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Make sure we always unhide the mouse pointer when the System menu is
[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 */
761187b6 98#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
99#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 100#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
101#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
102#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
103#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
104#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
105#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
106#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
107#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
108#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
109#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
110#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
111#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
112#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
113#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
114
115#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 130
131static const char *const ssh2_disconnect_reasons[] = {
132 NULL,
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
148};
9005f3ba 149
32874aea 150#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 154
32874aea 155#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 156
7d503c31 157/*
158 * Various remote-bug flags.
159 */
160#define BUG_CHOKES_ON_SSH1_IGNORE 1
161#define BUG_SSH2_HMAC 2
bd358db1 162#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
163
7d503c31 164
fb09bf1c 165#define GET_32BIT(cp) \
166 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
167 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
168 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
169 ((unsigned long)(unsigned char)(cp)[3]))
170
171#define PUT_32BIT(cp, value) { \
172 (cp)[0] = (unsigned char)((value) >> 24); \
173 (cp)[1] = (unsigned char)((value) >> 16); \
174 (cp)[2] = (unsigned char)((value) >> 8); \
175 (cp)[3] = (unsigned char)(value); }
176
7cca0d81 177enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 178
374330e2 179/* Coroutine mechanics for the sillier bits of the code */
180#define crBegin1 static int crLine = 0;
181#define crBegin2 switch(crLine) { case 0:;
182#define crBegin crBegin1; crBegin2;
183#define crFinish(z) } crLine = 0; return (z)
184#define crFinishV } crLine = 0; return
185#define crReturn(z) \
186 do {\
187 crLine=__LINE__; return (z); case __LINE__:;\
188 } while (0)
189#define crReturnV \
190 do {\
191 crLine=__LINE__; return; case __LINE__:;\
192 } while (0)
193#define crStop(z) do{ crLine = 0; return (z); }while(0)
194#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 195#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 196#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 197
32874aea 198extern char *x11_init(Socket *, char *, void *);
199extern void x11_close(Socket);
5471d09a 200extern int x11_send(Socket, char *, int);
9c964e85 201extern void x11_invent_auth(char *, int, char *, int);
5471d09a 202extern void x11_unthrottle(Socket s);
203extern void x11_override_throttle(Socket s, int enable);
9c964e85 204
d74d141c 205extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
206extern char *pfd_addforward(char *desthost, int destport, int port);
207extern void pfd_close(Socket s);
5471d09a 208extern int pfd_send(Socket s, char *data, int len);
d74d141c 209extern void pfd_confirm(Socket s);
5471d09a 210extern void pfd_unthrottle(Socket s);
211extern void pfd_override_throttle(Socket s, int enable);
212
213/*
214 * Buffer management constants. There are several of these for
215 * various different purposes:
216 *
217 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
218 * on a local data stream before we throttle the whole SSH
219 * connection (in SSH1 only). Throttling the whole connection is
220 * pretty drastic so we set this high in the hope it won't
221 * happen very often.
222 *
223 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
224 * on the SSH connection itself before we defensively throttle
225 * _all_ local data streams. This is pretty drastic too (though
226 * thankfully unlikely in SSH2 since the window mechanism should
227 * ensure that the server never has any need to throttle its end
228 * of the connection), so we set this high as well.
229 *
230 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
231 * channels.
232 */
233
234#define SSH1_BUFFER_LIMIT 32768
235#define SSH_MAX_BACKLOG 32768
236#define OUR_V2_WINSIZE 16384
d74d141c 237
5e8358ad 238/*
239 * Ciphers for SSH2. We miss out single-DES because it isn't
240 * supported; also 3DES and Blowfish are both done differently from
241 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
242 * endianness and different-sized keys.)
5e8358ad 243 */
0a3f1d48 244const static struct ssh2_ciphers *ciphers[] = {
245 &ssh2_aes,
246 &ssh2_blowfish,
247 &ssh2_3des,
8479e33c 248};
e5574168 249
a92dd380 250const static struct ssh_kex *kex_algs[] = {
a92dd380 251 &ssh_diffiehellman_gex,
32874aea 252 &ssh_diffiehellman
253};
e5574168 254
85cc02bb 255const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 256
32874aea 257static void nullmac_key(unsigned char *key)
258{
259}
260static void nullmac_generate(unsigned char *blk, int len,
261 unsigned long seq)
262{
263}
264static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
265{
266 return 1;
267}
57476f6b 268const static struct ssh_mac ssh_mac_none = {
d39f364a 269 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 270};
8b2715b2 271const static struct ssh_mac *macs[] = {
32874aea 272 &ssh_sha1, &ssh_md5, &ssh_mac_none
273};
8b2715b2 274const static struct ssh_mac *buggymacs[] = {
32874aea 275 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
276};
e5574168 277
32874aea 278static void ssh_comp_none_init(void)
279{
280}
4ba9b64b 281static int ssh_comp_none_block(unsigned char *block, int len,
32874aea 282 unsigned char **outblock, int *outlen)
283{
284 return 0;
285}
286static int ssh_comp_none_disable(void)
287{
4ba9b64b 288 return 0;
289}
57476f6b 290const static struct ssh_compress ssh_comp_none = {
4ba9b64b 291 "none",
292 ssh_comp_none_init, ssh_comp_none_block,
63b00c83 293 ssh_comp_none_init, ssh_comp_none_block,
294 ssh_comp_none_disable
e5574168 295};
4ba9b64b 296extern const struct ssh_compress ssh_zlib;
297const static struct ssh_compress *compressions[] = {
32874aea 298 &ssh_zlib, &ssh_comp_none
299};
374330e2 300
32874aea 301enum { /* channel types */
783415f8 302 CHAN_MAINSESSION,
303 CHAN_X11,
304 CHAN_AGENT,
bc240b21 305 CHAN_SOCKDATA,
306 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 307};
308
dacbd0e8 309/*
310 * 2-3-4 tree storing channels.
311 */
312struct ssh_channel {
d211621f 313 unsigned remoteid, localid;
dacbd0e8 314 int type;
315 int closes;
5471d09a 316 union {
317 struct ssh1_data_channel {
318 int throttling;
319 } v1;
320 struct ssh2_data_channel {
321 bufchain outbuffer;
322 unsigned remwindow, remmaxpkt;
323 unsigned locwindow;
324 } v2;
325 } v;
dacbd0e8 326 union {
32874aea 327 struct ssh_agent_channel {
328 unsigned char *message;
329 unsigned char msglen[4];
330 int lensofar, totallen;
331 } a;
332 struct ssh_x11_channel {
333 Socket s;
334 } x11;
d74d141c 335 struct ssh_pfd_channel {
336 Socket s;
337 } pfd;
dacbd0e8 338 } u;
339};
57476f6b 340
d74d141c 341/*
bc240b21 342 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
343 * 2 use this structure in different ways, reflecting SSH 2's
344 * altogether saner approach to port forwarding.
345 *
346 * In SSH 1, you arrange a remote forwarding by sending the server
347 * the remote port number, and the local destination host:port.
348 * When a connection comes in, the server sends you back that
349 * host:port pair, and you connect to it. This is a ready-made
350 * security hole if you're not on the ball: a malicious server
351 * could send you back _any_ host:port pair, so if you trustingly
352 * connect to the address it gives you then you've just opened the
353 * entire inside of your corporate network just by connecting
354 * through it to a dodgy SSH server. Hence, we must store a list of
355 * host:port pairs we _are_ trying to forward to, and reject a
356 * connection request from the server if it's not in the list.
357 *
358 * In SSH 2, each side of the connection minds its own business and
359 * doesn't send unnecessary information to the other. You arrange a
360 * remote forwarding by sending the server just the remote port
361 * number. When a connection comes in, the server tells you which
362 * of its ports was connected to; and _you_ have to remember what
363 * local host:port pair went with that port number.
364 *
365 * Hence: in SSH 1 this structure stores host:port pairs we intend
366 * to allow connections to, and is indexed by those host:port
367 * pairs. In SSH 2 it stores a mapping from source port to
368 * destination host:port pair, and is indexed by source port.
d74d141c 369 */
370struct ssh_rportfwd {
bc240b21 371 unsigned sport, dport;
372 char dhost[256];
d74d141c 373};
374
57476f6b 375struct Packet {
376 long length;
377 int type;
378 unsigned char *data;
379 unsigned char *body;
380 long savedpos;
381 long maxlen;
382};
383
0db56f73 384static SHA_State exhash, exhashbase;
57476f6b 385
8df7a775 386static Socket s = NULL;
57476f6b 387
388static unsigned char session_key[32];
4ba9b64b 389static int ssh1_compressing;
b96dc54c 390static int ssh1_remote_protoflags;
391static int ssh1_local_protoflags;
db7d555c 392static int ssh_agentfwd_enabled;
9c964e85 393static int ssh_X11_fwd_enabled;
7d503c31 394static int ssh_remote_bugs;
57476f6b 395static const struct ssh_cipher *cipher = NULL;
0a3f1d48 396static const struct ssh2_cipher *cscipher = NULL;
397static const struct ssh2_cipher *sccipher = NULL;
57476f6b 398static const struct ssh_mac *csmac = NULL;
399static const struct ssh_mac *scmac = NULL;
400static const struct ssh_compress *cscomp = NULL;
401static const struct ssh_compress *sccomp = NULL;
402static const struct ssh_kex *kex = NULL;
e055a386 403static const struct ssh_signkey *hostkey = NULL;
65a22376 404static unsigned char ssh2_session_id[20];
32874aea 405int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
406 int is_pw) = NULL;
57476f6b 407
408static char *savedhost;
409static int savedport;
410static int ssh_send_ok;
0965bee0 411static int ssh_echoing, ssh_editing;
57476f6b 412
32874aea 413static tree234 *ssh_channels; /* indexed by local id */
57476f6b 414static struct ssh_channel *mainchan; /* primary session channel */
415
d74d141c 416static tree234 *ssh_rportfwds;
417
57476f6b 418static enum {
3687d221 419 SSH_STATE_PREPACKET,
57476f6b 420 SSH_STATE_BEFORE_SIZE,
421 SSH_STATE_INTERMED,
422 SSH_STATE_SESSION,
423 SSH_STATE_CLOSED
3687d221 424} ssh_state = SSH_STATE_PREPACKET;
57476f6b 425
3687d221 426static int size_needed = FALSE, eof_needed = FALSE;
57476f6b 427
428static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
429static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
b185170a 430static unsigned char *deferred_send_data = NULL;
431static int deferred_len = 0, deferred_size = 0;
57476f6b 432
fd5e5847 433/*
434 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
435 * that fails. This variable is the means by which scp.c can reach
436 * into the SSH code and find out which one it got.
437 */
438int ssh_fallback_cmd = 0;
439
57476f6b 440static int ssh_version;
5471d09a 441static int ssh1_throttle_count;
442static int ssh_overall_bufsize;
443static int ssh_throttled_all;
444static int ssh1_stdout_throttling;
32874aea 445static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
57476f6b 446static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
447static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
448static void ssh_size(void);
32874aea 449static void ssh_special(Telnet_Special);
5471d09a 450static int ssh2_try_send(struct ssh_channel *c);
32874aea 451static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
452 int len);
5471d09a 453static void ssh_throttle_all(int enable, int bufsize);
454static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
32874aea 455static int (*s_rdpkt) (unsigned char **data, int *datalen);
5471d09a 456static int ssh_sendbuffer(void);
57476f6b 457
458static struct rdpkt1_state_tag {
459 long len, pad, biglen, to_read;
460 unsigned long realcrc, gotcrc;
461 unsigned char *p;
462 int i;
463 int chunk;
464} rdpkt1_state;
465
960e736a 466static struct rdpkt2_state_tag {
467 long len, pad, payload, packetlen, maclen;
468 int i;
469 int cipherblk;
470 unsigned long incoming_sequence;
471} rdpkt2_state;
472
32874aea 473static int ssh_channelcmp(void *av, void *bv)
474{
475 struct ssh_channel *a = (struct ssh_channel *) av;
476 struct ssh_channel *b = (struct ssh_channel *) bv;
477 if (a->localid < b->localid)
478 return -1;
479 if (a->localid > b->localid)
480 return +1;
dacbd0e8 481 return 0;
482}
32874aea 483static int ssh_channelfind(void *av, void *bv)
484{
485 unsigned *a = (unsigned *) av;
486 struct ssh_channel *b = (struct ssh_channel *) bv;
487 if (*a < b->localid)
488 return -1;
489 if (*a > b->localid)
490 return +1;
dacbd0e8 491 return 0;
492}
493
bc240b21 494static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 495{
496 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
497 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
498 int i;
bc240b21 499 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 500 return i < 0 ? -1 : +1;
bc240b21 501 if (a->dport > b->dport)
502 return +1;
503 if (a->dport < b->dport)
504 return -1;
505 return 0;
506}
507
508static int ssh_rportcmp_ssh2(void *av, void *bv)
509{
510 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
511 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 512
bc240b21 513 if (a->sport > b->sport)
d74d141c 514 return +1;
bc240b21 515 if (a->sport < b->sport)
516 return -1;
d74d141c 517 return 0;
518}
519
32874aea 520static int alloc_channel_id(void)
521{
260f3dec 522 const unsigned CHANNEL_NUMBER_OFFSET = 256;
523 unsigned low, high, mid;
d2371c81 524 int tsize;
525 struct ssh_channel *c;
526
527 /*
528 * First-fit allocation of channel numbers: always pick the
529 * lowest unused one. To do this, binary-search using the
530 * counted B-tree to find the largest channel ID which is in a
531 * contiguous sequence from the beginning. (Precisely
532 * everything in that sequence must have ID equal to its tree
533 * index plus CHANNEL_NUMBER_OFFSET.)
534 */
535 tsize = count234(ssh_channels);
536
32874aea 537 low = -1;
538 high = tsize;
d2371c81 539 while (high - low > 1) {
540 mid = (high + low) / 2;
541 c = index234(ssh_channels, mid);
542 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
543 low = mid; /* this one is fine */
544 else
545 high = mid; /* this one is past it */
546 }
547 /*
548 * Now low points to either -1, or the tree index of the
549 * largest ID in the initial sequence.
550 */
551 {
552 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
553 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
554 }
555 return low + 1 + CHANNEL_NUMBER_OFFSET;
556}
557
32874aea 558static void c_write(char *buf, int len)
559{
67779be7 560 if ((flags & FLAG_STDERR)) {
32874aea 561 int i;
562 for (i = 0; i < len; i++)
563 if (buf[i] != '\r')
564 fputc(buf[i], stderr);
fb09bf1c 565 return;
566 }
fe50e814 567 from_backend(1, buf, len);
3bdaf79d 568}
569
32874aea 570static void c_write_untrusted(char *buf, int len)
571{
a209e957 572 int i;
573 for (i = 0; i < len; i++) {
32874aea 574 if (buf[i] == '\n')
575 c_write("\r\n", 2);
576 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
577 c_write(buf + i, 1);
a209e957 578 }
579}
580
32874aea 581static void c_write_str(char *buf)
582{
1408a877 583 c_write(buf, strlen(buf));
584}
585
fb09bf1c 586/*
587 * Collect incoming data in the incoming packet buffer.
e5574168 588 * Decipher and verify the packet when it is completely read.
589 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 590 * Update the *data and *datalen variables.
591 * Return the additional nr of bytes needed, or 0 when
592 * a complete packet is available.
593 */
e5574168 594static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 595{
57476f6b 596 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 597
598 crBegin;
374330e2 599
32874aea 600 next_packet:
37508af4 601
fb09bf1c 602 pktin.type = 0;
603 pktin.length = 0;
374330e2 604
57476f6b 605 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 606 while ((*datalen) == 0)
32874aea 607 crReturn(4 - st->i);
57476f6b 608 st->len = (st->len << 8) + **data;
fb09bf1c 609 (*data)++, (*datalen)--;
610 }
374330e2 611
57476f6b 612 st->pad = 8 - (st->len % 8);
613 st->biglen = st->len + st->pad;
614 pktin.length = st->len - 5;
fb09bf1c 615
57476f6b 616 if (pktin.maxlen < st->biglen) {
617 pktin.maxlen = st->biglen;
32874aea 618 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
619 srealloc(pktin.data, st->biglen + APIEXTRA));
fb09bf1c 620 if (!pktin.data)
621 fatalbox("Out of memory");
622 }
374330e2 623
57476f6b 624 st->to_read = st->biglen;
625 st->p = pktin.data;
626 while (st->to_read > 0) {
32874aea 627 st->chunk = st->to_read;
fb09bf1c 628 while ((*datalen) == 0)
57476f6b 629 crReturn(st->to_read);
630 if (st->chunk > (*datalen))
631 st->chunk = (*datalen);
632 memcpy(st->p, *data, st->chunk);
633 *data += st->chunk;
634 *datalen -= st->chunk;
635 st->p += st->chunk;
636 st->to_read -= st->chunk;
fb09bf1c 637 }
374330e2 638
fb09bf1c 639 if (cipher)
57476f6b 640 cipher->decrypt(pktin.data, st->biglen);
765c4200 641#ifdef DUMP_PACKETS
642 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
643 dmemdump(pktin.data, st->biglen);
698a5108 644#endif
374330e2 645
32874aea 646 st->realcrc = crc32(pktin.data, st->biglen - 4);
647 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
57476f6b 648 if (st->gotcrc != st->realcrc) {
8d5de777 649 bombout(("Incorrect CRC received on packet"));
32874aea 650 crReturn(0);
fb09bf1c 651 }
572f871e 652
4ba9b64b 653 pktin.body = pktin.data + st->pad + 1;
654
655 if (ssh1_compressing) {
656 unsigned char *decompblk;
657 int decomplen;
765c4200 658#ifdef DUMP_PACKETS
659 debug(("Packet payload pre-decompression:\n"));
32874aea 660 dmemdump(pktin.body - 1, pktin.length + 1);
4ba9b64b 661#endif
32874aea 662 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
4ba9b64b 663 &decompblk, &decomplen);
664
665 if (pktin.maxlen < st->pad + decomplen) {
666 pktin.maxlen = st->pad + decomplen;
32874aea 667 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
668 pktin.body = pktin.data + st->pad + 1;
4ba9b64b 669 if (!pktin.data)
670 fatalbox("Out of memory");
671 }
672
32874aea 673 memcpy(pktin.body - 1, decompblk, decomplen);
dcbde236 674 sfree(decompblk);
32874aea 675 pktin.length = decomplen - 1;
765c4200 676#ifdef DUMP_PACKETS
677 debug(("Packet payload post-decompression:\n"));
32874aea 678 dmemdump(pktin.body - 1, pktin.length + 1);
4ba9b64b 679#endif
680 }
681
e5574168 682 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 683 pktin.type == SSH1_SMSG_STDERR_DATA ||
684 pktin.type == SSH1_MSG_DEBUG ||
685 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
686 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 687 long strlen = GET_32BIT(pktin.body);
8d5de777 688 if (strlen + 4 != pktin.length) {
689 bombout(("Received data packet with bogus string length"));
32874aea 690 crReturn(0);
691 }
fb09bf1c 692 }
693
4ba9b64b 694 pktin.type = pktin.body[-1];
695
e5574168 696 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 697 /* log debug message */
698 char buf[80];
699 int strlen = GET_32BIT(pktin.body);
700 strcpy(buf, "Remote: ");
32874aea 701 if (strlen > 70)
702 strlen = 70;
703 memcpy(buf + 8, pktin.body + 4, strlen);
704 buf[8 + strlen] = '\0';
fb09bf1c 705 logevent(buf);
706 goto next_packet;
e5574168 707 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 708 /* do nothing */
709 goto next_packet;
710 }
711
38c4a8da 712 if (pktin.type == SSH1_MSG_DISCONNECT) {
713 /* log reason code in disconnect message */
714 char buf[256];
260f3dec 715 unsigned msglen = GET_32BIT(pktin.body);
716 unsigned nowlen;
38c4a8da 717 strcpy(buf, "Remote sent disconnect: ");
718 nowlen = strlen(buf);
32874aea 719 if (msglen > sizeof(buf) - nowlen - 1)
720 msglen = sizeof(buf) - nowlen - 1;
721 memcpy(buf + nowlen, pktin.body + 4, msglen);
722 buf[nowlen + msglen] = '\0';
38c4a8da 723 logevent(buf);
4eb195cc 724 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
e14d0f19 725 crReturn(0);
38c4a8da 726 }
727
fb09bf1c 728 crFinish(0);
729}
730
e5574168 731static int ssh2_rdpkt(unsigned char **data, int *datalen)
732{
960e736a 733 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 734
735 crBegin;
736
32874aea 737 next_packet:
e5574168 738 pktin.type = 0;
739 pktin.length = 0;
960e736a 740 if (sccipher)
32874aea 741 st->cipherblk = sccipher->blksize;
e5574168 742 else
32874aea 743 st->cipherblk = 8;
960e736a 744 if (st->cipherblk < 8)
32874aea 745 st->cipherblk = 8;
960e736a 746
747 if (pktin.maxlen < st->cipherblk) {
748 pktin.maxlen = st->cipherblk;
32874aea 749 pktin.data =
750 (pktin.data ==
751 NULL ? smalloc(st->cipherblk +
752 APIEXTRA) : srealloc(pktin.data,
753 st->cipherblk +
754 APIEXTRA));
e5574168 755 if (!pktin.data)
756 fatalbox("Out of memory");
757 }
758
759 /*
760 * Acquire and decrypt the first block of the packet. This will
761 * contain the length and padding details.
762 */
32874aea 763 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 764 while ((*datalen) == 0)
32874aea 765 crReturn(st->cipherblk - st->i);
960e736a 766 pktin.data[st->i] = *(*data)++;
32874aea 767 (*datalen)--;
e5574168 768 }
4252c9cc 769
e5574168 770 if (sccipher)
32874aea 771 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 772
773 /*
774 * Now get the length and padding figures.
775 */
960e736a 776 st->len = GET_32BIT(pktin.data);
777 st->pad = pktin.data[4];
e5574168 778
779 /*
780 * This enables us to deduce the payload length.
781 */
960e736a 782 st->payload = st->len - st->pad - 1;
e5574168 783
960e736a 784 pktin.length = st->payload + 5;
e5574168 785
786 /*
787 * So now we can work out the total packet length.
788 */
960e736a 789 st->packetlen = st->len + 4;
790 st->maclen = scmac ? scmac->len : 0;
e5574168 791
792 /*
793 * Adjust memory allocation if packet is too big.
794 */
32874aea 795 if (pktin.maxlen < st->packetlen + st->maclen) {
796 pktin.maxlen = st->packetlen + st->maclen;
797 pktin.data =
798 (pktin.data ==
799 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
800 pktin.maxlen
801 +
802 APIEXTRA));
e5574168 803 if (!pktin.data)
804 fatalbox("Out of memory");
805 }
806
807 /*
808 * Read and decrypt the remainder of the packet.
809 */
32874aea 810 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
811 st->i++) {
e5574168 812 while ((*datalen) == 0)
960e736a 813 crReturn(st->packetlen + st->maclen - st->i);
814 pktin.data[st->i] = *(*data)++;
32874aea 815 (*datalen)--;
e5574168 816 }
817 /* Decrypt everything _except_ the MAC. */
818 if (sccipher)
32874aea 819 sccipher->decrypt(pktin.data + st->cipherblk,
820 st->packetlen - st->cipherblk);
e5574168 821
765c4200 822#ifdef DUMP_PACKETS
823 debug(("Got packet len=%d pad=%d\n", st->len, st->pad));
824 dmemdump(pktin.data, st->packetlen);
7cca0d81 825#endif
d39f364a 826
e5574168 827 /*
828 * Check the MAC.
829 */
32874aea 830 if (scmac
831 && !scmac->verify(pktin.data, st->len + 4,
832 st->incoming_sequence)) {
8d5de777 833 bombout(("Incorrect MAC received on packet"));
32874aea 834 crReturn(0);
8d5de777 835 }
32874aea 836 st->incoming_sequence++; /* whether or not we MACed */
e5574168 837
4ba9b64b 838 /*
839 * Decompress packet payload.
840 */
841 {
842 unsigned char *newpayload;
843 int newlen;
32874aea 844 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
4ba9b64b 845 &newpayload, &newlen)) {
32874aea 846 if (pktin.maxlen < newlen + 5) {
847 pktin.maxlen = newlen + 5;
848 pktin.data =
849 (pktin.data ==
850 NULL ? smalloc(pktin.maxlen +
851 APIEXTRA) : srealloc(pktin.data,
852 pktin.maxlen +
853 APIEXTRA));
4ba9b64b 854 if (!pktin.data)
855 fatalbox("Out of memory");
856 }
857 pktin.length = 5 + newlen;
32874aea 858 memcpy(pktin.data + 5, newpayload, newlen);
765c4200 859#ifdef DUMP_PACKETS
860 debug(("Post-decompression payload:\n"));
32874aea 861 dmemdump(pktin.data + 5, newlen);
4ba9b64b 862#endif
863
dcbde236 864 sfree(newpayload);
4ba9b64b 865 }
866 }
867
e5574168 868 pktin.savedpos = 6;
869 pktin.type = pktin.data[5];
e5574168 870
7cca0d81 871 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
32874aea 872 goto next_packet; /* FIXME: print DEBUG message */
e5574168 873
38c4a8da 874 if (pktin.type == SSH2_MSG_DISCONNECT) {
875 /* log reason code in disconnect message */
876 char buf[256];
32874aea 877 int reason = GET_32BIT(pktin.data + 6);
878 unsigned msglen = GET_32BIT(pktin.data + 10);
260f3dec 879 unsigned nowlen;
38c4a8da 880 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
881 sprintf(buf, "Received disconnect message (%s)",
882 ssh2_disconnect_reasons[reason]);
883 } else {
32874aea 884 sprintf(buf, "Received disconnect message (unknown type %d)",
885 reason);
38c4a8da 886 }
887 logevent(buf);
888 strcpy(buf, "Disconnection message text: ");
889 nowlen = strlen(buf);
32874aea 890 if (msglen > sizeof(buf) - nowlen - 1)
891 msglen = sizeof(buf) - nowlen - 1;
892 memcpy(buf + nowlen, pktin.data + 14, msglen);
893 buf[nowlen + msglen] = '\0';
38c4a8da 894 logevent(buf);
4eb195cc 895 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
896 reason,
897 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
898 ssh2_disconnect_reasons[reason] : "unknown",
899 buf+nowlen));
e14d0f19 900 crReturn(0);
38c4a8da 901 }
902
e5574168 903 crFinish(0);
904}
905
32874aea 906static void ssh1_pktout_size(int len)
907{
374330e2 908 int pad, biglen;
909
910 len += 5; /* type and CRC */
32874aea 911 pad = 8 - (len % 8);
374330e2 912 biglen = len + pad;
913
32874aea 914 pktout.length = len - 5;
374330e2 915 if (pktout.maxlen < biglen) {
916 pktout.maxlen = biglen;
8f203108 917#ifdef MSCRYPTOAPI
fb09bf1c 918 /* Allocate enough buffer space for extra block
8f203108 919 * for MS CryptEncrypt() */
32874aea 920 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
921 srealloc(pktout.data, biglen + 12));
8f203108 922#else
32874aea 923 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
924 srealloc(pktout.data, biglen + 4));
8f203108 925#endif
374330e2 926 if (!pktout.data)
927 fatalbox("Out of memory");
928 }
32874aea 929 pktout.body = pktout.data + 4 + pad + 1;
4ba9b64b 930}
374330e2 931
32874aea 932static void s_wrpkt_start(int type, int len)
933{
4ba9b64b 934 ssh1_pktout_size(len);
374330e2 935 pktout.type = type;
374330e2 936}
937
32874aea 938static int s_wrpkt_prepare(void)
939{
374330e2 940 int pad, len, biglen, i;
941 unsigned long crc;
942
4ba9b64b 943 pktout.body[-1] = pktout.type;
944
945 if (ssh1_compressing) {
946 unsigned char *compblk;
947 int complen;
ca35e638 948#ifdef DUMP_PACKETS
949 debug(("Packet payload pre-compression:\n"));
950 dmemdump(pktout.body - 1, pktout.length + 1);
951#endif
32874aea 952 zlib_compress_block(pktout.body - 1, pktout.length + 1,
4ba9b64b 953 &compblk, &complen);
32874aea 954 ssh1_pktout_size(complen - 1);
955 memcpy(pktout.body - 1, compblk, complen);
dcbde236 956 sfree(compblk);
4ba9b64b 957 }
958
374330e2 959 len = pktout.length + 5; /* type and CRC */
32874aea 960 pad = 8 - (len % 8);
374330e2 961 biglen = len + pad;
962
32874aea 963 for (i = 0; i < pad; i++)
964 pktout.data[i + 4] = random_byte();
965 crc = crc32(pktout.data + 4, biglen - 4);
966 PUT_32BIT(pktout.data + biglen, crc);
fb09bf1c 967 PUT_32BIT(pktout.data, len);
374330e2 968
765c4200 969#ifdef DUMP_PACKETS
32874aea 970 debug(("Sending packet len=%d\n", biglen + 4));
971 dmemdump(pktout.data, biglen + 4);
698a5108 972#endif
374330e2 973 if (cipher)
32874aea 974 cipher->encrypt(pktout.data + 4, biglen);
374330e2 975
32874aea 976 return biglen + 4;
39065bed 977}
978
32874aea 979static void s_wrpkt(void)
980{
5471d09a 981 int len, backlog;
39065bed 982 len = s_wrpkt_prepare();
5471d09a 983 backlog = sk_write(s, pktout.data, len);
984 if (backlog > SSH_MAX_BACKLOG)
985 ssh_throttle_all(1, backlog);
39065bed 986}
987
32874aea 988static void s_wrpkt_defer(void)
989{
39065bed 990 int len;
991 len = s_wrpkt_prepare();
992 if (deferred_len + len > deferred_size) {
32874aea 993 deferred_size = deferred_len + len + 128;
994 deferred_send_data = srealloc(deferred_send_data, deferred_size);
39065bed 995 }
32874aea 996 memcpy(deferred_send_data + deferred_len, pktout.data, len);
39065bed 997 deferred_len += len;
374330e2 998}
999
fb09bf1c 1000/*
39065bed 1001 * Construct a packet with the specified contents.
fb09bf1c 1002 */
39065bed 1003static void construct_packet(int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1004{
fb09bf1c 1005 unsigned char *p, *argp, argchar;
1006 unsigned long argint;
1007 int pktlen, argtype, arglen;
7cca0d81 1008 Bignum bn;
fb09bf1c 1009
1010 pktlen = 0;
39065bed 1011 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1012 switch (argtype) {
1013 case PKT_INT:
39065bed 1014 (void) va_arg(ap1, int);
fb09bf1c 1015 pktlen += 4;
1016 break;
1017 case PKT_CHAR:
39065bed 1018 (void) va_arg(ap1, char);
fb09bf1c 1019 pktlen++;
1020 break;
1021 case PKT_DATA:
39065bed 1022 (void) va_arg(ap1, unsigned char *);
1023 arglen = va_arg(ap1, int);
fb09bf1c 1024 pktlen += arglen;
1025 break;
1026 case PKT_STR:
39065bed 1027 argp = va_arg(ap1, unsigned char *);
fb09bf1c 1028 arglen = strlen(argp);
1029 pktlen += 4 + arglen;
1030 break;
7cca0d81 1031 case PKT_BIGNUM:
39065bed 1032 bn = va_arg(ap1, Bignum);
32874aea 1033 pktlen += ssh1_bignum_length(bn);
7cca0d81 1034 break;
fb09bf1c 1035 default:
1036 assert(0);
1037 }
1038 }
fb09bf1c 1039
1040 s_wrpkt_start(pkttype, pktlen);
1041 p = pktout.body;
1042
39065bed 1043 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1044 switch (argtype) {
1045 case PKT_INT:
39065bed 1046 argint = va_arg(ap2, int);
fb09bf1c 1047 PUT_32BIT(p, argint);
1048 p += 4;
1049 break;
1050 case PKT_CHAR:
39065bed 1051 argchar = va_arg(ap2, unsigned char);
fb09bf1c 1052 *p = argchar;
1053 p++;
1054 break;
1055 case PKT_DATA:
39065bed 1056 argp = va_arg(ap2, unsigned char *);
1057 arglen = va_arg(ap2, int);
fb09bf1c 1058 memcpy(p, argp, arglen);
1059 p += arglen;
1060 break;
1061 case PKT_STR:
39065bed 1062 argp = va_arg(ap2, unsigned char *);
fb09bf1c 1063 arglen = strlen(argp);
1064 PUT_32BIT(p, arglen);
1065 memcpy(p + 4, argp, arglen);
1066 p += 4 + arglen;
1067 break;
7cca0d81 1068 case PKT_BIGNUM:
39065bed 1069 bn = va_arg(ap2, Bignum);
32874aea 1070 p += ssh1_write_bignum(p, bn);
7cca0d81 1071 break;
fb09bf1c 1072 }
1073 }
39065bed 1074}
fb09bf1c 1075
32874aea 1076static void send_packet(int pkttype, ...)
1077{
39065bed 1078 va_list ap1, ap2;
1079 va_start(ap1, pkttype);
1080 va_start(ap2, pkttype);
1081 construct_packet(pkttype, ap1, ap2);
fb09bf1c 1082 s_wrpkt();
1083}
1084
32874aea 1085static void defer_packet(int pkttype, ...)
1086{
39065bed 1087 va_list ap1, ap2;
1088 va_start(ap1, pkttype);
1089 va_start(ap2, pkttype);
1090 construct_packet(pkttype, ap1, ap2);
1091 s_wrpkt_defer();
1092}
1093
32874aea 1094static int ssh_versioncmp(char *a, char *b)
1095{
9697bfd2 1096 char *ae, *be;
1097 unsigned long av, bv;
1098
43aa02a7 1099 av = strtoul(a, &ae, 10);
1100 bv = strtoul(b, &be, 10);
32874aea 1101 if (av != bv)
1102 return (av < bv ? -1 : +1);
1103 if (*ae == '.')
1104 ae++;
1105 if (*be == '.')
1106 be++;
43aa02a7 1107 av = strtoul(ae, &ae, 10);
1108 bv = strtoul(be, &be, 10);
32874aea 1109 if (av != bv)
1110 return (av < bv ? -1 : +1);
9697bfd2 1111 return 0;
1112}
1113
e5574168 1114
1115/*
a92dd380 1116 * Utility routines for putting an SSH-protocol `string' and
1117 * `uint32' into a SHA state.
e5574168 1118 */
1119#include <stdio.h>
32874aea 1120static void sha_string(SHA_State * s, void *str, int len)
1121{
e5574168 1122 unsigned char lenblk[4];
e5574168 1123 PUT_32BIT(lenblk, len);
e5574168 1124 SHA_Bytes(s, lenblk, 4);
e5574168 1125 SHA_Bytes(s, str, len);
1126}
1127
32874aea 1128static void sha_uint32(SHA_State * s, unsigned i)
1129{
a92dd380 1130 unsigned char intblk[4];
1131 PUT_32BIT(intblk, i);
1132 SHA_Bytes(s, intblk, 4);
1133}
1134
7cca0d81 1135/*
1136 * SSH2 packet construction functions.
1137 */
32874aea 1138static void ssh2_pkt_ensure(int length)
1139{
783415f8 1140 if (pktout.maxlen < length) {
32874aea 1141 pktout.maxlen = length + 256;
1142 pktout.data =
1143 (pktout.data ==
1144 NULL ? smalloc(pktout.maxlen +
1145 APIEXTRA) : srealloc(pktout.data,
1146 pktout.maxlen +
1147 APIEXTRA));
1148 if (!pktout.data)
1149 fatalbox("Out of memory");
7cca0d81 1150 }
783415f8 1151}
32874aea 1152static void ssh2_pkt_adddata(void *data, int len)
1153{
783415f8 1154 pktout.length += len;
1155 ssh2_pkt_ensure(pktout.length);
32874aea 1156 memcpy(pktout.data + pktout.length - len, data, len);
7cca0d81 1157}
32874aea 1158static void ssh2_pkt_addbyte(unsigned char byte)
1159{
7cca0d81 1160 ssh2_pkt_adddata(&byte, 1);
1161}
32874aea 1162static void ssh2_pkt_init(int pkt_type)
1163{
7cca0d81 1164 pktout.length = 5;
32874aea 1165 ssh2_pkt_addbyte((unsigned char) pkt_type);
7cca0d81 1166}
32874aea 1167static void ssh2_pkt_addbool(unsigned char value)
1168{
7cca0d81 1169 ssh2_pkt_adddata(&value, 1);
1170}
32874aea 1171static void ssh2_pkt_adduint32(unsigned long value)
1172{
7cca0d81 1173 unsigned char x[4];
1174 PUT_32BIT(x, value);
1175 ssh2_pkt_adddata(x, 4);
1176}
32874aea 1177static void ssh2_pkt_addstring_start(void)
1178{
7cca0d81 1179 ssh2_pkt_adduint32(0);
1180 pktout.savedpos = pktout.length;
1181}
32874aea 1182static void ssh2_pkt_addstring_str(char *data)
1183{
7cca0d81 1184 ssh2_pkt_adddata(data, strlen(data));
1185 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1186 pktout.length - pktout.savedpos);
7cca0d81 1187}
32874aea 1188static void ssh2_pkt_addstring_data(char *data, int len)
1189{
7cca0d81 1190 ssh2_pkt_adddata(data, len);
1191 PUT_32BIT(pktout.data + pktout.savedpos - 4,
32874aea 1192 pktout.length - pktout.savedpos);
7cca0d81 1193}
32874aea 1194static void ssh2_pkt_addstring(char *data)
1195{
7cca0d81 1196 ssh2_pkt_addstring_start();
1197 ssh2_pkt_addstring_str(data);
1198}
32874aea 1199static char *ssh2_mpint_fmt(Bignum b, int *len)
1200{
7cca0d81 1201 unsigned char *p;
32874aea 1202 int i, n = (bignum_bitcount(b) + 7) / 8;
3709bfe9 1203 p = smalloc(n + 1);
7cca0d81 1204 if (!p)
32874aea 1205 fatalbox("out of memory");
7cca0d81 1206 p[0] = 0;
3709bfe9 1207 for (i = 1; i <= n; i++)
32874aea 1208 p[i] = bignum_byte(b, n - i);
7cca0d81 1209 i = 0;
32874aea 1210 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1211 i++;
1212 memmove(p, p + i, n + 1 - i);
1213 *len = n + 1 - i;
7cca0d81 1214 return p;
1215}
32874aea 1216static void ssh2_pkt_addmp(Bignum b)
1217{
7cca0d81 1218 unsigned char *p;
1219 int len;
1220 p = ssh2_mpint_fmt(b, &len);
1221 ssh2_pkt_addstring_start();
1222 ssh2_pkt_addstring_data(p, len);
dcbde236 1223 sfree(p);
7cca0d81 1224}
b185170a 1225
1226/*
1227 * Construct an SSH2 final-form packet: compress it, encrypt it,
1228 * put the MAC on it. Final packet, ready to be sent, is stored in
1229 * pktout.data. Total length is returned.
1230 */
32874aea 1231static int ssh2_pkt_construct(void)
1232{
7cca0d81 1233 int cipherblk, maclen, padding, i;
1234 static unsigned long outgoing_sequence = 0;
1235
1236 /*
4ba9b64b 1237 * Compress packet payload.
1238 */
4ba9b64b 1239 {
1240 unsigned char *newpayload;
1241 int newlen;
ca35e638 1242#ifdef DUMP_PACKETS
1243 if (cscomp && cscomp != &ssh_comp_none) {
1244 debug(("Pre-compression payload:\n"));
1245 dmemdump(pktout.data + 5, pktout.length - 5);
1246 }
1247#endif
32874aea 1248 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
4ba9b64b 1249 &newpayload, &newlen)) {
1250 pktout.length = 5;
1251 ssh2_pkt_adddata(newpayload, newlen);
dcbde236 1252 sfree(newpayload);
4ba9b64b 1253 }
1254 }
1255
1256 /*
7cca0d81 1257 * Add padding. At least four bytes, and must also bring total
1258 * length (minus MAC) up to a multiple of the block size.
1259 */
32874aea 1260 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1261 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1262 padding = 4;
32874aea 1263 padding +=
1264 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
783415f8 1265 maclen = csmac ? csmac->len : 0;
1266 ssh2_pkt_ensure(pktout.length + padding + maclen);
7cca0d81 1267 pktout.data[4] = padding;
1268 for (i = 0; i < padding; i++)
32874aea 1269 pktout.data[pktout.length + i] = random_byte();
7cca0d81 1270 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1271 if (csmac)
32874aea 1272 csmac->generate(pktout.data, pktout.length + padding,
1273 outgoing_sequence);
1274 outgoing_sequence++; /* whether or not we MACed */
7cca0d81 1275
765c4200 1276#ifdef DUMP_PACKETS
32874aea 1277 debug(("Sending packet len=%d\n", pktout.length + padding));
1278 dmemdump(pktout.data, pktout.length + padding);
7cca0d81 1279#endif
1280
1281 if (cscipher)
32874aea 1282 cscipher->encrypt(pktout.data, pktout.length + padding);
7cca0d81 1283
b185170a 1284 /* Ready-to-send packet starts at pktout.data. We return length. */
1285 return pktout.length + padding + maclen;
1286}
1287
1288/*
1289 * Construct and send an SSH2 packet immediately.
1290 */
32874aea 1291static void ssh2_pkt_send(void)
1292{
5471d09a 1293 int len;
1294 int backlog;
1295 len = ssh2_pkt_construct();
1296 backlog = sk_write(s, pktout.data, len);
1297 if (backlog > SSH_MAX_BACKLOG)
1298 ssh_throttle_all(1, backlog);
b185170a 1299}
1300
1301/*
1302 * Construct an SSH2 packet and add it to a deferred data block.
1303 * Useful for sending multiple packets in a single sk_write() call,
1304 * to prevent a traffic-analysing listener from being able to work
1305 * out the length of any particular packet (such as the password
1306 * packet).
1307 *
1308 * Note that because SSH2 sequence-numbers its packets, this can
1309 * NOT be used as an m4-style `defer' allowing packets to be
1310 * constructed in one order and sent in another.
1311 */
32874aea 1312static void ssh2_pkt_defer(void)
1313{
b185170a 1314 int len = ssh2_pkt_construct();
1315 if (deferred_len + len > deferred_size) {
32874aea 1316 deferred_size = deferred_len + len + 128;
1317 deferred_send_data = srealloc(deferred_send_data, deferred_size);
b185170a 1318 }
32874aea 1319 memcpy(deferred_send_data + deferred_len, pktout.data, len);
b185170a 1320 deferred_len += len;
1321}
1322
1323/*
1324 * Send the whole deferred data block constructed by
39065bed 1325 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1326 */
32874aea 1327static void ssh_pkt_defersend(void)
1328{
5471d09a 1329 int backlog;
1330 backlog = sk_write(s, deferred_send_data, deferred_len);
b185170a 1331 deferred_len = deferred_size = 0;
1332 sfree(deferred_send_data);
1333 deferred_send_data = NULL;
5471d09a 1334 if (backlog > SSH_MAX_BACKLOG)
1335 ssh_throttle_all(1, backlog);
7cca0d81 1336}
1337
1338#if 0
32874aea 1339void bndebug(char *string, Bignum b)
1340{
7cca0d81 1341 unsigned char *p;
1342 int i, len;
1343 p = ssh2_mpint_fmt(b, &len);
1344 debug(("%s", string));
1345 for (i = 0; i < len; i++)
32874aea 1346 debug((" %02x", p[i]));
765c4200 1347 debug(("\n"));
dcbde236 1348 sfree(p);
7cca0d81 1349}
1350#endif
1351
32874aea 1352static void sha_mpint(SHA_State * s, Bignum b)
1353{
7cca0d81 1354 unsigned char *p;
1355 int len;
1356 p = ssh2_mpint_fmt(b, &len);
1357 sha_string(s, p, len);
dcbde236 1358 sfree(p);
7cca0d81 1359}
1360
1361/*
1362 * SSH2 packet decode functions.
1363 */
32874aea 1364static unsigned long ssh2_pkt_getuint32(void)
1365{
7cca0d81 1366 unsigned long value;
1367 if (pktin.length - pktin.savedpos < 4)
32874aea 1368 return 0; /* arrgh, no way to decline (FIXME?) */
1369 value = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1370 pktin.savedpos += 4;
1371 return value;
1372}
32874aea 1373static int ssh2_pkt_getbool(void)
1374{
65a22376 1375 unsigned long value;
1376 if (pktin.length - pktin.savedpos < 1)
32874aea 1377 return 0; /* arrgh, no way to decline (FIXME?) */
65a22376 1378 value = pktin.data[pktin.savedpos] != 0;
1379 pktin.savedpos++;
1380 return value;
1381}
32874aea 1382static void ssh2_pkt_getstring(char **p, int *length)
1383{
7cca0d81 1384 *p = NULL;
1385 if (pktin.length - pktin.savedpos < 4)
32874aea 1386 return;
1387 *length = GET_32BIT(pktin.data + pktin.savedpos);
7cca0d81 1388 pktin.savedpos += 4;
1389 if (pktin.length - pktin.savedpos < *length)
32874aea 1390 return;
1391 *p = pktin.data + pktin.savedpos;
7cca0d81 1392 pktin.savedpos += *length;
1393}
32874aea 1394static Bignum ssh2_pkt_getmp(void)
1395{
7cca0d81 1396 char *p;
3709bfe9 1397 int length;
7cca0d81 1398 Bignum b;
1399
1400 ssh2_pkt_getstring(&p, &length);
1401 if (!p)
32874aea 1402 return NULL;
8d5de777 1403 if (p[0] & 0x80) {
32874aea 1404 bombout(("internal error: Can't handle negative mpints"));
1405 return NULL;
8d5de777 1406 }
3709bfe9 1407 b = bignum_from_bytes(p, length);
7cca0d81 1408 return b;
1409}
1410
7d503c31 1411/*
1412 * Examine the remote side's version string and compare it against
1413 * a list of known buggy implementations.
1414 */
32874aea 1415static void ssh_detect_bugs(char *vstring)
1416{
1417 char *imp; /* pointer to implementation part */
7d503c31 1418 imp = vstring;
1419 imp += strcspn(imp, "-");
bd358db1 1420 if (*imp) imp++;
7d503c31 1421 imp += strcspn(imp, "-");
bd358db1 1422 if (*imp) imp++;
7d503c31 1423
1424 ssh_remote_bugs = 0;
1425
1426 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
32874aea 1427 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
bd358db1 1428 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
32874aea 1429 /*
1430 * These versions don't support SSH1_MSG_IGNORE, so we have
1431 * to use a different defence against password length
1432 * sniffing.
1433 */
1434 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1435 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1436 }
1437
bd358db1 1438 if (!strcmp(imp, "Cisco-1.25")) {
1439 /*
1440 * These versions need a plain password sent; they can't
1441 * handle having a null and a random length of data after
1442 * the password.
1443 */
1444 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1445 logevent("We believe remote version needs a plain SSH1 password");
1446 }
1447
7d503c31 1448 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
32874aea 1449 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1450 !strncmp(imp, "2.1 ", 4)) {
1451 /*
1452 * These versions have the HMAC bug.
1453 */
1454 ssh_remote_bugs |= BUG_SSH2_HMAC;
1455 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1456 }
1457}
1458
32874aea 1459static int do_ssh_init(unsigned char c)
1460{
2d466ffd 1461 static int vslen;
8df7a775 1462 static char version[10];
50526e47 1463 static char *vstring;
1464 static int vstrsize;
1465 static char *vlog;
8df7a775 1466 static int i;
374330e2 1467
8df7a775 1468 crBegin;
1469
1470 /* Search for the string "SSH-" in the input. */
374330e2 1471 i = 0;
8df7a775 1472 while (1) {
1473 static const int transS[] = { 1, 2, 2, 1 };
1474 static const int transH[] = { 0, 0, 3, 0 };
1475 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1476 if (c == 'S')
1477 i = transS[i];
1478 else if (c == 'H')
1479 i = transH[i];
1480 else if (c == '-')
1481 i = transminus[i];
1482 else
1483 i = 0;
8df7a775 1484 if (i < 0)
1485 break;
1486 crReturn(1); /* get another character */
374330e2 1487 }
8df7a775 1488
50526e47 1489 vstrsize = 16;
bd358db1 1490 vstring = smalloc(vstrsize);
c5e9c988 1491 strcpy(vstring, "SSH-");
50526e47 1492 vslen = 4;
374330e2 1493 i = 0;
1494 while (1) {
8df7a775 1495 crReturn(1); /* get another char */
32874aea 1496 if (vslen >= vstrsize - 1) {
1497 vstrsize += 16;
1498 vstring = srealloc(vstring, vstrsize);
1499 }
1500 vstring[vslen++] = c;
374330e2 1501 if (i >= 0) {
1502 if (c == '-') {
1503 version[i] = '\0';
1504 i = -1;
32874aea 1505 } else if (i < sizeof(version) - 1)
374330e2 1506 version[i++] = c;
32874aea 1507 } else if (c == '\n')
374330e2 1508 break;
1509 }
1510
db7d555c 1511 ssh_agentfwd_enabled = FALSE;
960e736a 1512 rdpkt2_state.incoming_sequence = 0;
1513
50526e47 1514 vstring[vslen] = 0;
9275ca8a 1515 vlog = smalloc(20 + vslen);
bd358db1 1516 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
c5e9c988 1517 sprintf(vlog, "Server version: %s", vstring);
c5e9c988 1518 logevent(vlog);
bd358db1 1519 ssh_detect_bugs(vstring);
9275ca8a 1520 sfree(vlog);
c5e9c988 1521
adf799dd 1522 /*
1523 * Server version "1.99" means we can choose whether we use v1
1524 * or v2 protocol. Choice is based on cfg.sshprot.
1525 */
1526 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
32874aea 1527 /*
1528 * This is a v2 server. Begin v2 protocol.
1529 */
1530 char verstring[80], vlog[100];
1531 sprintf(verstring, "SSH-2.0-%s", sshver);
1532 SHA_Init(&exhashbase);
1533 /*
1534 * Hash our version string and their version string.
1535 */
1536 sha_string(&exhashbase, verstring, strlen(verstring));
1537 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1538 sprintf(vlog, "We claim version: %s", verstring);
1539 logevent(vlog);
1540 strcat(verstring, "\n");
1541 logevent("Using SSH protocol version 2");
1542 sk_write(s, verstring, strlen(verstring));
1543 ssh_protocol = ssh2_protocol;
1544 ssh_version = 2;
1545 s_rdpkt = ssh2_rdpkt;
e5574168 1546 } else {
32874aea 1547 /*
1548 * This is a v1 server. Begin v1 protocol.
1549 */
1550 char verstring[80], vlog[100];
1551 sprintf(verstring, "SSH-%s-%s",
1552 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1553 sshver);
1554 sprintf(vlog, "We claim version: %s", verstring);
1555 logevent(vlog);
1556 strcat(verstring, "\n");
1557 logevent("Using SSH protocol version 1");
1558 sk_write(s, verstring, strlen(verstring));
1559 ssh_protocol = ssh1_protocol;
1560 ssh_version = 1;
1561 s_rdpkt = ssh1_rdpkt;
e5574168 1562 }
3687d221 1563 ssh_state = SSH_STATE_BEFORE_SIZE;
8df7a775 1564
50526e47 1565 sfree(vstring);
50526e47 1566
8df7a775 1567 crFinish(0);
1568}
1569
1570static void ssh_gotdata(unsigned char *data, int datalen)
1571{
1572 crBegin;
1573
1574 /*
1575 * To begin with, feed the characters one by one to the
1576 * protocol initialisation / selection function do_ssh_init().
1577 * When that returns 0, we're done with the initial greeting
1578 * exchange and can move on to packet discipline.
1579 */
1580 while (1) {
1581 int ret;
1582 if (datalen == 0)
1583 crReturnV; /* more data please */
1584 ret = do_ssh_init(*data);
32874aea 1585 data++;
1586 datalen--;
8df7a775 1587 if (ret == 0)
1588 break;
1589 }
1590
1591 /*
1592 * We emerge from that loop when the initial negotiation is
1593 * over and we have selected an s_rdpkt function. Now pass
1594 * everything to s_rdpkt, and then pass the resulting packets
1595 * to the proper protocol handler.
1596 */
1597 if (datalen == 0)
1598 crReturnV;
1599 while (1) {
1600 while (datalen > 0) {
32874aea 1601 if (s_rdpkt(&data, &datalen) == 0) {
e14d0f19 1602 if (ssh_state == SSH_STATE_CLOSED) {
1603 return;
1604 }
8df7a775 1605 ssh_protocol(NULL, 0, 1);
1606 if (ssh_state == SSH_STATE_CLOSED) {
1607 return;
1608 }
1609 }
1610 }
1611 crReturnV;
1612 }
1613 crFinishV;
1614}
1615
32874aea 1616static int ssh_closing(Plug plug, char *error_msg, int error_code,
1617 int calling_back)
1618{
7e78000d 1619 ssh_state = SSH_STATE_CLOSED;
f3ab576e 1620 if (s) {
1621 sk_close(s);
1622 s = NULL;
1623 }
7e78000d 1624 if (error_msg) {
32874aea 1625 /* A socket error has occurred. */
1626 connection_fatal(error_msg);
7e78000d 1627 } else {
1628 /* Otherwise, the remote side closed the connection normally. */
8df7a775 1629 }
7e78000d 1630 return 0;
1631}
1632
32874aea 1633static int ssh_receive(Plug plug, int urgent, char *data, int len)
1634{
1635 ssh_gotdata(data, len);
3257deae 1636 if (ssh_state == SSH_STATE_CLOSED) {
32874aea 1637 if (s) {
1638 sk_close(s);
1639 s = NULL;
1640 }
1641 return 0;
3257deae 1642 }
fef97f43 1643 return 1;
374330e2 1644}
1645
5471d09a 1646static void ssh_sent(Plug plug, int bufsize)
1647{
1648 /*
1649 * If the send backlog on the SSH socket itself clears, we
1650 * should unthrottle the whole world if it was throttled.
1651 */
1652 if (bufsize < SSH_MAX_BACKLOG)
1653 ssh_throttle_all(0, bufsize);
1654}
1655
fb09bf1c 1656/*
8df7a775 1657 * Connect to specified host and port.
1658 * Returns an error message, or NULL on success.
6e1ebb76 1659 * Also places the canonical host name into `realhost'. It must be
1660 * freed by the caller.
8df7a775 1661 */
1662static char *connect_to_host(char *host, int port, char **realhost)
1663{
7e78000d 1664 static struct plug_function_table fn_table = {
1665 ssh_closing,
5471d09a 1666 ssh_receive,
1667 ssh_sent,
1668 NULL
7e78000d 1669 }, *fn_table_ptr = &fn_table;
1670
8df7a775 1671 SockAddr addr;
1672 char *err;
1673#ifdef FWHACK
1674 char *FWhost;
1675 int FWport;
1676#endif
1677
32874aea 1678 savedhost = smalloc(1 + strlen(host));
8df7a775 1679 if (!savedhost)
1680 fatalbox("Out of memory");
1681 strcpy(savedhost, host);
1682
1683 if (port < 0)
1684 port = 22; /* default ssh port */
1685 savedport = port;
1686
1687#ifdef FWHACK
1688 FWhost = host;
1689 FWport = port;
1690 host = FWSTR;
1691 port = 23;
1692#endif
1693
1694 /*
1695 * Try to find host.
1696 */
3ad9d396 1697 {
1698 char buf[200];
1699 sprintf(buf, "Looking up host \"%.170s\"", host);
1700 logevent(buf);
1701 }
8df7a775 1702 addr = sk_namelookup(host, realhost);
32874aea 1703 if ((err = sk_addr_error(addr)))
8df7a775 1704 return err;
1705
1706#ifdef FWHACK
6e1ebb76 1707 *realhost = strdup(FWhost);
8df7a775 1708#endif
1709
1710 /*
1711 * Open socket.
1712 */
3ad9d396 1713 {
1714 char buf[200], addrbuf[100];
1715 sk_getaddr(addr, addrbuf, 100);
1716 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
1717 logevent(buf);
1718 }
7e78000d 1719 s = sk_new(addr, port, 0, 1, &fn_table_ptr);
32874aea 1720 if ((err = sk_socket_error(s)))
8df7a775 1721 return err;
1722
1723#ifdef FWHACK
1724 sk_write(s, "connect ", 8);
1725 sk_write(s, FWhost, strlen(FWhost));
1726 {
1727 char buf[20];
1728 sprintf(buf, " %d\n", FWport);
1729 sk_write(s, buf, strlen(buf));
1730 }
1731#endif
1732
1733 return NULL;
1734}
1735
1736/*
5471d09a 1737 * Throttle or unthrottle the SSH connection.
1738 */
1739static void ssh1_throttle(int adjust)
1740{
1741 int old_count = ssh1_throttle_count;
1742 ssh1_throttle_count += adjust;
1743 assert(ssh1_throttle_count >= 0);
1744 if (ssh1_throttle_count && !old_count) {
1745 sk_set_frozen(s, 1);
1746 } else if (!ssh1_throttle_count && old_count) {
1747 sk_set_frozen(s, 0);
1748 }
1749}
1750
1751/*
1752 * Throttle or unthrottle _all_ local data streams (for when sends
1753 * on the SSH connection itself back up).
1754 */
1755static void ssh_throttle_all(int enable, int bufsize)
1756{
1757 int i;
1758 struct ssh_channel *c;
1759
1760 if (enable == ssh_throttled_all)
1761 return;
1762 ssh_throttled_all = enable;
1763 ssh_overall_bufsize = bufsize;
1764 if (!ssh_channels)
1765 return;
1766 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
1767 switch (c->type) {
1768 case CHAN_MAINSESSION:
1769 /*
1770 * This is treated separately, outside the switch.
1771 */
1772 break;
1773 case CHAN_X11:
1774 x11_override_throttle(c->u.x11.s, enable);
1775 break;
1776 case CHAN_AGENT:
1777 /* Agent channels require no buffer management. */
1778 break;
1779 case CHAN_SOCKDATA:
1780 pfd_override_throttle(c->u.x11.s, enable);
1781 break;
1782 }
1783 }
1784}
1785
1786/*
fb09bf1c 1787 * Handle the key exchange and user authentication phases.
1788 */
e5574168 1789static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1790{
2d466ffd 1791 int i, j;
1792 static int len;
1793 static unsigned char *rsabuf, *keystr1, *keystr2;
374330e2 1794 unsigned char cookie[8];
1795 struct RSAKey servkey, hostkey;
1796 struct MD5Context md5c;
ccbfb941 1797 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1798 static int tried_publickey;
614a20a0 1799 static int tis_auth_refused, ccard_auth_refused;
7cca0d81 1800 static unsigned char session_id[16];
2d466ffd 1801 static int cipher_type;
b585ec46 1802 static char username[100];
374330e2 1803
374330e2 1804 crBegin;
1805
32874aea 1806 if (!ispkt)
1807 crWaitUntil(ispkt);
374330e2 1808
8d5de777 1809 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1810 bombout(("Public key packet not received"));
32874aea 1811 crReturn(0);
8d5de777 1812 }
374330e2 1813
c5e9c988 1814 logevent("Received public keys");
374330e2 1815
c5e9c988 1816 memcpy(cookie, pktin.body, 8);
374330e2 1817
32874aea 1818 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1819 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
374330e2 1820
c5e9c988 1821 /*
1c2a93c4 1822 * Log the host key fingerprint.
c5e9c988 1823 */
c5e9c988 1824 {
1825 char logmsg[80];
1c2a93c4 1826 logevent("Host key fingerprint is:");
c5e9c988 1827 strcpy(logmsg, " ");
32874aea 1828 hostkey.comment = NULL;
1829 rsa_fingerprint(logmsg + strlen(logmsg),
1830 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 1831 logevent(logmsg);
1832 }
1833
32874aea 1834 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1835 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1836 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
bea1ef5f 1837
32874aea 1838 ssh1_local_protoflags =
1839 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
b96dc54c 1840 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1841
c5e9c988 1842 MD5Init(&md5c);
374330e2 1843 MD5Update(&md5c, keystr2, hostkey.bytes);
1844 MD5Update(&md5c, keystr1, servkey.bytes);
1845 MD5Update(&md5c, pktin.body, 8);
374330e2 1846 MD5Final(session_id, &md5c);
1847
32874aea 1848 for (i = 0; i < 32; i++)
374330e2 1849 session_key[i] = random_byte();
1850
1851 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1852
dcbde236 1853 rsabuf = smalloc(len);
374330e2 1854 if (!rsabuf)
1855 fatalbox("Out of memory");
1856
89ee5268 1857 /*
1858 * Verify the host key.
1859 */
1860 {
32874aea 1861 /*
1862 * First format the key into a string.
1863 */
1864 int len = rsastr_len(&hostkey);
1865 char fingerprint[100];
1866 char *keystr = smalloc(len);
1867 if (!keystr)
1868 fatalbox("Out of memory");
1869 rsastr_fmt(keystr, &hostkey);
1870 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1871 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1872 fingerprint);
1873 sfree(keystr);
1874 }
1875
1876 for (i = 0; i < 32; i++) {
374330e2 1877 rsabuf[i] = session_key[i];
1878 if (i < 16)
1879 rsabuf[i] ^= session_id[i];
1880 }
1881
1882 if (hostkey.bytes > servkey.bytes) {
1883 rsaencrypt(rsabuf, 32, &servkey);
1884 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1885 } else {
1886 rsaencrypt(rsabuf, 32, &hostkey);
1887 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1888 }
1889
c5e9c988 1890 logevent("Encrypted session key");
1891
ca20bfcf 1892 {
1893 int cipher_chosen = 0, warn = 0;
1894 char *cipher_string = NULL;
1895 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
1896 int next_cipher = cfg.ssh_cipherlist[i];
1897 if (next_cipher == CIPHER_WARN) {
1898 /* If/when we choose a cipher, warn about it */
1899 warn = 1;
1900 } else if (next_cipher == CIPHER_AES) {
1901 /* XXX Probably don't need to mention this. */
1902 logevent("AES not supported in SSH1, skipping");
1903 } else {
1904 switch (next_cipher) {
1905 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
1906 cipher_string = "3DES"; break;
1907 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
1908 cipher_string = "Blowfish"; break;
1909 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
1910 cipher_string = "single-DES"; break;
1911 }
1912 if (supported_ciphers_mask & (1 << cipher_type))
1913 cipher_chosen = 1;
1914 }
1915 }
1916 if (!cipher_chosen) {
1917 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
1918 bombout(("Server violates SSH 1 protocol by not "
1919 "supporting 3DES encryption"));
1920 else
1921 /* shouldn't happen */
1922 bombout(("No supported ciphers found"));
a99a05c0 1923 crReturn(0);
1924 }
ca20bfcf 1925
1926 /* Warn about chosen cipher if necessary. */
1927 if (warn)
1928 askcipher(cipher_string, 0);
bea1ef5f 1929 }
ca20bfcf 1930
c5e9c988 1931 switch (cipher_type) {
32874aea 1932 case SSH_CIPHER_3DES:
1933 logevent("Using 3DES encryption");
1934 break;
1935 case SSH_CIPHER_DES:
1936 logevent("Using single-DES encryption");
1937 break;
1938 case SSH_CIPHER_BLOWFISH:
1939 logevent("Using Blowfish encryption");
1940 break;
c5e9c988 1941 }
bea1ef5f 1942
e5574168 1943 send_packet(SSH1_CMSG_SESSION_KEY,
32874aea 1944 PKT_CHAR, cipher_type,
1945 PKT_DATA, cookie, 8,
1946 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
1947 PKT_DATA, rsabuf, len,
1948 PKT_INT, ssh1_local_protoflags, PKT_END);
fb09bf1c 1949
c5e9c988 1950 logevent("Trying to enable encryption...");
374330e2 1951
dcbde236 1952 sfree(rsabuf);
374330e2 1953
5e8358ad 1954 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
32874aea 1955 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
374330e2 1956 cipher->sesskey(session_key);
1957
fb09bf1c 1958 crWaitUntil(ispkt);
374330e2 1959
8d5de777 1960 if (pktin.type != SSH1_SMSG_SUCCESS) {
1961 bombout(("Encryption not successfully enabled"));
32874aea 1962 crReturn(0);
8d5de777 1963 }
374330e2 1964
c5e9c988 1965 logevent("Successfully started encryption");
1966
374330e2 1967 fflush(stdout);
1968 {
374330e2 1969 static int pos = 0;
1970 static char c;
67779be7 1971 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
32874aea 1972 if (ssh_get_line) {
1973 if (!ssh_get_line("login as: ",
1974 username, sizeof(username), FALSE)) {
1975 /*
1976 * get_line failed to get a username.
1977 * Terminate.
1978 */
1979 logevent("No username provided. Abandoning session.");
1980 ssh_state = SSH_STATE_CLOSED;
1981 crReturn(1);
1982 }
1983 } else {
1984 c_write_str("login as: ");
1985 ssh_send_ok = 1;
1986 while (pos >= 0) {
1987 crWaitUntil(!ispkt);
1988 while (inlen--)
1989 switch (c = *in++) {
1990 case 10:
1991 case 13:
1992 username[pos] = 0;
1993 pos = -1;
1994 break;
1995 case 8:
1996 case 127:
1997 if (pos > 0) {
1998 c_write_str("\b \b");
1999 pos--;
2000 }
2001 break;
2002 case 21:
2003 case 27:
2004 while (pos > 0) {
2005 c_write_str("\b \b");
2006 pos--;
2007 }
2008 break;
2009 case 3:
2010 case 4:
2011 random_save_seed();
2012 exit(0);
2013 break;
2014 default:
2015 if (((c >= ' ' && c <= '~') ||
51b2fb65 2016 ((unsigned char) c >= 160))
2017 && pos < sizeof(username)-1) {
32874aea 2018 username[pos++] = c;
2019 c_write(&c, 1);
2020 }
2021 break;
2022 }
2023 }
2024 c_write_str("\r\n");
2025 username[strcspn(username, "\n\r")] = '\0';
2026 }
2027 } else {
374330e2 2028 strncpy(username, cfg.username, 99);
2029 username[99] = '\0';
374330e2 2030 }
fb09bf1c 2031
e5574168 2032 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 2033 {
32874aea 2034 char userlog[22 + sizeof(username)];
c5e9c988 2035 sprintf(userlog, "Sent username \"%s\"", username);
2036 logevent(userlog);
32874aea 2037 if (flags & FLAG_INTERACTIVE &&
2038 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2039 strcat(userlog, "\r\n");
32874aea 2040 c_write_str(userlog);
3c8e959b 2041 }
c5e9c988 2042 }
374330e2 2043 }
2044
fb09bf1c 2045 crWaitUntil(ispkt);
374330e2 2046
7cca0d81 2047 tried_publickey = 0;
614a20a0 2048 tis_auth_refused = ccard_auth_refused = 0;
7cca0d81 2049
e5574168 2050 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 2051 static char password[100];
a52f067e 2052 static char prompt[200];
374330e2 2053 static int pos;
2054 static char c;
32874aea 2055 static int pwpkt_type;
32874aea 2056 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2057
32874aea 2058 if (agent_exists()) {
2059 /*
2060 * Attempt RSA authentication using Pageant.
2061 */
2062 static unsigned char request[5], *response, *p;
2063 static int responselen;
2064 static int i, nkeys;
2065 static int authed = FALSE;
2066 void *r;
2067
2068 logevent("Pageant is running. Requesting keys.");
2069
2070 /* Request the keys held by the agent. */
2071 PUT_32BIT(request, 1);
2072 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2073 agent_query(request, 5, &r, &responselen);
2074 response = (unsigned char *) r;
2075 if (response && responselen >= 5 &&
2076 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2077 p = response + 5;
2078 nkeys = GET_32BIT(p);
2079 p += 4;
2080 {
2081 char buf[64];
2082 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2083 logevent(buf);
2084 }
2085 for (i = 0; i < nkeys; i++) {
2086 static struct RSAKey key;
2087 static Bignum challenge;
2088 static char *commentp;
2089 static int commentlen;
2090
2091 {
2092 char buf[64];
2093 sprintf(buf, "Trying Pageant key #%d", i);
2094 logevent(buf);
2095 }
2096 p += 4;
2097 p += ssh1_read_bignum(p, &key.exponent);
2098 p += ssh1_read_bignum(p, &key.modulus);
2099 commentlen = GET_32BIT(p);
2100 p += 4;
2101 commentp = p;
2102 p += commentlen;
2103 send_packet(SSH1_CMSG_AUTH_RSA,
2104 PKT_BIGNUM, key.modulus, PKT_END);
2105 crWaitUntil(ispkt);
2106 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2107 logevent("Key refused");
2108 continue;
2109 }
2110 logevent("Received RSA challenge");
2111 ssh1_read_bignum(pktin.body, &challenge);
2112 {
2113 char *agentreq, *q, *ret;
2d466ffd 2114 void *vret;
32874aea 2115 int len, retlen;
2116 len = 1 + 4; /* message type, bit count */
2117 len += ssh1_bignum_length(key.exponent);
2118 len += ssh1_bignum_length(key.modulus);
2119 len += ssh1_bignum_length(challenge);
2120 len += 16; /* session id */
2121 len += 4; /* response format */
2122 agentreq = smalloc(4 + len);
2123 PUT_32BIT(agentreq, len);
2124 q = agentreq + 4;
2125 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2126 PUT_32BIT(q, bignum_bitcount(key.modulus));
2127 q += 4;
2128 q += ssh1_write_bignum(q, key.exponent);
2129 q += ssh1_write_bignum(q, key.modulus);
2130 q += ssh1_write_bignum(q, challenge);
2131 memcpy(q, session_id, 16);
2132 q += 16;
2133 PUT_32BIT(q, 1); /* response format */
2d466ffd 2134 agent_query(agentreq, len + 4, &vret, &retlen);
2135 ret = vret;
32874aea 2136 sfree(agentreq);
2137 if (ret) {
2138 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2139 logevent("Sending Pageant's response");
2140 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2141 PKT_DATA, ret + 5, 16,
2142 PKT_END);
2143 sfree(ret);
2144 crWaitUntil(ispkt);
2145 if (pktin.type == SSH1_SMSG_SUCCESS) {
2146 logevent
2147 ("Pageant's response accepted");
2148 if (flags & FLAG_VERBOSE) {
2149 c_write_str
2150 ("Authenticated using RSA key \"");
2151 c_write(commentp, commentlen);
2152 c_write_str("\" from agent\r\n");
2153 }
2154 authed = TRUE;
2155 } else
2156 logevent
2157 ("Pageant's response not accepted");
2158 } else {
2159 logevent
2160 ("Pageant failed to answer challenge");
2161 sfree(ret);
2162 }
2163 } else {
2164 logevent("No reply received from Pageant");
2165 }
2166 }
2167 freebn(key.exponent);
2168 freebn(key.modulus);
2169 freebn(challenge);
2170 if (authed)
2171 break;
2172 }
2173 }
2174 if (authed)
2175 break;
2176 }
2177 if (*cfg.keyfile && !tried_publickey)
2178 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2179
614a20a0 2180 if (cfg.try_tis_auth &&
2181 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2182 !tis_auth_refused) {
32874aea 2183 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2184 logevent("Requested TIS authentication");
2185 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2186 crWaitUntil(ispkt);
2187 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2188 logevent("TIS authentication declined");
2189 if (flags & FLAG_INTERACTIVE)
2190 c_write_str("TIS authentication refused.\r\n");
614a20a0 2191 tis_auth_refused = 1;
2192 continue;
32874aea 2193 } else {
2194 int challengelen = ((pktin.body[0] << 24) |
2195 (pktin.body[1] << 16) |
2196 (pktin.body[2] << 8) |
2197 (pktin.body[3]));
2198 logevent("Received TIS challenge");
2199 if (challengelen > sizeof(prompt) - 1)
2200 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2201 memcpy(prompt, pktin.body + 4, challengelen);
614a20a0 2202 /* Prompt heuristic comes from OpenSSH */
2203 strncpy(prompt + challengelen,
2204 memchr(prompt, '\n', challengelen) ?
2205 "": "\r\nResponse: ",
2206 (sizeof prompt) - challengelen);
2207 prompt[(sizeof prompt) - 1] = '\0';
32874aea 2208 }
2209 }
614a20a0 2210 if (cfg.try_tis_auth &&
2211 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2212 !ccard_auth_refused) {
32874aea 2213 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2214 logevent("Requested CryptoCard authentication");
2215 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2216 crWaitUntil(ispkt);
2217 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2218 logevent("CryptoCard authentication declined");
2219 c_write_str("CryptoCard authentication refused.\r\n");
614a20a0 2220 ccard_auth_refused = 1;
2221 continue;
32874aea 2222 } else {
2223 int challengelen = ((pktin.body[0] << 24) |
2224 (pktin.body[1] << 16) |
2225 (pktin.body[2] << 8) |
2226 (pktin.body[3]));
2227 logevent("Received CryptoCard challenge");
2228 if (challengelen > sizeof(prompt) - 1)
2229 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2230 memcpy(prompt, pktin.body + 4, challengelen);
614a20a0 2231 strncpy(prompt + challengelen,
2232 memchr(prompt, '\n', challengelen) ?
2233 "" : "\r\nResponse: ",
32874aea 2234 sizeof(prompt) - challengelen);
2235 prompt[sizeof(prompt) - 1] = '\0';
2236 }
2237 }
2238 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2239 sprintf(prompt, "%.90s@%.90s's password: ",
2240 username, savedhost);
2241 }
2242 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2243 char *comment = NULL;
2244 if (flags & FLAG_VERBOSE)
2245 c_write_str("Trying public key authentication.\r\n");
2246 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2247 if (flags & FLAG_VERBOSE)
2248 c_write_str("No passphrase required.\r\n");
2249 goto tryauth;
2250 }
2251 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2252 sfree(comment);
2253 }
a52f067e 2254
614a20a0 2255 /*
2256 * Show password prompt, having first obtained it via a TIS
2257 * or CryptoCard exchange if we're doing TIS or CryptoCard
2258 * authentication.
2259 */
fa17a66e 2260 if (ssh_get_line) {
2261 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
32874aea 2262 /*
2263 * get_line failed to get a password (for example
2264 * because one was supplied on the command line
2265 * which has already failed to work). Terminate.
2266 */
2bc6a386 2267 send_packet(SSH1_MSG_DISCONNECT,
2268 PKT_STR, "No more passwords available to try",
2269 PKT_END);
2270 connection_fatal("Unable to authenticate");
32874aea 2271 ssh_state = SSH_STATE_CLOSED;
2272 crReturn(1);
2273 }
fb09bf1c 2274 } else {
614a20a0 2275 /* Prompt may have come from server. We've munged it a bit, so
2276 * we know it to be zero-terminated at least once. */
2277 c_write_untrusted(prompt, strlen(prompt));
32874aea 2278 pos = 0;
2279 ssh_send_ok = 1;
2280 while (pos >= 0) {
2281 crWaitUntil(!ispkt);
2282 while (inlen--)
2283 switch (c = *in++) {
2284 case 10:
2285 case 13:
2286 password[pos] = 0;
2287 pos = -1;
2288 break;
2289 case 8:
2290 case 127:
2291 if (pos > 0)
2292 pos--;
2293 break;
2294 case 21:
2295 case 27:
2296 pos = 0;
2297 break;
2298 case 3:
2299 case 4:
2300 random_save_seed();
2301 exit(0);
2302 break;
2303 default:
51b2fb65 2304 if (pos < sizeof(password)-1)
32874aea 2305 password[pos++] = c;
2306 break;
2307 }
2308 }
2309 c_write_str("\r\n");
2310 }
2311
2312 tryauth:
7cca0d81 2313 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2314 /*
2315 * Try public key authentication with the specified
2316 * key file.
2317 */
2318 static struct RSAKey pubkey;
2319 static Bignum challenge, response;
2320 static int i;
2321 static unsigned char buffer[32];
2322
2323 tried_publickey = 1;
2324 i = loadrsakey(cfg.keyfile, &pubkey, password);
2325 if (i == 0) {
7963af2f 2326 c_write_str("Couldn't load private key from ");
32874aea 2327 c_write_str(cfg.keyfile);
2328 c_write_str(".\r\n");
2329 continue; /* go and try password */
2330 }
2331 if (i == -1) {
2332 c_write_str("Wrong passphrase.\r\n");
2333 tried_publickey = 0;
2334 continue; /* try again */
2335 }
2336
2337 /*
2338 * Send a public key attempt.
2339 */
2340 send_packet(SSH1_CMSG_AUTH_RSA,
2341 PKT_BIGNUM, pubkey.modulus, PKT_END);
2342
2343 crWaitUntil(ispkt);
2344 if (pktin.type == SSH1_SMSG_FAILURE) {
2345 c_write_str("Server refused our public key.\r\n");
2346 continue; /* go and try password */
2347 }
2348 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2349 bombout(("Bizarre response to offer of public key"));
2350 crReturn(0);
2351 }
2352 ssh1_read_bignum(pktin.body, &challenge);
2353 response = rsadecrypt(challenge, &pubkey);
2354 freebn(pubkey.private_exponent); /* burn the evidence */
2355
2356 for (i = 0; i < 32; i++) {
2357 buffer[i] = bignum_byte(response, 31 - i);
2358 }
2359
2360 MD5Init(&md5c);
2361 MD5Update(&md5c, buffer, 32);
2362 MD5Update(&md5c, session_id, 16);
2363 MD5Final(buffer, &md5c);
2364
2365 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2366 PKT_DATA, buffer, 16, PKT_END);
2367
2368 crWaitUntil(ispkt);
2369 if (pktin.type == SSH1_SMSG_FAILURE) {
2370 if (flags & FLAG_VERBOSE)
2371 c_write_str
2372 ("Failed to authenticate with our public key.\r\n");
2373 continue; /* go and try password */
2374 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2375 bombout(
2376 ("Bizarre response to RSA authentication response"));
2377 crReturn(0);
2378 }
2379
2380 break; /* we're through! */
2381 } else {
2382 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2383 /*
2384 * Defence against traffic analysis: we send a
2385 * whole bunch of packets containing strings of
2386 * different lengths. One of these strings is the
2387 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2388 * The others are all random data in
2389 * SSH1_MSG_IGNORE packets. This way a passive
2390 * listener can't tell which is the password, and
2391 * hence can't deduce the password length.
2392 *
2393 * Anybody with a password length greater than 16
2394 * bytes is going to have enough entropy in their
2395 * password that a listener won't find it _that_
2396 * much help to know how long it is. So what we'll
2397 * do is:
2398 *
2399 * - if password length < 16, we send 15 packets
2400 * containing string lengths 1 through 15
2401 *
2402 * - otherwise, we let N be the nearest multiple
2403 * of 8 below the password length, and send 8
2404 * packets containing string lengths N through
2405 * N+7. This won't obscure the order of
2406 * magnitude of the password length, but it will
2407 * introduce a bit of extra uncertainty.
2408 *
2409 * A few servers (the old 1.2.18 through 1.2.22)
2410 * can't deal with SSH1_MSG_IGNORE. For these
2411 * servers, we need an alternative defence. We make
2412 * use of the fact that the password is interpreted
2413 * as a C string: so we can append a NUL, then some
2414 * random data.
bd358db1 2415 *
2416 * One server (a Cisco one) can deal with neither
2417 * SSH1_MSG_IGNORE _nor_ a padded password string.
2418 * For this server we are left with no defences
2419 * against password length sniffing.
32874aea 2420 */
bd358db1 2421 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 2422 /*
2423 * The server can deal with SSH1_MSG_IGNORE, so
2424 * we can use the primary defence.
2425 */
32874aea 2426 int bottom, top, pwlen, i;
2427 char *randomstr;
2428
2429 pwlen = strlen(password);
2430 if (pwlen < 16) {
2431 bottom = 0; /* zero length passwords are OK! :-) */
2432 top = 15;
2433 } else {
2434 bottom = pwlen & ~7;
2435 top = bottom + 7;
2436 }
2437
2438 assert(pwlen >= bottom && pwlen <= top);
2439
2440 randomstr = smalloc(top + 1);
2441
2442 for (i = bottom; i <= top; i++) {
2443 if (i == pwlen)
2444 defer_packet(pwpkt_type, PKT_STR, password,
2445 PKT_END);
2446 else {
2447 for (j = 0; j < i; j++) {
2448 do {
2449 randomstr[j] = random_byte();
2450 } while (randomstr[j] == '\0');
2451 }
2452 randomstr[i] = '\0';
2453 defer_packet(SSH1_MSG_IGNORE,
2454 PKT_STR, randomstr, PKT_END);
2455 }
2456 }
bd358db1 2457 logevent("Sending password with camouflage packets");
32874aea 2458 ssh_pkt_defersend();
bd358db1 2459 }
2460 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 2461 /*
2462 * The server can't deal with SSH1_MSG_IGNORE
2463 * but can deal with padded passwords, so we
2464 * can use the secondary defence.
2465 */
bd358db1 2466 char string[64];
2467 char *s;
2468 int len;
2469
2470 len = strlen(password);
2471 if (len < sizeof(string)) {
2472 s = string;
2473 strcpy(string, password);
2474 len++; /* cover the zero byte */
2475 while (len < sizeof(string)) {
2476 string[len++] = (char) random_byte();
2477 }
2478 } else {
2479 s = password;
2480 }
2481 logevent("Sending length-padded password");
2482 send_packet(pwpkt_type, PKT_INT, len,
2483 PKT_DATA, s, len, PKT_END);
2484 } else {
2485 /*
2486 * The server has _both_
2487 * BUG_CHOKES_ON_SSH1_IGNORE and
2488 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2489 * therefore nothing we can do.
2490 */
2491 int len;
2492 len = strlen(password);
2493 logevent("Sending unpadded password");
2494 send_packet(pwpkt_type, PKT_INT, len,
2495 PKT_DATA, password, len, PKT_END);
32874aea 2496 }
2497 } else {
2498 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2499 }
2500 }
c5e9c988 2501 logevent("Sent password");
374330e2 2502 memset(password, 0, strlen(password));
fb09bf1c 2503 crWaitUntil(ispkt);
e5574168 2504 if (pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2505 if (flags & FLAG_VERBOSE)
2506 c_write_str("Access denied\r\n");
c5e9c988 2507 logevent("Authentication refused");
e5574168 2508 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 2509 logevent("Received disconnect request");
32874aea 2510 ssh_state = SSH_STATE_CLOSED;
85ee8208 2511 crReturn(1);
e5574168 2512 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 2513 bombout(("Strange packet received, type %d", pktin.type));
32874aea 2514 crReturn(0);
374330e2 2515 }
2516 }
2517
c5e9c988 2518 logevent("Authentication successful");
2519
fb09bf1c 2520 crFinish(1);
2521}
2522
32874aea 2523void sshfwd_close(struct ssh_channel *c)
2524{
80e48603 2525 if (c && !c->closes) {
4ed34d25 2526 /*
2527 * If the channel's remoteid is -1, we have sent
2528 * CHANNEL_OPEN for this channel, but it hasn't even been
2529 * acknowledged by the server. So we must set a close flag
2530 * on it now, and then when the server acks the channel
2531 * open, we can close it then.
2532 */
2533 if (c->remoteid != -1) {
2534 if (ssh_version == 1) {
2535 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2536 PKT_END);
2537 } else {
2538 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2539 ssh2_pkt_adduint32(c->remoteid);
2540 ssh2_pkt_send();
2541 }
32874aea 2542 }
2543 c->closes = 1;
2544 if (c->type == CHAN_X11) {
2545 c->u.x11.s = NULL;
d74d141c 2546 logevent("Forwarded X11 connection terminated");
4ed34d25 2547 } else if (c->type == CHAN_SOCKDATA ||
2548 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 2549 c->u.pfd.s = NULL;
2550 logevent("Forwarded port closed");
32874aea 2551 }
2552 }
2553}
2554
5471d09a 2555int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 2556{
783415f8 2557 if (ssh_version == 1) {
32874aea 2558 send_packet(SSH1_MSG_CHANNEL_DATA,
2559 PKT_INT, c->remoteid,
2560 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 2561 /*
2562 * In SSH1 we can return 0 here - implying that forwarded
2563 * connections are never individually throttled - because
2564 * the only circumstance that can cause throttling will be
2565 * the whole SSH connection backing up, in which case
2566 * _everything_ will be throttled as a whole.
2567 */
2568 return 0;
783415f8 2569 } else {
32874aea 2570 ssh2_add_channel_data(c, buf, len);
5471d09a 2571 return ssh2_try_send(c);
2572 }
2573}
2574
2575void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2576{
2577 if (ssh_version == 1) {
2578 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2579 c->v.v1.throttling = 0;
2580 ssh1_throttle(-1);
2581 }
2582 } else {
2583 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 2584 }
9c964e85 2585}
2586
32874aea 2587static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2588{
fb09bf1c 2589 crBegin;
2590
2591 random_init();
2592
e5574168 2593 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 2594 crReturnV;
85ee8208 2595 }
2596 if (ssh_state == SSH_STATE_CLOSED)
32874aea 2597 crReturnV;
fb09bf1c 2598
979310f1 2599 if (cfg.agentfwd && agent_exists()) {
32874aea 2600 logevent("Requesting agent forwarding");
2601 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2602 do {
2603 crReturnV;
2604 } while (!ispkt);
2605 if (pktin.type != SSH1_SMSG_SUCCESS
2606 && pktin.type != SSH1_SMSG_FAILURE) {
2607 bombout(("Protocol confusion"));
2608 crReturnV;
2609 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2610 logevent("Agent forwarding refused");
2611 } else {
2612 logevent("Agent forwarding enabled");
db7d555c 2613 ssh_agentfwd_enabled = TRUE;
2614 }
dacbd0e8 2615 }
2616
9c964e85 2617 if (cfg.x11_forward) {
32874aea 2618 char proto[20], data[64];
2619 logevent("Requesting X11 forwarding");
2620 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2621 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2622 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2623 PKT_STR, proto, PKT_STR, data,
2624 PKT_INT, 0, PKT_END);
2625 } else {
2626 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2627 PKT_STR, proto, PKT_STR, data, PKT_END);
2628 }
2629 do {
2630 crReturnV;
2631 } while (!ispkt);
2632 if (pktin.type != SSH1_SMSG_SUCCESS
2633 && pktin.type != SSH1_SMSG_FAILURE) {
2634 bombout(("Protocol confusion"));
2635 crReturnV;
2636 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2637 logevent("X11 forwarding refused");
2638 } else {
2639 logevent("X11 forwarding enabled");
9c964e85 2640 ssh_X11_fwd_enabled = TRUE;
2641 }
2642 }
2643
d74d141c 2644 {
2645 char type, *e;
2646 int n;
2647 int sport,dport;
2648 char sports[256], dports[256], host[256];
2649 char buf[1024];
2650
bc240b21 2651 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 2652 /* Add port forwardings. */
2653 e = cfg.portfwd;
2654 while (*e) {
2655 type = *e++;
2656 n = 0;
2657 while (*e && *e != '\t')
2658 sports[n++] = *e++;
2659 sports[n] = 0;
2660 if (*e == '\t')
2661 e++;
2662 n = 0;
2663 while (*e && *e != ':')
2664 host[n++] = *e++;
2665 host[n] = 0;
2666 if (*e == ':')
2667 e++;
2668 n = 0;
2669 while (*e)
2670 dports[n++] = *e++;
2671 dports[n] = 0;
2672 e++;
2673 dport = atoi(dports);
2674 sport = atoi(sports);
2675 if (sport && dport) {
2676 if (type == 'L') {
2677 pfd_addforward(host, dport, sport);
2678 sprintf(buf, "Local port %d forwarding to %s:%d",
2679 sport, host, dport);
2680 logevent(buf);
2681 } else {
2682 struct ssh_rportfwd *pf;
2683 pf = smalloc(sizeof(*pf));
bc240b21 2684 strcpy(pf->dhost, host);
2685 pf->dport = dport;
d74d141c 2686 if (add234(ssh_rportfwds, pf) != pf) {
2687 sprintf(buf,
95bc8819 2688 "Duplicate remote port forwarding to %s:%d",
d74d141c 2689 host, dport);
2690 logevent(buf);
bc240b21 2691 sfree(pf);
d74d141c 2692 } else {
2693 sprintf(buf, "Requesting remote port %d forward to %s:%d",
2694 sport, host, dport);
2695 logevent(buf);
2696 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
2697 PKT_INT, sport,
2698 PKT_STR, host,
2699 PKT_INT, dport,
2700 PKT_END);
2701 }
2702 }
2703 }
2704 }
2705 }
2706
fef97f43 2707 if (!cfg.nopty) {
e5574168 2708 send_packet(SSH1_CMSG_REQUEST_PTY,
32874aea 2709 PKT_STR, cfg.termtype,
2710 PKT_INT, rows, PKT_INT, cols,
2711 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2712 ssh_state = SSH_STATE_INTERMED;
2713 do {
2714 crReturnV;
2715 } while (!ispkt);
2716 if (pktin.type != SSH1_SMSG_SUCCESS
2717 && pktin.type != SSH1_SMSG_FAILURE) {
2718 bombout(("Protocol confusion"));
2719 crReturnV;
2720 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2721 c_write_str("Server refused to allocate pty\r\n");
2722 ssh_editing = ssh_echoing = 1;
2723 }
c5e9c988 2724 logevent("Allocated pty");
0965bee0 2725 } else {
32874aea 2726 ssh_editing = ssh_echoing = 1;
374330e2 2727 }
2728
4ba9b64b 2729 if (cfg.compression) {
32874aea 2730 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2731 do {
2732 crReturnV;
2733 } while (!ispkt);
2734 if (pktin.type != SSH1_SMSG_SUCCESS
2735 && pktin.type != SSH1_SMSG_FAILURE) {
2736 bombout(("Protocol confusion"));
2737 crReturnV;
2738 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2739 c_write_str("Server refused to compress\r\n");
2740 }
4ba9b64b 2741 logevent("Started compression");
2742 ssh1_compressing = TRUE;
2743 zlib_compress_init();
2744 zlib_decompress_init();
2745 }
2746
fd5e5847 2747 /*
2748 * Start the shell or command.
2749 *
2750 * Special case: if the first-choice command is an SSH2
2751 * subsystem (hence not usable here) and the second choice
2752 * exists, we fall straight back to that.
2753 */
2754 {
2755 char *cmd = cfg.remote_cmd_ptr;
2756
2757 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
2758 cmd = cfg.remote_cmd_ptr2;
2759 ssh_fallback_cmd = TRUE;
2760 }
2761 if (*cmd)
2762 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
2763 else
2764 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2765 logevent("Started session");
2766 }
374330e2 2767
2768 ssh_state = SSH_STATE_SESSION;
2769 if (size_needed)
2770 ssh_size();
3687d221 2771 if (eof_needed)
32874aea 2772 ssh_special(TS_EOF);
374330e2 2773
760e88b2 2774 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
8ccc75b0 2775 ssh_send_ok = 1;
dacbd0e8 2776 ssh_channels = newtree234(ssh_channelcmp);
374330e2 2777 while (1) {
2778 crReturnV;
2779 if (ispkt) {
e5574168 2780 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
32874aea 2781 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 2782 long len = GET_32BIT(pktin.body);
5471d09a 2783 int bufsize =
2784 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2785 pktin.body + 4, len);
90347b95 2786 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 2787 ssh1_stdout_throttling = 1;
2788 ssh1_throttle(+1);
2789 }
e5574168 2790 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
32874aea 2791 ssh_state = SSH_STATE_CLOSED;
c5e9c988 2792 logevent("Received disconnect request");
32874aea 2793 crReturnV;
2794 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2795 /* Remote side is trying to open a channel to talk to our
2796 * X-Server. Give them back a local channel number. */
2797 struct ssh_channel *c;
9c964e85 2798
2799 logevent("Received X11 connect request");
2800 /* Refuse if X11 forwarding is disabled. */
2801 if (!ssh_X11_fwd_enabled) {
2802 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 2803 PKT_INT, GET_32BIT(pktin.body), PKT_END);
9c964e85 2804 logevent("Rejected X11 connect request");
2805 } else {
9c964e85 2806 c = smalloc(sizeof(struct ssh_channel));
2807
32874aea 2808 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2809 logevent("opening X11 forward connection failed");
2810 sfree(c);
2811 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2812 PKT_INT, GET_32BIT(pktin.body),
2813 PKT_END);
9c964e85 2814 } else {
32874aea 2815 logevent
2816 ("opening X11 forward connection succeeded");
2817 c->remoteid = GET_32BIT(pktin.body);
2818 c->localid = alloc_channel_id();
2819 c->closes = 0;
5471d09a 2820 c->v.v1.throttling = 0;
32874aea 2821 c->type = CHAN_X11; /* identify channel type */
2822 add234(ssh_channels, c);
2823 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2824 PKT_INT, c->remoteid, PKT_INT,
2825 c->localid, PKT_END);
2826 logevent("Opened X11 forward channel");
9c964e85 2827 }
2828 }
32874aea 2829 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2830 /* Remote side is trying to open a channel to talk to our
2831 * agent. Give them back a local channel number. */
2832 struct ssh_channel *c;
db7d555c 2833
2834 /* Refuse if agent forwarding is disabled. */
2835 if (!ssh_agentfwd_enabled) {
2836 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
32874aea 2837 PKT_INT, GET_32BIT(pktin.body), PKT_END);
db7d555c 2838 } else {
dcbde236 2839 c = smalloc(sizeof(struct ssh_channel));
db7d555c 2840 c->remoteid = GET_32BIT(pktin.body);
d2371c81 2841 c->localid = alloc_channel_id();
db7d555c 2842 c->closes = 0;
5471d09a 2843 c->v.v1.throttling = 0;
32874aea 2844 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 2845 c->u.a.lensofar = 0;
2846 add234(ssh_channels, c);
2847 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2848 PKT_INT, c->remoteid, PKT_INT, c->localid,
2849 PKT_END);
2850 }
d74d141c 2851 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
2852 /* Remote side is trying to open a channel to talk to a
2853 * forwarded port. Give them back a local channel number. */
2854 struct ssh_channel *c;
2855 struct ssh_rportfwd pf;
2856 int hostsize, port;
2857 char host[256], buf[1024];
2858 char *p, *h, *e;
2859 c = smalloc(sizeof(struct ssh_channel));
2860
2861 hostsize = GET_32BIT(pktin.body+4);
2862 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
2863 if (h+1 < host+sizeof(host))
2864 *h++ = *p;
95bc8819 2865 p++;
d74d141c 2866 }
2867 *h = 0;
2868 port = GET_32BIT(p);
2869
bc240b21 2870 strcpy(pf.dhost, host);
2871 pf.dport = port;
d74d141c 2872
2873 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
2874 sprintf(buf, "Rejected remote port open request for %s:%d",
2875 host, port);
2876 logevent(buf);
2877 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2878 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2879 } else {
2880 sprintf(buf, "Received remote port open request for %s:%d",
2881 host, port);
2882 logevent(buf);
2883 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
2884 if (e != NULL) {
2885 char buf[256];
2886 sprintf(buf, "Port open failed: %s", e);
2887 logevent(buf);
2888 sfree(c);
2889 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2890 PKT_INT, GET_32BIT(pktin.body),
2891 PKT_END);
2892 } else {
2893 c->remoteid = GET_32BIT(pktin.body);
2894 c->localid = alloc_channel_id();
2895 c->closes = 0;
5471d09a 2896 c->v.v1.throttling = 0;
d74d141c 2897 c->type = CHAN_SOCKDATA; /* identify channel type */
2898 add234(ssh_channels, c);
2899 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2900 PKT_INT, c->remoteid, PKT_INT,
2901 c->localid, PKT_END);
2902 logevent("Forwarded port opened successfully");
2903 }
2904 }
2905
2906 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
bc240b21 2907 unsigned int remoteid = GET_32BIT(pktin.body);
2908 unsigned int localid = GET_32BIT(pktin.body+4);
2909 struct ssh_channel *c;
2910
2911 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2912 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2913 c->remoteid = localid;
2914 c->type = CHAN_SOCKDATA;
7781f316 2915 c->v.v1.throttling = 0;
bc240b21 2916 pfd_confirm(c->u.pfd.s);
2917 }
d74d141c 2918
4ed34d25 2919 if (c && c->closes) {
2920 /*
2921 * We have a pending close on this channel,
2922 * which we decided on before the server acked
2923 * the channel open. So now we know the
2924 * remoteid, we can close it again.
2925 */
2926 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2927 PKT_END);
2928 }
2929
724cface 2930 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
2931 unsigned int remoteid = GET_32BIT(pktin.body);
2932 unsigned int localid = GET_32BIT(pktin.body+4);
2933 struct ssh_channel *c;
2934
2935 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2936 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2937 logevent("Forwarded connection refused by server");
2938 pfd_close(c->u.pfd.s);
2939 del234(ssh_channels, c);
2940 sfree(c);
2941 }
2942
db7d555c 2943 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
2944 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 2945 /* Remote side closes a channel. */
2946 unsigned i = GET_32BIT(pktin.body);
2947 struct ssh_channel *c;
2948 c = find234(ssh_channels, &i, ssh_channelfind);
2949 if (c) {
2950 int closetype;
2951 closetype =
2952 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
2953 if (!(c->closes & closetype))
2954 send_packet(pktin.type, PKT_INT, c->remoteid,
2955 PKT_END);
783415f8 2956 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 2957 logevent("Forwarded X11 connection terminated");
9c964e85 2958 assert(c->u.x11.s != NULL);
2959 x11_close(c->u.x11.s);
2960 c->u.x11.s = NULL;
2961 }
d74d141c 2962 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
2963 logevent("Forwarded port closed");
2964 assert(c->u.pfd.s != NULL);
2965 pfd_close(c->u.pfd.s);
2966 c->u.pfd.s = NULL;
2967 }
32874aea 2968 c->closes |= closetype;
2969 if (c->closes == 3) {
2970 del234(ssh_channels, c);
2971 sfree(c);
2972 }
2973 }
2974 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
2975 /* Data sent down one of our channels. */
2976 int i = GET_32BIT(pktin.body);
2977 int len = GET_32BIT(pktin.body + 4);
2978 unsigned char *p = pktin.body + 8;
2979 struct ssh_channel *c;
2980 c = find234(ssh_channels, &i, ssh_channelfind);
2981 if (c) {
5471d09a 2982 int bufsize;
32874aea 2983 switch (c->type) {
2984 case CHAN_X11:
5471d09a 2985 bufsize = x11_send(c->u.x11.s, p, len);
9c964e85 2986 break;
d74d141c 2987 case CHAN_SOCKDATA:
5471d09a 2988 bufsize = pfd_send(c->u.pfd.s, p, len);
bc240b21 2989 break;
32874aea 2990 case CHAN_AGENT:
2991 /* Data for an agent message. Buffer it. */
2992 while (len > 0) {
2993 if (c->u.a.lensofar < 4) {
2994 int l = min(4 - c->u.a.lensofar, len);
2995 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
2996 l);
2997 p += l;
2998 len -= l;
2999 c->u.a.lensofar += l;
3000 }
3001 if (c->u.a.lensofar == 4) {
3002 c->u.a.totallen =
3003 4 + GET_32BIT(c->u.a.msglen);
3004 c->u.a.message = smalloc(c->u.a.totallen);
3005 memcpy(c->u.a.message, c->u.a.msglen, 4);
3006 }
3007 if (c->u.a.lensofar >= 4 && len > 0) {
3008 int l =
3009 min(c->u.a.totallen - c->u.a.lensofar,
3010 len);
3011 memcpy(c->u.a.message + c->u.a.lensofar, p,
3012 l);
3013 p += l;
3014 len -= l;
3015 c->u.a.lensofar += l;
3016 }
3017 if (c->u.a.lensofar == c->u.a.totallen) {
3018 void *reply, *sentreply;
3019 int replylen;
3020 agent_query(c->u.a.message,
3021 c->u.a.totallen, &reply,
3022 &replylen);
3023 if (reply)
3024 sentreply = reply;
3025 else {
3026 /* Fake SSH_AGENT_FAILURE. */
3027 sentreply = "\0\0\0\1\5";
3028 replylen = 5;
3029 }
3030 send_packet(SSH1_MSG_CHANNEL_DATA,
3031 PKT_INT, c->remoteid,
3032 PKT_INT, replylen,
3033 PKT_DATA, sentreply, replylen,
3034 PKT_END);
3035 if (reply)
3036 sfree(reply);
3037 sfree(c->u.a.message);
3038 c->u.a.lensofar = 0;
3039 }
3040 }
5471d09a 3041 bufsize = 0; /* agent channels never back up */
32874aea 3042 break;
3043 }
90347b95 3044 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3045 c->v.v1.throttling = 1;
3046 ssh1_throttle(+1);
3047 }
32874aea 3048 }
e5574168 3049 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 3050 /* may be from EXEC_SHELL on some servers */
e5574168 3051 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 3052 /* may be from EXEC_SHELL on some servers
374330e2 3053 * if no pty is available or in other odd cases. Ignore */
e5574168 3054 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
3055 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 3056 /*
3057 * In case `helpful' firewalls or proxies tack
3058 * extra human-readable text on the end of the
3059 * session which we might mistake for another
3060 * encrypted packet, we close the session once
3061 * we've sent EXIT_CONFIRMATION.
3062 */
3063 ssh_state = SSH_STATE_CLOSED;
3064 crReturnV;
374330e2 3065 } else {
8d5de777 3066 bombout(("Strange packet received: type %d", pktin.type));
32874aea 3067 crReturnV;
374330e2 3068 }
3069 } else {
8df7a775 3070 while (inlen > 0) {
3071 int len = min(inlen, 512);
3072 send_packet(SSH1_CMSG_STDIN_DATA,
3073 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3074 in += len;
3075 inlen -= len;
3076 }
374330e2 3077 }
3078 }
3079
3080 crFinishV;
3081}
3082
3083/*
e5574168 3084 * Utility routine for decoding comma-separated strings in KEXINIT.
3085 */
32874aea 3086static int in_commasep_string(char *needle, char *haystack, int haylen)
3087{
e5574168 3088 int needlen = strlen(needle);
3089 while (1) {
32874aea 3090 /*
3091 * Is it at the start of the string?
3092 */
3093 if (haylen >= needlen && /* haystack is long enough */
3094 !memcmp(needle, haystack, needlen) && /* initial match */
3095 (haylen == needlen || haystack[needlen] == ',')
3096 /* either , or EOS follows */
3097 )
3098 return 1;
3099 /*
3100 * If not, search for the next comma and resume after that.
3101 * If no comma found, terminate.
3102 */
3103 while (haylen > 0 && *haystack != ',')
3104 haylen--, haystack++;
3105 if (haylen == 0)
3106 return 0;
3107 haylen--, haystack++; /* skip over comma itself */
e5574168 3108 }
3109}
3110
3111/*
d39f364a 3112 * SSH2 key creation method.
3113 */
32874aea 3114static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3115 char *keyspace)
3116{
d39f364a 3117 SHA_State s;
3118 /* First 20 bytes. */
3119 SHA_Init(&s);
3120 sha_mpint(&s, K);
3121 SHA_Bytes(&s, H, 20);
3122 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 3123 SHA_Bytes(&s, sessid, 20);
d39f364a 3124 SHA_Final(&s, keyspace);
3125 /* Next 20 bytes. */
3126 SHA_Init(&s);
3127 sha_mpint(&s, K);
3128 SHA_Bytes(&s, H, 20);
3129 SHA_Bytes(&s, keyspace, 20);
32874aea 3130 SHA_Final(&s, keyspace + 20);
d39f364a 3131}
3132
3133/*
7cca0d81 3134 * Handle the SSH2 transport layer.
e5574168 3135 */
7cca0d81 3136static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 3137{
ca20bfcf 3138 static int i, j, len, nbits, pbits, warn;
e5574168 3139 static char *str;
a92dd380 3140 static Bignum p, g, e, f, K;
3141 static int kex_init_value, kex_reply_value;
7591b9ff 3142 static const struct ssh_mac **maclist;
8b2715b2 3143 static int nmacs;
0a3f1d48 3144 static const struct ssh2_cipher *cscipher_tobe = NULL;
3145 static const struct ssh2_cipher *sccipher_tobe = NULL;
57476f6b 3146 static const struct ssh_mac *csmac_tobe = NULL;
3147 static const struct ssh_mac *scmac_tobe = NULL;
3148 static const struct ssh_compress *cscomp_tobe = NULL;
3149 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 3150 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 3151 static int hostkeylen, siglen;
e055a386 3152 static void *hkey; /* actual host key */
e5574168 3153 static unsigned char exchange_hash[20];
d39f364a 3154 static unsigned char keyspace[40];
ca20bfcf 3155 static int n_preferred_ciphers;
3156 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4ba9b64b 3157 static const struct ssh_compress *preferred_comp;
0db56f73 3158 static int first_kex;
e5574168 3159
3160 crBegin;
7cca0d81 3161 random_init();
0db56f73 3162 first_kex = 1;
e5574168 3163
5e8358ad 3164 /*
ca20bfcf 3165 * Set up the preferred ciphers. (NULL => warn below here)
5e8358ad 3166 */
ca20bfcf 3167 n_preferred_ciphers = 0;
3168 for (i = 0; i < CIPHER_MAX; i++) {
3169 switch (cfg.ssh_cipherlist[i]) {
3170 case CIPHER_BLOWFISH:
3171 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3172 n_preferred_ciphers++;
3173 break;
3174 case CIPHER_DES:
3175 /* Not supported in SSH2; silently drop */
3176 break;
3177 case CIPHER_3DES:
3178 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3179 n_preferred_ciphers++;
3180 break;
3181 case CIPHER_AES:
3182 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3183 n_preferred_ciphers++;
3184 break;
3185 case CIPHER_WARN:
3186 /* Flag for later. Don't bother if it's the last in
3187 * the list. */
3188 if (i < CIPHER_MAX - 1) {
3189 preferred_ciphers[n_preferred_ciphers] = NULL;
3190 n_preferred_ciphers++;
3191 }
3192 break;
3193 }
5e8358ad 3194 }
ca20bfcf 3195
3196 /*
3197 * Set up preferred compression.
3198 */
4ba9b64b 3199 if (cfg.compression)
3200 preferred_comp = &ssh_zlib;
3201 else
3202 preferred_comp = &ssh_comp_none;
5e8358ad 3203
7591b9ff 3204 /*
3205 * Be prepared to work around the buggy MAC problem.
3206 */
7d503c31 3207 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
32874aea 3208 maclist = buggymacs, nmacs = lenof(buggymacs);
7591b9ff 3209 else
32874aea 3210 maclist = macs, nmacs = lenof(macs);
7591b9ff 3211
32874aea 3212 begin_key_exchange:
e5574168 3213 /*
3214 * Construct and send our key exchange packet.
3215 */
3216 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3217 for (i = 0; i < 16; i++)
32874aea 3218 ssh2_pkt_addbyte((unsigned char) random_byte());
e5574168 3219 /* List key exchange algorithms. */
3220 ssh2_pkt_addstring_start();
3221 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 3222 ssh2_pkt_addstring_str(kex_algs[i]->name);
3223 if (i < lenof(kex_algs) - 1)
3224 ssh2_pkt_addstring_str(",");
e5574168 3225 }
3226 /* List server host key algorithms. */
3227 ssh2_pkt_addstring_start();
3228 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3229 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3230 if (i < lenof(hostkey_algs) - 1)
3231 ssh2_pkt_addstring_str(",");
e5574168 3232 }
3233 /* List client->server encryption algorithms. */
3234 ssh2_pkt_addstring_start();
ca20bfcf 3235 for (i = 0; i < n_preferred_ciphers; i++) {
3236 const struct ssh2_ciphers *c = preferred_ciphers[i];
3237 if (!c) continue; /* warning flag */
32874aea 3238 for (j = 0; j < c->nciphers; j++) {
3239 ssh2_pkt_addstring_str(c->list[j]->name);
ca20bfcf 3240 if (i < n_preferred_ciphers || j < c->nciphers - 1)
32874aea 3241 ssh2_pkt_addstring_str(",");
3242 }
e5574168 3243 }
3244 /* List server->client encryption algorithms. */
3245 ssh2_pkt_addstring_start();
ca20bfcf 3246 for (i = 0; i < n_preferred_ciphers; i++) {
3247 const struct ssh2_ciphers *c = preferred_ciphers[i];
3248 if (!c) continue; /* warning flag */
32874aea 3249 for (j = 0; j < c->nciphers; j++) {
3250 ssh2_pkt_addstring_str(c->list[j]->name);
ca20bfcf 3251 if (i < n_preferred_ciphers || j < c->nciphers - 1)
32874aea 3252 ssh2_pkt_addstring_str(",");
3253 }
e5574168 3254 }
3255 /* List client->server MAC algorithms. */
3256 ssh2_pkt_addstring_start();
8b2715b2 3257 for (i = 0; i < nmacs; i++) {
32874aea 3258 ssh2_pkt_addstring_str(maclist[i]->name);
3259 if (i < nmacs - 1)
3260 ssh2_pkt_addstring_str(",");
e5574168 3261 }
3262 /* List server->client MAC algorithms. */
3263 ssh2_pkt_addstring_start();
8b2715b2 3264 for (i = 0; i < nmacs; i++) {
32874aea 3265 ssh2_pkt_addstring_str(maclist[i]->name);
3266 if (i < nmacs - 1)
3267 ssh2_pkt_addstring_str(",");
e5574168 3268 }
3269 /* List client->server compression algorithms. */
3270 ssh2_pkt_addstring_start();
32874aea 3271 for (i = 0; i < lenof(compressions) + 1; i++) {
3272 const struct ssh_compress *c =
3273 i == 0 ? preferred_comp : compressions[i - 1];
3274 ssh2_pkt_addstring_str(c->name);
3275 if (i < lenof(compressions))
3276 ssh2_pkt_addstring_str(",");
e5574168 3277 }
3278 /* List server->client compression algorithms. */
3279 ssh2_pkt_addstring_start();
32874aea 3280 for (i = 0; i < lenof(compressions) + 1; i++) {
3281 const struct ssh_compress *c =
3282 i == 0 ? preferred_comp : compressions[i - 1];
3283 ssh2_pkt_addstring_str(c->name);
3284 if (i < lenof(compressions))
3285 ssh2_pkt_addstring_str(",");
e5574168 3286 }
3287 /* List client->server languages. Empty list. */
3288 ssh2_pkt_addstring_start();
3289 /* List server->client languages. Empty list. */
3290 ssh2_pkt_addstring_start();
3291 /* First KEX packet does _not_ follow, because we're not that brave. */
3292 ssh2_pkt_addbool(FALSE);
3293 /* Reserved. */
3294 ssh2_pkt_adduint32(0);
0db56f73 3295
3296 exhash = exhashbase;
32874aea 3297 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
0db56f73 3298
e5574168 3299 ssh2_pkt_send();
3300
32874aea 3301 if (!ispkt)
3302 crWaitUntil(ispkt);
3303 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
e5574168 3304
3305 /*
3306 * Now examine the other side's KEXINIT to see what we're up
3307 * to.
3308 */
7cca0d81 3309 if (pktin.type != SSH2_MSG_KEXINIT) {
32874aea 3310 bombout(("expected key exchange packet from server"));
3311 crReturn(0);
7cca0d81 3312 }
32874aea 3313 kex = NULL;
3314 hostkey = NULL;
3315 cscipher_tobe = NULL;
3316 sccipher_tobe = NULL;
3317 csmac_tobe = NULL;
3318 scmac_tobe = NULL;
3319 cscomp_tobe = NULL;
3320 sccomp_tobe = NULL;
3321 pktin.savedpos += 16; /* skip garbage cookie */
e5574168 3322 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3323 for (i = 0; i < lenof(kex_algs); i++) {
32874aea 3324 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3325 kex = kex_algs[i];
3326 break;
3327 }
e5574168 3328 }
3329 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3330 for (i = 0; i < lenof(hostkey_algs); i++) {
32874aea 3331 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3332 hostkey = hostkey_algs[i];
3333 break;
3334 }
e5574168 3335 }
3336 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
ca20bfcf 3337 warn = 0;
3338 for (i = 0; i < n_preferred_ciphers; i++) {
3339 const struct ssh2_ciphers *c = preferred_ciphers[i];
3340 if (!c) {
3341 warn = 1;
3342 } else {
3343 for (j = 0; j < c->nciphers; j++) {
3344 if (in_commasep_string(c->list[j]->name, str, len)) {
3345 cscipher_tobe = c->list[j];
3346 break;
3347 }
32874aea 3348 }
3349 }
ca20bfcf 3350 if (cscipher_tobe) {
3351 if (warn)
3352 askcipher(cscipher_tobe->name, 1);
32874aea 3353 break;
ca20bfcf 3354 }
e5574168 3355 }
3356 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
ca20bfcf 3357 warn = 0;
3358 for (i = 0; i < n_preferred_ciphers; i++) {
3359 const struct ssh2_ciphers *c = preferred_ciphers[i];
3360 if (!c) {
3361 warn = 1;
3362 } else {
3363 for (j = 0; j < c->nciphers; j++) {
3364 if (in_commasep_string(c->list[j]->name, str, len)) {
3365 sccipher_tobe = c->list[j];
3366 break;
3367 }
32874aea 3368 }
3369 }
ca20bfcf 3370 if (sccipher_tobe) {
3371 if (warn)
3372 askcipher(sccipher_tobe->name, 2);
32874aea 3373 break;
ca20bfcf 3374 }
e5574168 3375 }
3376 ssh2_pkt_getstring(&str, &len); /* client->server mac */
8b2715b2 3377 for (i = 0; i < nmacs; i++) {
32874aea 3378 if (in_commasep_string(maclist[i]->name, str, len)) {
3379 csmac_tobe = maclist[i];
3380 break;
3381 }
e5574168 3382 }
3383 ssh2_pkt_getstring(&str, &len); /* server->client mac */
8b2715b2 3384 for (i = 0; i < nmacs; i++) {
32874aea 3385 if (in_commasep_string(maclist[i]->name, str, len)) {
3386 scmac_tobe = maclist[i];
3387 break;
3388 }
e5574168 3389 }
3390 ssh2_pkt_getstring(&str, &len); /* client->server compression */
32874aea 3391 for (i = 0; i < lenof(compressions) + 1; i++) {
3392 const struct ssh_compress *c =
3393 i == 0 ? preferred_comp : compressions[i - 1];
3394 if (in_commasep_string(c->name, str, len)) {
3395 cscomp_tobe = c;
3396 break;
3397 }
e5574168 3398 }
3399 ssh2_pkt_getstring(&str, &len); /* server->client compression */
32874aea 3400 for (i = 0; i < lenof(compressions) + 1; i++) {
3401 const struct ssh_compress *c =
3402 i == 0 ? preferred_comp : compressions[i - 1];
3403 if (in_commasep_string(c->name, str, len)) {
3404 sccomp_tobe = c;
3405 break;
3406 }
e5574168 3407 }
e5574168 3408
3409 /*
7bd5a860 3410 * Work out the number of bits of key we will need from the key
3411 * exchange. We start with the maximum key length of either
3412 * cipher...
3413 */
3414 {
32874aea 3415 int csbits, scbits;
7bd5a860 3416
3417 csbits = cscipher_tobe->keylen;
3418 scbits = sccipher_tobe->keylen;
3419 nbits = (csbits > scbits ? csbits : scbits);
3420 }
3421 /* The keys only have 160-bit entropy, since they're based on
3422 * a SHA-1 hash. So cap the key size at 160 bits. */
32874aea 3423 if (nbits > 160)
3424 nbits = 160;
7bd5a860 3425
3426 /*
a92dd380 3427 * If we're doing Diffie-Hellman group exchange, start by
3428 * requesting a group.
e5574168 3429 */
a92dd380 3430 if (kex == &ssh_diffiehellman_gex) {
32874aea 3431 logevent("Doing Diffie-Hellman group exchange");
3432 /*
3433 * Work out how big a DH group we will need to allow that
3434 * much data.
7bd5a860 3435 */
32874aea 3436 pbits = 512 << ((nbits - 1) / 64);
3437 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3438 ssh2_pkt_adduint32(pbits);
3439 ssh2_pkt_send();
3440
3441 crWaitUntil(ispkt);
3442 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3443 bombout(("expected key exchange group packet from server"));
3444 crReturn(0);
3445 }
3446 p = ssh2_pkt_getmp();
3447 g = ssh2_pkt_getmp();
3448 dh_setup_group(p, g);
3449 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3450 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 3451 } else {
32874aea 3452 dh_setup_group1();
3453 kex_init_value = SSH2_MSG_KEXDH_INIT;
3454 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 3455 }
e5574168 3456
a92dd380 3457 logevent("Doing Diffie-Hellman key exchange");
e5574168 3458 /*
a92dd380 3459 * Now generate and send e for Diffie-Hellman.
e5574168 3460 */
32874aea 3461 e = dh_create_e(nbits * 2);
a92dd380 3462 ssh2_pkt_init(kex_init_value);
e5574168 3463 ssh2_pkt_addmp(e);
3464 ssh2_pkt_send();
3465
3466 crWaitUntil(ispkt);
a92dd380 3467 if (pktin.type != kex_reply_value) {
32874aea 3468 bombout(("expected key exchange reply packet from server"));
3469 crReturn(0);
7cca0d81 3470 }
e5574168 3471 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3472 f = ssh2_pkt_getmp();
e5574168 3473 ssh2_pkt_getstring(&sigdata, &siglen);
3474
3475 K = dh_find_K(f);
e5574168 3476
3477 sha_string(&exhash, hostkeydata, hostkeylen);
a92dd380 3478 if (kex == &ssh_diffiehellman_gex) {
32874aea 3479 sha_uint32(&exhash, pbits);
3480 sha_mpint(&exhash, p);
3481 sha_mpint(&exhash, g);
a92dd380 3482 }
e5574168 3483 sha_mpint(&exhash, e);
3484 sha_mpint(&exhash, f);
3485 sha_mpint(&exhash, K);
3486 SHA_Final(&exhash, exchange_hash);
3487
3709bfe9 3488 dh_cleanup();
3489
7cca0d81 3490#if 0
765c4200 3491 debug(("Exchange hash is:\n"));
3492 dmemdump(exchange_hash, 20);
7cca0d81 3493#endif
3494
e055a386 3495 hkey = hostkey->newkey(hostkeydata, hostkeylen);
f7259d10 3496 if (!hkey ||
3497 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3498 bombout(("Server's host key did not match the signature supplied"));
32874aea 3499 crReturn(0);
8d5de777 3500 }
e5574168 3501
3502 /*
7cca0d81 3503 * Authenticate remote host: verify host key. (We've already
3504 * checked the signature of the exchange hash.)
e5574168 3505 */
e055a386 3506 keystr = hostkey->fmtkey(hkey);
3507 fingerprint = hostkey->fingerprint(hkey);
d4857987 3508 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
32874aea 3509 keystr, fingerprint);
3510 if (first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 3511 logevent("Host key fingerprint is:");
3512 logevent(fingerprint);
3513 }
dcbde236 3514 sfree(fingerprint);
3515 sfree(keystr);
e055a386 3516 hostkey->freekey(hkey);
d39f364a 3517
3518 /*
7cca0d81 3519 * Send SSH2_MSG_NEWKEYS.
d39f364a 3520 */
3521 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3522 ssh2_pkt_send();
d39f364a 3523
3524 /*
8406eaf9 3525 * Expect SSH2_MSG_NEWKEYS from server.
3526 */
3527 crWaitUntil(ispkt);
3528 if (pktin.type != SSH2_MSG_NEWKEYS) {
3529 bombout(("expected new-keys packet from server"));
3530 crReturn(0);
3531 }
3532
3533 /*
d39f364a 3534 * Create and initialise session keys.
3535 */
3536 cscipher = cscipher_tobe;
3537 sccipher = sccipher_tobe;
3538 csmac = csmac_tobe;
3539 scmac = scmac_tobe;
3540 cscomp = cscomp_tobe;
3541 sccomp = sccomp_tobe;
4ba9b64b 3542 cscomp->compress_init();
3543 sccomp->decompress_init();
d39f364a 3544 /*
5e0d7cb8 3545 * Set IVs after keys. Here we use the exchange hash from the
3546 * _first_ key exchange.
d39f364a 3547 */
5e0d7cb8 3548 if (first_kex)
65a22376 3549 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3550 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
5e0d7cb8 3551 cscipher->setcskey(keyspace);
65a22376 3552 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
5e0d7cb8 3553 sccipher->setsckey(keyspace);
65a22376 3554 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
5e0d7cb8 3555 cscipher->setcsiv(keyspace);
65a22376 3556 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
5e0d7cb8 3557 sccipher->setsciv(keyspace);
65a22376 3558 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
5e0d7cb8 3559 csmac->setcskey(keyspace);
65a22376 3560 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
5e0d7cb8 3561 scmac->setsckey(keyspace);
d39f364a 3562
033b4cef 3563 /*
0db56f73 3564 * If this is the first key exchange phase, we must pass the
3565 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3566 * wants to see it but because it will need time to initialise
3567 * itself before it sees an actual packet. In subsequent key
3568 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3569 * it would only confuse the layer above.
3570 */
3571 if (!first_kex) {
32874aea 3572 crReturn(0);
0db56f73 3573 }
3574 first_kex = 0;
3575
3576 /*
7cca0d81 3577 * Now we're encrypting. Begin returning 1 to the protocol main
3578 * function so that other things can run on top of the
3579 * transport. If we ever see a KEXINIT, we must go back to the
3580 * start.
033b4cef 3581 */
e96adf72 3582 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 3583 crReturn(1);
e96adf72 3584 }
5e0d7cb8 3585 logevent("Server initiated key re-exchange");
7cca0d81 3586 goto begin_key_exchange;
e5574168 3587
3588 crFinish(1);
3589}
3590
7cca0d81 3591/*
783415f8 3592 * Add data to an SSH2 channel output buffer.
3593 */
32874aea 3594static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3595 int len)
3596{
5471d09a 3597 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 3598}
3599
3600/*
3601 * Attempt to send data on an SSH2 channel.
3602 */
5471d09a 3603static int ssh2_try_send(struct ssh_channel *c)
32874aea 3604{
5471d09a 3605 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3606 int len;
3607 void *data;
3608 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
3609 if ((unsigned)len > c->v.v2.remwindow)
3610 len = c->v.v2.remwindow;
3611 if ((unsigned)len > c->v.v2.remmaxpkt)
3612 len = c->v.v2.remmaxpkt;
32874aea 3613 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3614 ssh2_pkt_adduint32(c->remoteid);
3615 ssh2_pkt_addstring_start();
5471d09a 3616 ssh2_pkt_addstring_data(data, len);
32874aea 3617 ssh2_pkt_send();
5471d09a 3618 bufchain_consume(&c->v.v2.outbuffer, len);
3619 c->v.v2.remwindow -= len;
3620 }
3621
3622 /*
3623 * After having sent as much data as we can, return the amount
3624 * still buffered.
3625 */
3626 return bufchain_size(&c->v.v2.outbuffer);
3627}
3628
3629/*
3630 * Potentially enlarge the window on an SSH2 channel.
3631 */
3632static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
3633{
3634 if (newwin > c->v.v2.locwindow) {
3635 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3636 ssh2_pkt_adduint32(c->remoteid);
3637 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
3638 ssh2_pkt_send();
3639 c->v.v2.locwindow = newwin;
783415f8 3640 }
3641}
3642
3643/*
7cca0d81 3644 * Handle the SSH2 userauth and connection layers.
3645 */
3646static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3647{
65a22376 3648 static enum {
32874aea 3649 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
761187b6 3650 AUTH_PASSWORD,
3651 AUTH_KEYBOARD_INTERACTIVE
65a22376 3652 } method;
1408a877 3653 static enum {
32874aea 3654 AUTH_TYPE_NONE,
3655 AUTH_TYPE_PUBLICKEY,
3656 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3657 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
761187b6 3658 AUTH_TYPE_PASSWORD,
4bdf7c46 3659 AUTH_TYPE_KEYBOARD_INTERACTIVE,
3660 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
1408a877 3661 } type;
761187b6 3662 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
3663 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
b3186d64 3664 static int kbd_inter_running;
1408a877 3665 static int we_are_in;
761187b6 3666 static int num_prompts, echo;
65a22376 3667 static char username[100];
3668 static char pwprompt[200];
3669 static char password[100];
7cca0d81 3670
e5574168 3671 crBegin;
3672
7cca0d81 3673 /*
3674 * Request userauth protocol, and await a response to it.
3675 */
3676 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3677 ssh2_pkt_addstring("ssh-userauth");
3678 ssh2_pkt_send();
3679 crWaitUntilV(ispkt);
8d5de777 3680 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
32874aea 3681 bombout(("Server refused user authentication protocol"));
3682 crReturnV;
8d5de777 3683 }
7cca0d81 3684
3685 /*
1408a877 3686 * We repeat this whole loop, including the username prompt,
3687 * until we manage a successful authentication. If the user
3688 * types the wrong _password_, they are sent back to the
3689 * beginning to try another username. (If they specify a
3690 * username in the config, they are never asked, even if they
3691 * do give a wrong password.)
3692 *
3693 * I think this best serves the needs of
3694 *
3695 * - the people who have no configuration, no keys, and just
3696 * want to try repeated (username,password) pairs until they
3697 * type both correctly
3698 *
3699 * - people who have keys and configuration but occasionally
3700 * need to fall back to passwords
3701 *
3702 * - people with a key held in Pageant, who might not have
3703 * logged in to a particular machine before; so they want to
3704 * type a username, and then _either_ their key will be
3705 * accepted, _or_ they will type a password. If they mistype
3706 * the username they will want to be able to get back and
3707 * retype it!
7cca0d81 3708 */
1408a877 3709 do {
3710 static int pos;
7cca0d81 3711 static char c;
e5574168 3712
1408a877 3713 /*
3714 * Get a username.
3715 */
3716 pos = 0;
67779be7 3717 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
32874aea 3718 if (ssh_get_line) {
3719 if (!ssh_get_line("login as: ",
3720 username, sizeof(username), FALSE)) {
3721 /*
3722 * get_line failed to get a username.
3723 * Terminate.
3724 */
3725 logevent("No username provided. Abandoning session.");
3726 ssh_state = SSH_STATE_CLOSED;
3727 crReturnV;
3728 }
3729 } else {
3730 c_write_str("login as: ");
3731 ssh_send_ok = 1;
3732 while (pos >= 0) {
3733 crWaitUntilV(!ispkt);
3734 while (inlen--)
3735 switch (c = *in++) {
3736 case 10:
3737 case 13:
3738 username[pos] = 0;
3739 pos = -1;
3740 break;
3741 case 8:
3742 case 127:
3743 if (pos > 0) {
3744 c_write_str("\b \b");
3745 pos--;
3746 }
3747 break;
3748 case 21:
3749 case 27:
3750 while (pos > 0) {
3751 c_write_str("\b \b");
3752 pos--;
3753 }
3754 break;
3755 case 3:
3756 case 4:
3757 random_save_seed();
3758 exit(0);
3759 break;
3760 default:
3761 if (((c >= ' ' && c <= '~') ||
51b2fb65 3762 ((unsigned char) c >= 160))
3763 && pos < sizeof(username)-1) {
32874aea 3764 username[pos++] = c;
3765 c_write(&c, 1);
3766 }
3767 break;
3768 }
3769 }
3770 }
1408a877 3771 c_write_str("\r\n");
7cca0d81 3772 username[strcspn(username, "\n\r")] = '\0';
3773 } else {
3774 char stuff[200];
3775 strncpy(username, cfg.username, 99);
3776 username[99] = '\0';
65a22376 3777 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 3778 sprintf(stuff, "Using username \"%s\".\r\n", username);
1408a877 3779 c_write_str(stuff);
7cca0d81 3780 }
3781 }
3782
65a22376 3783 /*
1408a877 3784 * Send an authentication request using method "none": (a)
3785 * just in case it succeeds, and (b) so that we know what
3786 * authentication methods we can usefully try next.
65a22376 3787 */
1408a877 3788 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3789 ssh2_pkt_addstring(username);
32874aea 3790 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 3791 ssh2_pkt_addstring("none"); /* method */
3792 ssh2_pkt_send();
3793 type = AUTH_TYPE_NONE;
3794 gotit = FALSE;
3795 we_are_in = FALSE;
7cca0d81 3796
1408a877 3797 tried_pubkey_config = FALSE;
1983e559 3798 tried_agent = FALSE;
b3186d64 3799 tried_keyb_inter = FALSE;
3800 kbd_inter_running = FALSE;
65a22376 3801
1408a877 3802 while (1) {
3803 /*
3804 * Wait for the result of the last authentication request.
3805 */
3806 if (!gotit)
3807 crWaitUntilV(ispkt);
3808 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 3809 char *banner;
3810 int size;
3811 /*
3812 * Don't show the banner if we're operating in
3813 * non-verbose non-interactive mode. (It's probably
3814 * a script, which means nobody will read the
3815 * banner _anyway_, and moreover the printing of
3816 * the banner will screw up processing on the
3817 * output of (say) plink.)
3818 */
3819 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3820 ssh2_pkt_getstring(&banner, &size);
3821 if (banner)
3822 c_write_untrusted(banner, size);
3823 }
1408a877 3824 crWaitUntilV(ispkt);
3825 }
3826 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3827 logevent("Access granted");
3828 we_are_in = TRUE;
3829 break;
3830 }
65a22376 3831
b3186d64 3832 if (kbd_inter_running &&
3833 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
3834 /*
3835 * This is a further prompt in keyboard-interactive
3836 * authentication. Do nothing.
3837 */
6bb26b30 3838 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
b3186d64 3839 bombout(("Strange packet received during authentication: type %d",
1408a877 3840 pktin.type));
38c4a8da 3841 crReturnV;
65a22376 3842 }
3843
1408a877 3844 gotit = FALSE;
65a22376 3845
1408a877 3846 /*
3847 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3848 * we can look at the string in it and know what we can
3849 * helpfully try next.
3850 */
b3186d64 3851 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 3852 char *methods;
3853 int methlen;
3854 ssh2_pkt_getstring(&methods, &methlen);
b3186d64 3855 kbd_inter_running = FALSE;
1408a877 3856 if (!ssh2_pkt_getbool()) {
3857 /*
3858 * We have received an unequivocal Access
3859 * Denied. This can translate to a variety of
3860 * messages:
3861 *
3862 * - if we'd just tried "none" authentication,
3863 * it's not worth printing anything at all
3864 *
3865 * - if we'd just tried a public key _offer_,
3866 * the message should be "Server refused our
3867 * key" (or no message at all if the key
3868 * came from Pageant)
3869 *
3870 * - if we'd just tried anything else, the
3871 * message really should be "Access denied".
3872 *
3873 * Additionally, if we'd just tried password
3874 * authentication, we should break out of this
3875 * whole loop so as to go back to the username
3876 * prompt.
3877 */
3878 if (type == AUTH_TYPE_NONE) {
3879 /* do nothing */
3880 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3881 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3882 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3883 c_write_str("Server refused our key\r\n");
3884 logevent("Server refused public key");
4bdf7c46 3885 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
3886 /* server declined keyboard-interactive; ignore */
1408a877 3887 } else {
3888 c_write_str("Access denied\r\n");
3889 logevent("Access denied");
3890 if (type == AUTH_TYPE_PASSWORD) {
3891 we_are_in = FALSE;
3892 break;
3893 }
3894 }
3895 } else {
3896 c_write_str("Further authentication required\r\n");
3897 logevent("Further authentication required");
3898 }
65a22376 3899
32874aea 3900 can_pubkey =
3901 in_commasep_string("publickey", methods, methlen);
3902 can_passwd =
3903 in_commasep_string("password", methods, methlen);
761187b6 3904 can_keyb_inter =
3905 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 3906 }
65a22376 3907
1408a877 3908 method = 0;
65a22376 3909
78afa559 3910 if (!method && can_pubkey && agent_exists() && !tried_agent) {
1983e559 3911 /*
3912 * Attempt public-key authentication using Pageant.
3913 */
3914 static unsigned char request[5], *response, *p;
3915 static int responselen;
3916 static int i, nkeys;
3917 static int authed = FALSE;
3918 void *r;
3919
3920 tried_agent = TRUE;
3921
3922 logevent("Pageant is running. Requesting keys.");
3923
3924 /* Request the keys held by the agent. */
3925 PUT_32BIT(request, 1);
3926 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
3927 agent_query(request, 5, &r, &responselen);
32874aea 3928 response = (unsigned char *) r;
95797139 3929 if (response && responselen >= 5 &&
32874aea 3930 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
1983e559 3931 p = response + 5;
32874aea 3932 nkeys = GET_32BIT(p);
3933 p += 4;
3934 {
3935 char buf[64];
3936 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
3937 logevent(buf);
3938 }
1983e559 3939 for (i = 0; i < nkeys; i++) {
3940 static char *pkblob, *alg, *commentp;
3941 static int pklen, alglen, commentlen;
3942 static int siglen, retlen, len;
3943 static char *q, *agentreq, *ret;
2d466ffd 3944 void *vret;
1983e559 3945
32874aea 3946 {
3947 char buf[64];
3948 sprintf(buf, "Trying Pageant key #%d", i);
3949 logevent(buf);
3950 }
3951 pklen = GET_32BIT(p);
3952 p += 4;
3953 pkblob = p;
3954 p += pklen;
1983e559 3955 alglen = GET_32BIT(pkblob);
3956 alg = pkblob + 4;
32874aea 3957 commentlen = GET_32BIT(p);
3958 p += 4;
3959 commentp = p;
3960 p += commentlen;
1983e559 3961 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3962 ssh2_pkt_addstring(username);
32874aea 3963 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3964 ssh2_pkt_addstring("publickey"); /* method */
3965 ssh2_pkt_addbool(FALSE); /* no signature included */
1983e559 3966 ssh2_pkt_addstring_start();
3967 ssh2_pkt_addstring_data(alg, alglen);
3968 ssh2_pkt_addstring_start();
3969 ssh2_pkt_addstring_data(pkblob, pklen);
3970 ssh2_pkt_send();
3971
3972 crWaitUntilV(ispkt);
3973 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
3974 logevent("Key refused");
3975 continue;
3976 }
3977
32874aea 3978 if (flags & FLAG_VERBOSE) {
3979 c_write_str
3980 ("Authenticating with public key \"");
3981 c_write(commentp, commentlen);
3982 c_write_str("\" from agent\r\n");
3983 }
1983e559 3984
3985 /*
3986 * Server is willing to accept the key.
3987 * Construct a SIGN_REQUEST.
3988 */
3989 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3990 ssh2_pkt_addstring(username);
32874aea 3991 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3992 ssh2_pkt_addstring("publickey"); /* method */
1983e559 3993 ssh2_pkt_addbool(TRUE);
3994 ssh2_pkt_addstring_start();
3995 ssh2_pkt_addstring_data(alg, alglen);
3996 ssh2_pkt_addstring_start();
3997 ssh2_pkt_addstring_data(pkblob, pklen);
3998
3999 siglen = pktout.length - 5 + 4 + 20;
32874aea 4000 len = 1; /* message type */
4001 len += 4 + pklen; /* key blob */
4002 len += 4 + siglen; /* data to sign */
4003 len += 4; /* flags */
1983e559 4004 agentreq = smalloc(4 + len);
4005 PUT_32BIT(agentreq, len);
4006 q = agentreq + 4;
4007 *q++ = SSH2_AGENTC_SIGN_REQUEST;
32874aea 4008 PUT_32BIT(q, pklen);
4009 q += 4;
4010 memcpy(q, pkblob, pklen);
4011 q += pklen;
4012 PUT_32BIT(q, siglen);
4013 q += 4;
1983e559 4014 /* Now the data to be signed... */
32874aea 4015 PUT_32BIT(q, 20);
4016 q += 4;
4017 memcpy(q, ssh2_session_id, 20);
4018 q += 20;
4019 memcpy(q, pktout.data + 5, pktout.length - 5);
4020 q += pktout.length - 5;
1983e559 4021 /* And finally the (zero) flags word. */
4022 PUT_32BIT(q, 0);
2d466ffd 4023 agent_query(agentreq, len + 4, &vret, &retlen);
4024 ret = vret;
1983e559 4025 sfree(agentreq);
4026 if (ret) {
4027 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4028 logevent("Sending Pageant's response");
4029 ssh2_pkt_addstring_start();
32874aea 4030 ssh2_pkt_addstring_data(ret + 9,
4031 GET_32BIT(ret +
4032 5));
1983e559 4033 ssh2_pkt_send();
4034 authed = TRUE;
4035 break;
4036 } else {
32874aea 4037 logevent
4038 ("Pageant failed to answer challenge");
1983e559 4039 sfree(ret);
4040 }
4041 }
4042 }
4043 if (authed)
4044 continue;
4045 }
4046 }
4047
32874aea 4048 if (!method && can_pubkey && *cfg.keyfile
4049 && !tried_pubkey_config) {
1408a877 4050 unsigned char *pub_blob;
4051 char *algorithm, *comment;
4052 int pub_blob_len;
65a22376 4053
1408a877 4054 tried_pubkey_config = TRUE;
65a22376 4055
65a22376 4056 /*
1408a877 4057 * Try the public key supplied in the configuration.
4058 *
4059 * First, offer the public blob to see if the server is
4060 * willing to accept it.
65a22376 4061 */
1408a877 4062 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4063 &pub_blob_len);
4064 if (pub_blob) {
4065 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4066 ssh2_pkt_addstring(username);
32874aea 4067 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4068 ssh2_pkt_addstring("publickey"); /* method */
4069 ssh2_pkt_addbool(FALSE); /* no signature included */
1408a877 4070 ssh2_pkt_addstring(algorithm);
4071 ssh2_pkt_addstring_start();
4072 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4073 ssh2_pkt_send();
32874aea 4074 logevent("Offered public key"); /* FIXME */
1408a877 4075
4076 crWaitUntilV(ispkt);
4077 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4078 gotit = TRUE;
4079 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4080 continue; /* key refused; give up on it */
1408a877 4081 }
65a22376 4082
1408a877 4083 logevent("Offer of public key accepted");
65a22376 4084 /*
1408a877 4085 * Actually attempt a serious authentication using
4086 * the key.
65a22376 4087 */
1408a877 4088 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
32874aea 4089 sprintf(pwprompt,
4090 "Passphrase for key \"%.100s\": ",
4091 comment);
1408a877 4092 need_pw = TRUE;
4093 } else {
4094 need_pw = FALSE;
4095 }
4096 c_write_str("Authenticating with public key \"");
4097 c_write_str(comment);
4098 c_write_str("\"\r\n");
4099 method = AUTH_PUBLICKEY_FILE;
65a22376 4100 }
1408a877 4101 }
4102
af659722 4103 if (!method && can_keyb_inter && !tried_keyb_inter) {
4104 method = AUTH_KEYBOARD_INTERACTIVE;
4105 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4106 tried_keyb_inter = TRUE;
4107
4108 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4109 ssh2_pkt_addstring(username);
4110 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4111 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4112 ssh2_pkt_addstring(""); /* lang */
4113 ssh2_pkt_addstring("");
4114 ssh2_pkt_send();
4115
4116 crWaitUntilV(ispkt);
4117 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4118 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4119 gotit = TRUE;
4120 logevent("Keyboard-interactive authentication refused");
4121 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4122 continue;
4123 }
4124
4125 kbd_inter_running = TRUE;
4126 }
4127
4128 if (kbd_inter_running) {
4129 method = AUTH_KEYBOARD_INTERACTIVE;
4130 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4131 tried_keyb_inter = TRUE;
4132
4133 /* We've got packet with that "interactive" info
4134 dump banners, and set its prompt as ours */
4135 {
4136 char *name, *inst, *lang, *prompt;
4137 int name_len, inst_len, lang_len, prompt_len;
4138 ssh2_pkt_getstring(&name, &name_len);
4139 ssh2_pkt_getstring(&inst, &inst_len);
4140 ssh2_pkt_getstring(&lang, &lang_len);
4141 if (name_len > 0)
4142 c_write_untrusted(name, name_len);
4143 if (inst_len > 0)
4144 c_write_untrusted(inst, inst_len);
4145 num_prompts = ssh2_pkt_getuint32();
4146
4147 ssh2_pkt_getstring(&prompt, &prompt_len);
4148 strncpy(pwprompt, prompt, sizeof(pwprompt));
4149 need_pw = TRUE;
4150
4151 echo = ssh2_pkt_getbool();
4152 }
4153 }
4154
1408a877 4155 if (!method && can_passwd) {
4156 method = AUTH_PASSWORD;
32874aea 4157 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4158 savedhost);
1408a877 4159 need_pw = TRUE;
4160 }
4161
4162 if (need_pw) {
fa17a66e 4163 if (ssh_get_line) {
4164 if (!ssh_get_line(pwprompt, password,
32874aea 4165 sizeof(password), TRUE)) {
1408a877 4166 /*
fa17a66e 4167 * get_line failed to get a password (for
4168 * example because one was supplied on the
4169 * command line which has already failed to
4170 * work). Terminate.
1408a877 4171 */
2bc6a386 4172 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4173 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4174 ssh2_pkt_addstring
4175 ("No more passwords available to try");
4176 ssh2_pkt_addstring("en"); /* language tag */
4177 ssh2_pkt_send();
4178 connection_fatal("Unable to authenticate");
1408a877 4179 ssh_state = SSH_STATE_CLOSED;
4180 crReturnV;
4181 }
4182 } else {
4183 static int pos = 0;
4184 static char c;
4185
761187b6 4186 c_write_untrusted(pwprompt, strlen(pwprompt));
1408a877 4187 ssh_send_ok = 1;
4188
4189 pos = 0;
4190 while (pos >= 0) {
4191 crWaitUntilV(!ispkt);
32874aea 4192 while (inlen--)
4193 switch (c = *in++) {
4194 case 10:
4195 case 13:
4196 password[pos] = 0;
4197 pos = -1;
4198 break;
4199 case 8:
4200 case 127:
4201 if (pos > 0)
4202 pos--;
4203 break;
4204 case 21:
4205 case 27:
4206 pos = 0;
4207 break;
4208 case 3:
4209 case 4:
4210 random_save_seed();
4211 exit(0);
4212 break;
4213 default:
51b2fb65 4214 if (pos < sizeof(password)-1)
32874aea 4215 password[pos++] = c;
4216 break;
4217 }
65a22376 4218 }
1408a877 4219 c_write_str("\r\n");
65a22376 4220 }
65a22376 4221 }
65a22376 4222
1408a877 4223 if (method == AUTH_PUBLICKEY_FILE) {
4224 /*
4225 * We have our passphrase. Now try the actual authentication.
4226 */
4227 struct ssh2_userkey *key;
65a22376 4228
1408a877 4229 key = ssh2_load_userkey(cfg.keyfile, password);
4230 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4231 if (key == SSH2_WRONG_PASSPHRASE) {
4232 c_write_str("Wrong passphrase\r\n");
4233 tried_pubkey_config = FALSE;
4234 } else {
4235 c_write_str("Unable to load private key\r\n");
4236 tried_pubkey_config = TRUE;
4237 }
4238 /* Send a spurious AUTH_NONE to return to the top. */
4239 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4240 ssh2_pkt_addstring(username);
32874aea 4241 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4242 ssh2_pkt_addstring("none"); /* method */
1408a877 4243 ssh2_pkt_send();
4244 type = AUTH_TYPE_NONE;
4245 } else {
4246 unsigned char *blob, *sigdata;
4247 int blob_len, sigdata_len;
65a22376 4248
1408a877 4249 /*
4250 * We have loaded the private key and the server
4251 * has announced that it's willing to accept it.
4252 * Hallelujah. Generate a signature and send it.
4253 */
4254 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4255 ssh2_pkt_addstring(username);
32874aea 4256 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4257 ssh2_pkt_addstring("publickey"); /* method */
1408a877 4258 ssh2_pkt_addbool(TRUE);
4259 ssh2_pkt_addstring(key->alg->name);
4260 blob = key->alg->public_blob(key->data, &blob_len);
4261 ssh2_pkt_addstring_start();
4262 ssh2_pkt_addstring_data(blob, blob_len);
4263 sfree(blob);
4264
4265 /*
4266 * The data to be signed is:
4267 *
4268 * string session-id
4269 *
4270 * followed by everything so far placed in the
4271 * outgoing packet.
4272 */
4273 sigdata_len = pktout.length - 5 + 4 + 20;
4274 sigdata = smalloc(sigdata_len);
4275 PUT_32BIT(sigdata, 20);
32874aea 4276 memcpy(sigdata + 4, ssh2_session_id, 20);
4277 memcpy(sigdata + 24, pktout.data + 5,
4278 pktout.length - 5);
4279 blob =
4280 key->alg->sign(key->data, sigdata, sigdata_len,
4281 &blob_len);
1408a877 4282 ssh2_pkt_addstring_start();
4283 ssh2_pkt_addstring_data(blob, blob_len);
4284 sfree(blob);
4285 sfree(sigdata);
4286
4287 ssh2_pkt_send();
4288 type = AUTH_TYPE_PUBLICKEY;
4289 }
4290 } else if (method == AUTH_PASSWORD) {
65a22376 4291 /*
1408a877 4292 * We send the password packet lumped tightly together with
4293 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4294 * string long enough to make the total length of the two
4295 * packets constant. This should ensure that a passive
4296 * listener doing traffic analyis can't work out the length
4297 * of the password.
4298 *
4299 * For this to work, we need an assumption about the
4300 * maximum length of the password packet. I think 256 is
4301 * pretty conservative. Anyone using a password longer than
4302 * that probably doesn't have much to worry about from
4303 * people who find out how long their password is!
65a22376 4304 */
4305 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4306 ssh2_pkt_addstring(username);
32874aea 4307 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1408a877 4308 ssh2_pkt_addstring("password");
4309 ssh2_pkt_addbool(FALSE);
4310 ssh2_pkt_addstring(password);
4311 ssh2_pkt_defer();
65a22376 4312 /*
1408a877 4313 * We'll include a string that's an exact multiple of the
4314 * cipher block size. If the cipher is NULL for some
4315 * reason, we don't do this trick at all because we gain
4316 * nothing by it.
65a22376 4317 */
32874aea 4318 if (cscipher) {
4319 int stringlen, i;
4320
4321 stringlen = (256 - deferred_len);
4322 stringlen += cscipher->blksize - 1;
4323 stringlen -= (stringlen % cscipher->blksize);
4324 if (cscomp) {
4325 /*
4326 * Temporarily disable actual compression,
4327 * so we can guarantee to get this string
4328 * exactly the length we want it. The
4329 * compression-disabling routine should
4330 * return an integer indicating how many
4331 * bytes we should adjust our string length
4332 * by.
4333 */
4334 stringlen -= cscomp->disable_compression();
4335 }
1408a877 4336 ssh2_pkt_init(SSH2_MSG_IGNORE);
4337 ssh2_pkt_addstring_start();
6e9e9520 4338 for (i = 0; i < stringlen; i++) {
32874aea 4339 char c = (char) random_byte();
4340 ssh2_pkt_addstring_data(&c, 1);
65a22376 4341 }
1408a877 4342 ssh2_pkt_defer();
65a22376 4343 }
39065bed 4344 ssh_pkt_defersend();
0d43337a 4345 logevent("Sent password");
1408a877 4346 type = AUTH_TYPE_PASSWORD;
761187b6 4347 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4348 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4349 ssh2_pkt_adduint32(num_prompts);
4350 ssh2_pkt_addstring(password);
4351 memset(password, 0, sizeof(password));
4352 ssh2_pkt_send();
4353 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 4354 } else {
32874aea 4355 c_write_str
4356 ("No supported authentication methods left to try!\r\n");
4357 logevent
4358 ("No supported authentications offered. Disconnecting");
1408a877 4359 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4360 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
32874aea 4361 ssh2_pkt_addstring
4362 ("No supported authentication methods available");
4363 ssh2_pkt_addstring("en"); /* language tag */
1408a877 4364 ssh2_pkt_send();
4365 ssh_state = SSH_STATE_CLOSED;
4366 crReturnV;
65a22376 4367 }
65a22376 4368 }
1408a877 4369 } while (!we_are_in);
7cca0d81 4370
4371 /*
4372 * Now we're authenticated for the connection protocol. The
4373 * connection protocol will automatically have started at this
4374 * point; there's no need to send SERVICE_REQUEST.
4375 */
4376
4377 /*
4378 * So now create a channel with a session in it.
4379 */
d2371c81 4380 ssh_channels = newtree234(ssh_channelcmp);
dcbde236 4381 mainchan = smalloc(sizeof(struct ssh_channel));
d2371c81 4382 mainchan->localid = alloc_channel_id();
7cca0d81 4383 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4384 ssh2_pkt_addstring("session");
d211621f 4385 ssh2_pkt_adduint32(mainchan->localid);
5471d09a 4386 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4387 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
32874aea 4388 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 4389 ssh2_pkt_send();
4390 crWaitUntilV(ispkt);
4391 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
32874aea 4392 bombout(("Server refused to open a session"));
4393 crReturnV;
4394 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 4395 }
d211621f 4396 if (ssh2_pkt_getuint32() != mainchan->localid) {
32874aea 4397 bombout(("Server's channel confirmation cited wrong channel"));
4398 crReturnV;
7cca0d81 4399 }
d211621f 4400 mainchan->remoteid = ssh2_pkt_getuint32();
783415f8 4401 mainchan->type = CHAN_MAINSESSION;
4402 mainchan->closes = 0;
5471d09a 4403 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4404 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4405 bufchain_init(&mainchan->v.v2.outbuffer);
783415f8 4406 add234(ssh_channels, mainchan);
7cca0d81 4407 logevent("Opened channel for session");
4408
4409 /*
783415f8 4410 * Potentially enable X11 forwarding.
4411 */
4412 if (cfg.x11_forward) {
32874aea 4413 char proto[20], data[64];
4414 logevent("Requesting X11 forwarding");
4415 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4416 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4417 ssh2_pkt_adduint32(mainchan->remoteid);
4418 ssh2_pkt_addstring("x11-req");
4419 ssh2_pkt_addbool(1); /* want reply */
4420 ssh2_pkt_addbool(0); /* many connections */
4421 ssh2_pkt_addstring(proto);
4422 ssh2_pkt_addstring(data);
4423 ssh2_pkt_adduint32(0); /* screen number */
4424 ssh2_pkt_send();
4425
4426 do {
4427 crWaitUntilV(ispkt);
4428 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4429 unsigned i = ssh2_pkt_getuint32();
4430 struct ssh_channel *c;
4431 c = find234(ssh_channels, &i, ssh_channelfind);
4432 if (!c)
4433 continue; /* nonexistent channel */
5471d09a 4434 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4435 }
4436 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4437
4438 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4439 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 4440 bombout(("Unexpected response to X11 forwarding request:"
4441 " packet type %d", pktin.type));
32874aea 4442 crReturnV;
4443 }
4444 logevent("X11 forwarding refused");
4445 } else {
4446 logevent("X11 forwarding enabled");
783415f8 4447 ssh_X11_fwd_enabled = TRUE;
32874aea 4448 }
783415f8 4449 }
4450
4451 /*
bc240b21 4452 * Enable port forwardings.
4453 */
4454 {
4455 static char *e; /* preserve across crReturn */
4456 char type;
4457 int n;
4458 int sport,dport;
4459 char sports[256], dports[256], host[256];
4460 char buf[1024];
4461
4462 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4463 /* Add port forwardings. */
4464 e = cfg.portfwd;
4465 while (*e) {
4466 type = *e++;
4467 n = 0;
4468 while (*e && *e != '\t')
4469 sports[n++] = *e++;
4470 sports[n] = 0;
4471 if (*e == '\t')
4472 e++;
4473 n = 0;
4474 while (*e && *e != ':')
4475 host[n++] = *e++;
4476 host[n] = 0;
4477 if (*e == ':')
4478 e++;
4479 n = 0;
4480 while (*e)
4481 dports[n++] = *e++;
4482 dports[n] = 0;
4483 e++;
4484 dport = atoi(dports);
4485 sport = atoi(sports);
4486 if (sport && dport) {
4487 if (type == 'L') {
4488 pfd_addforward(host, dport, sport);
4489 sprintf(buf, "Local port %d forwarding to %s:%d",
4490 sport, host, dport);
4491 logevent(buf);
4492 } else {
4493 struct ssh_rportfwd *pf;
4494 pf = smalloc(sizeof(*pf));
4495 strcpy(pf->dhost, host);
4496 pf->dport = dport;
4497 pf->sport = sport;
4498 if (add234(ssh_rportfwds, pf) != pf) {
4499 sprintf(buf,
95bc8819 4500 "Duplicate remote port forwarding to %s:%d",
bc240b21 4501 host, dport);
4502 logevent(buf);
4503 sfree(pf);
4504 } else {
4505 sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)",
4506 sport, host, dport);
4507 logevent(buf);
4508 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4509 ssh2_pkt_addstring("tcpip-forward");
4510 ssh2_pkt_addbool(1);/* want reply */
4511 ssh2_pkt_addstring("127.0.0.1");
4512 ssh2_pkt_adduint32(sport);
4513 ssh2_pkt_send();
4514
4515 do {
4516 crWaitUntilV(ispkt);
4517 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4518 unsigned i = ssh2_pkt_getuint32();
4519 struct ssh_channel *c;
4520 c = find234(ssh_channels, &i, ssh_channelfind);
4521 if (!c)
4522 continue;/* nonexistent channel */
5471d09a 4523 c->v.v2.remwindow += ssh2_pkt_getuint32();
bc240b21 4524 }
4525 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4526
4527 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
4528 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
c9886e66 4529 bombout(("Unexpected response to port "
4530 "forwarding request: packet type %d",
4531 pktin.type));
bc240b21 4532 crReturnV;
4533 }
4534 logevent("Server refused this port forwarding");
4535 } else {
4536 logevent("Remote port forwarding enabled");
4537 }
4538 }
4539 }
4540 }
4541 }
4542 }
4543
4544 /*
36c2a3e9 4545 * Potentially enable agent forwarding.
4546 */
4547 if (cfg.agentfwd && agent_exists()) {
32874aea 4548 logevent("Requesting OpenSSH-style agent forwarding");
4549 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4550 ssh2_pkt_adduint32(mainchan->remoteid);
4551 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4552 ssh2_pkt_addbool(1); /* want reply */
4553 ssh2_pkt_send();
4554
4555 do {
4556 crWaitUntilV(ispkt);
4557 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4558 unsigned i = ssh2_pkt_getuint32();
4559 struct ssh_channel *c;
4560 c = find234(ssh_channels, &i, ssh_channelfind);
4561 if (!c)
4562 continue; /* nonexistent channel */
5471d09a 4563 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4564 }
4565 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4566
4567 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4568 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 4569 bombout(("Unexpected response to agent forwarding request:"
4570 " packet type %d", pktin.type));
32874aea 4571 crReturnV;
4572 }
4573 logevent("Agent forwarding refused");
4574 } else {
4575 logevent("Agent forwarding enabled");
36c2a3e9 4576 ssh_agentfwd_enabled = TRUE;
32874aea 4577 }
36c2a3e9 4578 }
4579
4580 /*
7cca0d81 4581 * Now allocate a pty for the session.
4582 */
67779be7 4583 if (!cfg.nopty) {
32874aea 4584 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4585 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4586 ssh2_pkt_addstring("pty-req");
4587 ssh2_pkt_addbool(1); /* want reply */
4588 ssh2_pkt_addstring(cfg.termtype);
4589 ssh2_pkt_adduint32(cols);
4590 ssh2_pkt_adduint32(rows);
4591 ssh2_pkt_adduint32(0); /* pixel width */
4592 ssh2_pkt_adduint32(0); /* pixel height */
4593 ssh2_pkt_addstring_start();
4594 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4595 ssh2_pkt_send();
4596 ssh_state = SSH_STATE_INTERMED;
4597
4598 do {
4599 crWaitUntilV(ispkt);
4600 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4601 unsigned i = ssh2_pkt_getuint32();
4602 struct ssh_channel *c;
4603 c = find234(ssh_channels, &i, ssh_channelfind);
4604 if (!c)
4605 continue; /* nonexistent channel */
5471d09a 4606 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4607 }
4608 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4609
4610 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4611 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 4612 bombout(("Unexpected response to pty request:"
4613 " packet type %d", pktin.type));
32874aea 4614 crReturnV;
4615 }
4616 c_write_str("Server refused to allocate pty\r\n");
4617 ssh_editing = ssh_echoing = 1;
4618 } else {
4619 logevent("Allocated pty");
4620 }
0965bee0 4621 } else {
32874aea 4622 ssh_editing = ssh_echoing = 1;
7cca0d81 4623 }
4624
4625 /*
fd5e5847 4626 * Start a shell or a remote command. We may have to attempt
4627 * this twice if the config data has provided a second choice
4628 * of command.
7cca0d81 4629 */
fd5e5847 4630 while (1) {
4631 int subsys;
4632 char *cmd;
4633
4634 if (ssh_fallback_cmd) {
4635 subsys = cfg.ssh_subsys2;
4636 cmd = cfg.remote_cmd_ptr2;
4637 } else {
4638 subsys = cfg.ssh_subsys;
4639 cmd = cfg.remote_cmd_ptr;
4640 }
4641
4642 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4643 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4644 if (subsys) {
4645 ssh2_pkt_addstring("subsystem");
4646 ssh2_pkt_addbool(1); /* want reply */
4647 ssh2_pkt_addstring(cmd);
4648 } else if (*cmd) {
4649 ssh2_pkt_addstring("exec");
4650 ssh2_pkt_addbool(1); /* want reply */
4651 ssh2_pkt_addstring(cmd);
4652 } else {
4653 ssh2_pkt_addstring("shell");
4654 ssh2_pkt_addbool(1); /* want reply */
32874aea 4655 }
fd5e5847 4656 ssh2_pkt_send();
4657 do {
4658 crWaitUntilV(ispkt);
4659 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4660 unsigned i = ssh2_pkt_getuint32();
4661 struct ssh_channel *c;
4662 c = find234(ssh_channels, &i, ssh_channelfind);
4663 if (!c)
4664 continue; /* nonexistent channel */
4665 c->v.v2.remwindow += ssh2_pkt_getuint32();
4666 }
4667 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4668 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4669 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
c9886e66 4670 bombout(("Unexpected response to shell/command request:"
4671 " packet type %d", pktin.type));
fd5e5847 4672 crReturnV;
4673 }
4674 /*
4675 * We failed to start the command. If this is the
4676 * fallback command, we really are finished; if it's
4677 * not, and if the fallback command exists, try falling
4678 * back to it before complaining.
4679 */
4680 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
4681 logevent("Primary command failed; attempting fallback");
4682 ssh_fallback_cmd = TRUE;
4683 continue;
4684 }
4685 bombout(("Server refused to start a shell/command"));
32874aea 4686 crReturnV;
fd5e5847 4687 } else {
4688 logevent("Started a shell/command");
32874aea 4689 }
fd5e5847 4690 break;
7cca0d81 4691 }
4692
6e48c3fe 4693 ssh_state = SSH_STATE_SESSION;
4694 if (size_needed)
4695 ssh_size();
3687d221 4696 if (eof_needed)
32874aea 4697 ssh_special(TS_EOF);
6e48c3fe 4698
7cca0d81 4699 /*
4700 * Transfer data!
4701 */
760e88b2 4702 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
8ccc75b0 4703 ssh_send_ok = 1;
7cca0d81 4704 while (1) {
32874aea 4705 static int try_send;
e5574168 4706 crReturnV;
32874aea 4707 try_send = FALSE;
7cca0d81 4708 if (ispkt) {
4709 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
32874aea 4710 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
4711 char *data;
4712 int length;
4713 unsigned i = ssh2_pkt_getuint32();
4714 struct ssh_channel *c;
4715 c = find234(ssh_channels, &i, ssh_channelfind);
4716 if (!c)
4717 continue; /* nonexistent channel */
4718 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
4719 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
4720 continue; /* extended but not stderr */
4721 ssh2_pkt_getstring(&data, &length);
4722 if (data) {
5471d09a 4723 int bufsize;
4724 c->v.v2.locwindow -= length;
32874aea 4725 switch (c->type) {
4726 case CHAN_MAINSESSION:
5471d09a 4727 bufsize =
4728 from_backend(pktin.type ==
4729 SSH2_MSG_CHANNEL_EXTENDED_DATA,
4730 data, length);
32874aea 4731 break;
4732 case CHAN_X11:
5471d09a 4733 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 4734 break;
d74d141c 4735 case CHAN_SOCKDATA:
5471d09a 4736 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 4737 break;
36c2a3e9 4738 case CHAN_AGENT:
32874aea 4739 while (length > 0) {
4740 if (c->u.a.lensofar < 4) {
4741 int l = min(4 - c->u.a.lensofar, length);
4742 memcpy(c->u.a.msglen + c->u.a.lensofar,
4743 data, l);
4744 data += l;
4745 length -= l;
4746 c->u.a.lensofar += l;
4747 }
4748 if (c->u.a.lensofar == 4) {
4749 c->u.a.totallen =
4750 4 + GET_32BIT(c->u.a.msglen);
4751 c->u.a.message = smalloc(c->u.a.totallen);
4752 memcpy(c->u.a.message, c->u.a.msglen, 4);
4753 }
4754 if (c->u.a.lensofar >= 4 && length > 0) {
4755 int l =
4756 min(c->u.a.totallen - c->u.a.lensofar,
4757 length);
4758 memcpy(c->u.a.message + c->u.a.lensofar,
4759 data, l);
4760 data += l;
4761 length -= l;
4762 c->u.a.lensofar += l;
4763 }
4764 if (c->u.a.lensofar == c->u.a.totallen) {
4765 void *reply, *sentreply;
4766 int replylen;
4767 agent_query(c->u.a.message,
4768 c->u.a.totallen, &reply,
4769 &replylen);
4770 if (reply)
4771 sentreply = reply;
4772 else {
4773 /* Fake SSH_AGENT_FAILURE. */
4774 sentreply = "\0\0\0\1\5";
4775 replylen = 5;
4776 }
4777 ssh2_add_channel_data(c, sentreply,
4778 replylen);
36c2a3e9 4779 try_send = TRUE;
32874aea 4780 if (reply)
4781 sfree(reply);
4782 sfree(c->u.a.message);
4783 c->u.a.lensofar = 0;
4784 }
4785 }
5471d09a 4786 bufsize = 0;
32874aea 4787 break;
4788 }
4789 /*
5471d09a 4790 * If we are not buffering too much data,
4791 * enlarge the window again at the remote side.
32874aea 4792 */
5471d09a 4793 if (bufsize < OUR_V2_WINSIZE)
4794 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 4795 }
7cca0d81 4796 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
32874aea 4797 ssh_state = SSH_STATE_CLOSED;
d211621f 4798 logevent("Received disconnect message");
32874aea 4799 crReturnV;
d211621f 4800 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
32874aea 4801 unsigned i = ssh2_pkt_getuint32();
4802 struct ssh_channel *c;
4803
4804 c = find234(ssh_channels, &i, ssh_channelfind);
4805 if (!c)
4806 continue; /* nonexistent channel */
4807
4808 if (c->type == CHAN_X11) {
4809 /*
4810 * Remote EOF on an X11 channel means we should
4811 * wrap up and close the channel ourselves.
4812 */
4813 x11_close(c->u.x11.s);
4814 sshfwd_close(c);
4815 } else if (c->type == CHAN_AGENT) {
36c2a3e9 4816 sshfwd_close(c);
d74d141c 4817 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 4818 pfd_close(c->u.pfd.s);
4819 sshfwd_close(c);
36c2a3e9 4820 }
d211621f 4821 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
32874aea 4822 unsigned i = ssh2_pkt_getuint32();
4823 struct ssh_channel *c;
4824
4825 c = find234(ssh_channels, &i, ssh_channelfind);
4826 if (!c)
4827 continue; /* nonexistent channel */
32874aea 4828 /* Do pre-close processing on the channel. */
4829 switch (c->type) {
4830 case CHAN_MAINSESSION:
4831 break; /* nothing to see here, move along */
4832 case CHAN_X11:
92f157bd 4833 if (c->u.x11.s != NULL)
4834 x11_close(c->u.x11.s);
4835 sshfwd_close(c);
32874aea 4836 break;
4837 case CHAN_AGENT:
92f157bd 4838 sshfwd_close(c);
32874aea 4839 break;
d74d141c 4840 case CHAN_SOCKDATA:
92f157bd 4841 if (c->u.pfd.s != NULL)
4842 pfd_close(c->u.pfd.s);
4843 sshfwd_close(c);
bc240b21 4844 break;
32874aea 4845 }
92f157bd 4846 if (c->closes == 0) {
4847 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4848 ssh2_pkt_adduint32(c->remoteid);
4849 ssh2_pkt_send();
4850 }
32874aea 4851 del234(ssh_channels, c);
5471d09a 4852 bufchain_clear(&c->v.v2.outbuffer);
32874aea 4853 sfree(c);
4854
4855 /*
4856 * See if that was the last channel left open.
4857 */
4858 if (count234(ssh_channels) == 0) {
4859 logevent("All channels closed. Disconnecting");
4860 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4861 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4862 ssh2_pkt_addstring("All open channels closed");
4863 ssh2_pkt_addstring("en"); /* language tag */
4864 ssh2_pkt_send();
4865 ssh_state = SSH_STATE_CLOSED;
4866 crReturnV;
4867 }
4868 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 4869 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
32874aea 4870 unsigned i = ssh2_pkt_getuint32();
4871 struct ssh_channel *c;
4872 c = find234(ssh_channels, &i, ssh_channelfind);
4873 if (!c)
4874 continue; /* nonexistent channel */
5471d09a 4875 c->v.v2.remwindow += ssh2_pkt_getuint32();
32874aea 4876 try_send = TRUE;
bc240b21 4877 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4878 unsigned i = ssh2_pkt_getuint32();
4879 struct ssh_channel *c;
4880 c = find234(ssh_channels, &i, ssh_channelfind);
4881 if (!c)
4882 continue; /* nonexistent channel */
4883 if (c->type != CHAN_SOCKDATA_DORMANT)
4884 continue; /* dunno why they're confirming this */
4885 c->remoteid = ssh2_pkt_getuint32();
4886 c->type = CHAN_SOCKDATA;
5471d09a 4887 c->v.v2.remwindow = ssh2_pkt_getuint32();
4888 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4889 bufchain_init(&c->v.v2.outbuffer);
4ed34d25 4890 if (c->u.pfd.s)
4891 pfd_confirm(c->u.pfd.s);
4892 if (c->closes) {
4893 /*
4894 * We have a pending close on this channel,
4895 * which we decided on before the server acked
4896 * the channel open. So now we know the
4897 * remoteid, we can close it again.
4898 */
4899 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4900 ssh2_pkt_adduint32(c->remoteid);
4901 ssh2_pkt_send();
4902 }
724cface 4903 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
4904 unsigned i = ssh2_pkt_getuint32();
4905 struct ssh_channel *c;
4906 c = find234(ssh_channels, &i, ssh_channelfind);
4907 if (!c)
4908 continue; /* nonexistent channel */
4909 if (c->type != CHAN_SOCKDATA_DORMANT)
4910 continue; /* dunno why they're failing this */
4911
4912 logevent("Forwarded connection refused by server");
4913
4914 pfd_close(c->u.pfd.s);
4915
4916 del234(ssh_channels, c);
4917 sfree(c);
ebb0a590 4918 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
4919 unsigned localid;
4920 char *type;
4921 int typelen, want_reply;
4922 struct ssh_channel *c;
4923
4924 localid = ssh2_pkt_getuint32();
4925 ssh2_pkt_getstring(&type, &typelen);
4926 want_reply = ssh2_pkt_getbool();
4927
4928 /*
4929 * First, check that the channel exists. Otherwise,
4930 * we can instantly disconnect with a rude message.
4931 */
4932 c = find234(ssh_channels, &localid, ssh_channelfind);
4933 if (!c) {
4934 char buf[80];
4935 sprintf(buf, "Received channel request for nonexistent"
4936 " channel %d", localid);
4937 logevent(buf);
4938 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4939 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4940 ssh2_pkt_addstring(buf);
4941 ssh2_pkt_addstring("en"); /* language tag */
4942 ssh2_pkt_send();
4943 connection_fatal(buf);
4944 ssh_state = SSH_STATE_CLOSED;
4945 crReturnV;
4946 }
4947
4948 /*
4949 * We don't recognise any form of channel request,
4950 * so we now either ignore the request or respond
4951 * with CHANNEL_FAILURE, depending on want_reply.
4952 */
4953 if (want_reply) {
4954 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
4955 ssh2_pkt_adduint32(c->remoteid);
4956 ssh2_pkt_send();
4957 }
783415f8 4958 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 4959 char *type;
4960 int typelen;
4961 char *error = NULL;
4962 struct ssh_channel *c;
bc240b21 4963 unsigned remid, winsize, pktsize;
32874aea 4964 ssh2_pkt_getstring(&type, &typelen);
4965 c = smalloc(sizeof(struct ssh_channel));
4966
bc240b21 4967 remid = ssh2_pkt_getuint32();
4968 winsize = ssh2_pkt_getuint32();
4969 pktsize = ssh2_pkt_getuint32();
4970
32874aea 4971 if (typelen == 3 && !memcmp(type, "x11", 3)) {
4972 if (!ssh_X11_fwd_enabled)
4973 error = "X11 forwarding is not enabled";
4974 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
4975 NULL) {
4976 error = "Unable to open an X11 connection";
4977 } else {
4978 c->type = CHAN_X11;
4979 }
bc240b21 4980 } else if (typelen == 15 &&
4981 !memcmp(type, "forwarded-tcpip", 15)) {
4982 struct ssh_rportfwd pf, *realpf;
4983 char *dummy;
4984 int dummylen;
4985 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
4986 pf.sport = ssh2_pkt_getuint32();
4987 realpf = find234(ssh_rportfwds, &pf, NULL);
4988 if (realpf == NULL) {
4989 error = "Remote port is not recognised";
4990 } else {
4991 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
4992 realpf->dport, c);
4993 char buf[1024];
4994 sprintf(buf, "Received remote port open request for %s:%d",
4995 realpf->dhost, realpf->dport);
4996 logevent(buf);
4997 if (e != NULL) {
4998 sprintf(buf, "Port open failed: %s", e);
4999 logevent(buf);
5000 error = "Port open failed";
5001 } else {
5002 logevent("Forwarded port opened successfully");
5003 c->type = CHAN_SOCKDATA;
5004 }
5005 }
32874aea 5006 } else if (typelen == 22 &&
36c2a3e9 5007 !memcmp(type, "auth-agent@openssh.com", 3)) {
32874aea 5008 if (!ssh_agentfwd_enabled)
5009 error = "Agent forwarding is not enabled";
36c2a3e9 5010 else {
32874aea 5011 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 5012 c->u.a.lensofar = 0;
32874aea 5013 }
5014 } else {
5015 error = "Unsupported channel type requested";
5016 }
5017
bc240b21 5018 c->remoteid = remid;
32874aea 5019 if (error) {
5020 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5021 ssh2_pkt_adduint32(c->remoteid);
5022 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5023 ssh2_pkt_addstring(error);
5024 ssh2_pkt_addstring("en"); /* language tag */
5025 ssh2_pkt_send();
5026 sfree(c);
5027 } else {
5028 c->localid = alloc_channel_id();
5029 c->closes = 0;
5471d09a 5030 c->v.v2.locwindow = OUR_V2_WINSIZE;
5031 c->v.v2.remwindow = winsize;
5032 c->v.v2.remmaxpkt = pktsize;
5033 bufchain_init(&c->v.v2.outbuffer);
32874aea 5034 add234(ssh_channels, c);
5035 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5036 ssh2_pkt_adduint32(c->remoteid);
5037 ssh2_pkt_adduint32(c->localid);
5471d09a 5038 ssh2_pkt_adduint32(c->v.v2.locwindow);
32874aea 5039 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5040 ssh2_pkt_send();
5041 }
7cca0d81 5042 } else {
8d5de777 5043 bombout(("Strange packet received: type %d", pktin.type));
32874aea 5044 crReturnV;
7cca0d81 5045 }
5046 } else {
32874aea 5047 /*
5048 * We have spare data. Add it to the channel buffer.
5049 */
5050 ssh2_add_channel_data(mainchan, in, inlen);
5051 try_send = TRUE;
5052 }
5053 if (try_send) {
5054 int i;
5055 struct ssh_channel *c;
5056 /*
5057 * Try to send data on all channels if we can.
5058 */
5471d09a 5059 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5060 int bufsize = ssh2_try_send(c);
5061 if (bufsize == 0) {
5062 switch (c->type) {
5063 case CHAN_MAINSESSION:
5064 /* stdin need not receive an unthrottle
5065 * notification since it will be polled */
5066 break;
5067 case CHAN_X11:
5068 x11_unthrottle(c->u.x11.s);
5069 break;
5070 case CHAN_AGENT:
5071 /* agent sockets are request/response and need no
5072 * buffer management */
5073 break;
5074 case CHAN_SOCKDATA:
5075 pfd_unthrottle(c->u.pfd.s);
5076 break;
5077 }
5078 }
5079 }
7cca0d81 5080 }
e5574168 5081 }
5082
5083 crFinishV;
5084}
5085
5086/*
7cca0d81 5087 * Handle the top-level SSH2 protocol.
5088 */
5089static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5090{
5091 if (do_ssh2_transport(in, inlen, ispkt) == 0)
32874aea 5092 return;
7cca0d81 5093 do_ssh2_authconn(in, inlen, ispkt);
5094}
5095
5096/*
8df7a775 5097 * Called to set up the connection.
374330e2 5098 *
5099 * Returns an error message, or NULL on success.
374330e2 5100 */
32874aea 5101static char *ssh_init(char *host, int port, char **realhost)
5102{
fb09bf1c 5103 char *p;
32874aea 5104
8f203108 5105#ifdef MSCRYPTOAPI
32874aea 5106 if (crypto_startup() == 0)
8f203108 5107 return "Microsoft high encryption pack not installed!";
5108#endif
374330e2 5109
8df7a775 5110 ssh_send_ok = 0;
0965bee0 5111 ssh_editing = 0;
5112 ssh_echoing = 0;
5471d09a 5113 ssh1_throttle_count = 0;
5114 ssh_overall_bufsize = 0;
fd5e5847 5115 ssh_fallback_cmd = 0;
8df7a775 5116
fb09bf1c 5117 p = connect_to_host(host, port, realhost);
5118 if (p != NULL)
5119 return p;
374330e2 5120
374330e2 5121 return NULL;
5122}
5123
5124/*
374330e2 5125 * Called to send data down the Telnet connection.
5126 */
5471d09a 5127static int ssh_send(char *buf, int len)
32874aea 5128{
f78051a1 5129 if (s == NULL || ssh_protocol == NULL)
5471d09a 5130 return 0;
374330e2 5131
5132 ssh_protocol(buf, len, 0);
5471d09a 5133
5134 return ssh_sendbuffer();
5135}
5136
5137/*
5138 * Called to query the current amount of buffered stdin data.
5139 */
5140static int ssh_sendbuffer(void)
5141{
5142 int override_value;
5143
5144 if (s == NULL || ssh_protocol == NULL)
5145 return 0;
5146
5147 /*
5148 * If the SSH socket itself has backed up, add the total backup
5149 * size on that to any individual buffer on the stdin channel.
5150 */
5151 override_value = 0;
5152 if (ssh_throttled_all)
5153 override_value = ssh_overall_bufsize;
5154
5155 if (ssh_version == 1) {
5156 return override_value;
5157 } else if (ssh_version == 2) {
5158 if (!mainchan || mainchan->closes > 0)
5159 return override_value;
5160 else
5161 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5162 }
5163
5164 return 0;
374330e2 5165}
5166
5167/*
6e48c3fe 5168 * Called to set the size of the window from SSH's POV.
374330e2 5169 */
32874aea 5170static void ssh_size(void)
5171{
374330e2 5172 switch (ssh_state) {
5173 case SSH_STATE_BEFORE_SIZE:
3687d221 5174 case SSH_STATE_PREPACKET:
21248260 5175 case SSH_STATE_CLOSED:
374330e2 5176 break; /* do nothing */
5177 case SSH_STATE_INTERMED:
5178 size_needed = TRUE; /* buffer for later */
5179 break;
5180 case SSH_STATE_SESSION:
32874aea 5181 if (!cfg.nopty) {
5182 if (ssh_version == 1) {
5183 send_packet(SSH1_CMSG_WINDOW_SIZE,
5184 PKT_INT, rows, PKT_INT, cols,
5185 PKT_INT, 0, PKT_INT, 0, PKT_END);
5186 } else {
5187 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5188 ssh2_pkt_adduint32(mainchan->remoteid);
5189 ssh2_pkt_addstring("window-change");
5190 ssh2_pkt_addbool(0);
5191 ssh2_pkt_adduint32(cols);
5192 ssh2_pkt_adduint32(rows);
5193 ssh2_pkt_adduint32(0);
5194 ssh2_pkt_adduint32(0);
5195 ssh2_pkt_send();
5196 }
5197 }
5198 break;
374330e2 5199 }
5200}
5201
5202/*
6abbf9e3 5203 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5204 * can send an EOF and collect resulting output (e.g. `plink
5205 * hostname sort').
374330e2 5206 */
32874aea 5207static void ssh_special(Telnet_Special code)
5208{
6abbf9e3 5209 if (code == TS_EOF) {
32874aea 5210 if (ssh_state != SSH_STATE_SESSION) {
5211 /*
5212 * Buffer the EOF in case we are pre-SESSION, so we can
5213 * send it as soon as we reach SESSION.
5214 */
5215 if (code == TS_EOF)
5216 eof_needed = TRUE;
5217 return;
5218 }
5219 if (ssh_version == 1) {
5220 send_packet(SSH1_CMSG_EOF, PKT_END);
5221 } else {
5222 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5223 ssh2_pkt_adduint32(mainchan->remoteid);
5224 ssh2_pkt_send();
5225 }
5226 logevent("Sent EOF message");
ec55b220 5227 } else if (code == TS_PING) {
32874aea 5228 if (ssh_state == SSH_STATE_CLOSED
5229 || ssh_state == SSH_STATE_PREPACKET) return;
5230 if (ssh_version == 1) {
5231 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5232 } else {
5233 ssh2_pkt_init(SSH2_MSG_IGNORE);
5234 ssh2_pkt_addstring_start();
5235 ssh2_pkt_send();
5236 }
6abbf9e3 5237 } else {
32874aea 5238 /* do nothing */
6abbf9e3 5239 }
374330e2 5240}
5241
d74d141c 5242void *new_sock_channel(Socket s)
5243{
5244 struct ssh_channel *c;
5245 c = smalloc(sizeof(struct ssh_channel));
5246
5247 if (c) {
bc240b21 5248 c->remoteid = -1; /* to be set when open confirmed */
d74d141c 5249 c->localid = alloc_channel_id();
5250 c->closes = 0;
bc240b21 5251 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 5252 c->u.pfd.s = s;
5253 add234(ssh_channels, c);
5254 }
5255 return c;
5256}
5257
5471d09a 5258/*
5259 * This is called when stdout/stderr (the entity to which
5260 * from_backend sends data) manages to clear some backlog.
5261 */
5262void ssh_unthrottle(int bufsize)
5263{
5264 if (ssh_version == 1) {
90347b95 5265 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5471d09a 5266 ssh1_stdout_throttling = 0;
5267 ssh1_throttle(-1);
5268 }
5269 } else {
5270 if (mainchan && mainchan->closes == 0)
5271 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5272 }
5273}
5274
d74d141c 5275void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5276{
5277 struct ssh_channel *c = (struct ssh_channel *)channel;
5278 char buf[1024];
5279
5280 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5281 logevent(buf);
5282
bc240b21 5283 if (ssh_version == 1) {
5284 send_packet(SSH1_MSG_PORT_OPEN,
5285 PKT_INT, c->localid,
5286 PKT_STR, hostname,
5287 PKT_INT, port,
5288 //PKT_STR, <org:orgport>,
5289 PKT_END);
5290 } else {
5291 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5292 ssh2_pkt_addstring("direct-tcpip");
5293 ssh2_pkt_adduint32(c->localid);
5471d09a 5294 c->v.v2.locwindow = OUR_V2_WINSIZE;
5295 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
bc240b21 5296 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5297 ssh2_pkt_addstring(hostname);
5298 ssh2_pkt_adduint32(port);
5299 /*
5300 * We make up values for the originator data; partly it's
5301 * too much hassle to keep track, and partly I'm not
5302 * convinced the server should be told details like that
5303 * about my local network configuration.
5304 */
5305 ssh2_pkt_addstring("client-side-connection");
5306 ssh2_pkt_adduint32(0);
5307 ssh2_pkt_send();
5308 }
d74d141c 5309}
5310
5311
32874aea 5312static Socket ssh_socket(void)
5313{
5314 return s;
5315}
8ccc75b0 5316
32874aea 5317static int ssh_sendok(void)
5318{
5319 return ssh_send_ok;
5320}
fb09bf1c 5321
32874aea 5322static int ssh_ldisc(int option)
5323{
5324 if (option == LD_ECHO)
5325 return ssh_echoing;
5326 if (option == LD_EDIT)
5327 return ssh_editing;
0965bee0 5328 return FALSE;
5329}
5330
374330e2 5331Backend ssh_backend = {
5332 ssh_init,
374330e2 5333 ssh_send,
5471d09a 5334 ssh_sendbuffer,
374330e2 5335 ssh_size,
4017be6d 5336 ssh_special,
8ccc75b0 5337 ssh_socket,
97db3be4 5338 ssh_sendok,
0965bee0 5339 ssh_ldisc,
5471d09a 5340 ssh_unthrottle,
97db3be4 5341 22
bc240b21 5342};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator