projects / u / mdw / putty / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
Oops - actually check in portfwd.c itself! (Makefile also modified
[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
765c4200 18/* uncomment this for packet level debugging */
19/* #define DUMP_PACKETS */
20
fb09bf1c 21#define logevent(s) { logevent(s); \
67779be7 22 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
b4453f49 23 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
fb09bf1c 24
3cd52910 25#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
4a8fc3c4 26 (s ? sk_close(s), s = NULL : 0), \
3cd52910 27 connection_fatal msg )
8d5de777 28
32874aea 29#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
30#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
31#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
32#define SSH1_CMSG_USER 4 /* 0x4 */
33#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
34#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
35#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
36#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
37#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
38#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
39#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
40#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
41#define SSH1_SMSG_SUCCESS 14 /* 0xe */
42#define SSH1_SMSG_FAILURE 15 /* 0xf */
43#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
44#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
45#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
46#define SSH1_CMSG_EOF 19 /* 0x13 */
47#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
48#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
49#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
50#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
51#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
52#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
53#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
54#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
55#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
56#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
57#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
58#define SSH1_MSG_IGNORE 32 /* 0x20 */
59#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
60#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
61#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
62#define SSH1_MSG_DEBUG 36 /* 0x24 */
63#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
64#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
65#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
66#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
67#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
68#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
69#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
70
71#define SSH1_AUTH_TIS 5 /* 0x5 */
72#define SSH1_AUTH_CCARD 16 /* 0x10 */
73
74#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 75/* Mask for protoflags we will echo back to server if seen */
32874aea 76#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
77
78#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
79#define SSH2_MSG_IGNORE 2 /* 0x2 */
80#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
81#define SSH2_MSG_DEBUG 4 /* 0x4 */
82#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
83#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
84#define SSH2_MSG_KEXINIT 20 /* 0x14 */
85#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
86#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
87#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
88#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
89#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
90#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
91#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
92#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
93#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
94#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
95#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
96#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
97#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
98#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
99#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
100#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
101#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
102#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
103#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
104#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
105#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
106#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
107#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
108#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
109#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
110#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
111#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
112
113#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
114#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
115#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
116#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
117#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
118#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
119#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
120#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
121#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
122#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
123#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
124#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
125#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
126#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
127#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 128
129static const char *const ssh2_disconnect_reasons[] = {
130 NULL,
131 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
132 "SSH_DISCONNECT_PROTOCOL_ERROR",
133 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
134 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
135 "SSH_DISCONNECT_MAC_ERROR",
136 "SSH_DISCONNECT_COMPRESSION_ERROR",
137 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
138 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
139 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
140 "SSH_DISCONNECT_CONNECTION_LOST",
141 "SSH_DISCONNECT_BY_APPLICATION",
142 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
143 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
144 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
145 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
146};
9005f3ba 147
32874aea 148#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
149#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
150#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
151#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 152
32874aea 153#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 154
7d503c31 155/*
156 * Various remote-bug flags.
157 */
158#define BUG_CHOKES_ON_SSH1_IGNORE 1
159#define BUG_SSH2_HMAC 2
160
fb09bf1c 161#define GET_32BIT(cp) \
162 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
163 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
164 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
165 ((unsigned long)(unsigned char)(cp)[3]))
166
167#define PUT_32BIT(cp, value) { \
168 (cp)[0] = (unsigned char)((value) >> 24); \
169 (cp)[1] = (unsigned char)((value) >> 16); \
170 (cp)[2] = (unsigned char)((value) >> 8); \
171 (cp)[3] = (unsigned char)(value); }
172
7cca0d81 173enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 174
374330e2 175/* Coroutine mechanics for the sillier bits of the code */
176#define crBegin1 static int crLine = 0;
177#define crBegin2 switch(crLine) { case 0:;
178#define crBegin crBegin1; crBegin2;
179#define crFinish(z) } crLine = 0; return (z)
180#define crFinishV } crLine = 0; return
181#define crReturn(z) \
182 do {\
183 crLine=__LINE__; return (z); case __LINE__:;\
184 } while (0)
185#define crReturnV \
186 do {\
187 crLine=__LINE__; return; case __LINE__:;\
188 } while (0)
189#define crStop(z) do{ crLine = 0; return (z); }while(0)
190#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 191#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 192#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 193
32874aea 194extern char *x11_init(Socket *, char *, void *);
195extern void x11_close(Socket);
196extern void x11_send(Socket, char *, int);
9c964e85 197extern void x11_invent_auth(char *, int, char *, int);
198
d74d141c 199extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
200extern char *pfd_addforward(char *desthost, int destport, int port);
201extern void pfd_close(Socket s);
202extern void pfd_send(Socket s, char *data, int len);
203extern void pfd_confirm(Socket s);
204
5e8358ad 205/*
206 * Ciphers for SSH2. We miss out single-DES because it isn't
207 * supported; also 3DES and Blowfish are both done differently from
208 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
209 * endianness and different-sized keys.)
5e8358ad 210 */
0a3f1d48 211const static struct ssh2_ciphers *ciphers[] = {
212 &ssh2_aes,
213 &ssh2_blowfish,
214 &ssh2_3des,
8479e33c 215};
e5574168 216
a92dd380 217const static struct ssh_kex *kex_algs[] = {
a92dd380 218 &ssh_diffiehellman_gex,
32874aea 219 &ssh_diffiehellman
220};
e5574168 221
85cc02bb 222const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 223
32874aea 224static void nullmac_key(unsigned char *key)
225{
226}
227static void nullmac_generate(unsigned char *blk, int len,
228 unsigned long seq)
229{
230}
231static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
232{
233 return 1;
234}
57476f6b 235const static struct ssh_mac ssh_mac_none = {
d39f364a 236 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 237};
8b2715b2 238const static struct ssh_mac *macs[] = {
32874aea 239 &ssh_sha1, &ssh_md5, &ssh_mac_none
240};
8b2715b2 241const static struct ssh_mac *buggymacs[] = {
32874aea 242 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
243};
e5574168 244
32874aea 245static void ssh_comp_none_init(void)
246{
247}
4ba9b64b 248static int ssh_comp_none_block(unsigned char *block, int len,
32874aea 249 unsigned char **outblock, int *outlen)
250{
251 return 0;
252}
253static int ssh_comp_none_disable(void)
254{
4ba9b64b 255 return 0;
256}
57476f6b 257const static struct ssh_compress ssh_comp_none = {
4ba9b64b 258 "none",
259 ssh_comp_none_init, ssh_comp_none_block,
63b00c83 260 ssh_comp_none_init, ssh_comp_none_block,
261 ssh_comp_none_disable
e5574168 262};
4ba9b64b 263extern const struct ssh_compress ssh_zlib;
264const static struct ssh_compress *compressions[] = {
32874aea 265 &ssh_zlib, &ssh_comp_none
266};
374330e2 267
32874aea 268enum { /* channel types */
783415f8 269 CHAN_MAINSESSION,
270 CHAN_X11,
271 CHAN_AGENT,
d74d141c 272 CHAN_SOCKDATA
783415f8 273};
274
dacbd0e8 275/*
276 * 2-3-4 tree storing channels.
277 */
278struct ssh_channel {
d211621f 279 unsigned remoteid, localid;
dacbd0e8 280 int type;
281 int closes;
783415f8 282 struct ssh2_data_channel {
32874aea 283 unsigned char *outbuffer;
284 unsigned outbuflen, outbufsize;
285 unsigned remwindow, remmaxpkt;
783415f8 286 } v2;
dacbd0e8 287 union {
32874aea 288 struct ssh_agent_channel {
289 unsigned char *message;
290 unsigned char msglen[4];
291 int lensofar, totallen;
292 } a;
293 struct ssh_x11_channel {
294 Socket s;
295 } x11;
d74d141c 296 struct ssh_pfd_channel {
297 Socket s;
298 } pfd;
dacbd0e8 299 } u;
300};
57476f6b 301
d74d141c 302/*
303 * 2-3-4 tree storing remote->local port forwardings (so we can
304 * reject any attempt to open a port we didn't explicitly ask to
305 * have forwarded).
306 */
307struct ssh_rportfwd {
308 unsigned port;
309 char host[256];
310};
311
57476f6b 312struct Packet {
313 long length;
314 int type;
315 unsigned char *data;
316 unsigned char *body;
317 long savedpos;
318 long maxlen;
319};
320
0db56f73 321static SHA_State exhash, exhashbase;
57476f6b 322
8df7a775 323static Socket s = NULL;
57476f6b 324
325static unsigned char session_key[32];
4ba9b64b 326static int ssh1_compressing;
b96dc54c 327static int ssh1_remote_protoflags;
328static int ssh1_local_protoflags;
db7d555c 329static int ssh_agentfwd_enabled;
9c964e85 330static int ssh_X11_fwd_enabled;
7d503c31 331static int ssh_remote_bugs;
57476f6b 332static const struct ssh_cipher *cipher = NULL;
0a3f1d48 333static const struct ssh2_cipher *cscipher = NULL;
334static const struct ssh2_cipher *sccipher = NULL;
57476f6b 335static const struct ssh_mac *csmac = NULL;
336static const struct ssh_mac *scmac = NULL;
337static const struct ssh_compress *cscomp = NULL;
338static const struct ssh_compress *sccomp = NULL;
339static const struct ssh_kex *kex = NULL;
e055a386 340static const struct ssh_signkey *hostkey = NULL;
65a22376 341static unsigned char ssh2_session_id[20];
32874aea 342int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
343 int is_pw) = NULL;
57476f6b 344
345static char *savedhost;
346static int savedport;
347static int ssh_send_ok;
0965bee0 348static int ssh_echoing, ssh_editing;
57476f6b 349
32874aea 350static tree234 *ssh_channels; /* indexed by local id */
57476f6b 351static struct ssh_channel *mainchan; /* primary session channel */
352
d74d141c 353static tree234 *ssh_rportfwds;
354
57476f6b 355static enum {
3687d221 356 SSH_STATE_PREPACKET,
57476f6b 357 SSH_STATE_BEFORE_SIZE,
358 SSH_STATE_INTERMED,
359 SSH_STATE_SESSION,
360 SSH_STATE_CLOSED
3687d221 361} ssh_state = SSH_STATE_PREPACKET;
57476f6b 362
3687d221 363static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 364
365static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
366static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
b185170a 367static unsigned char *deferred_send_data = NULL;
368static int deferred_len = 0, deferred_size = 0;
57476f6b 369
370static int ssh_version;
32874aea 371static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
57476f6b 372static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
373static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
374static void ssh_size(void);
32874aea 375static void ssh_special(Telnet_Special);
783415f8 376static void ssh2_try_send(struct ssh_channel *c);
32874aea 377static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
378 int len);
57476f6b 379
32874aea 380static int (*s_rdpkt) (unsigned char **data, int *datalen);
57476f6b 381
382static struct rdpkt1_state_tag {
383 long len, pad, biglen, to_read;
384 unsigned long realcrc, gotcrc;
385 unsigned char *p;
386 int i;
387 int chunk;
388} rdpkt1_state;
389
960e736a 390static struct rdpkt2_state_tag {
391 long len, pad, payload, packetlen, maclen;
392 int i;
393 int cipherblk;
394 unsigned long incoming_sequence;
395} rdpkt2_state;
396
32874aea 397static int ssh_channelcmp(void *av, void *bv)
398{
399 struct ssh_channel *a = (struct ssh_channel *) av;
400 struct ssh_channel *b = (struct ssh_channel *) bv;
401 if (a->localid < b->localid)
402 return -1;
403 if (a->localid > b->localid)
404 return +1;
dacbd0e8 405 return 0;
406}
32874aea 407static int ssh_channelfind(void *av, void *bv)
408{
409 unsigned *a = (unsigned *) av;
410 struct ssh_channel *b = (struct ssh_channel *) bv;
411 if (*a < b->localid)
412 return -1;
413 if (*a > b->localid)
414 return +1;
dacbd0e8 415 return 0;
416}
417
d74d141c 418static int ssh_rportcmp(void *av, void *bv)
419{
420 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
421 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
422 int i;
423 if ( (i = strcmp(a->host, b->host)) != 0)
424 return i < 0 ? -1 : +1;
425 if (a->port > b->port)
426 return +1;
427 return 0;
428}
429
32874aea 430static int alloc_channel_id(void)
431{
260f3dec 432 const unsigned CHANNEL_NUMBER_OFFSET = 256;
433 unsigned low, high, mid;
d2371c81 434 int tsize;
435 struct ssh_channel *c;
436
437 /*
438 * First-fit allocation of channel numbers: always pick the
439 * lowest unused one. To do this, binary-search using the
440 * counted B-tree to find the largest channel ID which is in a
441 * contiguous sequence from the beginning. (Precisely
442 * everything in that sequence must have ID equal to its tree
443 * index plus CHANNEL_NUMBER_OFFSET.)
444 */
445 tsize = count234(ssh_channels);
446
32874aea 447 low = -1;
448 high = tsize;
d2371c81 449 while (high - low > 1) {
450 mid = (high + low) / 2;
451 c = index234(ssh_channels, mid);
452 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
453 low = mid; /* this one is fine */
454 else
455 high = mid; /* this one is past it */
456 }
457 /*
458 * Now low points to either -1, or the tree index of the
459 * largest ID in the initial sequence.
460 */
461 {
462 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
463 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
464 }
465 return low + 1 + CHANNEL_NUMBER_OFFSET;
466}
467
32874aea 468static void c_write(char *buf, int len)
469{
67779be7 470 if ((flags & FLAG_STDERR)) {
32874aea 471 int i;
472 for (i = 0; i < len; i++)
473 if (buf[i] != '\r')
474 fputc(buf[i], stderr);
fb09bf1c 475 return;
476 }
fe50e814 477 from_backend(1, buf, len);
3bdaf79d 478}
479
32874aea 480static void c_write_untrusted(char *buf, int len)
481{
a209e957 482 int i;
483 for (i = 0; i < len; i++) {
32874aea 484 if (buf[i] == '\n')
485 c_write("\r\n", 2);
486 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
487 c_write(buf + i, 1);
a209e957 488 }
489}
490
32874aea 491static void c_write_str(char *buf)
492{
1408a877 493 c_write(buf, strlen(buf));
494}
495
fb09bf1c 496/*
497 * Collect incoming data in the incoming packet buffer.
e5574168 498 * Decipher and verify the packet when it is completely read.
499 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 500 * Update the *data and *datalen variables.
501 * Return the additional nr of bytes needed, or 0 when
502 * a complete packet is available.
503 */
e5574168 504static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 505{
57476f6b 506 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 507
508 crBegin;
374330e2 509
32874aea 510 next_packet:
37508af4 511
fb09bf1c 512 pktin.type = 0;
513 pktin.length = 0;
374330e2 514
57476f6b 515 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 516 while ((*datalen) == 0)
32874aea 517 crReturn(4 - st->i);
57476f6b 518 st->len = (st->len << 8) + **data;
fb09bf1c 519 (*data)++, (*datalen)--;
520 }
374330e2 521
fb09bf1c 522#ifdef FWHACK
32874aea 523 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
524 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 525 }
526#endif
374330e2 527
57476f6b 528 st->pad = 8 - (st->len % 8);
529 st->biglen = st->len + st->pad;
530 pktin.length = st->len - 5;
fb09bf1c 531
57476f6b 532 if (pktin.maxlen < st->biglen) {
533 pktin.maxlen = st->biglen;
32874aea 534 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
535 srealloc(pktin.data, st->biglen + APIEXTRA));
fb09bf1c 536 if (!pktin.data)
537 fatalbox("Out of memory");
538 }
374330e2 539
57476f6b 540 st->to_read = st->biglen;
541 st->p = pktin.data;
542 while (st->to_read > 0) {
32874aea 543 st->chunk = st->to_read;
fb09bf1c 544 while ((*datalen) == 0)
57476f6b 545 crReturn(st->to_read);
546 if (st->chunk > (*datalen))
547 st->chunk = (*datalen);
548 memcpy(st->p, *data, st->chunk);
549 *data += st->chunk;
550 *datalen -= st->chunk;
551 st->p += st->chunk;
552 st->to_read -= st->chunk;
fb09bf1c 553 }
374330e2 554
fb09bf1c 555 if (cipher)
57476f6b 556 cipher->decrypt(pktin.data, st->biglen);
765c4200 557#ifdef DUMP_PACKETS
558 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
559 dmemdump(pktin.data, st->biglen);
698a5108 560#endif
374330e2 561
32874aea 562 st->realcrc = crc32(pktin.data, st->biglen - 4);
563 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
57476f6b 564 if (st->gotcrc != st->realcrc) {
8d5de777 565 bombout(("Incorrect CRC received on packet"));
32874aea 566 crReturn(0);
fb09bf1c 567 }
572f871e 568
4ba9b64b 569 pktin.body = pktin.data + st->pad + 1;
570
571 if (ssh1_compressing) {
572 unsigned char *decompblk;
573 int decomplen;
765c4200 574#ifdef DUMP_PACKETS
575 debug(("Packet payload pre-decompression:\n"));
32874aea 576 dmemdump(pktin.body - 1, pktin.length + 1);
4ba9b64b 577#endif
32874aea 578 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
4ba9b64b 579 &decompblk, &decomplen);
580
581 if (pktin.maxlen < st->pad + decomplen) {
582 pktin.maxlen = st->pad + decomplen;
32874aea 583 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
584 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 585 if (!pktin.data)
586 fatalbox("Out of memory");
587 }
588
32874aea 589 memcpy(pktin.body - 1, decompblk, decomplen);
dcbde236 590 sfree(decompblk);
32874aea 591 pktin.length = decomplen - 1;
765c4200 592#ifdef DUMP_PACKETS
593 debug(("Packet payload post-decompression:\n"));
32874aea 594 dmemdump(pktin.body - 1, pktin.length + 1);
4ba9b64b 595#endif
596 }
597
e5574168 598 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 599 pktin.type == SSH1_SMSG_STDERR_DATA ||
600 pktin.type == SSH1_MSG_DEBUG ||
601 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
602 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 603 long strlen = GET_32BIT(pktin.body);
8d5de777 604 if (strlen + 4 != pktin.length) {
605 bombout(("Received data packet with bogus string length"));
32874aea 606 crReturn(0);
607 }
fb09bf1c 608 }
609
4ba9b64b 610 pktin.type = pktin.body[-1];
611
e5574168 612 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 613 /* log debug message */
614 char buf[80];
615 int strlen = GET_32BIT(pktin.body);
616 strcpy(buf, "Remote: ");
32874aea 617 if (strlen > 70)
618 strlen = 70;
619 memcpy(buf + 8, pktin.body + 4, strlen);
620 buf[8 + strlen] = '\0';
fb09bf1c 621 logevent(buf);
622 goto next_packet;
e5574168 623 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 624 /* do nothing */
625 goto next_packet;
626 }
627
38c4a8da 628 if (pktin.type == SSH1_MSG_DISCONNECT) {
629 /* log reason code in disconnect message */
630 char buf[256];
260f3dec 631 unsigned msglen = GET_32BIT(pktin.body);
632 unsigned nowlen;
38c4a8da 633 strcpy(buf, "Remote sent disconnect: ");
634 nowlen = strlen(buf);
32874aea 635 if (msglen > sizeof(buf) - nowlen - 1)
636 msglen = sizeof(buf) - nowlen - 1;
637 memcpy(buf + nowlen, pktin.body + 4, msglen);
638 buf[nowlen + msglen] = '\0';
38c4a8da 639 logevent(buf);
640 }
641
fb09bf1c 642 crFinish(0);
643}
644
e5574168 645static int ssh2_rdpkt(unsigned char **data, int *datalen)
646{
960e736a 647 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 648
649 crBegin;
650
32874aea 651 next_packet:
e5574168 652 pktin.type = 0;
653 pktin.length = 0;
960e736a 654 if (sccipher)
32874aea 655 st->cipherblk = sccipher->blksize;
e5574168 656 else
32874aea 657 st->cipherblk = 8;
960e736a 658 if (st->cipherblk < 8)
32874aea 659 st->cipherblk = 8;
960e736a 660
661 if (pktin.maxlen < st->cipherblk) {
662 pktin.maxlen = st->cipherblk;
32874aea 663 pktin.data =
664 (pktin.data ==
665 NULL ? smalloc(st->cipherblk +
666 APIEXTRA) : srealloc(pktin.data,
667 st->cipherblk +
668 APIEXTRA));
e5574168 669 if (!pktin.data)
670 fatalbox("Out of memory");
671 }
672
673 /*
674 * Acquire and decrypt the first block of the packet. This will
675 * contain the length and padding details.
676 */
32874aea 677 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 678 while ((*datalen) == 0)
32874aea 679 crReturn(st->cipherblk - st->i);
960e736a 680 pktin.data[st->i] = *(*data)++;
32874aea 681 (*datalen)--;
e5574168 682 }
683#ifdef FWHACK
32874aea 684 if (!memcmp(pktin.data, "Remo", 4)) { /* "Remo"te server has closed ... */
685 /* FIXME */
e5574168 686 }
687#endif
688 if (sccipher)
32874aea 689 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 690
691 /*
692 * Now get the length and padding figures.
693 */
960e736a 694 st->len = GET_32BIT(pktin.data);
695 st->pad = pktin.data[4];
e5574168 696
697 /*
698 * This enables us to deduce the payload length.
699 */
960e736a 700 st->payload = st->len - st->pad - 1;
e5574168 701
960e736a 702 pktin.length = st->payload + 5;
e5574168 703
704 /*
705 * So now we can work out the total packet length.
706 */
960e736a 707 st->packetlen = st->len + 4;
708 st->maclen = scmac ? scmac->len : 0;
e5574168 709
710 /*
711 * Adjust memory allocation if packet is too big.
712 */
32874aea 713 if (pktin.maxlen < st->packetlen + st->maclen) {
714 pktin.maxlen = st->packetlen + st->maclen;
715 pktin.data =
716 (pktin.data ==
717 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
718 pktin.maxlen
719 +
720 APIEXTRA));
e5574168 721 if (!pktin.data)
722 fatalbox("Out of memory");
723 }
724
725 /*
726 * Read and decrypt the remainder of the packet.
727 */
32874aea 728 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
729 st->i++) {
e5574168 730 while ((*datalen) == 0)
960e736a 731 crReturn(st->packetlen + st->maclen - st->i);
732 pktin.data[st->i] = *(*data)++;
32874aea 733 (*datalen)--;
e5574168 734 }
735 /* Decrypt everything _except_ the MAC. */
736 if (sccipher)
32874aea 737 sccipher->decrypt(pktin.data + st->cipherblk,
738 st->packetlen - st->cipherblk);
e5574168 739
765c4200 740#ifdef DUMP_PACKETS
741 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
742 dmemdump(pktin.data, st->packetlen);
7cca0d81 743#endif
d39f364a 744
e5574168 745 /*
746 * Check the MAC.
747 */
32874aea 748 if (scmac
749 && !scmac->verify(pktin.data, st->len + 4,
750 st->incoming_sequence)) {
8d5de777 751 bombout(("Incorrect MAC received on packet"));
32874aea 752 crReturn(0);
8d5de777 753 }
32874aea 754 st->incoming_sequence++; /* whether or not we MACed */
e5574168 755
4ba9b64b 756 /*
757 * Decompress packet payload.
758 */
759 {
760 unsigned char *newpayload;
761 int newlen;
32874aea 762 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
4ba9b64b 763 &newpayload, &newlen)) {
32874aea 764 if (pktin.maxlen < newlen + 5) {
765 pktin.maxlen = newlen + 5;
766 pktin.data =
767 (pktin.data ==
768 NULL ? smalloc(pktin.maxlen +
769 APIEXTRA) : srealloc(pktin.data,
770 pktin.maxlen +
771 APIEXTRA));
4ba9b64b 772 if (!pktin.data)
773 fatalbox("Out of memory");
774 }
775 pktin.length = 5 + newlen;
32874aea 776 memcpy(pktin.data + 5, newpayload, newlen);
765c4200 777#ifdef DUMP_PACKETS
778 debug(("Post-decompression payload:\n"));
32874aea 779 dmemdump(pktin.data + 5, newlen);
4ba9b64b 780#endif
781
dcbde236 782 sfree(newpayload);
4ba9b64b 783 }
784 }
785
e5574168 786 pktin.savedpos = 6;
787 pktin.type = pktin.data[5];
e5574168 788
7cca0d81 789 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
32874aea 790 goto next_packet; /* FIXME: print DEBUG message */
e5574168 791
38c4a8da 792 if (pktin.type == SSH2_MSG_DISCONNECT) {
793 /* log reason code in disconnect message */
794 char buf[256];
32874aea 795 int reason = GET_32BIT(pktin.data + 6);
796 unsigned msglen = GET_32BIT(pktin.data + 10);
260f3dec 797 unsigned nowlen;
38c4a8da 798 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
799 sprintf(buf, "Received disconnect message (%s)",
800 ssh2_disconnect_reasons[reason]);
801 } else {
32874aea 802 sprintf(buf, "Received disconnect message (unknown type %d)",
803 reason);
38c4a8da 804 }
805 logevent(buf);
806 strcpy(buf, "Disconnection message text: ");
807 nowlen = strlen(buf);
32874aea 808 if (msglen > sizeof(buf) - nowlen - 1)
809 msglen = sizeof(buf) - nowlen - 1;
810 memcpy(buf + nowlen, pktin.data + 14, msglen);
811 buf[nowlen + msglen] = '\0';
38c4a8da 812 logevent(buf);
813 }
814
e5574168 815 crFinish(0);
816}
817
32874aea 818static void ssh1_pktout_size(int len)
819{
374330e2 820 int pad, biglen;
821
822 len += 5; /* type and CRC */
32874aea 823 pad = 8 - (len % 8);
374330e2 824 biglen = len + pad;
825
32874aea 826 pktout.length = len - 5;
374330e2 827 if (pktout.maxlen < biglen) {
828 pktout.maxlen = biglen;
8f203108 829#ifdef MSCRYPTOAPI
fb09bf1c 830 /* Allocate enough buffer space for extra block
8f203108 831 * for MS CryptEncrypt() */
32874aea 832 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
833 srealloc(pktout.data, biglen + 12));
8f203108 834#else
32874aea 835 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
836 srealloc(pktout.data, biglen + 4));
8f203108 837#endif
374330e2 838 if (!pktout.data)
839 fatalbox("Out of memory");
840 }
32874aea 841 pktout.body = pktout.data + 4 + pad + 1;
4ba9b64b 842}
374330e2 843
32874aea 844static void s_wrpkt_start(int type, int len)
845{
4ba9b64b 846 ssh1_pktout_size(len);
374330e2 847 pktout.type = type;
374330e2 848}
849
32874aea 850static int s_wrpkt_prepare(void)
851{
374330e2 852 int pad, len, biglen, i;
853 unsigned long crc;
854
4ba9b64b 855 pktout.body[-1] = pktout.type;
856
765c4200 857#ifdef DUMP_PACKETS
7d503c31 858 debug(("Packet payload pre-compression:\n"));
32874aea 859 dmemdump(pktout.body - 1, pktout.length + 1);
7d503c31 860#endif
861
4ba9b64b 862 if (ssh1_compressing) {
863 unsigned char *compblk;
864 int complen;
32874aea 865 zlib_compress_block(pktout.body - 1, pktout.length + 1,
4ba9b64b 866 &compblk, &complen);
32874aea 867 ssh1_pktout_size(complen - 1);
868 memcpy(pktout.body - 1, compblk, complen);
dcbde236 869 sfree(compblk);
765c4200 870#ifdef DUMP_PACKETS
4ba9b64b 871 debug(("Packet payload post-compression:\n"));
32874aea 872 dmemdump(pktout.body - 1, pktout.length + 1);
4ba9b64b 873#endif
874 }
875
374330e2 876 len = pktout.length + 5; /* type and CRC */
32874aea 877 pad = 8 - (len % 8);
374330e2 878 biglen = len + pad;
879
32874aea 880 for (i = 0; i < pad; i++)
881 pktout.data[i + 4] = random_byte();
882 crc = crc32(pktout.data + 4, biglen - 4);
883 PUT_32BIT(pktout.data + biglen, crc);
fb09bf1c 884 PUT_32BIT(pktout.data, len);
374330e2 885
765c4200 886#ifdef DUMP_PACKETS
32874aea 887 debug(("Sending packet len=%d\n", biglen + 4));
888 dmemdump(pktout.data, biglen + 4);
698a5108 889#endif
374330e2 890 if (cipher)
32874aea 891 cipher->encrypt(pktout.data + 4, biglen);
374330e2 892
32874aea 893 return biglen + 4;
39065bed 894}
895
32874aea 896static void s_wrpkt(void)
897{
39065bed 898 int len;
899 len = s_wrpkt_prepare();
900 sk_write(s, pktout.data, len);
901}
902
32874aea 903static void s_wrpkt_defer(void)
904{
39065bed 905 int len;
906 len = s_wrpkt_prepare();
907 if (deferred_len + len > deferred_size) {
32874aea 908 deferred_size = deferred_len + len + 128;
909 deferred_send_data = srealloc(deferred_send_data, deferred_size);
39065bed 910 }
32874aea 911 memcpy(deferred_send_data + deferred_len, pktout.data, len);
39065bed 912 deferred_len += len;
374330e2 913}
914
fb09bf1c 915/*
39065bed 916 * Construct a packet with the specified contents.
fb09bf1c 917 */
39065bed 918static void construct_packet(int pkttype, va_list ap1, va_list ap2)
fb09bf1c 919{
fb09bf1c 920 unsigned char *p, *argp, argchar;
921 unsigned long argint;
922 int pktlen, argtype, arglen;
7cca0d81 923 Bignum bn;
fb09bf1c 924
925 pktlen = 0;
39065bed 926 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 927 switch (argtype) {
928 case PKT_INT:
39065bed 929 (void) va_arg(ap1, int);
fb09bf1c 930 pktlen += 4;
931 break;
932 case PKT_CHAR:
39065bed 933 (void) va_arg(ap1, char);
fb09bf1c 934 pktlen++;
935 break;
936 case PKT_DATA:
39065bed 937 (void) va_arg(ap1, unsigned char *);
938 arglen = va_arg(ap1, int);
fb09bf1c 939 pktlen += arglen;
940 break;
941 case PKT_STR:
39065bed 942 argp = va_arg(ap1, unsigned char *);
fb09bf1c 943 arglen = strlen(argp);
944 pktlen += 4 + arglen;
945 break;
7cca0d81 946 case PKT_BIGNUM:
39065bed 947 bn = va_arg(ap1, Bignum);
32874aea 948 pktlen += ssh1_bignum_length(bn);
7cca0d81 949 break;
fb09bf1c 950 default:
951 assert(0);
952 }
953 }
fb09bf1c 954
955 s_wrpkt_start(pkttype, pktlen);
956 p = pktout.body;
957
39065bed 958 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 959 switch (argtype) {
960 case PKT_INT:
39065bed 961 argint = va_arg(ap2, int);
fb09bf1c 962 PUT_32BIT(p, argint);
963 p += 4;
964 break;
965 case PKT_CHAR:
39065bed 966 argchar = va_arg(ap2, unsigned char);
fb09bf1c 967 *p = argchar;
968 p++;
969 break;
970 case PKT_DATA:
39065bed 971 argp = va_arg(ap2, unsigned char *);
972 arglen = va_arg(ap2, int);
fb09bf1c 973 memcpy(p, argp, arglen);
974 p += arglen;
975 break;
976 case PKT_STR:
39065bed 977 argp = va_arg(ap2, unsigned char *);
fb09bf1c 978 arglen = strlen(argp);
979 PUT_32BIT(p, arglen);
980 memcpy(p + 4, argp, arglen);
981 p += 4 + arglen;
982 break;
7cca0d81 983 case PKT_BIGNUM:
39065bed 984 bn = va_arg(ap2, Bignum);
32874aea 985 p += ssh1_write_bignum(p, bn);
7cca0d81 986 break;
fb09bf1c 987 }
988 }
39065bed 989}
fb09bf1c 990
32874aea 991static void send_packet(int pkttype, ...)
992{
39065bed 993 va_list ap1, ap2;
994 va_start(ap1, pkttype);
995 va_start(ap2, pkttype);
996 construct_packet(pkttype, ap1, ap2);
fb09bf1c 997 s_wrpkt();
998}
999
32874aea 1000static void defer_packet(int pkttype, ...)
1001{
39065bed 1002 va_list ap1, ap2;
1003 va_start(ap1, pkttype);
1004 va_start(ap2, pkttype);
1005 construct_packet(pkttype, ap1, ap2);
1006 s_wrpkt_defer();
1007}
1008
32874aea 1009static int ssh_versioncmp(char *a, char *b)
1010{
9697bfd2 1011 char *ae, *be;
1012 unsigned long av, bv;
1013
43aa02a7 1014 av = strtoul(a, &ae, 10);
1015 bv = strtoul(b, &be, 10);
32874aea 1016 if (av != bv)
1017 return (av < bv ? -1 : +1);
1018 if (*ae == '.')
1019 ae++;
1020 if (*be == '.')
1021 be++;
43aa02a7 1022 av = strtoul(ae, &ae, 10);
1023 bv = strtoul(be, &be, 10);
32874aea 1024 if (av != bv)
1025 return (av < bv ? -1 : +1);
9697bfd2 1026 return 0;
1027}
1028
e5574168 1029
1030/*
a92dd380 1031 * Utility routines for putting an SSH-protocol `string' and
1032 * `uint32' into a SHA state.
e5574168 1033 */
1034#include <stdio.h>
32874aea 1035static void sha_string(SHA_State * s, void *str, int len)
1036{
e5574168 1037 unsigned char lenblk[4];
e5574168 1038 PUT_32BIT(lenblk, len);
e5574168 1039 SHA_Bytes(s, lenblk, 4);
e5574168 1040 SHA_Bytes(s, str, len);
1041}
1042
32874aea 1043static void sha_uint32(SHA_State * s, unsigned i)
1044{
a92dd380 1045 unsigned char intblk[4];
1046 PUT_32BIT(intblk, i);
1047 SHA_Bytes(s, intblk, 4);
1048}
1049
7cca0d81 1050/*
1051 * SSH2 packet construction functions.
1052 */
32874aea 1053static void ssh2_pkt_ensure(int length)
1054{
783415f8 1055 if (pktout.maxlen < length) {
32874aea 1056 pktout.maxlen = length + 256;
1057 pktout.data =
1058 (pktout.data ==
1059 NULL ? smalloc(pktout.maxlen +
1060 APIEXTRA) : srealloc(pktout.data,
1061 pktout.maxlen +
1062 APIEXTRA));
1063 if (!pktout.data)
1064 fatalbox("Out of memory");
7cca0d81 1065 }
783415f8 1066}
32874aea 1067static void ssh2_pkt_adddata(void *data, int len)
1068{
783415f8 1069 pktout.length += len;
1070 ssh2_pkt_ensure(pktout.length);
32874aea 1071 memcpy(pktout.data + pktout.length - len, data, len);
7cca0d81 1072}
32874aea 1073static void ssh2_pkt_addbyte(unsigned char byte)
1074{
7cca0d81 1075 ssh2_pkt_adddata(&byte, 1);
1076}
32874aea 1077static void ssh2_pkt_init(int pkt_type)
1078{
7cca0d81 1079 pktout.length = 5;
32874aea 1080 ssh2_pkt_addbyte((unsigned char) pkt_type);
7cca0d81 1081}
32874aea 1082static void ssh2_pkt_addbool(unsigned char value)
1083{
7cca0d81 1084 ssh2_pkt_adddata(&value, 1);
1085}
32874aea 1086static void ssh2_pkt_adduint32(unsigned long value)
1087{
7cca0d81 1088 unsigned char x[4];
1089 PUT_32BIT(x, value);
1090 ssh2_pkt_adddata(x, 4);
1091}
32874aea 1092static void ssh2_pkt_addstring_start(void)
1093{
7cca0d81 1094 ssh2_pkt_adduint32(0);
1095 pktout.savedpos = pktout.length;
1096}
32874aea 1097static void ssh2_pkt_addstring_str(char *data)
1098{
7cca0d81 1099 ssh2_pkt_adddata(data, strlen(data));
1100 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1101 pktout.length - pktout.savedpos);
7cca0d81 1102}
32874aea 1103static void ssh2_pkt_addstring_data(char *data, int len)
1104{
7cca0d81 1105 ssh2_pkt_adddata(data, len);
1106 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1107 pktout.length - pktout.savedpos);
7cca0d81 1108}
32874aea 1109static void ssh2_pkt_addstring(char *data)
1110{
7cca0d81 1111 ssh2_pkt_addstring_start();
1112 ssh2_pkt_addstring_str(data);
1113}
32874aea 1114static char *ssh2_mpint_fmt(Bignum b, int *len)
1115{
7cca0d81 1116 unsigned char *p;
32874aea 1117 int i, n = (bignum_bitcount(b) + 7) / 8;
3709bfe9 1118 p = smalloc(n + 1);
7cca0d81 1119 if (!p)
32874aea 1120 fatalbox("out of memory");
7cca0d81 1121 p[0] = 0;
3709bfe9 1122 for (i = 1; i <= n; i++)
32874aea 1123 p[i] = bignum_byte(b, n - i);
7cca0d81 1124 i = 0;
32874aea 1125 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1126 i++;
1127 memmove(p, p + i, n + 1 - i);
1128 *len = n + 1 - i;
7cca0d81 1129 return p;
1130}
32874aea 1131static void ssh2_pkt_addmp(Bignum b)
1132{
7cca0d81 1133 unsigned char *p;
1134 int len;
1135 p = ssh2_mpint_fmt(b, &len);
1136 ssh2_pkt_addstring_start();
1137 ssh2_pkt_addstring_data(p, len);
dcbde236 1138 sfree(p);
7cca0d81 1139}
b185170a 1140
1141/*
1142 * Construct an SSH2 final-form packet: compress it, encrypt it,
1143 * put the MAC on it. Final packet, ready to be sent, is stored in
1144 * pktout.data. Total length is returned.
1145 */
32874aea 1146static int ssh2_pkt_construct(void)
1147{
7cca0d81 1148 int cipherblk, maclen, padding, i;
1149 static unsigned long outgoing_sequence = 0;
1150
1151 /*
4ba9b64b 1152 * Compress packet payload.
1153 */
765c4200 1154#ifdef DUMP_PACKETS
1155 debug(("Pre-compression payload:\n"));
32874aea 1156 dmemdump(pktout.data + 5, pktout.length - 5);
4ba9b64b 1157#endif
1158 {
1159 unsigned char *newpayload;
1160 int newlen;
32874aea 1161 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
4ba9b64b 1162 &newpayload, &newlen)) {
1163 pktout.length = 5;
1164 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 1165 sfree(newpayload);
4ba9b64b 1166 }
1167 }
1168
1169 /*
7cca0d81 1170 * Add padding. At least four bytes, and must also bring total
1171 * length (minus MAC) up to a multiple of the block size.
1172 */
32874aea 1173 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1174 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1175 padding = 4;
32874aea 1176 padding +=
1177 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 1178 maclen = csmac ? csmac->len : 0;
1179 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 1180 pktout.data[4] = padding;
1181 for (i = 0; i < padding; i++)
32874aea 1182 pktout.data[pktout.length + i] = random_byte();
7cca0d81 1183 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1184 if (csmac)
32874aea 1185 csmac->generate(pktout.data, pktout.length + padding,
1186 outgoing_sequence);
1187 outgoing_sequence++; /* whether or not we MACed */
7cca0d81 1188
765c4200 1189#ifdef DUMP_PACKETS
32874aea 1190 debug(("Sending packet len=%d\n", pktout.length + padding));
1191 dmemdump(pktout.data, pktout.length + padding);
7cca0d81 1192#endif
1193
1194 if (cscipher)
32874aea 1195 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 1196
b185170a 1197 /* Ready-to-send packet starts at pktout.data. We return length. */
1198 return pktout.length + padding + maclen;
1199}
1200
1201/*
1202 * Construct and send an SSH2 packet immediately.
1203 */
32874aea 1204static void ssh2_pkt_send(void)
1205{
b185170a 1206 int len = ssh2_pkt_construct();
1207 sk_write(s, pktout.data, len);
1208}
1209
1210/*
1211 * Construct an SSH2 packet and add it to a deferred data block.
1212 * Useful for sending multiple packets in a single sk_write() call,
1213 * to prevent a traffic-analysing listener from being able to work
1214 * out the length of any particular packet (such as the password
1215 * packet).
1216 *
1217 * Note that because SSH2 sequence-numbers its packets, this can
1218 * NOT be used as an m4-style `defer' allowing packets to be
1219 * constructed in one order and sent in another.
1220 */
32874aea 1221static void ssh2_pkt_defer(void)
1222{
b185170a 1223 int len = ssh2_pkt_construct();
1224 if (deferred_len + len > deferred_size) {
32874aea 1225 deferred_size = deferred_len + len + 128;
1226 deferred_send_data = srealloc(deferred_send_data, deferred_size);
b185170a 1227 }
32874aea 1228 memcpy(deferred_send_data + deferred_len, pktout.data, len);
b185170a 1229 deferred_len += len;
1230}
1231
1232/*
1233 * Send the whole deferred data block constructed by
39065bed 1234 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1235 */
32874aea 1236static void ssh_pkt_defersend(void)
1237{
b185170a 1238 sk_write(s, deferred_send_data, deferred_len);
1239 deferred_len = deferred_size = 0;
1240 sfree(deferred_send_data);
1241 deferred_send_data = NULL;
7cca0d81 1242}
1243
1244#if 0
32874aea 1245void bndebug(char *string, Bignum b)
1246{
7cca0d81 1247 unsigned char *p;
1248 int i, len;
1249 p = ssh2_mpint_fmt(b, &len);
1250 debug(("%s", string));
1251 for (i = 0; i < len; i++)
32874aea 1252 debug((" %02x", p[i]));
765c4200 1253 debug(("\n"));
dcbde236 1254 sfree(p);
7cca0d81 1255}
1256#endif
1257
32874aea 1258static void sha_mpint(SHA_State * s, Bignum b)
1259{
7cca0d81 1260 unsigned char *p;
1261 int len;
1262 p = ssh2_mpint_fmt(b, &len);
1263 sha_string(s, p, len);
dcbde236 1264 sfree(p);
7cca0d81 1265}
1266
1267/*
1268 * SSH2 packet decode functions.
1269 */
32874aea 1270static unsigned long ssh2_pkt_getuint32(void)
1271{
7cca0d81 1272 unsigned long value;
1273 if (pktin.length - pktin.savedpos < 4)
32874aea 1274 return 0; /* arrgh, no way to decline (FIXME?) */
1275 value = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1276 pktin.savedpos += 4;
1277 return value;
1278}
32874aea 1279static int ssh2_pkt_getbool(void)
1280{
65a22376 1281 unsigned long value;
1282 if (pktin.length - pktin.savedpos < 1)
32874aea 1283 return 0; /* arrgh, no way to decline (FIXME?) */
65a22376 1284 value = pktin.data[pktin.savedpos] != 0;
1285 pktin.savedpos++;
1286 return value;
1287}
32874aea 1288static void ssh2_pkt_getstring(char **p, int *length)
1289{
7cca0d81 1290 *p = NULL;
1291 if (pktin.length - pktin.savedpos < 4)
32874aea 1292 return;
1293 *length = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1294 pktin.savedpos += 4;
1295 if (pktin.length - pktin.savedpos < *length)
32874aea 1296 return;
1297 *p = pktin.data + pktin.savedpos;
7cca0d81 1298 pktin.savedpos += *length;
1299}
32874aea 1300static Bignum ssh2_pkt_getmp(void)
1301{
7cca0d81 1302 char *p;
3709bfe9 1303 int length;
7cca0d81 1304 Bignum b;
1305
1306 ssh2_pkt_getstring(&p, &length);
1307 if (!p)
32874aea 1308 return NULL;
8d5de777 1309 if (p[0] & 0x80) {
32874aea 1310 bombout(("internal error: Can't handle negative mpints"));
1311 return NULL;
8d5de777 1312 }
3709bfe9 1313 b = bignum_from_bytes(p, length);
7cca0d81 1314 return b;
1315}
1316
7d503c31 1317/*
1318 * Examine the remote side's version string and compare it against
1319 * a list of known buggy implementations.
1320 */
32874aea 1321static void ssh_detect_bugs(char *vstring)
1322{
1323 char *imp; /* pointer to implementation part */
7d503c31 1324 imp = vstring;
1325 imp += strcspn(imp, "-");
32874aea 1326 if (*imp)
1327 imp++;
7d503c31 1328 imp += strcspn(imp, "-");
32874aea 1329 if (*imp)
1330 imp++;
7d503c31 1331
1332 ssh_remote_bugs = 0;
1333
1334 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
32874aea 1335 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1336 !strcmp(imp, "1.2.22")) {
1337 /*
1338 * These versions don't support SSH1_MSG_IGNORE, so we have
1339 * to use a different defence against password length
1340 * sniffing.
1341 */
1342 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1343 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1344 }
1345
1346 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
32874aea 1347 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1348 !strncmp(imp, "2.1 ", 4)) {
1349 /*
1350 * These versions have the HMAC bug.
1351 */
1352 ssh_remote_bugs |= BUG_SSH2_HMAC;
1353 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1354 }
1355}
1356
32874aea 1357static int do_ssh_init(unsigned char c)
1358{
2d466ffd 1359 static int vslen;
8df7a775 1360 static char version[10];
50526e47 1361 static char *vstring;
1362 static int vstrsize;
1363 static char *vlog;
8df7a775 1364 static int i;
374330e2 1365
8df7a775 1366 crBegin;
1367
1368 /* Search for the string "SSH-" in the input. */
374330e2 1369 i = 0;
8df7a775 1370 while (1) {
1371 static const int transS[] = { 1, 2, 2, 1 };
1372 static const int transH[] = { 0, 0, 3, 0 };
1373 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1374 if (c == 'S')
1375 i = transS[i];
1376 else if (c == 'H')
1377 i = transH[i];
1378 else if (c == '-')
1379 i = transminus[i];
1380 else
1381 i = 0;
8df7a775 1382 if (i < 0)
1383 break;
1384 crReturn(1); /* get another character */
374330e2 1385 }
8df7a775 1386
50526e47 1387 vstring = smalloc(16);
1388 vstrsize = 16;
c5e9c988 1389 strcpy(vstring, "SSH-");
50526e47 1390 vslen = 4;
374330e2 1391 i = 0;
1392 while (1) {
8df7a775 1393 crReturn(1); /* get another char */
32874aea 1394 if (vslen >= vstrsize - 1) {
1395 vstrsize += 16;
1396 vstring = srealloc(vstring, vstrsize);
1397 }
1398 vstring[vslen++] = c;
374330e2 1399 if (i >= 0) {
1400 if (c == '-') {
1401 version[i] = '\0';
1402 i = -1;
32874aea 1403 } else if (i < sizeof(version) - 1)
374330e2 1404 version[i++] = c;
32874aea 1405 } else if (c == '\n')
374330e2 1406 break;
1407 }
1408
db7d555c 1409 ssh_agentfwd_enabled = FALSE;
960e736a 1410 rdpkt2_state.incoming_sequence = 0;
1411
50526e47 1412 vstring[vslen] = 0;
9275ca8a 1413 vlog = smalloc(20 + vslen);
c5e9c988 1414 sprintf(vlog, "Server version: %s", vstring);
7d503c31 1415 ssh_detect_bugs(vstring);
c5e9c988 1416 vlog[strcspn(vlog, "\r\n")] = '\0';
1417 logevent(vlog);
9275ca8a 1418 sfree(vlog);
c5e9c988 1419
adf799dd 1420 /*
1421 * Server version "1.99" means we can choose whether we use v1
1422 * or v2 protocol. Choice is based on cfg.sshprot.
1423 */
1424 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
32874aea 1425 /*
1426 * This is a v2 server. Begin v2 protocol.
1427 */
1428 char verstring[80], vlog[100];
1429 sprintf(verstring, "SSH-2.0-%s", sshver);
1430 SHA_Init(&exhashbase);
1431 /*
1432 * Hash our version string and their version string.
1433 */
1434 sha_string(&exhashbase, verstring, strlen(verstring));
1435 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1436 sprintf(vlog, "We claim version: %s", verstring);
1437 logevent(vlog);
1438 strcat(verstring, "\n");
1439 logevent("Using SSH protocol version 2");
1440 sk_write(s, verstring, strlen(verstring));
1441 ssh_protocol = ssh2_protocol;
1442 ssh_version = 2;
1443 s_rdpkt = ssh2_rdpkt;
e5574168 1444 } else {
32874aea 1445 /*
1446 * This is a v1 server. Begin v1 protocol.
1447 */
1448 char verstring[80], vlog[100];
1449 sprintf(verstring, "SSH-%s-%s",
1450 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1451 sshver);
1452 sprintf(vlog, "We claim version: %s", verstring);
1453 logevent(vlog);
1454 strcat(verstring, "\n");
1455 logevent("Using SSH protocol version 1");
1456 sk_write(s, verstring, strlen(verstring));
1457 ssh_protocol = ssh1_protocol;
1458 ssh_version = 1;
1459 s_rdpkt = ssh1_rdpkt;
e5574168 1460 }
3687d221 1461 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1462
50526e47 1463 sfree(vstring);
50526e47 1464
8df7a775 1465 crFinish(0);
1466}
1467
1468static void ssh_gotdata(unsigned char *data, int datalen)
1469{
1470 crBegin;
1471
1472 /*
1473 * To begin with, feed the characters one by one to the
1474 * protocol initialisation / selection function do_ssh_init().
1475 * When that returns 0, we're done with the initial greeting
1476 * exchange and can move on to packet discipline.
1477 */
1478 while (1) {
1479 int ret;
1480 if (datalen == 0)
1481 crReturnV; /* more data please */
1482 ret = do_ssh_init(*data);
32874aea 1483 data++;
1484 datalen--;
8df7a775 1485 if (ret == 0)
1486 break;
1487 }
1488
1489 /*
1490 * We emerge from that loop when the initial negotiation is
1491 * over and we have selected an s_rdpkt function. Now pass
1492 * everything to s_rdpkt, and then pass the resulting packets
1493 * to the proper protocol handler.
1494 */
1495 if (datalen == 0)
1496 crReturnV;
1497 while (1) {
1498 while (datalen > 0) {
32874aea 1499 if (s_rdpkt(&data, &datalen) == 0) {
8df7a775 1500 ssh_protocol(NULL, 0, 1);
1501 if (ssh_state == SSH_STATE_CLOSED) {
1502 return;
1503 }
1504 }
1505 }
1506 crReturnV;
1507 }
1508 crFinishV;
1509}
1510
32874aea 1511static int ssh_closing(Plug plug, char *error_msg, int error_code,
1512 int calling_back)
1513{
7e78000d 1514 ssh_state = SSH_STATE_CLOSED;
f3ab576e 1515 if (s) {
1516 sk_close(s);
1517 s = NULL;
1518 }
7e78000d 1519 if (error_msg) {
32874aea 1520 /* A socket error has occurred. */
1521 connection_fatal(error_msg);
7e78000d 1522 } else {
1523 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1524 }
7e78000d 1525 return 0;
1526}
1527
32874aea 1528static int ssh_receive(Plug plug, int urgent, char *data, int len)
1529{
1530 ssh_gotdata(data, len);
3257deae 1531 if (ssh_state == SSH_STATE_CLOSED) {
32874aea 1532 if (s) {
1533 sk_close(s);
1534 s = NULL;
1535 }
1536 return 0;
3257deae 1537 }
fef97f43 1538 return 1;
374330e2 1539}
1540
fb09bf1c 1541/*
8df7a775 1542 * Connect to specified host and port.
1543 * Returns an error message, or NULL on success.
6e1ebb76 1544 * Also places the canonical host name into `realhost'. It must be
1545 * freed by the caller.
8df7a775 1546 */
1547static char *connect_to_host(char *host, int port, char **realhost)
1548{
7e78000d 1549 static struct plug_function_table fn_table = {
1550 ssh_closing,
1551 ssh_receive
1552 }, *fn_table_ptr = &fn_table;
1553
8df7a775 1554 SockAddr addr;
1555 char *err;
1556#ifdef FWHACK
1557 char *FWhost;
1558 int FWport;
1559#endif
1560
32874aea 1561 savedhost = smalloc(1 + strlen(host));
8df7a775 1562 if (!savedhost)
1563 fatalbox("Out of memory");
1564 strcpy(savedhost, host);
1565
1566 if (port < 0)
1567 port = 22; /* default ssh port */
1568 savedport = port;
1569
1570#ifdef FWHACK
1571 FWhost = host;
1572 FWport = port;
1573 host = FWSTR;
1574 port = 23;
1575#endif
1576
1577 /*
1578 * Try to find host.
1579 */
1580 addr = sk_namelookup(host, realhost);
32874aea 1581 if ((err = sk_addr_error(addr)))
8df7a775 1582 return err;
1583
1584#ifdef FWHACK
6e1ebb76 1585 *realhost = strdup(FWhost);
8df7a775 1586#endif
1587
1588 /*
1589 * Open socket.
1590 */
7e78000d 1591 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
32874aea 1592 if ((err = sk_socket_error(s)))
8df7a775 1593 return err;
1594
1595#ifdef FWHACK
1596 sk_write(s, "connect ", 8);
1597 sk_write(s, FWhost, strlen(FWhost));
1598 {
1599 char buf[20];
1600 sprintf(buf, " %d\n", FWport);
1601 sk_write(s, buf, strlen(buf));
1602 }
1603#endif
1604
1605 return NULL;
1606}
1607
1608/*
fb09bf1c 1609 * Handle the key exchange and user authentication phases.
1610 */
e5574168 1611static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1612{
2d466ffd 1613 int i, j;
1614 static int len;
1615 static unsigned char *rsabuf, *keystr1, *keystr2;
374330e2 1616 unsigned char cookie[8];
1617 struct RSAKey servkey, hostkey;
1618 struct MD5Context md5c;
ccbfb941 1619 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1620 static int tried_publickey;
1621 static unsigned char session_id[16];
2d466ffd 1622 static int cipher_type;
b585ec46 1623 static char username[100];
374330e2 1624
374330e2 1625 crBegin;
1626
32874aea 1627 if (!ispkt)
1628 crWaitUntil(ispkt);
374330e2 1629
8d5de777 1630 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1631 bombout(("Public key packet not received"));
32874aea 1632 crReturn(0);
8d5de777 1633 }
374330e2 1634
c5e9c988 1635 logevent("Received public keys");
374330e2 1636
c5e9c988 1637 memcpy(cookie, pktin.body, 8);
374330e2 1638
32874aea 1639 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1640 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
374330e2 1641
c5e9c988 1642 /*
1c2a93c4 1643 * Log the host key fingerprint.
c5e9c988 1644 */
c5e9c988 1645 {
1646 char logmsg[80];
1c2a93c4 1647 logevent("Host key fingerprint is:");
c5e9c988 1648 strcpy(logmsg, " ");
32874aea 1649 hostkey.comment = NULL;
1650 rsa_fingerprint(logmsg + strlen(logmsg),
1651 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 1652 logevent(logmsg);
1653 }
1654
32874aea 1655 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1656 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1657 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
bea1ef5f 1658
32874aea 1659 ssh1_local_protoflags =
1660 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
b96dc54c 1661 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1662
c5e9c988 1663 MD5Init(&md5c);
374330e2 1664 MD5Update(&md5c, keystr2, hostkey.bytes);
1665 MD5Update(&md5c, keystr1, servkey.bytes);
1666 MD5Update(&md5c, pktin.body, 8);
374330e2 1667 MD5Final(session_id, &md5c);
1668
32874aea 1669 for (i = 0; i < 32; i++)
374330e2 1670 session_key[i] = random_byte();
1671
1672 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1673
dcbde236 1674 rsabuf = smalloc(len);
374330e2 1675 if (!rsabuf)
1676 fatalbox("Out of memory");
1677
89ee5268 1678 /*
1679 * Verify the host key.
1680 */
1681 {
32874aea 1682 /*
1683 * First format the key into a string.
1684 */
1685 int len = rsastr_len(&hostkey);
1686 char fingerprint[100];
1687 char *keystr = smalloc(len);
1688 if (!keystr)
1689 fatalbox("Out of memory");
1690 rsastr_fmt(keystr, &hostkey);
1691 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1692 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1693 fingerprint);
1694 sfree(keystr);
1695 }
1696
1697 for (i = 0; i < 32; i++) {
374330e2 1698 rsabuf[i] = session_key[i];
1699 if (i < 16)
1700 rsabuf[i] ^= session_id[i];
1701 }
1702
1703 if (hostkey.bytes > servkey.bytes) {
1704 rsaencrypt(rsabuf, 32, &servkey);
1705 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1706 } else {
1707 rsaencrypt(rsabuf, 32, &hostkey);
1708 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1709 }
1710
c5e9c988 1711 logevent("Encrypted session key");
1712
0a3f1d48 1713 switch (cfg.cipher) {
32874aea 1714 case CIPHER_BLOWFISH:
1715 cipher_type = SSH_CIPHER_BLOWFISH;
1716 break;
1717 case CIPHER_DES:
1718 cipher_type = SSH_CIPHER_DES;
1719 break;
1720 case CIPHER_3DES:
1721 cipher_type = SSH_CIPHER_3DES;
1722 break;
0a3f1d48 1723 case CIPHER_AES:
32874aea 1724 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1725 cipher_type = SSH_CIPHER_3DES;
1726 break;
0a3f1d48 1727 }
bea1ef5f 1728 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
32874aea 1729 c_write_str
1730 ("Selected cipher not supported, falling back to 3DES\r\n");
bea1ef5f 1731 cipher_type = SSH_CIPHER_3DES;
a99a05c0 1732 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1733 bombout(("Server violates SSH 1 protocol by "
1734 "not supporting 3DES encryption"));
1735 crReturn(0);
1736 }
bea1ef5f 1737 }
c5e9c988 1738 switch (cipher_type) {
32874aea 1739 case SSH_CIPHER_3DES:
1740 logevent("Using 3DES encryption");
1741 break;
1742 case SSH_CIPHER_DES:
1743 logevent("Using single-DES encryption");
1744 break;
1745 case SSH_CIPHER_BLOWFISH:
1746 logevent("Using Blowfish encryption");
1747 break;
c5e9c988 1748 }
bea1ef5f 1749
e5574168 1750 send_packet(SSH1_CMSG_SESSION_KEY,
32874aea 1751 PKT_CHAR, cipher_type,
1752 PKT_DATA, cookie, 8,
1753 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
1754 PKT_DATA, rsabuf, len,
1755 PKT_INT, ssh1_local_protoflags, PKT_END);
fb09bf1c 1756
c5e9c988 1757 logevent("Trying to enable encryption...");
374330e2 1758
dcbde236 1759 sfree(rsabuf);
374330e2 1760
5e8358ad 1761 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
32874aea 1762 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
374330e2 1763 cipher->sesskey(session_key);
1764
fb09bf1c 1765 crWaitUntil(ispkt);
374330e2 1766
8d5de777 1767 if (pktin.type != SSH1_SMSG_SUCCESS) {
1768 bombout(("Encryption not successfully enabled"));
32874aea 1769 crReturn(0);
8d5de777 1770 }
374330e2 1771
c5e9c988 1772 logevent("Successfully started encryption");
1773
374330e2 1774 fflush(stdout);
1775 {
374330e2 1776 static int pos = 0;
1777 static char c;
67779be7 1778 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
32874aea 1779 if (ssh_get_line) {
1780 if (!ssh_get_line("login as: ",
1781 username, sizeof(username), FALSE)) {
1782 /*
1783 * get_line failed to get a username.
1784 * Terminate.
1785 */
1786 logevent("No username provided. Abandoning session.");
1787 ssh_state = SSH_STATE_CLOSED;
1788 crReturn(1);
1789 }
1790 } else {
1791 c_write_str("login as: ");
1792 ssh_send_ok = 1;
1793 while (pos >= 0) {
1794 crWaitUntil(!ispkt);
1795 while (inlen--)
1796 switch (c = *in++) {
1797 case 10:
1798 case 13:
1799 username[pos] = 0;
1800 pos = -1;
1801 break;
1802 case 8:
1803 case 127:
1804 if (pos > 0) {
1805 c_write_str("\b \b");
1806 pos--;
1807 }
1808 break;
1809 case 21:
1810 case 27:
1811 while (pos > 0) {
1812 c_write_str("\b \b");
1813 pos--;
1814 }
1815 break;
1816 case 3:
1817 case 4:
1818 random_save_seed();
1819 exit(0);
1820 break;
1821 default:
1822 if (((c >= ' ' && c <= '~') ||
51b2fb65 1823 ((unsigned char) c >= 160))
1824 && pos < sizeof(username)-1) {
32874aea 1825 username[pos++] = c;
1826 c_write(&c, 1);
1827 }
1828 break;
1829 }
1830 }
1831 c_write_str("\r\n");
1832 username[strcspn(username, "\n\r")] = '\0';
1833 }
1834 } else {
374330e2 1835 strncpy(username, cfg.username, 99);
1836 username[99] = '\0';
374330e2 1837 }
fb09bf1c 1838
e5574168 1839 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1840 {
32874aea 1841 char userlog[22 + sizeof(username)];
c5e9c988 1842 sprintf(userlog, "Sent username \"%s\"", username);
1843 logevent(userlog);
32874aea 1844 if (flags & FLAG_INTERACTIVE &&
1845 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 1846 strcat(userlog, "\r\n");
32874aea 1847 c_write_str(userlog);
3c8e959b 1848 }
c5e9c988 1849 }
374330e2 1850 }
1851
fb09bf1c 1852 crWaitUntil(ispkt);
374330e2 1853
7cca0d81 1854 tried_publickey = 0;
1855
e5574168 1856 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1857 static char password[100];
a52f067e 1858 static char prompt[200];
374330e2 1859 static int pos;
1860 static char c;
32874aea 1861 static int pwpkt_type;
1862 /*
1863 * Show password prompt, having first obtained it via a TIS
1864 * or CryptoCard exchange if we're doing TIS or CryptoCard
1865 * authentication.
1866 */
1867 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
1868 if (agent_exists()) {
1869 /*
1870 * Attempt RSA authentication using Pageant.
1871 */
1872 static unsigned char request[5], *response, *p;
1873 static int responselen;
1874 static int i, nkeys;
1875 static int authed = FALSE;
1876 void *r;
1877
1878 logevent("Pageant is running. Requesting keys.");
1879
1880 /* Request the keys held by the agent. */
1881 PUT_32BIT(request, 1);
1882 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
1883 agent_query(request, 5, &r, &responselen);
1884 response = (unsigned char *) r;
1885 if (response && responselen >= 5 &&
1886 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
1887 p = response + 5;
1888 nkeys = GET_32BIT(p);
1889 p += 4;
1890 {
1891 char buf[64];
1892 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
1893 logevent(buf);
1894 }
1895 for (i = 0; i < nkeys; i++) {
1896 static struct RSAKey key;
1897 static Bignum challenge;
1898 static char *commentp;
1899 static int commentlen;
1900
1901 {
1902 char buf[64];
1903 sprintf(buf, "Trying Pageant key #%d", i);
1904 logevent(buf);
1905 }
1906 p += 4;
1907 p += ssh1_read_bignum(p, &key.exponent);
1908 p += ssh1_read_bignum(p, &key.modulus);
1909 commentlen = GET_32BIT(p);
1910 p += 4;
1911 commentp = p;
1912 p += commentlen;
1913 send_packet(SSH1_CMSG_AUTH_RSA,
1914 PKT_BIGNUM, key.modulus, PKT_END);
1915 crWaitUntil(ispkt);
1916 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1917 logevent("Key refused");
1918 continue;
1919 }
1920 logevent("Received RSA challenge");
1921 ssh1_read_bignum(pktin.body, &challenge);
1922 {
1923 char *agentreq, *q, *ret;
2d466ffd 1924 void *vret;
32874aea 1925 int len, retlen;
1926 len = 1 + 4; /* message type, bit count */
1927 len += ssh1_bignum_length(key.exponent);
1928 len += ssh1_bignum_length(key.modulus);
1929 len += ssh1_bignum_length(challenge);
1930 len += 16; /* session id */
1931 len += 4; /* response format */
1932 agentreq = smalloc(4 + len);
1933 PUT_32BIT(agentreq, len);
1934 q = agentreq + 4;
1935 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
1936 PUT_32BIT(q, bignum_bitcount(key.modulus));
1937 q += 4;
1938 q += ssh1_write_bignum(q, key.exponent);
1939 q += ssh1_write_bignum(q, key.modulus);
1940 q += ssh1_write_bignum(q, challenge);
1941 memcpy(q, session_id, 16);
1942 q += 16;
1943 PUT_32BIT(q, 1); /* response format */
2d466ffd 1944 agent_query(agentreq, len + 4, &vret, &retlen);
1945 ret = vret;
32874aea 1946 sfree(agentreq);
1947 if (ret) {
1948 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
1949 logevent("Sending Pageant's response");
1950 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1951 PKT_DATA, ret + 5, 16,
1952 PKT_END);
1953 sfree(ret);
1954 crWaitUntil(ispkt);
1955 if (pktin.type == SSH1_SMSG_SUCCESS) {
1956 logevent
1957 ("Pageant's response accepted");
1958 if (flags & FLAG_VERBOSE) {
1959 c_write_str
1960 ("Authenticated using RSA key \"");
1961 c_write(commentp, commentlen);
1962 c_write_str("\" from agent\r\n");
1963 }
1964 authed = TRUE;
1965 } else
1966 logevent
1967 ("Pageant's response not accepted");
1968 } else {
1969 logevent
1970 ("Pageant failed to answer challenge");
1971 sfree(ret);
1972 }
1973 } else {
1974 logevent("No reply received from Pageant");
1975 }
1976 }
1977 freebn(key.exponent);
1978 freebn(key.modulus);
1979 freebn(challenge);
1980 if (authed)
1981 break;
1982 }
1983 }
1984 if (authed)
1985 break;
1986 }
1987 if (*cfg.keyfile && !tried_publickey)
1988 pwpkt_type = SSH1_CMSG_AUTH_RSA;
1989
1990 if (pktin.type == SSH1_SMSG_FAILURE &&
1991 cfg.try_tis_auth &&
1992 (supported_auths_mask & (1 << SSH1_AUTH_TIS))) {
1993 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1994 logevent("Requested TIS authentication");
1995 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1996 crWaitUntil(ispkt);
1997 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1998 logevent("TIS authentication declined");
1999 if (flags & FLAG_INTERACTIVE)
2000 c_write_str("TIS authentication refused.\r\n");
2001 } else {
2002 int challengelen = ((pktin.body[0] << 24) |
2003 (pktin.body[1] << 16) |
2004 (pktin.body[2] << 8) |
2005 (pktin.body[3]));
2006 logevent("Received TIS challenge");
2007 if (challengelen > sizeof(prompt) - 1)
2008 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2009 memcpy(prompt, pktin.body + 4, challengelen);
2010 prompt[challengelen] = '\0';
2011 }
2012 }
2013 if (pktin.type == SSH1_SMSG_FAILURE &&
2014 cfg.try_tis_auth &&
2015 (supported_auths_mask & (1 << SSH1_AUTH_CCARD))) {
2016 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2017 logevent("Requested CryptoCard authentication");
2018 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2019 crWaitUntil(ispkt);
2020 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2021 logevent("CryptoCard authentication declined");
2022 c_write_str("CryptoCard authentication refused.\r\n");
2023 } else {
2024 int challengelen = ((pktin.body[0] << 24) |
2025 (pktin.body[1] << 16) |
2026 (pktin.body[2] << 8) |
2027 (pktin.body[3]));
2028 logevent("Received CryptoCard challenge");
2029 if (challengelen > sizeof(prompt) - 1)
2030 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2031 memcpy(prompt, pktin.body + 4, challengelen);
2032 strncpy(prompt + challengelen, "\r\nResponse : ",
2033 sizeof(prompt) - challengelen);
2034 prompt[sizeof(prompt) - 1] = '\0';
2035 }
2036 }
2037 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2038 sprintf(prompt, "%.90s@%.90s's password: ",
2039 username, savedhost);
2040 }
2041 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2042 char *comment = NULL;
2043 if (flags & FLAG_VERBOSE)
2044 c_write_str("Trying public key authentication.\r\n");
2045 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2046 if (flags & FLAG_VERBOSE)
2047 c_write_str("No passphrase required.\r\n");
2048 goto tryauth;
2049 }
2050 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2051 sfree(comment);
2052 }
a52f067e 2053
fa17a66e 2054 if (ssh_get_line) {
2055 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
32874aea 2056 /*
2057 * get_line failed to get a password (for example
2058 * because one was supplied on the command line
2059 * which has already failed to work). Terminate.
2060 */
2bc6a386 2061 send_packet(SSH1_MSG_DISCONNECT,
2062 PKT_STR, "No more passwords available to try",
2063 PKT_END);
2064 connection_fatal("Unable to authenticate");
32874aea 2065 ssh_state = SSH_STATE_CLOSED;
2066 crReturn(1);
2067 }
fb09bf1c 2068 } else {
32874aea 2069 c_write_str(prompt);
2070 pos = 0;
2071 ssh_send_ok = 1;
2072 while (pos >= 0) {
2073 crWaitUntil(!ispkt);
2074 while (inlen--)
2075 switch (c = *in++) {
2076 case 10:
2077 case 13:
2078 password[pos] = 0;
2079 pos = -1;
2080 break;
2081 case 8:
2082 case 127:
2083 if (pos > 0)
2084 pos--;
2085 break;
2086 case 21:
2087 case 27:
2088 pos = 0;
2089 break;
2090 case 3:
2091 case 4:
2092 random_save_seed();
2093 exit(0);
2094 break;
2095 default:
51b2fb65 2096 if (pos < sizeof(password)-1)
32874aea 2097 password[pos++] = c;
2098 break;
2099 }
2100 }
2101 c_write_str("\r\n");
2102 }
2103
2104 tryauth:
7cca0d81 2105 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2106 /*
2107 * Try public key authentication with the specified
2108 * key file.
2109 */
2110 static struct RSAKey pubkey;
2111 static Bignum challenge, response;
2112 static int i;
2113 static unsigned char buffer[32];
2114
2115 tried_publickey = 1;
2116 i = loadrsakey(cfg.keyfile, &pubkey, password);
2117 if (i == 0) {
2118 c_write_str("Couldn't load public key from ");
2119 c_write_str(cfg.keyfile);
2120 c_write_str(".\r\n");
2121 continue; /* go and try password */
2122 }
2123 if (i == -1) {
2124 c_write_str("Wrong passphrase.\r\n");
2125 tried_publickey = 0;
2126 continue; /* try again */
2127 }
2128
2129 /*
2130 * Send a public key attempt.
2131 */
2132 send_packet(SSH1_CMSG_AUTH_RSA,
2133 PKT_BIGNUM, pubkey.modulus, PKT_END);
2134
2135 crWaitUntil(ispkt);
2136 if (pktin.type == SSH1_SMSG_FAILURE) {
2137 c_write_str("Server refused our public key.\r\n");
2138 continue; /* go and try password */
2139 }
2140 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2141 bombout(("Bizarre response to offer of public key"));
2142 crReturn(0);
2143 }
2144 ssh1_read_bignum(pktin.body, &challenge);
2145 response = rsadecrypt(challenge, &pubkey);
2146 freebn(pubkey.private_exponent); /* burn the evidence */
2147
2148 for (i = 0; i < 32; i++) {
2149 buffer[i] = bignum_byte(response, 31 - i);
2150 }
2151
2152 MD5Init(&md5c);
2153 MD5Update(&md5c, buffer, 32);
2154 MD5Update(&md5c, session_id, 16);
2155 MD5Final(buffer, &md5c);
2156
2157 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2158 PKT_DATA, buffer, 16, PKT_END);
2159
2160 crWaitUntil(ispkt);
2161 if (pktin.type == SSH1_SMSG_FAILURE) {
2162 if (flags & FLAG_VERBOSE)
2163 c_write_str
2164 ("Failed to authenticate with our public key.\r\n");
2165 continue; /* go and try password */
2166 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2167 bombout(
2168 ("Bizarre response to RSA authentication response"));
2169 crReturn(0);
2170 }
2171
2172 break; /* we're through! */
2173 } else {
2174 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2175 /*
2176 * Defence against traffic analysis: we send a
2177 * whole bunch of packets containing strings of
2178 * different lengths. One of these strings is the
2179 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2180 * The others are all random data in
2181 * SSH1_MSG_IGNORE packets. This way a passive
2182 * listener can't tell which is the password, and
2183 * hence can't deduce the password length.
2184 *
2185 * Anybody with a password length greater than 16
2186 * bytes is going to have enough entropy in their
2187 * password that a listener won't find it _that_
2188 * much help to know how long it is. So what we'll
2189 * do is:
2190 *
2191 * - if password length < 16, we send 15 packets
2192 * containing string lengths 1 through 15
2193 *
2194 * - otherwise, we let N be the nearest multiple
2195 * of 8 below the password length, and send 8
2196 * packets containing string lengths N through
2197 * N+7. This won't obscure the order of
2198 * magnitude of the password length, but it will
2199 * introduce a bit of extra uncertainty.
2200 *
2201 * A few servers (the old 1.2.18 through 1.2.22)
2202 * can't deal with SSH1_MSG_IGNORE. For these
2203 * servers, we need an alternative defence. We make
2204 * use of the fact that the password is interpreted
2205 * as a C string: so we can append a NUL, then some
2206 * random data.
2207 */
2208 if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
2209 char string[64];
2210 char *s;
2211 int len;
2212
2213 len = strlen(password);
2214 if (len < sizeof(string)) {
2215 s = string;
2216 strcpy(string, password);
2217 len++; /* cover the zero byte */
2218 while (len < sizeof(string)) {
2219 string[len++] = (char) random_byte();
2220 }
2221 } else {
2222 s = password;
2223 }
2224 send_packet(pwpkt_type, PKT_INT, len,
2225 PKT_DATA, s, len, PKT_END);
2226 } else {
2227 int bottom, top, pwlen, i;
2228 char *randomstr;
2229
2230 pwlen = strlen(password);
2231 if (pwlen < 16) {
2232 bottom = 0; /* zero length passwords are OK! :-) */
2233 top = 15;
2234 } else {
2235 bottom = pwlen & ~7;
2236 top = bottom + 7;
2237 }
2238
2239 assert(pwlen >= bottom && pwlen <= top);
2240
2241 randomstr = smalloc(top + 1);
2242
2243 for (i = bottom; i <= top; i++) {
2244 if (i == pwlen)
2245 defer_packet(pwpkt_type, PKT_STR, password,
2246 PKT_END);
2247 else {
2248 for (j = 0; j < i; j++) {
2249 do {
2250 randomstr[j] = random_byte();
2251 } while (randomstr[j] == '\0');
2252 }
2253 randomstr[i] = '\0';
2254 defer_packet(SSH1_MSG_IGNORE,
2255 PKT_STR, randomstr, PKT_END);
2256 }
2257 }
2258 ssh_pkt_defersend();
2259 }
2260 } else {
2261 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2262 }
2263 }
c5e9c988 2264 logevent("Sent password");
374330e2 2265 memset(password, 0, strlen(password));
fb09bf1c 2266 crWaitUntil(ispkt);
e5574168 2267 if (pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2268 if (flags & FLAG_VERBOSE)
2269 c_write_str("Access denied\r\n");
c5e9c988 2270 logevent("Authentication refused");
e5574168 2271 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 2272 logevent("Received disconnect request");
32874aea 2273 ssh_state = SSH_STATE_CLOSED;
85ee8208 2274 crReturn(1);
e5574168 2275 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2276 bombout(("Strange packet received, type %d", pktin.type));
32874aea 2277 crReturn(0);
374330e2 2278 }
2279 }
2280
c5e9c988 2281 logevent("Authentication successful");
2282
fb09bf1c 2283 crFinish(1);
2284}
2285
32874aea 2286void sshfwd_close(struct ssh_channel *c)
2287{
80e48603 2288 if (c && !c->closes) {
32874aea 2289 if (ssh_version == 1) {
2290 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2291 PKT_END);
2292 } else {
2293 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2294 ssh2_pkt_adduint32(c->remoteid);
2295 ssh2_pkt_send();
2296 }
2297 c->closes = 1;
2298 if (c->type == CHAN_X11) {
2299 c->u.x11.s = NULL;
d74d141c 2300 logevent("Forwarded X11 connection terminated");
2301 } else if (c->type == CHAN_SOCKDATA) {
2302 c->u.pfd.s = NULL;
2303 logevent("Forwarded port closed");
32874aea 2304 }
2305 }
2306}
2307
2308void sshfwd_write(struct ssh_channel *c, char *buf, int len)
2309{
783415f8 2310 if (ssh_version == 1) {
32874aea 2311 send_packet(SSH1_MSG_CHANNEL_DATA,
2312 PKT_INT, c->remoteid,
2313 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
783415f8 2314 } else {
32874aea 2315 ssh2_add_channel_data(c, buf, len);
2316 ssh2_try_send(c);
783415f8 2317 }
9c964e85 2318}
2319
32874aea 2320static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2321{
fb09bf1c 2322 crBegin;
2323
2324 random_init();
2325
e5574168 2326 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 2327 crReturnV;
85ee8208 2328 }
2329 if (ssh_state == SSH_STATE_CLOSED)
32874aea 2330 crReturnV;
fb09bf1c 2331
979310f1 2332 if (cfg.agentfwd && agent_exists()) {
32874aea 2333 logevent("Requesting agent forwarding");
2334 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2335 do {
2336 crReturnV;
2337 } while (!ispkt);
2338 if (pktin.type != SSH1_SMSG_SUCCESS
2339 && pktin.type != SSH1_SMSG_FAILURE) {
2340 bombout(("Protocol confusion"));
2341 crReturnV;
2342 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2343 logevent("Agent forwarding refused");
2344 } else {
2345 logevent("Agent forwarding enabled");
db7d555c 2346 ssh_agentfwd_enabled = TRUE;
2347 }
dacbd0e8 2348 }
2349
9c964e85 2350 if (cfg.x11_forward) {
32874aea 2351 char proto[20], data[64];
2352 logevent("Requesting X11 forwarding");
2353 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2354 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2355 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2356 PKT_STR, proto, PKT_STR, data,
2357 PKT_INT, 0, PKT_END);
2358 } else {
2359 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2360 PKT_STR, proto, PKT_STR, data, PKT_END);
2361 }
2362 do {
2363 crReturnV;
2364 } while (!ispkt);
2365 if (pktin.type != SSH1_SMSG_SUCCESS
2366 && pktin.type != SSH1_SMSG_FAILURE) {
2367 bombout(("Protocol confusion"));
2368 crReturnV;
2369 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2370 logevent("X11 forwarding refused");
2371 } else {
2372 logevent("X11 forwarding enabled");
9c964e85 2373 ssh_X11_fwd_enabled = TRUE;
2374 }
2375 }
2376
d74d141c 2377 {
2378 char type, *e;
2379 int n;
2380 int sport,dport;
2381 char sports[256], dports[256], host[256];
2382 char buf[1024];
2383
2384 ssh_rportfwds = newtree234(ssh_rportcmp);
2385 /* Add port forwardings. */
2386 e = cfg.portfwd;
2387 while (*e) {
2388 type = *e++;
2389 n = 0;
2390 while (*e && *e != '\t')
2391 sports[n++] = *e++;
2392 sports[n] = 0;
2393 if (*e == '\t')
2394 e++;
2395 n = 0;
2396 while (*e && *e != ':')
2397 host[n++] = *e++;
2398 host[n] = 0;
2399 if (*e == ':')
2400 e++;
2401 n = 0;
2402 while (*e)
2403 dports[n++] = *e++;
2404 dports[n] = 0;
2405 e++;
2406 dport = atoi(dports);
2407 sport = atoi(sports);
2408 if (sport && dport) {
2409 if (type == 'L') {
2410 pfd_addforward(host, dport, sport);
2411 sprintf(buf, "Local port %d forwarding to %s:%d",
2412 sport, host, dport);
2413 logevent(buf);
2414 } else {
2415 struct ssh_rportfwd *pf;
2416 pf = smalloc(sizeof(*pf));
2417 strcpy(pf->host, host);
2418 pf->port = dport;
2419 if (add234(ssh_rportfwds, pf) != pf) {
2420 sprintf(buf,
2421 "Duplicate remote port forwarding to %s:%s",
2422 host, dport);
2423 logevent(buf);
2424 } else {
2425 sprintf(buf, "Requesting remote port %d forward to %s:%d",
2426 sport, host, dport);
2427 logevent(buf);
2428 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
2429 PKT_INT, sport,
2430 PKT_STR, host,
2431 PKT_INT, dport,
2432 PKT_END);
2433 }
2434 }
2435 }
2436 }
2437 }
2438
fef97f43 2439 if (!cfg.nopty) {
e5574168 2440 send_packet(SSH1_CMSG_REQUEST_PTY,
32874aea 2441 PKT_STR, cfg.termtype,
2442 PKT_INT, rows, PKT_INT, cols,
2443 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2444 ssh_state = SSH_STATE_INTERMED;
2445 do {
2446 crReturnV;
2447 } while (!ispkt);
2448 if (pktin.type != SSH1_SMSG_SUCCESS
2449 && pktin.type != SSH1_SMSG_FAILURE) {
2450 bombout(("Protocol confusion"));
2451 crReturnV;
2452 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2453 c_write_str("Server refused to allocate pty\r\n");
2454 ssh_editing = ssh_echoing = 1;
2455 }
c5e9c988 2456 logevent("Allocated pty");
0965bee0 2457 } else {
32874aea 2458 ssh_editing = ssh_echoing = 1;
374330e2 2459 }
2460
4ba9b64b 2461 if (cfg.compression) {
32874aea 2462 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2463 do {
2464 crReturnV;
2465 } while (!ispkt);
2466 if (pktin.type != SSH1_SMSG_SUCCESS
2467 && pktin.type != SSH1_SMSG_FAILURE) {
2468 bombout(("Protocol confusion"));
2469 crReturnV;
2470 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2471 c_write_str("Server refused to compress\r\n");
2472 }
4ba9b64b 2473 logevent("Started compression");
2474 ssh1_compressing = TRUE;
2475 zlib_compress_init();
2476 zlib_decompress_init();
2477 }
2478
96621a84 2479 if (*cfg.remote_cmd_ptr)
32874aea 2480 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd_ptr,
2481 PKT_END);
6abbf9e3 2482 else
32874aea 2483 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 2484 logevent("Started session");
374330e2 2485
2486 ssh_state = SSH_STATE_SESSION;
2487 if (size_needed)
2488 ssh_size();
3687d221 2489 if (eof_needed)
32874aea 2490 ssh_special(TS_EOF);
374330e2 2491
32874aea 2492 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 2493 ssh_send_ok = 1;
dacbd0e8 2494 ssh_channels = newtree234(ssh_channelcmp);
374330e2 2495 while (1) {
2496 crReturnV;
2497 if (ispkt) {
e5574168 2498 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 2499 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 2500 long len = GET_32BIT(pktin.body);
fe50e814 2501 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
32874aea 2502 pktin.body + 4, len);
e5574168 2503 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
32874aea 2504 ssh_state = SSH_STATE_CLOSED;
c5e9c988 2505 logevent("Received disconnect request");
32874aea 2506 crReturnV;
2507 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2508 /* Remote side is trying to open a channel to talk to our
2509 * X-Server. Give them back a local channel number. */
2510 struct ssh_channel *c;
9c964e85 2511
2512 logevent("Received X11 connect request");
2513 /* Refuse if X11 forwarding is disabled. */
2514 if (!ssh_X11_fwd_enabled) {
2515 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 2516 PKT_INT, GET_32BIT(pktin.body), PKT_END);
9c964e85 2517 logevent("Rejected X11 connect request");
2518 } else {
9c964e85 2519 c = smalloc(sizeof(struct ssh_channel));
2520
32874aea 2521 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2522 logevent("opening X11 forward connection failed");
2523 sfree(c);
2524 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2525 PKT_INT, GET_32BIT(pktin.body),
2526 PKT_END);
9c964e85 2527 } else {
32874aea 2528 logevent
2529 ("opening X11 forward connection succeeded");
2530 c->remoteid = GET_32BIT(pktin.body);
2531 c->localid = alloc_channel_id();
2532 c->closes = 0;
2533 c->type = CHAN_X11; /* identify channel type */
2534 add234(ssh_channels, c);
2535 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2536 PKT_INT, c->remoteid, PKT_INT,
2537 c->localid, PKT_END);
2538 logevent("Opened X11 forward channel");
9c964e85 2539 }
2540 }
32874aea 2541 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2542 /* Remote side is trying to open a channel to talk to our
2543 * agent. Give them back a local channel number. */
2544 struct ssh_channel *c;
db7d555c 2545
2546 /* Refuse if agent forwarding is disabled. */
2547 if (!ssh_agentfwd_enabled) {
2548 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 2549 PKT_INT, GET_32BIT(pktin.body), PKT_END);
db7d555c 2550 } else {
dcbde236 2551 c = smalloc(sizeof(struct ssh_channel));
db7d555c 2552 c->remoteid = GET_32BIT(pktin.body);
d2371c81 2553 c->localid = alloc_channel_id();
db7d555c 2554 c->closes = 0;
32874aea 2555 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 2556 c->u.a.lensofar = 0;
2557 add234(ssh_channels, c);
2558 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2559 PKT_INT, c->remoteid, PKT_INT, c->localid,
2560 PKT_END);
2561 }
d74d141c 2562 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
2563 /* Remote side is trying to open a channel to talk to a
2564 * forwarded port. Give them back a local channel number. */
2565 struct ssh_channel *c;
2566 struct ssh_rportfwd pf;
2567 int hostsize, port;
2568 char host[256], buf[1024];
2569 char *p, *h, *e;
2570 c = smalloc(sizeof(struct ssh_channel));
2571
2572 hostsize = GET_32BIT(pktin.body+4);
2573 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
2574 if (h+1 < host+sizeof(host))
2575 *h++ = *p;
2576 *p++;
2577 }
2578 *h = 0;
2579 port = GET_32BIT(p);
2580
2581 strcpy(pf.host, host);
2582 pf.port = port;
2583
2584 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
2585 sprintf(buf, "Rejected remote port open request for %s:%d",
2586 host, port);
2587 logevent(buf);
2588 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2589 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2590 } else {
2591 sprintf(buf, "Received remote port open request for %s:%d",
2592 host, port);
2593 logevent(buf);
2594 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
2595 if (e != NULL) {
2596 char buf[256];
2597 sprintf(buf, "Port open failed: %s", e);
2598 logevent(buf);
2599 sfree(c);
2600 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2601 PKT_INT, GET_32BIT(pktin.body),
2602 PKT_END);
2603 } else {
2604 c->remoteid = GET_32BIT(pktin.body);
2605 c->localid = alloc_channel_id();
2606 c->closes = 0;
2607 c->type = CHAN_SOCKDATA; /* identify channel type */
2608 add234(ssh_channels, c);
2609 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2610 PKT_INT, c->remoteid, PKT_INT,
2611 c->localid, PKT_END);
2612 logevent("Forwarded port opened successfully");
2613 }
2614 }
2615
2616 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
2617 unsigned int remoteid = GET_32BIT(pktin.body);
2618 unsigned int localid = GET_32BIT(pktin.body+4);
2619 struct ssh_channel *c;
2620
2621 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2622 if (c) {
2623 c->remoteid = localid;
2624 pfd_confirm(c->u.pfd.s);
2625 } else {
2626 sshfwd_close(c);
2627 }
2628
db7d555c 2629 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2630 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 2631 /* Remote side closes a channel. */
2632 unsigned i = GET_32BIT(pktin.body);
2633 struct ssh_channel *c;
2634 c = find234(ssh_channels, &i, ssh_channelfind);
2635 if (c) {
2636 int closetype;
2637 closetype =
2638 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2639 if (!(c->closes & closetype))
2640 send_packet(pktin.type, PKT_INT, c->remoteid,
2641 PKT_END);
783415f8 2642 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 2643 logevent("Forwarded X11 connection terminated");
9c964e85 2644 assert(c->u.x11.s != NULL);
2645 x11_close(c->u.x11.s);
2646 c->u.x11.s = NULL;
2647 }
d74d141c 2648 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
2649 logevent("Forwarded port closed");
2650 assert(c->u.pfd.s != NULL);
2651 pfd_close(c->u.pfd.s);
2652 c->u.pfd.s = NULL;
2653 }
32874aea 2654 c->closes |= closetype;
2655 if (c->closes == 3) {
2656 del234(ssh_channels, c);
2657 sfree(c);
2658 }
2659 }
2660 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2661 /* Data sent down one of our channels. */
2662 int i = GET_32BIT(pktin.body);
2663 int len = GET_32BIT(pktin.body + 4);
2664 unsigned char *p = pktin.body + 8;
2665 struct ssh_channel *c;
2666 c = find234(ssh_channels, &i, ssh_channelfind);
2667 if (c) {
2668 switch (c->type) {
2669 case CHAN_X11:
9c964e85 2670 x11_send(c->u.x11.s, p, len);
2671 break;
d74d141c 2672 case CHAN_SOCKDATA:
2673 pfd_send(c->u.pfd.s, p, len);
2674 break;
32874aea 2675 case CHAN_AGENT:
2676 /* Data for an agent message. Buffer it. */
2677 while (len > 0) {
2678 if (c->u.a.lensofar < 4) {
2679 int l = min(4 - c->u.a.lensofar, len);
2680 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
2681 l);
2682 p += l;
2683 len -= l;
2684 c->u.a.lensofar += l;
2685 }
2686 if (c->u.a.lensofar == 4) {
2687 c->u.a.totallen =
2688 4 + GET_32BIT(c->u.a.msglen);
2689 c->u.a.message = smalloc(c->u.a.totallen);
2690 memcpy(c->u.a.message, c->u.a.msglen, 4);
2691 }
2692 if (c->u.a.lensofar >= 4 && len > 0) {
2693 int l =
2694 min(c->u.a.totallen - c->u.a.lensofar,
2695 len);
2696 memcpy(c->u.a.message + c->u.a.lensofar, p,
2697 l);
2698 p += l;
2699 len -= l;
2700 c->u.a.lensofar += l;
2701 }
2702 if (c->u.a.lensofar == c->u.a.totallen) {
2703 void *reply, *sentreply;
2704 int replylen;
2705 agent_query(c->u.a.message,
2706 c->u.a.totallen, &reply,
2707 &replylen);
2708 if (reply)
2709 sentreply = reply;
2710 else {
2711 /* Fake SSH_AGENT_FAILURE. */
2712 sentreply = "\0\0\0\1\5";
2713 replylen = 5;
2714 }
2715 send_packet(SSH1_MSG_CHANNEL_DATA,
2716 PKT_INT, c->remoteid,
2717 PKT_INT, replylen,
2718 PKT_DATA, sentreply, replylen,
2719 PKT_END);
2720 if (reply)
2721 sfree(reply);
2722 sfree(c->u.a.message);
2723 c->u.a.lensofar = 0;
2724 }
2725 }
2726 break;
2727 }
2728 }
e5574168 2729 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 2730 /* may be from EXEC_SHELL on some servers */
e5574168 2731 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 2732 /* may be from EXEC_SHELL on some servers
374330e2 2733 * if no pty is available or in other odd cases. Ignore */
e5574168 2734 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
2735 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 2736 } else {
8d5de777 2737 bombout(("Strange packet received: type %d", pktin.type));
32874aea 2738 crReturnV;
374330e2 2739 }
2740 } else {
8df7a775 2741 while (inlen > 0) {
2742 int len = min(inlen, 512);
2743 send_packet(SSH1_CMSG_STDIN_DATA,
2744 PKT_INT, len, PKT_DATA, in, len, PKT_END);
2745 in += len;
2746 inlen -= len;
2747 }
374330e2 2748 }
2749 }
2750
2751 crFinishV;
2752}
2753
2754/*
e5574168 2755 * Utility routine for decoding comma-separated strings in KEXINIT.
2756 */
32874aea 2757static int in_commasep_string(char *needle, char *haystack, int haylen)
2758{
e5574168 2759 int needlen = strlen(needle);
2760 while (1) {
32874aea 2761 /*
2762 * Is it at the start of the string?
2763 */
2764 if (haylen >= needlen && /* haystack is long enough */
2765 !memcmp(needle, haystack, needlen) && /* initial match */
2766 (haylen == needlen || haystack[needlen] == ',')
2767 /* either , or EOS follows */
2768 )
2769 return 1;
2770 /*
2771 * If not, search for the next comma and resume after that.
2772 * If no comma found, terminate.
2773 */
2774 while (haylen > 0 && *haystack != ',')
2775 haylen--, haystack++;
2776 if (haylen == 0)
2777 return 0;
2778 haylen--, haystack++; /* skip over comma itself */
e5574168 2779 }
2780}
2781
2782/*
d39f364a 2783 * SSH2 key creation method.
2784 */
32874aea 2785static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
2786 char *keyspace)
2787{
d39f364a 2788 SHA_State s;
2789 /* First 20 bytes. */
2790 SHA_Init(&s);
2791 sha_mpint(&s, K);
2792 SHA_Bytes(&s, H, 20);
2793 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 2794 SHA_Bytes(&s, sessid, 20);
d39f364a 2795 SHA_Final(&s, keyspace);
2796 /* Next 20 bytes. */
2797 SHA_Init(&s);
2798 sha_mpint(&s, K);
2799 SHA_Bytes(&s, H, 20);
2800 SHA_Bytes(&s, keyspace, 20);
32874aea 2801 SHA_Final(&s, keyspace + 20);
d39f364a 2802}
2803
2804/*
7cca0d81 2805 * Handle the SSH2 transport layer.
e5574168 2806 */
7cca0d81 2807static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 2808{
7bd5a860 2809 static int i, j, len, nbits, pbits;
e5574168 2810 static char *str;
a92dd380 2811 static Bignum p, g, e, f, K;
2812 static int kex_init_value, kex_reply_value;
7591b9ff 2813 static const struct ssh_mac **maclist;
8b2715b2 2814 static int nmacs;
0a3f1d48 2815 static const struct ssh2_cipher *cscipher_tobe = NULL;
2816 static const struct ssh2_cipher *sccipher_tobe = NULL;
57476f6b 2817 static const struct ssh_mac *csmac_tobe = NULL;
2818 static const struct ssh_mac *scmac_tobe = NULL;
2819 static const struct ssh_compress *cscomp_tobe = NULL;
2820 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 2821 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 2822 static int hostkeylen, siglen;
e055a386 2823 static void *hkey; /* actual host key */
e5574168 2824 static unsigned char exchange_hash[20];
d39f364a 2825 static unsigned char keyspace[40];
0a3f1d48 2826 static const struct ssh2_ciphers *preferred_cipher;
4ba9b64b 2827 static const struct ssh_compress *preferred_comp;
0db56f73 2828 static int first_kex;
e5574168 2829
2830 crBegin;
7cca0d81 2831 random_init();
0db56f73 2832 first_kex = 1;
e5574168 2833
5e8358ad 2834 /*
4ba9b64b 2835 * Set up the preferred cipher and compression.
5e8358ad 2836 */
2837 if (cfg.cipher == CIPHER_BLOWFISH) {
32874aea 2838 preferred_cipher = &ssh2_blowfish;
5e8358ad 2839 } else if (cfg.cipher == CIPHER_DES) {
32874aea 2840 logevent("Single DES not supported in SSH2; using 3DES");
2841 preferred_cipher = &ssh2_3des;
5e8358ad 2842 } else if (cfg.cipher == CIPHER_3DES) {
32874aea 2843 preferred_cipher = &ssh2_3des;
0a3f1d48 2844 } else if (cfg.cipher == CIPHER_AES) {
32874aea 2845 preferred_cipher = &ssh2_aes;
5e8358ad 2846 } else {
32874aea 2847 /* Shouldn't happen, but we do want to initialise to _something_. */
2848 preferred_cipher = &ssh2_3des;
5e8358ad 2849 }
4ba9b64b 2850 if (cfg.compression)
2851 preferred_comp = &ssh_zlib;
2852 else
2853 preferred_comp = &ssh_comp_none;
5e8358ad 2854
7591b9ff 2855 /*
2856 * Be prepared to work around the buggy MAC problem.
2857 */
7d503c31 2858 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
32874aea 2859 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 2860 else
32874aea 2861 maclist = macs, nmacs = lenof(macs);
7591b9ff 2862
32874aea 2863 begin_key_exchange:
e5574168 2864 /*
2865 * Construct and send our key exchange packet.
2866 */
2867 ssh2_pkt_init(SSH2_MSG_KEXINIT);
2868 for (i = 0; i < 16; i++)
32874aea 2869 ssh2_pkt_addbyte((unsigned char) random_byte());
e5574168 2870 /* List key exchange algorithms. */
2871 ssh2_pkt_addstring_start();
2872 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 2873 ssh2_pkt_addstring_str(kex_algs[i]->name);
2874 if (i < lenof(kex_algs) - 1)
2875 ssh2_pkt_addstring_str(",");
e5574168 2876 }
2877 /* List server host key algorithms. */
2878 ssh2_pkt_addstring_start();
2879 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 2880 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
2881 if (i < lenof(hostkey_algs) - 1)
2882 ssh2_pkt_addstring_str(",");
e5574168 2883 }
2884 /* List client->server encryption algorithms. */
2885 ssh2_pkt_addstring_start();
32874aea 2886 for (i = 0; i < lenof(ciphers) + 1; i++) {
2887 const struct ssh2_ciphers *c =
2888 i == 0 ? preferred_cipher : ciphers[i - 1];
2889 for (j = 0; j < c->nciphers; j++) {
2890 ssh2_pkt_addstring_str(c->list[j]->name);
2891 if (i < lenof(ciphers) || j < c->nciphers - 1)
2892 ssh2_pkt_addstring_str(",");
2893 }
e5574168 2894 }
2895 /* List server->client encryption algorithms. */
2896 ssh2_pkt_addstring_start();
32874aea 2897 for (i = 0; i < lenof(ciphers) + 1; i++) {
2898 const struct ssh2_ciphers *c =
2899 i == 0 ? preferred_cipher : ciphers[i - 1];
2900 for (j = 0; j < c->nciphers; j++) {
2901 ssh2_pkt_addstring_str(c->list[j]->name);
2902 if (i < lenof(ciphers) || j < c->nciphers - 1)
2903 ssh2_pkt_addstring_str(",");
2904 }
e5574168 2905 }
2906 /* List client->server MAC algorithms. */
2907 ssh2_pkt_addstring_start();
8b2715b2 2908 for (i = 0; i < nmacs; i++) {
32874aea 2909 ssh2_pkt_addstring_str(maclist[i]->name);
2910 if (i < nmacs - 1)
2911 ssh2_pkt_addstring_str(",");
e5574168 2912 }
2913 /* List server->client MAC algorithms. */
2914 ssh2_pkt_addstring_start();
8b2715b2 2915 for (i = 0; i < nmacs; i++) {
32874aea 2916 ssh2_pkt_addstring_str(maclist[i]->name);
2917 if (i < nmacs - 1)
2918 ssh2_pkt_addstring_str(",");
e5574168 2919 }
2920 /* List client->server compression algorithms. */
2921 ssh2_pkt_addstring_start();
32874aea 2922 for (i = 0; i < lenof(compressions) + 1; i++) {
2923 const struct ssh_compress *c =
2924 i == 0 ? preferred_comp : compressions[i - 1];
2925 ssh2_pkt_addstring_str(c->name);
2926 if (i < lenof(compressions))
2927 ssh2_pkt_addstring_str(",");
e5574168 2928 }
2929 /* List server->client compression algorithms. */
2930 ssh2_pkt_addstring_start();
32874aea 2931 for (i = 0; i < lenof(compressions) + 1; i++) {
2932 const struct ssh_compress *c =
2933 i == 0 ? preferred_comp : compressions[i - 1];
2934 ssh2_pkt_addstring_str(c->name);
2935 if (i < lenof(compressions))
2936 ssh2_pkt_addstring_str(",");
e5574168 2937 }
2938 /* List client->server languages. Empty list. */
2939 ssh2_pkt_addstring_start();
2940 /* List server->client languages. Empty list. */
2941 ssh2_pkt_addstring_start();
2942 /* First KEX packet does _not_ follow, because we're not that brave. */
2943 ssh2_pkt_addbool(FALSE);
2944 /* Reserved. */
2945 ssh2_pkt_adduint32(0);
0db56f73 2946
2947 exhash = exhashbase;
32874aea 2948 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
0db56f73 2949
e5574168 2950 ssh2_pkt_send();
2951
32874aea 2952 if (!ispkt)
2953 crWaitUntil(ispkt);
2954 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
e5574168 2955
2956 /*
2957 * Now examine the other side's KEXINIT to see what we're up
2958 * to.
2959 */
7cca0d81 2960 if (pktin.type != SSH2_MSG_KEXINIT) {
32874aea 2961 bombout(("expected key exchange packet from server"));
2962 crReturn(0);
7cca0d81 2963 }
32874aea 2964 kex = NULL;
2965 hostkey = NULL;
2966 cscipher_tobe = NULL;
2967 sccipher_tobe = NULL;
2968 csmac_tobe = NULL;
2969 scmac_tobe = NULL;
2970 cscomp_tobe = NULL;
2971 sccomp_tobe = NULL;
2972 pktin.savedpos += 16; /* skip garbage cookie */
e5574168 2973 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
2974 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 2975 if (in_commasep_string(kex_algs[i]->name, str, len)) {
2976 kex = kex_algs[i];
2977 break;
2978 }
e5574168 2979 }
2980 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
2981 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 2982 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
2983 hostkey = hostkey_algs[i];
2984 break;
2985 }
e5574168 2986 }
2987 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
32874aea 2988 for (i = 0; i < lenof(ciphers) + 1; i++) {
2989 const struct ssh2_ciphers *c =
2990 i == 0 ? preferred_cipher : ciphers[i - 1];
2991 for (j = 0; j < c->nciphers; j++) {
2992 if (in_commasep_string(c->list[j]->name, str, len)) {
2993 cscipher_tobe = c->list[j];
2994 break;
2995 }
2996 }
2997 if (cscipher_tobe)
2998 break;
e5574168 2999 }
3000 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
32874aea 3001 for (i = 0; i < lenof(ciphers) + 1; i++) {
3002 const struct ssh2_ciphers *c =
3003 i == 0 ? preferred_cipher : ciphers[i - 1];
3004 for (j = 0; j < c->nciphers; j++) {
3005 if (in_commasep_string(c->list[j]->name, str, len)) {
3006 sccipher_tobe = c->list[j];
3007 break;
3008 }
3009 }
3010 if (sccipher_tobe)
3011 break;
e5574168 3012 }
3013 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 3014 for (i = 0; i < nmacs; i++) {
32874aea 3015 if (in_commasep_string(maclist[i]->name, str, len)) {
3016 csmac_tobe = maclist[i];
3017 break;
3018 }
e5574168 3019 }
3020 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 3021 for (i = 0; i < nmacs; i++) {
32874aea 3022 if (in_commasep_string(maclist[i]->name, str, len)) {
3023 scmac_tobe = maclist[i];
3024 break;
3025 }
e5574168 3026 }
3027 ssh2_pkt_getstring(&str, &len); /* client->server compression */
32874aea 3028 for (i = 0; i < lenof(compressions) + 1; i++) {
3029 const struct ssh_compress *c =
3030 i == 0 ? preferred_comp : compressions[i - 1];
3031 if (in_commasep_string(c->name, str, len)) {
3032 cscomp_tobe = c;
3033 break;
3034 }
e5574168 3035 }
3036 ssh2_pkt_getstring(&str, &len); /* server->client compression */
32874aea 3037 for (i = 0; i < lenof(compressions) + 1; i++) {
3038 const struct ssh_compress *c =
3039 i == 0 ? preferred_comp : compressions[i - 1];
3040 if (in_commasep_string(c->name, str, len)) {
3041 sccomp_tobe = c;
3042 break;
3043 }
e5574168 3044 }
e5574168 3045
3046 /*
7bd5a860 3047 * Work out the number of bits of key we will need from the key
3048 * exchange. We start with the maximum key length of either
3049 * cipher...
3050 */
3051 {
32874aea 3052 int csbits, scbits;
7bd5a860 3053
3054 csbits = cscipher_tobe->keylen;
3055 scbits = sccipher_tobe->keylen;
3056 nbits = (csbits > scbits ? csbits : scbits);
3057 }
3058 /* The keys only have 160-bit entropy, since they're based on
3059 * a SHA-1 hash. So cap the key size at 160 bits. */
32874aea 3060 if (nbits > 160)
3061 nbits = 160;
7bd5a860 3062
3063 /*
a92dd380 3064 * If we're doing Diffie-Hellman group exchange, start by
3065 * requesting a group.
e5574168 3066 */
a92dd380 3067 if (kex == &ssh_diffiehellman_gex) {
32874aea 3068 logevent("Doing Diffie-Hellman group exchange");
3069 /*
3070 * Work out how big a DH group we will need to allow that
3071 * much data.
7bd5a860 3072 */
32874aea 3073 pbits = 512 << ((nbits - 1) / 64);
3074 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3075 ssh2_pkt_adduint32(pbits);
3076 ssh2_pkt_send();
3077
3078 crWaitUntil(ispkt);
3079 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3080 bombout(("expected key exchange group packet from server"));
3081 crReturn(0);
3082 }
3083 p = ssh2_pkt_getmp();
3084 g = ssh2_pkt_getmp();
3085 dh_setup_group(p, g);
3086 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3087 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 3088 } else {
32874aea 3089 dh_setup_group1();
3090 kex_init_value = SSH2_MSG_KEXDH_INIT;
3091 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 3092 }
e5574168 3093
a92dd380 3094 logevent("Doing Diffie-Hellman key exchange");
e5574168 3095 /*
a92dd380 3096 * Now generate and send e for Diffie-Hellman.
e5574168 3097 */
32874aea 3098 e = dh_create_e(nbits * 2);
a92dd380 3099 ssh2_pkt_init(kex_init_value);
e5574168 3100 ssh2_pkt_addmp(e);
3101 ssh2_pkt_send();
3102
3103 crWaitUntil(ispkt);
a92dd380 3104 if (pktin.type != kex_reply_value) {
32874aea 3105 bombout(("expected key exchange reply packet from server"));
3106 crReturn(0);
7cca0d81 3107 }
e5574168 3108 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3109 f = ssh2_pkt_getmp();
e5574168 3110 ssh2_pkt_getstring(&sigdata, &siglen);
3111
3112 K = dh_find_K(f);
e5574168 3113
3114 sha_string(&exhash, hostkeydata, hostkeylen);
a92dd380 3115 if (kex == &ssh_diffiehellman_gex) {
32874aea 3116 sha_uint32(&exhash, pbits);
3117 sha_mpint(&exhash, p);
3118 sha_mpint(&exhash, g);
a92dd380 3119 }
e5574168 3120 sha_mpint(&exhash, e);
3121 sha_mpint(&exhash, f);
3122 sha_mpint(&exhash, K);
3123 SHA_Final(&exhash, exchange_hash);
3124
3709bfe9 3125 dh_cleanup();
3126
7cca0d81 3127#if 0
765c4200 3128 debug(("Exchange hash is:\n"));
3129 dmemdump(exchange_hash, 20);
7cca0d81 3130#endif
3131
e055a386 3132 hkey = hostkey->newkey(hostkeydata, hostkeylen);
f7259d10 3133 if (!hkey ||
3134 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3135 bombout(("Server's host key did not match the signature supplied"));
32874aea 3136 crReturn(0);
8d5de777 3137 }
e5574168 3138
3139 /*
7cca0d81 3140 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 3141 */
7cca0d81 3142 crWaitUntil(ispkt);
8d5de777 3143 if (pktin.type != SSH2_MSG_NEWKEYS) {
32874aea 3144 bombout(("expected new-keys packet from server"));
3145 crReturn(0);
8d5de777 3146 }
d39f364a 3147
3148 /*
7cca0d81 3149 * Authenticate remote host: verify host key. (We've already
3150 * checked the signature of the exchange hash.)
e5574168 3151 */
e055a386 3152 keystr = hostkey->fmtkey(hkey);
3153 fingerprint = hostkey->fingerprint(hkey);
d4857987 3154 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
32874aea 3155 keystr, fingerprint);
3156 if (first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 3157 logevent("Host key fingerprint is:");
3158 logevent(fingerprint);
3159 }
dcbde236 3160 sfree(fingerprint);
3161 sfree(keystr);
e055a386 3162 hostkey->freekey(hkey);
d39f364a 3163
3164 /*
7cca0d81 3165 * Send SSH2_MSG_NEWKEYS.
d39f364a 3166 */
3167 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3168 ssh2_pkt_send();
d39f364a 3169
3170 /*
3171 * Create and initialise session keys.
3172 */
3173 cscipher = cscipher_tobe;
3174 sccipher = sccipher_tobe;
3175 csmac = csmac_tobe;
3176 scmac = scmac_tobe;
3177 cscomp = cscomp_tobe;
3178 sccomp = sccomp_tobe;
4ba9b64b 3179 cscomp->compress_init();
3180 sccomp->decompress_init();
d39f364a 3181 /*
5e0d7cb8 3182 * Set IVs after keys. Here we use the exchange hash from the
3183 * _first_ key exchange.
d39f364a 3184 */
5e0d7cb8 3185 if (first_kex)
65a22376 3186 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3187 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
5e0d7cb8 3188 cscipher->setcskey(keyspace);
65a22376 3189 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
5e0d7cb8 3190 sccipher->setsckey(keyspace);
65a22376 3191 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
5e0d7cb8 3192 cscipher->setcsiv(keyspace);
65a22376 3193 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
5e0d7cb8 3194 sccipher->setsciv(keyspace);
65a22376 3195 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
5e0d7cb8 3196 csmac->setcskey(keyspace);
65a22376 3197 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
5e0d7cb8 3198 scmac->setsckey(keyspace);
d39f364a 3199
033b4cef 3200 /*
0db56f73 3201 * If this is the first key exchange phase, we must pass the
3202 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3203 * wants to see it but because it will need time to initialise
3204 * itself before it sees an actual packet. In subsequent key
3205 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3206 * it would only confuse the layer above.
3207 */
3208 if (!first_kex) {
32874aea 3209 crReturn(0);
0db56f73 3210 }
3211 first_kex = 0;
3212
3213 /*
7cca0d81 3214 * Now we're encrypting. Begin returning 1 to the protocol main
3215 * function so that other things can run on top of the
3216 * transport. If we ever see a KEXINIT, we must go back to the
3217 * start.
033b4cef 3218 */
e96adf72 3219 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 3220 crReturn(1);
e96adf72 3221 }
5e0d7cb8 3222 logevent("Server initiated key re-exchange");
7cca0d81 3223 goto begin_key_exchange;
e5574168 3224
3225 crFinish(1);
3226}
3227
7cca0d81 3228/*
783415f8 3229 * Add data to an SSH2 channel output buffer.
3230 */
32874aea 3231static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3232 int len)
3233{
3234 if (c->v2.outbufsize < c->v2.outbuflen + len) {
3235 c->v2.outbufsize = c->v2.outbuflen + len + 1024;
3236 c->v2.outbuffer = srealloc(c->v2.outbuffer, c->v2.outbufsize);
3237 }
3238 memcpy(c->v2.outbuffer + c->v2.outbuflen, buf, len);
783415f8 3239 c->v2.outbuflen += len;
3240}
3241
3242/*
3243 * Attempt to send data on an SSH2 channel.
3244 */
32874aea 3245static void ssh2_try_send(struct ssh_channel *c)
3246{
3247 while (c->v2.remwindow > 0 && c->v2.outbuflen > 0) {
3248 unsigned len = c->v2.remwindow;
3249 if (len > c->v2.outbuflen)
3250 len = c->v2.outbuflen;
3251 if (len > c->v2.remmaxpkt)
3252 len = c->v2.remmaxpkt;
3253 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3254 ssh2_pkt_adduint32(c->remoteid);
3255 ssh2_pkt_addstring_start();
3256 ssh2_pkt_addstring_data(c->v2.outbuffer, len);
3257 ssh2_pkt_send();
3258 c->v2.outbuflen -= len;
3259 memmove(c->v2.outbuffer, c->v2.outbuffer + len, c->v2.outbuflen);
3260 c->v2.remwindow -= len;
783415f8 3261 }
3262}
3263
3264/*
7cca0d81 3265 * Handle the SSH2 userauth and connection layers.
3266 */
3267static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3268{
65a22376 3269 static enum {
32874aea 3270 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
3271 AUTH_PASSWORD
65a22376 3272 } method;
1408a877 3273 static enum {
32874aea 3274 AUTH_TYPE_NONE,
3275 AUTH_TYPE_PUBLICKEY,
3276 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3277 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
3278 AUTH_TYPE_PASSWORD
1408a877 3279 } type;
1983e559 3280 static int gotit, need_pw, can_pubkey, can_passwd;
3281 static int tried_pubkey_config, tried_agent;
1408a877 3282 static int we_are_in;
65a22376 3283 static char username[100];
3284 static char pwprompt[200];
3285 static char password[100];
7cca0d81 3286
e5574168 3287 crBegin;
3288
7cca0d81 3289 /*
3290 * Request userauth protocol, and await a response to it.
3291 */
3292 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3293 ssh2_pkt_addstring("ssh-userauth");
3294 ssh2_pkt_send();
3295 crWaitUntilV(ispkt);
8d5de777 3296 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
32874aea 3297 bombout(("Server refused user authentication protocol"));
3298 crReturnV;
8d5de777 3299 }
7cca0d81 3300
3301 /*
1408a877 3302 * We repeat this whole loop, including the username prompt,
3303 * until we manage a successful authentication. If the user
3304 * types the wrong _password_, they are sent back to the
3305 * beginning to try another username. (If they specify a
3306 * username in the config, they are never asked, even if they
3307 * do give a wrong password.)
3308 *
3309 * I think this best serves the needs of
3310 *
3311 * - the people who have no configuration, no keys, and just
3312 * want to try repeated (username,password) pairs until they
3313 * type both correctly
3314 *
3315 * - people who have keys and configuration but occasionally
3316 * need to fall back to passwords
3317 *
3318 * - people with a key held in Pageant, who might not have
3319 * logged in to a particular machine before; so they want to
3320 * type a username, and then _either_ their key will be
3321 * accepted, _or_ they will type a password. If they mistype
3322 * the username they will want to be able to get back and
3323 * retype it!
7cca0d81 3324 */
1408a877 3325 do {
3326 static int pos;
7cca0d81 3327 static char c;
e5574168 3328
1408a877 3329 /*
3330 * Get a username.
3331 */
3332 pos = 0;
67779be7 3333 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
32874aea 3334 if (ssh_get_line) {
3335 if (!ssh_get_line("login as: ",
3336 username, sizeof(username), FALSE)) {
3337 /*
3338 * get_line failed to get a username.
3339 * Terminate.
3340 */
3341 logevent("No username provided. Abandoning session.");
3342 ssh_state = SSH_STATE_CLOSED;
3343 crReturnV;
3344 }
3345 } else {
3346 c_write_str("login as: ");
3347 ssh_send_ok = 1;
3348 while (pos >= 0) {
3349 crWaitUntilV(!ispkt);
3350 while (inlen--)
3351 switch (c = *in++) {
3352 case 10:
3353 case 13:
3354 username[pos] = 0;
3355 pos = -1;
3356 break;
3357 case 8:
3358 case 127:
3359 if (pos > 0) {
3360 c_write_str("\b \b");
3361 pos--;
3362 }
3363 break;
3364 case 21:
3365 case 27:
3366 while (pos > 0) {
3367 c_write_str("\b \b");
3368 pos--;
3369 }
3370 break;
3371 case 3:
3372 case 4:
3373 random_save_seed();
3374 exit(0);
3375 break;
3376 default:
3377 if (((c >= ' ' && c <= '~') ||
51b2fb65 3378 ((unsigned char) c >= 160))
3379 && pos < sizeof(username)-1) {
32874aea 3380 username[pos++] = c;
3381 c_write(&c, 1);
3382 }
3383 break;
3384 }
3385 }
3386 }
1408a877 3387 c_write_str("\r\n");
7cca0d81 3388 username[strcspn(username, "\n\r")] = '\0';
3389 } else {
3390 char stuff[200];
3391 strncpy(username, cfg.username, 99);
3392 username[99] = '\0';
65a22376 3393 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 3394 sprintf(stuff, "Using username \"%s\".\r\n", username);
1408a877 3395 c_write_str(stuff);
7cca0d81 3396 }
3397 }
3398
65a22376 3399 /*
1408a877 3400 * Send an authentication request using method "none": (a)
3401 * just in case it succeeds, and (b) so that we know what
3402 * authentication methods we can usefully try next.
65a22376 3403 */
1408a877 3404 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3405 ssh2_pkt_addstring(username);
32874aea 3406 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 3407 ssh2_pkt_addstring("none"); /* method */
3408 ssh2_pkt_send();
3409 type = AUTH_TYPE_NONE;
3410 gotit = FALSE;
3411 we_are_in = FALSE;
7cca0d81 3412
1408a877 3413 tried_pubkey_config = FALSE;
1983e559 3414 tried_agent = FALSE;
65a22376 3415
1408a877 3416 while (1) {
3417 /*
3418 * Wait for the result of the last authentication request.
3419 */
3420 if (!gotit)
3421 crWaitUntilV(ispkt);
3422 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 3423 char *banner;
3424 int size;
3425 /*
3426 * Don't show the banner if we're operating in
3427 * non-verbose non-interactive mode. (It's probably
3428 * a script, which means nobody will read the
3429 * banner _anyway_, and moreover the printing of
3430 * the banner will screw up processing on the
3431 * output of (say) plink.)
3432 */
3433 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3434 ssh2_pkt_getstring(&banner, &size);
3435 if (banner)
3436 c_write_untrusted(banner, size);
3437 }
1408a877 3438 crWaitUntilV(ispkt);
3439 }
3440 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3441 logevent("Access granted");
3442 we_are_in = TRUE;
3443 break;
3444 }
65a22376 3445
1408a877 3446 if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
32874aea 3447 bombout(
3448 ("Strange packet received during authentication: type %d",
1408a877 3449 pktin.type));
38c4a8da 3450 crReturnV;
65a22376 3451 }
3452
1408a877 3453 gotit = FALSE;
65a22376 3454
1408a877 3455 /*
3456 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3457 * we can look at the string in it and know what we can
3458 * helpfully try next.
3459 */
3460 {
3461 char *methods;
3462 int methlen;
3463 ssh2_pkt_getstring(&methods, &methlen);
3464 if (!ssh2_pkt_getbool()) {
3465 /*
3466 * We have received an unequivocal Access
3467 * Denied. This can translate to a variety of
3468 * messages:
3469 *
3470 * - if we'd just tried "none" authentication,
3471 * it's not worth printing anything at all
3472 *
3473 * - if we'd just tried a public key _offer_,
3474 * the message should be "Server refused our
3475 * key" (or no message at all if the key
3476 * came from Pageant)
3477 *
3478 * - if we'd just tried anything else, the
3479 * message really should be "Access denied".
3480 *
3481 * Additionally, if we'd just tried password
3482 * authentication, we should break out of this
3483 * whole loop so as to go back to the username
3484 * prompt.
3485 */
3486 if (type == AUTH_TYPE_NONE) {
3487 /* do nothing */
3488 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3489 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3490 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3491 c_write_str("Server refused our key\r\n");
3492 logevent("Server refused public key");
3493 } else {
3494 c_write_str("Access denied\r\n");
3495 logevent("Access denied");
3496 if (type == AUTH_TYPE_PASSWORD) {
3497 we_are_in = FALSE;
3498 break;
3499 }
3500 }
3501 } else {
3502 c_write_str("Further authentication required\r\n");
3503 logevent("Further authentication required");
3504 }
65a22376 3505
32874aea 3506 can_pubkey =
3507 in_commasep_string("publickey", methods, methlen);
3508 can_passwd =
3509 in_commasep_string("password", methods, methlen);
1408a877 3510 }
65a22376 3511
1408a877 3512 method = 0;
65a22376 3513
78afa559 3514 if (!method && can_pubkey && agent_exists() && !tried_agent) {
1983e559 3515 /*
3516 * Attempt public-key authentication using Pageant.
3517 */
3518 static unsigned char request[5], *response, *p;
3519 static int responselen;
3520 static int i, nkeys;
3521 static int authed = FALSE;
3522 void *r;
3523
3524 tried_agent = TRUE;
3525
3526 logevent("Pageant is running. Requesting keys.");
3527
3528 /* Request the keys held by the agent. */
3529 PUT_32BIT(request, 1);
3530 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3531 agent_query(request, 5, &r, &responselen);
32874aea 3532 response = (unsigned char *) r;
95797139 3533 if (response && responselen >= 5 &&
32874aea 3534 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
1983e559 3535 p = response + 5;
32874aea 3536 nkeys = GET_32BIT(p);
3537 p += 4;
3538 {
3539 char buf[64];
3540 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3541 logevent(buf);
3542 }
1983e559 3543 for (i = 0; i < nkeys; i++) {
3544 static char *pkblob, *alg, *commentp;
3545 static int pklen, alglen, commentlen;
3546 static int siglen, retlen, len;
3547 static char *q, *agentreq, *ret;
2d466ffd 3548 void *vret;
1983e559 3549
32874aea 3550 {
3551 char buf[64];
3552 sprintf(buf, "Trying Pageant key #%d", i);
3553 logevent(buf);
3554 }
3555 pklen = GET_32BIT(p);
3556 p += 4;
3557 pkblob = p;
3558 p += pklen;
1983e559 3559 alglen = GET_32BIT(pkblob);
3560 alg = pkblob + 4;
32874aea 3561 commentlen = GET_32BIT(p);
3562 p += 4;
3563 commentp = p;
3564 p += commentlen;
1983e559 3565 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3566 ssh2_pkt_addstring(username);
32874aea 3567 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3568 ssh2_pkt_addstring("publickey"); /* method */
3569 ssh2_pkt_addbool(FALSE); /* no signature included */
1983e559 3570 ssh2_pkt_addstring_start();
3571 ssh2_pkt_addstring_data(alg, alglen);
3572 ssh2_pkt_addstring_start();
3573 ssh2_pkt_addstring_data(pkblob, pklen);
3574 ssh2_pkt_send();
3575
3576 crWaitUntilV(ispkt);
3577 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3578 logevent("Key refused");
3579 continue;
3580 }
3581
32874aea 3582 if (flags & FLAG_VERBOSE) {
3583 c_write_str
3584 ("Authenticating with public key \"");
3585 c_write(commentp, commentlen);
3586 c_write_str("\" from agent\r\n");
3587 }
1983e559 3588
3589 /*
3590 * Server is willing to accept the key.
3591 * Construct a SIGN_REQUEST.
3592 */
3593 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3594 ssh2_pkt_addstring(username);
32874aea 3595 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3596 ssh2_pkt_addstring("publickey"); /* method */
1983e559 3597 ssh2_pkt_addbool(TRUE);
3598 ssh2_pkt_addstring_start();
3599 ssh2_pkt_addstring_data(alg, alglen);
3600 ssh2_pkt_addstring_start();
3601 ssh2_pkt_addstring_data(pkblob, pklen);
3602
3603 siglen = pktout.length - 5 + 4 + 20;
32874aea 3604 len = 1; /* message type */
3605 len += 4 + pklen; /* key blob */
3606 len += 4 + siglen; /* data to sign */
3607 len += 4; /* flags */
1983e559 3608 agentreq = smalloc(4 + len);
3609 PUT_32BIT(agentreq, len);
3610 q = agentreq + 4;
3611 *q++ = SSH2_AGENTC_SIGN_REQUEST;
32874aea 3612 PUT_32BIT(q, pklen);
3613 q += 4;
3614 memcpy(q, pkblob, pklen);
3615 q += pklen;
3616 PUT_32BIT(q, siglen);
3617 q += 4;
1983e559 3618 /* Now the data to be signed... */
32874aea 3619 PUT_32BIT(q, 20);
3620 q += 4;
3621 memcpy(q, ssh2_session_id, 20);
3622 q += 20;
3623 memcpy(q, pktout.data + 5, pktout.length - 5);
3624 q += pktout.length - 5;
1983e559 3625 /* And finally the (zero) flags word. */
3626 PUT_32BIT(q, 0);
2d466ffd 3627 agent_query(agentreq, len + 4, &vret, &retlen);
3628 ret = vret;
1983e559 3629 sfree(agentreq);
3630 if (ret) {
3631 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
3632 logevent("Sending Pageant's response");
3633 ssh2_pkt_addstring_start();
32874aea 3634 ssh2_pkt_addstring_data(ret + 9,
3635 GET_32BIT(ret +
3636 5));
1983e559 3637 ssh2_pkt_send();
3638 authed = TRUE;
3639 break;
3640 } else {
32874aea 3641 logevent
3642 ("Pageant failed to answer challenge");
1983e559 3643 sfree(ret);
3644 }
3645 }
3646 }
3647 if (authed)
3648 continue;
3649 }
3650 }
3651
32874aea 3652 if (!method && can_pubkey && *cfg.keyfile
3653 && !tried_pubkey_config) {
1408a877 3654 unsigned char *pub_blob;
3655 char *algorithm, *comment;
3656 int pub_blob_len;
65a22376 3657
1408a877 3658 tried_pubkey_config = TRUE;
65a22376 3659
65a22376 3660 /*
1408a877 3661 * Try the public key supplied in the configuration.
3662 *
3663 * First, offer the public blob to see if the server is
3664 * willing to accept it.
65a22376 3665 */
1408a877 3666 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
3667 &pub_blob_len);
3668 if (pub_blob) {
3669 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3670 ssh2_pkt_addstring(username);
32874aea 3671 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3672 ssh2_pkt_addstring("publickey"); /* method */
3673 ssh2_pkt_addbool(FALSE); /* no signature included */
1408a877 3674 ssh2_pkt_addstring(algorithm);
3675 ssh2_pkt_addstring_start();
3676 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
3677 ssh2_pkt_send();
32874aea 3678 logevent("Offered public key"); /* FIXME */
1408a877 3679
3680 crWaitUntilV(ispkt);
3681 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3682 gotit = TRUE;
3683 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 3684 continue; /* key refused; give up on it */
1408a877 3685 }
65a22376 3686
1408a877 3687 logevent("Offer of public key accepted");
65a22376 3688 /*
1408a877 3689 * Actually attempt a serious authentication using
3690 * the key.
65a22376 3691 */
1408a877 3692 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
32874aea 3693 sprintf(pwprompt,
3694 "Passphrase for key \"%.100s\": ",
3695 comment);
1408a877 3696 need_pw = TRUE;
3697 } else {
3698 need_pw = FALSE;
3699 }
3700 c_write_str("Authenticating with public key \"");
3701 c_write_str(comment);
3702 c_write_str("\"\r\n");
3703 method = AUTH_PUBLICKEY_FILE;
65a22376 3704 }
1408a877 3705 }
3706
3707 if (!method && can_passwd) {
3708 method = AUTH_PASSWORD;
32874aea 3709 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
3710 savedhost);
1408a877 3711 need_pw = TRUE;
3712 }
3713
3714 if (need_pw) {
fa17a66e 3715 if (ssh_get_line) {
3716 if (!ssh_get_line(pwprompt, password,
32874aea 3717 sizeof(password), TRUE)) {
1408a877 3718 /*
fa17a66e 3719 * get_line failed to get a password (for
3720 * example because one was supplied on the
3721 * command line which has already failed to
3722 * work). Terminate.
1408a877 3723 */
2bc6a386 3724 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3725 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
3726 ssh2_pkt_addstring
3727 ("No more passwords available to try");
3728 ssh2_pkt_addstring("en"); /* language tag */
3729 ssh2_pkt_send();
3730 connection_fatal("Unable to authenticate");
1408a877 3731 ssh_state = SSH_STATE_CLOSED;
3732 crReturnV;
3733 }
3734 } else {
3735 static int pos = 0;
3736 static char c;
3737
3738 c_write_str(pwprompt);
3739 ssh_send_ok = 1;
3740
3741 pos = 0;
3742 while (pos >= 0) {
3743 crWaitUntilV(!ispkt);
32874aea 3744 while (inlen--)
3745 switch (c = *in++) {
3746 case 10:
3747 case 13:
3748 password[pos] = 0;
3749 pos = -1;
3750 break;
3751 case 8:
3752 case 127:
3753 if (pos > 0)
3754 pos--;
3755 break;
3756 case 21:
3757 case 27:
3758 pos = 0;
3759 break;
3760 case 3:
3761 case 4:
3762 random_save_seed();
3763 exit(0);
3764 break;
3765 default:
51b2fb65 3766 if (pos < sizeof(password)-1)
32874aea 3767 password[pos++] = c;
3768 break;
3769 }
65a22376 3770 }
1408a877 3771 c_write_str("\r\n");
65a22376 3772 }
65a22376 3773 }
65a22376 3774
1408a877 3775 if (method == AUTH_PUBLICKEY_FILE) {
3776 /*
3777 * We have our passphrase. Now try the actual authentication.
3778 */
3779 struct ssh2_userkey *key;
65a22376 3780
1408a877 3781 key = ssh2_load_userkey(cfg.keyfile, password);
3782 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
3783 if (key == SSH2_WRONG_PASSPHRASE) {
3784 c_write_str("Wrong passphrase\r\n");
3785 tried_pubkey_config = FALSE;
3786 } else {
3787 c_write_str("Unable to load private key\r\n");
3788 tried_pubkey_config = TRUE;
3789 }
3790 /* Send a spurious AUTH_NONE to return to the top. */
3791 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3792 ssh2_pkt_addstring(username);
32874aea 3793 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3794 ssh2_pkt_addstring("none"); /* method */
1408a877 3795 ssh2_pkt_send();
3796 type = AUTH_TYPE_NONE;
3797 } else {
3798 unsigned char *blob, *sigdata;
3799 int blob_len, sigdata_len;
65a22376 3800
1408a877 3801 /*
3802 * We have loaded the private key and the server
3803 * has announced that it's willing to accept it.
3804 * Hallelujah. Generate a signature and send it.
3805 */
3806 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3807 ssh2_pkt_addstring(username);
32874aea 3808 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3809 ssh2_pkt_addstring("publickey"); /* method */
1408a877 3810 ssh2_pkt_addbool(TRUE);
3811 ssh2_pkt_addstring(key->alg->name);
3812 blob = key->alg->public_blob(key->data, &blob_len);
3813 ssh2_pkt_addstring_start();
3814 ssh2_pkt_addstring_data(blob, blob_len);
3815 sfree(blob);
3816
3817 /*
3818 * The data to be signed is:
3819 *
3820 * string session-id
3821 *
3822 * followed by everything so far placed in the
3823 * outgoing packet.
3824 */
3825 sigdata_len = pktout.length - 5 + 4 + 20;
3826 sigdata = smalloc(sigdata_len);
3827 PUT_32BIT(sigdata, 20);
32874aea 3828 memcpy(sigdata + 4, ssh2_session_id, 20);
3829 memcpy(sigdata + 24, pktout.data + 5,
3830 pktout.length - 5);
3831 blob =
3832 key->alg->sign(key->data, sigdata, sigdata_len,
3833 &blob_len);
1408a877 3834 ssh2_pkt_addstring_start();
3835 ssh2_pkt_addstring_data(blob, blob_len);
3836 sfree(blob);
3837 sfree(sigdata);
3838
3839 ssh2_pkt_send();
3840 type = AUTH_TYPE_PUBLICKEY;
3841 }
3842 } else if (method == AUTH_PASSWORD) {
65a22376 3843 /*
1408a877 3844 * We send the password packet lumped tightly together with
3845 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3846 * string long enough to make the total length of the two
3847 * packets constant. This should ensure that a passive
3848 * listener doing traffic analyis can't work out the length
3849 * of the password.
3850 *
3851 * For this to work, we need an assumption about the
3852 * maximum length of the password packet. I think 256 is
3853 * pretty conservative. Anyone using a password longer than
3854 * that probably doesn't have much to worry about from
3855 * people who find out how long their password is!
65a22376 3856 */
3857 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3858 ssh2_pkt_addstring(username);
32874aea 3859 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 3860 ssh2_pkt_addstring("password");
3861 ssh2_pkt_addbool(FALSE);
3862 ssh2_pkt_addstring(password);
3863 ssh2_pkt_defer();
65a22376 3864 /*
1408a877 3865 * We'll include a string that's an exact multiple of the
3866 * cipher block size. If the cipher is NULL for some
3867 * reason, we don't do this trick at all because we gain
3868 * nothing by it.
65a22376 3869 */
32874aea 3870 if (cscipher) {
3871 int stringlen, i;
3872
3873 stringlen = (256 - deferred_len);
3874 stringlen += cscipher->blksize - 1;
3875 stringlen -= (stringlen % cscipher->blksize);
3876 if (cscomp) {
3877 /*
3878 * Temporarily disable actual compression,
3879 * so we can guarantee to get this string
3880 * exactly the length we want it. The
3881 * compression-disabling routine should
3882 * return an integer indicating how many
3883 * bytes we should adjust our string length
3884 * by.
3885 */
3886 stringlen -= cscomp->disable_compression();
3887 }
1408a877 3888 ssh2_pkt_init(SSH2_MSG_IGNORE);
3889 ssh2_pkt_addstring_start();
6e9e9520 3890 for (i = 0; i < stringlen; i++) {
32874aea 3891 char c = (char) random_byte();
3892 ssh2_pkt_addstring_data(&c, 1);
65a22376 3893 }
1408a877 3894 ssh2_pkt_defer();
65a22376 3895 }
39065bed 3896 ssh_pkt_defersend();
0d43337a 3897 logevent("Sent password");
1408a877 3898 type = AUTH_TYPE_PASSWORD;
3899 } else {
32874aea 3900 c_write_str
3901 ("No supported authentication methods left to try!\r\n");
3902 logevent
3903 ("No supported authentications offered. Disconnecting");
1408a877 3904 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3905 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
32874aea 3906 ssh2_pkt_addstring
3907 ("No supported authentication methods available");
3908 ssh2_pkt_addstring("en"); /* language tag */
1408a877 3909 ssh2_pkt_send();
3910 ssh_state = SSH_STATE_CLOSED;
3911 crReturnV;
65a22376 3912 }
65a22376 3913 }
1408a877 3914 } while (!we_are_in);
7cca0d81 3915
3916 /*
3917 * Now we're authenticated for the connection protocol. The
3918 * connection protocol will automatically have started at this
3919 * point; there's no need to send SERVICE_REQUEST.
3920 */
3921
3922 /*
3923 * So now create a channel with a session in it.
3924 */
d2371c81 3925 ssh_channels = newtree234(ssh_channelcmp);
dcbde236 3926 mainchan = smalloc(sizeof(struct ssh_channel));
d2371c81 3927 mainchan->localid = alloc_channel_id();
7cca0d81 3928 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
3929 ssh2_pkt_addstring("session");
d211621f 3930 ssh2_pkt_adduint32(mainchan->localid);
32874aea 3931 ssh2_pkt_adduint32(0x8000UL); /* our window size */
3932 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 3933 ssh2_pkt_send();
3934 crWaitUntilV(ispkt);
3935 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
32874aea 3936 bombout(("Server refused to open a session"));
3937 crReturnV;
3938 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 3939 }
d211621f 3940 if (ssh2_pkt_getuint32() != mainchan->localid) {
32874aea 3941 bombout(("Server's channel confirmation cited wrong channel"));
3942 crReturnV;
7cca0d81 3943 }
d211621f 3944 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 3945 mainchan->type = CHAN_MAINSESSION;
3946 mainchan->closes = 0;
3947 mainchan->v2.remwindow = ssh2_pkt_getuint32();
3948 mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
3949 mainchan->v2.outbuffer = NULL;
3950 mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
783415f8 3951 add234(ssh_channels, mainchan);
7cca0d81 3952 logevent("Opened channel for session");
3953
3954 /*
783415f8 3955 * Potentially enable X11 forwarding.
3956 */
3957 if (cfg.x11_forward) {
32874aea 3958 char proto[20], data[64];
3959 logevent("Requesting X11 forwarding");
3960 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
3961 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
3962 ssh2_pkt_adduint32(mainchan->remoteid);
3963 ssh2_pkt_addstring("x11-req");
3964 ssh2_pkt_addbool(1); /* want reply */
3965 ssh2_pkt_addbool(0); /* many connections */
3966 ssh2_pkt_addstring(proto);
3967 ssh2_pkt_addstring(data);
3968 ssh2_pkt_adduint32(0); /* screen number */
3969 ssh2_pkt_send();
3970
3971 do {
3972 crWaitUntilV(ispkt);
3973 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
3974 unsigned i = ssh2_pkt_getuint32();
3975 struct ssh_channel *c;
3976 c = find234(ssh_channels, &i, ssh_channelfind);
3977 if (!c)
3978 continue; /* nonexistent channel */
3979 c->v2.remwindow += ssh2_pkt_getuint32();
3980 }
3981 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3982
3983 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
3984 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
3985 bombout(("Server got confused by X11 forwarding request"));
3986 crReturnV;
3987 }
3988 logevent("X11 forwarding refused");
3989 } else {
3990 logevent("X11 forwarding enabled");
783415f8 3991 ssh_X11_fwd_enabled = TRUE;
32874aea 3992 }
783415f8 3993 }
3994
3995 /*
36c2a3e9 3996 * Potentially enable agent forwarding.
3997 */
3998 if (cfg.agentfwd && agent_exists()) {
32874aea 3999 logevent("Requesting OpenSSH-style agent forwarding");
4000 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4001 ssh2_pkt_adduint32(mainchan->remoteid);
4002 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4003 ssh2_pkt_addbool(1); /* want reply */
4004 ssh2_pkt_send();
4005
4006 do {
4007 crWaitUntilV(ispkt);
4008 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4009 unsigned i = ssh2_pkt_getuint32();
4010 struct ssh_channel *c;
4011 c = find234(ssh_channels, &i, ssh_channelfind);
4012 if (!c)
4013 continue; /* nonexistent channel */
4014 c->v2.remwindow += ssh2_pkt_getuint32();
4015 }
4016 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4017
4018 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4019 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4020 bombout(
4021 ("Server got confused by agent forwarding request"));
4022 crReturnV;
4023 }
4024 logevent("Agent forwarding refused");
4025 } else {
4026 logevent("Agent forwarding enabled");
36c2a3e9 4027 ssh_agentfwd_enabled = TRUE;
32874aea 4028 }
36c2a3e9 4029 }
4030
4031 /*
7cca0d81 4032 * Now allocate a pty for the session.
4033 */
67779be7 4034 if (!cfg.nopty) {
32874aea 4035 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4036 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4037 ssh2_pkt_addstring("pty-req");
4038 ssh2_pkt_addbool(1); /* want reply */
4039 ssh2_pkt_addstring(cfg.termtype);
4040 ssh2_pkt_adduint32(cols);
4041 ssh2_pkt_adduint32(rows);
4042 ssh2_pkt_adduint32(0); /* pixel width */
4043 ssh2_pkt_adduint32(0); /* pixel height */
4044 ssh2_pkt_addstring_start();
4045 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4046 ssh2_pkt_send();
4047 ssh_state = SSH_STATE_INTERMED;
4048
4049 do {
4050 crWaitUntilV(ispkt);
4051 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4052 unsigned i = ssh2_pkt_getuint32();
4053 struct ssh_channel *c;
4054 c = find234(ssh_channels, &i, ssh_channelfind);
4055 if (!c)
4056 continue; /* nonexistent channel */
4057 c->v2.remwindow += ssh2_pkt_getuint32();
4058 }
4059 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4060
4061 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4062 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4063 bombout(("Server got confused by pty request"));
4064 crReturnV;
4065 }
4066 c_write_str("Server refused to allocate pty\r\n");
4067 ssh_editing = ssh_echoing = 1;
4068 } else {
4069 logevent("Allocated pty");
4070 }
0965bee0 4071 } else {
32874aea 4072 ssh_editing = ssh_echoing = 1;
7cca0d81 4073 }
4074
4075 /*
67779be7 4076 * Start a shell or a remote command.
7cca0d81 4077 */
4078 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
32874aea 4079 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4a8fc3c4 4080 if (cfg.ssh_subsys) {
32874aea 4081 ssh2_pkt_addstring("subsystem");
4082 ssh2_pkt_addbool(1); /* want reply */
4083 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
96621a84 4084 } else if (*cfg.remote_cmd_ptr) {
32874aea 4085 ssh2_pkt_addstring("exec");
4086 ssh2_pkt_addbool(1); /* want reply */
4087 ssh2_pkt_addstring(cfg.remote_cmd_ptr);
67779be7 4088 } else {
32874aea 4089 ssh2_pkt_addstring("shell");
4090 ssh2_pkt_addbool(1); /* want reply */
67779be7 4091 }
7cca0d81 4092 ssh2_pkt_send();
d211621f 4093 do {
32874aea 4094 crWaitUntilV(ispkt);
4095 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4096 unsigned i = ssh2_pkt_getuint32();
4097 struct ssh_channel *c;
4098 c = find234(ssh_channels, &i, ssh_channelfind);
4099 if (!c)
4100 continue; /* nonexistent channel */
4101 c->v2.remwindow += ssh2_pkt_getuint32();
4102 }
7cca0d81 4103 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4104 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
32874aea 4105 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4106 bombout(("Server got confused by shell/command request"));
4107 crReturnV;
4108 }
4109 bombout(("Server refused to start a shell/command"));
4110 crReturnV;
7cca0d81 4111 } else {
32874aea 4112 logevent("Started a shell/command");
7cca0d81 4113 }
4114
6e48c3fe 4115 ssh_state = SSH_STATE_SESSION;
4116 if (size_needed)
4117 ssh_size();
3687d221 4118 if (eof_needed)
32874aea 4119 ssh_special(TS_EOF);
6e48c3fe 4120
7cca0d81 4121 /*
4122 * Transfer data!
4123 */
32874aea 4124 ldisc_send(NULL, 0); /* cause ldisc to notice changes */
8ccc75b0 4125 ssh_send_ok = 1;
7cca0d81 4126 while (1) {
32874aea 4127 static int try_send;
e5574168 4128 crReturnV;
32874aea 4129 try_send = FALSE;
7cca0d81 4130 if (ispkt) {
4131 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
32874aea 4132 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
4133 char *data;
4134 int length;
4135 unsigned i = ssh2_pkt_getuint32();
4136 struct ssh_channel *c;
4137 c = find234(ssh_channels, &i, ssh_channelfind);
4138 if (!c)
4139 continue; /* nonexistent channel */
4140 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
4141 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
4142 continue; /* extended but not stderr */
4143 ssh2_pkt_getstring(&data, &length);
4144 if (data) {
4145 switch (c->type) {
4146 case CHAN_MAINSESSION:
4147 from_backend(pktin.type ==
4148 SSH2_MSG_CHANNEL_EXTENDED_DATA, data,
4149 length);
4150 break;
4151 case CHAN_X11:
4152 x11_send(c->u.x11.s, data, length);
4153 break;
d74d141c 4154 case CHAN_SOCKDATA:
4155 pfd_send(c->u.pfd.s, data, length);
4156 break;
36c2a3e9 4157 case CHAN_AGENT:
32874aea 4158 while (length > 0) {
4159 if (c->u.a.lensofar < 4) {
4160 int l = min(4 - c->u.a.lensofar, length);
4161 memcpy(c->u.a.msglen + c->u.a.lensofar,
4162 data, l);
4163 data += l;
4164 length -= l;
4165 c->u.a.lensofar += l;
4166 }
4167 if (c->u.a.lensofar == 4) {
4168 c->u.a.totallen =
4169 4 + GET_32BIT(c->u.a.msglen);
4170 c->u.a.message = smalloc(c->u.a.totallen);
4171 memcpy(c->u.a.message, c->u.a.msglen, 4);
4172 }
4173 if (c->u.a.lensofar >= 4 && length > 0) {
4174 int l =
4175 min(c->u.a.totallen - c->u.a.lensofar,
4176 length);
4177 memcpy(c->u.a.message + c->u.a.lensofar,
4178 data, l);
4179 data += l;
4180 length -= l;
4181 c->u.a.lensofar += l;
4182 }
4183 if (c->u.a.lensofar == c->u.a.totallen) {
4184 void *reply, *sentreply;
4185 int replylen;
4186 agent_query(c->u.a.message,
4187 c->u.a.totallen, &reply,
4188 &replylen);
4189 if (reply)
4190 sentreply = reply;
4191 else {
4192 /* Fake SSH_AGENT_FAILURE. */
4193 sentreply = "\0\0\0\1\5";
4194 replylen = 5;
4195 }
4196 ssh2_add_channel_data(c, sentreply,
4197 replylen);
36c2a3e9 4198 try_send = TRUE;
32874aea 4199 if (reply)
4200 sfree(reply);
4201 sfree(c->u.a.message);
4202 c->u.a.lensofar = 0;
4203 }
4204 }
4205 break;
4206 }
4207 /*
4208 * Enlarge the window again at the remote
4209 * side, just in case it ever runs down and
4210 * they fail to send us any more data.
4211 */
4212 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4213 ssh2_pkt_adduint32(c->remoteid);
4214 ssh2_pkt_adduint32(length);
4215 ssh2_pkt_send();
4216 }
7cca0d81 4217 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
32874aea 4218 ssh_state = SSH_STATE_CLOSED;
d211621f 4219 logevent("Received disconnect message");
32874aea 4220 crReturnV;
7cca0d81 4221 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
32874aea 4222 continue; /* exit status et al; ignore (FIXME?) */
d211621f 4223 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
32874aea 4224 unsigned i = ssh2_pkt_getuint32();
4225 struct ssh_channel *c;
4226
4227 c = find234(ssh_channels, &i, ssh_channelfind);
4228 if (!c)
4229 continue; /* nonexistent channel */
4230
4231 if (c->type == CHAN_X11) {
4232 /*
4233 * Remote EOF on an X11 channel means we should
4234 * wrap up and close the channel ourselves.
4235 */
4236 x11_close(c->u.x11.s);
4237 sshfwd_close(c);
4238 } else if (c->type == CHAN_AGENT) {
36c2a3e9 4239 sshfwd_close(c);
d74d141c 4240 } else if (c->type == CHAN_SOCKDATA) {
4241 pfd_close(c->u.pfd.s);
4242 sshfwd_close(c);
36c2a3e9 4243 }
d211621f 4244 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
32874aea 4245 unsigned i = ssh2_pkt_getuint32();
4246 struct ssh_channel *c;
4247
4248 c = find234(ssh_channels, &i, ssh_channelfind);
4249 if (!c)
4250 continue; /* nonexistent channel */
4251 if (c->closes == 0) {
4252 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4253 ssh2_pkt_adduint32(c->remoteid);
4254 ssh2_pkt_send();
4255 }
4256 /* Do pre-close processing on the channel. */
4257 switch (c->type) {
4258 case CHAN_MAINSESSION:
4259 break; /* nothing to see here, move along */
4260 case CHAN_X11:
4261 break;
4262 case CHAN_AGENT:
4263 break;
d74d141c 4264 case CHAN_SOCKDATA:
4265 break;
32874aea 4266 }
4267 del234(ssh_channels, c);
4268 sfree(c->v2.outbuffer);
4269 sfree(c);
4270
4271 /*
4272 * See if that was the last channel left open.
4273 */
4274 if (count234(ssh_channels) == 0) {
4275 logevent("All channels closed. Disconnecting");
4276 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4277 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4278 ssh2_pkt_addstring("All open channels closed");
4279 ssh2_pkt_addstring("en"); /* language tag */
4280 ssh2_pkt_send();
4281 ssh_state = SSH_STATE_CLOSED;
4282 crReturnV;
4283 }
4284 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 4285 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
32874aea 4286 unsigned i = ssh2_pkt_getuint32();
4287 struct ssh_channel *c;
4288 c = find234(ssh_channels, &i, ssh_channelfind);
4289 if (!c)
4290 continue; /* nonexistent channel */
4291 c->v2.remwindow += ssh2_pkt_getuint32();
4292 try_send = TRUE;
783415f8 4293 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 4294 char *type;
4295 int typelen;
4296 char *error = NULL;
4297 struct ssh_channel *c;
4298 ssh2_pkt_getstring(&type, &typelen);
4299 c = smalloc(sizeof(struct ssh_channel));
4300
4301 if (typelen == 3 && !memcmp(type, "x11", 3)) {
4302 if (!ssh_X11_fwd_enabled)
4303 error = "X11 forwarding is not enabled";
4304 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
4305 NULL) {
4306 error = "Unable to open an X11 connection";
4307 } else {
4308 c->type = CHAN_X11;
4309 }
4310 } else if (typelen == 22 &&
36c2a3e9 4311 !memcmp(type, "auth-agent@openssh.com", 3)) {
32874aea 4312 if (!ssh_agentfwd_enabled)
4313 error = "Agent forwarding is not enabled";
36c2a3e9 4314 else {
32874aea 4315 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 4316 c->u.a.lensofar = 0;
32874aea 4317 }
4318 } else {
4319 error = "Unsupported channel type requested";
4320 }
4321
4322 c->remoteid = ssh2_pkt_getuint32();
4323 if (error) {
4324 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
4325 ssh2_pkt_adduint32(c->remoteid);
4326 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
4327 ssh2_pkt_addstring(error);
4328 ssh2_pkt_addstring("en"); /* language tag */
4329 ssh2_pkt_send();
4330 sfree(c);
4331 } else {
4332 c->localid = alloc_channel_id();
4333 c->closes = 0;
4334 c->v2.remwindow = ssh2_pkt_getuint32();
4335 c->v2.remmaxpkt = ssh2_pkt_getuint32();
4336 c->v2.outbuffer = NULL;
4337 c->v2.outbuflen = c->v2.outbufsize = 0;
4338 add234(ssh_channels, c);
4339 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
4340 ssh2_pkt_adduint32(c->remoteid);
4341 ssh2_pkt_adduint32(c->localid);
4342 ssh2_pkt_adduint32(0x8000UL); /* our window size */
4343 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4344 ssh2_pkt_send();
4345 }
7cca0d81 4346 } else {
8d5de777 4347 bombout(("Strange packet received: type %d", pktin.type));
32874aea 4348 crReturnV;
7cca0d81 4349 }
4350 } else {
32874aea 4351 /*
4352 * We have spare data. Add it to the channel buffer.
4353 */
4354 ssh2_add_channel_data(mainchan, in, inlen);
4355 try_send = TRUE;
4356 }
4357 if (try_send) {
4358 int i;
4359 struct ssh_channel *c;
4360 /*
4361 * Try to send data on all channels if we can.
4362 */
4363 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++)
4364 ssh2_try_send(c);
7cca0d81 4365 }
e5574168 4366 }
4367
4368 crFinishV;
4369}
4370
4371/*
7cca0d81 4372 * Handle the top-level SSH2 protocol.
4373 */
4374static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
4375{
4376 if (do_ssh2_transport(in, inlen, ispkt) == 0)
32874aea 4377 return;
7cca0d81 4378 do_ssh2_authconn(in, inlen, ispkt);
4379}
4380
4381/*
8df7a775 4382 * Called to set up the connection.
374330e2 4383 *
4384 * Returns an error message, or NULL on success.
374330e2 4385 */
32874aea 4386static char *ssh_init(char *host, int port, char **realhost)
4387{
fb09bf1c 4388 char *p;
32874aea 4389
8f203108 4390#ifdef MSCRYPTOAPI
32874aea 4391 if (crypto_startup() == 0)
8f203108 4392 return "Microsoft high encryption pack not installed!";
4393#endif
374330e2 4394
8df7a775 4395 ssh_send_ok = 0;
0965bee0 4396 ssh_editing = 0;
4397 ssh_echoing = 0;
8df7a775 4398
fb09bf1c 4399 p = connect_to_host(host, port, realhost);
4400 if (p != NULL)
4401 return p;
374330e2 4402
374330e2 4403 return NULL;
4404}
4405
4406/*
374330e2 4407 * Called to send data down the Telnet connection.
4408 */
32874aea 4409static void ssh_send(char *buf, int len)
4410{
f78051a1 4411 if (s == NULL || ssh_protocol == NULL)
374330e2 4412 return;
4413
4414 ssh_protocol(buf, len, 0);
4415}
4416
4417/*
6e48c3fe 4418 * Called to set the size of the window from SSH's POV.
374330e2 4419 */
32874aea 4420static void ssh_size(void)
4421{
374330e2 4422 switch (ssh_state) {
4423 case SSH_STATE_BEFORE_SIZE:
3687d221 4424 case SSH_STATE_PREPACKET:
21248260 4425 case SSH_STATE_CLOSED:
374330e2 4426 break; /* do nothing */
4427 case SSH_STATE_INTERMED:
4428 size_needed = TRUE; /* buffer for later */
4429 break;
4430 case SSH_STATE_SESSION:
32874aea 4431 if (!cfg.nopty) {
4432 if (ssh_version == 1) {
4433 send_packet(SSH1_CMSG_WINDOW_SIZE,
4434 PKT_INT, rows, PKT_INT, cols,
4435 PKT_INT, 0, PKT_INT, 0, PKT_END);
4436 } else {
4437 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4438 ssh2_pkt_adduint32(mainchan->remoteid);
4439 ssh2_pkt_addstring("window-change");
4440 ssh2_pkt_addbool(0);
4441 ssh2_pkt_adduint32(cols);
4442 ssh2_pkt_adduint32(rows);
4443 ssh2_pkt_adduint32(0);
4444 ssh2_pkt_adduint32(0);
4445 ssh2_pkt_send();
4446 }
4447 }
4448 break;
374330e2 4449 }
4450}
4451
4452/*
6abbf9e3 4453 * Send Telnet special codes. TS_EOF is useful for `plink', so you
4454 * can send an EOF and collect resulting output (e.g. `plink
4455 * hostname sort').
374330e2 4456 */
32874aea 4457static void ssh_special(Telnet_Special code)
4458{
6abbf9e3 4459 if (code == TS_EOF) {
32874aea 4460 if (ssh_state != SSH_STATE_SESSION) {
4461 /*
4462 * Buffer the EOF in case we are pre-SESSION, so we can
4463 * send it as soon as we reach SESSION.
4464 */
4465 if (code == TS_EOF)
4466 eof_needed = TRUE;
4467 return;
4468 }
4469 if (ssh_version == 1) {
4470 send_packet(SSH1_CMSG_EOF, PKT_END);
4471 } else {
4472 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4473 ssh2_pkt_adduint32(mainchan->remoteid);
4474 ssh2_pkt_send();
4475 }
4476 logevent("Sent EOF message");
ec55b220 4477 } else if (code == TS_PING) {
32874aea 4478 if (ssh_state == SSH_STATE_CLOSED
4479 || ssh_state == SSH_STATE_PREPACKET) return;
4480 if (ssh_version == 1) {
4481 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
4482 } else {
4483 ssh2_pkt_init(SSH2_MSG_IGNORE);
4484 ssh2_pkt_addstring_start();
4485 ssh2_pkt_send();
4486 }
6abbf9e3 4487 } else {
32874aea 4488 /* do nothing */
6abbf9e3 4489 }
374330e2 4490}
4491
d74d141c 4492void *new_sock_channel(Socket s)
4493{
4494 struct ssh_channel *c;
4495 c = smalloc(sizeof(struct ssh_channel));
4496
4497 if (c) {
4498 c->remoteid = GET_32BIT(pktin.body);
4499 c->localid = alloc_channel_id();
4500 c->closes = 0;
4501 c->type = CHAN_SOCKDATA; /* identify channel type */
4502 c->u.pfd.s = s;
4503 add234(ssh_channels, c);
4504 }
4505 return c;
4506}
4507
4508void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
4509{
4510 struct ssh_channel *c = (struct ssh_channel *)channel;
4511 char buf[1024];
4512
4513 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
4514 logevent(buf);
4515
4516 send_packet(SSH1_MSG_PORT_OPEN,
4517 PKT_INT, c->localid,
4518 PKT_STR, hostname,
4519 PKT_INT, port,
4520 //PKT_STR, org,
4521 PKT_END);
4522}
4523
4524
32874aea 4525static Socket ssh_socket(void)
4526{
4527 return s;
4528}
8ccc75b0 4529
32874aea 4530static int ssh_sendok(void)
4531{
4532 return ssh_send_ok;
4533}
fb09bf1c 4534
32874aea 4535static int ssh_ldisc(int option)
4536{
4537 if (option == LD_ECHO)
4538 return ssh_echoing;
4539 if (option == LD_EDIT)
4540 return ssh_editing;
0965bee0 4541 return FALSE;
4542}
4543
374330e2 4544Backend ssh_backend = {
4545 ssh_init,
374330e2 4546 ssh_send,
4547 ssh_size,
4017be6d 4548 ssh_special,
8ccc75b0 4549 ssh_socket,
97db3be4 4550 ssh_sendok,
0965bee0 4551 ssh_ldisc,
97db3be4 4552 22
d74d141c 4553};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator