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Platform-independent fixes for NO_IPV6 compilation (prevent
[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 */
d1aaf71d 107#define SSH2_PKTCTX_DHGROUP 0x0001
00db133f 108#define SSH2_PKTCTX_DHGEX 0x0002
149d2abc 109#define SSH2_PKTCTX_KEX_MASK 0x000F
00db133f 110#define SSH2_PKTCTX_PUBLICKEY 0x0010
111#define SSH2_PKTCTX_PASSWORD 0x0020
112#define SSH2_PKTCTX_KBDINTER 0x0040
113#define SSH2_PKTCTX_AUTH_MASK 0x00F0
114
32874aea 115#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 130
131static const char *const ssh2_disconnect_reasons[] = {
132 NULL,
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
148};
9005f3ba 149
32874aea 150#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 154
32874aea 155#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 156
7d503c31 157/*
158 * Various remote-bug flags.
159 */
160#define BUG_CHOKES_ON_SSH1_IGNORE 1
161#define BUG_SSH2_HMAC 2
bd358db1 162#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 163#define BUG_CHOKES_ON_RSA 8
1dd353b5 164#define BUG_SSH2_RSA_PADDING 16
088bde77 165#define BUG_SSH2_DERIVEKEY 32
f382c87d 166#define BUG_SSH2_REKEY 64
dda87a28 167#define BUG_SSH2_PK_SESSIONID 128
bd358db1 168
00db133f 169#define translate(x) if (type == x) return #x
51470298 170#define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
ae9ae89f 171static char *ssh1_pkt_type(int type)
00db133f 172{
173 translate(SSH1_MSG_DISCONNECT);
174 translate(SSH1_SMSG_PUBLIC_KEY);
175 translate(SSH1_CMSG_SESSION_KEY);
176 translate(SSH1_CMSG_USER);
177 translate(SSH1_CMSG_AUTH_RSA);
178 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
179 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
180 translate(SSH1_CMSG_AUTH_PASSWORD);
181 translate(SSH1_CMSG_REQUEST_PTY);
182 translate(SSH1_CMSG_WINDOW_SIZE);
183 translate(SSH1_CMSG_EXEC_SHELL);
184 translate(SSH1_CMSG_EXEC_CMD);
185 translate(SSH1_SMSG_SUCCESS);
186 translate(SSH1_SMSG_FAILURE);
187 translate(SSH1_CMSG_STDIN_DATA);
188 translate(SSH1_SMSG_STDOUT_DATA);
189 translate(SSH1_SMSG_STDERR_DATA);
190 translate(SSH1_CMSG_EOF);
191 translate(SSH1_SMSG_EXIT_STATUS);
192 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
193 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
194 translate(SSH1_MSG_CHANNEL_DATA);
195 translate(SSH1_MSG_CHANNEL_CLOSE);
196 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
197 translate(SSH1_SMSG_X11_OPEN);
198 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
199 translate(SSH1_MSG_PORT_OPEN);
200 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
201 translate(SSH1_SMSG_AGENT_OPEN);
202 translate(SSH1_MSG_IGNORE);
203 translate(SSH1_CMSG_EXIT_CONFIRMATION);
204 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
205 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
206 translate(SSH1_MSG_DEBUG);
207 translate(SSH1_CMSG_REQUEST_COMPRESSION);
208 translate(SSH1_CMSG_AUTH_TIS);
209 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
210 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
211 translate(SSH1_CMSG_AUTH_CCARD);
212 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
213 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
214 return "unknown";
215}
ae9ae89f 216static char *ssh2_pkt_type(int pkt_ctx, int type)
00db133f 217{
218 translate(SSH2_MSG_DISCONNECT);
219 translate(SSH2_MSG_IGNORE);
220 translate(SSH2_MSG_UNIMPLEMENTED);
221 translate(SSH2_MSG_DEBUG);
222 translate(SSH2_MSG_SERVICE_REQUEST);
223 translate(SSH2_MSG_SERVICE_ACCEPT);
224 translate(SSH2_MSG_KEXINIT);
225 translate(SSH2_MSG_NEWKEYS);
d1aaf71d 226 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
227 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
00db133f 228 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
231 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
232 translate(SSH2_MSG_USERAUTH_REQUEST);
233 translate(SSH2_MSG_USERAUTH_FAILURE);
234 translate(SSH2_MSG_USERAUTH_SUCCESS);
235 translate(SSH2_MSG_USERAUTH_BANNER);
236 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
237 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
238 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
239 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
240 translate(SSH2_MSG_GLOBAL_REQUEST);
241 translate(SSH2_MSG_REQUEST_SUCCESS);
242 translate(SSH2_MSG_REQUEST_FAILURE);
243 translate(SSH2_MSG_CHANNEL_OPEN);
244 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
245 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
246 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
247 translate(SSH2_MSG_CHANNEL_DATA);
248 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
249 translate(SSH2_MSG_CHANNEL_EOF);
250 translate(SSH2_MSG_CHANNEL_CLOSE);
251 translate(SSH2_MSG_CHANNEL_REQUEST);
252 translate(SSH2_MSG_CHANNEL_SUCCESS);
253 translate(SSH2_MSG_CHANNEL_FAILURE);
254 return "unknown";
255}
256#undef translate
257#undef translatec
7d503c31 258
fb09bf1c 259#define GET_32BIT(cp) \
260 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
261 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
262 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
263 ((unsigned long)(unsigned char)(cp)[3]))
264
265#define PUT_32BIT(cp, value) { \
266 (cp)[0] = (unsigned char)((value) >> 24); \
267 (cp)[1] = (unsigned char)((value) >> 16); \
268 (cp)[2] = (unsigned char)((value) >> 8); \
269 (cp)[3] = (unsigned char)(value); }
270
9a10ecf4 271/* Enumeration values for fields in SSH-1 packets */
272enum {
273 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
274 /* These values are for communicating relevant semantics of
275 * fields to the packet logging code. */
276 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
277};
972a41c8 278
acddebd9 279/*
280 * Coroutine mechanics for the sillier bits of the code. If these
281 * macros look impenetrable to you, you might find it helpful to
282 * read
283 *
284 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
285 *
286 * which explains the theory behind these macros.
b624d1e6 287 *
288 * In particular, if you are getting `case expression not constant'
289 * errors when building with MS Visual Studio, this is because MS's
290 * Edit and Continue debugging feature causes their compiler to
291 * violate ANSI C. To disable Edit and Continue debugging:
292 *
293 * - right-click ssh.c in the FileView
294 * - click Settings
295 * - select the C/C++ tab and the General category
296 * - under `Debug info:', select anything _other_ than `Program
297 * Database for Edit and Continue'.
acddebd9 298 */
51470298 299#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
300#define crState(t) \
301 struct t *s; \
3d88e64d 302 if (!ssh->t) ssh->t = snew(struct t); \
51470298 303 s = ssh->t;
304#define crFinish(z) } *crLine = 0; return (z); }
305#define crFinishV } *crLine = 0; return; }
374330e2 306#define crReturn(z) \
307 do {\
51470298 308 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 309 } while (0)
310#define crReturnV \
311 do {\
51470298 312 *crLine=__LINE__; return; case __LINE__:;\
374330e2 313 } while (0)
51470298 314#define crStop(z) do{ *crLine = 0; return (z); }while(0)
315#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 316#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 317#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 318
51470298 319typedef struct ssh_tag *Ssh;
ff3187f6 320struct Packet;
321
322static struct Packet *ssh2_pkt_init(int pkt_type);
323static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
324static void ssh2_pkt_adduint32(struct Packet *, unsigned long value);
325static void ssh2_pkt_addstring_start(struct Packet *);
326static void ssh2_pkt_addstring_str(struct Packet *, char *data);
327static void ssh2_pkt_addstring_data(struct Packet *, char *data, int len);
328static void ssh2_pkt_addstring(struct Packet *, char *data);
d8baa528 329static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
ff3187f6 330static void ssh2_pkt_addmp(struct Packet *, Bignum b);
331static int ssh2_pkt_construct(Ssh, struct Packet *);
332static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 333static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 334static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
335 struct Packet *pktin);
336static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
337 struct Packet *pktin);
3d63ca2e 338
5471d09a 339/*
340 * Buffer management constants. There are several of these for
341 * various different purposes:
342 *
343 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
344 * on a local data stream before we throttle the whole SSH
345 * connection (in SSH1 only). Throttling the whole connection is
346 * pretty drastic so we set this high in the hope it won't
347 * happen very often.
348 *
349 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
350 * on the SSH connection itself before we defensively throttle
351 * _all_ local data streams. This is pretty drastic too (though
352 * thankfully unlikely in SSH2 since the window mechanism should
353 * ensure that the server never has any need to throttle its end
354 * of the connection), so we set this high as well.
355 *
356 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
357 * channels.
358 */
359
360#define SSH1_BUFFER_LIMIT 32768
361#define SSH_MAX_BACKLOG 32768
362#define OUR_V2_WINSIZE 16384
954d5c5a 363#define OUR_V2_MAXPKT 0x4000UL
d74d141c 364
85cc02bb 365const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 366
e0e1a00d 367static void *nullmac_make_context(void)
368{
369 return NULL;
370}
371static void nullmac_free_context(void *handle)
372{
373}
374static void nullmac_key(void *handle, unsigned char *key)
32874aea 375{
376}
e0e1a00d 377static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 378 unsigned long seq)
379{
380}
e0e1a00d 381static int nullmac_verify(void *handle, unsigned char *blk, int len,
382 unsigned long seq)
32874aea 383{
384 return 1;
385}
57476f6b 386const static struct ssh_mac ssh_mac_none = {
e0e1a00d 387 nullmac_make_context, nullmac_free_context, nullmac_key,
388 nullmac_generate, nullmac_verify, "none", 0
e5574168 389};
8b2715b2 390const static struct ssh_mac *macs[] = {
32874aea 391 &ssh_sha1, &ssh_md5, &ssh_mac_none
392};
8b2715b2 393const static struct ssh_mac *buggymacs[] = {
32874aea 394 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
395};
e5574168 396
5366aed8 397static void *ssh_comp_none_init(void)
398{
399 return NULL;
400}
401static void ssh_comp_none_cleanup(void *handle)
32874aea 402{
403}
5366aed8 404static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 405 unsigned char **outblock, int *outlen)
406{
407 return 0;
408}
5366aed8 409static int ssh_comp_none_disable(void *handle)
32874aea 410{
4ba9b64b 411 return 0;
412}
57476f6b 413const static struct ssh_compress ssh_comp_none = {
4ba9b64b 414 "none",
5366aed8 415 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
416 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
417 ssh_comp_none_disable, NULL
e5574168 418};
4ba9b64b 419extern const struct ssh_compress ssh_zlib;
420const static struct ssh_compress *compressions[] = {
32874aea 421 &ssh_zlib, &ssh_comp_none
422};
374330e2 423
32874aea 424enum { /* channel types */
783415f8 425 CHAN_MAINSESSION,
426 CHAN_X11,
427 CHAN_AGENT,
bc240b21 428 CHAN_SOCKDATA,
429 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 430};
431
dacbd0e8 432/*
433 * 2-3-4 tree storing channels.
434 */
435struct ssh_channel {
51470298 436 Ssh ssh; /* pointer back to main context */
d211621f 437 unsigned remoteid, localid;
dacbd0e8 438 int type;
64d6ff88 439 /* True if we opened this channel but server hasn't confirmed. */
440 int halfopen;
0357890f 441 /*
442 * In SSH1, this value contains four bits:
443 *
444 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
445 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
446 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
447 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
448 *
449 * A channel is completely finished with when all four bits are set.
450 */
dacbd0e8 451 int closes;
5471d09a 452 union {
453 struct ssh1_data_channel {
454 int throttling;
455 } v1;
456 struct ssh2_data_channel {
457 bufchain outbuffer;
458 unsigned remwindow, remmaxpkt;
459 unsigned locwindow;
460 } v2;
461 } v;
dacbd0e8 462 union {
32874aea 463 struct ssh_agent_channel {
464 unsigned char *message;
465 unsigned char msglen[4];
a03c9f9c 466 unsigned lensofar, totallen;
32874aea 467 } a;
468 struct ssh_x11_channel {
469 Socket s;
470 } x11;
d74d141c 471 struct ssh_pfd_channel {
472 Socket s;
473 } pfd;
dacbd0e8 474 } u;
475};
57476f6b 476
d74d141c 477/*
bc240b21 478 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
479 * 2 use this structure in different ways, reflecting SSH 2's
480 * altogether saner approach to port forwarding.
481 *
482 * In SSH 1, you arrange a remote forwarding by sending the server
483 * the remote port number, and the local destination host:port.
484 * When a connection comes in, the server sends you back that
485 * host:port pair, and you connect to it. This is a ready-made
486 * security hole if you're not on the ball: a malicious server
487 * could send you back _any_ host:port pair, so if you trustingly
488 * connect to the address it gives you then you've just opened the
489 * entire inside of your corporate network just by connecting
490 * through it to a dodgy SSH server. Hence, we must store a list of
491 * host:port pairs we _are_ trying to forward to, and reject a
492 * connection request from the server if it's not in the list.
493 *
494 * In SSH 2, each side of the connection minds its own business and
495 * doesn't send unnecessary information to the other. You arrange a
496 * remote forwarding by sending the server just the remote port
497 * number. When a connection comes in, the server tells you which
498 * of its ports was connected to; and _you_ have to remember what
499 * local host:port pair went with that port number.
500 *
06fadff5 501 * Hence, in SSH 1 this structure is indexed by destination
502 * host:port pair, whereas in SSH 2 it is indexed by source port.
d74d141c 503 */
fda2feb1 504struct ssh_portfwd; /* forward declaration */
505
d74d141c 506struct ssh_rportfwd {
bc240b21 507 unsigned sport, dport;
508 char dhost[256];
06fadff5 509 char *sportdesc;
fda2feb1 510 struct ssh_portfwd *pfrec;
d74d141c 511};
fda2feb1 512#define free_rportfwd(pf) ( \
513 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
514
515/*
516 * Separately to the rportfwd tree (which is for looking up port
517 * open requests from the server), a tree of _these_ structures is
518 * used to keep track of all the currently open port forwardings,
519 * so that we can reconfigure in mid-session if the user requests
520 * it.
521 */
522struct ssh_portfwd {
84328ddb 523 enum { DESTROY, KEEP, CREATE } status;
fda2feb1 524 int type;
525 unsigned sport, dport;
526 char *saddr, *daddr;
3fe92132 527 char *sserv, *dserv;
fda2feb1 528 struct ssh_rportfwd *remote;
05581745 529 int addressfamily;
fda2feb1 530 void *local;
531};
532#define free_portfwd(pf) ( \
3fe92132 533 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
534 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
d74d141c 535
57476f6b 536struct Packet {
537 long length;
95d2d262 538 long forcepad; /* Force padding to at least this length */
57476f6b 539 int type;
b09eaa88 540 unsigned long sequence;
57476f6b 541 unsigned char *data;
542 unsigned char *body;
543 long savedpos;
544 long maxlen;
9442dd57 545 long encrypted_len; /* for SSH2 total-size counting */
ff3187f6 546
547 /*
548 * State associated with packet logging
549 */
550 int logmode;
551 int nblanks;
552 struct logblank_t *blanks;
57476f6b 553};
554
1c1a7262 555static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 556 struct Packet *pktin);
1c1a7262 557static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 558 struct Packet *pktin);
b09eaa88 559static void ssh1_protocol_setup(Ssh ssh);
560static void ssh2_protocol_setup(Ssh ssh);
51470298 561static void ssh_size(void *handle, int width, int height);
562static void ssh_special(void *handle, Telnet_Special);
5471d09a 563static int ssh2_try_send(struct ssh_channel *c);
51470298 564static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
565static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 566static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 567static int ssh_sendbuffer(void *handle);
ac934965 568static int ssh_do_close(Ssh ssh, int notify_exit);
ff3187f6 569static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
570static int ssh2_pkt_getbool(struct Packet *pkt);
571static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 572static void ssh2_timer(void *ctx, long now);
1c1a7262 573static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
9442dd57 574 struct Packet *pktin);
57476f6b 575
51470298 576struct rdpkt1_state_tag {
57476f6b 577 long len, pad, biglen, to_read;
578 unsigned long realcrc, gotcrc;
579 unsigned char *p;
580 int i;
581 int chunk;
ff3187f6 582 struct Packet *pktin;
51470298 583};
57476f6b 584
51470298 585struct rdpkt2_state_tag {
960e736a 586 long len, pad, payload, packetlen, maclen;
587 int i;
588 int cipherblk;
589 unsigned long incoming_sequence;
ff3187f6 590 struct Packet *pktin;
51470298 591};
592
b09eaa88 593typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
06fadff5 594typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
595
596struct queued_handler;
597struct queued_handler {
598 int msg1, msg2;
599 chandler_fn_t handler;
600 void *ctx;
601 struct queued_handler *next;
602};
b09eaa88 603
51470298 604struct ssh_tag {
605 const struct plug_function_table *fn;
606 /* the above field _must_ be first in the structure */
607
608 SHA_State exhash, exhashbase;
609
610 Socket s;
611
b9d7bcad 612 void *ldisc;
a8327734 613 void *logctx;
b9d7bcad 614
51470298 615 unsigned char session_key[32];
616 int v1_compressing;
617 int v1_remote_protoflags;
618 int v1_local_protoflags;
619 int agentfwd_enabled;
620 int X11_fwd_enabled;
621 int remote_bugs;
622 const struct ssh_cipher *cipher;
371e569c 623 void *v1_cipher_ctx;
0183b242 624 void *crcda_ctx;
51470298 625 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 626 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 627 const struct ssh_mac *csmac, *scmac;
e0e1a00d 628 void *cs_mac_ctx, *sc_mac_ctx;
51470298 629 const struct ssh_compress *cscomp, *sccomp;
5366aed8 630 void *cs_comp_ctx, *sc_comp_ctx;
51470298 631 const struct ssh_kex *kex;
632 const struct ssh_signkey *hostkey;
633 unsigned char v2_session_id[20];
27cd7fc2 634 void *kex_ctx;
51470298 635
636 char *savedhost;
637 int savedport;
638 int send_ok;
639 int echoing, editing;
640
641 void *frontend;
642
db219738 643 int ospeed, ispeed; /* temporaries */
51470298 644 int term_width, term_height;
645
646 tree234 *channels; /* indexed by local id */
647 struct ssh_channel *mainchan; /* primary session channel */
648 int exitcode;
ac934965 649 int close_expected;
51470298 650
fda2feb1 651 tree234 *rportfwds, *portfwds;
51470298 652
653 enum {
654 SSH_STATE_PREPACKET,
655 SSH_STATE_BEFORE_SIZE,
656 SSH_STATE_INTERMED,
657 SSH_STATE_SESSION,
658 SSH_STATE_CLOSED
659 } state;
660
661 int size_needed, eof_needed;
662
590f6a5f 663 struct Packet **queue;
664 int queuelen, queuesize;
665 int queueing;
51470298 666 unsigned char *deferred_send_data;
667 int deferred_len, deferred_size;
668
669 /*
670 * Gross hack: pscp will try to start SFTP but fall back to
671 * scp1 if that fails. This variable is the means by which
672 * scp.c can reach into the SSH code and find out which one it
673 * got.
674 */
675 int fallback_cmd;
676
677 /*
678 * Used for username and password input.
679 */
680 char *userpass_input_buffer;
681 int userpass_input_buflen;
682 int userpass_input_bufpos;
683 int userpass_input_echo;
684
51470298 685 int pkt_ctx;
686
302121de 687 void *x11auth;
688
51470298 689 int version;
690 int v1_throttle_count;
691 int overall_bufsize;
692 int throttled_all;
693 int v1_stdout_throttling;
a8756193 694 unsigned long v2_outgoing_sequence;
51470298 695
696 int ssh1_rdpkt_crstate;
697 int ssh2_rdpkt_crstate;
698 int do_ssh_init_crstate;
699 int ssh_gotdata_crstate;
51470298 700 int do_ssh1_login_crstate;
b09eaa88 701 int do_ssh1_connection_crstate;
51470298 702 int do_ssh2_transport_crstate;
703 int do_ssh2_authconn_crstate;
704
705 void *do_ssh_init_state;
706 void *do_ssh1_login_state;
707 void *do_ssh2_transport_state;
708 void *do_ssh2_authconn_state;
709
710 struct rdpkt1_state_tag rdpkt1_state;
711 struct rdpkt2_state_tag rdpkt2_state;
712
b09eaa88 713 /* ssh1 and ssh2 use this for different things, but both use it */
714 int protocol_initial_phase_done;
715
1c1a7262 716 void (*protocol) (Ssh ssh, void *vin, int inlen,
ff3187f6 717 struct Packet *pkt);
718 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 719
720 /*
721 * We maintain a full _copy_ of a Config structure here, not
722 * merely a pointer to it. That way, when we're passed a new
723 * one for reconfiguration, we can check the differences and
724 * potentially reconfigure port forwardings etc in mid-session.
725 */
726 Config cfg;
839f10db 727
728 /*
3d9449a1 729 * Used to transfer data back from async callbacks.
839f10db 730 */
731 void *agent_response;
732 int agent_response_len;
3d9449a1 733 int user_response;
734
735 /*
736 * The SSH connection can be set as `frozen', meaning we are
737 * not currently accepting incoming data from the network. This
738 * is slightly more serious than setting the _socket_ as
739 * frozen, because we may already have had data passed to us
740 * from the network which we need to delay processing until
741 * after the freeze is lifted, so we also need a bufchain to
742 * store that data.
743 */
744 int frozen;
745 bufchain queued_incoming_data;
b09eaa88 746
747 /*
748 * Dispatch table for packet types that we may have to deal
749 * with at any time.
750 */
751 handler_fn_t packet_dispatch[256];
39934deb 752
753 /*
06fadff5 754 * Queues of one-off handler functions for success/failure
755 * indications from a request.
756 */
757 struct queued_handler *qhead, *qtail;
758
759 /*
39934deb 760 * This module deals with sending keepalives.
761 */
762 Pinger pinger;
9442dd57 763
764 /*
765 * Track incoming and outgoing data sizes and time, for
766 * size-based rekeys.
767 */
768 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
d57f70af 769 unsigned long max_data_size;
9442dd57 770 int kex_in_progress;
e6c1536e 771 long next_rekey, last_rekey;
e13bba36 772 char *deferred_rekey_reason; /* points to STATIC string; don't free */
51470298 773};
960e736a 774
382908ad 775#define logevent(s) logevent(ssh->frontend, s)
a8327734 776
777/* logevent, only printf-formatted. */
cbe2d68f 778static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 779{
780 va_list ap;
57356d63 781 char *buf;
a8327734 782
783 va_start(ap, fmt);
57356d63 784 buf = dupvprintf(fmt, ap);
a8327734 785 va_end(ap);
57356d63 786 logevent(buf);
57356d63 787 sfree(buf);
a8327734 788}
789
6b5cf8b4 790#define bombout(msg) \
791 do { \
792 char *text = dupprintf msg; \
ac934965 793 ssh_do_close(ssh, FALSE); \
6b5cf8b4 794 logevent(text); \
795 connection_fatal(ssh->frontend, "%s", text); \
796 sfree(text); \
797 } while (0)
a8327734 798
9a10ecf4 799/* Functions to leave bits out of the SSH packet log file. */
800
ff3187f6 801static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 802{
803 if (ssh->cfg.logomitpass)
ff3187f6 804 pkt->logmode = blanktype;
9a10ecf4 805}
806
ff3187f6 807static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 808{
809 if (ssh->cfg.logomitdata)
ff3187f6 810 pkt->logmode = blanktype;
9a10ecf4 811}
812
ff3187f6 813static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 814{
ff3187f6 815 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 816}
817
32874aea 818static int ssh_channelcmp(void *av, void *bv)
819{
820 struct ssh_channel *a = (struct ssh_channel *) av;
821 struct ssh_channel *b = (struct ssh_channel *) bv;
822 if (a->localid < b->localid)
823 return -1;
824 if (a->localid > b->localid)
825 return +1;
dacbd0e8 826 return 0;
827}
32874aea 828static int ssh_channelfind(void *av, void *bv)
829{
830 unsigned *a = (unsigned *) av;
831 struct ssh_channel *b = (struct ssh_channel *) bv;
832 if (*a < b->localid)
833 return -1;
834 if (*a > b->localid)
835 return +1;
dacbd0e8 836 return 0;
837}
838
bc240b21 839static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 840{
841 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
842 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
843 int i;
bc240b21 844 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 845 return i < 0 ? -1 : +1;
bc240b21 846 if (a->dport > b->dport)
847 return +1;
848 if (a->dport < b->dport)
849 return -1;
850 return 0;
851}
852
853static int ssh_rportcmp_ssh2(void *av, void *bv)
854{
855 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
856 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 857
bc240b21 858 if (a->sport > b->sport)
d74d141c 859 return +1;
bc240b21 860 if (a->sport < b->sport)
861 return -1;
d74d141c 862 return 0;
863}
864
fda2feb1 865/*
866 * Special form of strcmp which can cope with NULL inputs. NULL is
867 * defined to sort before even the empty string.
868 */
869static int nullstrcmp(const char *a, const char *b)
870{
871 if (a == NULL && b == NULL)
872 return 0;
873 if (a == NULL)
874 return -1;
875 if (b == NULL)
876 return +1;
877 return strcmp(a, b);
878}
879
880static int ssh_portcmp(void *av, void *bv)
881{
882 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
883 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
884 int i;
885 if (a->type > b->type)
886 return +1;
887 if (a->type < b->type)
888 return -1;
84328ddb 889 if (a->addressfamily > b->addressfamily)
890 return +1;
891 if (a->addressfamily < b->addressfamily)
892 return -1;
fda2feb1 893 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
894 return i < 0 ? -1 : +1;
895 if (a->sport > b->sport)
896 return +1;
897 if (a->sport < b->sport)
898 return -1;
899 if (a->type != 'D') {
900 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
901 return i < 0 ? -1 : +1;
902 if (a->dport > b->dport)
903 return +1;
904 if (a->dport < b->dport)
905 return -1;
906 }
907 return 0;
908}
909
51470298 910static int alloc_channel_id(Ssh ssh)
32874aea 911{
260f3dec 912 const unsigned CHANNEL_NUMBER_OFFSET = 256;
913 unsigned low, high, mid;
d2371c81 914 int tsize;
915 struct ssh_channel *c;
916
917 /*
918 * First-fit allocation of channel numbers: always pick the
919 * lowest unused one. To do this, binary-search using the
920 * counted B-tree to find the largest channel ID which is in a
921 * contiguous sequence from the beginning. (Precisely
922 * everything in that sequence must have ID equal to its tree
923 * index plus CHANNEL_NUMBER_OFFSET.)
924 */
51470298 925 tsize = count234(ssh->channels);
d2371c81 926
32874aea 927 low = -1;
928 high = tsize;
d2371c81 929 while (high - low > 1) {
930 mid = (high + low) / 2;
51470298 931 c = index234(ssh->channels, mid);
d2371c81 932 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
933 low = mid; /* this one is fine */
934 else
935 high = mid; /* this one is past it */
936 }
937 /*
938 * Now low points to either -1, or the tree index of the
939 * largest ID in the initial sequence.
940 */
941 {
942 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 943 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 944 }
945 return low + 1 + CHANNEL_NUMBER_OFFSET;
946}
947
9fab77dc 948static void c_write(Ssh ssh, const char *buf, int len)
32874aea 949{
67779be7 950 if ((flags & FLAG_STDERR)) {
32874aea 951 int i;
952 for (i = 0; i < len; i++)
953 if (buf[i] != '\r')
954 fputc(buf[i], stderr);
fb09bf1c 955 return;
956 }
51470298 957 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 958}
959
9fab77dc 960static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 961{
a209e957 962 int i;
963 for (i = 0; i < len; i++) {
32874aea 964 if (buf[i] == '\n')
51470298 965 c_write(ssh, "\r\n", 2);
32874aea 966 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 967 c_write(ssh, buf + i, 1);
a209e957 968 }
969}
970
9fab77dc 971static void c_write_str(Ssh ssh, const char *buf)
32874aea 972{
51470298 973 c_write(ssh, buf, strlen(buf));
1408a877 974}
975
ff3187f6 976static void ssh_free_packet(struct Packet *pkt)
977{
978 sfree(pkt->data);
979 sfree(pkt);
980}
981static struct Packet *ssh_new_packet(void)
982{
983 struct Packet *pkt = snew(struct Packet);
984
985 pkt->data = NULL;
986 pkt->maxlen = 0;
987 pkt->logmode = PKTLOG_EMIT;
988 pkt->nblanks = 0;
989 pkt->blanks = NULL;
990
991 return pkt;
992}
993
fb09bf1c 994/*
995 * Collect incoming data in the incoming packet buffer.
e5574168 996 * Decipher and verify the packet when it is completely read.
997 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 998 * Update the *data and *datalen variables.
ff3187f6 999 * Return a Packet structure when a packet is completed.
fb09bf1c 1000 */
ff3187f6 1001static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 1002{
51470298 1003 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 1004
51470298 1005 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 1006
ff3187f6 1007 st->pktin = ssh_new_packet();
1008
1009 st->pktin->type = 0;
1010 st->pktin->length = 0;
374330e2 1011
57476f6b 1012 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 1013 while ((*datalen) == 0)
ff3187f6 1014 crReturn(NULL);
57476f6b 1015 st->len = (st->len << 8) + **data;
fb09bf1c 1016 (*data)++, (*datalen)--;
1017 }
374330e2 1018
57476f6b 1019 st->pad = 8 - (st->len % 8);
1020 st->biglen = st->len + st->pad;
ff3187f6 1021 st->pktin->length = st->len - 5;
fb09bf1c 1022
ae0500e5 1023 if (st->biglen < 0) {
1024 bombout(("Extremely large packet length from server suggests"
1025 " data stream corruption"));
ff3187f6 1026 ssh_free_packet(st->pktin);
1027 crStop(NULL);
ae0500e5 1028 }
1029
ff3187f6 1030 st->pktin->maxlen = st->biglen;
1031 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 1032
57476f6b 1033 st->to_read = st->biglen;
ff3187f6 1034 st->p = st->pktin->data;
57476f6b 1035 while (st->to_read > 0) {
32874aea 1036 st->chunk = st->to_read;
fb09bf1c 1037 while ((*datalen) == 0)
ff3187f6 1038 crReturn(NULL);
57476f6b 1039 if (st->chunk > (*datalen))
1040 st->chunk = (*datalen);
1041 memcpy(st->p, *data, st->chunk);
1042 *data += st->chunk;
1043 *datalen -= st->chunk;
1044 st->p += st->chunk;
1045 st->to_read -= st->chunk;
fb09bf1c 1046 }
374330e2 1047
ff3187f6 1048 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 1049 st->biglen, NULL)) {
6b5cf8b4 1050 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 1051 ssh_free_packet(st->pktin);
1052 crStop(NULL);
9a3a93a5 1053 }
1054
51470298 1055 if (ssh->cipher)
ff3187f6 1056 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 1057
ff3187f6 1058 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1059 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 1060 if (st->gotcrc != st->realcrc) {
6b5cf8b4 1061 bombout(("Incorrect CRC received on packet"));
ff3187f6 1062 ssh_free_packet(st->pktin);
1063 crStop(NULL);
fb09bf1c 1064 }
572f871e 1065
ff3187f6 1066 st->pktin->body = st->pktin->data + st->pad + 1;
1067 st->pktin->savedpos = 0;
4ba9b64b 1068
51470298 1069 if (ssh->v1_compressing) {
4ba9b64b 1070 unsigned char *decompblk;
1071 int decomplen;
36b8d9bb 1072 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 1073 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 1074 &decompblk, &decomplen)) {
1075 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 1076 ssh_free_packet(st->pktin);
1077 crStop(NULL);
36b8d9bb 1078 }
4ba9b64b 1079
ff3187f6 1080 if (st->pktin->maxlen < st->pad + decomplen) {
1081 st->pktin->maxlen = st->pad + decomplen;
1082 st->pktin->data = sresize(st->pktin->data,
1083 st->pktin->maxlen + APIEXTRA,
3d88e64d 1084 unsigned char);
ff3187f6 1085 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 1086 }
1087
ff3187f6 1088 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 1089 sfree(decompblk);
ff3187f6 1090 st->pktin->length = decomplen - 1;
4ba9b64b 1091 }
1092
ff3187f6 1093 st->pktin->type = st->pktin->body[-1];
00db133f 1094
9a10ecf4 1095 /*
1096 * Log incoming packet, possibly omitting sensitive fields.
1097 */
1098 if (ssh->logctx) {
1099 int nblanks = 0;
1100 struct logblank_t blank;
1101 if (ssh->cfg.logomitdata) {
1102 int do_blank = FALSE, blank_prefix = 0;
1103 /* "Session data" packets - omit the data field */
ff3187f6 1104 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1105 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1106 do_blank = TRUE; blank_prefix = 0;
ff3187f6 1107 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
9a10ecf4 1108 do_blank = TRUE; blank_prefix = 4;
1109 }
1110 if (do_blank) {
1111 blank.offset = blank_prefix;
ff3187f6 1112 blank.len = st->pktin->length;
9a10ecf4 1113 blank.type = PKTLOG_OMIT;
1114 nblanks = 1;
1115 }
1116 }
a8327734 1117 log_packet(ssh->logctx,
ff3187f6 1118 PKT_INCOMING, st->pktin->type,
1119 ssh1_pkt_type(st->pktin->type),
1120 st->pktin->body, st->pktin->length,
9a10ecf4 1121 nblanks, &blank);
1122 }
00db133f 1123
ff3187f6 1124 crFinish(st->pktin);
fb09bf1c 1125}
1126
ff3187f6 1127static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1128{
51470298 1129 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1130
51470298 1131 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1132
ff3187f6 1133 st->pktin = ssh_new_packet();
1134
1135 st->pktin->type = 0;
1136 st->pktin->length = 0;
51470298 1137 if (ssh->sccipher)
1138 st->cipherblk = ssh->sccipher->blksize;
e5574168 1139 else
32874aea 1140 st->cipherblk = 8;
960e736a 1141 if (st->cipherblk < 8)
32874aea 1142 st->cipherblk = 8;
960e736a 1143
ff3187f6 1144 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
e5574168 1145
1146 /*
1147 * Acquire and decrypt the first block of the packet. This will
1148 * contain the length and padding details.
1149 */
32874aea 1150 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 1151 while ((*datalen) == 0)
ff3187f6 1152 crReturn(NULL);
1153 st->pktin->data[st->i] = *(*data)++;
32874aea 1154 (*datalen)--;
e5574168 1155 }
4252c9cc 1156
51470298 1157 if (ssh->sccipher)
371e569c 1158 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1159 st->pktin->data, st->cipherblk);
e5574168 1160
1161 /*
1162 * Now get the length and padding figures.
1163 */
ff3187f6 1164 st->len = GET_32BIT(st->pktin->data);
1165 st->pad = st->pktin->data[4];
e5574168 1166
1167 /*
717dc483 1168 * _Completely_ silly lengths should be stomped on before they
1169 * do us any more damage.
1170 */
1171 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
6b5cf8b4 1172 bombout(("Incoming packet was garbled on decryption"));
ff3187f6 1173 ssh_free_packet(st->pktin);
1174 crStop(NULL);
717dc483 1175 }
1176
1177 /*
e5574168 1178 * This enables us to deduce the payload length.
1179 */
960e736a 1180 st->payload = st->len - st->pad - 1;
e5574168 1181
ff3187f6 1182 st->pktin->length = st->payload + 5;
e5574168 1183
1184 /*
1185 * So now we can work out the total packet length.
1186 */
960e736a 1187 st->packetlen = st->len + 4;
51470298 1188 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 1189
1190 /*
ff3187f6 1191 * Allocate memory for the rest of the packet.
e5574168 1192 */
ff3187f6 1193 st->pktin->maxlen = st->packetlen + st->maclen;
1194 st->pktin->data = sresize(st->pktin->data,
1195 st->pktin->maxlen + APIEXTRA,
1196 unsigned char);
e5574168 1197
1198 /*
1199 * Read and decrypt the remainder of the packet.
1200 */
32874aea 1201 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1202 st->i++) {
e5574168 1203 while ((*datalen) == 0)
ff3187f6 1204 crReturn(NULL);
1205 st->pktin->data[st->i] = *(*data)++;
32874aea 1206 (*datalen)--;
e5574168 1207 }
1208 /* Decrypt everything _except_ the MAC. */
51470298 1209 if (ssh->sccipher)
371e569c 1210 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1211 st->pktin->data + st->cipherblk,
51470298 1212 st->packetlen - st->cipherblk);
e5574168 1213
9442dd57 1214 st->pktin->encrypted_len = st->packetlen;
1215
e5574168 1216 /*
1217 * Check the MAC.
1218 */
51470298 1219 if (ssh->scmac
ff3187f6 1220 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
51470298 1221 st->incoming_sequence)) {
6b5cf8b4 1222 bombout(("Incorrect MAC received on packet"));
ff3187f6 1223 ssh_free_packet(st->pktin);
1224 crStop(NULL);
8d5de777 1225 }
b09eaa88 1226
1227 st->pktin->sequence = st->incoming_sequence++;
e5574168 1228
4ba9b64b 1229 /*
1230 * Decompress packet payload.
1231 */
1232 {
1233 unsigned char *newpayload;
1234 int newlen;
51470298 1235 if (ssh->sccomp &&
5366aed8 1236 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1237 st->pktin->data + 5, st->pktin->length - 5,
51470298 1238 &newpayload, &newlen)) {
ff3187f6 1239 if (st->pktin->maxlen < newlen + 5) {
1240 st->pktin->maxlen = newlen + 5;
1241 st->pktin->data = sresize(st->pktin->data,
1242 st->pktin->maxlen + APIEXTRA,
3d88e64d 1243 unsigned char);
4ba9b64b 1244 }
ff3187f6 1245 st->pktin->length = 5 + newlen;
1246 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1247 sfree(newpayload);
4ba9b64b 1248 }
1249 }
1250
ff3187f6 1251 st->pktin->savedpos = 6;
1252 st->pktin->body = st->pktin->data;
1253 st->pktin->type = st->pktin->data[5];
e5574168 1254
9a10ecf4 1255 /*
1256 * Log incoming packet, possibly omitting sensitive fields.
1257 */
1258 if (ssh->logctx) {
1259 int nblanks = 0;
1260 struct logblank_t blank;
1261 if (ssh->cfg.logomitdata) {
1262 int do_blank = FALSE, blank_prefix = 0;
1263 /* "Session data" packets - omit the data field */
ff3187f6 1264 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1265 do_blank = TRUE; blank_prefix = 4;
ff3187f6 1266 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
9a10ecf4 1267 do_blank = TRUE; blank_prefix = 8;
1268 }
1269 if (do_blank) {
1270 blank.offset = blank_prefix;
ff3187f6 1271 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1272 blank.type = PKTLOG_OMIT;
1273 nblanks = 1;
1274 }
1275 }
ff3187f6 1276 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1277 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1278 st->pktin->data+6, st->pktin->length-6,
9a10ecf4 1279 nblanks, &blank);
1280 }
00db133f 1281
ff3187f6 1282 crFinish(st->pktin);
e5574168 1283}
1284
ff3187f6 1285static void ssh1_pktout_size(struct Packet *pkt, int len)
32874aea 1286{
374330e2 1287 int pad, biglen;
1288
1289 len += 5; /* type and CRC */
32874aea 1290 pad = 8 - (len % 8);
374330e2 1291 biglen = len + pad;
1292
ff3187f6 1293 pkt->length = len - 5;
1294 if (pkt->maxlen < biglen) {
1295 pkt->maxlen = biglen;
1296 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
374330e2 1297 }
ff3187f6 1298 pkt->body = pkt->data + 4 + pad + 1;
4ba9b64b 1299}
374330e2 1300
ff3187f6 1301static struct Packet *s_wrpkt_start(int type, int len)
32874aea 1302{
ff3187f6 1303 struct Packet *pkt = ssh_new_packet();
1304 ssh1_pktout_size(pkt, len);
1305 pkt->type = type;
9a10ecf4 1306 /* Initialise log omission state */
ff3187f6 1307 pkt->nblanks = 0;
1308 pkt->blanks = NULL;
1309 return pkt;
374330e2 1310}
1311
ff3187f6 1312static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
32874aea 1313{
fd7a4aad 1314 int pad, biglen, i;
374330e2 1315 unsigned long crc;
fd7a4aad 1316#ifdef __SC__
1317 /*
1318 * XXX various versions of SC (including 8.8.4) screw up the
1319 * register allocation in this function and use the same register
1320 * (D6) for len and as a temporary, with predictable results. The
1321 * following sledgehammer prevents this.
1322 */
1323 volatile
1324#endif
1325 int len;
374330e2 1326
ff3187f6 1327 pkt->body[-1] = pkt->type;
4ba9b64b 1328
a8327734 1329 if (ssh->logctx)
ff3187f6 1330 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1331 ssh1_pkt_type(pkt->type),
1332 pkt->body, pkt->length,
1333 pkt->nblanks, pkt->blanks);
1334 sfree(pkt->blanks); pkt->blanks = NULL;
1335 pkt->nblanks = 0;
00db133f 1336
51470298 1337 if (ssh->v1_compressing) {
4ba9b64b 1338 unsigned char *compblk;
1339 int complen;
5366aed8 1340 zlib_compress_block(ssh->cs_comp_ctx,
ff3187f6 1341 pkt->body - 1, pkt->length + 1,
4ba9b64b 1342 &compblk, &complen);
ff3187f6 1343 ssh1_pktout_size(pkt, complen - 1);
1344 memcpy(pkt->body - 1, compblk, complen);
dcbde236 1345 sfree(compblk);
4ba9b64b 1346 }
1347
ff3187f6 1348 len = pkt->length + 5; /* type and CRC */
32874aea 1349 pad = 8 - (len % 8);
374330e2 1350 biglen = len + pad;
1351
32874aea 1352 for (i = 0; i < pad; i++)
ff3187f6 1353 pkt->data[i + 4] = random_byte();
1354 crc = crc32_compute(pkt->data + 4, biglen - 4);
1355 PUT_32BIT(pkt->data + biglen, crc);
1356 PUT_32BIT(pkt->data, len);
374330e2 1357
51470298 1358 if (ssh->cipher)
ff3187f6 1359 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
374330e2 1360
32874aea 1361 return biglen + 4;
39065bed 1362}
1363
ff3187f6 1364static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1365{
5471d09a 1366 int len, backlog;
ff3187f6 1367 len = s_wrpkt_prepare(ssh, pkt);
1368 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1369 if (backlog > SSH_MAX_BACKLOG)
51470298 1370 ssh_throttle_all(ssh, 1, backlog);
39065bed 1371}
1372
ff3187f6 1373static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1374{
39065bed 1375 int len;
ff3187f6 1376 len = s_wrpkt_prepare(ssh, pkt);
51470298 1377 if (ssh->deferred_len + len > ssh->deferred_size) {
1378 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1379 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1380 ssh->deferred_size,
1381 unsigned char);
39065bed 1382 }
ff3187f6 1383 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1384 ssh->deferred_len += len;
374330e2 1385}
1386
fb09bf1c 1387/*
39065bed 1388 * Construct a packet with the specified contents.
fb09bf1c 1389 */
ff3187f6 1390static struct Packet *construct_packet(Ssh ssh, int pkttype,
1391 va_list ap1, va_list ap2)
fb09bf1c 1392{
fb09bf1c 1393 unsigned char *p, *argp, argchar;
1394 unsigned long argint;
1395 int pktlen, argtype, arglen;
7cca0d81 1396 Bignum bn;
ff3187f6 1397 struct Packet *pkt;
fb09bf1c 1398
1399 pktlen = 0;
39065bed 1400 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1401 switch (argtype) {
1402 case PKT_INT:
39065bed 1403 (void) va_arg(ap1, int);
fb09bf1c 1404 pktlen += 4;
1405 break;
1406 case PKT_CHAR:
1ec39246 1407 (void) va_arg(ap1, int);
fb09bf1c 1408 pktlen++;
1409 break;
1410 case PKT_DATA:
39065bed 1411 (void) va_arg(ap1, unsigned char *);
1412 arglen = va_arg(ap1, int);
fb09bf1c 1413 pktlen += arglen;
1414 break;
1415 case PKT_STR:
39065bed 1416 argp = va_arg(ap1, unsigned char *);
d8baa528 1417 arglen = strlen((char *)argp);
fb09bf1c 1418 pktlen += 4 + arglen;
1419 break;
7cca0d81 1420 case PKT_BIGNUM:
39065bed 1421 bn = va_arg(ap1, Bignum);
32874aea 1422 pktlen += ssh1_bignum_length(bn);
7cca0d81 1423 break;
9a10ecf4 1424 case PKTT_PASSWORD:
1425 case PKTT_DATA:
1426 case PKTT_OTHER:
1427 /* ignore this pass */
1428 break;
fb09bf1c 1429 default:
1430 assert(0);
1431 }
1432 }
fb09bf1c 1433
ff3187f6 1434 pkt = s_wrpkt_start(pkttype, pktlen);
1435 p = pkt->body;
fb09bf1c 1436
39065bed 1437 while ((argtype = va_arg(ap2, int)) != PKT_END) {
ff3187f6 1438 int offset = p - pkt->body, len = 0;
fb09bf1c 1439 switch (argtype) {
9a10ecf4 1440 /* Actual fields in the packet */
fb09bf1c 1441 case PKT_INT:
39065bed 1442 argint = va_arg(ap2, int);
fb09bf1c 1443 PUT_32BIT(p, argint);
9a10ecf4 1444 len = 4;
fb09bf1c 1445 break;
1446 case PKT_CHAR:
1ec39246 1447 argchar = (unsigned char) va_arg(ap2, int);
fb09bf1c 1448 *p = argchar;
9a10ecf4 1449 len = 1;
fb09bf1c 1450 break;
1451 case PKT_DATA:
39065bed 1452 argp = va_arg(ap2, unsigned char *);
1453 arglen = va_arg(ap2, int);
fb09bf1c 1454 memcpy(p, argp, arglen);
9a10ecf4 1455 len = arglen;
fb09bf1c 1456 break;
1457 case PKT_STR:
39065bed 1458 argp = va_arg(ap2, unsigned char *);
d8baa528 1459 arglen = strlen((char *)argp);
fb09bf1c 1460 PUT_32BIT(p, arglen);
1461 memcpy(p + 4, argp, arglen);
9a10ecf4 1462 len = arglen + 4;
fb09bf1c 1463 break;
7cca0d81 1464 case PKT_BIGNUM:
39065bed 1465 bn = va_arg(ap2, Bignum);
9a10ecf4 1466 len = ssh1_write_bignum(p, bn);
1467 break;
1468 /* Tokens for modifications to packet logging */
1469 case PKTT_PASSWORD:
ff3187f6 1470 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1471 break;
1472 case PKTT_DATA:
ff3187f6 1473 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1474 break;
9a10ecf4 1475 case PKTT_OTHER:
ff3187f6 1476 end_log_omission(ssh, pkt);
9a10ecf4 1477 break;
1478 }
1479 p += len;
1480 /* Deal with logfile omission, if required. */
ff3187f6 1481 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1482 pkt->nblanks++;
1483 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1484 struct logblank_t);
1485 pkt->blanks[pkt->nblanks-1].offset = offset;
1486 pkt->blanks[pkt->nblanks-1].len = len;
1487 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
fb09bf1c 1488 }
1489 }
ff3187f6 1490
1491 return pkt;
39065bed 1492}
fb09bf1c 1493
51470298 1494static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1495{
ff3187f6 1496 struct Packet *pkt;
39065bed 1497 va_list ap1, ap2;
1498 va_start(ap1, pkttype);
1499 va_start(ap2, pkttype);
ff3187f6 1500 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1501 va_end(ap2);
1502 va_end(ap1);
1503 s_wrpkt(ssh, pkt);
1504 ssh_free_packet(pkt);
fb09bf1c 1505}
1506
51470298 1507static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1508{
ff3187f6 1509 struct Packet *pkt;
39065bed 1510 va_list ap1, ap2;
1511 va_start(ap1, pkttype);
1512 va_start(ap2, pkttype);
ff3187f6 1513 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1514 va_end(ap2);
1515 va_end(ap1);
1516 s_wrpkt_defer(ssh, pkt);
1517 ssh_free_packet(pkt);
39065bed 1518}
1519
32874aea 1520static int ssh_versioncmp(char *a, char *b)
1521{
9697bfd2 1522 char *ae, *be;
1523 unsigned long av, bv;
1524
43aa02a7 1525 av = strtoul(a, &ae, 10);
1526 bv = strtoul(b, &be, 10);
32874aea 1527 if (av != bv)
1528 return (av < bv ? -1 : +1);
1529 if (*ae == '.')
1530 ae++;
1531 if (*be == '.')
1532 be++;
43aa02a7 1533 av = strtoul(ae, &ae, 10);
1534 bv = strtoul(be, &be, 10);
32874aea 1535 if (av != bv)
1536 return (av < bv ? -1 : +1);
9697bfd2 1537 return 0;
1538}
1539
e5574168 1540/*
a92dd380 1541 * Utility routines for putting an SSH-protocol `string' and
1542 * `uint32' into a SHA state.
e5574168 1543 */
1544#include <stdio.h>
32874aea 1545static void sha_string(SHA_State * s, void *str, int len)
1546{
e5574168 1547 unsigned char lenblk[4];
e5574168 1548 PUT_32BIT(lenblk, len);
e5574168 1549 SHA_Bytes(s, lenblk, 4);
e5574168 1550 SHA_Bytes(s, str, len);
1551}
1552
32874aea 1553static void sha_uint32(SHA_State * s, unsigned i)
1554{
a92dd380 1555 unsigned char intblk[4];
1556 PUT_32BIT(intblk, i);
1557 SHA_Bytes(s, intblk, 4);
1558}
1559
7cca0d81 1560/*
1561 * SSH2 packet construction functions.
1562 */
ff3187f6 1563static void ssh2_pkt_ensure(struct Packet *pkt, int length)
32874aea 1564{
ff3187f6 1565 if (pkt->maxlen < length) {
1566 pkt->maxlen = length + 256;
1567 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
7cca0d81 1568 }
783415f8 1569}
ff3187f6 1570static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1571{
ff3187f6 1572 if (pkt->logmode != PKTLOG_EMIT) {
1573 pkt->nblanks++;
1574 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1575 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1576 pkt->blanks[pkt->nblanks-1].len = len;
1577 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1578 }
1579 pkt->length += len;
1580 ssh2_pkt_ensure(pkt, pkt->length);
1581 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1582}
ff3187f6 1583static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1584{
ff3187f6 1585 ssh2_pkt_adddata(pkt, &byte, 1);
7cca0d81 1586}
ff3187f6 1587static struct Packet *ssh2_pkt_init(int pkt_type)
32874aea 1588{
ff3187f6 1589 struct Packet *pkt = ssh_new_packet();
1590 pkt->length = 5;
95d2d262 1591 pkt->forcepad = 0;
ff3187f6 1592 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1593 return pkt;
7cca0d81 1594}
ff3187f6 1595static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1596{
ff3187f6 1597 ssh2_pkt_adddata(pkt, &value, 1);
7cca0d81 1598}
ff3187f6 1599static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1600{
7cca0d81 1601 unsigned char x[4];
1602 PUT_32BIT(x, value);
ff3187f6 1603 ssh2_pkt_adddata(pkt, x, 4);
7cca0d81 1604}
ff3187f6 1605static void ssh2_pkt_addstring_start(struct Packet *pkt)
32874aea 1606{
ff3187f6 1607 ssh2_pkt_adduint32(pkt, 0);
1608 pkt->savedpos = pkt->length;
7cca0d81 1609}
ff3187f6 1610static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1611{
ff3187f6 1612 ssh2_pkt_adddata(pkt, data, strlen(data));
1613 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1614}
ff3187f6 1615static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1616{
ff3187f6 1617 ssh2_pkt_adddata(pkt, data, len);
1618 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1619}
ff3187f6 1620static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
32874aea 1621{
ff3187f6 1622 ssh2_pkt_addstring_start(pkt);
1623 ssh2_pkt_addstring_str(pkt, data);
7cca0d81 1624}
d8baa528 1625static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1626{
7cca0d81 1627 unsigned char *p;
32874aea 1628 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1629 p = snewn(n + 1, unsigned char);
7cca0d81 1630 if (!p)
32874aea 1631 fatalbox("out of memory");
7cca0d81 1632 p[0] = 0;
3709bfe9 1633 for (i = 1; i <= n; i++)
32874aea 1634 p[i] = bignum_byte(b, n - i);
7cca0d81 1635 i = 0;
32874aea 1636 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1637 i++;
1638 memmove(p, p + i, n + 1 - i);
1639 *len = n + 1 - i;
7cca0d81 1640 return p;
1641}
ff3187f6 1642static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1643{
7cca0d81 1644 unsigned char *p;
1645 int len;
1646 p = ssh2_mpint_fmt(b, &len);
ff3187f6 1647 ssh2_pkt_addstring_start(pkt);
1648 ssh2_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1649 sfree(p);
7cca0d81 1650}
b185170a 1651
1652/*
1653 * Construct an SSH2 final-form packet: compress it, encrypt it,
1654 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1655 * pkt->data. Total length is returned.
b185170a 1656 */
ff3187f6 1657static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1658{
7cca0d81 1659 int cipherblk, maclen, padding, i;
7cca0d81 1660
a8327734 1661 if (ssh->logctx)
ff3187f6 1662 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1663 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1664 pkt->data + 6, pkt->length - 6,
1665 pkt->nblanks, pkt->blanks);
1666 sfree(pkt->blanks); pkt->blanks = NULL;
1667 pkt->nblanks = 0;
00db133f 1668
7cca0d81 1669 /*
4ba9b64b 1670 * Compress packet payload.
1671 */
4ba9b64b 1672 {
1673 unsigned char *newpayload;
1674 int newlen;
51470298 1675 if (ssh->cscomp &&
ff3187f6 1676 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1677 pkt->length - 5,
51470298 1678 &newpayload, &newlen)) {
ff3187f6 1679 pkt->length = 5;
1680 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1681 sfree(newpayload);
4ba9b64b 1682 }
1683 }
1684
1685 /*
7cca0d81 1686 * Add padding. At least four bytes, and must also bring total
1687 * length (minus MAC) up to a multiple of the block size.
95d2d262 1688 * If pkt->forcepad is set, make sure the packet is at least that size
1689 * after padding.
7cca0d81 1690 */
51470298 1691 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1692 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1693 padding = 4;
95d2d262 1694 if (pkt->length + padding < pkt->forcepad)
1695 padding = pkt->forcepad - pkt->length;
32874aea 1696 padding +=
ff3187f6 1697 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
95d2d262 1698 assert(padding <= 255);
51470298 1699 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1700 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1701 pkt->data[4] = padding;
7cca0d81 1702 for (i = 0; i < padding; i++)
ff3187f6 1703 pkt->data[pkt->length + i] = random_byte();
1704 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1705 if (ssh->csmac)
ff3187f6 1706 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1707 pkt->length + padding,
51470298 1708 ssh->v2_outgoing_sequence);
1709 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1710
1711 if (ssh->cscipher)
371e569c 1712 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 1713 pkt->data, pkt->length + padding);
51470298 1714
9442dd57 1715 pkt->encrypted_len = pkt->length + padding;
1716
ff3187f6 1717 /* Ready-to-send packet starts at pkt->data. We return length. */
1718 return pkt->length + padding + maclen;
b185170a 1719}
1720
1721/*
590f6a5f 1722 * Routines called from the main SSH code to send packets. There
1723 * are quite a few of these, because we have two separate
1724 * mechanisms for delaying the sending of packets:
1725 *
1726 * - In order to send an IGNORE message and a password message in
1727 * a single fixed-length blob, we require the ability to
1728 * concatenate the encrypted forms of those two packets _into_ a
1729 * single blob and then pass it to our <network.h> transport
1730 * layer in one go. Hence, there's a deferment mechanism which
1731 * works after packet encryption.
1732 *
1733 * - In order to avoid sending any connection-layer messages
1734 * during repeat key exchange, we have to queue up any such
1735 * outgoing messages _before_ they are encrypted (and in
1736 * particular before they're allocated sequence numbers), and
1737 * then send them once we've finished.
1738 *
1739 * I call these mechanisms `defer' and `queue' respectively, so as
1740 * to distinguish them reasonably easily.
1741 *
1742 * The functions send_noqueue() and defer_noqueue() free the packet
1743 * structure they are passed. Every outgoing packet goes through
1744 * precisely one of these functions in its life; packets passed to
1745 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1746 * these or get queued, and then when the queue is later emptied
1747 * the packets are all passed to defer_noqueue().
b185170a 1748 */
590f6a5f 1749
1750/*
1751 * Send an SSH2 packet immediately, without queuing or deferring.
1752 */
1753static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1754{
5471d09a 1755 int len;
1756 int backlog;
ff3187f6 1757 len = ssh2_pkt_construct(ssh, pkt);
1758 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1759 if (backlog > SSH_MAX_BACKLOG)
51470298 1760 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1761
1762 ssh->outgoing_data_size += pkt->encrypted_len;
1763 if (!ssh->kex_in_progress &&
d57f70af 1764 ssh->max_data_size != 0 &&
1765 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 1766 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 1767
ff3187f6 1768 ssh_free_packet(pkt);
b185170a 1769}
1770
1771/*
590f6a5f 1772 * Defer an SSH2 packet.
b185170a 1773 */
590f6a5f 1774static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1775{
ff3187f6 1776 int len = ssh2_pkt_construct(ssh, pkt);
51470298 1777 if (ssh->deferred_len + len > ssh->deferred_size) {
1778 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1779 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1780 ssh->deferred_size,
1781 unsigned char);
b185170a 1782 }
ff3187f6 1783 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1784 ssh->deferred_len += len;
9442dd57 1785 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 1786 ssh_free_packet(pkt);
b185170a 1787}
1788
1789/*
590f6a5f 1790 * Queue an SSH2 packet.
1791 */
1792static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1793{
1794 assert(ssh->queueing);
1795
1796 if (ssh->queuelen >= ssh->queuesize) {
1797 ssh->queuesize = ssh->queuelen + 32;
1798 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1799 }
1800
1801 ssh->queue[ssh->queuelen++] = pkt;
1802}
1803
1804/*
1805 * Either queue or send a packet, depending on whether queueing is
1806 * set.
1807 */
1808static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1809{
1810 if (ssh->queueing)
1811 ssh2_pkt_queue(ssh, pkt);
1812 else
1813 ssh2_pkt_send_noqueue(ssh, pkt);
1814}
1815
95d2d262 1816#if 0 /* disused */
590f6a5f 1817/*
1818 * Either queue or defer a packet, depending on whether queueing is
1819 * set.
1820 */
1821static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1822{
1823 if (ssh->queueing)
1824 ssh2_pkt_queue(ssh, pkt);
1825 else
1826 ssh2_pkt_defer_noqueue(ssh, pkt);
1827}
95d2d262 1828#endif
590f6a5f 1829
1830/*
b185170a 1831 * Send the whole deferred data block constructed by
39065bed 1832 * ssh2_pkt_defer() or SSH1's defer_packet().
590f6a5f 1833 *
1834 * The expected use of the defer mechanism is that you call
1835 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1836 * not currently queueing, this simply sets up deferred_send_data
1837 * and then sends it. If we _are_ currently queueing, the calls to
1838 * ssh2_pkt_defer() put the deferred packets on to the queue
1839 * instead, and therefore ssh_pkt_defersend() has no deferred data
1840 * to send. Hence, there's no need to make it conditional on
1841 * ssh->queueing.
b185170a 1842 */
51470298 1843static void ssh_pkt_defersend(Ssh ssh)
32874aea 1844{
5471d09a 1845 int backlog;
d8baa528 1846 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1847 ssh->deferred_len);
51470298 1848 ssh->deferred_len = ssh->deferred_size = 0;
1849 sfree(ssh->deferred_send_data);
1850 ssh->deferred_send_data = NULL;
5471d09a 1851 if (backlog > SSH_MAX_BACKLOG)
51470298 1852 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1853
1854 ssh->outgoing_data_size += ssh->deferred_data_size;
1855 if (!ssh->kex_in_progress &&
d57f70af 1856 ssh->max_data_size != 0 &&
1857 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 1858 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 1859 ssh->deferred_data_size = 0;
7cca0d81 1860}
1861
590f6a5f 1862/*
1863 * Send all queued SSH2 packets. We send them by means of
1864 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1865 * packets that needed to be lumped together.
1866 */
1867static void ssh2_pkt_queuesend(Ssh ssh)
1868{
1869 int i;
1870
1871 assert(!ssh->queueing);
1872
1873 for (i = 0; i < ssh->queuelen; i++)
1874 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1875 ssh->queuelen = 0;
1876
1877 ssh_pkt_defersend(ssh);
1878}
1879
7cca0d81 1880#if 0
32874aea 1881void bndebug(char *string, Bignum b)
1882{
7cca0d81 1883 unsigned char *p;
1884 int i, len;
1885 p = ssh2_mpint_fmt(b, &len);
1886 debug(("%s", string));
1887 for (i = 0; i < len; i++)
32874aea 1888 debug((" %02x", p[i]));
765c4200 1889 debug(("\n"));
dcbde236 1890 sfree(p);
7cca0d81 1891}
1892#endif
1893
32874aea 1894static void sha_mpint(SHA_State * s, Bignum b)
1895{
7cca0d81 1896 unsigned char *p;
1897 int len;
1898 p = ssh2_mpint_fmt(b, &len);
1899 sha_string(s, p, len);
dcbde236 1900 sfree(p);
7cca0d81 1901}
1902
1903/*
0016d70b 1904 * Packet decode functions for both SSH1 and SSH2.
7cca0d81 1905 */
ff3187f6 1906static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 1907{
7cca0d81 1908 unsigned long value;
ff3187f6 1909 if (pkt->length - pkt->savedpos < 4)
32874aea 1910 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1911 value = GET_32BIT(pkt->body + pkt->savedpos);
1912 pkt->savedpos += 4;
7cca0d81 1913 return value;
1914}
ff3187f6 1915static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 1916{
65a22376 1917 unsigned long value;
ff3187f6 1918 if (pkt->length - pkt->savedpos < 1)
32874aea 1919 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1920 value = pkt->body[pkt->savedpos] != 0;
1921 pkt->savedpos++;
65a22376 1922 return value;
1923}
ff3187f6 1924static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 1925{
57356d63 1926 int len;
7cca0d81 1927 *p = NULL;
45068b27 1928 *length = 0;
ff3187f6 1929 if (pkt->length - pkt->savedpos < 4)
32874aea 1930 return;
ff3187f6 1931 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 1932 if (len < 0)
1933 return;
1934 *length = len;
ff3187f6 1935 pkt->savedpos += 4;
1936 if (pkt->length - pkt->savedpos < *length)
32874aea 1937 return;
ff3187f6 1938 *p = (char *)(pkt->body + pkt->savedpos);
1939 pkt->savedpos += *length;
7cca0d81 1940}
ff3187f6 1941static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 1942{
ff3187f6 1943 if (pkt->length - pkt->savedpos < length)
0016d70b 1944 return NULL;
ff3187f6 1945 pkt->savedpos += length;
1946 return pkt->body + (pkt->savedpos - length);
0016d70b 1947}
ff3187f6 1948static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 1949 unsigned char **keystr)
1950{
1951 int j;
1952
ff3187f6 1953 j = makekey(pkt->body + pkt->savedpos,
1954 pkt->length - pkt->savedpos,
0016d70b 1955 key, keystr, 0);
1956
1957 if (j < 0)
1958 return FALSE;
1959
ff3187f6 1960 pkt->savedpos += j;
1961 assert(pkt->savedpos < pkt->length);
0016d70b 1962
1963 return TRUE;
1964}
ff3187f6 1965static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 1966{
1967 int j;
1968 Bignum b;
1969
ff3187f6 1970 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1971 pkt->length - pkt->savedpos, &b);
0016d70b 1972
1973 if (j < 0)
1974 return NULL;
1975
ff3187f6 1976 pkt->savedpos += j;
0016d70b 1977 return b;
1978}
ff3187f6 1979static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 1980{
7cca0d81 1981 char *p;
3709bfe9 1982 int length;
7cca0d81 1983 Bignum b;
1984
ff3187f6 1985 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 1986 if (!p)
32874aea 1987 return NULL;
ff3187f6 1988 if (p[0] & 0x80)
32874aea 1989 return NULL;
d8baa528 1990 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1991 return b;
1992}
1993
7d503c31 1994/*
1dd353b5 1995 * Helper function to add an SSH2 signature blob to a packet.
1996 * Expects to be shown the public key blob as well as the signature
1997 * blob. Normally works just like ssh2_pkt_addstring, but will
1998 * fiddle with the signature packet if necessary for
1999 * BUG_SSH2_RSA_PADDING.
2000 */
ff3187f6 2001static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2002 void *pkblob_v, int pkblob_len,
1dd353b5 2003 void *sigblob_v, int sigblob_len)
2004{
2005 unsigned char *pkblob = (unsigned char *)pkblob_v;
2006 unsigned char *sigblob = (unsigned char *)sigblob_v;
2007
2008 /* dmemdump(pkblob, pkblob_len); */
2009 /* dmemdump(sigblob, sigblob_len); */
2010
2011 /*
2012 * See if this is in fact an ssh-rsa signature and a buggy
2013 * server; otherwise we can just do this the easy way.
2014 */
51470298 2015 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 2016 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2017 int pos, len, siglen;
2018
2019 /*
2020 * Find the byte length of the modulus.
2021 */
2022
2023 pos = 4+7; /* skip over "ssh-rsa" */
2024 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2025 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2026 pos += 4; /* find modulus itself */
2027 while (len > 0 && pkblob[pos] == 0)
2028 len--, pos++;
2029 /* debug(("modulus length is %d\n", len)); */
2030
2031 /*
2032 * Now find the signature integer.
2033 */
2034 pos = 4+7; /* skip over "ssh-rsa" */
2035 siglen = GET_32BIT(sigblob+pos);
2036 /* debug(("signature length is %d\n", siglen)); */
2037
2038 if (len != siglen) {
2039 unsigned char newlen[4];
ff3187f6 2040 ssh2_pkt_addstring_start(pkt);
2041 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2042 /* dmemdump(sigblob, pos); */
2043 pos += 4; /* point to start of actual sig */
2044 PUT_32BIT(newlen, len);
ff3187f6 2045 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2046 /* dmemdump(newlen, 4); */
2047 newlen[0] = 0;
2048 while (len-- > siglen) {
ff3187f6 2049 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2050 /* dmemdump(newlen, 1); */
2051 }
ff3187f6 2052 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2053 /* dmemdump(sigblob+pos, siglen); */
2054 return;
2055 }
2056
2057 /* Otherwise fall through and do it the easy way. */
2058 }
2059
ff3187f6 2060 ssh2_pkt_addstring_start(pkt);
2061 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2062}
2063
2064/*
7d503c31 2065 * Examine the remote side's version string and compare it against
2066 * a list of known buggy implementations.
2067 */
51470298 2068static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2069{
2070 char *imp; /* pointer to implementation part */
7d503c31 2071 imp = vstring;
2072 imp += strcspn(imp, "-");
bd358db1 2073 if (*imp) imp++;
7d503c31 2074 imp += strcspn(imp, "-");
bd358db1 2075 if (*imp) imp++;
7d503c31 2076
51470298 2077 ssh->remote_bugs = 0;
7d503c31 2078
5ecd7ad0 2079 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2080 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 2081 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2082 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2083 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2084 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2085 /*
2086 * These versions don't support SSH1_MSG_IGNORE, so we have
2087 * to use a different defence against password length
2088 * sniffing.
2089 */
51470298 2090 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 2091 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 2092 }
2093
5ecd7ad0 2094 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2095 (ssh->cfg.sshbug_plainpw1 == AUTO &&
46ac09aa 2096 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2097 /*
2098 * These versions need a plain password sent; they can't
2099 * handle having a null and a random length of data after
2100 * the password.
2101 */
51470298 2102 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 2103 logevent("We believe remote version needs a plain SSH1 password");
2104 }
2105
5ecd7ad0 2106 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2107 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 2108 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2109 /*
2110 * These versions apparently have no clue whatever about
2111 * RSA authentication and will panic and die if they see
2112 * an AUTH_RSA message.
2113 */
51470298 2114 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 2115 logevent("We believe remote version can't handle RSA authentication");
2116 }
2117
5ecd7ad0 2118 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2119 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 2120 !wc_match("* VShell", imp) &&
831301f6 2121 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2122 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2123 wc_match("2.1 *", imp)))) {
32874aea 2124 /*
2125 * These versions have the HMAC bug.
2126 */
51470298 2127 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 2128 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 2129 }
1dd353b5 2130
5ecd7ad0 2131 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2132 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 2133 !wc_match("* VShell", imp) &&
2856a1b9 2134 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2135 /*
2136 * These versions have the key-derivation bug (failing to
2137 * include the literal shared secret in the hashes that
2138 * generate the keys).
2139 */
51470298 2140 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 2141 logevent("We believe remote version has SSH2 key-derivation bug");
2142 }
2143
5ecd7ad0 2144 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2145 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 2146 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2147 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2148 /*
2149 * These versions have the SSH2 RSA padding bug.
2150 */
51470298 2151 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 2152 logevent("We believe remote version has SSH2 RSA padding bug");
2153 }
8e975795 2154
dda87a28 2155 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2156 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2157 wc_match("OpenSSH_2.[0-2]*", imp))) {
2158 /*
2159 * These versions have the SSH2 session-ID bug in
2160 * public-key authentication.
2161 */
2162 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2163 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2164 }
f382c87d 2165
2166 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2167 (ssh->cfg.sshbug_rekey2 == AUTO &&
e12d95a5 2168 (wc_match("OpenSSH_2.[0-4]*", imp) ||
2169 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2170 wc_match("Sun_SSH_1.0", imp) ||
7cb41bb2 2171 wc_match("Sun_SSH_1.0.1", imp)))) {
f382c87d 2172 /*
e12d95a5 2173 * These versions have the SSH2 rekey bug.
f382c87d 2174 */
2175 ssh->remote_bugs |= BUG_SSH2_REKEY;
e12d95a5 2176 logevent("We believe remote version has SSH2 rekey bug");
f382c87d 2177 }
7d503c31 2178}
2179
d38d6a1f 2180/*
2181 * The `software version' part of an SSH version string is required
2182 * to contain no spaces or minus signs.
2183 */
2184static void ssh_fix_verstring(char *str)
2185{
2186 /* Eat "SSH-<protoversion>-". */
2187 assert(*str == 'S'); str++;
2188 assert(*str == 'S'); str++;
2189 assert(*str == 'H'); str++;
2190 assert(*str == '-'); str++;
2191 while (*str && *str != '-') str++;
2192 assert(*str == '-'); str++;
2193
2194 /* Convert minus signs and spaces in the remaining string into
2195 * underscores. */
2196 while (*str) {
2197 if (*str == '-' || *str == ' ')
2198 *str = '_';
2199 str++;
2200 }
2201}
2202
51470298 2203static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2204{
51470298 2205 struct do_ssh_init_state {
2206 int vslen;
2207 char version[10];
2208 char *vstring;
2209 int vstrsize;
2210 int i;
2211 int proto1, proto2;
2212 };
2213 crState(do_ssh_init_state);
374330e2 2214
51470298 2215 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2216
2217 /* Search for the string "SSH-" in the input. */
51470298 2218 s->i = 0;
8df7a775 2219 while (1) {
2220 static const int transS[] = { 1, 2, 2, 1 };
2221 static const int transH[] = { 0, 0, 3, 0 };
2222 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 2223 if (c == 'S')
51470298 2224 s->i = transS[s->i];
32874aea 2225 else if (c == 'H')
51470298 2226 s->i = transH[s->i];
32874aea 2227 else if (c == '-')
51470298 2228 s->i = transminus[s->i];
32874aea 2229 else
51470298 2230 s->i = 0;
2231 if (s->i < 0)
8df7a775 2232 break;
2233 crReturn(1); /* get another character */
374330e2 2234 }
8df7a775 2235
51470298 2236 s->vstrsize = 16;
3d88e64d 2237 s->vstring = snewn(s->vstrsize, char);
51470298 2238 strcpy(s->vstring, "SSH-");
2239 s->vslen = 4;
2240 s->i = 0;
374330e2 2241 while (1) {
8df7a775 2242 crReturn(1); /* get another char */
51470298 2243 if (s->vslen >= s->vstrsize - 1) {
2244 s->vstrsize += 16;
3d88e64d 2245 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2246 }
51470298 2247 s->vstring[s->vslen++] = c;
2248 if (s->i >= 0) {
374330e2 2249 if (c == '-') {
51470298 2250 s->version[s->i] = '\0';
2251 s->i = -1;
2252 } else if (s->i < sizeof(s->version) - 1)
2253 s->version[s->i++] = c;
c4ffc4d0 2254 } else if (c == '\012')
374330e2 2255 break;
2256 }
2257
51470298 2258 ssh->agentfwd_enabled = FALSE;
2259 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2260
51470298 2261 s->vstring[s->vslen] = 0;
a7d4653a 2262 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
fb983202 2263 logeventf(ssh, "Server version: %s", s->vstring);
51470298 2264 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2265
adf799dd 2266 /*
38d228a2 2267 * Decide which SSH protocol version to support.
adf799dd 2268 */
38d228a2 2269
2270 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2271 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2272 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2273 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2274
86916870 2275 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2276 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2277 crStop(0);
38d228a2 2278 }
86916870 2279 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2280 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2281 crStop(0);
38d228a2 2282 }
2283
d38d6a1f 2284 {
2285 char *verstring;
2286
2287 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2288 /*
2289 * Construct a v2 version string.
2290 */
a7d4653a 2291 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
d38d6a1f 2292 ssh->version = 2;
2293 } else {
2294 /*
2295 * Construct a v1 version string.
2296 */
a7d4653a 2297 verstring = dupprintf("SSH-%s-%s\012",
d38d6a1f 2298 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2299 s->version : "1.5"),
2300 sshver);
2301 ssh->version = 1;
2302 }
2303
2304 ssh_fix_verstring(verstring);
2305
2306 if (ssh->version == 2) {
2307 /*
2308 * Hash our version string and their version string.
2309 */
2310 SHA_Init(&ssh->exhashbase);
0b351b6b 2311 sha_string(&ssh->exhashbase, verstring,
a7d4653a 2312 strcspn(verstring, "\015\012"));
0b351b6b 2313 sha_string(&ssh->exhashbase, s->vstring,
a7d4653a 2314 strcspn(s->vstring, "\015\012"));
d38d6a1f 2315
2316 /*
2317 * Initialise SSHv2 protocol.
2318 */
2319 ssh->protocol = ssh2_protocol;
2320 ssh2_protocol_setup(ssh);
2321 ssh->s_rdpkt = ssh2_rdpkt;
2322 } else {
2323 /*
2324 * Initialise SSHv1 protocol.
2325 */
2326 ssh->protocol = ssh1_protocol;
2327 ssh1_protocol_setup(ssh);
2328 ssh->s_rdpkt = ssh1_rdpkt;
2329 }
2330 logeventf(ssh, "We claim version: %.*s",
a7d4653a 2331 strcspn(verstring, "\015\012"), verstring);
51470298 2332 sk_write(ssh->s, verstring, strlen(verstring));
d38d6a1f 2333 sfree(verstring);
e5574168 2334 }
d38d6a1f 2335
2336 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2337
125105d1 2338 update_specials_menu(ssh->frontend);
51470298 2339 ssh->state = SSH_STATE_BEFORE_SIZE;
39934deb 2340 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
8df7a775 2341
51470298 2342 sfree(s->vstring);
50526e47 2343
8df7a775 2344 crFinish(0);
2345}
2346
3d9449a1 2347static void ssh_process_incoming_data(Ssh ssh,
2348 unsigned char **data, int *datalen)
2349{
2350 struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen);
2351 if (pktin) {
2352 ssh->protocol(ssh, NULL, 0, pktin);
2353 ssh_free_packet(pktin);
2354 }
2355}
2356
2357static void ssh_queue_incoming_data(Ssh ssh,
2358 unsigned char **data, int *datalen)
2359{
2360 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2361 *data += *datalen;
2362 *datalen = 0;
2363}
2364
2365static void ssh_process_queued_incoming_data(Ssh ssh)
2366{
2367 void *vdata;
2368 unsigned char *data;
2369 int len, origlen;
2370
2371 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2372 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2373 data = vdata;
2374 origlen = len;
2375
2376 while (!ssh->frozen && len > 0)
2377 ssh_process_incoming_data(ssh, &data, &len);
2378
2379 if (origlen > len)
2380 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2381 }
2382}
2383
2384static void ssh_set_frozen(Ssh ssh, int frozen)
2385{
a5a6f839 2386 if (ssh->s)
2387 sk_set_frozen(ssh->s, frozen);
3d9449a1 2388 ssh->frozen = frozen;
2389}
2390
51470298 2391static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2392{
51470298 2393 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2394
2395 /*
2396 * To begin with, feed the characters one by one to the
2397 * protocol initialisation / selection function do_ssh_init().
2398 * When that returns 0, we're done with the initial greeting
2399 * exchange and can move on to packet discipline.
2400 */
2401 while (1) {
51470298 2402 int ret; /* need not be kept across crReturn */
8df7a775 2403 if (datalen == 0)
2404 crReturnV; /* more data please */
51470298 2405 ret = do_ssh_init(ssh, *data);
32874aea 2406 data++;
2407 datalen--;
8df7a775 2408 if (ret == 0)
2409 break;
2410 }
2411
2412 /*
2413 * We emerge from that loop when the initial negotiation is
2414 * over and we have selected an s_rdpkt function. Now pass
2415 * everything to s_rdpkt, and then pass the resulting packets
2416 * to the proper protocol handler.
2417 */
2418 if (datalen == 0)
2419 crReturnV;
3d9449a1 2420
2421 /*
2422 * Process queued data if there is any.
2423 */
2424 ssh_process_queued_incoming_data(ssh);
2425
8df7a775 2426 while (1) {
2427 while (datalen > 0) {
3d9449a1 2428 if (ssh->frozen)
2429 ssh_queue_incoming_data(ssh, &data, &datalen);
2430
2431 ssh_process_incoming_data(ssh, &data, &datalen);
2432
ff3187f6 2433 if (ssh->state == SSH_STATE_CLOSED)
2434 return;
8df7a775 2435 }
2436 crReturnV;
2437 }
2438 crFinishV;
2439}
2440
ac934965 2441static int ssh_do_close(Ssh ssh, int notify_exit)
32874aea 2442{
80ffa58b 2443 int ret = 0;
36f94d1f 2444 struct ssh_channel *c;
2445
51470298 2446 ssh->state = SSH_STATE_CLOSED;
2447 if (ssh->s) {
2448 sk_close(ssh->s);
2449 ssh->s = NULL;
ac934965 2450 if (notify_exit)
2451 notify_remote_exit(ssh->frontend);
2452 else
2453 ret = 1;
f3ab576e 2454 }
36f94d1f 2455 /*
80ffa58b 2456 * Now we must shut down any port- and X-forwarded channels going
36f94d1f 2457 * through this connection.
2458 */
74a98066 2459 if (ssh->channels) {
80ffa58b 2460 while (NULL != (c = index234(ssh->channels, 0))) {
74a98066 2461 switch (c->type) {
2462 case CHAN_X11:
2463 x11_close(c->u.x11.s);
2464 break;
2465 case CHAN_SOCKDATA:
2466 pfd_close(c->u.pfd.s);
2467 break;
2468 }
80ffa58b 2469 del234(ssh->channels, c); /* moving next one to index 0 */
74a98066 2470 if (ssh->version == 2)
2471 bufchain_clear(&c->v.v2.outbuffer);
2472 sfree(c);
36f94d1f 2473 }
36f94d1f 2474 }
f8c9f9df 2475 /*
2476 * Go through port-forwardings, and close any associated
2477 * listening sockets.
2478 */
2479 if (ssh->portfwds) {
2480 struct ssh_portfwd *pf;
2481 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2482 /* Dispose of any listening socket. */
2483 if (pf->local)
2484 pfd_terminate(pf->local);
2485 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2486 free_portfwd(pf);
2487 }
2488 }
ac934965 2489
2490 return ret;
36f94d1f 2491}
2492
7555d6a5 2493static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2494 const char *error_msg, int error_code)
2495{
2496 Ssh ssh = (Ssh) plug;
2497 char addrbuf[256], *msg;
2498
2499 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2500
2501 if (type == 0)
2502 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2503 else
2504 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2505
2506 logevent(msg);
fb983202 2507 sfree(msg);
7555d6a5 2508}
2509
cbe2d68f 2510static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2511 int calling_back)
2512{
2513 Ssh ssh = (Ssh) plug;
ac934965 2514 int need_notify = ssh_do_close(ssh, FALSE);
2515
2516 if (!error_msg && !ssh->close_expected) {
2517 error_msg = "Server unexpectedly closed network connection";
2518 }
2519
7e78000d 2520 if (error_msg) {
32874aea 2521 /* A socket error has occurred. */
247308b5 2522 logevent(error_msg);
971bcc0a 2523 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2524 } else {
ac934965 2525 logevent("Server closed network connection");
8df7a775 2526 }
ac934965 2527 if (need_notify)
2528 notify_remote_exit(ssh->frontend);
7e78000d 2529 return 0;
2530}
2531
32874aea 2532static int ssh_receive(Plug plug, int urgent, char *data, int len)
2533{
51470298 2534 Ssh ssh = (Ssh) plug;
d8baa528 2535 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2536 if (ssh->state == SSH_STATE_CLOSED) {
ac934965 2537 ssh_do_close(ssh, TRUE);
32874aea 2538 return 0;
3257deae 2539 }
fef97f43 2540 return 1;
374330e2 2541}
2542
5471d09a 2543static void ssh_sent(Plug plug, int bufsize)
2544{
51470298 2545 Ssh ssh = (Ssh) plug;
5471d09a 2546 /*
2547 * If the send backlog on the SSH socket itself clears, we
2548 * should unthrottle the whole world if it was throttled.
2549 */
2550 if (bufsize < SSH_MAX_BACKLOG)
51470298 2551 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2552}
2553
fb09bf1c 2554/*
8df7a775 2555 * Connect to specified host and port.
2556 * Returns an error message, or NULL on success.
6e1ebb76 2557 * Also places the canonical host name into `realhost'. It must be
2558 * freed by the caller.
8df7a775 2559 */
cbe2d68f 2560static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2561 char **realhost, int nodelay, int keepalive)
8df7a775 2562{
51470298 2563 static const struct plug_function_table fn_table = {
7555d6a5 2564 ssh_log,
7e78000d 2565 ssh_closing,
5471d09a 2566 ssh_receive,
2567 ssh_sent,
2568 NULL
51470298 2569 };
7e78000d 2570
8df7a775 2571 SockAddr addr;
cbe2d68f 2572 const char *err;
8df7a775 2573
3d88e64d 2574 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2575 if (!ssh->savedhost)
8df7a775 2576 fatalbox("Out of memory");
51470298 2577 strcpy(ssh->savedhost, host);
8df7a775 2578
2579 if (port < 0)
2580 port = 22; /* default ssh port */
51470298 2581 ssh->savedport = port;
8df7a775 2582
2583 /*
2584 * Try to find host.
2585 */
05581745 2586 logeventf(ssh, "Looking up host \"%s\"%s", host,
2587 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2588 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2589 addr = name_lookup(host, port, realhost, &ssh->cfg,
2590 ssh->cfg.addressfamily);
170c1e6e 2591 if ((err = sk_addr_error(addr)) != NULL) {
2592 sk_addr_free(addr);
8df7a775 2593 return err;
170c1e6e 2594 }
8df7a775 2595
8df7a775 2596 /*
2597 * Open socket.
2598 */
51470298 2599 ssh->fn = &fn_table;
e8fa8f62 2600 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2601 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2602 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2603 ssh->s = NULL;
39934deb 2604 notify_remote_exit(ssh->frontend);
8df7a775 2605 return err;
67c4ba2e 2606 }
8df7a775 2607
8df7a775 2608 return NULL;
2609}
2610
2611/*
5471d09a 2612 * Throttle or unthrottle the SSH connection.
2613 */
51470298 2614static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2615{
51470298 2616 int old_count = ssh->v1_throttle_count;
2617 ssh->v1_throttle_count += adjust;
2618 assert(ssh->v1_throttle_count >= 0);
2619 if (ssh->v1_throttle_count && !old_count) {
3d9449a1 2620 ssh_set_frozen(ssh, 1);
51470298 2621 } else if (!ssh->v1_throttle_count && old_count) {
3d9449a1 2622 ssh_set_frozen(ssh, 0);
5471d09a 2623 }
2624}
2625
2626/*
2627 * Throttle or unthrottle _all_ local data streams (for when sends
2628 * on the SSH connection itself back up).
2629 */
51470298 2630static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2631{
2632 int i;
2633 struct ssh_channel *c;
2634
51470298 2635 if (enable == ssh->throttled_all)
5471d09a 2636 return;
51470298 2637 ssh->throttled_all = enable;
2638 ssh->overall_bufsize = bufsize;
2639 if (!ssh->channels)
5471d09a 2640 return;
51470298 2641 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2642 switch (c->type) {
2643 case CHAN_MAINSESSION:
2644 /*
2645 * This is treated separately, outside the switch.
2646 */
2647 break;
2648 case CHAN_X11:
2649 x11_override_throttle(c->u.x11.s, enable);
2650 break;
2651 case CHAN_AGENT:
2652 /* Agent channels require no buffer management. */
2653 break;
2654 case CHAN_SOCKDATA:
36f94d1f 2655 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2656 break;
2657 }
2658 }
2659}
2660
2661/*
51470298 2662 * Username and password input, abstracted off into routines
2663 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2664 */
0405e71f 2665
2666/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2667static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2668{
51470298 2669 ssh->userpass_input_buffer = buffer;
2670 ssh->userpass_input_buflen = buflen;
2671 ssh->userpass_input_bufpos = 0;
2672 ssh->userpass_input_echo = echo;
0405e71f 2673}
2674
2675/*
2676 * Process some terminal data in the course of username/password
2677 * input. Returns >0 for success (line of input returned in
2678 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2679 * for inconclusive (keep waiting for more input please).
2680 */
ae9ae89f 2681static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2682{
2683 char c;
2684
2685 while (inlen--) {
2686 switch (c = *in++) {
2687 case 10:
2688 case 13:
51470298 2689 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2690 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2691 return +1;
2692 break;
2693 case 8:
2694 case 127:
51470298 2695 if (ssh->userpass_input_bufpos > 0) {
2696 if (ssh->userpass_input_echo)
2697 c_write_str(ssh, "\b \b");
2698 ssh->userpass_input_bufpos--;
0405e71f 2699 }
2700 break;
2701 case 21:
2702 case 27:
51470298 2703 while (ssh->userpass_input_bufpos > 0) {
2704 if (ssh->userpass_input_echo)
2705 c_write_str(ssh, "\b \b");
2706 ssh->userpass_input_bufpos--;
0405e71f 2707 }
2708 break;
2709 case 3:
2710 case 4:
2711 return -1;
2712 break;
2713 default:
4692a14a 2714 /*
2715 * This simplistic check for printability is disabled
2716 * when we're doing password input, because some people
2717 * have control characters in their passwords.o
2718 */
2719 if ((!ssh->userpass_input_echo ||
2720 (c >= ' ' && c <= '~') ||
0405e71f 2721 ((unsigned char) c >= 160))
51470298 2722 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2723 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2724 if (ssh->userpass_input_echo)
2725 c_write(ssh, &c, 1);
0405e71f 2726 }
2727 break;
2728 }
2729 }
2730 return 0;
2731}
2732
f11d78f2 2733static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2734{
2735 Ssh ssh = (Ssh) sshv;
2736
2737 ssh->agent_response = reply;
2738 ssh->agent_response_len = replylen;
2739
2740 if (ssh->version == 1)
ff3187f6 2741 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2742 else
ff3187f6 2743 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2744}
2745
3d9449a1 2746static void ssh_dialog_callback(void *sshv, int ret)
2747{
2748 Ssh ssh = (Ssh) sshv;
2749
2750 ssh->user_response = ret;
2751
2752 if (ssh->version == 1)
2753 do_ssh1_login(ssh, NULL, -1, NULL);
2754 else
2755 do_ssh2_transport(ssh, NULL, -1, NULL);
2756
2757 /*
2758 * This may have unfrozen the SSH connection, so do a
2759 * queued-data run.
2760 */
2761 ssh_process_queued_incoming_data(ssh);
2762}
2763
f11d78f2 2764static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2765{
2766 struct ssh_channel *c = (struct ssh_channel *)cv;
2767 Ssh ssh = c->ssh;
2768 void *sentreply = reply;
2769
2770 if (!sentreply) {
2771 /* Fake SSH_AGENT_FAILURE. */
2772 sentreply = "\0\0\0\1\5";
2773 replylen = 5;
2774 }
2775 if (ssh->version == 2) {
2776 ssh2_add_channel_data(c, sentreply, replylen);
2777 ssh2_try_send(c);
2778 } else {
2779 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2780 PKT_INT, c->remoteid,
9a10ecf4 2781 PKTT_DATA,
839f10db 2782 PKT_INT, replylen,
2783 PKT_DATA, sentreply, replylen,
9a10ecf4 2784 PKTT_OTHER,
839f10db 2785 PKT_END);
2786 }
2787 if (reply)
2788 sfree(reply);
2789}
2790
0405e71f 2791/*
fb09bf1c 2792 * Handle the key exchange and user authentication phases.
2793 */
ff3187f6 2794static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2795 struct Packet *pktin)
fb09bf1c 2796{
0016d70b 2797 int i, j, ret;
2798 unsigned char cookie[8], *ptr;
374330e2 2799 struct RSAKey servkey, hostkey;
2800 struct MD5Context md5c;
51470298 2801 struct do_ssh1_login_state {
2802 int len;
2803 unsigned char *rsabuf, *keystr1, *keystr2;
2804 unsigned long supported_ciphers_mask, supported_auths_mask;
2805 int tried_publickey, tried_agent;
2806 int tis_auth_refused, ccard_auth_refused;
2807 unsigned char session_id[16];
2808 int cipher_type;
2809 char username[100];
2810 void *publickey_blob;
2811 int publickey_bloblen;
2812 char password[100];
2813 char prompt[200];
2814 int pos;
2815 char c;
2816 int pwpkt_type;
2817 unsigned char request[5], *response, *p;
2818 int responselen;
2819 int keyi, nkeys;
2820 int authed;
2821 struct RSAKey key;
2822 Bignum challenge;
2823 char *commentp;
2824 int commentlen;
3d9449a1 2825 int dlgret;
51470298 2826 };
2827 crState(do_ssh1_login_state);
2828
2829 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2830
ff3187f6 2831 if (!pktin)
2832 crWaitUntil(pktin);
374330e2 2833
ff3187f6 2834 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2835 bombout(("Public key packet not received"));
7ffdbc1a 2836 crStop(0);
8d5de777 2837 }
374330e2 2838
c5e9c988 2839 logevent("Received public keys");
374330e2 2840
ff3187f6 2841 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2842 if (!ptr) {
2843 bombout(("SSH1 public key packet stopped before random cookie"));
2844 crStop(0);
2845 }
2846 memcpy(cookie, ptr, 8);
374330e2 2847
ff3187f6 2848 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2849 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
ae0500e5 2850 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2851 crStop(0);
2852 }
374330e2 2853
c5e9c988 2854 /*
1c2a93c4 2855 * Log the host key fingerprint.
c5e9c988 2856 */
c5e9c988 2857 {
2858 char logmsg[80];
1c2a93c4 2859 logevent("Host key fingerprint is:");
c5e9c988 2860 strcpy(logmsg, " ");
32874aea 2861 hostkey.comment = NULL;
2862 rsa_fingerprint(logmsg + strlen(logmsg),
2863 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2864 logevent(logmsg);
2865 }
2866
ff3187f6 2867 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2868 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2869 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2870
51470298 2871 ssh->v1_local_protoflags =
2872 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2873 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2874
c5e9c988 2875 MD5Init(&md5c);
51470298 2876 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2877 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2878 MD5Update(&md5c, cookie, 8);
51470298 2879 MD5Final(s->session_id, &md5c);
374330e2 2880
32874aea 2881 for (i = 0; i < 32; i++)
51470298 2882 ssh->session_key[i] = random_byte();
374330e2 2883
0016d70b 2884 /*
2885 * Verify that the `bits' and `bytes' parameters match.
2886 */
2887 if (hostkey.bits > hostkey.bytes * 8 ||
2888 servkey.bits > servkey.bytes * 8) {
2889 bombout(("SSH1 public keys were badly formatted"));
2890 crStop(0);
2891 }
2892
51470298 2893 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2894
3d88e64d 2895 s->rsabuf = snewn(s->len, unsigned char);
51470298 2896 if (!s->rsabuf)
374330e2 2897 fatalbox("Out of memory");
2898
89ee5268 2899 /*
2900 * Verify the host key.
2901 */
2902 {
32874aea 2903 /*
2904 * First format the key into a string.
2905 */
2906 int len = rsastr_len(&hostkey);
2907 char fingerprint[100];
3d88e64d 2908 char *keystr = snewn(len, char);
32874aea 2909 if (!keystr)
2910 fatalbox("Out of memory");
2911 rsastr_fmt(keystr, &hostkey);
2912 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3d9449a1 2913
2914 ssh_set_frozen(ssh, 1);
2915 s->dlgret = verify_ssh_host_key(ssh->frontend,
2916 ssh->savedhost, ssh->savedport,
2917 "rsa", keystr, fingerprint,
2918 ssh_dialog_callback, ssh);
32874aea 2919 sfree(keystr);
3d9449a1 2920 if (s->dlgret < 0) {
2921 do {
2922 crReturn(0);
2923 if (pktin) {
2924 bombout(("Unexpected data from server while waiting"
2925 " for user host key response"));
2926 crStop(0);
2927 }
2928 } while (pktin || inlen > 0);
2929 s->dlgret = ssh->user_response;
2930 }
2931 ssh_set_frozen(ssh, 0);
2932
2933 if (s->dlgret == 0) {
2934 ssh->close_expected = TRUE;
2935 ssh_closing((Plug)ssh, NULL, 0, 0);
2b3f6c19 2936 crStop(0);
3d9449a1 2937 }
32874aea 2938 }
2939
2940 for (i = 0; i < 32; i++) {
51470298 2941 s->rsabuf[i] = ssh->session_key[i];
374330e2 2942 if (i < 16)
51470298 2943 s->rsabuf[i] ^= s->session_id[i];
374330e2 2944 }
2945
2946 if (hostkey.bytes > servkey.bytes) {
0016d70b 2947 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2948 if (ret)
2949 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2950 } else {
0016d70b 2951 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2952 if (ret)
2953 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2954 }
2955 if (!ret) {
2956 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2957 crStop(0);
374330e2 2958 }
2959
c5e9c988 2960 logevent("Encrypted session key");
2961
ca20bfcf 2962 {
2963 int cipher_chosen = 0, warn = 0;
2964 char *cipher_string = NULL;
51470298 2965 int i;
ca20bfcf 2966 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2967 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2968 if (next_cipher == CIPHER_WARN) {
2969 /* If/when we choose a cipher, warn about it */
2970 warn = 1;
2971 } else if (next_cipher == CIPHER_AES) {
2972 /* XXX Probably don't need to mention this. */
2973 logevent("AES not supported in SSH1, skipping");
2974 } else {
2975 switch (next_cipher) {
51470298 2976 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2977 cipher_string = "3DES"; break;
51470298 2978 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2979 cipher_string = "Blowfish"; break;
51470298 2980 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2981 cipher_string = "single-DES"; break;
2982 }
51470298 2983 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2984 cipher_chosen = 1;
2985 }
2986 }
2987 if (!cipher_chosen) {
51470298 2988 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2989 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2990 "supporting 3DES encryption"));
2991 else
2992 /* shouldn't happen */
6b5cf8b4 2993 bombout(("No supported ciphers found"));
7ffdbc1a 2994 crStop(0);
a99a05c0 2995 }
ca20bfcf 2996
2997 /* Warn about chosen cipher if necessary. */
bb348ab1 2998 if (warn) {
3d9449a1 2999 ssh_set_frozen(ssh, 1);
3000 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3001 ssh_dialog_callback, ssh);
3002 if (s->dlgret < 0) {
3003 do {
3004 crReturn(0);
3005 if (pktin) {
3006 bombout(("Unexpected data from server while waiting"
3007 " for user response"));
3008 crStop(0);
3009 }
3010 } while (pktin || inlen > 0);
3011 s->dlgret = ssh->user_response;
3012 }
3013 ssh_set_frozen(ssh, 0);
3014 if (s->dlgret == 0) {
3015 ssh->close_expected = TRUE;
3016 ssh_closing((Plug)ssh, NULL, 0, 0);
96ccde8b 3017 crStop(0);
3d9449a1 3018 }
bb348ab1 3019 }
bea1ef5f 3020 }
ca20bfcf 3021
51470298 3022 switch (s->cipher_type) {
32874aea 3023 case SSH_CIPHER_3DES:
3024 logevent("Using 3DES encryption");
3025 break;
3026 case SSH_CIPHER_DES:
3027 logevent("Using single-DES encryption");
3028 break;
3029 case SSH_CIPHER_BLOWFISH:
3030 logevent("Using Blowfish encryption");
3031 break;
c5e9c988 3032 }
bea1ef5f 3033
51470298 3034 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3035 PKT_CHAR, s->cipher_type,
32874aea 3036 PKT_DATA, cookie, 8,
51470298 3037 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3038 PKT_DATA, s->rsabuf, s->len,
3039 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 3040
c5e9c988 3041 logevent("Trying to enable encryption...");
374330e2 3042
51470298 3043 sfree(s->rsabuf);
374330e2 3044
51470298 3045 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3046 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3047 &ssh_3des);
371e569c 3048 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3049 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 3050 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 3051
0183b242 3052 ssh->crcda_ctx = crcda_make_context();
3053 logevent("Installing CRC compensation attack detector");
3054
679539d7 3055 if (servkey.modulus) {
3056 sfree(servkey.modulus);
3057 servkey.modulus = NULL;
3058 }
3059 if (servkey.exponent) {
3060 sfree(servkey.exponent);
3061 servkey.exponent = NULL;
3062 }
3063 if (hostkey.modulus) {
3064 sfree(hostkey.modulus);
3065 hostkey.modulus = NULL;
3066 }
3067 if (hostkey.exponent) {
3068 sfree(hostkey.exponent);
3069 hostkey.exponent = NULL;
3070 }
ff3187f6 3071 crWaitUntil(pktin);
374330e2 3072
ff3187f6 3073 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3074 bombout(("Encryption not successfully enabled"));
7ffdbc1a 3075 crStop(0);
8d5de777 3076 }
374330e2 3077
c5e9c988 3078 logevent("Successfully started encryption");
3079
374330e2 3080 fflush(stdout);
3081 {
aa09f7d0 3082 if (!*ssh->cfg.username) {
c0a81592 3083 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 3084 if (!ssh_get_line("login as: ",
51470298 3085 s->username, sizeof(s->username), FALSE)) {
32874aea 3086 /*
3087 * get_line failed to get a username.
3088 * Terminate.
3089 */
3090 logevent("No username provided. Abandoning session.");
ac934965 3091 ssh->close_expected = TRUE;
3bb2f322 3092 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3093 crStop(1);
32874aea 3094 }
3095 } else {
51470298 3096 int ret; /* need not be kept over crReturn */
3097 c_write_str(ssh, "login as: ");
3098 ssh->send_ok = 1;
0405e71f 3099
51470298 3100 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 3101 do {
ff3187f6 3102 crWaitUntil(!pktin);
51470298 3103 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3104 } while (ret == 0);
3105 if (ret < 0)
3106 cleanup_exit(0);
51470298 3107 c_write_str(ssh, "\r\n");
32874aea 3108 }
3109 } else {
86916870 3110 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 3111 s->username[sizeof(s->username)-1] = '\0';
374330e2 3112 }
fb09bf1c 3113
51470298 3114 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 3115 {
51470298 3116 char userlog[22 + sizeof(s->username)];
3117 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 3118 logevent(userlog);
32874aea 3119 if (flags & FLAG_INTERACTIVE &&
3120 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 3121 strcat(userlog, "\r\n");
51470298 3122 c_write_str(ssh, userlog);
3c8e959b 3123 }
c5e9c988 3124 }
374330e2 3125 }
3126
ff3187f6 3127 crWaitUntil(pktin);
374330e2 3128
51470298 3129 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 3130 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 3131 s->tried_publickey = s->tried_agent = 1;
0df73905 3132 } else {
51470298 3133 s->tried_publickey = s->tried_agent = 0;
0df73905 3134 }
51470298 3135 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 3136 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 3137 if (!filename_is_null(ssh->cfg.keyfile)) {
3138 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 3139 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 3140 s->publickey_blob = NULL;
396778f1 3141 } else
51470298 3142 s->publickey_blob = NULL;
7cca0d81 3143
ff3187f6 3144 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3145 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 3146
51470298 3147 if (agent_exists() && !s->tried_agent) {
32874aea 3148 /*
3149 * Attempt RSA authentication using Pageant.
3150 */
32874aea 3151 void *r;
3152
51470298 3153 s->authed = FALSE;
3154 s->tried_agent = 1;
32874aea 3155 logevent("Pageant is running. Requesting keys.");
3156
3157 /* Request the keys held by the agent. */
51470298 3158 PUT_32BIT(s->request, 1);
3159 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 3160 if (!agent_query(s->request, 5, &r, &s->responselen,
3161 ssh_agent_callback, ssh)) {
3162 do {
3163 crReturn(0);
ff3187f6 3164 if (pktin) {
839f10db 3165 bombout(("Unexpected data from server while waiting"
3166 " for agent response"));
3167 crStop(0);
3168 }
ff3187f6 3169 } while (pktin || inlen > 0);
839f10db 3170 r = ssh->agent_response;
3171 s->responselen = ssh->agent_response_len;
3172 }
51470298 3173 s->response = (unsigned char *) r;
3174 if (s->response && s->responselen >= 5 &&
3175 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3176 s->p = s->response + 5;
3177 s->nkeys = GET_32BIT(s->p);
3178 s->p += 4;
fb983202 3179 logeventf(ssh, "Pageant has %d SSH1 keys", s->nkeys);
51470298 3180 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
fb983202 3181 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
51470298 3182 if (s->publickey_blob &&
3183 !memcmp(s->p, s->publickey_blob,
3184 s->publickey_bloblen)) {
396778f1 3185 logevent("This key matches configured key file");
51470298 3186 s->tried_publickey = 1;
396778f1 3187 }
51470298 3188 s->p += 4;
0016d70b 3189 {
3190 int n, ok = FALSE;
3191 do { /* do while (0) to make breaking easy */
3192 n = ssh1_read_bignum
3193 (s->p, s->responselen-(s->p-s->response),
3194 &s->key.exponent);
3195 if (n < 0)
3196 break;
3197 s->p += n;
3198 n = ssh1_read_bignum
3199 (s->p, s->responselen-(s->p-s->response),
3200 &s->key.modulus);
3201 if (n < 0)
3202 break;
3203 s->p += n;
3204 if (s->responselen - (s->p-s->response) < 4)
3205 break;
3206 s->commentlen = GET_32BIT(s->p);
3207 s->p += 4;
3208 if (s->responselen - (s->p-s->response) <
3209 s->commentlen)
3210 break;
3211 s->commentp = (char *)s->p;
3212 s->p += s->commentlen;
3213 ok = TRUE;
3214 } while (0);
3215 if (!ok) {
3216 logevent("Pageant key list packet was truncated");
3217 break;
3218 }
3219 }
51470298 3220 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3221 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3222 crWaitUntil(pktin);
3223 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3224 logevent("Key refused");
3225 continue;
3226 }
3227 logevent("Received RSA challenge");
ff3187f6 3228 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3229 bombout(("Server's RSA challenge was badly formatted"));
3230 crStop(0);
3231 }
3232
32874aea 3233 {
3234 char *agentreq, *q, *ret;
2d466ffd 3235 void *vret;
32874aea 3236 int len, retlen;
3237 len = 1 + 4; /* message type, bit count */
51470298 3238 len += ssh1_bignum_length(s->key.exponent);
3239 len += ssh1_bignum_length(s->key.modulus);
3240 len += ssh1_bignum_length(s->challenge);
32874aea 3241 len += 16; /* session id */
3242 len += 4; /* response format */
3d88e64d 3243 agentreq = snewn(4 + len, char);
32874aea 3244 PUT_32BIT(agentreq, len);
3245 q = agentreq + 4;
3246 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3247 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3248 q += 4;
51470298 3249 q += ssh1_write_bignum(q, s->key.exponent);
3250 q += ssh1_write_bignum(q, s->key.modulus);
3251 q += ssh1_write_bignum(q, s->challenge);
3252 memcpy(q, s->session_id, 16);
32874aea 3253 q += 16;
3254 PUT_32BIT(q, 1); /* response format */
839f10db 3255 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3256 ssh_agent_callback, ssh)) {
3257 sfree(agentreq);
3258 do {
3259 crReturn(0);
ff3187f6 3260 if (pktin) {
839f10db 3261 bombout(("Unexpected data from server"
3262 " while waiting for agent"
3263 " response"));
3264 crStop(0);
3265 }
ff3187f6 3266 } while (pktin || inlen > 0);
839f10db 3267 vret = ssh->agent_response;
3268 retlen = ssh->agent_response_len;
3269 } else
3270 sfree(agentreq);
2d466ffd 3271 ret = vret;
32874aea 3272 if (ret) {
3273 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3274 logevent("Sending Pageant's response");
51470298 3275 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3276 PKT_DATA, ret + 5, 16,
3277 PKT_END);
3278 sfree(ret);
ff3187f6 3279 crWaitUntil(pktin);
3280 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3281 logevent
3282 ("Pageant's response accepted");
3283 if (flags & FLAG_VERBOSE) {
51470298 3284 c_write_str(ssh, "Authenticated using"
3285 " RSA key \"");
3286 c_write(ssh, s->commentp,
3287 s->commentlen);
3288 c_write_str(ssh, "\" from agent\r\n");
32874aea 3289 }
51470298 3290 s->authed = TRUE;
32874aea 3291 } else
3292 logevent
3293 ("Pageant's response not accepted");
3294 } else {
3295 logevent
3296 ("Pageant failed to answer challenge");
3297 sfree(ret);
3298 }
3299 } else {
3300 logevent("No reply received from Pageant");
3301 }
3302 }
51470298 3303 freebn(s->key.exponent);
3304 freebn(s->key.modulus);
3305 freebn(s->challenge);
3306 if (s->authed)
32874aea 3307 break;
3308 }
29b1d0b3 3309 sfree(s->response);
32874aea 3310 }
51470298 3311 if (s->authed)
32874aea 3312 break;
3313 }
9a30e26b 3314 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3315 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3316
86916870 3317 if (ssh->cfg.try_tis_auth &&
51470298 3318 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3319 !s->tis_auth_refused) {
3320 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3321 logevent("Requested TIS authentication");
51470298 3322 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3323 crWaitUntil(pktin);
3324 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3325 logevent("TIS authentication declined");
3326 if (flags & FLAG_INTERACTIVE)
51470298 3327 c_write_str(ssh, "TIS authentication refused.\r\n");
3328 s->tis_auth_refused = 1;
614a20a0 3329 continue;
32874aea 3330 } else {
0016d70b 3331 char *challenge;
3332 int challengelen;
3333
ff3187f6 3334 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3335 if (!challenge) {
3336 bombout(("TIS challenge packet was badly formed"));
3337 crStop(0);
3338 }
32874aea 3339 logevent("Received TIS challenge");
51470298 3340 if (challengelen > sizeof(s->prompt) - 1)
3341 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3342 memcpy(s->prompt, challenge, challengelen);
614a20a0 3343 /* Prompt heuristic comes from OpenSSH */
51470298 3344 strncpy(s->prompt + challengelen,
3345 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3346 "": "\r\nResponse: ",
51470298 3347 (sizeof s->prompt) - challengelen);
3348 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3349 }
3350 }
86916870 3351 if (ssh->cfg.try_tis_auth &&
51470298 3352 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3353 !s->ccard_auth_refused) {
3354 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3355 logevent("Requested CryptoCard authentication");
51470298 3356 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3357 crWaitUntil(pktin);
3358 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3359 logevent("CryptoCard authentication declined");
51470298 3360 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3361 s->ccard_auth_refused = 1;
614a20a0 3362 continue;
32874aea 3363 } else {
0016d70b 3364 char *challenge;
3365 int challengelen;
3366
ff3187f6 3367 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3368 if (!challenge) {
3369 bombout(("CryptoCard challenge packet was badly formed"));
3370 crStop(0);
3371 }
32874aea 3372 logevent("Received CryptoCard challenge");
51470298 3373 if (challengelen > sizeof(s->prompt) - 1)
3374 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3375 memcpy(s->prompt, challenge, challengelen);
51470298 3376 strncpy(s->prompt + challengelen,
3377 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3378 "" : "\r\nResponse: ",
51470298 3379 sizeof(s->prompt) - challengelen);
3380 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3381 }
3382 }
51470298 3383 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3384 sprintf(s->prompt, "%.90s@%.90s's password: ",
3385 s->username, ssh->savedhost);
32874aea 3386 }
51470298 3387 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3388 char *comment = NULL;
231ee168 3389 int type;
32874aea 3390 if (flags & FLAG_VERBOSE)
51470298 3391 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3392 logeventf(ssh, "Trying public key \"%s\"",
3393 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3394 type = key_type(&ssh->cfg.keyfile);
231ee168 3395 if (type != SSH_KEYTYPE_SSH1) {
fb983202 3396 char *msg = dupprintf("Key is of wrong type (%s)",
3397 key_type_to_str(type));
3398 logevent(msg);
3399 c_write_str(ssh, msg);
51470298 3400 c_write_str(ssh, "\r\n");
fb983202 3401 sfree(msg);
51470298 3402 s->tried_publickey = 1;
231ee168 3403 continue;
3404 }
9a30e26b 3405 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3406 if (flags & FLAG_VERBOSE)
51470298 3407 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3408 goto tryauth;
3409 }
51470298 3410 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3411 sfree(comment);
3412 }
a52f067e 3413
614a20a0 3414 /*
3415 * Show password prompt, having first obtained it via a TIS
3416 * or CryptoCard exchange if we're doing TIS or CryptoCard
3417 * authentication.
3418 */
fa17a66e 3419 if (ssh_get_line) {
51470298 3420 if (!ssh_get_line(s->prompt, s->password,
3421 sizeof(s->password), TRUE)) {
32874aea 3422 /*
3423 * get_line failed to get a password (for example
3424 * because one was supplied on the command line
3425 * which has already failed to work). Terminate.
3426 */
51470298 3427 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3428 PKT_STR, "No more passwords available to try",
3429 PKT_END);
247308b5 3430 logevent("Unable to authenticate");
a8327734 3431 connection_fatal(ssh->frontend, "Unable to authenticate");
ac934965 3432 ssh->close_expected = TRUE;
3bb2f322 3433 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3434 crStop(1);
32874aea 3435 }
fb09bf1c 3436 } else {
614a20a0 3437 /* Prompt may have come from server. We've munged it a bit, so
3438 * we know it to be zero-terminated at least once. */
51470298 3439 int ret; /* need not be saved over crReturn */
3440 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3441 s->pos = 0;
0405e71f 3442
51470298 3443 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3444 do {
ff3187f6 3445 crWaitUntil(!pktin);
51470298 3446 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3447 } while (ret == 0);
3448 if (ret < 0)
3449 cleanup_exit(0);
51470298 3450 c_write_str(ssh, "\r\n");
32874aea 3451 }
3452
3453 tryauth:
51470298 3454 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3455 /*
3456 * Try public key authentication with the specified
3457 * key file.
3458 */
51470298 3459 s->tried_publickey = 1;
3460
3461 {
222d54dc 3462 const char *error = NULL;
3463 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3464 &error);
51470298 3465 if (ret == 0) {
3466 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3467 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3468 c_write_str(ssh, " (");
3469 c_write_str(ssh, error);
3470 c_write_str(ssh, ").\r\n");
51470298 3471 continue; /* go and try password */
3472 }
3473 if (ret == -1) {
3474 c_write_str(ssh, "Wrong passphrase.\r\n");
3475 s->tried_publickey = 0;
3476 continue; /* try again */
3477 }
32874aea 3478 }
3479
3480 /*
3481 * Send a public key attempt.
3482 */
51470298 3483 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3484 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3485
ff3187f6 3486 crWaitUntil(pktin);
3487 if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3488 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3489 continue; /* go and try password */
3490 }
ff3187f6 3491 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3492 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3493 crStop(0);
32874aea 3494 }
32874aea 3495
51470298 3496 {
3497 int i;
3498 unsigned char buffer[32];
3499 Bignum challenge, response;
3500
ff3187f6 3501 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3502 bombout(("Server's RSA challenge was badly formatted"));
3503 crStop(0);
3504 }
51470298 3505 response = rsadecrypt(challenge, &s->key);
3506 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3507
51470298 3508 for (i = 0; i < 32; i++) {
3509 buffer[i] = bignum_byte(response, 31 - i);
3510 }
3511
3512 MD5Init(&md5c);
3513 MD5Update(&md5c, buffer, 32);
3514 MD5Update(&md5c, s->session_id, 16);
3515 MD5Final(buffer, &md5c);
32874aea 3516
51470298 3517 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3518 PKT_DATA, buffer, 16, PKT_END);
3519
3520 freebn(challenge);
3521 freebn(response);
3522 }
32874aea 3523
ff3187f6 3524 crWaitUntil(pktin);
3525 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3526 if (flags & FLAG_VERBOSE)
51470298 3527 c_write_str(ssh, "Failed to authenticate with"
3528 " our public key.\r\n");
32874aea 3529 continue; /* go and try password */
ff3187f6 3530 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3531 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3532 crStop(0);
32874aea 3533 }
3534
3535 break; /* we're through! */
3536 } else {
51470298 3537 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3538 /*
3539 * Defence against traffic analysis: we send a
3540 * whole bunch of packets containing strings of
3541 * different lengths. One of these strings is the
3542 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3543 * The others are all random data in
3544 * SSH1_MSG_IGNORE packets. This way a passive
3545 * listener can't tell which is the password, and
3546 * hence can't deduce the password length.
3547 *
3548 * Anybody with a password length greater than 16
3549 * bytes is going to have enough entropy in their
3550 * password that a listener won't find it _that_
3551 * much help to know how long it is. So what we'll
3552 * do is:
3553 *
3554 * - if password length < 16, we send 15 packets
3555 * containing string lengths 1 through 15
3556 *
3557 * - otherwise, we let N be the nearest multiple
3558 * of 8 below the password length, and send 8
3559 * packets containing string lengths N through
3560 * N+7. This won't obscure the order of
3561 * magnitude of the password length, but it will
3562 * introduce a bit of extra uncertainty.
3563 *
3564 * A few servers (the old 1.2.18 through 1.2.22)
3565 * can't deal with SSH1_MSG_IGNORE. For these
3566 * servers, we need an alternative defence. We make
3567 * use of the fact that the password is interpreted
3568 * as a C string: so we can append a NUL, then some
3569 * random data.
bd358db1 3570 *
3571 * One server (a Cisco one) can deal with neither
3572 * SSH1_MSG_IGNORE _nor_ a padded password string.
3573 * For this server we are left with no defences
3574 * against password length sniffing.
32874aea 3575 */
51470298 3576 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3577 /*
3578 * The server can deal with SSH1_MSG_IGNORE, so
3579 * we can use the primary defence.
3580 */
32874aea 3581 int bottom, top, pwlen, i;
3582 char *randomstr;
3583
51470298 3584 pwlen = strlen(s->password);
32874aea 3585 if (pwlen < 16) {
3586 bottom = 0; /* zero length passwords are OK! :-) */
3587 top = 15;
3588 } else {
3589 bottom = pwlen & ~7;
3590 top = bottom + 7;
3591 }
3592
3593 assert(pwlen >= bottom && pwlen <= top);
3594
3d88e64d 3595 randomstr = snewn(top + 1, char);
32874aea 3596
3597 for (i = bottom; i <= top; i++) {
9a10ecf4 3598 if (i == pwlen) {
51470298 3599 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3600 PKTT_PASSWORD, PKT_STR, s->password,
3601 PKTT_OTHER, PKT_END);
3602 } else {
32874aea 3603 for (j = 0; j < i; j++) {
3604 do {
3605 randomstr[j] = random_byte();
3606 } while (randomstr[j] == '\0');
3607 }
3608 randomstr[i] = '\0';
51470298 3609 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3610 PKT_STR, randomstr, PKT_END);
3611 }
3612 }
bd358db1 3613 logevent("Sending password with camouflage packets");
51470298 3614 ssh_pkt_defersend(ssh);
679539d7 3615 sfree(randomstr);
bd358db1 3616 }
51470298 3617 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3618 /*
3619 * The server can't deal with SSH1_MSG_IGNORE
3620 * but can deal with padded passwords, so we
3621 * can use the secondary defence.
3622 */
bd358db1 3623 char string[64];
51470298 3624 char *ss;
bd358db1 3625 int len;
3626
51470298 3627 len = strlen(s->password);
bd358db1 3628 if (len < sizeof(string)) {
51470298 3629 ss = string;
3630 strcpy(string, s->password);
bd358db1 3631 len++; /* cover the zero byte */
3632 while (len < sizeof(string)) {
3633 string[len++] = (char) random_byte();
3634 }
3635 } else {
51470298 3636 ss = s->password;
bd358db1 3637 }
3638 logevent("Sending length-padded password");
9a10ecf4 3639 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3640 PKT_INT, len, PKT_DATA, ss, len,
3641 PKTT_OTHER, PKT_END);
bd358db1 3642 } else {
3643 /*
3644 * The server has _both_
3645 * BUG_CHOKES_ON_SSH1_IGNORE and
3646 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3647 * therefore nothing we can do.
3648 */
3649 int len;
51470298 3650 len = strlen(s->password);
bd358db1 3651 logevent("Sending unpadded password");
9a10ecf4 3652 send_packet(ssh, s->pwpkt_type,
3653 PKTT_PASSWORD, PKT_INT, len,
3654 PKT_DATA, s->password, len,
3655 PKTT_OTHER, PKT_END);
32874aea 3656 }
3657 } else {
9a10ecf4 3658 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3659 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3660 }
3661 }
c5e9c988 3662 logevent("Sent password");
51470298 3663 memset(s->password, 0, strlen(s->password));
ff3187f6 3664 crWaitUntil(pktin);
3665 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3666 if (flags & FLAG_VERBOSE)
51470298 3667 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3668 logevent("Authentication refused");
ff3187f6 3669 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3670 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3671 crStop(0);
374330e2 3672 }
3673 }
3674
c5e9c988 3675 logevent("Authentication successful");
3676
fb09bf1c 3677 crFinish(1);
3678}
3679
32874aea 3680void sshfwd_close(struct ssh_channel *c)
3681{
51470298 3682 Ssh ssh = c->ssh;
3683
36f94d1f 3684 if (ssh->state != SSH_STATE_SESSION) {
3685 assert(ssh->state == SSH_STATE_CLOSED);
3686 return;
3687 }
3688
80e48603 3689 if (c && !c->closes) {
4ed34d25 3690 /*
64d6ff88 3691 * If halfopen is true, we have sent
4ed34d25 3692 * CHANNEL_OPEN for this channel, but it hasn't even been
3693 * acknowledged by the server. So we must set a close flag
3694 * on it now, and then when the server acks the channel
3695 * open, we can close it then.
3696 */
64d6ff88 3697 if (!c->halfopen) {
51470298 3698 if (ssh->version == 1) {
3699 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3700 PKT_END);
3701 } else {
ff3187f6 3702 struct Packet *pktout;
3703 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3704 ssh2_pkt_adduint32(pktout, c->remoteid);
3705 ssh2_pkt_send(ssh, pktout);
4ed34d25 3706 }
32874aea 3707 }
0357890f 3708 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3709 if (c->type == CHAN_X11) {
3710 c->u.x11.s = NULL;
d74d141c 3711 logevent("Forwarded X11 connection terminated");
4ed34d25 3712 } else if (c->type == CHAN_SOCKDATA ||
3713 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3714 c->u.pfd.s = NULL;
3715 logevent("Forwarded port closed");
32874aea 3716 }
3717 }
3718}
3719
5471d09a 3720int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3721{
51470298 3722 Ssh ssh = c->ssh;
3723
36f94d1f 3724 if (ssh->state != SSH_STATE_SESSION) {
3725 assert(ssh->state == SSH_STATE_CLOSED);
3726 return 0;
3727 }
3728
51470298 3729 if (ssh->version == 1) {
3730 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3731 PKT_INT, c->remoteid,
9a10ecf4 3732 PKTT_DATA,
3733 PKT_INT, len, PKT_DATA, buf, len,
3734 PKTT_OTHER, PKT_END);
5471d09a 3735 /*
3736 * In SSH1 we can return 0 here - implying that forwarded
3737 * connections are never individually throttled - because
3738 * the only circumstance that can cause throttling will be
3739 * the whole SSH connection backing up, in which case
3740 * _everything_ will be throttled as a whole.
3741 */
3742 return 0;
783415f8 3743 } else {
32874aea 3744 ssh2_add_channel_data(c, buf, len);
5471d09a 3745 return ssh2_try_send(c);
3746 }
3747}
3748
3749void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3750{
51470298 3751 Ssh ssh = c->ssh;
3752
36f94d1f 3753 if (ssh->state != SSH_STATE_SESSION) {
3754 assert(ssh->state == SSH_STATE_CLOSED);
3755 return;
3756 }
3757
51470298 3758 if (ssh->version == 1) {
5471d09a 3759 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3760 c->v.v1.throttling = 0;
51470298 3761 ssh1_throttle(ssh, -1);
5471d09a 3762 }
3763 } else {
3764 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3765 }
9c964e85 3766}
3767
06fadff5 3768static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3769{
3770 struct queued_handler *qh = ssh->qhead;
3771
3772 assert(qh != NULL);
3773
3774 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3775
3776 if (qh->msg1 > 0) {
3777 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3778 ssh->packet_dispatch[qh->msg1] = NULL;
3779 }
3780 if (qh->msg2 > 0) {
3781 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3782 ssh->packet_dispatch[qh->msg2] = NULL;
3783 }
3784
3785 if (qh->next) {
3786 ssh->qhead = qh->next;
3787
3788 if (ssh->qhead->msg1 > 0) {
3789 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3790 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3791 }
3792 if (ssh->qhead->msg2 > 0) {
3793 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3794 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3795 }
3796 } else {
3797 ssh->qhead = ssh->qtail = NULL;
3798 ssh->packet_dispatch[pktin->type] = NULL;
3799 }
3800
3801 qh->handler(ssh, pktin, qh->ctx);
3802
3803 sfree(qh);
3804}
3805
3806static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3807 chandler_fn_t handler, void *ctx)
3808{
3809 struct queued_handler *qh;
3810
3811 qh = snew(struct queued_handler);
3812 qh->msg1 = msg1;
3813 qh->msg2 = msg2;
3814 qh->handler = handler;
3815 qh->ctx = ctx;
3816 qh->next = NULL;
3817
3818 if (ssh->qtail == NULL) {
3819 ssh->qhead = qh;
3820
3821 if (qh->msg1 > 0) {
3822 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3823 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3824 }
3825 if (qh->msg2 > 0) {
3826 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3827 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3828 }
3829 } else {
3830 ssh->qtail->next = qh;
3831 }
3832 ssh->qtail = qh;
3833}
3834
3835static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3836{
3837 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3838
3839 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3840 SSH2_MSG_REQUEST_SUCCESS)) {
3841 logeventf(ssh, "Remote port forwarding from %s enabled",
3842 pf->sportdesc);
3843 } else {
3844 logeventf(ssh, "Remote port forwarding from %s refused",
3845 pf->sportdesc);
3846
3847 rpf = del234(ssh->rportfwds, pf);
3848 assert(rpf == pf);
fda2feb1 3849 free_rportfwd(pf);
06fadff5 3850 }
3851}
3852
3853static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3854{
84328ddb 3855 const char *portfwd_strptr = cfg->portfwd;
3856 struct ssh_portfwd *epf;
3857 int i;
06fadff5 3858
fda2feb1 3859 if (!ssh->portfwds) {
3860 ssh->portfwds = newtree234(ssh_portcmp);
3861 } else {
3862 /*
3863 * Go through the existing port forwardings and tag them
84328ddb 3864 * with status==DESTROY. Any that we want to keep will be
3865 * re-enabled (status==KEEP) as we go through the
3866 * configuration and find out which bits are the same as
3867 * they were before.
fda2feb1 3868 */
3869 struct ssh_portfwd *epf;
3870 int i;
3871 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 3872 epf->status = DESTROY;
fda2feb1 3873 }
3874
06fadff5 3875 while (*portfwd_strptr) {
84328ddb 3876 char address_family, type;
3877 int sport,dport,sserv,dserv;
3878 char sports[256], dports[256], saddr[256], host[256];
3879 int n;
3880
05581745 3881 address_family = 'A';
3882 type = 'L';
84328ddb 3883 if (*portfwd_strptr == 'A' ||
3884 *portfwd_strptr == '4' ||
3885 *portfwd_strptr == '6')
3886 address_family = *portfwd_strptr++;
3887 if (*portfwd_strptr == 'L' ||
3888 *portfwd_strptr == 'R' ||
3889 *portfwd_strptr == 'D')
3890 type = *portfwd_strptr++;
05581745 3891
06fadff5 3892 saddr[0] = '\0';
05581745 3893
06fadff5 3894 n = 0;
3895 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3896 if (*portfwd_strptr == ':') {
3897 /*
3898 * We've seen a colon in the middle of the
3899 * source port number. This means that
3900 * everything we've seen until now is the
3901 * source _address_, so we'll move it into
3902 * saddr and start sports from the beginning
3903 * again.
3904 */
3905 portfwd_strptr++;
3906 sports[n] = '\0';
3907 if (ssh->version == 1 && type == 'R') {
3908 logeventf(ssh, "SSH1 cannot handle remote source address "
3909 "spec \"%s\"; ignoring", sports);
3910 } else
3911 strcpy(saddr, sports);
3912 n = 0;
3913 }
019164b0 3914 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
06fadff5 3915 }
3916 sports[n] = 0;
3917 if (type != 'D') {
3918 if (*portfwd_strptr == '\t')
3919 portfwd_strptr++;
3920 n = 0;
3921 while (*portfwd_strptr && *portfwd_strptr != ':') {
019164b0 3922 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
06fadff5 3923 }
3924 host[n] = 0;
3925 if (*portfwd_strptr == ':')
3926 portfwd_strptr++;
3927 n = 0;
3928 while (*portfwd_strptr) {
019164b0 3929 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
06fadff5 3930 }
3931 dports[n] = 0;
3932 portfwd_strptr++;
3933 dport = atoi(dports);
3934 dserv = 0;
3935 if (dport == 0) {
3936 dserv = 1;
3937 dport = net_service_lookup(dports);
3938 if (!dport) {
3939 logeventf(ssh, "Service lookup failed for destination"
3940 " port \"%s\"", dports);
3941 }
3942 }
3943 } else {
3944 while (*portfwd_strptr) portfwd_strptr++;
a9e72926 3945 host[0] = 0;
3946 dports[0] = 0;
06fadff5 3947 dport = dserv = -1;
3948 portfwd_strptr++; /* eat the NUL and move to next one */
3949 }
3950 sport = atoi(sports);
3951 sserv = 0;
3952 if (sport == 0) {
3953 sserv = 1;
3954 sport = net_service_lookup(sports);
3955 if (!sport) {
3956 logeventf(ssh, "Service lookup failed for source"
3957 " port \"%s\"", sports);
3958 }
3959 }
3960 if (sport && dport) {
3961 /* Set up a description of the source port. */
fda2feb1 3962 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 3963
3964 pfrec = snew(struct ssh_portfwd);
3965 pfrec->type = type;
3966 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3fe92132 3967 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 3968 pfrec->sport = sport;
84328ddb 3969 pfrec->daddr = *host ? dupstr(host) : NULL;
3fe92132 3970 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 3971 pfrec->dport = dport;
3972 pfrec->local = NULL;
3973 pfrec->remote = NULL;
05581745 3974 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3975 address_family == '6' ? ADDRTYPE_IPV6 :
3976 ADDRTYPE_UNSPEC);
fda2feb1 3977
3978 epfrec = add234(ssh->portfwds, pfrec);
3979 if (epfrec != pfrec) {
3980 /*
3981 * We already have a port forwarding with precisely
3982 * these parameters. Hence, no need to do anything;
84328ddb 3983 * simply tag the existing one as KEEP.
fda2feb1 3984 */
84328ddb 3985 epfrec->status = KEEP;
fda2feb1 3986 free_portfwd(pfrec);
84328ddb 3987 } else {
3988 pfrec->status = CREATE;
3989 }
3990 }
3991 }
3992
3993 /*
3994 * Now go through and destroy any port forwardings which were
3995 * not re-enabled.
3996 */
3997 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3998 if (epf->status == DESTROY) {
3999 char *message;
4000
4001 message = dupprintf("%s port forwarding from %s%s%d",
4002 epf->type == 'L' ? "local" :
4003 epf->type == 'R' ? "remote" : "dynamic",
4004 epf->saddr ? epf->saddr : "",
4005 epf->saddr ? ":" : "",
4006 epf->sport);
4007
4008 if (epf->type != 'D') {
4009 char *msg2 = dupprintf("%s to %s:%d", message,
4010 epf->daddr, epf->dport);
4011 sfree(message);
4012 message = msg2;
4013 }
4014
4015 logeventf(ssh, "Cancelling %s", message);
4016 sfree(message);
4017
4018 if (epf->remote) {
4019 struct ssh_rportfwd *rpf = epf->remote;
4020 struct Packet *pktout;
4021
4022 /*
4023 * Cancel the port forwarding at the server
4024 * end.
4025 */
4026 if (ssh->version == 1) {
4027 /*
4028 * We cannot cancel listening ports on the
4029 * server side in SSH1! There's no message
4030 * to support it. Instead, we simply remove
4031 * the rportfwd record from the local end
4032 * so that any connections the server tries
4033 * to make on it are rejected.
4034 */
4035 } else {
4036 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4037 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4038 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4039 if (epf->saddr) {
4040 ssh2_pkt_addstring(pktout, epf->saddr);
4041 } else if (ssh->cfg.rport_acceptall) {
5188540b 4042 /* XXX: ssh->cfg.rport_acceptall may not represent
4043 * what was used to open the original connection,
4044 * since it's reconfigurable. */
84328ddb 4045 ssh2_pkt_addstring(pktout, "0.0.0.0");
4046 } else {
4047 ssh2_pkt_addstring(pktout, "127.0.0.1");
4048 }
4049 ssh2_pkt_adduint32(pktout, epf->sport);
4050 ssh2_pkt_send(ssh, pktout);
4051 }
4052
4053 del234(ssh->rportfwds, rpf);
4054 free_rportfwd(rpf);
4055 } else if (epf->local) {
4056 pfd_terminate(epf->local);
4057 }
4058
4059 delpos234(ssh->portfwds, i);
4060 free_portfwd(epf);
4061 i--; /* so we don't skip one in the list */
4062 }
4063
4064 /*
4065 * And finally, set up any new port forwardings (status==CREATE).
4066 */
4067 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4068 if (epf->status == CREATE) {
4069 char *sportdesc, *dportdesc;
3fe92132 4070 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 4071 epf->saddr ? epf->saddr : "",
4072 epf->saddr ? ":" : "",
3fe92132 4073 epf->sserv ? epf->sserv : "",
4074 epf->sserv ? "(" : "",
4075 epf->sport,
4076 epf->sserv ? ")" : "");
84328ddb 4077 if (epf->type == 'D') {
4078 dportdesc = NULL;
4079 } else {
3fe92132 4080 dportdesc = dupprintf("%s:%s%s%d%s",
4081 epf->daddr,
4082 epf->dserv ? epf->dserv : "",
4083 epf->dserv ? "(" : "",
4084 epf->dport,
4085 epf->dserv ? ")" : "");
84328ddb 4086 }
05581745 4087
84328ddb 4088 if (epf->type == 'L') {
4089 const char *err = pfd_addforward(epf->daddr, epf->dport,
4090 epf->saddr, epf->sport,
5188540b 4091 ssh, cfg,
84328ddb 4092 &epf->local,
4093 epf->addressfamily);
4094
4095 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4096 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4097 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4098 sportdesc, dportdesc,
4099 err ? " failed: " : "", err ? err : "");
4100 } else if (epf->type == 'D') {
06fadff5 4101 const char *err = pfd_addforward(NULL, -1,
84328ddb 4102 epf->saddr, epf->sport,
5188540b 4103 ssh, cfg,
84328ddb 4104 &epf->local,
4105 epf->addressfamily);
4106
4107 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4108 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4109 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4110 sportdesc,
4111 err ? " failed: " : "", err ? err : "");
06fadff5 4112 } else {
4113 struct ssh_rportfwd *pf;
4114
4115 /*
4116 * Ensure the remote port forwardings tree exists.
4117 */
4118 if (!ssh->rportfwds) {
4119 if (ssh->version == 1)
4120 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4121 else
4122 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4123 }
4124
4125 pf = snew(struct ssh_rportfwd);
84328ddb 4126 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4127 pf->dhost[lenof(pf->dhost)-1] = '\0';
4128 pf->dport = epf->dport;
4129 pf->sport = epf->sport;
06fadff5 4130 if (add234(ssh->rportfwds, pf) != pf) {
4131 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 4132 epf->daddr, epf->dport);
06fadff5 4133 sfree(pf);
4134 } else {
4135 logeventf(ssh, "Requesting remote port %s"
84328ddb 4136 " forward to %s", sportdesc, dportdesc);
06fadff5 4137
4138 pf->sportdesc = sportdesc;
4139 sportdesc = NULL;
84328ddb 4140 epf->remote = pf;
4141 pf->pfrec = epf;
06fadff5 4142
4143 if (ssh->version == 1) {
4144 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 4145 PKT_INT, epf->sport,
4146 PKT_STR, epf->daddr,
4147 PKT_INT, epf->dport,
06fadff5 4148 PKT_END);
4149 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4150 SSH1_SMSG_FAILURE,
4151 ssh_rportfwd_succfail, pf);
4152 } else {
4153 struct Packet *pktout;
4154 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4155 ssh2_pkt_addstring(pktout, "tcpip-forward");
4156 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 4157 if (epf->saddr) {
4158 ssh2_pkt_addstring(pktout, epf->saddr);
5188540b 4159 } else if (cfg->rport_acceptall) {
06fadff5 4160 ssh2_pkt_addstring(pktout, "0.0.0.0");
4161 } else {
4162 ssh2_pkt_addstring(pktout, "127.0.0.1");
4163 }
84328ddb 4164 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 4165 ssh2_pkt_send(ssh, pktout);
4166
4167 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4168 SSH2_MSG_REQUEST_FAILURE,
4169 ssh_rportfwd_succfail, pf);
4170 }
4171 }
4172 }
4173 sfree(sportdesc);
84328ddb 4174 sfree(dportdesc);
06fadff5 4175 }
06fadff5 4176}
4177
51df0ab5 4178static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4179{
4180 char *string;
4181 int stringlen, bufsize;
4182
4183 ssh_pkt_getstring(pktin, &string, &stringlen);
4184 if (string == NULL) {
4185 bombout(("Incoming terminal data packet was badly formed"));
4186 return;
4187 }
4188
4189 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4190 string, stringlen);
4191 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4192 ssh->v1_stdout_throttling = 1;
4193 ssh1_throttle(ssh, +1);
4194 }
4195}
4196
4197static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4198{
4199 /* Remote side is trying to open a channel to talk to our
4200 * X-Server. Give them back a local channel number. */
4201 struct ssh_channel *c;
4202 int remoteid = ssh_pkt_getuint32(pktin);
4203
4204 logevent("Received X11 connect request");
4205 /* Refuse if X11 forwarding is disabled. */
4206 if (!ssh->X11_fwd_enabled) {
4207 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4208 PKT_INT, remoteid, PKT_END);
4209 logevent("Rejected X11 connect request");
4210 } else {
4211 c = snew(struct ssh_channel);
4212 c->ssh = ssh;
4213
4214 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4215 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4216 logevent("Opening X11 forward connection failed");
4217 sfree(c);
4218 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4219 PKT_INT, remoteid, PKT_END);
4220 } else {
4221 logevent
4222 ("Opening X11 forward connection succeeded");
4223 c->remoteid = remoteid;
64d6ff88 4224 c->halfopen = FALSE;
51df0ab5 4225 c->localid = alloc_channel_id(ssh);
4226 c->closes = 0;
4227 c->v.v1.throttling = 0;
4228 c->type = CHAN_X11; /* identify channel type */
4229 add234(ssh->channels, c);
4230 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4231 PKT_INT, c->remoteid, PKT_INT,
4232 c->localid, PKT_END);
4233 logevent("Opened X11 forward channel");
4234 }
4235 }
4236}
4237
4238static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4239{
4240 /* Remote side is trying to open a channel to talk to our
4241 * agent. Give them back a local channel number. */
4242 struct ssh_channel *c;
4243 int remoteid = ssh_pkt_getuint32(pktin);
4244
4245 /* Refuse if agent forwarding is disabled. */
4246 if (!ssh->agentfwd_enabled) {
4247 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4248 PKT_INT, remoteid, PKT_END);
4249 } else {
4250 c = snew(struct ssh_channel);
4251 c->ssh = ssh;
4252 c->remoteid = remoteid;
64d6ff88 4253 c->halfopen = FALSE;
51df0ab5 4254 c->localid = alloc_channel_id(ssh);
4255 c->closes = 0;
4256 c->v.v1.throttling = 0;
4257 c->type = CHAN_AGENT; /* identify channel type */
4258 c->u.a.lensofar = 0;
4259 add234(ssh->channels, c);
4260 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4261 PKT_INT, c->remoteid, PKT_INT, c->localid,
4262 PKT_END);
4263 }
4264}
4265
4266static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4267{
4268 /* Remote side is trying to open a channel to talk to a
4269 * forwarded port. Give them back a local channel number. */
4270 struct ssh_channel *c;
05581745 4271 struct ssh_rportfwd pf, *pfp;
51df0ab5 4272 int remoteid;
4273 int hostsize, port;
fb983202 4274 char *host;
51df0ab5 4275 const char *e;
4276 c = snew(struct ssh_channel);
4277 c->ssh = ssh;
4278
4279 remoteid = ssh_pkt_getuint32(pktin);
4280 ssh_pkt_getstring(pktin, &host, &hostsize);
4281 port = ssh_pkt_getuint32(pktin);
4282
4283 if (hostsize >= lenof(pf.dhost))
4284 hostsize = lenof(pf.dhost)-1;
4285 memcpy(pf.dhost, host, hostsize);
4286 pf.dhost[hostsize] = '\0';
4287 pf.dport = port;
05581745 4288 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4289
05581745 4290 if (pfp == NULL) {
fb983202 4291 logeventf(ssh, "Rejected remote port open request for %s:%d",
4292 pf.dhost, port);
51df0ab5 4293 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4294 PKT_INT, remoteid, PKT_END);
4295 } else {
fb983202 4296 logeventf(ssh, "Received remote port open request for %s:%d",
4297 pf.dhost, port);
51df0ab5 4298 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
05581745 4299 c, &ssh->cfg, pfp->pfrec->addressfamily);
51df0ab5 4300 if (e != NULL) {
fb983202 4301 logeventf(ssh, "Port open failed: %s", e);
51df0ab5 4302 sfree(c);
4303 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4304 PKT_INT, remoteid, PKT_END);
4305 } else {
4306 c->remoteid = remoteid;
64d6ff88 4307 c->halfopen = FALSE;
51df0ab5 4308 c->localid = alloc_channel_id(ssh);
4309 c->closes = 0;
4310 c->v.v1.throttling = 0;
4311 c->type = CHAN_SOCKDATA; /* identify channel type */
4312 add234(ssh->channels, c);
4313 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4314 PKT_INT, c->remoteid, PKT_INT,
4315 c->localid, PKT_END);
4316 logevent("Forwarded port opened successfully");
4317 }
4318 }
4319}
4320
4321static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4322{
4323 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4324 unsigned int localid = ssh_pkt_getuint32(pktin);
4325 struct ssh_channel *c;
4326
4327 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4328 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4329 c->remoteid = localid;
64d6ff88 4330 c->halfopen = FALSE;
51df0ab5 4331 c->type = CHAN_SOCKDATA;
4332 c->v.v1.throttling = 0;
4333 pfd_confirm(c->u.pfd.s);
4334 }
4335
4336 if (c && c->closes) {
4337 /*
4338 * We have a pending close on this channel,
4339 * which we decided on before the server acked
4340 * the channel open. So now we know the
4341 * remoteid, we can close it again.
4342 */
4343 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4344 PKT_INT, c->remoteid, PKT_END);
4345 }
4346}
4347
4348static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4349{
4350 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4351 struct ssh_channel *c;
4352
4353 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4354 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4355 logevent("Forwarded connection refused by server");
4356 pfd_close(c->u.pfd.s);
4357 del234(ssh->channels, c);
4358 sfree(c);
4359 }
4360}
4361
4362static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4363{
4364 /* Remote side closes a channel. */
4365 unsigned i = ssh_pkt_getuint32(pktin);
4366 struct ssh_channel *c;
4367 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 4368 if (c && !c->halfopen) {
51df0ab5 4369 int closetype;
4370 closetype =
4371 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4372
4373 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4374 logevent("Forwarded X11 connection terminated");
4375 assert(c->u.x11.s != NULL);
4376 x11_close(c->u.x11.s);
4377 c->u.x11.s = NULL;
4378 }
4379 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4380 logevent("Forwarded port closed");
4381 assert(c->u.pfd.s != NULL);
4382 pfd_close(c->u.pfd.s);
4383 c->u.pfd.s = NULL;
4384 }
4385
4386 c->closes |= (closetype << 2); /* seen this message */
4387 if (!(c->closes & closetype)) {
4388 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4389 PKT_END);
4390 c->closes |= closetype; /* sent it too */
4391 }
4392
4393 if (c->closes == 15) {
4394 del234(ssh->channels, c);
4395 sfree(c);
4396 }
4397 } else {
4398 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4399 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4400 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4401 i));
4402 }
4403}
4404
4405static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4406{
4407 /* Data sent down one of our channels. */
4408 int i = ssh_pkt_getuint32(pktin);
4409 char *p;
6d44acc9 4410 int len;
51df0ab5 4411 struct ssh_channel *c;
4412
4413 ssh_pkt_getstring(pktin, &p, &len);
4414
4415 c = find234(ssh->channels, &i, ssh_channelfind);
4416 if (c) {
4417 int bufsize = 0;
4418 switch (c->type) {
4419 case CHAN_X11:
4420 bufsize = x11_send(c->u.x11.s, p, len);
4421 break;
4422 case CHAN_SOCKDATA:
4423 bufsize = pfd_send(c->u.pfd.s, p, len);
4424 break;
4425 case CHAN_AGENT:
4426 /* Data for an agent message. Buffer it. */
4427 while (len > 0) {
4428 if (c->u.a.lensofar < 4) {
aa63ab7e 4429 unsigned int l = min(4 - c->u.a.lensofar, len);
51df0ab5 4430 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4431 l);
4432 p += l;
4433 len -= l;
4434 c->u.a.lensofar += l;
4435 }
4436 if (c->u.a.lensofar == 4) {
4437 c->u.a.totallen =
4438 4 + GET_32BIT(c->u.a.msglen);
4439 c->u.a.message = snewn(c->u.a.totallen,
4440 unsigned char);
4441 memcpy(c->u.a.message, c->u.a.msglen, 4);
4442 }
4443 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 4444 unsigned int l =
51df0ab5 4445 min(c->u.a.totallen - c->u.a.lensofar,
4446 len);
4447 memcpy(c->u.a.message + c->u.a.lensofar, p,
4448 l);
4449 p += l;
4450 len -= l;
4451 c->u.a.lensofar += l;
4452 }
4453 if (c->u.a.lensofar == c->u.a.totallen) {
4454 void *reply;
4455 int replylen;
4456 if (agent_query(c->u.a.message,
4457 c->u.a.totallen,
4458 &reply, &replylen,
4459 ssh_agentf_callback, c))
4460 ssh_agentf_callback(c, reply, replylen);
4461 sfree(c->u.a.message);
4462 c->u.a.lensofar = 0;
4463 }
4464 }
4465 bufsize = 0; /* agent channels never back up */
4466 break;
4467 }
4468 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4469 c->v.v1.throttling = 1;
4470 ssh1_throttle(ssh, +1);
4471 }
4472 }
4473}
4474
4475static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4476{
51df0ab5 4477 ssh->exitcode = ssh_pkt_getuint32(pktin);
fb983202 4478 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
51df0ab5 4479 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4480 /*
4481 * In case `helpful' firewalls or proxies tack
4482 * extra human-readable text on the end of the
4483 * session which we might mistake for another
4484 * encrypted packet, we close the session once
4485 * we've sent EXIT_CONFIRMATION.
4486 */
ac934965 4487 ssh->close_expected = TRUE;
51df0ab5 4488 ssh_closing((Plug)ssh, NULL, 0, 0);
4489}
4490
b09eaa88 4491static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4492 struct Packet *pktin)
32874aea 4493{
b09eaa88 4494 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 4495
51df0ab5 4496 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4497 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4498 ssh1_smsg_stdout_stderr_data;
4499
4500 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4501 ssh1_msg_channel_open_confirmation;
4502 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4503 ssh1_msg_channel_open_failure;
4504 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4505 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4506 ssh1_msg_channel_close;
4507 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4508 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4509
86916870 4510 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 4511 logevent("Requesting agent forwarding");
51470298 4512 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 4513 do {
4514 crReturnV;
ff3187f6 4515 } while (!pktin);
4516 if (pktin->type != SSH1_SMSG_SUCCESS
4517 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4518 bombout(("Protocol confusion"));
7ffdbc1a 4519 crStopV;
ff3187f6 4520 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4521 logevent("Agent forwarding refused");
4522 } else {
4523 logevent("Agent forwarding enabled");
51470298 4524 ssh->agentfwd_enabled = TRUE;
51df0ab5 4525 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 4526 }
dacbd0e8 4527 }
4528
86916870 4529 if (ssh->cfg.x11_forward) {
32874aea 4530 char proto[20], data[64];
4531 logevent("Requesting X11 forwarding");
302121de 4532 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 4533 data, sizeof(data), ssh->cfg.x11_auth);
4534 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 4535 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4536 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4537 PKT_STR, proto, PKT_STR, data,
86916870 4538 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 4539 PKT_END);
32874aea 4540 } else {
51470298 4541 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4542 PKT_STR, proto, PKT_STR, data, PKT_END);
4543 }
4544 do {
4545 crReturnV;
ff3187f6 4546 } while (!pktin);
4547 if (pktin->type != SSH1_SMSG_SUCCESS
4548 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4549 bombout(("Protocol confusion"));
7ffdbc1a 4550 crStopV;
ff3187f6 4551 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4552 logevent("X11 forwarding refused");
4553 } else {
4554 logevent("X11 forwarding enabled");
51470298 4555 ssh->X11_fwd_enabled = TRUE;
51df0ab5 4556 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 4557 }
4558 }
4559
06fadff5 4560 ssh_setup_portfwd(ssh, &ssh->cfg);
4561 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 4562
86916870 4563 if (!ssh->cfg.nopty) {
a5dd8467 4564 /* Unpick the terminal-speed string. */
4565 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4566 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4567 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4568 /* Send the pty request. */
51470298 4569 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 4570 PKT_STR, ssh->cfg.termtype,
51470298 4571 PKT_INT, ssh->term_height,
4572 PKT_INT, ssh->term_width,
a5dd8467 4573 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 4574 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4575 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 4576 PKT_CHAR, 0, PKT_END);
51470298 4577 ssh->state = SSH_STATE_INTERMED;
32874aea 4578 do {
4579 crReturnV;
ff3187f6 4580 } while (!pktin);
4581 if (pktin->type != SSH1_SMSG_SUCCESS
4582 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4583 bombout(("Protocol confusion"));
7ffdbc1a 4584 crStopV;
ff3187f6 4585 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4586 c_write_str(ssh, "Server refused to allocate pty\r\n");
4587 ssh->editing = ssh->echoing = 1;
32874aea 4588 }
a5dd8467 4589 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4590 ssh->ospeed, ssh->ispeed);
0965bee0 4591 } else {
51470298 4592 ssh->editing = ssh->echoing = 1;
374330e2 4593 }
4594
86916870 4595 if (ssh->cfg.compression) {
51470298 4596 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4597 do {
4598 crReturnV;
ff3187f6 4599 } while (!pktin);
4600 if (pktin->type != SSH1_SMSG_SUCCESS
4601 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4602 bombout(("Protocol confusion"));
7ffdbc1a 4603 crStopV;
ff3187f6 4604 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4605 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4606 }
4ba9b64b 4607 logevent("Started compression");
51470298 4608 ssh->v1_compressing = TRUE;
5366aed8 4609 ssh->cs_comp_ctx = zlib_compress_init();
4610 logevent("Initialised zlib (RFC1950) compression");
4611 ssh->sc_comp_ctx = zlib_decompress_init();
4612 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4613 }
4614
fd5e5847 4615 /*
4616 * Start the shell or command.
4617 *
4618 * Special case: if the first-choice command is an SSH2
4619 * subsystem (hence not usable here) and the second choice
4620 * exists, we fall straight back to that.
4621 */
4622 {
86916870 4623 char *cmd = ssh->cfg.remote_cmd_ptr;
04c52f10 4624
4625 if (!cmd) cmd = ssh->cfg.remote_cmd;
fd5e5847 4626
86916870 4627 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4628 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 4629 ssh->fallback_cmd = TRUE;
fd5e5847 4630 }
4631 if (*cmd)
51470298 4632 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 4633 else
51470298 4634 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 4635 logevent("Started session");
4636 }
374330e2 4637
51470298 4638 ssh->state = SSH_STATE_SESSION;
4639 if (ssh->size_needed)
4640 ssh_size(ssh, ssh->term_width, ssh->term_height);
4641 if (ssh->eof_needed)
4642 ssh_special(ssh, TS_EOF);
374330e2 4643
b9d7bcad 4644 if (ssh->ldisc)
4645 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 4646 ssh->send_ok = 1;
4647 ssh->channels = newtree234(ssh_channelcmp);
374330e2 4648 while (1) {
d74d141c 4649
51df0ab5 4650 /*
4651 * By this point, most incoming packets are already being
4652 * handled by the dispatch table, and we need only pay
4653 * attention to the unusual ones.
4654 */
0357890f 4655
51df0ab5 4656 crReturnV;
4657 if (pktin) {
4658 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4659 /* may be from EXEC_SHELL on some servers */
ff3187f6 4660 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 4661 /* may be from EXEC_SHELL on some servers
374330e2 4662 * if no pty is available or in other odd cases. Ignore */
374330e2 4663 } else {
ff3187f6 4664 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 4665 crStopV;
374330e2 4666 }
4667 } else {
8df7a775 4668 while (inlen > 0) {
4669 int len = min(inlen, 512);
9a10ecf4 4670 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4671 PKT_INT, len, PKT_DATA, in, len,
4672 PKTT_OTHER, PKT_END);
8df7a775 4673 in += len;
4674 inlen -= len;
4675 }
374330e2 4676 }
4677 }
4678
4679 crFinishV;
4680}
4681
4682/*
b09eaa88 4683 * Handle the top-level SSH2 protocol.
4684 */
4685static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4686{
fb983202 4687 char *msg;
b09eaa88 4688 int msglen;
4689
4690 ssh_pkt_getstring(pktin, &msg, &msglen);
fb983202 4691 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 4692}
4693
4694static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4695{
4696 /* log reason code in disconnect message */
4697 char *msg;
4698 int msglen;
4699
4700 ssh_pkt_getstring(pktin, &msg, &msglen);
4701 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4702}
4703
409bfa77 4704static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
b09eaa88 4705{
4706 /* Do nothing, because we're ignoring it! Duhh. */
4707}
4708
4709static void ssh1_protocol_setup(Ssh ssh)
4710{
4711 int i;
4712
4713 /*
4714 * Most messages are handled by the coroutines.
4715 */
4716 for (i = 0; i < 256; i++)
4717 ssh->packet_dispatch[i] = NULL;
4718
4719 /*
4720 * These special message types we install handlers for.
4721 */
4722 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4723 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4724 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4725}
4726
1c1a7262 4727static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
b09eaa88 4728 struct Packet *pktin)
4729{
1c1a7262 4730 unsigned char *in=(unsigned char*)vin;
b09eaa88 4731 if (ssh->state == SSH_STATE_CLOSED)
4732 return;
4733
4734 if (pktin && ssh->packet_dispatch[pktin->type]) {
4735 ssh->packet_dispatch[pktin->type](ssh, pktin);
4736 return;
4737 }
4738
4739 if (!ssh->protocol_initial_phase_done) {
4740 if (do_ssh1_login(ssh, in, inlen, pktin))
4741 ssh->protocol_initial_phase_done = TRUE;
4742 else
4743 return;
4744 }
4745
4746 do_ssh1_connection(ssh, in, inlen, pktin);
4747}
4748
4749/*
e5574168 4750 * Utility routine for decoding comma-separated strings in KEXINIT.
4751 */
32874aea 4752static int in_commasep_string(char *needle, char *haystack, int haylen)
4753{
57356d63 4754 int needlen;
4755 if (!needle || !haystack) /* protect against null pointers */
4756 return 0;
4757 needlen = strlen(needle);
e5574168 4758 while (1) {
32874aea 4759 /*
4760 * Is it at the start of the string?
4761 */
4762 if (haylen >= needlen && /* haystack is long enough */
4763 !memcmp(needle, haystack, needlen) && /* initial match */
4764 (haylen == needlen || haystack[needlen] == ',')
4765 /* either , or EOS follows */
4766 )
4767 return 1;
4768 /*
4769 * If not, search for the next comma and resume after that.
4770 * If no comma found, terminate.
4771 */
4772 while (haylen > 0 && *haystack != ',')
4773 haylen--, haystack++;
4774 if (haylen == 0)
4775 return 0;
4776 haylen--, haystack++; /* skip over comma itself */
e5574168 4777 }
4778}
4779
4780/*
b59743d5 4781 * Similar routine for checking whether we have the first string in a list.
4782 */
4783static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4784{
4785 int needlen;
4786 if (!needle || !haystack) /* protect against null pointers */
4787 return 0;
4788 needlen = strlen(needle);
4789 /*
4790 * Is it at the start of the string?
4791 */
4792 if (haylen >= needlen && /* haystack is long enough */
4793 !memcmp(needle, haystack, needlen) && /* initial match */
4794 (haylen == needlen || haystack[needlen] == ',')
4795 /* either , or EOS follows */
4796 )
4797 return 1;
4798 return 0;
4799}
4800
4801
4802/*
d39f364a 4803 * SSH2 key creation method.
4804 */
d8baa528 4805static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4806 unsigned char *sessid, char chr,
4807 unsigned char *keyspace)
32874aea 4808{
d39f364a 4809 SHA_State s;
4810 /* First 20 bytes. */
4811 SHA_Init(&s);
51470298 4812 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4813 sha_mpint(&s, K);
d39f364a 4814 SHA_Bytes(&s, H, 20);
4815 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 4816 SHA_Bytes(&s, sessid, 20);
d39f364a 4817 SHA_Final(&s, keyspace);
4818 /* Next 20 bytes. */
4819 SHA_Init(&s);
51470298 4820 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4821 sha_mpint(&s, K);
d39f364a 4822 SHA_Bytes(&s, H, 20);
4823 SHA_Bytes(&s, keyspace, 20);
32874aea 4824 SHA_Final(&s, keyspace + 20);
d39f364a 4825}
4826
4827/*
7cca0d81 4828 * Handle the SSH2 transport layer.
e5574168 4829 */
1c1a7262 4830static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
ff3187f6 4831 struct Packet *pktin)
e5574168 4832{
1c1a7262 4833 unsigned char *in = (unsigned char *)vin;
51470298 4834 struct do_ssh2_transport_state {
4763c1c2 4835 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
51470298 4836 Bignum p, g, e, f, K;
4837 int kex_init_value, kex_reply_value;
4838 const struct ssh_mac **maclist;
4839 int nmacs;
4840 const struct ssh2_cipher *cscipher_tobe;
4841 const struct ssh2_cipher *sccipher_tobe;
4842 const struct ssh_mac *csmac_tobe;
4843 const struct ssh_mac *scmac_tobe;
4844 const struct ssh_compress *cscomp_tobe;
4845 const struct ssh_compress *sccomp_tobe;
4846 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4847 int hostkeylen, siglen;
4848 void *hkey; /* actual host key */
4849 unsigned char exchange_hash[20];
83e7d008 4850 int n_preferred_kex;
4851 const struct ssh_kex *preferred_kex[KEX_MAX];
51470298 4852 int n_preferred_ciphers;
4853 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4854 const struct ssh_compress *preferred_comp;
e13bba36 4855 int got_session_id, activated_authconn;
ff3187f6 4856 struct Packet *pktout;
3d9449a1 4857 int dlgret;
4858 int guessok;
4763c1c2 4859 int ignorepkt;
51470298 4860 };
4861 crState(do_ssh2_transport_state);
4862
4863 crBegin(ssh->do_ssh2_transport_crstate);
4864
4865 s->cscipher_tobe = s->sccipher_tobe = NULL;
4866 s->csmac_tobe = s->scmac_tobe = NULL;
4867 s->cscomp_tobe = s->sccomp_tobe = NULL;
4868
e13bba36 4869 s->got_session_id = s->activated_authconn = FALSE;
e5574168 4870
e13bba36 4871 /*
4872 * Be prepared to work around the buggy MAC problem.
4873 */
4874 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4875 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4876 else
4877 s->maclist = macs, s->nmacs = lenof(macs);
4878
4879 begin_key_exchange:
149d2abc 4880 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
51470298 4881 {
e13bba36 4882 int i, j, commalist_started;
4883
51470298 4884 /*
83e7d008 4885 * Set up the preferred key exchange. (NULL => warn below here)
4886 */
4887 s->n_preferred_kex = 0;
4888 for (i = 0; i < KEX_MAX; i++) {
4889 switch (ssh->cfg.ssh_kexlist[i]) {
4890 case KEX_DHGEX:
4891 s->preferred_kex[s->n_preferred_kex++] =
4892 &ssh_diffiehellman_gex;
4893 break;
4894 case KEX_DHGROUP14:
4895 s->preferred_kex[s->n_preferred_kex++] =
4896 &ssh_diffiehellman_group14;
4897 break;
4898 case KEX_DHGROUP1:
4899 s->preferred_kex[s->n_preferred_kex++] =
4900 &ssh_diffiehellman_group1;
4901 break;
4902 case CIPHER_WARN:
4903 /* Flag for later. Don't bother if it's the last in
4904 * the list. */
4905 if (i < KEX_MAX - 1) {
4906 s->preferred_kex[s->n_preferred_kex++] = NULL;
4907 }
4908 break;
4909 }
4910 }
83e7d008 4911
83e7d008 4912 /*
51470298 4913 * Set up the preferred ciphers. (NULL => warn below here)
4914 */
4915 s->n_preferred_ciphers = 0;
4916 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4917 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4918 case CIPHER_BLOWFISH:
4919 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4920 break;
4921 case CIPHER_DES:
86916870 4922 if (ssh->cfg.ssh2_des_cbc) {
51470298 4923 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4924 }
4925 break;
4926 case CIPHER_3DES:
4927 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4928 break;
4929 case CIPHER_AES:
4930 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4931 break;
4932 case CIPHER_WARN:
4933 /* Flag for later. Don't bother if it's the last in
4934 * the list. */
4935 if (i < CIPHER_MAX - 1) {
4936 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4937 }
4938 break;
ca20bfcf 4939 }
ca20bfcf 4940 }
7591b9ff 4941
e13bba36 4942 /*
4943 * Set up preferred compression.
4944 */
4945 if (ssh->cfg.compression)
4946 s->preferred_comp = &ssh_zlib;
4947 else
4948 s->preferred_comp = &ssh_comp_none;
51470298 4949
4950 /*
590f6a5f 4951 * Enable queueing of outgoing auth- or connection-layer
4952 * packets while we are in the middle of a key exchange.
4953 */
4954 ssh->queueing = TRUE;
4955
4956 /*
9442dd57 4957 * Flag that KEX is in progress.
4958 */
4959 ssh->kex_in_progress = TRUE;
4960
4961 /*
51470298 4962 * Construct and send our key exchange packet.
4963 */
ff3187f6 4964 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 4965 for (i = 0; i < 16; i++)
ff3187f6 4966 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 4967 /* List key exchange algorithms. */
ff3187f6 4968 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4969 commalist_started = 0;
4970 for (i = 0; i < s->n_preferred_kex; i++) {
4971 const struct ssh_kex *k = s->preferred_kex[i];
4972 if (!k) continue; /* warning flag */
4973 if (commalist_started)
ff3187f6 4974 ssh2_pkt_addstring_str(s->pktout, ",");
83e7d008 4975 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4976 commalist_started = 1;
32874aea 4977 }
51470298 4978 /* List server host key algorithms. */
ff3187f6 4979 ssh2_pkt_addstring_start(s->pktout);
51470298 4980 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 4981 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 4982 if (i < lenof(hostkey_algs) - 1)
ff3187f6 4983 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4984 }
51470298 4985 /* List client->server encryption algorithms. */
ff3187f6 4986 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4987 commalist_started = 0;
51470298 4988 for (i = 0; i < s->n_preferred_ciphers; i++) {
4989 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4990 if (!c) continue; /* warning flag */
4991 for (j = 0; j < c->nciphers; j++) {
83e7d008 4992 if (commalist_started)
ff3187f6 4993 ssh2_pkt_addstring_str(s->pktout, ",");
4994 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4995 commalist_started = 1;
51470298 4996 }
4997 }
4998 /* List server->client encryption algorithms. */
ff3187f6 4999 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5000 commalist_started = 0;
51470298 5001 for (i = 0; i < s->n_preferred_ciphers; i++) {
5002 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5003 if (!c) continue; /* warning flag */
5004 for (j = 0; j < c->nciphers; j++) {
83e7d008 5005 if (commalist_started)
ff3187f6 5006 ssh2_pkt_addstring_str(s->pktout, ",");
5007 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 5008 commalist_started = 1;
51470298 5009 }
5010 }
5011 /* List client->server MAC algorithms. */
ff3187f6 5012 ssh2_pkt_addstring_start(s->pktout);
51470298 5013 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5014 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5015 if (i < s->nmacs - 1)
ff3187f6 5016 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5017 }
5018 /* List server->client MAC algorithms. */
ff3187f6 5019 ssh2_pkt_addstring_start(s->pktout);
51470298 5020 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5021 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5022 if (i < s->nmacs - 1)
ff3187f6 5023 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5024 }
5025 /* List client->server compression algorithms. */
ff3187f6 5026 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 5027 assert(lenof(compressions) > 1);
ff3187f6 5028 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 5029 for (i = 0; i < lenof(compressions); i++) {
5030 const struct ssh_compress *c = compressions[i];
5031 if (c != s->preferred_comp) {
ff3187f6 5032 ssh2_pkt_addstring_str(s->pktout, ",");
5033 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 5034 }
51470298 5035 }
5036 /* List server->client compression algorithms. */
ff3187f6 5037 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 5038 assert(lenof(compressions) > 1);
ff3187f6 5039 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 5040 for (i = 0; i < lenof(compressions); i++) {
5041 const struct ssh_compress *c = compressions[i];
5042 if (c != s->preferred_comp) {
ff3187f6 5043 ssh2_pkt_addstring_str(s->pktout, ",");
5044 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 5045 }
51470298 5046 }
5047 /* List client->server languages. Empty list. */
ff3187f6 5048 ssh2_pkt_addstring_start(s->pktout);
51470298 5049 /* List server->client languages. Empty list. */
ff3187f6 5050 ssh2_pkt_addstring_start(s->pktout);
51470298 5051 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 5052 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 5053 /* Reserved. */
ff3187f6 5054 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 5055 }
0db56f73 5056
51470298 5057 ssh->exhash = ssh->exhashbase;
ff3187f6 5058 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
0db56f73 5059
590f6a5f 5060 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5061
ff3187f6 5062 if (!pktin)
5063 crWaitUntil(pktin);
5064 if (pktin->length > 5)
5065 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
e5574168 5066
5067 /*
5068 * Now examine the other side's KEXINIT to see what we're up
5069 * to.
5070 */
51470298 5071 {
4763c1c2 5072 char *str, *preferred;
3d9449a1 5073 int i, j, len;
51470298 5074
ff3187f6 5075 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 5076 bombout(("expected key exchange packet from server"));
7ffdbc1a 5077 crStop(0);
32874aea 5078 }
51470298 5079 ssh->kex = NULL;
5080 ssh->hostkey = NULL;
5081 s->cscipher_tobe = NULL;
5082 s->sccipher_tobe = NULL;
5083 s->csmac_tobe = NULL;
5084 s->scmac_tobe = NULL;
5085 s->cscomp_tobe = NULL;
5086 s->sccomp_tobe = NULL;
4763c1c2 5087 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5088
ff3187f6 5089 pktin->savedpos += 16; /* skip garbage cookie */
5090 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4763c1c2 5091
5092 preferred = NULL;
83e7d008 5093 for (i = 0; i < s->n_preferred_kex; i++) {
5094 const struct ssh_kex *k = s->preferred_kex[i];
5095 if (!k) {
4763c1c2 5096 s->warn_kex = TRUE;
5097 } else {
5098 if (!preferred) preferred = k->name;
5099 if (in_commasep_string(k->name, str, len))
5100 ssh->kex = k;
83e7d008 5101 }
4763c1c2 5102 if (ssh->kex)
51470298 5103 break;
32874aea 5104 }
83e7d008 5105 if (!ssh->kex) {
5106 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5107 str ? str : "(null)"));
5108 crStop(0);
5109 }
b59743d5 5110 /*
5111 * Note that the server's guess is considered wrong if it doesn't match
5112 * the first algorithm in our list, even if it's still the algorithm
5113 * we end up using.
5114 */
4763c1c2 5115 s->guessok = first_in_commasep_string(preferred, str, len);
ff3187f6 5116 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 5117 for (i = 0; i < lenof(hostkey_algs); i++) {
5118 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5119 ssh->hostkey = hostkey_algs[i];
5120 break;
5121 }
5122 }
3d9449a1 5123 s->guessok = s->guessok &&
b59743d5 5124 first_in_commasep_string(hostkey_algs[0]->name, str, len);
ff3187f6 5125 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 5126 for (i = 0; i < s->n_preferred_ciphers; i++) {
5127 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5128 if (!c) {
4763c1c2 5129 s->warn_cscipher = TRUE;
51470298 5130 } else {
5131 for (j = 0; j < c->nciphers; j++) {
5132 if (in_commasep_string(c->list[j]->name, str, len)) {
5133 s->cscipher_tobe = c->list[j];
5134 break;
5135 }
ca20bfcf 5136 }
32874aea 5137 }
4763c1c2 5138 if (s->cscipher_tobe)
51470298 5139 break;
32874aea 5140 }
51470298 5141 if (!s->cscipher_tobe) {
6b5cf8b4 5142 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 5143 str ? str : "(null)"));
7ffdbc1a 5144 crStop(0);
ca20bfcf 5145 }
0ef8f407 5146
ff3187f6 5147 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 5148 for (i = 0; i < s->n_preferred_ciphers; i++) {
5149 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5150 if (!c) {
4763c1c2 5151 s->warn_sccipher = TRUE;
51470298 5152 } else {
5153 for (j = 0; j < c->nciphers; j++) {
5154 if (in_commasep_string(c->list[j]->name, str, len)) {
5155 s->sccipher_tobe = c->list[j];
5156 break;
5157 }
ca20bfcf 5158 }
32874aea 5159 }
4763c1c2 5160 if (s->sccipher_tobe)
51470298 5161 break;
32874aea 5162 }
51470298 5163 if (!s->sccipher_tobe) {
6b5cf8b4 5164 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 5165 str ? str : "(null)"));
7ffdbc1a 5166 crStop(0);
ca20bfcf 5167 }
0ef8f407 5168
ff3187f6 5169 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 5170 for (i = 0; i < s->nmacs; i++) {
5171 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5172 s->csmac_tobe = s->maclist[i];
5173 break;
5174 }
32874aea 5175 }
ff3187f6 5176 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 5177 for (i = 0; i < s->nmacs; i++) {
5178 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5179 s->scmac_tobe = s->maclist[i];
5180 break;
5181 }
32874aea 5182 }
ff3187f6 5183 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 5184 for (i = 0; i < lenof(compressions) + 1; i++) {
5185 const struct ssh_compress *c =
5186 i == 0 ? s->preferred_comp : compressions[i - 1];
5187 if (in_commasep_string(c->name, str, len)) {
5188 s->cscomp_tobe = c;
5189 break;
5190 }
32874aea 5191 }
ff3187f6 5192 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5193 for (i = 0; i < lenof(compressions) + 1; i++) {
5194 const struct ssh_compress *c =
5195 i == 0 ? s->preferred_comp : compressions[i - 1];
5196 if (in_commasep_string(c->name, str, len)) {
5197 s->sccomp_tobe = c;
5198 break;
5199 }
32874aea 5200 }
b59743d5 5201 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5202 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
4763c1c2 5203 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5204
5205 if (s->warn_kex) {
5206 ssh_set_frozen(ssh, 1);
5207 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5208 ssh->kex->name,
5209 ssh_dialog_callback, ssh);
5210 if (s->dlgret < 0) {
5211 do {
5212 crReturn(0);
5213 if (pktin) {
5214 bombout(("Unexpected data from server while"
5215 " waiting for user response"));
5216 crStop(0);
5217 }
5218 } while (pktin || inlen > 0);
5219 s->dlgret = ssh->user_response;
5220 }
5221 ssh_set_frozen(ssh, 0);
5222 if (s->dlgret == 0) {
5223 ssh->close_expected = TRUE;
5224 ssh_closing((Plug)ssh, NULL, 0, 0);
a5a6f839 5225 crStop(0);
4763c1c2 5226 }
5227 }
5228
5229 if (s->warn_cscipher) {
5230 ssh_set_frozen(ssh, 1);
5231 s->dlgret = askalg(ssh->frontend,
5232 "client-to-server cipher",
5233 s->cscipher_tobe->name,
5234 ssh_dialog_callback, ssh);
5235 if (s->dlgret < 0) {
5236 do {
5237 crReturn(0);
5238 if (pktin) {
5239 bombout(("Unexpected data from server while"
5240 " waiting for user response"));
5241 crStop(0);
5242 }
5243 } while (pktin || inlen > 0);
5244 s->dlgret = ssh->user_response;
5245 }
5246 ssh_set_frozen(ssh, 0);
5247 if (s->dlgret == 0) {
5248 ssh->close_expected = TRUE;
5249 ssh_closing((Plug)ssh, NULL, 0, 0);
a5a6f839 5250 crStop(0);
4763c1c2 5251 }
5252 }
5253
5254 if (s->warn_sccipher) {
5255 ssh_set_frozen(ssh, 1);
5256 s->dlgret = askalg(ssh->frontend,
5257 "server-to-client cipher",
5258 s->sccipher_tobe->name,
5259 ssh_dialog_callback, ssh);
5260 if (s->dlgret < 0) {
5261 do {
5262 crReturn(0);
5263 if (pktin) {
5264 bombout(("Unexpected data from server while"
5265 " waiting for user response"));
5266 crStop(0);
5267 }
5268 } while (pktin || inlen > 0);
5269 s->dlgret = ssh->user_response;
5270 }
5271 ssh_set_frozen(ssh, 0);
5272 if (s->dlgret == 0) {
5273 ssh->close_expected = TRUE;
5274 ssh_closing((Plug)ssh, NULL, 0, 0);
a5a6f839 5275 crStop(0);
4763c1c2 5276 }
5277 }
5278
5279 if (s->ignorepkt) /* first_kex_packet_follows */
b59743d5 5280 crWaitUntil(pktin); /* Ignore packet */
e5574168 5281 }
e5574168 5282
5283 /*
7bd5a860 5284 * Work out the number of bits of key we will need from the key
5285 * exchange. We start with the maximum key length of either
5286 * cipher...
5287 */
5288 {
32874aea 5289 int csbits, scbits;
7bd5a860 5290
51470298 5291 csbits = s->cscipher_tobe->keylen;
5292 scbits = s->sccipher_tobe->keylen;
5293 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 5294 }
5295 /* The keys only have 160-bit entropy, since they're based on
5296 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 5297 if (s->nbits > 160)
5298 s->nbits = 160;
7bd5a860 5299
5300 /*
a92dd380 5301 * If we're doing Diffie-Hellman group exchange, start by
5302 * requesting a group.
e5574168 5303 */
d1aaf71d 5304 if (!ssh->kex->pdata) {
32874aea 5305 logevent("Doing Diffie-Hellman group exchange");
51470298 5306 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 5307 /*
5308 * Work out how big a DH group we will need to allow that
5309 * much data.
7bd5a860 5310 */
51470298 5311 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 5312 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5313 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 5314 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 5315
ff3187f6 5316 crWaitUntil(pktin);
5317 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 5318 bombout(("expected key exchange group packet from server"));
7ffdbc1a 5319 crStop(0);
32874aea 5320 }
ff3187f6 5321 s->p = ssh2_pkt_getmp(pktin);
5322 s->g = ssh2_pkt_getmp(pktin);
5323 if (!s->p || !s->g) {
5324 bombout(("unable to read mp-ints from incoming group packet"));
5325 crStop(0);
5326 }
d1aaf71d 5327 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
51470298 5328 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5329 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 5330 } else {
d1aaf71d 5331 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5332 ssh->kex_ctx = dh_setup_group(ssh->kex);
51470298 5333 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5334 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
d1aaf71d 5335 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5336 ssh->kex->groupname);
8d5de777 5337 }
e5574168 5338
a92dd380 5339 logevent("Doing Diffie-Hellman key exchange");
e5574168 5340 /*
a92dd380 5341 * Now generate and send e for Diffie-Hellman.
e5574168 5342 */
755e0524 5343 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
27cd7fc2 5344 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 5345 s->pktout = ssh2_pkt_init(s->kex_init_value);
5346 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 5347 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5348
755e0524 5349 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
ff3187f6 5350 crWaitUntil(pktin);
5351 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 5352 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 5353 crStop(0);
7cca0d81 5354 }
755e0524 5355 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
ff3187f6 5356 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5357 s->f = ssh2_pkt_getmp(pktin);
5358 if (!s->f) {
5359 bombout(("unable to parse key exchange reply packet"));
5360 crStop(0);
5361 }
5362 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 5363
27cd7fc2 5364 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 5365
755e0524 5366 /* We assume everything from now on will be quick, and it might
5367 * involve user interaction. */
5368 set_busy_status(ssh->frontend, BUSY_NOT);
5369
51470298 5370 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5371 if (ssh->kex == &ssh_diffiehellman_gex) {
5372 sha_uint32(&ssh->exhash, s->pbits);
5373 sha_mpint(&ssh->exhash, s->p);
5374 sha_mpint(&ssh->exhash, s->g);
a92dd380 5375 }
51470298 5376 sha_mpint(&ssh->exhash, s->e);
5377 sha_mpint(&ssh->exhash, s->f);
5378 sha_mpint(&ssh->exhash, s->K);
5379 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 5380
27cd7fc2 5381 dh_cleanup(ssh->kex_ctx);
fabd1805 5382 ssh->kex_ctx = NULL;
3709bfe9 5383
7cca0d81 5384#if 0
765c4200 5385 debug(("Exchange hash is:\n"));
51470298 5386 dmemdump(s->exchange_hash, 20);
7cca0d81 5387#endif
5388
51470298 5389 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5390 if (!s->hkey ||
5391 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 5392 (char *)s->exchange_hash, 20)) {
6b5cf8b4 5393 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 5394 crStop(0);
8d5de777 5395 }
e5574168 5396
5397 /*
7cca0d81 5398 * Authenticate remote host: verify host key. (We've already
5399 * checked the signature of the exchange hash.)
e5574168 5400 */
51470298 5401 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5402 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
3d9449a1 5403 ssh_set_frozen(ssh, 1);
5404 s->dlgret = verify_ssh_host_key(ssh->frontend,
5405 ssh->savedhost, ssh->savedport,
5406 ssh->hostkey->keytype, s->keystr,
5407 s->fingerprint,
5408 ssh_dialog_callback, ssh);
5409 if (s->dlgret < 0) {
5410 do {
5411 crReturn(0);
5412 if (pktin) {
5413 bombout(("Unexpected data from server while waiting"
5414 " for user host key response"));
5415 crStop(0);
5416 }
5417 } while (pktin || inlen > 0);
5418 s->dlgret = ssh->user_response;
5419 }
5420 ssh_set_frozen(ssh, 0);
5421 if (s->dlgret == 0) {
5422 ssh->close_expected = TRUE;
5423 ssh_closing((Plug)ssh, NULL, 0, 0);
5424 crStop(0);
5425 }
e13bba36 5426 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 5427 logevent("Host key fingerprint is:");
51470298 5428 logevent(s->fingerprint);
5e0d7cb8 5429 }
51470298 5430 sfree(s->fingerprint);
5431 sfree(s->keystr);
5432 ssh->hostkey->freekey(s->hkey);
d39f364a 5433
5434 /*
9442dd57 5435 * The exchange hash from the very first key exchange is also
5436 * the session id, used in session key construction and
5437 * authentication.
5438 */
e13bba36 5439 if (!s->got_session_id) {
9442dd57 5440 memcpy(ssh->v2_session_id, s->exchange_hash,
5441 sizeof(s->exchange_hash));
e13bba36 5442 s->got_session_id = TRUE;
5443 }
9442dd57 5444
5445 /*
7cca0d81 5446 * Send SSH2_MSG_NEWKEYS.
d39f364a 5447 */
ff3187f6 5448 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 5449 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 5450 ssh->outgoing_data_size = 0; /* start counting from here */
5451
5452 /*
5453 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 5454 * client-to-server session keys.
9442dd57 5455 */
5456 if (ssh->cs_cipher_ctx)
5457 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5458 ssh->cscipher = s->cscipher_tobe;
5459 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5460
5461 if (ssh->cs_mac_ctx)
5462 ssh->csmac->free_context(ssh->cs_mac_ctx);
5463 ssh->csmac = s->csmac_tobe;
5464 ssh->cs_mac_ctx = ssh->csmac->make_context();
5465
5466 if (ssh->cs_comp_ctx)
5467 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5468 ssh->cscomp = s->cscomp_tobe;
5469 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5470
5471 /*
5472 * Set IVs on client-to-server keys. Here we use the exchange
5473 * hash from the _first_ key exchange.
5474 */
5475 {
5476 unsigned char keyspace[40];
5477 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5478 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5479 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5480 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5481 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5482 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5483 }
5484
5485 logeventf(ssh, "Initialised %.200s client->server encryption",
5486 ssh->cscipher->text_name);
5487 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5488 ssh->csmac->text_name);
5489 if (ssh->cscomp->text_name)
5490 logeventf(ssh, "Initialised %s compression",
5491 ssh->cscomp->text_name);
590f6a5f 5492
5493 /*
5494 * Now our end of the key exchange is complete, we can send all
5495 * our queued higher-layer packets.
5496 */
5497 ssh->queueing = FALSE;
5498 ssh2_pkt_queuesend(ssh);
d39f364a 5499
5500 /*
8406eaf9 5501 * Expect SSH2_MSG_NEWKEYS from server.
5502 */
ff3187f6 5503 crWaitUntil(pktin);
5504 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 5505 bombout(("expected new-keys packet from server"));
7ffdbc1a 5506 crStop(0);
8406eaf9 5507 }
9442dd57 5508 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 5509
5510 /*
9442dd57 5511 * We've seen server NEWKEYS, so create and initialise
5512 * server-to-client session keys.
d39f364a 5513 */
371e569c 5514 if (ssh->sc_cipher_ctx)
5515 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 5516 ssh->sccipher = s->sccipher_tobe;
371e569c 5517 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 5518
e0e1a00d 5519 if (ssh->sc_mac_ctx)
5520 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 5521 ssh->scmac = s->scmac_tobe;
e0e1a00d 5522 ssh->sc_mac_ctx = ssh->scmac->make_context();
5523
5366aed8 5524 if (ssh->sc_comp_ctx)
5525 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 5526 ssh->sccomp = s->sccomp_tobe;
5366aed8 5527 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5528
d39f364a 5529 /*
9442dd57 5530 * Set IVs on server-to-client keys. Here we use the exchange
5531 * hash from the _first_ key exchange.
d39f364a 5532 */
51470298 5533 {
5534 unsigned char keyspace[40];
51470298 5535 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 5536 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 5537 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 5538 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 5539 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 5540 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 5541 }
57356d63 5542 logeventf(ssh, "Initialised %.200s server->client encryption",
5543 ssh->sccipher->text_name);
6c135243 5544 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5545 ssh->scmac->text_name);
57356d63 5546 if (ssh->sccomp->text_name)
5547 logeventf(ssh, "Initialised %s decompression",
5548 ssh->sccomp->text_name);
9442dd57 5549
5550 /*
5551 * Free key exchange data.
5552 */
679539d7 5553 freebn(s->f);
679539d7 5554 freebn(s->K);
b3949e7e 5555 if (ssh->kex == &ssh_diffiehellman_gex) {
5556 freebn(s->g);
5557 freebn(s->p);
5558 }
d39f364a 5559
033b4cef 5560 /*
e13bba36 5561 * Key exchange is over. Loop straight back round if we have a
5562 * deferred rekey reason.
5563 */
5564 if (ssh->deferred_rekey_reason) {
5565 logevent(ssh->deferred_rekey_reason);
5566 pktin = NULL;
5567 ssh->deferred_rekey_reason = NULL;
5568 goto begin_key_exchange;
5569 }
5570
5571 /*
5572 * Otherwise, schedule a timer for our next rekey.
9442dd57 5573 */
5574 ssh->kex_in_progress = FALSE;
e6c1536e 5575 ssh->last_rekey = GETTICKCOUNT();
d57f70af 5576 if (ssh->cfg.ssh_rekey_time != 0)
5577 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5578 ssh2_timer, ssh);
e13bba36 5579
9442dd57 5580 /*
0db56f73 5581 * If this is the first key exchange phase, we must pass the
5582 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5583 * wants to see it but because it will need time to initialise
5584 * itself before it sees an actual packet. In subsequent key
5585 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5586 * it would only confuse the layer above.
5587 */
e13bba36 5588 if (s->activated_authconn) {
b09eaa88 5589 crReturn(1);
0db56f73 5590 }
e13bba36 5591 s->activated_authconn = TRUE;
0db56f73 5592
5593 /*
7cca0d81 5594 * Now we're encrypting. Begin returning 1 to the protocol main
5595 * function so that other things can run on top of the
5596 * transport. If we ever see a KEXINIT, we must go back to the
5597 * start.
9442dd57 5598 *
5599 * We _also_ go back to the start if we see pktin==NULL and
5600 * inlen==-1, because this is a special signal meaning
5601 * `initiate client-driven rekey', and `in' contains a message
5602 * giving the reason for the rekey.
033b4cef 5603 */
9442dd57 5604 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5605 (!pktin && inlen == -1))) {
f382c87d 5606 wait_for_rekey:
32874aea 5607 crReturn(1);
e96adf72 5608 }
9442dd57 5609 if (pktin) {
5610 logevent("Server initiated key re-exchange");
5611 } else {
f382c87d 5612 /*
5613 * Special case: if the server bug is set that doesn't
5614 * allow rekeying, we give a different log message and
5615 * continue waiting. (If such a server _initiates_ a rekey,
5616 * we process it anyway!)
5617 */
5618 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5619 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5620 (char *)in);
5621 /* Reset the counters, so that at least this message doesn't
5622 * hit the event log _too_ often. */
5623 ssh->outgoing_data_size = 0;
5624 ssh->incoming_data_size = 0;
5625 if (ssh->cfg.ssh_rekey_time != 0) {
5626 ssh->next_rekey =
5627 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5628 ssh2_timer, ssh);
5629 }
5630 goto wait_for_rekey; /* this is utterly horrid */
5631 } else {
5632 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
f382c87d 5633 }
9442dd57 5634 }
7cca0d81 5635 goto begin_key_exchange;
e5574168 5636
5637 crFinish(1);
5638}
5639
7cca0d81 5640/*
783415f8 5641 * Add data to an SSH2 channel output buffer.
5642 */
32874aea 5643static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5644 int len)
5645{
5471d09a 5646 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 5647}
5648
5649/*
5650 * Attempt to send data on an SSH2 channel.
5651 */
5471d09a 5652static int ssh2_try_send(struct ssh_channel *c)
32874aea 5653{
51470298 5654 Ssh ssh = c->ssh;
ff3187f6 5655 struct Packet *pktout;
51470298 5656
5471d09a 5657 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5658 int len;
5659 void *data;
5660 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5661 if ((unsigned)len > c->v.v2.remwindow)
5662 len = c->v.v2.remwindow;
5663 if ((unsigned)len > c->v.v2.remmaxpkt)
5664 len = c->v.v2.remmaxpkt;
ff3187f6 5665 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5666 ssh2_pkt_adduint32(pktout, c->remoteid);
5667 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5668 ssh2_pkt_addstring_start(pktout);
5669 ssh2_pkt_addstring_data(pktout, data, len);
5670 end_log_omission(ssh, pktout);
5671 ssh2_pkt_send(ssh, pktout);
5471d09a 5672 bufchain_consume(&c->v.v2.outbuffer, len);
5673 c->v.v2.remwindow -= len;
5674 }
5675
5676 /*
5677 * After having sent as much data as we can, return the amount
5678 * still buffered.
5679 */
5680 return bufchain_size(&c->v.v2.outbuffer);
5681}
5682
5683/*
5684 * Potentially enlarge the window on an SSH2 channel.
5685 */
5686static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5687{
51470298 5688 Ssh ssh = c->ssh;
5689
6b69f42e 5690 /*
5691 * Never send WINDOW_ADJUST for a channel that the remote side
5692 * already thinks it's closed; there's no point, since it won't
5693 * be sending any more data anyway.
5694 */
5695 if (c->closes != 0)
5696 return;
5697
d252310a 5698 /*
5699 * Only send a WINDOW_ADJUST if there's significantly more window
5700 * available than the other end thinks there is. This saves us
5701 * sending a WINDOW_ADJUST for every character in a shell session.
5702 *
5703 * "Significant" is arbitrarily defined as half the window size.
5704 */
5705 if (newwin > c->v.v2.locwindow * 2) {
ff3187f6 5706 struct Packet *pktout;
5707
5708 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5709 ssh2_pkt_adduint32(pktout, c->remoteid);
5710 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5711 ssh2_pkt_send(ssh, pktout);
5471d09a 5712 c->v.v2.locwindow = newwin;
783415f8 5713 }
5714}
5715
51df0ab5 5716static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 5717{
5718 unsigned i = ssh_pkt_getuint32(pktin);
5719 struct ssh_channel *c;
5720 c = find234(ssh->channels, &i, ssh_channelfind);
5721 if (c && !c->closes)
5722 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5723}
5724
51df0ab5 5725static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5726{
5727 char *data;
6d44acc9 5728 int length;
51df0ab5 5729 unsigned i = ssh_pkt_getuint32(pktin);
5730 struct ssh_channel *c;
5731 c = find234(ssh->channels, &i, ssh_channelfind);
5732 if (!c)
5733 return; /* nonexistent channel */
5734 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5735 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5736 return; /* extended but not stderr */
5737 ssh_pkt_getstring(pktin, &data, &length);
5738 if (data) {
5739 int bufsize = 0;
5740 c->v.v2.locwindow -= length;
5741 switch (c->type) {
5742 case CHAN_MAINSESSION:
5743 bufsize =
5744 from_backend(ssh->frontend, pktin->type ==
5745 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5746 data, length);
5747 break;
5748 case CHAN_X11:
5749 bufsize = x11_send(c->u.x11.s, data, length);
5750 break;
5751 case CHAN_SOCKDATA:
5752 bufsize = pfd_send(c->u.pfd.s, data, length);
5753 break;
5754 case CHAN_AGENT:
5755 while (length > 0) {
5756 if (c->u.a.lensofar < 4) {
aa63ab7e 5757 unsigned int l = min(4 - c->u.a.lensofar, length);
51df0ab5 5758 memcpy(c->u.a.msglen + c->u.a.lensofar,
5759 data, l);
5760 data += l;
5761 length -= l;
5762 c->u.a.lensofar += l;
5763 }
5764 if (c->u.a.lensofar == 4) {
5765 c->u.a.totallen =
5766 4 + GET_32BIT(c->u.a.msglen);
5767 c->u.a.message = snewn(c->u.a.totallen,
5768 unsigned char);
5769 memcpy(c->u.a.message, c->u.a.msglen, 4);
5770 }
5771 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 5772 unsigned int l =
51df0ab5 5773 min(c->u.a.totallen - c->u.a.lensofar,
5774 length);
5775 memcpy(c->u.a.message + c->u.a.lensofar,
5776 data, l);
5777 data += l;
5778 length -= l;
5779 c->u.a.lensofar += l;
5780 }
5781 if (c->u.a.lensofar == c->u.a.totallen) {
5782 void *reply;
5783 int replylen;
5784 if (agent_query(c->u.a.message,
5785 c->u.a.totallen,
5786 &reply, &replylen,
5787 ssh_agentf_callback, c))
5788 ssh_agentf_callback(c, reply, replylen);
5789 sfree(c->u.a.message);
5790 c->u.a.lensofar = 0;
5791 }
5792 }
5793 bufsize = 0;
5794 break;
5795 }
5796 /*
5797 * If we are not buffering too much data,
5798 * enlarge the window again at the remote side.
5799 */
5800 if (bufsize < OUR_V2_WINSIZE)
5801 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5802 }
5803}
5804
5805static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5806{
5807 unsigned i = ssh_pkt_getuint32(pktin);
5808 struct ssh_channel *c;
5809
5810 c = find234(ssh->channels, &i, ssh_channelfind);
5811 if (!c)
5812 return; /* nonexistent channel */
5813
5814 if (c->type == CHAN_X11) {
5815 /*
5816 * Remote EOF on an X11 channel means we should
5817 * wrap up and close the channel ourselves.
5818 */
5819 x11_close(c->u.x11.s);
5820 sshfwd_close(c);
5821 } else if (c->type == CHAN_AGENT) {
5822 sshfwd_close(c);
5823 } else if (c->type == CHAN_SOCKDATA) {
5824 pfd_close(c->u.pfd.s);
5825 sshfwd_close(c);
5826 }
5827}
5828
5829static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5830{
5831 unsigned i = ssh_pkt_getuint32(pktin);
5832 struct ssh_channel *c;
5833 struct Packet *pktout;
5834
5835 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 5836 if (!c || c->halfopen) {
51df0ab5 5837 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5838 c ? "half-open" : "nonexistent", i));
5839 return;
5840 }
5841 /* Do pre-close processing on the channel. */
5842 switch (c->type) {
5843 case CHAN_MAINSESSION:
5844 ssh->mainchan = NULL;
5845 update_specials_menu(ssh->frontend);
5846 break;
5847 case CHAN_X11:
5848 if (c->u.x11.s != NULL)
5849 x11_close(c->u.x11.s);
5850 sshfwd_close(c);
5851 break;
5852 case CHAN_AGENT:
5853 sshfwd_close(c);
5854 break;
5855 case CHAN_SOCKDATA:
5856 if (c->u.pfd.s != NULL)
5857 pfd_close(c->u.pfd.s);
5858 sshfwd_close(c);
5859 break;
5860 }
5861 if (c->closes == 0) {
5862 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5863 ssh2_pkt_adduint32(pktout, c->remoteid);
5864 ssh2_pkt_send(ssh, pktout);
5865 }
5866 del234(ssh->channels, c);
5867 bufchain_clear(&c->v.v2.outbuffer);
5868 sfree(c);
5869
5870 /*
5871 * See if that was the last channel left open.
5872 * (This is only our termination condition if we're
5873 * not running in -N mode.)
5874 */
5875 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5876 logevent("All channels closed. Disconnecting");
5877#if 0
5878 /*
5879 * We used to send SSH_MSG_DISCONNECT here,
5880 * because I'd believed that _every_ conforming
5881 * SSH2 connection had to end with a disconnect
5882 * being sent by at least one side; apparently
5883 * I was wrong and it's perfectly OK to
5884 * unceremoniously slam the connection shut
5885 * when you're done, and indeed OpenSSH feels
5886 * this is more polite than sending a
5887 * DISCONNECT. So now we don't.
5888 */
5889 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5890 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5891 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5892 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5893 ssh2_pkt_send_noqueue(ssh, s->pktout);
5894#endif
ac934965 5895 ssh->close_expected = TRUE;
51df0ab5 5896 ssh_closing((Plug)ssh, NULL, 0, 0);
5897 }
5898}
5899
5900static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5901{
5902 unsigned i = ssh_pkt_getuint32(pktin);
5903 struct ssh_channel *c;
5904 struct Packet *pktout;
5905
5906 c = find234(ssh->channels, &i, ssh_channelfind);
5907 if (!c)
5908 return; /* nonexistent channel */
5909 if (c->type != CHAN_SOCKDATA_DORMANT)
5910 return; /* dunno why they're confirming this */
5911 c->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 5912 c->halfopen = FALSE;
51df0ab5 5913 c->type = CHAN_SOCKDATA;
5914 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5915 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5916 if (c->u.pfd.s)
5917 pfd_confirm(c->u.pfd.s);
5918 if (c->closes) {
5919 /*
5920 * We have a pending close on this channel,
5921 * which we decided on before the server acked
5922 * the channel open. So now we know the
5923 * remoteid, we can close it again.
5924 */
5925 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5926 ssh2_pkt_adduint32(pktout, c->remoteid);
5927 ssh2_pkt_send(ssh, pktout);
5928 }
5929}
5930
5931static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5932{
5933 static const char *const reasons[] = {
5934 "<unknown reason code>",
5935 "Administratively prohibited",
5936 "Connect failed",
5937 "Unknown channel type",
5938 "Resource shortage",
5939 };
5940 unsigned i = ssh_pkt_getuint32(pktin);
5941 unsigned reason_code;
5942 char *reason_string;
5943 int reason_length;
51df0ab5 5944 struct ssh_channel *c;
5945 c = find234(ssh->channels, &i, ssh_channelfind);
5946 if (!c)
5947 return; /* nonexistent channel */
5948 if (c->type != CHAN_SOCKDATA_DORMANT)
5949 return; /* dunno why they're failing this */
5950
5951 reason_code = ssh_pkt_getuint32(pktin);
5952 if (reason_code >= lenof(reasons))
5953 reason_code = 0; /* ensure reasons[reason_code] in range */
5954 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
fb983202 5955 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
5956 reasons[reason_code], reason_length, reason_string);
51df0ab5 5957
5958 pfd_close(c->u.pfd.s);
5959
5960 del234(ssh->channels, c);
5961 sfree(c);
5962}
5963
5964static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5965{
5966 unsigned localid;
5967 char *type;
5968 int typelen, want_reply;
5969 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5970 struct ssh_channel *c;
5971 struct Packet *pktout;
5972
5973 localid = ssh_pkt_getuint32(pktin);
5974 ssh_pkt_getstring(pktin, &type, &typelen);
5975 want_reply = ssh2_pkt_getbool(pktin);
5976
5977 /*
5978 * First, check that the channel exists. Otherwise,
5979 * we can instantly disconnect with a rude message.
5980 */
5981 c = find234(ssh->channels, &localid, ssh_channelfind);
5982 if (!c) {
5983 char buf[80];
5984 sprintf(buf, "Received channel request for nonexistent"
5985 " channel %d", localid);
5986 logevent(buf);
5987 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5988 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5989 ssh2_pkt_addstring(pktout, buf);
5990 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5991 ssh2_pkt_send_noqueue(ssh, pktout);
5992 connection_fatal(ssh->frontend, "%s", buf);
ac934965 5993 ssh->close_expected = TRUE;
51df0ab5 5994 ssh_closing((Plug)ssh, NULL, 0, 0);
5995 return;
5996 }
5997
5998 /*
5999 * Having got the channel number, we now look at
6000 * the request type string to see if it's something
6001 * we recognise.
6002 */
6003 if (c == ssh->mainchan) {
6004 /*
6005 * We recognise "exit-status" and "exit-signal" on
6006 * the primary channel.
6007 */
6008 if (typelen == 11 &&
6009 !memcmp(type, "exit-status", 11)) {
6010
6011 ssh->exitcode = ssh_pkt_getuint32(pktin);
6012 logeventf(ssh, "Server sent command exit status %d",
6013 ssh->exitcode);
6014 reply = SSH2_MSG_CHANNEL_SUCCESS;
6015
6016 } else if (typelen == 11 &&
6017 !memcmp(type, "exit-signal", 11)) {
6018
6019 int is_plausible = TRUE, is_int = FALSE;
6020 char *fmt_sig = "", *fmt_msg = "";
6021 char *msg;
6022 int msglen = 0, core = FALSE;
6023 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6024 * provide an `int' for the signal, despite its
6025 * having been a `string' in the drafts since at
6026 * least 2001. (Fixed in session.c 1.147.) Try to
6027 * infer which we can safely parse it as. */
6028 {
6029 unsigned char *p = pktin->body +
6030 pktin->savedpos;
6031 long len = pktin->length - pktin->savedpos;
6032 unsigned long num = GET_32BIT(p); /* what is it? */
6033 /* If it's 0, it hardly matters; assume string */
6034 if (num == 0) {
6035 is_int = FALSE;
6036 } else {
6037 int maybe_int = FALSE, maybe_str = FALSE;
6038#define CHECK_HYPOTHESIS(offset, result) \
6039 do { \
6040 long q = offset; \
6041 if (q >= 0 && q+4 <= len) { \
6042 q = q + 4 + GET_32BIT(p+q); \
6043 if (q >= 0 && q+4 <= len && \
c849ff23 6044 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
51df0ab5 6045 result = TRUE; \
6046 } \
6047 } while(0)
6048 CHECK_HYPOTHESIS(4+1, maybe_int);
6049 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6050#undef CHECK_HYPOTHESIS
6051 if (maybe_int && !maybe_str)
6052 is_int = TRUE;
6053 else if (!maybe_int && maybe_str)
6054 is_int = FALSE;
6055 else
6056 /* Crikey. Either or neither. Panic. */
6057 is_plausible = FALSE;
6058 }
6059 }
6060 if (is_plausible) {
6061 if (is_int) {
6062 /* Old non-standard OpenSSH. */
6063 int signum = ssh_pkt_getuint32(pktin);
6064 fmt_sig = dupprintf(" %d", signum);
6065 } else {
6066 /* As per the drafts. */
6067 char *sig;
6068 int siglen;
6069 ssh_pkt_getstring(pktin, &sig, &siglen);
6070 /* Signal name isn't supposed to be blank, but
6071 * let's cope gracefully if it is. */
6072 if (siglen) {
6073 fmt_sig = dupprintf(" \"%.*s\"",
6074 siglen, sig);
6075 }
6076 }
6077 core = ssh2_pkt_getbool(pktin);
6078 ssh_pkt_getstring(pktin, &msg, &msglen);
6079 if (msglen) {
6080 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6081 }
6082 /* ignore lang tag */
6083 } /* else don't attempt to parse */
6084 logeventf(ssh, "Server exited on signal%s%s%s",
6085 fmt_sig, core ? " (core dumped)" : "",
6086 fmt_msg);
6087 if (*fmt_sig) sfree(fmt_sig);
6088 if (*fmt_msg) sfree(fmt_msg);
6089 reply = SSH2_MSG_CHANNEL_SUCCESS;
6090
6091 }
6092 } else {
6093 /*
6094 * This is a channel request we don't know
6095 * about, so we now either ignore the request
6096 * or respond with CHANNEL_FAILURE, depending
6097 * on want_reply.
6098 */
6099 reply = SSH2_MSG_CHANNEL_FAILURE;
6100 }
6101 if (want_reply) {
6102 pktout = ssh2_pkt_init(reply);
6103 ssh2_pkt_adduint32(pktout, c->remoteid);
6104 ssh2_pkt_send(ssh, pktout);
6105 }
6106}
6107
6108static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6109{
6110 char *type;
6111 int typelen, want_reply;
6112 struct Packet *pktout;
6113
6114 ssh_pkt_getstring(pktin, &type, &typelen);
6115 want_reply = ssh2_pkt_getbool(pktin);
6116
6117 /*
6118 * We currently don't support any global requests
6119 * at all, so we either ignore the request or
6120 * respond with REQUEST_FAILURE, depending on
6121 * want_reply.
6122 */
6123 if (want_reply) {
6124 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6125 ssh2_pkt_send(ssh, pktout);
6126 }
6127}
6128
6129static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6130{
6131 char *type;
6132 int typelen;
6133 char *peeraddr;
6134 int peeraddrlen;
6135 int peerport;
6136 char *error = NULL;
6137 struct ssh_channel *c;
6138 unsigned remid, winsize, pktsize;
6139 struct Packet *pktout;
6140
6141 ssh_pkt_getstring(pktin, &type, &typelen);
6142 c = snew(struct ssh_channel);
6143 c->ssh = ssh;
6144
6145 remid = ssh_pkt_getuint32(pktin);
6146 winsize = ssh_pkt_getuint32(pktin);
6147 pktsize = ssh_pkt_getuint32(pktin);
6148
6149 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6150 char *addrstr;
6151
6152 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6153 addrstr = snewn(peeraddrlen+1, char);
6154 memcpy(addrstr, peeraddr, peeraddrlen);
6155 addrstr[peeraddrlen] = '\0';
6156 peerport = ssh_pkt_getuint32(pktin);
6157
6158 logeventf(ssh, "Received X11 connect request from %s:%d",
6159 addrstr, peerport);
6160
6161 if (!ssh->X11_fwd_enabled)
6162 error = "X11 forwarding is not enabled";
6163 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6164 ssh->x11auth, addrstr, peerport,
6165 &ssh->cfg) != NULL) {
6166 error = "Unable to open an X11 connection";
6167 } else {
6168 logevent("Opening X11 forward connection succeeded");
6169 c->type = CHAN_X11;
6170 }
6171
6172 sfree(addrstr);
6173 } else if (typelen == 15 &&
6174 !memcmp(type, "forwarded-tcpip", 15)) {
6175 struct ssh_rportfwd pf, *realpf;
6176 char *dummy;
6177 int dummylen;
6178 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6179 pf.sport = ssh_pkt_getuint32(pktin);
6180 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6181 peerport = ssh_pkt_getuint32(pktin);
6182 realpf = find234(ssh->rportfwds, &pf, NULL);
6183 logeventf(ssh, "Received remote port %d open request "
6184 "from %s:%d", pf.sport, peeraddr, peerport);
6185 if (realpf == NULL) {
6186 error = "Remote port is not recognised";
6187 } else {
6188 const char *e = pfd_newconnect(&c->u.pfd.s,
6189 realpf->dhost,
6190 realpf->dport, c,
05581745 6191 &ssh->cfg,
6192 realpf->pfrec->addressfamily);
51df0ab5 6193 logeventf(ssh, "Attempting to forward remote port to "
6194 "%s:%d", realpf->dhost, realpf->dport);
6195 if (e != NULL) {
6196 logeventf(ssh, "Port open failed: %s", e);
6197 error = "Port open failed";
6198 } else {
6199 logevent("Forwarded port opened successfully");
6200 c->type = CHAN_SOCKDATA;
6201 }
6202 }
6203 } else if (typelen == 22 &&
6204 !memcmp(type, "auth-agent@openssh.com", 3)) {
6205 if (!ssh->agentfwd_enabled)
6206 error = "Agent forwarding is not enabled";
6207 else {
6208 c->type = CHAN_AGENT; /* identify channel type */
6209 c->u.a.lensofar = 0;
6210 }
6211 } else {
6212 error = "Unsupported channel type requested";
6213 }
6214
6215 c->remoteid = remid;
64d6ff88 6216 c->halfopen = FALSE;
51df0ab5 6217 if (error) {
6218 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6219 ssh2_pkt_adduint32(pktout, c->remoteid);
6220 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6221 ssh2_pkt_addstring(pktout, error);
6222 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6223 ssh2_pkt_send(ssh, pktout);
6224 logeventf(ssh, "Rejected channel open: %s", error);
6225 sfree(c);
6226 } else {
6227 c->localid = alloc_channel_id(ssh);
6228 c->closes = 0;
6229 c->v.v2.locwindow = OUR_V2_WINSIZE;
6230 c->v.v2.remwindow = winsize;
6231 c->v.v2.remmaxpkt = pktsize;
6232 bufchain_init(&c->v.v2.outbuffer);
6233 add234(ssh->channels, c);
6234 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6235 ssh2_pkt_adduint32(pktout, c->remoteid);
6236 ssh2_pkt_adduint32(pktout, c->localid);
6237 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
954d5c5a 6238 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
51df0ab5 6239 ssh2_pkt_send(ssh, pktout);
6240 }
6241}
6242
783415f8 6243/*
7cca0d81 6244 * Handle the SSH2 userauth and connection layers.
6245 */
ff3187f6 6246static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6247 struct Packet *pktin)
7cca0d81 6248{
51470298 6249 struct do_ssh2_authconn_state {
6250 enum {
6251 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6252 AUTH_PASSWORD,
6253 AUTH_KEYBOARD_INTERACTIVE
6254 } method;
6255 enum {
6256 AUTH_TYPE_NONE,
6257 AUTH_TYPE_PUBLICKEY,
6258 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6259 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6260 AUTH_TYPE_PASSWORD,
6261 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6262 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6263 } type;
6264 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6ac3a551 6265 int tried_pubkey_config, tried_agent;
6266 int kbd_inter_running, kbd_inter_refused;
51470298 6267 int we_are_in;
6268 int num_prompts, curr_prompt, echo;
6269 char username[100];
6270 int got_username;
85fdbe25 6271 char pwprompt[512];
51470298 6272 char password[100];
6273 void *publickey_blob;
6274 int publickey_bloblen;
6275 unsigned char request[5], *response, *p;
6276 int responselen;
6277 int keyi, nkeys;
6278 int authed;
6279 char *pkblob, *alg, *commentp;
6280 int pklen, alglen, commentlen;
6281 int siglen, retlen, len;
6282 char *q, *agentreq, *ret;
6283 int try_send;
73feed4f 6284 int num_env, env_left, env_ok;
ff3187f6 6285 struct Packet *pktout;
51470298 6286 };
6287 crState(do_ssh2_authconn_state);
6288
6289 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 6290
7cca0d81 6291 /*
6292 * Request userauth protocol, and await a response to it.
6293 */
ff3187f6 6294 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6295 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6296 ssh2_pkt_send(ssh, s->pktout);
6297 crWaitUntilV(pktin);
6298 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 6299 bombout(("Server refused user authentication protocol"));
7ffdbc1a 6300 crStopV;
8d5de777 6301 }
7cca0d81 6302
6303 /*
1408a877 6304 * We repeat this whole loop, including the username prompt,
6305 * until we manage a successful authentication. If the user
51470298 6306 * types the wrong _password_, they can be sent back to the
6307 * beginning to try another username, if this is configured on.
6308 * (If they specify a username in the config, they are never
6309 * asked, even if they do give a wrong password.)
1408a877 6310 *
6311 * I think this best serves the needs of
6312 *
6313 * - the people who have no configuration, no keys, and just
6314 * want to try repeated (username,password) pairs until they
6315 * type both correctly
6316 *
6317 * - people who have keys and configuration but occasionally
6318 * need to fall back to passwords
6319 *
6320 * - people with a key held in Pageant, who might not have
6321 * logged in to a particular machine before; so they want to
6322 * type a username, and then _either_ their key will be
6323 * accepted, _or_ they will type a password. If they mistype
6324 * the username they will want to be able to get back and
6325 * retype it!
7cca0d81 6326 */
51470298 6327 s->username[0] = '\0';
6328 s->got_username = FALSE;
1408a877 6329 do {
1408a877 6330 /*
6331 * Get a username.
6332 */
86916870 6333 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 6334 /*
6335 * We got a username last time round this loop, and
6336 * with change_username turned off we don't try to get
6337 * it again.
6338 */
aa09f7d0 6339 } else if (!*ssh->cfg.username) {
c0a81592 6340 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 6341 if (!ssh_get_line("login as: ",
51470298 6342 s->username, sizeof(s->username), FALSE)) {
32874aea 6343 /*
6344 * get_line failed to get a username.
6345 * Terminate.
6346 */
6347 logevent("No username provided. Abandoning session.");
ac934965 6348 ssh->close_expected = TRUE;
3bb2f322 6349 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6350 crStopV;
32874aea 6351 }
6352 } else {
51470298 6353 int ret; /* need not be saved across crReturn */
6354 c_write_str(ssh, "login as: ");
6355 ssh->send_ok = 1;
6356 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 6357 do {
ff3187f6 6358 crWaitUntilV(!pktin);
51470298 6359 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6360 } while (ret == 0);
6361 if (ret < 0)
6362 cleanup_exit(0);
4ca0c9d1 6363 c_write_str(ssh, "\r\n");
32874aea 6364 }
51470298 6365 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 6366 } else {
57356d63 6367 char *stuff;
86916870 6368 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 6369 s->username[sizeof(s->username)-1] = '\0';
65a22376 6370 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 6371 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 6372 c_write_str(ssh, stuff);
57356d63 6373 sfree(stuff);
7cca0d81 6374 }
6375 }
51470298 6376 s->got_username = TRUE;
7cca0d81 6377
65a22376 6378 /*
1408a877 6379 * Send an authentication request using method "none": (a)
6380 * just in case it succeeds, and (b) so that we know what
6381 * authentication methods we can usefully try next.
65a22376 6382 */
51470298 6383 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6384
ff3187f6 6385 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6386 ssh2_pkt_addstring(s->pktout, s->username);
6387 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6388 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6389 ssh2_pkt_send(ssh, s->pktout);
51470298 6390 s->type = AUTH_TYPE_NONE;
6391 s->gotit = FALSE;
6392 s->we_are_in = FALSE;
6393
6394 s->tried_pubkey_config = FALSE;
6395 s->tried_agent = FALSE;
51470298 6396 s->kbd_inter_running = FALSE;
6ac3a551 6397 s->kbd_inter_refused = FALSE;
86916870 6398 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 6399 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 6400 int keytype;
6c6d9ed9 6401 logeventf(ssh, "Reading private key file \"%.150s\"",
6402 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 6403 keytype = key_type(&ssh->cfg.keyfile);
51470298 6404 if (keytype == SSH_KEYTYPE_SSH2) {
6405 s->publickey_blob =
9a30e26b 6406 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 6407 &s->publickey_bloblen, NULL);
51470298 6408 } else {
57356d63 6409 char *msgbuf;
c2ad7d0d 6410 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 6411 key_type_to_str(keytype));
57356d63 6412 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 6413 " (%s)\r\n",
6414 filename_to_str(&ssh->cfg.keyfile),
57356d63 6415 key_type_to_str(keytype));
51470298 6416 c_write_str(ssh, msgbuf);
57356d63 6417 sfree(msgbuf);
51470298 6418 s->publickey_blob = NULL;
231ee168 6419 }
396778f1 6420 } else
51470298 6421 s->publickey_blob = NULL;
65a22376 6422
1408a877 6423 while (1) {
6424 /*
6425 * Wait for the result of the last authentication request.
6426 */
51470298 6427 if (!s->gotit)
ff3187f6 6428 crWaitUntilV(pktin);
6429 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 6430 char *banner;
6431 int size;
6432 /*
6433 * Don't show the banner if we're operating in
6434 * non-verbose non-interactive mode. (It's probably
6435 * a script, which means nobody will read the
6436 * banner _anyway_, and moreover the printing of
6437 * the banner will screw up processing on the
6438 * output of (say) plink.)
6439 */
6440 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
ff3187f6 6441 ssh_pkt_getstring(pktin, &banner, &size);
32874aea 6442 if (banner)
51470298 6443 c_write_untrusted(ssh, banner, size);
32874aea 6444 }
ff3187f6 6445 crWaitUntilV(pktin);
1408a877 6446 }
ff3187f6 6447 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 6448 logevent("Access granted");
51470298 6449 s->we_are_in = TRUE;
1408a877 6450 break;
6451 }
65a22376 6452
51470298 6453 if (s->kbd_inter_running &&
ff3187f6 6454 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 6455 /*
45068b27 6456 * This is either a further set-of-prompts packet
6457 * in keyboard-interactive authentication, or it's
6458 * the same one and we came back here with `gotit'
6459 * set. In the former case, we must reset the
6460 * curr_prompt variable.
b3186d64 6461 */
51470298 6462 if (!s->gotit)
6463 s->curr_prompt = 0;
4c6e53e3 6464 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6465 /* FIXME: perhaps we should support this? */
6466 bombout(("PASSWD_CHANGEREQ not yet supported"));
6467 crStopV;
ff3187f6 6468 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 6469 bombout(("Strange packet received during authentication: type %d",
ff3187f6 6470 pktin->type));
7ffdbc1a 6471 crStopV;
65a22376 6472 }
6473
51470298 6474 s->gotit = FALSE;
65a22376 6475
1408a877 6476 /*
6477 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6478 * we can look at the string in it and know what we can
6479 * helpfully try next.
6480 */
ff3187f6 6481 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 6482 char *methods;
6483 int methlen;
ff3187f6 6484 ssh_pkt_getstring(pktin, &methods, &methlen);
51470298 6485 s->kbd_inter_running = FALSE;
ff3187f6 6486 if (!ssh2_pkt_getbool(pktin)) {
1408a877 6487 /*
6488 * We have received an unequivocal Access
6489 * Denied. This can translate to a variety of
6490 * messages:
6491 *
6492 * - if we'd just tried "none" authentication,
6493 * it's not worth printing anything at all
6494 *
6495 * - if we'd just tried a public key _offer_,
6496 * the message should be "Server refused our
6497 * key" (or no message at all if the key
6498 * came from Pageant)
6499 *
6500 * - if we'd just tried anything else, the
6501 * message really should be "Access denied".
6502 *
6503 * Additionally, if we'd just tried password
6504 * authentication, we should break out of this
6505 * whole loop so as to go back to the username
91f57d1f 6506 * prompt (iff we're configured to allow
6507 * username change attempts).
1408a877 6508 */
51470298 6509 if (s->type == AUTH_TYPE_NONE) {
1408a877 6510 /* do nothing */
51470298 6511 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6512 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6513 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6514 c_write_str(ssh, "Server refused our key\r\n");
1408a877 6515 logevent("Server refused public key");
51470298 6516 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 6517 /* server declined keyboard-interactive; ignore */
1408a877 6518 } else {
51470298 6519 c_write_str(ssh, "Access denied\r\n");
1408a877 6520 logevent("Access denied");
91f57d1f 6521 if (s->type == AUTH_TYPE_PASSWORD &&
6522 ssh->cfg.change_username) {
6c9dce7c 6523 /* XXX perhaps we should allow
6524 * keyboard-interactive to do this too? */
51470298 6525 s->we_are_in = FALSE;
1408a877 6526 break;
6527 }
6528 }
6529 } else {
51470298 6530 c_write_str(ssh, "Further authentication required\r\n");
1408a877 6531 logevent("Further authentication required");
6532 }
65a22376 6533
51470298 6534 s->can_pubkey =
32874aea 6535 in_commasep_string("publickey", methods, methlen);
51470298 6536 s->can_passwd =
32874aea 6537 in_commasep_string("password", methods, methlen);
86916870 6538 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 6539 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 6540 }
65a22376 6541
51470298 6542 s->method = 0;
6543 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 6544 s->need_pw = FALSE;
65a22376 6545
0405e71f 6546 /*
6547 * Most password/passphrase prompts will be
6548 * non-echoing, so we set this to 0 by default.
6549 * Exception is that some keyboard-interactive prompts
6550 * can be echoing, in which case we'll set this to 1.
6551 */
51470298 6552 s->echo = 0;
0405e71f 6553
51470298 6554 if (!s->method && s->can_pubkey &&
6555 agent_exists() && !s->tried_agent) {
1983e559 6556 /*
6557 * Attempt public-key authentication using Pageant.
6558 */
1983e559 6559 void *r;
51470298 6560 s->authed = FALSE;
1983e559 6561
51470298 6562 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6563 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6564
51470298 6565 s->tried_agent = TRUE;
1983e559 6566
6567 logevent("Pageant is running. Requesting keys.");
6568
6569 /* Request the keys held by the agent. */
51470298 6570 PUT_32BIT(s->request, 1);
6571 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 6572 if (!agent_query(s->request, 5, &r, &s->responselen,
6573 ssh_agent_callback, ssh)) {
6574 do {
6575 crReturnV;
ff3187f6 6576 if (pktin) {
839f10db 6577 bombout(("Unexpected data from server while"
6578 " waiting for agent response"));
6579 crStopV;
6580 }
ff3187f6 6581 } while (pktin || inlen > 0);
839f10db 6582 r = ssh->agent_response;
6583 s->responselen = ssh->agent_response_len;
6584 }
51470298 6585 s->response = (unsigned char *) r;
6586 if (s->response && s->responselen >= 5 &&
6587 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6588 s->p = s->response + 5;
6589 s->nkeys = GET_32BIT(s->p);
6590 s->p += 4;
fb983202 6591 logeventf(ssh, "Pageant has %d SSH2 keys", s->nkeys);
51470298 6592 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 6593 void *vret;
1983e559 6594
fb983202 6595 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
51470298 6596 s->pklen = GET_32BIT(s->p);
6597 s->p += 4;
6598 if (s->publickey_blob &&
6599 s->pklen == s->publickey_bloblen &&
6600 !memcmp(s->p, s->publickey_blob,
6601 s->publickey_bloblen)) {
396778f1 6602 logevent("This key matches configured key file");
51470298 6603 s->tried_pubkey_config = 1;
396778f1 6604 }
d8baa528 6605 s->pkblob = (char *)s->p;
51470298 6606 s->p += s->pklen;
6607 s->alglen = GET_32BIT(s->pkblob);
6608 s->alg = s->pkblob + 4;
6609 s->commentlen = GET_32BIT(s->p);
6610 s->p += 4;
d8baa528 6611 s->commentp = (char *)s->p;
51470298 6612 s->p += s->commentlen;
ff3187f6 6613 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6614 ssh2_pkt_addstring(s->pktout, s->username);
6615 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6616 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6617 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6618 ssh2_pkt_addstring_start(s->pktout);
6619 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6620 ssh2_pkt_addstring_start(s->pktout);
6621 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6622 ssh2_pkt_send(ssh, s->pktout);
6623
6624 crWaitUntilV(pktin);
6625 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 6626 logevent("Key refused");
6627 continue;
6628 }
6629
32874aea 6630 if (flags & FLAG_VERBOSE) {
51470298 6631 c_write_str(ssh, "Authenticating with "
6632 "public key \"");
6633 c_write(ssh, s->commentp, s->commentlen);
6634 c_write_str(ssh, "\" from agent\r\n");
32874aea 6635 }
1983e559 6636
6637 /*
6638 * Server is willing to accept the key.
6639 * Construct a SIGN_REQUEST.
6640 */
ff3187f6 6641 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6642 ssh2_pkt_addstring(s->pktout, s->username);
6643 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6644 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6645 ssh2_pkt_addbool(s->pktout, TRUE);
6646 ssh2_pkt_addstring_start(s->pktout);
6647 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6648 ssh2_pkt_addstring_start(s->pktout);
6649 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6650
6651 s->siglen = s->pktout->length - 5 + 4 + 20;
dda87a28 6652 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6653 s->siglen -= 4;
51470298 6654 s->len = 1; /* message type */
6655 s->len += 4 + s->pklen; /* key blob */
6656 s->len += 4 + s->siglen; /* data to sign */
6657 s->len += 4; /* flags */
3d88e64d 6658 s->agentreq = snewn(4 + s->len, char);
51470298 6659 PUT_32BIT(s->agentreq, s->len);
6660 s->q = s->agentreq + 4;
6661 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6662 PUT_32BIT(s->q, s->pklen);
6663 s->q += 4;
6664 memcpy(s->q, s->pkblob, s->pklen);
6665 s->q += s->pklen;
6666 PUT_32BIT(s->q, s->siglen);
6667 s->q += 4;
1983e559 6668 /* Now the data to be signed... */
dda87a28 6669 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6670 PUT_32BIT(s->q, 20);
6671 s->q += 4;
6672 }
51470298 6673 memcpy(s->q, ssh->v2_session_id, 20);
6674 s->q += 20;
ff3187f6 6675 memcpy(s->q, s->pktout->data + 5,
6676 s->pktout->length - 5);
6677 s->q += s->pktout->length - 5;
1983e559 6678 /* And finally the (zero) flags word. */
51470298 6679 PUT_32BIT(s->q, 0);
839f10db 6680 if (!agent_query(s->agentreq, s->len + 4,
6681 &vret, &s->retlen,
6682 ssh_agent_callback, ssh)) {
6683 do {
6684 crReturnV;
ff3187f6 6685 if (pktin) {
839f10db 6686 bombout(("Unexpected data from server"
6687 " while waiting for agent"
6688 " response"));
6689 crStopV;
6690 }
ff3187f6 6691 } while (pktin || inlen > 0);
839f10db 6692 vret = ssh->agent_response;
6693 s->retlen = ssh->agent_response_len;
6694 }
51470298 6695 s->ret = vret;
6696 sfree(s->agentreq);
6697 if (s->ret) {
6698 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 6699 logevent("Sending Pageant's response");
ff3187f6 6700 ssh2_add_sigblob(ssh, s->pktout,
6701 s->pkblob, s->pklen,
51470298 6702 s->ret + 9,
6703 GET_32BIT(s->ret + 5));
ff3187f6 6704 ssh2_pkt_send(ssh, s->pktout);
51470298 6705 s->authed = TRUE;
1983e559 6706 break;
6707 } else {
32874aea 6708 logevent
6709 ("Pageant failed to answer challenge");
51470298 6710 sfree(s->ret);
1983e559 6711 }
6712 }
6713 }
51470298 6714 if (s->authed)
1983e559 6715 continue;
6716 }
29b1d0b3 6717 sfree(s->response);
1983e559 6718 }
6719
51470298 6720 if (!s->method && s->can_pubkey && s->publickey_blob
6721 && !s->tried_pubkey_config) {
1408a877 6722 unsigned char *pub_blob;
6723 char *algorithm, *comment;
6724 int pub_blob_len;
65a22376 6725
51470298 6726 s->tried_pubkey_config = TRUE;
65a22376 6727
51470298 6728 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6729 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6730
65a22376 6731 /*
1408a877 6732 * Try the public key supplied in the configuration.
6733 *
6734 * First, offer the public blob to see if the server is
6735 * willing to accept it.
65a22376 6736 */
d8baa528 6737 pub_blob =
9a30e26b 6738 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 6739 &algorithm,
222d54dc 6740 &pub_blob_len,
6741 NULL);
1408a877 6742 if (pub_blob) {
ff3187f6 6743 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6744 ssh2_pkt_addstring(s->pktout, s->username);
6745 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6746 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6747 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6748 ssh2_pkt_addstring(s->pktout, algorithm);
6749 ssh2_pkt_addstring_start(s->pktout);
6750 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
d8baa528 6751 pub_blob_len);
ff3187f6 6752 ssh2_pkt_send(ssh, s->pktout);
a03c9f9c 6753 logevent("Offered public key");
1408a877 6754
ff3187f6 6755 crWaitUntilV(pktin);
6756 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
51470298 6757 s->gotit = TRUE;
6758 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 6759 continue; /* key refused; give up on it */
1408a877 6760 }
65a22376 6761
1408a877 6762 logevent("Offer of public key accepted");
65a22376 6763 /*
1408a877 6764 * Actually attempt a serious authentication using
6765 * the key.
65a22376 6766 */
9a30e26b 6767 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 6768 sprintf(s->pwprompt,
32874aea 6769 "Passphrase for key \"%.100s\": ",
6770 comment);
51470298 6771 s->need_pw = TRUE;
1408a877 6772 } else {
51470298 6773 s->need_pw = FALSE;
1408a877 6774 }
4e520718 6775 if (flags & FLAG_VERBOSE) {
6776 c_write_str(ssh, "Authenticating with public key \"");
6777 c_write_str(ssh, comment);
6778 c_write_str(ssh, "\"\r\n");
6779 }
51470298 6780 s->method = AUTH_PUBLICKEY_FILE;
65a22376 6781 }
1408a877 6782 }
6783
6f64ce13 6784 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6785 !s->kbd_inter_running) {
51470298 6786 s->method = AUTH_KEYBOARD_INTERACTIVE;
6787 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6788
51470298 6789 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6790 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6791
ff3187f6 6792 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6793 ssh2_pkt_addstring(s->pktout, s->username);
6794 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6795 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6796 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6797 ssh2_pkt_addstring(s->pktout, "");
6798 ssh2_pkt_send(ssh, s->pktout);
6799
6800 crWaitUntilV(pktin);
6801 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6802 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
51470298 6803 s->gotit = TRUE;
af659722 6804 logevent("Keyboard-interactive authentication refused");
51470298 6805 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6ac3a551 6806 s->kbd_inter_refused = TRUE; /* don't try it again */
af659722 6807 continue;
6808 }
6809
51470298 6810 s->kbd_inter_running = TRUE;
6811 s->curr_prompt = 0;
af659722 6812 }
6813
51470298 6814 if (s->kbd_inter_running) {
6815 s->method = AUTH_KEYBOARD_INTERACTIVE;
6816 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6817
51470298 6818 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6819 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6820
51470298 6821 if (s->curr_prompt == 0) {
45068b27 6822 /*
6823 * We've got a fresh USERAUTH_INFO_REQUEST.
6824 * Display header data, and start going through
6825 * the prompts.
6826 */
6827 char *name, *inst, *lang;
6828 int name_len, inst_len, lang_len;
6829
ff3187f6 6830 ssh_pkt_getstring(pktin, &name, &name_len);
6831 ssh_pkt_getstring(pktin, &inst, &inst_len);
6832 ssh_pkt_getstring(pktin, &lang, &lang_len);
45068b27 6833 if (name_len > 0) {
51470298 6834 c_write_untrusted(ssh, name, name_len);
6835 c_write_str(ssh, "\r\n");
45068b27 6836 }
6837 if (inst_len > 0) {
51470298 6838 c_write_untrusted(ssh, inst, inst_len);
6839 c_write_str(ssh, "\r\n");
45068b27 6840 }
ff3187f6 6841 s->num_prompts = ssh_pkt_getuint32(pktin);
45068b27 6842 }
af659722 6843
45068b27 6844 /*
6845 * If there are prompts remaining in the packet,
6846 * display one and get a response.
6847 */
51470298 6848 if (s->curr_prompt < s->num_prompts) {
45068b27 6849 char *prompt;
6850 int prompt_len;
af659722 6851
ff3187f6 6852 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
45068b27 6853 if (prompt_len > 0) {
85fdbe25 6854 static const char trunc[] = "<prompt truncated>: ";
6855 static const int prlen = sizeof(s->pwprompt) -
6856 lenof(trunc);
6857 if (prompt_len > prlen) {
6858 memcpy(s->pwprompt, prompt, prlen);
6859 strcpy(s->pwprompt + prlen, trunc);
6860 } else {
6861 memcpy(s->pwprompt, prompt, prompt_len);
6862 s->pwprompt[prompt_len] = '\0';
6863 }
45068b27 6864 } else {
51470298 6865 strcpy(s->pwprompt,
45068b27 6866 "<server failed to send prompt>: ");
6867 }
ff3187f6 6868 s->echo = ssh2_pkt_getbool(pktin);
51470298 6869 s->need_pw = TRUE;
45068b27 6870 } else
51470298 6871 s->need_pw = FALSE;
af659722 6872 }
6873
51470298 6874 if (!s->method && s->can_passwd) {
6875 s->method = AUTH_PASSWORD;
6876 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6877 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6878 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6879 ssh->savedhost);
6880 s->need_pw = TRUE;
1408a877 6881 }
6882
51470298 6883 if (s->need_pw) {
fa17a66e 6884 if (ssh_get_line) {
51470298 6885 if (!ssh_get_line(s->pwprompt, s->password,
6886 sizeof(s->password), TRUE)) {
1408a877 6887 /*
fa17a66e 6888 * get_line failed to get a password (for
6889 * example because one was supplied on the
6890 * command line which has already failed to
6891 * work). Terminate.
1408a877 6892 */
ff3187f6 6893 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6894 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6895 ssh2_pkt_addstring(s->pktout, "No more passwords available"
51470298 6896 " to try");
ff3187f6 6897 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6898 ssh2_pkt_send_noqueue(ssh, s->pktout);
247308b5 6899 logevent("Unable to authenticate");
a8327734 6900 connection_fatal(ssh->frontend,
6901 "Unable to authenticate");
ac934965 6902 ssh->close_expected = TRUE;
3bb2f322 6903 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6904 crStopV;
1408a877 6905 }
6906 } else {
51470298 6907 int ret; /* need not be saved across crReturn */
6908 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6909 ssh->send_ok = 1;
1408a877 6910
51470298 6911 setup_userpass_input(ssh, s->password,
6912 sizeof(s->password), s->echo);
0405e71f 6913 do {
ff3187f6 6914 crWaitUntilV(!pktin);
51470298 6915 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6916 } while (ret == 0);
6917 if (ret < 0)
6918 cleanup_exit(0);
51470298 6919 c_write_str(ssh, "\r\n");
65a22376 6920 }
65a22376 6921 }
65a22376 6922
51470298 6923 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 6924 /*
6925 * We have our passphrase. Now try the actual authentication.
6926 */
6927 struct ssh2_userkey *key;
222d54dc 6928 const char *error = NULL;
65a22376 6929
222d54dc 6930 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6931 &error);
1408a877 6932 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6933 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 6934 c_write_str(ssh, "Wrong passphrase\r\n");
6935 s->tried_pubkey_config = FALSE;
1408a877 6936 } else {
222d54dc 6937 c_write_str(ssh, "Unable to load private key (");
6938 c_write_str(ssh, error);
6939 c_write_str(ssh, ")\r\n");
51470298 6940 s->tried_pubkey_config = TRUE;
1408a877 6941 }
6942 /* Send a spurious AUTH_NONE to return to the top. */
ff3187f6 6943 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6944 ssh2_pkt_addstring(s->pktout, s->username);
6945 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6946 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6947 ssh2_pkt_send(ssh, s->pktout);
51470298 6948 s->type = AUTH_TYPE_NONE;
1408a877 6949 } else {
1dd353b5 6950 unsigned char *pkblob, *sigblob, *sigdata;
6951 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 6952 int p;
65a22376 6953
1408a877 6954 /*
6955 * We have loaded the private key and the server
6956 * has announced that it's willing to accept it.
6957 * Hallelujah. Generate a signature and send it.
6958 */
ff3187f6 6959 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6960 ssh2_pkt_addstring(s->pktout, s->username);
6961 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6962 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6963 ssh2_pkt_addbool(s->pktout, TRUE);
6964 ssh2_pkt_addstring(s->pktout, key->alg->name);
1dd353b5 6965 pkblob = key->alg->public_blob(key->data, &pkblob_len);
ff3187f6 6966 ssh2_pkt_addstring_start(s->pktout);
6967 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
1408a877 6968
6969 /*
6970 * The data to be signed is:
6971 *
6972 * string session-id
6973 *
6974 * followed by everything so far placed in the
6975 * outgoing packet.
6976 */
ff3187f6 6977 sigdata_len = s->pktout->length - 5 + 4 + 20;
dda87a28 6978 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6979 sigdata_len -= 4;
92d60585 6980 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 6981 p = 0;
6982 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6983 PUT_32BIT(sigdata+p, 20);
6984 p += 4;
6985 }
6986 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
ff3187f6 6987 memcpy(sigdata+p, s->pktout->data + 5,
6988 s->pktout->length - 5);
6989 p += s->pktout->length - 5;
dda87a28 6990 assert(p == sigdata_len);
d8baa528 6991 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 6992 sigdata_len, &sigblob_len);
ff3187f6 6993 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 6994 sigblob, sigblob_len);
6995 sfree(pkblob);
6996 sfree(sigblob);
1408a877 6997 sfree(sigdata);
6998
ff3187f6 6999 ssh2_pkt_send(ssh, s->pktout);
51470298 7000 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 7001 key->alg->freekey(key->data);
1408a877 7002 }
51470298 7003 } else if (s->method == AUTH_PASSWORD) {
65a22376 7004 /*
95d2d262 7005 * We pad out the password packet to 256 bytes to make
7006 * it harder for an attacker to find the length of the
7007 * user's password.
1408a877 7008 *
95d2d262 7009 * Anyone using a password longer than 256 bytes
7010 * probably doesn't have much to worry about from
1408a877 7011 * people who find out how long their password is!
65a22376 7012 */
ff3187f6 7013 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
95d2d262 7014 s->pktout->forcepad = 256;
ff3187f6 7015 ssh2_pkt_addstring(s->pktout, s->username);
7016 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7017 ssh2_pkt_addstring(s->pktout, "password");
7018 ssh2_pkt_addbool(s->pktout, FALSE);
7019 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7020 ssh2_pkt_addstring(s->pktout, s->password);
1409c1b3 7021 memset(s->password, 0, sizeof(s->password));
ff3187f6 7022 end_log_omission(ssh, s->pktout);
95d2d262 7023 ssh2_pkt_send(ssh, s->pktout);
0d43337a 7024 logevent("Sent password");
51470298 7025 s->type = AUTH_TYPE_PASSWORD;
7026 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
7027 if (s->curr_prompt == 0) {
ff3187f6 7028 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10e09fb5 7029 s->pktout->forcepad = 256;
ff3187f6 7030 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
45068b27 7031 }
51470298 7032 if (s->need_pw) { /* only add pw if we just got one! */
ff3187f6 7033 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7034 ssh2_pkt_addstring(s->pktout, s->password);
51470298 7035 memset(s->password, 0, sizeof(s->password));
ff3187f6 7036 end_log_omission(ssh, s->pktout);
51470298 7037 s->curr_prompt++;
45068b27 7038 }
51470298 7039 if (s->curr_prompt >= s->num_prompts) {
ff3187f6 7040 ssh2_pkt_send(ssh, s->pktout);
45068b27 7041 } else {
7042 /*
7043 * If there are prompts remaining, we set
7044 * `gotit' so that we won't attempt to get
7045 * another packet. Then we go back round the
7046 * loop and will end up retrieving another
7047 * prompt out of the existing packet. Funky or
7048 * what?
7049 */
51470298 7050 s->gotit = TRUE;
45068b27 7051 }
51470298 7052 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 7053 } else {
51470298 7054 c_write_str(ssh, "No supported authentication methods"
7055 " left to try!\r\n");
7056 logevent("No supported authentications offered."
7057 " Disconnecting");
ff3187f6 7058 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
7059 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
7060 ssh2_pkt_addstring(s->pktout, "No supported authentication"
51470298 7061 " methods available");
ff3187f6 7062 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 7063 ssh2_pkt_send_noqueue(ssh, s->pktout);
ac934965 7064 ssh->close_expected = TRUE;
3bb2f322 7065 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 7066 crStopV;
65a22376 7067 }
65a22376 7068 }
51470298 7069 } while (!s->we_are_in);
7cca0d81 7070
7071 /*
7072 * Now we're authenticated for the connection protocol. The
7073 * connection protocol will automatically have started at this
7074 * point; there's no need to send SERVICE_REQUEST.
7075 */
7076
0ed48730 7077 ssh->channels = newtree234(ssh_channelcmp);
7078
7cca0d81 7079 /*
b09eaa88 7080 * Set up handlers for some connection protocol messages, so we
7081 * don't have to handle them repeatedly in this coroutine.
7082 */
7083 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7084 ssh2_msg_channel_window_adjust;
51df0ab5 7085 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7086 ssh2_msg_global_request;
b09eaa88 7087
7088 /*
0ed48730 7089 * Create the main session channel.
7cca0d81 7090 */
0ed48730 7091 if (!ssh->cfg.ssh_no_shell) {
7092 ssh->mainchan = snew(struct ssh_channel);
7093 ssh->mainchan->ssh = ssh;
7094 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 7095 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7096 ssh2_pkt_addstring(s->pktout, "session");
7097 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 7098 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7099 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
954d5c5a 7100 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 7101 ssh2_pkt_send(ssh, s->pktout);
7102 crWaitUntilV(pktin);
7103 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 7104 bombout(("Server refused to open a session"));
7105 crStopV;
7106 /* FIXME: error data comes back in FAILURE packet */
7107 }
ff3187f6 7108 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 7109 bombout(("Server's channel confirmation cited wrong channel"));
7110 crStopV;
7111 }
ff3187f6 7112 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 7113 ssh->mainchan->halfopen = FALSE;
0ed48730 7114 ssh->mainchan->type = CHAN_MAINSESSION;
7115 ssh->mainchan->closes = 0;
ff3187f6 7116 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7117 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 7118 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7119 add234(ssh->channels, ssh->mainchan);
62638676 7120 update_specials_menu(ssh->frontend);
0ed48730 7121 logevent("Opened channel for session");
7122 } else
7123 ssh->mainchan = NULL;
7cca0d81 7124
7125 /*
51df0ab5 7126 * Now we have a channel, make dispatch table entries for
7127 * general channel-based messages.
7128 */
7129 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7130 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7131 ssh2_msg_channel_data;
7132 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7133 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7134 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7135 ssh2_msg_channel_open_confirmation;
7136 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7137 ssh2_msg_channel_open_failure;
7138 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7139 ssh2_msg_channel_request;
7140 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7141 ssh2_msg_channel_open;
7142
7143 /*
783415f8 7144 * Potentially enable X11 forwarding.
7145 */
0ed48730 7146 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 7147 char proto[20], data[64];
7148 logevent("Requesting X11 forwarding");
302121de 7149 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 7150 data, sizeof(data), ssh->cfg.x11_auth);
7151 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 7152 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7153 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7154 ssh2_pkt_addstring(s->pktout, "x11-req");
7155 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7156 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7157 ssh2_pkt_addstring(s->pktout, proto);
7158 ssh2_pkt_addstring(s->pktout, data);
7159 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7160 ssh2_pkt_send(ssh, s->pktout);
32874aea 7161
b09eaa88 7162 crWaitUntilV(pktin);
32874aea 7163
ff3187f6 7164 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7165 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7166 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 7167 " packet type %d", pktin->type));
7ffdbc1a 7168 crStopV;
32874aea 7169 }
7170 logevent("X11 forwarding refused");
7171 } else {
7172 logevent("X11 forwarding enabled");
51470298 7173 ssh->X11_fwd_enabled = TRUE;
32874aea 7174 }
783415f8 7175 }
7176
7177 /*
bc240b21 7178 * Enable port forwardings.
7179 */
06fadff5 7180 ssh_setup_portfwd(ssh, &ssh->cfg);
bc240b21 7181
7182 /*
36c2a3e9 7183 * Potentially enable agent forwarding.
7184 */
0ed48730 7185 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 7186 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 7187 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7188 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7189 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7190 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7191 ssh2_pkt_send(ssh, s->pktout);
32874aea 7192
b09eaa88 7193 crWaitUntilV(pktin);
32874aea 7194
ff3187f6 7195 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7196 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7197 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 7198 " packet type %d", pktin->type));
7ffdbc1a 7199 crStopV;
32874aea 7200 }
7201 logevent("Agent forwarding refused");
7202 } else {
7203 logevent("Agent forwarding enabled");
51470298 7204 ssh->agentfwd_enabled = TRUE;
32874aea 7205 }
36c2a3e9 7206 }
7207
7208 /*
7cca0d81 7209 * Now allocate a pty for the session.
7210 */
0ed48730 7211 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 7212 /* Unpick the terminal-speed string. */
7213 /* XXX perhaps we should allow no speeds to be sent. */
db219738 7214 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7215 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 7216 /* Build the pty request. */
ff3187f6 7217 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7218 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7219 ssh2_pkt_addstring(s->pktout, "pty-req");
7220 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7221 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7222 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7223 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7224 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7225 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7226 ssh2_pkt_addstring_start(s->pktout);
7227 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
7228 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7229 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
7230 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7231 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7232 ssh2_pkt_send(ssh, s->pktout);
51470298 7233 ssh->state = SSH_STATE_INTERMED;
32874aea 7234
b09eaa88 7235 crWaitUntilV(pktin);
32874aea 7236
ff3187f6 7237 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7238 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7239 bombout(("Unexpected response to pty request:"
ff3187f6 7240 " packet type %d", pktin->type));
7ffdbc1a 7241 crStopV;
32874aea 7242 }
51470298 7243 c_write_str(ssh, "Server refused to allocate pty\r\n");
7244 ssh->editing = ssh->echoing = 1;
32874aea 7245 } else {
a5dd8467 7246 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 7247 ssh->ospeed, ssh->ispeed);
32874aea 7248 }
0965bee0 7249 } else {
51470298 7250 ssh->editing = ssh->echoing = 1;
7cca0d81 7251 }
7252
7253 /*
73feed4f 7254 * Send environment variables.
7255 *
7256 * Simplest thing here is to send all the requests at once, and
7257 * then wait for a whole bunch of successes or failures.
7258 */
7259 if (ssh->mainchan && *ssh->cfg.environmt) {
7260 char *e = ssh->cfg.environmt;
7261 char *var, *varend, *val;
7262
7263 s->num_env = 0;
7264
7265 while (*e) {
7266 var = e;
7267 while (*e && *e != '\t') e++;
7268 varend = e;
7269 if (*e == '\t') e++;
7270 val = e;
7271 while (*e) e++;
7272 e++;
7273
ff3187f6 7274 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7275 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7276 ssh2_pkt_addstring(s->pktout, "env");
7277 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7278 ssh2_pkt_addstring_start(s->pktout);
7279 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7280 ssh2_pkt_addstring(s->pktout, val);
7281 ssh2_pkt_send(ssh, s->pktout);
73feed4f 7282
7283 s->num_env++;
7284 }
7285
7286 logeventf(ssh, "Sent %d environment variables", s->num_env);
7287
7288 s->env_ok = 0;
7289 s->env_left = s->num_env;
7290
7291 while (s->env_left > 0) {
b09eaa88 7292 crWaitUntilV(pktin);
73feed4f 7293
ff3187f6 7294 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7295 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 7296 bombout(("Unexpected response to environment request:"
ff3187f6 7297 " packet type %d", pktin->type));
73feed4f 7298 crStopV;
7299 }
7300 } else {
7301 s->env_ok++;
7302 }
7303
7304 s->env_left--;
7305 }
7306
7307 if (s->env_ok == s->num_env) {
7308 logevent("All environment variables successfully set");
7309 } else if (s->env_ok == 0) {
7310 logevent("All environment variables refused");
7311 c_write_str(ssh, "Server refused to set environment variables\r\n");
7312 } else {
7313 logeventf(ssh, "%d environment variables refused",
7314 s->num_env - s->env_ok);
7315 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7316 }
7317 }
7318
7319 /*
fd5e5847 7320 * Start a shell or a remote command. We may have to attempt
7321 * this twice if the config data has provided a second choice
7322 * of command.
7cca0d81 7323 */
0ed48730 7324 if (ssh->mainchan) while (1) {
fd5e5847 7325 int subsys;
7326 char *cmd;
7327
51470298 7328 if (ssh->fallback_cmd) {
86916870 7329 subsys = ssh->cfg.ssh_subsys2;
7330 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 7331 } else {
86916870 7332 subsys = ssh->cfg.ssh_subsys;
7333 cmd = ssh->cfg.remote_cmd_ptr;
04c52f10 7334 if (!cmd) cmd = ssh->cfg.remote_cmd;
fd5e5847 7335 }
7336
ff3187f6 7337 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7338 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 7339 if (subsys) {
ff3187f6 7340 ssh2_pkt_addstring(s->pktout, "subsystem");
7341 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7342 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7343 } else if (*cmd) {
ff3187f6 7344 ssh2_pkt_addstring(s->pktout, "exec");
7345 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7346 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7347 } else {
ff3187f6 7348 ssh2_pkt_addstring(s->pktout, "shell");
7349 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 7350 }
ff3187f6 7351 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 7352
7353 crWaitUntilV(pktin);
7354
ff3187f6 7355 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7356 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7357 bombout(("Unexpected response to shell/command request:"
ff3187f6 7358 " packet type %d", pktin->type));
7ffdbc1a 7359 crStopV;
fd5e5847 7360 }
7361 /*
7362 * We failed to start the command. If this is the
7363 * fallback command, we really are finished; if it's
7364 * not, and if the fallback command exists, try falling
7365 * back to it before complaining.
7366 */
86916870 7367 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 7368 logevent("Primary command failed; attempting fallback");
51470298 7369 ssh->fallback_cmd = TRUE;
fd5e5847 7370 continue;
7371 }
6b5cf8b4 7372 bombout(("Server refused to start a shell/command"));
7ffdbc1a 7373 crStopV;
fd5e5847 7374 } else {
7375 logevent("Started a shell/command");
32874aea 7376 }
fd5e5847 7377 break;
7cca0d81 7378 }
7379
51470298 7380 ssh->state = SSH_STATE_SESSION;
7381 if (ssh->size_needed)
7382 ssh_size(ssh, ssh->term_width, ssh->term_height);
7383 if (ssh->eof_needed)
7384 ssh_special(ssh, TS_EOF);
6e48c3fe 7385
7cca0d81 7386 /*
7387 * Transfer data!
7388 */
b9d7bcad 7389 if (ssh->ldisc)
7390 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 7391 if (ssh->mainchan)
7392 ssh->send_ok = 1;
7cca0d81 7393 while (1) {
e5574168 7394 crReturnV;
51470298 7395 s->try_send = FALSE;
ff3187f6 7396 if (pktin) {
2b7540a7 7397
51df0ab5 7398 /*
7399 * _All_ the connection-layer packets we expect to
7400 * receive are now handled by the dispatch table.
7401 * Anything that reaches here must be bogus.
7402 */
32874aea 7403
51df0ab5 7404 bombout(("Strange packet received: type %d", pktin->type));
7405 crStopV;
0ed48730 7406 } else if (ssh->mainchan) {
32874aea 7407 /*
7408 * We have spare data. Add it to the channel buffer.
7409 */
d8baa528 7410 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 7411 s->try_send = TRUE;
32874aea 7412 }
51470298 7413 if (s->try_send) {
32874aea 7414 int i;
7415 struct ssh_channel *c;
7416 /*
7417 * Try to send data on all channels if we can.
7418 */
51470298 7419 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 7420 int bufsize;
7421 if (c->closes)
7422 continue; /* don't send on closing channels */
7423 bufsize = ssh2_try_send(c);
5471d09a 7424 if (bufsize == 0) {
7425 switch (c->type) {
7426 case CHAN_MAINSESSION:
7427 /* stdin need not receive an unthrottle
7428 * notification since it will be polled */
7429 break;
7430 case CHAN_X11:
7431 x11_unthrottle(c->u.x11.s);
7432 break;
7433 case CHAN_AGENT:
7434 /* agent sockets are request/response and need no
7435 * buffer management */
7436 break;
7437 case CHAN_SOCKDATA:
7438 pfd_unthrottle(c->u.pfd.s);
7439 break;
7440 }
7441 }
7442 }
7cca0d81 7443 }
e5574168 7444 }
7445
7446 crFinishV;
7447}
7448
7449/*
b09eaa88 7450 * Handlers for SSH2 messages that might arrive at any moment.
7451 */
409bfa77 7452static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
b09eaa88 7453{
7454 /* log reason code in disconnect message */
7455 char *buf, *msg;
7456 int nowlen, reason, msglen;
7457
7458 reason = ssh_pkt_getuint32(pktin);
7459 ssh_pkt_getstring(pktin, &msg, &msglen);
7460
7461 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7462 buf = dupprintf("Received disconnect message (%s)",
7463 ssh2_disconnect_reasons[reason]);
7464 } else {
7465 buf = dupprintf("Received disconnect message (unknown"
7466 " type %d)", reason);
7467 }
7468 logevent(buf);
7469 sfree(buf);
7470 buf = dupprintf("Disconnection message text: %n%.*s",
7471 &nowlen, msglen, msg);
7472 logevent(buf);
7473 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7474 reason,
7475 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7476 ssh2_disconnect_reasons[reason] : "unknown",
7477 buf+nowlen));
7478 sfree(buf);
7479}
7480
409bfa77 7481static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
b09eaa88 7482{
7483 /* log the debug message */
fb983202 7484 char *msg;
b09eaa88 7485 int msglen;
7486 int always_display;
7487
7488 /* XXX maybe we should actually take notice of this */
7489 always_display = ssh2_pkt_getbool(pktin);
7490 ssh_pkt_getstring(pktin, &msg, &msglen);
7491
fb983202 7492 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 7493}
7494
409bfa77 7495static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
b09eaa88 7496{
7497 struct Packet *pktout;
7498 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7499 ssh2_pkt_adduint32(pktout, pktin->sequence);
7500 /*
7501 * UNIMPLEMENTED messages MUST appear in the same order as the
7502 * messages they respond to. Hence, never queue them.
7503 */
7504 ssh2_pkt_send_noqueue(ssh, pktout);
7505}
7506
7507/*
7cca0d81 7508 * Handle the top-level SSH2 protocol.
7509 */
b09eaa88 7510static void ssh2_protocol_setup(Ssh ssh)
7511{
7512 int i;
7513
7514 /*
7515 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7516 */
7517 for (i = 0; i < 256; i++)
7518 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7519
7520 /*
7521 * Any message we actually understand, we set to NULL so that
7522 * the coroutines will get it.
7523 */
7524 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7525 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7526 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7527 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7528 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7529 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7530 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7531 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7532 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7533 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7534 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7535 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7536 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7537 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7538 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7539 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7540 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7541 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7542 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7543 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7544 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7545 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7546 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7547 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7548 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7549 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7550 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7551 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7552 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7553 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7554 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7555 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7556 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7557
7558 /*
7559 * These special message types we install handlers for.
7560 */
7561 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7562 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7563 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7564}
7565
9442dd57 7566static void ssh2_timer(void *ctx, long now)
7567{
7568 Ssh ssh = (Ssh)ctx;
7569
e6c1536e 7570 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9442dd57 7571 now - ssh->next_rekey >= 0) {
f382c87d 7572 do_ssh2_transport(ssh, "timeout", -1, NULL);
9442dd57 7573 }
7574}
7575
1c1a7262 7576static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 7577 struct Packet *pktin)
7cca0d81 7578{
1c1a7262 7579 unsigned char *in = (unsigned char *)vin;
b09eaa88 7580 if (ssh->state == SSH_STATE_CLOSED)
7581 return;
7582
9442dd57 7583 if (pktin) {
7584 ssh->incoming_data_size += pktin->encrypted_len;
7585 if (!ssh->kex_in_progress &&
d57f70af 7586 ssh->max_data_size != 0 &&
7587 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 7588 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9442dd57 7589 }
7590
b09eaa88 7591 if (pktin && ssh->packet_dispatch[pktin->type]) {
7592 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 7593 return;
b09eaa88 7594 }
7595
7596 if (!ssh->protocol_initial_phase_done ||
7597 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7598 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7599 !ssh->protocol_initial_phase_done) {
7600 ssh->protocol_initial_phase_done = TRUE;
7601 /*
7602 * Allow authconn to initialise itself.
7603 */
7604 do_ssh2_authconn(ssh, NULL, 0, NULL);
7605 }
7606 } else {
7607 do_ssh2_authconn(ssh, in, inlen, pktin);
7608 }
7cca0d81 7609}
7610
7611/*
8df7a775 7612 * Called to set up the connection.
374330e2 7613 *
7614 * Returns an error message, or NULL on success.
374330e2 7615 */
cbe2d68f 7616static const char *ssh_init(void *frontend_handle, void **backend_handle,
7617 Config *cfg,
79bf227b 7618 char *host, int port, char **realhost, int nodelay,
7619 int keepalive)
32874aea 7620{
cbe2d68f 7621 const char *p;
51470298 7622 Ssh ssh;
7623
3d88e64d 7624 ssh = snew(struct ssh_tag);
86916870 7625 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 7626 ssh->version = 0; /* when not ready yet */
51470298 7627 ssh->s = NULL;
7628 ssh->cipher = NULL;
371e569c 7629 ssh->v1_cipher_ctx = NULL;
0183b242 7630 ssh->crcda_ctx = NULL;
51470298 7631 ssh->cscipher = NULL;
371e569c 7632 ssh->cs_cipher_ctx = NULL;
51470298 7633 ssh->sccipher = NULL;
371e569c 7634 ssh->sc_cipher_ctx = NULL;
51470298 7635 ssh->csmac = NULL;
a8327734 7636 ssh->cs_mac_ctx = NULL;
51470298 7637 ssh->scmac = NULL;
e0e1a00d 7638 ssh->sc_mac_ctx = NULL;
51470298 7639 ssh->cscomp = NULL;
5366aed8 7640 ssh->cs_comp_ctx = NULL;
51470298 7641 ssh->sccomp = NULL;
5366aed8 7642 ssh->sc_comp_ctx = NULL;
51470298 7643 ssh->kex = NULL;
389aa499 7644 ssh->kex_ctx = NULL;
51470298 7645 ssh->hostkey = NULL;
7646 ssh->exitcode = -1;
ac934965 7647 ssh->close_expected = FALSE;
51470298 7648 ssh->state = SSH_STATE_PREPACKET;
7649 ssh->size_needed = FALSE;
7650 ssh->eof_needed = FALSE;
b9d7bcad 7651 ssh->ldisc = NULL;
a8327734 7652 ssh->logctx = NULL;
51470298 7653 ssh->deferred_send_data = NULL;
7654 ssh->deferred_len = 0;
7655 ssh->deferred_size = 0;
7656 ssh->fallback_cmd = 0;
7657 ssh->pkt_ctx = 0;
302121de 7658 ssh->x11auth = NULL;
be738459 7659 ssh->v1_compressing = FALSE;
51470298 7660 ssh->v2_outgoing_sequence = 0;
7661 ssh->ssh1_rdpkt_crstate = 0;
7662 ssh->ssh2_rdpkt_crstate = 0;
7663 ssh->do_ssh_init_crstate = 0;
7664 ssh->ssh_gotdata_crstate = 0;
b09eaa88 7665 ssh->do_ssh1_connection_crstate = 0;
51470298 7666 ssh->do_ssh1_login_crstate = 0;
7667 ssh->do_ssh2_transport_crstate = 0;
7668 ssh->do_ssh2_authconn_crstate = 0;
7669 ssh->do_ssh_init_state = NULL;
7670 ssh->do_ssh1_login_state = NULL;
7671 ssh->do_ssh2_transport_state = NULL;
7672 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 7673 ssh->mainchan = NULL;
968d2d92 7674 ssh->throttled_all = 0;
7675 ssh->v1_stdout_throttling = 0;
590f6a5f 7676 ssh->queue = NULL;
7677 ssh->queuelen = ssh->queuesize = 0;
7678 ssh->queueing = FALSE;
06fadff5 7679 ssh->qhead = ssh->qtail = NULL;
e13bba36 7680 ssh->deferred_rekey_reason = NULL;
3d9449a1 7681 bufchain_init(&ssh->queued_incoming_data);
7682 ssh->frozen = FALSE;
51470298 7683
7684 *backend_handle = ssh;
32874aea 7685
8f203108 7686#ifdef MSCRYPTOAPI
32874aea 7687 if (crypto_startup() == 0)
8f203108 7688 return "Microsoft high encryption pack not installed!";
7689#endif
374330e2 7690
51470298 7691 ssh->frontend = frontend_handle;
86916870 7692 ssh->term_width = ssh->cfg.width;
7693 ssh->term_height = ssh->cfg.height;
887035a5 7694
fabd1805 7695 ssh->channels = NULL;
7696 ssh->rportfwds = NULL;
f47a5ffb 7697 ssh->portfwds = NULL;
fabd1805 7698
51470298 7699 ssh->send_ok = 0;
7700 ssh->editing = 0;
7701 ssh->echoing = 0;
7702 ssh->v1_throttle_count = 0;
7703 ssh->overall_bufsize = 0;
7704 ssh->fallback_cmd = 0;
8df7a775 7705
3648d4c5 7706 ssh->protocol = NULL;
7707
b09eaa88 7708 ssh->protocol_initial_phase_done = FALSE;
7709
39934deb 7710 ssh->pinger = NULL;
7711
9442dd57 7712 ssh->incoming_data_size = ssh->outgoing_data_size =
7713 ssh->deferred_data_size = 0L;
d57f70af 7714 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9442dd57 7715 ssh->kex_in_progress = FALSE;
7716
79bf227b 7717 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 7718 if (p != NULL)
7719 return p;
374330e2 7720
5d17ccfc 7721 random_ref();
7722
374330e2 7723 return NULL;
7724}
7725
fabd1805 7726static void ssh_free(void *handle)
7727{
7728 Ssh ssh = (Ssh) handle;
7729 struct ssh_channel *c;
7730 struct ssh_rportfwd *pf;
7731
7732 if (ssh->v1_cipher_ctx)
7733 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7734 if (ssh->cs_cipher_ctx)
7735 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7736 if (ssh->sc_cipher_ctx)
7737 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7738 if (ssh->cs_mac_ctx)
7739 ssh->csmac->free_context(ssh->cs_mac_ctx);
7740 if (ssh->sc_mac_ctx)
7741 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 7742 if (ssh->cs_comp_ctx) {
7743 if (ssh->cscomp)
7744 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7745 else
7746 zlib_compress_cleanup(ssh->cs_comp_ctx);
7747 }
7748 if (ssh->sc_comp_ctx) {
7749 if (ssh->sccomp)
7750 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7751 else
7752 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7753 }
fabd1805 7754 if (ssh->kex_ctx)
7755 dh_cleanup(ssh->kex_ctx);
7756 sfree(ssh->savedhost);
7757
590f6a5f 7758 while (ssh->queuelen-- > 0)
7759 ssh_free_packet(ssh->queue[ssh->queuelen]);
7760 sfree(ssh->queue);
7761
06fadff5 7762 while (ssh->qhead) {
7763 struct queued_handler *qh = ssh->qhead;
7764 ssh->qhead = qh->next;
7765 sfree(ssh->qhead);
7766 }
7767 ssh->qhead = ssh->qtail = NULL;
7768
fabd1805 7769 if (ssh->channels) {
7770 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7771 switch (c->type) {
7772 case CHAN_X11:
7773 if (c->u.x11.s != NULL)
7774 x11_close(c->u.x11.s);
7775 break;
7776 case CHAN_SOCKDATA:
7777 if (c->u.pfd.s != NULL)
7778 pfd_close(c->u.pfd.s);
7779 break;
7780 }
7781 sfree(c);
7782 }
7783 freetree234(ssh->channels);
cdb52705 7784 ssh->channels = NULL;
fabd1805 7785 }
7786
7787 if (ssh->rportfwds) {
7788 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7789 sfree(pf);
7790 freetree234(ssh->rportfwds);
cdb52705 7791 ssh->rportfwds = NULL;
fabd1805 7792 }
7793 sfree(ssh->deferred_send_data);
7794 if (ssh->x11auth)
7795 x11_free_auth(ssh->x11auth);
7796 sfree(ssh->do_ssh_init_state);
7797 sfree(ssh->do_ssh1_login_state);
7798 sfree(ssh->do_ssh2_transport_state);
7799 sfree(ssh->do_ssh2_authconn_state);
679539d7 7800 if (ssh->crcda_ctx) {
7801 crcda_free_context(ssh->crcda_ctx);
7802 ssh->crcda_ctx = NULL;
7803 }
fabd1805 7804 if (ssh->s)
ac934965 7805 ssh_do_close(ssh, TRUE);
9442dd57 7806 expire_timer_context(ssh);
39934deb 7807 if (ssh->pinger)
7808 pinger_free(ssh->pinger);
3d9449a1 7809 bufchain_clear(&ssh->queued_incoming_data);
ee50e8b6 7810 sfree(ssh);
5d17ccfc 7811
7812 random_unref();
fabd1805 7813}
7814
374330e2 7815/*
86916870 7816 * Reconfigure the SSH backend.
86916870 7817 */
7818static void ssh_reconfig(void *handle, Config *cfg)
7819{
7820 Ssh ssh = (Ssh) handle;
e13bba36 7821 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 7822 unsigned long old_max_data_size;
7823
39934deb 7824 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
fda2feb1 7825 ssh_setup_portfwd(ssh, cfg);
e6c1536e 7826
7827 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7828 cfg->ssh_rekey_time != 0) {
7829 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7830 long now = GETTICKCOUNT();
7831
7832 if (new_next - now < 0) {
f382c87d 7833 rekeying = "timeout shortened";
e6c1536e 7834 } else {
7835 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7836 }
7837 }
7838
7839 old_max_data_size = ssh->max_data_size;
7840 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7841 if (old_max_data_size != ssh->max_data_size &&
7842 ssh->max_data_size != 0) {
7843 if (ssh->outgoing_data_size > ssh->max_data_size ||
7844 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 7845 rekeying = "data limit lowered";
e6c1536e 7846 }
7847
e13bba36 7848 if (ssh->cfg.compression != cfg->compression) {
f382c87d 7849 rekeying = "compression setting changed";
e13bba36 7850 rekey_mandatory = TRUE;
7851 }
7852
7853 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7854 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7855 sizeof(ssh->cfg.ssh_cipherlist))) {
f382c87d 7856 rekeying = "cipher settings changed";
e13bba36 7857 rekey_mandatory = TRUE;
e6c1536e 7858 }
7859
86916870 7860 ssh->cfg = *cfg; /* STRUCTURE COPY */
e13bba36 7861
7862 if (rekeying) {
7863 if (!ssh->kex_in_progress) {
7864 do_ssh2_transport(ssh, rekeying, -1, NULL);
7865 } else if (rekey_mandatory) {
7866 ssh->deferred_rekey_reason = rekeying;
7867 }
7868 }
86916870 7869}
7870
7871/*
374330e2 7872 * Called to send data down the Telnet connection.
7873 */
51470298 7874static int ssh_send(void *handle, char *buf, int len)
32874aea 7875{
51470298 7876 Ssh ssh = (Ssh) handle;
7877
7878 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7879 return 0;
374330e2 7880
d8baa528 7881 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 7882
51470298 7883 return ssh_sendbuffer(ssh);
5471d09a 7884}
7885
7886/*
7887 * Called to query the current amount of buffered stdin data.
7888 */
51470298 7889static int ssh_sendbuffer(void *handle)
5471d09a 7890{
51470298 7891 Ssh ssh = (Ssh) handle;
5471d09a 7892 int override_value;
7893
51470298 7894 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7895 return 0;
7896
7897 /*
7898 * If the SSH socket itself has backed up, add the total backup
7899 * size on that to any individual buffer on the stdin channel.
7900 */
7901 override_value = 0;
51470298 7902 if (ssh->throttled_all)
7903 override_value = ssh->overall_bufsize;
5471d09a 7904
51470298 7905 if (ssh->version == 1) {
5471d09a 7906 return override_value;
51470298 7907 } else if (ssh->version == 2) {
7908 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 7909 return override_value;
7910 else
51470298 7911 return (override_value +
7912 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 7913 }
7914
7915 return 0;
374330e2 7916}
7917
7918/*
6e48c3fe 7919 * Called to set the size of the window from SSH's POV.
374330e2 7920 */
51470298 7921static void ssh_size(void *handle, int width, int height)
32874aea 7922{
51470298 7923 Ssh ssh = (Ssh) handle;
ff3187f6 7924 struct Packet *pktout;
51470298 7925
7926 ssh->term_width = width;
7927 ssh->term_height = height;
f278d6f8 7928
51470298 7929 switch (ssh->state) {
374330e2 7930 case SSH_STATE_BEFORE_SIZE:
3687d221 7931 case SSH_STATE_PREPACKET:
21248260 7932 case SSH_STATE_CLOSED:
374330e2 7933 break; /* do nothing */
7934 case SSH_STATE_INTERMED:
51470298 7935 ssh->size_needed = TRUE; /* buffer for later */
374330e2 7936 break;
7937 case SSH_STATE_SESSION:
86916870 7938 if (!ssh->cfg.nopty) {
51470298 7939 if (ssh->version == 1) {
7940 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7941 PKT_INT, ssh->term_height,
7942 PKT_INT, ssh->term_width,
32874aea 7943 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 7944 } else if (ssh->mainchan) {
ff3187f6 7945 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7946 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7947 ssh2_pkt_addstring(pktout, "window-change");
7948 ssh2_pkt_addbool(pktout, 0);
7949 ssh2_pkt_adduint32(pktout, ssh->term_width);
7950 ssh2_pkt_adduint32(pktout, ssh->term_height);
7951 ssh2_pkt_adduint32(pktout, 0);
7952 ssh2_pkt_adduint32(pktout, 0);
7953 ssh2_pkt_send(ssh, pktout);
32874aea 7954 }
7955 }
7956 break;
374330e2 7957 }
7958}
7959
7960/*
125105d1 7961 * Return a list of the special codes that make sense in this
7962 * protocol.
7963 */
7964static const struct telnet_special *ssh_get_specials(void *handle)
7965{
786ba75e 7966 static const struct telnet_special ssh1_ignore_special[] = {
7967 {"IGNORE message", TS_NOP}
7968 };
7969 static const struct telnet_special ssh2_transport_specials[] = {
62638676 7970 {"IGNORE message", TS_NOP},
9442dd57 7971 {"Repeat key exchange", TS_REKEY},
62638676 7972 };
7973 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 7974 {NULL, TS_SEP},
7975 {"Break", TS_BRK},
786ba75e 7976 /* These are the signal names defined by draft-ietf-secsh-connect-23.
6f2d0cde 7977 * They include all the ISO C signals, but are a subset of the POSIX
7978 * required signals. */
7979 {"SIGINT (Interrupt)", TS_SIGINT},
7980 {"SIGTERM (Terminate)", TS_SIGTERM},
7981 {"SIGKILL (Kill)", TS_SIGKILL},
7982 {"SIGQUIT (Quit)", TS_SIGQUIT},
7983 {"SIGHUP (Hangup)", TS_SIGHUP},
7984 {"More signals", TS_SUBMENU},
7985 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7986 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7987 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7988 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7989 {NULL, TS_EXITMENU}
62638676 7990 };
7991 static const struct telnet_special specials_end[] = {
6f2d0cde 7992 {NULL, TS_EXITMENU}
62638676 7993 };
786ba75e 7994 /* XXX review this length for any changes: */
7995 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
62638676 7996 lenof(ssh2_session_specials) +
7997 lenof(specials_end)];
125105d1 7998 Ssh ssh = (Ssh) handle;
62638676 7999 int i = 0;
8000#define ADD_SPECIALS(name) \
8001 do { \
8002 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8003 memcpy(&ssh_specials[i], name, sizeof name); \
8004 i += lenof(name); \
8005 } while(0)
125105d1 8006
8007 if (ssh->version == 1) {
62638676 8008 /* Don't bother offering IGNORE if we've decided the remote
8009 * won't cope with it, since we wouldn't bother sending it if
8010 * asked anyway. */
8011 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 8012 ADD_SPECIALS(ssh1_ignore_special);
125105d1 8013 } else if (ssh->version == 2) {
786ba75e 8014 ADD_SPECIALS(ssh2_transport_specials);
62638676 8015 if (ssh->mainchan)
8016 ADD_SPECIALS(ssh2_session_specials);
8017 } /* else we're not ready yet */
8018
8019 if (i) {
8020 ADD_SPECIALS(specials_end);
8021 return ssh_specials;
8022 } else {
125105d1 8023 return NULL;
62638676 8024 }
8025#undef ADD_SPECIALS
125105d1 8026}
8027
8028/*
6abbf9e3 8029 * Send Telnet special codes. TS_EOF is useful for `plink', so you
8030 * can send an EOF and collect resulting output (e.g. `plink
8031 * hostname sort').
374330e2 8032 */
51470298 8033static void ssh_special(void *handle, Telnet_Special code)
32874aea 8034{
51470298 8035 Ssh ssh = (Ssh) handle;
ff3187f6 8036 struct Packet *pktout;
51470298 8037
6abbf9e3 8038 if (code == TS_EOF) {
51470298 8039 if (ssh->state != SSH_STATE_SESSION) {
32874aea 8040 /*
8041 * Buffer the EOF in case we are pre-SESSION, so we can
8042 * send it as soon as we reach SESSION.
8043 */
8044 if (code == TS_EOF)
51470298 8045 ssh->eof_needed = TRUE;
32874aea 8046 return;
8047 }
51470298 8048 if (ssh->version == 1) {
8049 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 8050 } else if (ssh->mainchan) {
ff3187f6 8051 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8052 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8053 ssh2_pkt_send(ssh, pktout);
32874aea 8054 }
8055 logevent("Sent EOF message");
125105d1 8056 } else if (code == TS_PING || code == TS_NOP) {
51470298 8057 if (ssh->state == SSH_STATE_CLOSED
8058 || ssh->state == SSH_STATE_PREPACKET) return;
8059 if (ssh->version == 1) {
8060 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8061 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 8062 } else {
ff3187f6 8063 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8064 ssh2_pkt_addstring_start(pktout);
590f6a5f 8065 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 8066 }
9442dd57 8067 } else if (code == TS_REKEY) {
8068 if (!ssh->kex_in_progress && ssh->version == 2) {
f382c87d 8069 do_ssh2_transport(ssh, "at user request", -1, NULL);
9442dd57 8070 }
125105d1 8071 } else if (code == TS_BRK) {
8072 if (ssh->state == SSH_STATE_CLOSED
8073 || ssh->state == SSH_STATE_PREPACKET) return;
8074 if (ssh->version == 1) {
8075 logevent("Unable to send BREAK signal in SSH1");
0ed48730 8076 } else if (ssh->mainchan) {
ff3187f6 8077 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8078 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8079 ssh2_pkt_addstring(pktout, "break");
8080 ssh2_pkt_addbool(pktout, 0);
8081 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8082 ssh2_pkt_send(ssh, pktout);
125105d1 8083 }
6abbf9e3 8084 } else {
6f2d0cde 8085 /* Is is a POSIX signal? */
8086 char *signame = NULL;
8087 if (code == TS_SIGABRT) signame = "ABRT";
8088 if (code == TS_SIGALRM) signame = "ALRM";
8089 if (code == TS_SIGFPE) signame = "FPE";
8090 if (code == TS_SIGHUP) signame = "HUP";
8091 if (code == TS_SIGILL) signame = "ILL";
8092 if (code == TS_SIGINT) signame = "INT";
8093 if (code == TS_SIGKILL) signame = "KILL";
8094 if (code == TS_SIGPIPE) signame = "PIPE";
8095 if (code == TS_SIGQUIT) signame = "QUIT";
8096 if (code == TS_SIGSEGV) signame = "SEGV";
8097 if (code == TS_SIGTERM) signame = "TERM";
8098 if (code == TS_SIGUSR1) signame = "USR1";
8099 if (code == TS_SIGUSR2) signame = "USR2";
8100 /* The SSH-2 protocol does in principle support arbitrary named
8101 * signals, including signame@domain, but we don't support those. */
8102 if (signame) {
8103 /* It's a signal. */
8104 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 8105 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8106 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8107 ssh2_pkt_addstring(pktout, "signal");
8108 ssh2_pkt_addbool(pktout, 0);
8109 ssh2_pkt_addstring(pktout, signame);
8110 ssh2_pkt_send(ssh, pktout);
6f2d0cde 8111 logeventf(ssh, "Sent signal SIG%s", signame);
8112 }
8113 } else {
8114 /* Never heard of it. Do nothing */
8115 }
6abbf9e3 8116 }
374330e2 8117}
8118
51470298 8119void *new_sock_channel(void *handle, Socket s)
d74d141c 8120{
51470298 8121 Ssh ssh = (Ssh) handle;
d74d141c 8122 struct ssh_channel *c;
3d88e64d 8123 c = snew(struct ssh_channel);
51470298 8124 c->ssh = ssh;
d74d141c 8125
8126 if (c) {
64d6ff88 8127 c->halfopen = TRUE;
51470298 8128 c->localid = alloc_channel_id(ssh);
d74d141c 8129 c->closes = 0;
bc240b21 8130 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 8131 c->u.pfd.s = s;
013dd8c0 8132 bufchain_init(&c->v.v2.outbuffer);
51470298 8133 add234(ssh->channels, c);
d74d141c 8134 }
8135 return c;
8136}
8137
5471d09a 8138/*
8139 * This is called when stdout/stderr (the entity to which
8140 * from_backend sends data) manages to clear some backlog.
8141 */
ae9ae89f 8142static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 8143{
51470298 8144 Ssh ssh = (Ssh) handle;
8145 if (ssh->version == 1) {
8146 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8147 ssh->v1_stdout_throttling = 0;
8148 ssh1_throttle(ssh, -1);
5471d09a 8149 }
8150 } else {
51470298 8151 if (ssh->mainchan && ssh->mainchan->closes == 0)
8152 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 8153 }
8154}
8155
6b78788a 8156void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 8157{
8158 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 8159 Ssh ssh = c->ssh;
ff3187f6 8160 struct Packet *pktout;
d74d141c 8161
57356d63 8162 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 8163
51470298 8164 if (ssh->version == 1) {
8165 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 8166 PKT_INT, c->localid,
8167 PKT_STR, hostname,
8168 PKT_INT, port,
31fb1866 8169 /* PKT_STR, <org:orgport>, */
bc240b21 8170 PKT_END);
8171 } else {
ff3187f6 8172 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8173 ssh2_pkt_addstring(pktout, "direct-tcpip");
8174 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 8175 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 8176 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
954d5c5a 8177 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 8178 ssh2_pkt_addstring(pktout, hostname);
8179 ssh2_pkt_adduint32(pktout, port);
bc240b21 8180 /*
8181 * We make up values for the originator data; partly it's
8182 * too much hassle to keep track, and partly I'm not
8183 * convinced the server should be told details like that
8184 * about my local network configuration.
8185 */
ff3187f6 8186 ssh2_pkt_addstring(pktout, "client-side-connection");
8187 ssh2_pkt_adduint32(pktout, 0);
8188 ssh2_pkt_send(ssh, pktout);
bc240b21 8189 }
d74d141c 8190}
8191
51470298 8192static Socket ssh_socket(void *handle)
32874aea 8193{
51470298 8194 Ssh ssh = (Ssh) handle;
8195 return ssh->s;
32874aea 8196}
8ccc75b0 8197
51470298 8198static int ssh_sendok(void *handle)
32874aea 8199{
51470298 8200 Ssh ssh = (Ssh) handle;
8201 return ssh->send_ok;
32874aea 8202}
fb09bf1c 8203
51470298 8204static int ssh_ldisc(void *handle, int option)
32874aea 8205{
51470298 8206 Ssh ssh = (Ssh) handle;
32874aea 8207 if (option == LD_ECHO)
51470298 8208 return ssh->echoing;
32874aea 8209 if (option == LD_EDIT)
51470298 8210 return ssh->editing;
0965bee0 8211 return FALSE;
8212}
8213
b9d7bcad 8214static void ssh_provide_ldisc(void *handle, void *ldisc)
8215{
8216 Ssh ssh = (Ssh) handle;
8217 ssh->ldisc = ldisc;
8218}
8219
a8327734 8220static void ssh_provide_logctx(void *handle, void *logctx)
8221{
8222 Ssh ssh = (Ssh) handle;
8223 ssh->logctx = logctx;
8224}
8225
51470298 8226static int ssh_return_exitcode(void *handle)
8227{
8228 Ssh ssh = (Ssh) handle;
3bb2f322 8229 if (ssh->s != NULL)
8230 return -1;
8231 else
8232 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 8233}
8234
8235/*
f89c3294 8236 * cfg_info for SSH is the currently running version of the
8237 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8238 */
8239static int ssh_cfg_info(void *handle)
8240{
8241 Ssh ssh = (Ssh) handle;
8242 return ssh->version;
8243}
8244
8245/*
51470298 8246 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8247 * that fails. This variable is the means by which scp.c can reach
8248 * into the SSH code and find out which one it got.
8249 */
8250extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 8251{
51470298 8252 Ssh ssh = (Ssh) handle;
8253 return ssh->fallback_cmd;
d8d6c7e5 8254}
8255
374330e2 8256Backend ssh_backend = {
8257 ssh_init,
fabd1805 8258 ssh_free,
86916870 8259 ssh_reconfig,
374330e2 8260 ssh_send,
5471d09a 8261 ssh_sendbuffer,
374330e2 8262 ssh_size,
4017be6d 8263 ssh_special,
125105d1 8264 ssh_get_specials,
8ccc75b0 8265 ssh_socket,
d8d6c7e5 8266 ssh_return_exitcode,
97db3be4 8267 ssh_sendok,
0965bee0 8268 ssh_ldisc,
b9d7bcad 8269 ssh_provide_ldisc,
a8327734 8270 ssh_provide_logctx,
5471d09a 8271 ssh_unthrottle,
f89c3294 8272 ssh_cfg_info,
97db3be4 8273 22
bc240b21 8274};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator