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Revamp interface to verify_ssh_host_key() and askalg(). Each of them
[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{
2386 sk_set_frozen(ssh->s, frozen);
2387 ssh->frozen = frozen;
2388}
2389
51470298 2390static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2391{
51470298 2392 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2393
2394 /*
2395 * To begin with, feed the characters one by one to the
2396 * protocol initialisation / selection function do_ssh_init().
2397 * When that returns 0, we're done with the initial greeting
2398 * exchange and can move on to packet discipline.
2399 */
2400 while (1) {
51470298 2401 int ret; /* need not be kept across crReturn */
8df7a775 2402 if (datalen == 0)
2403 crReturnV; /* more data please */
51470298 2404 ret = do_ssh_init(ssh, *data);
32874aea 2405 data++;
2406 datalen--;
8df7a775 2407 if (ret == 0)
2408 break;
2409 }
2410
2411 /*
2412 * We emerge from that loop when the initial negotiation is
2413 * over and we have selected an s_rdpkt function. Now pass
2414 * everything to s_rdpkt, and then pass the resulting packets
2415 * to the proper protocol handler.
2416 */
2417 if (datalen == 0)
2418 crReturnV;
3d9449a1 2419
2420 /*
2421 * Process queued data if there is any.
2422 */
2423 ssh_process_queued_incoming_data(ssh);
2424
8df7a775 2425 while (1) {
2426 while (datalen > 0) {
3d9449a1 2427 if (ssh->frozen)
2428 ssh_queue_incoming_data(ssh, &data, &datalen);
2429
2430 ssh_process_incoming_data(ssh, &data, &datalen);
2431
ff3187f6 2432 if (ssh->state == SSH_STATE_CLOSED)
2433 return;
8df7a775 2434 }
2435 crReturnV;
2436 }
2437 crFinishV;
2438}
2439
ac934965 2440static int ssh_do_close(Ssh ssh, int notify_exit)
32874aea 2441{
80ffa58b 2442 int ret = 0;
36f94d1f 2443 struct ssh_channel *c;
2444
51470298 2445 ssh->state = SSH_STATE_CLOSED;
2446 if (ssh->s) {
2447 sk_close(ssh->s);
2448 ssh->s = NULL;
ac934965 2449 if (notify_exit)
2450 notify_remote_exit(ssh->frontend);
2451 else
2452 ret = 1;
f3ab576e 2453 }
36f94d1f 2454 /*
80ffa58b 2455 * Now we must shut down any port- and X-forwarded channels going
36f94d1f 2456 * through this connection.
2457 */
74a98066 2458 if (ssh->channels) {
80ffa58b 2459 while (NULL != (c = index234(ssh->channels, 0))) {
74a98066 2460 switch (c->type) {
2461 case CHAN_X11:
2462 x11_close(c->u.x11.s);
2463 break;
2464 case CHAN_SOCKDATA:
2465 pfd_close(c->u.pfd.s);
2466 break;
2467 }
80ffa58b 2468 del234(ssh->channels, c); /* moving next one to index 0 */
74a98066 2469 if (ssh->version == 2)
2470 bufchain_clear(&c->v.v2.outbuffer);
2471 sfree(c);
36f94d1f 2472 }
36f94d1f 2473 }
f8c9f9df 2474 /*
2475 * Go through port-forwardings, and close any associated
2476 * listening sockets.
2477 */
2478 if (ssh->portfwds) {
2479 struct ssh_portfwd *pf;
2480 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2481 /* Dispose of any listening socket. */
2482 if (pf->local)
2483 pfd_terminate(pf->local);
2484 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2485 free_portfwd(pf);
2486 }
2487 }
ac934965 2488
2489 return ret;
36f94d1f 2490}
2491
7555d6a5 2492static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2493 const char *error_msg, int error_code)
2494{
2495 Ssh ssh = (Ssh) plug;
2496 char addrbuf[256], *msg;
2497
2498 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2499
2500 if (type == 0)
2501 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2502 else
2503 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2504
2505 logevent(msg);
fb983202 2506 sfree(msg);
7555d6a5 2507}
2508
cbe2d68f 2509static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2510 int calling_back)
2511{
2512 Ssh ssh = (Ssh) plug;
ac934965 2513 int need_notify = ssh_do_close(ssh, FALSE);
2514
2515 if (!error_msg && !ssh->close_expected) {
2516 error_msg = "Server unexpectedly closed network connection";
2517 }
2518
7e78000d 2519 if (error_msg) {
32874aea 2520 /* A socket error has occurred. */
247308b5 2521 logevent(error_msg);
971bcc0a 2522 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2523 } else {
ac934965 2524 logevent("Server closed network connection");
8df7a775 2525 }
ac934965 2526 if (need_notify)
2527 notify_remote_exit(ssh->frontend);
7e78000d 2528 return 0;
2529}
2530
32874aea 2531static int ssh_receive(Plug plug, int urgent, char *data, int len)
2532{
51470298 2533 Ssh ssh = (Ssh) plug;
d8baa528 2534 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2535 if (ssh->state == SSH_STATE_CLOSED) {
ac934965 2536 ssh_do_close(ssh, TRUE);
32874aea 2537 return 0;
3257deae 2538 }
fef97f43 2539 return 1;
374330e2 2540}
2541
5471d09a 2542static void ssh_sent(Plug plug, int bufsize)
2543{
51470298 2544 Ssh ssh = (Ssh) plug;
5471d09a 2545 /*
2546 * If the send backlog on the SSH socket itself clears, we
2547 * should unthrottle the whole world if it was throttled.
2548 */
2549 if (bufsize < SSH_MAX_BACKLOG)
51470298 2550 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2551}
2552
fb09bf1c 2553/*
8df7a775 2554 * Connect to specified host and port.
2555 * Returns an error message, or NULL on success.
6e1ebb76 2556 * Also places the canonical host name into `realhost'. It must be
2557 * freed by the caller.
8df7a775 2558 */
cbe2d68f 2559static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2560 char **realhost, int nodelay, int keepalive)
8df7a775 2561{
51470298 2562 static const struct plug_function_table fn_table = {
7555d6a5 2563 ssh_log,
7e78000d 2564 ssh_closing,
5471d09a 2565 ssh_receive,
2566 ssh_sent,
2567 NULL
51470298 2568 };
7e78000d 2569
8df7a775 2570 SockAddr addr;
cbe2d68f 2571 const char *err;
8df7a775 2572
3d88e64d 2573 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2574 if (!ssh->savedhost)
8df7a775 2575 fatalbox("Out of memory");
51470298 2576 strcpy(ssh->savedhost, host);
8df7a775 2577
2578 if (port < 0)
2579 port = 22; /* default ssh port */
51470298 2580 ssh->savedport = port;
8df7a775 2581
2582 /*
2583 * Try to find host.
2584 */
05581745 2585 logeventf(ssh, "Looking up host \"%s\"%s", host,
2586 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2587 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2588 addr = name_lookup(host, port, realhost, &ssh->cfg,
2589 ssh->cfg.addressfamily);
170c1e6e 2590 if ((err = sk_addr_error(addr)) != NULL) {
2591 sk_addr_free(addr);
8df7a775 2592 return err;
170c1e6e 2593 }
8df7a775 2594
8df7a775 2595 /*
2596 * Open socket.
2597 */
51470298 2598 ssh->fn = &fn_table;
e8fa8f62 2599 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2600 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2601 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2602 ssh->s = NULL;
39934deb 2603 notify_remote_exit(ssh->frontend);
8df7a775 2604 return err;
67c4ba2e 2605 }
8df7a775 2606
8df7a775 2607 return NULL;
2608}
2609
2610/*
5471d09a 2611 * Throttle or unthrottle the SSH connection.
2612 */
51470298 2613static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2614{
51470298 2615 int old_count = ssh->v1_throttle_count;
2616 ssh->v1_throttle_count += adjust;
2617 assert(ssh->v1_throttle_count >= 0);
2618 if (ssh->v1_throttle_count && !old_count) {
3d9449a1 2619 ssh_set_frozen(ssh, 1);
51470298 2620 } else if (!ssh->v1_throttle_count && old_count) {
3d9449a1 2621 ssh_set_frozen(ssh, 0);
5471d09a 2622 }
2623}
2624
2625/*
2626 * Throttle or unthrottle _all_ local data streams (for when sends
2627 * on the SSH connection itself back up).
2628 */
51470298 2629static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2630{
2631 int i;
2632 struct ssh_channel *c;
2633
51470298 2634 if (enable == ssh->throttled_all)
5471d09a 2635 return;
51470298 2636 ssh->throttled_all = enable;
2637 ssh->overall_bufsize = bufsize;
2638 if (!ssh->channels)
5471d09a 2639 return;
51470298 2640 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2641 switch (c->type) {
2642 case CHAN_MAINSESSION:
2643 /*
2644 * This is treated separately, outside the switch.
2645 */
2646 break;
2647 case CHAN_X11:
2648 x11_override_throttle(c->u.x11.s, enable);
2649 break;
2650 case CHAN_AGENT:
2651 /* Agent channels require no buffer management. */
2652 break;
2653 case CHAN_SOCKDATA:
36f94d1f 2654 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2655 break;
2656 }
2657 }
2658}
2659
2660/*
51470298 2661 * Username and password input, abstracted off into routines
2662 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2663 */
0405e71f 2664
2665/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2666static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2667{
51470298 2668 ssh->userpass_input_buffer = buffer;
2669 ssh->userpass_input_buflen = buflen;
2670 ssh->userpass_input_bufpos = 0;
2671 ssh->userpass_input_echo = echo;
0405e71f 2672}
2673
2674/*
2675 * Process some terminal data in the course of username/password
2676 * input. Returns >0 for success (line of input returned in
2677 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2678 * for inconclusive (keep waiting for more input please).
2679 */
ae9ae89f 2680static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2681{
2682 char c;
2683
2684 while (inlen--) {
2685 switch (c = *in++) {
2686 case 10:
2687 case 13:
51470298 2688 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2689 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2690 return +1;
2691 break;
2692 case 8:
2693 case 127:
51470298 2694 if (ssh->userpass_input_bufpos > 0) {
2695 if (ssh->userpass_input_echo)
2696 c_write_str(ssh, "\b \b");
2697 ssh->userpass_input_bufpos--;
0405e71f 2698 }
2699 break;
2700 case 21:
2701 case 27:
51470298 2702 while (ssh->userpass_input_bufpos > 0) {
2703 if (ssh->userpass_input_echo)
2704 c_write_str(ssh, "\b \b");
2705 ssh->userpass_input_bufpos--;
0405e71f 2706 }
2707 break;
2708 case 3:
2709 case 4:
2710 return -1;
2711 break;
2712 default:
4692a14a 2713 /*
2714 * This simplistic check for printability is disabled
2715 * when we're doing password input, because some people
2716 * have control characters in their passwords.o
2717 */
2718 if ((!ssh->userpass_input_echo ||
2719 (c >= ' ' && c <= '~') ||
0405e71f 2720 ((unsigned char) c >= 160))
51470298 2721 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2722 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2723 if (ssh->userpass_input_echo)
2724 c_write(ssh, &c, 1);
0405e71f 2725 }
2726 break;
2727 }
2728 }
2729 return 0;
2730}
2731
f11d78f2 2732static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2733{
2734 Ssh ssh = (Ssh) sshv;
2735
2736 ssh->agent_response = reply;
2737 ssh->agent_response_len = replylen;
2738
2739 if (ssh->version == 1)
ff3187f6 2740 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2741 else
ff3187f6 2742 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2743}
2744
3d9449a1 2745static void ssh_dialog_callback(void *sshv, int ret)
2746{
2747 Ssh ssh = (Ssh) sshv;
2748
2749 ssh->user_response = ret;
2750
2751 if (ssh->version == 1)
2752 do_ssh1_login(ssh, NULL, -1, NULL);
2753 else
2754 do_ssh2_transport(ssh, NULL, -1, NULL);
2755
2756 /*
2757 * This may have unfrozen the SSH connection, so do a
2758 * queued-data run.
2759 */
2760 ssh_process_queued_incoming_data(ssh);
2761}
2762
f11d78f2 2763static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2764{
2765 struct ssh_channel *c = (struct ssh_channel *)cv;
2766 Ssh ssh = c->ssh;
2767 void *sentreply = reply;
2768
2769 if (!sentreply) {
2770 /* Fake SSH_AGENT_FAILURE. */
2771 sentreply = "\0\0\0\1\5";
2772 replylen = 5;
2773 }
2774 if (ssh->version == 2) {
2775 ssh2_add_channel_data(c, sentreply, replylen);
2776 ssh2_try_send(c);
2777 } else {
2778 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2779 PKT_INT, c->remoteid,
9a10ecf4 2780 PKTT_DATA,
839f10db 2781 PKT_INT, replylen,
2782 PKT_DATA, sentreply, replylen,
9a10ecf4 2783 PKTT_OTHER,
839f10db 2784 PKT_END);
2785 }
2786 if (reply)
2787 sfree(reply);
2788}
2789
0405e71f 2790/*
fb09bf1c 2791 * Handle the key exchange and user authentication phases.
2792 */
ff3187f6 2793static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2794 struct Packet *pktin)
fb09bf1c 2795{
0016d70b 2796 int i, j, ret;
2797 unsigned char cookie[8], *ptr;
374330e2 2798 struct RSAKey servkey, hostkey;
2799 struct MD5Context md5c;
51470298 2800 struct do_ssh1_login_state {
2801 int len;
2802 unsigned char *rsabuf, *keystr1, *keystr2;
2803 unsigned long supported_ciphers_mask, supported_auths_mask;
2804 int tried_publickey, tried_agent;
2805 int tis_auth_refused, ccard_auth_refused;
2806 unsigned char session_id[16];
2807 int cipher_type;
2808 char username[100];
2809 void *publickey_blob;
2810 int publickey_bloblen;
2811 char password[100];
2812 char prompt[200];
2813 int pos;
2814 char c;
2815 int pwpkt_type;
2816 unsigned char request[5], *response, *p;
2817 int responselen;
2818 int keyi, nkeys;
2819 int authed;
2820 struct RSAKey key;
2821 Bignum challenge;
2822 char *commentp;
2823 int commentlen;
3d9449a1 2824 int dlgret;
51470298 2825 };
2826 crState(do_ssh1_login_state);
2827
2828 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2829
ff3187f6 2830 if (!pktin)
2831 crWaitUntil(pktin);
374330e2 2832
ff3187f6 2833 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2834 bombout(("Public key packet not received"));
7ffdbc1a 2835 crStop(0);
8d5de777 2836 }
374330e2 2837
c5e9c988 2838 logevent("Received public keys");
374330e2 2839
ff3187f6 2840 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2841 if (!ptr) {
2842 bombout(("SSH1 public key packet stopped before random cookie"));
2843 crStop(0);
2844 }
2845 memcpy(cookie, ptr, 8);
374330e2 2846
ff3187f6 2847 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2848 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
ae0500e5 2849 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2850 crStop(0);
2851 }
374330e2 2852
c5e9c988 2853 /*
1c2a93c4 2854 * Log the host key fingerprint.
c5e9c988 2855 */
c5e9c988 2856 {
2857 char logmsg[80];
1c2a93c4 2858 logevent("Host key fingerprint is:");
c5e9c988 2859 strcpy(logmsg, " ");
32874aea 2860 hostkey.comment = NULL;
2861 rsa_fingerprint(logmsg + strlen(logmsg),
2862 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2863 logevent(logmsg);
2864 }
2865
ff3187f6 2866 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2867 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2868 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2869
51470298 2870 ssh->v1_local_protoflags =
2871 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2872 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2873
c5e9c988 2874 MD5Init(&md5c);
51470298 2875 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2876 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2877 MD5Update(&md5c, cookie, 8);
51470298 2878 MD5Final(s->session_id, &md5c);
374330e2 2879
32874aea 2880 for (i = 0; i < 32; i++)
51470298 2881 ssh->session_key[i] = random_byte();
374330e2 2882
0016d70b 2883 /*
2884 * Verify that the `bits' and `bytes' parameters match.
2885 */
2886 if (hostkey.bits > hostkey.bytes * 8 ||
2887 servkey.bits > servkey.bytes * 8) {
2888 bombout(("SSH1 public keys were badly formatted"));
2889 crStop(0);
2890 }
2891
51470298 2892 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2893
3d88e64d 2894 s->rsabuf = snewn(s->len, unsigned char);
51470298 2895 if (!s->rsabuf)
374330e2 2896 fatalbox("Out of memory");
2897
89ee5268 2898 /*
2899 * Verify the host key.
2900 */
2901 {
32874aea 2902 /*
2903 * First format the key into a string.
2904 */
2905 int len = rsastr_len(&hostkey);
2906 char fingerprint[100];
3d88e64d 2907 char *keystr = snewn(len, char);
32874aea 2908 if (!keystr)
2909 fatalbox("Out of memory");
2910 rsastr_fmt(keystr, &hostkey);
2911 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3d9449a1 2912
2913 ssh_set_frozen(ssh, 1);
2914 s->dlgret = verify_ssh_host_key(ssh->frontend,
2915 ssh->savedhost, ssh->savedport,
2916 "rsa", keystr, fingerprint,
2917 ssh_dialog_callback, ssh);
32874aea 2918 sfree(keystr);
3d9449a1 2919 if (s->dlgret < 0) {
2920 do {
2921 crReturn(0);
2922 if (pktin) {
2923 bombout(("Unexpected data from server while waiting"
2924 " for user host key response"));
2925 crStop(0);
2926 }
2927 } while (pktin || inlen > 0);
2928 s->dlgret = ssh->user_response;
2929 }
2930 ssh_set_frozen(ssh, 0);
2931
2932 if (s->dlgret == 0) {
2933 ssh->close_expected = TRUE;
2934 ssh_closing((Plug)ssh, NULL, 0, 0);
2935 }
32874aea 2936 }
2937
2938 for (i = 0; i < 32; i++) {
51470298 2939 s->rsabuf[i] = ssh->session_key[i];
374330e2 2940 if (i < 16)
51470298 2941 s->rsabuf[i] ^= s->session_id[i];
374330e2 2942 }
2943
2944 if (hostkey.bytes > servkey.bytes) {
0016d70b 2945 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2946 if (ret)
2947 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2948 } else {
0016d70b 2949 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2950 if (ret)
2951 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2952 }
2953 if (!ret) {
2954 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2955 crStop(0);
374330e2 2956 }
2957
c5e9c988 2958 logevent("Encrypted session key");
2959
ca20bfcf 2960 {
2961 int cipher_chosen = 0, warn = 0;
2962 char *cipher_string = NULL;
51470298 2963 int i;
ca20bfcf 2964 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2965 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2966 if (next_cipher == CIPHER_WARN) {
2967 /* If/when we choose a cipher, warn about it */
2968 warn = 1;
2969 } else if (next_cipher == CIPHER_AES) {
2970 /* XXX Probably don't need to mention this. */
2971 logevent("AES not supported in SSH1, skipping");
2972 } else {
2973 switch (next_cipher) {
51470298 2974 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2975 cipher_string = "3DES"; break;
51470298 2976 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2977 cipher_string = "Blowfish"; break;
51470298 2978 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2979 cipher_string = "single-DES"; break;
2980 }
51470298 2981 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2982 cipher_chosen = 1;
2983 }
2984 }
2985 if (!cipher_chosen) {
51470298 2986 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2987 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2988 "supporting 3DES encryption"));
2989 else
2990 /* shouldn't happen */
6b5cf8b4 2991 bombout(("No supported ciphers found"));
7ffdbc1a 2992 crStop(0);
a99a05c0 2993 }
ca20bfcf 2994
2995 /* Warn about chosen cipher if necessary. */
bb348ab1 2996 if (warn) {
3d9449a1 2997 ssh_set_frozen(ssh, 1);
2998 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
2999 ssh_dialog_callback, ssh);
3000 if (s->dlgret < 0) {
3001 do {
3002 crReturn(0);
3003 if (pktin) {
3004 bombout(("Unexpected data from server while waiting"
3005 " for user response"));
3006 crStop(0);
3007 }
3008 } while (pktin || inlen > 0);
3009 s->dlgret = ssh->user_response;
3010 }
3011 ssh_set_frozen(ssh, 0);
3012 if (s->dlgret == 0) {
3013 ssh->close_expected = TRUE;
3014 ssh_closing((Plug)ssh, NULL, 0, 0);
3015 }
bb348ab1 3016 }
bea1ef5f 3017 }
ca20bfcf 3018
51470298 3019 switch (s->cipher_type) {
32874aea 3020 case SSH_CIPHER_3DES:
3021 logevent("Using 3DES encryption");
3022 break;
3023 case SSH_CIPHER_DES:
3024 logevent("Using single-DES encryption");
3025 break;
3026 case SSH_CIPHER_BLOWFISH:
3027 logevent("Using Blowfish encryption");
3028 break;
c5e9c988 3029 }
bea1ef5f 3030
51470298 3031 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3032 PKT_CHAR, s->cipher_type,
32874aea 3033 PKT_DATA, cookie, 8,
51470298 3034 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3035 PKT_DATA, s->rsabuf, s->len,
3036 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 3037
c5e9c988 3038 logevent("Trying to enable encryption...");
374330e2 3039
51470298 3040 sfree(s->rsabuf);
374330e2 3041
51470298 3042 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3043 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3044 &ssh_3des);
371e569c 3045 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3046 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 3047 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 3048
0183b242 3049 ssh->crcda_ctx = crcda_make_context();
3050 logevent("Installing CRC compensation attack detector");
3051
679539d7 3052 if (servkey.modulus) {
3053 sfree(servkey.modulus);
3054 servkey.modulus = NULL;
3055 }
3056 if (servkey.exponent) {
3057 sfree(servkey.exponent);
3058 servkey.exponent = NULL;
3059 }
3060 if (hostkey.modulus) {
3061 sfree(hostkey.modulus);
3062 hostkey.modulus = NULL;
3063 }
3064 if (hostkey.exponent) {
3065 sfree(hostkey.exponent);
3066 hostkey.exponent = NULL;
3067 }
ff3187f6 3068 crWaitUntil(pktin);
374330e2 3069
ff3187f6 3070 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3071 bombout(("Encryption not successfully enabled"));
7ffdbc1a 3072 crStop(0);
8d5de777 3073 }
374330e2 3074
c5e9c988 3075 logevent("Successfully started encryption");
3076
374330e2 3077 fflush(stdout);
3078 {
aa09f7d0 3079 if (!*ssh->cfg.username) {
c0a81592 3080 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 3081 if (!ssh_get_line("login as: ",
51470298 3082 s->username, sizeof(s->username), FALSE)) {
32874aea 3083 /*
3084 * get_line failed to get a username.
3085 * Terminate.
3086 */
3087 logevent("No username provided. Abandoning session.");
ac934965 3088 ssh->close_expected = TRUE;
3bb2f322 3089 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3090 crStop(1);
32874aea 3091 }
3092 } else {
51470298 3093 int ret; /* need not be kept over crReturn */
3094 c_write_str(ssh, "login as: ");
3095 ssh->send_ok = 1;
0405e71f 3096
51470298 3097 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 3098 do {
ff3187f6 3099 crWaitUntil(!pktin);
51470298 3100 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3101 } while (ret == 0);
3102 if (ret < 0)
3103 cleanup_exit(0);
51470298 3104 c_write_str(ssh, "\r\n");
32874aea 3105 }
3106 } else {
86916870 3107 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 3108 s->username[sizeof(s->username)-1] = '\0';
374330e2 3109 }
fb09bf1c 3110
51470298 3111 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 3112 {
51470298 3113 char userlog[22 + sizeof(s->username)];
3114 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 3115 logevent(userlog);
32874aea 3116 if (flags & FLAG_INTERACTIVE &&
3117 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 3118 strcat(userlog, "\r\n");
51470298 3119 c_write_str(ssh, userlog);
3c8e959b 3120 }
c5e9c988 3121 }
374330e2 3122 }
3123
ff3187f6 3124 crWaitUntil(pktin);
374330e2 3125
51470298 3126 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 3127 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 3128 s->tried_publickey = s->tried_agent = 1;
0df73905 3129 } else {
51470298 3130 s->tried_publickey = s->tried_agent = 0;
0df73905 3131 }
51470298 3132 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 3133 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 3134 if (!filename_is_null(ssh->cfg.keyfile)) {
3135 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 3136 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 3137 s->publickey_blob = NULL;
396778f1 3138 } else
51470298 3139 s->publickey_blob = NULL;
7cca0d81 3140
ff3187f6 3141 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3142 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 3143
51470298 3144 if (agent_exists() && !s->tried_agent) {
32874aea 3145 /*
3146 * Attempt RSA authentication using Pageant.
3147 */
32874aea 3148 void *r;
3149
51470298 3150 s->authed = FALSE;
3151 s->tried_agent = 1;
32874aea 3152 logevent("Pageant is running. Requesting keys.");
3153
3154 /* Request the keys held by the agent. */
51470298 3155 PUT_32BIT(s->request, 1);
3156 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 3157 if (!agent_query(s->request, 5, &r, &s->responselen,
3158 ssh_agent_callback, ssh)) {
3159 do {
3160 crReturn(0);
ff3187f6 3161 if (pktin) {
839f10db 3162 bombout(("Unexpected data from server while waiting"
3163 " for agent response"));
3164 crStop(0);
3165 }
ff3187f6 3166 } while (pktin || inlen > 0);
839f10db 3167 r = ssh->agent_response;
3168 s->responselen = ssh->agent_response_len;
3169 }
51470298 3170 s->response = (unsigned char *) r;
3171 if (s->response && s->responselen >= 5 &&
3172 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3173 s->p = s->response + 5;
3174 s->nkeys = GET_32BIT(s->p);
3175 s->p += 4;
fb983202 3176 logeventf(ssh, "Pageant has %d SSH1 keys", s->nkeys);
51470298 3177 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
fb983202 3178 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
51470298 3179 if (s->publickey_blob &&
3180 !memcmp(s->p, s->publickey_blob,
3181 s->publickey_bloblen)) {
396778f1 3182 logevent("This key matches configured key file");
51470298 3183 s->tried_publickey = 1;
396778f1 3184 }
51470298 3185 s->p += 4;
0016d70b 3186 {
3187 int n, ok = FALSE;
3188 do { /* do while (0) to make breaking easy */
3189 n = ssh1_read_bignum
3190 (s->p, s->responselen-(s->p-s->response),
3191 &s->key.exponent);
3192 if (n < 0)
3193 break;
3194 s->p += n;
3195 n = ssh1_read_bignum
3196 (s->p, s->responselen-(s->p-s->response),
3197 &s->key.modulus);
3198 if (n < 0)
3199 break;
3200 s->p += n;
3201 if (s->responselen - (s->p-s->response) < 4)
3202 break;
3203 s->commentlen = GET_32BIT(s->p);
3204 s->p += 4;
3205 if (s->responselen - (s->p-s->response) <
3206 s->commentlen)
3207 break;
3208 s->commentp = (char *)s->p;
3209 s->p += s->commentlen;
3210 ok = TRUE;
3211 } while (0);
3212 if (!ok) {
3213 logevent("Pageant key list packet was truncated");
3214 break;
3215 }
3216 }
51470298 3217 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3218 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3219 crWaitUntil(pktin);
3220 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3221 logevent("Key refused");
3222 continue;
3223 }
3224 logevent("Received RSA challenge");
ff3187f6 3225 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3226 bombout(("Server's RSA challenge was badly formatted"));
3227 crStop(0);
3228 }
3229
32874aea 3230 {
3231 char *agentreq, *q, *ret;
2d466ffd 3232 void *vret;
32874aea 3233 int len, retlen;
3234 len = 1 + 4; /* message type, bit count */
51470298 3235 len += ssh1_bignum_length(s->key.exponent);
3236 len += ssh1_bignum_length(s->key.modulus);
3237 len += ssh1_bignum_length(s->challenge);
32874aea 3238 len += 16; /* session id */
3239 len += 4; /* response format */
3d88e64d 3240 agentreq = snewn(4 + len, char);
32874aea 3241 PUT_32BIT(agentreq, len);
3242 q = agentreq + 4;
3243 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3244 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3245 q += 4;
51470298 3246 q += ssh1_write_bignum(q, s->key.exponent);
3247 q += ssh1_write_bignum(q, s->key.modulus);
3248 q += ssh1_write_bignum(q, s->challenge);
3249 memcpy(q, s->session_id, 16);
32874aea 3250 q += 16;
3251 PUT_32BIT(q, 1); /* response format */
839f10db 3252 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3253 ssh_agent_callback, ssh)) {
3254 sfree(agentreq);
3255 do {
3256 crReturn(0);
ff3187f6 3257 if (pktin) {
839f10db 3258 bombout(("Unexpected data from server"
3259 " while waiting for agent"
3260 " response"));
3261 crStop(0);
3262 }
ff3187f6 3263 } while (pktin || inlen > 0);
839f10db 3264 vret = ssh->agent_response;
3265 retlen = ssh->agent_response_len;
3266 } else
3267 sfree(agentreq);
2d466ffd 3268 ret = vret;
32874aea 3269 if (ret) {
3270 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3271 logevent("Sending Pageant's response");
51470298 3272 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3273 PKT_DATA, ret + 5, 16,
3274 PKT_END);
3275 sfree(ret);
ff3187f6 3276 crWaitUntil(pktin);
3277 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3278 logevent
3279 ("Pageant's response accepted");
3280 if (flags & FLAG_VERBOSE) {
51470298 3281 c_write_str(ssh, "Authenticated using"
3282 " RSA key \"");
3283 c_write(ssh, s->commentp,
3284 s->commentlen);
3285 c_write_str(ssh, "\" from agent\r\n");
32874aea 3286 }
51470298 3287 s->authed = TRUE;
32874aea 3288 } else
3289 logevent
3290 ("Pageant's response not accepted");
3291 } else {
3292 logevent
3293 ("Pageant failed to answer challenge");
3294 sfree(ret);
3295 }
3296 } else {
3297 logevent("No reply received from Pageant");
3298 }
3299 }
51470298 3300 freebn(s->key.exponent);
3301 freebn(s->key.modulus);
3302 freebn(s->challenge);
3303 if (s->authed)
32874aea 3304 break;
3305 }
29b1d0b3 3306 sfree(s->response);
32874aea 3307 }
51470298 3308 if (s->authed)
32874aea 3309 break;
3310 }
9a30e26b 3311 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3312 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3313
86916870 3314 if (ssh->cfg.try_tis_auth &&
51470298 3315 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3316 !s->tis_auth_refused) {
3317 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3318 logevent("Requested TIS authentication");
51470298 3319 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3320 crWaitUntil(pktin);
3321 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3322 logevent("TIS authentication declined");
3323 if (flags & FLAG_INTERACTIVE)
51470298 3324 c_write_str(ssh, "TIS authentication refused.\r\n");
3325 s->tis_auth_refused = 1;
614a20a0 3326 continue;
32874aea 3327 } else {
0016d70b 3328 char *challenge;
3329 int challengelen;
3330
ff3187f6 3331 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3332 if (!challenge) {
3333 bombout(("TIS challenge packet was badly formed"));
3334 crStop(0);
3335 }
32874aea 3336 logevent("Received TIS challenge");
51470298 3337 if (challengelen > sizeof(s->prompt) - 1)
3338 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3339 memcpy(s->prompt, challenge, challengelen);
614a20a0 3340 /* Prompt heuristic comes from OpenSSH */
51470298 3341 strncpy(s->prompt + challengelen,
3342 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3343 "": "\r\nResponse: ",
51470298 3344 (sizeof s->prompt) - challengelen);
3345 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3346 }
3347 }
86916870 3348 if (ssh->cfg.try_tis_auth &&
51470298 3349 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3350 !s->ccard_auth_refused) {
3351 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3352 logevent("Requested CryptoCard authentication");
51470298 3353 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3354 crWaitUntil(pktin);
3355 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3356 logevent("CryptoCard authentication declined");
51470298 3357 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3358 s->ccard_auth_refused = 1;
614a20a0 3359 continue;
32874aea 3360 } else {
0016d70b 3361 char *challenge;
3362 int challengelen;
3363
ff3187f6 3364 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3365 if (!challenge) {
3366 bombout(("CryptoCard challenge packet was badly formed"));
3367 crStop(0);
3368 }
32874aea 3369 logevent("Received CryptoCard challenge");
51470298 3370 if (challengelen > sizeof(s->prompt) - 1)
3371 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3372 memcpy(s->prompt, challenge, challengelen);
51470298 3373 strncpy(s->prompt + challengelen,
3374 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3375 "" : "\r\nResponse: ",
51470298 3376 sizeof(s->prompt) - challengelen);
3377 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3378 }
3379 }
51470298 3380 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3381 sprintf(s->prompt, "%.90s@%.90s's password: ",
3382 s->username, ssh->savedhost);
32874aea 3383 }
51470298 3384 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3385 char *comment = NULL;
231ee168 3386 int type;
32874aea 3387 if (flags & FLAG_VERBOSE)
51470298 3388 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3389 logeventf(ssh, "Trying public key \"%s\"",
3390 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3391 type = key_type(&ssh->cfg.keyfile);
231ee168 3392 if (type != SSH_KEYTYPE_SSH1) {
fb983202 3393 char *msg = dupprintf("Key is of wrong type (%s)",
3394 key_type_to_str(type));
3395 logevent(msg);
3396 c_write_str(ssh, msg);
51470298 3397 c_write_str(ssh, "\r\n");
fb983202 3398 sfree(msg);
51470298 3399 s->tried_publickey = 1;
231ee168 3400 continue;
3401 }
9a30e26b 3402 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3403 if (flags & FLAG_VERBOSE)
51470298 3404 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3405 goto tryauth;
3406 }
51470298 3407 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3408 sfree(comment);
3409 }
a52f067e 3410
614a20a0 3411 /*
3412 * Show password prompt, having first obtained it via a TIS
3413 * or CryptoCard exchange if we're doing TIS or CryptoCard
3414 * authentication.
3415 */
fa17a66e 3416 if (ssh_get_line) {
51470298 3417 if (!ssh_get_line(s->prompt, s->password,
3418 sizeof(s->password), TRUE)) {
32874aea 3419 /*
3420 * get_line failed to get a password (for example
3421 * because one was supplied on the command line
3422 * which has already failed to work). Terminate.
3423 */
51470298 3424 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3425 PKT_STR, "No more passwords available to try",
3426 PKT_END);
247308b5 3427 logevent("Unable to authenticate");
a8327734 3428 connection_fatal(ssh->frontend, "Unable to authenticate");
ac934965 3429 ssh->close_expected = TRUE;
3bb2f322 3430 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3431 crStop(1);
32874aea 3432 }
fb09bf1c 3433 } else {
614a20a0 3434 /* Prompt may have come from server. We've munged it a bit, so
3435 * we know it to be zero-terminated at least once. */
51470298 3436 int ret; /* need not be saved over crReturn */
3437 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3438 s->pos = 0;
0405e71f 3439
51470298 3440 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3441 do {
ff3187f6 3442 crWaitUntil(!pktin);
51470298 3443 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3444 } while (ret == 0);
3445 if (ret < 0)
3446 cleanup_exit(0);
51470298 3447 c_write_str(ssh, "\r\n");
32874aea 3448 }
3449
3450 tryauth:
51470298 3451 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3452 /*
3453 * Try public key authentication with the specified
3454 * key file.
3455 */
51470298 3456 s->tried_publickey = 1;
3457
3458 {
222d54dc 3459 const char *error = NULL;
3460 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3461 &error);
51470298 3462 if (ret == 0) {
3463 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3464 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3465 c_write_str(ssh, " (");
3466 c_write_str(ssh, error);
3467 c_write_str(ssh, ").\r\n");
51470298 3468 continue; /* go and try password */
3469 }
3470 if (ret == -1) {
3471 c_write_str(ssh, "Wrong passphrase.\r\n");
3472 s->tried_publickey = 0;
3473 continue; /* try again */
3474 }
32874aea 3475 }
3476
3477 /*
3478 * Send a public key attempt.
3479 */
51470298 3480 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3481 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3482
ff3187f6 3483 crWaitUntil(pktin);
3484 if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3485 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3486 continue; /* go and try password */
3487 }
ff3187f6 3488 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3489 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3490 crStop(0);
32874aea 3491 }
32874aea 3492
51470298 3493 {
3494 int i;
3495 unsigned char buffer[32];
3496 Bignum challenge, response;
3497
ff3187f6 3498 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3499 bombout(("Server's RSA challenge was badly formatted"));
3500 crStop(0);
3501 }
51470298 3502 response = rsadecrypt(challenge, &s->key);
3503 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3504
51470298 3505 for (i = 0; i < 32; i++) {
3506 buffer[i] = bignum_byte(response, 31 - i);
3507 }
3508
3509 MD5Init(&md5c);
3510 MD5Update(&md5c, buffer, 32);
3511 MD5Update(&md5c, s->session_id, 16);
3512 MD5Final(buffer, &md5c);
32874aea 3513
51470298 3514 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3515 PKT_DATA, buffer, 16, PKT_END);
3516
3517 freebn(challenge);
3518 freebn(response);
3519 }
32874aea 3520
ff3187f6 3521 crWaitUntil(pktin);
3522 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3523 if (flags & FLAG_VERBOSE)
51470298 3524 c_write_str(ssh, "Failed to authenticate with"
3525 " our public key.\r\n");
32874aea 3526 continue; /* go and try password */
ff3187f6 3527 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3528 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3529 crStop(0);
32874aea 3530 }
3531
3532 break; /* we're through! */
3533 } else {
51470298 3534 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3535 /*
3536 * Defence against traffic analysis: we send a
3537 * whole bunch of packets containing strings of
3538 * different lengths. One of these strings is the
3539 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3540 * The others are all random data in
3541 * SSH1_MSG_IGNORE packets. This way a passive
3542 * listener can't tell which is the password, and
3543 * hence can't deduce the password length.
3544 *
3545 * Anybody with a password length greater than 16
3546 * bytes is going to have enough entropy in their
3547 * password that a listener won't find it _that_
3548 * much help to know how long it is. So what we'll
3549 * do is:
3550 *
3551 * - if password length < 16, we send 15 packets
3552 * containing string lengths 1 through 15
3553 *
3554 * - otherwise, we let N be the nearest multiple
3555 * of 8 below the password length, and send 8
3556 * packets containing string lengths N through
3557 * N+7. This won't obscure the order of
3558 * magnitude of the password length, but it will
3559 * introduce a bit of extra uncertainty.
3560 *
3561 * A few servers (the old 1.2.18 through 1.2.22)
3562 * can't deal with SSH1_MSG_IGNORE. For these
3563 * servers, we need an alternative defence. We make
3564 * use of the fact that the password is interpreted
3565 * as a C string: so we can append a NUL, then some
3566 * random data.
bd358db1 3567 *
3568 * One server (a Cisco one) can deal with neither
3569 * SSH1_MSG_IGNORE _nor_ a padded password string.
3570 * For this server we are left with no defences
3571 * against password length sniffing.
32874aea 3572 */
51470298 3573 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3574 /*
3575 * The server can deal with SSH1_MSG_IGNORE, so
3576 * we can use the primary defence.
3577 */
32874aea 3578 int bottom, top, pwlen, i;
3579 char *randomstr;
3580
51470298 3581 pwlen = strlen(s->password);
32874aea 3582 if (pwlen < 16) {
3583 bottom = 0; /* zero length passwords are OK! :-) */
3584 top = 15;
3585 } else {
3586 bottom = pwlen & ~7;
3587 top = bottom + 7;
3588 }
3589
3590 assert(pwlen >= bottom && pwlen <= top);
3591
3d88e64d 3592 randomstr = snewn(top + 1, char);
32874aea 3593
3594 for (i = bottom; i <= top; i++) {
9a10ecf4 3595 if (i == pwlen) {
51470298 3596 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3597 PKTT_PASSWORD, PKT_STR, s->password,
3598 PKTT_OTHER, PKT_END);
3599 } else {
32874aea 3600 for (j = 0; j < i; j++) {
3601 do {
3602 randomstr[j] = random_byte();
3603 } while (randomstr[j] == '\0');
3604 }
3605 randomstr[i] = '\0';
51470298 3606 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3607 PKT_STR, randomstr, PKT_END);
3608 }
3609 }
bd358db1 3610 logevent("Sending password with camouflage packets");
51470298 3611 ssh_pkt_defersend(ssh);
679539d7 3612 sfree(randomstr);
bd358db1 3613 }
51470298 3614 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3615 /*
3616 * The server can't deal with SSH1_MSG_IGNORE
3617 * but can deal with padded passwords, so we
3618 * can use the secondary defence.
3619 */
bd358db1 3620 char string[64];
51470298 3621 char *ss;
bd358db1 3622 int len;
3623
51470298 3624 len = strlen(s->password);
bd358db1 3625 if (len < sizeof(string)) {
51470298 3626 ss = string;
3627 strcpy(string, s->password);
bd358db1 3628 len++; /* cover the zero byte */
3629 while (len < sizeof(string)) {
3630 string[len++] = (char) random_byte();
3631 }
3632 } else {
51470298 3633 ss = s->password;
bd358db1 3634 }
3635 logevent("Sending length-padded password");
9a10ecf4 3636 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3637 PKT_INT, len, PKT_DATA, ss, len,
3638 PKTT_OTHER, PKT_END);
bd358db1 3639 } else {
3640 /*
3641 * The server has _both_
3642 * BUG_CHOKES_ON_SSH1_IGNORE and
3643 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3644 * therefore nothing we can do.
3645 */
3646 int len;
51470298 3647 len = strlen(s->password);
bd358db1 3648 logevent("Sending unpadded password");
9a10ecf4 3649 send_packet(ssh, s->pwpkt_type,
3650 PKTT_PASSWORD, PKT_INT, len,
3651 PKT_DATA, s->password, len,
3652 PKTT_OTHER, PKT_END);
32874aea 3653 }
3654 } else {
9a10ecf4 3655 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3656 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3657 }
3658 }
c5e9c988 3659 logevent("Sent password");
51470298 3660 memset(s->password, 0, strlen(s->password));
ff3187f6 3661 crWaitUntil(pktin);
3662 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3663 if (flags & FLAG_VERBOSE)
51470298 3664 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3665 logevent("Authentication refused");
ff3187f6 3666 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3667 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3668 crStop(0);
374330e2 3669 }
3670 }
3671
c5e9c988 3672 logevent("Authentication successful");
3673
fb09bf1c 3674 crFinish(1);
3675}
3676
32874aea 3677void sshfwd_close(struct ssh_channel *c)
3678{
51470298 3679 Ssh ssh = c->ssh;
3680
36f94d1f 3681 if (ssh->state != SSH_STATE_SESSION) {
3682 assert(ssh->state == SSH_STATE_CLOSED);
3683 return;
3684 }
3685
80e48603 3686 if (c && !c->closes) {
4ed34d25 3687 /*
64d6ff88 3688 * If halfopen is true, we have sent
4ed34d25 3689 * CHANNEL_OPEN for this channel, but it hasn't even been
3690 * acknowledged by the server. So we must set a close flag
3691 * on it now, and then when the server acks the channel
3692 * open, we can close it then.
3693 */
64d6ff88 3694 if (!c->halfopen) {
51470298 3695 if (ssh->version == 1) {
3696 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3697 PKT_END);
3698 } else {
ff3187f6 3699 struct Packet *pktout;
3700 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3701 ssh2_pkt_adduint32(pktout, c->remoteid);
3702 ssh2_pkt_send(ssh, pktout);
4ed34d25 3703 }
32874aea 3704 }
0357890f 3705 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3706 if (c->type == CHAN_X11) {
3707 c->u.x11.s = NULL;
d74d141c 3708 logevent("Forwarded X11 connection terminated");
4ed34d25 3709 } else if (c->type == CHAN_SOCKDATA ||
3710 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3711 c->u.pfd.s = NULL;
3712 logevent("Forwarded port closed");
32874aea 3713 }
3714 }
3715}
3716
5471d09a 3717int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3718{
51470298 3719 Ssh ssh = c->ssh;
3720
36f94d1f 3721 if (ssh->state != SSH_STATE_SESSION) {
3722 assert(ssh->state == SSH_STATE_CLOSED);
3723 return 0;
3724 }
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
36f94d1f 3750 if (ssh->state != SSH_STATE_SESSION) {
3751 assert(ssh->state == SSH_STATE_CLOSED);
3752 return;
3753 }
3754
51470298 3755 if (ssh->version == 1) {
5471d09a 3756 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3757 c->v.v1.throttling = 0;
51470298 3758 ssh1_throttle(ssh, -1);
5471d09a 3759 }
3760 } else {
3761 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3762 }
9c964e85 3763}
3764
06fadff5 3765static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3766{
3767 struct queued_handler *qh = ssh->qhead;
3768
3769 assert(qh != NULL);
3770
3771 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3772
3773 if (qh->msg1 > 0) {
3774 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3775 ssh->packet_dispatch[qh->msg1] = NULL;
3776 }
3777 if (qh->msg2 > 0) {
3778 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3779 ssh->packet_dispatch[qh->msg2] = NULL;
3780 }
3781
3782 if (qh->next) {
3783 ssh->qhead = qh->next;
3784
3785 if (ssh->qhead->msg1 > 0) {
3786 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3787 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3788 }
3789 if (ssh->qhead->msg2 > 0) {
3790 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3791 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3792 }
3793 } else {
3794 ssh->qhead = ssh->qtail = NULL;
3795 ssh->packet_dispatch[pktin->type] = NULL;
3796 }
3797
3798 qh->handler(ssh, pktin, qh->ctx);
3799
3800 sfree(qh);
3801}
3802
3803static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3804 chandler_fn_t handler, void *ctx)
3805{
3806 struct queued_handler *qh;
3807
3808 qh = snew(struct queued_handler);
3809 qh->msg1 = msg1;
3810 qh->msg2 = msg2;
3811 qh->handler = handler;
3812 qh->ctx = ctx;
3813 qh->next = NULL;
3814
3815 if (ssh->qtail == NULL) {
3816 ssh->qhead = qh;
3817
3818 if (qh->msg1 > 0) {
3819 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3820 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3821 }
3822 if (qh->msg2 > 0) {
3823 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3824 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3825 }
3826 } else {
3827 ssh->qtail->next = qh;
3828 }
3829 ssh->qtail = qh;
3830}
3831
3832static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3833{
3834 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3835
3836 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3837 SSH2_MSG_REQUEST_SUCCESS)) {
3838 logeventf(ssh, "Remote port forwarding from %s enabled",
3839 pf->sportdesc);
3840 } else {
3841 logeventf(ssh, "Remote port forwarding from %s refused",
3842 pf->sportdesc);
3843
3844 rpf = del234(ssh->rportfwds, pf);
3845 assert(rpf == pf);
fda2feb1 3846 free_rportfwd(pf);
06fadff5 3847 }
3848}
3849
3850static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3851{
84328ddb 3852 const char *portfwd_strptr = cfg->portfwd;
3853 struct ssh_portfwd *epf;
3854 int i;
06fadff5 3855
fda2feb1 3856 if (!ssh->portfwds) {
3857 ssh->portfwds = newtree234(ssh_portcmp);
3858 } else {
3859 /*
3860 * Go through the existing port forwardings and tag them
84328ddb 3861 * with status==DESTROY. Any that we want to keep will be
3862 * re-enabled (status==KEEP) as we go through the
3863 * configuration and find out which bits are the same as
3864 * they were before.
fda2feb1 3865 */
3866 struct ssh_portfwd *epf;
3867 int i;
3868 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 3869 epf->status = DESTROY;
fda2feb1 3870 }
3871
06fadff5 3872 while (*portfwd_strptr) {
84328ddb 3873 char address_family, type;
3874 int sport,dport,sserv,dserv;
3875 char sports[256], dports[256], saddr[256], host[256];
3876 int n;
3877
05581745 3878 address_family = 'A';
3879 type = 'L';
84328ddb 3880 if (*portfwd_strptr == 'A' ||
3881 *portfwd_strptr == '4' ||
3882 *portfwd_strptr == '6')
3883 address_family = *portfwd_strptr++;
3884 if (*portfwd_strptr == 'L' ||
3885 *portfwd_strptr == 'R' ||
3886 *portfwd_strptr == 'D')
3887 type = *portfwd_strptr++;
05581745 3888
06fadff5 3889 saddr[0] = '\0';
05581745 3890
06fadff5 3891 n = 0;
3892 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3893 if (*portfwd_strptr == ':') {
3894 /*
3895 * We've seen a colon in the middle of the
3896 * source port number. This means that
3897 * everything we've seen until now is the
3898 * source _address_, so we'll move it into
3899 * saddr and start sports from the beginning
3900 * again.
3901 */
3902 portfwd_strptr++;
3903 sports[n] = '\0';
3904 if (ssh->version == 1 && type == 'R') {
3905 logeventf(ssh, "SSH1 cannot handle remote source address "
3906 "spec \"%s\"; ignoring", sports);
3907 } else
3908 strcpy(saddr, sports);
3909 n = 0;
3910 }
3911 if (n < 255) sports[n++] = *portfwd_strptr++;
3912 }
3913 sports[n] = 0;
3914 if (type != 'D') {
3915 if (*portfwd_strptr == '\t')
3916 portfwd_strptr++;
3917 n = 0;
3918 while (*portfwd_strptr && *portfwd_strptr != ':') {
3919 if (n < 255) host[n++] = *portfwd_strptr++;
3920 }
3921 host[n] = 0;
3922 if (*portfwd_strptr == ':')
3923 portfwd_strptr++;
3924 n = 0;
3925 while (*portfwd_strptr) {
3926 if (n < 255) dports[n++] = *portfwd_strptr++;
3927 }
3928 dports[n] = 0;
3929 portfwd_strptr++;
3930 dport = atoi(dports);
3931 dserv = 0;
3932 if (dport == 0) {
3933 dserv = 1;
3934 dport = net_service_lookup(dports);
3935 if (!dport) {
3936 logeventf(ssh, "Service lookup failed for destination"
3937 " port \"%s\"", dports);
3938 }
3939 }
3940 } else {
3941 while (*portfwd_strptr) portfwd_strptr++;
a9e72926 3942 host[0] = 0;
3943 dports[0] = 0;
06fadff5 3944 dport = dserv = -1;
3945 portfwd_strptr++; /* eat the NUL and move to next one */
3946 }
3947 sport = atoi(sports);
3948 sserv = 0;
3949 if (sport == 0) {
3950 sserv = 1;
3951 sport = net_service_lookup(sports);
3952 if (!sport) {
3953 logeventf(ssh, "Service lookup failed for source"
3954 " port \"%s\"", sports);
3955 }
3956 }
3957 if (sport && dport) {
3958 /* Set up a description of the source port. */
fda2feb1 3959 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 3960
3961 pfrec = snew(struct ssh_portfwd);
3962 pfrec->type = type;
3963 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3fe92132 3964 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 3965 pfrec->sport = sport;
84328ddb 3966 pfrec->daddr = *host ? dupstr(host) : NULL;
3fe92132 3967 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 3968 pfrec->dport = dport;
3969 pfrec->local = NULL;
3970 pfrec->remote = NULL;
05581745 3971 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3972 address_family == '6' ? ADDRTYPE_IPV6 :
3973 ADDRTYPE_UNSPEC);
fda2feb1 3974
3975 epfrec = add234(ssh->portfwds, pfrec);
3976 if (epfrec != pfrec) {
3977 /*
3978 * We already have a port forwarding with precisely
3979 * these parameters. Hence, no need to do anything;
84328ddb 3980 * simply tag the existing one as KEEP.
fda2feb1 3981 */
84328ddb 3982 epfrec->status = KEEP;
fda2feb1 3983 free_portfwd(pfrec);
84328ddb 3984 } else {
3985 pfrec->status = CREATE;
3986 }
3987 }
3988 }
3989
3990 /*
3991 * Now go through and destroy any port forwardings which were
3992 * not re-enabled.
3993 */
3994 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3995 if (epf->status == DESTROY) {
3996 char *message;
3997
3998 message = dupprintf("%s port forwarding from %s%s%d",
3999 epf->type == 'L' ? "local" :
4000 epf->type == 'R' ? "remote" : "dynamic",
4001 epf->saddr ? epf->saddr : "",
4002 epf->saddr ? ":" : "",
4003 epf->sport);
4004
4005 if (epf->type != 'D') {
4006 char *msg2 = dupprintf("%s to %s:%d", message,
4007 epf->daddr, epf->dport);
4008 sfree(message);
4009 message = msg2;
4010 }
4011
4012 logeventf(ssh, "Cancelling %s", message);
4013 sfree(message);
4014
4015 if (epf->remote) {
4016 struct ssh_rportfwd *rpf = epf->remote;
4017 struct Packet *pktout;
4018
4019 /*
4020 * Cancel the port forwarding at the server
4021 * end.
4022 */
4023 if (ssh->version == 1) {
4024 /*
4025 * We cannot cancel listening ports on the
4026 * server side in SSH1! There's no message
4027 * to support it. Instead, we simply remove
4028 * the rportfwd record from the local end
4029 * so that any connections the server tries
4030 * to make on it are rejected.
4031 */
4032 } else {
4033 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4034 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4035 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4036 if (epf->saddr) {
4037 ssh2_pkt_addstring(pktout, epf->saddr);
4038 } else if (ssh->cfg.rport_acceptall) {
5188540b 4039 /* XXX: ssh->cfg.rport_acceptall may not represent
4040 * what was used to open the original connection,
4041 * since it's reconfigurable. */
84328ddb 4042 ssh2_pkt_addstring(pktout, "0.0.0.0");
4043 } else {
4044 ssh2_pkt_addstring(pktout, "127.0.0.1");
4045 }
4046 ssh2_pkt_adduint32(pktout, epf->sport);
4047 ssh2_pkt_send(ssh, pktout);
4048 }
4049
4050 del234(ssh->rportfwds, rpf);
4051 free_rportfwd(rpf);
4052 } else if (epf->local) {
4053 pfd_terminate(epf->local);
4054 }
4055
4056 delpos234(ssh->portfwds, i);
4057 free_portfwd(epf);
4058 i--; /* so we don't skip one in the list */
4059 }
4060
4061 /*
4062 * And finally, set up any new port forwardings (status==CREATE).
4063 */
4064 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4065 if (epf->status == CREATE) {
4066 char *sportdesc, *dportdesc;
3fe92132 4067 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 4068 epf->saddr ? epf->saddr : "",
4069 epf->saddr ? ":" : "",
3fe92132 4070 epf->sserv ? epf->sserv : "",
4071 epf->sserv ? "(" : "",
4072 epf->sport,
4073 epf->sserv ? ")" : "");
84328ddb 4074 if (epf->type == 'D') {
4075 dportdesc = NULL;
4076 } else {
3fe92132 4077 dportdesc = dupprintf("%s:%s%s%d%s",
4078 epf->daddr,
4079 epf->dserv ? epf->dserv : "",
4080 epf->dserv ? "(" : "",
4081 epf->dport,
4082 epf->dserv ? ")" : "");
84328ddb 4083 }
05581745 4084
84328ddb 4085 if (epf->type == 'L') {
4086 const char *err = pfd_addforward(epf->daddr, epf->dport,
4087 epf->saddr, epf->sport,
5188540b 4088 ssh, cfg,
84328ddb 4089 &epf->local,
4090 epf->addressfamily);
4091
4092 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4093 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4094 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4095 sportdesc, dportdesc,
4096 err ? " failed: " : "", err ? err : "");
4097 } else if (epf->type == 'D') {
06fadff5 4098 const char *err = pfd_addforward(NULL, -1,
84328ddb 4099 epf->saddr, epf->sport,
5188540b 4100 ssh, cfg,
84328ddb 4101 &epf->local,
4102 epf->addressfamily);
4103
4104 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4105 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4106 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4107 sportdesc,
4108 err ? " failed: " : "", err ? err : "");
06fadff5 4109 } else {
4110 struct ssh_rportfwd *pf;
4111
4112 /*
4113 * Ensure the remote port forwardings tree exists.
4114 */
4115 if (!ssh->rportfwds) {
4116 if (ssh->version == 1)
4117 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4118 else
4119 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4120 }
4121
4122 pf = snew(struct ssh_rportfwd);
84328ddb 4123 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4124 pf->dhost[lenof(pf->dhost)-1] = '\0';
4125 pf->dport = epf->dport;
4126 pf->sport = epf->sport;
06fadff5 4127 if (add234(ssh->rportfwds, pf) != pf) {
4128 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 4129 epf->daddr, epf->dport);
06fadff5 4130 sfree(pf);
4131 } else {
4132 logeventf(ssh, "Requesting remote port %s"
84328ddb 4133 " forward to %s", sportdesc, dportdesc);
06fadff5 4134
4135 pf->sportdesc = sportdesc;
4136 sportdesc = NULL;
84328ddb 4137 epf->remote = pf;
4138 pf->pfrec = epf;
06fadff5 4139
4140 if (ssh->version == 1) {
4141 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 4142 PKT_INT, epf->sport,
4143 PKT_STR, epf->daddr,
4144 PKT_INT, epf->dport,
06fadff5 4145 PKT_END);
4146 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4147 SSH1_SMSG_FAILURE,
4148 ssh_rportfwd_succfail, pf);
4149 } else {
4150 struct Packet *pktout;
4151 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4152 ssh2_pkt_addstring(pktout, "tcpip-forward");
4153 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 4154 if (epf->saddr) {
4155 ssh2_pkt_addstring(pktout, epf->saddr);
5188540b 4156 } else if (cfg->rport_acceptall) {
06fadff5 4157 ssh2_pkt_addstring(pktout, "0.0.0.0");
4158 } else {
4159 ssh2_pkt_addstring(pktout, "127.0.0.1");
4160 }
84328ddb 4161 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 4162 ssh2_pkt_send(ssh, pktout);
4163
4164 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4165 SSH2_MSG_REQUEST_FAILURE,
4166 ssh_rportfwd_succfail, pf);
4167 }
4168 }
4169 }
4170 sfree(sportdesc);
84328ddb 4171 sfree(dportdesc);
06fadff5 4172 }
06fadff5 4173}
4174
51df0ab5 4175static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4176{
4177 char *string;
4178 int stringlen, bufsize;
4179
4180 ssh_pkt_getstring(pktin, &string, &stringlen);
4181 if (string == NULL) {
4182 bombout(("Incoming terminal data packet was badly formed"));
4183 return;
4184 }
4185
4186 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4187 string, stringlen);
4188 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4189 ssh->v1_stdout_throttling = 1;
4190 ssh1_throttle(ssh, +1);
4191 }
4192}
4193
4194static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4195{
4196 /* Remote side is trying to open a channel to talk to our
4197 * X-Server. Give them back a local channel number. */
4198 struct ssh_channel *c;
4199 int remoteid = ssh_pkt_getuint32(pktin);
4200
4201 logevent("Received X11 connect request");
4202 /* Refuse if X11 forwarding is disabled. */
4203 if (!ssh->X11_fwd_enabled) {
4204 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4205 PKT_INT, remoteid, PKT_END);
4206 logevent("Rejected X11 connect request");
4207 } else {
4208 c = snew(struct ssh_channel);
4209 c->ssh = ssh;
4210
4211 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4212 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4213 logevent("Opening X11 forward connection failed");
4214 sfree(c);
4215 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4216 PKT_INT, remoteid, PKT_END);
4217 } else {
4218 logevent
4219 ("Opening X11 forward connection succeeded");
4220 c->remoteid = remoteid;
64d6ff88 4221 c->halfopen = FALSE;
51df0ab5 4222 c->localid = alloc_channel_id(ssh);
4223 c->closes = 0;
4224 c->v.v1.throttling = 0;
4225 c->type = CHAN_X11; /* identify channel type */
4226 add234(ssh->channels, c);
4227 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4228 PKT_INT, c->remoteid, PKT_INT,
4229 c->localid, PKT_END);
4230 logevent("Opened X11 forward channel");
4231 }
4232 }
4233}
4234
4235static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4236{
4237 /* Remote side is trying to open a channel to talk to our
4238 * agent. Give them back a local channel number. */
4239 struct ssh_channel *c;
4240 int remoteid = ssh_pkt_getuint32(pktin);
4241
4242 /* Refuse if agent forwarding is disabled. */
4243 if (!ssh->agentfwd_enabled) {
4244 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4245 PKT_INT, remoteid, PKT_END);
4246 } else {
4247 c = snew(struct ssh_channel);
4248 c->ssh = ssh;
4249 c->remoteid = remoteid;
64d6ff88 4250 c->halfopen = FALSE;
51df0ab5 4251 c->localid = alloc_channel_id(ssh);
4252 c->closes = 0;
4253 c->v.v1.throttling = 0;
4254 c->type = CHAN_AGENT; /* identify channel type */
4255 c->u.a.lensofar = 0;
4256 add234(ssh->channels, c);
4257 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4258 PKT_INT, c->remoteid, PKT_INT, c->localid,
4259 PKT_END);
4260 }
4261}
4262
4263static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4264{
4265 /* Remote side is trying to open a channel to talk to a
4266 * forwarded port. Give them back a local channel number. */
4267 struct ssh_channel *c;
05581745 4268 struct ssh_rportfwd pf, *pfp;
51df0ab5 4269 int remoteid;
4270 int hostsize, port;
fb983202 4271 char *host;
51df0ab5 4272 const char *e;
4273 c = snew(struct ssh_channel);
4274 c->ssh = ssh;
4275
4276 remoteid = ssh_pkt_getuint32(pktin);
4277 ssh_pkt_getstring(pktin, &host, &hostsize);
4278 port = ssh_pkt_getuint32(pktin);
4279
4280 if (hostsize >= lenof(pf.dhost))
4281 hostsize = lenof(pf.dhost)-1;
4282 memcpy(pf.dhost, host, hostsize);
4283 pf.dhost[hostsize] = '\0';
4284 pf.dport = port;
05581745 4285 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4286
05581745 4287 if (pfp == NULL) {
fb983202 4288 logeventf(ssh, "Rejected remote port open request for %s:%d",
4289 pf.dhost, port);
51df0ab5 4290 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4291 PKT_INT, remoteid, PKT_END);
4292 } else {
fb983202 4293 logeventf(ssh, "Received remote port open request for %s:%d",
4294 pf.dhost, port);
51df0ab5 4295 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
05581745 4296 c, &ssh->cfg, pfp->pfrec->addressfamily);
51df0ab5 4297 if (e != NULL) {
fb983202 4298 logeventf(ssh, "Port open failed: %s", e);
51df0ab5 4299 sfree(c);
4300 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4301 PKT_INT, remoteid, PKT_END);
4302 } else {
4303 c->remoteid = remoteid;
64d6ff88 4304 c->halfopen = FALSE;
51df0ab5 4305 c->localid = alloc_channel_id(ssh);
4306 c->closes = 0;
4307 c->v.v1.throttling = 0;
4308 c->type = CHAN_SOCKDATA; /* identify channel type */
4309 add234(ssh->channels, c);
4310 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4311 PKT_INT, c->remoteid, PKT_INT,
4312 c->localid, PKT_END);
4313 logevent("Forwarded port opened successfully");
4314 }
4315 }
4316}
4317
4318static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4319{
4320 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4321 unsigned int localid = ssh_pkt_getuint32(pktin);
4322 struct ssh_channel *c;
4323
4324 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4325 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4326 c->remoteid = localid;
64d6ff88 4327 c->halfopen = FALSE;
51df0ab5 4328 c->type = CHAN_SOCKDATA;
4329 c->v.v1.throttling = 0;
4330 pfd_confirm(c->u.pfd.s);
4331 }
4332
4333 if (c && c->closes) {
4334 /*
4335 * We have a pending close on this channel,
4336 * which we decided on before the server acked
4337 * the channel open. So now we know the
4338 * remoteid, we can close it again.
4339 */
4340 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4341 PKT_INT, c->remoteid, PKT_END);
4342 }
4343}
4344
4345static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4346{
4347 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4348 struct ssh_channel *c;
4349
4350 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4351 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4352 logevent("Forwarded connection refused by server");
4353 pfd_close(c->u.pfd.s);
4354 del234(ssh->channels, c);
4355 sfree(c);
4356 }
4357}
4358
4359static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4360{
4361 /* Remote side closes a channel. */
4362 unsigned i = ssh_pkt_getuint32(pktin);
4363 struct ssh_channel *c;
4364 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 4365 if (c && !c->halfopen) {
51df0ab5 4366 int closetype;
4367 closetype =
4368 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4369
4370 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4371 logevent("Forwarded X11 connection terminated");
4372 assert(c->u.x11.s != NULL);
4373 x11_close(c->u.x11.s);
4374 c->u.x11.s = NULL;
4375 }
4376 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4377 logevent("Forwarded port closed");
4378 assert(c->u.pfd.s != NULL);
4379 pfd_close(c->u.pfd.s);
4380 c->u.pfd.s = NULL;
4381 }
4382
4383 c->closes |= (closetype << 2); /* seen this message */
4384 if (!(c->closes & closetype)) {
4385 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4386 PKT_END);
4387 c->closes |= closetype; /* sent it too */
4388 }
4389
4390 if (c->closes == 15) {
4391 del234(ssh->channels, c);
4392 sfree(c);
4393 }
4394 } else {
4395 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4396 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4397 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4398 i));
4399 }
4400}
4401
4402static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4403{
4404 /* Data sent down one of our channels. */
4405 int i = ssh_pkt_getuint32(pktin);
4406 char *p;
6d44acc9 4407 int len;
51df0ab5 4408 struct ssh_channel *c;
4409
4410 ssh_pkt_getstring(pktin, &p, &len);
4411
4412 c = find234(ssh->channels, &i, ssh_channelfind);
4413 if (c) {
4414 int bufsize = 0;
4415 switch (c->type) {
4416 case CHAN_X11:
4417 bufsize = x11_send(c->u.x11.s, p, len);
4418 break;
4419 case CHAN_SOCKDATA:
4420 bufsize = pfd_send(c->u.pfd.s, p, len);
4421 break;
4422 case CHAN_AGENT:
4423 /* Data for an agent message. Buffer it. */
4424 while (len > 0) {
4425 if (c->u.a.lensofar < 4) {
aa63ab7e 4426 unsigned int l = min(4 - c->u.a.lensofar, len);
51df0ab5 4427 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4428 l);
4429 p += l;
4430 len -= l;
4431 c->u.a.lensofar += l;
4432 }
4433 if (c->u.a.lensofar == 4) {
4434 c->u.a.totallen =
4435 4 + GET_32BIT(c->u.a.msglen);
4436 c->u.a.message = snewn(c->u.a.totallen,
4437 unsigned char);
4438 memcpy(c->u.a.message, c->u.a.msglen, 4);
4439 }
4440 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 4441 unsigned int l =
51df0ab5 4442 min(c->u.a.totallen - c->u.a.lensofar,
4443 len);
4444 memcpy(c->u.a.message + c->u.a.lensofar, p,
4445 l);
4446 p += l;
4447 len -= l;
4448 c->u.a.lensofar += l;
4449 }
4450 if (c->u.a.lensofar == c->u.a.totallen) {
4451 void *reply;
4452 int replylen;
4453 if (agent_query(c->u.a.message,
4454 c->u.a.totallen,
4455 &reply, &replylen,
4456 ssh_agentf_callback, c))
4457 ssh_agentf_callback(c, reply, replylen);
4458 sfree(c->u.a.message);
4459 c->u.a.lensofar = 0;
4460 }
4461 }
4462 bufsize = 0; /* agent channels never back up */
4463 break;
4464 }
4465 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4466 c->v.v1.throttling = 1;
4467 ssh1_throttle(ssh, +1);
4468 }
4469 }
4470}
4471
4472static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4473{
51df0ab5 4474 ssh->exitcode = ssh_pkt_getuint32(pktin);
fb983202 4475 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
51df0ab5 4476 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4477 /*
4478 * In case `helpful' firewalls or proxies tack
4479 * extra human-readable text on the end of the
4480 * session which we might mistake for another
4481 * encrypted packet, we close the session once
4482 * we've sent EXIT_CONFIRMATION.
4483 */
ac934965 4484 ssh->close_expected = TRUE;
51df0ab5 4485 ssh_closing((Plug)ssh, NULL, 0, 0);
4486}
4487
b09eaa88 4488static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4489 struct Packet *pktin)
32874aea 4490{
b09eaa88 4491 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 4492
51df0ab5 4493 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4494 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4495 ssh1_smsg_stdout_stderr_data;
4496
4497 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4498 ssh1_msg_channel_open_confirmation;
4499 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4500 ssh1_msg_channel_open_failure;
4501 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4502 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4503 ssh1_msg_channel_close;
4504 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4505 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4506
86916870 4507 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 4508 logevent("Requesting agent forwarding");
51470298 4509 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 4510 do {
4511 crReturnV;
ff3187f6 4512 } while (!pktin);
4513 if (pktin->type != SSH1_SMSG_SUCCESS
4514 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4515 bombout(("Protocol confusion"));
7ffdbc1a 4516 crStopV;
ff3187f6 4517 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4518 logevent("Agent forwarding refused");
4519 } else {
4520 logevent("Agent forwarding enabled");
51470298 4521 ssh->agentfwd_enabled = TRUE;
51df0ab5 4522 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 4523 }
dacbd0e8 4524 }
4525
86916870 4526 if (ssh->cfg.x11_forward) {
32874aea 4527 char proto[20], data[64];
4528 logevent("Requesting X11 forwarding");
302121de 4529 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 4530 data, sizeof(data), ssh->cfg.x11_auth);
4531 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 4532 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4533 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4534 PKT_STR, proto, PKT_STR, data,
86916870 4535 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 4536 PKT_END);
32874aea 4537 } else {
51470298 4538 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4539 PKT_STR, proto, PKT_STR, data, PKT_END);
4540 }
4541 do {
4542 crReturnV;
ff3187f6 4543 } while (!pktin);
4544 if (pktin->type != SSH1_SMSG_SUCCESS
4545 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4546 bombout(("Protocol confusion"));
7ffdbc1a 4547 crStopV;
ff3187f6 4548 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4549 logevent("X11 forwarding refused");
4550 } else {
4551 logevent("X11 forwarding enabled");
51470298 4552 ssh->X11_fwd_enabled = TRUE;
51df0ab5 4553 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 4554 }
4555 }
4556
06fadff5 4557 ssh_setup_portfwd(ssh, &ssh->cfg);
4558 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 4559
86916870 4560 if (!ssh->cfg.nopty) {
a5dd8467 4561 /* Unpick the terminal-speed string. */
4562 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4563 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4564 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4565 /* Send the pty request. */
51470298 4566 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 4567 PKT_STR, ssh->cfg.termtype,
51470298 4568 PKT_INT, ssh->term_height,
4569 PKT_INT, ssh->term_width,
a5dd8467 4570 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 4571 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4572 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 4573 PKT_CHAR, 0, PKT_END);
51470298 4574 ssh->state = SSH_STATE_INTERMED;
32874aea 4575 do {
4576 crReturnV;
ff3187f6 4577 } while (!pktin);
4578 if (pktin->type != SSH1_SMSG_SUCCESS
4579 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4580 bombout(("Protocol confusion"));
7ffdbc1a 4581 crStopV;
ff3187f6 4582 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4583 c_write_str(ssh, "Server refused to allocate pty\r\n");
4584 ssh->editing = ssh->echoing = 1;
32874aea 4585 }
a5dd8467 4586 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4587 ssh->ospeed, ssh->ispeed);
0965bee0 4588 } else {
51470298 4589 ssh->editing = ssh->echoing = 1;
374330e2 4590 }
4591
86916870 4592 if (ssh->cfg.compression) {
51470298 4593 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4594 do {
4595 crReturnV;
ff3187f6 4596 } while (!pktin);
4597 if (pktin->type != SSH1_SMSG_SUCCESS
4598 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4599 bombout(("Protocol confusion"));
7ffdbc1a 4600 crStopV;
ff3187f6 4601 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4602 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4603 }
4ba9b64b 4604 logevent("Started compression");
51470298 4605 ssh->v1_compressing = TRUE;
5366aed8 4606 ssh->cs_comp_ctx = zlib_compress_init();
4607 logevent("Initialised zlib (RFC1950) compression");
4608 ssh->sc_comp_ctx = zlib_decompress_init();
4609 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4610 }
4611
fd5e5847 4612 /*
4613 * Start the shell or command.
4614 *
4615 * Special case: if the first-choice command is an SSH2
4616 * subsystem (hence not usable here) and the second choice
4617 * exists, we fall straight back to that.
4618 */
4619 {
86916870 4620 char *cmd = ssh->cfg.remote_cmd_ptr;
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 {
4830 int nbits, pbits, warn;
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;
51470298 4854 };
4855 crState(do_ssh2_transport_state);
4856
4857 crBegin(ssh->do_ssh2_transport_crstate);
4858
4859 s->cscipher_tobe = s->sccipher_tobe = NULL;
4860 s->csmac_tobe = s->scmac_tobe = NULL;
4861 s->cscomp_tobe = s->sccomp_tobe = NULL;
4862
e13bba36 4863 s->got_session_id = s->activated_authconn = FALSE;
e5574168 4864
e13bba36 4865 /*
4866 * Be prepared to work around the buggy MAC problem.
4867 */
4868 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4869 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4870 else
4871 s->maclist = macs, s->nmacs = lenof(macs);
4872
4873 begin_key_exchange:
149d2abc 4874 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
51470298 4875 {
e13bba36 4876 int i, j, commalist_started;
4877
51470298 4878 /*
83e7d008 4879 * Set up the preferred key exchange. (NULL => warn below here)
4880 */
4881 s->n_preferred_kex = 0;
4882 for (i = 0; i < KEX_MAX; i++) {
4883 switch (ssh->cfg.ssh_kexlist[i]) {
4884 case KEX_DHGEX:
4885 s->preferred_kex[s->n_preferred_kex++] =
4886 &ssh_diffiehellman_gex;
4887 break;
4888 case KEX_DHGROUP14:
4889 s->preferred_kex[s->n_preferred_kex++] =
4890 &ssh_diffiehellman_group14;
4891 break;
4892 case KEX_DHGROUP1:
4893 s->preferred_kex[s->n_preferred_kex++] =
4894 &ssh_diffiehellman_group1;
4895 break;
4896 case CIPHER_WARN:
4897 /* Flag for later. Don't bother if it's the last in
4898 * the list. */
4899 if (i < KEX_MAX - 1) {
4900 s->preferred_kex[s->n_preferred_kex++] = NULL;
4901 }
4902 break;
4903 }
4904 }
83e7d008 4905
83e7d008 4906 /*
51470298 4907 * Set up the preferred ciphers. (NULL => warn below here)
4908 */
4909 s->n_preferred_ciphers = 0;
4910 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4911 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4912 case CIPHER_BLOWFISH:
4913 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4914 break;
4915 case CIPHER_DES:
86916870 4916 if (ssh->cfg.ssh2_des_cbc) {
51470298 4917 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4918 }
4919 break;
4920 case CIPHER_3DES:
4921 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4922 break;
4923 case CIPHER_AES:
4924 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4925 break;
4926 case CIPHER_WARN:
4927 /* Flag for later. Don't bother if it's the last in
4928 * the list. */
4929 if (i < CIPHER_MAX - 1) {
4930 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4931 }
4932 break;
ca20bfcf 4933 }
ca20bfcf 4934 }
7591b9ff 4935
e13bba36 4936 /*
4937 * Set up preferred compression.
4938 */
4939 if (ssh->cfg.compression)
4940 s->preferred_comp = &ssh_zlib;
4941 else
4942 s->preferred_comp = &ssh_comp_none;
51470298 4943
4944 /*
590f6a5f 4945 * Enable queueing of outgoing auth- or connection-layer
4946 * packets while we are in the middle of a key exchange.
4947 */
4948 ssh->queueing = TRUE;
4949
4950 /*
9442dd57 4951 * Flag that KEX is in progress.
4952 */
4953 ssh->kex_in_progress = TRUE;
4954
4955 /*
51470298 4956 * Construct and send our key exchange packet.
4957 */
ff3187f6 4958 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 4959 for (i = 0; i < 16; i++)
ff3187f6 4960 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 4961 /* List key exchange algorithms. */
ff3187f6 4962 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4963 commalist_started = 0;
4964 for (i = 0; i < s->n_preferred_kex; i++) {
4965 const struct ssh_kex *k = s->preferred_kex[i];
4966 if (!k) continue; /* warning flag */
4967 if (commalist_started)
ff3187f6 4968 ssh2_pkt_addstring_str(s->pktout, ",");
83e7d008 4969 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4970 commalist_started = 1;
32874aea 4971 }
51470298 4972 /* List server host key algorithms. */
ff3187f6 4973 ssh2_pkt_addstring_start(s->pktout);
51470298 4974 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 4975 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 4976 if (i < lenof(hostkey_algs) - 1)
ff3187f6 4977 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4978 }
51470298 4979 /* List client->server encryption algorithms. */
ff3187f6 4980 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4981 commalist_started = 0;
51470298 4982 for (i = 0; i < s->n_preferred_ciphers; i++) {
4983 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4984 if (!c) continue; /* warning flag */
4985 for (j = 0; j < c->nciphers; j++) {
83e7d008 4986 if (commalist_started)
ff3187f6 4987 ssh2_pkt_addstring_str(s->pktout, ",");
4988 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4989 commalist_started = 1;
51470298 4990 }
4991 }
4992 /* List server->client encryption algorithms. */
ff3187f6 4993 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4994 commalist_started = 0;
51470298 4995 for (i = 0; i < s->n_preferred_ciphers; i++) {
4996 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4997 if (!c) continue; /* warning flag */
4998 for (j = 0; j < c->nciphers; j++) {
83e7d008 4999 if (commalist_started)
ff3187f6 5000 ssh2_pkt_addstring_str(s->pktout, ",");
5001 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 5002 commalist_started = 1;
51470298 5003 }
5004 }
5005 /* List client->server MAC algorithms. */
ff3187f6 5006 ssh2_pkt_addstring_start(s->pktout);
51470298 5007 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5008 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5009 if (i < s->nmacs - 1)
ff3187f6 5010 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5011 }
5012 /* List server->client MAC algorithms. */
ff3187f6 5013 ssh2_pkt_addstring_start(s->pktout);
51470298 5014 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5015 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5016 if (i < s->nmacs - 1)
ff3187f6 5017 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5018 }
5019 /* List client->server compression algorithms. */
ff3187f6 5020 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 5021 assert(lenof(compressions) > 1);
ff3187f6 5022 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 5023 for (i = 0; i < lenof(compressions); i++) {
5024 const struct ssh_compress *c = compressions[i];
5025 if (c != s->preferred_comp) {
ff3187f6 5026 ssh2_pkt_addstring_str(s->pktout, ",");
5027 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 5028 }
51470298 5029 }
5030 /* List server->client compression algorithms. */
ff3187f6 5031 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 5032 assert(lenof(compressions) > 1);
ff3187f6 5033 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 5034 for (i = 0; i < lenof(compressions); i++) {
5035 const struct ssh_compress *c = compressions[i];
5036 if (c != s->preferred_comp) {
ff3187f6 5037 ssh2_pkt_addstring_str(s->pktout, ",");
5038 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 5039 }
51470298 5040 }
5041 /* List client->server languages. Empty list. */
ff3187f6 5042 ssh2_pkt_addstring_start(s->pktout);
51470298 5043 /* List server->client languages. Empty list. */
ff3187f6 5044 ssh2_pkt_addstring_start(s->pktout);
51470298 5045 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 5046 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 5047 /* Reserved. */
ff3187f6 5048 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 5049 }
0db56f73 5050
51470298 5051 ssh->exhash = ssh->exhashbase;
ff3187f6 5052 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
0db56f73 5053
590f6a5f 5054 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5055
ff3187f6 5056 if (!pktin)
5057 crWaitUntil(pktin);
5058 if (pktin->length > 5)
5059 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
e5574168 5060
5061 /*
5062 * Now examine the other side's KEXINIT to see what we're up
5063 * to.
5064 */
51470298 5065 {
5066 char *str;
3d9449a1 5067 int i, j, len;
51470298 5068
ff3187f6 5069 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 5070 bombout(("expected key exchange packet from server"));
7ffdbc1a 5071 crStop(0);
32874aea 5072 }
51470298 5073 ssh->kex = NULL;
5074 ssh->hostkey = NULL;
5075 s->cscipher_tobe = NULL;
5076 s->sccipher_tobe = NULL;
5077 s->csmac_tobe = NULL;
5078 s->scmac_tobe = NULL;
5079 s->cscomp_tobe = NULL;
5080 s->sccomp_tobe = NULL;
ff3187f6 5081 pktin->savedpos += 16; /* skip garbage cookie */
5082 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
83e7d008 5083 s->warn = 0;
5084 for (i = 0; i < s->n_preferred_kex; i++) {
5085 const struct ssh_kex *k = s->preferred_kex[i];
5086 if (!k) {
5087 s->warn = 1;
5088 } else if (in_commasep_string(k->name, str, len)) {
5089 ssh->kex = k;
5090 }
5091 if (ssh->kex) {
bb348ab1 5092 if (s->warn) {
3d9449a1 5093 ssh_set_frozen(ssh, 1);
5094 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5095 ssh->kex->name,
5096 ssh_dialog_callback, ssh);
5097 if (s->dlgret < 0) {
5098 do {
5099 crReturn(0);
5100 if (pktin) {
5101 bombout(("Unexpected data from server while"
5102 " waiting for user response"));
5103 crStop(0);
5104 }
5105 } while (pktin || inlen > 0);
5106 s->dlgret = ssh->user_response;
5107 }
5108 ssh_set_frozen(ssh, 0);
5109 if (s->dlgret == 0) {
5110 ssh->close_expected = TRUE;
5111 ssh_closing((Plug)ssh, NULL, 0, 0);
5112 }
bb348ab1 5113 }
51470298 5114 break;
5115 }
32874aea 5116 }
83e7d008 5117 if (!ssh->kex) {
5118 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5119 str ? str : "(null)"));
5120 crStop(0);
5121 }
b59743d5 5122 /*
5123 * Note that the server's guess is considered wrong if it doesn't match
5124 * the first algorithm in our list, even if it's still the algorithm
5125 * we end up using.
5126 */
3d9449a1 5127 s->guessok =
b59743d5 5128 first_in_commasep_string(s->preferred_kex[0]->name, str, len);
ff3187f6 5129 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 5130 for (i = 0; i < lenof(hostkey_algs); i++) {
5131 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5132 ssh->hostkey = hostkey_algs[i];
5133 break;
5134 }
5135 }
3d9449a1 5136 s->guessok = s->guessok &&
b59743d5 5137 first_in_commasep_string(hostkey_algs[0]->name, str, len);
ff3187f6 5138 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 5139 s->warn = 0;
5140 for (i = 0; i < s->n_preferred_ciphers; i++) {
5141 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5142 if (!c) {
5143 s->warn = 1;
5144 } else {
5145 for (j = 0; j < c->nciphers; j++) {
5146 if (in_commasep_string(c->list[j]->name, str, len)) {
5147 s->cscipher_tobe = c->list[j];
5148 break;
5149 }
ca20bfcf 5150 }
32874aea 5151 }
51470298 5152 if (s->cscipher_tobe) {
bb348ab1 5153 if (s->warn) {
3d9449a1 5154 ssh_set_frozen(ssh, 1);
5155 s->dlgret = askalg(ssh->frontend,
5156 "client-to-server cipher",
5157 s->cscipher_tobe->name,
5158 ssh_dialog_callback, ssh);
5159 if (s->dlgret < 0) {
5160 do {
5161 crReturn(0);
5162 if (pktin) {
5163 bombout(("Unexpected data from server while"
5164 " waiting for user response"));
5165 crStop(0);
5166 }
5167 } while (pktin || inlen > 0);
5168 s->dlgret = ssh->user_response;
5169 }
5170 ssh_set_frozen(ssh, 0);
5171 if (s->dlgret == 0) {
5172 ssh->close_expected = TRUE;
5173 ssh_closing((Plug)ssh, NULL, 0, 0);
5174 }
bb348ab1 5175 }
51470298 5176 break;
5177 }
32874aea 5178 }
51470298 5179 if (!s->cscipher_tobe) {
6b5cf8b4 5180 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 5181 str ? str : "(null)"));
7ffdbc1a 5182 crStop(0);
ca20bfcf 5183 }
0ef8f407 5184
ff3187f6 5185 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 5186 s->warn = 0;
5187 for (i = 0; i < s->n_preferred_ciphers; i++) {
5188 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5189 if (!c) {
5190 s->warn = 1;
5191 } else {
5192 for (j = 0; j < c->nciphers; j++) {
5193 if (in_commasep_string(c->list[j]->name, str, len)) {
5194 s->sccipher_tobe = c->list[j];
5195 break;
5196 }
ca20bfcf 5197 }
32874aea 5198 }
51470298 5199 if (s->sccipher_tobe) {
bb348ab1 5200 if (s->warn) {
3d9449a1 5201 ssh_set_frozen(ssh, 1);
5202 s->dlgret = askalg(ssh->frontend,
5203 "server-to-client cipher",
5204 s->sccipher_tobe->name,
5205 ssh_dialog_callback, ssh);
5206 if (s->dlgret < 0) {
5207 do {
5208 crReturn(0);
5209 if (pktin) {
5210 bombout(("Unexpected data from server while"
5211 " waiting for user response"));
5212 crStop(0);
5213 }
5214 } while (pktin || inlen > 0);
5215 s->dlgret = ssh->user_response;
5216 }
5217 ssh_set_frozen(ssh, 0);
5218 if (s->dlgret == 0) {
5219 ssh->close_expected = TRUE;
5220 ssh_closing((Plug)ssh, NULL, 0, 0);
5221 }
bb348ab1 5222 }
51470298 5223 break;
5224 }
32874aea 5225 }
51470298 5226 if (!s->sccipher_tobe) {
6b5cf8b4 5227 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 5228 str ? str : "(null)"));
7ffdbc1a 5229 crStop(0);
ca20bfcf 5230 }
0ef8f407 5231
ff3187f6 5232 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 5233 for (i = 0; i < s->nmacs; i++) {
5234 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5235 s->csmac_tobe = s->maclist[i];
5236 break;
5237 }
32874aea 5238 }
ff3187f6 5239 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 5240 for (i = 0; i < s->nmacs; i++) {
5241 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5242 s->scmac_tobe = s->maclist[i];
5243 break;
5244 }
32874aea 5245 }
ff3187f6 5246 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 5247 for (i = 0; i < lenof(compressions) + 1; i++) {
5248 const struct ssh_compress *c =
5249 i == 0 ? s->preferred_comp : compressions[i - 1];
5250 if (in_commasep_string(c->name, str, len)) {
5251 s->cscomp_tobe = c;
5252 break;
5253 }
32874aea 5254 }
ff3187f6 5255 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5256 for (i = 0; i < lenof(compressions) + 1; i++) {
5257 const struct ssh_compress *c =
5258 i == 0 ? s->preferred_comp : compressions[i - 1];
5259 if (in_commasep_string(c->name, str, len)) {
5260 s->sccomp_tobe = c;
5261 break;
5262 }
32874aea 5263 }
b59743d5 5264 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5265 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
3d9449a1 5266 if (ssh2_pkt_getbool(pktin) && !s->guessok) /* first_kex_packet_follows */
b59743d5 5267 crWaitUntil(pktin); /* Ignore packet */
e5574168 5268 }
e5574168 5269
5270 /*
7bd5a860 5271 * Work out the number of bits of key we will need from the key
5272 * exchange. We start with the maximum key length of either
5273 * cipher...
5274 */
5275 {
32874aea 5276 int csbits, scbits;
7bd5a860 5277
51470298 5278 csbits = s->cscipher_tobe->keylen;
5279 scbits = s->sccipher_tobe->keylen;
5280 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 5281 }
5282 /* The keys only have 160-bit entropy, since they're based on
5283 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 5284 if (s->nbits > 160)
5285 s->nbits = 160;
7bd5a860 5286
5287 /*
a92dd380 5288 * If we're doing Diffie-Hellman group exchange, start by
5289 * requesting a group.
e5574168 5290 */
d1aaf71d 5291 if (!ssh->kex->pdata) {
32874aea 5292 logevent("Doing Diffie-Hellman group exchange");
51470298 5293 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 5294 /*
5295 * Work out how big a DH group we will need to allow that
5296 * much data.
7bd5a860 5297 */
51470298 5298 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 5299 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5300 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 5301 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 5302
ff3187f6 5303 crWaitUntil(pktin);
5304 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 5305 bombout(("expected key exchange group packet from server"));
7ffdbc1a 5306 crStop(0);
32874aea 5307 }
ff3187f6 5308 s->p = ssh2_pkt_getmp(pktin);
5309 s->g = ssh2_pkt_getmp(pktin);
5310 if (!s->p || !s->g) {
5311 bombout(("unable to read mp-ints from incoming group packet"));
5312 crStop(0);
5313 }
d1aaf71d 5314 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
51470298 5315 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5316 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 5317 } else {
d1aaf71d 5318 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5319 ssh->kex_ctx = dh_setup_group(ssh->kex);
51470298 5320 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5321 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
d1aaf71d 5322 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5323 ssh->kex->groupname);
8d5de777 5324 }
e5574168 5325
a92dd380 5326 logevent("Doing Diffie-Hellman key exchange");
e5574168 5327 /*
a92dd380 5328 * Now generate and send e for Diffie-Hellman.
e5574168 5329 */
755e0524 5330 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
27cd7fc2 5331 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 5332 s->pktout = ssh2_pkt_init(s->kex_init_value);
5333 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 5334 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5335
755e0524 5336 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
ff3187f6 5337 crWaitUntil(pktin);
5338 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 5339 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 5340 crStop(0);
7cca0d81 5341 }
755e0524 5342 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
ff3187f6 5343 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5344 s->f = ssh2_pkt_getmp(pktin);
5345 if (!s->f) {
5346 bombout(("unable to parse key exchange reply packet"));
5347 crStop(0);
5348 }
5349 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 5350
27cd7fc2 5351 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 5352
755e0524 5353 /* We assume everything from now on will be quick, and it might
5354 * involve user interaction. */
5355 set_busy_status(ssh->frontend, BUSY_NOT);
5356
51470298 5357 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5358 if (ssh->kex == &ssh_diffiehellman_gex) {
5359 sha_uint32(&ssh->exhash, s->pbits);
5360 sha_mpint(&ssh->exhash, s->p);
5361 sha_mpint(&ssh->exhash, s->g);
a92dd380 5362 }
51470298 5363 sha_mpint(&ssh->exhash, s->e);
5364 sha_mpint(&ssh->exhash, s->f);
5365 sha_mpint(&ssh->exhash, s->K);
5366 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 5367
27cd7fc2 5368 dh_cleanup(ssh->kex_ctx);
fabd1805 5369 ssh->kex_ctx = NULL;
3709bfe9 5370
7cca0d81 5371#if 0
765c4200 5372 debug(("Exchange hash is:\n"));
51470298 5373 dmemdump(s->exchange_hash, 20);
7cca0d81 5374#endif
5375
51470298 5376 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5377 if (!s->hkey ||
5378 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 5379 (char *)s->exchange_hash, 20)) {
6b5cf8b4 5380 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 5381 crStop(0);
8d5de777 5382 }
e5574168 5383
5384 /*
7cca0d81 5385 * Authenticate remote host: verify host key. (We've already
5386 * checked the signature of the exchange hash.)
e5574168 5387 */
51470298 5388 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5389 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
3d9449a1 5390 ssh_set_frozen(ssh, 1);
5391 s->dlgret = verify_ssh_host_key(ssh->frontend,
5392 ssh->savedhost, ssh->savedport,
5393 ssh->hostkey->keytype, s->keystr,
5394 s->fingerprint,
5395 ssh_dialog_callback, ssh);
5396 if (s->dlgret < 0) {
5397 do {
5398 crReturn(0);
5399 if (pktin) {
5400 bombout(("Unexpected data from server while waiting"
5401 " for user host key response"));
5402 crStop(0);
5403 }
5404 } while (pktin || inlen > 0);
5405 s->dlgret = ssh->user_response;
5406 }
5407 ssh_set_frozen(ssh, 0);
5408 if (s->dlgret == 0) {
5409 ssh->close_expected = TRUE;
5410 ssh_closing((Plug)ssh, NULL, 0, 0);
5411 crStop(0);
5412 }
e13bba36 5413 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 5414 logevent("Host key fingerprint is:");
51470298 5415 logevent(s->fingerprint);
5e0d7cb8 5416 }
51470298 5417 sfree(s->fingerprint);
5418 sfree(s->keystr);
5419 ssh->hostkey->freekey(s->hkey);
d39f364a 5420
5421 /*
9442dd57 5422 * The exchange hash from the very first key exchange is also
5423 * the session id, used in session key construction and
5424 * authentication.
5425 */
e13bba36 5426 if (!s->got_session_id) {
9442dd57 5427 memcpy(ssh->v2_session_id, s->exchange_hash,
5428 sizeof(s->exchange_hash));
e13bba36 5429 s->got_session_id = TRUE;
5430 }
9442dd57 5431
5432 /*
7cca0d81 5433 * Send SSH2_MSG_NEWKEYS.
d39f364a 5434 */
ff3187f6 5435 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 5436 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 5437 ssh->outgoing_data_size = 0; /* start counting from here */
5438
5439 /*
5440 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 5441 * client-to-server session keys.
9442dd57 5442 */
5443 if (ssh->cs_cipher_ctx)
5444 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5445 ssh->cscipher = s->cscipher_tobe;
5446 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5447
5448 if (ssh->cs_mac_ctx)
5449 ssh->csmac->free_context(ssh->cs_mac_ctx);
5450 ssh->csmac = s->csmac_tobe;
5451 ssh->cs_mac_ctx = ssh->csmac->make_context();
5452
5453 if (ssh->cs_comp_ctx)
5454 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5455 ssh->cscomp = s->cscomp_tobe;
5456 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5457
5458 /*
5459 * Set IVs on client-to-server keys. Here we use the exchange
5460 * hash from the _first_ key exchange.
5461 */
5462 {
5463 unsigned char keyspace[40];
5464 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5465 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5466 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5467 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5468 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5469 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5470 }
5471
5472 logeventf(ssh, "Initialised %.200s client->server encryption",
5473 ssh->cscipher->text_name);
5474 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5475 ssh->csmac->text_name);
5476 if (ssh->cscomp->text_name)
5477 logeventf(ssh, "Initialised %s compression",
5478 ssh->cscomp->text_name);
590f6a5f 5479
5480 /*
5481 * Now our end of the key exchange is complete, we can send all
5482 * our queued higher-layer packets.
5483 */
5484 ssh->queueing = FALSE;
5485 ssh2_pkt_queuesend(ssh);
d39f364a 5486
5487 /*
8406eaf9 5488 * Expect SSH2_MSG_NEWKEYS from server.
5489 */
ff3187f6 5490 crWaitUntil(pktin);
5491 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 5492 bombout(("expected new-keys packet from server"));
7ffdbc1a 5493 crStop(0);
8406eaf9 5494 }
9442dd57 5495 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 5496
5497 /*
9442dd57 5498 * We've seen server NEWKEYS, so create and initialise
5499 * server-to-client session keys.
d39f364a 5500 */
371e569c 5501 if (ssh->sc_cipher_ctx)
5502 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 5503 ssh->sccipher = s->sccipher_tobe;
371e569c 5504 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 5505
e0e1a00d 5506 if (ssh->sc_mac_ctx)
5507 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 5508 ssh->scmac = s->scmac_tobe;
e0e1a00d 5509 ssh->sc_mac_ctx = ssh->scmac->make_context();
5510
5366aed8 5511 if (ssh->sc_comp_ctx)
5512 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 5513 ssh->sccomp = s->sccomp_tobe;
5366aed8 5514 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5515
d39f364a 5516 /*
9442dd57 5517 * Set IVs on server-to-client keys. Here we use the exchange
5518 * hash from the _first_ key exchange.
d39f364a 5519 */
51470298 5520 {
5521 unsigned char keyspace[40];
51470298 5522 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 5523 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 5524 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 5525 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 5526 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 5527 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 5528 }
57356d63 5529 logeventf(ssh, "Initialised %.200s server->client encryption",
5530 ssh->sccipher->text_name);
6c135243 5531 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5532 ssh->scmac->text_name);
57356d63 5533 if (ssh->sccomp->text_name)
5534 logeventf(ssh, "Initialised %s decompression",
5535 ssh->sccomp->text_name);
9442dd57 5536
5537 /*
5538 * Free key exchange data.
5539 */
679539d7 5540 freebn(s->f);
679539d7 5541 freebn(s->K);
b3949e7e 5542 if (ssh->kex == &ssh_diffiehellman_gex) {
5543 freebn(s->g);
5544 freebn(s->p);
5545 }
d39f364a 5546
033b4cef 5547 /*
e13bba36 5548 * Key exchange is over. Loop straight back round if we have a
5549 * deferred rekey reason.
5550 */
5551 if (ssh->deferred_rekey_reason) {
5552 logevent(ssh->deferred_rekey_reason);
5553 pktin = NULL;
5554 ssh->deferred_rekey_reason = NULL;
5555 goto begin_key_exchange;
5556 }
5557
5558 /*
5559 * Otherwise, schedule a timer for our next rekey.
9442dd57 5560 */
5561 ssh->kex_in_progress = FALSE;
e6c1536e 5562 ssh->last_rekey = GETTICKCOUNT();
d57f70af 5563 if (ssh->cfg.ssh_rekey_time != 0)
5564 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5565 ssh2_timer, ssh);
e13bba36 5566
9442dd57 5567 /*
0db56f73 5568 * If this is the first key exchange phase, we must pass the
5569 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5570 * wants to see it but because it will need time to initialise
5571 * itself before it sees an actual packet. In subsequent key
5572 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5573 * it would only confuse the layer above.
5574 */
e13bba36 5575 if (s->activated_authconn) {
b09eaa88 5576 crReturn(1);
0db56f73 5577 }
e13bba36 5578 s->activated_authconn = TRUE;
0db56f73 5579
5580 /*
7cca0d81 5581 * Now we're encrypting. Begin returning 1 to the protocol main
5582 * function so that other things can run on top of the
5583 * transport. If we ever see a KEXINIT, we must go back to the
5584 * start.
9442dd57 5585 *
5586 * We _also_ go back to the start if we see pktin==NULL and
5587 * inlen==-1, because this is a special signal meaning
5588 * `initiate client-driven rekey', and `in' contains a message
5589 * giving the reason for the rekey.
033b4cef 5590 */
9442dd57 5591 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5592 (!pktin && inlen == -1))) {
f382c87d 5593 wait_for_rekey:
32874aea 5594 crReturn(1);
e96adf72 5595 }
9442dd57 5596 if (pktin) {
5597 logevent("Server initiated key re-exchange");
5598 } else {
f382c87d 5599 /*
5600 * Special case: if the server bug is set that doesn't
5601 * allow rekeying, we give a different log message and
5602 * continue waiting. (If such a server _initiates_ a rekey,
5603 * we process it anyway!)
5604 */
5605 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5606 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5607 (char *)in);
5608 /* Reset the counters, so that at least this message doesn't
5609 * hit the event log _too_ often. */
5610 ssh->outgoing_data_size = 0;
5611 ssh->incoming_data_size = 0;
5612 if (ssh->cfg.ssh_rekey_time != 0) {
5613 ssh->next_rekey =
5614 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5615 ssh2_timer, ssh);
5616 }
5617 goto wait_for_rekey; /* this is utterly horrid */
5618 } else {
5619 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
f382c87d 5620 }
9442dd57 5621 }
7cca0d81 5622 goto begin_key_exchange;
e5574168 5623
5624 crFinish(1);
5625}
5626
7cca0d81 5627/*
783415f8 5628 * Add data to an SSH2 channel output buffer.
5629 */
32874aea 5630static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5631 int len)
5632{
5471d09a 5633 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 5634}
5635
5636/*
5637 * Attempt to send data on an SSH2 channel.
5638 */
5471d09a 5639static int ssh2_try_send(struct ssh_channel *c)
32874aea 5640{
51470298 5641 Ssh ssh = c->ssh;
ff3187f6 5642 struct Packet *pktout;
51470298 5643
5471d09a 5644 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5645 int len;
5646 void *data;
5647 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5648 if ((unsigned)len > c->v.v2.remwindow)
5649 len = c->v.v2.remwindow;
5650 if ((unsigned)len > c->v.v2.remmaxpkt)
5651 len = c->v.v2.remmaxpkt;
ff3187f6 5652 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5653 ssh2_pkt_adduint32(pktout, c->remoteid);
5654 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5655 ssh2_pkt_addstring_start(pktout);
5656 ssh2_pkt_addstring_data(pktout, data, len);
5657 end_log_omission(ssh, pktout);
5658 ssh2_pkt_send(ssh, pktout);
5471d09a 5659 bufchain_consume(&c->v.v2.outbuffer, len);
5660 c->v.v2.remwindow -= len;
5661 }
5662
5663 /*
5664 * After having sent as much data as we can, return the amount
5665 * still buffered.
5666 */
5667 return bufchain_size(&c->v.v2.outbuffer);
5668}
5669
5670/*
5671 * Potentially enlarge the window on an SSH2 channel.
5672 */
5673static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5674{
51470298 5675 Ssh ssh = c->ssh;
5676
6b69f42e 5677 /*
5678 * Never send WINDOW_ADJUST for a channel that the remote side
5679 * already thinks it's closed; there's no point, since it won't
5680 * be sending any more data anyway.
5681 */
5682 if (c->closes != 0)
5683 return;
5684
d252310a 5685 /*
5686 * Only send a WINDOW_ADJUST if there's significantly more window
5687 * available than the other end thinks there is. This saves us
5688 * sending a WINDOW_ADJUST for every character in a shell session.
5689 *
5690 * "Significant" is arbitrarily defined as half the window size.
5691 */
5692 if (newwin > c->v.v2.locwindow * 2) {
ff3187f6 5693 struct Packet *pktout;
5694
5695 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5696 ssh2_pkt_adduint32(pktout, c->remoteid);
5697 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5698 ssh2_pkt_send(ssh, pktout);
5471d09a 5699 c->v.v2.locwindow = newwin;
783415f8 5700 }
5701}
5702
51df0ab5 5703static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 5704{
5705 unsigned i = ssh_pkt_getuint32(pktin);
5706 struct ssh_channel *c;
5707 c = find234(ssh->channels, &i, ssh_channelfind);
5708 if (c && !c->closes)
5709 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5710}
5711
51df0ab5 5712static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5713{
5714 char *data;
6d44acc9 5715 int length;
51df0ab5 5716 unsigned i = ssh_pkt_getuint32(pktin);
5717 struct ssh_channel *c;
5718 c = find234(ssh->channels, &i, ssh_channelfind);
5719 if (!c)
5720 return; /* nonexistent channel */
5721 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5722 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5723 return; /* extended but not stderr */
5724 ssh_pkt_getstring(pktin, &data, &length);
5725 if (data) {
5726 int bufsize = 0;
5727 c->v.v2.locwindow -= length;
5728 switch (c->type) {
5729 case CHAN_MAINSESSION:
5730 bufsize =
5731 from_backend(ssh->frontend, pktin->type ==
5732 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5733 data, length);
5734 break;
5735 case CHAN_X11:
5736 bufsize = x11_send(c->u.x11.s, data, length);
5737 break;
5738 case CHAN_SOCKDATA:
5739 bufsize = pfd_send(c->u.pfd.s, data, length);
5740 break;
5741 case CHAN_AGENT:
5742 while (length > 0) {
5743 if (c->u.a.lensofar < 4) {
aa63ab7e 5744 unsigned int l = min(4 - c->u.a.lensofar, length);
51df0ab5 5745 memcpy(c->u.a.msglen + c->u.a.lensofar,
5746 data, l);
5747 data += l;
5748 length -= l;
5749 c->u.a.lensofar += l;
5750 }
5751 if (c->u.a.lensofar == 4) {
5752 c->u.a.totallen =
5753 4 + GET_32BIT(c->u.a.msglen);
5754 c->u.a.message = snewn(c->u.a.totallen,
5755 unsigned char);
5756 memcpy(c->u.a.message, c->u.a.msglen, 4);
5757 }
5758 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 5759 unsigned int l =
51df0ab5 5760 min(c->u.a.totallen - c->u.a.lensofar,
5761 length);
5762 memcpy(c->u.a.message + c->u.a.lensofar,
5763 data, l);
5764 data += l;
5765 length -= l;
5766 c->u.a.lensofar += l;
5767 }
5768 if (c->u.a.lensofar == c->u.a.totallen) {
5769 void *reply;
5770 int replylen;
5771 if (agent_query(c->u.a.message,
5772 c->u.a.totallen,
5773 &reply, &replylen,
5774 ssh_agentf_callback, c))
5775 ssh_agentf_callback(c, reply, replylen);
5776 sfree(c->u.a.message);
5777 c->u.a.lensofar = 0;
5778 }
5779 }
5780 bufsize = 0;
5781 break;
5782 }
5783 /*
5784 * If we are not buffering too much data,
5785 * enlarge the window again at the remote side.
5786 */
5787 if (bufsize < OUR_V2_WINSIZE)
5788 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5789 }
5790}
5791
5792static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5793{
5794 unsigned i = ssh_pkt_getuint32(pktin);
5795 struct ssh_channel *c;
5796
5797 c = find234(ssh->channels, &i, ssh_channelfind);
5798 if (!c)
5799 return; /* nonexistent channel */
5800
5801 if (c->type == CHAN_X11) {
5802 /*
5803 * Remote EOF on an X11 channel means we should
5804 * wrap up and close the channel ourselves.
5805 */
5806 x11_close(c->u.x11.s);
5807 sshfwd_close(c);
5808 } else if (c->type == CHAN_AGENT) {
5809 sshfwd_close(c);
5810 } else if (c->type == CHAN_SOCKDATA) {
5811 pfd_close(c->u.pfd.s);
5812 sshfwd_close(c);
5813 }
5814}
5815
5816static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5817{
5818 unsigned i = ssh_pkt_getuint32(pktin);
5819 struct ssh_channel *c;
5820 struct Packet *pktout;
5821
5822 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 5823 if (!c || c->halfopen) {
51df0ab5 5824 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5825 c ? "half-open" : "nonexistent", i));
5826 return;
5827 }
5828 /* Do pre-close processing on the channel. */
5829 switch (c->type) {
5830 case CHAN_MAINSESSION:
5831 ssh->mainchan = NULL;
5832 update_specials_menu(ssh->frontend);
5833 break;
5834 case CHAN_X11:
5835 if (c->u.x11.s != NULL)
5836 x11_close(c->u.x11.s);
5837 sshfwd_close(c);
5838 break;
5839 case CHAN_AGENT:
5840 sshfwd_close(c);
5841 break;
5842 case CHAN_SOCKDATA:
5843 if (c->u.pfd.s != NULL)
5844 pfd_close(c->u.pfd.s);
5845 sshfwd_close(c);
5846 break;
5847 }
5848 if (c->closes == 0) {
5849 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5850 ssh2_pkt_adduint32(pktout, c->remoteid);
5851 ssh2_pkt_send(ssh, pktout);
5852 }
5853 del234(ssh->channels, c);
5854 bufchain_clear(&c->v.v2.outbuffer);
5855 sfree(c);
5856
5857 /*
5858 * See if that was the last channel left open.
5859 * (This is only our termination condition if we're
5860 * not running in -N mode.)
5861 */
5862 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5863 logevent("All channels closed. Disconnecting");
5864#if 0
5865 /*
5866 * We used to send SSH_MSG_DISCONNECT here,
5867 * because I'd believed that _every_ conforming
5868 * SSH2 connection had to end with a disconnect
5869 * being sent by at least one side; apparently
5870 * I was wrong and it's perfectly OK to
5871 * unceremoniously slam the connection shut
5872 * when you're done, and indeed OpenSSH feels
5873 * this is more polite than sending a
5874 * DISCONNECT. So now we don't.
5875 */
5876 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5877 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5878 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5879 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5880 ssh2_pkt_send_noqueue(ssh, s->pktout);
5881#endif
ac934965 5882 ssh->close_expected = TRUE;
51df0ab5 5883 ssh_closing((Plug)ssh, NULL, 0, 0);
5884 }
5885}
5886
5887static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5888{
5889 unsigned i = ssh_pkt_getuint32(pktin);
5890 struct ssh_channel *c;
5891 struct Packet *pktout;
5892
5893 c = find234(ssh->channels, &i, ssh_channelfind);
5894 if (!c)
5895 return; /* nonexistent channel */
5896 if (c->type != CHAN_SOCKDATA_DORMANT)
5897 return; /* dunno why they're confirming this */
5898 c->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 5899 c->halfopen = FALSE;
51df0ab5 5900 c->type = CHAN_SOCKDATA;
5901 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5902 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5903 if (c->u.pfd.s)
5904 pfd_confirm(c->u.pfd.s);
5905 if (c->closes) {
5906 /*
5907 * We have a pending close on this channel,
5908 * which we decided on before the server acked
5909 * the channel open. So now we know the
5910 * remoteid, we can close it again.
5911 */
5912 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5913 ssh2_pkt_adduint32(pktout, c->remoteid);
5914 ssh2_pkt_send(ssh, pktout);
5915 }
5916}
5917
5918static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5919{
5920 static const char *const reasons[] = {
5921 "<unknown reason code>",
5922 "Administratively prohibited",
5923 "Connect failed",
5924 "Unknown channel type",
5925 "Resource shortage",
5926 };
5927 unsigned i = ssh_pkt_getuint32(pktin);
5928 unsigned reason_code;
5929 char *reason_string;
5930 int reason_length;
51df0ab5 5931 struct ssh_channel *c;
5932 c = find234(ssh->channels, &i, ssh_channelfind);
5933 if (!c)
5934 return; /* nonexistent channel */
5935 if (c->type != CHAN_SOCKDATA_DORMANT)
5936 return; /* dunno why they're failing this */
5937
5938 reason_code = ssh_pkt_getuint32(pktin);
5939 if (reason_code >= lenof(reasons))
5940 reason_code = 0; /* ensure reasons[reason_code] in range */
5941 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
fb983202 5942 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
5943 reasons[reason_code], reason_length, reason_string);
51df0ab5 5944
5945 pfd_close(c->u.pfd.s);
5946
5947 del234(ssh->channels, c);
5948 sfree(c);
5949}
5950
5951static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5952{
5953 unsigned localid;
5954 char *type;
5955 int typelen, want_reply;
5956 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5957 struct ssh_channel *c;
5958 struct Packet *pktout;
5959
5960 localid = ssh_pkt_getuint32(pktin);
5961 ssh_pkt_getstring(pktin, &type, &typelen);
5962 want_reply = ssh2_pkt_getbool(pktin);
5963
5964 /*
5965 * First, check that the channel exists. Otherwise,
5966 * we can instantly disconnect with a rude message.
5967 */
5968 c = find234(ssh->channels, &localid, ssh_channelfind);
5969 if (!c) {
5970 char buf[80];
5971 sprintf(buf, "Received channel request for nonexistent"
5972 " channel %d", localid);
5973 logevent(buf);
5974 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5975 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5976 ssh2_pkt_addstring(pktout, buf);
5977 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5978 ssh2_pkt_send_noqueue(ssh, pktout);
5979 connection_fatal(ssh->frontend, "%s", buf);
ac934965 5980 ssh->close_expected = TRUE;
51df0ab5 5981 ssh_closing((Plug)ssh, NULL, 0, 0);
5982 return;
5983 }
5984
5985 /*
5986 * Having got the channel number, we now look at
5987 * the request type string to see if it's something
5988 * we recognise.
5989 */
5990 if (c == ssh->mainchan) {
5991 /*
5992 * We recognise "exit-status" and "exit-signal" on
5993 * the primary channel.
5994 */
5995 if (typelen == 11 &&
5996 !memcmp(type, "exit-status", 11)) {
5997
5998 ssh->exitcode = ssh_pkt_getuint32(pktin);
5999 logeventf(ssh, "Server sent command exit status %d",
6000 ssh->exitcode);
6001 reply = SSH2_MSG_CHANNEL_SUCCESS;
6002
6003 } else if (typelen == 11 &&
6004 !memcmp(type, "exit-signal", 11)) {
6005
6006 int is_plausible = TRUE, is_int = FALSE;
6007 char *fmt_sig = "", *fmt_msg = "";
6008 char *msg;
6009 int msglen = 0, core = FALSE;
6010 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6011 * provide an `int' for the signal, despite its
6012 * having been a `string' in the drafts since at
6013 * least 2001. (Fixed in session.c 1.147.) Try to
6014 * infer which we can safely parse it as. */
6015 {
6016 unsigned char *p = pktin->body +
6017 pktin->savedpos;
6018 long len = pktin->length - pktin->savedpos;
6019 unsigned long num = GET_32BIT(p); /* what is it? */
6020 /* If it's 0, it hardly matters; assume string */
6021 if (num == 0) {
6022 is_int = FALSE;
6023 } else {
6024 int maybe_int = FALSE, maybe_str = FALSE;
6025#define CHECK_HYPOTHESIS(offset, result) \
6026 do { \
6027 long q = offset; \
6028 if (q >= 0 && q+4 <= len) { \
6029 q = q + 4 + GET_32BIT(p+q); \
6030 if (q >= 0 && q+4 <= len && \
c849ff23 6031 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
51df0ab5 6032 result = TRUE; \
6033 } \
6034 } while(0)
6035 CHECK_HYPOTHESIS(4+1, maybe_int);
6036 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6037#undef CHECK_HYPOTHESIS
6038 if (maybe_int && !maybe_str)
6039 is_int = TRUE;
6040 else if (!maybe_int && maybe_str)
6041 is_int = FALSE;
6042 else
6043 /* Crikey. Either or neither. Panic. */
6044 is_plausible = FALSE;
6045 }
6046 }
6047 if (is_plausible) {
6048 if (is_int) {
6049 /* Old non-standard OpenSSH. */
6050 int signum = ssh_pkt_getuint32(pktin);
6051 fmt_sig = dupprintf(" %d", signum);
6052 } else {
6053 /* As per the drafts. */
6054 char *sig;
6055 int siglen;
6056 ssh_pkt_getstring(pktin, &sig, &siglen);
6057 /* Signal name isn't supposed to be blank, but
6058 * let's cope gracefully if it is. */
6059 if (siglen) {
6060 fmt_sig = dupprintf(" \"%.*s\"",
6061 siglen, sig);
6062 }
6063 }
6064 core = ssh2_pkt_getbool(pktin);
6065 ssh_pkt_getstring(pktin, &msg, &msglen);
6066 if (msglen) {
6067 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6068 }
6069 /* ignore lang tag */
6070 } /* else don't attempt to parse */
6071 logeventf(ssh, "Server exited on signal%s%s%s",
6072 fmt_sig, core ? " (core dumped)" : "",
6073 fmt_msg);
6074 if (*fmt_sig) sfree(fmt_sig);
6075 if (*fmt_msg) sfree(fmt_msg);
6076 reply = SSH2_MSG_CHANNEL_SUCCESS;
6077
6078 }
6079 } else {
6080 /*
6081 * This is a channel request we don't know
6082 * about, so we now either ignore the request
6083 * or respond with CHANNEL_FAILURE, depending
6084 * on want_reply.
6085 */
6086 reply = SSH2_MSG_CHANNEL_FAILURE;
6087 }
6088 if (want_reply) {
6089 pktout = ssh2_pkt_init(reply);
6090 ssh2_pkt_adduint32(pktout, c->remoteid);
6091 ssh2_pkt_send(ssh, pktout);
6092 }
6093}
6094
6095static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6096{
6097 char *type;
6098 int typelen, want_reply;
6099 struct Packet *pktout;
6100
6101 ssh_pkt_getstring(pktin, &type, &typelen);
6102 want_reply = ssh2_pkt_getbool(pktin);
6103
6104 /*
6105 * We currently don't support any global requests
6106 * at all, so we either ignore the request or
6107 * respond with REQUEST_FAILURE, depending on
6108 * want_reply.
6109 */
6110 if (want_reply) {
6111 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6112 ssh2_pkt_send(ssh, pktout);
6113 }
6114}
6115
6116static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6117{
6118 char *type;
6119 int typelen;
6120 char *peeraddr;
6121 int peeraddrlen;
6122 int peerport;
6123 char *error = NULL;
6124 struct ssh_channel *c;
6125 unsigned remid, winsize, pktsize;
6126 struct Packet *pktout;
6127
6128 ssh_pkt_getstring(pktin, &type, &typelen);
6129 c = snew(struct ssh_channel);
6130 c->ssh = ssh;
6131
6132 remid = ssh_pkt_getuint32(pktin);
6133 winsize = ssh_pkt_getuint32(pktin);
6134 pktsize = ssh_pkt_getuint32(pktin);
6135
6136 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6137 char *addrstr;
6138
6139 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6140 addrstr = snewn(peeraddrlen+1, char);
6141 memcpy(addrstr, peeraddr, peeraddrlen);
6142 addrstr[peeraddrlen] = '\0';
6143 peerport = ssh_pkt_getuint32(pktin);
6144
6145 logeventf(ssh, "Received X11 connect request from %s:%d",
6146 addrstr, peerport);
6147
6148 if (!ssh->X11_fwd_enabled)
6149 error = "X11 forwarding is not enabled";
6150 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6151 ssh->x11auth, addrstr, peerport,
6152 &ssh->cfg) != NULL) {
6153 error = "Unable to open an X11 connection";
6154 } else {
6155 logevent("Opening X11 forward connection succeeded");
6156 c->type = CHAN_X11;
6157 }
6158
6159 sfree(addrstr);
6160 } else if (typelen == 15 &&
6161 !memcmp(type, "forwarded-tcpip", 15)) {
6162 struct ssh_rportfwd pf, *realpf;
6163 char *dummy;
6164 int dummylen;
6165 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6166 pf.sport = ssh_pkt_getuint32(pktin);
6167 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6168 peerport = ssh_pkt_getuint32(pktin);
6169 realpf = find234(ssh->rportfwds, &pf, NULL);
6170 logeventf(ssh, "Received remote port %d open request "
6171 "from %s:%d", pf.sport, peeraddr, peerport);
6172 if (realpf == NULL) {
6173 error = "Remote port is not recognised";
6174 } else {
6175 const char *e = pfd_newconnect(&c->u.pfd.s,
6176 realpf->dhost,
6177 realpf->dport, c,
05581745 6178 &ssh->cfg,
6179 realpf->pfrec->addressfamily);
51df0ab5 6180 logeventf(ssh, "Attempting to forward remote port to "
6181 "%s:%d", realpf->dhost, realpf->dport);
6182 if (e != NULL) {
6183 logeventf(ssh, "Port open failed: %s", e);
6184 error = "Port open failed";
6185 } else {
6186 logevent("Forwarded port opened successfully");
6187 c->type = CHAN_SOCKDATA;
6188 }
6189 }
6190 } else if (typelen == 22 &&
6191 !memcmp(type, "auth-agent@openssh.com", 3)) {
6192 if (!ssh->agentfwd_enabled)
6193 error = "Agent forwarding is not enabled";
6194 else {
6195 c->type = CHAN_AGENT; /* identify channel type */
6196 c->u.a.lensofar = 0;
6197 }
6198 } else {
6199 error = "Unsupported channel type requested";
6200 }
6201
6202 c->remoteid = remid;
64d6ff88 6203 c->halfopen = FALSE;
51df0ab5 6204 if (error) {
6205 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6206 ssh2_pkt_adduint32(pktout, c->remoteid);
6207 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6208 ssh2_pkt_addstring(pktout, error);
6209 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6210 ssh2_pkt_send(ssh, pktout);
6211 logeventf(ssh, "Rejected channel open: %s", error);
6212 sfree(c);
6213 } else {
6214 c->localid = alloc_channel_id(ssh);
6215 c->closes = 0;
6216 c->v.v2.locwindow = OUR_V2_WINSIZE;
6217 c->v.v2.remwindow = winsize;
6218 c->v.v2.remmaxpkt = pktsize;
6219 bufchain_init(&c->v.v2.outbuffer);
6220 add234(ssh->channels, c);
6221 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6222 ssh2_pkt_adduint32(pktout, c->remoteid);
6223 ssh2_pkt_adduint32(pktout, c->localid);
6224 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
954d5c5a 6225 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
51df0ab5 6226 ssh2_pkt_send(ssh, pktout);
6227 }
6228}
6229
783415f8 6230/*
7cca0d81 6231 * Handle the SSH2 userauth and connection layers.
6232 */
ff3187f6 6233static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6234 struct Packet *pktin)
7cca0d81 6235{
51470298 6236 struct do_ssh2_authconn_state {
6237 enum {
6238 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6239 AUTH_PASSWORD,
6240 AUTH_KEYBOARD_INTERACTIVE
6241 } method;
6242 enum {
6243 AUTH_TYPE_NONE,
6244 AUTH_TYPE_PUBLICKEY,
6245 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6246 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6247 AUTH_TYPE_PASSWORD,
6248 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6249 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6250 } type;
6251 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6ac3a551 6252 int tried_pubkey_config, tried_agent;
6253 int kbd_inter_running, kbd_inter_refused;
51470298 6254 int we_are_in;
6255 int num_prompts, curr_prompt, echo;
6256 char username[100];
6257 int got_username;
85fdbe25 6258 char pwprompt[512];
51470298 6259 char password[100];
6260 void *publickey_blob;
6261 int publickey_bloblen;
6262 unsigned char request[5], *response, *p;
6263 int responselen;
6264 int keyi, nkeys;
6265 int authed;
6266 char *pkblob, *alg, *commentp;
6267 int pklen, alglen, commentlen;
6268 int siglen, retlen, len;
6269 char *q, *agentreq, *ret;
6270 int try_send;
73feed4f 6271 int num_env, env_left, env_ok;
ff3187f6 6272 struct Packet *pktout;
51470298 6273 };
6274 crState(do_ssh2_authconn_state);
6275
6276 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 6277
7cca0d81 6278 /*
6279 * Request userauth protocol, and await a response to it.
6280 */
ff3187f6 6281 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6282 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6283 ssh2_pkt_send(ssh, s->pktout);
6284 crWaitUntilV(pktin);
6285 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 6286 bombout(("Server refused user authentication protocol"));
7ffdbc1a 6287 crStopV;
8d5de777 6288 }
7cca0d81 6289
6290 /*
1408a877 6291 * We repeat this whole loop, including the username prompt,
6292 * until we manage a successful authentication. If the user
51470298 6293 * types the wrong _password_, they can be sent back to the
6294 * beginning to try another username, if this is configured on.
6295 * (If they specify a username in the config, they are never
6296 * asked, even if they do give a wrong password.)
1408a877 6297 *
6298 * I think this best serves the needs of
6299 *
6300 * - the people who have no configuration, no keys, and just
6301 * want to try repeated (username,password) pairs until they
6302 * type both correctly
6303 *
6304 * - people who have keys and configuration but occasionally
6305 * need to fall back to passwords
6306 *
6307 * - people with a key held in Pageant, who might not have
6308 * logged in to a particular machine before; so they want to
6309 * type a username, and then _either_ their key will be
6310 * accepted, _or_ they will type a password. If they mistype
6311 * the username they will want to be able to get back and
6312 * retype it!
7cca0d81 6313 */
51470298 6314 s->username[0] = '\0';
6315 s->got_username = FALSE;
1408a877 6316 do {
1408a877 6317 /*
6318 * Get a username.
6319 */
86916870 6320 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 6321 /*
6322 * We got a username last time round this loop, and
6323 * with change_username turned off we don't try to get
6324 * it again.
6325 */
aa09f7d0 6326 } else if (!*ssh->cfg.username) {
c0a81592 6327 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 6328 if (!ssh_get_line("login as: ",
51470298 6329 s->username, sizeof(s->username), FALSE)) {
32874aea 6330 /*
6331 * get_line failed to get a username.
6332 * Terminate.
6333 */
6334 logevent("No username provided. Abandoning session.");
ac934965 6335 ssh->close_expected = TRUE;
3bb2f322 6336 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6337 crStopV;
32874aea 6338 }
6339 } else {
51470298 6340 int ret; /* need not be saved across crReturn */
6341 c_write_str(ssh, "login as: ");
6342 ssh->send_ok = 1;
6343 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 6344 do {
ff3187f6 6345 crWaitUntilV(!pktin);
51470298 6346 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6347 } while (ret == 0);
6348 if (ret < 0)
6349 cleanup_exit(0);
4ca0c9d1 6350 c_write_str(ssh, "\r\n");
32874aea 6351 }
51470298 6352 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 6353 } else {
57356d63 6354 char *stuff;
86916870 6355 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 6356 s->username[sizeof(s->username)-1] = '\0';
65a22376 6357 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 6358 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 6359 c_write_str(ssh, stuff);
57356d63 6360 sfree(stuff);
7cca0d81 6361 }
6362 }
51470298 6363 s->got_username = TRUE;
7cca0d81 6364
65a22376 6365 /*
1408a877 6366 * Send an authentication request using method "none": (a)
6367 * just in case it succeeds, and (b) so that we know what
6368 * authentication methods we can usefully try next.
65a22376 6369 */
51470298 6370 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6371
ff3187f6 6372 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6373 ssh2_pkt_addstring(s->pktout, s->username);
6374 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6375 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6376 ssh2_pkt_send(ssh, s->pktout);
51470298 6377 s->type = AUTH_TYPE_NONE;
6378 s->gotit = FALSE;
6379 s->we_are_in = FALSE;
6380
6381 s->tried_pubkey_config = FALSE;
6382 s->tried_agent = FALSE;
51470298 6383 s->kbd_inter_running = FALSE;
6ac3a551 6384 s->kbd_inter_refused = FALSE;
86916870 6385 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 6386 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 6387 int keytype;
6c6d9ed9 6388 logeventf(ssh, "Reading private key file \"%.150s\"",
6389 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 6390 keytype = key_type(&ssh->cfg.keyfile);
51470298 6391 if (keytype == SSH_KEYTYPE_SSH2) {
6392 s->publickey_blob =
9a30e26b 6393 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 6394 &s->publickey_bloblen, NULL);
51470298 6395 } else {
57356d63 6396 char *msgbuf;
c2ad7d0d 6397 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 6398 key_type_to_str(keytype));
57356d63 6399 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 6400 " (%s)\r\n",
6401 filename_to_str(&ssh->cfg.keyfile),
57356d63 6402 key_type_to_str(keytype));
51470298 6403 c_write_str(ssh, msgbuf);
57356d63 6404 sfree(msgbuf);
51470298 6405 s->publickey_blob = NULL;
231ee168 6406 }
396778f1 6407 } else
51470298 6408 s->publickey_blob = NULL;
65a22376 6409
1408a877 6410 while (1) {
6411 /*
6412 * Wait for the result of the last authentication request.
6413 */
51470298 6414 if (!s->gotit)
ff3187f6 6415 crWaitUntilV(pktin);
6416 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 6417 char *banner;
6418 int size;
6419 /*
6420 * Don't show the banner if we're operating in
6421 * non-verbose non-interactive mode. (It's probably
6422 * a script, which means nobody will read the
6423 * banner _anyway_, and moreover the printing of
6424 * the banner will screw up processing on the
6425 * output of (say) plink.)
6426 */
6427 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
ff3187f6 6428 ssh_pkt_getstring(pktin, &banner, &size);
32874aea 6429 if (banner)
51470298 6430 c_write_untrusted(ssh, banner, size);
32874aea 6431 }
ff3187f6 6432 crWaitUntilV(pktin);
1408a877 6433 }
ff3187f6 6434 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 6435 logevent("Access granted");
51470298 6436 s->we_are_in = TRUE;
1408a877 6437 break;
6438 }
65a22376 6439
51470298 6440 if (s->kbd_inter_running &&
ff3187f6 6441 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 6442 /*
45068b27 6443 * This is either a further set-of-prompts packet
6444 * in keyboard-interactive authentication, or it's
6445 * the same one and we came back here with `gotit'
6446 * set. In the former case, we must reset the
6447 * curr_prompt variable.
b3186d64 6448 */
51470298 6449 if (!s->gotit)
6450 s->curr_prompt = 0;
4c6e53e3 6451 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6452 /* FIXME: perhaps we should support this? */
6453 bombout(("PASSWD_CHANGEREQ not yet supported"));
6454 crStopV;
ff3187f6 6455 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 6456 bombout(("Strange packet received during authentication: type %d",
ff3187f6 6457 pktin->type));
7ffdbc1a 6458 crStopV;
65a22376 6459 }
6460
51470298 6461 s->gotit = FALSE;
65a22376 6462
1408a877 6463 /*
6464 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6465 * we can look at the string in it and know what we can
6466 * helpfully try next.
6467 */
ff3187f6 6468 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 6469 char *methods;
6470 int methlen;
ff3187f6 6471 ssh_pkt_getstring(pktin, &methods, &methlen);
51470298 6472 s->kbd_inter_running = FALSE;
ff3187f6 6473 if (!ssh2_pkt_getbool(pktin)) {
1408a877 6474 /*
6475 * We have received an unequivocal Access
6476 * Denied. This can translate to a variety of
6477 * messages:
6478 *
6479 * - if we'd just tried "none" authentication,
6480 * it's not worth printing anything at all
6481 *
6482 * - if we'd just tried a public key _offer_,
6483 * the message should be "Server refused our
6484 * key" (or no message at all if the key
6485 * came from Pageant)
6486 *
6487 * - if we'd just tried anything else, the
6488 * message really should be "Access denied".
6489 *
6490 * Additionally, if we'd just tried password
6491 * authentication, we should break out of this
6492 * whole loop so as to go back to the username
91f57d1f 6493 * prompt (iff we're configured to allow
6494 * username change attempts).
1408a877 6495 */
51470298 6496 if (s->type == AUTH_TYPE_NONE) {
1408a877 6497 /* do nothing */
51470298 6498 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6499 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6500 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6501 c_write_str(ssh, "Server refused our key\r\n");
1408a877 6502 logevent("Server refused public key");
51470298 6503 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 6504 /* server declined keyboard-interactive; ignore */
1408a877 6505 } else {
51470298 6506 c_write_str(ssh, "Access denied\r\n");
1408a877 6507 logevent("Access denied");
91f57d1f 6508 if (s->type == AUTH_TYPE_PASSWORD &&
6509 ssh->cfg.change_username) {
6c9dce7c 6510 /* XXX perhaps we should allow
6511 * keyboard-interactive to do this too? */
51470298 6512 s->we_are_in = FALSE;
1408a877 6513 break;
6514 }
6515 }
6516 } else {
51470298 6517 c_write_str(ssh, "Further authentication required\r\n");
1408a877 6518 logevent("Further authentication required");
6519 }
65a22376 6520
51470298 6521 s->can_pubkey =
32874aea 6522 in_commasep_string("publickey", methods, methlen);
51470298 6523 s->can_passwd =
32874aea 6524 in_commasep_string("password", methods, methlen);
86916870 6525 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 6526 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 6527 }
65a22376 6528
51470298 6529 s->method = 0;
6530 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 6531 s->need_pw = FALSE;
65a22376 6532
0405e71f 6533 /*
6534 * Most password/passphrase prompts will be
6535 * non-echoing, so we set this to 0 by default.
6536 * Exception is that some keyboard-interactive prompts
6537 * can be echoing, in which case we'll set this to 1.
6538 */
51470298 6539 s->echo = 0;
0405e71f 6540
51470298 6541 if (!s->method && s->can_pubkey &&
6542 agent_exists() && !s->tried_agent) {
1983e559 6543 /*
6544 * Attempt public-key authentication using Pageant.
6545 */
1983e559 6546 void *r;
51470298 6547 s->authed = FALSE;
1983e559 6548
51470298 6549 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6550 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6551
51470298 6552 s->tried_agent = TRUE;
1983e559 6553
6554 logevent("Pageant is running. Requesting keys.");
6555
6556 /* Request the keys held by the agent. */
51470298 6557 PUT_32BIT(s->request, 1);
6558 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 6559 if (!agent_query(s->request, 5, &r, &s->responselen,
6560 ssh_agent_callback, ssh)) {
6561 do {
6562 crReturnV;
ff3187f6 6563 if (pktin) {
839f10db 6564 bombout(("Unexpected data from server while"
6565 " waiting for agent response"));
6566 crStopV;
6567 }
ff3187f6 6568 } while (pktin || inlen > 0);
839f10db 6569 r = ssh->agent_response;
6570 s->responselen = ssh->agent_response_len;
6571 }
51470298 6572 s->response = (unsigned char *) r;
6573 if (s->response && s->responselen >= 5 &&
6574 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6575 s->p = s->response + 5;
6576 s->nkeys = GET_32BIT(s->p);
6577 s->p += 4;
fb983202 6578 logeventf(ssh, "Pageant has %d SSH2 keys", s->nkeys);
51470298 6579 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 6580 void *vret;
1983e559 6581
fb983202 6582 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
51470298 6583 s->pklen = GET_32BIT(s->p);
6584 s->p += 4;
6585 if (s->publickey_blob &&
6586 s->pklen == s->publickey_bloblen &&
6587 !memcmp(s->p, s->publickey_blob,
6588 s->publickey_bloblen)) {
396778f1 6589 logevent("This key matches configured key file");
51470298 6590 s->tried_pubkey_config = 1;
396778f1 6591 }
d8baa528 6592 s->pkblob = (char *)s->p;
51470298 6593 s->p += s->pklen;
6594 s->alglen = GET_32BIT(s->pkblob);
6595 s->alg = s->pkblob + 4;
6596 s->commentlen = GET_32BIT(s->p);
6597 s->p += 4;
d8baa528 6598 s->commentp = (char *)s->p;
51470298 6599 s->p += s->commentlen;
ff3187f6 6600 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6601 ssh2_pkt_addstring(s->pktout, s->username);
6602 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6603 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6604 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6605 ssh2_pkt_addstring_start(s->pktout);
6606 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6607 ssh2_pkt_addstring_start(s->pktout);
6608 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6609 ssh2_pkt_send(ssh, s->pktout);
6610
6611 crWaitUntilV(pktin);
6612 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 6613 logevent("Key refused");
6614 continue;
6615 }
6616
32874aea 6617 if (flags & FLAG_VERBOSE) {
51470298 6618 c_write_str(ssh, "Authenticating with "
6619 "public key \"");
6620 c_write(ssh, s->commentp, s->commentlen);
6621 c_write_str(ssh, "\" from agent\r\n");
32874aea 6622 }
1983e559 6623
6624 /*
6625 * Server is willing to accept the key.
6626 * Construct a SIGN_REQUEST.
6627 */
ff3187f6 6628 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6629 ssh2_pkt_addstring(s->pktout, s->username);
6630 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6631 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6632 ssh2_pkt_addbool(s->pktout, TRUE);
6633 ssh2_pkt_addstring_start(s->pktout);
6634 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6635 ssh2_pkt_addstring_start(s->pktout);
6636 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6637
6638 s->siglen = s->pktout->length - 5 + 4 + 20;
dda87a28 6639 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6640 s->siglen -= 4;
51470298 6641 s->len = 1; /* message type */
6642 s->len += 4 + s->pklen; /* key blob */
6643 s->len += 4 + s->siglen; /* data to sign */
6644 s->len += 4; /* flags */
3d88e64d 6645 s->agentreq = snewn(4 + s->len, char);
51470298 6646 PUT_32BIT(s->agentreq, s->len);
6647 s->q = s->agentreq + 4;
6648 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6649 PUT_32BIT(s->q, s->pklen);
6650 s->q += 4;
6651 memcpy(s->q, s->pkblob, s->pklen);
6652 s->q += s->pklen;
6653 PUT_32BIT(s->q, s->siglen);
6654 s->q += 4;
1983e559 6655 /* Now the data to be signed... */
dda87a28 6656 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6657 PUT_32BIT(s->q, 20);
6658 s->q += 4;
6659 }
51470298 6660 memcpy(s->q, ssh->v2_session_id, 20);
6661 s->q += 20;
ff3187f6 6662 memcpy(s->q, s->pktout->data + 5,
6663 s->pktout->length - 5);
6664 s->q += s->pktout->length - 5;
1983e559 6665 /* And finally the (zero) flags word. */
51470298 6666 PUT_32BIT(s->q, 0);
839f10db 6667 if (!agent_query(s->agentreq, s->len + 4,
6668 &vret, &s->retlen,
6669 ssh_agent_callback, ssh)) {
6670 do {
6671 crReturnV;
ff3187f6 6672 if (pktin) {
839f10db 6673 bombout(("Unexpected data from server"
6674 " while waiting for agent"
6675 " response"));
6676 crStopV;
6677 }
ff3187f6 6678 } while (pktin || inlen > 0);
839f10db 6679 vret = ssh->agent_response;
6680 s->retlen = ssh->agent_response_len;
6681 }
51470298 6682 s->ret = vret;
6683 sfree(s->agentreq);
6684 if (s->ret) {
6685 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 6686 logevent("Sending Pageant's response");
ff3187f6 6687 ssh2_add_sigblob(ssh, s->pktout,
6688 s->pkblob, s->pklen,
51470298 6689 s->ret + 9,
6690 GET_32BIT(s->ret + 5));
ff3187f6 6691 ssh2_pkt_send(ssh, s->pktout);
51470298 6692 s->authed = TRUE;
1983e559 6693 break;
6694 } else {
32874aea 6695 logevent
6696 ("Pageant failed to answer challenge");
51470298 6697 sfree(s->ret);
1983e559 6698 }
6699 }
6700 }
51470298 6701 if (s->authed)
1983e559 6702 continue;
6703 }
29b1d0b3 6704 sfree(s->response);
1983e559 6705 }
6706
51470298 6707 if (!s->method && s->can_pubkey && s->publickey_blob
6708 && !s->tried_pubkey_config) {
1408a877 6709 unsigned char *pub_blob;
6710 char *algorithm, *comment;
6711 int pub_blob_len;
65a22376 6712
51470298 6713 s->tried_pubkey_config = TRUE;
65a22376 6714
51470298 6715 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6716 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6717
65a22376 6718 /*
1408a877 6719 * Try the public key supplied in the configuration.
6720 *
6721 * First, offer the public blob to see if the server is
6722 * willing to accept it.
65a22376 6723 */
d8baa528 6724 pub_blob =
9a30e26b 6725 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 6726 &algorithm,
222d54dc 6727 &pub_blob_len,
6728 NULL);
1408a877 6729 if (pub_blob) {
ff3187f6 6730 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6731 ssh2_pkt_addstring(s->pktout, s->username);
6732 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6733 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6734 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6735 ssh2_pkt_addstring(s->pktout, algorithm);
6736 ssh2_pkt_addstring_start(s->pktout);
6737 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
d8baa528 6738 pub_blob_len);
ff3187f6 6739 ssh2_pkt_send(ssh, s->pktout);
a03c9f9c 6740 logevent("Offered public key");
1408a877 6741
ff3187f6 6742 crWaitUntilV(pktin);
6743 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
51470298 6744 s->gotit = TRUE;
6745 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 6746 continue; /* key refused; give up on it */
1408a877 6747 }
65a22376 6748
1408a877 6749 logevent("Offer of public key accepted");
65a22376 6750 /*
1408a877 6751 * Actually attempt a serious authentication using
6752 * the key.
65a22376 6753 */
9a30e26b 6754 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 6755 sprintf(s->pwprompt,
32874aea 6756 "Passphrase for key \"%.100s\": ",
6757 comment);
51470298 6758 s->need_pw = TRUE;
1408a877 6759 } else {
51470298 6760 s->need_pw = FALSE;
1408a877 6761 }
4e520718 6762 if (flags & FLAG_VERBOSE) {
6763 c_write_str(ssh, "Authenticating with public key \"");
6764 c_write_str(ssh, comment);
6765 c_write_str(ssh, "\"\r\n");
6766 }
51470298 6767 s->method = AUTH_PUBLICKEY_FILE;
65a22376 6768 }
1408a877 6769 }
6770
6f64ce13 6771 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6772 !s->kbd_inter_running) {
51470298 6773 s->method = AUTH_KEYBOARD_INTERACTIVE;
6774 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6775
51470298 6776 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6777 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6778
ff3187f6 6779 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6780 ssh2_pkt_addstring(s->pktout, s->username);
6781 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6782 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6783 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6784 ssh2_pkt_addstring(s->pktout, "");
6785 ssh2_pkt_send(ssh, s->pktout);
6786
6787 crWaitUntilV(pktin);
6788 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6789 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
51470298 6790 s->gotit = TRUE;
af659722 6791 logevent("Keyboard-interactive authentication refused");
51470298 6792 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6ac3a551 6793 s->kbd_inter_refused = TRUE; /* don't try it again */
af659722 6794 continue;
6795 }
6796
51470298 6797 s->kbd_inter_running = TRUE;
6798 s->curr_prompt = 0;
af659722 6799 }
6800
51470298 6801 if (s->kbd_inter_running) {
6802 s->method = AUTH_KEYBOARD_INTERACTIVE;
6803 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6804
51470298 6805 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6806 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6807
51470298 6808 if (s->curr_prompt == 0) {
45068b27 6809 /*
6810 * We've got a fresh USERAUTH_INFO_REQUEST.
6811 * Display header data, and start going through
6812 * the prompts.
6813 */
6814 char *name, *inst, *lang;
6815 int name_len, inst_len, lang_len;
6816
ff3187f6 6817 ssh_pkt_getstring(pktin, &name, &name_len);
6818 ssh_pkt_getstring(pktin, &inst, &inst_len);
6819 ssh_pkt_getstring(pktin, &lang, &lang_len);
45068b27 6820 if (name_len > 0) {
51470298 6821 c_write_untrusted(ssh, name, name_len);
6822 c_write_str(ssh, "\r\n");
45068b27 6823 }
6824 if (inst_len > 0) {
51470298 6825 c_write_untrusted(ssh, inst, inst_len);
6826 c_write_str(ssh, "\r\n");
45068b27 6827 }
ff3187f6 6828 s->num_prompts = ssh_pkt_getuint32(pktin);
45068b27 6829 }
af659722 6830
45068b27 6831 /*
6832 * If there are prompts remaining in the packet,
6833 * display one and get a response.
6834 */
51470298 6835 if (s->curr_prompt < s->num_prompts) {
45068b27 6836 char *prompt;
6837 int prompt_len;
af659722 6838
ff3187f6 6839 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
45068b27 6840 if (prompt_len > 0) {
85fdbe25 6841 static const char trunc[] = "<prompt truncated>: ";
6842 static const int prlen = sizeof(s->pwprompt) -
6843 lenof(trunc);
6844 if (prompt_len > prlen) {
6845 memcpy(s->pwprompt, prompt, prlen);
6846 strcpy(s->pwprompt + prlen, trunc);
6847 } else {
6848 memcpy(s->pwprompt, prompt, prompt_len);
6849 s->pwprompt[prompt_len] = '\0';
6850 }
45068b27 6851 } else {
51470298 6852 strcpy(s->pwprompt,
45068b27 6853 "<server failed to send prompt>: ");
6854 }
ff3187f6 6855 s->echo = ssh2_pkt_getbool(pktin);
51470298 6856 s->need_pw = TRUE;
45068b27 6857 } else
51470298 6858 s->need_pw = FALSE;
af659722 6859 }
6860
51470298 6861 if (!s->method && s->can_passwd) {
6862 s->method = AUTH_PASSWORD;
6863 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6864 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6865 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6866 ssh->savedhost);
6867 s->need_pw = TRUE;
1408a877 6868 }
6869
51470298 6870 if (s->need_pw) {
fa17a66e 6871 if (ssh_get_line) {
51470298 6872 if (!ssh_get_line(s->pwprompt, s->password,
6873 sizeof(s->password), TRUE)) {
1408a877 6874 /*
fa17a66e 6875 * get_line failed to get a password (for
6876 * example because one was supplied on the
6877 * command line which has already failed to
6878 * work). Terminate.
1408a877 6879 */
ff3187f6 6880 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6881 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6882 ssh2_pkt_addstring(s->pktout, "No more passwords available"
51470298 6883 " to try");
ff3187f6 6884 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6885 ssh2_pkt_send_noqueue(ssh, s->pktout);
247308b5 6886 logevent("Unable to authenticate");
a8327734 6887 connection_fatal(ssh->frontend,
6888 "Unable to authenticate");
ac934965 6889 ssh->close_expected = TRUE;
3bb2f322 6890 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6891 crStopV;
1408a877 6892 }
6893 } else {
51470298 6894 int ret; /* need not be saved across crReturn */
6895 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6896 ssh->send_ok = 1;
1408a877 6897
51470298 6898 setup_userpass_input(ssh, s->password,
6899 sizeof(s->password), s->echo);
0405e71f 6900 do {
ff3187f6 6901 crWaitUntilV(!pktin);
51470298 6902 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6903 } while (ret == 0);
6904 if (ret < 0)
6905 cleanup_exit(0);
51470298 6906 c_write_str(ssh, "\r\n");
65a22376 6907 }
65a22376 6908 }
65a22376 6909
51470298 6910 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 6911 /*
6912 * We have our passphrase. Now try the actual authentication.
6913 */
6914 struct ssh2_userkey *key;
222d54dc 6915 const char *error = NULL;
65a22376 6916
222d54dc 6917 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6918 &error);
1408a877 6919 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6920 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 6921 c_write_str(ssh, "Wrong passphrase\r\n");
6922 s->tried_pubkey_config = FALSE;
1408a877 6923 } else {
222d54dc 6924 c_write_str(ssh, "Unable to load private key (");
6925 c_write_str(ssh, error);
6926 c_write_str(ssh, ")\r\n");
51470298 6927 s->tried_pubkey_config = TRUE;
1408a877 6928 }
6929 /* Send a spurious AUTH_NONE to return to the top. */
ff3187f6 6930 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6931 ssh2_pkt_addstring(s->pktout, s->username);
6932 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6933 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6934 ssh2_pkt_send(ssh, s->pktout);
51470298 6935 s->type = AUTH_TYPE_NONE;
1408a877 6936 } else {
1dd353b5 6937 unsigned char *pkblob, *sigblob, *sigdata;
6938 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 6939 int p;
65a22376 6940
1408a877 6941 /*
6942 * We have loaded the private key and the server
6943 * has announced that it's willing to accept it.
6944 * Hallelujah. Generate a signature and send it.
6945 */
ff3187f6 6946 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6947 ssh2_pkt_addstring(s->pktout, s->username);
6948 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6949 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6950 ssh2_pkt_addbool(s->pktout, TRUE);
6951 ssh2_pkt_addstring(s->pktout, key->alg->name);
1dd353b5 6952 pkblob = key->alg->public_blob(key->data, &pkblob_len);
ff3187f6 6953 ssh2_pkt_addstring_start(s->pktout);
6954 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
1408a877 6955
6956 /*
6957 * The data to be signed is:
6958 *
6959 * string session-id
6960 *
6961 * followed by everything so far placed in the
6962 * outgoing packet.
6963 */
ff3187f6 6964 sigdata_len = s->pktout->length - 5 + 4 + 20;
dda87a28 6965 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6966 sigdata_len -= 4;
92d60585 6967 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 6968 p = 0;
6969 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6970 PUT_32BIT(sigdata+p, 20);
6971 p += 4;
6972 }
6973 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
ff3187f6 6974 memcpy(sigdata+p, s->pktout->data + 5,
6975 s->pktout->length - 5);
6976 p += s->pktout->length - 5;
dda87a28 6977 assert(p == sigdata_len);
d8baa528 6978 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 6979 sigdata_len, &sigblob_len);
ff3187f6 6980 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 6981 sigblob, sigblob_len);
6982 sfree(pkblob);
6983 sfree(sigblob);
1408a877 6984 sfree(sigdata);
6985
ff3187f6 6986 ssh2_pkt_send(ssh, s->pktout);
51470298 6987 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 6988 key->alg->freekey(key->data);
1408a877 6989 }
51470298 6990 } else if (s->method == AUTH_PASSWORD) {
65a22376 6991 /*
95d2d262 6992 * We pad out the password packet to 256 bytes to make
6993 * it harder for an attacker to find the length of the
6994 * user's password.
1408a877 6995 *
95d2d262 6996 * Anyone using a password longer than 256 bytes
6997 * probably doesn't have much to worry about from
1408a877 6998 * people who find out how long their password is!
65a22376 6999 */
ff3187f6 7000 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
95d2d262 7001 s->pktout->forcepad = 256;
ff3187f6 7002 ssh2_pkt_addstring(s->pktout, s->username);
7003 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7004 ssh2_pkt_addstring(s->pktout, "password");
7005 ssh2_pkt_addbool(s->pktout, FALSE);
7006 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7007 ssh2_pkt_addstring(s->pktout, s->password);
1409c1b3 7008 memset(s->password, 0, sizeof(s->password));
ff3187f6 7009 end_log_omission(ssh, s->pktout);
95d2d262 7010 ssh2_pkt_send(ssh, s->pktout);
0d43337a 7011 logevent("Sent password");
51470298 7012 s->type = AUTH_TYPE_PASSWORD;
7013 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
7014 if (s->curr_prompt == 0) {
ff3187f6 7015 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
10e09fb5 7016 s->pktout->forcepad = 256;
ff3187f6 7017 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
45068b27 7018 }
51470298 7019 if (s->need_pw) { /* only add pw if we just got one! */
ff3187f6 7020 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7021 ssh2_pkt_addstring(s->pktout, s->password);
51470298 7022 memset(s->password, 0, sizeof(s->password));
ff3187f6 7023 end_log_omission(ssh, s->pktout);
51470298 7024 s->curr_prompt++;
45068b27 7025 }
51470298 7026 if (s->curr_prompt >= s->num_prompts) {
ff3187f6 7027 ssh2_pkt_send(ssh, s->pktout);
45068b27 7028 } else {
7029 /*
7030 * If there are prompts remaining, we set
7031 * `gotit' so that we won't attempt to get
7032 * another packet. Then we go back round the
7033 * loop and will end up retrieving another
7034 * prompt out of the existing packet. Funky or
7035 * what?
7036 */
51470298 7037 s->gotit = TRUE;
45068b27 7038 }
51470298 7039 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 7040 } else {
51470298 7041 c_write_str(ssh, "No supported authentication methods"
7042 " left to try!\r\n");
7043 logevent("No supported authentications offered."
7044 " Disconnecting");
ff3187f6 7045 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
7046 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
7047 ssh2_pkt_addstring(s->pktout, "No supported authentication"
51470298 7048 " methods available");
ff3187f6 7049 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 7050 ssh2_pkt_send_noqueue(ssh, s->pktout);
ac934965 7051 ssh->close_expected = TRUE;
3bb2f322 7052 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 7053 crStopV;
65a22376 7054 }
65a22376 7055 }
51470298 7056 } while (!s->we_are_in);
7cca0d81 7057
7058 /*
7059 * Now we're authenticated for the connection protocol. The
7060 * connection protocol will automatically have started at this
7061 * point; there's no need to send SERVICE_REQUEST.
7062 */
7063
0ed48730 7064 ssh->channels = newtree234(ssh_channelcmp);
7065
7cca0d81 7066 /*
b09eaa88 7067 * Set up handlers for some connection protocol messages, so we
7068 * don't have to handle them repeatedly in this coroutine.
7069 */
7070 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7071 ssh2_msg_channel_window_adjust;
51df0ab5 7072 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7073 ssh2_msg_global_request;
b09eaa88 7074
7075 /*
0ed48730 7076 * Create the main session channel.
7cca0d81 7077 */
0ed48730 7078 if (!ssh->cfg.ssh_no_shell) {
7079 ssh->mainchan = snew(struct ssh_channel);
7080 ssh->mainchan->ssh = ssh;
7081 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 7082 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7083 ssh2_pkt_addstring(s->pktout, "session");
7084 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 7085 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7086 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
954d5c5a 7087 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 7088 ssh2_pkt_send(ssh, s->pktout);
7089 crWaitUntilV(pktin);
7090 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 7091 bombout(("Server refused to open a session"));
7092 crStopV;
7093 /* FIXME: error data comes back in FAILURE packet */
7094 }
ff3187f6 7095 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 7096 bombout(("Server's channel confirmation cited wrong channel"));
7097 crStopV;
7098 }
ff3187f6 7099 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 7100 ssh->mainchan->halfopen = FALSE;
0ed48730 7101 ssh->mainchan->type = CHAN_MAINSESSION;
7102 ssh->mainchan->closes = 0;
ff3187f6 7103 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7104 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 7105 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7106 add234(ssh->channels, ssh->mainchan);
62638676 7107 update_specials_menu(ssh->frontend);
0ed48730 7108 logevent("Opened channel for session");
7109 } else
7110 ssh->mainchan = NULL;
7cca0d81 7111
7112 /*
51df0ab5 7113 * Now we have a channel, make dispatch table entries for
7114 * general channel-based messages.
7115 */
7116 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7117 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7118 ssh2_msg_channel_data;
7119 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7120 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7121 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7122 ssh2_msg_channel_open_confirmation;
7123 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7124 ssh2_msg_channel_open_failure;
7125 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7126 ssh2_msg_channel_request;
7127 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7128 ssh2_msg_channel_open;
7129
7130 /*
783415f8 7131 * Potentially enable X11 forwarding.
7132 */
0ed48730 7133 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 7134 char proto[20], data[64];
7135 logevent("Requesting X11 forwarding");
302121de 7136 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 7137 data, sizeof(data), ssh->cfg.x11_auth);
7138 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 7139 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7140 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7141 ssh2_pkt_addstring(s->pktout, "x11-req");
7142 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7143 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7144 ssh2_pkt_addstring(s->pktout, proto);
7145 ssh2_pkt_addstring(s->pktout, data);
7146 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7147 ssh2_pkt_send(ssh, s->pktout);
32874aea 7148
b09eaa88 7149 crWaitUntilV(pktin);
32874aea 7150
ff3187f6 7151 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7152 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7153 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 7154 " packet type %d", pktin->type));
7ffdbc1a 7155 crStopV;
32874aea 7156 }
7157 logevent("X11 forwarding refused");
7158 } else {
7159 logevent("X11 forwarding enabled");
51470298 7160 ssh->X11_fwd_enabled = TRUE;
32874aea 7161 }
783415f8 7162 }
7163
7164 /*
bc240b21 7165 * Enable port forwardings.
7166 */
06fadff5 7167 ssh_setup_portfwd(ssh, &ssh->cfg);
bc240b21 7168
7169 /*
36c2a3e9 7170 * Potentially enable agent forwarding.
7171 */
0ed48730 7172 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 7173 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 7174 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7175 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7176 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7177 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7178 ssh2_pkt_send(ssh, s->pktout);
32874aea 7179
b09eaa88 7180 crWaitUntilV(pktin);
32874aea 7181
ff3187f6 7182 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7183 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7184 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 7185 " packet type %d", pktin->type));
7ffdbc1a 7186 crStopV;
32874aea 7187 }
7188 logevent("Agent forwarding refused");
7189 } else {
7190 logevent("Agent forwarding enabled");
51470298 7191 ssh->agentfwd_enabled = TRUE;
32874aea 7192 }
36c2a3e9 7193 }
7194
7195 /*
7cca0d81 7196 * Now allocate a pty for the session.
7197 */
0ed48730 7198 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 7199 /* Unpick the terminal-speed string. */
7200 /* XXX perhaps we should allow no speeds to be sent. */
db219738 7201 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7202 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 7203 /* Build the pty request. */
ff3187f6 7204 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7205 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7206 ssh2_pkt_addstring(s->pktout, "pty-req");
7207 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7208 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7209 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7210 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7211 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7212 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7213 ssh2_pkt_addstring_start(s->pktout);
7214 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
7215 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7216 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
7217 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7218 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7219 ssh2_pkt_send(ssh, s->pktout);
51470298 7220 ssh->state = SSH_STATE_INTERMED;
32874aea 7221
b09eaa88 7222 crWaitUntilV(pktin);
32874aea 7223
ff3187f6 7224 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7225 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7226 bombout(("Unexpected response to pty request:"
ff3187f6 7227 " packet type %d", pktin->type));
7ffdbc1a 7228 crStopV;
32874aea 7229 }
51470298 7230 c_write_str(ssh, "Server refused to allocate pty\r\n");
7231 ssh->editing = ssh->echoing = 1;
32874aea 7232 } else {
a5dd8467 7233 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 7234 ssh->ospeed, ssh->ispeed);
32874aea 7235 }
0965bee0 7236 } else {
51470298 7237 ssh->editing = ssh->echoing = 1;
7cca0d81 7238 }
7239
7240 /*
73feed4f 7241 * Send environment variables.
7242 *
7243 * Simplest thing here is to send all the requests at once, and
7244 * then wait for a whole bunch of successes or failures.
7245 */
7246 if (ssh->mainchan && *ssh->cfg.environmt) {
7247 char *e = ssh->cfg.environmt;
7248 char *var, *varend, *val;
7249
7250 s->num_env = 0;
7251
7252 while (*e) {
7253 var = e;
7254 while (*e && *e != '\t') e++;
7255 varend = e;
7256 if (*e == '\t') e++;
7257 val = e;
7258 while (*e) e++;
7259 e++;
7260
ff3187f6 7261 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7262 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7263 ssh2_pkt_addstring(s->pktout, "env");
7264 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7265 ssh2_pkt_addstring_start(s->pktout);
7266 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7267 ssh2_pkt_addstring(s->pktout, val);
7268 ssh2_pkt_send(ssh, s->pktout);
73feed4f 7269
7270 s->num_env++;
7271 }
7272
7273 logeventf(ssh, "Sent %d environment variables", s->num_env);
7274
7275 s->env_ok = 0;
7276 s->env_left = s->num_env;
7277
7278 while (s->env_left > 0) {
b09eaa88 7279 crWaitUntilV(pktin);
73feed4f 7280
ff3187f6 7281 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7282 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 7283 bombout(("Unexpected response to environment request:"
ff3187f6 7284 " packet type %d", pktin->type));
73feed4f 7285 crStopV;
7286 }
7287 } else {
7288 s->env_ok++;
7289 }
7290
7291 s->env_left--;
7292 }
7293
7294 if (s->env_ok == s->num_env) {
7295 logevent("All environment variables successfully set");
7296 } else if (s->env_ok == 0) {
7297 logevent("All environment variables refused");
7298 c_write_str(ssh, "Server refused to set environment variables\r\n");
7299 } else {
7300 logeventf(ssh, "%d environment variables refused",
7301 s->num_env - s->env_ok);
7302 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7303 }
7304 }
7305
7306 /*
fd5e5847 7307 * Start a shell or a remote command. We may have to attempt
7308 * this twice if the config data has provided a second choice
7309 * of command.
7cca0d81 7310 */
0ed48730 7311 if (ssh->mainchan) while (1) {
fd5e5847 7312 int subsys;
7313 char *cmd;
7314
51470298 7315 if (ssh->fallback_cmd) {
86916870 7316 subsys = ssh->cfg.ssh_subsys2;
7317 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 7318 } else {
86916870 7319 subsys = ssh->cfg.ssh_subsys;
7320 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 7321 }
7322
ff3187f6 7323 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7324 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 7325 if (subsys) {
ff3187f6 7326 ssh2_pkt_addstring(s->pktout, "subsystem");
7327 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7328 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7329 } else if (*cmd) {
ff3187f6 7330 ssh2_pkt_addstring(s->pktout, "exec");
7331 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7332 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7333 } else {
ff3187f6 7334 ssh2_pkt_addstring(s->pktout, "shell");
7335 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 7336 }
ff3187f6 7337 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 7338
7339 crWaitUntilV(pktin);
7340
ff3187f6 7341 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7342 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7343 bombout(("Unexpected response to shell/command request:"
ff3187f6 7344 " packet type %d", pktin->type));
7ffdbc1a 7345 crStopV;
fd5e5847 7346 }
7347 /*
7348 * We failed to start the command. If this is the
7349 * fallback command, we really are finished; if it's
7350 * not, and if the fallback command exists, try falling
7351 * back to it before complaining.
7352 */
86916870 7353 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 7354 logevent("Primary command failed; attempting fallback");
51470298 7355 ssh->fallback_cmd = TRUE;
fd5e5847 7356 continue;
7357 }
6b5cf8b4 7358 bombout(("Server refused to start a shell/command"));
7ffdbc1a 7359 crStopV;
fd5e5847 7360 } else {
7361 logevent("Started a shell/command");
32874aea 7362 }
fd5e5847 7363 break;
7cca0d81 7364 }
7365
51470298 7366 ssh->state = SSH_STATE_SESSION;
7367 if (ssh->size_needed)
7368 ssh_size(ssh, ssh->term_width, ssh->term_height);
7369 if (ssh->eof_needed)
7370 ssh_special(ssh, TS_EOF);
6e48c3fe 7371
7cca0d81 7372 /*
7373 * Transfer data!
7374 */
b9d7bcad 7375 if (ssh->ldisc)
7376 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 7377 if (ssh->mainchan)
7378 ssh->send_ok = 1;
7cca0d81 7379 while (1) {
e5574168 7380 crReturnV;
51470298 7381 s->try_send = FALSE;
ff3187f6 7382 if (pktin) {
2b7540a7 7383
51df0ab5 7384 /*
7385 * _All_ the connection-layer packets we expect to
7386 * receive are now handled by the dispatch table.
7387 * Anything that reaches here must be bogus.
7388 */
32874aea 7389
51df0ab5 7390 bombout(("Strange packet received: type %d", pktin->type));
7391 crStopV;
0ed48730 7392 } else if (ssh->mainchan) {
32874aea 7393 /*
7394 * We have spare data. Add it to the channel buffer.
7395 */
d8baa528 7396 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 7397 s->try_send = TRUE;
32874aea 7398 }
51470298 7399 if (s->try_send) {
32874aea 7400 int i;
7401 struct ssh_channel *c;
7402 /*
7403 * Try to send data on all channels if we can.
7404 */
51470298 7405 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 7406 int bufsize;
7407 if (c->closes)
7408 continue; /* don't send on closing channels */
7409 bufsize = ssh2_try_send(c);
5471d09a 7410 if (bufsize == 0) {
7411 switch (c->type) {
7412 case CHAN_MAINSESSION:
7413 /* stdin need not receive an unthrottle
7414 * notification since it will be polled */
7415 break;
7416 case CHAN_X11:
7417 x11_unthrottle(c->u.x11.s);
7418 break;
7419 case CHAN_AGENT:
7420 /* agent sockets are request/response and need no
7421 * buffer management */
7422 break;
7423 case CHAN_SOCKDATA:
7424 pfd_unthrottle(c->u.pfd.s);
7425 break;
7426 }
7427 }
7428 }
7cca0d81 7429 }
e5574168 7430 }
7431
7432 crFinishV;
7433}
7434
7435/*
b09eaa88 7436 * Handlers for SSH2 messages that might arrive at any moment.
7437 */
409bfa77 7438static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
b09eaa88 7439{
7440 /* log reason code in disconnect message */
7441 char *buf, *msg;
7442 int nowlen, reason, msglen;
7443
7444 reason = ssh_pkt_getuint32(pktin);
7445 ssh_pkt_getstring(pktin, &msg, &msglen);
7446
7447 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7448 buf = dupprintf("Received disconnect message (%s)",
7449 ssh2_disconnect_reasons[reason]);
7450 } else {
7451 buf = dupprintf("Received disconnect message (unknown"
7452 " type %d)", reason);
7453 }
7454 logevent(buf);
7455 sfree(buf);
7456 buf = dupprintf("Disconnection message text: %n%.*s",
7457 &nowlen, msglen, msg);
7458 logevent(buf);
7459 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7460 reason,
7461 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7462 ssh2_disconnect_reasons[reason] : "unknown",
7463 buf+nowlen));
7464 sfree(buf);
7465}
7466
409bfa77 7467static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
b09eaa88 7468{
7469 /* log the debug message */
fb983202 7470 char *msg;
b09eaa88 7471 int msglen;
7472 int always_display;
7473
7474 /* XXX maybe we should actually take notice of this */
7475 always_display = ssh2_pkt_getbool(pktin);
7476 ssh_pkt_getstring(pktin, &msg, &msglen);
7477
fb983202 7478 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 7479}
7480
409bfa77 7481static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
b09eaa88 7482{
7483 struct Packet *pktout;
7484 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7485 ssh2_pkt_adduint32(pktout, pktin->sequence);
7486 /*
7487 * UNIMPLEMENTED messages MUST appear in the same order as the
7488 * messages they respond to. Hence, never queue them.
7489 */
7490 ssh2_pkt_send_noqueue(ssh, pktout);
7491}
7492
7493/*
7cca0d81 7494 * Handle the top-level SSH2 protocol.
7495 */
b09eaa88 7496static void ssh2_protocol_setup(Ssh ssh)
7497{
7498 int i;
7499
7500 /*
7501 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7502 */
7503 for (i = 0; i < 256; i++)
7504 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7505
7506 /*
7507 * Any message we actually understand, we set to NULL so that
7508 * the coroutines will get it.
7509 */
7510 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7511 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7512 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7513 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7514 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7515 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7516 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7517 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7518 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7519 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7520 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7521 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7522 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7523 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7524 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7525 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7526 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7527 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7528 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7529 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7530 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7531 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7532 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7533 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7534 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7535 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7536 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7537 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7538 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7539 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7540 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7541 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7542 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7543
7544 /*
7545 * These special message types we install handlers for.
7546 */
7547 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7548 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7549 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7550}
7551
9442dd57 7552static void ssh2_timer(void *ctx, long now)
7553{
7554 Ssh ssh = (Ssh)ctx;
7555
e6c1536e 7556 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9442dd57 7557 now - ssh->next_rekey >= 0) {
f382c87d 7558 do_ssh2_transport(ssh, "timeout", -1, NULL);
9442dd57 7559 }
7560}
7561
1c1a7262 7562static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 7563 struct Packet *pktin)
7cca0d81 7564{
1c1a7262 7565 unsigned char *in = (unsigned char *)vin;
b09eaa88 7566 if (ssh->state == SSH_STATE_CLOSED)
7567 return;
7568
9442dd57 7569 if (pktin) {
7570 ssh->incoming_data_size += pktin->encrypted_len;
7571 if (!ssh->kex_in_progress &&
d57f70af 7572 ssh->max_data_size != 0 &&
7573 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 7574 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9442dd57 7575 }
7576
b09eaa88 7577 if (pktin && ssh->packet_dispatch[pktin->type]) {
7578 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 7579 return;
b09eaa88 7580 }
7581
7582 if (!ssh->protocol_initial_phase_done ||
7583 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7584 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7585 !ssh->protocol_initial_phase_done) {
7586 ssh->protocol_initial_phase_done = TRUE;
7587 /*
7588 * Allow authconn to initialise itself.
7589 */
7590 do_ssh2_authconn(ssh, NULL, 0, NULL);
7591 }
7592 } else {
7593 do_ssh2_authconn(ssh, in, inlen, pktin);
7594 }
7cca0d81 7595}
7596
7597/*
8df7a775 7598 * Called to set up the connection.
374330e2 7599 *
7600 * Returns an error message, or NULL on success.
374330e2 7601 */
cbe2d68f 7602static const char *ssh_init(void *frontend_handle, void **backend_handle,
7603 Config *cfg,
79bf227b 7604 char *host, int port, char **realhost, int nodelay,
7605 int keepalive)
32874aea 7606{
cbe2d68f 7607 const char *p;
51470298 7608 Ssh ssh;
7609
3d88e64d 7610 ssh = snew(struct ssh_tag);
86916870 7611 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 7612 ssh->version = 0; /* when not ready yet */
51470298 7613 ssh->s = NULL;
7614 ssh->cipher = NULL;
371e569c 7615 ssh->v1_cipher_ctx = NULL;
0183b242 7616 ssh->crcda_ctx = NULL;
51470298 7617 ssh->cscipher = NULL;
371e569c 7618 ssh->cs_cipher_ctx = NULL;
51470298 7619 ssh->sccipher = NULL;
371e569c 7620 ssh->sc_cipher_ctx = NULL;
51470298 7621 ssh->csmac = NULL;
a8327734 7622 ssh->cs_mac_ctx = NULL;
51470298 7623 ssh->scmac = NULL;
e0e1a00d 7624 ssh->sc_mac_ctx = NULL;
51470298 7625 ssh->cscomp = NULL;
5366aed8 7626 ssh->cs_comp_ctx = NULL;
51470298 7627 ssh->sccomp = NULL;
5366aed8 7628 ssh->sc_comp_ctx = NULL;
51470298 7629 ssh->kex = NULL;
389aa499 7630 ssh->kex_ctx = NULL;
51470298 7631 ssh->hostkey = NULL;
7632 ssh->exitcode = -1;
ac934965 7633 ssh->close_expected = FALSE;
51470298 7634 ssh->state = SSH_STATE_PREPACKET;
7635 ssh->size_needed = FALSE;
7636 ssh->eof_needed = FALSE;
b9d7bcad 7637 ssh->ldisc = NULL;
a8327734 7638 ssh->logctx = NULL;
51470298 7639 ssh->deferred_send_data = NULL;
7640 ssh->deferred_len = 0;
7641 ssh->deferred_size = 0;
7642 ssh->fallback_cmd = 0;
7643 ssh->pkt_ctx = 0;
302121de 7644 ssh->x11auth = NULL;
be738459 7645 ssh->v1_compressing = FALSE;
51470298 7646 ssh->v2_outgoing_sequence = 0;
7647 ssh->ssh1_rdpkt_crstate = 0;
7648 ssh->ssh2_rdpkt_crstate = 0;
7649 ssh->do_ssh_init_crstate = 0;
7650 ssh->ssh_gotdata_crstate = 0;
b09eaa88 7651 ssh->do_ssh1_connection_crstate = 0;
51470298 7652 ssh->do_ssh1_login_crstate = 0;
7653 ssh->do_ssh2_transport_crstate = 0;
7654 ssh->do_ssh2_authconn_crstate = 0;
7655 ssh->do_ssh_init_state = NULL;
7656 ssh->do_ssh1_login_state = NULL;
7657 ssh->do_ssh2_transport_state = NULL;
7658 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 7659 ssh->mainchan = NULL;
968d2d92 7660 ssh->throttled_all = 0;
7661 ssh->v1_stdout_throttling = 0;
590f6a5f 7662 ssh->queue = NULL;
7663 ssh->queuelen = ssh->queuesize = 0;
7664 ssh->queueing = FALSE;
06fadff5 7665 ssh->qhead = ssh->qtail = NULL;
e13bba36 7666 ssh->deferred_rekey_reason = NULL;
3d9449a1 7667 bufchain_init(&ssh->queued_incoming_data);
7668 ssh->frozen = FALSE;
51470298 7669
7670 *backend_handle = ssh;
32874aea 7671
8f203108 7672#ifdef MSCRYPTOAPI
32874aea 7673 if (crypto_startup() == 0)
8f203108 7674 return "Microsoft high encryption pack not installed!";
7675#endif
374330e2 7676
51470298 7677 ssh->frontend = frontend_handle;
86916870 7678 ssh->term_width = ssh->cfg.width;
7679 ssh->term_height = ssh->cfg.height;
887035a5 7680
fabd1805 7681 ssh->channels = NULL;
7682 ssh->rportfwds = NULL;
f47a5ffb 7683 ssh->portfwds = NULL;
fabd1805 7684
51470298 7685 ssh->send_ok = 0;
7686 ssh->editing = 0;
7687 ssh->echoing = 0;
7688 ssh->v1_throttle_count = 0;
7689 ssh->overall_bufsize = 0;
7690 ssh->fallback_cmd = 0;
8df7a775 7691
3648d4c5 7692 ssh->protocol = NULL;
7693
b09eaa88 7694 ssh->protocol_initial_phase_done = FALSE;
7695
39934deb 7696 ssh->pinger = NULL;
7697
9442dd57 7698 ssh->incoming_data_size = ssh->outgoing_data_size =
7699 ssh->deferred_data_size = 0L;
d57f70af 7700 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9442dd57 7701 ssh->kex_in_progress = FALSE;
7702
79bf227b 7703 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 7704 if (p != NULL)
7705 return p;
374330e2 7706
5d17ccfc 7707 random_ref();
7708
374330e2 7709 return NULL;
7710}
7711
fabd1805 7712static void ssh_free(void *handle)
7713{
7714 Ssh ssh = (Ssh) handle;
7715 struct ssh_channel *c;
7716 struct ssh_rportfwd *pf;
7717
7718 if (ssh->v1_cipher_ctx)
7719 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7720 if (ssh->cs_cipher_ctx)
7721 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7722 if (ssh->sc_cipher_ctx)
7723 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7724 if (ssh->cs_mac_ctx)
7725 ssh->csmac->free_context(ssh->cs_mac_ctx);
7726 if (ssh->sc_mac_ctx)
7727 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 7728 if (ssh->cs_comp_ctx) {
7729 if (ssh->cscomp)
7730 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7731 else
7732 zlib_compress_cleanup(ssh->cs_comp_ctx);
7733 }
7734 if (ssh->sc_comp_ctx) {
7735 if (ssh->sccomp)
7736 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7737 else
7738 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7739 }
fabd1805 7740 if (ssh->kex_ctx)
7741 dh_cleanup(ssh->kex_ctx);
7742 sfree(ssh->savedhost);
7743
590f6a5f 7744 while (ssh->queuelen-- > 0)
7745 ssh_free_packet(ssh->queue[ssh->queuelen]);
7746 sfree(ssh->queue);
7747
06fadff5 7748 while (ssh->qhead) {
7749 struct queued_handler *qh = ssh->qhead;
7750 ssh->qhead = qh->next;
7751 sfree(ssh->qhead);
7752 }
7753 ssh->qhead = ssh->qtail = NULL;
7754
fabd1805 7755 if (ssh->channels) {
7756 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7757 switch (c->type) {
7758 case CHAN_X11:
7759 if (c->u.x11.s != NULL)
7760 x11_close(c->u.x11.s);
7761 break;
7762 case CHAN_SOCKDATA:
7763 if (c->u.pfd.s != NULL)
7764 pfd_close(c->u.pfd.s);
7765 break;
7766 }
7767 sfree(c);
7768 }
7769 freetree234(ssh->channels);
cdb52705 7770 ssh->channels = NULL;
fabd1805 7771 }
7772
7773 if (ssh->rportfwds) {
7774 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7775 sfree(pf);
7776 freetree234(ssh->rportfwds);
cdb52705 7777 ssh->rportfwds = NULL;
fabd1805 7778 }
7779 sfree(ssh->deferred_send_data);
7780 if (ssh->x11auth)
7781 x11_free_auth(ssh->x11auth);
7782 sfree(ssh->do_ssh_init_state);
7783 sfree(ssh->do_ssh1_login_state);
7784 sfree(ssh->do_ssh2_transport_state);
7785 sfree(ssh->do_ssh2_authconn_state);
679539d7 7786 if (ssh->crcda_ctx) {
7787 crcda_free_context(ssh->crcda_ctx);
7788 ssh->crcda_ctx = NULL;
7789 }
fabd1805 7790 if (ssh->s)
ac934965 7791 ssh_do_close(ssh, TRUE);
9442dd57 7792 expire_timer_context(ssh);
39934deb 7793 if (ssh->pinger)
7794 pinger_free(ssh->pinger);
3d9449a1 7795 bufchain_clear(&ssh->queued_incoming_data);
ee50e8b6 7796 sfree(ssh);
5d17ccfc 7797
7798 random_unref();
fabd1805 7799}
7800
374330e2 7801/*
86916870 7802 * Reconfigure the SSH backend.
86916870 7803 */
7804static void ssh_reconfig(void *handle, Config *cfg)
7805{
7806 Ssh ssh = (Ssh) handle;
e13bba36 7807 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 7808 unsigned long old_max_data_size;
7809
39934deb 7810 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
fda2feb1 7811 ssh_setup_portfwd(ssh, cfg);
e6c1536e 7812
7813 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7814 cfg->ssh_rekey_time != 0) {
7815 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7816 long now = GETTICKCOUNT();
7817
7818 if (new_next - now < 0) {
f382c87d 7819 rekeying = "timeout shortened";
e6c1536e 7820 } else {
7821 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7822 }
7823 }
7824
7825 old_max_data_size = ssh->max_data_size;
7826 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7827 if (old_max_data_size != ssh->max_data_size &&
7828 ssh->max_data_size != 0) {
7829 if (ssh->outgoing_data_size > ssh->max_data_size ||
7830 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 7831 rekeying = "data limit lowered";
e6c1536e 7832 }
7833
e13bba36 7834 if (ssh->cfg.compression != cfg->compression) {
f382c87d 7835 rekeying = "compression setting changed";
e13bba36 7836 rekey_mandatory = TRUE;
7837 }
7838
7839 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7840 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7841 sizeof(ssh->cfg.ssh_cipherlist))) {
f382c87d 7842 rekeying = "cipher settings changed";
e13bba36 7843 rekey_mandatory = TRUE;
e6c1536e 7844 }
7845
86916870 7846 ssh->cfg = *cfg; /* STRUCTURE COPY */
e13bba36 7847
7848 if (rekeying) {
7849 if (!ssh->kex_in_progress) {
7850 do_ssh2_transport(ssh, rekeying, -1, NULL);
7851 } else if (rekey_mandatory) {
7852 ssh->deferred_rekey_reason = rekeying;
7853 }
7854 }
86916870 7855}
7856
7857/*
374330e2 7858 * Called to send data down the Telnet connection.
7859 */
51470298 7860static int ssh_send(void *handle, char *buf, int len)
32874aea 7861{
51470298 7862 Ssh ssh = (Ssh) handle;
7863
7864 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7865 return 0;
374330e2 7866
d8baa528 7867 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 7868
51470298 7869 return ssh_sendbuffer(ssh);
5471d09a 7870}
7871
7872/*
7873 * Called to query the current amount of buffered stdin data.
7874 */
51470298 7875static int ssh_sendbuffer(void *handle)
5471d09a 7876{
51470298 7877 Ssh ssh = (Ssh) handle;
5471d09a 7878 int override_value;
7879
51470298 7880 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7881 return 0;
7882
7883 /*
7884 * If the SSH socket itself has backed up, add the total backup
7885 * size on that to any individual buffer on the stdin channel.
7886 */
7887 override_value = 0;
51470298 7888 if (ssh->throttled_all)
7889 override_value = ssh->overall_bufsize;
5471d09a 7890
51470298 7891 if (ssh->version == 1) {
5471d09a 7892 return override_value;
51470298 7893 } else if (ssh->version == 2) {
7894 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 7895 return override_value;
7896 else
51470298 7897 return (override_value +
7898 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 7899 }
7900
7901 return 0;
374330e2 7902}
7903
7904/*
6e48c3fe 7905 * Called to set the size of the window from SSH's POV.
374330e2 7906 */
51470298 7907static void ssh_size(void *handle, int width, int height)
32874aea 7908{
51470298 7909 Ssh ssh = (Ssh) handle;
ff3187f6 7910 struct Packet *pktout;
51470298 7911
7912 ssh->term_width = width;
7913 ssh->term_height = height;
f278d6f8 7914
51470298 7915 switch (ssh->state) {
374330e2 7916 case SSH_STATE_BEFORE_SIZE:
3687d221 7917 case SSH_STATE_PREPACKET:
21248260 7918 case SSH_STATE_CLOSED:
374330e2 7919 break; /* do nothing */
7920 case SSH_STATE_INTERMED:
51470298 7921 ssh->size_needed = TRUE; /* buffer for later */
374330e2 7922 break;
7923 case SSH_STATE_SESSION:
86916870 7924 if (!ssh->cfg.nopty) {
51470298 7925 if (ssh->version == 1) {
7926 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7927 PKT_INT, ssh->term_height,
7928 PKT_INT, ssh->term_width,
32874aea 7929 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 7930 } else if (ssh->mainchan) {
ff3187f6 7931 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7932 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7933 ssh2_pkt_addstring(pktout, "window-change");
7934 ssh2_pkt_addbool(pktout, 0);
7935 ssh2_pkt_adduint32(pktout, ssh->term_width);
7936 ssh2_pkt_adduint32(pktout, ssh->term_height);
7937 ssh2_pkt_adduint32(pktout, 0);
7938 ssh2_pkt_adduint32(pktout, 0);
7939 ssh2_pkt_send(ssh, pktout);
32874aea 7940 }
7941 }
7942 break;
374330e2 7943 }
7944}
7945
7946/*
125105d1 7947 * Return a list of the special codes that make sense in this
7948 * protocol.
7949 */
7950static const struct telnet_special *ssh_get_specials(void *handle)
7951{
786ba75e 7952 static const struct telnet_special ssh1_ignore_special[] = {
7953 {"IGNORE message", TS_NOP}
7954 };
7955 static const struct telnet_special ssh2_transport_specials[] = {
62638676 7956 {"IGNORE message", TS_NOP},
9442dd57 7957 {"Repeat key exchange", TS_REKEY},
62638676 7958 };
7959 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 7960 {NULL, TS_SEP},
7961 {"Break", TS_BRK},
786ba75e 7962 /* These are the signal names defined by draft-ietf-secsh-connect-23.
6f2d0cde 7963 * They include all the ISO C signals, but are a subset of the POSIX
7964 * required signals. */
7965 {"SIGINT (Interrupt)", TS_SIGINT},
7966 {"SIGTERM (Terminate)", TS_SIGTERM},
7967 {"SIGKILL (Kill)", TS_SIGKILL},
7968 {"SIGQUIT (Quit)", TS_SIGQUIT},
7969 {"SIGHUP (Hangup)", TS_SIGHUP},
7970 {"More signals", TS_SUBMENU},
7971 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7972 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7973 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7974 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7975 {NULL, TS_EXITMENU}
62638676 7976 };
7977 static const struct telnet_special specials_end[] = {
6f2d0cde 7978 {NULL, TS_EXITMENU}
62638676 7979 };
786ba75e 7980 /* XXX review this length for any changes: */
7981 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
62638676 7982 lenof(ssh2_session_specials) +
7983 lenof(specials_end)];
125105d1 7984 Ssh ssh = (Ssh) handle;
62638676 7985 int i = 0;
7986#define ADD_SPECIALS(name) \
7987 do { \
7988 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7989 memcpy(&ssh_specials[i], name, sizeof name); \
7990 i += lenof(name); \
7991 } while(0)
125105d1 7992
7993 if (ssh->version == 1) {
62638676 7994 /* Don't bother offering IGNORE if we've decided the remote
7995 * won't cope with it, since we wouldn't bother sending it if
7996 * asked anyway. */
7997 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 7998 ADD_SPECIALS(ssh1_ignore_special);
125105d1 7999 } else if (ssh->version == 2) {
786ba75e 8000 ADD_SPECIALS(ssh2_transport_specials);
62638676 8001 if (ssh->mainchan)
8002 ADD_SPECIALS(ssh2_session_specials);
8003 } /* else we're not ready yet */
8004
8005 if (i) {
8006 ADD_SPECIALS(specials_end);
8007 return ssh_specials;
8008 } else {
125105d1 8009 return NULL;
62638676 8010 }
8011#undef ADD_SPECIALS
125105d1 8012}
8013
8014/*
6abbf9e3 8015 * Send Telnet special codes. TS_EOF is useful for `plink', so you
8016 * can send an EOF and collect resulting output (e.g. `plink
8017 * hostname sort').
374330e2 8018 */
51470298 8019static void ssh_special(void *handle, Telnet_Special code)
32874aea 8020{
51470298 8021 Ssh ssh = (Ssh) handle;
ff3187f6 8022 struct Packet *pktout;
51470298 8023
6abbf9e3 8024 if (code == TS_EOF) {
51470298 8025 if (ssh->state != SSH_STATE_SESSION) {
32874aea 8026 /*
8027 * Buffer the EOF in case we are pre-SESSION, so we can
8028 * send it as soon as we reach SESSION.
8029 */
8030 if (code == TS_EOF)
51470298 8031 ssh->eof_needed = TRUE;
32874aea 8032 return;
8033 }
51470298 8034 if (ssh->version == 1) {
8035 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 8036 } else if (ssh->mainchan) {
ff3187f6 8037 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8038 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8039 ssh2_pkt_send(ssh, pktout);
32874aea 8040 }
8041 logevent("Sent EOF message");
125105d1 8042 } else if (code == TS_PING || code == TS_NOP) {
51470298 8043 if (ssh->state == SSH_STATE_CLOSED
8044 || ssh->state == SSH_STATE_PREPACKET) return;
8045 if (ssh->version == 1) {
8046 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8047 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 8048 } else {
ff3187f6 8049 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8050 ssh2_pkt_addstring_start(pktout);
590f6a5f 8051 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 8052 }
9442dd57 8053 } else if (code == TS_REKEY) {
8054 if (!ssh->kex_in_progress && ssh->version == 2) {
f382c87d 8055 do_ssh2_transport(ssh, "at user request", -1, NULL);
9442dd57 8056 }
125105d1 8057 } else if (code == TS_BRK) {
8058 if (ssh->state == SSH_STATE_CLOSED
8059 || ssh->state == SSH_STATE_PREPACKET) return;
8060 if (ssh->version == 1) {
8061 logevent("Unable to send BREAK signal in SSH1");
0ed48730 8062 } else if (ssh->mainchan) {
ff3187f6 8063 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8064 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8065 ssh2_pkt_addstring(pktout, "break");
8066 ssh2_pkt_addbool(pktout, 0);
8067 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8068 ssh2_pkt_send(ssh, pktout);
125105d1 8069 }
6abbf9e3 8070 } else {
6f2d0cde 8071 /* Is is a POSIX signal? */
8072 char *signame = NULL;
8073 if (code == TS_SIGABRT) signame = "ABRT";
8074 if (code == TS_SIGALRM) signame = "ALRM";
8075 if (code == TS_SIGFPE) signame = "FPE";
8076 if (code == TS_SIGHUP) signame = "HUP";
8077 if (code == TS_SIGILL) signame = "ILL";
8078 if (code == TS_SIGINT) signame = "INT";
8079 if (code == TS_SIGKILL) signame = "KILL";
8080 if (code == TS_SIGPIPE) signame = "PIPE";
8081 if (code == TS_SIGQUIT) signame = "QUIT";
8082 if (code == TS_SIGSEGV) signame = "SEGV";
8083 if (code == TS_SIGTERM) signame = "TERM";
8084 if (code == TS_SIGUSR1) signame = "USR1";
8085 if (code == TS_SIGUSR2) signame = "USR2";
8086 /* The SSH-2 protocol does in principle support arbitrary named
8087 * signals, including signame@domain, but we don't support those. */
8088 if (signame) {
8089 /* It's a signal. */
8090 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 8091 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8092 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8093 ssh2_pkt_addstring(pktout, "signal");
8094 ssh2_pkt_addbool(pktout, 0);
8095 ssh2_pkt_addstring(pktout, signame);
8096 ssh2_pkt_send(ssh, pktout);
6f2d0cde 8097 logeventf(ssh, "Sent signal SIG%s", signame);
8098 }
8099 } else {
8100 /* Never heard of it. Do nothing */
8101 }
6abbf9e3 8102 }
374330e2 8103}
8104
51470298 8105void *new_sock_channel(void *handle, Socket s)
d74d141c 8106{
51470298 8107 Ssh ssh = (Ssh) handle;
d74d141c 8108 struct ssh_channel *c;
3d88e64d 8109 c = snew(struct ssh_channel);
51470298 8110 c->ssh = ssh;
d74d141c 8111
8112 if (c) {
64d6ff88 8113 c->halfopen = TRUE;
51470298 8114 c->localid = alloc_channel_id(ssh);
d74d141c 8115 c->closes = 0;
bc240b21 8116 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 8117 c->u.pfd.s = s;
013dd8c0 8118 bufchain_init(&c->v.v2.outbuffer);
51470298 8119 add234(ssh->channels, c);
d74d141c 8120 }
8121 return c;
8122}
8123
5471d09a 8124/*
8125 * This is called when stdout/stderr (the entity to which
8126 * from_backend sends data) manages to clear some backlog.
8127 */
ae9ae89f 8128static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 8129{
51470298 8130 Ssh ssh = (Ssh) handle;
8131 if (ssh->version == 1) {
8132 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8133 ssh->v1_stdout_throttling = 0;
8134 ssh1_throttle(ssh, -1);
5471d09a 8135 }
8136 } else {
51470298 8137 if (ssh->mainchan && ssh->mainchan->closes == 0)
8138 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 8139 }
8140}
8141
6b78788a 8142void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 8143{
8144 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 8145 Ssh ssh = c->ssh;
ff3187f6 8146 struct Packet *pktout;
d74d141c 8147
57356d63 8148 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 8149
51470298 8150 if (ssh->version == 1) {
8151 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 8152 PKT_INT, c->localid,
8153 PKT_STR, hostname,
8154 PKT_INT, port,
31fb1866 8155 /* PKT_STR, <org:orgport>, */
bc240b21 8156 PKT_END);
8157 } else {
ff3187f6 8158 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8159 ssh2_pkt_addstring(pktout, "direct-tcpip");
8160 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 8161 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 8162 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
954d5c5a 8163 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 8164 ssh2_pkt_addstring(pktout, hostname);
8165 ssh2_pkt_adduint32(pktout, port);
bc240b21 8166 /*
8167 * We make up values for the originator data; partly it's
8168 * too much hassle to keep track, and partly I'm not
8169 * convinced the server should be told details like that
8170 * about my local network configuration.
8171 */
ff3187f6 8172 ssh2_pkt_addstring(pktout, "client-side-connection");
8173 ssh2_pkt_adduint32(pktout, 0);
8174 ssh2_pkt_send(ssh, pktout);
bc240b21 8175 }
d74d141c 8176}
8177
51470298 8178static Socket ssh_socket(void *handle)
32874aea 8179{
51470298 8180 Ssh ssh = (Ssh) handle;
8181 return ssh->s;
32874aea 8182}
8ccc75b0 8183
51470298 8184static int ssh_sendok(void *handle)
32874aea 8185{
51470298 8186 Ssh ssh = (Ssh) handle;
8187 return ssh->send_ok;
32874aea 8188}
fb09bf1c 8189
51470298 8190static int ssh_ldisc(void *handle, int option)
32874aea 8191{
51470298 8192 Ssh ssh = (Ssh) handle;
32874aea 8193 if (option == LD_ECHO)
51470298 8194 return ssh->echoing;
32874aea 8195 if (option == LD_EDIT)
51470298 8196 return ssh->editing;
0965bee0 8197 return FALSE;
8198}
8199
b9d7bcad 8200static void ssh_provide_ldisc(void *handle, void *ldisc)
8201{
8202 Ssh ssh = (Ssh) handle;
8203 ssh->ldisc = ldisc;
8204}
8205
a8327734 8206static void ssh_provide_logctx(void *handle, void *logctx)
8207{
8208 Ssh ssh = (Ssh) handle;
8209 ssh->logctx = logctx;
8210}
8211
51470298 8212static int ssh_return_exitcode(void *handle)
8213{
8214 Ssh ssh = (Ssh) handle;
3bb2f322 8215 if (ssh->s != NULL)
8216 return -1;
8217 else
8218 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 8219}
8220
8221/*
f89c3294 8222 * cfg_info for SSH is the currently running version of the
8223 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8224 */
8225static int ssh_cfg_info(void *handle)
8226{
8227 Ssh ssh = (Ssh) handle;
8228 return ssh->version;
8229}
8230
8231/*
51470298 8232 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8233 * that fails. This variable is the means by which scp.c can reach
8234 * into the SSH code and find out which one it got.
8235 */
8236extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 8237{
51470298 8238 Ssh ssh = (Ssh) handle;
8239 return ssh->fallback_cmd;
d8d6c7e5 8240}
8241
374330e2 8242Backend ssh_backend = {
8243 ssh_init,
fabd1805 8244 ssh_free,
86916870 8245 ssh_reconfig,
374330e2 8246 ssh_send,
5471d09a 8247 ssh_sendbuffer,
374330e2 8248 ssh_size,
4017be6d 8249 ssh_special,
125105d1 8250 ssh_get_specials,
8ccc75b0 8251 ssh_socket,
d8d6c7e5 8252 ssh_return_exitcode,
97db3be4 8253 ssh_sendok,
0965bee0 8254 ssh_ldisc,
b9d7bcad 8255 ssh_provide_ldisc,
a8327734 8256 ssh_provide_logctx,
5471d09a 8257 ssh_unthrottle,
f89c3294 8258 ssh_cfg_info,
97db3be4 8259 22
bc240b21 8260};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator