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Over-enthusiastic assertions in the port forwarding code removed.
[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
2425184b 2520 if (need_notify)
2521 notify_remote_exit(ssh->frontend);
2522
7e78000d 2523 if (error_msg) {
32874aea 2524 /* A socket error has occurred. */
247308b5 2525 logevent(error_msg);
971bcc0a 2526 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2527 } else {
ac934965 2528 logevent("Server closed network connection");
8df7a775 2529 }
7e78000d 2530 return 0;
2531}
2532
32874aea 2533static int ssh_receive(Plug plug, int urgent, char *data, int len)
2534{
51470298 2535 Ssh ssh = (Ssh) plug;
d8baa528 2536 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2537 if (ssh->state == SSH_STATE_CLOSED) {
ac934965 2538 ssh_do_close(ssh, TRUE);
32874aea 2539 return 0;
3257deae 2540 }
fef97f43 2541 return 1;
374330e2 2542}
2543
5471d09a 2544static void ssh_sent(Plug plug, int bufsize)
2545{
51470298 2546 Ssh ssh = (Ssh) plug;
5471d09a 2547 /*
2548 * If the send backlog on the SSH socket itself clears, we
2549 * should unthrottle the whole world if it was throttled.
2550 */
2551 if (bufsize < SSH_MAX_BACKLOG)
51470298 2552 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2553}
2554
fb09bf1c 2555/*
8df7a775 2556 * Connect to specified host and port.
2557 * Returns an error message, or NULL on success.
6e1ebb76 2558 * Also places the canonical host name into `realhost'. It must be
2559 * freed by the caller.
8df7a775 2560 */
cbe2d68f 2561static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2562 char **realhost, int nodelay, int keepalive)
8df7a775 2563{
51470298 2564 static const struct plug_function_table fn_table = {
7555d6a5 2565 ssh_log,
7e78000d 2566 ssh_closing,
5471d09a 2567 ssh_receive,
2568 ssh_sent,
2569 NULL
51470298 2570 };
7e78000d 2571
8df7a775 2572 SockAddr addr;
cbe2d68f 2573 const char *err;
8df7a775 2574
3d88e64d 2575 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2576 if (!ssh->savedhost)
8df7a775 2577 fatalbox("Out of memory");
51470298 2578 strcpy(ssh->savedhost, host);
8df7a775 2579
2580 if (port < 0)
2581 port = 22; /* default ssh port */
51470298 2582 ssh->savedport = port;
8df7a775 2583
2584 /*
2585 * Try to find host.
2586 */
05581745 2587 logeventf(ssh, "Looking up host \"%s\"%s", host,
2588 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2589 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2590 addr = name_lookup(host, port, realhost, &ssh->cfg,
2591 ssh->cfg.addressfamily);
170c1e6e 2592 if ((err = sk_addr_error(addr)) != NULL) {
2593 sk_addr_free(addr);
8df7a775 2594 return err;
170c1e6e 2595 }
8df7a775 2596
8df7a775 2597 /*
2598 * Open socket.
2599 */
51470298 2600 ssh->fn = &fn_table;
e8fa8f62 2601 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2602 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2603 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2604 ssh->s = NULL;
39934deb 2605 notify_remote_exit(ssh->frontend);
8df7a775 2606 return err;
67c4ba2e 2607 }
8df7a775 2608
8df7a775 2609 return NULL;
2610}
2611
2612/*
5471d09a 2613 * Throttle or unthrottle the SSH connection.
2614 */
51470298 2615static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2616{
51470298 2617 int old_count = ssh->v1_throttle_count;
2618 ssh->v1_throttle_count += adjust;
2619 assert(ssh->v1_throttle_count >= 0);
2620 if (ssh->v1_throttle_count && !old_count) {
3d9449a1 2621 ssh_set_frozen(ssh, 1);
51470298 2622 } else if (!ssh->v1_throttle_count && old_count) {
3d9449a1 2623 ssh_set_frozen(ssh, 0);
5471d09a 2624 }
2625}
2626
2627/*
2628 * Throttle or unthrottle _all_ local data streams (for when sends
2629 * on the SSH connection itself back up).
2630 */
51470298 2631static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2632{
2633 int i;
2634 struct ssh_channel *c;
2635
51470298 2636 if (enable == ssh->throttled_all)
5471d09a 2637 return;
51470298 2638 ssh->throttled_all = enable;
2639 ssh->overall_bufsize = bufsize;
2640 if (!ssh->channels)
5471d09a 2641 return;
51470298 2642 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2643 switch (c->type) {
2644 case CHAN_MAINSESSION:
2645 /*
2646 * This is treated separately, outside the switch.
2647 */
2648 break;
2649 case CHAN_X11:
2650 x11_override_throttle(c->u.x11.s, enable);
2651 break;
2652 case CHAN_AGENT:
2653 /* Agent channels require no buffer management. */
2654 break;
2655 case CHAN_SOCKDATA:
36f94d1f 2656 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2657 break;
2658 }
2659 }
2660}
2661
2662/*
51470298 2663 * Username and password input, abstracted off into routines
2664 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2665 */
0405e71f 2666
2667/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2668static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2669{
51470298 2670 ssh->userpass_input_buffer = buffer;
2671 ssh->userpass_input_buflen = buflen;
2672 ssh->userpass_input_bufpos = 0;
2673 ssh->userpass_input_echo = echo;
0405e71f 2674}
2675
2676/*
2677 * Process some terminal data in the course of username/password
2678 * input. Returns >0 for success (line of input returned in
2679 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2680 * for inconclusive (keep waiting for more input please).
2681 */
ae9ae89f 2682static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2683{
2684 char c;
2685
2686 while (inlen--) {
2687 switch (c = *in++) {
2688 case 10:
2689 case 13:
51470298 2690 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2691 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2692 return +1;
2693 break;
2694 case 8:
2695 case 127:
51470298 2696 if (ssh->userpass_input_bufpos > 0) {
2697 if (ssh->userpass_input_echo)
2698 c_write_str(ssh, "\b \b");
2699 ssh->userpass_input_bufpos--;
0405e71f 2700 }
2701 break;
2702 case 21:
2703 case 27:
51470298 2704 while (ssh->userpass_input_bufpos > 0) {
2705 if (ssh->userpass_input_echo)
2706 c_write_str(ssh, "\b \b");
2707 ssh->userpass_input_bufpos--;
0405e71f 2708 }
2709 break;
2710 case 3:
2711 case 4:
2712 return -1;
2713 break;
2714 default:
4692a14a 2715 /*
2716 * This simplistic check for printability is disabled
2717 * when we're doing password input, because some people
2718 * have control characters in their passwords.o
2719 */
2720 if ((!ssh->userpass_input_echo ||
2721 (c >= ' ' && c <= '~') ||
0405e71f 2722 ((unsigned char) c >= 160))
51470298 2723 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2724 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2725 if (ssh->userpass_input_echo)
2726 c_write(ssh, &c, 1);
0405e71f 2727 }
2728 break;
2729 }
2730 }
2731 return 0;
2732}
2733
f11d78f2 2734static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2735{
2736 Ssh ssh = (Ssh) sshv;
2737
2738 ssh->agent_response = reply;
2739 ssh->agent_response_len = replylen;
2740
2741 if (ssh->version == 1)
ff3187f6 2742 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2743 else
ff3187f6 2744 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2745}
2746
3d9449a1 2747static void ssh_dialog_callback(void *sshv, int ret)
2748{
2749 Ssh ssh = (Ssh) sshv;
2750
2751 ssh->user_response = ret;
2752
2753 if (ssh->version == 1)
2754 do_ssh1_login(ssh, NULL, -1, NULL);
2755 else
2756 do_ssh2_transport(ssh, NULL, -1, NULL);
2757
2758 /*
2759 * This may have unfrozen the SSH connection, so do a
2760 * queued-data run.
2761 */
2762 ssh_process_queued_incoming_data(ssh);
2763}
2764
f11d78f2 2765static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2766{
2767 struct ssh_channel *c = (struct ssh_channel *)cv;
2768 Ssh ssh = c->ssh;
2769 void *sentreply = reply;
2770
2771 if (!sentreply) {
2772 /* Fake SSH_AGENT_FAILURE. */
2773 sentreply = "\0\0\0\1\5";
2774 replylen = 5;
2775 }
2776 if (ssh->version == 2) {
2777 ssh2_add_channel_data(c, sentreply, replylen);
2778 ssh2_try_send(c);
2779 } else {
2780 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2781 PKT_INT, c->remoteid,
9a10ecf4 2782 PKTT_DATA,
839f10db 2783 PKT_INT, replylen,
2784 PKT_DATA, sentreply, replylen,
9a10ecf4 2785 PKTT_OTHER,
839f10db 2786 PKT_END);
2787 }
2788 if (reply)
2789 sfree(reply);
2790}
2791
0405e71f 2792/*
fb09bf1c 2793 * Handle the key exchange and user authentication phases.
2794 */
ff3187f6 2795static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2796 struct Packet *pktin)
fb09bf1c 2797{
0016d70b 2798 int i, j, ret;
2799 unsigned char cookie[8], *ptr;
374330e2 2800 struct RSAKey servkey, hostkey;
2801 struct MD5Context md5c;
51470298 2802 struct do_ssh1_login_state {
2803 int len;
2804 unsigned char *rsabuf, *keystr1, *keystr2;
2805 unsigned long supported_ciphers_mask, supported_auths_mask;
2806 int tried_publickey, tried_agent;
2807 int tis_auth_refused, ccard_auth_refused;
2808 unsigned char session_id[16];
2809 int cipher_type;
2810 char username[100];
2811 void *publickey_blob;
2812 int publickey_bloblen;
2813 char password[100];
2814 char prompt[200];
2815 int pos;
2816 char c;
2817 int pwpkt_type;
2818 unsigned char request[5], *response, *p;
2819 int responselen;
2820 int keyi, nkeys;
2821 int authed;
2822 struct RSAKey key;
2823 Bignum challenge;
2824 char *commentp;
2825 int commentlen;
3d9449a1 2826 int dlgret;
51470298 2827 };
2828 crState(do_ssh1_login_state);
2829
2830 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2831
ff3187f6 2832 if (!pktin)
2833 crWaitUntil(pktin);
374330e2 2834
ff3187f6 2835 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2836 bombout(("Public key packet not received"));
7ffdbc1a 2837 crStop(0);
8d5de777 2838 }
374330e2 2839
c5e9c988 2840 logevent("Received public keys");
374330e2 2841
ff3187f6 2842 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2843 if (!ptr) {
2844 bombout(("SSH1 public key packet stopped before random cookie"));
2845 crStop(0);
2846 }
2847 memcpy(cookie, ptr, 8);
374330e2 2848
ff3187f6 2849 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2850 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
ae0500e5 2851 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2852 crStop(0);
2853 }
374330e2 2854
c5e9c988 2855 /*
1c2a93c4 2856 * Log the host key fingerprint.
c5e9c988 2857 */
c5e9c988 2858 {
2859 char logmsg[80];
1c2a93c4 2860 logevent("Host key fingerprint is:");
c5e9c988 2861 strcpy(logmsg, " ");
32874aea 2862 hostkey.comment = NULL;
2863 rsa_fingerprint(logmsg + strlen(logmsg),
2864 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2865 logevent(logmsg);
2866 }
2867
ff3187f6 2868 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2869 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2870 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2871
51470298 2872 ssh->v1_local_protoflags =
2873 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2874 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2875
c5e9c988 2876 MD5Init(&md5c);
51470298 2877 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2878 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2879 MD5Update(&md5c, cookie, 8);
51470298 2880 MD5Final(s->session_id, &md5c);
374330e2 2881
32874aea 2882 for (i = 0; i < 32; i++)
51470298 2883 ssh->session_key[i] = random_byte();
374330e2 2884
0016d70b 2885 /*
2886 * Verify that the `bits' and `bytes' parameters match.
2887 */
2888 if (hostkey.bits > hostkey.bytes * 8 ||
2889 servkey.bits > servkey.bytes * 8) {
2890 bombout(("SSH1 public keys were badly formatted"));
2891 crStop(0);
2892 }
2893
51470298 2894 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2895
3d88e64d 2896 s->rsabuf = snewn(s->len, unsigned char);
51470298 2897 if (!s->rsabuf)
374330e2 2898 fatalbox("Out of memory");
2899
89ee5268 2900 /*
2901 * Verify the host key.
2902 */
2903 {
32874aea 2904 /*
2905 * First format the key into a string.
2906 */
2907 int len = rsastr_len(&hostkey);
2908 char fingerprint[100];
3d88e64d 2909 char *keystr = snewn(len, char);
32874aea 2910 if (!keystr)
2911 fatalbox("Out of memory");
2912 rsastr_fmt(keystr, &hostkey);
2913 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3d9449a1 2914
2915 ssh_set_frozen(ssh, 1);
2916 s->dlgret = verify_ssh_host_key(ssh->frontend,
2917 ssh->savedhost, ssh->savedport,
2918 "rsa", keystr, fingerprint,
2919 ssh_dialog_callback, ssh);
32874aea 2920 sfree(keystr);
3d9449a1 2921 if (s->dlgret < 0) {
2922 do {
2923 crReturn(0);
2924 if (pktin) {
2925 bombout(("Unexpected data from server while waiting"
2926 " for user host key response"));
2927 crStop(0);
2928 }
2929 } while (pktin || inlen > 0);
2930 s->dlgret = ssh->user_response;
2931 }
2932 ssh_set_frozen(ssh, 0);
2933
2934 if (s->dlgret == 0) {
2935 ssh->close_expected = TRUE;
2936 ssh_closing((Plug)ssh, NULL, 0, 0);
2b3f6c19 2937 crStop(0);
3d9449a1 2938 }
32874aea 2939 }
2940
2941 for (i = 0; i < 32; i++) {
51470298 2942 s->rsabuf[i] = ssh->session_key[i];
374330e2 2943 if (i < 16)
51470298 2944 s->rsabuf[i] ^= s->session_id[i];
374330e2 2945 }
2946
2947 if (hostkey.bytes > servkey.bytes) {
0016d70b 2948 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2949 if (ret)
2950 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2951 } else {
0016d70b 2952 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2953 if (ret)
2954 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2955 }
2956 if (!ret) {
2957 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2958 crStop(0);
374330e2 2959 }
2960
c5e9c988 2961 logevent("Encrypted session key");
2962
ca20bfcf 2963 {
2964 int cipher_chosen = 0, warn = 0;
2965 char *cipher_string = NULL;
51470298 2966 int i;
ca20bfcf 2967 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2968 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2969 if (next_cipher == CIPHER_WARN) {
2970 /* If/when we choose a cipher, warn about it */
2971 warn = 1;
2972 } else if (next_cipher == CIPHER_AES) {
2973 /* XXX Probably don't need to mention this. */
2974 logevent("AES not supported in SSH1, skipping");
2975 } else {
2976 switch (next_cipher) {
51470298 2977 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2978 cipher_string = "3DES"; break;
51470298 2979 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2980 cipher_string = "Blowfish"; break;
51470298 2981 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2982 cipher_string = "single-DES"; break;
2983 }
51470298 2984 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2985 cipher_chosen = 1;
2986 }
2987 }
2988 if (!cipher_chosen) {
51470298 2989 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2990 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2991 "supporting 3DES encryption"));
2992 else
2993 /* shouldn't happen */
6b5cf8b4 2994 bombout(("No supported ciphers found"));
7ffdbc1a 2995 crStop(0);
a99a05c0 2996 }
ca20bfcf 2997
2998 /* Warn about chosen cipher if necessary. */
bb348ab1 2999 if (warn) {
3d9449a1 3000 ssh_set_frozen(ssh, 1);
3001 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3002 ssh_dialog_callback, ssh);
3003 if (s->dlgret < 0) {
3004 do {
3005 crReturn(0);
3006 if (pktin) {
3007 bombout(("Unexpected data from server while waiting"
3008 " for user response"));
3009 crStop(0);
3010 }
3011 } while (pktin || inlen > 0);
3012 s->dlgret = ssh->user_response;
3013 }
3014 ssh_set_frozen(ssh, 0);
3015 if (s->dlgret == 0) {
3016 ssh->close_expected = TRUE;
3017 ssh_closing((Plug)ssh, NULL, 0, 0);
96ccde8b 3018 crStop(0);
3d9449a1 3019 }
bb348ab1 3020 }
bea1ef5f 3021 }
ca20bfcf 3022
51470298 3023 switch (s->cipher_type) {
32874aea 3024 case SSH_CIPHER_3DES:
3025 logevent("Using 3DES encryption");
3026 break;
3027 case SSH_CIPHER_DES:
3028 logevent("Using single-DES encryption");
3029 break;
3030 case SSH_CIPHER_BLOWFISH:
3031 logevent("Using Blowfish encryption");
3032 break;
c5e9c988 3033 }
bea1ef5f 3034
51470298 3035 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3036 PKT_CHAR, s->cipher_type,
32874aea 3037 PKT_DATA, cookie, 8,
51470298 3038 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3039 PKT_DATA, s->rsabuf, s->len,
3040 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 3041
c5e9c988 3042 logevent("Trying to enable encryption...");
374330e2 3043
51470298 3044 sfree(s->rsabuf);
374330e2 3045
51470298 3046 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3047 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3048 &ssh_3des);
371e569c 3049 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3050 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 3051 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 3052
0183b242 3053 ssh->crcda_ctx = crcda_make_context();
3054 logevent("Installing CRC compensation attack detector");
3055
679539d7 3056 if (servkey.modulus) {
3057 sfree(servkey.modulus);
3058 servkey.modulus = NULL;
3059 }
3060 if (servkey.exponent) {
3061 sfree(servkey.exponent);
3062 servkey.exponent = NULL;
3063 }
3064 if (hostkey.modulus) {
3065 sfree(hostkey.modulus);
3066 hostkey.modulus = NULL;
3067 }
3068 if (hostkey.exponent) {
3069 sfree(hostkey.exponent);
3070 hostkey.exponent = NULL;
3071 }
ff3187f6 3072 crWaitUntil(pktin);
374330e2 3073
ff3187f6 3074 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3075 bombout(("Encryption not successfully enabled"));
7ffdbc1a 3076 crStop(0);
8d5de777 3077 }
374330e2 3078
c5e9c988 3079 logevent("Successfully started encryption");
3080
374330e2 3081 fflush(stdout);
3082 {
aa09f7d0 3083 if (!*ssh->cfg.username) {
c0a81592 3084 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 3085 if (!ssh_get_line("login as: ",
51470298 3086 s->username, sizeof(s->username), FALSE)) {
32874aea 3087 /*
3088 * get_line failed to get a username.
3089 * Terminate.
3090 */
3091 logevent("No username provided. Abandoning session.");
ac934965 3092 ssh->close_expected = TRUE;
3bb2f322 3093 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3094 crStop(1);
32874aea 3095 }
3096 } else {
51470298 3097 int ret; /* need not be kept over crReturn */
3098 c_write_str(ssh, "login as: ");
3099 ssh->send_ok = 1;
0405e71f 3100
51470298 3101 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 3102 do {
ff3187f6 3103 crWaitUntil(!pktin);
51470298 3104 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3105 } while (ret == 0);
3106 if (ret < 0)
3107 cleanup_exit(0);
51470298 3108 c_write_str(ssh, "\r\n");
32874aea 3109 }
3110 } else {
86916870 3111 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 3112 s->username[sizeof(s->username)-1] = '\0';
374330e2 3113 }
fb09bf1c 3114
51470298 3115 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 3116 {
51470298 3117 char userlog[22 + sizeof(s->username)];
3118 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 3119 logevent(userlog);
32874aea 3120 if (flags & FLAG_INTERACTIVE &&
3121 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 3122 strcat(userlog, "\r\n");
51470298 3123 c_write_str(ssh, userlog);
3c8e959b 3124 }
c5e9c988 3125 }
374330e2 3126 }
3127
ff3187f6 3128 crWaitUntil(pktin);
374330e2 3129
51470298 3130 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 3131 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 3132 s->tried_publickey = s->tried_agent = 1;
0df73905 3133 } else {
51470298 3134 s->tried_publickey = s->tried_agent = 0;
0df73905 3135 }
51470298 3136 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 3137 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 3138 if (!filename_is_null(ssh->cfg.keyfile)) {
3139 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 3140 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 3141 s->publickey_blob = NULL;
396778f1 3142 } else
51470298 3143 s->publickey_blob = NULL;
7cca0d81 3144
ff3187f6 3145 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3146 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 3147
51470298 3148 if (agent_exists() && !s->tried_agent) {
32874aea 3149 /*
3150 * Attempt RSA authentication using Pageant.
3151 */
32874aea 3152 void *r;
3153
51470298 3154 s->authed = FALSE;
3155 s->tried_agent = 1;
32874aea 3156 logevent("Pageant is running. Requesting keys.");
3157
3158 /* Request the keys held by the agent. */
51470298 3159 PUT_32BIT(s->request, 1);
3160 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 3161 if (!agent_query(s->request, 5, &r, &s->responselen,
3162 ssh_agent_callback, ssh)) {
3163 do {
3164 crReturn(0);
ff3187f6 3165 if (pktin) {
839f10db 3166 bombout(("Unexpected data from server while waiting"
3167 " for agent response"));
3168 crStop(0);
3169 }
ff3187f6 3170 } while (pktin || inlen > 0);
839f10db 3171 r = ssh->agent_response;
3172 s->responselen = ssh->agent_response_len;
3173 }
51470298 3174 s->response = (unsigned char *) r;
3175 if (s->response && s->responselen >= 5 &&
3176 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3177 s->p = s->response + 5;
3178 s->nkeys = GET_32BIT(s->p);
3179 s->p += 4;
fb983202 3180 logeventf(ssh, "Pageant has %d SSH1 keys", s->nkeys);
51470298 3181 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
fb983202 3182 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
51470298 3183 if (s->publickey_blob &&
3184 !memcmp(s->p, s->publickey_blob,
3185 s->publickey_bloblen)) {
396778f1 3186 logevent("This key matches configured key file");
51470298 3187 s->tried_publickey = 1;
396778f1 3188 }
51470298 3189 s->p += 4;
0016d70b 3190 {
3191 int n, ok = FALSE;
3192 do { /* do while (0) to make breaking easy */
3193 n = ssh1_read_bignum
3194 (s->p, s->responselen-(s->p-s->response),
3195 &s->key.exponent);
3196 if (n < 0)
3197 break;
3198 s->p += n;
3199 n = ssh1_read_bignum
3200 (s->p, s->responselen-(s->p-s->response),
3201 &s->key.modulus);
3202 if (n < 0)
3203 break;
3204 s->p += n;
3205 if (s->responselen - (s->p-s->response) < 4)
3206 break;
3207 s->commentlen = GET_32BIT(s->p);
3208 s->p += 4;
3209 if (s->responselen - (s->p-s->response) <
3210 s->commentlen)
3211 break;
3212 s->commentp = (char *)s->p;
3213 s->p += s->commentlen;
3214 ok = TRUE;
3215 } while (0);
3216 if (!ok) {
3217 logevent("Pageant key list packet was truncated");
3218 break;
3219 }
3220 }
51470298 3221 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3222 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3223 crWaitUntil(pktin);
3224 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3225 logevent("Key refused");
3226 continue;
3227 }
3228 logevent("Received RSA challenge");
ff3187f6 3229 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3230 bombout(("Server's RSA challenge was badly formatted"));
3231 crStop(0);
3232 }
3233
32874aea 3234 {
3235 char *agentreq, *q, *ret;
2d466ffd 3236 void *vret;
32874aea 3237 int len, retlen;
3238 len = 1 + 4; /* message type, bit count */
51470298 3239 len += ssh1_bignum_length(s->key.exponent);
3240 len += ssh1_bignum_length(s->key.modulus);
3241 len += ssh1_bignum_length(s->challenge);
32874aea 3242 len += 16; /* session id */
3243 len += 4; /* response format */
3d88e64d 3244 agentreq = snewn(4 + len, char);
32874aea 3245 PUT_32BIT(agentreq, len);
3246 q = agentreq + 4;
3247 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3248 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3249 q += 4;
51470298 3250 q += ssh1_write_bignum(q, s->key.exponent);
3251 q += ssh1_write_bignum(q, s->key.modulus);
3252 q += ssh1_write_bignum(q, s->challenge);
3253 memcpy(q, s->session_id, 16);
32874aea 3254 q += 16;
3255 PUT_32BIT(q, 1); /* response format */
839f10db 3256 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3257 ssh_agent_callback, ssh)) {
3258 sfree(agentreq);
3259 do {
3260 crReturn(0);
ff3187f6 3261 if (pktin) {
839f10db 3262 bombout(("Unexpected data from server"
3263 " while waiting for agent"
3264 " response"));
3265 crStop(0);
3266 }
ff3187f6 3267 } while (pktin || inlen > 0);
839f10db 3268 vret = ssh->agent_response;
3269 retlen = ssh->agent_response_len;
3270 } else
3271 sfree(agentreq);
2d466ffd 3272 ret = vret;
32874aea 3273 if (ret) {
3274 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3275 logevent("Sending Pageant's response");
51470298 3276 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3277 PKT_DATA, ret + 5, 16,
3278 PKT_END);
3279 sfree(ret);
ff3187f6 3280 crWaitUntil(pktin);
3281 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3282 logevent
3283 ("Pageant's response accepted");
3284 if (flags & FLAG_VERBOSE) {
51470298 3285 c_write_str(ssh, "Authenticated using"
3286 " RSA key \"");
3287 c_write(ssh, s->commentp,
3288 s->commentlen);
3289 c_write_str(ssh, "\" from agent\r\n");
32874aea 3290 }
51470298 3291 s->authed = TRUE;
32874aea 3292 } else
3293 logevent
3294 ("Pageant's response not accepted");
3295 } else {
3296 logevent
3297 ("Pageant failed to answer challenge");
3298 sfree(ret);
3299 }
3300 } else {
3301 logevent("No reply received from Pageant");
3302 }
3303 }
51470298 3304 freebn(s->key.exponent);
3305 freebn(s->key.modulus);
3306 freebn(s->challenge);
3307 if (s->authed)
32874aea 3308 break;
3309 }
29b1d0b3 3310 sfree(s->response);
32874aea 3311 }
51470298 3312 if (s->authed)
32874aea 3313 break;
3314 }
9a30e26b 3315 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3316 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3317
86916870 3318 if (ssh->cfg.try_tis_auth &&
51470298 3319 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3320 !s->tis_auth_refused) {
3321 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3322 logevent("Requested TIS authentication");
51470298 3323 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3324 crWaitUntil(pktin);
3325 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3326 logevent("TIS authentication declined");
3327 if (flags & FLAG_INTERACTIVE)
51470298 3328 c_write_str(ssh, "TIS authentication refused.\r\n");
3329 s->tis_auth_refused = 1;
614a20a0 3330 continue;
32874aea 3331 } else {
0016d70b 3332 char *challenge;
3333 int challengelen;
3334
ff3187f6 3335 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3336 if (!challenge) {
3337 bombout(("TIS challenge packet was badly formed"));
3338 crStop(0);
3339 }
32874aea 3340 logevent("Received TIS challenge");
51470298 3341 if (challengelen > sizeof(s->prompt) - 1)
3342 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3343 memcpy(s->prompt, challenge, challengelen);
614a20a0 3344 /* Prompt heuristic comes from OpenSSH */
51470298 3345 strncpy(s->prompt + challengelen,
3346 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3347 "": "\r\nResponse: ",
51470298 3348 (sizeof s->prompt) - challengelen);
3349 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3350 }
3351 }
86916870 3352 if (ssh->cfg.try_tis_auth &&
51470298 3353 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3354 !s->ccard_auth_refused) {
3355 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3356 logevent("Requested CryptoCard authentication");
51470298 3357 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3358 crWaitUntil(pktin);
3359 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3360 logevent("CryptoCard authentication declined");
51470298 3361 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3362 s->ccard_auth_refused = 1;
614a20a0 3363 continue;
32874aea 3364 } else {
0016d70b 3365 char *challenge;
3366 int challengelen;
3367
ff3187f6 3368 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3369 if (!challenge) {
3370 bombout(("CryptoCard challenge packet was badly formed"));
3371 crStop(0);
3372 }
32874aea 3373 logevent("Received CryptoCard challenge");
51470298 3374 if (challengelen > sizeof(s->prompt) - 1)
3375 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3376 memcpy(s->prompt, challenge, challengelen);
51470298 3377 strncpy(s->prompt + challengelen,
3378 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3379 "" : "\r\nResponse: ",
51470298 3380 sizeof(s->prompt) - challengelen);
3381 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3382 }
3383 }
51470298 3384 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3385 sprintf(s->prompt, "%.90s@%.90s's password: ",
3386 s->username, ssh->savedhost);
32874aea 3387 }
51470298 3388 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3389 char *comment = NULL;
231ee168 3390 int type;
32874aea 3391 if (flags & FLAG_VERBOSE)
51470298 3392 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3393 logeventf(ssh, "Trying public key \"%s\"",
3394 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3395 type = key_type(&ssh->cfg.keyfile);
231ee168 3396 if (type != SSH_KEYTYPE_SSH1) {
fb983202 3397 char *msg = dupprintf("Key is of wrong type (%s)",
3398 key_type_to_str(type));
3399 logevent(msg);
3400 c_write_str(ssh, msg);
51470298 3401 c_write_str(ssh, "\r\n");
fb983202 3402 sfree(msg);
51470298 3403 s->tried_publickey = 1;
231ee168 3404 continue;
3405 }
9a30e26b 3406 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3407 if (flags & FLAG_VERBOSE)
51470298 3408 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3409 goto tryauth;
3410 }
51470298 3411 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3412 sfree(comment);
3413 }
a52f067e 3414
614a20a0 3415 /*
3416 * Show password prompt, having first obtained it via a TIS
3417 * or CryptoCard exchange if we're doing TIS or CryptoCard
3418 * authentication.
3419 */
fa17a66e 3420 if (ssh_get_line) {
51470298 3421 if (!ssh_get_line(s->prompt, s->password,
3422 sizeof(s->password), TRUE)) {
32874aea 3423 /*
3424 * get_line failed to get a password (for example
3425 * because one was supplied on the command line
3426 * which has already failed to work). Terminate.
3427 */
51470298 3428 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3429 PKT_STR, "No more passwords available to try",
3430 PKT_END);
247308b5 3431 logevent("Unable to authenticate");
a8327734 3432 connection_fatal(ssh->frontend, "Unable to authenticate");
ac934965 3433 ssh->close_expected = TRUE;
3bb2f322 3434 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3435 crStop(1);
32874aea 3436 }
fb09bf1c 3437 } else {
614a20a0 3438 /* Prompt may have come from server. We've munged it a bit, so
3439 * we know it to be zero-terminated at least once. */
51470298 3440 int ret; /* need not be saved over crReturn */
3441 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3442 s->pos = 0;
0405e71f 3443
51470298 3444 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3445 do {
ff3187f6 3446 crWaitUntil(!pktin);
51470298 3447 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3448 } while (ret == 0);
3449 if (ret < 0)
3450 cleanup_exit(0);
51470298 3451 c_write_str(ssh, "\r\n");
32874aea 3452 }
3453
3454 tryauth:
51470298 3455 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3456 /*
3457 * Try public key authentication with the specified
3458 * key file.
3459 */
51470298 3460 s->tried_publickey = 1;
3461
3462 {
222d54dc 3463 const char *error = NULL;
3464 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3465 &error);
51470298 3466 if (ret == 0) {
3467 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3468 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3469 c_write_str(ssh, " (");
3470 c_write_str(ssh, error);
3471 c_write_str(ssh, ").\r\n");
51470298 3472 continue; /* go and try password */
3473 }
3474 if (ret == -1) {
3475 c_write_str(ssh, "Wrong passphrase.\r\n");
3476 s->tried_publickey = 0;
3477 continue; /* try again */
3478 }
32874aea 3479 }
3480
3481 /*
3482 * Send a public key attempt.
3483 */
51470298 3484 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3485 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3486
ff3187f6 3487 crWaitUntil(pktin);
3488 if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3489 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3490 continue; /* go and try password */
3491 }
ff3187f6 3492 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3493 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3494 crStop(0);
32874aea 3495 }
32874aea 3496
51470298 3497 {
3498 int i;
3499 unsigned char buffer[32];
3500 Bignum challenge, response;
3501
ff3187f6 3502 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3503 bombout(("Server's RSA challenge was badly formatted"));
3504 crStop(0);
3505 }
51470298 3506 response = rsadecrypt(challenge, &s->key);
3507 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3508
51470298 3509 for (i = 0; i < 32; i++) {
3510 buffer[i] = bignum_byte(response, 31 - i);
3511 }
3512
3513 MD5Init(&md5c);
3514 MD5Update(&md5c, buffer, 32);
3515 MD5Update(&md5c, s->session_id, 16);
3516 MD5Final(buffer, &md5c);
32874aea 3517
51470298 3518 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3519 PKT_DATA, buffer, 16, PKT_END);
3520
3521 freebn(challenge);
3522 freebn(response);
3523 }
32874aea 3524
ff3187f6 3525 crWaitUntil(pktin);
3526 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3527 if (flags & FLAG_VERBOSE)
51470298 3528 c_write_str(ssh, "Failed to authenticate with"
3529 " our public key.\r\n");
32874aea 3530 continue; /* go and try password */
ff3187f6 3531 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3532 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3533 crStop(0);
32874aea 3534 }
3535
3536 break; /* we're through! */
3537 } else {
51470298 3538 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3539 /*
3540 * Defence against traffic analysis: we send a
3541 * whole bunch of packets containing strings of
3542 * different lengths. One of these strings is the
3543 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3544 * The others are all random data in
3545 * SSH1_MSG_IGNORE packets. This way a passive
3546 * listener can't tell which is the password, and
3547 * hence can't deduce the password length.
3548 *
3549 * Anybody with a password length greater than 16
3550 * bytes is going to have enough entropy in their
3551 * password that a listener won't find it _that_
3552 * much help to know how long it is. So what we'll
3553 * do is:
3554 *
3555 * - if password length < 16, we send 15 packets
3556 * containing string lengths 1 through 15
3557 *
3558 * - otherwise, we let N be the nearest multiple
3559 * of 8 below the password length, and send 8
3560 * packets containing string lengths N through
3561 * N+7. This won't obscure the order of
3562 * magnitude of the password length, but it will
3563 * introduce a bit of extra uncertainty.
3564 *
3565 * A few servers (the old 1.2.18 through 1.2.22)
3566 * can't deal with SSH1_MSG_IGNORE. For these
3567 * servers, we need an alternative defence. We make
3568 * use of the fact that the password is interpreted
3569 * as a C string: so we can append a NUL, then some
3570 * random data.
bd358db1 3571 *
3572 * One server (a Cisco one) can deal with neither
3573 * SSH1_MSG_IGNORE _nor_ a padded password string.
3574 * For this server we are left with no defences
3575 * against password length sniffing.
32874aea 3576 */
51470298 3577 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3578 /*
3579 * The server can deal with SSH1_MSG_IGNORE, so
3580 * we can use the primary defence.
3581 */
32874aea 3582 int bottom, top, pwlen, i;
3583 char *randomstr;
3584
51470298 3585 pwlen = strlen(s->password);
32874aea 3586 if (pwlen < 16) {
3587 bottom = 0; /* zero length passwords are OK! :-) */
3588 top = 15;
3589 } else {
3590 bottom = pwlen & ~7;
3591 top = bottom + 7;
3592 }
3593
3594 assert(pwlen >= bottom && pwlen <= top);
3595
3d88e64d 3596 randomstr = snewn(top + 1, char);
32874aea 3597
3598 for (i = bottom; i <= top; i++) {
9a10ecf4 3599 if (i == pwlen) {
51470298 3600 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3601 PKTT_PASSWORD, PKT_STR, s->password,
3602 PKTT_OTHER, PKT_END);
3603 } else {
32874aea 3604 for (j = 0; j < i; j++) {
3605 do {
3606 randomstr[j] = random_byte();
3607 } while (randomstr[j] == '\0');
3608 }
3609 randomstr[i] = '\0';
51470298 3610 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3611 PKT_STR, randomstr, PKT_END);
3612 }
3613 }
bd358db1 3614 logevent("Sending password with camouflage packets");
51470298 3615 ssh_pkt_defersend(ssh);
679539d7 3616 sfree(randomstr);
bd358db1 3617 }
51470298 3618 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3619 /*
3620 * The server can't deal with SSH1_MSG_IGNORE
3621 * but can deal with padded passwords, so we
3622 * can use the secondary defence.
3623 */
bd358db1 3624 char string[64];
51470298 3625 char *ss;
bd358db1 3626 int len;
3627
51470298 3628 len = strlen(s->password);
bd358db1 3629 if (len < sizeof(string)) {
51470298 3630 ss = string;
3631 strcpy(string, s->password);
bd358db1 3632 len++; /* cover the zero byte */
3633 while (len < sizeof(string)) {
3634 string[len++] = (char) random_byte();
3635 }
3636 } else {
51470298 3637 ss = s->password;
bd358db1 3638 }
3639 logevent("Sending length-padded password");
9a10ecf4 3640 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3641 PKT_INT, len, PKT_DATA, ss, len,
3642 PKTT_OTHER, PKT_END);
bd358db1 3643 } else {
3644 /*
3645 * The server has _both_
3646 * BUG_CHOKES_ON_SSH1_IGNORE and
3647 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3648 * therefore nothing we can do.
3649 */
3650 int len;
51470298 3651 len = strlen(s->password);
bd358db1 3652 logevent("Sending unpadded password");
9a10ecf4 3653 send_packet(ssh, s->pwpkt_type,
3654 PKTT_PASSWORD, PKT_INT, len,
3655 PKT_DATA, s->password, len,
3656 PKTT_OTHER, PKT_END);
32874aea 3657 }
3658 } else {
9a10ecf4 3659 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3660 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3661 }
3662 }
c5e9c988 3663 logevent("Sent password");
51470298 3664 memset(s->password, 0, strlen(s->password));
ff3187f6 3665 crWaitUntil(pktin);
3666 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3667 if (flags & FLAG_VERBOSE)
51470298 3668 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3669 logevent("Authentication refused");
ff3187f6 3670 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3671 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3672 crStop(0);
374330e2 3673 }
3674 }
3675
c5e9c988 3676 logevent("Authentication successful");
3677
fb09bf1c 3678 crFinish(1);
3679}
3680
32874aea 3681void sshfwd_close(struct ssh_channel *c)
3682{
51470298 3683 Ssh ssh = c->ssh;
3684
1ef619ae 3685 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 3686 return;
36f94d1f 3687
80e48603 3688 if (c && !c->closes) {
4ed34d25 3689 /*
64d6ff88 3690 * If halfopen is true, we have sent
4ed34d25 3691 * CHANNEL_OPEN for this channel, but it hasn't even been
3692 * acknowledged by the server. So we must set a close flag
3693 * on it now, and then when the server acks the channel
3694 * open, we can close it then.
3695 */
64d6ff88 3696 if (!c->halfopen) {
51470298 3697 if (ssh->version == 1) {
3698 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3699 PKT_END);
3700 } else {
ff3187f6 3701 struct Packet *pktout;
3702 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3703 ssh2_pkt_adduint32(pktout, c->remoteid);
3704 ssh2_pkt_send(ssh, pktout);
4ed34d25 3705 }
32874aea 3706 }
0357890f 3707 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3708 if (c->type == CHAN_X11) {
3709 c->u.x11.s = NULL;
d74d141c 3710 logevent("Forwarded X11 connection terminated");
4ed34d25 3711 } else if (c->type == CHAN_SOCKDATA ||
3712 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3713 c->u.pfd.s = NULL;
3714 logevent("Forwarded port closed");
32874aea 3715 }
3716 }
3717}
3718
5471d09a 3719int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3720{
51470298 3721 Ssh ssh = c->ssh;
3722
1ef619ae 3723 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 3724 return 0;
36f94d1f 3725
51470298 3726 if (ssh->version == 1) {
3727 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3728 PKT_INT, c->remoteid,
9a10ecf4 3729 PKTT_DATA,
3730 PKT_INT, len, PKT_DATA, buf, len,
3731 PKTT_OTHER, PKT_END);
5471d09a 3732 /*
3733 * In SSH1 we can return 0 here - implying that forwarded
3734 * connections are never individually throttled - because
3735 * the only circumstance that can cause throttling will be
3736 * the whole SSH connection backing up, in which case
3737 * _everything_ will be throttled as a whole.
3738 */
3739 return 0;
783415f8 3740 } else {
32874aea 3741 ssh2_add_channel_data(c, buf, len);
5471d09a 3742 return ssh2_try_send(c);
3743 }
3744}
3745
3746void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3747{
51470298 3748 Ssh ssh = c->ssh;
3749
1ef619ae 3750 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 3751 return;
36f94d1f 3752
51470298 3753 if (ssh->version == 1) {
5471d09a 3754 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3755 c->v.v1.throttling = 0;
51470298 3756 ssh1_throttle(ssh, -1);
5471d09a 3757 }
3758 } else {
3759 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3760 }
9c964e85 3761}
3762
06fadff5 3763static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3764{
3765 struct queued_handler *qh = ssh->qhead;
3766
3767 assert(qh != NULL);
3768
3769 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3770
3771 if (qh->msg1 > 0) {
3772 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3773 ssh->packet_dispatch[qh->msg1] = NULL;
3774 }
3775 if (qh->msg2 > 0) {
3776 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3777 ssh->packet_dispatch[qh->msg2] = NULL;
3778 }
3779
3780 if (qh->next) {
3781 ssh->qhead = qh->next;
3782
3783 if (ssh->qhead->msg1 > 0) {
3784 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3785 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3786 }
3787 if (ssh->qhead->msg2 > 0) {
3788 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3789 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3790 }
3791 } else {
3792 ssh->qhead = ssh->qtail = NULL;
3793 ssh->packet_dispatch[pktin->type] = NULL;
3794 }
3795
3796 qh->handler(ssh, pktin, qh->ctx);
3797
3798 sfree(qh);
3799}
3800
3801static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3802 chandler_fn_t handler, void *ctx)
3803{
3804 struct queued_handler *qh;
3805
3806 qh = snew(struct queued_handler);
3807 qh->msg1 = msg1;
3808 qh->msg2 = msg2;
3809 qh->handler = handler;
3810 qh->ctx = ctx;
3811 qh->next = NULL;
3812
3813 if (ssh->qtail == NULL) {
3814 ssh->qhead = qh;
3815
3816 if (qh->msg1 > 0) {
3817 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3818 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3819 }
3820 if (qh->msg2 > 0) {
3821 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3822 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3823 }
3824 } else {
3825 ssh->qtail->next = qh;
3826 }
3827 ssh->qtail = qh;
3828}
3829
3830static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3831{
3832 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3833
3834 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3835 SSH2_MSG_REQUEST_SUCCESS)) {
3836 logeventf(ssh, "Remote port forwarding from %s enabled",
3837 pf->sportdesc);
3838 } else {
3839 logeventf(ssh, "Remote port forwarding from %s refused",
3840 pf->sportdesc);
3841
3842 rpf = del234(ssh->rportfwds, pf);
3843 assert(rpf == pf);
fda2feb1 3844 free_rportfwd(pf);
06fadff5 3845 }
3846}
3847
3848static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3849{
84328ddb 3850 const char *portfwd_strptr = cfg->portfwd;
3851 struct ssh_portfwd *epf;
3852 int i;
06fadff5 3853
fda2feb1 3854 if (!ssh->portfwds) {
3855 ssh->portfwds = newtree234(ssh_portcmp);
3856 } else {
3857 /*
3858 * Go through the existing port forwardings and tag them
84328ddb 3859 * with status==DESTROY. Any that we want to keep will be
3860 * re-enabled (status==KEEP) as we go through the
3861 * configuration and find out which bits are the same as
3862 * they were before.
fda2feb1 3863 */
3864 struct ssh_portfwd *epf;
3865 int i;
3866 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 3867 epf->status = DESTROY;
fda2feb1 3868 }
3869
06fadff5 3870 while (*portfwd_strptr) {
84328ddb 3871 char address_family, type;
3872 int sport,dport,sserv,dserv;
3873 char sports[256], dports[256], saddr[256], host[256];
3874 int n;
3875
05581745 3876 address_family = 'A';
3877 type = 'L';
84328ddb 3878 if (*portfwd_strptr == 'A' ||
3879 *portfwd_strptr == '4' ||
3880 *portfwd_strptr == '6')
3881 address_family = *portfwd_strptr++;
3882 if (*portfwd_strptr == 'L' ||
3883 *portfwd_strptr == 'R' ||
3884 *portfwd_strptr == 'D')
3885 type = *portfwd_strptr++;
05581745 3886
06fadff5 3887 saddr[0] = '\0';
05581745 3888
06fadff5 3889 n = 0;
3890 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3891 if (*portfwd_strptr == ':') {
3892 /*
3893 * We've seen a colon in the middle of the
3894 * source port number. This means that
3895 * everything we've seen until now is the
3896 * source _address_, so we'll move it into
3897 * saddr and start sports from the beginning
3898 * again.
3899 */
3900 portfwd_strptr++;
3901 sports[n] = '\0';
3902 if (ssh->version == 1 && type == 'R') {
3903 logeventf(ssh, "SSH1 cannot handle remote source address "
3904 "spec \"%s\"; ignoring", sports);
3905 } else
3906 strcpy(saddr, sports);
3907 n = 0;
3908 }
019164b0 3909 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
06fadff5 3910 }
3911 sports[n] = 0;
3912 if (type != 'D') {
3913 if (*portfwd_strptr == '\t')
3914 portfwd_strptr++;
3915 n = 0;
3916 while (*portfwd_strptr && *portfwd_strptr != ':') {
019164b0 3917 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
06fadff5 3918 }
3919 host[n] = 0;
3920 if (*portfwd_strptr == ':')
3921 portfwd_strptr++;
3922 n = 0;
3923 while (*portfwd_strptr) {
019164b0 3924 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
06fadff5 3925 }
3926 dports[n] = 0;
3927 portfwd_strptr++;
3928 dport = atoi(dports);
3929 dserv = 0;
3930 if (dport == 0) {
3931 dserv = 1;
3932 dport = net_service_lookup(dports);
3933 if (!dport) {
3934 logeventf(ssh, "Service lookup failed for destination"
3935 " port \"%s\"", dports);
3936 }
3937 }
3938 } else {
3939 while (*portfwd_strptr) portfwd_strptr++;
a9e72926 3940 host[0] = 0;
3941 dports[0] = 0;
06fadff5 3942 dport = dserv = -1;
3943 portfwd_strptr++; /* eat the NUL and move to next one */
3944 }
3945 sport = atoi(sports);
3946 sserv = 0;
3947 if (sport == 0) {
3948 sserv = 1;
3949 sport = net_service_lookup(sports);
3950 if (!sport) {
3951 logeventf(ssh, "Service lookup failed for source"
3952 " port \"%s\"", sports);
3953 }
3954 }
3955 if (sport && dport) {
3956 /* Set up a description of the source port. */
fda2feb1 3957 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 3958
3959 pfrec = snew(struct ssh_portfwd);
3960 pfrec->type = type;
3961 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3fe92132 3962 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 3963 pfrec->sport = sport;
84328ddb 3964 pfrec->daddr = *host ? dupstr(host) : NULL;
3fe92132 3965 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 3966 pfrec->dport = dport;
3967 pfrec->local = NULL;
3968 pfrec->remote = NULL;
05581745 3969 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3970 address_family == '6' ? ADDRTYPE_IPV6 :
3971 ADDRTYPE_UNSPEC);
fda2feb1 3972
3973 epfrec = add234(ssh->portfwds, pfrec);
3974 if (epfrec != pfrec) {
3975 /*
3976 * We already have a port forwarding with precisely
3977 * these parameters. Hence, no need to do anything;
84328ddb 3978 * simply tag the existing one as KEEP.
fda2feb1 3979 */
84328ddb 3980 epfrec->status = KEEP;
fda2feb1 3981 free_portfwd(pfrec);
84328ddb 3982 } else {
3983 pfrec->status = CREATE;
3984 }
3985 }
3986 }
3987
3988 /*
3989 * Now go through and destroy any port forwardings which were
3990 * not re-enabled.
3991 */
3992 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3993 if (epf->status == DESTROY) {
3994 char *message;
3995
3996 message = dupprintf("%s port forwarding from %s%s%d",
3997 epf->type == 'L' ? "local" :
3998 epf->type == 'R' ? "remote" : "dynamic",
3999 epf->saddr ? epf->saddr : "",
4000 epf->saddr ? ":" : "",
4001 epf->sport);
4002
4003 if (epf->type != 'D') {
4004 char *msg2 = dupprintf("%s to %s:%d", message,
4005 epf->daddr, epf->dport);
4006 sfree(message);
4007 message = msg2;
4008 }
4009
4010 logeventf(ssh, "Cancelling %s", message);
4011 sfree(message);
4012
4013 if (epf->remote) {
4014 struct ssh_rportfwd *rpf = epf->remote;
4015 struct Packet *pktout;
4016
4017 /*
4018 * Cancel the port forwarding at the server
4019 * end.
4020 */
4021 if (ssh->version == 1) {
4022 /*
4023 * We cannot cancel listening ports on the
4024 * server side in SSH1! There's no message
4025 * to support it. Instead, we simply remove
4026 * the rportfwd record from the local end
4027 * so that any connections the server tries
4028 * to make on it are rejected.
4029 */
4030 } else {
4031 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4032 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4033 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4034 if (epf->saddr) {
4035 ssh2_pkt_addstring(pktout, epf->saddr);
4036 } else if (ssh->cfg.rport_acceptall) {
5188540b 4037 /* XXX: ssh->cfg.rport_acceptall may not represent
4038 * what was used to open the original connection,
4039 * since it's reconfigurable. */
84328ddb 4040 ssh2_pkt_addstring(pktout, "0.0.0.0");
4041 } else {
4042 ssh2_pkt_addstring(pktout, "127.0.0.1");
4043 }
4044 ssh2_pkt_adduint32(pktout, epf->sport);
4045 ssh2_pkt_send(ssh, pktout);
4046 }
4047
4048 del234(ssh->rportfwds, rpf);
4049 free_rportfwd(rpf);
4050 } else if (epf->local) {
4051 pfd_terminate(epf->local);
4052 }
4053
4054 delpos234(ssh->portfwds, i);
4055 free_portfwd(epf);
4056 i--; /* so we don't skip one in the list */
4057 }
4058
4059 /*
4060 * And finally, set up any new port forwardings (status==CREATE).
4061 */
4062 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4063 if (epf->status == CREATE) {
4064 char *sportdesc, *dportdesc;
3fe92132 4065 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 4066 epf->saddr ? epf->saddr : "",
4067 epf->saddr ? ":" : "",
3fe92132 4068 epf->sserv ? epf->sserv : "",
4069 epf->sserv ? "(" : "",
4070 epf->sport,
4071 epf->sserv ? ")" : "");
84328ddb 4072 if (epf->type == 'D') {
4073 dportdesc = NULL;
4074 } else {
3fe92132 4075 dportdesc = dupprintf("%s:%s%s%d%s",
4076 epf->daddr,
4077 epf->dserv ? epf->dserv : "",
4078 epf->dserv ? "(" : "",
4079 epf->dport,
4080 epf->dserv ? ")" : "");
84328ddb 4081 }
05581745 4082
84328ddb 4083 if (epf->type == 'L') {
4084 const char *err = pfd_addforward(epf->daddr, epf->dport,
4085 epf->saddr, epf->sport,
5188540b 4086 ssh, cfg,
84328ddb 4087 &epf->local,
4088 epf->addressfamily);
4089
4090 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4091 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4092 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4093 sportdesc, dportdesc,
4094 err ? " failed: " : "", err ? err : "");
4095 } else if (epf->type == 'D') {
06fadff5 4096 const char *err = pfd_addforward(NULL, -1,
84328ddb 4097 epf->saddr, epf->sport,
5188540b 4098 ssh, cfg,
84328ddb 4099 &epf->local,
4100 epf->addressfamily);
4101
4102 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4103 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4104 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4105 sportdesc,
4106 err ? " failed: " : "", err ? err : "");
06fadff5 4107 } else {
4108 struct ssh_rportfwd *pf;
4109
4110 /*
4111 * Ensure the remote port forwardings tree exists.
4112 */
4113 if (!ssh->rportfwds) {
4114 if (ssh->version == 1)
4115 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4116 else
4117 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4118 }
4119
4120 pf = snew(struct ssh_rportfwd);
84328ddb 4121 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4122 pf->dhost[lenof(pf->dhost)-1] = '\0';
4123 pf->dport = epf->dport;
4124 pf->sport = epf->sport;
06fadff5 4125 if (add234(ssh->rportfwds, pf) != pf) {
4126 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 4127 epf->daddr, epf->dport);
06fadff5 4128 sfree(pf);
4129 } else {
4130 logeventf(ssh, "Requesting remote port %s"
84328ddb 4131 " forward to %s", sportdesc, dportdesc);
06fadff5 4132
4133 pf->sportdesc = sportdesc;
4134 sportdesc = NULL;
84328ddb 4135 epf->remote = pf;
4136 pf->pfrec = epf;
06fadff5 4137
4138 if (ssh->version == 1) {
4139 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 4140 PKT_INT, epf->sport,
4141 PKT_STR, epf->daddr,
4142 PKT_INT, epf->dport,
06fadff5 4143 PKT_END);
4144 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4145 SSH1_SMSG_FAILURE,
4146 ssh_rportfwd_succfail, pf);
4147 } else {
4148 struct Packet *pktout;
4149 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4150 ssh2_pkt_addstring(pktout, "tcpip-forward");
4151 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 4152 if (epf->saddr) {
4153 ssh2_pkt_addstring(pktout, epf->saddr);
5188540b 4154 } else if (cfg->rport_acceptall) {
06fadff5 4155 ssh2_pkt_addstring(pktout, "0.0.0.0");
4156 } else {
4157 ssh2_pkt_addstring(pktout, "127.0.0.1");
4158 }
84328ddb 4159 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 4160 ssh2_pkt_send(ssh, pktout);
4161
4162 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4163 SSH2_MSG_REQUEST_FAILURE,
4164 ssh_rportfwd_succfail, pf);
4165 }
4166 }
4167 }
4168 sfree(sportdesc);
84328ddb 4169 sfree(dportdesc);
06fadff5 4170 }
06fadff5 4171}
4172
51df0ab5 4173static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4174{
4175 char *string;
4176 int stringlen, bufsize;
4177
4178 ssh_pkt_getstring(pktin, &string, &stringlen);
4179 if (string == NULL) {
4180 bombout(("Incoming terminal data packet was badly formed"));
4181 return;
4182 }
4183
4184 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4185 string, stringlen);
4186 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4187 ssh->v1_stdout_throttling = 1;
4188 ssh1_throttle(ssh, +1);
4189 }
4190}
4191
4192static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4193{
4194 /* Remote side is trying to open a channel to talk to our
4195 * X-Server. Give them back a local channel number. */
4196 struct ssh_channel *c;
4197 int remoteid = ssh_pkt_getuint32(pktin);
4198
4199 logevent("Received X11 connect request");
4200 /* Refuse if X11 forwarding is disabled. */
4201 if (!ssh->X11_fwd_enabled) {
4202 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4203 PKT_INT, remoteid, PKT_END);
4204 logevent("Rejected X11 connect request");
4205 } else {
4206 c = snew(struct ssh_channel);
4207 c->ssh = ssh;
4208
4209 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4210 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4211 logevent("Opening X11 forward connection failed");
4212 sfree(c);
4213 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4214 PKT_INT, remoteid, PKT_END);
4215 } else {
4216 logevent
4217 ("Opening X11 forward connection succeeded");
4218 c->remoteid = remoteid;
64d6ff88 4219 c->halfopen = FALSE;
51df0ab5 4220 c->localid = alloc_channel_id(ssh);
4221 c->closes = 0;
4222 c->v.v1.throttling = 0;
4223 c->type = CHAN_X11; /* identify channel type */
4224 add234(ssh->channels, c);
4225 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4226 PKT_INT, c->remoteid, PKT_INT,
4227 c->localid, PKT_END);
4228 logevent("Opened X11 forward channel");
4229 }
4230 }
4231}
4232
4233static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4234{
4235 /* Remote side is trying to open a channel to talk to our
4236 * agent. Give them back a local channel number. */
4237 struct ssh_channel *c;
4238 int remoteid = ssh_pkt_getuint32(pktin);
4239
4240 /* Refuse if agent forwarding is disabled. */
4241 if (!ssh->agentfwd_enabled) {
4242 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4243 PKT_INT, remoteid, PKT_END);
4244 } else {
4245 c = snew(struct ssh_channel);
4246 c->ssh = ssh;
4247 c->remoteid = remoteid;
64d6ff88 4248 c->halfopen = FALSE;
51df0ab5 4249 c->localid = alloc_channel_id(ssh);
4250 c->closes = 0;
4251 c->v.v1.throttling = 0;
4252 c->type = CHAN_AGENT; /* identify channel type */
4253 c->u.a.lensofar = 0;
4254 add234(ssh->channels, c);
4255 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4256 PKT_INT, c->remoteid, PKT_INT, c->localid,
4257 PKT_END);
4258 }
4259}
4260
4261static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4262{
4263 /* Remote side is trying to open a channel to talk to a
4264 * forwarded port. Give them back a local channel number. */
4265 struct ssh_channel *c;
05581745 4266 struct ssh_rportfwd pf, *pfp;
51df0ab5 4267 int remoteid;
4268 int hostsize, port;
fb983202 4269 char *host;
51df0ab5 4270 const char *e;
4271 c = snew(struct ssh_channel);
4272 c->ssh = ssh;
4273
4274 remoteid = ssh_pkt_getuint32(pktin);
4275 ssh_pkt_getstring(pktin, &host, &hostsize);
4276 port = ssh_pkt_getuint32(pktin);
4277
4278 if (hostsize >= lenof(pf.dhost))
4279 hostsize = lenof(pf.dhost)-1;
4280 memcpy(pf.dhost, host, hostsize);
4281 pf.dhost[hostsize] = '\0';
4282 pf.dport = port;
05581745 4283 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4284
05581745 4285 if (pfp == NULL) {
fb983202 4286 logeventf(ssh, "Rejected remote port open request for %s:%d",
4287 pf.dhost, port);
51df0ab5 4288 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4289 PKT_INT, remoteid, PKT_END);
4290 } else {
fb983202 4291 logeventf(ssh, "Received remote port open request for %s:%d",
4292 pf.dhost, port);
51df0ab5 4293 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
05581745 4294 c, &ssh->cfg, pfp->pfrec->addressfamily);
51df0ab5 4295 if (e != NULL) {
fb983202 4296 logeventf(ssh, "Port open failed: %s", e);
51df0ab5 4297 sfree(c);
4298 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4299 PKT_INT, remoteid, PKT_END);
4300 } else {
4301 c->remoteid = remoteid;
64d6ff88 4302 c->halfopen = FALSE;
51df0ab5 4303 c->localid = alloc_channel_id(ssh);
4304 c->closes = 0;
4305 c->v.v1.throttling = 0;
4306 c->type = CHAN_SOCKDATA; /* identify channel type */
4307 add234(ssh->channels, c);
4308 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4309 PKT_INT, c->remoteid, PKT_INT,
4310 c->localid, PKT_END);
4311 logevent("Forwarded port opened successfully");
4312 }
4313 }
4314}
4315
4316static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4317{
4318 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4319 unsigned int localid = ssh_pkt_getuint32(pktin);
4320 struct ssh_channel *c;
4321
4322 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4323 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4324 c->remoteid = localid;
64d6ff88 4325 c->halfopen = FALSE;
51df0ab5 4326 c->type = CHAN_SOCKDATA;
4327 c->v.v1.throttling = 0;
4328 pfd_confirm(c->u.pfd.s);
4329 }
4330
4331 if (c && c->closes) {
4332 /*
4333 * We have a pending close on this channel,
4334 * which we decided on before the server acked
4335 * the channel open. So now we know the
4336 * remoteid, we can close it again.
4337 */
4338 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4339 PKT_INT, c->remoteid, PKT_END);
4340 }
4341}
4342
4343static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4344{
4345 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4346 struct ssh_channel *c;
4347
4348 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4349 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4350 logevent("Forwarded connection refused by server");
4351 pfd_close(c->u.pfd.s);
4352 del234(ssh->channels, c);
4353 sfree(c);
4354 }
4355}
4356
4357static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4358{
4359 /* Remote side closes a channel. */
4360 unsigned i = ssh_pkt_getuint32(pktin);
4361 struct ssh_channel *c;
4362 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 4363 if (c && !c->halfopen) {
51df0ab5 4364 int closetype;
4365 closetype =
4366 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4367
4368 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4369 logevent("Forwarded X11 connection terminated");
4370 assert(c->u.x11.s != NULL);
4371 x11_close(c->u.x11.s);
4372 c->u.x11.s = NULL;
4373 }
4374 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4375 logevent("Forwarded port closed");
4376 assert(c->u.pfd.s != NULL);
4377 pfd_close(c->u.pfd.s);
4378 c->u.pfd.s = NULL;
4379 }
4380
4381 c->closes |= (closetype << 2); /* seen this message */
4382 if (!(c->closes & closetype)) {
4383 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4384 PKT_END);
4385 c->closes |= closetype; /* sent it too */
4386 }
4387
4388 if (c->closes == 15) {
4389 del234(ssh->channels, c);
4390 sfree(c);
4391 }
4392 } else {
4393 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4394 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4395 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4396 i));
4397 }
4398}
4399
4400static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4401{
4402 /* Data sent down one of our channels. */
4403 int i = ssh_pkt_getuint32(pktin);
4404 char *p;
6d44acc9 4405 int len;
51df0ab5 4406 struct ssh_channel *c;
4407
4408 ssh_pkt_getstring(pktin, &p, &len);
4409
4410 c = find234(ssh->channels, &i, ssh_channelfind);
4411 if (c) {
4412 int bufsize = 0;
4413 switch (c->type) {
4414 case CHAN_X11:
4415 bufsize = x11_send(c->u.x11.s, p, len);
4416 break;
4417 case CHAN_SOCKDATA:
4418 bufsize = pfd_send(c->u.pfd.s, p, len);
4419 break;
4420 case CHAN_AGENT:
4421 /* Data for an agent message. Buffer it. */
4422 while (len > 0) {
4423 if (c->u.a.lensofar < 4) {
aa63ab7e 4424 unsigned int l = min(4 - c->u.a.lensofar, len);
51df0ab5 4425 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4426 l);
4427 p += l;
4428 len -= l;
4429 c->u.a.lensofar += l;
4430 }
4431 if (c->u.a.lensofar == 4) {
4432 c->u.a.totallen =
4433 4 + GET_32BIT(c->u.a.msglen);
4434 c->u.a.message = snewn(c->u.a.totallen,
4435 unsigned char);
4436 memcpy(c->u.a.message, c->u.a.msglen, 4);
4437 }
4438 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 4439 unsigned int l =
51df0ab5 4440 min(c->u.a.totallen - c->u.a.lensofar,
4441 len);
4442 memcpy(c->u.a.message + c->u.a.lensofar, p,
4443 l);
4444 p += l;
4445 len -= l;
4446 c->u.a.lensofar += l;
4447 }
4448 if (c->u.a.lensofar == c->u.a.totallen) {
4449 void *reply;
4450 int replylen;
4451 if (agent_query(c->u.a.message,
4452 c->u.a.totallen,
4453 &reply, &replylen,
4454 ssh_agentf_callback, c))
4455 ssh_agentf_callback(c, reply, replylen);
4456 sfree(c->u.a.message);
4457 c->u.a.lensofar = 0;
4458 }
4459 }
4460 bufsize = 0; /* agent channels never back up */
4461 break;
4462 }
4463 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4464 c->v.v1.throttling = 1;
4465 ssh1_throttle(ssh, +1);
4466 }
4467 }
4468}
4469
4470static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4471{
51df0ab5 4472 ssh->exitcode = ssh_pkt_getuint32(pktin);
fb983202 4473 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
51df0ab5 4474 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4475 /*
4476 * In case `helpful' firewalls or proxies tack
4477 * extra human-readable text on the end of the
4478 * session which we might mistake for another
4479 * encrypted packet, we close the session once
4480 * we've sent EXIT_CONFIRMATION.
4481 */
ac934965 4482 ssh->close_expected = TRUE;
51df0ab5 4483 ssh_closing((Plug)ssh, NULL, 0, 0);
4484}
4485
b09eaa88 4486static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4487 struct Packet *pktin)
32874aea 4488{
b09eaa88 4489 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 4490
51df0ab5 4491 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4492 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4493 ssh1_smsg_stdout_stderr_data;
4494
4495 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4496 ssh1_msg_channel_open_confirmation;
4497 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4498 ssh1_msg_channel_open_failure;
4499 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4500 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4501 ssh1_msg_channel_close;
4502 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4503 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4504
86916870 4505 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 4506 logevent("Requesting agent forwarding");
51470298 4507 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 4508 do {
4509 crReturnV;
ff3187f6 4510 } while (!pktin);
4511 if (pktin->type != SSH1_SMSG_SUCCESS
4512 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4513 bombout(("Protocol confusion"));
7ffdbc1a 4514 crStopV;
ff3187f6 4515 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4516 logevent("Agent forwarding refused");
4517 } else {
4518 logevent("Agent forwarding enabled");
51470298 4519 ssh->agentfwd_enabled = TRUE;
51df0ab5 4520 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 4521 }
dacbd0e8 4522 }
4523
86916870 4524 if (ssh->cfg.x11_forward) {
32874aea 4525 char proto[20], data[64];
4526 logevent("Requesting X11 forwarding");
302121de 4527 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 4528 data, sizeof(data), ssh->cfg.x11_auth);
4529 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 4530 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4531 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4532 PKT_STR, proto, PKT_STR, data,
86916870 4533 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 4534 PKT_END);
32874aea 4535 } else {
51470298 4536 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4537 PKT_STR, proto, PKT_STR, data, PKT_END);
4538 }
4539 do {
4540 crReturnV;
ff3187f6 4541 } while (!pktin);
4542 if (pktin->type != SSH1_SMSG_SUCCESS
4543 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4544 bombout(("Protocol confusion"));
7ffdbc1a 4545 crStopV;
ff3187f6 4546 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4547 logevent("X11 forwarding refused");
4548 } else {
4549 logevent("X11 forwarding enabled");
51470298 4550 ssh->X11_fwd_enabled = TRUE;
51df0ab5 4551 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 4552 }
4553 }
4554
06fadff5 4555 ssh_setup_portfwd(ssh, &ssh->cfg);
4556 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 4557
86916870 4558 if (!ssh->cfg.nopty) {
a5dd8467 4559 /* Unpick the terminal-speed string. */
4560 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4561 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4562 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4563 /* Send the pty request. */
51470298 4564 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 4565 PKT_STR, ssh->cfg.termtype,
51470298 4566 PKT_INT, ssh->term_height,
4567 PKT_INT, ssh->term_width,
a5dd8467 4568 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 4569 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4570 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 4571 PKT_CHAR, 0, PKT_END);
51470298 4572 ssh->state = SSH_STATE_INTERMED;
32874aea 4573 do {
4574 crReturnV;
ff3187f6 4575 } while (!pktin);
4576 if (pktin->type != SSH1_SMSG_SUCCESS
4577 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4578 bombout(("Protocol confusion"));
7ffdbc1a 4579 crStopV;
ff3187f6 4580 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4581 c_write_str(ssh, "Server refused to allocate pty\r\n");
4582 ssh->editing = ssh->echoing = 1;
32874aea 4583 }
a5dd8467 4584 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4585 ssh->ospeed, ssh->ispeed);
0965bee0 4586 } else {
51470298 4587 ssh->editing = ssh->echoing = 1;
374330e2 4588 }
4589
86916870 4590 if (ssh->cfg.compression) {
51470298 4591 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4592 do {
4593 crReturnV;
ff3187f6 4594 } while (!pktin);
4595 if (pktin->type != SSH1_SMSG_SUCCESS
4596 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4597 bombout(("Protocol confusion"));
7ffdbc1a 4598 crStopV;
ff3187f6 4599 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4600 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4601 }
4ba9b64b 4602 logevent("Started compression");
51470298 4603 ssh->v1_compressing = TRUE;
5366aed8 4604 ssh->cs_comp_ctx = zlib_compress_init();
4605 logevent("Initialised zlib (RFC1950) compression");
4606 ssh->sc_comp_ctx = zlib_decompress_init();
4607 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4608 }
4609
fd5e5847 4610 /*
4611 * Start the shell or command.
4612 *
4613 * Special case: if the first-choice command is an SSH2
4614 * subsystem (hence not usable here) and the second choice
4615 * exists, we fall straight back to that.
4616 */
4617 {
86916870 4618 char *cmd = ssh->cfg.remote_cmd_ptr;
04c52f10 4619
4620 if (!cmd) cmd = ssh->cfg.remote_cmd;
fd5e5847 4621
86916870 4622 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4623 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 4624 ssh->fallback_cmd = TRUE;
fd5e5847 4625 }
4626 if (*cmd)
51470298 4627 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 4628 else
51470298 4629 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 4630 logevent("Started session");
4631 }
374330e2 4632
51470298 4633 ssh->state = SSH_STATE_SESSION;
4634 if (ssh->size_needed)
4635 ssh_size(ssh, ssh->term_width, ssh->term_height);
4636 if (ssh->eof_needed)
4637 ssh_special(ssh, TS_EOF);
374330e2 4638
b9d7bcad 4639 if (ssh->ldisc)
4640 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 4641 ssh->send_ok = 1;
4642 ssh->channels = newtree234(ssh_channelcmp);
374330e2 4643 while (1) {
d74d141c 4644
51df0ab5 4645 /*
4646 * By this point, most incoming packets are already being
4647 * handled by the dispatch table, and we need only pay
4648 * attention to the unusual ones.
4649 */
0357890f 4650
51df0ab5 4651 crReturnV;
4652 if (pktin) {
4653 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4654 /* may be from EXEC_SHELL on some servers */
ff3187f6 4655 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 4656 /* may be from EXEC_SHELL on some servers
374330e2 4657 * if no pty is available or in other odd cases. Ignore */
374330e2 4658 } else {
ff3187f6 4659 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 4660 crStopV;
374330e2 4661 }
4662 } else {
8df7a775 4663 while (inlen > 0) {
4664 int len = min(inlen, 512);
9a10ecf4 4665 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4666 PKT_INT, len, PKT_DATA, in, len,
4667 PKTT_OTHER, PKT_END);
8df7a775 4668 in += len;
4669 inlen -= len;
4670 }
374330e2 4671 }
4672 }
4673
4674 crFinishV;
4675}
4676
4677/*
b09eaa88 4678 * Handle the top-level SSH2 protocol.
4679 */
4680static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4681{
fb983202 4682 char *msg;
b09eaa88 4683 int msglen;
4684
4685 ssh_pkt_getstring(pktin, &msg, &msglen);
fb983202 4686 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 4687}
4688
4689static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4690{
4691 /* log reason code in disconnect message */
4692 char *msg;
4693 int msglen;
4694
4695 ssh_pkt_getstring(pktin, &msg, &msglen);
4696 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4697}
4698
409bfa77 4699static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
b09eaa88 4700{
4701 /* Do nothing, because we're ignoring it! Duhh. */
4702}
4703
4704static void ssh1_protocol_setup(Ssh ssh)
4705{
4706 int i;
4707
4708 /*
4709 * Most messages are handled by the coroutines.
4710 */
4711 for (i = 0; i < 256; i++)
4712 ssh->packet_dispatch[i] = NULL;
4713
4714 /*
4715 * These special message types we install handlers for.
4716 */
4717 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4718 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4719 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4720}
4721
1c1a7262 4722static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
b09eaa88 4723 struct Packet *pktin)
4724{
1c1a7262 4725 unsigned char *in=(unsigned char*)vin;
b09eaa88 4726 if (ssh->state == SSH_STATE_CLOSED)
4727 return;
4728
4729 if (pktin && ssh->packet_dispatch[pktin->type]) {
4730 ssh->packet_dispatch[pktin->type](ssh, pktin);
4731 return;
4732 }
4733
4734 if (!ssh->protocol_initial_phase_done) {
4735 if (do_ssh1_login(ssh, in, inlen, pktin))
4736 ssh->protocol_initial_phase_done = TRUE;
4737 else
4738 return;
4739 }
4740
4741 do_ssh1_connection(ssh, in, inlen, pktin);
4742}
4743
4744/*
e5574168 4745 * Utility routine for decoding comma-separated strings in KEXINIT.
4746 */
32874aea 4747static int in_commasep_string(char *needle, char *haystack, int haylen)
4748{
57356d63 4749 int needlen;
4750 if (!needle || !haystack) /* protect against null pointers */
4751 return 0;
4752 needlen = strlen(needle);
e5574168 4753 while (1) {
32874aea 4754 /*
4755 * Is it at the start of the string?
4756 */
4757 if (haylen >= needlen && /* haystack is long enough */
4758 !memcmp(needle, haystack, needlen) && /* initial match */
4759 (haylen == needlen || haystack[needlen] == ',')
4760 /* either , or EOS follows */
4761 )
4762 return 1;
4763 /*
4764 * If not, search for the next comma and resume after that.
4765 * If no comma found, terminate.
4766 */
4767 while (haylen > 0 && *haystack != ',')
4768 haylen--, haystack++;
4769 if (haylen == 0)
4770 return 0;
4771 haylen--, haystack++; /* skip over comma itself */
e5574168 4772 }
4773}
4774
4775/*
b59743d5 4776 * Similar routine for checking whether we have the first string in a list.
4777 */
4778static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4779{
4780 int needlen;
4781 if (!needle || !haystack) /* protect against null pointers */
4782 return 0;
4783 needlen = strlen(needle);
4784 /*
4785 * Is it at the start of the string?
4786 */
4787 if (haylen >= needlen && /* haystack is long enough */
4788 !memcmp(needle, haystack, needlen) && /* initial match */
4789 (haylen == needlen || haystack[needlen] == ',')
4790 /* either , or EOS follows */
4791 )
4792 return 1;
4793 return 0;
4794}
4795
4796
4797/*
d39f364a 4798 * SSH2 key creation method.
4799 */
d8baa528 4800static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4801 unsigned char *sessid, char chr,
4802 unsigned char *keyspace)
32874aea 4803{
d39f364a 4804 SHA_State s;
4805 /* First 20 bytes. */
4806 SHA_Init(&s);
51470298 4807 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4808 sha_mpint(&s, K);
d39f364a 4809 SHA_Bytes(&s, H, 20);
4810 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 4811 SHA_Bytes(&s, sessid, 20);
d39f364a 4812 SHA_Final(&s, keyspace);
4813 /* Next 20 bytes. */
4814 SHA_Init(&s);
51470298 4815 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4816 sha_mpint(&s, K);
d39f364a 4817 SHA_Bytes(&s, H, 20);
4818 SHA_Bytes(&s, keyspace, 20);
32874aea 4819 SHA_Final(&s, keyspace + 20);
d39f364a 4820}
4821
4822/*
7cca0d81 4823 * Handle the SSH2 transport layer.
e5574168 4824 */
1c1a7262 4825static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
ff3187f6 4826 struct Packet *pktin)
e5574168 4827{
1c1a7262 4828 unsigned char *in = (unsigned char *)vin;
51470298 4829 struct do_ssh2_transport_state {
4763c1c2 4830 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
51470298 4831 Bignum p, g, e, f, K;
4832 int kex_init_value, kex_reply_value;
4833 const struct ssh_mac **maclist;
4834 int nmacs;
4835 const struct ssh2_cipher *cscipher_tobe;
4836 const struct ssh2_cipher *sccipher_tobe;
4837 const struct ssh_mac *csmac_tobe;
4838 const struct ssh_mac *scmac_tobe;
4839 const struct ssh_compress *cscomp_tobe;
4840 const struct ssh_compress *sccomp_tobe;
4841 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4842 int hostkeylen, siglen;
4843 void *hkey; /* actual host key */
4844 unsigned char exchange_hash[20];
83e7d008 4845 int n_preferred_kex;
4846 const struct ssh_kex *preferred_kex[KEX_MAX];
51470298 4847 int n_preferred_ciphers;
4848 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4849 const struct ssh_compress *preferred_comp;
e13bba36 4850 int got_session_id, activated_authconn;
ff3187f6 4851 struct Packet *pktout;
3d9449a1 4852 int dlgret;
4853 int guessok;
4763c1c2 4854 int ignorepkt;
51470298 4855 };
4856 crState(do_ssh2_transport_state);
4857
4858 crBegin(ssh->do_ssh2_transport_crstate);
4859
4860 s->cscipher_tobe = s->sccipher_tobe = NULL;
4861 s->csmac_tobe = s->scmac_tobe = NULL;
4862 s->cscomp_tobe = s->sccomp_tobe = NULL;
4863
e13bba36 4864 s->got_session_id = s->activated_authconn = FALSE;
e5574168 4865
e13bba36 4866 /*
4867 * Be prepared to work around the buggy MAC problem.
4868 */
4869 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4870 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4871 else
4872 s->maclist = macs, s->nmacs = lenof(macs);
4873
4874 begin_key_exchange:
149d2abc 4875 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
51470298 4876 {
e13bba36 4877 int i, j, commalist_started;
4878
51470298 4879 /*
83e7d008 4880 * Set up the preferred key exchange. (NULL => warn below here)
4881 */
4882 s->n_preferred_kex = 0;
4883 for (i = 0; i < KEX_MAX; i++) {
4884 switch (ssh->cfg.ssh_kexlist[i]) {
4885 case KEX_DHGEX:
4886 s->preferred_kex[s->n_preferred_kex++] =
4887 &ssh_diffiehellman_gex;
4888 break;
4889 case KEX_DHGROUP14:
4890 s->preferred_kex[s->n_preferred_kex++] =
4891 &ssh_diffiehellman_group14;
4892 break;
4893 case KEX_DHGROUP1:
4894 s->preferred_kex[s->n_preferred_kex++] =
4895 &ssh_diffiehellman_group1;
4896 break;
4897 case CIPHER_WARN:
4898 /* Flag for later. Don't bother if it's the last in
4899 * the list. */
4900 if (i < KEX_MAX - 1) {
4901 s->preferred_kex[s->n_preferred_kex++] = NULL;
4902 }
4903 break;
4904 }
4905 }
83e7d008 4906
83e7d008 4907 /*
51470298 4908 * Set up the preferred ciphers. (NULL => warn below here)
4909 */
4910 s->n_preferred_ciphers = 0;
4911 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4912 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4913 case CIPHER_BLOWFISH:
4914 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4915 break;
4916 case CIPHER_DES:
86916870 4917 if (ssh->cfg.ssh2_des_cbc) {
51470298 4918 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4919 }
4920 break;
4921 case CIPHER_3DES:
4922 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4923 break;
4924 case CIPHER_AES:
4925 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4926 break;
4927 case CIPHER_WARN:
4928 /* Flag for later. Don't bother if it's the last in
4929 * the list. */
4930 if (i < CIPHER_MAX - 1) {
4931 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4932 }
4933 break;
ca20bfcf 4934 }
ca20bfcf 4935 }
7591b9ff 4936
e13bba36 4937 /*
4938 * Set up preferred compression.
4939 */
4940 if (ssh->cfg.compression)
4941 s->preferred_comp = &ssh_zlib;
4942 else
4943 s->preferred_comp = &ssh_comp_none;
51470298 4944
4945 /*
590f6a5f 4946 * Enable queueing of outgoing auth- or connection-layer
4947 * packets while we are in the middle of a key exchange.
4948 */
4949 ssh->queueing = TRUE;
4950
4951 /*
9442dd57 4952 * Flag that KEX is in progress.
4953 */
4954 ssh->kex_in_progress = TRUE;
4955
4956 /*
51470298 4957 * Construct and send our key exchange packet.
4958 */
ff3187f6 4959 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 4960 for (i = 0; i < 16; i++)
ff3187f6 4961 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 4962 /* List key exchange algorithms. */
ff3187f6 4963 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4964 commalist_started = 0;
4965 for (i = 0; i < s->n_preferred_kex; i++) {
4966 const struct ssh_kex *k = s->preferred_kex[i];
4967 if (!k) continue; /* warning flag */
4968 if (commalist_started)
ff3187f6 4969 ssh2_pkt_addstring_str(s->pktout, ",");
83e7d008 4970 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4971 commalist_started = 1;
32874aea 4972 }
51470298 4973 /* List server host key algorithms. */
ff3187f6 4974 ssh2_pkt_addstring_start(s->pktout);
51470298 4975 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 4976 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 4977 if (i < lenof(hostkey_algs) - 1)
ff3187f6 4978 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4979 }
51470298 4980 /* List client->server encryption algorithms. */
ff3187f6 4981 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4982 commalist_started = 0;
51470298 4983 for (i = 0; i < s->n_preferred_ciphers; i++) {
4984 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4985 if (!c) continue; /* warning flag */
4986 for (j = 0; j < c->nciphers; j++) {
83e7d008 4987 if (commalist_started)
ff3187f6 4988 ssh2_pkt_addstring_str(s->pktout, ",");
4989 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4990 commalist_started = 1;
51470298 4991 }
4992 }
4993 /* List server->client encryption algorithms. */
ff3187f6 4994 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4995 commalist_started = 0;
51470298 4996 for (i = 0; i < s->n_preferred_ciphers; i++) {
4997 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4998 if (!c) continue; /* warning flag */
4999 for (j = 0; j < c->nciphers; j++) {
83e7d008 5000 if (commalist_started)
ff3187f6 5001 ssh2_pkt_addstring_str(s->pktout, ",");
5002 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 5003 commalist_started = 1;
51470298 5004 }
5005 }
5006 /* List client->server MAC algorithms. */
ff3187f6 5007 ssh2_pkt_addstring_start(s->pktout);
51470298 5008 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5009 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5010 if (i < s->nmacs - 1)
ff3187f6 5011 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5012 }
5013 /* List server->client MAC algorithms. */
ff3187f6 5014 ssh2_pkt_addstring_start(s->pktout);
51470298 5015 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5016 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5017 if (i < s->nmacs - 1)
ff3187f6 5018 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5019 }
5020 /* List client->server compression algorithms. */
ff3187f6 5021 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 5022 assert(lenof(compressions) > 1);
ff3187f6 5023 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 5024 for (i = 0; i < lenof(compressions); i++) {
5025 const struct ssh_compress *c = compressions[i];
5026 if (c != s->preferred_comp) {
ff3187f6 5027 ssh2_pkt_addstring_str(s->pktout, ",");
5028 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 5029 }
51470298 5030 }
5031 /* List server->client compression algorithms. */
ff3187f6 5032 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 5033 assert(lenof(compressions) > 1);
ff3187f6 5034 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 5035 for (i = 0; i < lenof(compressions); i++) {
5036 const struct ssh_compress *c = compressions[i];
5037 if (c != s->preferred_comp) {
ff3187f6 5038 ssh2_pkt_addstring_str(s->pktout, ",");
5039 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 5040 }
51470298 5041 }
5042 /* List client->server languages. Empty list. */
ff3187f6 5043 ssh2_pkt_addstring_start(s->pktout);
51470298 5044 /* List server->client languages. Empty list. */
ff3187f6 5045 ssh2_pkt_addstring_start(s->pktout);
51470298 5046 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 5047 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 5048 /* Reserved. */
ff3187f6 5049 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 5050 }
0db56f73 5051
51470298 5052 ssh->exhash = ssh->exhashbase;
ff3187f6 5053 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
0db56f73 5054
590f6a5f 5055 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5056
ff3187f6 5057 if (!pktin)
5058 crWaitUntil(pktin);
5059 if (pktin->length > 5)
5060 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
e5574168 5061
5062 /*
5063 * Now examine the other side's KEXINIT to see what we're up
5064 * to.
5065 */
51470298 5066 {
4763c1c2 5067 char *str, *preferred;
3d9449a1 5068 int i, j, len;
51470298 5069
ff3187f6 5070 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 5071 bombout(("expected key exchange packet from server"));
7ffdbc1a 5072 crStop(0);
32874aea 5073 }
51470298 5074 ssh->kex = NULL;
5075 ssh->hostkey = NULL;
5076 s->cscipher_tobe = NULL;
5077 s->sccipher_tobe = NULL;
5078 s->csmac_tobe = NULL;
5079 s->scmac_tobe = NULL;
5080 s->cscomp_tobe = NULL;
5081 s->sccomp_tobe = NULL;
4763c1c2 5082 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5083
ff3187f6 5084 pktin->savedpos += 16; /* skip garbage cookie */
5085 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4763c1c2 5086
5087 preferred = NULL;
83e7d008 5088 for (i = 0; i < s->n_preferred_kex; i++) {
5089 const struct ssh_kex *k = s->preferred_kex[i];
5090 if (!k) {
4763c1c2 5091 s->warn_kex = TRUE;
5092 } else {
5093 if (!preferred) preferred = k->name;
5094 if (in_commasep_string(k->name, str, len))
5095 ssh->kex = k;
83e7d008 5096 }
4763c1c2 5097 if (ssh->kex)
51470298 5098 break;
32874aea 5099 }
83e7d008 5100 if (!ssh->kex) {
5101 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5102 str ? str : "(null)"));
5103 crStop(0);
5104 }
b59743d5 5105 /*
5106 * Note that the server's guess is considered wrong if it doesn't match
5107 * the first algorithm in our list, even if it's still the algorithm
5108 * we end up using.
5109 */
4763c1c2 5110 s->guessok = first_in_commasep_string(preferred, str, len);
ff3187f6 5111 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 5112 for (i = 0; i < lenof(hostkey_algs); i++) {
5113 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5114 ssh->hostkey = hostkey_algs[i];
5115 break;
5116 }
5117 }
3d9449a1 5118 s->guessok = s->guessok &&
b59743d5 5119 first_in_commasep_string(hostkey_algs[0]->name, str, len);
ff3187f6 5120 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 5121 for (i = 0; i < s->n_preferred_ciphers; i++) {
5122 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5123 if (!c) {
4763c1c2 5124 s->warn_cscipher = TRUE;
51470298 5125 } else {
5126 for (j = 0; j < c->nciphers; j++) {
5127 if (in_commasep_string(c->list[j]->name, str, len)) {
5128 s->cscipher_tobe = c->list[j];
5129 break;
5130 }
ca20bfcf 5131 }
32874aea 5132 }
4763c1c2 5133 if (s->cscipher_tobe)
51470298 5134 break;
32874aea 5135 }
51470298 5136 if (!s->cscipher_tobe) {
6b5cf8b4 5137 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 5138 str ? str : "(null)"));
7ffdbc1a 5139 crStop(0);
ca20bfcf 5140 }
0ef8f407 5141
ff3187f6 5142 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 5143 for (i = 0; i < s->n_preferred_ciphers; i++) {
5144 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5145 if (!c) {
4763c1c2 5146 s->warn_sccipher = TRUE;
51470298 5147 } else {
5148 for (j = 0; j < c->nciphers; j++) {
5149 if (in_commasep_string(c->list[j]->name, str, len)) {
5150 s->sccipher_tobe = c->list[j];
5151 break;
5152 }
ca20bfcf 5153 }
32874aea 5154 }
4763c1c2 5155 if (s->sccipher_tobe)
51470298 5156 break;
32874aea 5157 }
51470298 5158 if (!s->sccipher_tobe) {
6b5cf8b4 5159 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 5160 str ? str : "(null)"));
7ffdbc1a 5161 crStop(0);
ca20bfcf 5162 }
0ef8f407 5163
ff3187f6 5164 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 5165 for (i = 0; i < s->nmacs; i++) {
5166 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5167 s->csmac_tobe = s->maclist[i];
5168 break;
5169 }
32874aea 5170 }
ff3187f6 5171 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 5172 for (i = 0; i < s->nmacs; i++) {
5173 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5174 s->scmac_tobe = s->maclist[i];
5175 break;
5176 }
32874aea 5177 }
ff3187f6 5178 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 5179 for (i = 0; i < lenof(compressions) + 1; i++) {
5180 const struct ssh_compress *c =
5181 i == 0 ? s->preferred_comp : compressions[i - 1];
5182 if (in_commasep_string(c->name, str, len)) {
5183 s->cscomp_tobe = c;
5184 break;
5185 }
32874aea 5186 }
ff3187f6 5187 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5188 for (i = 0; i < lenof(compressions) + 1; i++) {
5189 const struct ssh_compress *c =
5190 i == 0 ? s->preferred_comp : compressions[i - 1];
5191 if (in_commasep_string(c->name, str, len)) {
5192 s->sccomp_tobe = c;
5193 break;
5194 }
32874aea 5195 }
b59743d5 5196 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5197 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
4763c1c2 5198 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5199
5200 if (s->warn_kex) {
5201 ssh_set_frozen(ssh, 1);
5202 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5203 ssh->kex->name,
5204 ssh_dialog_callback, ssh);
5205 if (s->dlgret < 0) {
5206 do {
5207 crReturn(0);
5208 if (pktin) {
5209 bombout(("Unexpected data from server while"
5210 " waiting for user response"));
5211 crStop(0);
5212 }
5213 } while (pktin || inlen > 0);
5214 s->dlgret = ssh->user_response;
5215 }
5216 ssh_set_frozen(ssh, 0);
5217 if (s->dlgret == 0) {
5218 ssh->close_expected = TRUE;
5219 ssh_closing((Plug)ssh, NULL, 0, 0);
a5a6f839 5220 crStop(0);
4763c1c2 5221 }
5222 }
5223
5224 if (s->warn_cscipher) {
5225 ssh_set_frozen(ssh, 1);
5226 s->dlgret = askalg(ssh->frontend,
5227 "client-to-server cipher",
5228 s->cscipher_tobe->name,
5229 ssh_dialog_callback, ssh);
5230 if (s->dlgret < 0) {
5231 do {
5232 crReturn(0);
5233 if (pktin) {
5234 bombout(("Unexpected data from server while"
5235 " waiting for user response"));
5236 crStop(0);
5237 }
5238 } while (pktin || inlen > 0);
5239 s->dlgret = ssh->user_response;
5240 }
5241 ssh_set_frozen(ssh, 0);
5242 if (s->dlgret == 0) {
5243 ssh->close_expected = TRUE;
5244 ssh_closing((Plug)ssh, NULL, 0, 0);
a5a6f839 5245 crStop(0);
4763c1c2 5246 }
5247 }
5248
5249 if (s->warn_sccipher) {
5250 ssh_set_frozen(ssh, 1);
5251 s->dlgret = askalg(ssh->frontend,
5252 "server-to-client cipher",
5253 s->sccipher_tobe->name,
5254 ssh_dialog_callback, ssh);
5255 if (s->dlgret < 0) {
5256 do {
5257 crReturn(0);
5258 if (pktin) {
5259 bombout(("Unexpected data from server while"
5260 " waiting for user response"));
5261 crStop(0);
5262 }
5263 } while (pktin || inlen > 0);
5264 s->dlgret = ssh->user_response;
5265 }
5266 ssh_set_frozen(ssh, 0);
5267 if (s->dlgret == 0) {
5268 ssh->close_expected = TRUE;
5269 ssh_closing((Plug)ssh, NULL, 0, 0);
a5a6f839 5270 crStop(0);
4763c1c2 5271 }
5272 }
5273
5274 if (s->ignorepkt) /* first_kex_packet_follows */
b59743d5 5275 crWaitUntil(pktin); /* Ignore packet */
e5574168 5276 }
e5574168 5277
5278 /*
7bd5a860 5279 * Work out the number of bits of key we will need from the key
5280 * exchange. We start with the maximum key length of either
5281 * cipher...
5282 */
5283 {
32874aea 5284 int csbits, scbits;
7bd5a860 5285
51470298 5286 csbits = s->cscipher_tobe->keylen;
5287 scbits = s->sccipher_tobe->keylen;
5288 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 5289 }
5290 /* The keys only have 160-bit entropy, since they're based on
5291 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 5292 if (s->nbits > 160)
5293 s->nbits = 160;
7bd5a860 5294
5295 /*
a92dd380 5296 * If we're doing Diffie-Hellman group exchange, start by
5297 * requesting a group.
e5574168 5298 */
d1aaf71d 5299 if (!ssh->kex->pdata) {
32874aea 5300 logevent("Doing Diffie-Hellman group exchange");
51470298 5301 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 5302 /*
5303 * Work out how big a DH group we will need to allow that
5304 * much data.
7bd5a860 5305 */
51470298 5306 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 5307 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5308 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 5309 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 5310
ff3187f6 5311 crWaitUntil(pktin);
5312 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 5313 bombout(("expected key exchange group packet from server"));
7ffdbc1a 5314 crStop(0);
32874aea 5315 }
ff3187f6 5316 s->p = ssh2_pkt_getmp(pktin);
5317 s->g = ssh2_pkt_getmp(pktin);
5318 if (!s->p || !s->g) {
5319 bombout(("unable to read mp-ints from incoming group packet"));
5320 crStop(0);
5321 }
d1aaf71d 5322 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
51470298 5323 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5324 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 5325 } else {
d1aaf71d 5326 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5327 ssh->kex_ctx = dh_setup_group(ssh->kex);
51470298 5328 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5329 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
d1aaf71d 5330 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5331 ssh->kex->groupname);
8d5de777 5332 }
e5574168 5333
a92dd380 5334 logevent("Doing Diffie-Hellman key exchange");
e5574168 5335 /*
a92dd380 5336 * Now generate and send e for Diffie-Hellman.
e5574168 5337 */
755e0524 5338 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
27cd7fc2 5339 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 5340 s->pktout = ssh2_pkt_init(s->kex_init_value);
5341 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 5342 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5343
755e0524 5344 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
ff3187f6 5345 crWaitUntil(pktin);
5346 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 5347 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 5348 crStop(0);
7cca0d81 5349 }
755e0524 5350 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
ff3187f6 5351 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5352 s->f = ssh2_pkt_getmp(pktin);
5353 if (!s->f) {
5354 bombout(("unable to parse key exchange reply packet"));
5355 crStop(0);
5356 }
5357 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 5358
27cd7fc2 5359 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 5360
755e0524 5361 /* We assume everything from now on will be quick, and it might
5362 * involve user interaction. */
5363 set_busy_status(ssh->frontend, BUSY_NOT);
5364
51470298 5365 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5366 if (ssh->kex == &ssh_diffiehellman_gex) {
5367 sha_uint32(&ssh->exhash, s->pbits);
5368 sha_mpint(&ssh->exhash, s->p);
5369 sha_mpint(&ssh->exhash, s->g);
a92dd380 5370 }
51470298 5371 sha_mpint(&ssh->exhash, s->e);
5372 sha_mpint(&ssh->exhash, s->f);
5373 sha_mpint(&ssh->exhash, s->K);
5374 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 5375
27cd7fc2 5376 dh_cleanup(ssh->kex_ctx);
fabd1805 5377 ssh->kex_ctx = NULL;
3709bfe9 5378
7cca0d81 5379#if 0
765c4200 5380 debug(("Exchange hash is:\n"));
51470298 5381 dmemdump(s->exchange_hash, 20);
7cca0d81 5382#endif
5383
51470298 5384 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5385 if (!s->hkey ||
5386 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 5387 (char *)s->exchange_hash, 20)) {
6b5cf8b4 5388 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 5389 crStop(0);
8d5de777 5390 }
e5574168 5391
5392 /*
7cca0d81 5393 * Authenticate remote host: verify host key. (We've already
5394 * checked the signature of the exchange hash.)
e5574168 5395 */
51470298 5396 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5397 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
3d9449a1 5398 ssh_set_frozen(ssh, 1);
5399 s->dlgret = verify_ssh_host_key(ssh->frontend,
5400 ssh->savedhost, ssh->savedport,
5401 ssh->hostkey->keytype, s->keystr,
5402 s->fingerprint,
5403 ssh_dialog_callback, ssh);
5404 if (s->dlgret < 0) {
5405 do {
5406 crReturn(0);
5407 if (pktin) {
5408 bombout(("Unexpected data from server while waiting"
5409 " for user host key response"));
5410 crStop(0);
5411 }
5412 } while (pktin || inlen > 0);
5413 s->dlgret = ssh->user_response;
5414 }
5415 ssh_set_frozen(ssh, 0);
5416 if (s->dlgret == 0) {
5417 ssh->close_expected = TRUE;
5418 ssh_closing((Plug)ssh, NULL, 0, 0);
5419 crStop(0);
5420 }
e13bba36 5421 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 5422 logevent("Host key fingerprint is:");
51470298 5423 logevent(s->fingerprint);
5e0d7cb8 5424 }
51470298 5425 sfree(s->fingerprint);
5426 sfree(s->keystr);
5427 ssh->hostkey->freekey(s->hkey);
d39f364a 5428
5429 /*
9442dd57 5430 * The exchange hash from the very first key exchange is also
5431 * the session id, used in session key construction and
5432 * authentication.
5433 */
e13bba36 5434 if (!s->got_session_id) {
9442dd57 5435 memcpy(ssh->v2_session_id, s->exchange_hash,
5436 sizeof(s->exchange_hash));
e13bba36 5437 s->got_session_id = TRUE;
5438 }
9442dd57 5439
5440 /*
7cca0d81 5441 * Send SSH2_MSG_NEWKEYS.
d39f364a 5442 */
ff3187f6 5443 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 5444 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 5445 ssh->outgoing_data_size = 0; /* start counting from here */
5446
5447 /*
5448 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 5449 * client-to-server session keys.
9442dd57 5450 */
5451 if (ssh->cs_cipher_ctx)
5452 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5453 ssh->cscipher = s->cscipher_tobe;
5454 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5455
5456 if (ssh->cs_mac_ctx)
5457 ssh->csmac->free_context(ssh->cs_mac_ctx);
5458 ssh->csmac = s->csmac_tobe;
5459 ssh->cs_mac_ctx = ssh->csmac->make_context();
5460
5461 if (ssh->cs_comp_ctx)
5462 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5463 ssh->cscomp = s->cscomp_tobe;
5464 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5465
5466 /*
5467 * Set IVs on client-to-server keys. Here we use the exchange
5468 * hash from the _first_ key exchange.
5469 */
5470 {
5471 unsigned char keyspace[40];
5472 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5473 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5474 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5475 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5476 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5477 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5478 }
5479
5480 logeventf(ssh, "Initialised %.200s client->server encryption",
5481 ssh->cscipher->text_name);
5482 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5483 ssh->csmac->text_name);
5484 if (ssh->cscomp->text_name)
5485 logeventf(ssh, "Initialised %s compression",
5486 ssh->cscomp->text_name);
590f6a5f 5487
5488 /*
5489 * Now our end of the key exchange is complete, we can send all
5490 * our queued higher-layer packets.
5491 */
5492 ssh->queueing = FALSE;
5493 ssh2_pkt_queuesend(ssh);
d39f364a 5494
5495 /*
8406eaf9 5496 * Expect SSH2_MSG_NEWKEYS from server.
5497 */
ff3187f6 5498 crWaitUntil(pktin);
5499 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 5500 bombout(("expected new-keys packet from server"));
7ffdbc1a 5501 crStop(0);
8406eaf9 5502 }
9442dd57 5503 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 5504
5505 /*
9442dd57 5506 * We've seen server NEWKEYS, so create and initialise
5507 * server-to-client session keys.
d39f364a 5508 */
371e569c 5509 if (ssh->sc_cipher_ctx)
5510 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 5511 ssh->sccipher = s->sccipher_tobe;
371e569c 5512 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 5513
e0e1a00d 5514 if (ssh->sc_mac_ctx)
5515 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 5516 ssh->scmac = s->scmac_tobe;
e0e1a00d 5517 ssh->sc_mac_ctx = ssh->scmac->make_context();
5518
5366aed8 5519 if (ssh->sc_comp_ctx)
5520 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 5521 ssh->sccomp = s->sccomp_tobe;
5366aed8 5522 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5523
d39f364a 5524 /*
9442dd57 5525 * Set IVs on server-to-client keys. Here we use the exchange
5526 * hash from the _first_ key exchange.
d39f364a 5527 */
51470298 5528 {
5529 unsigned char keyspace[40];
51470298 5530 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 5531 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 5532 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 5533 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 5534 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 5535 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 5536 }
57356d63 5537 logeventf(ssh, "Initialised %.200s server->client encryption",
5538 ssh->sccipher->text_name);
6c135243 5539 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5540 ssh->scmac->text_name);
57356d63 5541 if (ssh->sccomp->text_name)
5542 logeventf(ssh, "Initialised %s decompression",
5543 ssh->sccomp->text_name);
9442dd57 5544
5545 /*
5546 * Free key exchange data.
5547 */
679539d7 5548 freebn(s->f);
679539d7 5549 freebn(s->K);
b3949e7e 5550 if (ssh->kex == &ssh_diffiehellman_gex) {
5551 freebn(s->g);
5552 freebn(s->p);
5553 }
d39f364a 5554
033b4cef 5555 /*
e13bba36 5556 * Key exchange is over. Loop straight back round if we have a
5557 * deferred rekey reason.
5558 */
5559 if (ssh->deferred_rekey_reason) {
5560 logevent(ssh->deferred_rekey_reason);
5561 pktin = NULL;
5562 ssh->deferred_rekey_reason = NULL;
5563 goto begin_key_exchange;
5564 }
5565
5566 /*
5567 * Otherwise, schedule a timer for our next rekey.
9442dd57 5568 */
5569 ssh->kex_in_progress = FALSE;
e6c1536e 5570 ssh->last_rekey = GETTICKCOUNT();
d57f70af 5571 if (ssh->cfg.ssh_rekey_time != 0)
5572 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5573 ssh2_timer, ssh);
e13bba36 5574
9442dd57 5575 /*
0db56f73 5576 * If this is the first key exchange phase, we must pass the
5577 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5578 * wants to see it but because it will need time to initialise
5579 * itself before it sees an actual packet. In subsequent key
5580 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5581 * it would only confuse the layer above.
5582 */
e13bba36 5583 if (s->activated_authconn) {
b09eaa88 5584 crReturn(1);
0db56f73 5585 }
e13bba36 5586 s->activated_authconn = TRUE;
0db56f73 5587
5588 /*
7cca0d81 5589 * Now we're encrypting. Begin returning 1 to the protocol main
5590 * function so that other things can run on top of the
5591 * transport. If we ever see a KEXINIT, we must go back to the
5592 * start.
9442dd57 5593 *
5594 * We _also_ go back to the start if we see pktin==NULL and
5595 * inlen==-1, because this is a special signal meaning
5596 * `initiate client-driven rekey', and `in' contains a message
5597 * giving the reason for the rekey.
033b4cef 5598 */
9442dd57 5599 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5600 (!pktin && inlen == -1))) {
f382c87d 5601 wait_for_rekey:
32874aea 5602 crReturn(1);
e96adf72 5603 }
9442dd57 5604 if (pktin) {
5605 logevent("Server initiated key re-exchange");
5606 } else {
f382c87d 5607 /*
5608 * Special case: if the server bug is set that doesn't
5609 * allow rekeying, we give a different log message and
5610 * continue waiting. (If such a server _initiates_ a rekey,
5611 * we process it anyway!)
5612 */
5613 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5614 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5615 (char *)in);
5616 /* Reset the counters, so that at least this message doesn't
5617 * hit the event log _too_ often. */
5618 ssh->outgoing_data_size = 0;
5619 ssh->incoming_data_size = 0;
5620 if (ssh->cfg.ssh_rekey_time != 0) {
5621 ssh->next_rekey =
5622 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5623 ssh2_timer, ssh);
5624 }
5625 goto wait_for_rekey; /* this is utterly horrid */
5626 } else {
5627 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
f382c87d 5628 }
9442dd57 5629 }
7cca0d81 5630 goto begin_key_exchange;
e5574168 5631
5632 crFinish(1);
5633}
5634
7cca0d81 5635/*
783415f8 5636 * Add data to an SSH2 channel output buffer.
5637 */
32874aea 5638static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5639 int len)
5640{
5471d09a 5641 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 5642}
5643
5644/*
5645 * Attempt to send data on an SSH2 channel.
5646 */
5471d09a 5647static int ssh2_try_send(struct ssh_channel *c)
32874aea 5648{
51470298 5649 Ssh ssh = c->ssh;
ff3187f6 5650 struct Packet *pktout;
51470298 5651
5471d09a 5652 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5653 int len;
5654 void *data;
5655 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5656 if ((unsigned)len > c->v.v2.remwindow)
5657 len = c->v.v2.remwindow;
5658 if ((unsigned)len > c->v.v2.remmaxpkt)
5659 len = c->v.v2.remmaxpkt;
ff3187f6 5660 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5661 ssh2_pkt_adduint32(pktout, c->remoteid);
5662 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5663 ssh2_pkt_addstring_start(pktout);
5664 ssh2_pkt_addstring_data(pktout, data, len);
5665 end_log_omission(ssh, pktout);
5666 ssh2_pkt_send(ssh, pktout);
5471d09a 5667 bufchain_consume(&c->v.v2.outbuffer, len);
5668 c->v.v2.remwindow -= len;
5669 }
5670
5671 /*
5672 * After having sent as much data as we can, return the amount
5673 * still buffered.
5674 */
5675 return bufchain_size(&c->v.v2.outbuffer);
5676}
5677
5678/*
5679 * Potentially enlarge the window on an SSH2 channel.
5680 */
5681static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5682{
51470298 5683 Ssh ssh = c->ssh;
5684
6b69f42e 5685 /*
5686 * Never send WINDOW_ADJUST for a channel that the remote side
5687 * already thinks it's closed; there's no point, since it won't
5688 * be sending any more data anyway.
5689 */
5690 if (c->closes != 0)
5691 return;
5692
d252310a 5693 /*
5694 * Only send a WINDOW_ADJUST if there's significantly more window
5695 * available than the other end thinks there is. This saves us
5696 * sending a WINDOW_ADJUST for every character in a shell session.
5697 *
5698 * "Significant" is arbitrarily defined as half the window size.
5699 */
5700 if (newwin > c->v.v2.locwindow * 2) {
ff3187f6 5701 struct Packet *pktout;
5702
5703 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5704 ssh2_pkt_adduint32(pktout, c->remoteid);
5705 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5706 ssh2_pkt_send(ssh, pktout);
5471d09a 5707 c->v.v2.locwindow = newwin;
783415f8 5708 }
5709}
5710
51df0ab5 5711static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 5712{
5713 unsigned i = ssh_pkt_getuint32(pktin);
5714 struct ssh_channel *c;
5715 c = find234(ssh->channels, &i, ssh_channelfind);
5716 if (c && !c->closes)
5717 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5718}
5719
51df0ab5 5720static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5721{
5722 char *data;
6d44acc9 5723 int length;
51df0ab5 5724 unsigned i = ssh_pkt_getuint32(pktin);
5725 struct ssh_channel *c;
5726 c = find234(ssh->channels, &i, ssh_channelfind);
5727 if (!c)
5728 return; /* nonexistent channel */
5729 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5730 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5731 return; /* extended but not stderr */
5732 ssh_pkt_getstring(pktin, &data, &length);
5733 if (data) {
5734 int bufsize = 0;
5735 c->v.v2.locwindow -= length;
5736 switch (c->type) {
5737 case CHAN_MAINSESSION:
5738 bufsize =
5739 from_backend(ssh->frontend, pktin->type ==
5740 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5741 data, length);
5742 break;
5743 case CHAN_X11:
5744 bufsize = x11_send(c->u.x11.s, data, length);
5745 break;
5746 case CHAN_SOCKDATA:
5747 bufsize = pfd_send(c->u.pfd.s, data, length);
5748 break;
5749 case CHAN_AGENT:
5750 while (length > 0) {
5751 if (c->u.a.lensofar < 4) {
aa63ab7e 5752 unsigned int l = min(4 - c->u.a.lensofar, length);
51df0ab5 5753 memcpy(c->u.a.msglen + c->u.a.lensofar,
5754 data, l);
5755 data += l;
5756 length -= l;
5757 c->u.a.lensofar += l;
5758 }
5759 if (c->u.a.lensofar == 4) {
5760 c->u.a.totallen =
5761 4 + GET_32BIT(c->u.a.msglen);
5762 c->u.a.message = snewn(c->u.a.totallen,
5763 unsigned char);
5764 memcpy(c->u.a.message, c->u.a.msglen, 4);
5765 }
5766 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 5767 unsigned int l =
51df0ab5 5768 min(c->u.a.totallen - c->u.a.lensofar,
5769 length);
5770 memcpy(c->u.a.message + c->u.a.lensofar,
5771 data, l);
5772 data += l;
5773 length -= l;
5774 c->u.a.lensofar += l;
5775 }
5776 if (c->u.a.lensofar == c->u.a.totallen) {
5777 void *reply;
5778 int replylen;
5779 if (agent_query(c->u.a.message,
5780 c->u.a.totallen,
5781 &reply, &replylen,
5782 ssh_agentf_callback, c))
5783 ssh_agentf_callback(c, reply, replylen);
5784 sfree(c->u.a.message);
5785 c->u.a.lensofar = 0;
5786 }
5787 }
5788 bufsize = 0;
5789 break;
5790 }
5791 /*
5792 * If we are not buffering too much data,
5793 * enlarge the window again at the remote side.
5794 */
5795 if (bufsize < OUR_V2_WINSIZE)
5796 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5797 }
5798}
5799
5800static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5801{
5802 unsigned i = ssh_pkt_getuint32(pktin);
5803 struct ssh_channel *c;
5804
5805 c = find234(ssh->channels, &i, ssh_channelfind);
5806 if (!c)
5807 return; /* nonexistent channel */
5808
5809 if (c->type == CHAN_X11) {
5810 /*
5811 * Remote EOF on an X11 channel means we should
5812 * wrap up and close the channel ourselves.
5813 */
5814 x11_close(c->u.x11.s);
5815 sshfwd_close(c);
5816 } else if (c->type == CHAN_AGENT) {
5817 sshfwd_close(c);
5818 } else if (c->type == CHAN_SOCKDATA) {
5819 pfd_close(c->u.pfd.s);
5820 sshfwd_close(c);
5821 }
5822}
5823
5824static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5825{
5826 unsigned i = ssh_pkt_getuint32(pktin);
5827 struct ssh_channel *c;
5828 struct Packet *pktout;
5829
5830 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 5831 if (!c || c->halfopen) {
51df0ab5 5832 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5833 c ? "half-open" : "nonexistent", i));
5834 return;
5835 }
5836 /* Do pre-close processing on the channel. */
5837 switch (c->type) {
5838 case CHAN_MAINSESSION:
5839 ssh->mainchan = NULL;
5840 update_specials_menu(ssh->frontend);
5841 break;
5842 case CHAN_X11:
5843 if (c->u.x11.s != NULL)
5844 x11_close(c->u.x11.s);
5845 sshfwd_close(c);
5846 break;
5847 case CHAN_AGENT:
5848 sshfwd_close(c);
5849 break;
5850 case CHAN_SOCKDATA:
5851 if (c->u.pfd.s != NULL)
5852 pfd_close(c->u.pfd.s);
5853 sshfwd_close(c);
5854 break;
5855 }
5856 if (c->closes == 0) {
5857 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5858 ssh2_pkt_adduint32(pktout, c->remoteid);
5859 ssh2_pkt_send(ssh, pktout);
5860 }
5861 del234(ssh->channels, c);
5862 bufchain_clear(&c->v.v2.outbuffer);
5863 sfree(c);
5864
5865 /*
5866 * See if that was the last channel left open.
5867 * (This is only our termination condition if we're
5868 * not running in -N mode.)
5869 */
5870 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5871 logevent("All channels closed. Disconnecting");
5872#if 0
5873 /*
5874 * We used to send SSH_MSG_DISCONNECT here,
5875 * because I'd believed that _every_ conforming
5876 * SSH2 connection had to end with a disconnect
5877 * being sent by at least one side; apparently
5878 * I was wrong and it's perfectly OK to
5879 * unceremoniously slam the connection shut
5880 * when you're done, and indeed OpenSSH feels
5881 * this is more polite than sending a
5882 * DISCONNECT. So now we don't.
5883 */
5884 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5885 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5886 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5887 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5888 ssh2_pkt_send_noqueue(ssh, s->pktout);
5889#endif
ac934965 5890 ssh->close_expected = TRUE;
51df0ab5 5891 ssh_closing((Plug)ssh, NULL, 0, 0);
5892 }
5893}
5894
5895static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5896{
5897 unsigned i = ssh_pkt_getuint32(pktin);
5898 struct ssh_channel *c;
5899 struct Packet *pktout;
5900
5901 c = find234(ssh->channels, &i, ssh_channelfind);
5902 if (!c)
5903 return; /* nonexistent channel */
5904 if (c->type != CHAN_SOCKDATA_DORMANT)
5905 return; /* dunno why they're confirming this */
5906 c->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 5907 c->halfopen = FALSE;
51df0ab5 5908 c->type = CHAN_SOCKDATA;
5909 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5910 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5911 if (c->u.pfd.s)
5912 pfd_confirm(c->u.pfd.s);
5913 if (c->closes) {
5914 /*
5915 * We have a pending close on this channel,
5916 * which we decided on before the server acked
5917 * the channel open. So now we know the
5918 * remoteid, we can close it again.
5919 */
5920 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5921 ssh2_pkt_adduint32(pktout, c->remoteid);
5922 ssh2_pkt_send(ssh, pktout);
5923 }
5924}
5925
5926static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5927{
5928 static const char *const reasons[] = {
5929 "<unknown reason code>",
5930 "Administratively prohibited",
5931 "Connect failed",
5932 "Unknown channel type",
5933 "Resource shortage",
5934 };
5935 unsigned i = ssh_pkt_getuint32(pktin);
5936 unsigned reason_code;
5937 char *reason_string;
5938 int reason_length;
51df0ab5 5939 struct ssh_channel *c;
5940 c = find234(ssh->channels, &i, ssh_channelfind);
5941 if (!c)
5942 return; /* nonexistent channel */
5943 if (c->type != CHAN_SOCKDATA_DORMANT)
5944 return; /* dunno why they're failing this */
5945
5946 reason_code = ssh_pkt_getuint32(pktin);
5947 if (reason_code >= lenof(reasons))
5948 reason_code = 0; /* ensure reasons[reason_code] in range */
5949 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
fb983202 5950 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
5951 reasons[reason_code], reason_length, reason_string);
51df0ab5 5952
5953 pfd_close(c->u.pfd.s);
5954
5955 del234(ssh->channels, c);
5956 sfree(c);
5957}
5958
5959static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5960{
5961 unsigned localid;
5962 char *type;
5963 int typelen, want_reply;
5964 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5965 struct ssh_channel *c;
5966 struct Packet *pktout;
5967
5968 localid = ssh_pkt_getuint32(pktin);
5969 ssh_pkt_getstring(pktin, &type, &typelen);
5970 want_reply = ssh2_pkt_getbool(pktin);
5971
5972 /*
5973 * First, check that the channel exists. Otherwise,
5974 * we can instantly disconnect with a rude message.
5975 */
5976 c = find234(ssh->channels, &localid, ssh_channelfind);
5977 if (!c) {
5978 char buf[80];
5979 sprintf(buf, "Received channel request for nonexistent"
5980 " channel %d", localid);
5981 logevent(buf);
5982 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5983 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5984 ssh2_pkt_addstring(pktout, buf);
5985 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5986 ssh2_pkt_send_noqueue(ssh, pktout);
5987 connection_fatal(ssh->frontend, "%s", buf);
ac934965 5988 ssh->close_expected = TRUE;
51df0ab5 5989 ssh_closing((Plug)ssh, NULL, 0, 0);
5990 return;
5991 }
5992
5993 /*
5994 * Having got the channel number, we now look at
5995 * the request type string to see if it's something
5996 * we recognise.
5997 */
5998 if (c == ssh->mainchan) {
5999 /*
6000 * We recognise "exit-status" and "exit-signal" on
6001 * the primary channel.
6002 */
6003 if (typelen == 11 &&
6004 !memcmp(type, "exit-status", 11)) {
6005
6006 ssh->exitcode = ssh_pkt_getuint32(pktin);
6007 logeventf(ssh, "Server sent command exit status %d",
6008 ssh->exitcode);
6009 reply = SSH2_MSG_CHANNEL_SUCCESS;
6010
6011 } else if (typelen == 11 &&
6012 !memcmp(type, "exit-signal", 11)) {
6013
6014 int is_plausible = TRUE, is_int = FALSE;
6015 char *fmt_sig = "", *fmt_msg = "";
6016 char *msg;
6017 int msglen = 0, core = FALSE;
6018 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6019 * provide an `int' for the signal, despite its
6020 * having been a `string' in the drafts since at
6021 * least 2001. (Fixed in session.c 1.147.) Try to
6022 * infer which we can safely parse it as. */
6023 {
6024 unsigned char *p = pktin->body +
6025 pktin->savedpos;
6026 long len = pktin->length - pktin->savedpos;
6027 unsigned long num = GET_32BIT(p); /* what is it? */
6028 /* If it's 0, it hardly matters; assume string */
6029 if (num == 0) {
6030 is_int = FALSE;
6031 } else {
6032 int maybe_int = FALSE, maybe_str = FALSE;
6033#define CHECK_HYPOTHESIS(offset, result) \
6034 do { \
6035 long q = offset; \
6036 if (q >= 0 && q+4 <= len) { \
6037 q = q + 4 + GET_32BIT(p+q); \
6038 if (q >= 0 && q+4 <= len && \
c849ff23 6039 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
51df0ab5 6040 result = TRUE; \
6041 } \
6042 } while(0)
6043 CHECK_HYPOTHESIS(4+1, maybe_int);
6044 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6045#undef CHECK_HYPOTHESIS
6046 if (maybe_int && !maybe_str)
6047 is_int = TRUE;
6048 else if (!maybe_int && maybe_str)
6049 is_int = FALSE;
6050 else
6051 /* Crikey. Either or neither. Panic. */
6052 is_plausible = FALSE;
6053 }
6054 }
6055 if (is_plausible) {
6056 if (is_int) {
6057 /* Old non-standard OpenSSH. */
6058 int signum = ssh_pkt_getuint32(pktin);
6059 fmt_sig = dupprintf(" %d", signum);
6060 } else {
6061 /* As per the drafts. */
6062 char *sig;
6063 int siglen;
6064 ssh_pkt_getstring(pktin, &sig, &siglen);
6065 /* Signal name isn't supposed to be blank, but
6066 * let's cope gracefully if it is. */
6067 if (siglen) {
6068 fmt_sig = dupprintf(" \"%.*s\"",
6069 siglen, sig);
6070 }
6071 }
6072 core = ssh2_pkt_getbool(pktin);
6073 ssh_pkt_getstring(pktin, &msg, &msglen);
6074 if (msglen) {
6075 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6076 }
6077 /* ignore lang tag */
6078 } /* else don't attempt to parse */
6079 logeventf(ssh, "Server exited on signal%s%s%s",
6080 fmt_sig, core ? " (core dumped)" : "",
6081 fmt_msg);
6082 if (*fmt_sig) sfree(fmt_sig);
6083 if (*fmt_msg) sfree(fmt_msg);
6084 reply = SSH2_MSG_CHANNEL_SUCCESS;
6085
6086 }
6087 } else {
6088 /*
6089 * This is a channel request we don't know
6090 * about, so we now either ignore the request
6091 * or respond with CHANNEL_FAILURE, depending
6092 * on want_reply.
6093 */
6094 reply = SSH2_MSG_CHANNEL_FAILURE;
6095 }
6096 if (want_reply) {
6097 pktout = ssh2_pkt_init(reply);
6098 ssh2_pkt_adduint32(pktout, c->remoteid);
6099 ssh2_pkt_send(ssh, pktout);
6100 }
6101}
6102
6103static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6104{
6105 char *type;
6106 int typelen, want_reply;
6107 struct Packet *pktout;
6108
6109 ssh_pkt_getstring(pktin, &type, &typelen);
6110 want_reply = ssh2_pkt_getbool(pktin);
6111
6112 /*
6113 * We currently don't support any global requests
6114 * at all, so we either ignore the request or
6115 * respond with REQUEST_FAILURE, depending on
6116 * want_reply.
6117 */
6118 if (want_reply) {
6119 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6120 ssh2_pkt_send(ssh, pktout);
6121 }
6122}
6123
6124static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6125{
6126 char *type;
6127 int typelen;
6128 char *peeraddr;
6129 int peeraddrlen;
6130 int peerport;
6131 char *error = NULL;
6132 struct ssh_channel *c;
6133 unsigned remid, winsize, pktsize;
6134 struct Packet *pktout;
6135
6136 ssh_pkt_getstring(pktin, &type, &typelen);
6137 c = snew(struct ssh_channel);
6138 c->ssh = ssh;
6139
6140 remid = ssh_pkt_getuint32(pktin);
6141 winsize = ssh_pkt_getuint32(pktin);
6142 pktsize = ssh_pkt_getuint32(pktin);
6143
6144 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6145 char *addrstr;
6146
6147 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6148 addrstr = snewn(peeraddrlen+1, char);
6149 memcpy(addrstr, peeraddr, peeraddrlen);
6150 addrstr[peeraddrlen] = '\0';
6151 peerport = ssh_pkt_getuint32(pktin);
6152
6153 logeventf(ssh, "Received X11 connect request from %s:%d",
6154 addrstr, peerport);
6155
6156 if (!ssh->X11_fwd_enabled)
6157 error = "X11 forwarding is not enabled";
6158 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6159 ssh->x11auth, addrstr, peerport,
6160 &ssh->cfg) != NULL) {
6161 error = "Unable to open an X11 connection";
6162 } else {
6163 logevent("Opening X11 forward connection succeeded");
6164 c->type = CHAN_X11;
6165 }
6166
6167 sfree(addrstr);
6168 } else if (typelen == 15 &&
6169 !memcmp(type, "forwarded-tcpip", 15)) {
6170 struct ssh_rportfwd pf, *realpf;
6171 char *dummy;
6172 int dummylen;
6173 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6174 pf.sport = ssh_pkt_getuint32(pktin);
6175 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6176 peerport = ssh_pkt_getuint32(pktin);
6177 realpf = find234(ssh->rportfwds, &pf, NULL);
6178 logeventf(ssh, "Received remote port %d open request "
6179 "from %s:%d", pf.sport, peeraddr, peerport);
6180 if (realpf == NULL) {
6181 error = "Remote port is not recognised";
6182 } else {
6183 const char *e = pfd_newconnect(&c->u.pfd.s,
6184 realpf->dhost,
6185 realpf->dport, c,
05581745 6186 &ssh->cfg,
6187 realpf->pfrec->addressfamily);
51df0ab5 6188 logeventf(ssh, "Attempting to forward remote port to "
6189 "%s:%d", realpf->dhost, realpf->dport);
6190 if (e != NULL) {
6191 logeventf(ssh, "Port open failed: %s", e);
6192 error = "Port open failed";
6193 } else {
6194 logevent("Forwarded port opened successfully");
6195 c->type = CHAN_SOCKDATA;
6196 }
6197 }
6198 } else if (typelen == 22 &&
6199 !memcmp(type, "auth-agent@openssh.com", 3)) {
6200 if (!ssh->agentfwd_enabled)
6201 error = "Agent forwarding is not enabled";
6202 else {
6203 c->type = CHAN_AGENT; /* identify channel type */
6204 c->u.a.lensofar = 0;
6205 }
6206 } else {
6207 error = "Unsupported channel type requested";
6208 }
6209
6210 c->remoteid = remid;
64d6ff88 6211 c->halfopen = FALSE;
51df0ab5 6212 if (error) {
6213 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6214 ssh2_pkt_adduint32(pktout, c->remoteid);
6215 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6216 ssh2_pkt_addstring(pktout, error);
6217 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6218 ssh2_pkt_send(ssh, pktout);
6219 logeventf(ssh, "Rejected channel open: %s", error);
6220 sfree(c);
6221 } else {
6222 c->localid = alloc_channel_id(ssh);
6223 c->closes = 0;
6224 c->v.v2.locwindow = OUR_V2_WINSIZE;
6225 c->v.v2.remwindow = winsize;
6226 c->v.v2.remmaxpkt = pktsize;
6227 bufchain_init(&c->v.v2.outbuffer);
6228 add234(ssh->channels, c);
6229 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6230 ssh2_pkt_adduint32(pktout, c->remoteid);
6231 ssh2_pkt_adduint32(pktout, c->localid);
6232 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
954d5c5a 6233 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
51df0ab5 6234 ssh2_pkt_send(ssh, pktout);
6235 }
6236}
6237
783415f8 6238/*
7cca0d81 6239 * Handle the SSH2 userauth and connection layers.
6240 */
ff3187f6 6241static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6242 struct Packet *pktin)
7cca0d81 6243{
51470298 6244 struct do_ssh2_authconn_state {
6245 enum {
6246 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6247 AUTH_PASSWORD,
6248 AUTH_KEYBOARD_INTERACTIVE
6249 } method;
6250 enum {
6251 AUTH_TYPE_NONE,
6252 AUTH_TYPE_PUBLICKEY,
6253 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6254 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6255 AUTH_TYPE_PASSWORD,
6256 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6257 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6258 } type;
6259 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6ac3a551 6260 int tried_pubkey_config, tried_agent;
6261 int kbd_inter_running, kbd_inter_refused;
51470298 6262 int we_are_in;
6263 int num_prompts, curr_prompt, echo;
6264 char username[100];
6265 int got_username;
85fdbe25 6266 char pwprompt[512];
51470298 6267 char password[100];
6268 void *publickey_blob;
6269 int publickey_bloblen;
6270 unsigned char request[5], *response, *p;
6271 int responselen;
6272 int keyi, nkeys;
6273 int authed;
6274 char *pkblob, *alg, *commentp;
6275 int pklen, alglen, commentlen;
6276 int siglen, retlen, len;
6277 char *q, *agentreq, *ret;
6278 int try_send;
73feed4f 6279 int num_env, env_left, env_ok;
ff3187f6 6280 struct Packet *pktout;
51470298 6281 };
6282 crState(do_ssh2_authconn_state);
6283
6284 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 6285
7cca0d81 6286 /*
6287 * Request userauth protocol, and await a response to it.
6288 */
ff3187f6 6289 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6290 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6291 ssh2_pkt_send(ssh, s->pktout);
6292 crWaitUntilV(pktin);
6293 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 6294 bombout(("Server refused user authentication protocol"));
7ffdbc1a 6295 crStopV;
8d5de777 6296 }
7cca0d81 6297
6298 /*
1408a877 6299 * We repeat this whole loop, including the username prompt,
6300 * until we manage a successful authentication. If the user
51470298 6301 * types the wrong _password_, they can be sent back to the
6302 * beginning to try another username, if this is configured on.
6303 * (If they specify a username in the config, they are never
6304 * asked, even if they do give a wrong password.)
1408a877 6305 *
6306 * I think this best serves the needs of
6307 *
6308 * - the people who have no configuration, no keys, and just
6309 * want to try repeated (username,password) pairs until they
6310 * type both correctly
6311 *
6312 * - people who have keys and configuration but occasionally
6313 * need to fall back to passwords
6314 *
6315 * - people with a key held in Pageant, who might not have
6316 * logged in to a particular machine before; so they want to
6317 * type a username, and then _either_ their key will be
6318 * accepted, _or_ they will type a password. If they mistype
6319 * the username they will want to be able to get back and
6320 * retype it!
7cca0d81 6321 */
51470298 6322 s->username[0] = '\0';
6323 s->got_username = FALSE;
1408a877 6324 do {
1408a877 6325 /*
6326 * Get a username.
6327 */
86916870 6328 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 6329 /*
6330 * We got a username last time round this loop, and
6331 * with change_username turned off we don't try to get
6332 * it again.
6333 */
aa09f7d0 6334 } else if (!*ssh->cfg.username) {
c0a81592 6335 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 6336 if (!ssh_get_line("login as: ",
51470298 6337 s->username, sizeof(s->username), FALSE)) {
32874aea 6338 /*
6339 * get_line failed to get a username.
6340 * Terminate.
6341 */
6342 logevent("No username provided. Abandoning session.");
ac934965 6343 ssh->close_expected = TRUE;
3bb2f322 6344 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6345 crStopV;
32874aea 6346 }
6347 } else {
51470298 6348 int ret; /* need not be saved across crReturn */
6349 c_write_str(ssh, "login as: ");
6350 ssh->send_ok = 1;
6351 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 6352 do {
ff3187f6 6353 crWaitUntilV(!pktin);
51470298 6354 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6355 } while (ret == 0);
6356 if (ret < 0)
6357 cleanup_exit(0);
4ca0c9d1 6358 c_write_str(ssh, "\r\n");
32874aea 6359 }
51470298 6360 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 6361 } else {
57356d63 6362 char *stuff;
86916870 6363 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 6364 s->username[sizeof(s->username)-1] = '\0';
65a22376 6365 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 6366 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 6367 c_write_str(ssh, stuff);
57356d63 6368 sfree(stuff);
7cca0d81 6369 }
6370 }
51470298 6371 s->got_username = TRUE;
7cca0d81 6372
65a22376 6373 /*
1408a877 6374 * Send an authentication request using method "none": (a)
6375 * just in case it succeeds, and (b) so that we know what
6376 * authentication methods we can usefully try next.
65a22376 6377 */
51470298 6378 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6379
ff3187f6 6380 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6381 ssh2_pkt_addstring(s->pktout, s->username);
6382 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6383 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6384 ssh2_pkt_send(ssh, s->pktout);
51470298 6385 s->type = AUTH_TYPE_NONE;
6386 s->gotit = FALSE;
6387 s->we_are_in = FALSE;
6388
6389 s->tried_pubkey_config = FALSE;
6390 s->tried_agent = FALSE;
51470298 6391 s->kbd_inter_running = FALSE;
6ac3a551 6392 s->kbd_inter_refused = FALSE;
86916870 6393 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 6394 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 6395 int keytype;
6c6d9ed9 6396 logeventf(ssh, "Reading private key file \"%.150s\"",
6397 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 6398 keytype = key_type(&ssh->cfg.keyfile);
51470298 6399 if (keytype == SSH_KEYTYPE_SSH2) {
6400 s->publickey_blob =
9a30e26b 6401 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 6402 &s->publickey_bloblen, NULL);
51470298 6403 } else {
57356d63 6404 char *msgbuf;
c2ad7d0d 6405 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 6406 key_type_to_str(keytype));
57356d63 6407 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 6408 " (%s)\r\n",
6409 filename_to_str(&ssh->cfg.keyfile),
57356d63 6410 key_type_to_str(keytype));
51470298 6411 c_write_str(ssh, msgbuf);
57356d63 6412 sfree(msgbuf);
51470298 6413 s->publickey_blob = NULL;
231ee168 6414 }
396778f1 6415 } else
51470298 6416 s->publickey_blob = NULL;
65a22376 6417
1408a877 6418 while (1) {
6419 /*
6420 * Wait for the result of the last authentication request.
6421 */
51470298 6422 if (!s->gotit)
ff3187f6 6423 crWaitUntilV(pktin);
6424 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 6425 char *banner;
6426 int size;
6427 /*
6428 * Don't show the banner if we're operating in
6429 * non-verbose non-interactive mode. (It's probably
6430 * a script, which means nobody will read the
6431 * banner _anyway_, and moreover the printing of
6432 * the banner will screw up processing on the
6433 * output of (say) plink.)
6434 */
6435 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
ff3187f6 6436 ssh_pkt_getstring(pktin, &banner, &size);
32874aea 6437 if (banner)
51470298 6438 c_write_untrusted(ssh, banner, size);
32874aea 6439 }
ff3187f6 6440 crWaitUntilV(pktin);
1408a877 6441 }
ff3187f6 6442 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 6443 logevent("Access granted");
51470298 6444 s->we_are_in = TRUE;
1408a877 6445 break;
6446 }
65a22376 6447
51470298 6448 if (s->kbd_inter_running &&
ff3187f6 6449 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 6450 /*
45068b27 6451 * This is either a further set-of-prompts packet
6452 * in keyboard-interactive authentication, or it's
6453 * the same one and we came back here with `gotit'
6454 * set. In the former case, we must reset the
6455 * curr_prompt variable.
b3186d64 6456 */
51470298 6457 if (!s->gotit)
6458 s->curr_prompt = 0;
4c6e53e3 6459 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6460 /* FIXME: perhaps we should support this? */
6461 bombout(("PASSWD_CHANGEREQ not yet supported"));
6462 crStopV;
ff3187f6 6463 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 6464 bombout(("Strange packet received during authentication: type %d",
ff3187f6 6465 pktin->type));
7ffdbc1a 6466 crStopV;
65a22376 6467 }
6468
51470298 6469 s->gotit = FALSE;
65a22376 6470
1408a877 6471 /*
6472 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6473 * we can look at the string in it and know what we can
6474 * helpfully try next.
6475 */
ff3187f6 6476 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 6477 char *methods;
6478 int methlen;
ff3187f6 6479 ssh_pkt_getstring(pktin, &methods, &methlen);
51470298 6480 s->kbd_inter_running = FALSE;
ff3187f6 6481 if (!ssh2_pkt_getbool(pktin)) {
1408a877 6482 /*
6483 * We have received an unequivocal Access
6484 * Denied. This can translate to a variety of
6485 * messages:
6486 *
6487 * - if we'd just tried "none" authentication,
6488 * it's not worth printing anything at all
6489 *
6490 * - if we'd just tried a public key _offer_,
6491 * the message should be "Server refused our
6492 * key" (or no message at all if the key
6493 * came from Pageant)
6494 *
6495 * - if we'd just tried anything else, the
6496 * message really should be "Access denied".
6497 *
6498 * Additionally, if we'd just tried password
6499 * authentication, we should break out of this
6500 * whole loop so as to go back to the username
91f57d1f 6501 * prompt (iff we're configured to allow
6502 * username change attempts).
1408a877 6503 */
51470298 6504 if (s->type == AUTH_TYPE_NONE) {
1408a877 6505 /* do nothing */
51470298 6506 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6507 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6508 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6509 c_write_str(ssh, "Server refused our key\r\n");
1408a877 6510 logevent("Server refused public key");
51470298 6511 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 6512 /* server declined keyboard-interactive; ignore */
1408a877 6513 } else {
51470298 6514 c_write_str(ssh, "Access denied\r\n");
1408a877 6515 logevent("Access denied");
91f57d1f 6516 if (s->type == AUTH_TYPE_PASSWORD &&
6517 ssh->cfg.change_username) {
6c9dce7c 6518 /* XXX perhaps we should allow
6519 * keyboard-interactive to do this too? */
51470298 6520 s->we_are_in = FALSE;
1408a877 6521 break;
6522 }
6523 }
6524 } else {
51470298 6525 c_write_str(ssh, "Further authentication required\r\n");
1408a877 6526 logevent("Further authentication required");
6527 }
65a22376 6528
51470298 6529 s->can_pubkey =
32874aea 6530 in_commasep_string("publickey", methods, methlen);
51470298 6531 s->can_passwd =
32874aea 6532 in_commasep_string("password", methods, methlen);
86916870 6533 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 6534 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 6535 }
65a22376 6536
51470298 6537 s->method = 0;
6538 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 6539 s->need_pw = FALSE;
65a22376 6540
0405e71f 6541 /*
6542 * Most password/passphrase prompts will be
6543 * non-echoing, so we set this to 0 by default.
6544 * Exception is that some keyboard-interactive prompts
6545 * can be echoing, in which case we'll set this to 1.
6546 */
51470298 6547 s->echo = 0;
0405e71f 6548
51470298 6549 if (!s->method && s->can_pubkey &&
6550 agent_exists() && !s->tried_agent) {
1983e559 6551 /*
6552 * Attempt public-key authentication using Pageant.
6553 */
1983e559 6554 void *r;
51470298 6555 s->authed = FALSE;
1983e559 6556
51470298 6557 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6558 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6559
51470298 6560 s->tried_agent = TRUE;
1983e559 6561
6562 logevent("Pageant is running. Requesting keys.");
6563
6564 /* Request the keys held by the agent. */
51470298 6565 PUT_32BIT(s->request, 1);
6566 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 6567 if (!agent_query(s->request, 5, &r, &s->responselen,
6568 ssh_agent_callback, ssh)) {
6569 do {
6570 crReturnV;
ff3187f6 6571 if (pktin) {
839f10db 6572 bombout(("Unexpected data from server while"
6573 " waiting for agent response"));
6574 crStopV;
6575 }
ff3187f6 6576 } while (pktin || inlen > 0);
839f10db 6577 r = ssh->agent_response;
6578 s->responselen = ssh->agent_response_len;
6579 }
51470298 6580 s->response = (unsigned char *) r;
6581 if (s->response && s->responselen >= 5 &&
6582 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6583 s->p = s->response + 5;
6584 s->nkeys = GET_32BIT(s->p);
6585 s->p += 4;
fb983202 6586 logeventf(ssh, "Pageant has %d SSH2 keys", s->nkeys);
51470298 6587 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 6588 void *vret;
1983e559 6589
fb983202 6590 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
51470298 6591 s->pklen = GET_32BIT(s->p);
6592 s->p += 4;
6593 if (s->publickey_blob &&
6594 s->pklen == s->publickey_bloblen &&
6595 !memcmp(s->p, s->publickey_blob,
6596 s->publickey_bloblen)) {
396778f1 6597 logevent("This key matches configured key file");
51470298 6598 s->tried_pubkey_config = 1;
396778f1 6599 }
d8baa528 6600 s->pkblob = (char *)s->p;
51470298 6601 s->p += s->pklen;
6602 s->alglen = GET_32BIT(s->pkblob);
6603 s->alg = s->pkblob + 4;
6604 s->commentlen = GET_32BIT(s->p);
6605 s->p += 4;
d8baa528 6606 s->commentp = (char *)s->p;
51470298 6607 s->p += s->commentlen;
ff3187f6 6608 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6609 ssh2_pkt_addstring(s->pktout, s->username);
6610 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6611 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6612 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6613 ssh2_pkt_addstring_start(s->pktout);
6614 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6615 ssh2_pkt_addstring_start(s->pktout);
6616 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6617 ssh2_pkt_send(ssh, s->pktout);
6618
6619 crWaitUntilV(pktin);
6620 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 6621 logevent("Key refused");
6622 continue;
6623 }
6624
32874aea 6625 if (flags & FLAG_VERBOSE) {
51470298 6626 c_write_str(ssh, "Authenticating with "
6627 "public key \"");
6628 c_write(ssh, s->commentp, s->commentlen);
6629 c_write_str(ssh, "\" from agent\r\n");
32874aea 6630 }
1983e559 6631
6632 /*
6633 * Server is willing to accept the key.
6634 * Construct a SIGN_REQUEST.
6635 */
ff3187f6 6636 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6637 ssh2_pkt_addstring(s->pktout, s->username);
6638 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6639 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6640 ssh2_pkt_addbool(s->pktout, TRUE);
6641 ssh2_pkt_addstring_start(s->pktout);
6642 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6643 ssh2_pkt_addstring_start(s->pktout);
6644 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6645
6646 s->siglen = s->pktout->length - 5 + 4 + 20;
dda87a28 6647 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6648 s->siglen -= 4;
51470298 6649 s->len = 1; /* message type */
6650 s->len += 4 + s->pklen; /* key blob */
6651 s->len += 4 + s->siglen; /* data to sign */
6652 s->len += 4; /* flags */
3d88e64d 6653 s->agentreq = snewn(4 + s->len, char);
51470298 6654 PUT_32BIT(s->agentreq, s->len);
6655 s->q = s->agentreq + 4;
6656 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6657 PUT_32BIT(s->q, s->pklen);
6658 s->q += 4;
6659 memcpy(s->q, s->pkblob, s->pklen);
6660 s->q += s->pklen;
6661 PUT_32BIT(s->q, s->siglen);
6662 s->q += 4;
1983e559 6663 /* Now the data to be signed... */
dda87a28 6664 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6665 PUT_32BIT(s->q, 20);
6666 s->q += 4;
6667 }
51470298 6668 memcpy(s->q, ssh->v2_session_id, 20);
6669 s->q += 20;
ff3187f6 6670 memcpy(s->q, s->pktout->data + 5,
6671 s->pktout->length - 5);
6672 s->q += s->pktout->length - 5;
1983e559 6673 /* And finally the (zero) flags word. */
51470298 6674 PUT_32BIT(s->q, 0);
839f10db 6675 if (!agent_query(s->agentreq, s->len + 4,
6676 &vret, &s->retlen,
6677 ssh_agent_callback, ssh)) {
6678 do {
6679 crReturnV;
ff3187f6 6680 if (pktin) {
839f10db 6681 bombout(("Unexpected data from server"
6682 " while waiting for agent"
6683 " response"));
6684 crStopV;
6685 }
ff3187f6 6686 } while (pktin || inlen > 0);
839f10db 6687 vret = ssh->agent_response;
6688 s->retlen = ssh->agent_response_len;
6689 }
51470298 6690 s->ret = vret;
6691 sfree(s->agentreq);
6692 if (s->ret) {
6693 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 6694 logevent("Sending Pageant's response");
ff3187f6 6695 ssh2_add_sigblob(ssh, s->pktout,
6696 s->pkblob, s->pklen,
51470298 6697 s->ret + 9,
6698 GET_32BIT(s->ret + 5));
ff3187f6 6699 ssh2_pkt_send(ssh, s->pktout);
51470298 6700 s->authed = TRUE;
1983e559 6701 break;
6702 } else {
32874aea 6703 logevent
6704 ("Pageant failed to answer challenge");
51470298 6705 sfree(s->ret);
1983e559 6706 }
6707 }
6708 }
51470298 6709 if (s->authed)
1983e559 6710 continue;
6711 }
29b1d0b3 6712 sfree(s->response);
1983e559 6713 }
6714
51470298 6715 if (!s->method && s->can_pubkey && s->publickey_blob
6716 && !s->tried_pubkey_config) {
1408a877 6717 unsigned char *pub_blob;
6718 char *algorithm, *comment;
6719 int pub_blob_len;
65a22376 6720
51470298 6721 s->tried_pubkey_config = TRUE;
65a22376 6722
51470298 6723 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6724 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6725
65a22376 6726 /*
1408a877 6727 * Try the public key supplied in the configuration.
6728 *
6729 * First, offer the public blob to see if the server is
6730 * willing to accept it.
65a22376 6731 */
d8baa528 6732 pub_blob =
9a30e26b 6733 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 6734 &algorithm,
222d54dc 6735 &pub_blob_len,
6736 NULL);
1408a877 6737 if (pub_blob) {
ff3187f6 6738 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6739 ssh2_pkt_addstring(s->pktout, s->username);
6740 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6741 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6742 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6743 ssh2_pkt_addstring(s->pktout, algorithm);
6744 ssh2_pkt_addstring_start(s->pktout);
6745 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
d8baa528 6746 pub_blob_len);
ff3187f6 6747 ssh2_pkt_send(ssh, s->pktout);
a03c9f9c 6748 logevent("Offered public key");
1408a877 6749
ff3187f6 6750 crWaitUntilV(pktin);
6751 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
51470298 6752 s->gotit = TRUE;
6753 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 6754 continue; /* key refused; give up on it */
1408a877 6755 }
65a22376 6756
1408a877 6757 logevent("Offer of public key accepted");
65a22376 6758 /*
1408a877 6759 * Actually attempt a serious authentication using
6760 * the key.
65a22376 6761 */
9a30e26b 6762 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 6763 sprintf(s->pwprompt,
32874aea 6764 "Passphrase for key \"%.100s\": ",
6765 comment);
51470298 6766 s->need_pw = TRUE;
1408a877 6767 } else {
51470298 6768 s->need_pw = FALSE;
1408a877 6769 }
4e520718 6770 if (flags & FLAG_VERBOSE) {
6771 c_write_str(ssh, "Authenticating with public key \"");
6772 c_write_str(ssh, comment);
6773 c_write_str(ssh, "\"\r\n");
6774 }
51470298 6775 s->method = AUTH_PUBLICKEY_FILE;
65a22376 6776 }
1408a877 6777 }
6778
6f64ce13 6779 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6780 !s->kbd_inter_running) {
51470298 6781 s->method = AUTH_KEYBOARD_INTERACTIVE;
6782 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6783
51470298 6784 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6785 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6786
ff3187f6 6787 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6788 ssh2_pkt_addstring(s->pktout, s->username);
6789 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6790 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6791 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6792 ssh2_pkt_addstring(s->pktout, "");
6793 ssh2_pkt_send(ssh, s->pktout);
6794
6795 crWaitUntilV(pktin);
6796 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6797 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
51470298 6798 s->gotit = TRUE;
af659722 6799 logevent("Keyboard-interactive authentication refused");
51470298 6800 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6ac3a551 6801 s->kbd_inter_refused = TRUE; /* don't try it again */
af659722 6802 continue;
6803 }
6804
51470298 6805 s->kbd_inter_running = TRUE;
6806 s->curr_prompt = 0;
af659722 6807 }
6808
51470298 6809 if (s->kbd_inter_running) {
6810 s->method = AUTH_KEYBOARD_INTERACTIVE;
6811 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6812
51470298 6813 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6814 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6815
51470298 6816 if (s->curr_prompt == 0) {
45068b27 6817 /*
6818 * We've got a fresh USERAUTH_INFO_REQUEST.
6819 * Display header data, and start going through
6820 * the prompts.
6821 */
6822 char *name, *inst, *lang;
6823 int name_len, inst_len, lang_len;
6824
ff3187f6 6825 ssh_pkt_getstring(pktin, &name, &name_len);
6826 ssh_pkt_getstring(pktin, &inst, &inst_len);
6827 ssh_pkt_getstring(pktin, &lang, &lang_len);
45068b27 6828 if (name_len > 0) {
51470298 6829 c_write_untrusted(ssh, name, name_len);
6830 c_write_str(ssh, "\r\n");
45068b27 6831 }
6832 if (inst_len > 0) {
51470298 6833 c_write_untrusted(ssh, inst, inst_len);
6834 c_write_str(ssh, "\r\n");
45068b27 6835 }
ff3187f6 6836 s->num_prompts = ssh_pkt_getuint32(pktin);
45068b27 6837 }
af659722 6838
45068b27 6839 /*
6840 * If there are prompts remaining in the packet,
6841 * display one and get a response.
6842 */
51470298 6843 if (s->curr_prompt < s->num_prompts) {
45068b27 6844 char *prompt;
6845 int prompt_len;
af659722 6846
ff3187f6 6847 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
45068b27 6848 if (prompt_len > 0) {
85fdbe25 6849 static const char trunc[] = "<prompt truncated>: ";
6850 static const int prlen = sizeof(s->pwprompt) -
6851 lenof(trunc);
6852 if (prompt_len > prlen) {
6853 memcpy(s->pwprompt, prompt, prlen);
6854 strcpy(s->pwprompt + prlen, trunc);
6855 } else {
6856 memcpy(s->pwprompt, prompt, prompt_len);
6857 s->pwprompt[prompt_len] = '\0';
6858 }
45068b27 6859 } else {
51470298 6860 strcpy(s->pwprompt,
45068b27 6861 "<server failed to send prompt>: ");
6862 }
ff3187f6 6863 s->echo = ssh2_pkt_getbool(pktin);
51470298 6864 s->need_pw = TRUE;
45068b27 6865 } else
51470298 6866 s->need_pw = FALSE;
af659722 6867 }
6868
51470298 6869 if (!s->method && s->can_passwd) {
6870 s->method = AUTH_PASSWORD;
6871 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6872 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6873 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6874 ssh->savedhost);
6875 s->need_pw = TRUE;
1408a877 6876 }
6877
51470298 6878 if (s->need_pw) {
fa17a66e 6879 if (ssh_get_line) {
51470298 6880 if (!ssh_get_line(s->pwprompt, s->password,
6881 sizeof(s->password), TRUE)) {
1408a877 6882 /*
fa17a66e 6883 * get_line failed to get a password (for
6884 * example because one was supplied on the
6885 * command line which has already failed to
6886 * work). Terminate.
1408a877 6887 */
ff3187f6 6888 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6889 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6890 ssh2_pkt_addstring(s->pktout, "No more passwords available"
51470298 6891 " to try");
ff3187f6 6892 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6893 ssh2_pkt_send_noqueue(ssh, s->pktout);
247308b5 6894 logevent("Unable to authenticate");
a8327734 6895 connection_fatal(ssh->frontend,
6896 "Unable to authenticate");
ac934965 6897 ssh->close_expected = TRUE;
3bb2f322 6898 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6899 crStopV;
1408a877 6900 }
6901 } else {
51470298 6902 int ret; /* need not be saved across crReturn */
6903 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6904 ssh->send_ok = 1;
1408a877 6905
51470298 6906 setup_userpass_input(ssh, s->password,
6907 sizeof(s->password), s->echo);
0405e71f 6908 do {
ff3187f6 6909 crWaitUntilV(!pktin);
51470298 6910 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6911 } while (ret == 0);
6912 if (ret < 0)
6913 cleanup_exit(0);
51470298 6914 c_write_str(ssh, "\r\n");
65a22376 6915 }
65a22376 6916 }
65a22376 6917
51470298 6918 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 6919 /*
6920 * We have our passphrase. Now try the actual authentication.
6921 */
6922 struct ssh2_userkey *key;
222d54dc 6923 const char *error = NULL;
65a22376 6924
222d54dc 6925 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6926 &error);
1408a877 6927 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6928 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 6929 c_write_str(ssh, "Wrong passphrase\r\n");
6930 s->tried_pubkey_config = FALSE;
1408a877 6931 } else {
222d54dc 6932 c_write_str(ssh, "Unable to load private key (");
6933 c_write_str(ssh, error);
6934 c_write_str(ssh, ")\r\n");
51470298 6935 s->tried_pubkey_config = TRUE;
1408a877 6936 }
6937 /* Send a spurious AUTH_NONE to return to the top. */
ff3187f6 6938 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6939 ssh2_pkt_addstring(s->pktout, s->username);
6940 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6941 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6942 ssh2_pkt_send(ssh, s->pktout);
51470298 6943 s->type = AUTH_TYPE_NONE;
1408a877 6944 } else {
1dd353b5 6945 unsigned char *pkblob, *sigblob, *sigdata;
6946 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 6947 int p;
65a22376 6948
1408a877 6949 /*
6950 * We have loaded the private key and the server
6951 * has announced that it's willing to accept it.
6952 * Hallelujah. Generate a signature and send it.
6953 */
ff3187f6 6954 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6955 ssh2_pkt_addstring(s->pktout, s->username);
6956 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6957 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6958 ssh2_pkt_addbool(s->pktout, TRUE);
6959 ssh2_pkt_addstring(s->pktout, key->alg->name);
1dd353b5 6960 pkblob = key->alg->public_blob(key->data, &pkblob_len);
ff3187f6 6961 ssh2_pkt_addstring_start(s->pktout);
6962 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
1408a877 6963
6964 /*
6965 * The data to be signed is:
6966 *
6967 * string session-id
6968 *
6969 * followed by everything so far placed in the
6970 * outgoing packet.
6971 */
ff3187f6 6972 sigdata_len = s->pktout->length - 5 + 4 + 20;
dda87a28 6973 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6974 sigdata_len -= 4;
92d60585 6975 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 6976 p = 0;
6977 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6978 PUT_32BIT(sigdata+p, 20);
6979 p += 4;
6980 }
6981 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
ff3187f6 6982 memcpy(sigdata+p, s->pktout->data + 5,
6983 s->pktout->length - 5);
6984 p += s->pktout->length - 5;
dda87a28 6985 assert(p == sigdata_len);
d8baa528 6986 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 6987 sigdata_len, &sigblob_len);
ff3187f6 6988 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 6989 sigblob, sigblob_len);
6990 sfree(pkblob);
6991 sfree(sigblob);
1408a877 6992 sfree(sigdata);
6993
ff3187f6 6994 ssh2_pkt_send(ssh, s->pktout);
51470298 6995 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 6996 key->alg->freekey(key->data);
1408a877 6997 }
51470298 6998 } else if (s->method == AUTH_PASSWORD) {
65a22376 6999 /*
95d2d262 7000 * We pad out the password packet to 256 bytes to make
7001 * it harder for an attacker to find the length of the
7002 * user's password.
1408a877 7003 *
95d2d262 7004 * Anyone using a password longer than 256 bytes
7005 * probably doesn't have much to worry about from
1408a877 7006 * people who find out how long their password is!
65a22376 7007 */
ff3187f6 7008 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
95d2d262 7009 s->pktout->forcepad = 256;
ff3187f6 7010 ssh2_pkt_addstring(s->pktout, s->username);
7011 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7012 ssh2_pkt_addstring(s->pktout, "password");
7013 ssh2_pkt_addbool(s->pktout, FALSE);
7014 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7015 ssh2_pkt_addstring(s->pktout, s->password);
1409c1b3 7016 memset(s->password, 0, sizeof(s->password));
ff3187f6 7017 end_log_omission(ssh, s->pktout);
95d2d262 7018 ssh2_pkt_send(ssh, s->pktout);
0d43337a 7019 logevent("Sent password");
51470298 7020 s->type = AUTH_TYPE_PASSWORD;
7021 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
7022 if (s->curr_prompt == 0) {
ff3187f6 7023 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10e09fb5 7024 s->pktout->forcepad = 256;
ff3187f6 7025 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
45068b27 7026 }
51470298 7027 if (s->need_pw) { /* only add pw if we just got one! */
ff3187f6 7028 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7029 ssh2_pkt_addstring(s->pktout, s->password);
51470298 7030 memset(s->password, 0, sizeof(s->password));
ff3187f6 7031 end_log_omission(ssh, s->pktout);
51470298 7032 s->curr_prompt++;
45068b27 7033 }
51470298 7034 if (s->curr_prompt >= s->num_prompts) {
ff3187f6 7035 ssh2_pkt_send(ssh, s->pktout);
45068b27 7036 } else {
7037 /*
7038 * If there are prompts remaining, we set
7039 * `gotit' so that we won't attempt to get
7040 * another packet. Then we go back round the
7041 * loop and will end up retrieving another
7042 * prompt out of the existing packet. Funky or
7043 * what?
7044 */
51470298 7045 s->gotit = TRUE;
45068b27 7046 }
51470298 7047 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 7048 } else {
51470298 7049 c_write_str(ssh, "No supported authentication methods"
7050 " left to try!\r\n");
7051 logevent("No supported authentications offered."
7052 " Disconnecting");
ff3187f6 7053 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
7054 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
7055 ssh2_pkt_addstring(s->pktout, "No supported authentication"
51470298 7056 " methods available");
ff3187f6 7057 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 7058 ssh2_pkt_send_noqueue(ssh, s->pktout);
ac934965 7059 ssh->close_expected = TRUE;
3bb2f322 7060 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 7061 crStopV;
65a22376 7062 }
65a22376 7063 }
51470298 7064 } while (!s->we_are_in);
7cca0d81 7065
7066 /*
7067 * Now we're authenticated for the connection protocol. The
7068 * connection protocol will automatically have started at this
7069 * point; there's no need to send SERVICE_REQUEST.
7070 */
7071
0ed48730 7072 ssh->channels = newtree234(ssh_channelcmp);
7073
7cca0d81 7074 /*
b09eaa88 7075 * Set up handlers for some connection protocol messages, so we
7076 * don't have to handle them repeatedly in this coroutine.
7077 */
7078 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7079 ssh2_msg_channel_window_adjust;
51df0ab5 7080 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7081 ssh2_msg_global_request;
b09eaa88 7082
7083 /*
0ed48730 7084 * Create the main session channel.
7cca0d81 7085 */
0ed48730 7086 if (!ssh->cfg.ssh_no_shell) {
7087 ssh->mainchan = snew(struct ssh_channel);
7088 ssh->mainchan->ssh = ssh;
7089 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 7090 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7091 ssh2_pkt_addstring(s->pktout, "session");
7092 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 7093 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7094 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
954d5c5a 7095 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 7096 ssh2_pkt_send(ssh, s->pktout);
7097 crWaitUntilV(pktin);
7098 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 7099 bombout(("Server refused to open a session"));
7100 crStopV;
7101 /* FIXME: error data comes back in FAILURE packet */
7102 }
ff3187f6 7103 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 7104 bombout(("Server's channel confirmation cited wrong channel"));
7105 crStopV;
7106 }
ff3187f6 7107 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 7108 ssh->mainchan->halfopen = FALSE;
0ed48730 7109 ssh->mainchan->type = CHAN_MAINSESSION;
7110 ssh->mainchan->closes = 0;
ff3187f6 7111 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7112 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 7113 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7114 add234(ssh->channels, ssh->mainchan);
62638676 7115 update_specials_menu(ssh->frontend);
0ed48730 7116 logevent("Opened channel for session");
7117 } else
7118 ssh->mainchan = NULL;
7cca0d81 7119
7120 /*
51df0ab5 7121 * Now we have a channel, make dispatch table entries for
7122 * general channel-based messages.
7123 */
7124 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7125 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7126 ssh2_msg_channel_data;
7127 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7128 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7129 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7130 ssh2_msg_channel_open_confirmation;
7131 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7132 ssh2_msg_channel_open_failure;
7133 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7134 ssh2_msg_channel_request;
7135 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7136 ssh2_msg_channel_open;
7137
7138 /*
783415f8 7139 * Potentially enable X11 forwarding.
7140 */
0ed48730 7141 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 7142 char proto[20], data[64];
7143 logevent("Requesting X11 forwarding");
302121de 7144 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 7145 data, sizeof(data), ssh->cfg.x11_auth);
7146 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 7147 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7148 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7149 ssh2_pkt_addstring(s->pktout, "x11-req");
7150 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7151 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7152 ssh2_pkt_addstring(s->pktout, proto);
7153 ssh2_pkt_addstring(s->pktout, data);
7154 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7155 ssh2_pkt_send(ssh, s->pktout);
32874aea 7156
b09eaa88 7157 crWaitUntilV(pktin);
32874aea 7158
ff3187f6 7159 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7160 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7161 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 7162 " packet type %d", pktin->type));
7ffdbc1a 7163 crStopV;
32874aea 7164 }
7165 logevent("X11 forwarding refused");
7166 } else {
7167 logevent("X11 forwarding enabled");
51470298 7168 ssh->X11_fwd_enabled = TRUE;
32874aea 7169 }
783415f8 7170 }
7171
7172 /*
bc240b21 7173 * Enable port forwardings.
7174 */
06fadff5 7175 ssh_setup_portfwd(ssh, &ssh->cfg);
bc240b21 7176
7177 /*
36c2a3e9 7178 * Potentially enable agent forwarding.
7179 */
0ed48730 7180 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 7181 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 7182 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7183 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7184 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7185 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7186 ssh2_pkt_send(ssh, s->pktout);
32874aea 7187
b09eaa88 7188 crWaitUntilV(pktin);
32874aea 7189
ff3187f6 7190 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7191 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7192 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 7193 " packet type %d", pktin->type));
7ffdbc1a 7194 crStopV;
32874aea 7195 }
7196 logevent("Agent forwarding refused");
7197 } else {
7198 logevent("Agent forwarding enabled");
51470298 7199 ssh->agentfwd_enabled = TRUE;
32874aea 7200 }
36c2a3e9 7201 }
7202
7203 /*
7cca0d81 7204 * Now allocate a pty for the session.
7205 */
0ed48730 7206 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 7207 /* Unpick the terminal-speed string. */
7208 /* XXX perhaps we should allow no speeds to be sent. */
db219738 7209 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7210 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 7211 /* Build the pty request. */
ff3187f6 7212 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7213 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7214 ssh2_pkt_addstring(s->pktout, "pty-req");
7215 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7216 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7217 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7218 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7219 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7220 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7221 ssh2_pkt_addstring_start(s->pktout);
7222 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
7223 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7224 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
7225 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7226 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7227 ssh2_pkt_send(ssh, s->pktout);
51470298 7228 ssh->state = SSH_STATE_INTERMED;
32874aea 7229
b09eaa88 7230 crWaitUntilV(pktin);
32874aea 7231
ff3187f6 7232 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7233 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7234 bombout(("Unexpected response to pty request:"
ff3187f6 7235 " packet type %d", pktin->type));
7ffdbc1a 7236 crStopV;
32874aea 7237 }
51470298 7238 c_write_str(ssh, "Server refused to allocate pty\r\n");
7239 ssh->editing = ssh->echoing = 1;
32874aea 7240 } else {
a5dd8467 7241 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 7242 ssh->ospeed, ssh->ispeed);
32874aea 7243 }
0965bee0 7244 } else {
51470298 7245 ssh->editing = ssh->echoing = 1;
7cca0d81 7246 }
7247
7248 /*
73feed4f 7249 * Send environment variables.
7250 *
7251 * Simplest thing here is to send all the requests at once, and
7252 * then wait for a whole bunch of successes or failures.
7253 */
7254 if (ssh->mainchan && *ssh->cfg.environmt) {
7255 char *e = ssh->cfg.environmt;
7256 char *var, *varend, *val;
7257
7258 s->num_env = 0;
7259
7260 while (*e) {
7261 var = e;
7262 while (*e && *e != '\t') e++;
7263 varend = e;
7264 if (*e == '\t') e++;
7265 val = e;
7266 while (*e) e++;
7267 e++;
7268
ff3187f6 7269 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7270 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7271 ssh2_pkt_addstring(s->pktout, "env");
7272 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7273 ssh2_pkt_addstring_start(s->pktout);
7274 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7275 ssh2_pkt_addstring(s->pktout, val);
7276 ssh2_pkt_send(ssh, s->pktout);
73feed4f 7277
7278 s->num_env++;
7279 }
7280
7281 logeventf(ssh, "Sent %d environment variables", s->num_env);
7282
7283 s->env_ok = 0;
7284 s->env_left = s->num_env;
7285
7286 while (s->env_left > 0) {
b09eaa88 7287 crWaitUntilV(pktin);
73feed4f 7288
ff3187f6 7289 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7290 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 7291 bombout(("Unexpected response to environment request:"
ff3187f6 7292 " packet type %d", pktin->type));
73feed4f 7293 crStopV;
7294 }
7295 } else {
7296 s->env_ok++;
7297 }
7298
7299 s->env_left--;
7300 }
7301
7302 if (s->env_ok == s->num_env) {
7303 logevent("All environment variables successfully set");
7304 } else if (s->env_ok == 0) {
7305 logevent("All environment variables refused");
7306 c_write_str(ssh, "Server refused to set environment variables\r\n");
7307 } else {
7308 logeventf(ssh, "%d environment variables refused",
7309 s->num_env - s->env_ok);
7310 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7311 }
7312 }
7313
7314 /*
fd5e5847 7315 * Start a shell or a remote command. We may have to attempt
7316 * this twice if the config data has provided a second choice
7317 * of command.
7cca0d81 7318 */
0ed48730 7319 if (ssh->mainchan) while (1) {
fd5e5847 7320 int subsys;
7321 char *cmd;
7322
51470298 7323 if (ssh->fallback_cmd) {
86916870 7324 subsys = ssh->cfg.ssh_subsys2;
7325 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 7326 } else {
86916870 7327 subsys = ssh->cfg.ssh_subsys;
7328 cmd = ssh->cfg.remote_cmd_ptr;
04c52f10 7329 if (!cmd) cmd = ssh->cfg.remote_cmd;
fd5e5847 7330 }
7331
ff3187f6 7332 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7333 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 7334 if (subsys) {
ff3187f6 7335 ssh2_pkt_addstring(s->pktout, "subsystem");
7336 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7337 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7338 } else if (*cmd) {
ff3187f6 7339 ssh2_pkt_addstring(s->pktout, "exec");
7340 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7341 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7342 } else {
ff3187f6 7343 ssh2_pkt_addstring(s->pktout, "shell");
7344 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 7345 }
ff3187f6 7346 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 7347
7348 crWaitUntilV(pktin);
7349
ff3187f6 7350 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7351 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7352 bombout(("Unexpected response to shell/command request:"
ff3187f6 7353 " packet type %d", pktin->type));
7ffdbc1a 7354 crStopV;
fd5e5847 7355 }
7356 /*
7357 * We failed to start the command. If this is the
7358 * fallback command, we really are finished; if it's
7359 * not, and if the fallback command exists, try falling
7360 * back to it before complaining.
7361 */
86916870 7362 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 7363 logevent("Primary command failed; attempting fallback");
51470298 7364 ssh->fallback_cmd = TRUE;
fd5e5847 7365 continue;
7366 }
6b5cf8b4 7367 bombout(("Server refused to start a shell/command"));
7ffdbc1a 7368 crStopV;
fd5e5847 7369 } else {
7370 logevent("Started a shell/command");
32874aea 7371 }
fd5e5847 7372 break;
7cca0d81 7373 }
7374
51470298 7375 ssh->state = SSH_STATE_SESSION;
7376 if (ssh->size_needed)
7377 ssh_size(ssh, ssh->term_width, ssh->term_height);
7378 if (ssh->eof_needed)
7379 ssh_special(ssh, TS_EOF);
6e48c3fe 7380
7cca0d81 7381 /*
7382 * Transfer data!
7383 */
b9d7bcad 7384 if (ssh->ldisc)
7385 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 7386 if (ssh->mainchan)
7387 ssh->send_ok = 1;
7cca0d81 7388 while (1) {
e5574168 7389 crReturnV;
51470298 7390 s->try_send = FALSE;
ff3187f6 7391 if (pktin) {
2b7540a7 7392
51df0ab5 7393 /*
7394 * _All_ the connection-layer packets we expect to
7395 * receive are now handled by the dispatch table.
7396 * Anything that reaches here must be bogus.
7397 */
32874aea 7398
51df0ab5 7399 bombout(("Strange packet received: type %d", pktin->type));
7400 crStopV;
0ed48730 7401 } else if (ssh->mainchan) {
32874aea 7402 /*
7403 * We have spare data. Add it to the channel buffer.
7404 */
d8baa528 7405 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 7406 s->try_send = TRUE;
32874aea 7407 }
51470298 7408 if (s->try_send) {
32874aea 7409 int i;
7410 struct ssh_channel *c;
7411 /*
7412 * Try to send data on all channels if we can.
7413 */
51470298 7414 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 7415 int bufsize;
7416 if (c->closes)
7417 continue; /* don't send on closing channels */
7418 bufsize = ssh2_try_send(c);
5471d09a 7419 if (bufsize == 0) {
7420 switch (c->type) {
7421 case CHAN_MAINSESSION:
7422 /* stdin need not receive an unthrottle
7423 * notification since it will be polled */
7424 break;
7425 case CHAN_X11:
7426 x11_unthrottle(c->u.x11.s);
7427 break;
7428 case CHAN_AGENT:
7429 /* agent sockets are request/response and need no
7430 * buffer management */
7431 break;
7432 case CHAN_SOCKDATA:
7433 pfd_unthrottle(c->u.pfd.s);
7434 break;
7435 }
7436 }
7437 }
7cca0d81 7438 }
e5574168 7439 }
7440
7441 crFinishV;
7442}
7443
7444/*
b09eaa88 7445 * Handlers for SSH2 messages that might arrive at any moment.
7446 */
409bfa77 7447static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
b09eaa88 7448{
7449 /* log reason code in disconnect message */
7450 char *buf, *msg;
7451 int nowlen, reason, msglen;
7452
7453 reason = ssh_pkt_getuint32(pktin);
7454 ssh_pkt_getstring(pktin, &msg, &msglen);
7455
7456 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7457 buf = dupprintf("Received disconnect message (%s)",
7458 ssh2_disconnect_reasons[reason]);
7459 } else {
7460 buf = dupprintf("Received disconnect message (unknown"
7461 " type %d)", reason);
7462 }
7463 logevent(buf);
7464 sfree(buf);
7465 buf = dupprintf("Disconnection message text: %n%.*s",
7466 &nowlen, msglen, msg);
7467 logevent(buf);
7468 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7469 reason,
7470 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7471 ssh2_disconnect_reasons[reason] : "unknown",
7472 buf+nowlen));
7473 sfree(buf);
7474}
7475
409bfa77 7476static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
b09eaa88 7477{
7478 /* log the debug message */
fb983202 7479 char *msg;
b09eaa88 7480 int msglen;
7481 int always_display;
7482
7483 /* XXX maybe we should actually take notice of this */
7484 always_display = ssh2_pkt_getbool(pktin);
7485 ssh_pkt_getstring(pktin, &msg, &msglen);
7486
fb983202 7487 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 7488}
7489
409bfa77 7490static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
b09eaa88 7491{
7492 struct Packet *pktout;
7493 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7494 ssh2_pkt_adduint32(pktout, pktin->sequence);
7495 /*
7496 * UNIMPLEMENTED messages MUST appear in the same order as the
7497 * messages they respond to. Hence, never queue them.
7498 */
7499 ssh2_pkt_send_noqueue(ssh, pktout);
7500}
7501
7502/*
7cca0d81 7503 * Handle the top-level SSH2 protocol.
7504 */
b09eaa88 7505static void ssh2_protocol_setup(Ssh ssh)
7506{
7507 int i;
7508
7509 /*
7510 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7511 */
7512 for (i = 0; i < 256; i++)
7513 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7514
7515 /*
7516 * Any message we actually understand, we set to NULL so that
7517 * the coroutines will get it.
7518 */
7519 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7520 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7521 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7522 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7523 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7524 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7525 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7526 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7527 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7528 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7529 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7530 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7531 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7532 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7533 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7534 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7535 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7536 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7537 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7538 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7539 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7540 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7541 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7542 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7543 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7544 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7545 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7546 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7547 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7548 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7549 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7550 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7551 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7552
7553 /*
7554 * These special message types we install handlers for.
7555 */
7556 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7557 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7558 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7559}
7560
9442dd57 7561static void ssh2_timer(void *ctx, long now)
7562{
7563 Ssh ssh = (Ssh)ctx;
7564
e6c1536e 7565 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9442dd57 7566 now - ssh->next_rekey >= 0) {
f382c87d 7567 do_ssh2_transport(ssh, "timeout", -1, NULL);
9442dd57 7568 }
7569}
7570
1c1a7262 7571static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 7572 struct Packet *pktin)
7cca0d81 7573{
1c1a7262 7574 unsigned char *in = (unsigned char *)vin;
b09eaa88 7575 if (ssh->state == SSH_STATE_CLOSED)
7576 return;
7577
9442dd57 7578 if (pktin) {
7579 ssh->incoming_data_size += pktin->encrypted_len;
7580 if (!ssh->kex_in_progress &&
d57f70af 7581 ssh->max_data_size != 0 &&
7582 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 7583 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9442dd57 7584 }
7585
b09eaa88 7586 if (pktin && ssh->packet_dispatch[pktin->type]) {
7587 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 7588 return;
b09eaa88 7589 }
7590
7591 if (!ssh->protocol_initial_phase_done ||
7592 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7593 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7594 !ssh->protocol_initial_phase_done) {
7595 ssh->protocol_initial_phase_done = TRUE;
7596 /*
7597 * Allow authconn to initialise itself.
7598 */
7599 do_ssh2_authconn(ssh, NULL, 0, NULL);
7600 }
7601 } else {
7602 do_ssh2_authconn(ssh, in, inlen, pktin);
7603 }
7cca0d81 7604}
7605
7606/*
8df7a775 7607 * Called to set up the connection.
374330e2 7608 *
7609 * Returns an error message, or NULL on success.
374330e2 7610 */
cbe2d68f 7611static const char *ssh_init(void *frontend_handle, void **backend_handle,
7612 Config *cfg,
79bf227b 7613 char *host, int port, char **realhost, int nodelay,
7614 int keepalive)
32874aea 7615{
cbe2d68f 7616 const char *p;
51470298 7617 Ssh ssh;
7618
3d88e64d 7619 ssh = snew(struct ssh_tag);
86916870 7620 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 7621 ssh->version = 0; /* when not ready yet */
51470298 7622 ssh->s = NULL;
7623 ssh->cipher = NULL;
371e569c 7624 ssh->v1_cipher_ctx = NULL;
0183b242 7625 ssh->crcda_ctx = NULL;
51470298 7626 ssh->cscipher = NULL;
371e569c 7627 ssh->cs_cipher_ctx = NULL;
51470298 7628 ssh->sccipher = NULL;
371e569c 7629 ssh->sc_cipher_ctx = NULL;
51470298 7630 ssh->csmac = NULL;
a8327734 7631 ssh->cs_mac_ctx = NULL;
51470298 7632 ssh->scmac = NULL;
e0e1a00d 7633 ssh->sc_mac_ctx = NULL;
51470298 7634 ssh->cscomp = NULL;
5366aed8 7635 ssh->cs_comp_ctx = NULL;
51470298 7636 ssh->sccomp = NULL;
5366aed8 7637 ssh->sc_comp_ctx = NULL;
51470298 7638 ssh->kex = NULL;
389aa499 7639 ssh->kex_ctx = NULL;
51470298 7640 ssh->hostkey = NULL;
7641 ssh->exitcode = -1;
ac934965 7642 ssh->close_expected = FALSE;
51470298 7643 ssh->state = SSH_STATE_PREPACKET;
7644 ssh->size_needed = FALSE;
7645 ssh->eof_needed = FALSE;
b9d7bcad 7646 ssh->ldisc = NULL;
a8327734 7647 ssh->logctx = NULL;
51470298 7648 ssh->deferred_send_data = NULL;
7649 ssh->deferred_len = 0;
7650 ssh->deferred_size = 0;
7651 ssh->fallback_cmd = 0;
7652 ssh->pkt_ctx = 0;
302121de 7653 ssh->x11auth = NULL;
be738459 7654 ssh->v1_compressing = FALSE;
51470298 7655 ssh->v2_outgoing_sequence = 0;
7656 ssh->ssh1_rdpkt_crstate = 0;
7657 ssh->ssh2_rdpkt_crstate = 0;
7658 ssh->do_ssh_init_crstate = 0;
7659 ssh->ssh_gotdata_crstate = 0;
b09eaa88 7660 ssh->do_ssh1_connection_crstate = 0;
51470298 7661 ssh->do_ssh1_login_crstate = 0;
7662 ssh->do_ssh2_transport_crstate = 0;
7663 ssh->do_ssh2_authconn_crstate = 0;
7664 ssh->do_ssh_init_state = NULL;
7665 ssh->do_ssh1_login_state = NULL;
7666 ssh->do_ssh2_transport_state = NULL;
7667 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 7668 ssh->mainchan = NULL;
968d2d92 7669 ssh->throttled_all = 0;
7670 ssh->v1_stdout_throttling = 0;
590f6a5f 7671 ssh->queue = NULL;
7672 ssh->queuelen = ssh->queuesize = 0;
7673 ssh->queueing = FALSE;
06fadff5 7674 ssh->qhead = ssh->qtail = NULL;
e13bba36 7675 ssh->deferred_rekey_reason = NULL;
3d9449a1 7676 bufchain_init(&ssh->queued_incoming_data);
7677 ssh->frozen = FALSE;
51470298 7678
7679 *backend_handle = ssh;
32874aea 7680
8f203108 7681#ifdef MSCRYPTOAPI
32874aea 7682 if (crypto_startup() == 0)
8f203108 7683 return "Microsoft high encryption pack not installed!";
7684#endif
374330e2 7685
51470298 7686 ssh->frontend = frontend_handle;
86916870 7687 ssh->term_width = ssh->cfg.width;
7688 ssh->term_height = ssh->cfg.height;
887035a5 7689
fabd1805 7690 ssh->channels = NULL;
7691 ssh->rportfwds = NULL;
f47a5ffb 7692 ssh->portfwds = NULL;
fabd1805 7693
51470298 7694 ssh->send_ok = 0;
7695 ssh->editing = 0;
7696 ssh->echoing = 0;
7697 ssh->v1_throttle_count = 0;
7698 ssh->overall_bufsize = 0;
7699 ssh->fallback_cmd = 0;
8df7a775 7700
3648d4c5 7701 ssh->protocol = NULL;
7702
b09eaa88 7703 ssh->protocol_initial_phase_done = FALSE;
7704
39934deb 7705 ssh->pinger = NULL;
7706
9442dd57 7707 ssh->incoming_data_size = ssh->outgoing_data_size =
7708 ssh->deferred_data_size = 0L;
d57f70af 7709 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9442dd57 7710 ssh->kex_in_progress = FALSE;
7711
79bf227b 7712 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 7713 if (p != NULL)
7714 return p;
374330e2 7715
5d17ccfc 7716 random_ref();
7717
374330e2 7718 return NULL;
7719}
7720
fabd1805 7721static void ssh_free(void *handle)
7722{
7723 Ssh ssh = (Ssh) handle;
7724 struct ssh_channel *c;
7725 struct ssh_rportfwd *pf;
7726
7727 if (ssh->v1_cipher_ctx)
7728 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7729 if (ssh->cs_cipher_ctx)
7730 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7731 if (ssh->sc_cipher_ctx)
7732 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7733 if (ssh->cs_mac_ctx)
7734 ssh->csmac->free_context(ssh->cs_mac_ctx);
7735 if (ssh->sc_mac_ctx)
7736 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 7737 if (ssh->cs_comp_ctx) {
7738 if (ssh->cscomp)
7739 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7740 else
7741 zlib_compress_cleanup(ssh->cs_comp_ctx);
7742 }
7743 if (ssh->sc_comp_ctx) {
7744 if (ssh->sccomp)
7745 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7746 else
7747 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7748 }
fabd1805 7749 if (ssh->kex_ctx)
7750 dh_cleanup(ssh->kex_ctx);
7751 sfree(ssh->savedhost);
7752
590f6a5f 7753 while (ssh->queuelen-- > 0)
7754 ssh_free_packet(ssh->queue[ssh->queuelen]);
7755 sfree(ssh->queue);
7756
06fadff5 7757 while (ssh->qhead) {
7758 struct queued_handler *qh = ssh->qhead;
7759 ssh->qhead = qh->next;
7760 sfree(ssh->qhead);
7761 }
7762 ssh->qhead = ssh->qtail = NULL;
7763
fabd1805 7764 if (ssh->channels) {
7765 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7766 switch (c->type) {
7767 case CHAN_X11:
7768 if (c->u.x11.s != NULL)
7769 x11_close(c->u.x11.s);
7770 break;
7771 case CHAN_SOCKDATA:
7772 if (c->u.pfd.s != NULL)
7773 pfd_close(c->u.pfd.s);
7774 break;
7775 }
7776 sfree(c);
7777 }
7778 freetree234(ssh->channels);
cdb52705 7779 ssh->channels = NULL;
fabd1805 7780 }
7781
7782 if (ssh->rportfwds) {
7783 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7784 sfree(pf);
7785 freetree234(ssh->rportfwds);
cdb52705 7786 ssh->rportfwds = NULL;
fabd1805 7787 }
7788 sfree(ssh->deferred_send_data);
7789 if (ssh->x11auth)
7790 x11_free_auth(ssh->x11auth);
7791 sfree(ssh->do_ssh_init_state);
7792 sfree(ssh->do_ssh1_login_state);
7793 sfree(ssh->do_ssh2_transport_state);
7794 sfree(ssh->do_ssh2_authconn_state);
679539d7 7795 if (ssh->crcda_ctx) {
7796 crcda_free_context(ssh->crcda_ctx);
7797 ssh->crcda_ctx = NULL;
7798 }
fabd1805 7799 if (ssh->s)
ac934965 7800 ssh_do_close(ssh, TRUE);
9442dd57 7801 expire_timer_context(ssh);
39934deb 7802 if (ssh->pinger)
7803 pinger_free(ssh->pinger);
3d9449a1 7804 bufchain_clear(&ssh->queued_incoming_data);
ee50e8b6 7805 sfree(ssh);
5d17ccfc 7806
7807 random_unref();
fabd1805 7808}
7809
374330e2 7810/*
86916870 7811 * Reconfigure the SSH backend.
86916870 7812 */
7813static void ssh_reconfig(void *handle, Config *cfg)
7814{
7815 Ssh ssh = (Ssh) handle;
e13bba36 7816 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 7817 unsigned long old_max_data_size;
7818
39934deb 7819 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
fda2feb1 7820 ssh_setup_portfwd(ssh, cfg);
e6c1536e 7821
7822 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7823 cfg->ssh_rekey_time != 0) {
7824 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7825 long now = GETTICKCOUNT();
7826
7827 if (new_next - now < 0) {
f382c87d 7828 rekeying = "timeout shortened";
e6c1536e 7829 } else {
7830 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7831 }
7832 }
7833
7834 old_max_data_size = ssh->max_data_size;
7835 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7836 if (old_max_data_size != ssh->max_data_size &&
7837 ssh->max_data_size != 0) {
7838 if (ssh->outgoing_data_size > ssh->max_data_size ||
7839 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 7840 rekeying = "data limit lowered";
e6c1536e 7841 }
7842
e13bba36 7843 if (ssh->cfg.compression != cfg->compression) {
f382c87d 7844 rekeying = "compression setting changed";
e13bba36 7845 rekey_mandatory = TRUE;
7846 }
7847
7848 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7849 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7850 sizeof(ssh->cfg.ssh_cipherlist))) {
f382c87d 7851 rekeying = "cipher settings changed";
e13bba36 7852 rekey_mandatory = TRUE;
e6c1536e 7853 }
7854
86916870 7855 ssh->cfg = *cfg; /* STRUCTURE COPY */
e13bba36 7856
7857 if (rekeying) {
7858 if (!ssh->kex_in_progress) {
7859 do_ssh2_transport(ssh, rekeying, -1, NULL);
7860 } else if (rekey_mandatory) {
7861 ssh->deferred_rekey_reason = rekeying;
7862 }
7863 }
86916870 7864}
7865
7866/*
374330e2 7867 * Called to send data down the Telnet connection.
7868 */
51470298 7869static int ssh_send(void *handle, char *buf, int len)
32874aea 7870{
51470298 7871 Ssh ssh = (Ssh) handle;
7872
7873 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7874 return 0;
374330e2 7875
d8baa528 7876 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 7877
51470298 7878 return ssh_sendbuffer(ssh);
5471d09a 7879}
7880
7881/*
7882 * Called to query the current amount of buffered stdin data.
7883 */
51470298 7884static int ssh_sendbuffer(void *handle)
5471d09a 7885{
51470298 7886 Ssh ssh = (Ssh) handle;
5471d09a 7887 int override_value;
7888
51470298 7889 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7890 return 0;
7891
7892 /*
7893 * If the SSH socket itself has backed up, add the total backup
7894 * size on that to any individual buffer on the stdin channel.
7895 */
7896 override_value = 0;
51470298 7897 if (ssh->throttled_all)
7898 override_value = ssh->overall_bufsize;
5471d09a 7899
51470298 7900 if (ssh->version == 1) {
5471d09a 7901 return override_value;
51470298 7902 } else if (ssh->version == 2) {
7903 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 7904 return override_value;
7905 else
51470298 7906 return (override_value +
7907 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 7908 }
7909
7910 return 0;
374330e2 7911}
7912
7913/*
6e48c3fe 7914 * Called to set the size of the window from SSH's POV.
374330e2 7915 */
51470298 7916static void ssh_size(void *handle, int width, int height)
32874aea 7917{
51470298 7918 Ssh ssh = (Ssh) handle;
ff3187f6 7919 struct Packet *pktout;
51470298 7920
7921 ssh->term_width = width;
7922 ssh->term_height = height;
f278d6f8 7923
51470298 7924 switch (ssh->state) {
374330e2 7925 case SSH_STATE_BEFORE_SIZE:
3687d221 7926 case SSH_STATE_PREPACKET:
21248260 7927 case SSH_STATE_CLOSED:
374330e2 7928 break; /* do nothing */
7929 case SSH_STATE_INTERMED:
51470298 7930 ssh->size_needed = TRUE; /* buffer for later */
374330e2 7931 break;
7932 case SSH_STATE_SESSION:
86916870 7933 if (!ssh->cfg.nopty) {
51470298 7934 if (ssh->version == 1) {
7935 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7936 PKT_INT, ssh->term_height,
7937 PKT_INT, ssh->term_width,
32874aea 7938 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 7939 } else if (ssh->mainchan) {
ff3187f6 7940 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7941 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7942 ssh2_pkt_addstring(pktout, "window-change");
7943 ssh2_pkt_addbool(pktout, 0);
7944 ssh2_pkt_adduint32(pktout, ssh->term_width);
7945 ssh2_pkt_adduint32(pktout, ssh->term_height);
7946 ssh2_pkt_adduint32(pktout, 0);
7947 ssh2_pkt_adduint32(pktout, 0);
7948 ssh2_pkt_send(ssh, pktout);
32874aea 7949 }
7950 }
7951 break;
374330e2 7952 }
7953}
7954
7955/*
125105d1 7956 * Return a list of the special codes that make sense in this
7957 * protocol.
7958 */
7959static const struct telnet_special *ssh_get_specials(void *handle)
7960{
786ba75e 7961 static const struct telnet_special ssh1_ignore_special[] = {
7962 {"IGNORE message", TS_NOP}
7963 };
7964 static const struct telnet_special ssh2_transport_specials[] = {
62638676 7965 {"IGNORE message", TS_NOP},
9442dd57 7966 {"Repeat key exchange", TS_REKEY},
62638676 7967 };
7968 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 7969 {NULL, TS_SEP},
7970 {"Break", TS_BRK},
786ba75e 7971 /* These are the signal names defined by draft-ietf-secsh-connect-23.
6f2d0cde 7972 * They include all the ISO C signals, but are a subset of the POSIX
7973 * required signals. */
7974 {"SIGINT (Interrupt)", TS_SIGINT},
7975 {"SIGTERM (Terminate)", TS_SIGTERM},
7976 {"SIGKILL (Kill)", TS_SIGKILL},
7977 {"SIGQUIT (Quit)", TS_SIGQUIT},
7978 {"SIGHUP (Hangup)", TS_SIGHUP},
7979 {"More signals", TS_SUBMENU},
7980 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7981 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7982 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7983 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7984 {NULL, TS_EXITMENU}
62638676 7985 };
7986 static const struct telnet_special specials_end[] = {
6f2d0cde 7987 {NULL, TS_EXITMENU}
62638676 7988 };
786ba75e 7989 /* XXX review this length for any changes: */
7990 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
62638676 7991 lenof(ssh2_session_specials) +
7992 lenof(specials_end)];
125105d1 7993 Ssh ssh = (Ssh) handle;
62638676 7994 int i = 0;
7995#define ADD_SPECIALS(name) \
7996 do { \
7997 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7998 memcpy(&ssh_specials[i], name, sizeof name); \
7999 i += lenof(name); \
8000 } while(0)
125105d1 8001
8002 if (ssh->version == 1) {
62638676 8003 /* Don't bother offering IGNORE if we've decided the remote
8004 * won't cope with it, since we wouldn't bother sending it if
8005 * asked anyway. */
8006 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 8007 ADD_SPECIALS(ssh1_ignore_special);
125105d1 8008 } else if (ssh->version == 2) {
786ba75e 8009 ADD_SPECIALS(ssh2_transport_specials);
62638676 8010 if (ssh->mainchan)
8011 ADD_SPECIALS(ssh2_session_specials);
8012 } /* else we're not ready yet */
8013
8014 if (i) {
8015 ADD_SPECIALS(specials_end);
8016 return ssh_specials;
8017 } else {
125105d1 8018 return NULL;
62638676 8019 }
8020#undef ADD_SPECIALS
125105d1 8021}
8022
8023/*
6abbf9e3 8024 * Send Telnet special codes. TS_EOF is useful for `plink', so you
8025 * can send an EOF and collect resulting output (e.g. `plink
8026 * hostname sort').
374330e2 8027 */
51470298 8028static void ssh_special(void *handle, Telnet_Special code)
32874aea 8029{
51470298 8030 Ssh ssh = (Ssh) handle;
ff3187f6 8031 struct Packet *pktout;
51470298 8032
6abbf9e3 8033 if (code == TS_EOF) {
51470298 8034 if (ssh->state != SSH_STATE_SESSION) {
32874aea 8035 /*
8036 * Buffer the EOF in case we are pre-SESSION, so we can
8037 * send it as soon as we reach SESSION.
8038 */
8039 if (code == TS_EOF)
51470298 8040 ssh->eof_needed = TRUE;
32874aea 8041 return;
8042 }
51470298 8043 if (ssh->version == 1) {
8044 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 8045 } else if (ssh->mainchan) {
ff3187f6 8046 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8047 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8048 ssh2_pkt_send(ssh, pktout);
32874aea 8049 }
8050 logevent("Sent EOF message");
125105d1 8051 } else if (code == TS_PING || code == TS_NOP) {
51470298 8052 if (ssh->state == SSH_STATE_CLOSED
8053 || ssh->state == SSH_STATE_PREPACKET) return;
8054 if (ssh->version == 1) {
8055 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8056 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 8057 } else {
ff3187f6 8058 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8059 ssh2_pkt_addstring_start(pktout);
590f6a5f 8060 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 8061 }
9442dd57 8062 } else if (code == TS_REKEY) {
8063 if (!ssh->kex_in_progress && ssh->version == 2) {
f382c87d 8064 do_ssh2_transport(ssh, "at user request", -1, NULL);
9442dd57 8065 }
125105d1 8066 } else if (code == TS_BRK) {
8067 if (ssh->state == SSH_STATE_CLOSED
8068 || ssh->state == SSH_STATE_PREPACKET) return;
8069 if (ssh->version == 1) {
8070 logevent("Unable to send BREAK signal in SSH1");
0ed48730 8071 } else if (ssh->mainchan) {
ff3187f6 8072 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8073 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8074 ssh2_pkt_addstring(pktout, "break");
8075 ssh2_pkt_addbool(pktout, 0);
8076 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8077 ssh2_pkt_send(ssh, pktout);
125105d1 8078 }
6abbf9e3 8079 } else {
6f2d0cde 8080 /* Is is a POSIX signal? */
8081 char *signame = NULL;
8082 if (code == TS_SIGABRT) signame = "ABRT";
8083 if (code == TS_SIGALRM) signame = "ALRM";
8084 if (code == TS_SIGFPE) signame = "FPE";
8085 if (code == TS_SIGHUP) signame = "HUP";
8086 if (code == TS_SIGILL) signame = "ILL";
8087 if (code == TS_SIGINT) signame = "INT";
8088 if (code == TS_SIGKILL) signame = "KILL";
8089 if (code == TS_SIGPIPE) signame = "PIPE";
8090 if (code == TS_SIGQUIT) signame = "QUIT";
8091 if (code == TS_SIGSEGV) signame = "SEGV";
8092 if (code == TS_SIGTERM) signame = "TERM";
8093 if (code == TS_SIGUSR1) signame = "USR1";
8094 if (code == TS_SIGUSR2) signame = "USR2";
8095 /* The SSH-2 protocol does in principle support arbitrary named
8096 * signals, including signame@domain, but we don't support those. */
8097 if (signame) {
8098 /* It's a signal. */
8099 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 8100 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8101 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8102 ssh2_pkt_addstring(pktout, "signal");
8103 ssh2_pkt_addbool(pktout, 0);
8104 ssh2_pkt_addstring(pktout, signame);
8105 ssh2_pkt_send(ssh, pktout);
6f2d0cde 8106 logeventf(ssh, "Sent signal SIG%s", signame);
8107 }
8108 } else {
8109 /* Never heard of it. Do nothing */
8110 }
6abbf9e3 8111 }
374330e2 8112}
8113
51470298 8114void *new_sock_channel(void *handle, Socket s)
d74d141c 8115{
51470298 8116 Ssh ssh = (Ssh) handle;
d74d141c 8117 struct ssh_channel *c;
3d88e64d 8118 c = snew(struct ssh_channel);
51470298 8119 c->ssh = ssh;
d74d141c 8120
8121 if (c) {
64d6ff88 8122 c->halfopen = TRUE;
51470298 8123 c->localid = alloc_channel_id(ssh);
d74d141c 8124 c->closes = 0;
bc240b21 8125 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 8126 c->u.pfd.s = s;
013dd8c0 8127 bufchain_init(&c->v.v2.outbuffer);
51470298 8128 add234(ssh->channels, c);
d74d141c 8129 }
8130 return c;
8131}
8132
5471d09a 8133/*
8134 * This is called when stdout/stderr (the entity to which
8135 * from_backend sends data) manages to clear some backlog.
8136 */
ae9ae89f 8137static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 8138{
51470298 8139 Ssh ssh = (Ssh) handle;
8140 if (ssh->version == 1) {
8141 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8142 ssh->v1_stdout_throttling = 0;
8143 ssh1_throttle(ssh, -1);
5471d09a 8144 }
8145 } else {
51470298 8146 if (ssh->mainchan && ssh->mainchan->closes == 0)
8147 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 8148 }
8149}
8150
6b78788a 8151void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 8152{
8153 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 8154 Ssh ssh = c->ssh;
ff3187f6 8155 struct Packet *pktout;
d74d141c 8156
57356d63 8157 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 8158
51470298 8159 if (ssh->version == 1) {
8160 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 8161 PKT_INT, c->localid,
8162 PKT_STR, hostname,
8163 PKT_INT, port,
31fb1866 8164 /* PKT_STR, <org:orgport>, */
bc240b21 8165 PKT_END);
8166 } else {
ff3187f6 8167 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8168 ssh2_pkt_addstring(pktout, "direct-tcpip");
8169 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 8170 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 8171 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
954d5c5a 8172 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 8173 ssh2_pkt_addstring(pktout, hostname);
8174 ssh2_pkt_adduint32(pktout, port);
bc240b21 8175 /*
8176 * We make up values for the originator data; partly it's
8177 * too much hassle to keep track, and partly I'm not
8178 * convinced the server should be told details like that
8179 * about my local network configuration.
8180 */
ff3187f6 8181 ssh2_pkt_addstring(pktout, "client-side-connection");
8182 ssh2_pkt_adduint32(pktout, 0);
8183 ssh2_pkt_send(ssh, pktout);
bc240b21 8184 }
d74d141c 8185}
8186
51470298 8187static Socket ssh_socket(void *handle)
32874aea 8188{
51470298 8189 Ssh ssh = (Ssh) handle;
8190 return ssh->s;
32874aea 8191}
8ccc75b0 8192
51470298 8193static int ssh_sendok(void *handle)
32874aea 8194{
51470298 8195 Ssh ssh = (Ssh) handle;
8196 return ssh->send_ok;
32874aea 8197}
fb09bf1c 8198
51470298 8199static int ssh_ldisc(void *handle, int option)
32874aea 8200{
51470298 8201 Ssh ssh = (Ssh) handle;
32874aea 8202 if (option == LD_ECHO)
51470298 8203 return ssh->echoing;
32874aea 8204 if (option == LD_EDIT)
51470298 8205 return ssh->editing;
0965bee0 8206 return FALSE;
8207}
8208
b9d7bcad 8209static void ssh_provide_ldisc(void *handle, void *ldisc)
8210{
8211 Ssh ssh = (Ssh) handle;
8212 ssh->ldisc = ldisc;
8213}
8214
a8327734 8215static void ssh_provide_logctx(void *handle, void *logctx)
8216{
8217 Ssh ssh = (Ssh) handle;
8218 ssh->logctx = logctx;
8219}
8220
51470298 8221static int ssh_return_exitcode(void *handle)
8222{
8223 Ssh ssh = (Ssh) handle;
3bb2f322 8224 if (ssh->s != NULL)
8225 return -1;
8226 else
8227 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 8228}
8229
8230/*
f89c3294 8231 * cfg_info for SSH is the currently running version of the
8232 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8233 */
8234static int ssh_cfg_info(void *handle)
8235{
8236 Ssh ssh = (Ssh) handle;
8237 return ssh->version;
8238}
8239
8240/*
51470298 8241 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8242 * that fails. This variable is the means by which scp.c can reach
8243 * into the SSH code and find out which one it got.
8244 */
8245extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 8246{
51470298 8247 Ssh ssh = (Ssh) handle;
8248 return ssh->fallback_cmd;
d8d6c7e5 8249}
8250
374330e2 8251Backend ssh_backend = {
8252 ssh_init,
fabd1805 8253 ssh_free,
86916870 8254 ssh_reconfig,
374330e2 8255 ssh_send,
5471d09a 8256 ssh_sendbuffer,
374330e2 8257 ssh_size,
4017be6d 8258 ssh_special,
125105d1 8259 ssh_get_specials,
8ccc75b0 8260 ssh_socket,
d8d6c7e5 8261 ssh_return_exitcode,
97db3be4 8262 ssh_sendok,
0965bee0 8263 ssh_ldisc,
b9d7bcad 8264 ssh_provide_ldisc,
a8327734 8265 ssh_provide_logctx,
5471d09a 8266 ssh_unthrottle,
f89c3294 8267 ssh_cfg_info,
97db3be4 8268 22
bc240b21 8269};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator