_mpint(&exhash, p);
2776 sha_mpint(&exhash, g);
2777 }
e5574168 2778 sha_mpint(&exhash, e);
2779 sha_mpint(&exhash, f);
2780 sha_mpint(&exhash, K);
2781 SHA_Final(&exhash, exchange_hash);
2782
3709bfe9 2783 dh_cleanup();
2784
7cca0d81 2785#if 0
e5574168 2786 debug(("Exchange hash is:\r\n"));
2787 for (i = 0; i < 20; i++)
2788 debug((" %02x", exchange_hash[i]));
2789 debug(("\r\n"));
7cca0d81 2790#endif
2791
e055a386 2792 hkey = hostkey->newkey(hostkeydata, hostkeylen);
2793 if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
8d5de777 2794 bombout(("Server failed host key check"));
2795 crReturn(0);
2796 }
e5574168 2797
2798 /*
7cca0d81 2799 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2800 */
7cca0d81 2801 crWaitUntil(ispkt);
8d5de777 2802 if (pktin.type != SSH2_MSG_NEWKEYS) {
2803 bombout(("expected new-keys packet from server"));
2804 crReturn(0);
2805 }
d39f364a 2806
2807 /*
7cca0d81 2808 * Authenticate remote host: verify host key. (We've already
2809 * checked the signature of the exchange hash.)
e5574168 2810 */
e055a386 2811 keystr = hostkey->fmtkey(hkey);
2812 fingerprint = hostkey->fingerprint(hkey);
d4857987 2813 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2814 keystr, fingerprint);
a92dd380 2815 if (first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 2816 logevent("Host key fingerprint is:");
2817 logevent(fingerprint);
2818 }
dcbde236 2819 sfree(fingerprint);
2820 sfree(keystr);
e055a386 2821 hostkey->freekey(hkey);
d39f364a 2822
2823 /*
7cca0d81 2824 * Send SSH2_MSG_NEWKEYS.
d39f364a 2825 */
2826 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2827 ssh2_pkt_send();
d39f364a 2828
2829 /*
2830 * Create and initialise session keys.
2831 */
2832 cscipher = cscipher_tobe;
2833 sccipher = sccipher_tobe;
2834 csmac = csmac_tobe;
2835 scmac = scmac_tobe;
2836 cscomp = cscomp_tobe;
2837 sccomp = sccomp_tobe;
4ba9b64b 2838 cscomp->compress_init();
2839 sccomp->decompress_init();
d39f364a 2840 /*
5e0d7cb8 2841 * Set IVs after keys. Here we use the exchange hash from the
2842 * _first_ key exchange.
d39f364a 2843 */
5e0d7cb8 2844 if (first_kex)
65a22376 2845 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
2846 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
5e0d7cb8 2847 cscipher->setcskey(keyspace);
65a22376 2848 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
5e0d7cb8 2849 sccipher->setsckey(keyspace);
65a22376 2850 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
5e0d7cb8 2851 cscipher->setcsiv(keyspace);
65a22376 2852 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
5e0d7cb8 2853 sccipher->setsciv(keyspace);
65a22376 2854 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
5e0d7cb8 2855 csmac->setcskey(keyspace);
65a22376 2856 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
5e0d7cb8 2857 scmac->setsckey(keyspace);
d39f364a 2858
033b4cef 2859 /*
0db56f73 2860 * If this is the first key exchange phase, we must pass the
2861 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2862 * wants to see it but because it will need time to initialise
2863 * itself before it sees an actual packet. In subsequent key
2864 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2865 * it would only confuse the layer above.
2866 */
2867 if (!first_kex) {
2868 crReturn(0);
2869 }
2870 first_kex = 0;
2871
2872 /*
7cca0d81 2873 * Now we're encrypting. Begin returning 1 to the protocol main
2874 * function so that other things can run on top of the
2875 * transport. If we ever see a KEXINIT, we must go back to the
2876 * start.
033b4cef 2877 */
e96adf72 2878 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
7cca0d81 2879 crReturn(1);
e96adf72 2880 }
5e0d7cb8 2881 logevent("Server initiated key re-exchange");
7cca0d81 2882 goto begin_key_exchange;
e5574168 2883
2884 crFinish(1);
2885}
2886
7cca0d81 2887/*
783415f8 2888 * Add data to an SSH2 channel output buffer.
2889 */
2890static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) {
2891 if (c->v2.outbufsize <
2892 c->v2.outbuflen + len) {
2893 c->v2.outbufsize =
2894 c->v2.outbuflen + len + 1024;
2895 c->v2.outbuffer = srealloc(c->v2.outbuffer,
2896 c->v2.outbufsize);
2897 }
2898 memcpy(c->v2.outbuffer + c->v2.outbuflen,
2899 buf, len);
2900 c->v2.outbuflen += len;
2901}
2902
2903/*
2904 * Attempt to send data on an SSH2 channel.
2905 */
2906static void ssh2_try_send(struct ssh_channel *c) {
2907 while (c->v2.remwindow > 0 &&
2908 c->v2.outbuflen > 0) {
2909 unsigned len = c->v2.remwindow;
2910 if (len > c->v2.outbuflen)
2911 len = c->v2.outbuflen;
2912 if (len > c->v2.remmaxpkt)
2913 len = c->v2.remmaxpkt;
2914 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2915 ssh2_pkt_adduint32(c->remoteid);
2916 ssh2_pkt_addstring_start();
2917 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
2918 ssh2_pkt_send();
2919 c->v2.outbuflen -= len;
2920 memmove(c->v2.outbuffer, c->v2.outbuffer+len,
2921 c->v2.outbuflen);
2922 c->v2.remwindow -= len;
2923 }
2924}
2925
2926/*
7cca0d81 2927 * Handle the SSH2 userauth and connection layers.
2928 */
2929static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2930{
7cca0d81 2931 static unsigned long remote_winsize;
2932 static unsigned long remote_maxpkt;
65a22376 2933 static enum {
2934 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE, AUTH_PASSWORD
2935 } method;
1408a877 2936 static enum {
2937 AUTH_TYPE_NONE,
2938 AUTH_TYPE_PUBLICKEY,
2939 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
2940 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
2941 AUTH_TYPE_PASSWORD
2942 } type;
1983e559 2943 static int gotit, need_pw, can_pubkey, can_passwd;
2944 static int tried_pubkey_config, tried_agent;
1408a877 2945 static int we_are_in;
65a22376 2946 static char username[100];
2947 static char pwprompt[200];
2948 static char password[100];
7cca0d81 2949
e5574168 2950 crBegin;
2951
7cca0d81 2952 /*
2953 * Request userauth protocol, and await a response to it.
2954 */
2955 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2956 ssh2_pkt_addstring("ssh-userauth");
2957 ssh2_pkt_send();
2958 crWaitUntilV(ispkt);
8d5de777 2959 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2960 bombout(("Server refused user authentication protocol"));
2961 crReturnV;
2962 }
7cca0d81 2963
2964 /*
1408a877 2965 * We repeat this whole loop, including the username prompt,
2966 * until we manage a successful authentication. If the user
2967 * types the wrong _password_, they are sent back to the
2968 * beginning to try another username. (If they specify a
2969 * username in the config, they are never asked, even if they
2970 * do give a wrong password.)
2971 *
2972 * I think this best serves the needs of
2973 *
2974 * - the people who have no configuration, no keys, and just
2975 * want to try repeated (username,password) pairs until they
2976 * type both correctly
2977 *
2978 * - people who have keys and configuration but occasionally
2979 * need to fall back to passwords
2980 *
2981 * - people with a key held in Pageant, who might not have
2982 * logged in to a particular machine before; so they want to
2983 * type a username, and then _either_ their key will be
2984 * accepted, _or_ they will type a password. If they mistype
2985 * the username they will want to be able to get back and
2986 * retype it!
7cca0d81 2987 */
1408a877 2988 do {
2989 static int pos;
7cca0d81 2990 static char c;
e5574168 2991
1408a877 2992 /*
2993 * Get a username.
2994 */
2995 pos = 0;
67779be7 2996 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
fa17a66e 2997 if (ssh_get_line) {
2998 if (!ssh_get_line("login as: ",
2999 username, sizeof(username), FALSE)) {
3000 /*
3001 * get_line failed to get a username.
3002 * Terminate.
3003 */
3004 logevent("No username provided. Abandoning session.");
3005 ssh_state = SSH_STATE_CLOSED;
dae2b91f 3006 crReturnV;
fa17a66e 3007 }
3008 } else {
3009 c_write_str("login as: ");
3010 ssh_send_ok = 1;
3011 while (pos >= 0) {
3012 crWaitUntilV(!ispkt);
3013 while (inlen--) switch (c = *in++) {
3014 case 10: case 13:
3015 username[pos] = 0;
3016 pos = -1;
3017 break;
3018 case 8: case 127:
3019 if (pos > 0) {
3020 c_write_str("\b \b");
3021 pos--;
3022 }
3023 break;
3024 case 21: case 27:
3025 while (pos > 0) {
3026 c_write_str("\b \b");
3027 pos--;
3028 }
3029 break;
3030 case 3: case 4:
3031 random_save_seed();
3032 exit(0);
3033 break;
3034 default:
3035 if (((c >= ' ' && c <= '~') ||
3036 ((unsigned char)c >= 160)) && pos < 40) {
3037 username[pos++] = c;
3038 c_write(&c, 1);
3039 }
3040 break;
3041 }
3042 }
3043 }
1408a877 3044 c_write_str("\r\n");
7cca0d81 3045 username[strcspn(username, "\n\r")] = '\0';
3046 } else {
3047 char stuff[200];
3048 strncpy(username, cfg.username, 99);
3049 username[99] = '\0';
65a22376 3050 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 3051 sprintf(stuff, "Using username \"%s\".\r\n", username);
1408a877 3052 c_write_str(stuff);
7cca0d81 3053 }
3054 }
3055
65a22376 3056 /*
1408a877 3057 * Send an authentication request using method "none": (a)
3058 * just in case it succeeds, and (b) so that we know what
3059 * authentication methods we can usefully try next.
65a22376 3060 */
1408a877 3061 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3062 ssh2_pkt_addstring(username);
3063 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3064 ssh2_pkt_addstring("none"); /* method */
3065 ssh2_pkt_send();
3066 type = AUTH_TYPE_NONE;
3067 gotit = FALSE;
3068 we_are_in = FALSE;
7cca0d81 3069
1408a877 3070 tried_pubkey_config = FALSE;
1983e559 3071 tried_agent = FALSE;
65a22376 3072
1408a877 3073 while (1) {
3074 /*
3075 * Wait for the result of the last authentication request.
3076 */
3077 if (!gotit)
3078 crWaitUntilV(ispkt);
3079 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
a209e957 3080 char *banner;
3081 int size;
10446215 3082 /*
3083 * Don't show the banner if we're operating in
3084 * non-verbose non-interactive mode. (It's probably
3085 * a script, which means nobody will read the
3086 * banner _anyway_, and moreover the printing of
3087 * the banner will screw up processing on the
3088 * output of (say) plink.)
3089 */
3090 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3091 ssh2_pkt_getstring(&banner, &size);
3092 if (banner)
3093 c_write_untrusted(banner, size);
3094 }
1408a877 3095 crWaitUntilV(ispkt);
3096 }
3097 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3098 logevent("Access granted");
3099 we_are_in = TRUE;
3100 break;
3101 }
65a22376 3102
1408a877 3103 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
3104 bombout(("Strange packet received during authentication: type %d",
3105 pktin.type));
38c4a8da 3106 crReturnV;
65a22376 3107 }
3108
1408a877 3109 gotit = FALSE;
65a22376 3110
1408a877 3111 /*
3112 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3113 * we can look at the string in it and know what we can
3114 * helpfully try next.
3115 */
3116 {
3117 char *methods;
3118 int methlen;
3119 ssh2_pkt_getstring(&methods, &methlen);
3120 if (!ssh2_pkt_getbool()) {
3121 /*
3122 * We have received an unequivocal Access
3123 * Denied. This can translate to a variety of
3124 * messages:
3125 *
3126 * - if we'd just tried "none" authentication,
3127 * it's not worth printing anything at all
3128 *
3129 * - if we'd just tried a public key _offer_,
3130 * the message should be "Server refused our
3131 * key" (or no message at all if the key
3132 * came from Pageant)
3133 *
3134 * - if we'd just tried anything else, the
3135 * message really should be "Access denied".
3136 *
3137 * Additionally, if we'd just tried password
3138 * authentication, we should break out of this
3139 * whole loop so as to go back to the username
3140 * prompt.
3141 */
3142 if (type == AUTH_TYPE_NONE) {
3143 /* do nothing */
3144 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3145 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3146 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3147 c_write_str("Server refused our key\r\n");
3148 logevent("Server refused public key");
3149 } else {
3150 c_write_str("Access denied\r\n");
3151 logevent("Access denied");
3152 if (type == AUTH_TYPE_PASSWORD) {
3153 we_are_in = FALSE;
3154 break;
3155 }
3156 }
3157 } else {
3158 c_write_str("Further authentication required\r\n");
3159 logevent("Further authentication required");
3160 }
65a22376 3161
1408a877 3162 can_pubkey = in_commasep_string("publickey", methods, methlen);
3163 can_passwd = in_commasep_string("password", methods, methlen);
3164 }
65a22376 3165
1408a877 3166 method = 0;
65a22376 3167
1983e559 3168 if (!method && can_pubkey && agent_exists && !tried_agent) {
3169 /*
3170 * Attempt public-key authentication using Pageant.
3171 */
3172 static unsigned char request[5], *response, *p;
3173 static int responselen;
3174 static int i, nkeys;
3175 static int authed = FALSE;
3176 void *r;
3177
3178 tried_agent = TRUE;
3179
3180 logevent("Pageant is running. Requesting keys.");
3181
3182 /* Request the keys held by the agent. */
3183 PUT_32BIT(request, 1);
3184 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3185 agent_query(request, 5, &r, &responselen);
3186 response = (unsigned char *)r;
95797139 3187 if (response && responselen >= 5 &&
3188 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
1983e559 3189 p = response + 5;
3190 nkeys = GET_32BIT(p); p += 4;
6328ea7a 3191 { char buf[64]; sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
1983e559 3192 logevent(buf); }
3193 for (i = 0; i < nkeys; i++) {
3194 static char *pkblob, *alg, *commentp;
3195 static int pklen, alglen, commentlen;
3196 static int siglen, retlen, len;
3197 static char *q, *agentreq, *ret;
3198
3199 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
3200 logevent(buf); }
3201 pklen = GET_32BIT(p); p += 4;
3202 pkblob = p; p += pklen;
3203 alglen = GET_32BIT(pkblob);
3204 alg = pkblob + 4;
3205 commentlen = GET_32BIT(p); p += 4;
3206 commentp = p; p += commentlen;
3207 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3208 ssh2_pkt_addstring(username);
3209 ssh2_pkt_addstring("ssh-connection");/* service requested */
3210 ssh2_pkt_addstring("publickey");/* method */
3211 ssh2_pkt_addbool(FALSE); /* no signature included */
3212 ssh2_pkt_addstring_start();
3213 ssh2_pkt_addstring_data(alg, alglen);
3214 ssh2_pkt_addstring_start();
3215 ssh2_pkt_addstring_data(pkblob, pklen);
3216 ssh2_pkt_send();
3217
3218 crWaitUntilV(ispkt);
3219 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3220 logevent("Key refused");
3221 continue;
3222 }
3223
10446215 3224 if (flags & FLAG_VERBOSE) {
3225 c_write_str("Authenticating with public key \"");
3226 c_write(commentp, commentlen);
3227 c_write_str("\" from agent\r\n");
3228 }
1983e559 3229
3230 /*
3231 * Server is willing to accept the key.
3232 * Construct a SIGN_REQUEST.
3233 */
3234 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3235 ssh2_pkt_addstring(username);
3236 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3237 ssh2_pkt_addstring("publickey"); /* method */
3238 ssh2_pkt_addbool(TRUE);
3239 ssh2_pkt_addstring_start();
3240 ssh2_pkt_addstring_data(alg, alglen);
3241 ssh2_pkt_addstring_start();
3242 ssh2_pkt_addstring_data(pkblob, pklen);
3243
3244 siglen = pktout.length - 5 + 4 + 20;
3245 len = 1; /* message type */
3246 len += 4 + pklen; /* key blob */
3247 len += 4 + siglen; /* data to sign */
3248 len += 4; /* flags */
3249 agentreq = smalloc(4 + len);
3250 PUT_32BIT(agentreq, len);
3251 q = agentreq + 4;
3252 *q++ = SSH2_AGENTC_SIGN_REQUEST;
3253 PUT_32BIT(q, pklen); q += 4;
3254 memcpy(q, pkblob, pklen); q += pklen;
3255 PUT_32BIT(q, siglen); q += 4;
3256 /* Now the data to be signed... */
3257 PUT_32BIT(q, 20); q += 4;
3258 memcpy(q, ssh2_session_id, 20); q += 20;
3259 memcpy(q, pktout.data+5, pktout.length-5);
3260 q += pktout.length-5;
3261 /* And finally the (zero) flags word. */
3262 PUT_32BIT(q, 0);
3263 agent_query(agentreq, len+4, &ret, &retlen);
3264 sfree(agentreq);
3265 if (ret) {
3266 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3267 logevent("Sending Pageant's response");
3268 ssh2_pkt_addstring_start();
3269 ssh2_pkt_addstring_data(ret+9, GET_32BIT(ret+5));
3270 ssh2_pkt_send();
3271 authed = TRUE;
3272 break;
3273 } else {
3274 logevent("Pageant failed to answer challenge");
3275 sfree(ret);
3276 }
3277 }
3278 }
3279 if (authed)
3280 continue;
3281 }
3282 }
3283
1408a877 3284 if (!method && can_pubkey && *cfg.keyfile && !tried_pubkey_config) {
3285 unsigned char *pub_blob;
3286 char *algorithm, *comment;
3287 int pub_blob_len;
65a22376 3288
1408a877 3289 tried_pubkey_config = TRUE;
65a22376 3290
65a22376 3291 /*
1408a877 3292 * Try the public key supplied in the configuration.
3293 *
3294 * First, offer the public blob to see if the server is
3295 * willing to accept it.
65a22376 3296 */
1408a877 3297 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3298 &pub_blob_len);
3299 if (pub_blob) {
3300 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3301 ssh2_pkt_addstring(username);
3302 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3303 ssh2_pkt_addstring("publickey");/* method */
3304 ssh2_pkt_addbool(FALSE); /* no signature included */
3305 ssh2_pkt_addstring(algorithm);
3306 ssh2_pkt_addstring_start();
3307 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3308 ssh2_pkt_send();
3309 logevent("Offered public key"); /* FIXME */
3310
3311 crWaitUntilV(ispkt);
3312 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3313 gotit = TRUE;
3314 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
3315 continue; /* key refused; give up on it */
3316 }
65a22376 3317
1408a877 3318 logevent("Offer of public key accepted");
65a22376 3319 /*
1408a877 3320 * Actually attempt a serious authentication using
3321 * the key.
65a22376 3322 */
1408a877 3323 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
3324 sprintf(pwprompt, "Passphrase for key \"%.100s\": ", comment);
3325 need_pw = TRUE;
3326 } else {
3327 need_pw = FALSE;
3328 }
3329 c_write_str("Authenticating with public key \"");
3330 c_write_str(comment);
3331 c_write_str("\"\r\n");
3332 method = AUTH_PUBLICKEY_FILE;
65a22376 3333 }
1408a877 3334 }
3335
3336 if (!method && can_passwd) {
3337 method = AUTH_PASSWORD;
3338 sprintf(pwprompt, "%.90s@%.90s's password: ", username, savedhost);
3339 need_pw = TRUE;
3340 }
3341
3342 if (need_pw) {
fa17a66e 3343 if (ssh_get_line) {
3344 if (!ssh_get_line(pwprompt, password,
3345 sizeof(password), TRUE)) {
1408a877 3346 /*
fa17a66e 3347 * get_line failed to get a password (for
3348 * example because one was supplied on the
3349 * command line which has already failed to
3350 * work). Terminate.
1408a877 3351 */
3352 logevent("No more passwords to try");
3353 ssh_state = SSH_STATE_CLOSED;
3354 crReturnV;
3355 }
3356 } else {
3357 static int pos = 0;
3358 static char c;
3359
3360 c_write_str(pwprompt);
3361 ssh_send_ok = 1;
3362
3363 pos = 0;
3364 while (pos >= 0) {
3365 crWaitUntilV(!ispkt);
3366 while (inlen--) switch (c = *in++) {
3367 case 10: case 13:
3368 password[pos] = 0;
3369 pos = -1;
3370 break;
3371 case 8: case 127:
3372 if (pos > 0)
3373 pos--;
3374 break;
3375 case 21: case 27:
3376 pos = 0;
3377 break;
3378 case 3: case 4:
3379 random_save_seed();
3380 exit(0);
3381 break;
3382 default:
3383 if (((c >= ' ' && c <= '~') ||
3384 ((unsigned char)c >= 160)) && pos < 40)
3385 password[pos++] = c;
3386 break;
3387 }
65a22376 3388 }
1408a877 3389 c_write_str("\r\n");
65a22376 3390 }
65a22376 3391 }
65a22376 3392
1408a877 3393 if (method == AUTH_PUBLICKEY_FILE) {
3394 /*
3395 * We have our passphrase. Now try the actual authentication.
3396 */
3397 struct ssh2_userkey *key;
65a22376 3398
1408a877 3399 key = ssh2_load_userkey(cfg.keyfile, password);
3400 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3401 if (key == SSH2_WRONG_PASSPHRASE) {
3402 c_write_str("Wrong passphrase\r\n");
3403 tried_pubkey_config = FALSE;
3404 } else {
3405 c_write_str("Unable to load private key\r\n");
3406 tried_pubkey_config = TRUE;
3407 }
3408 /* Send a spurious AUTH_NONE to return to the top. */
3409 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3410 ssh2_pkt_addstring(username);
3411 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3412 ssh2_pkt_addstring("none"); /* method */
3413 ssh2_pkt_send();
3414 type = AUTH_TYPE_NONE;
3415 } else {
3416 unsigned char *blob, *sigdata;
3417 int blob_len, sigdata_len;
65a22376 3418
1408a877 3419 /*
3420 * We have loaded the private key and the server
3421 * has announced that it's willing to accept it.
3422 * Hallelujah. Generate a signature and send it.
3423 */
3424 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3425 ssh2_pkt_addstring(username);
3426 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3427 ssh2_pkt_addstring("publickey"); /* method */
3428 ssh2_pkt_addbool(TRUE);
3429 ssh2_pkt_addstring(key->alg->name);
3430 blob = key->alg->public_blob(key->data, &blob_len);
3431 ssh2_pkt_addstring_start();
3432 ssh2_pkt_addstring_data(blob, blob_len);
3433 sfree(blob);
3434
3435 /*
3436 * The data to be signed is:
3437 *
3438 * string session-id
3439 *
3440 * followed by everything so far placed in the
3441 * outgoing packet.
3442 */
3443 sigdata_len = pktout.length - 5 + 4 + 20;
3444 sigdata = smalloc(sigdata_len);
3445 PUT_32BIT(sigdata, 20);
3446 memcpy(sigdata+4, ssh2_session_id, 20);
3447 memcpy(sigdata+24, pktout.data+5, pktout.length-5);
3448 blob = key->alg->sign(key->data, sigdata, sigdata_len, &blob_len);
3449 ssh2_pkt_addstring_start();
3450 ssh2_pkt_addstring_data(blob, blob_len);
3451 sfree(blob);
3452 sfree(sigdata);
3453
3454 ssh2_pkt_send();
3455 type = AUTH_TYPE_PUBLICKEY;
3456 }
3457 } else if (method == AUTH_PASSWORD) {
65a22376 3458 /*
1408a877 3459 * We send the password packet lumped tightly together with
3460 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3461 * string long enough to make the total length of the two
3462 * packets constant. This should ensure that a passive
3463 * listener doing traffic analyis can't work out the length
3464 * of the password.
3465 *
3466 * For this to work, we need an assumption about the
3467 * maximum length of the password packet. I think 256 is
3468 * pretty conservative. Anyone using a password longer than
3469 * that probably doesn't have much to worry about from
3470 * people who find out how long their password is!
65a22376 3471 */
3472 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3473 ssh2_pkt_addstring(username);
3474 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 3475 ssh2_pkt_addstring("password");
3476 ssh2_pkt_addbool(FALSE);
3477 ssh2_pkt_addstring(password);
3478 ssh2_pkt_defer();
65a22376 3479 /*
1408a877 3480 * We'll include a string that's an exact multiple of the
3481 * cipher block size. If the cipher is NULL for some
3482 * reason, we don't do this trick at all because we gain
3483 * nothing by it.
65a22376 3484 */
6e9e9520 3485 if (cscipher) {
3486 int stringlen, i;
3487
3488 stringlen = (256 - deferred_len);
3489 stringlen += cscipher->blksize - 1;
3490 stringlen -= (stringlen % cscipher->blksize);
3491 if (cscomp) {
3492 /*
3493 * Temporarily disable actual compression,
3494 * so we can guarantee to get this string
3495 * exactly the length we want it. The
3496 * compression-disabling routine should
3497 * return an integer indicating how many
3498 * bytes we should adjust our string length
3499 * by.
3500 */
3501 stringlen -= cscomp->disable_compression();
3502 }
1408a877 3503 ssh2_pkt_init(SSH2_MSG_IGNORE);
3504 ssh2_pkt_addstring_start();
6e9e9520 3505 for (i = 0; i < stringlen; i++) {
3506 char c = (char)random_byte();
3507 ssh2_pkt_addstring_data(&c, 1);
65a22376 3508 }
1408a877 3509 ssh2_pkt_defer();
65a22376 3510 }
39065bed 3511 ssh_pkt_defersend();
0d43337a 3512 logevent("Sent password");
1408a877 3513 type = AUTH_TYPE_PASSWORD;
3514 } else {
3515 c_write_str("No supported authentication methods left to try!\r\n");
3516 logevent("No supported authentications offered. Disconnecting");
3517 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3518 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3519 ssh2_pkt_addstring("No supported authentication methods available");
3520 ssh2_pkt_addstring("en"); /* language tag */
3521 ssh2_pkt_send();
3522 ssh_state = SSH_STATE_CLOSED;
3523 crReturnV;
65a22376 3524 }
65a22376 3525 }
1408a877 3526 } while (!we_are_in);
7cca0d81 3527
3528 /*
3529 * Now we're authenticated for the connection protocol. The
3530 * connection protocol will automatically have started at this
3531 * point; there's no need to send SERVICE_REQUEST.
3532 */
3533
3534 /*
3535 * So now create a channel with a session in it.
3536 */
d2371c81 3537 ssh_channels = newtree234(ssh_channelcmp);
dcbde236 3538 mainchan = smalloc(sizeof(struct ssh_channel));
d2371c81 3539 mainchan->localid = alloc_channel_id();
7cca0d81 3540 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3541 ssh2_pkt_addstring("session");
d211621f 3542 ssh2_pkt_adduint32(mainchan->localid);
cf6e59d6 3543 ssh2_pkt_adduint32(0x8000UL); /* our window size */
d211621f 3544 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 3545 ssh2_pkt_send();
3546 crWaitUntilV(ispkt);
3547 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 3548 bombout(("Server refused to open a session"));
3549 crReturnV;
7cca0d81 3550 /* FIXME: error data comes back in FAILURE packet */
3551 }
d211621f 3552 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 3553 bombout(("Server's channel confirmation cited wrong channel"));
3554 crReturnV;
7cca0d81 3555 }
d211621f 3556 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 3557 mainchan->type = CHAN_MAINSESSION;
3558 mainchan->closes = 0;
3559 mainchan->v2.remwindow = ssh2_pkt_getuint32();
3560 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
3561 mainchan->v2.outbuffer = NULL;
3562 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
783415f8 3563 add234(ssh_channels, mainchan);
7cca0d81 3564 logevent("Opened channel for session");
3565
3566 /*
783415f8 3567 * Potentially enable X11 forwarding.
3568 */
3569 if (cfg.x11_forward) {
3570 char proto[20], data[64];
3571 logevent("Requesting X11 forwarding");
3572 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3573 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3574 ssh2_pkt_adduint32(mainchan->remoteid);
3575 ssh2_pkt_addstring("x11-req");
3576 ssh2_pkt_addbool(1); /* want reply */
3577 ssh2_pkt_addbool(0); /* many connections */
3578 ssh2_pkt_addstring(proto);
3579 ssh2_pkt_addstring(data);
3580 ssh2_pkt_adduint32(0); /* screen number */
3581 ssh2_pkt_send();
3582
3583 do {
3584 crWaitUntilV(ispkt);
3585 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3586 unsigned i = ssh2_pkt_getuint32();
3587 struct ssh_channel *c;
3588 c = find234(ssh_channels, &i, ssh_channelfind);
3589 if (!c)
3590 continue; /* nonexistent channel */
3591 c->v2.remwindow += ssh2_pkt_getuint32();
3592 }
3593 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3594
3595 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3596 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3597 bombout(("Server got confused by X11 forwarding request"));
3598 crReturnV;
3599 }
3600 logevent("X11 forwarding refused");
3601 } else {
3602 logevent("X11 forwarding enabled");
3603 ssh_X11_fwd_enabled = TRUE;
3604 }
3605 }
3606
3607 /*
36c2a3e9 3608 * Potentially enable agent forwarding.
3609 */
3610 if (cfg.agentfwd && agent_exists()) {
36c2a3e9 3611 logevent("Requesting OpenSSH-style agent forwarding");
36c2a3e9 3612 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3613 ssh2_pkt_adduint32(mainchan->remoteid);
3614 ssh2_pkt_addstring("auth-agent-req@openssh.com");
3615 ssh2_pkt_addbool(1); /* want reply */
3616 ssh2_pkt_send();
3617
3618 do {
3619 crWaitUntilV(ispkt);
3620 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3621 unsigned i = ssh2_pkt_getuint32();
3622 struct ssh_channel *c;
3623 c = find234(ssh_channels, &i, ssh_channelfind);
3624 if (!c)
3625 continue; /* nonexistent channel */
3626 c->v2.remwindow += ssh2_pkt_getuint32();
3627 }
3628 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3629
3630 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3631 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3632 bombout(("Server got confused by agent forwarding request"));
3633 crReturnV;
3634 }
3635 logevent("Agent forwarding refused");
3636 } else {
3637 logevent("Agent forwarding enabled");
3638 ssh_agentfwd_enabled = TRUE;
3639 }
3640 }
3641
3642 /*
7cca0d81 3643 * Now allocate a pty for the session.
3644 */
67779be7 3645 if (!cfg.nopty) {
3646 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3647 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
3648 ssh2_pkt_addstring("pty-req");
3649 ssh2_pkt_addbool(1); /* want reply */
3650 ssh2_pkt_addstring(cfg.termtype);
3651 ssh2_pkt_adduint32(cols);
3652 ssh2_pkt_adduint32(rows);
3653 ssh2_pkt_adduint32(0); /* pixel width */
3654 ssh2_pkt_adduint32(0); /* pixel height */
3655 ssh2_pkt_addstring_start();
3656 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
3657 ssh2_pkt_send();
6e48c3fe 3658 ssh_state = SSH_STATE_INTERMED;
7cca0d81 3659
67779be7 3660 do {
3661 crWaitUntilV(ispkt);
3662 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 3663 unsigned i = ssh2_pkt_getuint32();
3664 struct ssh_channel *c;
3665 c = find234(ssh_channels, &i, ssh_channelfind);
3666 if (!c)
3667 continue; /* nonexistent channel */
3668 c->v2.remwindow += ssh2_pkt_getuint32();
67779be7 3669 }
3670 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 3671
67779be7 3672 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3673 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 3674 bombout(("Server got confused by pty request"));
3675 crReturnV;
67779be7 3676 }
1408a877 3677 c_write_str("Server refused to allocate pty\r\n");
0965bee0 3678 ssh_editing = ssh_echoing = 1;
67779be7 3679 } else {
3680 logevent("Allocated pty");
7cca0d81 3681 }
0965bee0 3682 } else {
3683 ssh_editing = ssh_echoing = 1;
7cca0d81 3684 }
3685
3686 /*
67779be7 3687 * Start a shell or a remote command.
7cca0d81 3688 */
3689 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 3690 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4a8fc3c4 3691 if (cfg.ssh_subsys) {
3692 ssh2_pkt_addstring("subsystem");
3693 ssh2_pkt_addbool(1); /* want reply */
96621a84 3694 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
3695 } else if (*cfg.remote_cmd_ptr) {
67779be7 3696 ssh2_pkt_addstring("exec");
3697 ssh2_pkt_addbool(1); /* want reply */
96621a84 3698 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
67779be7 3699 } else {
3700 ssh2_pkt_addstring("shell");
3701 ssh2_pkt_addbool(1); /* want reply */
3702 }
7cca0d81 3703 ssh2_pkt_send();
d211621f 3704 do {
7cca0d81 3705 crWaitUntilV(ispkt);
d211621f 3706 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 3707 unsigned i = ssh2_pkt_getuint32();
3708 struct ssh_channel *c;
3709 c = find234(ssh_channels, &i, ssh_channelfind);
3710 if (!c)
3711 continue; /* nonexistent channel */
3712 c->v2.remwindow += ssh2_pkt_getuint32();
d211621f 3713 }
7cca0d81 3714 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3715 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3716 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 3717 bombout(("Server got confused by shell/command request"));
3718 crReturnV;
7cca0d81 3719 }
8d5de777 3720 bombout(("Server refused to start a shell/command"));
3721 crReturnV;
7cca0d81 3722 } else {
8d5de777 3723 logevent("Started a shell/command");
7cca0d81 3724 }
3725
6e48c3fe 3726 ssh_state = SSH_STATE_SESSION;
3727 if (size_needed)
3728 ssh_size();
3687d221 3729 if (eof_needed)
3730 ssh_special(TS_EOF);
6e48c3fe 3731
7cca0d81 3732 /*
3733 * Transfer data!
3734 */
0965bee0 3735 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 3736 ssh_send_ok = 1;
7cca0d81 3737 while (1) {
d211621f 3738 static int try_send;
e5574168 3739 crReturnV;
d211621f 3740 try_send = FALSE;
7cca0d81 3741 if (ispkt) {
3742 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
3743 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
3744 char *data;
3745 int length;
783415f8 3746 unsigned i = ssh2_pkt_getuint32();
3747 struct ssh_channel *c;
3748 c = find234(ssh_channels, &i, ssh_channelfind);
3749 if (!c)
3750 continue; /* nonexistent channel */
7cca0d81 3751 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
3752 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
3753 continue; /* extended but not stderr */
3754 ssh2_pkt_getstring(&data, &length);
d211621f 3755 if (data) {
783415f8 3756 switch (c->type) {
3757 case CHAN_MAINSESSION:
3758 from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA,
3759 data, length);
3760 break;
3761 case CHAN_X11:
3762 x11_send(c->u.x11.s, data, length);
3763 break;
36c2a3e9 3764 case CHAN_AGENT:
3765 while (length > 0) {
3766 if (c->u.a.lensofar < 4) {
3767 int l = min(4 - c->u.a.lensofar, length);
3768 memcpy(c->u.a.msglen + c->u.a.lensofar, data, l);
3769 data += l; length -= l; c->u.a.lensofar += l;
3770 }
3771 if (c->u.a.lensofar == 4) {
3772 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
3773 c->u.a.message = smalloc(c->u.a.totallen);
3774 memcpy(c->u.a.message, c->u.a.msglen, 4);
3775 }
3776 if (c->u.a.lensofar >= 4 && length > 0) {
3777 int l = min(c->u.a.totallen - c->u.a.lensofar,
3778 length);
3779 memcpy(c->u.a.message + c->u.a.lensofar, data, l);
3780 data += l; length -= l; c->u.a.lensofar += l;
3781 }
3782 if (c->u.a.lensofar == c->u.a.totallen) {
3783 void *reply, *sentreply;
3784 int replylen;
3785 agent_query(c->u.a.message, c->u.a.totallen,
3786 &reply, &replylen);
3787 if (reply)
3788 sentreply = reply;
3789 else {
3790 /* Fake SSH_AGENT_FAILURE. */
3791 sentreply = "\0\0\0\1\5";
3792 replylen = 5;
3793 }
3794 ssh2_add_channel_data(c, sentreply, replylen);
3795 try_send = TRUE;
3796 if (reply)
3797 sfree(reply);
3798 sfree(c->u.a.message);
3799 c->u.a.lensofar = 0;
3800 }
3801 }
3802 break;
783415f8 3803 }
d211621f 3804 /*
783415f8 3805 * Enlarge the window again at the remote
3806 * side, just in case it ever runs down and
3807 * they fail to send us any more data.
d211621f 3808 */
3809 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
783415f8 3810 ssh2_pkt_adduint32(c->remoteid);
d211621f 3811 ssh2_pkt_adduint32(length);
3812 ssh2_pkt_send();
3813 }
7cca0d81 3814 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
3815 ssh_state = SSH_STATE_CLOSED;
d211621f 3816 logevent("Received disconnect message");
3257deae 3817 crReturnV;
7cca0d81 3818 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
3819 continue; /* exit status et al; ignore (FIXME?) */
d211621f 3820 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
783415f8 3821 unsigned i = ssh2_pkt_getuint32();
3822 struct ssh_channel *c;
3823
3824 c = find234(ssh_channels, &i, ssh_channelfind);
3825 if (!c)
3826 continue; /* nonexistent channel */
3827
3828 if (c->type == CHAN_X11) {
3829 /*
3830 * Remote EOF on an X11 channel means we should
3831 * wrap up and close the channel ourselves.
3832 */
3833 x11_close(c->u.x11.s);
3834 sshfwd_close(c);
36c2a3e9 3835 } else if (c->type == CHAN_AGENT) {
3836 sshfwd_close(c);
3837 }
d211621f 3838 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
783415f8 3839 unsigned i = ssh2_pkt_getuint32();
3840 struct ssh_channel *c;
783415f8 3841
3842 c = find234(ssh_channels, &i, ssh_channelfind);
3843 if (!c)
3844 continue; /* nonexistent channel */
3845 if (c->closes == 0) {
3846 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3847 ssh2_pkt_adduint32(c->remoteid);
3848 ssh2_pkt_send();
3849 }
3850 /* Do pre-close processing on the channel. */
3851 switch (c->type) {
3852 case CHAN_MAINSESSION:
3853 break; /* nothing to see here, move along */
3854 case CHAN_X11:
3855 break;
36c2a3e9 3856 case CHAN_AGENT:
3857 break;
783415f8 3858 }
3859 del234(ssh_channels, c);
3860 sfree(c->v2.outbuffer);
3861 sfree(c);
3862
3863 /*
3864 * See if that was the last channel left open.
3865 */
d2371c81 3866 if (count234(ssh_channels) == 0) {
d211621f 3867 logevent("All channels closed. Disconnecting");
3868 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
9005f3ba 3869 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3870 ssh2_pkt_addstring("All open channels closed");
3871 ssh2_pkt_addstring("en"); /* language tag */
d211621f 3872 ssh2_pkt_send();
cf6e59d6 3873 ssh_state = SSH_STATE_CLOSED;
3257deae 3874 crReturnV;
d211621f 3875 }
3876 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 3877 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
783415f8 3878 unsigned i = ssh2_pkt_getuint32();
3879 struct ssh_channel *c;
3880 c = find234(ssh_channels, &i, ssh_channelfind);
3881 if (!c)
3882 continue; /* nonexistent channel */
0993479d 3883 c->v2.remwindow += ssh2_pkt_getuint32();
d211621f 3884 try_send = TRUE;
783415f8 3885 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
3886 char *type;
3887 int typelen;
3888 char *error = NULL;
3889 struct ssh_channel *c;
3890 ssh2_pkt_getstring(&type, &typelen);
3891 c = smalloc(sizeof(struct ssh_channel));
3892
3893 if (typelen == 3 && !memcmp(type, "x11", 3)) {
783415f8 3894 if (!ssh_X11_fwd_enabled)
3895 error = "X11 forwarding is not enabled";
0c6c9a70 3896 else if ( x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL ) {
783415f8 3897 error = "Unable to open an X11 connection";
3898 } else {
3899 c->type = CHAN_X11;
3900 }
36c2a3e9 3901 } else if (typelen == 22 &&
3902 !memcmp(type, "auth-agent@openssh.com", 3)) {
3903 if (!ssh_agentfwd_enabled)
3904 error = "Agent forwarding is not enabled";
3905 else {
3906 c->type = CHAN_AGENT; /* identify channel type */
3907 c->u.a.lensofar = 0;
3908 }
783415f8 3909 } else {
3910 error = "Unsupported channel type requested";
3911 }
3912
3913 c->remoteid = ssh2_pkt_getuint32();
3914 if (error) {
3915 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
3916 ssh2_pkt_adduint32(c->remoteid);
3917 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
3918 ssh2_pkt_addstring(error);
3919 ssh2_pkt_addstring("en"); /* language tag */
3920 ssh2_pkt_send();
3921 sfree(c);
3922 } else {
3923 struct ssh_channel *d;
3924 unsigned i;
783415f8 3925
d2371c81 3926 c->localid = alloc_channel_id();
783415f8 3927 c->closes = 0;
3928 c->v2.remwindow = ssh2_pkt_getuint32();
3929 c->v2.remmaxpkt = ssh2_pkt_getuint32();
3930 c->v2.outbuffer = NULL;
3931 c->v2.outbuflen = c->v2.outbufsize = 0;
3932 add234(ssh_channels, c);
3933 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
3934 ssh2_pkt_adduint32(c->remoteid);
3935 ssh2_pkt_adduint32(c->localid);
3936 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3937 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
3938 ssh2_pkt_send();
3939 }
7cca0d81 3940 } else {
8d5de777 3941 bombout(("Strange packet received: type %d", pktin.type));
3942 crReturnV;
7cca0d81 3943 }
3944 } else {
d211621f 3945 /*
3946 * We have spare data. Add it to the channel buffer.
3947 */
783415f8 3948 ssh2_add_channel_data(mainchan, in, inlen);
d211621f 3949 try_send = TRUE;
7cca0d81 3950 }
d211621f 3951 if (try_send) {
d2371c81 3952 int i;
783415f8 3953 struct ssh_channel *c;
d211621f 3954 /*
783415f8 3955 * Try to send data on all channels if we can.
d211621f 3956 */
d2371c81 3957 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++)
783415f8 3958 ssh2_try_send(c);
d211621f 3959 }
e5574168 3960 }
3961
3962 crFinishV;
3963}
3964
3965/*
7cca0d81 3966 * Handle the top-level SSH2 protocol.
3967 */
3968static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
3969{
3970 if (do_ssh2_transport(in, inlen, ispkt) == 0)
3971 return;
3972 do_ssh2_authconn(in, inlen, ispkt);
3973}
3974
3975/*
8df7a775 3976 * Called to set up the connection.
374330e2 3977 *
3978 * Returns an error message, or NULL on success.
374330e2 3979 */
8df7a775 3980static char *ssh_init (char *host, int port, char **realhost) {
fb09bf1c 3981 char *p;
8f203108 3982
3983#ifdef MSCRYPTOAPI
3984 if(crypto_startup() == 0)
3985 return "Microsoft high encryption pack not installed!";
3986#endif
374330e2 3987
8df7a775 3988 ssh_send_ok = 0;
0965bee0 3989 ssh_editing = 0;
3990 ssh_echoing = 0;
8df7a775 3991
fb09bf1c 3992 p = connect_to_host(host, port, realhost);
3993 if (p != NULL)
3994 return p;
374330e2 3995
374330e2 3996 return NULL;
3997}
3998
3999/*
374330e2 4000 * Called to send data down the Telnet connection.
4001 */
4002static void ssh_send (char *buf, int len) {
f78051a1 4003 if (s == NULL || ssh_protocol == NULL)
374330e2 4004 return;
4005
4006 ssh_protocol(buf, len, 0);
4007}
4008
4009/*
6e48c3fe 4010 * Called to set the size of the window from SSH's POV.
374330e2 4011 */
4012static void ssh_size(void) {
4013 switch (ssh_state) {
4014 case SSH_STATE_BEFORE_SIZE:
3687d221 4015 case SSH_STATE_PREPACKET:
21248260 4016 case SSH_STATE_CLOSED:
374330e2 4017 break; /* do nothing */
4018 case SSH_STATE_INTERMED:
4019 size_needed = TRUE; /* buffer for later */
4020 break;
4021 case SSH_STATE_SESSION:
fef97f43 4022 if (!cfg.nopty) {
6e48c3fe 4023 if (ssh_version == 1) {
4024 send_packet(SSH1_CMSG_WINDOW_SIZE,
4025 PKT_INT, rows, PKT_INT, cols,
4026 PKT_INT, 0, PKT_INT, 0, PKT_END);
4027 } else {
4028 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4029 ssh2_pkt_adduint32(mainchan->remoteid);
4030 ssh2_pkt_addstring("window-change");
4031 ssh2_pkt_addbool(0);
4032 ssh2_pkt_adduint32(cols);
4033 ssh2_pkt_adduint32(rows);
4034 ssh2_pkt_adduint32(0);
4035 ssh2_pkt_adduint32(0);
4036 ssh2_pkt_send();
4037 }
fef97f43 4038 }
3687d221 4039 break;
374330e2 4040 }
4041}
4042
4043/*
6abbf9e3 4044 * Send Telnet special codes. TS_EOF is useful for `plink', so you
4045 * can send an EOF and collect resulting output (e.g. `plink
4046 * hostname sort').
374330e2 4047 */
4048static void ssh_special (Telnet_Special code) {
6abbf9e3 4049 if (code == TS_EOF) {
3687d221 4050 if (ssh_state != SSH_STATE_SESSION) {
4051 /*
4052 * Buffer the EOF in case we are pre-SESSION, so we can
4053 * send it as soon as we reach SESSION.
4054 */
4055 if (code == TS_EOF)
4056 eof_needed = TRUE;
4057 return;
4058 }
67779be7 4059 if (ssh_version == 1) {
6abbf9e3 4060 send_packet(SSH1_CMSG_EOF, PKT_END);
4061 } else {
4062 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 4063 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 4064 ssh2_pkt_send();
4065 }
67779be7 4066 logevent("Sent EOF message");
ec55b220 4067 } else if (code == TS_PING) {
3687d221 4068 if (ssh_state == SSH_STATE_CLOSED || ssh_state == SSH_STATE_PREPACKET)
4069 return;
ec55b220 4070 if (ssh_version == 1) {
4071 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
4072 } else {
4073 ssh2_pkt_init(SSH2_MSG_IGNORE);
4074 ssh2_pkt_addstring_start();
4075 ssh2_pkt_send();
4076 }
6abbf9e3 4077 } else {
4078 /* do nothing */
4079 }
374330e2 4080}
4081
8df7a775 4082static Socket ssh_socket(void) { return s; }
8ccc75b0 4083
4084static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 4085
0965bee0 4086static int ssh_ldisc(int option) {
4087 if (option == LD_ECHO) return ssh_echoing;
4088 if (option == LD_EDIT) return ssh_editing;
4089 return FALSE;
4090}
4091
374330e2 4092Backend ssh_backend = {
4093 ssh_init,
374330e2 4094 ssh_send,
4095 ssh_size,
4017be6d 4096 ssh_special,
8ccc75b0 4097 ssh_socket,
97db3be4 4098 ssh_sendok,
0965bee0 4099 ssh_ldisc,
97db3be4 4100 22
374330e2 4101};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator