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Force gcc to use x86's built-in 64/32->32,32 division instruction
[u/mdw/putty] / ssh.c
CommitLineData
374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
374330e2 5
6#include "putty.h"
dacbd0e8 7#include "tree234.h"
fb09bf1c 8#include "ssh.h"
374330e2 9
10#ifndef FALSE
11#define FALSE 0
12#endif
13#ifndef TRUE
14#define TRUE 1
15#endif
16
32874aea 17#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20#define SSH1_CMSG_USER 4 /* 0x4 */
21#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29#define SSH1_SMSG_SUCCESS 14 /* 0xe */
30#define SSH1_SMSG_FAILURE 15 /* 0xf */
31#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34#define SSH1_CMSG_EOF 19 /* 0x13 */
35#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46#define SSH1_MSG_IGNORE 32 /* 0x20 */
47#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50#define SSH1_MSG_DEBUG 36 /* 0x24 */
51#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
58
59#define SSH1_AUTH_TIS 5 /* 0x5 */
60#define SSH1_AUTH_CCARD 16 /* 0x10 */
61
62#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 63/* Mask for protoflags we will echo back to server if seen */
32874aea 64#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
65
66#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67#define SSH2_MSG_IGNORE 2 /* 0x2 */
68#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69#define SSH2_MSG_DEBUG 4 /* 0x4 */
70#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72#define SSH2_MSG_KEXINIT 20 /* 0x14 */
73#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 86#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 88#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
102
00db133f 103/*
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
106 */
107#define SSH2_PKTCTX_DHGROUP1 0x0001
108#define SSH2_PKTCTX_DHGEX 0x0002
109#define SSH2_PKTCTX_PUBLICKEY 0x0010
110#define SSH2_PKTCTX_PASSWORD 0x0020
111#define SSH2_PKTCTX_KBDINTER 0x0040
112#define SSH2_PKTCTX_AUTH_MASK 0x00F0
113
32874aea 114#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 129
130static const char *const ssh2_disconnect_reasons[] = {
131 NULL,
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
147};
9005f3ba 148
32874aea 149#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 153
32874aea 154#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 155
7d503c31 156/*
157 * Various remote-bug flags.
158 */
159#define BUG_CHOKES_ON_SSH1_IGNORE 1
160#define BUG_SSH2_HMAC 2
bd358db1 161#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 162#define BUG_CHOKES_ON_RSA 8
1dd353b5 163#define BUG_SSH2_RSA_PADDING 16
088bde77 164#define BUG_SSH2_DERIVEKEY 32
8e975795 165#define BUG_SSH2_DH_GEX 64
dda87a28 166#define BUG_SSH2_PK_SESSIONID 128
bd358db1 167
00db133f 168#define translate(x) if (type == x) return #x
51470298 169#define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
ae9ae89f 170static char *ssh1_pkt_type(int type)
00db133f 171{
172 translate(SSH1_MSG_DISCONNECT);
173 translate(SSH1_SMSG_PUBLIC_KEY);
174 translate(SSH1_CMSG_SESSION_KEY);
175 translate(SSH1_CMSG_USER);
176 translate(SSH1_CMSG_AUTH_RSA);
177 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
178 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
179 translate(SSH1_CMSG_AUTH_PASSWORD);
180 translate(SSH1_CMSG_REQUEST_PTY);
181 translate(SSH1_CMSG_WINDOW_SIZE);
182 translate(SSH1_CMSG_EXEC_SHELL);
183 translate(SSH1_CMSG_EXEC_CMD);
184 translate(SSH1_SMSG_SUCCESS);
185 translate(SSH1_SMSG_FAILURE);
186 translate(SSH1_CMSG_STDIN_DATA);
187 translate(SSH1_SMSG_STDOUT_DATA);
188 translate(SSH1_SMSG_STDERR_DATA);
189 translate(SSH1_CMSG_EOF);
190 translate(SSH1_SMSG_EXIT_STATUS);
191 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
192 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
193 translate(SSH1_MSG_CHANNEL_DATA);
194 translate(SSH1_MSG_CHANNEL_CLOSE);
195 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
196 translate(SSH1_SMSG_X11_OPEN);
197 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
198 translate(SSH1_MSG_PORT_OPEN);
199 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
200 translate(SSH1_SMSG_AGENT_OPEN);
201 translate(SSH1_MSG_IGNORE);
202 translate(SSH1_CMSG_EXIT_CONFIRMATION);
203 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
204 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
205 translate(SSH1_MSG_DEBUG);
206 translate(SSH1_CMSG_REQUEST_COMPRESSION);
207 translate(SSH1_CMSG_AUTH_TIS);
208 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
209 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
210 translate(SSH1_CMSG_AUTH_CCARD);
211 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
212 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
213 return "unknown";
214}
ae9ae89f 215static char *ssh2_pkt_type(int pkt_ctx, int type)
00db133f 216{
217 translate(SSH2_MSG_DISCONNECT);
218 translate(SSH2_MSG_IGNORE);
219 translate(SSH2_MSG_UNIMPLEMENTED);
220 translate(SSH2_MSG_DEBUG);
221 translate(SSH2_MSG_SERVICE_REQUEST);
222 translate(SSH2_MSG_SERVICE_ACCEPT);
223 translate(SSH2_MSG_KEXINIT);
224 translate(SSH2_MSG_NEWKEYS);
225 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
226 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
227 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
231 translate(SSH2_MSG_USERAUTH_REQUEST);
232 translate(SSH2_MSG_USERAUTH_FAILURE);
233 translate(SSH2_MSG_USERAUTH_SUCCESS);
234 translate(SSH2_MSG_USERAUTH_BANNER);
235 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
236 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
237 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
238 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
239 translate(SSH2_MSG_GLOBAL_REQUEST);
240 translate(SSH2_MSG_REQUEST_SUCCESS);
241 translate(SSH2_MSG_REQUEST_FAILURE);
242 translate(SSH2_MSG_CHANNEL_OPEN);
243 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
244 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
245 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
246 translate(SSH2_MSG_CHANNEL_DATA);
247 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
248 translate(SSH2_MSG_CHANNEL_EOF);
249 translate(SSH2_MSG_CHANNEL_CLOSE);
250 translate(SSH2_MSG_CHANNEL_REQUEST);
251 translate(SSH2_MSG_CHANNEL_SUCCESS);
252 translate(SSH2_MSG_CHANNEL_FAILURE);
253 return "unknown";
254}
255#undef translate
256#undef translatec
7d503c31 257
fb09bf1c 258#define GET_32BIT(cp) \
259 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
260 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
261 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
262 ((unsigned long)(unsigned char)(cp)[3]))
263
264#define PUT_32BIT(cp, value) { \
265 (cp)[0] = (unsigned char)((value) >> 24); \
266 (cp)[1] = (unsigned char)((value) >> 16); \
267 (cp)[2] = (unsigned char)((value) >> 8); \
268 (cp)[3] = (unsigned char)(value); }
269
7cca0d81 270enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 271
acddebd9 272/*
273 * Coroutine mechanics for the sillier bits of the code. If these
274 * macros look impenetrable to you, you might find it helpful to
275 * read
276 *
277 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
278 *
279 * which explains the theory behind these macros.
b624d1e6 280 *
281 * In particular, if you are getting `case expression not constant'
282 * errors when building with MS Visual Studio, this is because MS's
283 * Edit and Continue debugging feature causes their compiler to
284 * violate ANSI C. To disable Edit and Continue debugging:
285 *
286 * - right-click ssh.c in the FileView
287 * - click Settings
288 * - select the C/C++ tab and the General category
289 * - under `Debug info:', select anything _other_ than `Program
290 * Database for Edit and Continue'.
acddebd9 291 */
51470298 292#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
293#define crState(t) \
294 struct t *s; \
3d88e64d 295 if (!ssh->t) ssh->t = snew(struct t); \
51470298 296 s = ssh->t;
297#define crFinish(z) } *crLine = 0; return (z); }
298#define crFinishV } *crLine = 0; return; }
374330e2 299#define crReturn(z) \
300 do {\
51470298 301 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 302 } while (0)
303#define crReturnV \
304 do {\
51470298 305 *crLine=__LINE__; return; case __LINE__:;\
374330e2 306 } while (0)
51470298 307#define crStop(z) do{ *crLine = 0; return (z); }while(0)
308#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 309#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 310#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 311
51470298 312typedef struct ssh_tag *Ssh;
313
51470298 314static void ssh2_pkt_init(Ssh, int pkt_type);
315static void ssh2_pkt_addbool(Ssh, unsigned char value);
316static void ssh2_pkt_adduint32(Ssh, unsigned long value);
317static void ssh2_pkt_addstring_start(Ssh);
318static void ssh2_pkt_addstring_str(Ssh, char *data);
319static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
320static void ssh2_pkt_addstring(Ssh, char *data);
d8baa528 321static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
51470298 322static void ssh2_pkt_addmp(Ssh, Bignum b);
323static int ssh2_pkt_construct(Ssh);
324static void ssh2_pkt_send(Ssh);
3d63ca2e 325
5471d09a 326/*
327 * Buffer management constants. There are several of these for
328 * various different purposes:
329 *
330 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
331 * on a local data stream before we throttle the whole SSH
332 * connection (in SSH1 only). Throttling the whole connection is
333 * pretty drastic so we set this high in the hope it won't
334 * happen very often.
335 *
336 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
337 * on the SSH connection itself before we defensively throttle
338 * _all_ local data streams. This is pretty drastic too (though
339 * thankfully unlikely in SSH2 since the window mechanism should
340 * ensure that the server never has any need to throttle its end
341 * of the connection), so we set this high as well.
342 *
343 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
344 * channels.
345 */
346
347#define SSH1_BUFFER_LIMIT 32768
348#define SSH_MAX_BACKLOG 32768
349#define OUR_V2_WINSIZE 16384
d74d141c 350
a92dd380 351const static struct ssh_kex *kex_algs[] = {
a92dd380 352 &ssh_diffiehellman_gex,
32874aea 353 &ssh_diffiehellman
354};
e5574168 355
85cc02bb 356const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 357
e0e1a00d 358static void *nullmac_make_context(void)
359{
360 return NULL;
361}
362static void nullmac_free_context(void *handle)
363{
364}
365static void nullmac_key(void *handle, unsigned char *key)
32874aea 366{
367}
e0e1a00d 368static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 369 unsigned long seq)
370{
371}
e0e1a00d 372static int nullmac_verify(void *handle, unsigned char *blk, int len,
373 unsigned long seq)
32874aea 374{
375 return 1;
376}
57476f6b 377const static struct ssh_mac ssh_mac_none = {
e0e1a00d 378 nullmac_make_context, nullmac_free_context, nullmac_key,
379 nullmac_generate, nullmac_verify, "none", 0
e5574168 380};
8b2715b2 381const static struct ssh_mac *macs[] = {
32874aea 382 &ssh_sha1, &ssh_md5, &ssh_mac_none
383};
8b2715b2 384const static struct ssh_mac *buggymacs[] = {
32874aea 385 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
386};
e5574168 387
5366aed8 388static void *ssh_comp_none_init(void)
389{
390 return NULL;
391}
392static void ssh_comp_none_cleanup(void *handle)
32874aea 393{
394}
5366aed8 395static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 396 unsigned char **outblock, int *outlen)
397{
398 return 0;
399}
5366aed8 400static int ssh_comp_none_disable(void *handle)
32874aea 401{
4ba9b64b 402 return 0;
403}
57476f6b 404const static struct ssh_compress ssh_comp_none = {
4ba9b64b 405 "none",
5366aed8 406 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
407 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
408 ssh_comp_none_disable, NULL
e5574168 409};
4ba9b64b 410extern const struct ssh_compress ssh_zlib;
411const static struct ssh_compress *compressions[] = {
32874aea 412 &ssh_zlib, &ssh_comp_none
413};
374330e2 414
32874aea 415enum { /* channel types */
783415f8 416 CHAN_MAINSESSION,
417 CHAN_X11,
418 CHAN_AGENT,
bc240b21 419 CHAN_SOCKDATA,
420 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 421};
422
dacbd0e8 423/*
424 * 2-3-4 tree storing channels.
425 */
426struct ssh_channel {
51470298 427 Ssh ssh; /* pointer back to main context */
d211621f 428 unsigned remoteid, localid;
dacbd0e8 429 int type;
0357890f 430 /*
431 * In SSH1, this value contains four bits:
432 *
433 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
434 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
435 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
436 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
437 *
438 * A channel is completely finished with when all four bits are set.
439 */
dacbd0e8 440 int closes;
5471d09a 441 union {
442 struct ssh1_data_channel {
443 int throttling;
444 } v1;
445 struct ssh2_data_channel {
446 bufchain outbuffer;
447 unsigned remwindow, remmaxpkt;
448 unsigned locwindow;
449 } v2;
450 } v;
dacbd0e8 451 union {
32874aea 452 struct ssh_agent_channel {
453 unsigned char *message;
454 unsigned char msglen[4];
455 int lensofar, totallen;
456 } a;
457 struct ssh_x11_channel {
458 Socket s;
459 } x11;
d74d141c 460 struct ssh_pfd_channel {
461 Socket s;
462 } pfd;
dacbd0e8 463 } u;
464};
57476f6b 465
d74d141c 466/*
bc240b21 467 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
468 * 2 use this structure in different ways, reflecting SSH 2's
469 * altogether saner approach to port forwarding.
470 *
471 * In SSH 1, you arrange a remote forwarding by sending the server
472 * the remote port number, and the local destination host:port.
473 * When a connection comes in, the server sends you back that
474 * host:port pair, and you connect to it. This is a ready-made
475 * security hole if you're not on the ball: a malicious server
476 * could send you back _any_ host:port pair, so if you trustingly
477 * connect to the address it gives you then you've just opened the
478 * entire inside of your corporate network just by connecting
479 * through it to a dodgy SSH server. Hence, we must store a list of
480 * host:port pairs we _are_ trying to forward to, and reject a
481 * connection request from the server if it's not in the list.
482 *
483 * In SSH 2, each side of the connection minds its own business and
484 * doesn't send unnecessary information to the other. You arrange a
485 * remote forwarding by sending the server just the remote port
486 * number. When a connection comes in, the server tells you which
487 * of its ports was connected to; and _you_ have to remember what
488 * local host:port pair went with that port number.
489 *
490 * Hence: in SSH 1 this structure stores host:port pairs we intend
491 * to allow connections to, and is indexed by those host:port
492 * pairs. In SSH 2 it stores a mapping from source port to
493 * destination host:port pair, and is indexed by source port.
d74d141c 494 */
495struct ssh_rportfwd {
bc240b21 496 unsigned sport, dport;
497 char dhost[256];
d74d141c 498};
499
57476f6b 500struct Packet {
501 long length;
502 int type;
503 unsigned char *data;
504 unsigned char *body;
505 long savedpos;
506 long maxlen;
507};
508
51470298 509static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
510static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
511static void ssh_size(void *handle, int width, int height);
512static void ssh_special(void *handle, Telnet_Special);
5471d09a 513static int ssh2_try_send(struct ssh_channel *c);
51470298 514static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
515static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 516static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 517static int ssh_sendbuffer(void *handle);
57476f6b 518
51470298 519struct rdpkt1_state_tag {
57476f6b 520 long len, pad, biglen, to_read;
521 unsigned long realcrc, gotcrc;
522 unsigned char *p;
523 int i;
524 int chunk;
51470298 525};
57476f6b 526
51470298 527struct rdpkt2_state_tag {
960e736a 528 long len, pad, payload, packetlen, maclen;
529 int i;
530 int cipherblk;
531 unsigned long incoming_sequence;
51470298 532};
533
534struct ssh_tag {
535 const struct plug_function_table *fn;
536 /* the above field _must_ be first in the structure */
537
538 SHA_State exhash, exhashbase;
539
540 Socket s;
541
b9d7bcad 542 void *ldisc;
a8327734 543 void *logctx;
b9d7bcad 544
51470298 545 unsigned char session_key[32];
546 int v1_compressing;
547 int v1_remote_protoflags;
548 int v1_local_protoflags;
549 int agentfwd_enabled;
550 int X11_fwd_enabled;
551 int remote_bugs;
552 const struct ssh_cipher *cipher;
371e569c 553 void *v1_cipher_ctx;
0183b242 554 void *crcda_ctx;
51470298 555 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 556 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 557 const struct ssh_mac *csmac, *scmac;
e0e1a00d 558 void *cs_mac_ctx, *sc_mac_ctx;
51470298 559 const struct ssh_compress *cscomp, *sccomp;
5366aed8 560 void *cs_comp_ctx, *sc_comp_ctx;
51470298 561 const struct ssh_kex *kex;
562 const struct ssh_signkey *hostkey;
563 unsigned char v2_session_id[20];
27cd7fc2 564 void *kex_ctx;
51470298 565
566 char *savedhost;
567 int savedport;
568 int send_ok;
569 int echoing, editing;
570
571 void *frontend;
572
573 int term_width, term_height;
574
575 tree234 *channels; /* indexed by local id */
576 struct ssh_channel *mainchan; /* primary session channel */
577 int exitcode;
578
579 tree234 *rportfwds;
580
581 enum {
582 SSH_STATE_PREPACKET,
583 SSH_STATE_BEFORE_SIZE,
584 SSH_STATE_INTERMED,
585 SSH_STATE_SESSION,
586 SSH_STATE_CLOSED
587 } state;
588
589 int size_needed, eof_needed;
590
591 struct Packet pktin;
592 struct Packet pktout;
593 unsigned char *deferred_send_data;
594 int deferred_len, deferred_size;
595
596 /*
597 * Gross hack: pscp will try to start SFTP but fall back to
598 * scp1 if that fails. This variable is the means by which
599 * scp.c can reach into the SSH code and find out which one it
600 * got.
601 */
602 int fallback_cmd;
603
604 /*
605 * Used for username and password input.
606 */
607 char *userpass_input_buffer;
608 int userpass_input_buflen;
609 int userpass_input_bufpos;
610 int userpass_input_echo;
611
612 char *portfwd_strptr;
613 int pkt_ctx;
614
302121de 615 void *x11auth;
616
51470298 617 int version;
618 int v1_throttle_count;
619 int overall_bufsize;
620 int throttled_all;
621 int v1_stdout_throttling;
622 int v2_outgoing_sequence;
623
624 int ssh1_rdpkt_crstate;
625 int ssh2_rdpkt_crstate;
626 int do_ssh_init_crstate;
627 int ssh_gotdata_crstate;
628 int ssh1_protocol_crstate;
629 int do_ssh1_login_crstate;
630 int do_ssh2_transport_crstate;
631 int do_ssh2_authconn_crstate;
632
633 void *do_ssh_init_state;
634 void *do_ssh1_login_state;
635 void *do_ssh2_transport_state;
636 void *do_ssh2_authconn_state;
637
638 struct rdpkt1_state_tag rdpkt1_state;
639 struct rdpkt2_state_tag rdpkt2_state;
640
641 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
642 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 643
644 /*
645 * We maintain a full _copy_ of a Config structure here, not
646 * merely a pointer to it. That way, when we're passed a new
647 * one for reconfiguration, we can check the differences and
648 * potentially reconfigure port forwardings etc in mid-session.
649 */
650 Config cfg;
51470298 651};
960e736a 652
382908ad 653#define logevent(s) logevent(ssh->frontend, s)
a8327734 654
655/* logevent, only printf-formatted. */
ae9ae89f 656static void logeventf(Ssh ssh, char *fmt, ...)
a8327734 657{
658 va_list ap;
57356d63 659 char *buf;
a8327734 660
661 va_start(ap, fmt);
57356d63 662 buf = dupvprintf(fmt, ap);
a8327734 663 va_end(ap);
57356d63 664 logevent(buf);
57356d63 665 sfree(buf);
a8327734 666}
667
6b5cf8b4 668#define bombout(msg) \
669 do { \
670 char *text = dupprintf msg; \
671 ssh->state = SSH_STATE_CLOSED; \
672 if (ssh->s) { sk_close(ssh->s); ssh->s = NULL; } \
673 logevent(text); \
674 connection_fatal(ssh->frontend, "%s", text); \
675 sfree(text); \
676 } while (0)
a8327734 677
32874aea 678static int ssh_channelcmp(void *av, void *bv)
679{
680 struct ssh_channel *a = (struct ssh_channel *) av;
681 struct ssh_channel *b = (struct ssh_channel *) bv;
682 if (a->localid < b->localid)
683 return -1;
684 if (a->localid > b->localid)
685 return +1;
dacbd0e8 686 return 0;
687}
32874aea 688static int ssh_channelfind(void *av, void *bv)
689{
690 unsigned *a = (unsigned *) av;
691 struct ssh_channel *b = (struct ssh_channel *) bv;
692 if (*a < b->localid)
693 return -1;
694 if (*a > b->localid)
695 return +1;
dacbd0e8 696 return 0;
697}
698
bc240b21 699static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 700{
701 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
702 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
703 int i;
bc240b21 704 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 705 return i < 0 ? -1 : +1;
bc240b21 706 if (a->dport > b->dport)
707 return +1;
708 if (a->dport < b->dport)
709 return -1;
710 return 0;
711}
712
713static int ssh_rportcmp_ssh2(void *av, void *bv)
714{
715 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
716 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 717
bc240b21 718 if (a->sport > b->sport)
d74d141c 719 return +1;
bc240b21 720 if (a->sport < b->sport)
721 return -1;
d74d141c 722 return 0;
723}
724
51470298 725static int alloc_channel_id(Ssh ssh)
32874aea 726{
260f3dec 727 const unsigned CHANNEL_NUMBER_OFFSET = 256;
728 unsigned low, high, mid;
d2371c81 729 int tsize;
730 struct ssh_channel *c;
731
732 /*
733 * First-fit allocation of channel numbers: always pick the
734 * lowest unused one. To do this, binary-search using the
735 * counted B-tree to find the largest channel ID which is in a
736 * contiguous sequence from the beginning. (Precisely
737 * everything in that sequence must have ID equal to its tree
738 * index plus CHANNEL_NUMBER_OFFSET.)
739 */
51470298 740 tsize = count234(ssh->channels);
d2371c81 741
32874aea 742 low = -1;
743 high = tsize;
d2371c81 744 while (high - low > 1) {
745 mid = (high + low) / 2;
51470298 746 c = index234(ssh->channels, mid);
d2371c81 747 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
748 low = mid; /* this one is fine */
749 else
750 high = mid; /* this one is past it */
751 }
752 /*
753 * Now low points to either -1, or the tree index of the
754 * largest ID in the initial sequence.
755 */
756 {
757 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 758 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 759 }
760 return low + 1 + CHANNEL_NUMBER_OFFSET;
761}
762
9fab77dc 763static void c_write(Ssh ssh, const char *buf, int len)
32874aea 764{
67779be7 765 if ((flags & FLAG_STDERR)) {
32874aea 766 int i;
767 for (i = 0; i < len; i++)
768 if (buf[i] != '\r')
769 fputc(buf[i], stderr);
fb09bf1c 770 return;
771 }
51470298 772 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 773}
774
9fab77dc 775static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 776{
a209e957 777 int i;
778 for (i = 0; i < len; i++) {
32874aea 779 if (buf[i] == '\n')
51470298 780 c_write(ssh, "\r\n", 2);
32874aea 781 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 782 c_write(ssh, buf + i, 1);
a209e957 783 }
784}
785
9fab77dc 786static void c_write_str(Ssh ssh, const char *buf)
32874aea 787{
51470298 788 c_write(ssh, buf, strlen(buf));
1408a877 789}
790
fb09bf1c 791/*
792 * Collect incoming data in the incoming packet buffer.
e5574168 793 * Decipher and verify the packet when it is completely read.
794 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 795 * Update the *data and *datalen variables.
796 * Return the additional nr of bytes needed, or 0 when
797 * a complete packet is available.
798 */
51470298 799static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 800{
51470298 801 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 802
51470298 803 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 804
32874aea 805 next_packet:
37508af4 806
51470298 807 ssh->pktin.type = 0;
808 ssh->pktin.length = 0;
374330e2 809
57476f6b 810 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 811 while ((*datalen) == 0)
32874aea 812 crReturn(4 - st->i);
57476f6b 813 st->len = (st->len << 8) + **data;
fb09bf1c 814 (*data)++, (*datalen)--;
815 }
374330e2 816
57476f6b 817 st->pad = 8 - (st->len % 8);
818 st->biglen = st->len + st->pad;
51470298 819 ssh->pktin.length = st->len - 5;
fb09bf1c 820
51470298 821 if (ssh->pktin.maxlen < st->biglen) {
822 ssh->pktin.maxlen = st->biglen;
3d88e64d 823 ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA,
824 unsigned char);
fb09bf1c 825 }
374330e2 826
57476f6b 827 st->to_read = st->biglen;
51470298 828 st->p = ssh->pktin.data;
57476f6b 829 while (st->to_read > 0) {
32874aea 830 st->chunk = st->to_read;
fb09bf1c 831 while ((*datalen) == 0)
57476f6b 832 crReturn(st->to_read);
833 if (st->chunk > (*datalen))
834 st->chunk = (*datalen);
835 memcpy(st->p, *data, st->chunk);
836 *data += st->chunk;
837 *datalen -= st->chunk;
838 st->p += st->chunk;
839 st->to_read -= st->chunk;
fb09bf1c 840 }
374330e2 841
0183b242 842 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
843 st->biglen, NULL)) {
6b5cf8b4 844 bombout(("Network attack (CRC compensation) detected!"));
7ffdbc1a 845 crStop(0);
9a3a93a5 846 }
847
51470298 848 if (ssh->cipher)
371e569c 849 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
374330e2 850
51470298 851 st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
852 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
57476f6b 853 if (st->gotcrc != st->realcrc) {
6b5cf8b4 854 bombout(("Incorrect CRC received on packet"));
7ffdbc1a 855 crStop(0);
fb09bf1c 856 }
572f871e 857
51470298 858 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
4ba9b64b 859
51470298 860 if (ssh->v1_compressing) {
4ba9b64b 861 unsigned char *decompblk;
862 int decomplen;
5366aed8 863 zlib_decompress_block(ssh->sc_comp_ctx,
864 ssh->pktin.body - 1, ssh->pktin.length + 1,
4ba9b64b 865 &decompblk, &decomplen);
866
51470298 867 if (ssh->pktin.maxlen < st->pad + decomplen) {
868 ssh->pktin.maxlen = st->pad + decomplen;
3d88e64d 869 ssh->pktin.data = sresize(ssh->pktin.data,
870 ssh->pktin.maxlen + APIEXTRA,
871 unsigned char);
51470298 872 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
4ba9b64b 873 }
874
51470298 875 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
dcbde236 876 sfree(decompblk);
51470298 877 ssh->pktin.length = decomplen - 1;
4ba9b64b 878 }
879
51470298 880 ssh->pktin.type = ssh->pktin.body[-1];
00db133f 881
a8327734 882 if (ssh->logctx)
883 log_packet(ssh->logctx,
884 PKT_INCOMING, ssh->pktin.type,
885 ssh1_pkt_type(ssh->pktin.type),
886 ssh->pktin.body, ssh->pktin.length);
00db133f 887
51470298 888 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
889 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
890 ssh->pktin.type == SSH1_MSG_DEBUG ||
891 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
892 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
893 long stringlen = GET_32BIT(ssh->pktin.body);
894 if (stringlen + 4 != ssh->pktin.length) {
6b5cf8b4 895 bombout(("Received data packet with bogus string length"));
7ffdbc1a 896 crStop(0);
32874aea 897 }
fb09bf1c 898 }
899
51470298 900 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 901 /* log debug message */
eb4504cc 902 char buf[512];
51470298 903 int stringlen = GET_32BIT(ssh->pktin.body);
eb4504cc 904 strcpy(buf, "Remote debug message: ");
905 if (stringlen > 480)
906 stringlen = 480;
51470298 907 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
3d63ca2e 908 buf[8 + stringlen] = '\0';
fb09bf1c 909 logevent(buf);
910 goto next_packet;
51470298 911 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 912 /* do nothing */
913 goto next_packet;
914 }
915
51470298 916 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
38c4a8da 917 /* log reason code in disconnect message */
918 char buf[256];
51470298 919 unsigned msglen = GET_32BIT(ssh->pktin.body);
260f3dec 920 unsigned nowlen;
38c4a8da 921 strcpy(buf, "Remote sent disconnect: ");
922 nowlen = strlen(buf);
32874aea 923 if (msglen > sizeof(buf) - nowlen - 1)
924 msglen = sizeof(buf) - nowlen - 1;
51470298 925 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
32874aea 926 buf[nowlen + msglen] = '\0';
247308b5 927 /* logevent(buf); (this is now done within the bombout macro) */
6b5cf8b4 928 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
7ffdbc1a 929 crStop(0);
38c4a8da 930 }
931
fb09bf1c 932 crFinish(0);
933}
934
51470298 935static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 936{
51470298 937 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 938
51470298 939 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 940
32874aea 941 next_packet:
51470298 942 ssh->pktin.type = 0;
943 ssh->pktin.length = 0;
944 if (ssh->sccipher)
945 st->cipherblk = ssh->sccipher->blksize;
e5574168 946 else
32874aea 947 st->cipherblk = 8;
960e736a 948 if (st->cipherblk < 8)
32874aea 949 st->cipherblk = 8;
960e736a 950
51470298 951 if (ssh->pktin.maxlen < st->cipherblk) {
952 ssh->pktin.maxlen = st->cipherblk;
3d88e64d 953 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
954 unsigned char);
e5574168 955 }
956
957 /*
958 * Acquire and decrypt the first block of the packet. This will
959 * contain the length and padding details.
960 */
32874aea 961 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 962 while ((*datalen) == 0)
32874aea 963 crReturn(st->cipherblk - st->i);
51470298 964 ssh->pktin.data[st->i] = *(*data)++;
32874aea 965 (*datalen)--;
e5574168 966 }
4252c9cc 967
51470298 968 if (ssh->sccipher)
371e569c 969 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
970 ssh->pktin.data, st->cipherblk);
e5574168 971
972 /*
973 * Now get the length and padding figures.
974 */
51470298 975 st->len = GET_32BIT(ssh->pktin.data);
976 st->pad = ssh->pktin.data[4];
e5574168 977
978 /*
717dc483 979 * _Completely_ silly lengths should be stomped on before they
980 * do us any more damage.
981 */
982 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
6b5cf8b4 983 bombout(("Incoming packet was garbled on decryption"));
7ffdbc1a 984 crStop(0);
717dc483 985 }
986
987 /*
e5574168 988 * This enables us to deduce the payload length.
989 */
960e736a 990 st->payload = st->len - st->pad - 1;
e5574168 991
51470298 992 ssh->pktin.length = st->payload + 5;
e5574168 993
994 /*
995 * So now we can work out the total packet length.
996 */
960e736a 997 st->packetlen = st->len + 4;
51470298 998 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 999
1000 /*
1001 * Adjust memory allocation if packet is too big.
1002 */
51470298 1003 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1004 ssh->pktin.maxlen = st->packetlen + st->maclen;
3d88e64d 1005 ssh->pktin.data = sresize(ssh->pktin.data,
1006 ssh->pktin.maxlen + APIEXTRA,
1007 unsigned char);
e5574168 1008 }
1009
1010 /*
1011 * Read and decrypt the remainder of the packet.
1012 */
32874aea 1013 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1014 st->i++) {
e5574168 1015 while ((*datalen) == 0)
960e736a 1016 crReturn(st->packetlen + st->maclen - st->i);
51470298 1017 ssh->pktin.data[st->i] = *(*data)++;
32874aea 1018 (*datalen)--;
e5574168 1019 }
1020 /* Decrypt everything _except_ the MAC. */
51470298 1021 if (ssh->sccipher)
371e569c 1022 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1023 ssh->pktin.data + st->cipherblk,
51470298 1024 st->packetlen - st->cipherblk);
e5574168 1025
1026 /*
1027 * Check the MAC.
1028 */
51470298 1029 if (ssh->scmac
e0e1a00d 1030 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
51470298 1031 st->incoming_sequence)) {
6b5cf8b4 1032 bombout(("Incorrect MAC received on packet"));
7ffdbc1a 1033 crStop(0);
8d5de777 1034 }
32874aea 1035 st->incoming_sequence++; /* whether or not we MACed */
e5574168 1036
4ba9b64b 1037 /*
1038 * Decompress packet payload.
1039 */
1040 {
1041 unsigned char *newpayload;
1042 int newlen;
51470298 1043 if (ssh->sccomp &&
5366aed8 1044 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1045 ssh->pktin.data + 5, ssh->pktin.length - 5,
51470298 1046 &newpayload, &newlen)) {
1047 if (ssh->pktin.maxlen < newlen + 5) {
1048 ssh->pktin.maxlen = newlen + 5;
3d88e64d 1049 ssh->pktin.data = sresize(ssh->pktin.data,
1050 ssh->pktin.maxlen + APIEXTRA,
1051 unsigned char);
4ba9b64b 1052 }
51470298 1053 ssh->pktin.length = 5 + newlen;
1054 memcpy(ssh->pktin.data + 5, newpayload, newlen);
dcbde236 1055 sfree(newpayload);
4ba9b64b 1056 }
1057 }
1058
51470298 1059 ssh->pktin.savedpos = 6;
1060 ssh->pktin.type = ssh->pktin.data[5];
e5574168 1061
a8327734 1062 if (ssh->logctx)
1063 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1064 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1065 ssh->pktin.data+6, ssh->pktin.length-6);
00db133f 1066
51470298 1067 switch (ssh->pktin.type) {
3d63ca2e 1068 /*
1069 * These packets we must handle instantly.
1070 */
1071 case SSH2_MSG_DISCONNECT:
1072 {
1073 /* log reason code in disconnect message */
57356d63 1074 char *buf;
1075 int nowlen;
51470298 1076 int reason = GET_32BIT(ssh->pktin.data + 6);
1077 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
57356d63 1078
3d63ca2e 1079 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
57356d63 1080 buf = dupprintf("Received disconnect message (%s)",
1081 ssh2_disconnect_reasons[reason]);
3d63ca2e 1082 } else {
57356d63 1083 buf = dupprintf("Received disconnect message (unknown"
1084 " type %d)", reason);
3d63ca2e 1085 }
1086 logevent(buf);
57356d63 1087 sfree(buf);
1088 buf = dupprintf("Disconnection message text: %n%.*s",
33b82b22 1089 &nowlen, msglen, ssh->pktin.data + 14);
3d63ca2e 1090 logevent(buf);
6b5cf8b4 1091 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
3d63ca2e 1092 reason,
1093 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1094 ssh2_disconnect_reasons[reason] : "unknown",
1095 buf+nowlen));
57356d63 1096 sfree(buf);
7ffdbc1a 1097 crStop(0);
3d63ca2e 1098 }
1099 break;
1100 case SSH2_MSG_IGNORE:
1101 goto next_packet;
1102 case SSH2_MSG_DEBUG:
1103 {
1104 /* log the debug message */
1105 char buf[512];
51470298 1106 /* int display = ssh->pktin.body[6]; */
1107 int stringlen = GET_32BIT(ssh->pktin.data+7);
3d63ca2e 1108 int prefix;
1109 strcpy(buf, "Remote debug message: ");
1110 prefix = strlen(buf);
51470298 1111 if (stringlen > (int)(sizeof(buf)-prefix-1))
3d63ca2e 1112 stringlen = sizeof(buf)-prefix-1;
51470298 1113 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
3d63ca2e 1114 buf[prefix + stringlen] = '\0';
1115 logevent(buf);
38c4a8da 1116 }
3d63ca2e 1117 goto next_packet; /* FIXME: print the debug message */
1118
1119 /*
1120 * These packets we need do nothing about here.
1121 */
1122 case SSH2_MSG_UNIMPLEMENTED:
1123 case SSH2_MSG_SERVICE_REQUEST:
1124 case SSH2_MSG_SERVICE_ACCEPT:
1125 case SSH2_MSG_KEXINIT:
1126 case SSH2_MSG_NEWKEYS:
1127 case SSH2_MSG_KEXDH_INIT:
1128 case SSH2_MSG_KEXDH_REPLY:
1129 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1130 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1131 case SSH2_MSG_KEX_DH_GEX_INIT:
1132 case SSH2_MSG_KEX_DH_GEX_REPLY:
1133 case SSH2_MSG_USERAUTH_REQUEST:
1134 case SSH2_MSG_USERAUTH_FAILURE:
1135 case SSH2_MSG_USERAUTH_SUCCESS:
1136 case SSH2_MSG_USERAUTH_BANNER:
1137 case SSH2_MSG_USERAUTH_PK_OK:
1138 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1139 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1140 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1141 case SSH2_MSG_GLOBAL_REQUEST:
1142 case SSH2_MSG_REQUEST_SUCCESS:
1143 case SSH2_MSG_REQUEST_FAILURE:
1144 case SSH2_MSG_CHANNEL_OPEN:
1145 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1146 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1147 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1148 case SSH2_MSG_CHANNEL_DATA:
1149 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1150 case SSH2_MSG_CHANNEL_EOF:
1151 case SSH2_MSG_CHANNEL_CLOSE:
1152 case SSH2_MSG_CHANNEL_REQUEST:
1153 case SSH2_MSG_CHANNEL_SUCCESS:
1154 case SSH2_MSG_CHANNEL_FAILURE:
1155 break;
1156
1157 /*
1158 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1159 */
1160 default:
51470298 1161 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1162 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1163 ssh2_pkt_send(ssh);
3d63ca2e 1164 break;
38c4a8da 1165 }
1166
e5574168 1167 crFinish(0);
1168}
1169
51470298 1170static void ssh1_pktout_size(Ssh ssh, int len)
32874aea 1171{
374330e2 1172 int pad, biglen;
1173
1174 len += 5; /* type and CRC */
32874aea 1175 pad = 8 - (len % 8);
374330e2 1176 biglen = len + pad;
1177
51470298 1178 ssh->pktout.length = len - 5;
1179 if (ssh->pktout.maxlen < biglen) {
1180 ssh->pktout.maxlen = biglen;
8f203108 1181#ifdef MSCRYPTOAPI
fb09bf1c 1182 /* Allocate enough buffer space for extra block
8f203108 1183 * for MS CryptEncrypt() */
3d88e64d 1184 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1185 unsigned char);
8f203108 1186#else
3d88e64d 1187 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1188 unsigned char);
8f203108 1189#endif
374330e2 1190 }
51470298 1191 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
4ba9b64b 1192}
374330e2 1193
51470298 1194static void s_wrpkt_start(Ssh ssh, int type, int len)
32874aea 1195{
51470298 1196 ssh1_pktout_size(ssh, len);
1197 ssh->pktout.type = type;
374330e2 1198}
1199
51470298 1200static int s_wrpkt_prepare(Ssh ssh)
32874aea 1201{
fd7a4aad 1202 int pad, biglen, i;
374330e2 1203 unsigned long crc;
fd7a4aad 1204#ifdef __SC__
1205 /*
1206 * XXX various versions of SC (including 8.8.4) screw up the
1207 * register allocation in this function and use the same register
1208 * (D6) for len and as a temporary, with predictable results. The
1209 * following sledgehammer prevents this.
1210 */
1211 volatile
1212#endif
1213 int len;
374330e2 1214
51470298 1215 ssh->pktout.body[-1] = ssh->pktout.type;
4ba9b64b 1216
a8327734 1217 if (ssh->logctx)
1218 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1219 ssh1_pkt_type(ssh->pktout.type),
1220 ssh->pktout.body, ssh->pktout.length);
00db133f 1221
51470298 1222 if (ssh->v1_compressing) {
4ba9b64b 1223 unsigned char *compblk;
1224 int complen;
5366aed8 1225 zlib_compress_block(ssh->cs_comp_ctx,
1226 ssh->pktout.body - 1, ssh->pktout.length + 1,
4ba9b64b 1227 &compblk, &complen);
51470298 1228 ssh1_pktout_size(ssh, complen - 1);
1229 memcpy(ssh->pktout.body - 1, compblk, complen);
dcbde236 1230 sfree(compblk);
4ba9b64b 1231 }
1232
51470298 1233 len = ssh->pktout.length + 5; /* type and CRC */
32874aea 1234 pad = 8 - (len % 8);
374330e2 1235 biglen = len + pad;
1236
32874aea 1237 for (i = 0; i < pad; i++)
51470298 1238 ssh->pktout.data[i + 4] = random_byte();
1239 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1240 PUT_32BIT(ssh->pktout.data + biglen, crc);
1241 PUT_32BIT(ssh->pktout.data, len);
374330e2 1242
51470298 1243 if (ssh->cipher)
371e569c 1244 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
374330e2 1245
32874aea 1246 return biglen + 4;
39065bed 1247}
1248
51470298 1249static void s_wrpkt(Ssh ssh)
32874aea 1250{
5471d09a 1251 int len, backlog;
51470298 1252 len = s_wrpkt_prepare(ssh);
d8baa528 1253 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
5471d09a 1254 if (backlog > SSH_MAX_BACKLOG)
51470298 1255 ssh_throttle_all(ssh, 1, backlog);
39065bed 1256}
1257
51470298 1258static void s_wrpkt_defer(Ssh ssh)
32874aea 1259{
39065bed 1260 int len;
51470298 1261 len = s_wrpkt_prepare(ssh);
1262 if (ssh->deferred_len + len > ssh->deferred_size) {
1263 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1264 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1265 ssh->deferred_size,
1266 unsigned char);
39065bed 1267 }
51470298 1268 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1269 ssh->deferred_len += len;
374330e2 1270}
1271
fb09bf1c 1272/*
39065bed 1273 * Construct a packet with the specified contents.
fb09bf1c 1274 */
51470298 1275static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
fb09bf1c 1276{
fb09bf1c 1277 unsigned char *p, *argp, argchar;
1278 unsigned long argint;
1279 int pktlen, argtype, arglen;
7cca0d81 1280 Bignum bn;
fb09bf1c 1281
1282 pktlen = 0;
39065bed 1283 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1284 switch (argtype) {
1285 case PKT_INT:
39065bed 1286 (void) va_arg(ap1, int);
fb09bf1c 1287 pktlen += 4;
1288 break;
1289 case PKT_CHAR:
1ec39246 1290 (void) va_arg(ap1, int);
fb09bf1c 1291 pktlen++;
1292 break;
1293 case PKT_DATA:
39065bed 1294 (void) va_arg(ap1, unsigned char *);
1295 arglen = va_arg(ap1, int);
fb09bf1c 1296 pktlen += arglen;
1297 break;
1298 case PKT_STR:
39065bed 1299 argp = va_arg(ap1, unsigned char *);
d8baa528 1300 arglen = strlen((char *)argp);
fb09bf1c 1301 pktlen += 4 + arglen;
1302 break;
7cca0d81 1303 case PKT_BIGNUM:
39065bed 1304 bn = va_arg(ap1, Bignum);
32874aea 1305 pktlen += ssh1_bignum_length(bn);
7cca0d81 1306 break;
fb09bf1c 1307 default:
1308 assert(0);
1309 }
1310 }
fb09bf1c 1311
51470298 1312 s_wrpkt_start(ssh, pkttype, pktlen);
1313 p = ssh->pktout.body;
fb09bf1c 1314
39065bed 1315 while ((argtype = va_arg(ap2, int)) != PKT_END) {
fb09bf1c 1316 switch (argtype) {
1317 case PKT_INT:
39065bed 1318 argint = va_arg(ap2, int);
fb09bf1c 1319 PUT_32BIT(p, argint);
1320 p += 4;
1321 break;
1322 case PKT_CHAR:
1ec39246 1323 argchar = (unsigned char) va_arg(ap2, int);
fb09bf1c 1324 *p = argchar;
1325 p++;
1326 break;
1327 case PKT_DATA:
39065bed 1328 argp = va_arg(ap2, unsigned char *);
1329 arglen = va_arg(ap2, int);
fb09bf1c 1330 memcpy(p, argp, arglen);
1331 p += arglen;
1332 break;
1333 case PKT_STR:
39065bed 1334 argp = va_arg(ap2, unsigned char *);
d8baa528 1335 arglen = strlen((char *)argp);
fb09bf1c 1336 PUT_32BIT(p, arglen);
1337 memcpy(p + 4, argp, arglen);
1338 p += 4 + arglen;
1339 break;
7cca0d81 1340 case PKT_BIGNUM:
39065bed 1341 bn = va_arg(ap2, Bignum);
32874aea 1342 p += ssh1_write_bignum(p, bn);
7cca0d81 1343 break;
fb09bf1c 1344 }
1345 }
39065bed 1346}
fb09bf1c 1347
51470298 1348static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1349{
39065bed 1350 va_list ap1, ap2;
1351 va_start(ap1, pkttype);
1352 va_start(ap2, pkttype);
51470298 1353 construct_packet(ssh, pkttype, ap1, ap2);
1354 s_wrpkt(ssh);
fb09bf1c 1355}
1356
51470298 1357static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1358{
39065bed 1359 va_list ap1, ap2;
1360 va_start(ap1, pkttype);
1361 va_start(ap2, pkttype);
51470298 1362 construct_packet(ssh, pkttype, ap1, ap2);
1363 s_wrpkt_defer(ssh);
39065bed 1364}
1365
32874aea 1366static int ssh_versioncmp(char *a, char *b)
1367{
9697bfd2 1368 char *ae, *be;
1369 unsigned long av, bv;
1370
43aa02a7 1371 av = strtoul(a, &ae, 10);
1372 bv = strtoul(b, &be, 10);
32874aea 1373 if (av != bv)
1374 return (av < bv ? -1 : +1);
1375 if (*ae == '.')
1376 ae++;
1377 if (*be == '.')
1378 be++;
43aa02a7 1379 av = strtoul(ae, &ae, 10);
1380 bv = strtoul(be, &be, 10);
32874aea 1381 if (av != bv)
1382 return (av < bv ? -1 : +1);
9697bfd2 1383 return 0;
1384}
1385
e5574168 1386/*
a92dd380 1387 * Utility routines for putting an SSH-protocol `string' and
1388 * `uint32' into a SHA state.
e5574168 1389 */
1390#include <stdio.h>
32874aea 1391static void sha_string(SHA_State * s, void *str, int len)
1392{
e5574168 1393 unsigned char lenblk[4];
e5574168 1394 PUT_32BIT(lenblk, len);
e5574168 1395 SHA_Bytes(s, lenblk, 4);
e5574168 1396 SHA_Bytes(s, str, len);
1397}
1398
32874aea 1399static void sha_uint32(SHA_State * s, unsigned i)
1400{
a92dd380 1401 unsigned char intblk[4];
1402 PUT_32BIT(intblk, i);
1403 SHA_Bytes(s, intblk, 4);
1404}
1405
7cca0d81 1406/*
1407 * SSH2 packet construction functions.
1408 */
51470298 1409static void ssh2_pkt_ensure(Ssh ssh, int length)
32874aea 1410{
51470298 1411 if (ssh->pktout.maxlen < length) {
1412 ssh->pktout.maxlen = length + 256;
3d88e64d 1413 ssh->pktout.data = sresize(ssh->pktout.data,
1414 ssh->pktout.maxlen + APIEXTRA,
1415 unsigned char);
51470298 1416 if (!ssh->pktout.data)
32874aea 1417 fatalbox("Out of memory");
7cca0d81 1418 }
783415f8 1419}
51470298 1420static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
32874aea 1421{
51470298 1422 ssh->pktout.length += len;
1423 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1424 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
7cca0d81 1425}
51470298 1426static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
32874aea 1427{
51470298 1428 ssh2_pkt_adddata(ssh, &byte, 1);
7cca0d81 1429}
51470298 1430static void ssh2_pkt_init(Ssh ssh, int pkt_type)
32874aea 1431{
51470298 1432 ssh->pktout.length = 5;
1433 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
7cca0d81 1434}
51470298 1435static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
32874aea 1436{
51470298 1437 ssh2_pkt_adddata(ssh, &value, 1);
7cca0d81 1438}
51470298 1439static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
32874aea 1440{
7cca0d81 1441 unsigned char x[4];
1442 PUT_32BIT(x, value);
51470298 1443 ssh2_pkt_adddata(ssh, x, 4);
7cca0d81 1444}
51470298 1445static void ssh2_pkt_addstring_start(Ssh ssh)
32874aea 1446{
51470298 1447 ssh2_pkt_adduint32(ssh, 0);
1448 ssh->pktout.savedpos = ssh->pktout.length;
7cca0d81 1449}
51470298 1450static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
32874aea 1451{
51470298 1452 ssh2_pkt_adddata(ssh, data, strlen(data));
1453 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1454 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1455}
51470298 1456static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
32874aea 1457{
51470298 1458 ssh2_pkt_adddata(ssh, data, len);
1459 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1460 ssh->pktout.length - ssh->pktout.savedpos);
7cca0d81 1461}
51470298 1462static void ssh2_pkt_addstring(Ssh ssh, char *data)
32874aea 1463{
51470298 1464 ssh2_pkt_addstring_start(ssh);
1465 ssh2_pkt_addstring_str(ssh, data);
7cca0d81 1466}
d8baa528 1467static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1468{
7cca0d81 1469 unsigned char *p;
32874aea 1470 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1471 p = snewn(n + 1, unsigned char);
7cca0d81 1472 if (!p)
32874aea 1473 fatalbox("out of memory");
7cca0d81 1474 p[0] = 0;
3709bfe9 1475 for (i = 1; i <= n; i++)
32874aea 1476 p[i] = bignum_byte(b, n - i);
7cca0d81 1477 i = 0;
32874aea 1478 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1479 i++;
1480 memmove(p, p + i, n + 1 - i);
1481 *len = n + 1 - i;
7cca0d81 1482 return p;
1483}
51470298 1484static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
32874aea 1485{
7cca0d81 1486 unsigned char *p;
1487 int len;
1488 p = ssh2_mpint_fmt(b, &len);
51470298 1489 ssh2_pkt_addstring_start(ssh);
d8baa528 1490 ssh2_pkt_addstring_data(ssh, (char *)p, len);
dcbde236 1491 sfree(p);
7cca0d81 1492}
b185170a 1493
1494/*
1495 * Construct an SSH2 final-form packet: compress it, encrypt it,
1496 * put the MAC on it. Final packet, ready to be sent, is stored in
51470298 1497 * ssh->pktout.data. Total length is returned.
b185170a 1498 */
51470298 1499static int ssh2_pkt_construct(Ssh ssh)
32874aea 1500{
7cca0d81 1501 int cipherblk, maclen, padding, i;
7cca0d81 1502
a8327734 1503 if (ssh->logctx)
1504 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1505 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1506 ssh->pktout.data + 6, ssh->pktout.length - 6);
00db133f 1507
7cca0d81 1508 /*
4ba9b64b 1509 * Compress packet payload.
1510 */
4ba9b64b 1511 {
1512 unsigned char *newpayload;
1513 int newlen;
51470298 1514 if (ssh->cscomp &&
5366aed8 1515 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1516 ssh->pktout.length - 5,
51470298 1517 &newpayload, &newlen)) {
1518 ssh->pktout.length = 5;
1519 ssh2_pkt_adddata(ssh, newpayload, newlen);
dcbde236 1520 sfree(newpayload);
4ba9b64b 1521 }
1522 }
1523
1524 /*
7cca0d81 1525 * Add padding. At least four bytes, and must also bring total
1526 * length (minus MAC) up to a multiple of the block size.
1527 */
51470298 1528 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1529 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1530 padding = 4;
32874aea 1531 padding +=
51470298 1532 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1533 maclen = ssh->csmac ? ssh->csmac->len : 0;
1534 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1535 ssh->pktout.data[4] = padding;
7cca0d81 1536 for (i = 0; i < padding; i++)
51470298 1537 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1538 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1539 if (ssh->csmac)
e0e1a00d 1540 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1541 ssh->pktout.length + padding,
51470298 1542 ssh->v2_outgoing_sequence);
1543 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1544
1545 if (ssh->cscipher)
371e569c 1546 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1547 ssh->pktout.data, ssh->pktout.length + padding);
51470298 1548
1549 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1550 return ssh->pktout.length + padding + maclen;
b185170a 1551}
1552
1553/*
1554 * Construct and send an SSH2 packet immediately.
1555 */
51470298 1556static void ssh2_pkt_send(Ssh ssh)
32874aea 1557{
5471d09a 1558 int len;
1559 int backlog;
51470298 1560 len = ssh2_pkt_construct(ssh);
d8baa528 1561 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
5471d09a 1562 if (backlog > SSH_MAX_BACKLOG)
51470298 1563 ssh_throttle_all(ssh, 1, backlog);
b185170a 1564}
1565
1566/*
1567 * Construct an SSH2 packet and add it to a deferred data block.
1568 * Useful for sending multiple packets in a single sk_write() call,
1569 * to prevent a traffic-analysing listener from being able to work
1570 * out the length of any particular packet (such as the password
1571 * packet).
1572 *
1573 * Note that because SSH2 sequence-numbers its packets, this can
1574 * NOT be used as an m4-style `defer' allowing packets to be
1575 * constructed in one order and sent in another.
1576 */
51470298 1577static void ssh2_pkt_defer(Ssh ssh)
32874aea 1578{
51470298 1579 int len = ssh2_pkt_construct(ssh);
1580 if (ssh->deferred_len + len > ssh->deferred_size) {
1581 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1582 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1583 ssh->deferred_size,
1584 unsigned char);
b185170a 1585 }
51470298 1586 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1587 ssh->deferred_len += len;
b185170a 1588}
1589
1590/*
1591 * Send the whole deferred data block constructed by
39065bed 1592 * ssh2_pkt_defer() or SSH1's defer_packet().
b185170a 1593 */
51470298 1594static void ssh_pkt_defersend(Ssh ssh)
32874aea 1595{
5471d09a 1596 int backlog;
d8baa528 1597 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1598 ssh->deferred_len);
51470298 1599 ssh->deferred_len = ssh->deferred_size = 0;
1600 sfree(ssh->deferred_send_data);
1601 ssh->deferred_send_data = NULL;
5471d09a 1602 if (backlog > SSH_MAX_BACKLOG)
51470298 1603 ssh_throttle_all(ssh, 1, backlog);
7cca0d81 1604}
1605
1606#if 0
32874aea 1607void bndebug(char *string, Bignum b)
1608{
7cca0d81 1609 unsigned char *p;
1610 int i, len;
1611 p = ssh2_mpint_fmt(b, &len);
1612 debug(("%s", string));
1613 for (i = 0; i < len; i++)
32874aea 1614 debug((" %02x", p[i]));
765c4200 1615 debug(("\n"));
dcbde236 1616 sfree(p);
7cca0d81 1617}
1618#endif
1619
32874aea 1620static void sha_mpint(SHA_State * s, Bignum b)
1621{
7cca0d81 1622 unsigned char *p;
1623 int len;
1624 p = ssh2_mpint_fmt(b, &len);
1625 sha_string(s, p, len);
dcbde236 1626 sfree(p);
7cca0d81 1627}
1628
1629/*
1630 * SSH2 packet decode functions.
1631 */
51470298 1632static unsigned long ssh2_pkt_getuint32(Ssh ssh)
32874aea 1633{
7cca0d81 1634 unsigned long value;
51470298 1635 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1636 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1637 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1638 ssh->pktin.savedpos += 4;
7cca0d81 1639 return value;
1640}
51470298 1641static int ssh2_pkt_getbool(Ssh ssh)
32874aea 1642{
65a22376 1643 unsigned long value;
51470298 1644 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
32874aea 1645 return 0; /* arrgh, no way to decline (FIXME?) */
51470298 1646 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1647 ssh->pktin.savedpos++;
65a22376 1648 return value;
1649}
51470298 1650static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
32874aea 1651{
57356d63 1652 int len;
7cca0d81 1653 *p = NULL;
45068b27 1654 *length = 0;
51470298 1655 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
32874aea 1656 return;
57356d63 1657 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1658 if (len < 0)
1659 return;
1660 *length = len;
51470298 1661 ssh->pktin.savedpos += 4;
1662 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
32874aea 1663 return;
d8baa528 1664 *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos);
51470298 1665 ssh->pktin.savedpos += *length;
7cca0d81 1666}
51470298 1667static Bignum ssh2_pkt_getmp(Ssh ssh)
32874aea 1668{
7cca0d81 1669 char *p;
3709bfe9 1670 int length;
7cca0d81 1671 Bignum b;
1672
51470298 1673 ssh2_pkt_getstring(ssh, &p, &length);
7cca0d81 1674 if (!p)
32874aea 1675 return NULL;
8d5de777 1676 if (p[0] & 0x80) {
6b5cf8b4 1677 bombout(("internal error: Can't handle negative mpints"));
32874aea 1678 return NULL;
8d5de777 1679 }
d8baa528 1680 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1681 return b;
1682}
1683
7d503c31 1684/*
1dd353b5 1685 * Helper function to add an SSH2 signature blob to a packet.
1686 * Expects to be shown the public key blob as well as the signature
1687 * blob. Normally works just like ssh2_pkt_addstring, but will
1688 * fiddle with the signature packet if necessary for
1689 * BUG_SSH2_RSA_PADDING.
1690 */
51470298 1691static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1dd353b5 1692 void *sigblob_v, int sigblob_len)
1693{
1694 unsigned char *pkblob = (unsigned char *)pkblob_v;
1695 unsigned char *sigblob = (unsigned char *)sigblob_v;
1696
1697 /* dmemdump(pkblob, pkblob_len); */
1698 /* dmemdump(sigblob, sigblob_len); */
1699
1700 /*
1701 * See if this is in fact an ssh-rsa signature and a buggy
1702 * server; otherwise we can just do this the easy way.
1703 */
51470298 1704 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1705 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1706 int pos, len, siglen;
1707
1708 /*
1709 * Find the byte length of the modulus.
1710 */
1711
1712 pos = 4+7; /* skip over "ssh-rsa" */
1713 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1714 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1715 pos += 4; /* find modulus itself */
1716 while (len > 0 && pkblob[pos] == 0)
1717 len--, pos++;
1718 /* debug(("modulus length is %d\n", len)); */
1719
1720 /*
1721 * Now find the signature integer.
1722 */
1723 pos = 4+7; /* skip over "ssh-rsa" */
1724 siglen = GET_32BIT(sigblob+pos);
1725 /* debug(("signature length is %d\n", siglen)); */
1726
1727 if (len != siglen) {
1728 unsigned char newlen[4];
51470298 1729 ssh2_pkt_addstring_start(ssh);
d8baa528 1730 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1dd353b5 1731 /* dmemdump(sigblob, pos); */
1732 pos += 4; /* point to start of actual sig */
1733 PUT_32BIT(newlen, len);
d8baa528 1734 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1dd353b5 1735 /* dmemdump(newlen, 4); */
1736 newlen[0] = 0;
1737 while (len-- > siglen) {
d8baa528 1738 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1dd353b5 1739 /* dmemdump(newlen, 1); */
1740 }
d8baa528 1741 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1dd353b5 1742 /* dmemdump(sigblob+pos, siglen); */
1743 return;
1744 }
1745
1746 /* Otherwise fall through and do it the easy way. */
1747 }
1748
51470298 1749 ssh2_pkt_addstring_start(ssh);
d8baa528 1750 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1dd353b5 1751}
1752
1753/*
7d503c31 1754 * Examine the remote side's version string and compare it against
1755 * a list of known buggy implementations.
1756 */
51470298 1757static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 1758{
1759 char *imp; /* pointer to implementation part */
7d503c31 1760 imp = vstring;
1761 imp += strcspn(imp, "-");
bd358db1 1762 if (*imp) imp++;
7d503c31 1763 imp += strcspn(imp, "-");
bd358db1 1764 if (*imp) imp++;
7d503c31 1765
51470298 1766 ssh->remote_bugs = 0;
7d503c31 1767
5ecd7ad0 1768 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1769 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 1770 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1771 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1772 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
32874aea 1773 /*
1774 * These versions don't support SSH1_MSG_IGNORE, so we have
1775 * to use a different defence against password length
1776 * sniffing.
1777 */
51470298 1778 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 1779 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1780 }
1781
5ecd7ad0 1782 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1783 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2c9c6388 1784 (!strcmp(imp, "Cisco-1.25")))) {
bd358db1 1785 /*
1786 * These versions need a plain password sent; they can't
1787 * handle having a null and a random length of data after
1788 * the password.
1789 */
51470298 1790 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 1791 logevent("We believe remote version needs a plain SSH1 password");
1792 }
1793
5ecd7ad0 1794 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1795 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 1796 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 1797 /*
1798 * These versions apparently have no clue whatever about
1799 * RSA authentication and will panic and die if they see
1800 * an AUTH_RSA message.
1801 */
51470298 1802 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 1803 logevent("We believe remote version can't handle RSA authentication");
1804 }
1805
5ecd7ad0 1806 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1807 (ssh->cfg.sshbug_hmac2 == AUTO &&
831301f6 1808 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1809 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1810 wc_match("2.1 *", imp)))) {
32874aea 1811 /*
1812 * These versions have the HMAC bug.
1813 */
51470298 1814 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 1815 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 1816 }
1dd353b5 1817
5ecd7ad0 1818 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
1819 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2856a1b9 1820 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 1821 /*
1822 * These versions have the key-derivation bug (failing to
1823 * include the literal shared secret in the hashes that
1824 * generate the keys).
1825 */
51470298 1826 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 1827 logevent("We believe remote version has SSH2 key-derivation bug");
1828 }
1829
5ecd7ad0 1830 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
1831 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 1832 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1833 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 1834 /*
1835 * These versions have the SSH2 RSA padding bug.
1836 */
51470298 1837 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 1838 logevent("We believe remote version has SSH2 RSA padding bug");
1839 }
8e975795 1840
dda87a28 1841 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
1842 (ssh->cfg.sshbug_pksessid2 == AUTO &&
1843 wc_match("OpenSSH_2.[0-2]*", imp))) {
1844 /*
1845 * These versions have the SSH2 session-ID bug in
1846 * public-key authentication.
1847 */
1848 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
1849 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1850 }
1851
5ecd7ad0 1852 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
8e975795 1853 /*
831301f6 1854 * User specified the SSH2 DH GEX bug.
8e975795 1855 */
51470298 1856 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
8e975795 1857 logevent("We believe remote version has SSH2 DH group exchange bug");
1858 }
7d503c31 1859}
1860
51470298 1861static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 1862{
51470298 1863 struct do_ssh_init_state {
1864 int vslen;
1865 char version[10];
1866 char *vstring;
1867 int vstrsize;
1868 int i;
1869 int proto1, proto2;
1870 };
1871 crState(do_ssh_init_state);
374330e2 1872
51470298 1873 crBegin(ssh->do_ssh_init_crstate);
8df7a775 1874
1875 /* Search for the string "SSH-" in the input. */
51470298 1876 s->i = 0;
8df7a775 1877 while (1) {
1878 static const int transS[] = { 1, 2, 2, 1 };
1879 static const int transH[] = { 0, 0, 3, 0 };
1880 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 1881 if (c == 'S')
51470298 1882 s->i = transS[s->i];
32874aea 1883 else if (c == 'H')
51470298 1884 s->i = transH[s->i];
32874aea 1885 else if (c == '-')
51470298 1886 s->i = transminus[s->i];
32874aea 1887 else
51470298 1888 s->i = 0;
1889 if (s->i < 0)
8df7a775 1890 break;
1891 crReturn(1); /* get another character */
374330e2 1892 }
8df7a775 1893
51470298 1894 s->vstrsize = 16;
3d88e64d 1895 s->vstring = snewn(s->vstrsize, char);
51470298 1896 strcpy(s->vstring, "SSH-");
1897 s->vslen = 4;
1898 s->i = 0;
374330e2 1899 while (1) {
8df7a775 1900 crReturn(1); /* get another char */
51470298 1901 if (s->vslen >= s->vstrsize - 1) {
1902 s->vstrsize += 16;
3d88e64d 1903 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 1904 }
51470298 1905 s->vstring[s->vslen++] = c;
1906 if (s->i >= 0) {
374330e2 1907 if (c == '-') {
51470298 1908 s->version[s->i] = '\0';
1909 s->i = -1;
1910 } else if (s->i < sizeof(s->version) - 1)
1911 s->version[s->i++] = c;
c4ffc4d0 1912 } else if (c == '\012')
374330e2 1913 break;
1914 }
1915
51470298 1916 ssh->agentfwd_enabled = FALSE;
1917 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 1918
51470298 1919 s->vstring[s->vslen] = 0;
1920 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1921 {
1922 char *vlog;
3d88e64d 1923 vlog = snewn(20 + s->vslen, char);
51470298 1924 sprintf(vlog, "Server version: %s", s->vstring);
1925 logevent(vlog);
1926 sfree(vlog);
1927 }
1928 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 1929
adf799dd 1930 /*
38d228a2 1931 * Decide which SSH protocol version to support.
adf799dd 1932 */
38d228a2 1933
1934 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 1935 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 1936 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 1937 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 1938
86916870 1939 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 1940 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 1941 crStop(0);
38d228a2 1942 }
86916870 1943 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 1944 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 1945 crStop(0);
38d228a2 1946 }
1947
86916870 1948 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
32874aea 1949 /*
38d228a2 1950 * Use v2 protocol.
32874aea 1951 */
1952 char verstring[80], vlog[100];
1953 sprintf(verstring, "SSH-2.0-%s", sshver);
51470298 1954 SHA_Init(&ssh->exhashbase);
32874aea 1955 /*
1956 * Hash our version string and their version string.
1957 */
51470298 1958 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1959 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
32874aea 1960 sprintf(vlog, "We claim version: %s", verstring);
1961 logevent(vlog);
c4ffc4d0 1962 strcat(verstring, "\012");
32874aea 1963 logevent("Using SSH protocol version 2");
51470298 1964 sk_write(ssh->s, verstring, strlen(verstring));
1965 ssh->protocol = ssh2_protocol;
1966 ssh->version = 2;
1967 ssh->s_rdpkt = ssh2_rdpkt;
e5574168 1968 } else {
32874aea 1969 /*
38d228a2 1970 * Use v1 protocol.
32874aea 1971 */
1972 char verstring[80], vlog[100];
1973 sprintf(verstring, "SSH-%s-%s",
51470298 1974 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
32874aea 1975 sshver);
1976 sprintf(vlog, "We claim version: %s", verstring);
1977 logevent(vlog);
c4ffc4d0 1978 strcat(verstring, "\012");
759712a6 1979
32874aea 1980 logevent("Using SSH protocol version 1");
51470298 1981 sk_write(ssh->s, verstring, strlen(verstring));
1982 ssh->protocol = ssh1_protocol;
1983 ssh->version = 1;
1984 ssh->s_rdpkt = ssh1_rdpkt;
e5574168 1985 }
125105d1 1986 update_specials_menu(ssh->frontend);
51470298 1987 ssh->state = SSH_STATE_BEFORE_SIZE;
8df7a775 1988
51470298 1989 sfree(s->vstring);
50526e47 1990
8df7a775 1991 crFinish(0);
1992}
1993
51470298 1994static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 1995{
51470298 1996 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 1997
1998 /*
1999 * To begin with, feed the characters one by one to the
2000 * protocol initialisation / selection function do_ssh_init().
2001 * When that returns 0, we're done with the initial greeting
2002 * exchange and can move on to packet discipline.
2003 */
2004 while (1) {
51470298 2005 int ret; /* need not be kept across crReturn */
8df7a775 2006 if (datalen == 0)
2007 crReturnV; /* more data please */
51470298 2008 ret = do_ssh_init(ssh, *data);
32874aea 2009 data++;
2010 datalen--;
8df7a775 2011 if (ret == 0)
2012 break;
2013 }
2014
2015 /*
2016 * We emerge from that loop when the initial negotiation is
2017 * over and we have selected an s_rdpkt function. Now pass
2018 * everything to s_rdpkt, and then pass the resulting packets
2019 * to the proper protocol handler.
2020 */
2021 if (datalen == 0)
2022 crReturnV;
2023 while (1) {
2024 while (datalen > 0) {
51470298 2025 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2026 if (ssh->state == SSH_STATE_CLOSED) {
e14d0f19 2027 return;
2028 }
51470298 2029 ssh->protocol(ssh, NULL, 0, 1);
2030 if (ssh->state == SSH_STATE_CLOSED) {
8df7a775 2031 return;
2032 }
2033 }
2034 }
2035 crReturnV;
2036 }
2037 crFinishV;
2038}
2039
32874aea 2040static int ssh_closing(Plug plug, char *error_msg, int error_code,
2041 int calling_back)
2042{
51470298 2043 Ssh ssh = (Ssh) plug;
2044 ssh->state = SSH_STATE_CLOSED;
2045 if (ssh->s) {
2046 sk_close(ssh->s);
2047 ssh->s = NULL;
f3ab576e 2048 }
7e78000d 2049 if (error_msg) {
32874aea 2050 /* A socket error has occurred. */
247308b5 2051 logevent(error_msg);
a8327734 2052 connection_fatal(ssh->frontend, error_msg);
7e78000d 2053 } else {
2054 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2055 }
7e78000d 2056 return 0;
2057}
2058
32874aea 2059static int ssh_receive(Plug plug, int urgent, char *data, int len)
2060{
51470298 2061 Ssh ssh = (Ssh) plug;
d8baa528 2062 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2063 if (ssh->state == SSH_STATE_CLOSED) {
2064 if (ssh->s) {
2065 sk_close(ssh->s);
2066 ssh->s = NULL;
32874aea 2067 }
2068 return 0;
3257deae 2069 }
fef97f43 2070 return 1;
374330e2 2071}
2072
5471d09a 2073static void ssh_sent(Plug plug, int bufsize)
2074{
51470298 2075 Ssh ssh = (Ssh) plug;
5471d09a 2076 /*
2077 * If the send backlog on the SSH socket itself clears, we
2078 * should unthrottle the whole world if it was throttled.
2079 */
2080 if (bufsize < SSH_MAX_BACKLOG)
51470298 2081 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2082}
2083
fb09bf1c 2084/*
8df7a775 2085 * Connect to specified host and port.
2086 * Returns an error message, or NULL on success.
6e1ebb76 2087 * Also places the canonical host name into `realhost'. It must be
2088 * freed by the caller.
8df7a775 2089 */
51470298 2090static char *connect_to_host(Ssh ssh, char *host, int port,
2091 char **realhost, int nodelay)
8df7a775 2092{
51470298 2093 static const struct plug_function_table fn_table = {
7e78000d 2094 ssh_closing,
5471d09a 2095 ssh_receive,
2096 ssh_sent,
2097 NULL
51470298 2098 };
7e78000d 2099
8df7a775 2100 SockAddr addr;
2101 char *err;
8df7a775 2102
3d88e64d 2103 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2104 if (!ssh->savedhost)
8df7a775 2105 fatalbox("Out of memory");
51470298 2106 strcpy(ssh->savedhost, host);
8df7a775 2107
2108 if (port < 0)
2109 port = 22; /* default ssh port */
51470298 2110 ssh->savedport = port;
8df7a775 2111
2112 /*
2113 * Try to find host.
2114 */
57356d63 2115 logeventf(ssh, "Looking up host \"%s\"", host);
e8fa8f62 2116 addr = name_lookup(host, port, realhost, &ssh->cfg);
70e5d0fd 2117 if ((err = sk_addr_error(addr)) != NULL)
8df7a775 2118 return err;
2119
8df7a775 2120 /*
2121 * Open socket.
2122 */
3ad9d396 2123 {
57356d63 2124 char addrbuf[100];
3ad9d396 2125 sk_getaddr(addr, addrbuf, 100);
57356d63 2126 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2127 }
51470298 2128 ssh->fn = &fn_table;
e8fa8f62 2129 ssh->s = new_connection(addr, *realhost, port,
2130 0, 1, nodelay, (Plug) ssh, &ssh->cfg);
70e5d0fd 2131 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2132 ssh->s = NULL;
8df7a775 2133 return err;
67c4ba2e 2134 }
8df7a775 2135
8df7a775 2136 return NULL;
2137}
2138
2139/*
5471d09a 2140 * Throttle or unthrottle the SSH connection.
2141 */
51470298 2142static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2143{
51470298 2144 int old_count = ssh->v1_throttle_count;
2145 ssh->v1_throttle_count += adjust;
2146 assert(ssh->v1_throttle_count >= 0);
2147 if (ssh->v1_throttle_count && !old_count) {
2148 sk_set_frozen(ssh->s, 1);
2149 } else if (!ssh->v1_throttle_count && old_count) {
2150 sk_set_frozen(ssh->s, 0);
5471d09a 2151 }
2152}
2153
2154/*
2155 * Throttle or unthrottle _all_ local data streams (for when sends
2156 * on the SSH connection itself back up).
2157 */
51470298 2158static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2159{
2160 int i;
2161 struct ssh_channel *c;
2162
51470298 2163 if (enable == ssh->throttled_all)
5471d09a 2164 return;
51470298 2165 ssh->throttled_all = enable;
2166 ssh->overall_bufsize = bufsize;
2167 if (!ssh->channels)
5471d09a 2168 return;
51470298 2169 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2170 switch (c->type) {
2171 case CHAN_MAINSESSION:
2172 /*
2173 * This is treated separately, outside the switch.
2174 */
2175 break;
2176 case CHAN_X11:
2177 x11_override_throttle(c->u.x11.s, enable);
2178 break;
2179 case CHAN_AGENT:
2180 /* Agent channels require no buffer management. */
2181 break;
2182 case CHAN_SOCKDATA:
2183 pfd_override_throttle(c->u.x11.s, enable);
2184 break;
2185 }
2186 }
2187}
2188
2189/*
51470298 2190 * Username and password input, abstracted off into routines
2191 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2192 */
0405e71f 2193
2194/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2195static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2196{
51470298 2197 ssh->userpass_input_buffer = buffer;
2198 ssh->userpass_input_buflen = buflen;
2199 ssh->userpass_input_bufpos = 0;
2200 ssh->userpass_input_echo = echo;
0405e71f 2201}
2202
2203/*
2204 * Process some terminal data in the course of username/password
2205 * input. Returns >0 for success (line of input returned in
2206 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2207 * for inconclusive (keep waiting for more input please).
2208 */
ae9ae89f 2209static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2210{
2211 char c;
2212
2213 while (inlen--) {
2214 switch (c = *in++) {
2215 case 10:
2216 case 13:
51470298 2217 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2218 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2219 return +1;
2220 break;
2221 case 8:
2222 case 127:
51470298 2223 if (ssh->userpass_input_bufpos > 0) {
2224 if (ssh->userpass_input_echo)
2225 c_write_str(ssh, "\b \b");
2226 ssh->userpass_input_bufpos--;
0405e71f 2227 }
2228 break;
2229 case 21:
2230 case 27:
51470298 2231 while (ssh->userpass_input_bufpos > 0) {
2232 if (ssh->userpass_input_echo)
2233 c_write_str(ssh, "\b \b");
2234 ssh->userpass_input_bufpos--;
0405e71f 2235 }
2236 break;
2237 case 3:
2238 case 4:
2239 return -1;
2240 break;
2241 default:
4692a14a 2242 /*
2243 * This simplistic check for printability is disabled
2244 * when we're doing password input, because some people
2245 * have control characters in their passwords.o
2246 */
2247 if ((!ssh->userpass_input_echo ||
2248 (c >= ' ' && c <= '~') ||
0405e71f 2249 ((unsigned char) c >= 160))
51470298 2250 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2251 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2252 if (ssh->userpass_input_echo)
2253 c_write(ssh, &c, 1);
0405e71f 2254 }
2255 break;
2256 }
2257 }
2258 return 0;
2259}
2260
2261/*
fb09bf1c 2262 * Handle the key exchange and user authentication phases.
2263 */
51470298 2264static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
fb09bf1c 2265{
2d466ffd 2266 int i, j;
374330e2 2267 unsigned char cookie[8];
2268 struct RSAKey servkey, hostkey;
2269 struct MD5Context md5c;
51470298 2270 struct do_ssh1_login_state {
2271 int len;
2272 unsigned char *rsabuf, *keystr1, *keystr2;
2273 unsigned long supported_ciphers_mask, supported_auths_mask;
2274 int tried_publickey, tried_agent;
2275 int tis_auth_refused, ccard_auth_refused;
2276 unsigned char session_id[16];
2277 int cipher_type;
2278 char username[100];
2279 void *publickey_blob;
2280 int publickey_bloblen;
2281 char password[100];
2282 char prompt[200];
2283 int pos;
2284 char c;
2285 int pwpkt_type;
2286 unsigned char request[5], *response, *p;
2287 int responselen;
2288 int keyi, nkeys;
2289 int authed;
2290 struct RSAKey key;
2291 Bignum challenge;
2292 char *commentp;
2293 int commentlen;
2294 };
2295 crState(do_ssh1_login_state);
2296
2297 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2298
32874aea 2299 if (!ispkt)
2300 crWaitUntil(ispkt);
374330e2 2301
51470298 2302 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2303 bombout(("Public key packet not received"));
7ffdbc1a 2304 crStop(0);
8d5de777 2305 }
374330e2 2306
c5e9c988 2307 logevent("Received public keys");
374330e2 2308
51470298 2309 memcpy(cookie, ssh->pktin.body, 8);
374330e2 2310
51470298 2311 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2312 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
374330e2 2313
c5e9c988 2314 /*
1c2a93c4 2315 * Log the host key fingerprint.
c5e9c988 2316 */
c5e9c988 2317 {
2318 char logmsg[80];
1c2a93c4 2319 logevent("Host key fingerprint is:");
c5e9c988 2320 strcpy(logmsg, " ");
32874aea 2321 hostkey.comment = NULL;
2322 rsa_fingerprint(logmsg + strlen(logmsg),
2323 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2324 logevent(logmsg);
2325 }
2326
51470298 2327 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2328 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2329 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
bea1ef5f 2330
51470298 2331 ssh->v1_local_protoflags =
2332 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2333 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2334
c5e9c988 2335 MD5Init(&md5c);
51470298 2336 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2337 MD5Update(&md5c, s->keystr1, servkey.bytes);
2338 MD5Update(&md5c, ssh->pktin.body, 8);
2339 MD5Final(s->session_id, &md5c);
374330e2 2340
32874aea 2341 for (i = 0; i < 32; i++)
51470298 2342 ssh->session_key[i] = random_byte();
374330e2 2343
51470298 2344 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2345
3d88e64d 2346 s->rsabuf = snewn(s->len, unsigned char);
51470298 2347 if (!s->rsabuf)
374330e2 2348 fatalbox("Out of memory");
2349
89ee5268 2350 /*
2351 * Verify the host key.
2352 */
2353 {
32874aea 2354 /*
2355 * First format the key into a string.
2356 */
2357 int len = rsastr_len(&hostkey);
2358 char fingerprint[100];
3d88e64d 2359 char *keystr = snewn(len, char);
32874aea 2360 if (!keystr)
2361 fatalbox("Out of memory");
2362 rsastr_fmt(keystr, &hostkey);
2363 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2364 verify_ssh_host_key(ssh->frontend,
2365 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2366 fingerprint);
2367 sfree(keystr);
2368 }
2369
2370 for (i = 0; i < 32; i++) {
51470298 2371 s->rsabuf[i] = ssh->session_key[i];
374330e2 2372 if (i < 16)
51470298 2373 s->rsabuf[i] ^= s->session_id[i];
374330e2 2374 }
2375
2376 if (hostkey.bytes > servkey.bytes) {
51470298 2377 rsaencrypt(s->rsabuf, 32, &servkey);
2378 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2379 } else {
51470298 2380 rsaencrypt(s->rsabuf, 32, &hostkey);
2381 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
374330e2 2382 }
2383
c5e9c988 2384 logevent("Encrypted session key");
2385
ca20bfcf 2386 {
2387 int cipher_chosen = 0, warn = 0;
2388 char *cipher_string = NULL;
51470298 2389 int i;
ca20bfcf 2390 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2391 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2392 if (next_cipher == CIPHER_WARN) {
2393 /* If/when we choose a cipher, warn about it */
2394 warn = 1;
2395 } else if (next_cipher == CIPHER_AES) {
2396 /* XXX Probably don't need to mention this. */
2397 logevent("AES not supported in SSH1, skipping");
2398 } else {
2399 switch (next_cipher) {
51470298 2400 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2401 cipher_string = "3DES"; break;
51470298 2402 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2403 cipher_string = "Blowfish"; break;
51470298 2404 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2405 cipher_string = "single-DES"; break;
2406 }
51470298 2407 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2408 cipher_chosen = 1;
2409 }
2410 }
2411 if (!cipher_chosen) {
51470298 2412 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2413 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2414 "supporting 3DES encryption"));
2415 else
2416 /* shouldn't happen */
6b5cf8b4 2417 bombout(("No supported ciphers found"));
7ffdbc1a 2418 crStop(0);
a99a05c0 2419 }
ca20bfcf 2420
2421 /* Warn about chosen cipher if necessary. */
2422 if (warn)
a8327734 2423 askcipher(ssh->frontend, cipher_string, 0);
bea1ef5f 2424 }
ca20bfcf 2425
51470298 2426 switch (s->cipher_type) {
32874aea 2427 case SSH_CIPHER_3DES:
2428 logevent("Using 3DES encryption");
2429 break;
2430 case SSH_CIPHER_DES:
2431 logevent("Using single-DES encryption");
2432 break;
2433 case SSH_CIPHER_BLOWFISH:
2434 logevent("Using Blowfish encryption");
2435 break;
c5e9c988 2436 }
bea1ef5f 2437
51470298 2438 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2439 PKT_CHAR, s->cipher_type,
32874aea 2440 PKT_DATA, cookie, 8,
51470298 2441 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2442 PKT_DATA, s->rsabuf, s->len,
2443 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2444
c5e9c988 2445 logevent("Trying to enable encryption...");
374330e2 2446
51470298 2447 sfree(s->rsabuf);
374330e2 2448
51470298 2449 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2450 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2451 &ssh_3des);
371e569c 2452 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2453 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2454 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2455
0183b242 2456 ssh->crcda_ctx = crcda_make_context();
2457 logevent("Installing CRC compensation attack detector");
2458
fb09bf1c 2459 crWaitUntil(ispkt);
374330e2 2460
51470298 2461 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2462 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2463 crStop(0);
8d5de777 2464 }
374330e2 2465
c5e9c988 2466 logevent("Successfully started encryption");
2467
374330e2 2468 fflush(stdout);
2469 {
86916870 2470 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
c0a81592 2471 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2472 if (!ssh_get_line("login as: ",
51470298 2473 s->username, sizeof(s->username), FALSE)) {
32874aea 2474 /*
2475 * get_line failed to get a username.
2476 * Terminate.
2477 */
2478 logevent("No username provided. Abandoning session.");
3bb2f322 2479 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2480 crStop(1);
32874aea 2481 }
2482 } else {
51470298 2483 int ret; /* need not be kept over crReturn */
2484 c_write_str(ssh, "login as: ");
2485 ssh->send_ok = 1;
0405e71f 2486
51470298 2487 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2488 do {
32874aea 2489 crWaitUntil(!ispkt);
51470298 2490 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2491 } while (ret == 0);
2492 if (ret < 0)
2493 cleanup_exit(0);
51470298 2494 c_write_str(ssh, "\r\n");
32874aea 2495 }
2496 } else {
86916870 2497 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2498 s->username[sizeof(s->username)-1] = '\0';
374330e2 2499 }
fb09bf1c 2500
51470298 2501 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2502 {
51470298 2503 char userlog[22 + sizeof(s->username)];
2504 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2505 logevent(userlog);
32874aea 2506 if (flags & FLAG_INTERACTIVE &&
2507 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2508 strcat(userlog, "\r\n");
51470298 2509 c_write_str(ssh, userlog);
3c8e959b 2510 }
c5e9c988 2511 }
374330e2 2512 }
2513
fb09bf1c 2514 crWaitUntil(ispkt);
374330e2 2515
51470298 2516 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2517 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2518 s->tried_publickey = s->tried_agent = 1;
0df73905 2519 } else {
51470298 2520 s->tried_publickey = s->tried_agent = 0;
0df73905 2521 }
51470298 2522 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2523 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2524 if (!filename_is_null(ssh->cfg.keyfile)) {
2525 if (!rsakey_pubblob(&ssh->cfg.keyfile,
51470298 2526 &s->publickey_blob, &s->publickey_bloblen))
2527 s->publickey_blob = NULL;
396778f1 2528 } else
51470298 2529 s->publickey_blob = NULL;
7cca0d81 2530
51470298 2531 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2532 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2533
51470298 2534 if (agent_exists() && !s->tried_agent) {
32874aea 2535 /*
2536 * Attempt RSA authentication using Pageant.
2537 */
32874aea 2538 void *r;
2539
51470298 2540 s->authed = FALSE;
2541 s->tried_agent = 1;
32874aea 2542 logevent("Pageant is running. Requesting keys.");
2543
2544 /* Request the keys held by the agent. */
51470298 2545 PUT_32BIT(s->request, 1);
2546 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2547 agent_query(s->request, 5, &r, &s->responselen);
2548 s->response = (unsigned char *) r;
2549 if (s->response && s->responselen >= 5 &&
2550 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2551 s->p = s->response + 5;
2552 s->nkeys = GET_32BIT(s->p);
2553 s->p += 4;
32874aea 2554 {
2555 char buf[64];
51470298 2556 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 2557 logevent(buf);
2558 }
51470298 2559 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 2560 {
2561 char buf[64];
51470298 2562 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 2563 logevent(buf);
2564 }
51470298 2565 if (s->publickey_blob &&
2566 !memcmp(s->p, s->publickey_blob,
2567 s->publickey_bloblen)) {
396778f1 2568 logevent("This key matches configured key file");
51470298 2569 s->tried_publickey = 1;
396778f1 2570 }
51470298 2571 s->p += 4;
2572 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2573 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2574 s->commentlen = GET_32BIT(s->p);
2575 s->p += 4;
d8baa528 2576 s->commentp = (char *)s->p;
51470298 2577 s->p += s->commentlen;
2578 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2579 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2580 crWaitUntil(ispkt);
51470298 2581 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2582 logevent("Key refused");
2583 continue;
2584 }
2585 logevent("Received RSA challenge");
51470298 2586 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
32874aea 2587 {
2588 char *agentreq, *q, *ret;
2d466ffd 2589 void *vret;
32874aea 2590 int len, retlen;
2591 len = 1 + 4; /* message type, bit count */
51470298 2592 len += ssh1_bignum_length(s->key.exponent);
2593 len += ssh1_bignum_length(s->key.modulus);
2594 len += ssh1_bignum_length(s->challenge);
32874aea 2595 len += 16; /* session id */
2596 len += 4; /* response format */
3d88e64d 2597 agentreq = snewn(4 + len, char);
32874aea 2598 PUT_32BIT(agentreq, len);
2599 q = agentreq + 4;
2600 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 2601 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 2602 q += 4;
51470298 2603 q += ssh1_write_bignum(q, s->key.exponent);
2604 q += ssh1_write_bignum(q, s->key.modulus);
2605 q += ssh1_write_bignum(q, s->challenge);
2606 memcpy(q, s->session_id, 16);
32874aea 2607 q += 16;
2608 PUT_32BIT(q, 1); /* response format */
2d466ffd 2609 agent_query(agentreq, len + 4, &vret, &retlen);
2610 ret = vret;
32874aea 2611 sfree(agentreq);
2612 if (ret) {
2613 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2614 logevent("Sending Pageant's response");
51470298 2615 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 2616 PKT_DATA, ret + 5, 16,
2617 PKT_END);
2618 sfree(ret);
2619 crWaitUntil(ispkt);
51470298 2620 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
32874aea 2621 logevent
2622 ("Pageant's response accepted");
2623 if (flags & FLAG_VERBOSE) {
51470298 2624 c_write_str(ssh, "Authenticated using"
2625 " RSA key \"");
2626 c_write(ssh, s->commentp,
2627 s->commentlen);
2628 c_write_str(ssh, "\" from agent\r\n");
32874aea 2629 }
51470298 2630 s->authed = TRUE;
32874aea 2631 } else
2632 logevent
2633 ("Pageant's response not accepted");
2634 } else {
2635 logevent
2636 ("Pageant failed to answer challenge");
2637 sfree(ret);
2638 }
2639 } else {
2640 logevent("No reply received from Pageant");
2641 }
2642 }
51470298 2643 freebn(s->key.exponent);
2644 freebn(s->key.modulus);
2645 freebn(s->challenge);
2646 if (s->authed)
32874aea 2647 break;
2648 }
2649 }
51470298 2650 if (s->authed)
32874aea 2651 break;
2652 }
9a30e26b 2653 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 2654 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 2655
86916870 2656 if (ssh->cfg.try_tis_auth &&
51470298 2657 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2658 !s->tis_auth_refused) {
2659 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 2660 logevent("Requested TIS authentication");
51470298 2661 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
32874aea 2662 crWaitUntil(ispkt);
51470298 2663 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 2664 logevent("TIS authentication declined");
2665 if (flags & FLAG_INTERACTIVE)
51470298 2666 c_write_str(ssh, "TIS authentication refused.\r\n");
2667 s->tis_auth_refused = 1;
614a20a0 2668 continue;
32874aea 2669 } else {
51470298 2670 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2671 logevent("Received TIS challenge");
51470298 2672 if (challengelen > sizeof(s->prompt) - 1)
2673 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2674 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
614a20a0 2675 /* Prompt heuristic comes from OpenSSH */
51470298 2676 strncpy(s->prompt + challengelen,
2677 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2678 "": "\r\nResponse: ",
51470298 2679 (sizeof s->prompt) - challengelen);
2680 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 2681 }
2682 }
86916870 2683 if (ssh->cfg.try_tis_auth &&
51470298 2684 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2685 !s->ccard_auth_refused) {
2686 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 2687 logevent("Requested CryptoCard authentication");
51470298 2688 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
32874aea 2689 crWaitUntil(ispkt);
51470298 2690 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 2691 logevent("CryptoCard authentication declined");
51470298 2692 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2693 s->ccard_auth_refused = 1;
614a20a0 2694 continue;
32874aea 2695 } else {
51470298 2696 int challengelen = GET_32BIT(ssh->pktin.body);
32874aea 2697 logevent("Received CryptoCard challenge");
51470298 2698 if (challengelen > sizeof(s->prompt) - 1)
2699 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2700 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2701 strncpy(s->prompt + challengelen,
2702 memchr(s->prompt, '\n', challengelen) ?
614a20a0 2703 "" : "\r\nResponse: ",
51470298 2704 sizeof(s->prompt) - challengelen);
2705 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 2706 }
2707 }
51470298 2708 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2709 sprintf(s->prompt, "%.90s@%.90s's password: ",
2710 s->username, ssh->savedhost);
32874aea 2711 }
51470298 2712 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2713 char *comment = NULL;
231ee168 2714 int type;
2715 char msgbuf[256];
32874aea 2716 if (flags & FLAG_VERBOSE)
51470298 2717 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 2718 logeventf(ssh, "Trying public key \"%s\"",
2719 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 2720 type = key_type(&ssh->cfg.keyfile);
231ee168 2721 if (type != SSH_KEYTYPE_SSH1) {
2722 sprintf(msgbuf, "Key is of wrong type (%s)",
2723 key_type_to_str(type));
2724 logevent(msgbuf);
51470298 2725 c_write_str(ssh, msgbuf);
2726 c_write_str(ssh, "\r\n");
2727 s->tried_publickey = 1;
231ee168 2728 continue;
2729 }
9a30e26b 2730 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 2731 if (flags & FLAG_VERBOSE)
51470298 2732 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 2733 goto tryauth;
2734 }
51470298 2735 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 2736 sfree(comment);
2737 }
a52f067e 2738
614a20a0 2739 /*
2740 * Show password prompt, having first obtained it via a TIS
2741 * or CryptoCard exchange if we're doing TIS or CryptoCard
2742 * authentication.
2743 */
fa17a66e 2744 if (ssh_get_line) {
51470298 2745 if (!ssh_get_line(s->prompt, s->password,
2746 sizeof(s->password), TRUE)) {
32874aea 2747 /*
2748 * get_line failed to get a password (for example
2749 * because one was supplied on the command line
2750 * which has already failed to work). Terminate.
2751 */
51470298 2752 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 2753 PKT_STR, "No more passwords available to try",
2754 PKT_END);
247308b5 2755 logevent("Unable to authenticate");
a8327734 2756 connection_fatal(ssh->frontend, "Unable to authenticate");
3bb2f322 2757 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2758 crStop(1);
32874aea 2759 }
fb09bf1c 2760 } else {
614a20a0 2761 /* Prompt may have come from server. We've munged it a bit, so
2762 * we know it to be zero-terminated at least once. */
51470298 2763 int ret; /* need not be saved over crReturn */
2764 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2765 s->pos = 0;
0405e71f 2766
51470298 2767 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 2768 do {
32874aea 2769 crWaitUntil(!ispkt);
51470298 2770 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2771 } while (ret == 0);
2772 if (ret < 0)
2773 cleanup_exit(0);
51470298 2774 c_write_str(ssh, "\r\n");
32874aea 2775 }
2776
2777 tryauth:
51470298 2778 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 2779 /*
2780 * Try public key authentication with the specified
2781 * key file.
2782 */
51470298 2783 s->tried_publickey = 1;
2784
2785 {
9a30e26b 2786 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password);
51470298 2787 if (ret == 0) {
2788 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 2789 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
51470298 2790 c_write_str(ssh, ".\r\n");
2791 continue; /* go and try password */
2792 }
2793 if (ret == -1) {
2794 c_write_str(ssh, "Wrong passphrase.\r\n");
2795 s->tried_publickey = 0;
2796 continue; /* try again */
2797 }
32874aea 2798 }
2799
2800 /*
2801 * Send a public key attempt.
2802 */
51470298 2803 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2804 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 2805
2806 crWaitUntil(ispkt);
51470298 2807 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2808 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 2809 continue; /* go and try password */
2810 }
51470298 2811 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 2812 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 2813 crStop(0);
32874aea 2814 }
32874aea 2815
51470298 2816 {
2817 int i;
2818 unsigned char buffer[32];
2819 Bignum challenge, response;
2820
2821 ssh1_read_bignum(ssh->pktin.body, &challenge);
2822 response = rsadecrypt(challenge, &s->key);
2823 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 2824
51470298 2825 for (i = 0; i < 32; i++) {
2826 buffer[i] = bignum_byte(response, 31 - i);
2827 }
2828
2829 MD5Init(&md5c);
2830 MD5Update(&md5c, buffer, 32);
2831 MD5Update(&md5c, s->session_id, 16);
2832 MD5Final(buffer, &md5c);
32874aea 2833
51470298 2834 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2835 PKT_DATA, buffer, 16, PKT_END);
2836
2837 freebn(challenge);
2838 freebn(response);
2839 }
32874aea 2840
2841 crWaitUntil(ispkt);
51470298 2842 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2843 if (flags & FLAG_VERBOSE)
51470298 2844 c_write_str(ssh, "Failed to authenticate with"
2845 " our public key.\r\n");
32874aea 2846 continue; /* go and try password */
51470298 2847 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2848 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 2849 crStop(0);
32874aea 2850 }
2851
2852 break; /* we're through! */
2853 } else {
51470298 2854 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 2855 /*
2856 * Defence against traffic analysis: we send a
2857 * whole bunch of packets containing strings of
2858 * different lengths. One of these strings is the
2859 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2860 * The others are all random data in
2861 * SSH1_MSG_IGNORE packets. This way a passive
2862 * listener can't tell which is the password, and
2863 * hence can't deduce the password length.
2864 *
2865 * Anybody with a password length greater than 16
2866 * bytes is going to have enough entropy in their
2867 * password that a listener won't find it _that_
2868 * much help to know how long it is. So what we'll
2869 * do is:
2870 *
2871 * - if password length < 16, we send 15 packets
2872 * containing string lengths 1 through 15
2873 *
2874 * - otherwise, we let N be the nearest multiple
2875 * of 8 below the password length, and send 8
2876 * packets containing string lengths N through
2877 * N+7. This won't obscure the order of
2878 * magnitude of the password length, but it will
2879 * introduce a bit of extra uncertainty.
2880 *
2881 * A few servers (the old 1.2.18 through 1.2.22)
2882 * can't deal with SSH1_MSG_IGNORE. For these
2883 * servers, we need an alternative defence. We make
2884 * use of the fact that the password is interpreted
2885 * as a C string: so we can append a NUL, then some
2886 * random data.
bd358db1 2887 *
2888 * One server (a Cisco one) can deal with neither
2889 * SSH1_MSG_IGNORE _nor_ a padded password string.
2890 * For this server we are left with no defences
2891 * against password length sniffing.
32874aea 2892 */
51470298 2893 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 2894 /*
2895 * The server can deal with SSH1_MSG_IGNORE, so
2896 * we can use the primary defence.
2897 */
32874aea 2898 int bottom, top, pwlen, i;
2899 char *randomstr;
2900
51470298 2901 pwlen = strlen(s->password);
32874aea 2902 if (pwlen < 16) {
2903 bottom = 0; /* zero length passwords are OK! :-) */
2904 top = 15;
2905 } else {
2906 bottom = pwlen & ~7;
2907 top = bottom + 7;
2908 }
2909
2910 assert(pwlen >= bottom && pwlen <= top);
2911
3d88e64d 2912 randomstr = snewn(top + 1, char);
32874aea 2913
2914 for (i = bottom; i <= top; i++) {
2915 if (i == pwlen)
51470298 2916 defer_packet(ssh, s->pwpkt_type,
2917 PKT_STR, s->password, PKT_END);
32874aea 2918 else {
2919 for (j = 0; j < i; j++) {
2920 do {
2921 randomstr[j] = random_byte();
2922 } while (randomstr[j] == '\0');
2923 }
2924 randomstr[i] = '\0';
51470298 2925 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 2926 PKT_STR, randomstr, PKT_END);
2927 }
2928 }
bd358db1 2929 logevent("Sending password with camouflage packets");
51470298 2930 ssh_pkt_defersend(ssh);
bd358db1 2931 }
51470298 2932 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 2933 /*
2934 * The server can't deal with SSH1_MSG_IGNORE
2935 * but can deal with padded passwords, so we
2936 * can use the secondary defence.
2937 */
bd358db1 2938 char string[64];
51470298 2939 char *ss;
bd358db1 2940 int len;
2941
51470298 2942 len = strlen(s->password);
bd358db1 2943 if (len < sizeof(string)) {
51470298 2944 ss = string;
2945 strcpy(string, s->password);
bd358db1 2946 len++; /* cover the zero byte */
2947 while (len < sizeof(string)) {
2948 string[len++] = (char) random_byte();
2949 }
2950 } else {
51470298 2951 ss = s->password;
bd358db1 2952 }
2953 logevent("Sending length-padded password");
51470298 2954 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2955 PKT_DATA, ss, len, PKT_END);
bd358db1 2956 } else {
2957 /*
2958 * The server has _both_
2959 * BUG_CHOKES_ON_SSH1_IGNORE and
2960 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2961 * therefore nothing we can do.
2962 */
2963 int len;
51470298 2964 len = strlen(s->password);
bd358db1 2965 logevent("Sending unpadded password");
51470298 2966 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2967 PKT_DATA, s->password, len, PKT_END);
32874aea 2968 }
2969 } else {
51470298 2970 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
32874aea 2971 }
2972 }
c5e9c988 2973 logevent("Sent password");
51470298 2974 memset(s->password, 0, strlen(s->password));
fb09bf1c 2975 crWaitUntil(ispkt);
51470298 2976 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 2977 if (flags & FLAG_VERBOSE)
51470298 2978 c_write_str(ssh, "Access denied\r\n");
c5e9c988 2979 logevent("Authentication refused");
51470298 2980 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2981 bombout(("Strange packet received, type %d", ssh->pktin.type));
7ffdbc1a 2982 crStop(0);
374330e2 2983 }
2984 }
2985
c5e9c988 2986 logevent("Authentication successful");
2987
fb09bf1c 2988 crFinish(1);
2989}
2990
32874aea 2991void sshfwd_close(struct ssh_channel *c)
2992{
51470298 2993 Ssh ssh = c->ssh;
2994
80e48603 2995 if (c && !c->closes) {
4ed34d25 2996 /*
2997 * If the channel's remoteid is -1, we have sent
2998 * CHANNEL_OPEN for this channel, but it hasn't even been
2999 * acknowledged by the server. So we must set a close flag
3000 * on it now, and then when the server acks the channel
3001 * open, we can close it then.
3002 */
36cac739 3003 if (((int)c->remoteid) != -1) {
51470298 3004 if (ssh->version == 1) {
3005 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3006 PKT_END);
3007 } else {
51470298 3008 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3009 ssh2_pkt_adduint32(ssh, c->remoteid);
3010 ssh2_pkt_send(ssh);
4ed34d25 3011 }
32874aea 3012 }
0357890f 3013 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3014 if (c->type == CHAN_X11) {
3015 c->u.x11.s = NULL;
d74d141c 3016 logevent("Forwarded X11 connection terminated");
4ed34d25 3017 } else if (c->type == CHAN_SOCKDATA ||
3018 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3019 c->u.pfd.s = NULL;
3020 logevent("Forwarded port closed");
32874aea 3021 }
3022 }
3023}
3024
5471d09a 3025int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3026{
51470298 3027 Ssh ssh = c->ssh;
3028
3029 if (ssh->version == 1) {
3030 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3031 PKT_INT, c->remoteid,
3032 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
5471d09a 3033 /*
3034 * In SSH1 we can return 0 here - implying that forwarded
3035 * connections are never individually throttled - because
3036 * the only circumstance that can cause throttling will be
3037 * the whole SSH connection backing up, in which case
3038 * _everything_ will be throttled as a whole.
3039 */
3040 return 0;
783415f8 3041 } else {
32874aea 3042 ssh2_add_channel_data(c, buf, len);
5471d09a 3043 return ssh2_try_send(c);
3044 }
3045}
3046
3047void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3048{
51470298 3049 Ssh ssh = c->ssh;
3050
3051 if (ssh->version == 1) {
5471d09a 3052 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3053 c->v.v1.throttling = 0;
51470298 3054 ssh1_throttle(ssh, -1);
5471d09a 3055 }
3056 } else {
3057 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3058 }
9c964e85 3059}
3060
51470298 3061static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
32874aea 3062{
51470298 3063 crBegin(ssh->ssh1_protocol_crstate);
fb09bf1c 3064
3065 random_init();
3066
51470298 3067 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
fb09bf1c 3068 crReturnV;
85ee8208 3069 }
51470298 3070 if (ssh->state == SSH_STATE_CLOSED)
32874aea 3071 crReturnV;
fb09bf1c 3072
86916870 3073 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 3074 logevent("Requesting agent forwarding");
51470298 3075 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 3076 do {
3077 crReturnV;
3078 } while (!ispkt);
51470298 3079 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3080 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3081 bombout(("Protocol confusion"));
7ffdbc1a 3082 crStopV;
51470298 3083 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3084 logevent("Agent forwarding refused");
3085 } else {
3086 logevent("Agent forwarding enabled");
51470298 3087 ssh->agentfwd_enabled = TRUE;
db7d555c 3088 }
dacbd0e8 3089 }
3090
86916870 3091 if (ssh->cfg.x11_forward) {
32874aea 3092 char proto[20], data[64];
3093 logevent("Requesting X11 forwarding");
302121de 3094 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 3095 data, sizeof(data), ssh->cfg.x11_auth);
3096 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 3097 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3098 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3099 PKT_STR, proto, PKT_STR, data,
86916870 3100 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 3101 PKT_END);
32874aea 3102 } else {
51470298 3103 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3104 PKT_STR, proto, PKT_STR, data, PKT_END);
3105 }
3106 do {
3107 crReturnV;
3108 } while (!ispkt);
51470298 3109 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3110 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3111 bombout(("Protocol confusion"));
7ffdbc1a 3112 crStopV;
51470298 3113 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
32874aea 3114 logevent("X11 forwarding refused");
3115 } else {
3116 logevent("X11 forwarding enabled");
51470298 3117 ssh->X11_fwd_enabled = TRUE;
9c964e85 3118 }
3119 }
3120
d74d141c 3121 {
9bf696b1 3122 char type;
d74d141c 3123 int n;
a4fc0d74 3124 int sport,dport,sserv,dserv;
6ee9b735 3125 char sports[256], dports[256], saddr[256], host[256];
d74d141c 3126
51470298 3127 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3128 /* Add port forwardings. */
86916870 3129 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 3130 while (*ssh->portfwd_strptr) {
3131 type = *ssh->portfwd_strptr++;
6ee9b735 3132 saddr[0] = '\0';
d74d141c 3133 n = 0;
6ee9b735 3134 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3135 if (*ssh->portfwd_strptr == ':') {
3136 /*
3137 * We've seen a colon in the middle of the
3138 * source port number. This means that
3139 * everything we've seen until now is the
3140 * source _address_, so we'll move it into
3141 * saddr and start sports from the beginning
3142 * again.
3143 */
3144 ssh->portfwd_strptr++;
3145 sports[n] = '\0';
3146 strcpy(saddr, sports);
3147 n = 0;
3148 }
3149 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3150 }
d74d141c 3151 sports[n] = 0;
820ebe3b 3152 if (type != 'D') {
3153 if (*ssh->portfwd_strptr == '\t')
3154 ssh->portfwd_strptr++;
3155 n = 0;
3156 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3157 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3158 }
3159 host[n] = 0;
3160 if (*ssh->portfwd_strptr == ':')
3161 ssh->portfwd_strptr++;
3162 n = 0;
3163 while (*ssh->portfwd_strptr) {
3164 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3165 }
3166 dports[n] = 0;
51470298 3167 ssh->portfwd_strptr++;
820ebe3b 3168 dport = atoi(dports);
3169 dserv = 0;
3170 if (dport == 0) {
3171 dserv = 1;
3172 dport = net_service_lookup(dports);
3173 if (!dport) {
3174 logeventf(ssh, "Service lookup failed for"
3175 " destination port \"%s\"", dports);
3176 }
a4fc0d74 3177 }
820ebe3b 3178 } else {
3179 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 3180 dport = dserv = -1;
a4fc0d74 3181 }
d74d141c 3182 sport = atoi(sports);
a4fc0d74 3183 sserv = 0;
3184 if (sport == 0) {
3185 sserv = 1;
68a49acb 3186 sport = net_service_lookup(sports);
3187 if (!sport) {
57356d63 3188 logeventf(ssh, "Service lookup failed for source"
3189 " port \"%s\"", sports);
a4fc0d74 3190 }
3191 }
d74d141c 3192 if (sport && dport) {
3193 if (type == 'L') {
6ee9b735 3194 pfd_addforward(host, dport, *saddr ? saddr : NULL,
e8fa8f62 3195 sport, ssh, &ssh->cfg);
6ee9b735 3196 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3197 " forwarding to %s:%.*s%.*s%d%.*s",
3198 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3199 (int)(*saddr?1:0), ":",
57356d63 3200 (int)(sserv ? strlen(sports) : 0), sports,
3201 sserv, "(", sport, sserv, ")",
3202 host,
3203 (int)(dserv ? strlen(dports) : 0), dports,
3204 dserv, "(", dport, dserv, ")");
820ebe3b 3205 } else if (type == 'D') {
3206 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
3207 sport, ssh, &ssh->cfg);
3208 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3209 " doing SOCKS dynamic forwarding",
3210 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3211 (int)(*saddr?1:0), ":",
3212 (int)(sserv ? strlen(sports) : 0), sports,
3213 sserv, "(", sport, sserv, ")");
d74d141c 3214 } else {
3215 struct ssh_rportfwd *pf;
3d88e64d 3216 pf = snew(struct ssh_rportfwd);
bc240b21 3217 strcpy(pf->dhost, host);
3218 pf->dport = dport;
6ee9b735 3219 if (saddr) {
3220 logeventf(ssh,
3221 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3222 saddr, sport);
3223 }
51470298 3224 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 3225 logeventf(ssh,
3226 "Duplicate remote port forwarding to %s:%d",
3227 host, dport);
bc240b21 3228 sfree(pf);
d74d141c 3229 } else {
57356d63 3230 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3231 " forward to %s:%.*s%.*s%d%.*s",
3232 (int)(sserv ? strlen(sports) : 0), sports,
3233 sserv, "(", sport, sserv, ")",
3234 host,
3235 (int)(dserv ? strlen(dports) : 0), dports,
3236 dserv, "(", dport, dserv, ")");
51470298 3237 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
d74d141c 3238 PKT_INT, sport,
3239 PKT_STR, host,
3240 PKT_INT, dport,
3241 PKT_END);
9bf696b1 3242 do {
3243 crReturnV;
3244 } while (!ispkt);
51470298 3245 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3246 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3247 bombout(("Protocol confusion"));
7ffdbc1a 3248 crStopV;
51470298 3249 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3250 c_write_str(ssh, "Server refused port"
3251 " forwarding\r\n");
9bf696b1 3252 }
3253 logevent("Remote port forwarding enabled");
d74d141c 3254 }
3255 }
3256 }
3257 }
3258 }
3259
86916870 3260 if (!ssh->cfg.nopty) {
51470298 3261 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 3262 PKT_STR, ssh->cfg.termtype,
51470298 3263 PKT_INT, ssh->term_height,
3264 PKT_INT, ssh->term_width,
32874aea 3265 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
51470298 3266 ssh->state = SSH_STATE_INTERMED;
32874aea 3267 do {
3268 crReturnV;
3269 } while (!ispkt);
51470298 3270 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3271 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3272 bombout(("Protocol confusion"));
7ffdbc1a 3273 crStopV;
51470298 3274 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3275 c_write_str(ssh, "Server refused to allocate pty\r\n");
3276 ssh->editing = ssh->echoing = 1;
32874aea 3277 }
c5e9c988 3278 logevent("Allocated pty");
0965bee0 3279 } else {
51470298 3280 ssh->editing = ssh->echoing = 1;
374330e2 3281 }
3282
86916870 3283 if (ssh->cfg.compression) {
51470298 3284 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 3285 do {
3286 crReturnV;
3287 } while (!ispkt);
51470298 3288 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3289 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3290 bombout(("Protocol confusion"));
7ffdbc1a 3291 crStopV;
51470298 3292 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3293 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 3294 }
4ba9b64b 3295 logevent("Started compression");
51470298 3296 ssh->v1_compressing = TRUE;
5366aed8 3297 ssh->cs_comp_ctx = zlib_compress_init();
3298 logevent("Initialised zlib (RFC1950) compression");
3299 ssh->sc_comp_ctx = zlib_decompress_init();
3300 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 3301 }
3302
fd5e5847 3303 /*
3304 * Start the shell or command.
3305 *
3306 * Special case: if the first-choice command is an SSH2
3307 * subsystem (hence not usable here) and the second choice
3308 * exists, we fall straight back to that.
3309 */
3310 {
86916870 3311 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 3312
86916870 3313 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3314 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 3315 ssh->fallback_cmd = TRUE;
fd5e5847 3316 }
3317 if (*cmd)
51470298 3318 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 3319 else
51470298 3320 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 3321 logevent("Started session");
3322 }
374330e2 3323
51470298 3324 ssh->state = SSH_STATE_SESSION;
3325 if (ssh->size_needed)
3326 ssh_size(ssh, ssh->term_width, ssh->term_height);
3327 if (ssh->eof_needed)
3328 ssh_special(ssh, TS_EOF);
374330e2 3329
b9d7bcad 3330 if (ssh->ldisc)
3331 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 3332 ssh->send_ok = 1;
3333 ssh->channels = newtree234(ssh_channelcmp);
374330e2 3334 while (1) {
3335 crReturnV;
3336 if (ispkt) {
51470298 3337 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3338 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3339 long len = GET_32BIT(ssh->pktin.body);
5471d09a 3340 int bufsize =
51470298 3341 from_backend(ssh->frontend,
3342 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
d8baa528 3343 (char *)(ssh->pktin.body) + 4, len);
51470298 3344 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3345 ssh->v1_stdout_throttling = 1;
3346 ssh1_throttle(ssh, +1);
5471d09a 3347 }
51470298 3348 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3bb2f322 3349 ssh_closing((Plug)ssh, NULL, 0, 0);
c5e9c988 3350 logevent("Received disconnect request");
7ffdbc1a 3351 crStopV;
51470298 3352 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
32874aea 3353 /* Remote side is trying to open a channel to talk to our
3354 * X-Server. Give them back a local channel number. */
3355 struct ssh_channel *c;
9c964e85 3356
3357 logevent("Received X11 connect request");
3358 /* Refuse if X11 forwarding is disabled. */
51470298 3359 if (!ssh->X11_fwd_enabled) {
3360 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3361 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
9c964e85 3362 logevent("Rejected X11 connect request");
3363 } else {
3d88e64d 3364 c = snew(struct ssh_channel);
51470298 3365 c->ssh = ssh;
9c964e85 3366
86916870 3367 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
e8fa8f62 3368 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
32874aea 3369 logevent("opening X11 forward connection failed");
3370 sfree(c);
51470298 3371 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3372 PKT_INT, GET_32BIT(ssh->pktin.body),
32874aea 3373 PKT_END);
9c964e85 3374 } else {
32874aea 3375 logevent
3376 ("opening X11 forward connection succeeded");
51470298 3377 c->remoteid = GET_32BIT(ssh->pktin.body);
3378 c->localid = alloc_channel_id(ssh);
32874aea 3379 c->closes = 0;
5471d09a 3380 c->v.v1.throttling = 0;
32874aea 3381 c->type = CHAN_X11; /* identify channel type */
51470298 3382 add234(ssh->channels, c);
3383 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
32874aea 3384 PKT_INT, c->remoteid, PKT_INT,
3385 c->localid, PKT_END);
3386 logevent("Opened X11 forward channel");
9c964e85 3387 }
3388 }
51470298 3389 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
32874aea 3390 /* Remote side is trying to open a channel to talk to our
3391 * agent. Give them back a local channel number. */
3392 struct ssh_channel *c;
db7d555c 3393
3394 /* Refuse if agent forwarding is disabled. */
51470298 3395 if (!ssh->agentfwd_enabled) {
3396 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3397 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
db7d555c 3398 } else {
3d88e64d 3399 c = snew(struct ssh_channel);
51470298 3400 c->ssh = ssh;
3401 c->remoteid = GET_32BIT(ssh->pktin.body);
3402 c->localid = alloc_channel_id(ssh);
db7d555c 3403 c->closes = 0;
5471d09a 3404 c->v.v1.throttling = 0;
32874aea 3405 c->type = CHAN_AGENT; /* identify channel type */
db7d555c 3406 c->u.a.lensofar = 0;
51470298 3407 add234(ssh->channels, c);
3408 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
db7d555c 3409 PKT_INT, c->remoteid, PKT_INT, c->localid,
3410 PKT_END);
3411 }
51470298 3412 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
d74d141c 3413 /* Remote side is trying to open a channel to talk to a
3414 * forwarded port. Give them back a local channel number. */
3415 struct ssh_channel *c;
3416 struct ssh_rportfwd pf;
3417 int hostsize, port;
3418 char host[256], buf[1024];
3419 char *p, *h, *e;
3d88e64d 3420 c = snew(struct ssh_channel);
51470298 3421 c->ssh = ssh;
d74d141c 3422
51470298 3423 hostsize = GET_32BIT(ssh->pktin.body+4);
d8baa528 3424 for (h = host, p = (char *)(ssh->pktin.body+8);
3425 hostsize != 0; hostsize--) {
d74d141c 3426 if (h+1 < host+sizeof(host))
3427 *h++ = *p;
95bc8819 3428 p++;
d74d141c 3429 }
3430 *h = 0;
3431 port = GET_32BIT(p);
3432
bc240b21 3433 strcpy(pf.dhost, host);
3434 pf.dport = port;
d74d141c 3435
51470298 3436 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
d74d141c 3437 sprintf(buf, "Rejected remote port open request for %s:%d",
3438 host, port);
3439 logevent(buf);
51470298 3440 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3441 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
d74d141c 3442 } else {
3443 sprintf(buf, "Received remote port open request for %s:%d",
3444 host, port);
3445 logevent(buf);
e8fa8f62 3446 e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg);
d74d141c 3447 if (e != NULL) {
3448 char buf[256];
3449 sprintf(buf, "Port open failed: %s", e);
3450 logevent(buf);
3451 sfree(c);
51470298 3452 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3453 PKT_INT, GET_32BIT(ssh->pktin.body),
d74d141c 3454 PKT_END);
3455 } else {
51470298 3456 c->remoteid = GET_32BIT(ssh->pktin.body);
3457 c->localid = alloc_channel_id(ssh);
d74d141c 3458 c->closes = 0;
5471d09a 3459 c->v.v1.throttling = 0;
d74d141c 3460 c->type = CHAN_SOCKDATA; /* identify channel type */
51470298 3461 add234(ssh->channels, c);
3462 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
d74d141c 3463 PKT_INT, c->remoteid, PKT_INT,
3464 c->localid, PKT_END);
3465 logevent("Forwarded port opened successfully");
3466 }
3467 }
3468
51470298 3469 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3470 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3471 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
bc240b21 3472 struct ssh_channel *c;
3473
51470298 3474 c = find234(ssh->channels, &remoteid, ssh_channelfind);
bc240b21 3475 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3476 c->remoteid = localid;
3477 c->type = CHAN_SOCKDATA;
7781f316 3478 c->v.v1.throttling = 0;
bc240b21 3479 pfd_confirm(c->u.pfd.s);
3480 }
d74d141c 3481
4ed34d25 3482 if (c && c->closes) {
3483 /*
3484 * We have a pending close on this channel,
3485 * which we decided on before the server acked
3486 * the channel open. So now we know the
3487 * remoteid, we can close it again.
3488 */
51470298 3489 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3490 PKT_INT, c->remoteid, PKT_END);
4ed34d25 3491 }
3492
51470298 3493 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3494 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
724cface 3495 struct ssh_channel *c;
3496
51470298 3497 c = find234(ssh->channels, &remoteid, ssh_channelfind);
724cface 3498 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3499 logevent("Forwarded connection refused by server");
3500 pfd_close(c->u.pfd.s);
51470298 3501 del234(ssh->channels, c);
724cface 3502 sfree(c);
3503 }
3504
51470298 3505 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3506 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
32874aea 3507 /* Remote side closes a channel. */
51470298 3508 unsigned i = GET_32BIT(ssh->pktin.body);
32874aea 3509 struct ssh_channel *c;
51470298 3510 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 3511 if (c && ((int)c->remoteid) != -1) {
32874aea 3512 int closetype;
3513 closetype =
51470298 3514 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
0357890f 3515
783415f8 3516 if ((c->closes == 0) && (c->type == CHAN_X11)) {
d74d141c 3517 logevent("Forwarded X11 connection terminated");
9c964e85 3518 assert(c->u.x11.s != NULL);
3519 x11_close(c->u.x11.s);
3520 c->u.x11.s = NULL;
3521 }
d74d141c 3522 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3523 logevent("Forwarded port closed");
3524 assert(c->u.pfd.s != NULL);
3525 pfd_close(c->u.pfd.s);
3526 c->u.pfd.s = NULL;
3527 }
0357890f 3528
3529 c->closes |= (closetype << 2); /* seen this message */
3530 if (!(c->closes & closetype)) {
51470298 3531 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
0357890f 3532 PKT_END);
3533 c->closes |= closetype; /* sent it too */
3534 }
3535
3536 if (c->closes == 15) {
51470298 3537 del234(ssh->channels, c);
32874aea 3538 sfree(c);
3539 }
d0d844c1 3540 } else {
6b5cf8b4 3541 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
51470298 3542 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
d0d844c1 3543 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3544 i));
7ffdbc1a 3545 crStopV;
32874aea 3546 }
51470298 3547 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
32874aea 3548 /* Data sent down one of our channels. */
51470298 3549 int i = GET_32BIT(ssh->pktin.body);
3550 int len = GET_32BIT(ssh->pktin.body + 4);
3551 unsigned char *p = ssh->pktin.body + 8;
32874aea 3552 struct ssh_channel *c;
51470298 3553 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 3554 if (c) {
7ffdbc1a 3555 int bufsize = 0;
32874aea 3556 switch (c->type) {
3557 case CHAN_X11:
d8baa528 3558 bufsize = x11_send(c->u.x11.s, (char *)p, len);
9c964e85 3559 break;
d74d141c 3560 case CHAN_SOCKDATA:
d8baa528 3561 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
bc240b21 3562 break;
32874aea 3563 case CHAN_AGENT:
3564 /* Data for an agent message. Buffer it. */
3565 while (len > 0) {
3566 if (c->u.a.lensofar < 4) {
3567 int l = min(4 - c->u.a.lensofar, len);
3568 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3569 l);
3570 p += l;
3571 len -= l;
3572 c->u.a.lensofar += l;
3573 }
3574 if (c->u.a.lensofar == 4) {
3575 c->u.a.totallen =
3576 4 + GET_32BIT(c->u.a.msglen);
3d88e64d 3577 c->u.a.message = snewn(c->u.a.totallen,
3578 unsigned char);
32874aea 3579 memcpy(c->u.a.message, c->u.a.msglen, 4);
3580 }
3581 if (c->u.a.lensofar >= 4 && len > 0) {
3582 int l =
3583 min(c->u.a.totallen - c->u.a.lensofar,
3584 len);
3585 memcpy(c->u.a.message + c->u.a.lensofar, p,
3586 l);
3587 p += l;
3588 len -= l;
3589 c->u.a.lensofar += l;
3590 }
3591 if (c->u.a.lensofar == c->u.a.totallen) {
3592 void *reply, *sentreply;
3593 int replylen;
3594 agent_query(c->u.a.message,
3595 c->u.a.totallen, &reply,
3596 &replylen);
3597 if (reply)
3598 sentreply = reply;
3599 else {
3600 /* Fake SSH_AGENT_FAILURE. */
3601 sentreply = "\0\0\0\1\5";
3602 replylen = 5;
3603 }
51470298 3604 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3605 PKT_INT, c->remoteid,
3606 PKT_INT, replylen,
3607 PKT_DATA, sentreply, replylen,
3608 PKT_END);
3609 if (reply)
3610 sfree(reply);
3611 sfree(c->u.a.message);
3612 c->u.a.lensofar = 0;
3613 }
3614 }
5471d09a 3615 bufsize = 0; /* agent channels never back up */
32874aea 3616 break;
3617 }
90347b95 3618 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
5471d09a 3619 c->v.v1.throttling = 1;
51470298 3620 ssh1_throttle(ssh, +1);
5471d09a 3621 }
32874aea 3622 }
51470298 3623 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 3624 /* may be from EXEC_SHELL on some servers */
51470298 3625 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 3626 /* may be from EXEC_SHELL on some servers
374330e2 3627 * if no pty is available or in other odd cases. Ignore */
51470298 3628 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
d8d6c7e5 3629 char buf[100];
51470298 3630 ssh->exitcode = GET_32BIT(ssh->pktin.body);
d8d6c7e5 3631 sprintf(buf, "Server sent command exit status %d",
51470298 3632 ssh->exitcode);
d8d6c7e5 3633 logevent(buf);
51470298 3634 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4252c9cc 3635 /*
3636 * In case `helpful' firewalls or proxies tack
3637 * extra human-readable text on the end of the
3638 * session which we might mistake for another
3639 * encrypted packet, we close the session once
3640 * we've sent EXIT_CONFIRMATION.
3641 */
3bb2f322 3642 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3643 crStopV;
374330e2 3644 } else {
6b5cf8b4 3645 bombout(("Strange packet received: type %d", ssh->pktin.type));
7ffdbc1a 3646 crStopV;
374330e2 3647 }
3648 } else {
8df7a775 3649 while (inlen > 0) {
3650 int len = min(inlen, 512);
51470298 3651 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
8df7a775 3652 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3653 in += len;
3654 inlen -= len;
3655 }
374330e2 3656 }
3657 }
3658
3659 crFinishV;
3660}
3661
3662/*
e5574168 3663 * Utility routine for decoding comma-separated strings in KEXINIT.
3664 */
32874aea 3665static int in_commasep_string(char *needle, char *haystack, int haylen)
3666{
57356d63 3667 int needlen;
3668 if (!needle || !haystack) /* protect against null pointers */
3669 return 0;
3670 needlen = strlen(needle);
e5574168 3671 while (1) {
32874aea 3672 /*
3673 * Is it at the start of the string?
3674 */
3675 if (haylen >= needlen && /* haystack is long enough */
3676 !memcmp(needle, haystack, needlen) && /* initial match */
3677 (haylen == needlen || haystack[needlen] == ',')
3678 /* either , or EOS follows */
3679 )
3680 return 1;
3681 /*
3682 * If not, search for the next comma and resume after that.
3683 * If no comma found, terminate.
3684 */
3685 while (haylen > 0 && *haystack != ',')
3686 haylen--, haystack++;
3687 if (haylen == 0)
3688 return 0;
3689 haylen--, haystack++; /* skip over comma itself */
e5574168 3690 }
3691}
3692
3693/*
d39f364a 3694 * SSH2 key creation method.
3695 */
d8baa528 3696static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3697 unsigned char *sessid, char chr,
3698 unsigned char *keyspace)
32874aea 3699{
d39f364a 3700 SHA_State s;
3701 /* First 20 bytes. */
3702 SHA_Init(&s);
51470298 3703 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 3704 sha_mpint(&s, K);
d39f364a 3705 SHA_Bytes(&s, H, 20);
3706 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 3707 SHA_Bytes(&s, sessid, 20);
d39f364a 3708 SHA_Final(&s, keyspace);
3709 /* Next 20 bytes. */
3710 SHA_Init(&s);
51470298 3711 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 3712 sha_mpint(&s, K);
d39f364a 3713 SHA_Bytes(&s, H, 20);
3714 SHA_Bytes(&s, keyspace, 20);
32874aea 3715 SHA_Final(&s, keyspace + 20);
d39f364a 3716}
3717
3718/*
7cca0d81 3719 * Handle the SSH2 transport layer.
e5574168 3720 */
51470298 3721static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
e5574168 3722{
51470298 3723 struct do_ssh2_transport_state {
3724 int nbits, pbits, warn;
3725 Bignum p, g, e, f, K;
3726 int kex_init_value, kex_reply_value;
3727 const struct ssh_mac **maclist;
3728 int nmacs;
3729 const struct ssh2_cipher *cscipher_tobe;
3730 const struct ssh2_cipher *sccipher_tobe;
3731 const struct ssh_mac *csmac_tobe;
3732 const struct ssh_mac *scmac_tobe;
3733 const struct ssh_compress *cscomp_tobe;
3734 const struct ssh_compress *sccomp_tobe;
3735 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3736 int hostkeylen, siglen;
3737 void *hkey; /* actual host key */
3738 unsigned char exchange_hash[20];
3739 int n_preferred_ciphers;
3740 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3741 const struct ssh_compress *preferred_comp;
3742 int first_kex;
3743 };
3744 crState(do_ssh2_transport_state);
3745
3746 crBegin(ssh->do_ssh2_transport_crstate);
3747
3748 s->cscipher_tobe = s->sccipher_tobe = NULL;
3749 s->csmac_tobe = s->scmac_tobe = NULL;
3750 s->cscomp_tobe = s->sccomp_tobe = NULL;
3751
7cca0d81 3752 random_init();
51470298 3753 s->first_kex = 1;
e5574168 3754
51470298 3755 {
3756 int i;
3757 /*
3758 * Set up the preferred ciphers. (NULL => warn below here)
3759 */
3760 s->n_preferred_ciphers = 0;
3761 for (i = 0; i < CIPHER_MAX; i++) {
86916870 3762 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 3763 case CIPHER_BLOWFISH:
3764 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3765 break;
3766 case CIPHER_DES:
86916870 3767 if (ssh->cfg.ssh2_des_cbc) {
51470298 3768 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3769 }
3770 break;
3771 case CIPHER_3DES:
3772 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3773 break;
3774 case CIPHER_AES:
3775 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3776 break;
3777 case CIPHER_WARN:
3778 /* Flag for later. Don't bother if it's the last in
3779 * the list. */
3780 if (i < CIPHER_MAX - 1) {
3781 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3782 }
3783 break;
ca20bfcf 3784 }
ca20bfcf 3785 }
5e8358ad 3786 }
ca20bfcf 3787
3788 /*
3789 * Set up preferred compression.
3790 */
86916870 3791 if (ssh->cfg.compression)
51470298 3792 s->preferred_comp = &ssh_zlib;
4ba9b64b 3793 else
51470298 3794 s->preferred_comp = &ssh_comp_none;
5e8358ad 3795
7591b9ff 3796 /*
3797 * Be prepared to work around the buggy MAC problem.
3798 */
51470298 3799 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3800 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
7591b9ff 3801 else
51470298 3802 s->maclist = macs, s->nmacs = lenof(macs);
7591b9ff 3803
32874aea 3804 begin_key_exchange:
51470298 3805 {
3806 int i, j, cipherstr_started;
3807
3808 /*
3809 * Construct and send our key exchange packet.
3810 */
3811 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3812 for (i = 0; i < 16; i++)
3813 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3814 /* List key exchange algorithms. */
3815 ssh2_pkt_addstring_start(ssh);
3816 for (i = 0; i < lenof(kex_algs); i++) {
3817 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3818 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3819 continue;
3820 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3821 if (i < lenof(kex_algs) - 1)
3822 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3823 }
51470298 3824 /* List server host key algorithms. */
3825 ssh2_pkt_addstring_start(ssh);
3826 for (i = 0; i < lenof(hostkey_algs); i++) {
3827 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3828 if (i < lenof(hostkey_algs) - 1)
3829 ssh2_pkt_addstring_str(ssh, ",");
32874aea 3830 }
51470298 3831 /* List client->server encryption algorithms. */
3832 ssh2_pkt_addstring_start(ssh);
3833 cipherstr_started = 0;
3834 for (i = 0; i < s->n_preferred_ciphers; i++) {
3835 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3836 if (!c) continue; /* warning flag */
3837 for (j = 0; j < c->nciphers; j++) {
3838 if (cipherstr_started)
3839 ssh2_pkt_addstring_str(ssh, ",");
3840 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3841 cipherstr_started = 1;
3842 }
3843 }
3844 /* List server->client encryption algorithms. */
3845 ssh2_pkt_addstring_start(ssh);
3846 cipherstr_started = 0;
3847 for (i = 0; i < s->n_preferred_ciphers; i++) {
3848 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3849 if (!c) continue; /* warning flag */
3850 for (j = 0; j < c->nciphers; j++) {
3851 if (cipherstr_started)
3852 ssh2_pkt_addstring_str(ssh, ",");
3853 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3854 cipherstr_started = 1;
3855 }
3856 }
3857 /* List client->server MAC algorithms. */
3858 ssh2_pkt_addstring_start(ssh);
3859 for (i = 0; i < s->nmacs; i++) {
3860 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3861 if (i < s->nmacs - 1)
3862 ssh2_pkt_addstring_str(ssh, ",");
3863 }
3864 /* List server->client MAC algorithms. */
3865 ssh2_pkt_addstring_start(ssh);
3866 for (i = 0; i < s->nmacs; i++) {
3867 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3868 if (i < s->nmacs - 1)
3869 ssh2_pkt_addstring_str(ssh, ",");
3870 }
3871 /* List client->server compression algorithms. */
3872 ssh2_pkt_addstring_start(ssh);
3873 for (i = 0; i < lenof(compressions) + 1; i++) {
3874 const struct ssh_compress *c =
3875 i == 0 ? s->preferred_comp : compressions[i - 1];
3876 ssh2_pkt_addstring_str(ssh, c->name);
3877 if (i < lenof(compressions))
3878 ssh2_pkt_addstring_str(ssh, ",");
3879 }
3880 /* List server->client compression algorithms. */
3881 ssh2_pkt_addstring_start(ssh);
3882 for (i = 0; i < lenof(compressions) + 1; i++) {
3883 const struct ssh_compress *c =
3884 i == 0 ? s->preferred_comp : compressions[i - 1];
3885 ssh2_pkt_addstring_str(ssh, c->name);
3886 if (i < lenof(compressions))
3887 ssh2_pkt_addstring_str(ssh, ",");
3888 }
3889 /* List client->server languages. Empty list. */
3890 ssh2_pkt_addstring_start(ssh);
3891 /* List server->client languages. Empty list. */
3892 ssh2_pkt_addstring_start(ssh);
3893 /* First KEX packet does _not_ follow, because we're not that brave. */
3894 ssh2_pkt_addbool(ssh, FALSE);
3895 /* Reserved. */
3896 ssh2_pkt_adduint32(ssh, 0);
e5574168 3897 }
0db56f73 3898
51470298 3899 ssh->exhash = ssh->exhashbase;
3900 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
0db56f73 3901
51470298 3902 ssh2_pkt_send(ssh);
e5574168 3903
32874aea 3904 if (!ispkt)
3905 crWaitUntil(ispkt);
57356d63 3906 if (ssh->pktin.length > 5)
3907 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
e5574168 3908
3909 /*
3910 * Now examine the other side's KEXINIT to see what we're up
3911 * to.
3912 */
51470298 3913 {
3914 char *str;
3915 int i, j, len;
3916
3917 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
6b5cf8b4 3918 bombout(("expected key exchange packet from server"));
7ffdbc1a 3919 crStop(0);
32874aea 3920 }
51470298 3921 ssh->kex = NULL;
3922 ssh->hostkey = NULL;
3923 s->cscipher_tobe = NULL;
3924 s->sccipher_tobe = NULL;
3925 s->csmac_tobe = NULL;
3926 s->scmac_tobe = NULL;
3927 s->cscomp_tobe = NULL;
3928 s->sccomp_tobe = NULL;
3929 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3930 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3931 for (i = 0; i < lenof(kex_algs); i++) {
3932 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3933 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3934 continue;
3935 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3936 ssh->kex = kex_algs[i];
3937 break;
3938 }
32874aea 3939 }
51470298 3940 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3941 for (i = 0; i < lenof(hostkey_algs); i++) {
3942 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3943 ssh->hostkey = hostkey_algs[i];
3944 break;
3945 }
3946 }
3947 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3948 s->warn = 0;
3949 for (i = 0; i < s->n_preferred_ciphers; i++) {
3950 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3951 if (!c) {
3952 s->warn = 1;
3953 } else {
3954 for (j = 0; j < c->nciphers; j++) {
3955 if (in_commasep_string(c->list[j]->name, str, len)) {
3956 s->cscipher_tobe = c->list[j];
3957 break;
3958 }
ca20bfcf 3959 }
32874aea 3960 }
51470298 3961 if (s->cscipher_tobe) {
3962 if (s->warn)
a8327734 3963 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
51470298 3964 break;
3965 }
32874aea 3966 }
51470298 3967 if (!s->cscipher_tobe) {
6b5cf8b4 3968 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 3969 str ? str : "(null)"));
7ffdbc1a 3970 crStop(0);
ca20bfcf 3971 }
0ef8f407 3972
51470298 3973 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3974 s->warn = 0;
3975 for (i = 0; i < s->n_preferred_ciphers; i++) {
3976 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3977 if (!c) {
3978 s->warn = 1;
3979 } else {
3980 for (j = 0; j < c->nciphers; j++) {
3981 if (in_commasep_string(c->list[j]->name, str, len)) {
3982 s->sccipher_tobe = c->list[j];
3983 break;
3984 }
ca20bfcf 3985 }
32874aea 3986 }
51470298 3987 if (s->sccipher_tobe) {
3988 if (s->warn)
a8327734 3989 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
51470298 3990 break;
3991 }
32874aea 3992 }
51470298 3993 if (!s->sccipher_tobe) {
6b5cf8b4 3994 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 3995 str ? str : "(null)"));
7ffdbc1a 3996 crStop(0);
ca20bfcf 3997 }
0ef8f407 3998
51470298 3999 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
4000 for (i = 0; i < s->nmacs; i++) {
4001 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4002 s->csmac_tobe = s->maclist[i];
4003 break;
4004 }
32874aea 4005 }
51470298 4006 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
4007 for (i = 0; i < s->nmacs; i++) {
4008 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4009 s->scmac_tobe = s->maclist[i];
4010 break;
4011 }
32874aea 4012 }
51470298 4013 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
4014 for (i = 0; i < lenof(compressions) + 1; i++) {
4015 const struct ssh_compress *c =
4016 i == 0 ? s->preferred_comp : compressions[i - 1];
4017 if (in_commasep_string(c->name, str, len)) {
4018 s->cscomp_tobe = c;
4019 break;
4020 }
32874aea 4021 }
51470298 4022 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
4023 for (i = 0; i < lenof(compressions) + 1; i++) {
4024 const struct ssh_compress *c =
4025 i == 0 ? s->preferred_comp : compressions[i - 1];
4026 if (in_commasep_string(c->name, str, len)) {
4027 s->sccomp_tobe = c;
4028 break;
4029 }
32874aea 4030 }
e5574168 4031 }
e5574168 4032
4033 /*
7bd5a860 4034 * Work out the number of bits of key we will need from the key
4035 * exchange. We start with the maximum key length of either
4036 * cipher...
4037 */
4038 {
32874aea 4039 int csbits, scbits;
7bd5a860 4040
51470298 4041 csbits = s->cscipher_tobe->keylen;
4042 scbits = s->sccipher_tobe->keylen;
4043 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 4044 }
4045 /* The keys only have 160-bit entropy, since they're based on
4046 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 4047 if (s->nbits > 160)
4048 s->nbits = 160;
7bd5a860 4049
4050 /*
a92dd380 4051 * If we're doing Diffie-Hellman group exchange, start by
4052 * requesting a group.
e5574168 4053 */
51470298 4054 if (ssh->kex == &ssh_diffiehellman_gex) {
32874aea 4055 logevent("Doing Diffie-Hellman group exchange");
51470298 4056 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 4057 /*
4058 * Work out how big a DH group we will need to allow that
4059 * much data.
7bd5a860 4060 */
51470298 4061 s->pbits = 512 << ((s->nbits - 1) / 64);
4062 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4063 ssh2_pkt_adduint32(ssh, s->pbits);
4064 ssh2_pkt_send(ssh);
32874aea 4065
4066 crWaitUntil(ispkt);
51470298 4067 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 4068 bombout(("expected key exchange group packet from server"));
7ffdbc1a 4069 crStop(0);
32874aea 4070 }
51470298 4071 s->p = ssh2_pkt_getmp(ssh);
4072 s->g = ssh2_pkt_getmp(ssh);
27cd7fc2 4073 ssh->kex_ctx = dh_setup_group(s->p, s->g);
51470298 4074 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4075 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 4076 } else {
51470298 4077 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
27cd7fc2 4078 ssh->kex_ctx = dh_setup_group1();
51470298 4079 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4080 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 4081 }
e5574168 4082
a92dd380 4083 logevent("Doing Diffie-Hellman key exchange");
e5574168 4084 /*
a92dd380 4085 * Now generate and send e for Diffie-Hellman.
e5574168 4086 */
27cd7fc2 4087 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
51470298 4088 ssh2_pkt_init(ssh, s->kex_init_value);
4089 ssh2_pkt_addmp(ssh, s->e);
4090 ssh2_pkt_send(ssh);
e5574168 4091
4092 crWaitUntil(ispkt);
51470298 4093 if (ssh->pktin.type != s->kex_reply_value) {
6b5cf8b4 4094 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 4095 crStop(0);
7cca0d81 4096 }
51470298 4097 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4098 s->f = ssh2_pkt_getmp(ssh);
4099 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
e5574168 4100
27cd7fc2 4101 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 4102
51470298 4103 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4104 if (ssh->kex == &ssh_diffiehellman_gex) {
4105 sha_uint32(&ssh->exhash, s->pbits);
4106 sha_mpint(&ssh->exhash, s->p);
4107 sha_mpint(&ssh->exhash, s->g);
a92dd380 4108 }
51470298 4109 sha_mpint(&ssh->exhash, s->e);
4110 sha_mpint(&ssh->exhash, s->f);
4111 sha_mpint(&ssh->exhash, s->K);
4112 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 4113
27cd7fc2 4114 dh_cleanup(ssh->kex_ctx);
fabd1805 4115 ssh->kex_ctx = NULL;
3709bfe9 4116
7cca0d81 4117#if 0
765c4200 4118 debug(("Exchange hash is:\n"));
51470298 4119 dmemdump(s->exchange_hash, 20);
7cca0d81 4120#endif
4121
51470298 4122 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4123 if (!s->hkey ||
4124 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 4125 (char *)s->exchange_hash, 20)) {
6b5cf8b4 4126 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 4127 crStop(0);
8d5de777 4128 }
e5574168 4129
4130 /*
7cca0d81 4131 * Authenticate remote host: verify host key. (We've already
4132 * checked the signature of the exchange hash.)
e5574168 4133 */
51470298 4134 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4135 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
a8327734 4136 verify_ssh_host_key(ssh->frontend,
4137 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 4138 s->keystr, s->fingerprint);
4139 if (s->first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 4140 logevent("Host key fingerprint is:");
51470298 4141 logevent(s->fingerprint);
5e0d7cb8 4142 }
51470298 4143 sfree(s->fingerprint);
4144 sfree(s->keystr);
4145 ssh->hostkey->freekey(s->hkey);
d39f364a 4146
4147 /*
7cca0d81 4148 * Send SSH2_MSG_NEWKEYS.
d39f364a 4149 */
51470298 4150 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4151 ssh2_pkt_send(ssh);
d39f364a 4152
4153 /*
8406eaf9 4154 * Expect SSH2_MSG_NEWKEYS from server.
4155 */
4156 crWaitUntil(ispkt);
51470298 4157 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 4158 bombout(("expected new-keys packet from server"));
7ffdbc1a 4159 crStop(0);
8406eaf9 4160 }
4161
4162 /*
d39f364a 4163 * Create and initialise session keys.
4164 */
371e569c 4165 if (ssh->cs_cipher_ctx)
4166 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
51470298 4167 ssh->cscipher = s->cscipher_tobe;
371e569c 4168 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
e0e1a00d 4169
371e569c 4170 if (ssh->sc_cipher_ctx)
4171 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 4172 ssh->sccipher = s->sccipher_tobe;
371e569c 4173 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 4174
4175 if (ssh->cs_mac_ctx)
4176 ssh->csmac->free_context(ssh->cs_mac_ctx);
51470298 4177 ssh->csmac = s->csmac_tobe;
e0e1a00d 4178 ssh->cs_mac_ctx = ssh->csmac->make_context();
4179
4180 if (ssh->sc_mac_ctx)
4181 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 4182 ssh->scmac = s->scmac_tobe;
e0e1a00d 4183 ssh->sc_mac_ctx = ssh->scmac->make_context();
4184
5366aed8 4185 if (ssh->cs_comp_ctx)
4186 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
51470298 4187 ssh->cscomp = s->cscomp_tobe;
5366aed8 4188 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4189
4190 if (ssh->sc_comp_ctx)
4191 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 4192 ssh->sccomp = s->sccomp_tobe;
5366aed8 4193 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4194
d39f364a 4195 /*
5e0d7cb8 4196 * Set IVs after keys. Here we use the exchange hash from the
4197 * _first_ key exchange.
d39f364a 4198 */
51470298 4199 {
4200 unsigned char keyspace[40];
4201 if (s->first_kex)
4202 memcpy(ssh->v2_session_id, s->exchange_hash,
4203 sizeof(s->exchange_hash));
4204 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
371e569c 4205 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
51470298 4206 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 4207 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 4208 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
371e569c 4209 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
51470298 4210 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 4211 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 4212 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
e0e1a00d 4213 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
51470298 4214 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 4215 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 4216 }
57356d63 4217 logeventf(ssh, "Initialised %.200s client->server encryption",
4218 ssh->cscipher->text_name);
4219 logeventf(ssh, "Initialised %.200s server->client encryption",
4220 ssh->sccipher->text_name);
4221 if (ssh->cscomp->text_name)
4222 logeventf(ssh, "Initialised %s compression",
4223 ssh->cscomp->text_name);
4224 if (ssh->sccomp->text_name)
4225 logeventf(ssh, "Initialised %s decompression",
4226 ssh->sccomp->text_name);
d39f364a 4227
033b4cef 4228 /*
0db56f73 4229 * If this is the first key exchange phase, we must pass the
4230 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4231 * wants to see it but because it will need time to initialise
4232 * itself before it sees an actual packet. In subsequent key
4233 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4234 * it would only confuse the layer above.
4235 */
51470298 4236 if (!s->first_kex) {
32874aea 4237 crReturn(0);
0db56f73 4238 }
51470298 4239 s->first_kex = 0;
0db56f73 4240
4241 /*
7cca0d81 4242 * Now we're encrypting. Begin returning 1 to the protocol main
4243 * function so that other things can run on top of the
4244 * transport. If we ever see a KEXINIT, we must go back to the
4245 * start.
033b4cef 4246 */
51470298 4247 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
32874aea 4248 crReturn(1);
e96adf72 4249 }
5e0d7cb8 4250 logevent("Server initiated key re-exchange");
7cca0d81 4251 goto begin_key_exchange;
e5574168 4252
4253 crFinish(1);
4254}
4255
7cca0d81 4256/*
783415f8 4257 * Add data to an SSH2 channel output buffer.
4258 */
32874aea 4259static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4260 int len)
4261{
5471d09a 4262 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4263}
4264
4265/*
4266 * Attempt to send data on an SSH2 channel.
4267 */
5471d09a 4268static int ssh2_try_send(struct ssh_channel *c)
32874aea 4269{
51470298 4270 Ssh ssh = c->ssh;
4271
5471d09a 4272 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4273 int len;
4274 void *data;
4275 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4276 if ((unsigned)len > c->v.v2.remwindow)
4277 len = c->v.v2.remwindow;
4278 if ((unsigned)len > c->v.v2.remmaxpkt)
4279 len = c->v.v2.remmaxpkt;
51470298 4280 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4281 ssh2_pkt_adduint32(ssh, c->remoteid);
4282 ssh2_pkt_addstring_start(ssh);
4283 ssh2_pkt_addstring_data(ssh, data, len);
4284 ssh2_pkt_send(ssh);
5471d09a 4285 bufchain_consume(&c->v.v2.outbuffer, len);
4286 c->v.v2.remwindow -= len;
4287 }
4288
4289 /*
4290 * After having sent as much data as we can, return the amount
4291 * still buffered.
4292 */
4293 return bufchain_size(&c->v.v2.outbuffer);
4294}
4295
4296/*
4297 * Potentially enlarge the window on an SSH2 channel.
4298 */
4299static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4300{
51470298 4301 Ssh ssh = c->ssh;
4302
6b69f42e 4303 /*
4304 * Never send WINDOW_ADJUST for a channel that the remote side
4305 * already thinks it's closed; there's no point, since it won't
4306 * be sending any more data anyway.
4307 */
4308 if (c->closes != 0)
4309 return;
4310
5471d09a 4311 if (newwin > c->v.v2.locwindow) {
51470298 4312 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4313 ssh2_pkt_adduint32(ssh, c->remoteid);
4314 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4315 ssh2_pkt_send(ssh);
5471d09a 4316 c->v.v2.locwindow = newwin;
783415f8 4317 }
4318}
4319
4320/*
7cca0d81 4321 * Handle the SSH2 userauth and connection layers.
4322 */
51470298 4323static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 4324{
51470298 4325 struct do_ssh2_authconn_state {
4326 enum {
4327 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4328 AUTH_PASSWORD,
4329 AUTH_KEYBOARD_INTERACTIVE
4330 } method;
4331 enum {
4332 AUTH_TYPE_NONE,
4333 AUTH_TYPE_PUBLICKEY,
4334 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4335 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4336 AUTH_TYPE_PASSWORD,
4337 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4338 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4339 } type;
4340 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4341 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4342 int kbd_inter_running;
4343 int we_are_in;
4344 int num_prompts, curr_prompt, echo;
4345 char username[100];
4346 int got_username;
4347 char pwprompt[200];
4348 char password[100];
4349 void *publickey_blob;
4350 int publickey_bloblen;
4351 unsigned char request[5], *response, *p;
4352 int responselen;
4353 int keyi, nkeys;
4354 int authed;
4355 char *pkblob, *alg, *commentp;
4356 int pklen, alglen, commentlen;
4357 int siglen, retlen, len;
4358 char *q, *agentreq, *ret;
4359 int try_send;
4360 };
4361 crState(do_ssh2_authconn_state);
4362
4363 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 4364
7cca0d81 4365 /*
4366 * Request userauth protocol, and await a response to it.
4367 */
51470298 4368 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4369 ssh2_pkt_addstring(ssh, "ssh-userauth");
4370 ssh2_pkt_send(ssh);
7cca0d81 4371 crWaitUntilV(ispkt);
51470298 4372 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 4373 bombout(("Server refused user authentication protocol"));
7ffdbc1a 4374 crStopV;
8d5de777 4375 }
7cca0d81 4376
4377 /*
1408a877 4378 * We repeat this whole loop, including the username prompt,
4379 * until we manage a successful authentication. If the user
51470298 4380 * types the wrong _password_, they can be sent back to the
4381 * beginning to try another username, if this is configured on.
4382 * (If they specify a username in the config, they are never
4383 * asked, even if they do give a wrong password.)
1408a877 4384 *
4385 * I think this best serves the needs of
4386 *
4387 * - the people who have no configuration, no keys, and just
4388 * want to try repeated (username,password) pairs until they
4389 * type both correctly
4390 *
4391 * - people who have keys and configuration but occasionally
4392 * need to fall back to passwords
4393 *
4394 * - people with a key held in Pageant, who might not have
4395 * logged in to a particular machine before; so they want to
4396 * type a username, and then _either_ their key will be
4397 * accepted, _or_ they will type a password. If they mistype
4398 * the username they will want to be able to get back and
4399 * retype it!
7cca0d81 4400 */
51470298 4401 s->username[0] = '\0';
4402 s->got_username = FALSE;
1408a877 4403 do {
1408a877 4404 /*
4405 * Get a username.
4406 */
86916870 4407 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 4408 /*
4409 * We got a username last time round this loop, and
4410 * with change_username turned off we don't try to get
4411 * it again.
4412 */
86916870 4413 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
c0a81592 4414 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 4415 if (!ssh_get_line("login as: ",
51470298 4416 s->username, sizeof(s->username), FALSE)) {
32874aea 4417 /*
4418 * get_line failed to get a username.
4419 * Terminate.
4420 */
4421 logevent("No username provided. Abandoning session.");
3bb2f322 4422 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 4423 crStopV;
32874aea 4424 }
4425 } else {
51470298 4426 int ret; /* need not be saved across crReturn */
4427 c_write_str(ssh, "login as: ");
4428 ssh->send_ok = 1;
4429 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 4430 do {
32874aea 4431 crWaitUntilV(!ispkt);
51470298 4432 ret = process_userpass_input(ssh, in, inlen);
0405e71f 4433 } while (ret == 0);
4434 if (ret < 0)
4435 cleanup_exit(0);
4ca0c9d1 4436 c_write_str(ssh, "\r\n");
32874aea 4437 }
51470298 4438 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 4439 } else {
57356d63 4440 char *stuff;
86916870 4441 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 4442 s->username[sizeof(s->username)-1] = '\0';
65a22376 4443 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 4444 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 4445 c_write_str(ssh, stuff);
57356d63 4446 sfree(stuff);
7cca0d81 4447 }
4448 }
51470298 4449 s->got_username = TRUE;
7cca0d81 4450
65a22376 4451 /*
1408a877 4452 * Send an authentication request using method "none": (a)
4453 * just in case it succeeds, and (b) so that we know what
4454 * authentication methods we can usefully try next.
65a22376 4455 */
51470298 4456 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4457
4458 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4459 ssh2_pkt_addstring(ssh, s->username);
4460 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4461 ssh2_pkt_addstring(ssh, "none"); /* method */
4462 ssh2_pkt_send(ssh);
4463 s->type = AUTH_TYPE_NONE;
4464 s->gotit = FALSE;
4465 s->we_are_in = FALSE;
4466
4467 s->tried_pubkey_config = FALSE;
4468 s->tried_agent = FALSE;
4469 s->tried_keyb_inter = FALSE;
4470 s->kbd_inter_running = FALSE;
86916870 4471 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 4472 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 4473 int keytype;
6c6d9ed9 4474 logeventf(ssh, "Reading private key file \"%.150s\"",
4475 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 4476 keytype = key_type(&ssh->cfg.keyfile);
51470298 4477 if (keytype == SSH_KEYTYPE_SSH2) {
4478 s->publickey_blob =
9a30e26b 4479 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
51470298 4480 &s->publickey_bloblen);
4481 } else {
57356d63 4482 char *msgbuf;
c2ad7d0d 4483 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 4484 key_type_to_str(keytype));
57356d63 4485 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 4486 " (%s)\r\n",
4487 filename_to_str(&ssh->cfg.keyfile),
57356d63 4488 key_type_to_str(keytype));
51470298 4489 c_write_str(ssh, msgbuf);
57356d63 4490 sfree(msgbuf);
51470298 4491 s->publickey_blob = NULL;
231ee168 4492 }
396778f1 4493 } else
51470298 4494 s->publickey_blob = NULL;
65a22376 4495
1408a877 4496 while (1) {
4497 /*
4498 * Wait for the result of the last authentication request.
4499 */
51470298 4500 if (!s->gotit)
1408a877 4501 crWaitUntilV(ispkt);
51470298 4502 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 4503 char *banner;
4504 int size;
4505 /*
4506 * Don't show the banner if we're operating in
4507 * non-verbose non-interactive mode. (It's probably
4508 * a script, which means nobody will read the
4509 * banner _anyway_, and moreover the printing of
4510 * the banner will screw up processing on the
4511 * output of (say) plink.)
4512 */
4513 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
51470298 4514 ssh2_pkt_getstring(ssh, &banner, &size);
32874aea 4515 if (banner)
51470298 4516 c_write_untrusted(ssh, banner, size);
32874aea 4517 }
1408a877 4518 crWaitUntilV(ispkt);
4519 }
51470298 4520 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 4521 logevent("Access granted");
51470298 4522 s->we_are_in = TRUE;
1408a877 4523 break;
4524 }
65a22376 4525
51470298 4526 if (s->kbd_inter_running &&
4527 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 4528 /*
45068b27 4529 * This is either a further set-of-prompts packet
4530 * in keyboard-interactive authentication, or it's
4531 * the same one and we came back here with `gotit'
4532 * set. In the former case, we must reset the
4533 * curr_prompt variable.
b3186d64 4534 */
51470298 4535 if (!s->gotit)
4536 s->curr_prompt = 0;
4537 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 4538 bombout(("Strange packet received during authentication: type %d",
51470298 4539 ssh->pktin.type));
7ffdbc1a 4540 crStopV;
65a22376 4541 }
4542
51470298 4543 s->gotit = FALSE;
65a22376 4544
1408a877 4545 /*
4546 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4547 * we can look at the string in it and know what we can
4548 * helpfully try next.
4549 */
51470298 4550 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 4551 char *methods;
4552 int methlen;
51470298 4553 ssh2_pkt_getstring(ssh, &methods, &methlen);
4554 s->kbd_inter_running = FALSE;
4555 if (!ssh2_pkt_getbool(ssh)) {
1408a877 4556 /*
4557 * We have received an unequivocal Access
4558 * Denied. This can translate to a variety of
4559 * messages:
4560 *
4561 * - if we'd just tried "none" authentication,
4562 * it's not worth printing anything at all
4563 *
4564 * - if we'd just tried a public key _offer_,
4565 * the message should be "Server refused our
4566 * key" (or no message at all if the key
4567 * came from Pageant)
4568 *
4569 * - if we'd just tried anything else, the
4570 * message really should be "Access denied".
4571 *
4572 * Additionally, if we'd just tried password
4573 * authentication, we should break out of this
4574 * whole loop so as to go back to the username
4575 * prompt.
4576 */
51470298 4577 if (s->type == AUTH_TYPE_NONE) {
1408a877 4578 /* do nothing */
51470298 4579 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4580 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4581 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4582 c_write_str(ssh, "Server refused our key\r\n");
1408a877 4583 logevent("Server refused public key");
51470298 4584 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 4585 /* server declined keyboard-interactive; ignore */
1408a877 4586 } else {
51470298 4587 c_write_str(ssh, "Access denied\r\n");
1408a877 4588 logevent("Access denied");
51470298 4589 if (s->type == AUTH_TYPE_PASSWORD) {
4590 s->we_are_in = FALSE;
1408a877 4591 break;
4592 }
4593 }
4594 } else {
51470298 4595 c_write_str(ssh, "Further authentication required\r\n");
1408a877 4596 logevent("Further authentication required");
4597 }
65a22376 4598
51470298 4599 s->can_pubkey =
32874aea 4600 in_commasep_string("publickey", methods, methlen);
51470298 4601 s->can_passwd =
32874aea 4602 in_commasep_string("password", methods, methlen);
86916870 4603 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 4604 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 4605 }
65a22376 4606
51470298 4607 s->method = 0;
4608 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
65a22376 4609
0405e71f 4610 /*
4611 * Most password/passphrase prompts will be
4612 * non-echoing, so we set this to 0 by default.
4613 * Exception is that some keyboard-interactive prompts
4614 * can be echoing, in which case we'll set this to 1.
4615 */
51470298 4616 s->echo = 0;
0405e71f 4617
51470298 4618 if (!s->method && s->can_pubkey &&
4619 agent_exists() && !s->tried_agent) {
1983e559 4620 /*
4621 * Attempt public-key authentication using Pageant.
4622 */
1983e559 4623 void *r;
51470298 4624 s->authed = FALSE;
1983e559 4625
51470298 4626 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4627 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4628
51470298 4629 s->tried_agent = TRUE;
1983e559 4630
4631 logevent("Pageant is running. Requesting keys.");
4632
4633 /* Request the keys held by the agent. */
51470298 4634 PUT_32BIT(s->request, 1);
4635 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4636 agent_query(s->request, 5, &r, &s->responselen);
4637 s->response = (unsigned char *) r;
4638 if (s->response && s->responselen >= 5 &&
4639 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4640 s->p = s->response + 5;
4641 s->nkeys = GET_32BIT(s->p);
4642 s->p += 4;
32874aea 4643 {
4644 char buf[64];
51470298 4645 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 4646 logevent(buf);
4647 }
51470298 4648 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 4649 void *vret;
1983e559 4650
32874aea 4651 {
4652 char buf[64];
51470298 4653 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 4654 logevent(buf);
4655 }
51470298 4656 s->pklen = GET_32BIT(s->p);
4657 s->p += 4;
4658 if (s->publickey_blob &&
4659 s->pklen == s->publickey_bloblen &&
4660 !memcmp(s->p, s->publickey_blob,
4661 s->publickey_bloblen)) {
396778f1 4662 logevent("This key matches configured key file");
51470298 4663 s->tried_pubkey_config = 1;
396778f1 4664 }
d8baa528 4665 s->pkblob = (char *)s->p;
51470298 4666 s->p += s->pklen;
4667 s->alglen = GET_32BIT(s->pkblob);
4668 s->alg = s->pkblob + 4;
4669 s->commentlen = GET_32BIT(s->p);
4670 s->p += 4;
d8baa528 4671 s->commentp = (char *)s->p;
51470298 4672 s->p += s->commentlen;
4673 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4674 ssh2_pkt_addstring(ssh, s->username);
4675 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4676 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4677 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4678 ssh2_pkt_addstring_start(ssh);
4679 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4680 ssh2_pkt_addstring_start(ssh);
4681 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4682 ssh2_pkt_send(ssh);
1983e559 4683
4684 crWaitUntilV(ispkt);
51470298 4685 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 4686 logevent("Key refused");
4687 continue;
4688 }
4689
32874aea 4690 if (flags & FLAG_VERBOSE) {
51470298 4691 c_write_str(ssh, "Authenticating with "
4692 "public key \"");
4693 c_write(ssh, s->commentp, s->commentlen);
4694 c_write_str(ssh, "\" from agent\r\n");
32874aea 4695 }
1983e559 4696
4697 /*
4698 * Server is willing to accept the key.
4699 * Construct a SIGN_REQUEST.
4700 */
51470298 4701 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4702 ssh2_pkt_addstring(ssh, s->username);
4703 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4704 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4705 ssh2_pkt_addbool(ssh, TRUE);
4706 ssh2_pkt_addstring_start(ssh);
4707 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4708 ssh2_pkt_addstring_start(ssh);
4709 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4710
4711 s->siglen = ssh->pktout.length - 5 + 4 + 20;
dda87a28 4712 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4713 s->siglen -= 4;
51470298 4714 s->len = 1; /* message type */
4715 s->len += 4 + s->pklen; /* key blob */
4716 s->len += 4 + s->siglen; /* data to sign */
4717 s->len += 4; /* flags */
3d88e64d 4718 s->agentreq = snewn(4 + s->len, char);
51470298 4719 PUT_32BIT(s->agentreq, s->len);
4720 s->q = s->agentreq + 4;
4721 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4722 PUT_32BIT(s->q, s->pklen);
4723 s->q += 4;
4724 memcpy(s->q, s->pkblob, s->pklen);
4725 s->q += s->pklen;
4726 PUT_32BIT(s->q, s->siglen);
4727 s->q += 4;
1983e559 4728 /* Now the data to be signed... */
dda87a28 4729 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
4730 PUT_32BIT(s->q, 20);
4731 s->q += 4;
4732 }
51470298 4733 memcpy(s->q, ssh->v2_session_id, 20);
4734 s->q += 20;
4735 memcpy(s->q, ssh->pktout.data + 5,
4736 ssh->pktout.length - 5);
4737 s->q += ssh->pktout.length - 5;
1983e559 4738 /* And finally the (zero) flags word. */
51470298 4739 PUT_32BIT(s->q, 0);
4740 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4741 s->ret = vret;
4742 sfree(s->agentreq);
4743 if (s->ret) {
4744 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 4745 logevent("Sending Pageant's response");
51470298 4746 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4747 s->ret + 9,
4748 GET_32BIT(s->ret + 5));
4749 ssh2_pkt_send(ssh);
4750 s->authed = TRUE;
1983e559 4751 break;
4752 } else {
32874aea 4753 logevent
4754 ("Pageant failed to answer challenge");
51470298 4755 sfree(s->ret);
1983e559 4756 }
4757 }
4758 }
51470298 4759 if (s->authed)
1983e559 4760 continue;
4761 }
4762 }
4763
51470298 4764 if (!s->method && s->can_pubkey && s->publickey_blob
4765 && !s->tried_pubkey_config) {
1408a877 4766 unsigned char *pub_blob;
4767 char *algorithm, *comment;
4768 int pub_blob_len;
65a22376 4769
51470298 4770 s->tried_pubkey_config = TRUE;
65a22376 4771
51470298 4772 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4773 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 4774
65a22376 4775 /*
1408a877 4776 * Try the public key supplied in the configuration.
4777 *
4778 * First, offer the public blob to see if the server is
4779 * willing to accept it.
65a22376 4780 */
d8baa528 4781 pub_blob =
9a30e26b 4782 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 4783 &algorithm,
4784 &pub_blob_len);
1408a877 4785 if (pub_blob) {
51470298 4786 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4787 ssh2_pkt_addstring(ssh, s->username);
4788 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4789 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4790 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4791 ssh2_pkt_addstring(ssh, algorithm);
4792 ssh2_pkt_addstring_start(ssh);
d8baa528 4793 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4794 pub_blob_len);
51470298 4795 ssh2_pkt_send(ssh);
32874aea 4796 logevent("Offered public key"); /* FIXME */
1408a877 4797
4798 crWaitUntilV(ispkt);
51470298 4799 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4800 s->gotit = TRUE;
4801 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 4802 continue; /* key refused; give up on it */
1408a877 4803 }
65a22376 4804
1408a877 4805 logevent("Offer of public key accepted");
65a22376 4806 /*
1408a877 4807 * Actually attempt a serious authentication using
4808 * the key.
65a22376 4809 */
9a30e26b 4810 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 4811 sprintf(s->pwprompt,
32874aea 4812 "Passphrase for key \"%.100s\": ",
4813 comment);
51470298 4814 s->need_pw = TRUE;
1408a877 4815 } else {
51470298 4816 s->need_pw = FALSE;
1408a877 4817 }
51470298 4818 c_write_str(ssh, "Authenticating with public key \"");
4819 c_write_str(ssh, comment);
4820 c_write_str(ssh, "\"\r\n");
4821 s->method = AUTH_PUBLICKEY_FILE;
65a22376 4822 }
1408a877 4823 }
4824
51470298 4825 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4826 s->method = AUTH_KEYBOARD_INTERACTIVE;
4827 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4828 s->tried_keyb_inter = TRUE;
af659722 4829
51470298 4830 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4831 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 4832
51470298 4833 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4834 ssh2_pkt_addstring(ssh, s->username);
4835 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4836 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4837 ssh2_pkt_addstring(ssh, ""); /* lang */
4838 ssh2_pkt_addstring(ssh, "");
4839 ssh2_pkt_send(ssh);
af659722 4840
4841 crWaitUntilV(ispkt);
51470298 4842 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4843 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4844 s->gotit = TRUE;
af659722 4845 logevent("Keyboard-interactive authentication refused");
51470298 4846 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
af659722 4847 continue;
4848 }
4849
51470298 4850 s->kbd_inter_running = TRUE;
4851 s->curr_prompt = 0;
af659722 4852 }
4853
51470298 4854 if (s->kbd_inter_running) {
4855 s->method = AUTH_KEYBOARD_INTERACTIVE;
4856 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4857 s->tried_keyb_inter = TRUE;
af659722 4858
51470298 4859 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4860 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 4861
51470298 4862 if (s->curr_prompt == 0) {
45068b27 4863 /*
4864 * We've got a fresh USERAUTH_INFO_REQUEST.
4865 * Display header data, and start going through
4866 * the prompts.
4867 */
4868 char *name, *inst, *lang;
4869 int name_len, inst_len, lang_len;
4870
51470298 4871 ssh2_pkt_getstring(ssh, &name, &name_len);
4872 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4873 ssh2_pkt_getstring(ssh, &lang, &lang_len);
45068b27 4874 if (name_len > 0) {
51470298 4875 c_write_untrusted(ssh, name, name_len);
4876 c_write_str(ssh, "\r\n");
45068b27 4877 }
4878 if (inst_len > 0) {
51470298 4879 c_write_untrusted(ssh, inst, inst_len);
4880 c_write_str(ssh, "\r\n");
45068b27 4881 }
51470298 4882 s->num_prompts = ssh2_pkt_getuint32(ssh);
45068b27 4883 }
af659722 4884
45068b27 4885 /*
4886 * If there are prompts remaining in the packet,
4887 * display one and get a response.
4888 */
51470298 4889 if (s->curr_prompt < s->num_prompts) {
45068b27 4890 char *prompt;
4891 int prompt_len;
af659722 4892
51470298 4893 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
45068b27 4894 if (prompt_len > 0) {
51470298 4895 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4896 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4897 prompt_len : sizeof(s->pwprompt)-1] = '\0';
45068b27 4898 } else {
51470298 4899 strcpy(s->pwprompt,
45068b27 4900 "<server failed to send prompt>: ");
4901 }
51470298 4902 s->echo = ssh2_pkt_getbool(ssh);
4903 s->need_pw = TRUE;
45068b27 4904 } else
51470298 4905 s->need_pw = FALSE;
af659722 4906 }
4907
51470298 4908 if (!s->method && s->can_passwd) {
4909 s->method = AUTH_PASSWORD;
4910 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4911 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4912 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4913 ssh->savedhost);
4914 s->need_pw = TRUE;
1408a877 4915 }
4916
51470298 4917 if (s->need_pw) {
fa17a66e 4918 if (ssh_get_line) {
51470298 4919 if (!ssh_get_line(s->pwprompt, s->password,
4920 sizeof(s->password), TRUE)) {
1408a877 4921 /*
fa17a66e 4922 * get_line failed to get a password (for
4923 * example because one was supplied on the
4924 * command line which has already failed to
4925 * work). Terminate.
1408a877 4926 */
51470298 4927 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4928 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4929 ssh2_pkt_addstring(ssh, "No more passwords available"
4930 " to try");
4931 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4932 ssh2_pkt_send(ssh);
247308b5 4933 logevent("Unable to authenticate");
a8327734 4934 connection_fatal(ssh->frontend,
4935 "Unable to authenticate");
3bb2f322 4936 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 4937 crStopV;
1408a877 4938 }
4939 } else {
51470298 4940 int ret; /* need not be saved across crReturn */
4941 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4942 ssh->send_ok = 1;
1408a877 4943
51470298 4944 setup_userpass_input(ssh, s->password,
4945 sizeof(s->password), s->echo);
0405e71f 4946 do {
1408a877 4947 crWaitUntilV(!ispkt);
51470298 4948 ret = process_userpass_input(ssh, in, inlen);
0405e71f 4949 } while (ret == 0);
4950 if (ret < 0)
4951 cleanup_exit(0);
51470298 4952 c_write_str(ssh, "\r\n");
65a22376 4953 }
65a22376 4954 }
65a22376 4955
51470298 4956 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 4957 /*
4958 * We have our passphrase. Now try the actual authentication.
4959 */
4960 struct ssh2_userkey *key;
65a22376 4961
9a30e26b 4962 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password);
1408a877 4963 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4964 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 4965 c_write_str(ssh, "Wrong passphrase\r\n");
4966 s->tried_pubkey_config = FALSE;
1408a877 4967 } else {
51470298 4968 c_write_str(ssh, "Unable to load private key\r\n");
4969 s->tried_pubkey_config = TRUE;
1408a877 4970 }
4971 /* Send a spurious AUTH_NONE to return to the top. */
51470298 4972 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4973 ssh2_pkt_addstring(ssh, s->username);
4974 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4975 ssh2_pkt_addstring(ssh, "none"); /* method */
4976 ssh2_pkt_send(ssh);
4977 s->type = AUTH_TYPE_NONE;
1408a877 4978 } else {
1dd353b5 4979 unsigned char *pkblob, *sigblob, *sigdata;
4980 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 4981 int p;
65a22376 4982
1408a877 4983 /*
4984 * We have loaded the private key and the server
4985 * has announced that it's willing to accept it.
4986 * Hallelujah. Generate a signature and send it.
4987 */
51470298 4988 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4989 ssh2_pkt_addstring(ssh, s->username);
4990 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4991 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4992 ssh2_pkt_addbool(ssh, TRUE);
4993 ssh2_pkt_addstring(ssh, key->alg->name);
1dd353b5 4994 pkblob = key->alg->public_blob(key->data, &pkblob_len);
51470298 4995 ssh2_pkt_addstring_start(ssh);
d8baa528 4996 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
1408a877 4997
4998 /*
4999 * The data to be signed is:
5000 *
5001 * string session-id
5002 *
5003 * followed by everything so far placed in the
5004 * outgoing packet.
5005 */
51470298 5006 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
dda87a28 5007 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5008 sigdata_len -= 4;
92d60585 5009 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 5010 p = 0;
5011 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5012 PUT_32BIT(sigdata+p, 20);
5013 p += 4;
5014 }
5015 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5016 memcpy(sigdata+p, ssh->pktout.data + 5,
51470298 5017 ssh->pktout.length - 5);
dda87a28 5018 p += ssh->pktout.length - 5;
5019 assert(p == sigdata_len);
d8baa528 5020 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 5021 sigdata_len, &sigblob_len);
51470298 5022 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
1dd353b5 5023 sigblob, sigblob_len);
5024 sfree(pkblob);
5025 sfree(sigblob);
1408a877 5026 sfree(sigdata);
5027
51470298 5028 ssh2_pkt_send(ssh);
5029 s->type = AUTH_TYPE_PUBLICKEY;
1408a877 5030 }
51470298 5031 } else if (s->method == AUTH_PASSWORD) {
65a22376 5032 /*
1408a877 5033 * We send the password packet lumped tightly together with
5034 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5035 * string long enough to make the total length of the two
5036 * packets constant. This should ensure that a passive
5037 * listener doing traffic analyis can't work out the length
5038 * of the password.
5039 *
5040 * For this to work, we need an assumption about the
5041 * maximum length of the password packet. I think 256 is
5042 * pretty conservative. Anyone using a password longer than
5043 * that probably doesn't have much to worry about from
5044 * people who find out how long their password is!
65a22376 5045 */
51470298 5046 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5047 ssh2_pkt_addstring(ssh, s->username);
5048 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5049 ssh2_pkt_addstring(ssh, "password");
5050 ssh2_pkt_addbool(ssh, FALSE);
5051 ssh2_pkt_addstring(ssh, s->password);
1409c1b3 5052 memset(s->password, 0, sizeof(s->password));
51470298 5053 ssh2_pkt_defer(ssh);
65a22376 5054 /*
1408a877 5055 * We'll include a string that's an exact multiple of the
5056 * cipher block size. If the cipher is NULL for some
5057 * reason, we don't do this trick at all because we gain
5058 * nothing by it.
65a22376 5059 */
51470298 5060 if (ssh->cscipher) {
32874aea 5061 int stringlen, i;
5062
51470298 5063 stringlen = (256 - ssh->deferred_len);
5064 stringlen += ssh->cscipher->blksize - 1;
5065 stringlen -= (stringlen % ssh->cscipher->blksize);
5066 if (ssh->cscomp) {
32874aea 5067 /*
5068 * Temporarily disable actual compression,
5069 * so we can guarantee to get this string
5070 * exactly the length we want it. The
5071 * compression-disabling routine should
5072 * return an integer indicating how many
5073 * bytes we should adjust our string length
5074 * by.
5075 */
5366aed8 5076 stringlen -=
5077 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 5078 }
51470298 5079 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5080 ssh2_pkt_addstring_start(ssh);
6e9e9520 5081 for (i = 0; i < stringlen; i++) {
32874aea 5082 char c = (char) random_byte();
51470298 5083 ssh2_pkt_addstring_data(ssh, &c, 1);
65a22376 5084 }
51470298 5085 ssh2_pkt_defer(ssh);
65a22376 5086 }
51470298 5087 ssh_pkt_defersend(ssh);
0d43337a 5088 logevent("Sent password");
51470298 5089 s->type = AUTH_TYPE_PASSWORD;
5090 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5091 if (s->curr_prompt == 0) {
5092 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5093 ssh2_pkt_adduint32(ssh, s->num_prompts);
45068b27 5094 }
51470298 5095 if (s->need_pw) { /* only add pw if we just got one! */
5096 ssh2_pkt_addstring(ssh, s->password);
5097 memset(s->password, 0, sizeof(s->password));
5098 s->curr_prompt++;
45068b27 5099 }
51470298 5100 if (s->curr_prompt >= s->num_prompts) {
5101 ssh2_pkt_send(ssh);
45068b27 5102 } else {
5103 /*
5104 * If there are prompts remaining, we set
5105 * `gotit' so that we won't attempt to get
5106 * another packet. Then we go back round the
5107 * loop and will end up retrieving another
5108 * prompt out of the existing packet. Funky or
5109 * what?
5110 */
51470298 5111 s->gotit = TRUE;
45068b27 5112 }
51470298 5113 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 5114 } else {
51470298 5115 c_write_str(ssh, "No supported authentication methods"
5116 " left to try!\r\n");
5117 logevent("No supported authentications offered."
5118 " Disconnecting");
5119 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5120 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5121 ssh2_pkt_addstring(ssh, "No supported authentication"
5122 " methods available");
5123 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5124 ssh2_pkt_send(ssh);
3bb2f322 5125 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5126 crStopV;
65a22376 5127 }
65a22376 5128 }
51470298 5129 } while (!s->we_are_in);
7cca0d81 5130
5131 /*
5132 * Now we're authenticated for the connection protocol. The
5133 * connection protocol will automatically have started at this
5134 * point; there's no need to send SERVICE_REQUEST.
5135 */
5136
5137 /*
5138 * So now create a channel with a session in it.
5139 */
51470298 5140 ssh->channels = newtree234(ssh_channelcmp);
3d88e64d 5141 ssh->mainchan = snew(struct ssh_channel);
51470298 5142 ssh->mainchan->ssh = ssh;
5143 ssh->mainchan->localid = alloc_channel_id(ssh);
5144 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5145 ssh2_pkt_addstring(ssh, "session");
5146 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5147 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5148 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5149 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5150 ssh2_pkt_send(ssh);
7cca0d81 5151 crWaitUntilV(ispkt);
51470298 5152 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6b5cf8b4 5153 bombout(("Server refused to open a session"));
7ffdbc1a 5154 crStopV;
32874aea 5155 /* FIXME: error data comes back in FAILURE packet */
7cca0d81 5156 }
51470298 5157 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
6b5cf8b4 5158 bombout(("Server's channel confirmation cited wrong channel"));
7ffdbc1a 5159 crStopV;
7cca0d81 5160 }
51470298 5161 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5162 ssh->mainchan->type = CHAN_MAINSESSION;
5163 ssh->mainchan->closes = 0;
5164 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5165 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5166 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5167 add234(ssh->channels, ssh->mainchan);
7cca0d81 5168 logevent("Opened channel for session");
5169
5170 /*
783415f8 5171 * Potentially enable X11 forwarding.
5172 */
86916870 5173 if (ssh->cfg.x11_forward) {
32874aea 5174 char proto[20], data[64];
5175 logevent("Requesting X11 forwarding");
302121de 5176 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 5177 data, sizeof(data), ssh->cfg.x11_auth);
5178 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 5179 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5180 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5181 ssh2_pkt_addstring(ssh, "x11-req");
5182 ssh2_pkt_addbool(ssh, 1); /* want reply */
5183 ssh2_pkt_addbool(ssh, 0); /* many connections */
5184 ssh2_pkt_addstring(ssh, proto);
5185 ssh2_pkt_addstring(ssh, data);
86916870 5186 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
51470298 5187 ssh2_pkt_send(ssh);
32874aea 5188
5189 do {
5190 crWaitUntilV(ispkt);
51470298 5191 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5192 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5193 struct ssh_channel *c;
51470298 5194 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5195 if (!c)
5196 continue; /* nonexistent channel */
51470298 5197 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5198 }
51470298 5199 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5200
51470298 5201 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5202 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5203 bombout(("Unexpected response to X11 forwarding request:"
51470298 5204 " packet type %d", ssh->pktin.type));
7ffdbc1a 5205 crStopV;
32874aea 5206 }
5207 logevent("X11 forwarding refused");
5208 } else {
5209 logevent("X11 forwarding enabled");
51470298 5210 ssh->X11_fwd_enabled = TRUE;
32874aea 5211 }
783415f8 5212 }
5213
5214 /*
bc240b21 5215 * Enable port forwardings.
5216 */
5217 {
bc240b21 5218 char type;
5219 int n;
a4fc0d74 5220 int sport,dport,sserv,dserv;
6ee9b735 5221 char sports[256], dports[256], saddr[256], host[256];
bc240b21 5222
51470298 5223 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
bc240b21 5224 /* Add port forwardings. */
86916870 5225 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 5226 while (*ssh->portfwd_strptr) {
5227 type = *ssh->portfwd_strptr++;
6ee9b735 5228 saddr[0] = '\0';
bc240b21 5229 n = 0;
6ee9b735 5230 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5231 if (*ssh->portfwd_strptr == ':') {
5232 /*
5233 * We've seen a colon in the middle of the
5234 * source port number. This means that
5235 * everything we've seen until now is the
5236 * source _address_, so we'll move it into
5237 * saddr and start sports from the beginning
5238 * again.
5239 */
5240 ssh->portfwd_strptr++;
5241 sports[n] = '\0';
5242 strcpy(saddr, sports);
5243 n = 0;
5244 }
5245 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5246 }
bc240b21 5247 sports[n] = 0;
820ebe3b 5248 if (type != 'D') {
5249 if (*ssh->portfwd_strptr == '\t')
5250 ssh->portfwd_strptr++;
5251 n = 0;
5252 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5253 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5254 }
5255 host[n] = 0;
5256 if (*ssh->portfwd_strptr == ':')
5257 ssh->portfwd_strptr++;
5258 n = 0;
5259 while (*ssh->portfwd_strptr) {
5260 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5261 }
5262 dports[n] = 0;
51470298 5263 ssh->portfwd_strptr++;
820ebe3b 5264 dport = atoi(dports);
5265 dserv = 0;
5266 if (dport == 0) {
5267 dserv = 1;
5268 dport = net_service_lookup(dports);
5269 if (!dport) {
5270 logeventf(ssh, "Service lookup failed for destination"
5271 " port \"%s\"", dports);
5272 }
a4fc0d74 5273 }
820ebe3b 5274 } else {
5275 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 5276 dport = dserv = -1;
a4fc0d74 5277 }
bc240b21 5278 sport = atoi(sports);
a4fc0d74 5279 sserv = 0;
5280 if (sport == 0) {
5281 sserv = 1;
68a49acb 5282 sport = net_service_lookup(sports);
5283 if (!sport) {
57356d63 5284 logeventf(ssh, "Service lookup failed for source"
5285 " port \"%s\"", sports);
a4fc0d74 5286 }
5287 }
bc240b21 5288 if (sport && dport) {
5289 if (type == 'L') {
6ee9b735 5290 pfd_addforward(host, dport, *saddr ? saddr : NULL,
e8fa8f62 5291 sport, ssh, &ssh->cfg);
6ee9b735 5292 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5293 " forwarding to %s:%.*s%.*s%d%.*s",
5294 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5295 (int)(*saddr?1:0), ":",
57356d63 5296 (int)(sserv ? strlen(sports) : 0), sports,
5297 sserv, "(", sport, sserv, ")",
5298 host,
5299 (int)(dserv ? strlen(dports) : 0), dports,
5300 dserv, "(", dport, dserv, ")");
820ebe3b 5301 } else if (type == 'D') {
5302 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
5303 sport, ssh, &ssh->cfg);
5304 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5305 " doing SOCKS dynamic forwarding",
5306 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5307 (int)(*saddr?1:0), ":",
5308 (int)(sserv ? strlen(sports) : 0), sports,
5309 sserv, "(", sport, sserv, ")");
bc240b21 5310 } else {
5311 struct ssh_rportfwd *pf;
3d88e64d 5312 pf = snew(struct ssh_rportfwd);
bc240b21 5313 strcpy(pf->dhost, host);
5314 pf->dport = dport;
5315 pf->sport = sport;
51470298 5316 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 5317 logeventf(ssh, "Duplicate remote port forwarding"
5318 " to %s:%d", host, dport);
bc240b21 5319 sfree(pf);
5320 } else {
6ee9b735 5321 logeventf(ssh, "Requesting remote port "
5322 "%.*s%.*s%.*s%.*s%d%.*s"
57356d63 5323 " forward to %s:%.*s%.*s%d%.*s",
6ee9b735 5324 (int)(*saddr?strlen(saddr):0),
5325 *saddr?saddr:NULL,
5326 (int)(*saddr?1:0), ":",
57356d63 5327 (int)(sserv ? strlen(sports) : 0), sports,
5328 sserv, "(", sport, sserv, ")",
5329 host,
5330 (int)(dserv ? strlen(dports) : 0), dports,
5331 dserv, "(", dport, dserv, ")");
51470298 5332 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5333 ssh2_pkt_addstring(ssh, "tcpip-forward");
5334 ssh2_pkt_addbool(ssh, 1);/* want reply */
6ee9b735 5335 if (*saddr)
5336 ssh2_pkt_addstring(ssh, saddr);
86916870 5337 if (ssh->cfg.rport_acceptall)
51470298 5338 ssh2_pkt_addstring(ssh, "0.0.0.0");
beefa433 5339 else
51470298 5340 ssh2_pkt_addstring(ssh, "127.0.0.1");
5341 ssh2_pkt_adduint32(ssh, sport);
5342 ssh2_pkt_send(ssh);
bc240b21 5343
5344 do {
5345 crWaitUntilV(ispkt);
51470298 5346 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5347 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5348 struct ssh_channel *c;
51470298 5349 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5350 if (!c)
5351 continue;/* nonexistent channel */
51470298 5352 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
bc240b21 5353 }
51470298 5354 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
bc240b21 5355
51470298 5356 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5357 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
6b5cf8b4 5358 bombout(("Unexpected response to port "
c9886e66 5359 "forwarding request: packet type %d",
51470298 5360 ssh->pktin.type));
7ffdbc1a 5361 crStopV;
bc240b21 5362 }
5363 logevent("Server refused this port forwarding");
5364 } else {
5365 logevent("Remote port forwarding enabled");
5366 }
5367 }
5368 }
5369 }
5370 }
5371 }
5372
5373 /*
36c2a3e9 5374 * Potentially enable agent forwarding.
5375 */
86916870 5376 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 5377 logevent("Requesting OpenSSH-style agent forwarding");
51470298 5378 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5379 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5380 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5381 ssh2_pkt_addbool(ssh, 1); /* want reply */
5382 ssh2_pkt_send(ssh);
32874aea 5383
5384 do {
5385 crWaitUntilV(ispkt);
51470298 5386 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5387 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5388 struct ssh_channel *c;
51470298 5389 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5390 if (!c)
5391 continue; /* nonexistent channel */
51470298 5392 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5393 }
51470298 5394 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5395
51470298 5396 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5397 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5398 bombout(("Unexpected response to agent forwarding request:"
51470298 5399 " packet type %d", ssh->pktin.type));
7ffdbc1a 5400 crStopV;
32874aea 5401 }
5402 logevent("Agent forwarding refused");
5403 } else {
5404 logevent("Agent forwarding enabled");
51470298 5405 ssh->agentfwd_enabled = TRUE;
32874aea 5406 }
36c2a3e9 5407 }
5408
5409 /*
7cca0d81 5410 * Now allocate a pty for the session.
5411 */
86916870 5412 if (!ssh->cfg.nopty) {
51470298 5413 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5414 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5415 ssh2_pkt_addstring(ssh, "pty-req");
5416 ssh2_pkt_addbool(ssh, 1); /* want reply */
86916870 5417 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
51470298 5418 ssh2_pkt_adduint32(ssh, ssh->term_width);
5419 ssh2_pkt_adduint32(ssh, ssh->term_height);
5420 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5421 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5422 ssh2_pkt_addstring_start(ssh);
5423 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5424 ssh2_pkt_send(ssh);
5425 ssh->state = SSH_STATE_INTERMED;
32874aea 5426
5427 do {
5428 crWaitUntilV(ispkt);
51470298 5429 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5430 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5431 struct ssh_channel *c;
51470298 5432 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5433 if (!c)
5434 continue; /* nonexistent channel */
51470298 5435 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
32874aea 5436 }
51470298 5437 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
32874aea 5438
51470298 5439 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5440 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5441 bombout(("Unexpected response to pty request:"
51470298 5442 " packet type %d", ssh->pktin.type));
7ffdbc1a 5443 crStopV;
32874aea 5444 }
51470298 5445 c_write_str(ssh, "Server refused to allocate pty\r\n");
5446 ssh->editing = ssh->echoing = 1;
32874aea 5447 } else {
5448 logevent("Allocated pty");
5449 }
0965bee0 5450 } else {
51470298 5451 ssh->editing = ssh->echoing = 1;
7cca0d81 5452 }
5453
5454 /*
fd5e5847 5455 * Start a shell or a remote command. We may have to attempt
5456 * this twice if the config data has provided a second choice
5457 * of command.
7cca0d81 5458 */
fd5e5847 5459 while (1) {
5460 int subsys;
5461 char *cmd;
5462
51470298 5463 if (ssh->fallback_cmd) {
86916870 5464 subsys = ssh->cfg.ssh_subsys2;
5465 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 5466 } else {
86916870 5467 subsys = ssh->cfg.ssh_subsys;
5468 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 5469 }
5470
51470298 5471 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5472 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 5473 if (subsys) {
51470298 5474 ssh2_pkt_addstring(ssh, "subsystem");
5475 ssh2_pkt_addbool(ssh, 1); /* want reply */
5476 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5477 } else if (*cmd) {
51470298 5478 ssh2_pkt_addstring(ssh, "exec");
5479 ssh2_pkt_addbool(ssh, 1); /* want reply */
5480 ssh2_pkt_addstring(ssh, cmd);
fd5e5847 5481 } else {
51470298 5482 ssh2_pkt_addstring(ssh, "shell");
5483 ssh2_pkt_addbool(ssh, 1); /* want reply */
32874aea 5484 }
51470298 5485 ssh2_pkt_send(ssh);
fd5e5847 5486 do {
5487 crWaitUntilV(ispkt);
51470298 5488 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5489 unsigned i = ssh2_pkt_getuint32(ssh);
fd5e5847 5490 struct ssh_channel *c;
51470298 5491 c = find234(ssh->channels, &i, ssh_channelfind);
fd5e5847 5492 if (!c)
5493 continue; /* nonexistent channel */
51470298 5494 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
fd5e5847 5495 }
51470298 5496 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5497 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5498 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 5499 bombout(("Unexpected response to shell/command request:"
51470298 5500 " packet type %d", ssh->pktin.type));
7ffdbc1a 5501 crStopV;
fd5e5847 5502 }
5503 /*
5504 * We failed to start the command. If this is the
5505 * fallback command, we really are finished; if it's
5506 * not, and if the fallback command exists, try falling
5507 * back to it before complaining.
5508 */
86916870 5509 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 5510 logevent("Primary command failed; attempting fallback");
51470298 5511 ssh->fallback_cmd = TRUE;
fd5e5847 5512 continue;
5513 }
6b5cf8b4 5514 bombout(("Server refused to start a shell/command"));
7ffdbc1a 5515 crStopV;
fd5e5847 5516 } else {
5517 logevent("Started a shell/command");
32874aea 5518 }
fd5e5847 5519 break;
7cca0d81 5520 }
5521
51470298 5522 ssh->state = SSH_STATE_SESSION;
5523 if (ssh->size_needed)
5524 ssh_size(ssh, ssh->term_width, ssh->term_height);
5525 if (ssh->eof_needed)
5526 ssh_special(ssh, TS_EOF);
6e48c3fe 5527
7cca0d81 5528 /*
5529 * Transfer data!
5530 */
b9d7bcad 5531 if (ssh->ldisc)
5532 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 5533 ssh->send_ok = 1;
7cca0d81 5534 while (1) {
e5574168 5535 crReturnV;
51470298 5536 s->try_send = FALSE;
7cca0d81 5537 if (ispkt) {
51470298 5538 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5539 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
32874aea 5540 char *data;
5541 int length;
51470298 5542 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5543 struct ssh_channel *c;
51470298 5544 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5545 if (!c)
5546 continue; /* nonexistent channel */
51470298 5547 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5548 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
32874aea 5549 continue; /* extended but not stderr */
51470298 5550 ssh2_pkt_getstring(ssh, &data, &length);
32874aea 5551 if (data) {
7ffdbc1a 5552 int bufsize = 0;
5471d09a 5553 c->v.v2.locwindow -= length;
32874aea 5554 switch (c->type) {
5555 case CHAN_MAINSESSION:
5471d09a 5556 bufsize =
51470298 5557 from_backend(ssh->frontend, ssh->pktin.type ==
5471d09a 5558 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5559 data, length);
32874aea 5560 break;
5561 case CHAN_X11:
5471d09a 5562 bufsize = x11_send(c->u.x11.s, data, length);
32874aea 5563 break;
d74d141c 5564 case CHAN_SOCKDATA:
5471d09a 5565 bufsize = pfd_send(c->u.pfd.s, data, length);
bc240b21 5566 break;
36c2a3e9 5567 case CHAN_AGENT:
32874aea 5568 while (length > 0) {
5569 if (c->u.a.lensofar < 4) {
5570 int l = min(4 - c->u.a.lensofar, length);
5571 memcpy(c->u.a.msglen + c->u.a.lensofar,
5572 data, l);
5573 data += l;
5574 length -= l;
5575 c->u.a.lensofar += l;
5576 }
5577 if (c->u.a.lensofar == 4) {
5578 c->u.a.totallen =
5579 4 + GET_32BIT(c->u.a.msglen);
3d88e64d 5580 c->u.a.message = snewn(c->u.a.totallen,
5581 unsigned char);
32874aea 5582 memcpy(c->u.a.message, c->u.a.msglen, 4);
5583 }
5584 if (c->u.a.lensofar >= 4 && length > 0) {
5585 int l =
5586 min(c->u.a.totallen - c->u.a.lensofar,
5587 length);
5588 memcpy(c->u.a.message + c->u.a.lensofar,
5589 data, l);
5590 data += l;
5591 length -= l;
5592 c->u.a.lensofar += l;
5593 }
5594 if (c->u.a.lensofar == c->u.a.totallen) {
5595 void *reply, *sentreply;
5596 int replylen;
5597 agent_query(c->u.a.message,
5598 c->u.a.totallen, &reply,
5599 &replylen);
5600 if (reply)
5601 sentreply = reply;
5602 else {
5603 /* Fake SSH_AGENT_FAILURE. */
5604 sentreply = "\0\0\0\1\5";
5605 replylen = 5;
5606 }
51470298 5607 ssh2_add_channel_data(c, sentreply, replylen);
5608 s->try_send = TRUE;
32874aea 5609 if (reply)
5610 sfree(reply);
5611 sfree(c->u.a.message);
5612 c->u.a.lensofar = 0;
5613 }
5614 }
5471d09a 5615 bufsize = 0;
32874aea 5616 break;
5617 }
5618 /*
5471d09a 5619 * If we are not buffering too much data,
5620 * enlarge the window again at the remote side.
32874aea 5621 */
5471d09a 5622 if (bufsize < OUR_V2_WINSIZE)
5623 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
32874aea 5624 }
51470298 5625 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5626 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5627 struct ssh_channel *c;
5628
51470298 5629 c = find234(ssh->channels, &i, ssh_channelfind);
32874aea 5630 if (!c)
5631 continue; /* nonexistent channel */
5632
5633 if (c->type == CHAN_X11) {
5634 /*
5635 * Remote EOF on an X11 channel means we should
5636 * wrap up and close the channel ourselves.
5637 */
5638 x11_close(c->u.x11.s);
5639 sshfwd_close(c);
5640 } else if (c->type == CHAN_AGENT) {
36c2a3e9 5641 sshfwd_close(c);
d74d141c 5642 } else if (c->type == CHAN_SOCKDATA) {
bc240b21 5643 pfd_close(c->u.pfd.s);
5644 sshfwd_close(c);
36c2a3e9 5645 }
51470298 5646 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5647 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5648 struct ssh_channel *c;
5649
51470298 5650 c = find234(ssh->channels, &i, ssh_channelfind);
d0d844c1 5651 if (!c || ((int)c->remoteid) == -1) {
6b5cf8b4 5652 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
d0d844c1 5653 c ? "half-open" : "nonexistent", i));
7ffdbc1a 5654 crStopV;
d0d844c1 5655 }
32874aea 5656 /* Do pre-close processing on the channel. */
5657 switch (c->type) {
5658 case CHAN_MAINSESSION:
5659 break; /* nothing to see here, move along */
5660 case CHAN_X11:
92f157bd 5661 if (c->u.x11.s != NULL)
5662 x11_close(c->u.x11.s);
5663 sshfwd_close(c);
32874aea 5664 break;
5665 case CHAN_AGENT:
92f157bd 5666 sshfwd_close(c);
32874aea 5667 break;
d74d141c 5668 case CHAN_SOCKDATA:
92f157bd 5669 if (c->u.pfd.s != NULL)
5670 pfd_close(c->u.pfd.s);
5671 sshfwd_close(c);
bc240b21 5672 break;
32874aea 5673 }
92f157bd 5674 if (c->closes == 0) {
51470298 5675 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5676 ssh2_pkt_adduint32(ssh, c->remoteid);
5677 ssh2_pkt_send(ssh);
92f157bd 5678 }
51470298 5679 del234(ssh->channels, c);
5471d09a 5680 bufchain_clear(&c->v.v2.outbuffer);
32874aea 5681 sfree(c);
5682
5683 /*
5684 * See if that was the last channel left open.
5685 */
51470298 5686 if (count234(ssh->channels) == 0) {
3bb2f322 5687 logevent("All channels closed. Disconnecting");
ca2914d1 5688#if 0
5689 /*
5690 * We used to send SSH_MSG_DISCONNECT here,
5691 * because I'd believed that _every_ conforming
5692 * SSH2 connection had to end with a disconnect
5693 * being sent by at least one side; apparently
5694 * I was wrong and it's perfectly OK to
5695 * unceremoniously slam the connection shut
5696 * when you're done, and indeed OpenSSH feels
5697 * this is more polite than sending a
5698 * DISCONNECT. So now we don't.
5699 */
51470298 5700 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5701 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5702 ssh2_pkt_addstring(ssh, "All open channels closed");
5703 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5704 ssh2_pkt_send(ssh);
ca2914d1 5705#endif
3bb2f322 5706 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5707 crStopV;
32874aea 5708 }
5709 continue; /* remote sends close; ignore (FIXME) */
51470298 5710 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5711 unsigned i = ssh2_pkt_getuint32(ssh);
32874aea 5712 struct ssh_channel *c;
51470298 5713 c = find234(ssh->channels, &i, ssh_channelfind);
a6253970 5714 if (!c || c->closes)
5715 continue; /* nonexistent or closing channel */
51470298 5716 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5717 s->try_send = TRUE;
5718 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5719 unsigned i = ssh2_pkt_getuint32(ssh);
bc240b21 5720 struct ssh_channel *c;
51470298 5721 c = find234(ssh->channels, &i, ssh_channelfind);
bc240b21 5722 if (!c)
5723 continue; /* nonexistent channel */
5724 if (c->type != CHAN_SOCKDATA_DORMANT)
5725 continue; /* dunno why they're confirming this */
51470298 5726 c->remoteid = ssh2_pkt_getuint32(ssh);
bc240b21 5727 c->type = CHAN_SOCKDATA;
51470298 5728 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5729 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
4ed34d25 5730 if (c->u.pfd.s)
5731 pfd_confirm(c->u.pfd.s);
5732 if (c->closes) {
5733 /*
5734 * We have a pending close on this channel,
5735 * which we decided on before the server acked
5736 * the channel open. So now we know the
5737 * remoteid, we can close it again.
5738 */
51470298 5739 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5740 ssh2_pkt_adduint32(ssh, c->remoteid);
5741 ssh2_pkt_send(ssh);
4ed34d25 5742 }
51470298 5743 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5744 unsigned i = ssh2_pkt_getuint32(ssh);
724cface 5745 struct ssh_channel *c;
51470298 5746 c = find234(ssh->channels, &i, ssh_channelfind);
724cface 5747 if (!c)
5748 continue; /* nonexistent channel */
5749 if (c->type != CHAN_SOCKDATA_DORMANT)
5750 continue; /* dunno why they're failing this */
5751
5752 logevent("Forwarded connection refused by server");
5753
5754 pfd_close(c->u.pfd.s);
5755
51470298 5756 del234(ssh->channels, c);
724cface 5757 sfree(c);
51470298 5758 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
ebb0a590 5759 unsigned localid;
5760 char *type;
5761 int typelen, want_reply;
5762 struct ssh_channel *c;
5763
51470298 5764 localid = ssh2_pkt_getuint32(ssh);
5765 ssh2_pkt_getstring(ssh, &type, &typelen);
5766 want_reply = ssh2_pkt_getbool(ssh);
ebb0a590 5767
5768 /*
5769 * First, check that the channel exists. Otherwise,
5770 * we can instantly disconnect with a rude message.
5771 */
51470298 5772 c = find234(ssh->channels, &localid, ssh_channelfind);
ebb0a590 5773 if (!c) {
5774 char buf[80];
5775 sprintf(buf, "Received channel request for nonexistent"
5776 " channel %d", localid);
5777 logevent(buf);
51470298 5778 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5779 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5780 ssh2_pkt_addstring(ssh, buf);
5781 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5782 ssh2_pkt_send(ssh);
6b5cf8b4 5783 connection_fatal(ssh->frontend, "%s", buf);
3bb2f322 5784 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5785 crStopV;
ebb0a590 5786 }
5787
5788 /*
d8d6c7e5 5789 * Having got the channel number, we now look at
5790 * the request type string to see if it's something
5791 * we recognise.
ebb0a590 5792 */
d8d6c7e5 5793 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
51470298 5794 c == ssh->mainchan) {
d8d6c7e5 5795 /* We recognise "exit-status" on the primary channel. */
5796 char buf[100];
51470298 5797 ssh->exitcode = ssh2_pkt_getuint32(ssh);
d8d6c7e5 5798 sprintf(buf, "Server sent command exit status %d",
51470298 5799 ssh->exitcode);
d8d6c7e5 5800 logevent(buf);
5801 if (want_reply) {
51470298 5802 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5803 ssh2_pkt_adduint32(ssh, c->remoteid);
5804 ssh2_pkt_send(ssh);
d8d6c7e5 5805 }
5806 } else {
5807 /*
5808 * This is a channel request we don't know
5809 * about, so we now either ignore the request
5810 * or respond with CHANNEL_FAILURE, depending
5811 * on want_reply.
5812 */
5813 if (want_reply) {
51470298 5814 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5815 ssh2_pkt_adduint32(ssh, c->remoteid);
5816 ssh2_pkt_send(ssh);
d8d6c7e5 5817 }
ebb0a590 5818 }
51470298 5819 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
697d4856 5820 char *type;
5821 int typelen, want_reply;
5822
51470298 5823 ssh2_pkt_getstring(ssh, &type, &typelen);
5824 want_reply = ssh2_pkt_getbool(ssh);
697d4856 5825
5826 /*
5827 * We currently don't support any global requests
5828 * at all, so we either ignore the request or
5829 * respond with REQUEST_FAILURE, depending on
5830 * want_reply.
5831 */
5832 if (want_reply) {
51470298 5833 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5834 ssh2_pkt_send(ssh);
697d4856 5835 }
51470298 5836 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
32874aea 5837 char *type;
5838 int typelen;
b3ebaa28 5839 char *peeraddr;
5840 int peeraddrlen;
2e5b14c0 5841 int peerport;
32874aea 5842 char *error = NULL;
5843 struct ssh_channel *c;
bc240b21 5844 unsigned remid, winsize, pktsize;
51470298 5845 ssh2_pkt_getstring(ssh, &type, &typelen);
3d88e64d 5846 c = snew(struct ssh_channel);
51470298 5847 c->ssh = ssh;
32874aea 5848
51470298 5849 remid = ssh2_pkt_getuint32(ssh);
5850 winsize = ssh2_pkt_getuint32(ssh);
5851 pktsize = ssh2_pkt_getuint32(ssh);
bc240b21 5852
32874aea 5853 if (typelen == 3 && !memcmp(type, "x11", 3)) {
df85f78b 5854 char *addrstr;
5855
5856 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5857 addrstr = snewn(peeraddrlen+1, char);
b3ebaa28 5858 memcpy(addrstr, peeraddr, peeraddrlen);
5859 peeraddr[peeraddrlen] = '\0';
2e5b14c0 5860 peerport = ssh2_pkt_getuint32(ssh);
b3ebaa28 5861
51470298 5862 if (!ssh->X11_fwd_enabled)
32874aea 5863 error = "X11 forwarding is not enabled";
86916870 5864 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
2e5b14c0 5865 ssh->x11auth, addrstr, peerport,
e8fa8f62 5866 &ssh->cfg) != NULL) {
32874aea 5867 error = "Unable to open an X11 connection";
5868 } else {
5869 c->type = CHAN_X11;
5870 }
b3ebaa28 5871
5872 sfree(addrstr);
bc240b21 5873 } else if (typelen == 15 &&
5874 !memcmp(type, "forwarded-tcpip", 15)) {
5875 struct ssh_rportfwd pf, *realpf;
5876 char *dummy;
5877 int dummylen;
51470298 5878 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5879 pf.sport = ssh2_pkt_getuint32(ssh);
2e5b14c0 5880 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5881 peerport = ssh2_pkt_getuint32(ssh);
51470298 5882 realpf = find234(ssh->rportfwds, &pf, NULL);
bc240b21 5883 if (realpf == NULL) {
5884 error = "Remote port is not recognised";
5885 } else {
5886 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
e8fa8f62 5887 realpf->dport, c, &ssh->cfg);
57356d63 5888 logeventf(ssh, "Received remote port open request"
5889 " for %s:%d", realpf->dhost, realpf->dport);
bc240b21 5890 if (e != NULL) {
57356d63 5891 logeventf(ssh, "Port open failed: %s", e);
bc240b21 5892 error = "Port open failed";
5893 } else {
5894 logevent("Forwarded port opened successfully");
5895 c->type = CHAN_SOCKDATA;
5896 }
5897 }
32874aea 5898 } else if (typelen == 22 &&
36c2a3e9 5899 !memcmp(type, "auth-agent@openssh.com", 3)) {
51470298 5900 if (!ssh->agentfwd_enabled)
32874aea 5901 error = "Agent forwarding is not enabled";
36c2a3e9 5902 else {
32874aea 5903 c->type = CHAN_AGENT; /* identify channel type */
36c2a3e9 5904 c->u.a.lensofar = 0;
32874aea 5905 }
5906 } else {
5907 error = "Unsupported channel type requested";
5908 }
5909
bc240b21 5910 c->remoteid = remid;
32874aea 5911 if (error) {
51470298 5912 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5913 ssh2_pkt_adduint32(ssh, c->remoteid);
5914 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5915 ssh2_pkt_addstring(ssh, error);
5916 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5917 ssh2_pkt_send(ssh);
32874aea 5918 sfree(c);
5919 } else {
51470298 5920 c->localid = alloc_channel_id(ssh);
32874aea 5921 c->closes = 0;
5471d09a 5922 c->v.v2.locwindow = OUR_V2_WINSIZE;
5923 c->v.v2.remwindow = winsize;
5924 c->v.v2.remmaxpkt = pktsize;
5925 bufchain_init(&c->v.v2.outbuffer);
51470298 5926 add234(ssh->channels, c);
5927 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5928 ssh2_pkt_adduint32(ssh, c->remoteid);
5929 ssh2_pkt_adduint32(ssh, c->localid);
5930 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5931 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5932 ssh2_pkt_send(ssh);
32874aea 5933 }
7cca0d81 5934 } else {
6b5cf8b4 5935 bombout(("Strange packet received: type %d", ssh->pktin.type));
7ffdbc1a 5936 crStopV;
7cca0d81 5937 }
5938 } else {
32874aea 5939 /*
5940 * We have spare data. Add it to the channel buffer.
5941 */
d8baa528 5942 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 5943 s->try_send = TRUE;
32874aea 5944 }
51470298 5945 if (s->try_send) {
32874aea 5946 int i;
5947 struct ssh_channel *c;
5948 /*
5949 * Try to send data on all channels if we can.
5950 */
51470298 5951 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 5952 int bufsize;
5953 if (c->closes)
5954 continue; /* don't send on closing channels */
5955 bufsize = ssh2_try_send(c);
5471d09a 5956 if (bufsize == 0) {
5957 switch (c->type) {
5958 case CHAN_MAINSESSION:
5959 /* stdin need not receive an unthrottle
5960 * notification since it will be polled */
5961 break;
5962 case CHAN_X11:
5963 x11_unthrottle(c->u.x11.s);
5964 break;
5965 case CHAN_AGENT:
5966 /* agent sockets are request/response and need no
5967 * buffer management */
5968 break;
5969 case CHAN_SOCKDATA:
5970 pfd_unthrottle(c->u.pfd.s);
5971 break;
5972 }
5973 }
5974 }
7cca0d81 5975 }
e5574168 5976 }
5977
5978 crFinishV;
5979}
5980
5981/*
7cca0d81 5982 * Handle the top-level SSH2 protocol.
5983 */
51470298 5984static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
7cca0d81 5985{
51470298 5986 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
32874aea 5987 return;
51470298 5988 do_ssh2_authconn(ssh, in, inlen, ispkt);
7cca0d81 5989}
5990
5991/*
8df7a775 5992 * Called to set up the connection.
374330e2 5993 *
5994 * Returns an error message, or NULL on success.
374330e2 5995 */
51470298 5996static char *ssh_init(void *frontend_handle, void **backend_handle,
86916870 5997 Config *cfg,
887035a5 5998 char *host, int port, char **realhost, int nodelay)
32874aea 5999{
fb09bf1c 6000 char *p;
51470298 6001 Ssh ssh;
6002
3d88e64d 6003 ssh = snew(struct ssh_tag);
86916870 6004 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 6005 ssh->version = 0; /* when not ready yet */
51470298 6006 ssh->s = NULL;
6007 ssh->cipher = NULL;
371e569c 6008 ssh->v1_cipher_ctx = NULL;
0183b242 6009 ssh->crcda_ctx = NULL;
51470298 6010 ssh->cscipher = NULL;
371e569c 6011 ssh->cs_cipher_ctx = NULL;
51470298 6012 ssh->sccipher = NULL;
371e569c 6013 ssh->sc_cipher_ctx = NULL;
51470298 6014 ssh->csmac = NULL;
a8327734 6015 ssh->cs_mac_ctx = NULL;
51470298 6016 ssh->scmac = NULL;
e0e1a00d 6017 ssh->sc_mac_ctx = NULL;
51470298 6018 ssh->cscomp = NULL;
5366aed8 6019 ssh->cs_comp_ctx = NULL;
51470298 6020 ssh->sccomp = NULL;
5366aed8 6021 ssh->sc_comp_ctx = NULL;
51470298 6022 ssh->kex = NULL;
389aa499 6023 ssh->kex_ctx = NULL;
51470298 6024 ssh->hostkey = NULL;
6025 ssh->exitcode = -1;
6026 ssh->state = SSH_STATE_PREPACKET;
6027 ssh->size_needed = FALSE;
6028 ssh->eof_needed = FALSE;
b9d7bcad 6029 ssh->ldisc = NULL;
a8327734 6030 ssh->logctx = NULL;
51470298 6031 {
6032 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6033 ssh->pktin = ssh->pktout = empty;
6034 }
6035 ssh->deferred_send_data = NULL;
6036 ssh->deferred_len = 0;
6037 ssh->deferred_size = 0;
6038 ssh->fallback_cmd = 0;
6039 ssh->pkt_ctx = 0;
302121de 6040 ssh->x11auth = NULL;
be738459 6041 ssh->v1_compressing = FALSE;
51470298 6042 ssh->v2_outgoing_sequence = 0;
6043 ssh->ssh1_rdpkt_crstate = 0;
6044 ssh->ssh2_rdpkt_crstate = 0;
6045 ssh->do_ssh_init_crstate = 0;
6046 ssh->ssh_gotdata_crstate = 0;
6047 ssh->ssh1_protocol_crstate = 0;
6048 ssh->do_ssh1_login_crstate = 0;
6049 ssh->do_ssh2_transport_crstate = 0;
6050 ssh->do_ssh2_authconn_crstate = 0;
6051 ssh->do_ssh_init_state = NULL;
6052 ssh->do_ssh1_login_state = NULL;
6053 ssh->do_ssh2_transport_state = NULL;
6054 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 6055 ssh->mainchan = NULL;
968d2d92 6056 ssh->throttled_all = 0;
6057 ssh->v1_stdout_throttling = 0;
51470298 6058
6059 *backend_handle = ssh;
32874aea 6060
8f203108 6061#ifdef MSCRYPTOAPI
32874aea 6062 if (crypto_startup() == 0)
8f203108 6063 return "Microsoft high encryption pack not installed!";
6064#endif
374330e2 6065
51470298 6066 ssh->frontend = frontend_handle;
86916870 6067 ssh->term_width = ssh->cfg.width;
6068 ssh->term_height = ssh->cfg.height;
887035a5 6069
fabd1805 6070 ssh->channels = NULL;
6071 ssh->rportfwds = NULL;
6072
51470298 6073 ssh->send_ok = 0;
6074 ssh->editing = 0;
6075 ssh->echoing = 0;
6076 ssh->v1_throttle_count = 0;
6077 ssh->overall_bufsize = 0;
6078 ssh->fallback_cmd = 0;
8df7a775 6079
3648d4c5 6080 ssh->protocol = NULL;
6081
51470298 6082 p = connect_to_host(ssh, host, port, realhost, nodelay);
fb09bf1c 6083 if (p != NULL)
6084 return p;
374330e2 6085
374330e2 6086 return NULL;
6087}
6088
fabd1805 6089static void ssh_free(void *handle)
6090{
6091 Ssh ssh = (Ssh) handle;
6092 struct ssh_channel *c;
6093 struct ssh_rportfwd *pf;
6094
6095 if (ssh->v1_cipher_ctx)
6096 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6097 if (ssh->cs_cipher_ctx)
6098 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6099 if (ssh->sc_cipher_ctx)
6100 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6101 if (ssh->cs_mac_ctx)
6102 ssh->csmac->free_context(ssh->cs_mac_ctx);
6103 if (ssh->sc_mac_ctx)
6104 ssh->scmac->free_context(ssh->sc_mac_ctx);
6105 if (ssh->cs_comp_ctx)
6106 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6107 if (ssh->sc_comp_ctx)
6108 ssh->sccomp->compress_cleanup(ssh->sc_comp_ctx);
6109 if (ssh->kex_ctx)
6110 dh_cleanup(ssh->kex_ctx);
6111 sfree(ssh->savedhost);
6112
6113 if (ssh->channels) {
6114 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6115 switch (c->type) {
6116 case CHAN_X11:
6117 if (c->u.x11.s != NULL)
6118 x11_close(c->u.x11.s);
6119 break;
6120 case CHAN_SOCKDATA:
6121 if (c->u.pfd.s != NULL)
6122 pfd_close(c->u.pfd.s);
6123 break;
6124 }
6125 sfree(c);
6126 }
6127 freetree234(ssh->channels);
6128 }
6129
6130 if (ssh->rportfwds) {
6131 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6132 sfree(pf);
6133 freetree234(ssh->rportfwds);
6134 }
6135 sfree(ssh->deferred_send_data);
6136 if (ssh->x11auth)
6137 x11_free_auth(ssh->x11auth);
6138 sfree(ssh->do_ssh_init_state);
6139 sfree(ssh->do_ssh1_login_state);
6140 sfree(ssh->do_ssh2_transport_state);
6141 sfree(ssh->do_ssh2_authconn_state);
6142
6143 if (ssh->s)
6144 sk_close(ssh->s);
6145 sfree(ssh);
6146}
6147
374330e2 6148/*
86916870 6149 * Reconfigure the SSH backend.
6150 *
6151 * Currently, this function does nothing very useful. In future,
6152 * however, we could do some handy things with it. For example, we
6153 * could make the port forwarding configurer active in the Change
6154 * Settings box, and this routine could close down existing
6155 * forwardings and open up new ones in response to changes.
6156 */
6157static void ssh_reconfig(void *handle, Config *cfg)
6158{
6159 Ssh ssh = (Ssh) handle;
6160 ssh->cfg = *cfg; /* STRUCTURE COPY */
6161}
6162
6163/*
374330e2 6164 * Called to send data down the Telnet connection.
6165 */
51470298 6166static int ssh_send(void *handle, char *buf, int len)
32874aea 6167{
51470298 6168 Ssh ssh = (Ssh) handle;
6169
6170 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 6171 return 0;
374330e2 6172
d8baa528 6173 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 6174
51470298 6175 return ssh_sendbuffer(ssh);
5471d09a 6176}
6177
6178/*
6179 * Called to query the current amount of buffered stdin data.
6180 */
51470298 6181static int ssh_sendbuffer(void *handle)
5471d09a 6182{
51470298 6183 Ssh ssh = (Ssh) handle;
5471d09a 6184 int override_value;
6185
51470298 6186 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 6187 return 0;
6188
6189 /*
6190 * If the SSH socket itself has backed up, add the total backup
6191 * size on that to any individual buffer on the stdin channel.
6192 */
6193 override_value = 0;
51470298 6194 if (ssh->throttled_all)
6195 override_value = ssh->overall_bufsize;
5471d09a 6196
51470298 6197 if (ssh->version == 1) {
5471d09a 6198 return override_value;
51470298 6199 } else if (ssh->version == 2) {
6200 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 6201 return override_value;
6202 else
51470298 6203 return (override_value +
6204 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 6205 }
6206
6207 return 0;
374330e2 6208}
6209
6210/*
6e48c3fe 6211 * Called to set the size of the window from SSH's POV.
374330e2 6212 */
51470298 6213static void ssh_size(void *handle, int width, int height)
32874aea 6214{
51470298 6215 Ssh ssh = (Ssh) handle;
6216
6217 ssh->term_width = width;
6218 ssh->term_height = height;
f278d6f8 6219
51470298 6220 switch (ssh->state) {
374330e2 6221 case SSH_STATE_BEFORE_SIZE:
3687d221 6222 case SSH_STATE_PREPACKET:
21248260 6223 case SSH_STATE_CLOSED:
374330e2 6224 break; /* do nothing */
6225 case SSH_STATE_INTERMED:
51470298 6226 ssh->size_needed = TRUE; /* buffer for later */
374330e2 6227 break;
6228 case SSH_STATE_SESSION:
86916870 6229 if (!ssh->cfg.nopty) {
51470298 6230 if (ssh->version == 1) {
6231 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6232 PKT_INT, ssh->term_height,
6233 PKT_INT, ssh->term_width,
32874aea 6234 PKT_INT, 0, PKT_INT, 0, PKT_END);
6235 } else {
51470298 6236 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6237 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6238 ssh2_pkt_addstring(ssh, "window-change");
6239 ssh2_pkt_addbool(ssh, 0);
6240 ssh2_pkt_adduint32(ssh, ssh->term_width);
6241 ssh2_pkt_adduint32(ssh, ssh->term_height);
6242 ssh2_pkt_adduint32(ssh, 0);
6243 ssh2_pkt_adduint32(ssh, 0);
6244 ssh2_pkt_send(ssh);
32874aea 6245 }
6246 }
6247 break;
374330e2 6248 }
6249}
6250
6251/*
125105d1 6252 * Return a list of the special codes that make sense in this
6253 * protocol.
6254 */
6255static const struct telnet_special *ssh_get_specials(void *handle)
6256{
6257 Ssh ssh = (Ssh) handle;
6258
6259 if (ssh->version == 1) {
6260 static const struct telnet_special ssh1_specials[] = {
6261 {"IGNORE message", TS_NOP},
6262 {NULL, 0}
6263 };
6264 return ssh1_specials;
6265 } else if (ssh->version == 2) {
6266 static const struct telnet_special ssh2_specials[] = {
6267 {"Break", TS_BRK},
6268 {"IGNORE message", TS_NOP},
6269 {NULL, 0}
6270 };
6271 return ssh2_specials;
6272 } else
6273 return NULL;
6274}
6275
6276/*
6abbf9e3 6277 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6278 * can send an EOF and collect resulting output (e.g. `plink
6279 * hostname sort').
374330e2 6280 */
51470298 6281static void ssh_special(void *handle, Telnet_Special code)
32874aea 6282{
51470298 6283 Ssh ssh = (Ssh) handle;
6284
6abbf9e3 6285 if (code == TS_EOF) {
51470298 6286 if (ssh->state != SSH_STATE_SESSION) {
32874aea 6287 /*
6288 * Buffer the EOF in case we are pre-SESSION, so we can
6289 * send it as soon as we reach SESSION.
6290 */
6291 if (code == TS_EOF)
51470298 6292 ssh->eof_needed = TRUE;
32874aea 6293 return;
6294 }
51470298 6295 if (ssh->version == 1) {
6296 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
32874aea 6297 } else {
51470298 6298 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6299 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6300 ssh2_pkt_send(ssh);
32874aea 6301 }
6302 logevent("Sent EOF message");
125105d1 6303 } else if (code == TS_PING || code == TS_NOP) {
51470298 6304 if (ssh->state == SSH_STATE_CLOSED
6305 || ssh->state == SSH_STATE_PREPACKET) return;
6306 if (ssh->version == 1) {
6307 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6308 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 6309 } else {
51470298 6310 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6311 ssh2_pkt_addstring_start(ssh);
6312 ssh2_pkt_send(ssh);
32874aea 6313 }
125105d1 6314 } else if (code == TS_BRK) {
6315 if (ssh->state == SSH_STATE_CLOSED
6316 || ssh->state == SSH_STATE_PREPACKET) return;
6317 if (ssh->version == 1) {
6318 logevent("Unable to send BREAK signal in SSH1");
6319 } else {
6320 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6321 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6322 ssh2_pkt_addstring(ssh, "break");
6323 ssh2_pkt_addbool(ssh, 0);
6324 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6325 ssh2_pkt_send(ssh);
6326 }
6abbf9e3 6327 } else {
32874aea 6328 /* do nothing */
6abbf9e3 6329 }
374330e2 6330}
6331
51470298 6332void *new_sock_channel(void *handle, Socket s)
d74d141c 6333{
51470298 6334 Ssh ssh = (Ssh) handle;
d74d141c 6335 struct ssh_channel *c;
3d88e64d 6336 c = snew(struct ssh_channel);
51470298 6337 c->ssh = ssh;
d74d141c 6338
6339 if (c) {
bc240b21 6340 c->remoteid = -1; /* to be set when open confirmed */
51470298 6341 c->localid = alloc_channel_id(ssh);
d74d141c 6342 c->closes = 0;
bc240b21 6343 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 6344 c->u.pfd.s = s;
013dd8c0 6345 bufchain_init(&c->v.v2.outbuffer);
51470298 6346 add234(ssh->channels, c);
d74d141c 6347 }
6348 return c;
6349}
6350
5471d09a 6351/*
6352 * This is called when stdout/stderr (the entity to which
6353 * from_backend sends data) manages to clear some backlog.
6354 */
ae9ae89f 6355static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 6356{
51470298 6357 Ssh ssh = (Ssh) handle;
6358 if (ssh->version == 1) {
6359 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6360 ssh->v1_stdout_throttling = 0;
6361 ssh1_throttle(ssh, -1);
5471d09a 6362 }
6363 } else {
51470298 6364 if (ssh->mainchan && ssh->mainchan->closes == 0)
6365 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 6366 }
6367}
6368
6b78788a 6369void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 6370{
6371 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 6372 Ssh ssh = c->ssh;
d74d141c 6373
57356d63 6374 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 6375
51470298 6376 if (ssh->version == 1) {
6377 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 6378 PKT_INT, c->localid,
6379 PKT_STR, hostname,
6380 PKT_INT, port,
6381 //PKT_STR, <org:orgport>,
6382 PKT_END);
6383 } else {
51470298 6384 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6385 ssh2_pkt_addstring(ssh, "direct-tcpip");
6386 ssh2_pkt_adduint32(ssh, c->localid);
5471d09a 6387 c->v.v2.locwindow = OUR_V2_WINSIZE;
51470298 6388 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6389 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6390 ssh2_pkt_addstring(ssh, hostname);
6391 ssh2_pkt_adduint32(ssh, port);
bc240b21 6392 /*
6393 * We make up values for the originator data; partly it's
6394 * too much hassle to keep track, and partly I'm not
6395 * convinced the server should be told details like that
6396 * about my local network configuration.
6397 */
51470298 6398 ssh2_pkt_addstring(ssh, "client-side-connection");
6399 ssh2_pkt_adduint32(ssh, 0);
6400 ssh2_pkt_send(ssh);
bc240b21 6401 }
d74d141c 6402}
6403
6404
51470298 6405static Socket ssh_socket(void *handle)
32874aea 6406{
51470298 6407 Ssh ssh = (Ssh) handle;
6408 return ssh->s;
32874aea 6409}
8ccc75b0 6410
51470298 6411static int ssh_sendok(void *handle)
32874aea 6412{
51470298 6413 Ssh ssh = (Ssh) handle;
6414 return ssh->send_ok;
32874aea 6415}
fb09bf1c 6416
51470298 6417static int ssh_ldisc(void *handle, int option)
32874aea 6418{
51470298 6419 Ssh ssh = (Ssh) handle;
32874aea 6420 if (option == LD_ECHO)
51470298 6421 return ssh->echoing;
32874aea 6422 if (option == LD_EDIT)
51470298 6423 return ssh->editing;
0965bee0 6424 return FALSE;
6425}
6426
b9d7bcad 6427static void ssh_provide_ldisc(void *handle, void *ldisc)
6428{
6429 Ssh ssh = (Ssh) handle;
6430 ssh->ldisc = ldisc;
6431}
6432
a8327734 6433static void ssh_provide_logctx(void *handle, void *logctx)
6434{
6435 Ssh ssh = (Ssh) handle;
6436 ssh->logctx = logctx;
6437}
6438
51470298 6439static int ssh_return_exitcode(void *handle)
6440{
6441 Ssh ssh = (Ssh) handle;
3bb2f322 6442 if (ssh->s != NULL)
6443 return -1;
6444 else
6445 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 6446}
6447
6448/*
6449 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6450 * that fails. This variable is the means by which scp.c can reach
6451 * into the SSH code and find out which one it got.
6452 */
6453extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 6454{
51470298 6455 Ssh ssh = (Ssh) handle;
6456 return ssh->fallback_cmd;
d8d6c7e5 6457}
6458
374330e2 6459Backend ssh_backend = {
6460 ssh_init,
fabd1805 6461 ssh_free,
86916870 6462 ssh_reconfig,
374330e2 6463 ssh_send,
5471d09a 6464 ssh_sendbuffer,
374330e2 6465 ssh_size,
4017be6d 6466 ssh_special,
125105d1 6467 ssh_get_specials,
8ccc75b0 6468 ssh_socket,
d8d6c7e5 6469 ssh_return_exitcode,
97db3be4 6470 ssh_sendok,
0965bee0 6471 ssh_ldisc,
b9d7bcad 6472 ssh_provide_ldisc,
a8327734 6473 ssh_provide_logctx,
5471d09a 6474 ssh_unthrottle,
97db3be4 6475 22
bc240b21 6476};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator