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In SSH2, rather than sending an SSH_MSG_IGNORE after every password, just
[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;
0357890f 439 /*
440 * In SSH1, this value contains four bits:
441 *
442 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
443 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
444 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
445 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
446 *
447 * A channel is completely finished with when all four bits are set.
448 */
dacbd0e8 449 int closes;
5471d09a 450 union {
451 struct ssh1_data_channel {
452 int throttling;
453 } v1;
454 struct ssh2_data_channel {
455 bufchain outbuffer;
456 unsigned remwindow, remmaxpkt;
457 unsigned locwindow;
458 } v2;
459 } v;
dacbd0e8 460 union {
32874aea 461 struct ssh_agent_channel {
462 unsigned char *message;
463 unsigned char msglen[4];
a03c9f9c 464 unsigned lensofar, totallen;
32874aea 465 } a;
466 struct ssh_x11_channel {
467 Socket s;
468 } x11;
d74d141c 469 struct ssh_pfd_channel {
470 Socket s;
471 } pfd;
dacbd0e8 472 } u;
473};
57476f6b 474
d74d141c 475/*
bc240b21 476 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
477 * 2 use this structure in different ways, reflecting SSH 2's
478 * altogether saner approach to port forwarding.
479 *
480 * In SSH 1, you arrange a remote forwarding by sending the server
481 * the remote port number, and the local destination host:port.
482 * When a connection comes in, the server sends you back that
483 * host:port pair, and you connect to it. This is a ready-made
484 * security hole if you're not on the ball: a malicious server
485 * could send you back _any_ host:port pair, so if you trustingly
486 * connect to the address it gives you then you've just opened the
487 * entire inside of your corporate network just by connecting
488 * through it to a dodgy SSH server. Hence, we must store a list of
489 * host:port pairs we _are_ trying to forward to, and reject a
490 * connection request from the server if it's not in the list.
491 *
492 * In SSH 2, each side of the connection minds its own business and
493 * doesn't send unnecessary information to the other. You arrange a
494 * remote forwarding by sending the server just the remote port
495 * number. When a connection comes in, the server tells you which
496 * of its ports was connected to; and _you_ have to remember what
497 * local host:port pair went with that port number.
498 *
06fadff5 499 * Hence, in SSH 1 this structure is indexed by destination
500 * host:port pair, whereas in SSH 2 it is indexed by source port.
d74d141c 501 */
fda2feb1 502struct ssh_portfwd; /* forward declaration */
503
d74d141c 504struct ssh_rportfwd {
bc240b21 505 unsigned sport, dport;
506 char dhost[256];
06fadff5 507 char *sportdesc;
fda2feb1 508 struct ssh_portfwd *pfrec;
d74d141c 509};
fda2feb1 510#define free_rportfwd(pf) ( \
511 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
512
513/*
514 * Separately to the rportfwd tree (which is for looking up port
515 * open requests from the server), a tree of _these_ structures is
516 * used to keep track of all the currently open port forwardings,
517 * so that we can reconfigure in mid-session if the user requests
518 * it.
519 */
520struct ssh_portfwd {
84328ddb 521 enum { DESTROY, KEEP, CREATE } status;
fda2feb1 522 int type;
523 unsigned sport, dport;
524 char *saddr, *daddr;
3fe92132 525 char *sserv, *dserv;
fda2feb1 526 struct ssh_rportfwd *remote;
05581745 527 int addressfamily;
fda2feb1 528 void *local;
529};
530#define free_portfwd(pf) ( \
3fe92132 531 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
532 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
d74d141c 533
57476f6b 534struct Packet {
535 long length;
95d2d262 536 long forcepad; /* Force padding to at least this length */
57476f6b 537 int type;
b09eaa88 538 unsigned long sequence;
57476f6b 539 unsigned char *data;
540 unsigned char *body;
541 long savedpos;
542 long maxlen;
9442dd57 543 long encrypted_len; /* for SSH2 total-size counting */
ff3187f6 544
545 /*
546 * State associated with packet logging
547 */
548 int logmode;
549 int nblanks;
550 struct logblank_t *blanks;
57476f6b 551};
552
ff3187f6 553static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
554 struct Packet *pktin);
555static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
556 struct Packet *pktin);
b09eaa88 557static void ssh1_protocol_setup(Ssh ssh);
558static void ssh2_protocol_setup(Ssh ssh);
51470298 559static void ssh_size(void *handle, int width, int height);
560static void ssh_special(void *handle, Telnet_Special);
5471d09a 561static int ssh2_try_send(struct ssh_channel *c);
51470298 562static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
563static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 564static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 565static int ssh_sendbuffer(void *handle);
ac934965 566static int ssh_do_close(Ssh ssh, int notify_exit);
ff3187f6 567static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
568static int ssh2_pkt_getbool(struct Packet *pkt);
569static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 570static void ssh2_timer(void *ctx, long now);
571static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
572 struct Packet *pktin);
57476f6b 573
51470298 574struct rdpkt1_state_tag {
57476f6b 575 long len, pad, biglen, to_read;
576 unsigned long realcrc, gotcrc;
577 unsigned char *p;
578 int i;
579 int chunk;
ff3187f6 580 struct Packet *pktin;
51470298 581};
57476f6b 582
51470298 583struct rdpkt2_state_tag {
960e736a 584 long len, pad, payload, packetlen, maclen;
585 int i;
586 int cipherblk;
587 unsigned long incoming_sequence;
ff3187f6 588 struct Packet *pktin;
51470298 589};
590
b09eaa88 591typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
06fadff5 592typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
593
594struct queued_handler;
595struct queued_handler {
596 int msg1, msg2;
597 chandler_fn_t handler;
598 void *ctx;
599 struct queued_handler *next;
600};
b09eaa88 601
51470298 602struct ssh_tag {
603 const struct plug_function_table *fn;
604 /* the above field _must_ be first in the structure */
605
606 SHA_State exhash, exhashbase;
607
608 Socket s;
609
b9d7bcad 610 void *ldisc;
a8327734 611 void *logctx;
b9d7bcad 612
51470298 613 unsigned char session_key[32];
614 int v1_compressing;
615 int v1_remote_protoflags;
616 int v1_local_protoflags;
617 int agentfwd_enabled;
618 int X11_fwd_enabled;
619 int remote_bugs;
620 const struct ssh_cipher *cipher;
371e569c 621 void *v1_cipher_ctx;
0183b242 622 void *crcda_ctx;
51470298 623 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 624 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 625 const struct ssh_mac *csmac, *scmac;
e0e1a00d 626 void *cs_mac_ctx, *sc_mac_ctx;
51470298 627 const struct ssh_compress *cscomp, *sccomp;
5366aed8 628 void *cs_comp_ctx, *sc_comp_ctx;
51470298 629 const struct ssh_kex *kex;
630 const struct ssh_signkey *hostkey;
631 unsigned char v2_session_id[20];
27cd7fc2 632 void *kex_ctx;
51470298 633
634 char *savedhost;
635 int savedport;
636 int send_ok;
637 int echoing, editing;
638
639 void *frontend;
640
db219738 641 int ospeed, ispeed; /* temporaries */
51470298 642 int term_width, term_height;
643
644 tree234 *channels; /* indexed by local id */
645 struct ssh_channel *mainchan; /* primary session channel */
646 int exitcode;
ac934965 647 int close_expected;
51470298 648
fda2feb1 649 tree234 *rportfwds, *portfwds;
51470298 650
651 enum {
652 SSH_STATE_PREPACKET,
653 SSH_STATE_BEFORE_SIZE,
654 SSH_STATE_INTERMED,
655 SSH_STATE_SESSION,
656 SSH_STATE_CLOSED
657 } state;
658
659 int size_needed, eof_needed;
660
590f6a5f 661 struct Packet **queue;
662 int queuelen, queuesize;
663 int queueing;
51470298 664 unsigned char *deferred_send_data;
665 int deferred_len, deferred_size;
666
667 /*
668 * Gross hack: pscp will try to start SFTP but fall back to
669 * scp1 if that fails. This variable is the means by which
670 * scp.c can reach into the SSH code and find out which one it
671 * got.
672 */
673 int fallback_cmd;
674
675 /*
676 * Used for username and password input.
677 */
678 char *userpass_input_buffer;
679 int userpass_input_buflen;
680 int userpass_input_bufpos;
681 int userpass_input_echo;
682
51470298 683 int pkt_ctx;
684
302121de 685 void *x11auth;
686
51470298 687 int version;
688 int v1_throttle_count;
689 int overall_bufsize;
690 int throttled_all;
691 int v1_stdout_throttling;
692 int v2_outgoing_sequence;
693
694 int ssh1_rdpkt_crstate;
695 int ssh2_rdpkt_crstate;
696 int do_ssh_init_crstate;
697 int ssh_gotdata_crstate;
51470298 698 int do_ssh1_login_crstate;
b09eaa88 699 int do_ssh1_connection_crstate;
51470298 700 int do_ssh2_transport_crstate;
701 int do_ssh2_authconn_crstate;
702
703 void *do_ssh_init_state;
704 void *do_ssh1_login_state;
705 void *do_ssh2_transport_state;
706 void *do_ssh2_authconn_state;
707
708 struct rdpkt1_state_tag rdpkt1_state;
709 struct rdpkt2_state_tag rdpkt2_state;
710
b09eaa88 711 /* ssh1 and ssh2 use this for different things, but both use it */
712 int protocol_initial_phase_done;
713
ff3187f6 714 void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
715 struct Packet *pkt);
716 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 717
718 /*
719 * We maintain a full _copy_ of a Config structure here, not
720 * merely a pointer to it. That way, when we're passed a new
721 * one for reconfiguration, we can check the differences and
722 * potentially reconfigure port forwardings etc in mid-session.
723 */
724 Config cfg;
839f10db 725
726 /*
727 * Used to transfer data back from async agent callbacks.
728 */
729 void *agent_response;
730 int agent_response_len;
b09eaa88 731
732 /*
733 * Dispatch table for packet types that we may have to deal
734 * with at any time.
735 */
736 handler_fn_t packet_dispatch[256];
39934deb 737
738 /*
06fadff5 739 * Queues of one-off handler functions for success/failure
740 * indications from a request.
741 */
742 struct queued_handler *qhead, *qtail;
743
744 /*
39934deb 745 * This module deals with sending keepalives.
746 */
747 Pinger pinger;
9442dd57 748
749 /*
750 * Track incoming and outgoing data sizes and time, for
751 * size-based rekeys.
752 */
753 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
d57f70af 754 unsigned long max_data_size;
9442dd57 755 int kex_in_progress;
e6c1536e 756 long next_rekey, last_rekey;
e13bba36 757 char *deferred_rekey_reason; /* points to STATIC string; don't free */
51470298 758};
960e736a 759
382908ad 760#define logevent(s) logevent(ssh->frontend, s)
a8327734 761
762/* logevent, only printf-formatted. */
cbe2d68f 763static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 764{
765 va_list ap;
57356d63 766 char *buf;
a8327734 767
768 va_start(ap, fmt);
57356d63 769 buf = dupvprintf(fmt, ap);
a8327734 770 va_end(ap);
57356d63 771 logevent(buf);
57356d63 772 sfree(buf);
a8327734 773}
774
6b5cf8b4 775#define bombout(msg) \
776 do { \
777 char *text = dupprintf msg; \
ac934965 778 ssh_do_close(ssh, FALSE); \
6b5cf8b4 779 logevent(text); \
780 connection_fatal(ssh->frontend, "%s", text); \
781 sfree(text); \
782 } while (0)
a8327734 783
9a10ecf4 784/* Functions to leave bits out of the SSH packet log file. */
785
ff3187f6 786static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 787{
788 if (ssh->cfg.logomitpass)
ff3187f6 789 pkt->logmode = blanktype;
9a10ecf4 790}
791
ff3187f6 792static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 793{
794 if (ssh->cfg.logomitdata)
ff3187f6 795 pkt->logmode = blanktype;
9a10ecf4 796}
797
ff3187f6 798static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 799{
ff3187f6 800 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 801}
802
32874aea 803static int ssh_channelcmp(void *av, void *bv)
804{
805 struct ssh_channel *a = (struct ssh_channel *) av;
806 struct ssh_channel *b = (struct ssh_channel *) bv;
807 if (a->localid < b->localid)
808 return -1;
809 if (a->localid > b->localid)
810 return +1;
dacbd0e8 811 return 0;
812}
32874aea 813static int ssh_channelfind(void *av, void *bv)
814{
815 unsigned *a = (unsigned *) av;
816 struct ssh_channel *b = (struct ssh_channel *) bv;
817 if (*a < b->localid)
818 return -1;
819 if (*a > b->localid)
820 return +1;
dacbd0e8 821 return 0;
822}
823
bc240b21 824static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 825{
826 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
827 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
828 int i;
bc240b21 829 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 830 return i < 0 ? -1 : +1;
bc240b21 831 if (a->dport > b->dport)
832 return +1;
833 if (a->dport < b->dport)
834 return -1;
835 return 0;
836}
837
838static int ssh_rportcmp_ssh2(void *av, void *bv)
839{
840 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
841 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 842
bc240b21 843 if (a->sport > b->sport)
d74d141c 844 return +1;
bc240b21 845 if (a->sport < b->sport)
846 return -1;
d74d141c 847 return 0;
848}
849
fda2feb1 850/*
851 * Special form of strcmp which can cope with NULL inputs. NULL is
852 * defined to sort before even the empty string.
853 */
854static int nullstrcmp(const char *a, const char *b)
855{
856 if (a == NULL && b == NULL)
857 return 0;
858 if (a == NULL)
859 return -1;
860 if (b == NULL)
861 return +1;
862 return strcmp(a, b);
863}
864
865static int ssh_portcmp(void *av, void *bv)
866{
867 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
868 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
869 int i;
870 if (a->type > b->type)
871 return +1;
872 if (a->type < b->type)
873 return -1;
84328ddb 874 if (a->addressfamily > b->addressfamily)
875 return +1;
876 if (a->addressfamily < b->addressfamily)
877 return -1;
fda2feb1 878 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
879 return i < 0 ? -1 : +1;
880 if (a->sport > b->sport)
881 return +1;
882 if (a->sport < b->sport)
883 return -1;
884 if (a->type != 'D') {
885 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
886 return i < 0 ? -1 : +1;
887 if (a->dport > b->dport)
888 return +1;
889 if (a->dport < b->dport)
890 return -1;
891 }
892 return 0;
893}
894
51470298 895static int alloc_channel_id(Ssh ssh)
32874aea 896{
260f3dec 897 const unsigned CHANNEL_NUMBER_OFFSET = 256;
898 unsigned low, high, mid;
d2371c81 899 int tsize;
900 struct ssh_channel *c;
901
902 /*
903 * First-fit allocation of channel numbers: always pick the
904 * lowest unused one. To do this, binary-search using the
905 * counted B-tree to find the largest channel ID which is in a
906 * contiguous sequence from the beginning. (Precisely
907 * everything in that sequence must have ID equal to its tree
908 * index plus CHANNEL_NUMBER_OFFSET.)
909 */
51470298 910 tsize = count234(ssh->channels);
d2371c81 911
32874aea 912 low = -1;
913 high = tsize;
d2371c81 914 while (high - low > 1) {
915 mid = (high + low) / 2;
51470298 916 c = index234(ssh->channels, mid);
d2371c81 917 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
918 low = mid; /* this one is fine */
919 else
920 high = mid; /* this one is past it */
921 }
922 /*
923 * Now low points to either -1, or the tree index of the
924 * largest ID in the initial sequence.
925 */
926 {
927 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 928 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 929 }
930 return low + 1 + CHANNEL_NUMBER_OFFSET;
931}
932
9fab77dc 933static void c_write(Ssh ssh, const char *buf, int len)
32874aea 934{
67779be7 935 if ((flags & FLAG_STDERR)) {
32874aea 936 int i;
937 for (i = 0; i < len; i++)
938 if (buf[i] != '\r')
939 fputc(buf[i], stderr);
fb09bf1c 940 return;
941 }
51470298 942 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 943}
944
9fab77dc 945static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 946{
a209e957 947 int i;
948 for (i = 0; i < len; i++) {
32874aea 949 if (buf[i] == '\n')
51470298 950 c_write(ssh, "\r\n", 2);
32874aea 951 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 952 c_write(ssh, buf + i, 1);
a209e957 953 }
954}
955
9fab77dc 956static void c_write_str(Ssh ssh, const char *buf)
32874aea 957{
51470298 958 c_write(ssh, buf, strlen(buf));
1408a877 959}
960
ff3187f6 961static void ssh_free_packet(struct Packet *pkt)
962{
963 sfree(pkt->data);
964 sfree(pkt);
965}
966static struct Packet *ssh_new_packet(void)
967{
968 struct Packet *pkt = snew(struct Packet);
969
970 pkt->data = NULL;
971 pkt->maxlen = 0;
972 pkt->logmode = PKTLOG_EMIT;
973 pkt->nblanks = 0;
974 pkt->blanks = NULL;
975
976 return pkt;
977}
978
fb09bf1c 979/*
980 * Collect incoming data in the incoming packet buffer.
e5574168 981 * Decipher and verify the packet when it is completely read.
982 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 983 * Update the *data and *datalen variables.
ff3187f6 984 * Return a Packet structure when a packet is completed.
fb09bf1c 985 */
ff3187f6 986static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 987{
51470298 988 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 989
51470298 990 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 991
ff3187f6 992 st->pktin = ssh_new_packet();
993
994 st->pktin->type = 0;
995 st->pktin->length = 0;
374330e2 996
57476f6b 997 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 998 while ((*datalen) == 0)
ff3187f6 999 crReturn(NULL);
57476f6b 1000 st->len = (st->len << 8) + **data;
fb09bf1c 1001 (*data)++, (*datalen)--;
1002 }
374330e2 1003
57476f6b 1004 st->pad = 8 - (st->len % 8);
1005 st->biglen = st->len + st->pad;
ff3187f6 1006 st->pktin->length = st->len - 5;
fb09bf1c 1007
ae0500e5 1008 if (st->biglen < 0) {
1009 bombout(("Extremely large packet length from server suggests"
1010 " data stream corruption"));
ff3187f6 1011 ssh_free_packet(st->pktin);
1012 crStop(NULL);
ae0500e5 1013 }
1014
ff3187f6 1015 st->pktin->maxlen = st->biglen;
1016 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 1017
57476f6b 1018 st->to_read = st->biglen;
ff3187f6 1019 st->p = st->pktin->data;
57476f6b 1020 while (st->to_read > 0) {
32874aea 1021 st->chunk = st->to_read;
fb09bf1c 1022 while ((*datalen) == 0)
ff3187f6 1023 crReturn(NULL);
57476f6b 1024 if (st->chunk > (*datalen))
1025 st->chunk = (*datalen);
1026 memcpy(st->p, *data, st->chunk);
1027 *data += st->chunk;
1028 *datalen -= st->chunk;
1029 st->p += st->chunk;
1030 st->to_read -= st->chunk;
fb09bf1c 1031 }
374330e2 1032
ff3187f6 1033 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 1034 st->biglen, NULL)) {
6b5cf8b4 1035 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 1036 ssh_free_packet(st->pktin);
1037 crStop(NULL);
9a3a93a5 1038 }
1039
51470298 1040 if (ssh->cipher)
ff3187f6 1041 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 1042
ff3187f6 1043 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1044 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 1045 if (st->gotcrc != st->realcrc) {
6b5cf8b4 1046 bombout(("Incorrect CRC received on packet"));
ff3187f6 1047 ssh_free_packet(st->pktin);
1048 crStop(NULL);
fb09bf1c 1049 }
572f871e 1050
ff3187f6 1051 st->pktin->body = st->pktin->data + st->pad + 1;
1052 st->pktin->savedpos = 0;
4ba9b64b 1053
51470298 1054 if (ssh->v1_compressing) {
4ba9b64b 1055 unsigned char *decompblk;
1056 int decomplen;
36b8d9bb 1057 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 1058 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 1059 &decompblk, &decomplen)) {
1060 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 1061 ssh_free_packet(st->pktin);
1062 crStop(NULL);
36b8d9bb 1063 }
4ba9b64b 1064
ff3187f6 1065 if (st->pktin->maxlen < st->pad + decomplen) {
1066 st->pktin->maxlen = st->pad + decomplen;
1067 st->pktin->data = sresize(st->pktin->data,
1068 st->pktin->maxlen + APIEXTRA,
3d88e64d 1069 unsigned char);
ff3187f6 1070 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 1071 }
1072
ff3187f6 1073 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 1074 sfree(decompblk);
ff3187f6 1075 st->pktin->length = decomplen - 1;
4ba9b64b 1076 }
1077
ff3187f6 1078 st->pktin->type = st->pktin->body[-1];
00db133f 1079
9a10ecf4 1080 /*
1081 * Log incoming packet, possibly omitting sensitive fields.
1082 */
1083 if (ssh->logctx) {
1084 int nblanks = 0;
1085 struct logblank_t blank;
1086 if (ssh->cfg.logomitdata) {
1087 int do_blank = FALSE, blank_prefix = 0;
1088 /* "Session data" packets - omit the data field */
ff3187f6 1089 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1090 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1091 do_blank = TRUE; blank_prefix = 0;
ff3187f6 1092 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
9a10ecf4 1093 do_blank = TRUE; blank_prefix = 4;
1094 }
1095 if (do_blank) {
1096 blank.offset = blank_prefix;
ff3187f6 1097 blank.len = st->pktin->length;
9a10ecf4 1098 blank.type = PKTLOG_OMIT;
1099 nblanks = 1;
1100 }
1101 }
a8327734 1102 log_packet(ssh->logctx,
ff3187f6 1103 PKT_INCOMING, st->pktin->type,
1104 ssh1_pkt_type(st->pktin->type),
1105 st->pktin->body, st->pktin->length,
9a10ecf4 1106 nblanks, &blank);
1107 }
00db133f 1108
ff3187f6 1109 crFinish(st->pktin);
fb09bf1c 1110}
1111
ff3187f6 1112static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1113{
51470298 1114 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1115
51470298 1116 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1117
ff3187f6 1118 st->pktin = ssh_new_packet();
1119
1120 st->pktin->type = 0;
1121 st->pktin->length = 0;
51470298 1122 if (ssh->sccipher)
1123 st->cipherblk = ssh->sccipher->blksize;
e5574168 1124 else
32874aea 1125 st->cipherblk = 8;
960e736a 1126 if (st->cipherblk < 8)
32874aea 1127 st->cipherblk = 8;
960e736a 1128
ff3187f6 1129 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
e5574168 1130
1131 /*
1132 * Acquire and decrypt the first block of the packet. This will
1133 * contain the length and padding details.
1134 */
32874aea 1135 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 1136 while ((*datalen) == 0)
ff3187f6 1137 crReturn(NULL);
1138 st->pktin->data[st->i] = *(*data)++;
32874aea 1139 (*datalen)--;
e5574168 1140 }
4252c9cc 1141
51470298 1142 if (ssh->sccipher)
371e569c 1143 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1144 st->pktin->data, st->cipherblk);
e5574168 1145
1146 /*
1147 * Now get the length and padding figures.
1148 */
ff3187f6 1149 st->len = GET_32BIT(st->pktin->data);
1150 st->pad = st->pktin->data[4];
e5574168 1151
1152 /*
717dc483 1153 * _Completely_ silly lengths should be stomped on before they
1154 * do us any more damage.
1155 */
1156 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
6b5cf8b4 1157 bombout(("Incoming packet was garbled on decryption"));
ff3187f6 1158 ssh_free_packet(st->pktin);
1159 crStop(NULL);
717dc483 1160 }
1161
1162 /*
e5574168 1163 * This enables us to deduce the payload length.
1164 */
960e736a 1165 st->payload = st->len - st->pad - 1;
e5574168 1166
ff3187f6 1167 st->pktin->length = st->payload + 5;
e5574168 1168
1169 /*
1170 * So now we can work out the total packet length.
1171 */
960e736a 1172 st->packetlen = st->len + 4;
51470298 1173 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 1174
1175 /*
ff3187f6 1176 * Allocate memory for the rest of the packet.
e5574168 1177 */
ff3187f6 1178 st->pktin->maxlen = st->packetlen + st->maclen;
1179 st->pktin->data = sresize(st->pktin->data,
1180 st->pktin->maxlen + APIEXTRA,
1181 unsigned char);
e5574168 1182
1183 /*
1184 * Read and decrypt the remainder of the packet.
1185 */
32874aea 1186 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1187 st->i++) {
e5574168 1188 while ((*datalen) == 0)
ff3187f6 1189 crReturn(NULL);
1190 st->pktin->data[st->i] = *(*data)++;
32874aea 1191 (*datalen)--;
e5574168 1192 }
1193 /* Decrypt everything _except_ the MAC. */
51470298 1194 if (ssh->sccipher)
371e569c 1195 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1196 st->pktin->data + st->cipherblk,
51470298 1197 st->packetlen - st->cipherblk);
e5574168 1198
9442dd57 1199 st->pktin->encrypted_len = st->packetlen;
1200
e5574168 1201 /*
1202 * Check the MAC.
1203 */
51470298 1204 if (ssh->scmac
ff3187f6 1205 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
51470298 1206 st->incoming_sequence)) {
6b5cf8b4 1207 bombout(("Incorrect MAC received on packet"));
ff3187f6 1208 ssh_free_packet(st->pktin);
1209 crStop(NULL);
8d5de777 1210 }
b09eaa88 1211
1212 st->pktin->sequence = st->incoming_sequence++;
e5574168 1213
4ba9b64b 1214 /*
1215 * Decompress packet payload.
1216 */
1217 {
1218 unsigned char *newpayload;
1219 int newlen;
51470298 1220 if (ssh->sccomp &&
5366aed8 1221 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1222 st->pktin->data + 5, st->pktin->length - 5,
51470298 1223 &newpayload, &newlen)) {
ff3187f6 1224 if (st->pktin->maxlen < newlen + 5) {
1225 st->pktin->maxlen = newlen + 5;
1226 st->pktin->data = sresize(st->pktin->data,
1227 st->pktin->maxlen + APIEXTRA,
3d88e64d 1228 unsigned char);
4ba9b64b 1229 }
ff3187f6 1230 st->pktin->length = 5 + newlen;
1231 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1232 sfree(newpayload);
4ba9b64b 1233 }
1234 }
1235
ff3187f6 1236 st->pktin->savedpos = 6;
1237 st->pktin->body = st->pktin->data;
1238 st->pktin->type = st->pktin->data[5];
e5574168 1239
9a10ecf4 1240 /*
1241 * Log incoming packet, possibly omitting sensitive fields.
1242 */
1243 if (ssh->logctx) {
1244 int nblanks = 0;
1245 struct logblank_t blank;
1246 if (ssh->cfg.logomitdata) {
1247 int do_blank = FALSE, blank_prefix = 0;
1248 /* "Session data" packets - omit the data field */
ff3187f6 1249 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1250 do_blank = TRUE; blank_prefix = 4;
ff3187f6 1251 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
9a10ecf4 1252 do_blank = TRUE; blank_prefix = 8;
1253 }
1254 if (do_blank) {
1255 blank.offset = blank_prefix;
ff3187f6 1256 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1257 blank.type = PKTLOG_OMIT;
1258 nblanks = 1;
1259 }
1260 }
ff3187f6 1261 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1262 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1263 st->pktin->data+6, st->pktin->length-6,
9a10ecf4 1264 nblanks, &blank);
1265 }
00db133f 1266
ff3187f6 1267 crFinish(st->pktin);
e5574168 1268}
1269
ff3187f6 1270static void ssh1_pktout_size(struct Packet *pkt, int len)
32874aea 1271{
374330e2 1272 int pad, biglen;
1273
1274 len += 5; /* type and CRC */
32874aea 1275 pad = 8 - (len % 8);
374330e2 1276 biglen = len + pad;
1277
ff3187f6 1278 pkt->length = len - 5;
1279 if (pkt->maxlen < biglen) {
1280 pkt->maxlen = biglen;
1281 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
374330e2 1282 }
ff3187f6 1283 pkt->body = pkt->data + 4 + pad + 1;
4ba9b64b 1284}
374330e2 1285
ff3187f6 1286static struct Packet *s_wrpkt_start(int type, int len)
32874aea 1287{
ff3187f6 1288 struct Packet *pkt = ssh_new_packet();
1289 ssh1_pktout_size(pkt, len);
1290 pkt->type = type;
9a10ecf4 1291 /* Initialise log omission state */
ff3187f6 1292 pkt->nblanks = 0;
1293 pkt->blanks = NULL;
1294 return pkt;
374330e2 1295}
1296
ff3187f6 1297static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
32874aea 1298{
fd7a4aad 1299 int pad, biglen, i;
374330e2 1300 unsigned long crc;
fd7a4aad 1301#ifdef __SC__
1302 /*
1303 * XXX various versions of SC (including 8.8.4) screw up the
1304 * register allocation in this function and use the same register
1305 * (D6) for len and as a temporary, with predictable results. The
1306 * following sledgehammer prevents this.
1307 */
1308 volatile
1309#endif
1310 int len;
374330e2 1311
ff3187f6 1312 pkt->body[-1] = pkt->type;
4ba9b64b 1313
a8327734 1314 if (ssh->logctx)
ff3187f6 1315 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1316 ssh1_pkt_type(pkt->type),
1317 pkt->body, pkt->length,
1318 pkt->nblanks, pkt->blanks);
1319 sfree(pkt->blanks); pkt->blanks = NULL;
1320 pkt->nblanks = 0;
00db133f 1321
51470298 1322 if (ssh->v1_compressing) {
4ba9b64b 1323 unsigned char *compblk;
1324 int complen;
5366aed8 1325 zlib_compress_block(ssh->cs_comp_ctx,
ff3187f6 1326 pkt->body - 1, pkt->length + 1,
4ba9b64b 1327 &compblk, &complen);
ff3187f6 1328 ssh1_pktout_size(pkt, complen - 1);
1329 memcpy(pkt->body - 1, compblk, complen);
dcbde236 1330 sfree(compblk);
4ba9b64b 1331 }
1332
ff3187f6 1333 len = pkt->length + 5; /* type and CRC */
32874aea 1334 pad = 8 - (len % 8);
374330e2 1335 biglen = len + pad;
1336
32874aea 1337 for (i = 0; i < pad; i++)
ff3187f6 1338 pkt->data[i + 4] = random_byte();
1339 crc = crc32_compute(pkt->data + 4, biglen - 4);
1340 PUT_32BIT(pkt->data + biglen, crc);
1341 PUT_32BIT(pkt->data, len);
374330e2 1342
51470298 1343 if (ssh->cipher)
ff3187f6 1344 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
374330e2 1345
32874aea 1346 return biglen + 4;
39065bed 1347}
1348
ff3187f6 1349static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1350{
5471d09a 1351 int len, backlog;
ff3187f6 1352 len = s_wrpkt_prepare(ssh, pkt);
1353 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1354 if (backlog > SSH_MAX_BACKLOG)
51470298 1355 ssh_throttle_all(ssh, 1, backlog);
39065bed 1356}
1357
ff3187f6 1358static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1359{
39065bed 1360 int len;
ff3187f6 1361 len = s_wrpkt_prepare(ssh, pkt);
51470298 1362 if (ssh->deferred_len + len > ssh->deferred_size) {
1363 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1364 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1365 ssh->deferred_size,
1366 unsigned char);
39065bed 1367 }
ff3187f6 1368 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1369 ssh->deferred_len += len;
374330e2 1370}
1371
fb09bf1c 1372/*
39065bed 1373 * Construct a packet with the specified contents.
fb09bf1c 1374 */
ff3187f6 1375static struct Packet *construct_packet(Ssh ssh, int pkttype,
1376 va_list ap1, va_list ap2)
fb09bf1c 1377{
fb09bf1c 1378 unsigned char *p, *argp, argchar;
1379 unsigned long argint;
1380 int pktlen, argtype, arglen;
7cca0d81 1381 Bignum bn;
ff3187f6 1382 struct Packet *pkt;
fb09bf1c 1383
1384 pktlen = 0;
39065bed 1385 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1386 switch (argtype) {
1387 case PKT_INT:
39065bed 1388 (void) va_arg(ap1, int);
fb09bf1c 1389 pktlen += 4;
1390 break;
1391 case PKT_CHAR:
1ec39246 1392 (void) va_arg(ap1, int);
fb09bf1c 1393 pktlen++;
1394 break;
1395 case PKT_DATA:
39065bed 1396 (void) va_arg(ap1, unsigned char *);
1397 arglen = va_arg(ap1, int);
fb09bf1c 1398 pktlen += arglen;
1399 break;
1400 case PKT_STR:
39065bed 1401 argp = va_arg(ap1, unsigned char *);
d8baa528 1402 arglen = strlen((char *)argp);
fb09bf1c 1403 pktlen += 4 + arglen;
1404 break;
7cca0d81 1405 case PKT_BIGNUM:
39065bed 1406 bn = va_arg(ap1, Bignum);
32874aea 1407 pktlen += ssh1_bignum_length(bn);
7cca0d81 1408 break;
9a10ecf4 1409 case PKTT_PASSWORD:
1410 case PKTT_DATA:
1411 case PKTT_OTHER:
1412 /* ignore this pass */
1413 break;
fb09bf1c 1414 default:
1415 assert(0);
1416 }
1417 }
fb09bf1c 1418
ff3187f6 1419 pkt = s_wrpkt_start(pkttype, pktlen);
1420 p = pkt->body;
fb09bf1c 1421
39065bed 1422 while ((argtype = va_arg(ap2, int)) != PKT_END) {
ff3187f6 1423 int offset = p - pkt->body, len = 0;
fb09bf1c 1424 switch (argtype) {
9a10ecf4 1425 /* Actual fields in the packet */
fb09bf1c 1426 case PKT_INT:
39065bed 1427 argint = va_arg(ap2, int);
fb09bf1c 1428 PUT_32BIT(p, argint);
9a10ecf4 1429 len = 4;
fb09bf1c 1430 break;
1431 case PKT_CHAR:
1ec39246 1432 argchar = (unsigned char) va_arg(ap2, int);
fb09bf1c 1433 *p = argchar;
9a10ecf4 1434 len = 1;
fb09bf1c 1435 break;
1436 case PKT_DATA:
39065bed 1437 argp = va_arg(ap2, unsigned char *);
1438 arglen = va_arg(ap2, int);
fb09bf1c 1439 memcpy(p, argp, arglen);
9a10ecf4 1440 len = arglen;
fb09bf1c 1441 break;
1442 case PKT_STR:
39065bed 1443 argp = va_arg(ap2, unsigned char *);
d8baa528 1444 arglen = strlen((char *)argp);
fb09bf1c 1445 PUT_32BIT(p, arglen);
1446 memcpy(p + 4, argp, arglen);
9a10ecf4 1447 len = arglen + 4;
fb09bf1c 1448 break;
7cca0d81 1449 case PKT_BIGNUM:
39065bed 1450 bn = va_arg(ap2, Bignum);
9a10ecf4 1451 len = ssh1_write_bignum(p, bn);
1452 break;
1453 /* Tokens for modifications to packet logging */
1454 case PKTT_PASSWORD:
ff3187f6 1455 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1456 break;
1457 case PKTT_DATA:
ff3187f6 1458 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1459 break;
9a10ecf4 1460 case PKTT_OTHER:
ff3187f6 1461 end_log_omission(ssh, pkt);
9a10ecf4 1462 break;
1463 }
1464 p += len;
1465 /* Deal with logfile omission, if required. */
ff3187f6 1466 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1467 pkt->nblanks++;
1468 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1469 struct logblank_t);
1470 pkt->blanks[pkt->nblanks-1].offset = offset;
1471 pkt->blanks[pkt->nblanks-1].len = len;
1472 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
fb09bf1c 1473 }
1474 }
ff3187f6 1475
1476 return pkt;
39065bed 1477}
fb09bf1c 1478
51470298 1479static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1480{
ff3187f6 1481 struct Packet *pkt;
39065bed 1482 va_list ap1, ap2;
1483 va_start(ap1, pkttype);
1484 va_start(ap2, pkttype);
ff3187f6 1485 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1486 va_end(ap2);
1487 va_end(ap1);
1488 s_wrpkt(ssh, pkt);
1489 ssh_free_packet(pkt);
fb09bf1c 1490}
1491
51470298 1492static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1493{
ff3187f6 1494 struct Packet *pkt;
39065bed 1495 va_list ap1, ap2;
1496 va_start(ap1, pkttype);
1497 va_start(ap2, pkttype);
ff3187f6 1498 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1499 va_end(ap2);
1500 va_end(ap1);
1501 s_wrpkt_defer(ssh, pkt);
1502 ssh_free_packet(pkt);
39065bed 1503}
1504
32874aea 1505static int ssh_versioncmp(char *a, char *b)
1506{
9697bfd2 1507 char *ae, *be;
1508 unsigned long av, bv;
1509
43aa02a7 1510 av = strtoul(a, &ae, 10);
1511 bv = strtoul(b, &be, 10);
32874aea 1512 if (av != bv)
1513 return (av < bv ? -1 : +1);
1514 if (*ae == '.')
1515 ae++;
1516 if (*be == '.')
1517 be++;
43aa02a7 1518 av = strtoul(ae, &ae, 10);
1519 bv = strtoul(be, &be, 10);
32874aea 1520 if (av != bv)
1521 return (av < bv ? -1 : +1);
9697bfd2 1522 return 0;
1523}
1524
e5574168 1525/*
a92dd380 1526 * Utility routines for putting an SSH-protocol `string' and
1527 * `uint32' into a SHA state.
e5574168 1528 */
1529#include <stdio.h>
32874aea 1530static void sha_string(SHA_State * s, void *str, int len)
1531{
e5574168 1532 unsigned char lenblk[4];
e5574168 1533 PUT_32BIT(lenblk, len);
e5574168 1534 SHA_Bytes(s, lenblk, 4);
e5574168 1535 SHA_Bytes(s, str, len);
1536}
1537
32874aea 1538static void sha_uint32(SHA_State * s, unsigned i)
1539{
a92dd380 1540 unsigned char intblk[4];
1541 PUT_32BIT(intblk, i);
1542 SHA_Bytes(s, intblk, 4);
1543}
1544
7cca0d81 1545/*
1546 * SSH2 packet construction functions.
1547 */
ff3187f6 1548static void ssh2_pkt_ensure(struct Packet *pkt, int length)
32874aea 1549{
ff3187f6 1550 if (pkt->maxlen < length) {
1551 pkt->maxlen = length + 256;
1552 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
7cca0d81 1553 }
783415f8 1554}
ff3187f6 1555static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1556{
ff3187f6 1557 if (pkt->logmode != PKTLOG_EMIT) {
1558 pkt->nblanks++;
1559 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1560 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1561 pkt->blanks[pkt->nblanks-1].len = len;
1562 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1563 }
1564 pkt->length += len;
1565 ssh2_pkt_ensure(pkt, pkt->length);
1566 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1567}
ff3187f6 1568static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1569{
ff3187f6 1570 ssh2_pkt_adddata(pkt, &byte, 1);
7cca0d81 1571}
ff3187f6 1572static struct Packet *ssh2_pkt_init(int pkt_type)
32874aea 1573{
ff3187f6 1574 struct Packet *pkt = ssh_new_packet();
1575 pkt->length = 5;
95d2d262 1576 pkt->forcepad = 0;
ff3187f6 1577 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1578 return pkt;
7cca0d81 1579}
ff3187f6 1580static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1581{
ff3187f6 1582 ssh2_pkt_adddata(pkt, &value, 1);
7cca0d81 1583}
ff3187f6 1584static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1585{
7cca0d81 1586 unsigned char x[4];
1587 PUT_32BIT(x, value);
ff3187f6 1588 ssh2_pkt_adddata(pkt, x, 4);
7cca0d81 1589}
ff3187f6 1590static void ssh2_pkt_addstring_start(struct Packet *pkt)
32874aea 1591{
ff3187f6 1592 ssh2_pkt_adduint32(pkt, 0);
1593 pkt->savedpos = pkt->length;
7cca0d81 1594}
ff3187f6 1595static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1596{
ff3187f6 1597 ssh2_pkt_adddata(pkt, data, strlen(data));
1598 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1599}
ff3187f6 1600static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1601{
ff3187f6 1602 ssh2_pkt_adddata(pkt, data, len);
1603 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1604}
ff3187f6 1605static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
32874aea 1606{
ff3187f6 1607 ssh2_pkt_addstring_start(pkt);
1608 ssh2_pkt_addstring_str(pkt, data);
7cca0d81 1609}
d8baa528 1610static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1611{
7cca0d81 1612 unsigned char *p;
32874aea 1613 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1614 p = snewn(n + 1, unsigned char);
7cca0d81 1615 if (!p)
32874aea 1616 fatalbox("out of memory");
7cca0d81 1617 p[0] = 0;
3709bfe9 1618 for (i = 1; i <= n; i++)
32874aea 1619 p[i] = bignum_byte(b, n - i);
7cca0d81 1620 i = 0;
32874aea 1621 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1622 i++;
1623 memmove(p, p + i, n + 1 - i);
1624 *len = n + 1 - i;
7cca0d81 1625 return p;
1626}
ff3187f6 1627static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1628{
7cca0d81 1629 unsigned char *p;
1630 int len;
1631 p = ssh2_mpint_fmt(b, &len);
ff3187f6 1632 ssh2_pkt_addstring_start(pkt);
1633 ssh2_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1634 sfree(p);
7cca0d81 1635}
b185170a 1636
1637/*
1638 * Construct an SSH2 final-form packet: compress it, encrypt it,
1639 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1640 * pkt->data. Total length is returned.
b185170a 1641 */
ff3187f6 1642static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1643{
7cca0d81 1644 int cipherblk, maclen, padding, i;
7cca0d81 1645
a8327734 1646 if (ssh->logctx)
ff3187f6 1647 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1648 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1649 pkt->data + 6, pkt->length - 6,
1650 pkt->nblanks, pkt->blanks);
1651 sfree(pkt->blanks); pkt->blanks = NULL;
1652 pkt->nblanks = 0;
00db133f 1653
7cca0d81 1654 /*
4ba9b64b 1655 * Compress packet payload.
1656 */
4ba9b64b 1657 {
1658 unsigned char *newpayload;
1659 int newlen;
51470298 1660 if (ssh->cscomp &&
ff3187f6 1661 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1662 pkt->length - 5,
51470298 1663 &newpayload, &newlen)) {
ff3187f6 1664 pkt->length = 5;
1665 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1666 sfree(newpayload);
4ba9b64b 1667 }
1668 }
1669
1670 /*
7cca0d81 1671 * Add padding. At least four bytes, and must also bring total
1672 * length (minus MAC) up to a multiple of the block size.
95d2d262 1673 * If pkt->forcepad is set, make sure the packet is at least that size
1674 * after padding.
7cca0d81 1675 */
51470298 1676 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1677 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1678 padding = 4;
95d2d262 1679 if (pkt->length + padding < pkt->forcepad)
1680 padding = pkt->forcepad - pkt->length;
32874aea 1681 padding +=
ff3187f6 1682 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
95d2d262 1683 assert(padding <= 255);
51470298 1684 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1685 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1686 pkt->data[4] = padding;
7cca0d81 1687 for (i = 0; i < padding; i++)
ff3187f6 1688 pkt->data[pkt->length + i] = random_byte();
1689 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1690 if (ssh->csmac)
ff3187f6 1691 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1692 pkt->length + padding,
51470298 1693 ssh->v2_outgoing_sequence);
1694 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1695
1696 if (ssh->cscipher)
371e569c 1697 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 1698 pkt->data, pkt->length + padding);
51470298 1699
9442dd57 1700 pkt->encrypted_len = pkt->length + padding;
1701
ff3187f6 1702 /* Ready-to-send packet starts at pkt->data. We return length. */
1703 return pkt->length + padding + maclen;
b185170a 1704}
1705
1706/*
590f6a5f 1707 * Routines called from the main SSH code to send packets. There
1708 * are quite a few of these, because we have two separate
1709 * mechanisms for delaying the sending of packets:
1710 *
1711 * - In order to send an IGNORE message and a password message in
1712 * a single fixed-length blob, we require the ability to
1713 * concatenate the encrypted forms of those two packets _into_ a
1714 * single blob and then pass it to our <network.h> transport
1715 * layer in one go. Hence, there's a deferment mechanism which
1716 * works after packet encryption.
1717 *
1718 * - In order to avoid sending any connection-layer messages
1719 * during repeat key exchange, we have to queue up any such
1720 * outgoing messages _before_ they are encrypted (and in
1721 * particular before they're allocated sequence numbers), and
1722 * then send them once we've finished.
1723 *
1724 * I call these mechanisms `defer' and `queue' respectively, so as
1725 * to distinguish them reasonably easily.
1726 *
1727 * The functions send_noqueue() and defer_noqueue() free the packet
1728 * structure they are passed. Every outgoing packet goes through
1729 * precisely one of these functions in its life; packets passed to
1730 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1731 * these or get queued, and then when the queue is later emptied
1732 * the packets are all passed to defer_noqueue().
b185170a 1733 */
590f6a5f 1734
1735/*
1736 * Send an SSH2 packet immediately, without queuing or deferring.
1737 */
1738static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1739{
5471d09a 1740 int len;
1741 int backlog;
ff3187f6 1742 len = ssh2_pkt_construct(ssh, pkt);
1743 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1744 if (backlog > SSH_MAX_BACKLOG)
51470298 1745 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1746
1747 ssh->outgoing_data_size += pkt->encrypted_len;
1748 if (!ssh->kex_in_progress &&
d57f70af 1749 ssh->max_data_size != 0 &&
1750 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 1751 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 1752
ff3187f6 1753 ssh_free_packet(pkt);
b185170a 1754}
1755
1756/*
590f6a5f 1757 * Defer an SSH2 packet.
b185170a 1758 */
590f6a5f 1759static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1760{
ff3187f6 1761 int len = ssh2_pkt_construct(ssh, pkt);
51470298 1762 if (ssh->deferred_len + len > ssh->deferred_size) {
1763 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1764 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1765 ssh->deferred_size,
1766 unsigned char);
b185170a 1767 }
ff3187f6 1768 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1769 ssh->deferred_len += len;
9442dd57 1770 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 1771 ssh_free_packet(pkt);
b185170a 1772}
1773
1774/*
590f6a5f 1775 * Queue an SSH2 packet.
1776 */
1777static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1778{
1779 assert(ssh->queueing);
1780
1781 if (ssh->queuelen >= ssh->queuesize) {
1782 ssh->queuesize = ssh->queuelen + 32;
1783 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1784 }
1785
1786 ssh->queue[ssh->queuelen++] = pkt;
1787}
1788
1789/*
1790 * Either queue or send a packet, depending on whether queueing is
1791 * set.
1792 */
1793static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1794{
1795 if (ssh->queueing)
1796 ssh2_pkt_queue(ssh, pkt);
1797 else
1798 ssh2_pkt_send_noqueue(ssh, pkt);
1799}
1800
95d2d262 1801#if 0 /* disused */
590f6a5f 1802/*
1803 * Either queue or defer a packet, depending on whether queueing is
1804 * set.
1805 */
1806static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1807{
1808 if (ssh->queueing)
1809 ssh2_pkt_queue(ssh, pkt);
1810 else
1811 ssh2_pkt_defer_noqueue(ssh, pkt);
1812}
95d2d262 1813#endif
590f6a5f 1814
1815/*
b185170a 1816 * Send the whole deferred data block constructed by
39065bed 1817 * ssh2_pkt_defer() or SSH1's defer_packet().
590f6a5f 1818 *
1819 * The expected use of the defer mechanism is that you call
1820 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1821 * not currently queueing, this simply sets up deferred_send_data
1822 * and then sends it. If we _are_ currently queueing, the calls to
1823 * ssh2_pkt_defer() put the deferred packets on to the queue
1824 * instead, and therefore ssh_pkt_defersend() has no deferred data
1825 * to send. Hence, there's no need to make it conditional on
1826 * ssh->queueing.
b185170a 1827 */
51470298 1828static void ssh_pkt_defersend(Ssh ssh)
32874aea 1829{
5471d09a 1830 int backlog;
d8baa528 1831 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1832 ssh->deferred_len);
51470298 1833 ssh->deferred_len = ssh->deferred_size = 0;
1834 sfree(ssh->deferred_send_data);
1835 ssh->deferred_send_data = NULL;
5471d09a 1836 if (backlog > SSH_MAX_BACKLOG)
51470298 1837 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1838
1839 ssh->outgoing_data_size += ssh->deferred_data_size;
1840 if (!ssh->kex_in_progress &&
d57f70af 1841 ssh->max_data_size != 0 &&
1842 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 1843 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 1844 ssh->deferred_data_size = 0;
7cca0d81 1845}
1846
590f6a5f 1847/*
1848 * Send all queued SSH2 packets. We send them by means of
1849 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1850 * packets that needed to be lumped together.
1851 */
1852static void ssh2_pkt_queuesend(Ssh ssh)
1853{
1854 int i;
1855
1856 assert(!ssh->queueing);
1857
1858 for (i = 0; i < ssh->queuelen; i++)
1859 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1860 ssh->queuelen = 0;
1861
1862 ssh_pkt_defersend(ssh);
1863}
1864
7cca0d81 1865#if 0
32874aea 1866void bndebug(char *string, Bignum b)
1867{
7cca0d81 1868 unsigned char *p;
1869 int i, len;
1870 p = ssh2_mpint_fmt(b, &len);
1871 debug(("%s", string));
1872 for (i = 0; i < len; i++)
32874aea 1873 debug((" %02x", p[i]));
765c4200 1874 debug(("\n"));
dcbde236 1875 sfree(p);
7cca0d81 1876}
1877#endif
1878
32874aea 1879static void sha_mpint(SHA_State * s, Bignum b)
1880{
7cca0d81 1881 unsigned char *p;
1882 int len;
1883 p = ssh2_mpint_fmt(b, &len);
1884 sha_string(s, p, len);
dcbde236 1885 sfree(p);
7cca0d81 1886}
1887
1888/*
0016d70b 1889 * Packet decode functions for both SSH1 and SSH2.
7cca0d81 1890 */
ff3187f6 1891static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 1892{
7cca0d81 1893 unsigned long value;
ff3187f6 1894 if (pkt->length - pkt->savedpos < 4)
32874aea 1895 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1896 value = GET_32BIT(pkt->body + pkt->savedpos);
1897 pkt->savedpos += 4;
7cca0d81 1898 return value;
1899}
ff3187f6 1900static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 1901{
65a22376 1902 unsigned long value;
ff3187f6 1903 if (pkt->length - pkt->savedpos < 1)
32874aea 1904 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1905 value = pkt->body[pkt->savedpos] != 0;
1906 pkt->savedpos++;
65a22376 1907 return value;
1908}
ff3187f6 1909static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 1910{
57356d63 1911 int len;
7cca0d81 1912 *p = NULL;
45068b27 1913 *length = 0;
ff3187f6 1914 if (pkt->length - pkt->savedpos < 4)
32874aea 1915 return;
ff3187f6 1916 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 1917 if (len < 0)
1918 return;
1919 *length = len;
ff3187f6 1920 pkt->savedpos += 4;
1921 if (pkt->length - pkt->savedpos < *length)
32874aea 1922 return;
ff3187f6 1923 *p = (char *)(pkt->body + pkt->savedpos);
1924 pkt->savedpos += *length;
7cca0d81 1925}
ff3187f6 1926static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 1927{
ff3187f6 1928 if (pkt->length - pkt->savedpos < length)
0016d70b 1929 return NULL;
ff3187f6 1930 pkt->savedpos += length;
1931 return pkt->body + (pkt->savedpos - length);
0016d70b 1932}
ff3187f6 1933static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 1934 unsigned char **keystr)
1935{
1936 int j;
1937
ff3187f6 1938 j = makekey(pkt->body + pkt->savedpos,
1939 pkt->length - pkt->savedpos,
0016d70b 1940 key, keystr, 0);
1941
1942 if (j < 0)
1943 return FALSE;
1944
ff3187f6 1945 pkt->savedpos += j;
1946 assert(pkt->savedpos < pkt->length);
0016d70b 1947
1948 return TRUE;
1949}
ff3187f6 1950static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 1951{
1952 int j;
1953 Bignum b;
1954
ff3187f6 1955 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1956 pkt->length - pkt->savedpos, &b);
0016d70b 1957
1958 if (j < 0)
1959 return NULL;
1960
ff3187f6 1961 pkt->savedpos += j;
0016d70b 1962 return b;
1963}
ff3187f6 1964static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 1965{
7cca0d81 1966 char *p;
3709bfe9 1967 int length;
7cca0d81 1968 Bignum b;
1969
ff3187f6 1970 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 1971 if (!p)
32874aea 1972 return NULL;
ff3187f6 1973 if (p[0] & 0x80)
32874aea 1974 return NULL;
d8baa528 1975 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1976 return b;
1977}
1978
7d503c31 1979/*
1dd353b5 1980 * Helper function to add an SSH2 signature blob to a packet.
1981 * Expects to be shown the public key blob as well as the signature
1982 * blob. Normally works just like ssh2_pkt_addstring, but will
1983 * fiddle with the signature packet if necessary for
1984 * BUG_SSH2_RSA_PADDING.
1985 */
ff3187f6 1986static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1987 void *pkblob_v, int pkblob_len,
1dd353b5 1988 void *sigblob_v, int sigblob_len)
1989{
1990 unsigned char *pkblob = (unsigned char *)pkblob_v;
1991 unsigned char *sigblob = (unsigned char *)sigblob_v;
1992
1993 /* dmemdump(pkblob, pkblob_len); */
1994 /* dmemdump(sigblob, sigblob_len); */
1995
1996 /*
1997 * See if this is in fact an ssh-rsa signature and a buggy
1998 * server; otherwise we can just do this the easy way.
1999 */
51470298 2000 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 2001 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2002 int pos, len, siglen;
2003
2004 /*
2005 * Find the byte length of the modulus.
2006 */
2007
2008 pos = 4+7; /* skip over "ssh-rsa" */
2009 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2010 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2011 pos += 4; /* find modulus itself */
2012 while (len > 0 && pkblob[pos] == 0)
2013 len--, pos++;
2014 /* debug(("modulus length is %d\n", len)); */
2015
2016 /*
2017 * Now find the signature integer.
2018 */
2019 pos = 4+7; /* skip over "ssh-rsa" */
2020 siglen = GET_32BIT(sigblob+pos);
2021 /* debug(("signature length is %d\n", siglen)); */
2022
2023 if (len != siglen) {
2024 unsigned char newlen[4];
ff3187f6 2025 ssh2_pkt_addstring_start(pkt);
2026 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2027 /* dmemdump(sigblob, pos); */
2028 pos += 4; /* point to start of actual sig */
2029 PUT_32BIT(newlen, len);
ff3187f6 2030 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2031 /* dmemdump(newlen, 4); */
2032 newlen[0] = 0;
2033 while (len-- > siglen) {
ff3187f6 2034 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2035 /* dmemdump(newlen, 1); */
2036 }
ff3187f6 2037 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2038 /* dmemdump(sigblob+pos, siglen); */
2039 return;
2040 }
2041
2042 /* Otherwise fall through and do it the easy way. */
2043 }
2044
ff3187f6 2045 ssh2_pkt_addstring_start(pkt);
2046 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2047}
2048
2049/*
7d503c31 2050 * Examine the remote side's version string and compare it against
2051 * a list of known buggy implementations.
2052 */
51470298 2053static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2054{
2055 char *imp; /* pointer to implementation part */
7d503c31 2056 imp = vstring;
2057 imp += strcspn(imp, "-");
bd358db1 2058 if (*imp) imp++;
7d503c31 2059 imp += strcspn(imp, "-");
bd358db1 2060 if (*imp) imp++;
7d503c31 2061
51470298 2062 ssh->remote_bugs = 0;
7d503c31 2063
5ecd7ad0 2064 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2065 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 2066 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2067 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2068 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2069 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2070 /*
2071 * These versions don't support SSH1_MSG_IGNORE, so we have
2072 * to use a different defence against password length
2073 * sniffing.
2074 */
51470298 2075 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 2076 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 2077 }
2078
5ecd7ad0 2079 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2080 (ssh->cfg.sshbug_plainpw1 == AUTO &&
46ac09aa 2081 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2082 /*
2083 * These versions need a plain password sent; they can't
2084 * handle having a null and a random length of data after
2085 * the password.
2086 */
51470298 2087 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 2088 logevent("We believe remote version needs a plain SSH1 password");
2089 }
2090
5ecd7ad0 2091 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2092 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 2093 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2094 /*
2095 * These versions apparently have no clue whatever about
2096 * RSA authentication and will panic and die if they see
2097 * an AUTH_RSA message.
2098 */
51470298 2099 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 2100 logevent("We believe remote version can't handle RSA authentication");
2101 }
2102
5ecd7ad0 2103 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2104 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 2105 !wc_match("* VShell", imp) &&
831301f6 2106 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2107 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2108 wc_match("2.1 *", imp)))) {
32874aea 2109 /*
2110 * These versions have the HMAC bug.
2111 */
51470298 2112 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 2113 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 2114 }
1dd353b5 2115
5ecd7ad0 2116 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2117 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 2118 !wc_match("* VShell", imp) &&
2856a1b9 2119 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2120 /*
2121 * These versions have the key-derivation bug (failing to
2122 * include the literal shared secret in the hashes that
2123 * generate the keys).
2124 */
51470298 2125 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 2126 logevent("We believe remote version has SSH2 key-derivation bug");
2127 }
2128
5ecd7ad0 2129 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2130 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 2131 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2132 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2133 /*
2134 * These versions have the SSH2 RSA padding bug.
2135 */
51470298 2136 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 2137 logevent("We believe remote version has SSH2 RSA padding bug");
2138 }
8e975795 2139
dda87a28 2140 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2141 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2142 wc_match("OpenSSH_2.[0-2]*", imp))) {
2143 /*
2144 * These versions have the SSH2 session-ID bug in
2145 * public-key authentication.
2146 */
2147 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2148 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2149 }
f382c87d 2150
2151 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2152 (ssh->cfg.sshbug_rekey2 == AUTO &&
e12d95a5 2153 (wc_match("OpenSSH_2.[0-4]*", imp) ||
2154 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2155 wc_match("Sun_SSH_1.0", imp) ||
7cb41bb2 2156 wc_match("Sun_SSH_1.0.1", imp)))) {
f382c87d 2157 /*
e12d95a5 2158 * These versions have the SSH2 rekey bug.
f382c87d 2159 */
2160 ssh->remote_bugs |= BUG_SSH2_REKEY;
e12d95a5 2161 logevent("We believe remote version has SSH2 rekey bug");
f382c87d 2162 }
7d503c31 2163}
2164
d38d6a1f 2165/*
2166 * The `software version' part of an SSH version string is required
2167 * to contain no spaces or minus signs.
2168 */
2169static void ssh_fix_verstring(char *str)
2170{
2171 /* Eat "SSH-<protoversion>-". */
2172 assert(*str == 'S'); str++;
2173 assert(*str == 'S'); str++;
2174 assert(*str == 'H'); str++;
2175 assert(*str == '-'); str++;
2176 while (*str && *str != '-') str++;
2177 assert(*str == '-'); str++;
2178
2179 /* Convert minus signs and spaces in the remaining string into
2180 * underscores. */
2181 while (*str) {
2182 if (*str == '-' || *str == ' ')
2183 *str = '_';
2184 str++;
2185 }
2186}
2187
51470298 2188static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2189{
51470298 2190 struct do_ssh_init_state {
2191 int vslen;
2192 char version[10];
2193 char *vstring;
2194 int vstrsize;
2195 int i;
2196 int proto1, proto2;
2197 };
2198 crState(do_ssh_init_state);
374330e2 2199
51470298 2200 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2201
2202 /* Search for the string "SSH-" in the input. */
51470298 2203 s->i = 0;
8df7a775 2204 while (1) {
2205 static const int transS[] = { 1, 2, 2, 1 };
2206 static const int transH[] = { 0, 0, 3, 0 };
2207 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 2208 if (c == 'S')
51470298 2209 s->i = transS[s->i];
32874aea 2210 else if (c == 'H')
51470298 2211 s->i = transH[s->i];
32874aea 2212 else if (c == '-')
51470298 2213 s->i = transminus[s->i];
32874aea 2214 else
51470298 2215 s->i = 0;
2216 if (s->i < 0)
8df7a775 2217 break;
2218 crReturn(1); /* get another character */
374330e2 2219 }
8df7a775 2220
51470298 2221 s->vstrsize = 16;
3d88e64d 2222 s->vstring = snewn(s->vstrsize, char);
51470298 2223 strcpy(s->vstring, "SSH-");
2224 s->vslen = 4;
2225 s->i = 0;
374330e2 2226 while (1) {
8df7a775 2227 crReturn(1); /* get another char */
51470298 2228 if (s->vslen >= s->vstrsize - 1) {
2229 s->vstrsize += 16;
3d88e64d 2230 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2231 }
51470298 2232 s->vstring[s->vslen++] = c;
2233 if (s->i >= 0) {
374330e2 2234 if (c == '-') {
51470298 2235 s->version[s->i] = '\0';
2236 s->i = -1;
2237 } else if (s->i < sizeof(s->version) - 1)
2238 s->version[s->i++] = c;
c4ffc4d0 2239 } else if (c == '\012')
374330e2 2240 break;
2241 }
2242
51470298 2243 ssh->agentfwd_enabled = FALSE;
2244 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2245
51470298 2246 s->vstring[s->vslen] = 0;
a7d4653a 2247 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
51470298 2248 {
2249 char *vlog;
3d88e64d 2250 vlog = snewn(20 + s->vslen, char);
51470298 2251 sprintf(vlog, "Server version: %s", s->vstring);
2252 logevent(vlog);
2253 sfree(vlog);
2254 }
2255 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2256
adf799dd 2257 /*
38d228a2 2258 * Decide which SSH protocol version to support.
adf799dd 2259 */
38d228a2 2260
2261 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2262 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2263 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2264 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2265
86916870 2266 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2267 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2268 crStop(0);
38d228a2 2269 }
86916870 2270 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2271 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2272 crStop(0);
38d228a2 2273 }
2274
d38d6a1f 2275 {
2276 char *verstring;
2277
2278 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2279 /*
2280 * Construct a v2 version string.
2281 */
a7d4653a 2282 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
d38d6a1f 2283 ssh->version = 2;
2284 } else {
2285 /*
2286 * Construct a v1 version string.
2287 */
a7d4653a 2288 verstring = dupprintf("SSH-%s-%s\012",
d38d6a1f 2289 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2290 s->version : "1.5"),
2291 sshver);
2292 ssh->version = 1;
2293 }
2294
2295 ssh_fix_verstring(verstring);
2296
2297 if (ssh->version == 2) {
2298 /*
2299 * Hash our version string and their version string.
2300 */
2301 SHA_Init(&ssh->exhashbase);
0b351b6b 2302 sha_string(&ssh->exhashbase, verstring,
a7d4653a 2303 strcspn(verstring, "\015\012"));
0b351b6b 2304 sha_string(&ssh->exhashbase, s->vstring,
a7d4653a 2305 strcspn(s->vstring, "\015\012"));
d38d6a1f 2306
2307 /*
2308 * Initialise SSHv2 protocol.
2309 */
2310 ssh->protocol = ssh2_protocol;
2311 ssh2_protocol_setup(ssh);
2312 ssh->s_rdpkt = ssh2_rdpkt;
2313 } else {
2314 /*
2315 * Initialise SSHv1 protocol.
2316 */
2317 ssh->protocol = ssh1_protocol;
2318 ssh1_protocol_setup(ssh);
2319 ssh->s_rdpkt = ssh1_rdpkt;
2320 }
2321 logeventf(ssh, "We claim version: %.*s",
a7d4653a 2322 strcspn(verstring, "\015\012"), verstring);
51470298 2323 sk_write(ssh->s, verstring, strlen(verstring));
d38d6a1f 2324 sfree(verstring);
e5574168 2325 }
d38d6a1f 2326
2327 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2328
125105d1 2329 update_specials_menu(ssh->frontend);
51470298 2330 ssh->state = SSH_STATE_BEFORE_SIZE;
39934deb 2331 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
8df7a775 2332
51470298 2333 sfree(s->vstring);
50526e47 2334
8df7a775 2335 crFinish(0);
2336}
2337
51470298 2338static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2339{
51470298 2340 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2341
2342 /*
2343 * To begin with, feed the characters one by one to the
2344 * protocol initialisation / selection function do_ssh_init().
2345 * When that returns 0, we're done with the initial greeting
2346 * exchange and can move on to packet discipline.
2347 */
2348 while (1) {
51470298 2349 int ret; /* need not be kept across crReturn */
8df7a775 2350 if (datalen == 0)
2351 crReturnV; /* more data please */
51470298 2352 ret = do_ssh_init(ssh, *data);
32874aea 2353 data++;
2354 datalen--;
8df7a775 2355 if (ret == 0)
2356 break;
2357 }
2358
2359 /*
2360 * We emerge from that loop when the initial negotiation is
2361 * over and we have selected an s_rdpkt function. Now pass
2362 * everything to s_rdpkt, and then pass the resulting packets
2363 * to the proper protocol handler.
2364 */
2365 if (datalen == 0)
2366 crReturnV;
2367 while (1) {
2368 while (datalen > 0) {
ff3187f6 2369 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2370 if (pktin) {
2371 ssh->protocol(ssh, NULL, 0, pktin);
2372 ssh_free_packet(pktin);
8df7a775 2373 }
ff3187f6 2374 if (ssh->state == SSH_STATE_CLOSED)
2375 return;
8df7a775 2376 }
2377 crReturnV;
2378 }
2379 crFinishV;
2380}
2381
ac934965 2382static int ssh_do_close(Ssh ssh, int notify_exit)
32874aea 2383{
ac934965 2384 int i, ret = 0;
36f94d1f 2385 struct ssh_channel *c;
2386
51470298 2387 ssh->state = SSH_STATE_CLOSED;
2388 if (ssh->s) {
2389 sk_close(ssh->s);
2390 ssh->s = NULL;
ac934965 2391 if (notify_exit)
2392 notify_remote_exit(ssh->frontend);
2393 else
2394 ret = 1;
f3ab576e 2395 }
36f94d1f 2396 /*
2397 * Now we must shut down any port and X forwardings going
2398 * through this connection.
2399 */
74a98066 2400 if (ssh->channels) {
2401 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2402 switch (c->type) {
2403 case CHAN_X11:
2404 x11_close(c->u.x11.s);
2405 break;
2406 case CHAN_SOCKDATA:
2407 pfd_close(c->u.pfd.s);
2408 break;
2409 }
2410 del234(ssh->channels, c);
2411 if (ssh->version == 2)
2412 bufchain_clear(&c->v.v2.outbuffer);
2413 sfree(c);
36f94d1f 2414 }
36f94d1f 2415 }
ac934965 2416
2417 return ret;
36f94d1f 2418}
2419
7555d6a5 2420static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2421 const char *error_msg, int error_code)
2422{
2423 Ssh ssh = (Ssh) plug;
2424 char addrbuf[256], *msg;
2425
2426 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2427
2428 if (type == 0)
2429 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2430 else
2431 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2432
2433 logevent(msg);
2434}
2435
cbe2d68f 2436static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2437 int calling_back)
2438{
2439 Ssh ssh = (Ssh) plug;
ac934965 2440 int need_notify = ssh_do_close(ssh, FALSE);
2441
2442 if (!error_msg && !ssh->close_expected) {
2443 error_msg = "Server unexpectedly closed network connection";
2444 }
2445
7e78000d 2446 if (error_msg) {
32874aea 2447 /* A socket error has occurred. */
247308b5 2448 logevent(error_msg);
971bcc0a 2449 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2450 } else {
ac934965 2451 logevent("Server closed network connection");
8df7a775 2452 }
ac934965 2453 if (need_notify)
2454 notify_remote_exit(ssh->frontend);
7e78000d 2455 return 0;
2456}
2457
32874aea 2458static int ssh_receive(Plug plug, int urgent, char *data, int len)
2459{
51470298 2460 Ssh ssh = (Ssh) plug;
d8baa528 2461 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2462 if (ssh->state == SSH_STATE_CLOSED) {
ac934965 2463 ssh_do_close(ssh, TRUE);
32874aea 2464 return 0;
3257deae 2465 }
fef97f43 2466 return 1;
374330e2 2467}
2468
5471d09a 2469static void ssh_sent(Plug plug, int bufsize)
2470{
51470298 2471 Ssh ssh = (Ssh) plug;
5471d09a 2472 /*
2473 * If the send backlog on the SSH socket itself clears, we
2474 * should unthrottle the whole world if it was throttled.
2475 */
2476 if (bufsize < SSH_MAX_BACKLOG)
51470298 2477 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2478}
2479
fb09bf1c 2480/*
8df7a775 2481 * Connect to specified host and port.
2482 * Returns an error message, or NULL on success.
6e1ebb76 2483 * Also places the canonical host name into `realhost'. It must be
2484 * freed by the caller.
8df7a775 2485 */
cbe2d68f 2486static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2487 char **realhost, int nodelay, int keepalive)
8df7a775 2488{
51470298 2489 static const struct plug_function_table fn_table = {
7555d6a5 2490 ssh_log,
7e78000d 2491 ssh_closing,
5471d09a 2492 ssh_receive,
2493 ssh_sent,
2494 NULL
51470298 2495 };
7e78000d 2496
8df7a775 2497 SockAddr addr;
cbe2d68f 2498 const char *err;
8df7a775 2499
3d88e64d 2500 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2501 if (!ssh->savedhost)
8df7a775 2502 fatalbox("Out of memory");
51470298 2503 strcpy(ssh->savedhost, host);
8df7a775 2504
2505 if (port < 0)
2506 port = 22; /* default ssh port */
51470298 2507 ssh->savedport = port;
8df7a775 2508
2509 /*
2510 * Try to find host.
2511 */
05581745 2512 logeventf(ssh, "Looking up host \"%s\"%s", host,
2513 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2514 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2515 addr = name_lookup(host, port, realhost, &ssh->cfg,
2516 ssh->cfg.addressfamily);
170c1e6e 2517 if ((err = sk_addr_error(addr)) != NULL) {
2518 sk_addr_free(addr);
8df7a775 2519 return err;
170c1e6e 2520 }
8df7a775 2521
8df7a775 2522 /*
2523 * Open socket.
2524 */
51470298 2525 ssh->fn = &fn_table;
e8fa8f62 2526 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2527 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2528 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2529 ssh->s = NULL;
39934deb 2530 notify_remote_exit(ssh->frontend);
8df7a775 2531 return err;
67c4ba2e 2532 }
8df7a775 2533
8df7a775 2534 return NULL;
2535}
2536
2537/*
5471d09a 2538 * Throttle or unthrottle the SSH connection.
2539 */
51470298 2540static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2541{
51470298 2542 int old_count = ssh->v1_throttle_count;
2543 ssh->v1_throttle_count += adjust;
2544 assert(ssh->v1_throttle_count >= 0);
2545 if (ssh->v1_throttle_count && !old_count) {
2546 sk_set_frozen(ssh->s, 1);
2547 } else if (!ssh->v1_throttle_count && old_count) {
2548 sk_set_frozen(ssh->s, 0);
5471d09a 2549 }
2550}
2551
2552/*
2553 * Throttle or unthrottle _all_ local data streams (for when sends
2554 * on the SSH connection itself back up).
2555 */
51470298 2556static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2557{
2558 int i;
2559 struct ssh_channel *c;
2560
51470298 2561 if (enable == ssh->throttled_all)
5471d09a 2562 return;
51470298 2563 ssh->throttled_all = enable;
2564 ssh->overall_bufsize = bufsize;
2565 if (!ssh->channels)
5471d09a 2566 return;
51470298 2567 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2568 switch (c->type) {
2569 case CHAN_MAINSESSION:
2570 /*
2571 * This is treated separately, outside the switch.
2572 */
2573 break;
2574 case CHAN_X11:
2575 x11_override_throttle(c->u.x11.s, enable);
2576 break;
2577 case CHAN_AGENT:
2578 /* Agent channels require no buffer management. */
2579 break;
2580 case CHAN_SOCKDATA:
36f94d1f 2581 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2582 break;
2583 }
2584 }
2585}
2586
2587/*
51470298 2588 * Username and password input, abstracted off into routines
2589 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2590 */
0405e71f 2591
2592/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2593static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2594{
51470298 2595 ssh->userpass_input_buffer = buffer;
2596 ssh->userpass_input_buflen = buflen;
2597 ssh->userpass_input_bufpos = 0;
2598 ssh->userpass_input_echo = echo;
0405e71f 2599}
2600
2601/*
2602 * Process some terminal data in the course of username/password
2603 * input. Returns >0 for success (line of input returned in
2604 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2605 * for inconclusive (keep waiting for more input please).
2606 */
ae9ae89f 2607static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2608{
2609 char c;
2610
2611 while (inlen--) {
2612 switch (c = *in++) {
2613 case 10:
2614 case 13:
51470298 2615 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2616 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2617 return +1;
2618 break;
2619 case 8:
2620 case 127:
51470298 2621 if (ssh->userpass_input_bufpos > 0) {
2622 if (ssh->userpass_input_echo)
2623 c_write_str(ssh, "\b \b");
2624 ssh->userpass_input_bufpos--;
0405e71f 2625 }
2626 break;
2627 case 21:
2628 case 27:
51470298 2629 while (ssh->userpass_input_bufpos > 0) {
2630 if (ssh->userpass_input_echo)
2631 c_write_str(ssh, "\b \b");
2632 ssh->userpass_input_bufpos--;
0405e71f 2633 }
2634 break;
2635 case 3:
2636 case 4:
2637 return -1;
2638 break;
2639 default:
4692a14a 2640 /*
2641 * This simplistic check for printability is disabled
2642 * when we're doing password input, because some people
2643 * have control characters in their passwords.o
2644 */
2645 if ((!ssh->userpass_input_echo ||
2646 (c >= ' ' && c <= '~') ||
0405e71f 2647 ((unsigned char) c >= 160))
51470298 2648 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2649 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2650 if (ssh->userpass_input_echo)
2651 c_write(ssh, &c, 1);
0405e71f 2652 }
2653 break;
2654 }
2655 }
2656 return 0;
2657}
2658
f11d78f2 2659static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2660{
2661 Ssh ssh = (Ssh) sshv;
2662
2663 ssh->agent_response = reply;
2664 ssh->agent_response_len = replylen;
2665
2666 if (ssh->version == 1)
ff3187f6 2667 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2668 else
ff3187f6 2669 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2670}
2671
f11d78f2 2672static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2673{
2674 struct ssh_channel *c = (struct ssh_channel *)cv;
2675 Ssh ssh = c->ssh;
2676 void *sentreply = reply;
2677
2678 if (!sentreply) {
2679 /* Fake SSH_AGENT_FAILURE. */
2680 sentreply = "\0\0\0\1\5";
2681 replylen = 5;
2682 }
2683 if (ssh->version == 2) {
2684 ssh2_add_channel_data(c, sentreply, replylen);
2685 ssh2_try_send(c);
2686 } else {
2687 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2688 PKT_INT, c->remoteid,
9a10ecf4 2689 PKTT_DATA,
839f10db 2690 PKT_INT, replylen,
2691 PKT_DATA, sentreply, replylen,
9a10ecf4 2692 PKTT_OTHER,
839f10db 2693 PKT_END);
2694 }
2695 if (reply)
2696 sfree(reply);
2697}
2698
0405e71f 2699/*
fb09bf1c 2700 * Handle the key exchange and user authentication phases.
2701 */
ff3187f6 2702static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2703 struct Packet *pktin)
fb09bf1c 2704{
0016d70b 2705 int i, j, ret;
2706 unsigned char cookie[8], *ptr;
374330e2 2707 struct RSAKey servkey, hostkey;
2708 struct MD5Context md5c;
51470298 2709 struct do_ssh1_login_state {
2710 int len;
2711 unsigned char *rsabuf, *keystr1, *keystr2;
2712 unsigned long supported_ciphers_mask, supported_auths_mask;
2713 int tried_publickey, tried_agent;
2714 int tis_auth_refused, ccard_auth_refused;
2715 unsigned char session_id[16];
2716 int cipher_type;
2717 char username[100];
2718 void *publickey_blob;
2719 int publickey_bloblen;
2720 char password[100];
2721 char prompt[200];
2722 int pos;
2723 char c;
2724 int pwpkt_type;
2725 unsigned char request[5], *response, *p;
2726 int responselen;
2727 int keyi, nkeys;
2728 int authed;
2729 struct RSAKey key;
2730 Bignum challenge;
2731 char *commentp;
2732 int commentlen;
2733 };
2734 crState(do_ssh1_login_state);
2735
2736 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2737
ff3187f6 2738 if (!pktin)
2739 crWaitUntil(pktin);
374330e2 2740
ff3187f6 2741 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2742 bombout(("Public key packet not received"));
7ffdbc1a 2743 crStop(0);
8d5de777 2744 }
374330e2 2745
c5e9c988 2746 logevent("Received public keys");
374330e2 2747
ff3187f6 2748 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2749 if (!ptr) {
2750 bombout(("SSH1 public key packet stopped before random cookie"));
2751 crStop(0);
2752 }
2753 memcpy(cookie, ptr, 8);
374330e2 2754
ff3187f6 2755 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2756 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
ae0500e5 2757 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2758 crStop(0);
2759 }
374330e2 2760
c5e9c988 2761 /*
1c2a93c4 2762 * Log the host key fingerprint.
c5e9c988 2763 */
c5e9c988 2764 {
2765 char logmsg[80];
1c2a93c4 2766 logevent("Host key fingerprint is:");
c5e9c988 2767 strcpy(logmsg, " ");
32874aea 2768 hostkey.comment = NULL;
2769 rsa_fingerprint(logmsg + strlen(logmsg),
2770 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2771 logevent(logmsg);
2772 }
2773
ff3187f6 2774 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2775 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2776 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2777
51470298 2778 ssh->v1_local_protoflags =
2779 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2780 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2781
c5e9c988 2782 MD5Init(&md5c);
51470298 2783 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2784 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2785 MD5Update(&md5c, cookie, 8);
51470298 2786 MD5Final(s->session_id, &md5c);
374330e2 2787
32874aea 2788 for (i = 0; i < 32; i++)
51470298 2789 ssh->session_key[i] = random_byte();
374330e2 2790
0016d70b 2791 /*
2792 * Verify that the `bits' and `bytes' parameters match.
2793 */
2794 if (hostkey.bits > hostkey.bytes * 8 ||
2795 servkey.bits > servkey.bytes * 8) {
2796 bombout(("SSH1 public keys were badly formatted"));
2797 crStop(0);
2798 }
2799
51470298 2800 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2801
3d88e64d 2802 s->rsabuf = snewn(s->len, unsigned char);
51470298 2803 if (!s->rsabuf)
374330e2 2804 fatalbox("Out of memory");
2805
89ee5268 2806 /*
2807 * Verify the host key.
2808 */
2809 {
32874aea 2810 /*
2811 * First format the key into a string.
2812 */
2813 int len = rsastr_len(&hostkey);
2814 char fingerprint[100];
3d88e64d 2815 char *keystr = snewn(len, char);
32874aea 2816 if (!keystr)
2817 fatalbox("Out of memory");
2818 rsastr_fmt(keystr, &hostkey);
2819 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2820 verify_ssh_host_key(ssh->frontend,
2821 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2822 fingerprint);
2823 sfree(keystr);
2824 }
2825
2826 for (i = 0; i < 32; i++) {
51470298 2827 s->rsabuf[i] = ssh->session_key[i];
374330e2 2828 if (i < 16)
51470298 2829 s->rsabuf[i] ^= s->session_id[i];
374330e2 2830 }
2831
2832 if (hostkey.bytes > servkey.bytes) {
0016d70b 2833 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2834 if (ret)
2835 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2836 } else {
0016d70b 2837 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2838 if (ret)
2839 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2840 }
2841 if (!ret) {
2842 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2843 crStop(0);
374330e2 2844 }
2845
c5e9c988 2846 logevent("Encrypted session key");
2847
ca20bfcf 2848 {
2849 int cipher_chosen = 0, warn = 0;
2850 char *cipher_string = NULL;
51470298 2851 int i;
ca20bfcf 2852 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2853 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2854 if (next_cipher == CIPHER_WARN) {
2855 /* If/when we choose a cipher, warn about it */
2856 warn = 1;
2857 } else if (next_cipher == CIPHER_AES) {
2858 /* XXX Probably don't need to mention this. */
2859 logevent("AES not supported in SSH1, skipping");
2860 } else {
2861 switch (next_cipher) {
51470298 2862 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2863 cipher_string = "3DES"; break;
51470298 2864 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2865 cipher_string = "Blowfish"; break;
51470298 2866 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2867 cipher_string = "single-DES"; break;
2868 }
51470298 2869 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2870 cipher_chosen = 1;
2871 }
2872 }
2873 if (!cipher_chosen) {
51470298 2874 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2875 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2876 "supporting 3DES encryption"));
2877 else
2878 /* shouldn't happen */
6b5cf8b4 2879 bombout(("No supported ciphers found"));
7ffdbc1a 2880 crStop(0);
a99a05c0 2881 }
ca20bfcf 2882
2883 /* Warn about chosen cipher if necessary. */
bb348ab1 2884 if (warn) {
2885 sk_set_frozen(ssh->s, 1);
83e7d008 2886 askalg(ssh->frontend, "cipher", cipher_string);
bb348ab1 2887 sk_set_frozen(ssh->s, 0);
2888 }
bea1ef5f 2889 }
ca20bfcf 2890
51470298 2891 switch (s->cipher_type) {
32874aea 2892 case SSH_CIPHER_3DES:
2893 logevent("Using 3DES encryption");
2894 break;
2895 case SSH_CIPHER_DES:
2896 logevent("Using single-DES encryption");
2897 break;
2898 case SSH_CIPHER_BLOWFISH:
2899 logevent("Using Blowfish encryption");
2900 break;
c5e9c988 2901 }
bea1ef5f 2902
51470298 2903 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2904 PKT_CHAR, s->cipher_type,
32874aea 2905 PKT_DATA, cookie, 8,
51470298 2906 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2907 PKT_DATA, s->rsabuf, s->len,
2908 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2909
c5e9c988 2910 logevent("Trying to enable encryption...");
374330e2 2911
51470298 2912 sfree(s->rsabuf);
374330e2 2913
51470298 2914 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2915 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2916 &ssh_3des);
371e569c 2917 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2918 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2919 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2920
0183b242 2921 ssh->crcda_ctx = crcda_make_context();
2922 logevent("Installing CRC compensation attack detector");
2923
679539d7 2924 if (servkey.modulus) {
2925 sfree(servkey.modulus);
2926 servkey.modulus = NULL;
2927 }
2928 if (servkey.exponent) {
2929 sfree(servkey.exponent);
2930 servkey.exponent = NULL;
2931 }
2932 if (hostkey.modulus) {
2933 sfree(hostkey.modulus);
2934 hostkey.modulus = NULL;
2935 }
2936 if (hostkey.exponent) {
2937 sfree(hostkey.exponent);
2938 hostkey.exponent = NULL;
2939 }
ff3187f6 2940 crWaitUntil(pktin);
374330e2 2941
ff3187f6 2942 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2943 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2944 crStop(0);
8d5de777 2945 }
374330e2 2946
c5e9c988 2947 logevent("Successfully started encryption");
2948
374330e2 2949 fflush(stdout);
2950 {
aa09f7d0 2951 if (!*ssh->cfg.username) {
c0a81592 2952 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2953 if (!ssh_get_line("login as: ",
51470298 2954 s->username, sizeof(s->username), FALSE)) {
32874aea 2955 /*
2956 * get_line failed to get a username.
2957 * Terminate.
2958 */
2959 logevent("No username provided. Abandoning session.");
ac934965 2960 ssh->close_expected = TRUE;
3bb2f322 2961 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2962 crStop(1);
32874aea 2963 }
2964 } else {
51470298 2965 int ret; /* need not be kept over crReturn */
2966 c_write_str(ssh, "login as: ");
2967 ssh->send_ok = 1;
0405e71f 2968
51470298 2969 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2970 do {
ff3187f6 2971 crWaitUntil(!pktin);
51470298 2972 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2973 } while (ret == 0);
2974 if (ret < 0)
2975 cleanup_exit(0);
51470298 2976 c_write_str(ssh, "\r\n");
32874aea 2977 }
2978 } else {
86916870 2979 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2980 s->username[sizeof(s->username)-1] = '\0';
374330e2 2981 }
fb09bf1c 2982
51470298 2983 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2984 {
51470298 2985 char userlog[22 + sizeof(s->username)];
2986 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2987 logevent(userlog);
32874aea 2988 if (flags & FLAG_INTERACTIVE &&
2989 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2990 strcat(userlog, "\r\n");
51470298 2991 c_write_str(ssh, userlog);
3c8e959b 2992 }
c5e9c988 2993 }
374330e2 2994 }
2995
ff3187f6 2996 crWaitUntil(pktin);
374330e2 2997
51470298 2998 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2999 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 3000 s->tried_publickey = s->tried_agent = 1;
0df73905 3001 } else {
51470298 3002 s->tried_publickey = s->tried_agent = 0;
0df73905 3003 }
51470298 3004 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 3005 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 3006 if (!filename_is_null(ssh->cfg.keyfile)) {
3007 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 3008 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 3009 s->publickey_blob = NULL;
396778f1 3010 } else
51470298 3011 s->publickey_blob = NULL;
7cca0d81 3012
ff3187f6 3013 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3014 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 3015
51470298 3016 if (agent_exists() && !s->tried_agent) {
32874aea 3017 /*
3018 * Attempt RSA authentication using Pageant.
3019 */
32874aea 3020 void *r;
3021
51470298 3022 s->authed = FALSE;
3023 s->tried_agent = 1;
32874aea 3024 logevent("Pageant is running. Requesting keys.");
3025
3026 /* Request the keys held by the agent. */
51470298 3027 PUT_32BIT(s->request, 1);
3028 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 3029 if (!agent_query(s->request, 5, &r, &s->responselen,
3030 ssh_agent_callback, ssh)) {
3031 do {
3032 crReturn(0);
ff3187f6 3033 if (pktin) {
839f10db 3034 bombout(("Unexpected data from server while waiting"
3035 " for agent response"));
3036 crStop(0);
3037 }
ff3187f6 3038 } while (pktin || inlen > 0);
839f10db 3039 r = ssh->agent_response;
3040 s->responselen = ssh->agent_response_len;
3041 }
51470298 3042 s->response = (unsigned char *) r;
3043 if (s->response && s->responselen >= 5 &&
3044 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3045 s->p = s->response + 5;
3046 s->nkeys = GET_32BIT(s->p);
3047 s->p += 4;
32874aea 3048 {
3049 char buf[64];
51470298 3050 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 3051 logevent(buf);
3052 }
51470298 3053 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 3054 {
3055 char buf[64];
51470298 3056 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 3057 logevent(buf);
3058 }
51470298 3059 if (s->publickey_blob &&
3060 !memcmp(s->p, s->publickey_blob,
3061 s->publickey_bloblen)) {
396778f1 3062 logevent("This key matches configured key file");
51470298 3063 s->tried_publickey = 1;
396778f1 3064 }
51470298 3065 s->p += 4;
0016d70b 3066 {
3067 int n, ok = FALSE;
3068 do { /* do while (0) to make breaking easy */
3069 n = ssh1_read_bignum
3070 (s->p, s->responselen-(s->p-s->response),
3071 &s->key.exponent);
3072 if (n < 0)
3073 break;
3074 s->p += n;
3075 n = ssh1_read_bignum
3076 (s->p, s->responselen-(s->p-s->response),
3077 &s->key.modulus);
3078 if (n < 0)
3079 break;
3080 s->p += n;
3081 if (s->responselen - (s->p-s->response) < 4)
3082 break;
3083 s->commentlen = GET_32BIT(s->p);
3084 s->p += 4;
3085 if (s->responselen - (s->p-s->response) <
3086 s->commentlen)
3087 break;
3088 s->commentp = (char *)s->p;
3089 s->p += s->commentlen;
3090 ok = TRUE;
3091 } while (0);
3092 if (!ok) {
3093 logevent("Pageant key list packet was truncated");
3094 break;
3095 }
3096 }
51470298 3097 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3098 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3099 crWaitUntil(pktin);
3100 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3101 logevent("Key refused");
3102 continue;
3103 }
3104 logevent("Received RSA challenge");
ff3187f6 3105 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3106 bombout(("Server's RSA challenge was badly formatted"));
3107 crStop(0);
3108 }
3109
32874aea 3110 {
3111 char *agentreq, *q, *ret;
2d466ffd 3112 void *vret;
32874aea 3113 int len, retlen;
3114 len = 1 + 4; /* message type, bit count */
51470298 3115 len += ssh1_bignum_length(s->key.exponent);
3116 len += ssh1_bignum_length(s->key.modulus);
3117 len += ssh1_bignum_length(s->challenge);
32874aea 3118 len += 16; /* session id */
3119 len += 4; /* response format */
3d88e64d 3120 agentreq = snewn(4 + len, char);
32874aea 3121 PUT_32BIT(agentreq, len);
3122 q = agentreq + 4;
3123 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3124 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3125 q += 4;
51470298 3126 q += ssh1_write_bignum(q, s->key.exponent);
3127 q += ssh1_write_bignum(q, s->key.modulus);
3128 q += ssh1_write_bignum(q, s->challenge);
3129 memcpy(q, s->session_id, 16);
32874aea 3130 q += 16;
3131 PUT_32BIT(q, 1); /* response format */
839f10db 3132 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3133 ssh_agent_callback, ssh)) {
3134 sfree(agentreq);
3135 do {
3136 crReturn(0);
ff3187f6 3137 if (pktin) {
839f10db 3138 bombout(("Unexpected data from server"
3139 " while waiting for agent"
3140 " response"));
3141 crStop(0);
3142 }
ff3187f6 3143 } while (pktin || inlen > 0);
839f10db 3144 vret = ssh->agent_response;
3145 retlen = ssh->agent_response_len;
3146 } else
3147 sfree(agentreq);
2d466ffd 3148 ret = vret;
32874aea 3149 if (ret) {
3150 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3151 logevent("Sending Pageant's response");
51470298 3152 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3153 PKT_DATA, ret + 5, 16,
3154 PKT_END);
3155 sfree(ret);
ff3187f6 3156 crWaitUntil(pktin);
3157 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3158 logevent
3159 ("Pageant's response accepted");
3160 if (flags & FLAG_VERBOSE) {
51470298 3161 c_write_str(ssh, "Authenticated using"
3162 " RSA key \"");
3163 c_write(ssh, s->commentp,
3164 s->commentlen);
3165 c_write_str(ssh, "\" from agent\r\n");
32874aea 3166 }
51470298 3167 s->authed = TRUE;
32874aea 3168 } else
3169 logevent
3170 ("Pageant's response not accepted");
3171 } else {
3172 logevent
3173 ("Pageant failed to answer challenge");
3174 sfree(ret);
3175 }
3176 } else {
3177 logevent("No reply received from Pageant");
3178 }
3179 }
51470298 3180 freebn(s->key.exponent);
3181 freebn(s->key.modulus);
3182 freebn(s->challenge);
3183 if (s->authed)
32874aea 3184 break;
3185 }
29b1d0b3 3186 sfree(s->response);
32874aea 3187 }
51470298 3188 if (s->authed)
32874aea 3189 break;
3190 }
9a30e26b 3191 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3192 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3193
86916870 3194 if (ssh->cfg.try_tis_auth &&
51470298 3195 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3196 !s->tis_auth_refused) {
3197 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3198 logevent("Requested TIS authentication");
51470298 3199 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3200 crWaitUntil(pktin);
3201 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3202 logevent("TIS authentication declined");
3203 if (flags & FLAG_INTERACTIVE)
51470298 3204 c_write_str(ssh, "TIS authentication refused.\r\n");
3205 s->tis_auth_refused = 1;
614a20a0 3206 continue;
32874aea 3207 } else {
0016d70b 3208 char *challenge;
3209 int challengelen;
3210
ff3187f6 3211 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3212 if (!challenge) {
3213 bombout(("TIS challenge packet was badly formed"));
3214 crStop(0);
3215 }
32874aea 3216 logevent("Received TIS challenge");
51470298 3217 if (challengelen > sizeof(s->prompt) - 1)
3218 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3219 memcpy(s->prompt, challenge, challengelen);
614a20a0 3220 /* Prompt heuristic comes from OpenSSH */
51470298 3221 strncpy(s->prompt + challengelen,
3222 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3223 "": "\r\nResponse: ",
51470298 3224 (sizeof s->prompt) - challengelen);
3225 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3226 }
3227 }
86916870 3228 if (ssh->cfg.try_tis_auth &&
51470298 3229 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3230 !s->ccard_auth_refused) {
3231 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3232 logevent("Requested CryptoCard authentication");
51470298 3233 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3234 crWaitUntil(pktin);
3235 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3236 logevent("CryptoCard authentication declined");
51470298 3237 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3238 s->ccard_auth_refused = 1;
614a20a0 3239 continue;
32874aea 3240 } else {
0016d70b 3241 char *challenge;
3242 int challengelen;
3243
ff3187f6 3244 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3245 if (!challenge) {
3246 bombout(("CryptoCard challenge packet was badly formed"));
3247 crStop(0);
3248 }
32874aea 3249 logevent("Received CryptoCard challenge");
51470298 3250 if (challengelen > sizeof(s->prompt) - 1)
3251 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3252 memcpy(s->prompt, challenge, challengelen);
51470298 3253 strncpy(s->prompt + challengelen,
3254 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3255 "" : "\r\nResponse: ",
51470298 3256 sizeof(s->prompt) - challengelen);
3257 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3258 }
3259 }
51470298 3260 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3261 sprintf(s->prompt, "%.90s@%.90s's password: ",
3262 s->username, ssh->savedhost);
32874aea 3263 }
51470298 3264 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3265 char *comment = NULL;
231ee168 3266 int type;
3267 char msgbuf[256];
32874aea 3268 if (flags & FLAG_VERBOSE)
51470298 3269 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3270 logeventf(ssh, "Trying public key \"%s\"",
3271 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3272 type = key_type(&ssh->cfg.keyfile);
231ee168 3273 if (type != SSH_KEYTYPE_SSH1) {
3274 sprintf(msgbuf, "Key is of wrong type (%s)",
3275 key_type_to_str(type));
3276 logevent(msgbuf);
51470298 3277 c_write_str(ssh, msgbuf);
3278 c_write_str(ssh, "\r\n");
3279 s->tried_publickey = 1;
231ee168 3280 continue;
3281 }
9a30e26b 3282 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3283 if (flags & FLAG_VERBOSE)
51470298 3284 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3285 goto tryauth;
3286 }
51470298 3287 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3288 sfree(comment);
3289 }
a52f067e 3290
614a20a0 3291 /*
3292 * Show password prompt, having first obtained it via a TIS
3293 * or CryptoCard exchange if we're doing TIS or CryptoCard
3294 * authentication.
3295 */
fa17a66e 3296 if (ssh_get_line) {
51470298 3297 if (!ssh_get_line(s->prompt, s->password,
3298 sizeof(s->password), TRUE)) {
32874aea 3299 /*
3300 * get_line failed to get a password (for example
3301 * because one was supplied on the command line
3302 * which has already failed to work). Terminate.
3303 */
51470298 3304 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3305 PKT_STR, "No more passwords available to try",
3306 PKT_END);
247308b5 3307 logevent("Unable to authenticate");
a8327734 3308 connection_fatal(ssh->frontend, "Unable to authenticate");
ac934965 3309 ssh->close_expected = TRUE;
3bb2f322 3310 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3311 crStop(1);
32874aea 3312 }
fb09bf1c 3313 } else {
614a20a0 3314 /* Prompt may have come from server. We've munged it a bit, so
3315 * we know it to be zero-terminated at least once. */
51470298 3316 int ret; /* need not be saved over crReturn */
3317 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3318 s->pos = 0;
0405e71f 3319
51470298 3320 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3321 do {
ff3187f6 3322 crWaitUntil(!pktin);
51470298 3323 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3324 } while (ret == 0);
3325 if (ret < 0)
3326 cleanup_exit(0);
51470298 3327 c_write_str(ssh, "\r\n");
32874aea 3328 }
3329
3330 tryauth:
51470298 3331 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3332 /*
3333 * Try public key authentication with the specified
3334 * key file.
3335 */
51470298 3336 s->tried_publickey = 1;
3337
3338 {
222d54dc 3339 const char *error = NULL;
3340 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3341 &error);
51470298 3342 if (ret == 0) {
3343 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3344 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3345 c_write_str(ssh, " (");
3346 c_write_str(ssh, error);
3347 c_write_str(ssh, ").\r\n");
51470298 3348 continue; /* go and try password */
3349 }
3350 if (ret == -1) {
3351 c_write_str(ssh, "Wrong passphrase.\r\n");
3352 s->tried_publickey = 0;
3353 continue; /* try again */
3354 }
32874aea 3355 }
3356
3357 /*
3358 * Send a public key attempt.
3359 */
51470298 3360 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3361 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3362
ff3187f6 3363 crWaitUntil(pktin);
3364 if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3365 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3366 continue; /* go and try password */
3367 }
ff3187f6 3368 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3369 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3370 crStop(0);
32874aea 3371 }
32874aea 3372
51470298 3373 {
3374 int i;
3375 unsigned char buffer[32];
3376 Bignum challenge, response;
3377
ff3187f6 3378 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3379 bombout(("Server's RSA challenge was badly formatted"));
3380 crStop(0);
3381 }
51470298 3382 response = rsadecrypt(challenge, &s->key);
3383 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3384
51470298 3385 for (i = 0; i < 32; i++) {
3386 buffer[i] = bignum_byte(response, 31 - i);
3387 }
3388
3389 MD5Init(&md5c);
3390 MD5Update(&md5c, buffer, 32);
3391 MD5Update(&md5c, s->session_id, 16);
3392 MD5Final(buffer, &md5c);
32874aea 3393
51470298 3394 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3395 PKT_DATA, buffer, 16, PKT_END);
3396
3397 freebn(challenge);
3398 freebn(response);
3399 }
32874aea 3400
ff3187f6 3401 crWaitUntil(pktin);
3402 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3403 if (flags & FLAG_VERBOSE)
51470298 3404 c_write_str(ssh, "Failed to authenticate with"
3405 " our public key.\r\n");
32874aea 3406 continue; /* go and try password */
ff3187f6 3407 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3408 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3409 crStop(0);
32874aea 3410 }
3411
3412 break; /* we're through! */
3413 } else {
51470298 3414 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3415 /*
3416 * Defence against traffic analysis: we send a
3417 * whole bunch of packets containing strings of
3418 * different lengths. One of these strings is the
3419 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3420 * The others are all random data in
3421 * SSH1_MSG_IGNORE packets. This way a passive
3422 * listener can't tell which is the password, and
3423 * hence can't deduce the password length.
3424 *
3425 * Anybody with a password length greater than 16
3426 * bytes is going to have enough entropy in their
3427 * password that a listener won't find it _that_
3428 * much help to know how long it is. So what we'll
3429 * do is:
3430 *
3431 * - if password length < 16, we send 15 packets
3432 * containing string lengths 1 through 15
3433 *
3434 * - otherwise, we let N be the nearest multiple
3435 * of 8 below the password length, and send 8
3436 * packets containing string lengths N through
3437 * N+7. This won't obscure the order of
3438 * magnitude of the password length, but it will
3439 * introduce a bit of extra uncertainty.
3440 *
3441 * A few servers (the old 1.2.18 through 1.2.22)
3442 * can't deal with SSH1_MSG_IGNORE. For these
3443 * servers, we need an alternative defence. We make
3444 * use of the fact that the password is interpreted
3445 * as a C string: so we can append a NUL, then some
3446 * random data.
bd358db1 3447 *
3448 * One server (a Cisco one) can deal with neither
3449 * SSH1_MSG_IGNORE _nor_ a padded password string.
3450 * For this server we are left with no defences
3451 * against password length sniffing.
32874aea 3452 */
51470298 3453 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3454 /*
3455 * The server can deal with SSH1_MSG_IGNORE, so
3456 * we can use the primary defence.
3457 */
32874aea 3458 int bottom, top, pwlen, i;
3459 char *randomstr;
3460
51470298 3461 pwlen = strlen(s->password);
32874aea 3462 if (pwlen < 16) {
3463 bottom = 0; /* zero length passwords are OK! :-) */
3464 top = 15;
3465 } else {
3466 bottom = pwlen & ~7;
3467 top = bottom + 7;
3468 }
3469
3470 assert(pwlen >= bottom && pwlen <= top);
3471
3d88e64d 3472 randomstr = snewn(top + 1, char);
32874aea 3473
3474 for (i = bottom; i <= top; i++) {
9a10ecf4 3475 if (i == pwlen) {
51470298 3476 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3477 PKTT_PASSWORD, PKT_STR, s->password,
3478 PKTT_OTHER, PKT_END);
3479 } else {
32874aea 3480 for (j = 0; j < i; j++) {
3481 do {
3482 randomstr[j] = random_byte();
3483 } while (randomstr[j] == '\0');
3484 }
3485 randomstr[i] = '\0';
51470298 3486 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3487 PKT_STR, randomstr, PKT_END);
3488 }
3489 }
bd358db1 3490 logevent("Sending password with camouflage packets");
51470298 3491 ssh_pkt_defersend(ssh);
679539d7 3492 sfree(randomstr);
bd358db1 3493 }
51470298 3494 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3495 /*
3496 * The server can't deal with SSH1_MSG_IGNORE
3497 * but can deal with padded passwords, so we
3498 * can use the secondary defence.
3499 */
bd358db1 3500 char string[64];
51470298 3501 char *ss;
bd358db1 3502 int len;
3503
51470298 3504 len = strlen(s->password);
bd358db1 3505 if (len < sizeof(string)) {
51470298 3506 ss = string;
3507 strcpy(string, s->password);
bd358db1 3508 len++; /* cover the zero byte */
3509 while (len < sizeof(string)) {
3510 string[len++] = (char) random_byte();
3511 }
3512 } else {
51470298 3513 ss = s->password;
bd358db1 3514 }
3515 logevent("Sending length-padded password");
9a10ecf4 3516 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3517 PKT_INT, len, PKT_DATA, ss, len,
3518 PKTT_OTHER, PKT_END);
bd358db1 3519 } else {
3520 /*
3521 * The server has _both_
3522 * BUG_CHOKES_ON_SSH1_IGNORE and
3523 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3524 * therefore nothing we can do.
3525 */
3526 int len;
51470298 3527 len = strlen(s->password);
bd358db1 3528 logevent("Sending unpadded password");
9a10ecf4 3529 send_packet(ssh, s->pwpkt_type,
3530 PKTT_PASSWORD, PKT_INT, len,
3531 PKT_DATA, s->password, len,
3532 PKTT_OTHER, PKT_END);
32874aea 3533 }
3534 } else {
9a10ecf4 3535 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3536 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3537 }
3538 }
c5e9c988 3539 logevent("Sent password");
51470298 3540 memset(s->password, 0, strlen(s->password));
ff3187f6 3541 crWaitUntil(pktin);
3542 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3543 if (flags & FLAG_VERBOSE)
51470298 3544 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3545 logevent("Authentication refused");
ff3187f6 3546 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3547 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3548 crStop(0);
374330e2 3549 }
3550 }
3551
c5e9c988 3552 logevent("Authentication successful");
3553
fb09bf1c 3554 crFinish(1);
3555}
3556
32874aea 3557void sshfwd_close(struct ssh_channel *c)
3558{
51470298 3559 Ssh ssh = c->ssh;
3560
36f94d1f 3561 if (ssh->state != SSH_STATE_SESSION) {
3562 assert(ssh->state == SSH_STATE_CLOSED);
3563 return;
3564 }
3565
80e48603 3566 if (c && !c->closes) {
4ed34d25 3567 /*
3568 * If the channel's remoteid is -1, we have sent
3569 * CHANNEL_OPEN for this channel, but it hasn't even been
3570 * acknowledged by the server. So we must set a close flag
3571 * on it now, and then when the server acks the channel
3572 * open, we can close it then.
3573 */
36cac739 3574 if (((int)c->remoteid) != -1) {
51470298 3575 if (ssh->version == 1) {
3576 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3577 PKT_END);
3578 } else {
ff3187f6 3579 struct Packet *pktout;
3580 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3581 ssh2_pkt_adduint32(pktout, c->remoteid);
3582 ssh2_pkt_send(ssh, pktout);
4ed34d25 3583 }
32874aea 3584 }
0357890f 3585 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3586 if (c->type == CHAN_X11) {
3587 c->u.x11.s = NULL;
d74d141c 3588 logevent("Forwarded X11 connection terminated");
4ed34d25 3589 } else if (c->type == CHAN_SOCKDATA ||
3590 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3591 c->u.pfd.s = NULL;
3592 logevent("Forwarded port closed");
32874aea 3593 }
3594 }
3595}
3596
5471d09a 3597int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3598{
51470298 3599 Ssh ssh = c->ssh;
3600
36f94d1f 3601 if (ssh->state != SSH_STATE_SESSION) {
3602 assert(ssh->state == SSH_STATE_CLOSED);
3603 return 0;
3604 }
3605
51470298 3606 if (ssh->version == 1) {
3607 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3608 PKT_INT, c->remoteid,
9a10ecf4 3609 PKTT_DATA,
3610 PKT_INT, len, PKT_DATA, buf, len,
3611 PKTT_OTHER, PKT_END);
5471d09a 3612 /*
3613 * In SSH1 we can return 0 here - implying that forwarded
3614 * connections are never individually throttled - because
3615 * the only circumstance that can cause throttling will be
3616 * the whole SSH connection backing up, in which case
3617 * _everything_ will be throttled as a whole.
3618 */
3619 return 0;
783415f8 3620 } else {
32874aea 3621 ssh2_add_channel_data(c, buf, len);
5471d09a 3622 return ssh2_try_send(c);
3623 }
3624}
3625
3626void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3627{
51470298 3628 Ssh ssh = c->ssh;
3629
36f94d1f 3630 if (ssh->state != SSH_STATE_SESSION) {
3631 assert(ssh->state == SSH_STATE_CLOSED);
3632 return;
3633 }
3634
51470298 3635 if (ssh->version == 1) {
5471d09a 3636 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3637 c->v.v1.throttling = 0;
51470298 3638 ssh1_throttle(ssh, -1);
5471d09a 3639 }
3640 } else {
3641 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3642 }
9c964e85 3643}
3644
06fadff5 3645static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3646{
3647 struct queued_handler *qh = ssh->qhead;
3648
3649 assert(qh != NULL);
3650
3651 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3652
3653 if (qh->msg1 > 0) {
3654 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3655 ssh->packet_dispatch[qh->msg1] = NULL;
3656 }
3657 if (qh->msg2 > 0) {
3658 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3659 ssh->packet_dispatch[qh->msg2] = NULL;
3660 }
3661
3662 if (qh->next) {
3663 ssh->qhead = qh->next;
3664
3665 if (ssh->qhead->msg1 > 0) {
3666 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3667 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3668 }
3669 if (ssh->qhead->msg2 > 0) {
3670 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3671 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3672 }
3673 } else {
3674 ssh->qhead = ssh->qtail = NULL;
3675 ssh->packet_dispatch[pktin->type] = NULL;
3676 }
3677
3678 qh->handler(ssh, pktin, qh->ctx);
3679
3680 sfree(qh);
3681}
3682
3683static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3684 chandler_fn_t handler, void *ctx)
3685{
3686 struct queued_handler *qh;
3687
3688 qh = snew(struct queued_handler);
3689 qh->msg1 = msg1;
3690 qh->msg2 = msg2;
3691 qh->handler = handler;
3692 qh->ctx = ctx;
3693 qh->next = NULL;
3694
3695 if (ssh->qtail == NULL) {
3696 ssh->qhead = qh;
3697
3698 if (qh->msg1 > 0) {
3699 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3700 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3701 }
3702 if (qh->msg2 > 0) {
3703 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3704 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3705 }
3706 } else {
3707 ssh->qtail->next = qh;
3708 }
3709 ssh->qtail = qh;
3710}
3711
3712static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3713{
3714 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3715
3716 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3717 SSH2_MSG_REQUEST_SUCCESS)) {
3718 logeventf(ssh, "Remote port forwarding from %s enabled",
3719 pf->sportdesc);
3720 } else {
3721 logeventf(ssh, "Remote port forwarding from %s refused",
3722 pf->sportdesc);
3723
3724 rpf = del234(ssh->rportfwds, pf);
3725 assert(rpf == pf);
fda2feb1 3726 free_rportfwd(pf);
06fadff5 3727 }
3728}
3729
3730static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3731{
84328ddb 3732 const char *portfwd_strptr = cfg->portfwd;
3733 struct ssh_portfwd *epf;
3734 int i;
06fadff5 3735
fda2feb1 3736 if (!ssh->portfwds) {
3737 ssh->portfwds = newtree234(ssh_portcmp);
3738 } else {
3739 /*
3740 * Go through the existing port forwardings and tag them
84328ddb 3741 * with status==DESTROY. Any that we want to keep will be
3742 * re-enabled (status==KEEP) as we go through the
3743 * configuration and find out which bits are the same as
3744 * they were before.
fda2feb1 3745 */
3746 struct ssh_portfwd *epf;
3747 int i;
3748 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 3749 epf->status = DESTROY;
fda2feb1 3750 }
3751
06fadff5 3752 while (*portfwd_strptr) {
84328ddb 3753 char address_family, type;
3754 int sport,dport,sserv,dserv;
3755 char sports[256], dports[256], saddr[256], host[256];
3756 int n;
3757
05581745 3758 address_family = 'A';
3759 type = 'L';
84328ddb 3760 if (*portfwd_strptr == 'A' ||
3761 *portfwd_strptr == '4' ||
3762 *portfwd_strptr == '6')
3763 address_family = *portfwd_strptr++;
3764 if (*portfwd_strptr == 'L' ||
3765 *portfwd_strptr == 'R' ||
3766 *portfwd_strptr == 'D')
3767 type = *portfwd_strptr++;
05581745 3768
06fadff5 3769 saddr[0] = '\0';
05581745 3770
06fadff5 3771 n = 0;
3772 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3773 if (*portfwd_strptr == ':') {
3774 /*
3775 * We've seen a colon in the middle of the
3776 * source port number. This means that
3777 * everything we've seen until now is the
3778 * source _address_, so we'll move it into
3779 * saddr and start sports from the beginning
3780 * again.
3781 */
3782 portfwd_strptr++;
3783 sports[n] = '\0';
3784 if (ssh->version == 1 && type == 'R') {
3785 logeventf(ssh, "SSH1 cannot handle remote source address "
3786 "spec \"%s\"; ignoring", sports);
3787 } else
3788 strcpy(saddr, sports);
3789 n = 0;
3790 }
3791 if (n < 255) sports[n++] = *portfwd_strptr++;
3792 }
3793 sports[n] = 0;
3794 if (type != 'D') {
3795 if (*portfwd_strptr == '\t')
3796 portfwd_strptr++;
3797 n = 0;
3798 while (*portfwd_strptr && *portfwd_strptr != ':') {
3799 if (n < 255) host[n++] = *portfwd_strptr++;
3800 }
3801 host[n] = 0;
3802 if (*portfwd_strptr == ':')
3803 portfwd_strptr++;
3804 n = 0;
3805 while (*portfwd_strptr) {
3806 if (n < 255) dports[n++] = *portfwd_strptr++;
3807 }
3808 dports[n] = 0;
3809 portfwd_strptr++;
3810 dport = atoi(dports);
3811 dserv = 0;
3812 if (dport == 0) {
3813 dserv = 1;
3814 dport = net_service_lookup(dports);
3815 if (!dport) {
3816 logeventf(ssh, "Service lookup failed for destination"
3817 " port \"%s\"", dports);
3818 }
3819 }
3820 } else {
3821 while (*portfwd_strptr) portfwd_strptr++;
3822 dport = dserv = -1;
3823 portfwd_strptr++; /* eat the NUL and move to next one */
3824 }
3825 sport = atoi(sports);
3826 sserv = 0;
3827 if (sport == 0) {
3828 sserv = 1;
3829 sport = net_service_lookup(sports);
3830 if (!sport) {
3831 logeventf(ssh, "Service lookup failed for source"
3832 " port \"%s\"", sports);
3833 }
3834 }
3835 if (sport && dport) {
3836 /* Set up a description of the source port. */
fda2feb1 3837 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 3838
3839 pfrec = snew(struct ssh_portfwd);
3840 pfrec->type = type;
3841 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3fe92132 3842 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 3843 pfrec->sport = sport;
84328ddb 3844 pfrec->daddr = *host ? dupstr(host) : NULL;
3fe92132 3845 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 3846 pfrec->dport = dport;
3847 pfrec->local = NULL;
3848 pfrec->remote = NULL;
05581745 3849 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3850 address_family == '6' ? ADDRTYPE_IPV6 :
3851 ADDRTYPE_UNSPEC);
fda2feb1 3852
3853 epfrec = add234(ssh->portfwds, pfrec);
3854 if (epfrec != pfrec) {
3855 /*
3856 * We already have a port forwarding with precisely
3857 * these parameters. Hence, no need to do anything;
84328ddb 3858 * simply tag the existing one as KEEP.
fda2feb1 3859 */
84328ddb 3860 epfrec->status = KEEP;
fda2feb1 3861 free_portfwd(pfrec);
84328ddb 3862 } else {
3863 pfrec->status = CREATE;
3864 }
3865 }
3866 }
3867
3868 /*
3869 * Now go through and destroy any port forwardings which were
3870 * not re-enabled.
3871 */
3872 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3873 if (epf->status == DESTROY) {
3874 char *message;
3875
3876 message = dupprintf("%s port forwarding from %s%s%d",
3877 epf->type == 'L' ? "local" :
3878 epf->type == 'R' ? "remote" : "dynamic",
3879 epf->saddr ? epf->saddr : "",
3880 epf->saddr ? ":" : "",
3881 epf->sport);
3882
3883 if (epf->type != 'D') {
3884 char *msg2 = dupprintf("%s to %s:%d", message,
3885 epf->daddr, epf->dport);
3886 sfree(message);
3887 message = msg2;
3888 }
3889
3890 logeventf(ssh, "Cancelling %s", message);
3891 sfree(message);
3892
3893 if (epf->remote) {
3894 struct ssh_rportfwd *rpf = epf->remote;
3895 struct Packet *pktout;
3896
3897 /*
3898 * Cancel the port forwarding at the server
3899 * end.
3900 */
3901 if (ssh->version == 1) {
3902 /*
3903 * We cannot cancel listening ports on the
3904 * server side in SSH1! There's no message
3905 * to support it. Instead, we simply remove
3906 * the rportfwd record from the local end
3907 * so that any connections the server tries
3908 * to make on it are rejected.
3909 */
3910 } else {
3911 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3912 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
3913 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
3914 if (epf->saddr) {
3915 ssh2_pkt_addstring(pktout, epf->saddr);
3916 } else if (ssh->cfg.rport_acceptall) {
3917 ssh2_pkt_addstring(pktout, "0.0.0.0");
3918 } else {
3919 ssh2_pkt_addstring(pktout, "127.0.0.1");
3920 }
3921 ssh2_pkt_adduint32(pktout, epf->sport);
3922 ssh2_pkt_send(ssh, pktout);
3923 }
3924
3925 del234(ssh->rportfwds, rpf);
3926 free_rportfwd(rpf);
3927 } else if (epf->local) {
3928 pfd_terminate(epf->local);
3929 }
3930
3931 delpos234(ssh->portfwds, i);
3932 free_portfwd(epf);
3933 i--; /* so we don't skip one in the list */
3934 }
3935
3936 /*
3937 * And finally, set up any new port forwardings (status==CREATE).
3938 */
3939 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3940 if (epf->status == CREATE) {
3941 char *sportdesc, *dportdesc;
3fe92132 3942 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 3943 epf->saddr ? epf->saddr : "",
3944 epf->saddr ? ":" : "",
3fe92132 3945 epf->sserv ? epf->sserv : "",
3946 epf->sserv ? "(" : "",
3947 epf->sport,
3948 epf->sserv ? ")" : "");
84328ddb 3949 if (epf->type == 'D') {
3950 dportdesc = NULL;
3951 } else {
3fe92132 3952 dportdesc = dupprintf("%s:%s%s%d%s",
3953 epf->daddr,
3954 epf->dserv ? epf->dserv : "",
3955 epf->dserv ? "(" : "",
3956 epf->dport,
3957 epf->dserv ? ")" : "");
84328ddb 3958 }
05581745 3959
84328ddb 3960 if (epf->type == 'L') {
3961 const char *err = pfd_addforward(epf->daddr, epf->dport,
3962 epf->saddr, epf->sport,
3963 ssh, &ssh->cfg,
3964 &epf->local,
3965 epf->addressfamily);
3966
3967 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
3968 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3969 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3970 sportdesc, dportdesc,
3971 err ? " failed: " : "", err ? err : "");
3972 } else if (epf->type == 'D') {
06fadff5 3973 const char *err = pfd_addforward(NULL, -1,
84328ddb 3974 epf->saddr, epf->sport,
3975 ssh, &ssh->cfg,
3976 &epf->local,
3977 epf->addressfamily);
3978
3979 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
3980 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3981 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3982 sportdesc,
3983 err ? " failed: " : "", err ? err : "");
06fadff5 3984 } else {
3985 struct ssh_rportfwd *pf;
3986
3987 /*
3988 * Ensure the remote port forwardings tree exists.
3989 */
3990 if (!ssh->rportfwds) {
3991 if (ssh->version == 1)
3992 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3993 else
3994 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
3995 }
3996
3997 pf = snew(struct ssh_rportfwd);
84328ddb 3998 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
3999 pf->dhost[lenof(pf->dhost)-1] = '\0';
4000 pf->dport = epf->dport;
4001 pf->sport = epf->sport;
06fadff5 4002 if (add234(ssh->rportfwds, pf) != pf) {
4003 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 4004 epf->daddr, epf->dport);
06fadff5 4005 sfree(pf);
4006 } else {
4007 logeventf(ssh, "Requesting remote port %s"
84328ddb 4008 " forward to %s", sportdesc, dportdesc);
06fadff5 4009
4010 pf->sportdesc = sportdesc;
4011 sportdesc = NULL;
84328ddb 4012 epf->remote = pf;
4013 pf->pfrec = epf;
06fadff5 4014
4015 if (ssh->version == 1) {
4016 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 4017 PKT_INT, epf->sport,
4018 PKT_STR, epf->daddr,
4019 PKT_INT, epf->dport,
06fadff5 4020 PKT_END);
4021 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4022 SSH1_SMSG_FAILURE,
4023 ssh_rportfwd_succfail, pf);
4024 } else {
4025 struct Packet *pktout;
4026 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4027 ssh2_pkt_addstring(pktout, "tcpip-forward");
4028 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 4029 if (epf->saddr) {
4030 ssh2_pkt_addstring(pktout, epf->saddr);
06fadff5 4031 } else if (ssh->cfg.rport_acceptall) {
4032 ssh2_pkt_addstring(pktout, "0.0.0.0");
4033 } else {
4034 ssh2_pkt_addstring(pktout, "127.0.0.1");
4035 }
84328ddb 4036 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 4037 ssh2_pkt_send(ssh, pktout);
4038
4039 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4040 SSH2_MSG_REQUEST_FAILURE,
4041 ssh_rportfwd_succfail, pf);
4042 }
4043 }
4044 }
4045 sfree(sportdesc);
84328ddb 4046 sfree(dportdesc);
06fadff5 4047 }
06fadff5 4048}
4049
51df0ab5 4050static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4051{
4052 char *string;
4053 int stringlen, bufsize;
4054
4055 ssh_pkt_getstring(pktin, &string, &stringlen);
4056 if (string == NULL) {
4057 bombout(("Incoming terminal data packet was badly formed"));
4058 return;
4059 }
4060
4061 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4062 string, stringlen);
4063 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4064 ssh->v1_stdout_throttling = 1;
4065 ssh1_throttle(ssh, +1);
4066 }
4067}
4068
4069static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4070{
4071 /* Remote side is trying to open a channel to talk to our
4072 * X-Server. Give them back a local channel number. */
4073 struct ssh_channel *c;
4074 int remoteid = ssh_pkt_getuint32(pktin);
4075
4076 logevent("Received X11 connect request");
4077 /* Refuse if X11 forwarding is disabled. */
4078 if (!ssh->X11_fwd_enabled) {
4079 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4080 PKT_INT, remoteid, PKT_END);
4081 logevent("Rejected X11 connect request");
4082 } else {
4083 c = snew(struct ssh_channel);
4084 c->ssh = ssh;
4085
4086 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4087 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4088 logevent("Opening X11 forward connection failed");
4089 sfree(c);
4090 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4091 PKT_INT, remoteid, PKT_END);
4092 } else {
4093 logevent
4094 ("Opening X11 forward connection succeeded");
4095 c->remoteid = remoteid;
4096 c->localid = alloc_channel_id(ssh);
4097 c->closes = 0;
4098 c->v.v1.throttling = 0;
4099 c->type = CHAN_X11; /* identify channel type */
4100 add234(ssh->channels, c);
4101 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4102 PKT_INT, c->remoteid, PKT_INT,
4103 c->localid, PKT_END);
4104 logevent("Opened X11 forward channel");
4105 }
4106 }
4107}
4108
4109static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4110{
4111 /* Remote side is trying to open a channel to talk to our
4112 * agent. Give them back a local channel number. */
4113 struct ssh_channel *c;
4114 int remoteid = ssh_pkt_getuint32(pktin);
4115
4116 /* Refuse if agent forwarding is disabled. */
4117 if (!ssh->agentfwd_enabled) {
4118 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4119 PKT_INT, remoteid, PKT_END);
4120 } else {
4121 c = snew(struct ssh_channel);
4122 c->ssh = ssh;
4123 c->remoteid = remoteid;
4124 c->localid = alloc_channel_id(ssh);
4125 c->closes = 0;
4126 c->v.v1.throttling = 0;
4127 c->type = CHAN_AGENT; /* identify channel type */
4128 c->u.a.lensofar = 0;
4129 add234(ssh->channels, c);
4130 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4131 PKT_INT, c->remoteid, PKT_INT, c->localid,
4132 PKT_END);
4133 }
4134}
4135
4136static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4137{
4138 /* Remote side is trying to open a channel to talk to a
4139 * forwarded port. Give them back a local channel number. */
4140 struct ssh_channel *c;
05581745 4141 struct ssh_rportfwd pf, *pfp;
51df0ab5 4142 int remoteid;
4143 int hostsize, port;
4144 char *host, buf[1024];
4145 const char *e;
4146 c = snew(struct ssh_channel);
4147 c->ssh = ssh;
4148
4149 remoteid = ssh_pkt_getuint32(pktin);
4150 ssh_pkt_getstring(pktin, &host, &hostsize);
4151 port = ssh_pkt_getuint32(pktin);
4152
4153 if (hostsize >= lenof(pf.dhost))
4154 hostsize = lenof(pf.dhost)-1;
4155 memcpy(pf.dhost, host, hostsize);
4156 pf.dhost[hostsize] = '\0';
4157 pf.dport = port;
05581745 4158 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4159
05581745 4160 if (pfp == NULL) {
51df0ab5 4161 sprintf(buf, "Rejected remote port open request for %s:%d",
4162 pf.dhost, port);
4163 logevent(buf);
4164 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4165 PKT_INT, remoteid, PKT_END);
4166 } else {
4167 sprintf(buf, "Received remote port open request for %s:%d",
4168 pf.dhost, port);
4169 logevent(buf);
4170 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
05581745 4171 c, &ssh->cfg, pfp->pfrec->addressfamily);
51df0ab5 4172 if (e != NULL) {
4173 char buf[256];
4174 sprintf(buf, "Port open failed: %s", e);
4175 logevent(buf);
4176 sfree(c);
4177 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4178 PKT_INT, remoteid, PKT_END);
4179 } else {
4180 c->remoteid = remoteid;
4181 c->localid = alloc_channel_id(ssh);
4182 c->closes = 0;
4183 c->v.v1.throttling = 0;
4184 c->type = CHAN_SOCKDATA; /* identify channel type */
4185 add234(ssh->channels, c);
4186 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4187 PKT_INT, c->remoteid, PKT_INT,
4188 c->localid, PKT_END);
4189 logevent("Forwarded port opened successfully");
4190 }
4191 }
4192}
4193
4194static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4195{
4196 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4197 unsigned int localid = ssh_pkt_getuint32(pktin);
4198 struct ssh_channel *c;
4199
4200 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4201 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4202 c->remoteid = localid;
4203 c->type = CHAN_SOCKDATA;
4204 c->v.v1.throttling = 0;
4205 pfd_confirm(c->u.pfd.s);
4206 }
4207
4208 if (c && c->closes) {
4209 /*
4210 * We have a pending close on this channel,
4211 * which we decided on before the server acked
4212 * the channel open. So now we know the
4213 * remoteid, we can close it again.
4214 */
4215 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4216 PKT_INT, c->remoteid, PKT_END);
4217 }
4218}
4219
4220static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4221{
4222 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4223 struct ssh_channel *c;
4224
4225 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4226 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4227 logevent("Forwarded connection refused by server");
4228 pfd_close(c->u.pfd.s);
4229 del234(ssh->channels, c);
4230 sfree(c);
4231 }
4232}
4233
4234static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4235{
4236 /* Remote side closes a channel. */
4237 unsigned i = ssh_pkt_getuint32(pktin);
4238 struct ssh_channel *c;
4239 c = find234(ssh->channels, &i, ssh_channelfind);
4240 if (c && ((int)c->remoteid) != -1) {
4241 int closetype;
4242 closetype =
4243 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4244
4245 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4246 logevent("Forwarded X11 connection terminated");
4247 assert(c->u.x11.s != NULL);
4248 x11_close(c->u.x11.s);
4249 c->u.x11.s = NULL;
4250 }
4251 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4252 logevent("Forwarded port closed");
4253 assert(c->u.pfd.s != NULL);
4254 pfd_close(c->u.pfd.s);
4255 c->u.pfd.s = NULL;
4256 }
4257
4258 c->closes |= (closetype << 2); /* seen this message */
4259 if (!(c->closes & closetype)) {
4260 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4261 PKT_END);
4262 c->closes |= closetype; /* sent it too */
4263 }
4264
4265 if (c->closes == 15) {
4266 del234(ssh->channels, c);
4267 sfree(c);
4268 }
4269 } else {
4270 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4271 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4272 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4273 i));
4274 }
4275}
4276
4277static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4278{
4279 /* Data sent down one of our channels. */
4280 int i = ssh_pkt_getuint32(pktin);
4281 char *p;
aa63ab7e 4282 unsigned int len;
51df0ab5 4283 struct ssh_channel *c;
4284
4285 ssh_pkt_getstring(pktin, &p, &len);
4286
4287 c = find234(ssh->channels, &i, ssh_channelfind);
4288 if (c) {
4289 int bufsize = 0;
4290 switch (c->type) {
4291 case CHAN_X11:
4292 bufsize = x11_send(c->u.x11.s, p, len);
4293 break;
4294 case CHAN_SOCKDATA:
4295 bufsize = pfd_send(c->u.pfd.s, p, len);
4296 break;
4297 case CHAN_AGENT:
4298 /* Data for an agent message. Buffer it. */
4299 while (len > 0) {
4300 if (c->u.a.lensofar < 4) {
aa63ab7e 4301 unsigned int l = min(4 - c->u.a.lensofar, len);
51df0ab5 4302 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4303 l);
4304 p += l;
4305 len -= l;
4306 c->u.a.lensofar += l;
4307 }
4308 if (c->u.a.lensofar == 4) {
4309 c->u.a.totallen =
4310 4 + GET_32BIT(c->u.a.msglen);
4311 c->u.a.message = snewn(c->u.a.totallen,
4312 unsigned char);
4313 memcpy(c->u.a.message, c->u.a.msglen, 4);
4314 }
4315 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 4316 unsigned int l =
51df0ab5 4317 min(c->u.a.totallen - c->u.a.lensofar,
4318 len);
4319 memcpy(c->u.a.message + c->u.a.lensofar, p,
4320 l);
4321 p += l;
4322 len -= l;
4323 c->u.a.lensofar += l;
4324 }
4325 if (c->u.a.lensofar == c->u.a.totallen) {
4326 void *reply;
4327 int replylen;
4328 if (agent_query(c->u.a.message,
4329 c->u.a.totallen,
4330 &reply, &replylen,
4331 ssh_agentf_callback, c))
4332 ssh_agentf_callback(c, reply, replylen);
4333 sfree(c->u.a.message);
4334 c->u.a.lensofar = 0;
4335 }
4336 }
4337 bufsize = 0; /* agent channels never back up */
4338 break;
4339 }
4340 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4341 c->v.v1.throttling = 1;
4342 ssh1_throttle(ssh, +1);
4343 }
4344 }
4345}
4346
4347static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4348{
4349 char buf[100];
4350 ssh->exitcode = ssh_pkt_getuint32(pktin);
4351 sprintf(buf, "Server sent command exit status %d",
4352 ssh->exitcode);
4353 logevent(buf);
4354 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4355 /*
4356 * In case `helpful' firewalls or proxies tack
4357 * extra human-readable text on the end of the
4358 * session which we might mistake for another
4359 * encrypted packet, we close the session once
4360 * we've sent EXIT_CONFIRMATION.
4361 */
ac934965 4362 ssh->close_expected = TRUE;
51df0ab5 4363 ssh_closing((Plug)ssh, NULL, 0, 0);
4364}
4365
b09eaa88 4366static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4367 struct Packet *pktin)
32874aea 4368{
b09eaa88 4369 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 4370
51df0ab5 4371 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4372 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4373 ssh1_smsg_stdout_stderr_data;
4374
4375 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4376 ssh1_msg_channel_open_confirmation;
4377 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4378 ssh1_msg_channel_open_failure;
4379 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4380 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4381 ssh1_msg_channel_close;
4382 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4383 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4384
86916870 4385 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 4386 logevent("Requesting agent forwarding");
51470298 4387 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 4388 do {
4389 crReturnV;
ff3187f6 4390 } while (!pktin);
4391 if (pktin->type != SSH1_SMSG_SUCCESS
4392 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4393 bombout(("Protocol confusion"));
7ffdbc1a 4394 crStopV;
ff3187f6 4395 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4396 logevent("Agent forwarding refused");
4397 } else {
4398 logevent("Agent forwarding enabled");
51470298 4399 ssh->agentfwd_enabled = TRUE;
51df0ab5 4400 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 4401 }
dacbd0e8 4402 }
4403
86916870 4404 if (ssh->cfg.x11_forward) {
32874aea 4405 char proto[20], data[64];
4406 logevent("Requesting X11 forwarding");
302121de 4407 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 4408 data, sizeof(data), ssh->cfg.x11_auth);
4409 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 4410 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4411 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4412 PKT_STR, proto, PKT_STR, data,
86916870 4413 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 4414 PKT_END);
32874aea 4415 } else {
51470298 4416 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 4417 PKT_STR, proto, PKT_STR, data, PKT_END);
4418 }
4419 do {
4420 crReturnV;
ff3187f6 4421 } while (!pktin);
4422 if (pktin->type != SSH1_SMSG_SUCCESS
4423 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4424 bombout(("Protocol confusion"));
7ffdbc1a 4425 crStopV;
ff3187f6 4426 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4427 logevent("X11 forwarding refused");
4428 } else {
4429 logevent("X11 forwarding enabled");
51470298 4430 ssh->X11_fwd_enabled = TRUE;
51df0ab5 4431 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 4432 }
4433 }
4434
06fadff5 4435 ssh_setup_portfwd(ssh, &ssh->cfg);
4436 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 4437
86916870 4438 if (!ssh->cfg.nopty) {
a5dd8467 4439 /* Unpick the terminal-speed string. */
4440 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4441 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4442 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4443 /* Send the pty request. */
51470298 4444 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 4445 PKT_STR, ssh->cfg.termtype,
51470298 4446 PKT_INT, ssh->term_height,
4447 PKT_INT, ssh->term_width,
a5dd8467 4448 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 4449 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4450 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 4451 PKT_CHAR, 0, PKT_END);
51470298 4452 ssh->state = SSH_STATE_INTERMED;
32874aea 4453 do {
4454 crReturnV;
ff3187f6 4455 } while (!pktin);
4456 if (pktin->type != SSH1_SMSG_SUCCESS
4457 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4458 bombout(("Protocol confusion"));
7ffdbc1a 4459 crStopV;
ff3187f6 4460 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4461 c_write_str(ssh, "Server refused to allocate pty\r\n");
4462 ssh->editing = ssh->echoing = 1;
32874aea 4463 }
a5dd8467 4464 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4465 ssh->ospeed, ssh->ispeed);
0965bee0 4466 } else {
51470298 4467 ssh->editing = ssh->echoing = 1;
374330e2 4468 }
4469
86916870 4470 if (ssh->cfg.compression) {
51470298 4471 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4472 do {
4473 crReturnV;
ff3187f6 4474 } while (!pktin);
4475 if (pktin->type != SSH1_SMSG_SUCCESS
4476 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4477 bombout(("Protocol confusion"));
7ffdbc1a 4478 crStopV;
ff3187f6 4479 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4480 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4481 }
4ba9b64b 4482 logevent("Started compression");
51470298 4483 ssh->v1_compressing = TRUE;
5366aed8 4484 ssh->cs_comp_ctx = zlib_compress_init();
4485 logevent("Initialised zlib (RFC1950) compression");
4486 ssh->sc_comp_ctx = zlib_decompress_init();
4487 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4488 }
4489
fd5e5847 4490 /*
4491 * Start the shell or command.
4492 *
4493 * Special case: if the first-choice command is an SSH2
4494 * subsystem (hence not usable here) and the second choice
4495 * exists, we fall straight back to that.
4496 */
4497 {
86916870 4498 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 4499
86916870 4500 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4501 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 4502 ssh->fallback_cmd = TRUE;
fd5e5847 4503 }
4504 if (*cmd)
51470298 4505 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 4506 else
51470298 4507 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 4508 logevent("Started session");
4509 }
374330e2 4510
51470298 4511 ssh->state = SSH_STATE_SESSION;
4512 if (ssh->size_needed)
4513 ssh_size(ssh, ssh->term_width, ssh->term_height);
4514 if (ssh->eof_needed)
4515 ssh_special(ssh, TS_EOF);
374330e2 4516
b9d7bcad 4517 if (ssh->ldisc)
4518 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 4519 ssh->send_ok = 1;
4520 ssh->channels = newtree234(ssh_channelcmp);
374330e2 4521 while (1) {
d74d141c 4522
51df0ab5 4523 /*
4524 * By this point, most incoming packets are already being
4525 * handled by the dispatch table, and we need only pay
4526 * attention to the unusual ones.
4527 */
0357890f 4528
51df0ab5 4529 crReturnV;
4530 if (pktin) {
4531 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4532 /* may be from EXEC_SHELL on some servers */
ff3187f6 4533 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 4534 /* may be from EXEC_SHELL on some servers
374330e2 4535 * if no pty is available or in other odd cases. Ignore */
374330e2 4536 } else {
ff3187f6 4537 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 4538 crStopV;
374330e2 4539 }
4540 } else {
8df7a775 4541 while (inlen > 0) {
4542 int len = min(inlen, 512);
9a10ecf4 4543 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4544 PKT_INT, len, PKT_DATA, in, len,
4545 PKTT_OTHER, PKT_END);
8df7a775 4546 in += len;
4547 inlen -= len;
4548 }
374330e2 4549 }
4550 }
4551
4552 crFinishV;
4553}
4554
4555/*
b09eaa88 4556 * Handle the top-level SSH2 protocol.
4557 */
4558static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4559{
4560 char *buf, *msg;
4561 int msglen;
4562
4563 ssh_pkt_getstring(pktin, &msg, &msglen);
4564 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4565 logevent(buf);
4566 sfree(buf);
4567}
4568
4569static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4570{
4571 /* log reason code in disconnect message */
4572 char *msg;
4573 int msglen;
4574
4575 ssh_pkt_getstring(pktin, &msg, &msglen);
4576 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4577}
4578
4579void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4580{
4581 /* Do nothing, because we're ignoring it! Duhh. */
4582}
4583
4584static void ssh1_protocol_setup(Ssh ssh)
4585{
4586 int i;
4587
4588 /*
4589 * Most messages are handled by the coroutines.
4590 */
4591 for (i = 0; i < 256; i++)
4592 ssh->packet_dispatch[i] = NULL;
4593
4594 /*
4595 * These special message types we install handlers for.
4596 */
4597 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4598 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4599 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4600}
4601
4602static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4603 struct Packet *pktin)
4604{
4605 if (ssh->state == SSH_STATE_CLOSED)
4606 return;
4607
4608 if (pktin && ssh->packet_dispatch[pktin->type]) {
4609 ssh->packet_dispatch[pktin->type](ssh, pktin);
4610 return;
4611 }
4612
4613 if (!ssh->protocol_initial_phase_done) {
4614 if (do_ssh1_login(ssh, in, inlen, pktin))
4615 ssh->protocol_initial_phase_done = TRUE;
4616 else
4617 return;
4618 }
4619
4620 do_ssh1_connection(ssh, in, inlen, pktin);
4621}
4622
4623/*
e5574168 4624 * Utility routine for decoding comma-separated strings in KEXINIT.
4625 */
32874aea 4626static int in_commasep_string(char *needle, char *haystack, int haylen)
4627{
57356d63 4628 int needlen;
4629 if (!needle || !haystack) /* protect against null pointers */
4630 return 0;
4631 needlen = strlen(needle);
e5574168 4632 while (1) {
32874aea 4633 /*
4634 * Is it at the start of the string?
4635 */
4636 if (haylen >= needlen && /* haystack is long enough */
4637 !memcmp(needle, haystack, needlen) && /* initial match */
4638 (haylen == needlen || haystack[needlen] == ',')
4639 /* either , or EOS follows */
4640 )
4641 return 1;
4642 /*
4643 * If not, search for the next comma and resume after that.
4644 * If no comma found, terminate.
4645 */
4646 while (haylen > 0 && *haystack != ',')
4647 haylen--, haystack++;
4648 if (haylen == 0)
4649 return 0;
4650 haylen--, haystack++; /* skip over comma itself */
e5574168 4651 }
4652}
4653
4654/*
d39f364a 4655 * SSH2 key creation method.
4656 */
d8baa528 4657static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4658 unsigned char *sessid, char chr,
4659 unsigned char *keyspace)
32874aea 4660{
d39f364a 4661 SHA_State s;
4662 /* First 20 bytes. */
4663 SHA_Init(&s);
51470298 4664 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4665 sha_mpint(&s, K);
d39f364a 4666 SHA_Bytes(&s, H, 20);
4667 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 4668 SHA_Bytes(&s, sessid, 20);
d39f364a 4669 SHA_Final(&s, keyspace);
4670 /* Next 20 bytes. */
4671 SHA_Init(&s);
51470298 4672 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4673 sha_mpint(&s, K);
d39f364a 4674 SHA_Bytes(&s, H, 20);
4675 SHA_Bytes(&s, keyspace, 20);
32874aea 4676 SHA_Final(&s, keyspace + 20);
d39f364a 4677}
4678
4679/*
7cca0d81 4680 * Handle the SSH2 transport layer.
e5574168 4681 */
ff3187f6 4682static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4683 struct Packet *pktin)
e5574168 4684{
51470298 4685 struct do_ssh2_transport_state {
4686 int nbits, pbits, warn;
4687 Bignum p, g, e, f, K;
4688 int kex_init_value, kex_reply_value;
4689 const struct ssh_mac **maclist;
4690 int nmacs;
4691 const struct ssh2_cipher *cscipher_tobe;
4692 const struct ssh2_cipher *sccipher_tobe;
4693 const struct ssh_mac *csmac_tobe;
4694 const struct ssh_mac *scmac_tobe;
4695 const struct ssh_compress *cscomp_tobe;
4696 const struct ssh_compress *sccomp_tobe;
4697 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4698 int hostkeylen, siglen;
4699 void *hkey; /* actual host key */
4700 unsigned char exchange_hash[20];
83e7d008 4701 int n_preferred_kex;
4702 const struct ssh_kex *preferred_kex[KEX_MAX];
51470298 4703 int n_preferred_ciphers;
4704 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4705 const struct ssh_compress *preferred_comp;
e13bba36 4706 int got_session_id, activated_authconn;
ff3187f6 4707 struct Packet *pktout;
51470298 4708 };
4709 crState(do_ssh2_transport_state);
4710
4711 crBegin(ssh->do_ssh2_transport_crstate);
4712
4713 s->cscipher_tobe = s->sccipher_tobe = NULL;
4714 s->csmac_tobe = s->scmac_tobe = NULL;
4715 s->cscomp_tobe = s->sccomp_tobe = NULL;
4716
e13bba36 4717 s->got_session_id = s->activated_authconn = FALSE;
e5574168 4718
e13bba36 4719 /*
4720 * Be prepared to work around the buggy MAC problem.
4721 */
4722 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4723 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4724 else
4725 s->maclist = macs, s->nmacs = lenof(macs);
4726
4727 begin_key_exchange:
149d2abc 4728 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
51470298 4729 {
e13bba36 4730 int i, j, commalist_started;
4731
51470298 4732 /*
83e7d008 4733 * Set up the preferred key exchange. (NULL => warn below here)
4734 */
4735 s->n_preferred_kex = 0;
4736 for (i = 0; i < KEX_MAX; i++) {
4737 switch (ssh->cfg.ssh_kexlist[i]) {
4738 case KEX_DHGEX:
4739 s->preferred_kex[s->n_preferred_kex++] =
4740 &ssh_diffiehellman_gex;
4741 break;
4742 case KEX_DHGROUP14:
4743 s->preferred_kex[s->n_preferred_kex++] =
4744 &ssh_diffiehellman_group14;
4745 break;
4746 case KEX_DHGROUP1:
4747 s->preferred_kex[s->n_preferred_kex++] =
4748 &ssh_diffiehellman_group1;
4749 break;
4750 case CIPHER_WARN:
4751 /* Flag for later. Don't bother if it's the last in
4752 * the list. */
4753 if (i < KEX_MAX - 1) {
4754 s->preferred_kex[s->n_preferred_kex++] = NULL;
4755 }
4756 break;
4757 }
4758 }
83e7d008 4759
83e7d008 4760 /*
51470298 4761 * Set up the preferred ciphers. (NULL => warn below here)
4762 */
4763 s->n_preferred_ciphers = 0;
4764 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4765 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4766 case CIPHER_BLOWFISH:
4767 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4768 break;
4769 case CIPHER_DES:
86916870 4770 if (ssh->cfg.ssh2_des_cbc) {
51470298 4771 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4772 }
4773 break;
4774 case CIPHER_3DES:
4775 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4776 break;
4777 case CIPHER_AES:
4778 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4779 break;
4780 case CIPHER_WARN:
4781 /* Flag for later. Don't bother if it's the last in
4782 * the list. */
4783 if (i < CIPHER_MAX - 1) {
4784 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4785 }
4786 break;
ca20bfcf 4787 }
ca20bfcf 4788 }
7591b9ff 4789
e13bba36 4790 /*
4791 * Set up preferred compression.
4792 */
4793 if (ssh->cfg.compression)
4794 s->preferred_comp = &ssh_zlib;
4795 else
4796 s->preferred_comp = &ssh_comp_none;
51470298 4797
4798 /*
590f6a5f 4799 * Enable queueing of outgoing auth- or connection-layer
4800 * packets while we are in the middle of a key exchange.
4801 */
4802 ssh->queueing = TRUE;
4803
4804 /*
9442dd57 4805 * Flag that KEX is in progress.
4806 */
4807 ssh->kex_in_progress = TRUE;
4808
4809 /*
51470298 4810 * Construct and send our key exchange packet.
4811 */
ff3187f6 4812 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 4813 for (i = 0; i < 16; i++)
ff3187f6 4814 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 4815 /* List key exchange algorithms. */
ff3187f6 4816 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4817 commalist_started = 0;
4818 for (i = 0; i < s->n_preferred_kex; i++) {
4819 const struct ssh_kex *k = s->preferred_kex[i];
4820 if (!k) continue; /* warning flag */
4821 if (commalist_started)
ff3187f6 4822 ssh2_pkt_addstring_str(s->pktout, ",");
83e7d008 4823 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4824 commalist_started = 1;
32874aea 4825 }
51470298 4826 /* List server host key algorithms. */
ff3187f6 4827 ssh2_pkt_addstring_start(s->pktout);
51470298 4828 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 4829 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 4830 if (i < lenof(hostkey_algs) - 1)
ff3187f6 4831 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4832 }
51470298 4833 /* List client->server encryption algorithms. */
ff3187f6 4834 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4835 commalist_started = 0;
51470298 4836 for (i = 0; i < s->n_preferred_ciphers; i++) {
4837 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4838 if (!c) continue; /* warning flag */
4839 for (j = 0; j < c->nciphers; j++) {
83e7d008 4840 if (commalist_started)
ff3187f6 4841 ssh2_pkt_addstring_str(s->pktout, ",");
4842 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4843 commalist_started = 1;
51470298 4844 }
4845 }
4846 /* List server->client encryption algorithms. */
ff3187f6 4847 ssh2_pkt_addstring_start(s->pktout);
83e7d008 4848 commalist_started = 0;
51470298 4849 for (i = 0; i < s->n_preferred_ciphers; i++) {
4850 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4851 if (!c) continue; /* warning flag */
4852 for (j = 0; j < c->nciphers; j++) {
83e7d008 4853 if (commalist_started)
ff3187f6 4854 ssh2_pkt_addstring_str(s->pktout, ",");
4855 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 4856 commalist_started = 1;
51470298 4857 }
4858 }
4859 /* List client->server MAC algorithms. */
ff3187f6 4860 ssh2_pkt_addstring_start(s->pktout);
51470298 4861 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4862 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4863 if (i < s->nmacs - 1)
ff3187f6 4864 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4865 }
4866 /* List server->client MAC algorithms. */
ff3187f6 4867 ssh2_pkt_addstring_start(s->pktout);
51470298 4868 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4869 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4870 if (i < s->nmacs - 1)
ff3187f6 4871 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4872 }
4873 /* List client->server compression algorithms. */
ff3187f6 4874 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4875 assert(lenof(compressions) > 1);
ff3187f6 4876 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4877 for (i = 0; i < lenof(compressions); i++) {
4878 const struct ssh_compress *c = compressions[i];
4879 if (c != s->preferred_comp) {
ff3187f6 4880 ssh2_pkt_addstring_str(s->pktout, ",");
4881 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4882 }
51470298 4883 }
4884 /* List server->client compression algorithms. */
ff3187f6 4885 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4886 assert(lenof(compressions) > 1);
ff3187f6 4887 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4888 for (i = 0; i < lenof(compressions); i++) {
4889 const struct ssh_compress *c = compressions[i];
4890 if (c != s->preferred_comp) {
ff3187f6 4891 ssh2_pkt_addstring_str(s->pktout, ",");
4892 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4893 }
51470298 4894 }
4895 /* List client->server languages. Empty list. */
ff3187f6 4896 ssh2_pkt_addstring_start(s->pktout);
51470298 4897 /* List server->client languages. Empty list. */
ff3187f6 4898 ssh2_pkt_addstring_start(s->pktout);
51470298 4899 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 4900 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 4901 /* Reserved. */
ff3187f6 4902 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 4903 }
0db56f73 4904
51470298 4905 ssh->exhash = ssh->exhashbase;
ff3187f6 4906 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
0db56f73 4907
590f6a5f 4908 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4909
ff3187f6 4910 if (!pktin)
4911 crWaitUntil(pktin);
4912 if (pktin->length > 5)
4913 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
e5574168 4914
4915 /*
4916 * Now examine the other side's KEXINIT to see what we're up
4917 * to.
4918 */
51470298 4919 {
4920 char *str;
4921 int i, j, len;
4922
ff3187f6 4923 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 4924 bombout(("expected key exchange packet from server"));
7ffdbc1a 4925 crStop(0);
32874aea 4926 }
51470298 4927 ssh->kex = NULL;
4928 ssh->hostkey = NULL;
4929 s->cscipher_tobe = NULL;
4930 s->sccipher_tobe = NULL;
4931 s->csmac_tobe = NULL;
4932 s->scmac_tobe = NULL;
4933 s->cscomp_tobe = NULL;
4934 s->sccomp_tobe = NULL;
ff3187f6 4935 pktin->savedpos += 16; /* skip garbage cookie */
4936 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
83e7d008 4937 s->warn = 0;
4938 for (i = 0; i < s->n_preferred_kex; i++) {
4939 const struct ssh_kex *k = s->preferred_kex[i];
4940 if (!k) {
4941 s->warn = 1;
4942 } else if (in_commasep_string(k->name, str, len)) {
4943 ssh->kex = k;
4944 }
4945 if (ssh->kex) {
bb348ab1 4946 if (s->warn) {
4947 sk_set_frozen(ssh->s, 1);
83e7d008 4948 askalg(ssh->frontend, "key-exchange algorithm",
4949 ssh->kex->name);
bb348ab1 4950 sk_set_frozen(ssh->s, 0);
4951 }
51470298 4952 break;
4953 }
32874aea 4954 }
83e7d008 4955 if (!ssh->kex) {
4956 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
4957 str ? str : "(null)"));
4958 crStop(0);
4959 }
ff3187f6 4960 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 4961 for (i = 0; i < lenof(hostkey_algs); i++) {
4962 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4963 ssh->hostkey = hostkey_algs[i];
4964 break;
4965 }
4966 }
ff3187f6 4967 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 4968 s->warn = 0;
4969 for (i = 0; i < s->n_preferred_ciphers; i++) {
4970 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4971 if (!c) {
4972 s->warn = 1;
4973 } else {
4974 for (j = 0; j < c->nciphers; j++) {
4975 if (in_commasep_string(c->list[j]->name, str, len)) {
4976 s->cscipher_tobe = c->list[j];
4977 break;
4978 }
ca20bfcf 4979 }
32874aea 4980 }
51470298 4981 if (s->cscipher_tobe) {
bb348ab1 4982 if (s->warn) {
4983 sk_set_frozen(ssh->s, 1);
83e7d008 4984 askalg(ssh->frontend, "client-to-server cipher",
4985 s->cscipher_tobe->name);
bb348ab1 4986 sk_set_frozen(ssh->s, 0);
4987 }
51470298 4988 break;
4989 }
32874aea 4990 }
51470298 4991 if (!s->cscipher_tobe) {
6b5cf8b4 4992 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 4993 str ? str : "(null)"));
7ffdbc1a 4994 crStop(0);
ca20bfcf 4995 }
0ef8f407 4996
ff3187f6 4997 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 4998 s->warn = 0;
4999 for (i = 0; i < s->n_preferred_ciphers; i++) {
5000 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5001 if (!c) {
5002 s->warn = 1;
5003 } else {
5004 for (j = 0; j < c->nciphers; j++) {
5005 if (in_commasep_string(c->list[j]->name, str, len)) {
5006 s->sccipher_tobe = c->list[j];
5007 break;
5008 }
ca20bfcf 5009 }
32874aea 5010 }
51470298 5011 if (s->sccipher_tobe) {
bb348ab1 5012 if (s->warn) {
5013 sk_set_frozen(ssh->s, 1);
83e7d008 5014 askalg(ssh->frontend, "server-to-client cipher",
5015 s->sccipher_tobe->name);
bb348ab1 5016 sk_set_frozen(ssh->s, 0);
5017 }
51470298 5018 break;
5019 }
32874aea 5020 }
51470298 5021 if (!s->sccipher_tobe) {
6b5cf8b4 5022 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 5023 str ? str : "(null)"));
7ffdbc1a 5024 crStop(0);
ca20bfcf 5025 }
0ef8f407 5026
ff3187f6 5027 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 5028 for (i = 0; i < s->nmacs; i++) {
5029 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5030 s->csmac_tobe = s->maclist[i];
5031 break;
5032 }
32874aea 5033 }
ff3187f6 5034 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 5035 for (i = 0; i < s->nmacs; i++) {
5036 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5037 s->scmac_tobe = s->maclist[i];
5038 break;
5039 }
32874aea 5040 }
ff3187f6 5041 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 5042 for (i = 0; i < lenof(compressions) + 1; i++) {
5043 const struct ssh_compress *c =
5044 i == 0 ? s->preferred_comp : compressions[i - 1];
5045 if (in_commasep_string(c->name, str, len)) {
5046 s->cscomp_tobe = c;
5047 break;
5048 }
32874aea 5049 }
ff3187f6 5050 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5051 for (i = 0; i < lenof(compressions) + 1; i++) {
5052 const struct ssh_compress *c =
5053 i == 0 ? s->preferred_comp : compressions[i - 1];
5054 if (in_commasep_string(c->name, str, len)) {
5055 s->sccomp_tobe = c;
5056 break;
5057 }
32874aea 5058 }
e5574168 5059 }
e5574168 5060
5061 /*
7bd5a860 5062 * Work out the number of bits of key we will need from the key
5063 * exchange. We start with the maximum key length of either
5064 * cipher...
5065 */
5066 {
32874aea 5067 int csbits, scbits;
7bd5a860 5068
51470298 5069 csbits = s->cscipher_tobe->keylen;
5070 scbits = s->sccipher_tobe->keylen;
5071 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 5072 }
5073 /* The keys only have 160-bit entropy, since they're based on
5074 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 5075 if (s->nbits > 160)
5076 s->nbits = 160;
7bd5a860 5077
5078 /*
a92dd380 5079 * If we're doing Diffie-Hellman group exchange, start by
5080 * requesting a group.
e5574168 5081 */
d1aaf71d 5082 if (!ssh->kex->pdata) {
32874aea 5083 logevent("Doing Diffie-Hellman group exchange");
51470298 5084 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 5085 /*
5086 * Work out how big a DH group we will need to allow that
5087 * much data.
7bd5a860 5088 */
51470298 5089 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 5090 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5091 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 5092 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 5093
ff3187f6 5094 crWaitUntil(pktin);
5095 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 5096 bombout(("expected key exchange group packet from server"));
7ffdbc1a 5097 crStop(0);
32874aea 5098 }
ff3187f6 5099 s->p = ssh2_pkt_getmp(pktin);
5100 s->g = ssh2_pkt_getmp(pktin);
5101 if (!s->p || !s->g) {
5102 bombout(("unable to read mp-ints from incoming group packet"));
5103 crStop(0);
5104 }
d1aaf71d 5105 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
51470298 5106 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5107 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 5108 } else {
d1aaf71d 5109 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5110 ssh->kex_ctx = dh_setup_group(ssh->kex);
51470298 5111 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5112 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
d1aaf71d 5113 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5114 ssh->kex->groupname);
8d5de777 5115 }
e5574168 5116
a92dd380 5117 logevent("Doing Diffie-Hellman key exchange");
e5574168 5118 /*
a92dd380 5119 * Now generate and send e for Diffie-Hellman.
e5574168 5120 */
27cd7fc2 5121 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 5122 s->pktout = ssh2_pkt_init(s->kex_init_value);
5123 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 5124 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5125
ff3187f6 5126 crWaitUntil(pktin);
5127 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 5128 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 5129 crStop(0);
7cca0d81 5130 }
ff3187f6 5131 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5132 s->f = ssh2_pkt_getmp(pktin);
5133 if (!s->f) {
5134 bombout(("unable to parse key exchange reply packet"));
5135 crStop(0);
5136 }
5137 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 5138
27cd7fc2 5139 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 5140
51470298 5141 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5142 if (ssh->kex == &ssh_diffiehellman_gex) {
5143 sha_uint32(&ssh->exhash, s->pbits);
5144 sha_mpint(&ssh->exhash, s->p);
5145 sha_mpint(&ssh->exhash, s->g);
a92dd380 5146 }
51470298 5147 sha_mpint(&ssh->exhash, s->e);
5148 sha_mpint(&ssh->exhash, s->f);
5149 sha_mpint(&ssh->exhash, s->K);
5150 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 5151
27cd7fc2 5152 dh_cleanup(ssh->kex_ctx);
fabd1805 5153 ssh->kex_ctx = NULL;
3709bfe9 5154
7cca0d81 5155#if 0
765c4200 5156 debug(("Exchange hash is:\n"));
51470298 5157 dmemdump(s->exchange_hash, 20);
7cca0d81 5158#endif
5159
51470298 5160 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5161 if (!s->hkey ||
5162 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 5163 (char *)s->exchange_hash, 20)) {
6b5cf8b4 5164 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 5165 crStop(0);
8d5de777 5166 }
e5574168 5167
5168 /*
7cca0d81 5169 * Authenticate remote host: verify host key. (We've already
5170 * checked the signature of the exchange hash.)
e5574168 5171 */
51470298 5172 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5173 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
bb348ab1 5174 sk_set_frozen(ssh->s, 1);
a8327734 5175 verify_ssh_host_key(ssh->frontend,
5176 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 5177 s->keystr, s->fingerprint);
bb348ab1 5178 sk_set_frozen(ssh->s, 0);
e13bba36 5179 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 5180 logevent("Host key fingerprint is:");
51470298 5181 logevent(s->fingerprint);
5e0d7cb8 5182 }
51470298 5183 sfree(s->fingerprint);
5184 sfree(s->keystr);
5185 ssh->hostkey->freekey(s->hkey);
d39f364a 5186
5187 /*
9442dd57 5188 * The exchange hash from the very first key exchange is also
5189 * the session id, used in session key construction and
5190 * authentication.
5191 */
e13bba36 5192 if (!s->got_session_id) {
9442dd57 5193 memcpy(ssh->v2_session_id, s->exchange_hash,
5194 sizeof(s->exchange_hash));
e13bba36 5195 s->got_session_id = TRUE;
5196 }
9442dd57 5197
5198 /*
7cca0d81 5199 * Send SSH2_MSG_NEWKEYS.
d39f364a 5200 */
ff3187f6 5201 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 5202 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 5203 ssh->outgoing_data_size = 0; /* start counting from here */
5204
5205 /*
5206 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 5207 * client-to-server session keys.
9442dd57 5208 */
5209 if (ssh->cs_cipher_ctx)
5210 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5211 ssh->cscipher = s->cscipher_tobe;
5212 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5213
5214 if (ssh->cs_mac_ctx)
5215 ssh->csmac->free_context(ssh->cs_mac_ctx);
5216 ssh->csmac = s->csmac_tobe;
5217 ssh->cs_mac_ctx = ssh->csmac->make_context();
5218
5219 if (ssh->cs_comp_ctx)
5220 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5221 ssh->cscomp = s->cscomp_tobe;
5222 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5223
5224 /*
5225 * Set IVs on client-to-server keys. Here we use the exchange
5226 * hash from the _first_ key exchange.
5227 */
5228 {
5229 unsigned char keyspace[40];
5230 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5231 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5232 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5233 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5234 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5235 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5236 }
5237
5238 logeventf(ssh, "Initialised %.200s client->server encryption",
5239 ssh->cscipher->text_name);
5240 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5241 ssh->csmac->text_name);
5242 if (ssh->cscomp->text_name)
5243 logeventf(ssh, "Initialised %s compression",
5244 ssh->cscomp->text_name);
590f6a5f 5245
5246 /*
5247 * Now our end of the key exchange is complete, we can send all
5248 * our queued higher-layer packets.
5249 */
5250 ssh->queueing = FALSE;
5251 ssh2_pkt_queuesend(ssh);
d39f364a 5252
5253 /*
8406eaf9 5254 * Expect SSH2_MSG_NEWKEYS from server.
5255 */
ff3187f6 5256 crWaitUntil(pktin);
5257 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 5258 bombout(("expected new-keys packet from server"));
7ffdbc1a 5259 crStop(0);
8406eaf9 5260 }
9442dd57 5261 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 5262
5263 /*
9442dd57 5264 * We've seen server NEWKEYS, so create and initialise
5265 * server-to-client session keys.
d39f364a 5266 */
371e569c 5267 if (ssh->sc_cipher_ctx)
5268 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 5269 ssh->sccipher = s->sccipher_tobe;
371e569c 5270 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 5271
e0e1a00d 5272 if (ssh->sc_mac_ctx)
5273 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 5274 ssh->scmac = s->scmac_tobe;
e0e1a00d 5275 ssh->sc_mac_ctx = ssh->scmac->make_context();
5276
5366aed8 5277 if (ssh->sc_comp_ctx)
5278 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 5279 ssh->sccomp = s->sccomp_tobe;
5366aed8 5280 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5281
d39f364a 5282 /*
9442dd57 5283 * Set IVs on server-to-client keys. Here we use the exchange
5284 * hash from the _first_ key exchange.
d39f364a 5285 */
51470298 5286 {
5287 unsigned char keyspace[40];
51470298 5288 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 5289 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 5290 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 5291 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 5292 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 5293 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 5294 }
57356d63 5295 logeventf(ssh, "Initialised %.200s server->client encryption",
5296 ssh->sccipher->text_name);
6c135243 5297 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5298 ssh->scmac->text_name);
57356d63 5299 if (ssh->sccomp->text_name)
5300 logeventf(ssh, "Initialised %s decompression",
5301 ssh->sccomp->text_name);
9442dd57 5302
5303 /*
5304 * Free key exchange data.
5305 */
679539d7 5306 freebn(s->f);
679539d7 5307 freebn(s->K);
b3949e7e 5308 if (ssh->kex == &ssh_diffiehellman_gex) {
5309 freebn(s->g);
5310 freebn(s->p);
5311 }
d39f364a 5312
033b4cef 5313 /*
e13bba36 5314 * Key exchange is over. Loop straight back round if we have a
5315 * deferred rekey reason.
5316 */
5317 if (ssh->deferred_rekey_reason) {
5318 logevent(ssh->deferred_rekey_reason);
5319 pktin = NULL;
5320 ssh->deferred_rekey_reason = NULL;
5321 goto begin_key_exchange;
5322 }
5323
5324 /*
5325 * Otherwise, schedule a timer for our next rekey.
9442dd57 5326 */
5327 ssh->kex_in_progress = FALSE;
e6c1536e 5328 ssh->last_rekey = GETTICKCOUNT();
d57f70af 5329 if (ssh->cfg.ssh_rekey_time != 0)
5330 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5331 ssh2_timer, ssh);
e13bba36 5332
9442dd57 5333 /*
0db56f73 5334 * If this is the first key exchange phase, we must pass the
5335 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5336 * wants to see it but because it will need time to initialise
5337 * itself before it sees an actual packet. In subsequent key
5338 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5339 * it would only confuse the layer above.
5340 */
e13bba36 5341 if (s->activated_authconn) {
b09eaa88 5342 crReturn(1);
0db56f73 5343 }
e13bba36 5344 s->activated_authconn = TRUE;
0db56f73 5345
5346 /*
7cca0d81 5347 * Now we're encrypting. Begin returning 1 to the protocol main
5348 * function so that other things can run on top of the
5349 * transport. If we ever see a KEXINIT, we must go back to the
5350 * start.
9442dd57 5351 *
5352 * We _also_ go back to the start if we see pktin==NULL and
5353 * inlen==-1, because this is a special signal meaning
5354 * `initiate client-driven rekey', and `in' contains a message
5355 * giving the reason for the rekey.
033b4cef 5356 */
9442dd57 5357 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5358 (!pktin && inlen == -1))) {
f382c87d 5359 wait_for_rekey:
32874aea 5360 crReturn(1);
e96adf72 5361 }
9442dd57 5362 if (pktin) {
5363 logevent("Server initiated key re-exchange");
5364 } else {
f382c87d 5365 /*
5366 * Special case: if the server bug is set that doesn't
5367 * allow rekeying, we give a different log message and
5368 * continue waiting. (If such a server _initiates_ a rekey,
5369 * we process it anyway!)
5370 */
5371 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5372 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5373 (char *)in);
5374 /* Reset the counters, so that at least this message doesn't
5375 * hit the event log _too_ often. */
5376 ssh->outgoing_data_size = 0;
5377 ssh->incoming_data_size = 0;
5378 if (ssh->cfg.ssh_rekey_time != 0) {
5379 ssh->next_rekey =
5380 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5381 ssh2_timer, ssh);
5382 }
5383 goto wait_for_rekey; /* this is utterly horrid */
5384 } else {
5385 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
f382c87d 5386 }
9442dd57 5387 }
7cca0d81 5388 goto begin_key_exchange;
e5574168 5389
5390 crFinish(1);
5391}
5392
7cca0d81 5393/*
783415f8 5394 * Add data to an SSH2 channel output buffer.
5395 */
32874aea 5396static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5397 int len)
5398{
5471d09a 5399 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 5400}
5401
5402/*
5403 * Attempt to send data on an SSH2 channel.
5404 */
5471d09a 5405static int ssh2_try_send(struct ssh_channel *c)
32874aea 5406{
51470298 5407 Ssh ssh = c->ssh;
ff3187f6 5408 struct Packet *pktout;
51470298 5409
5471d09a 5410 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5411 int len;
5412 void *data;
5413 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5414 if ((unsigned)len > c->v.v2.remwindow)
5415 len = c->v.v2.remwindow;
5416 if ((unsigned)len > c->v.v2.remmaxpkt)
5417 len = c->v.v2.remmaxpkt;
ff3187f6 5418 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5419 ssh2_pkt_adduint32(pktout, c->remoteid);
5420 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5421 ssh2_pkt_addstring_start(pktout);
5422 ssh2_pkt_addstring_data(pktout, data, len);
5423 end_log_omission(ssh, pktout);
5424 ssh2_pkt_send(ssh, pktout);
5471d09a 5425 bufchain_consume(&c->v.v2.outbuffer, len);
5426 c->v.v2.remwindow -= len;
5427 }
5428
5429 /*
5430 * After having sent as much data as we can, return the amount
5431 * still buffered.
5432 */
5433 return bufchain_size(&c->v.v2.outbuffer);
5434}
5435
5436/*
5437 * Potentially enlarge the window on an SSH2 channel.
5438 */
5439static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5440{
51470298 5441 Ssh ssh = c->ssh;
5442
6b69f42e 5443 /*
5444 * Never send WINDOW_ADJUST for a channel that the remote side
5445 * already thinks it's closed; there's no point, since it won't
5446 * be sending any more data anyway.
5447 */
5448 if (c->closes != 0)
5449 return;
5450
d252310a 5451 /*
5452 * Only send a WINDOW_ADJUST if there's significantly more window
5453 * available than the other end thinks there is. This saves us
5454 * sending a WINDOW_ADJUST for every character in a shell session.
5455 *
5456 * "Significant" is arbitrarily defined as half the window size.
5457 */
5458 if (newwin > c->v.v2.locwindow * 2) {
ff3187f6 5459 struct Packet *pktout;
5460
5461 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5462 ssh2_pkt_adduint32(pktout, c->remoteid);
5463 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5464 ssh2_pkt_send(ssh, pktout);
5471d09a 5465 c->v.v2.locwindow = newwin;
783415f8 5466 }
5467}
5468
51df0ab5 5469static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 5470{
5471 unsigned i = ssh_pkt_getuint32(pktin);
5472 struct ssh_channel *c;
5473 c = find234(ssh->channels, &i, ssh_channelfind);
5474 if (c && !c->closes)
5475 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5476}
5477
51df0ab5 5478static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5479{
5480 char *data;
aa63ab7e 5481 unsigned int length;
51df0ab5 5482 unsigned i = ssh_pkt_getuint32(pktin);
5483 struct ssh_channel *c;
5484 c = find234(ssh->channels, &i, ssh_channelfind);
5485 if (!c)
5486 return; /* nonexistent channel */
5487 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5488 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5489 return; /* extended but not stderr */
5490 ssh_pkt_getstring(pktin, &data, &length);
5491 if (data) {
5492 int bufsize = 0;
5493 c->v.v2.locwindow -= length;
5494 switch (c->type) {
5495 case CHAN_MAINSESSION:
5496 bufsize =
5497 from_backend(ssh->frontend, pktin->type ==
5498 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5499 data, length);
5500 break;
5501 case CHAN_X11:
5502 bufsize = x11_send(c->u.x11.s, data, length);
5503 break;
5504 case CHAN_SOCKDATA:
5505 bufsize = pfd_send(c->u.pfd.s, data, length);
5506 break;
5507 case CHAN_AGENT:
5508 while (length > 0) {
5509 if (c->u.a.lensofar < 4) {
aa63ab7e 5510 unsigned int l = min(4 - c->u.a.lensofar, length);
51df0ab5 5511 memcpy(c->u.a.msglen + c->u.a.lensofar,
5512 data, l);
5513 data += l;
5514 length -= l;
5515 c->u.a.lensofar += l;
5516 }
5517 if (c->u.a.lensofar == 4) {
5518 c->u.a.totallen =
5519 4 + GET_32BIT(c->u.a.msglen);
5520 c->u.a.message = snewn(c->u.a.totallen,
5521 unsigned char);
5522 memcpy(c->u.a.message, c->u.a.msglen, 4);
5523 }
5524 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 5525 unsigned int l =
51df0ab5 5526 min(c->u.a.totallen - c->u.a.lensofar,
5527 length);
5528 memcpy(c->u.a.message + c->u.a.lensofar,
5529 data, l);
5530 data += l;
5531 length -= l;
5532 c->u.a.lensofar += l;
5533 }
5534 if (c->u.a.lensofar == c->u.a.totallen) {
5535 void *reply;
5536 int replylen;
5537 if (agent_query(c->u.a.message,
5538 c->u.a.totallen,
5539 &reply, &replylen,
5540 ssh_agentf_callback, c))
5541 ssh_agentf_callback(c, reply, replylen);
5542 sfree(c->u.a.message);
5543 c->u.a.lensofar = 0;
5544 }
5545 }
5546 bufsize = 0;
5547 break;
5548 }
5549 /*
5550 * If we are not buffering too much data,
5551 * enlarge the window again at the remote side.
5552 */
5553 if (bufsize < OUR_V2_WINSIZE)
5554 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5555 }
5556}
5557
5558static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5559{
5560 unsigned i = ssh_pkt_getuint32(pktin);
5561 struct ssh_channel *c;
5562
5563 c = find234(ssh->channels, &i, ssh_channelfind);
5564 if (!c)
5565 return; /* nonexistent channel */
5566
5567 if (c->type == CHAN_X11) {
5568 /*
5569 * Remote EOF on an X11 channel means we should
5570 * wrap up and close the channel ourselves.
5571 */
5572 x11_close(c->u.x11.s);
5573 sshfwd_close(c);
5574 } else if (c->type == CHAN_AGENT) {
5575 sshfwd_close(c);
5576 } else if (c->type == CHAN_SOCKDATA) {
5577 pfd_close(c->u.pfd.s);
5578 sshfwd_close(c);
5579 }
5580}
5581
5582static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5583{
5584 unsigned i = ssh_pkt_getuint32(pktin);
5585 struct ssh_channel *c;
5586 struct Packet *pktout;
5587
5588 c = find234(ssh->channels, &i, ssh_channelfind);
5589 if (!c || ((int)c->remoteid) == -1) {
5590 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5591 c ? "half-open" : "nonexistent", i));
5592 return;
5593 }
5594 /* Do pre-close processing on the channel. */
5595 switch (c->type) {
5596 case CHAN_MAINSESSION:
5597 ssh->mainchan = NULL;
5598 update_specials_menu(ssh->frontend);
5599 break;
5600 case CHAN_X11:
5601 if (c->u.x11.s != NULL)
5602 x11_close(c->u.x11.s);
5603 sshfwd_close(c);
5604 break;
5605 case CHAN_AGENT:
5606 sshfwd_close(c);
5607 break;
5608 case CHAN_SOCKDATA:
5609 if (c->u.pfd.s != NULL)
5610 pfd_close(c->u.pfd.s);
5611 sshfwd_close(c);
5612 break;
5613 }
5614 if (c->closes == 0) {
5615 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5616 ssh2_pkt_adduint32(pktout, c->remoteid);
5617 ssh2_pkt_send(ssh, pktout);
5618 }
5619 del234(ssh->channels, c);
5620 bufchain_clear(&c->v.v2.outbuffer);
5621 sfree(c);
5622
5623 /*
5624 * See if that was the last channel left open.
5625 * (This is only our termination condition if we're
5626 * not running in -N mode.)
5627 */
5628 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5629 logevent("All channels closed. Disconnecting");
5630#if 0
5631 /*
5632 * We used to send SSH_MSG_DISCONNECT here,
5633 * because I'd believed that _every_ conforming
5634 * SSH2 connection had to end with a disconnect
5635 * being sent by at least one side; apparently
5636 * I was wrong and it's perfectly OK to
5637 * unceremoniously slam the connection shut
5638 * when you're done, and indeed OpenSSH feels
5639 * this is more polite than sending a
5640 * DISCONNECT. So now we don't.
5641 */
5642 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5643 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5644 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5645 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5646 ssh2_pkt_send_noqueue(ssh, s->pktout);
5647#endif
ac934965 5648 ssh->close_expected = TRUE;
51df0ab5 5649 ssh_closing((Plug)ssh, NULL, 0, 0);
5650 }
5651}
5652
5653static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5654{
5655 unsigned i = ssh_pkt_getuint32(pktin);
5656 struct ssh_channel *c;
5657 struct Packet *pktout;
5658
5659 c = find234(ssh->channels, &i, ssh_channelfind);
5660 if (!c)
5661 return; /* nonexistent channel */
5662 if (c->type != CHAN_SOCKDATA_DORMANT)
5663 return; /* dunno why they're confirming this */
5664 c->remoteid = ssh_pkt_getuint32(pktin);
5665 c->type = CHAN_SOCKDATA;
5666 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5667 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5668 if (c->u.pfd.s)
5669 pfd_confirm(c->u.pfd.s);
5670 if (c->closes) {
5671 /*
5672 * We have a pending close on this channel,
5673 * which we decided on before the server acked
5674 * the channel open. So now we know the
5675 * remoteid, we can close it again.
5676 */
5677 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5678 ssh2_pkt_adduint32(pktout, c->remoteid);
5679 ssh2_pkt_send(ssh, pktout);
5680 }
5681}
5682
5683static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5684{
5685 static const char *const reasons[] = {
5686 "<unknown reason code>",
5687 "Administratively prohibited",
5688 "Connect failed",
5689 "Unknown channel type",
5690 "Resource shortage",
5691 };
5692 unsigned i = ssh_pkt_getuint32(pktin);
5693 unsigned reason_code;
5694 char *reason_string;
5695 int reason_length;
5696 char *message;
5697 struct ssh_channel *c;
5698 c = find234(ssh->channels, &i, ssh_channelfind);
5699 if (!c)
5700 return; /* nonexistent channel */
5701 if (c->type != CHAN_SOCKDATA_DORMANT)
5702 return; /* dunno why they're failing this */
5703
5704 reason_code = ssh_pkt_getuint32(pktin);
5705 if (reason_code >= lenof(reasons))
5706 reason_code = 0; /* ensure reasons[reason_code] in range */
5707 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5708 message = dupprintf("Forwarded connection refused by"
5709 " server: %s [%.*s]", reasons[reason_code],
5710 reason_length, reason_string);
5711 logevent(message);
5712 sfree(message);
5713
5714 pfd_close(c->u.pfd.s);
5715
5716 del234(ssh->channels, c);
5717 sfree(c);
5718}
5719
5720static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5721{
5722 unsigned localid;
5723 char *type;
5724 int typelen, want_reply;
5725 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5726 struct ssh_channel *c;
5727 struct Packet *pktout;
5728
5729 localid = ssh_pkt_getuint32(pktin);
5730 ssh_pkt_getstring(pktin, &type, &typelen);
5731 want_reply = ssh2_pkt_getbool(pktin);
5732
5733 /*
5734 * First, check that the channel exists. Otherwise,
5735 * we can instantly disconnect with a rude message.
5736 */
5737 c = find234(ssh->channels, &localid, ssh_channelfind);
5738 if (!c) {
5739 char buf[80];
5740 sprintf(buf, "Received channel request for nonexistent"
5741 " channel %d", localid);
5742 logevent(buf);
5743 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5744 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5745 ssh2_pkt_addstring(pktout, buf);
5746 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5747 ssh2_pkt_send_noqueue(ssh, pktout);
5748 connection_fatal(ssh->frontend, "%s", buf);
ac934965 5749 ssh->close_expected = TRUE;
51df0ab5 5750 ssh_closing((Plug)ssh, NULL, 0, 0);
5751 return;
5752 }
5753
5754 /*
5755 * Having got the channel number, we now look at
5756 * the request type string to see if it's something
5757 * we recognise.
5758 */
5759 if (c == ssh->mainchan) {
5760 /*
5761 * We recognise "exit-status" and "exit-signal" on
5762 * the primary channel.
5763 */
5764 if (typelen == 11 &&
5765 !memcmp(type, "exit-status", 11)) {
5766
5767 ssh->exitcode = ssh_pkt_getuint32(pktin);
5768 logeventf(ssh, "Server sent command exit status %d",
5769 ssh->exitcode);
5770 reply = SSH2_MSG_CHANNEL_SUCCESS;
5771
5772 } else if (typelen == 11 &&
5773 !memcmp(type, "exit-signal", 11)) {
5774
5775 int is_plausible = TRUE, is_int = FALSE;
5776 char *fmt_sig = "", *fmt_msg = "";
5777 char *msg;
5778 int msglen = 0, core = FALSE;
5779 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5780 * provide an `int' for the signal, despite its
5781 * having been a `string' in the drafts since at
5782 * least 2001. (Fixed in session.c 1.147.) Try to
5783 * infer which we can safely parse it as. */
5784 {
5785 unsigned char *p = pktin->body +
5786 pktin->savedpos;
5787 long len = pktin->length - pktin->savedpos;
5788 unsigned long num = GET_32BIT(p); /* what is it? */
5789 /* If it's 0, it hardly matters; assume string */
5790 if (num == 0) {
5791 is_int = FALSE;
5792 } else {
5793 int maybe_int = FALSE, maybe_str = FALSE;
5794#define CHECK_HYPOTHESIS(offset, result) \
5795 do { \
5796 long q = offset; \
5797 if (q >= 0 && q+4 <= len) { \
5798 q = q + 4 + GET_32BIT(p+q); \
5799 if (q >= 0 && q+4 <= len && \
5800 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5801 result = TRUE; \
5802 } \
5803 } while(0)
5804 CHECK_HYPOTHESIS(4+1, maybe_int);
5805 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5806#undef CHECK_HYPOTHESIS
5807 if (maybe_int && !maybe_str)
5808 is_int = TRUE;
5809 else if (!maybe_int && maybe_str)
5810 is_int = FALSE;
5811 else
5812 /* Crikey. Either or neither. Panic. */
5813 is_plausible = FALSE;
5814 }
5815 }
5816 if (is_plausible) {
5817 if (is_int) {
5818 /* Old non-standard OpenSSH. */
5819 int signum = ssh_pkt_getuint32(pktin);
5820 fmt_sig = dupprintf(" %d", signum);
5821 } else {
5822 /* As per the drafts. */
5823 char *sig;
5824 int siglen;
5825 ssh_pkt_getstring(pktin, &sig, &siglen);
5826 /* Signal name isn't supposed to be blank, but
5827 * let's cope gracefully if it is. */
5828 if (siglen) {
5829 fmt_sig = dupprintf(" \"%.*s\"",
5830 siglen, sig);
5831 }
5832 }
5833 core = ssh2_pkt_getbool(pktin);
5834 ssh_pkt_getstring(pktin, &msg, &msglen);
5835 if (msglen) {
5836 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5837 }
5838 /* ignore lang tag */
5839 } /* else don't attempt to parse */
5840 logeventf(ssh, "Server exited on signal%s%s%s",
5841 fmt_sig, core ? " (core dumped)" : "",
5842 fmt_msg);
5843 if (*fmt_sig) sfree(fmt_sig);
5844 if (*fmt_msg) sfree(fmt_msg);
5845 reply = SSH2_MSG_CHANNEL_SUCCESS;
5846
5847 }
5848 } else {
5849 /*
5850 * This is a channel request we don't know
5851 * about, so we now either ignore the request
5852 * or respond with CHANNEL_FAILURE, depending
5853 * on want_reply.
5854 */
5855 reply = SSH2_MSG_CHANNEL_FAILURE;
5856 }
5857 if (want_reply) {
5858 pktout = ssh2_pkt_init(reply);
5859 ssh2_pkt_adduint32(pktout, c->remoteid);
5860 ssh2_pkt_send(ssh, pktout);
5861 }
5862}
5863
5864static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5865{
5866 char *type;
5867 int typelen, want_reply;
5868 struct Packet *pktout;
5869
5870 ssh_pkt_getstring(pktin, &type, &typelen);
5871 want_reply = ssh2_pkt_getbool(pktin);
5872
5873 /*
5874 * We currently don't support any global requests
5875 * at all, so we either ignore the request or
5876 * respond with REQUEST_FAILURE, depending on
5877 * want_reply.
5878 */
5879 if (want_reply) {
5880 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5881 ssh2_pkt_send(ssh, pktout);
5882 }
5883}
5884
5885static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5886{
5887 char *type;
5888 int typelen;
5889 char *peeraddr;
5890 int peeraddrlen;
5891 int peerport;
5892 char *error = NULL;
5893 struct ssh_channel *c;
5894 unsigned remid, winsize, pktsize;
5895 struct Packet *pktout;
5896
5897 ssh_pkt_getstring(pktin, &type, &typelen);
5898 c = snew(struct ssh_channel);
5899 c->ssh = ssh;
5900
5901 remid = ssh_pkt_getuint32(pktin);
5902 winsize = ssh_pkt_getuint32(pktin);
5903 pktsize = ssh_pkt_getuint32(pktin);
5904
5905 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5906 char *addrstr;
5907
5908 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5909 addrstr = snewn(peeraddrlen+1, char);
5910 memcpy(addrstr, peeraddr, peeraddrlen);
5911 addrstr[peeraddrlen] = '\0';
5912 peerport = ssh_pkt_getuint32(pktin);
5913
5914 logeventf(ssh, "Received X11 connect request from %s:%d",
5915 addrstr, peerport);
5916
5917 if (!ssh->X11_fwd_enabled)
5918 error = "X11 forwarding is not enabled";
5919 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5920 ssh->x11auth, addrstr, peerport,
5921 &ssh->cfg) != NULL) {
5922 error = "Unable to open an X11 connection";
5923 } else {
5924 logevent("Opening X11 forward connection succeeded");
5925 c->type = CHAN_X11;
5926 }
5927
5928 sfree(addrstr);
5929 } else if (typelen == 15 &&
5930 !memcmp(type, "forwarded-tcpip", 15)) {
5931 struct ssh_rportfwd pf, *realpf;
5932 char *dummy;
5933 int dummylen;
5934 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5935 pf.sport = ssh_pkt_getuint32(pktin);
5936 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5937 peerport = ssh_pkt_getuint32(pktin);
5938 realpf = find234(ssh->rportfwds, &pf, NULL);
5939 logeventf(ssh, "Received remote port %d open request "
5940 "from %s:%d", pf.sport, peeraddr, peerport);
5941 if (realpf == NULL) {
5942 error = "Remote port is not recognised";
5943 } else {
5944 const char *e = pfd_newconnect(&c->u.pfd.s,
5945 realpf->dhost,
5946 realpf->dport, c,
05581745 5947 &ssh->cfg,
5948 realpf->pfrec->addressfamily);
51df0ab5 5949 logeventf(ssh, "Attempting to forward remote port to "
5950 "%s:%d", realpf->dhost, realpf->dport);
5951 if (e != NULL) {
5952 logeventf(ssh, "Port open failed: %s", e);
5953 error = "Port open failed";
5954 } else {
5955 logevent("Forwarded port opened successfully");
5956 c->type = CHAN_SOCKDATA;
5957 }
5958 }
5959 } else if (typelen == 22 &&
5960 !memcmp(type, "auth-agent@openssh.com", 3)) {
5961 if (!ssh->agentfwd_enabled)
5962 error = "Agent forwarding is not enabled";
5963 else {
5964 c->type = CHAN_AGENT; /* identify channel type */
5965 c->u.a.lensofar = 0;
5966 }
5967 } else {
5968 error = "Unsupported channel type requested";
5969 }
5970
5971 c->remoteid = remid;
5972 if (error) {
5973 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5974 ssh2_pkt_adduint32(pktout, c->remoteid);
5975 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5976 ssh2_pkt_addstring(pktout, error);
5977 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5978 ssh2_pkt_send(ssh, pktout);
5979 logeventf(ssh, "Rejected channel open: %s", error);
5980 sfree(c);
5981 } else {
5982 c->localid = alloc_channel_id(ssh);
5983 c->closes = 0;
5984 c->v.v2.locwindow = OUR_V2_WINSIZE;
5985 c->v.v2.remwindow = winsize;
5986 c->v.v2.remmaxpkt = pktsize;
5987 bufchain_init(&c->v.v2.outbuffer);
5988 add234(ssh->channels, c);
5989 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5990 ssh2_pkt_adduint32(pktout, c->remoteid);
5991 ssh2_pkt_adduint32(pktout, c->localid);
5992 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
954d5c5a 5993 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
51df0ab5 5994 ssh2_pkt_send(ssh, pktout);
5995 }
5996}
5997
783415f8 5998/*
7cca0d81 5999 * Handle the SSH2 userauth and connection layers.
6000 */
ff3187f6 6001static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6002 struct Packet *pktin)
7cca0d81 6003{
51470298 6004 struct do_ssh2_authconn_state {
6005 enum {
6006 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6007 AUTH_PASSWORD,
6008 AUTH_KEYBOARD_INTERACTIVE
6009 } method;
6010 enum {
6011 AUTH_TYPE_NONE,
6012 AUTH_TYPE_PUBLICKEY,
6013 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6014 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6015 AUTH_TYPE_PASSWORD,
6016 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6017 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6018 } type;
6019 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6ac3a551 6020 int tried_pubkey_config, tried_agent;
6021 int kbd_inter_running, kbd_inter_refused;
51470298 6022 int we_are_in;
6023 int num_prompts, curr_prompt, echo;
6024 char username[100];
6025 int got_username;
85fdbe25 6026 char pwprompt[512];
51470298 6027 char password[100];
6028 void *publickey_blob;
6029 int publickey_bloblen;
6030 unsigned char request[5], *response, *p;
6031 int responselen;
6032 int keyi, nkeys;
6033 int authed;
6034 char *pkblob, *alg, *commentp;
6035 int pklen, alglen, commentlen;
6036 int siglen, retlen, len;
6037 char *q, *agentreq, *ret;
6038 int try_send;
73feed4f 6039 int num_env, env_left, env_ok;
ff3187f6 6040 struct Packet *pktout;
51470298 6041 };
6042 crState(do_ssh2_authconn_state);
6043
6044 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 6045
7cca0d81 6046 /*
6047 * Request userauth protocol, and await a response to it.
6048 */
ff3187f6 6049 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6050 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6051 ssh2_pkt_send(ssh, s->pktout);
6052 crWaitUntilV(pktin);
6053 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 6054 bombout(("Server refused user authentication protocol"));
7ffdbc1a 6055 crStopV;
8d5de777 6056 }
7cca0d81 6057
6058 /*
1408a877 6059 * We repeat this whole loop, including the username prompt,
6060 * until we manage a successful authentication. If the user
51470298 6061 * types the wrong _password_, they can be sent back to the
6062 * beginning to try another username, if this is configured on.
6063 * (If they specify a username in the config, they are never
6064 * asked, even if they do give a wrong password.)
1408a877 6065 *
6066 * I think this best serves the needs of
6067 *
6068 * - the people who have no configuration, no keys, and just
6069 * want to try repeated (username,password) pairs until they
6070 * type both correctly
6071 *
6072 * - people who have keys and configuration but occasionally
6073 * need to fall back to passwords
6074 *
6075 * - people with a key held in Pageant, who might not have
6076 * logged in to a particular machine before; so they want to
6077 * type a username, and then _either_ their key will be
6078 * accepted, _or_ they will type a password. If they mistype
6079 * the username they will want to be able to get back and
6080 * retype it!
7cca0d81 6081 */
51470298 6082 s->username[0] = '\0';
6083 s->got_username = FALSE;
1408a877 6084 do {
1408a877 6085 /*
6086 * Get a username.
6087 */
86916870 6088 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 6089 /*
6090 * We got a username last time round this loop, and
6091 * with change_username turned off we don't try to get
6092 * it again.
6093 */
aa09f7d0 6094 } else if (!*ssh->cfg.username) {
c0a81592 6095 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 6096 if (!ssh_get_line("login as: ",
51470298 6097 s->username, sizeof(s->username), FALSE)) {
32874aea 6098 /*
6099 * get_line failed to get a username.
6100 * Terminate.
6101 */
6102 logevent("No username provided. Abandoning session.");
ac934965 6103 ssh->close_expected = TRUE;
3bb2f322 6104 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6105 crStopV;
32874aea 6106 }
6107 } else {
51470298 6108 int ret; /* need not be saved across crReturn */
6109 c_write_str(ssh, "login as: ");
6110 ssh->send_ok = 1;
6111 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 6112 do {
ff3187f6 6113 crWaitUntilV(!pktin);
51470298 6114 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6115 } while (ret == 0);
6116 if (ret < 0)
6117 cleanup_exit(0);
4ca0c9d1 6118 c_write_str(ssh, "\r\n");
32874aea 6119 }
51470298 6120 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 6121 } else {
57356d63 6122 char *stuff;
86916870 6123 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 6124 s->username[sizeof(s->username)-1] = '\0';
65a22376 6125 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 6126 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 6127 c_write_str(ssh, stuff);
57356d63 6128 sfree(stuff);
7cca0d81 6129 }
6130 }
51470298 6131 s->got_username = TRUE;
7cca0d81 6132
65a22376 6133 /*
1408a877 6134 * Send an authentication request using method "none": (a)
6135 * just in case it succeeds, and (b) so that we know what
6136 * authentication methods we can usefully try next.
65a22376 6137 */
51470298 6138 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6139
ff3187f6 6140 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6141 ssh2_pkt_addstring(s->pktout, s->username);
6142 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6143 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6144 ssh2_pkt_send(ssh, s->pktout);
51470298 6145 s->type = AUTH_TYPE_NONE;
6146 s->gotit = FALSE;
6147 s->we_are_in = FALSE;
6148
6149 s->tried_pubkey_config = FALSE;
6150 s->tried_agent = FALSE;
51470298 6151 s->kbd_inter_running = FALSE;
6ac3a551 6152 s->kbd_inter_refused = FALSE;
86916870 6153 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 6154 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 6155 int keytype;
6c6d9ed9 6156 logeventf(ssh, "Reading private key file \"%.150s\"",
6157 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 6158 keytype = key_type(&ssh->cfg.keyfile);
51470298 6159 if (keytype == SSH_KEYTYPE_SSH2) {
6160 s->publickey_blob =
9a30e26b 6161 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 6162 &s->publickey_bloblen, NULL);
51470298 6163 } else {
57356d63 6164 char *msgbuf;
c2ad7d0d 6165 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 6166 key_type_to_str(keytype));
57356d63 6167 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 6168 " (%s)\r\n",
6169 filename_to_str(&ssh->cfg.keyfile),
57356d63 6170 key_type_to_str(keytype));
51470298 6171 c_write_str(ssh, msgbuf);
57356d63 6172 sfree(msgbuf);
51470298 6173 s->publickey_blob = NULL;
231ee168 6174 }
396778f1 6175 } else
51470298 6176 s->publickey_blob = NULL;
65a22376 6177
1408a877 6178 while (1) {
6179 /*
6180 * Wait for the result of the last authentication request.
6181 */
51470298 6182 if (!s->gotit)
ff3187f6 6183 crWaitUntilV(pktin);
6184 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 6185 char *banner;
6186 int size;
6187 /*
6188 * Don't show the banner if we're operating in
6189 * non-verbose non-interactive mode. (It's probably
6190 * a script, which means nobody will read the
6191 * banner _anyway_, and moreover the printing of
6192 * the banner will screw up processing on the
6193 * output of (say) plink.)
6194 */
6195 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
ff3187f6 6196 ssh_pkt_getstring(pktin, &banner, &size);
32874aea 6197 if (banner)
51470298 6198 c_write_untrusted(ssh, banner, size);
32874aea 6199 }
ff3187f6 6200 crWaitUntilV(pktin);
1408a877 6201 }
ff3187f6 6202 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 6203 logevent("Access granted");
51470298 6204 s->we_are_in = TRUE;
1408a877 6205 break;
6206 }
65a22376 6207
51470298 6208 if (s->kbd_inter_running &&
ff3187f6 6209 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 6210 /*
45068b27 6211 * This is either a further set-of-prompts packet
6212 * in keyboard-interactive authentication, or it's
6213 * the same one and we came back here with `gotit'
6214 * set. In the former case, we must reset the
6215 * curr_prompt variable.
b3186d64 6216 */
51470298 6217 if (!s->gotit)
6218 s->curr_prompt = 0;
4c6e53e3 6219 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6220 /* FIXME: perhaps we should support this? */
6221 bombout(("PASSWD_CHANGEREQ not yet supported"));
6222 crStopV;
ff3187f6 6223 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 6224 bombout(("Strange packet received during authentication: type %d",
ff3187f6 6225 pktin->type));
7ffdbc1a 6226 crStopV;
65a22376 6227 }
6228
51470298 6229 s->gotit = FALSE;
65a22376 6230
1408a877 6231 /*
6232 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6233 * we can look at the string in it and know what we can
6234 * helpfully try next.
6235 */
ff3187f6 6236 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 6237 char *methods;
6238 int methlen;
ff3187f6 6239 ssh_pkt_getstring(pktin, &methods, &methlen);
51470298 6240 s->kbd_inter_running = FALSE;
ff3187f6 6241 if (!ssh2_pkt_getbool(pktin)) {
1408a877 6242 /*
6243 * We have received an unequivocal Access
6244 * Denied. This can translate to a variety of
6245 * messages:
6246 *
6247 * - if we'd just tried "none" authentication,
6248 * it's not worth printing anything at all
6249 *
6250 * - if we'd just tried a public key _offer_,
6251 * the message should be "Server refused our
6252 * key" (or no message at all if the key
6253 * came from Pageant)
6254 *
6255 * - if we'd just tried anything else, the
6256 * message really should be "Access denied".
6257 *
6258 * Additionally, if we'd just tried password
6259 * authentication, we should break out of this
6260 * whole loop so as to go back to the username
91f57d1f 6261 * prompt (iff we're configured to allow
6262 * username change attempts).
1408a877 6263 */
51470298 6264 if (s->type == AUTH_TYPE_NONE) {
1408a877 6265 /* do nothing */
51470298 6266 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6267 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6268 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6269 c_write_str(ssh, "Server refused our key\r\n");
1408a877 6270 logevent("Server refused public key");
51470298 6271 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 6272 /* server declined keyboard-interactive; ignore */
1408a877 6273 } else {
51470298 6274 c_write_str(ssh, "Access denied\r\n");
1408a877 6275 logevent("Access denied");
91f57d1f 6276 if (s->type == AUTH_TYPE_PASSWORD &&
6277 ssh->cfg.change_username) {
6c9dce7c 6278 /* XXX perhaps we should allow
6279 * keyboard-interactive to do this too? */
51470298 6280 s->we_are_in = FALSE;
1408a877 6281 break;
6282 }
6283 }
6284 } else {
51470298 6285 c_write_str(ssh, "Further authentication required\r\n");
1408a877 6286 logevent("Further authentication required");
6287 }
65a22376 6288
51470298 6289 s->can_pubkey =
32874aea 6290 in_commasep_string("publickey", methods, methlen);
51470298 6291 s->can_passwd =
32874aea 6292 in_commasep_string("password", methods, methlen);
86916870 6293 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 6294 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 6295 }
65a22376 6296
51470298 6297 s->method = 0;
6298 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 6299 s->need_pw = FALSE;
65a22376 6300
0405e71f 6301 /*
6302 * Most password/passphrase prompts will be
6303 * non-echoing, so we set this to 0 by default.
6304 * Exception is that some keyboard-interactive prompts
6305 * can be echoing, in which case we'll set this to 1.
6306 */
51470298 6307 s->echo = 0;
0405e71f 6308
51470298 6309 if (!s->method && s->can_pubkey &&
6310 agent_exists() && !s->tried_agent) {
1983e559 6311 /*
6312 * Attempt public-key authentication using Pageant.
6313 */
1983e559 6314 void *r;
51470298 6315 s->authed = FALSE;
1983e559 6316
51470298 6317 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6318 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6319
51470298 6320 s->tried_agent = TRUE;
1983e559 6321
6322 logevent("Pageant is running. Requesting keys.");
6323
6324 /* Request the keys held by the agent. */
51470298 6325 PUT_32BIT(s->request, 1);
6326 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 6327 if (!agent_query(s->request, 5, &r, &s->responselen,
6328 ssh_agent_callback, ssh)) {
6329 do {
6330 crReturnV;
ff3187f6 6331 if (pktin) {
839f10db 6332 bombout(("Unexpected data from server while"
6333 " waiting for agent response"));
6334 crStopV;
6335 }
ff3187f6 6336 } while (pktin || inlen > 0);
839f10db 6337 r = ssh->agent_response;
6338 s->responselen = ssh->agent_response_len;
6339 }
51470298 6340 s->response = (unsigned char *) r;
6341 if (s->response && s->responselen >= 5 &&
6342 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6343 s->p = s->response + 5;
6344 s->nkeys = GET_32BIT(s->p);
6345 s->p += 4;
32874aea 6346 {
6347 char buf[64];
51470298 6348 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 6349 logevent(buf);
6350 }
51470298 6351 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 6352 void *vret;
1983e559 6353
32874aea 6354 {
6355 char buf[64];
51470298 6356 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 6357 logevent(buf);
6358 }
51470298 6359 s->pklen = GET_32BIT(s->p);
6360 s->p += 4;
6361 if (s->publickey_blob &&
6362 s->pklen == s->publickey_bloblen &&
6363 !memcmp(s->p, s->publickey_blob,
6364 s->publickey_bloblen)) {
396778f1 6365 logevent("This key matches configured key file");
51470298 6366 s->tried_pubkey_config = 1;
396778f1 6367 }
d8baa528 6368 s->pkblob = (char *)s->p;
51470298 6369 s->p += s->pklen;
6370 s->alglen = GET_32BIT(s->pkblob);
6371 s->alg = s->pkblob + 4;
6372 s->commentlen = GET_32BIT(s->p);
6373 s->p += 4;
d8baa528 6374 s->commentp = (char *)s->p;
51470298 6375 s->p += s->commentlen;
ff3187f6 6376 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6377 ssh2_pkt_addstring(s->pktout, s->username);
6378 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6379 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6380 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6381 ssh2_pkt_addstring_start(s->pktout);
6382 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6383 ssh2_pkt_addstring_start(s->pktout);
6384 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6385 ssh2_pkt_send(ssh, s->pktout);
6386
6387 crWaitUntilV(pktin);
6388 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 6389 logevent("Key refused");
6390 continue;
6391 }
6392
32874aea 6393 if (flags & FLAG_VERBOSE) {
51470298 6394 c_write_str(ssh, "Authenticating with "
6395 "public key \"");
6396 c_write(ssh, s->commentp, s->commentlen);
6397 c_write_str(ssh, "\" from agent\r\n");
32874aea 6398 }
1983e559 6399
6400 /*
6401 * Server is willing to accept the key.
6402 * Construct a SIGN_REQUEST.
6403 */
ff3187f6 6404 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6405 ssh2_pkt_addstring(s->pktout, s->username);
6406 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6407 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6408 ssh2_pkt_addbool(s->pktout, TRUE);
6409 ssh2_pkt_addstring_start(s->pktout);
6410 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6411 ssh2_pkt_addstring_start(s->pktout);
6412 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6413
6414 s->siglen = s->pktout->length - 5 + 4 + 20;
dda87a28 6415 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6416 s->siglen -= 4;
51470298 6417 s->len = 1; /* message type */
6418 s->len += 4 + s->pklen; /* key blob */
6419 s->len += 4 + s->siglen; /* data to sign */
6420 s->len += 4; /* flags */
3d88e64d 6421 s->agentreq = snewn(4 + s->len, char);
51470298 6422 PUT_32BIT(s->agentreq, s->len);
6423 s->q = s->agentreq + 4;
6424 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6425 PUT_32BIT(s->q, s->pklen);
6426 s->q += 4;
6427 memcpy(s->q, s->pkblob, s->pklen);
6428 s->q += s->pklen;
6429 PUT_32BIT(s->q, s->siglen);
6430 s->q += 4;
1983e559 6431 /* Now the data to be signed... */
dda87a28 6432 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6433 PUT_32BIT(s->q, 20);
6434 s->q += 4;
6435 }
51470298 6436 memcpy(s->q, ssh->v2_session_id, 20);
6437 s->q += 20;
ff3187f6 6438 memcpy(s->q, s->pktout->data + 5,
6439 s->pktout->length - 5);
6440 s->q += s->pktout->length - 5;
1983e559 6441 /* And finally the (zero) flags word. */
51470298 6442 PUT_32BIT(s->q, 0);
839f10db 6443 if (!agent_query(s->agentreq, s->len + 4,
6444 &vret, &s->retlen,
6445 ssh_agent_callback, ssh)) {
6446 do {
6447 crReturnV;
ff3187f6 6448 if (pktin) {
839f10db 6449 bombout(("Unexpected data from server"
6450 " while waiting for agent"
6451 " response"));
6452 crStopV;
6453 }
ff3187f6 6454 } while (pktin || inlen > 0);
839f10db 6455 vret = ssh->agent_response;
6456 s->retlen = ssh->agent_response_len;
6457 }
51470298 6458 s->ret = vret;
6459 sfree(s->agentreq);
6460 if (s->ret) {
6461 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 6462 logevent("Sending Pageant's response");
ff3187f6 6463 ssh2_add_sigblob(ssh, s->pktout,
6464 s->pkblob, s->pklen,
51470298 6465 s->ret + 9,
6466 GET_32BIT(s->ret + 5));
ff3187f6 6467 ssh2_pkt_send(ssh, s->pktout);
51470298 6468 s->authed = TRUE;
1983e559 6469 break;
6470 } else {
32874aea 6471 logevent
6472 ("Pageant failed to answer challenge");
51470298 6473 sfree(s->ret);
1983e559 6474 }
6475 }
6476 }
51470298 6477 if (s->authed)
1983e559 6478 continue;
6479 }
29b1d0b3 6480 sfree(s->response);
1983e559 6481 }
6482
51470298 6483 if (!s->method && s->can_pubkey && s->publickey_blob
6484 && !s->tried_pubkey_config) {
1408a877 6485 unsigned char *pub_blob;
6486 char *algorithm, *comment;
6487 int pub_blob_len;
65a22376 6488
51470298 6489 s->tried_pubkey_config = TRUE;
65a22376 6490
51470298 6491 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6492 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6493
65a22376 6494 /*
1408a877 6495 * Try the public key supplied in the configuration.
6496 *
6497 * First, offer the public blob to see if the server is
6498 * willing to accept it.
65a22376 6499 */
d8baa528 6500 pub_blob =
9a30e26b 6501 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 6502 &algorithm,
222d54dc 6503 &pub_blob_len,
6504 NULL);
1408a877 6505 if (pub_blob) {
ff3187f6 6506 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6507 ssh2_pkt_addstring(s->pktout, s->username);
6508 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6509 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6510 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6511 ssh2_pkt_addstring(s->pktout, algorithm);
6512 ssh2_pkt_addstring_start(s->pktout);
6513 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
d8baa528 6514 pub_blob_len);
ff3187f6 6515 ssh2_pkt_send(ssh, s->pktout);
a03c9f9c 6516 logevent("Offered public key");
1408a877 6517
ff3187f6 6518 crWaitUntilV(pktin);
6519 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
51470298 6520 s->gotit = TRUE;
6521 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 6522 continue; /* key refused; give up on it */
1408a877 6523 }
65a22376 6524
1408a877 6525 logevent("Offer of public key accepted");
65a22376 6526 /*
1408a877 6527 * Actually attempt a serious authentication using
6528 * the key.
65a22376 6529 */
9a30e26b 6530 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 6531 sprintf(s->pwprompt,
32874aea 6532 "Passphrase for key \"%.100s\": ",
6533 comment);
51470298 6534 s->need_pw = TRUE;
1408a877 6535 } else {
51470298 6536 s->need_pw = FALSE;
1408a877 6537 }
4e520718 6538 if (flags & FLAG_VERBOSE) {
6539 c_write_str(ssh, "Authenticating with public key \"");
6540 c_write_str(ssh, comment);
6541 c_write_str(ssh, "\"\r\n");
6542 }
51470298 6543 s->method = AUTH_PUBLICKEY_FILE;
65a22376 6544 }
1408a877 6545 }
6546
6f64ce13 6547 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6548 !s->kbd_inter_running) {
51470298 6549 s->method = AUTH_KEYBOARD_INTERACTIVE;
6550 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6551
51470298 6552 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6553 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6554
ff3187f6 6555 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6556 ssh2_pkt_addstring(s->pktout, s->username);
6557 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6558 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6559 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6560 ssh2_pkt_addstring(s->pktout, "");
6561 ssh2_pkt_send(ssh, s->pktout);
6562
6563 crWaitUntilV(pktin);
6564 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6565 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
51470298 6566 s->gotit = TRUE;
af659722 6567 logevent("Keyboard-interactive authentication refused");
51470298 6568 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6ac3a551 6569 s->kbd_inter_refused = TRUE; /* don't try it again */
af659722 6570 continue;
6571 }
6572
51470298 6573 s->kbd_inter_running = TRUE;
6574 s->curr_prompt = 0;
af659722 6575 }
6576
51470298 6577 if (s->kbd_inter_running) {
6578 s->method = AUTH_KEYBOARD_INTERACTIVE;
6579 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
af659722 6580
51470298 6581 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6582 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6583
51470298 6584 if (s->curr_prompt == 0) {
45068b27 6585 /*
6586 * We've got a fresh USERAUTH_INFO_REQUEST.
6587 * Display header data, and start going through
6588 * the prompts.
6589 */
6590 char *name, *inst, *lang;
6591 int name_len, inst_len, lang_len;
6592
ff3187f6 6593 ssh_pkt_getstring(pktin, &name, &name_len);
6594 ssh_pkt_getstring(pktin, &inst, &inst_len);
6595 ssh_pkt_getstring(pktin, &lang, &lang_len);
45068b27 6596 if (name_len > 0) {
51470298 6597 c_write_untrusted(ssh, name, name_len);
6598 c_write_str(ssh, "\r\n");
45068b27 6599 }
6600 if (inst_len > 0) {
51470298 6601 c_write_untrusted(ssh, inst, inst_len);
6602 c_write_str(ssh, "\r\n");
45068b27 6603 }
ff3187f6 6604 s->num_prompts = ssh_pkt_getuint32(pktin);
45068b27 6605 }
af659722 6606
45068b27 6607 /*
6608 * If there are prompts remaining in the packet,
6609 * display one and get a response.
6610 */
51470298 6611 if (s->curr_prompt < s->num_prompts) {
45068b27 6612 char *prompt;
6613 int prompt_len;
af659722 6614
ff3187f6 6615 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
45068b27 6616 if (prompt_len > 0) {
85fdbe25 6617 static const char trunc[] = "<prompt truncated>: ";
6618 static const int prlen = sizeof(s->pwprompt) -
6619 lenof(trunc);
6620 if (prompt_len > prlen) {
6621 memcpy(s->pwprompt, prompt, prlen);
6622 strcpy(s->pwprompt + prlen, trunc);
6623 } else {
6624 memcpy(s->pwprompt, prompt, prompt_len);
6625 s->pwprompt[prompt_len] = '\0';
6626 }
45068b27 6627 } else {
51470298 6628 strcpy(s->pwprompt,
45068b27 6629 "<server failed to send prompt>: ");
6630 }
ff3187f6 6631 s->echo = ssh2_pkt_getbool(pktin);
51470298 6632 s->need_pw = TRUE;
45068b27 6633 } else
51470298 6634 s->need_pw = FALSE;
af659722 6635 }
6636
51470298 6637 if (!s->method && s->can_passwd) {
6638 s->method = AUTH_PASSWORD;
6639 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6640 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6641 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6642 ssh->savedhost);
6643 s->need_pw = TRUE;
1408a877 6644 }
6645
51470298 6646 if (s->need_pw) {
fa17a66e 6647 if (ssh_get_line) {
51470298 6648 if (!ssh_get_line(s->pwprompt, s->password,
6649 sizeof(s->password), TRUE)) {
1408a877 6650 /*
fa17a66e 6651 * get_line failed to get a password (for
6652 * example because one was supplied on the
6653 * command line which has already failed to
6654 * work). Terminate.
1408a877 6655 */
ff3187f6 6656 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6657 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6658 ssh2_pkt_addstring(s->pktout, "No more passwords available"
51470298 6659 " to try");
ff3187f6 6660 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6661 ssh2_pkt_send_noqueue(ssh, s->pktout);
247308b5 6662 logevent("Unable to authenticate");
a8327734 6663 connection_fatal(ssh->frontend,
6664 "Unable to authenticate");
ac934965 6665 ssh->close_expected = TRUE;
3bb2f322 6666 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6667 crStopV;
1408a877 6668 }
6669 } else {
51470298 6670 int ret; /* need not be saved across crReturn */
6671 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6672 ssh->send_ok = 1;
1408a877 6673
51470298 6674 setup_userpass_input(ssh, s->password,
6675 sizeof(s->password), s->echo);
0405e71f 6676 do {
ff3187f6 6677 crWaitUntilV(!pktin);
51470298 6678 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6679 } while (ret == 0);
6680 if (ret < 0)
6681 cleanup_exit(0);
51470298 6682 c_write_str(ssh, "\r\n");
65a22376 6683 }
65a22376 6684 }
65a22376 6685
51470298 6686 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 6687 /*
6688 * We have our passphrase. Now try the actual authentication.
6689 */
6690 struct ssh2_userkey *key;
222d54dc 6691 const char *error = NULL;
65a22376 6692
222d54dc 6693 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6694 &error);
1408a877 6695 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6696 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 6697 c_write_str(ssh, "Wrong passphrase\r\n");
6698 s->tried_pubkey_config = FALSE;
1408a877 6699 } else {
222d54dc 6700 c_write_str(ssh, "Unable to load private key (");
6701 c_write_str(ssh, error);
6702 c_write_str(ssh, ")\r\n");
51470298 6703 s->tried_pubkey_config = TRUE;
1408a877 6704 }
6705 /* Send a spurious AUTH_NONE to return to the top. */
ff3187f6 6706 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6707 ssh2_pkt_addstring(s->pktout, s->username);
6708 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6709 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6710 ssh2_pkt_send(ssh, s->pktout);
51470298 6711 s->type = AUTH_TYPE_NONE;
1408a877 6712 } else {
1dd353b5 6713 unsigned char *pkblob, *sigblob, *sigdata;
6714 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 6715 int p;
65a22376 6716
1408a877 6717 /*
6718 * We have loaded the private key and the server
6719 * has announced that it's willing to accept it.
6720 * Hallelujah. Generate a signature and send it.
6721 */
ff3187f6 6722 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6723 ssh2_pkt_addstring(s->pktout, s->username);
6724 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6725 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6726 ssh2_pkt_addbool(s->pktout, TRUE);
6727 ssh2_pkt_addstring(s->pktout, key->alg->name);
1dd353b5 6728 pkblob = key->alg->public_blob(key->data, &pkblob_len);
ff3187f6 6729 ssh2_pkt_addstring_start(s->pktout);
6730 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
1408a877 6731
6732 /*
6733 * The data to be signed is:
6734 *
6735 * string session-id
6736 *
6737 * followed by everything so far placed in the
6738 * outgoing packet.
6739 */
ff3187f6 6740 sigdata_len = s->pktout->length - 5 + 4 + 20;
dda87a28 6741 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6742 sigdata_len -= 4;
92d60585 6743 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 6744 p = 0;
6745 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6746 PUT_32BIT(sigdata+p, 20);
6747 p += 4;
6748 }
6749 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
ff3187f6 6750 memcpy(sigdata+p, s->pktout->data + 5,
6751 s->pktout->length - 5);
6752 p += s->pktout->length - 5;
dda87a28 6753 assert(p == sigdata_len);
d8baa528 6754 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 6755 sigdata_len, &sigblob_len);
ff3187f6 6756 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 6757 sigblob, sigblob_len);
6758 sfree(pkblob);
6759 sfree(sigblob);
1408a877 6760 sfree(sigdata);
6761
ff3187f6 6762 ssh2_pkt_send(ssh, s->pktout);
51470298 6763 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 6764 key->alg->freekey(key->data);
1408a877 6765 }
51470298 6766 } else if (s->method == AUTH_PASSWORD) {
65a22376 6767 /*
95d2d262 6768 * We pad out the password packet to 256 bytes to make
6769 * it harder for an attacker to find the length of the
6770 * user's password.
1408a877 6771 *
95d2d262 6772 * Anyone using a password longer than 256 bytes
6773 * probably doesn't have much to worry about from
1408a877 6774 * people who find out how long their password is!
65a22376 6775 */
ff3187f6 6776 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
95d2d262 6777 s->pktout->forcepad = 256;
ff3187f6 6778 ssh2_pkt_addstring(s->pktout, s->username);
6779 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6780 ssh2_pkt_addstring(s->pktout, "password");
6781 ssh2_pkt_addbool(s->pktout, FALSE);
6782 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6783 ssh2_pkt_addstring(s->pktout, s->password);
1409c1b3 6784 memset(s->password, 0, sizeof(s->password));
ff3187f6 6785 end_log_omission(ssh, s->pktout);
95d2d262 6786 ssh2_pkt_send(ssh, s->pktout);
0d43337a 6787 logevent("Sent password");
51470298 6788 s->type = AUTH_TYPE_PASSWORD;
6789 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6790 if (s->curr_prompt == 0) {
ff3187f6 6791 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6792 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
45068b27 6793 }
51470298 6794 if (s->need_pw) { /* only add pw if we just got one! */
ff3187f6 6795 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6796 ssh2_pkt_addstring(s->pktout, s->password);
51470298 6797 memset(s->password, 0, sizeof(s->password));
ff3187f6 6798 end_log_omission(ssh, s->pktout);
51470298 6799 s->curr_prompt++;
45068b27 6800 }
51470298 6801 if (s->curr_prompt >= s->num_prompts) {
ff3187f6 6802 ssh2_pkt_send(ssh, s->pktout);
45068b27 6803 } else {
6804 /*
6805 * If there are prompts remaining, we set
6806 * `gotit' so that we won't attempt to get
6807 * another packet. Then we go back round the
6808 * loop and will end up retrieving another
6809 * prompt out of the existing packet. Funky or
6810 * what?
6811 */
51470298 6812 s->gotit = TRUE;
45068b27 6813 }
51470298 6814 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 6815 } else {
51470298 6816 c_write_str(ssh, "No supported authentication methods"
6817 " left to try!\r\n");
6818 logevent("No supported authentications offered."
6819 " Disconnecting");
ff3187f6 6820 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6821 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6822 ssh2_pkt_addstring(s->pktout, "No supported authentication"
51470298 6823 " methods available");
ff3187f6 6824 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6825 ssh2_pkt_send_noqueue(ssh, s->pktout);
ac934965 6826 ssh->close_expected = TRUE;
3bb2f322 6827 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6828 crStopV;
65a22376 6829 }
65a22376 6830 }
51470298 6831 } while (!s->we_are_in);
7cca0d81 6832
6833 /*
6834 * Now we're authenticated for the connection protocol. The
6835 * connection protocol will automatically have started at this
6836 * point; there's no need to send SERVICE_REQUEST.
6837 */
6838
0ed48730 6839 ssh->channels = newtree234(ssh_channelcmp);
6840
7cca0d81 6841 /*
b09eaa88 6842 * Set up handlers for some connection protocol messages, so we
6843 * don't have to handle them repeatedly in this coroutine.
6844 */
6845 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6846 ssh2_msg_channel_window_adjust;
51df0ab5 6847 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6848 ssh2_msg_global_request;
b09eaa88 6849
6850 /*
0ed48730 6851 * Create the main session channel.
7cca0d81 6852 */
0ed48730 6853 if (!ssh->cfg.ssh_no_shell) {
6854 ssh->mainchan = snew(struct ssh_channel);
6855 ssh->mainchan->ssh = ssh;
6856 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 6857 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6858 ssh2_pkt_addstring(s->pktout, "session");
6859 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 6860 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 6861 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
954d5c5a 6862 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 6863 ssh2_pkt_send(ssh, s->pktout);
6864 crWaitUntilV(pktin);
6865 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 6866 bombout(("Server refused to open a session"));
6867 crStopV;
6868 /* FIXME: error data comes back in FAILURE packet */
6869 }
ff3187f6 6870 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 6871 bombout(("Server's channel confirmation cited wrong channel"));
6872 crStopV;
6873 }
ff3187f6 6874 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
0ed48730 6875 ssh->mainchan->type = CHAN_MAINSESSION;
6876 ssh->mainchan->closes = 0;
ff3187f6 6877 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6878 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 6879 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6880 add234(ssh->channels, ssh->mainchan);
62638676 6881 update_specials_menu(ssh->frontend);
0ed48730 6882 logevent("Opened channel for session");
6883 } else
6884 ssh->mainchan = NULL;
7cca0d81 6885
6886 /*
51df0ab5 6887 * Now we have a channel, make dispatch table entries for
6888 * general channel-based messages.
6889 */
6890 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6891 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6892 ssh2_msg_channel_data;
6893 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6894 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6895 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6896 ssh2_msg_channel_open_confirmation;
6897 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6898 ssh2_msg_channel_open_failure;
6899 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6900 ssh2_msg_channel_request;
6901 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6902 ssh2_msg_channel_open;
6903
6904 /*
783415f8 6905 * Potentially enable X11 forwarding.
6906 */
0ed48730 6907 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 6908 char proto[20], data[64];
6909 logevent("Requesting X11 forwarding");
302121de 6910 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 6911 data, sizeof(data), ssh->cfg.x11_auth);
6912 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 6913 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6914 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6915 ssh2_pkt_addstring(s->pktout, "x11-req");
6916 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6917 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6918 ssh2_pkt_addstring(s->pktout, proto);
6919 ssh2_pkt_addstring(s->pktout, data);
6920 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6921 ssh2_pkt_send(ssh, s->pktout);
32874aea 6922
b09eaa88 6923 crWaitUntilV(pktin);
32874aea 6924
ff3187f6 6925 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6926 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6927 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 6928 " packet type %d", pktin->type));
7ffdbc1a 6929 crStopV;
32874aea 6930 }
6931 logevent("X11 forwarding refused");
6932 } else {
6933 logevent("X11 forwarding enabled");
51470298 6934 ssh->X11_fwd_enabled = TRUE;
32874aea 6935 }
783415f8 6936 }
6937
6938 /*
bc240b21 6939 * Enable port forwardings.
6940 */
06fadff5 6941 ssh_setup_portfwd(ssh, &ssh->cfg);
bc240b21 6942
6943 /*
36c2a3e9 6944 * Potentially enable agent forwarding.
6945 */
0ed48730 6946 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 6947 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 6948 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6949 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6950 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6951 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6952 ssh2_pkt_send(ssh, s->pktout);
32874aea 6953
b09eaa88 6954 crWaitUntilV(pktin);
32874aea 6955
ff3187f6 6956 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6957 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6958 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 6959 " packet type %d", pktin->type));
7ffdbc1a 6960 crStopV;
32874aea 6961 }
6962 logevent("Agent forwarding refused");
6963 } else {
6964 logevent("Agent forwarding enabled");
51470298 6965 ssh->agentfwd_enabled = TRUE;
32874aea 6966 }
36c2a3e9 6967 }
6968
6969 /*
7cca0d81 6970 * Now allocate a pty for the session.
6971 */
0ed48730 6972 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 6973 /* Unpick the terminal-speed string. */
6974 /* XXX perhaps we should allow no speeds to be sent. */
db219738 6975 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6976 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 6977 /* Build the pty request. */
ff3187f6 6978 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6979 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6980 ssh2_pkt_addstring(s->pktout, "pty-req");
6981 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6982 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6983 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6984 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6985 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6986 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6987 ssh2_pkt_addstring_start(s->pktout);
6988 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6989 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6990 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6991 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6992 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6993 ssh2_pkt_send(ssh, s->pktout);
51470298 6994 ssh->state = SSH_STATE_INTERMED;
32874aea 6995
b09eaa88 6996 crWaitUntilV(pktin);
32874aea 6997
ff3187f6 6998 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6999 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7000 bombout(("Unexpected response to pty request:"
ff3187f6 7001 " packet type %d", pktin->type));
7ffdbc1a 7002 crStopV;
32874aea 7003 }
51470298 7004 c_write_str(ssh, "Server refused to allocate pty\r\n");
7005 ssh->editing = ssh->echoing = 1;
32874aea 7006 } else {
a5dd8467 7007 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 7008 ssh->ospeed, ssh->ispeed);
32874aea 7009 }
0965bee0 7010 } else {
51470298 7011 ssh->editing = ssh->echoing = 1;
7cca0d81 7012 }
7013
7014 /*
73feed4f 7015 * Send environment variables.
7016 *
7017 * Simplest thing here is to send all the requests at once, and
7018 * then wait for a whole bunch of successes or failures.
7019 */
7020 if (ssh->mainchan && *ssh->cfg.environmt) {
7021 char *e = ssh->cfg.environmt;
7022 char *var, *varend, *val;
7023
7024 s->num_env = 0;
7025
7026 while (*e) {
7027 var = e;
7028 while (*e && *e != '\t') e++;
7029 varend = e;
7030 if (*e == '\t') e++;
7031 val = e;
7032 while (*e) e++;
7033 e++;
7034
ff3187f6 7035 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7036 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7037 ssh2_pkt_addstring(s->pktout, "env");
7038 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7039 ssh2_pkt_addstring_start(s->pktout);
7040 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7041 ssh2_pkt_addstring(s->pktout, val);
7042 ssh2_pkt_send(ssh, s->pktout);
73feed4f 7043
7044 s->num_env++;
7045 }
7046
7047 logeventf(ssh, "Sent %d environment variables", s->num_env);
7048
7049 s->env_ok = 0;
7050 s->env_left = s->num_env;
7051
7052 while (s->env_left > 0) {
b09eaa88 7053 crWaitUntilV(pktin);
73feed4f 7054
ff3187f6 7055 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7056 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 7057 bombout(("Unexpected response to environment request:"
ff3187f6 7058 " packet type %d", pktin->type));
73feed4f 7059 crStopV;
7060 }
7061 } else {
7062 s->env_ok++;
7063 }
7064
7065 s->env_left--;
7066 }
7067
7068 if (s->env_ok == s->num_env) {
7069 logevent("All environment variables successfully set");
7070 } else if (s->env_ok == 0) {
7071 logevent("All environment variables refused");
7072 c_write_str(ssh, "Server refused to set environment variables\r\n");
7073 } else {
7074 logeventf(ssh, "%d environment variables refused",
7075 s->num_env - s->env_ok);
7076 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7077 }
7078 }
7079
7080 /*
fd5e5847 7081 * Start a shell or a remote command. We may have to attempt
7082 * this twice if the config data has provided a second choice
7083 * of command.
7cca0d81 7084 */
0ed48730 7085 if (ssh->mainchan) while (1) {
fd5e5847 7086 int subsys;
7087 char *cmd;
7088
51470298 7089 if (ssh->fallback_cmd) {
86916870 7090 subsys = ssh->cfg.ssh_subsys2;
7091 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 7092 } else {
86916870 7093 subsys = ssh->cfg.ssh_subsys;
7094 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 7095 }
7096
ff3187f6 7097 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7098 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 7099 if (subsys) {
ff3187f6 7100 ssh2_pkt_addstring(s->pktout, "subsystem");
7101 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7102 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7103 } else if (*cmd) {
ff3187f6 7104 ssh2_pkt_addstring(s->pktout, "exec");
7105 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7106 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7107 } else {
ff3187f6 7108 ssh2_pkt_addstring(s->pktout, "shell");
7109 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 7110 }
ff3187f6 7111 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 7112
7113 crWaitUntilV(pktin);
7114
ff3187f6 7115 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7116 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7117 bombout(("Unexpected response to shell/command request:"
ff3187f6 7118 " packet type %d", pktin->type));
7ffdbc1a 7119 crStopV;
fd5e5847 7120 }
7121 /*
7122 * We failed to start the command. If this is the
7123 * fallback command, we really are finished; if it's
7124 * not, and if the fallback command exists, try falling
7125 * back to it before complaining.
7126 */
86916870 7127 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 7128 logevent("Primary command failed; attempting fallback");
51470298 7129 ssh->fallback_cmd = TRUE;
fd5e5847 7130 continue;
7131 }
6b5cf8b4 7132 bombout(("Server refused to start a shell/command"));
7ffdbc1a 7133 crStopV;
fd5e5847 7134 } else {
7135 logevent("Started a shell/command");
32874aea 7136 }
fd5e5847 7137 break;
7cca0d81 7138 }
7139
51470298 7140 ssh->state = SSH_STATE_SESSION;
7141 if (ssh->size_needed)
7142 ssh_size(ssh, ssh->term_width, ssh->term_height);
7143 if (ssh->eof_needed)
7144 ssh_special(ssh, TS_EOF);
6e48c3fe 7145
7cca0d81 7146 /*
7147 * Transfer data!
7148 */
b9d7bcad 7149 if (ssh->ldisc)
7150 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 7151 if (ssh->mainchan)
7152 ssh->send_ok = 1;
7cca0d81 7153 while (1) {
e5574168 7154 crReturnV;
51470298 7155 s->try_send = FALSE;
ff3187f6 7156 if (pktin) {
2b7540a7 7157
51df0ab5 7158 /*
7159 * _All_ the connection-layer packets we expect to
7160 * receive are now handled by the dispatch table.
7161 * Anything that reaches here must be bogus.
7162 */
32874aea 7163
51df0ab5 7164 bombout(("Strange packet received: type %d", pktin->type));
7165 crStopV;
0ed48730 7166 } else if (ssh->mainchan) {
32874aea 7167 /*
7168 * We have spare data. Add it to the channel buffer.
7169 */
d8baa528 7170 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 7171 s->try_send = TRUE;
32874aea 7172 }
51470298 7173 if (s->try_send) {
32874aea 7174 int i;
7175 struct ssh_channel *c;
7176 /*
7177 * Try to send data on all channels if we can.
7178 */
51470298 7179 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 7180 int bufsize;
7181 if (c->closes)
7182 continue; /* don't send on closing channels */
7183 bufsize = ssh2_try_send(c);
5471d09a 7184 if (bufsize == 0) {
7185 switch (c->type) {
7186 case CHAN_MAINSESSION:
7187 /* stdin need not receive an unthrottle
7188 * notification since it will be polled */
7189 break;
7190 case CHAN_X11:
7191 x11_unthrottle(c->u.x11.s);
7192 break;
7193 case CHAN_AGENT:
7194 /* agent sockets are request/response and need no
7195 * buffer management */
7196 break;
7197 case CHAN_SOCKDATA:
7198 pfd_unthrottle(c->u.pfd.s);
7199 break;
7200 }
7201 }
7202 }
7cca0d81 7203 }
e5574168 7204 }
7205
7206 crFinishV;
7207}
7208
7209/*
b09eaa88 7210 * Handlers for SSH2 messages that might arrive at any moment.
7211 */
7212void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7213{
7214 /* log reason code in disconnect message */
7215 char *buf, *msg;
7216 int nowlen, reason, msglen;
7217
7218 reason = ssh_pkt_getuint32(pktin);
7219 ssh_pkt_getstring(pktin, &msg, &msglen);
7220
7221 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7222 buf = dupprintf("Received disconnect message (%s)",
7223 ssh2_disconnect_reasons[reason]);
7224 } else {
7225 buf = dupprintf("Received disconnect message (unknown"
7226 " type %d)", reason);
7227 }
7228 logevent(buf);
7229 sfree(buf);
7230 buf = dupprintf("Disconnection message text: %n%.*s",
7231 &nowlen, msglen, msg);
7232 logevent(buf);
7233 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7234 reason,
7235 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7236 ssh2_disconnect_reasons[reason] : "unknown",
7237 buf+nowlen));
7238 sfree(buf);
7239}
7240
7241void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7242{
7243 /* log the debug message */
7244 char *buf, *msg;
7245 int msglen;
7246 int always_display;
7247
7248 /* XXX maybe we should actually take notice of this */
7249 always_display = ssh2_pkt_getbool(pktin);
7250 ssh_pkt_getstring(pktin, &msg, &msglen);
7251
7252 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
7253 logevent(buf);
7254 sfree(buf);
7255}
7256
7257void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7258{
7259 struct Packet *pktout;
7260 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7261 ssh2_pkt_adduint32(pktout, pktin->sequence);
7262 /*
7263 * UNIMPLEMENTED messages MUST appear in the same order as the
7264 * messages they respond to. Hence, never queue them.
7265 */
7266 ssh2_pkt_send_noqueue(ssh, pktout);
7267}
7268
7269/*
7cca0d81 7270 * Handle the top-level SSH2 protocol.
7271 */
b09eaa88 7272static void ssh2_protocol_setup(Ssh ssh)
7273{
7274 int i;
7275
7276 /*
7277 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7278 */
7279 for (i = 0; i < 256; i++)
7280 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7281
7282 /*
7283 * Any message we actually understand, we set to NULL so that
7284 * the coroutines will get it.
7285 */
7286 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7287 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7288 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7289 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7290 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7291 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7292 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7293 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7294 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7295 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7296 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7297 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7298 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7299 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7300 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7301 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7302 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7303 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7304 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7305 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7306 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7307 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7308 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7309 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7310 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7311 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7312 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7313 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7314 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7315 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7316 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7317 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7318 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7319
7320 /*
7321 * These special message types we install handlers for.
7322 */
7323 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7324 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7325 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7326}
7327
9442dd57 7328static void ssh2_timer(void *ctx, long now)
7329{
7330 Ssh ssh = (Ssh)ctx;
7331
e6c1536e 7332 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9442dd57 7333 now - ssh->next_rekey >= 0) {
f382c87d 7334 do_ssh2_transport(ssh, "timeout", -1, NULL);
9442dd57 7335 }
7336}
7337
ff3187f6 7338static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7339 struct Packet *pktin)
7cca0d81 7340{
b09eaa88 7341 if (ssh->state == SSH_STATE_CLOSED)
7342 return;
7343
9442dd57 7344 if (pktin) {
7345 ssh->incoming_data_size += pktin->encrypted_len;
7346 if (!ssh->kex_in_progress &&
d57f70af 7347 ssh->max_data_size != 0 &&
7348 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 7349 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9442dd57 7350 }
7351
b09eaa88 7352 if (pktin && ssh->packet_dispatch[pktin->type]) {
7353 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 7354 return;
b09eaa88 7355 }
7356
7357 if (!ssh->protocol_initial_phase_done ||
7358 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7359 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7360 !ssh->protocol_initial_phase_done) {
7361 ssh->protocol_initial_phase_done = TRUE;
7362 /*
7363 * Allow authconn to initialise itself.
7364 */
7365 do_ssh2_authconn(ssh, NULL, 0, NULL);
7366 }
7367 } else {
7368 do_ssh2_authconn(ssh, in, inlen, pktin);
7369 }
7cca0d81 7370}
7371
7372/*
8df7a775 7373 * Called to set up the connection.
374330e2 7374 *
7375 * Returns an error message, or NULL on success.
374330e2 7376 */
cbe2d68f 7377static const char *ssh_init(void *frontend_handle, void **backend_handle,
7378 Config *cfg,
79bf227b 7379 char *host, int port, char **realhost, int nodelay,
7380 int keepalive)
32874aea 7381{
cbe2d68f 7382 const char *p;
51470298 7383 Ssh ssh;
7384
3d88e64d 7385 ssh = snew(struct ssh_tag);
86916870 7386 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 7387 ssh->version = 0; /* when not ready yet */
51470298 7388 ssh->s = NULL;
7389 ssh->cipher = NULL;
371e569c 7390 ssh->v1_cipher_ctx = NULL;
0183b242 7391 ssh->crcda_ctx = NULL;
51470298 7392 ssh->cscipher = NULL;
371e569c 7393 ssh->cs_cipher_ctx = NULL;
51470298 7394 ssh->sccipher = NULL;
371e569c 7395 ssh->sc_cipher_ctx = NULL;
51470298 7396 ssh->csmac = NULL;
a8327734 7397 ssh->cs_mac_ctx = NULL;
51470298 7398 ssh->scmac = NULL;
e0e1a00d 7399 ssh->sc_mac_ctx = NULL;
51470298 7400 ssh->cscomp = NULL;
5366aed8 7401 ssh->cs_comp_ctx = NULL;
51470298 7402 ssh->sccomp = NULL;
5366aed8 7403 ssh->sc_comp_ctx = NULL;
51470298 7404 ssh->kex = NULL;
389aa499 7405 ssh->kex_ctx = NULL;
51470298 7406 ssh->hostkey = NULL;
7407 ssh->exitcode = -1;
ac934965 7408 ssh->close_expected = FALSE;
51470298 7409 ssh->state = SSH_STATE_PREPACKET;
7410 ssh->size_needed = FALSE;
7411 ssh->eof_needed = FALSE;
b9d7bcad 7412 ssh->ldisc = NULL;
a8327734 7413 ssh->logctx = NULL;
51470298 7414 ssh->deferred_send_data = NULL;
7415 ssh->deferred_len = 0;
7416 ssh->deferred_size = 0;
7417 ssh->fallback_cmd = 0;
7418 ssh->pkt_ctx = 0;
302121de 7419 ssh->x11auth = NULL;
be738459 7420 ssh->v1_compressing = FALSE;
51470298 7421 ssh->v2_outgoing_sequence = 0;
7422 ssh->ssh1_rdpkt_crstate = 0;
7423 ssh->ssh2_rdpkt_crstate = 0;
7424 ssh->do_ssh_init_crstate = 0;
7425 ssh->ssh_gotdata_crstate = 0;
b09eaa88 7426 ssh->do_ssh1_connection_crstate = 0;
51470298 7427 ssh->do_ssh1_login_crstate = 0;
7428 ssh->do_ssh2_transport_crstate = 0;
7429 ssh->do_ssh2_authconn_crstate = 0;
7430 ssh->do_ssh_init_state = NULL;
7431 ssh->do_ssh1_login_state = NULL;
7432 ssh->do_ssh2_transport_state = NULL;
7433 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 7434 ssh->mainchan = NULL;
968d2d92 7435 ssh->throttled_all = 0;
7436 ssh->v1_stdout_throttling = 0;
590f6a5f 7437 ssh->queue = NULL;
7438 ssh->queuelen = ssh->queuesize = 0;
7439 ssh->queueing = FALSE;
06fadff5 7440 ssh->qhead = ssh->qtail = NULL;
e13bba36 7441 ssh->deferred_rekey_reason = NULL;
51470298 7442
7443 *backend_handle = ssh;
32874aea 7444
8f203108 7445#ifdef MSCRYPTOAPI
32874aea 7446 if (crypto_startup() == 0)
8f203108 7447 return "Microsoft high encryption pack not installed!";
7448#endif
374330e2 7449
51470298 7450 ssh->frontend = frontend_handle;
86916870 7451 ssh->term_width = ssh->cfg.width;
7452 ssh->term_height = ssh->cfg.height;
887035a5 7453
fabd1805 7454 ssh->channels = NULL;
7455 ssh->rportfwds = NULL;
f47a5ffb 7456 ssh->portfwds = NULL;
fabd1805 7457
51470298 7458 ssh->send_ok = 0;
7459 ssh->editing = 0;
7460 ssh->echoing = 0;
7461 ssh->v1_throttle_count = 0;
7462 ssh->overall_bufsize = 0;
7463 ssh->fallback_cmd = 0;
8df7a775 7464
3648d4c5 7465 ssh->protocol = NULL;
7466
b09eaa88 7467 ssh->protocol_initial_phase_done = FALSE;
7468
39934deb 7469 ssh->pinger = NULL;
7470
9442dd57 7471 ssh->incoming_data_size = ssh->outgoing_data_size =
7472 ssh->deferred_data_size = 0L;
d57f70af 7473 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9442dd57 7474 ssh->kex_in_progress = FALSE;
7475
79bf227b 7476 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 7477 if (p != NULL)
7478 return p;
374330e2 7479
5d17ccfc 7480 random_ref();
7481
374330e2 7482 return NULL;
7483}
7484
fabd1805 7485static void ssh_free(void *handle)
7486{
7487 Ssh ssh = (Ssh) handle;
7488 struct ssh_channel *c;
7489 struct ssh_rportfwd *pf;
7490
7491 if (ssh->v1_cipher_ctx)
7492 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7493 if (ssh->cs_cipher_ctx)
7494 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7495 if (ssh->sc_cipher_ctx)
7496 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7497 if (ssh->cs_mac_ctx)
7498 ssh->csmac->free_context(ssh->cs_mac_ctx);
7499 if (ssh->sc_mac_ctx)
7500 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 7501 if (ssh->cs_comp_ctx) {
7502 if (ssh->cscomp)
7503 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7504 else
7505 zlib_compress_cleanup(ssh->cs_comp_ctx);
7506 }
7507 if (ssh->sc_comp_ctx) {
7508 if (ssh->sccomp)
7509 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7510 else
7511 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7512 }
fabd1805 7513 if (ssh->kex_ctx)
7514 dh_cleanup(ssh->kex_ctx);
7515 sfree(ssh->savedhost);
7516
590f6a5f 7517 while (ssh->queuelen-- > 0)
7518 ssh_free_packet(ssh->queue[ssh->queuelen]);
7519 sfree(ssh->queue);
7520
06fadff5 7521 while (ssh->qhead) {
7522 struct queued_handler *qh = ssh->qhead;
7523 ssh->qhead = qh->next;
7524 sfree(ssh->qhead);
7525 }
7526 ssh->qhead = ssh->qtail = NULL;
7527
fabd1805 7528 if (ssh->channels) {
7529 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7530 switch (c->type) {
7531 case CHAN_X11:
7532 if (c->u.x11.s != NULL)
7533 x11_close(c->u.x11.s);
7534 break;
7535 case CHAN_SOCKDATA:
7536 if (c->u.pfd.s != NULL)
7537 pfd_close(c->u.pfd.s);
7538 break;
7539 }
7540 sfree(c);
7541 }
7542 freetree234(ssh->channels);
cdb52705 7543 ssh->channels = NULL;
fabd1805 7544 }
7545
7546 if (ssh->rportfwds) {
7547 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7548 sfree(pf);
7549 freetree234(ssh->rportfwds);
cdb52705 7550 ssh->rportfwds = NULL;
fabd1805 7551 }
7552 sfree(ssh->deferred_send_data);
7553 if (ssh->x11auth)
7554 x11_free_auth(ssh->x11auth);
7555 sfree(ssh->do_ssh_init_state);
7556 sfree(ssh->do_ssh1_login_state);
7557 sfree(ssh->do_ssh2_transport_state);
7558 sfree(ssh->do_ssh2_authconn_state);
679539d7 7559 if (ssh->crcda_ctx) {
7560 crcda_free_context(ssh->crcda_ctx);
7561 ssh->crcda_ctx = NULL;
7562 }
fabd1805 7563 if (ssh->s)
ac934965 7564 ssh_do_close(ssh, TRUE);
9442dd57 7565 expire_timer_context(ssh);
39934deb 7566 if (ssh->pinger)
7567 pinger_free(ssh->pinger);
ee50e8b6 7568 sfree(ssh);
5d17ccfc 7569
7570 random_unref();
fabd1805 7571}
7572
374330e2 7573/*
86916870 7574 * Reconfigure the SSH backend.
86916870 7575 */
7576static void ssh_reconfig(void *handle, Config *cfg)
7577{
7578 Ssh ssh = (Ssh) handle;
e13bba36 7579 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 7580 unsigned long old_max_data_size;
7581
39934deb 7582 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
fda2feb1 7583 ssh_setup_portfwd(ssh, cfg);
e6c1536e 7584
7585 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7586 cfg->ssh_rekey_time != 0) {
7587 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7588 long now = GETTICKCOUNT();
7589
7590 if (new_next - now < 0) {
f382c87d 7591 rekeying = "timeout shortened";
e6c1536e 7592 } else {
7593 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7594 }
7595 }
7596
7597 old_max_data_size = ssh->max_data_size;
7598 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7599 if (old_max_data_size != ssh->max_data_size &&
7600 ssh->max_data_size != 0) {
7601 if (ssh->outgoing_data_size > ssh->max_data_size ||
7602 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 7603 rekeying = "data limit lowered";
e6c1536e 7604 }
7605
e13bba36 7606 if (ssh->cfg.compression != cfg->compression) {
f382c87d 7607 rekeying = "compression setting changed";
e13bba36 7608 rekey_mandatory = TRUE;
7609 }
7610
7611 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7612 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7613 sizeof(ssh->cfg.ssh_cipherlist))) {
f382c87d 7614 rekeying = "cipher settings changed";
e13bba36 7615 rekey_mandatory = TRUE;
e6c1536e 7616 }
7617
86916870 7618 ssh->cfg = *cfg; /* STRUCTURE COPY */
e13bba36 7619
7620 if (rekeying) {
7621 if (!ssh->kex_in_progress) {
7622 do_ssh2_transport(ssh, rekeying, -1, NULL);
7623 } else if (rekey_mandatory) {
7624 ssh->deferred_rekey_reason = rekeying;
7625 }
7626 }
86916870 7627}
7628
7629/*
374330e2 7630 * Called to send data down the Telnet connection.
7631 */
51470298 7632static int ssh_send(void *handle, char *buf, int len)
32874aea 7633{
51470298 7634 Ssh ssh = (Ssh) handle;
7635
7636 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7637 return 0;
374330e2 7638
d8baa528 7639 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 7640
51470298 7641 return ssh_sendbuffer(ssh);
5471d09a 7642}
7643
7644/*
7645 * Called to query the current amount of buffered stdin data.
7646 */
51470298 7647static int ssh_sendbuffer(void *handle)
5471d09a 7648{
51470298 7649 Ssh ssh = (Ssh) handle;
5471d09a 7650 int override_value;
7651
51470298 7652 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7653 return 0;
7654
7655 /*
7656 * If the SSH socket itself has backed up, add the total backup
7657 * size on that to any individual buffer on the stdin channel.
7658 */
7659 override_value = 0;
51470298 7660 if (ssh->throttled_all)
7661 override_value = ssh->overall_bufsize;
5471d09a 7662
51470298 7663 if (ssh->version == 1) {
5471d09a 7664 return override_value;
51470298 7665 } else if (ssh->version == 2) {
7666 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 7667 return override_value;
7668 else
51470298 7669 return (override_value +
7670 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 7671 }
7672
7673 return 0;
374330e2 7674}
7675
7676/*
6e48c3fe 7677 * Called to set the size of the window from SSH's POV.
374330e2 7678 */
51470298 7679static void ssh_size(void *handle, int width, int height)
32874aea 7680{
51470298 7681 Ssh ssh = (Ssh) handle;
ff3187f6 7682 struct Packet *pktout;
51470298 7683
7684 ssh->term_width = width;
7685 ssh->term_height = height;
f278d6f8 7686
51470298 7687 switch (ssh->state) {
374330e2 7688 case SSH_STATE_BEFORE_SIZE:
3687d221 7689 case SSH_STATE_PREPACKET:
21248260 7690 case SSH_STATE_CLOSED:
374330e2 7691 break; /* do nothing */
7692 case SSH_STATE_INTERMED:
51470298 7693 ssh->size_needed = TRUE; /* buffer for later */
374330e2 7694 break;
7695 case SSH_STATE_SESSION:
86916870 7696 if (!ssh->cfg.nopty) {
51470298 7697 if (ssh->version == 1) {
7698 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7699 PKT_INT, ssh->term_height,
7700 PKT_INT, ssh->term_width,
32874aea 7701 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 7702 } else if (ssh->mainchan) {
ff3187f6 7703 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7704 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7705 ssh2_pkt_addstring(pktout, "window-change");
7706 ssh2_pkt_addbool(pktout, 0);
7707 ssh2_pkt_adduint32(pktout, ssh->term_width);
7708 ssh2_pkt_adduint32(pktout, ssh->term_height);
7709 ssh2_pkt_adduint32(pktout, 0);
7710 ssh2_pkt_adduint32(pktout, 0);
7711 ssh2_pkt_send(ssh, pktout);
32874aea 7712 }
7713 }
7714 break;
374330e2 7715 }
7716}
7717
7718/*
125105d1 7719 * Return a list of the special codes that make sense in this
7720 * protocol.
7721 */
7722static const struct telnet_special *ssh_get_specials(void *handle)
7723{
786ba75e 7724 static const struct telnet_special ssh1_ignore_special[] = {
7725 {"IGNORE message", TS_NOP}
7726 };
7727 static const struct telnet_special ssh2_transport_specials[] = {
62638676 7728 {"IGNORE message", TS_NOP},
9442dd57 7729 {"Repeat key exchange", TS_REKEY},
62638676 7730 };
7731 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 7732 {NULL, TS_SEP},
7733 {"Break", TS_BRK},
786ba75e 7734 /* These are the signal names defined by draft-ietf-secsh-connect-23.
6f2d0cde 7735 * They include all the ISO C signals, but are a subset of the POSIX
7736 * required signals. */
7737 {"SIGINT (Interrupt)", TS_SIGINT},
7738 {"SIGTERM (Terminate)", TS_SIGTERM},
7739 {"SIGKILL (Kill)", TS_SIGKILL},
7740 {"SIGQUIT (Quit)", TS_SIGQUIT},
7741 {"SIGHUP (Hangup)", TS_SIGHUP},
7742 {"More signals", TS_SUBMENU},
7743 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7744 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7745 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7746 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7747 {NULL, TS_EXITMENU}
62638676 7748 };
7749 static const struct telnet_special specials_end[] = {
6f2d0cde 7750 {NULL, TS_EXITMENU}
62638676 7751 };
786ba75e 7752 /* XXX review this length for any changes: */
7753 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
62638676 7754 lenof(ssh2_session_specials) +
7755 lenof(specials_end)];
125105d1 7756 Ssh ssh = (Ssh) handle;
62638676 7757 int i = 0;
7758#define ADD_SPECIALS(name) \
7759 do { \
7760 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7761 memcpy(&ssh_specials[i], name, sizeof name); \
7762 i += lenof(name); \
7763 } while(0)
125105d1 7764
7765 if (ssh->version == 1) {
62638676 7766 /* Don't bother offering IGNORE if we've decided the remote
7767 * won't cope with it, since we wouldn't bother sending it if
7768 * asked anyway. */
7769 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 7770 ADD_SPECIALS(ssh1_ignore_special);
125105d1 7771 } else if (ssh->version == 2) {
786ba75e 7772 ADD_SPECIALS(ssh2_transport_specials);
62638676 7773 if (ssh->mainchan)
7774 ADD_SPECIALS(ssh2_session_specials);
7775 } /* else we're not ready yet */
7776
7777 if (i) {
7778 ADD_SPECIALS(specials_end);
7779 return ssh_specials;
7780 } else {
125105d1 7781 return NULL;
62638676 7782 }
7783#undef ADD_SPECIALS
125105d1 7784}
7785
7786/*
6abbf9e3 7787 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7788 * can send an EOF and collect resulting output (e.g. `plink
7789 * hostname sort').
374330e2 7790 */
51470298 7791static void ssh_special(void *handle, Telnet_Special code)
32874aea 7792{
51470298 7793 Ssh ssh = (Ssh) handle;
ff3187f6 7794 struct Packet *pktout;
51470298 7795
6abbf9e3 7796 if (code == TS_EOF) {
51470298 7797 if (ssh->state != SSH_STATE_SESSION) {
32874aea 7798 /*
7799 * Buffer the EOF in case we are pre-SESSION, so we can
7800 * send it as soon as we reach SESSION.
7801 */
7802 if (code == TS_EOF)
51470298 7803 ssh->eof_needed = TRUE;
32874aea 7804 return;
7805 }
51470298 7806 if (ssh->version == 1) {
7807 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 7808 } else if (ssh->mainchan) {
ff3187f6 7809 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7810 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7811 ssh2_pkt_send(ssh, pktout);
32874aea 7812 }
7813 logevent("Sent EOF message");
125105d1 7814 } else if (code == TS_PING || code == TS_NOP) {
51470298 7815 if (ssh->state == SSH_STATE_CLOSED
7816 || ssh->state == SSH_STATE_PREPACKET) return;
7817 if (ssh->version == 1) {
7818 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7819 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 7820 } else {
ff3187f6 7821 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7822 ssh2_pkt_addstring_start(pktout);
590f6a5f 7823 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 7824 }
9442dd57 7825 } else if (code == TS_REKEY) {
7826 if (!ssh->kex_in_progress && ssh->version == 2) {
f382c87d 7827 do_ssh2_transport(ssh, "at user request", -1, NULL);
9442dd57 7828 }
125105d1 7829 } else if (code == TS_BRK) {
7830 if (ssh->state == SSH_STATE_CLOSED
7831 || ssh->state == SSH_STATE_PREPACKET) return;
7832 if (ssh->version == 1) {
7833 logevent("Unable to send BREAK signal in SSH1");
0ed48730 7834 } else if (ssh->mainchan) {
ff3187f6 7835 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7836 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7837 ssh2_pkt_addstring(pktout, "break");
7838 ssh2_pkt_addbool(pktout, 0);
7839 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7840 ssh2_pkt_send(ssh, pktout);
125105d1 7841 }
6abbf9e3 7842 } else {
6f2d0cde 7843 /* Is is a POSIX signal? */
7844 char *signame = NULL;
7845 if (code == TS_SIGABRT) signame = "ABRT";
7846 if (code == TS_SIGALRM) signame = "ALRM";
7847 if (code == TS_SIGFPE) signame = "FPE";
7848 if (code == TS_SIGHUP) signame = "HUP";
7849 if (code == TS_SIGILL) signame = "ILL";
7850 if (code == TS_SIGINT) signame = "INT";
7851 if (code == TS_SIGKILL) signame = "KILL";
7852 if (code == TS_SIGPIPE) signame = "PIPE";
7853 if (code == TS_SIGQUIT) signame = "QUIT";
7854 if (code == TS_SIGSEGV) signame = "SEGV";
7855 if (code == TS_SIGTERM) signame = "TERM";
7856 if (code == TS_SIGUSR1) signame = "USR1";
7857 if (code == TS_SIGUSR2) signame = "USR2";
7858 /* The SSH-2 protocol does in principle support arbitrary named
7859 * signals, including signame@domain, but we don't support those. */
7860 if (signame) {
7861 /* It's a signal. */
7862 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 7863 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7864 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7865 ssh2_pkt_addstring(pktout, "signal");
7866 ssh2_pkt_addbool(pktout, 0);
7867 ssh2_pkt_addstring(pktout, signame);
7868 ssh2_pkt_send(ssh, pktout);
6f2d0cde 7869 logeventf(ssh, "Sent signal SIG%s", signame);
7870 }
7871 } else {
7872 /* Never heard of it. Do nothing */
7873 }
6abbf9e3 7874 }
374330e2 7875}
7876
51470298 7877void *new_sock_channel(void *handle, Socket s)
d74d141c 7878{
51470298 7879 Ssh ssh = (Ssh) handle;
d74d141c 7880 struct ssh_channel *c;
3d88e64d 7881 c = snew(struct ssh_channel);
51470298 7882 c->ssh = ssh;
d74d141c 7883
7884 if (c) {
bc240b21 7885 c->remoteid = -1; /* to be set when open confirmed */
51470298 7886 c->localid = alloc_channel_id(ssh);
d74d141c 7887 c->closes = 0;
bc240b21 7888 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 7889 c->u.pfd.s = s;
013dd8c0 7890 bufchain_init(&c->v.v2.outbuffer);
51470298 7891 add234(ssh->channels, c);
d74d141c 7892 }
7893 return c;
7894}
7895
5471d09a 7896/*
7897 * This is called when stdout/stderr (the entity to which
7898 * from_backend sends data) manages to clear some backlog.
7899 */
ae9ae89f 7900static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 7901{
51470298 7902 Ssh ssh = (Ssh) handle;
7903 if (ssh->version == 1) {
7904 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7905 ssh->v1_stdout_throttling = 0;
7906 ssh1_throttle(ssh, -1);
5471d09a 7907 }
7908 } else {
51470298 7909 if (ssh->mainchan && ssh->mainchan->closes == 0)
7910 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 7911 }
7912}
7913
6b78788a 7914void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 7915{
7916 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 7917 Ssh ssh = c->ssh;
ff3187f6 7918 struct Packet *pktout;
d74d141c 7919
57356d63 7920 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 7921
51470298 7922 if (ssh->version == 1) {
7923 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 7924 PKT_INT, c->localid,
7925 PKT_STR, hostname,
7926 PKT_INT, port,
31fb1866 7927 /* PKT_STR, <org:orgport>, */
bc240b21 7928 PKT_END);
7929 } else {
ff3187f6 7930 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7931 ssh2_pkt_addstring(pktout, "direct-tcpip");
7932 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 7933 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7934 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
954d5c5a 7935 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 7936 ssh2_pkt_addstring(pktout, hostname);
7937 ssh2_pkt_adduint32(pktout, port);
bc240b21 7938 /*
7939 * We make up values for the originator data; partly it's
7940 * too much hassle to keep track, and partly I'm not
7941 * convinced the server should be told details like that
7942 * about my local network configuration.
7943 */
ff3187f6 7944 ssh2_pkt_addstring(pktout, "client-side-connection");
7945 ssh2_pkt_adduint32(pktout, 0);
7946 ssh2_pkt_send(ssh, pktout);
bc240b21 7947 }
d74d141c 7948}
7949
51470298 7950static Socket ssh_socket(void *handle)
32874aea 7951{
51470298 7952 Ssh ssh = (Ssh) handle;
7953 return ssh->s;
32874aea 7954}
8ccc75b0 7955
51470298 7956static int ssh_sendok(void *handle)
32874aea 7957{
51470298 7958 Ssh ssh = (Ssh) handle;
7959 return ssh->send_ok;
32874aea 7960}
fb09bf1c 7961
51470298 7962static int ssh_ldisc(void *handle, int option)
32874aea 7963{
51470298 7964 Ssh ssh = (Ssh) handle;
32874aea 7965 if (option == LD_ECHO)
51470298 7966 return ssh->echoing;
32874aea 7967 if (option == LD_EDIT)
51470298 7968 return ssh->editing;
0965bee0 7969 return FALSE;
7970}
7971
b9d7bcad 7972static void ssh_provide_ldisc(void *handle, void *ldisc)
7973{
7974 Ssh ssh = (Ssh) handle;
7975 ssh->ldisc = ldisc;
7976}
7977
a8327734 7978static void ssh_provide_logctx(void *handle, void *logctx)
7979{
7980 Ssh ssh = (Ssh) handle;
7981 ssh->logctx = logctx;
7982}
7983
51470298 7984static int ssh_return_exitcode(void *handle)
7985{
7986 Ssh ssh = (Ssh) handle;
3bb2f322 7987 if (ssh->s != NULL)
7988 return -1;
7989 else
7990 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 7991}
7992
7993/*
f89c3294 7994 * cfg_info for SSH is the currently running version of the
7995 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
7996 */
7997static int ssh_cfg_info(void *handle)
7998{
7999 Ssh ssh = (Ssh) handle;
8000 return ssh->version;
8001}
8002
8003/*
51470298 8004 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8005 * that fails. This variable is the means by which scp.c can reach
8006 * into the SSH code and find out which one it got.
8007 */
8008extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 8009{
51470298 8010 Ssh ssh = (Ssh) handle;
8011 return ssh->fallback_cmd;
d8d6c7e5 8012}
8013
374330e2 8014Backend ssh_backend = {
8015 ssh_init,
fabd1805 8016 ssh_free,
86916870 8017 ssh_reconfig,
374330e2 8018 ssh_send,
5471d09a 8019 ssh_sendbuffer,
374330e2 8020 ssh_size,
4017be6d 8021 ssh_special,
125105d1 8022 ssh_get_specials,
8ccc75b0 8023 ssh_socket,
d8d6c7e5 8024 ssh_return_exitcode,
97db3be4 8025 ssh_sendok,
0965bee0 8026 ssh_ldisc,
b9d7bcad 8027 ssh_provide_ldisc,
a8327734 8028 ssh_provide_logctx,
5471d09a 8029 ssh_unthrottle,
f89c3294 8030 ssh_cfg_info,
97db3be4 8031 22
bc240b21 8032};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator