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term_bidi_cache_store() now has a need to distinguish between the
[u/mdw/putty] / ssh.c
CommitLineData
374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
374330e2 5
6#include "putty.h"
dacbd0e8 7#include "tree234.h"
fb09bf1c 8#include "ssh.h"
374330e2 9
10#ifndef FALSE
11#define FALSE 0
12#endif
13#ifndef TRUE
14#define TRUE 1
15#endif
16
32874aea 17#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20#define SSH1_CMSG_USER 4 /* 0x4 */
21#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29#define SSH1_SMSG_SUCCESS 14 /* 0xe */
30#define SSH1_SMSG_FAILURE 15 /* 0xf */
31#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34#define SSH1_CMSG_EOF 19 /* 0x13 */
35#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46#define SSH1_MSG_IGNORE 32 /* 0x20 */
47#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50#define SSH1_MSG_DEBUG 36 /* 0x24 */
51#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
58
59#define SSH1_AUTH_TIS 5 /* 0x5 */
60#define SSH1_AUTH_CCARD 16 /* 0x10 */
61
62#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 63/* Mask for protoflags we will echo back to server if seen */
32874aea 64#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
65
66#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67#define SSH2_MSG_IGNORE 2 /* 0x2 */
68#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69#define SSH2_MSG_DEBUG 4 /* 0x4 */
70#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72#define SSH2_MSG_KEXINIT 20 /* 0x14 */
73#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 86#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 88#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
102
00db133f 103/*
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
106 */
107#define SSH2_PKTCTX_DHGROUP1 0x0001
108#define SSH2_PKTCTX_DHGEX 0x0002
109#define SSH2_PKTCTX_PUBLICKEY 0x0010
110#define SSH2_PKTCTX_PASSWORD 0x0020
111#define SSH2_PKTCTX_KBDINTER 0x0040
112#define SSH2_PKTCTX_AUTH_MASK 0x00F0
113
32874aea 114#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 129
130static const char *const ssh2_disconnect_reasons[] = {
131 NULL,
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
147};
9005f3ba 148
32874aea 149#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 153
32874aea 154#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 155
7d503c31 156/*
157 * Various remote-bug flags.
158 */
159#define BUG_CHOKES_ON_SSH1_IGNORE 1
160#define BUG_SSH2_HMAC 2
bd358db1 161#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 162#define BUG_CHOKES_ON_RSA 8
1dd353b5 163#define BUG_SSH2_RSA_PADDING 16
088bde77 164#define BUG_SSH2_DERIVEKEY 32
8e975795 165#define BUG_SSH2_DH_GEX 64
dda87a28 166#define BUG_SSH2_PK_SESSIONID 128
bd358db1 167
00db133f 168#define translate(x) if (type == x) return #x
51470298 169#define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
ae9ae89f 170static char *ssh1_pkt_type(int type)
00db133f 171{
172 translate(SSH1_MSG_DISCONNECT);
173 translate(SSH1_SMSG_PUBLIC_KEY);
174 translate(SSH1_CMSG_SESSION_KEY);
175 translate(SSH1_CMSG_USER);
176 translate(SSH1_CMSG_AUTH_RSA);
177 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
178 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
179 translate(SSH1_CMSG_AUTH_PASSWORD);
180 translate(SSH1_CMSG_REQUEST_PTY);
181 translate(SSH1_CMSG_WINDOW_SIZE);
182 translate(SSH1_CMSG_EXEC_SHELL);
183 translate(SSH1_CMSG_EXEC_CMD);
184 translate(SSH1_SMSG_SUCCESS);
185 translate(SSH1_SMSG_FAILURE);
186 translate(SSH1_CMSG_STDIN_DATA);
187 translate(SSH1_SMSG_STDOUT_DATA);
188 translate(SSH1_SMSG_STDERR_DATA);
189 translate(SSH1_CMSG_EOF);
190 translate(SSH1_SMSG_EXIT_STATUS);
191 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
192 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
193 translate(SSH1_MSG_CHANNEL_DATA);
194 translate(SSH1_MSG_CHANNEL_CLOSE);
195 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
196 translate(SSH1_SMSG_X11_OPEN);
197 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
198 translate(SSH1_MSG_PORT_OPEN);
199 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
200 translate(SSH1_SMSG_AGENT_OPEN);
201 translate(SSH1_MSG_IGNORE);
202 translate(SSH1_CMSG_EXIT_CONFIRMATION);
203 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
204 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
205 translate(SSH1_MSG_DEBUG);
206 translate(SSH1_CMSG_REQUEST_COMPRESSION);
207 translate(SSH1_CMSG_AUTH_TIS);
208 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
209 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
210 translate(SSH1_CMSG_AUTH_CCARD);
211 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
212 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
213 return "unknown";
214}
ae9ae89f 215static char *ssh2_pkt_type(int pkt_ctx, int type)
00db133f 216{
217 translate(SSH2_MSG_DISCONNECT);
218 translate(SSH2_MSG_IGNORE);
219 translate(SSH2_MSG_UNIMPLEMENTED);
220 translate(SSH2_MSG_DEBUG);
221 translate(SSH2_MSG_SERVICE_REQUEST);
222 translate(SSH2_MSG_SERVICE_ACCEPT);
223 translate(SSH2_MSG_KEXINIT);
224 translate(SSH2_MSG_NEWKEYS);
225 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
226 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
227 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
231 translate(SSH2_MSG_USERAUTH_REQUEST);
232 translate(SSH2_MSG_USERAUTH_FAILURE);
233 translate(SSH2_MSG_USERAUTH_SUCCESS);
234 translate(SSH2_MSG_USERAUTH_BANNER);
235 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
236 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
237 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
238 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
239 translate(SSH2_MSG_GLOBAL_REQUEST);
240 translate(SSH2_MSG_REQUEST_SUCCESS);
241 translate(SSH2_MSG_REQUEST_FAILURE);
242 translate(SSH2_MSG_CHANNEL_OPEN);
243 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
244 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
245 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
246 translate(SSH2_MSG_CHANNEL_DATA);
247 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
248 translate(SSH2_MSG_CHANNEL_EOF);
249 translate(SSH2_MSG_CHANNEL_CLOSE);
250 translate(SSH2_MSG_CHANNEL_REQUEST);
251 translate(SSH2_MSG_CHANNEL_SUCCESS);
252 translate(SSH2_MSG_CHANNEL_FAILURE);
253 return "unknown";
254}
255#undef translate
256#undef translatec
7d503c31 257
fb09bf1c 258#define GET_32BIT(cp) \
259 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
260 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
261 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
262 ((unsigned long)(unsigned char)(cp)[3]))
263
264#define PUT_32BIT(cp, value) { \
265 (cp)[0] = (unsigned char)((value) >> 24); \
266 (cp)[1] = (unsigned char)((value) >> 16); \
267 (cp)[2] = (unsigned char)((value) >> 8); \
268 (cp)[3] = (unsigned char)(value); }
269
9a10ecf4 270/* Enumeration values for fields in SSH-1 packets */
271enum {
272 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
273 /* These values are for communicating relevant semantics of
274 * fields to the packet logging code. */
275 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
276};
972a41c8 277
acddebd9 278/*
279 * Coroutine mechanics for the sillier bits of the code. If these
280 * macros look impenetrable to you, you might find it helpful to
281 * read
282 *
283 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
284 *
285 * which explains the theory behind these macros.
b624d1e6 286 *
287 * In particular, if you are getting `case expression not constant'
288 * errors when building with MS Visual Studio, this is because MS's
289 * Edit and Continue debugging feature causes their compiler to
290 * violate ANSI C. To disable Edit and Continue debugging:
291 *
292 * - right-click ssh.c in the FileView
293 * - click Settings
294 * - select the C/C++ tab and the General category
295 * - under `Debug info:', select anything _other_ than `Program
296 * Database for Edit and Continue'.
acddebd9 297 */
51470298 298#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
299#define crState(t) \
300 struct t *s; \
3d88e64d 301 if (!ssh->t) ssh->t = snew(struct t); \
51470298 302 s = ssh->t;
303#define crFinish(z) } *crLine = 0; return (z); }
304#define crFinishV } *crLine = 0; return; }
374330e2 305#define crReturn(z) \
306 do {\
51470298 307 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 308 } while (0)
309#define crReturnV \
310 do {\
51470298 311 *crLine=__LINE__; return; case __LINE__:;\
374330e2 312 } while (0)
51470298 313#define crStop(z) do{ *crLine = 0; return (z); }while(0)
314#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 315#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 316#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 317
51470298 318typedef struct ssh_tag *Ssh;
ff3187f6 319struct Packet;
320
321static struct Packet *ssh2_pkt_init(int pkt_type);
322static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
323static void ssh2_pkt_adduint32(struct Packet *, unsigned long value);
324static void ssh2_pkt_addstring_start(struct Packet *);
325static void ssh2_pkt_addstring_str(struct Packet *, char *data);
326static void ssh2_pkt_addstring_data(struct Packet *, char *data, int len);
327static void ssh2_pkt_addstring(struct Packet *, char *data);
d8baa528 328static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
ff3187f6 329static void ssh2_pkt_addmp(struct Packet *, Bignum b);
330static int ssh2_pkt_construct(Ssh, struct Packet *);
331static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 332static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 333static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
334 struct Packet *pktin);
335static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
336 struct Packet *pktin);
3d63ca2e 337
5471d09a 338/*
339 * Buffer management constants. There are several of these for
340 * various different purposes:
341 *
342 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
343 * on a local data stream before we throttle the whole SSH
344 * connection (in SSH1 only). Throttling the whole connection is
345 * pretty drastic so we set this high in the hope it won't
346 * happen very often.
347 *
348 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
349 * on the SSH connection itself before we defensively throttle
350 * _all_ local data streams. This is pretty drastic too (though
351 * thankfully unlikely in SSH2 since the window mechanism should
352 * ensure that the server never has any need to throttle its end
353 * of the connection), so we set this high as well.
354 *
355 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
356 * channels.
357 */
358
359#define SSH1_BUFFER_LIMIT 32768
360#define SSH_MAX_BACKLOG 32768
361#define OUR_V2_WINSIZE 16384
d74d141c 362
a92dd380 363const static struct ssh_kex *kex_algs[] = {
a92dd380 364 &ssh_diffiehellman_gex,
32874aea 365 &ssh_diffiehellman
366};
e5574168 367
85cc02bb 368const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 369
e0e1a00d 370static void *nullmac_make_context(void)
371{
372 return NULL;
373}
374static void nullmac_free_context(void *handle)
375{
376}
377static void nullmac_key(void *handle, unsigned char *key)
32874aea 378{
379}
e0e1a00d 380static void nullmac_generate(void *handle, unsigned char *blk, int len,
32874aea 381 unsigned long seq)
382{
383}
e0e1a00d 384static int nullmac_verify(void *handle, unsigned char *blk, int len,
385 unsigned long seq)
32874aea 386{
387 return 1;
388}
57476f6b 389const static struct ssh_mac ssh_mac_none = {
e0e1a00d 390 nullmac_make_context, nullmac_free_context, nullmac_key,
391 nullmac_generate, nullmac_verify, "none", 0
e5574168 392};
8b2715b2 393const static struct ssh_mac *macs[] = {
32874aea 394 &ssh_sha1, &ssh_md5, &ssh_mac_none
395};
8b2715b2 396const static struct ssh_mac *buggymacs[] = {
32874aea 397 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
398};
e5574168 399
5366aed8 400static void *ssh_comp_none_init(void)
401{
402 return NULL;
403}
404static void ssh_comp_none_cleanup(void *handle)
32874aea 405{
406}
5366aed8 407static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 408 unsigned char **outblock, int *outlen)
409{
410 return 0;
411}
5366aed8 412static int ssh_comp_none_disable(void *handle)
32874aea 413{
4ba9b64b 414 return 0;
415}
57476f6b 416const static struct ssh_compress ssh_comp_none = {
4ba9b64b 417 "none",
5366aed8 418 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
419 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
420 ssh_comp_none_disable, NULL
e5574168 421};
4ba9b64b 422extern const struct ssh_compress ssh_zlib;
423const static struct ssh_compress *compressions[] = {
32874aea 424 &ssh_zlib, &ssh_comp_none
425};
374330e2 426
32874aea 427enum { /* channel types */
783415f8 428 CHAN_MAINSESSION,
429 CHAN_X11,
430 CHAN_AGENT,
bc240b21 431 CHAN_SOCKDATA,
432 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 433};
434
dacbd0e8 435/*
436 * 2-3-4 tree storing channels.
437 */
438struct ssh_channel {
51470298 439 Ssh ssh; /* pointer back to main context */
d211621f 440 unsigned remoteid, localid;
dacbd0e8 441 int type;
0357890f 442 /*
443 * In SSH1, this value contains four bits:
444 *
445 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
446 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
447 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
448 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
449 *
450 * A channel is completely finished with when all four bits are set.
451 */
dacbd0e8 452 int closes;
5471d09a 453 union {
454 struct ssh1_data_channel {
455 int throttling;
456 } v1;
457 struct ssh2_data_channel {
458 bufchain outbuffer;
459 unsigned remwindow, remmaxpkt;
460 unsigned locwindow;
461 } v2;
462 } v;
dacbd0e8 463 union {
32874aea 464 struct ssh_agent_channel {
465 unsigned char *message;
466 unsigned char msglen[4];
a03c9f9c 467 unsigned lensofar, totallen;
32874aea 468 } a;
469 struct ssh_x11_channel {
470 Socket s;
471 } x11;
d74d141c 472 struct ssh_pfd_channel {
473 Socket s;
474 } pfd;
dacbd0e8 475 } u;
476};
57476f6b 477
d74d141c 478/*
bc240b21 479 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
480 * 2 use this structure in different ways, reflecting SSH 2's
481 * altogether saner approach to port forwarding.
482 *
483 * In SSH 1, you arrange a remote forwarding by sending the server
484 * the remote port number, and the local destination host:port.
485 * When a connection comes in, the server sends you back that
486 * host:port pair, and you connect to it. This is a ready-made
487 * security hole if you're not on the ball: a malicious server
488 * could send you back _any_ host:port pair, so if you trustingly
489 * connect to the address it gives you then you've just opened the
490 * entire inside of your corporate network just by connecting
491 * through it to a dodgy SSH server. Hence, we must store a list of
492 * host:port pairs we _are_ trying to forward to, and reject a
493 * connection request from the server if it's not in the list.
494 *
495 * In SSH 2, each side of the connection minds its own business and
496 * doesn't send unnecessary information to the other. You arrange a
497 * remote forwarding by sending the server just the remote port
498 * number. When a connection comes in, the server tells you which
499 * of its ports was connected to; and _you_ have to remember what
500 * local host:port pair went with that port number.
501 *
502 * Hence: in SSH 1 this structure stores host:port pairs we intend
503 * to allow connections to, and is indexed by those host:port
504 * pairs. In SSH 2 it stores a mapping from source port to
505 * destination host:port pair, and is indexed by source port.
d74d141c 506 */
507struct ssh_rportfwd {
bc240b21 508 unsigned sport, dport;
509 char dhost[256];
d74d141c 510};
511
57476f6b 512struct Packet {
513 long length;
514 int type;
b09eaa88 515 unsigned long sequence;
57476f6b 516 unsigned char *data;
517 unsigned char *body;
518 long savedpos;
519 long maxlen;
9442dd57 520 long encrypted_len; /* for SSH2 total-size counting */
ff3187f6 521
522 /*
523 * State associated with packet logging
524 */
525 int logmode;
526 int nblanks;
527 struct logblank_t *blanks;
57476f6b 528};
529
ff3187f6 530static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
531 struct Packet *pktin);
532static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
533 struct Packet *pktin);
b09eaa88 534static void ssh1_protocol_setup(Ssh ssh);
535static void ssh2_protocol_setup(Ssh ssh);
51470298 536static void ssh_size(void *handle, int width, int height);
537static void ssh_special(void *handle, Telnet_Special);
5471d09a 538static int ssh2_try_send(struct ssh_channel *c);
51470298 539static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
540static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 541static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 542static int ssh_sendbuffer(void *handle);
36f94d1f 543static void ssh_do_close(Ssh ssh);
ff3187f6 544static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
545static int ssh2_pkt_getbool(struct Packet *pkt);
546static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 547static void ssh2_timer(void *ctx, long now);
548static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
549 struct Packet *pktin);
57476f6b 550
51470298 551struct rdpkt1_state_tag {
57476f6b 552 long len, pad, biglen, to_read;
553 unsigned long realcrc, gotcrc;
554 unsigned char *p;
555 int i;
556 int chunk;
ff3187f6 557 struct Packet *pktin;
51470298 558};
57476f6b 559
51470298 560struct rdpkt2_state_tag {
960e736a 561 long len, pad, payload, packetlen, maclen;
562 int i;
563 int cipherblk;
564 unsigned long incoming_sequence;
ff3187f6 565 struct Packet *pktin;
51470298 566};
567
b09eaa88 568typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
569
51470298 570struct ssh_tag {
571 const struct plug_function_table *fn;
572 /* the above field _must_ be first in the structure */
573
574 SHA_State exhash, exhashbase;
575
576 Socket s;
577
b9d7bcad 578 void *ldisc;
a8327734 579 void *logctx;
b9d7bcad 580
51470298 581 unsigned char session_key[32];
582 int v1_compressing;
583 int v1_remote_protoflags;
584 int v1_local_protoflags;
585 int agentfwd_enabled;
586 int X11_fwd_enabled;
587 int remote_bugs;
588 const struct ssh_cipher *cipher;
371e569c 589 void *v1_cipher_ctx;
0183b242 590 void *crcda_ctx;
51470298 591 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 592 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 593 const struct ssh_mac *csmac, *scmac;
e0e1a00d 594 void *cs_mac_ctx, *sc_mac_ctx;
51470298 595 const struct ssh_compress *cscomp, *sccomp;
5366aed8 596 void *cs_comp_ctx, *sc_comp_ctx;
51470298 597 const struct ssh_kex *kex;
598 const struct ssh_signkey *hostkey;
599 unsigned char v2_session_id[20];
27cd7fc2 600 void *kex_ctx;
51470298 601
602 char *savedhost;
603 int savedport;
604 int send_ok;
605 int echoing, editing;
606
607 void *frontend;
608
db219738 609 int ospeed, ispeed; /* temporaries */
51470298 610 int term_width, term_height;
611
612 tree234 *channels; /* indexed by local id */
613 struct ssh_channel *mainchan; /* primary session channel */
614 int exitcode;
615
616 tree234 *rportfwds;
617
618 enum {
619 SSH_STATE_PREPACKET,
620 SSH_STATE_BEFORE_SIZE,
621 SSH_STATE_INTERMED,
622 SSH_STATE_SESSION,
623 SSH_STATE_CLOSED
624 } state;
625
626 int size_needed, eof_needed;
627
590f6a5f 628 struct Packet **queue;
629 int queuelen, queuesize;
630 int queueing;
51470298 631 unsigned char *deferred_send_data;
632 int deferred_len, deferred_size;
633
634 /*
635 * Gross hack: pscp will try to start SFTP but fall back to
636 * scp1 if that fails. This variable is the means by which
637 * scp.c can reach into the SSH code and find out which one it
638 * got.
639 */
640 int fallback_cmd;
641
642 /*
643 * Used for username and password input.
644 */
645 char *userpass_input_buffer;
646 int userpass_input_buflen;
647 int userpass_input_bufpos;
648 int userpass_input_echo;
649
650 char *portfwd_strptr;
651 int pkt_ctx;
652
302121de 653 void *x11auth;
654
51470298 655 int version;
656 int v1_throttle_count;
657 int overall_bufsize;
658 int throttled_all;
659 int v1_stdout_throttling;
660 int v2_outgoing_sequence;
661
662 int ssh1_rdpkt_crstate;
663 int ssh2_rdpkt_crstate;
664 int do_ssh_init_crstate;
665 int ssh_gotdata_crstate;
51470298 666 int do_ssh1_login_crstate;
b09eaa88 667 int do_ssh1_connection_crstate;
51470298 668 int do_ssh2_transport_crstate;
669 int do_ssh2_authconn_crstate;
670
671 void *do_ssh_init_state;
672 void *do_ssh1_login_state;
673 void *do_ssh2_transport_state;
674 void *do_ssh2_authconn_state;
675
676 struct rdpkt1_state_tag rdpkt1_state;
677 struct rdpkt2_state_tag rdpkt2_state;
678
b09eaa88 679 /* ssh1 and ssh2 use this for different things, but both use it */
680 int protocol_initial_phase_done;
681
ff3187f6 682 void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
683 struct Packet *pkt);
684 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 685
686 /*
687 * We maintain a full _copy_ of a Config structure here, not
688 * merely a pointer to it. That way, when we're passed a new
689 * one for reconfiguration, we can check the differences and
690 * potentially reconfigure port forwardings etc in mid-session.
691 */
692 Config cfg;
839f10db 693
694 /*
695 * Used to transfer data back from async agent callbacks.
696 */
697 void *agent_response;
698 int agent_response_len;
b09eaa88 699
700 /*
701 * Dispatch table for packet types that we may have to deal
702 * with at any time.
703 */
704 handler_fn_t packet_dispatch[256];
39934deb 705
706 /*
707 * This module deals with sending keepalives.
708 */
709 Pinger pinger;
9442dd57 710
711 /*
712 * Track incoming and outgoing data sizes and time, for
713 * size-based rekeys.
714 */
715 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
716 int kex_in_progress;
717 long next_rekey;
51470298 718};
960e736a 719
9442dd57 720#define MAX_DATA_BEFORE_REKEY (0x40000000UL)
721#define REKEY_TIMEOUT (3600 * TICKSPERSEC)
722
382908ad 723#define logevent(s) logevent(ssh->frontend, s)
a8327734 724
725/* logevent, only printf-formatted. */
cbe2d68f 726static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 727{
728 va_list ap;
57356d63 729 char *buf;
a8327734 730
731 va_start(ap, fmt);
57356d63 732 buf = dupvprintf(fmt, ap);
a8327734 733 va_end(ap);
57356d63 734 logevent(buf);
57356d63 735 sfree(buf);
a8327734 736}
737
6b5cf8b4 738#define bombout(msg) \
739 do { \
740 char *text = dupprintf msg; \
36f94d1f 741 ssh_do_close(ssh); \
6b5cf8b4 742 logevent(text); \
743 connection_fatal(ssh->frontend, "%s", text); \
744 sfree(text); \
745 } while (0)
a8327734 746
9a10ecf4 747/* Functions to leave bits out of the SSH packet log file. */
748
ff3187f6 749static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 750{
751 if (ssh->cfg.logomitpass)
ff3187f6 752 pkt->logmode = blanktype;
9a10ecf4 753}
754
ff3187f6 755static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 756{
757 if (ssh->cfg.logomitdata)
ff3187f6 758 pkt->logmode = blanktype;
9a10ecf4 759}
760
ff3187f6 761static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 762{
ff3187f6 763 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 764}
765
32874aea 766static int ssh_channelcmp(void *av, void *bv)
767{
768 struct ssh_channel *a = (struct ssh_channel *) av;
769 struct ssh_channel *b = (struct ssh_channel *) bv;
770 if (a->localid < b->localid)
771 return -1;
772 if (a->localid > b->localid)
773 return +1;
dacbd0e8 774 return 0;
775}
32874aea 776static int ssh_channelfind(void *av, void *bv)
777{
778 unsigned *a = (unsigned *) av;
779 struct ssh_channel *b = (struct ssh_channel *) bv;
780 if (*a < b->localid)
781 return -1;
782 if (*a > b->localid)
783 return +1;
dacbd0e8 784 return 0;
785}
786
bc240b21 787static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 788{
789 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
790 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
791 int i;
bc240b21 792 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 793 return i < 0 ? -1 : +1;
bc240b21 794 if (a->dport > b->dport)
795 return +1;
796 if (a->dport < b->dport)
797 return -1;
798 return 0;
799}
800
801static int ssh_rportcmp_ssh2(void *av, void *bv)
802{
803 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
804 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 805
bc240b21 806 if (a->sport > b->sport)
d74d141c 807 return +1;
bc240b21 808 if (a->sport < b->sport)
809 return -1;
d74d141c 810 return 0;
811}
812
51470298 813static int alloc_channel_id(Ssh ssh)
32874aea 814{
260f3dec 815 const unsigned CHANNEL_NUMBER_OFFSET = 256;
816 unsigned low, high, mid;
d2371c81 817 int tsize;
818 struct ssh_channel *c;
819
820 /*
821 * First-fit allocation of channel numbers: always pick the
822 * lowest unused one. To do this, binary-search using the
823 * counted B-tree to find the largest channel ID which is in a
824 * contiguous sequence from the beginning. (Precisely
825 * everything in that sequence must have ID equal to its tree
826 * index plus CHANNEL_NUMBER_OFFSET.)
827 */
51470298 828 tsize = count234(ssh->channels);
d2371c81 829
32874aea 830 low = -1;
831 high = tsize;
d2371c81 832 while (high - low > 1) {
833 mid = (high + low) / 2;
51470298 834 c = index234(ssh->channels, mid);
d2371c81 835 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
836 low = mid; /* this one is fine */
837 else
838 high = mid; /* this one is past it */
839 }
840 /*
841 * Now low points to either -1, or the tree index of the
842 * largest ID in the initial sequence.
843 */
844 {
845 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 846 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 847 }
848 return low + 1 + CHANNEL_NUMBER_OFFSET;
849}
850
9fab77dc 851static void c_write(Ssh ssh, const char *buf, int len)
32874aea 852{
67779be7 853 if ((flags & FLAG_STDERR)) {
32874aea 854 int i;
855 for (i = 0; i < len; i++)
856 if (buf[i] != '\r')
857 fputc(buf[i], stderr);
fb09bf1c 858 return;
859 }
51470298 860 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 861}
862
9fab77dc 863static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 864{
a209e957 865 int i;
866 for (i = 0; i < len; i++) {
32874aea 867 if (buf[i] == '\n')
51470298 868 c_write(ssh, "\r\n", 2);
32874aea 869 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
51470298 870 c_write(ssh, buf + i, 1);
a209e957 871 }
872}
873
9fab77dc 874static void c_write_str(Ssh ssh, const char *buf)
32874aea 875{
51470298 876 c_write(ssh, buf, strlen(buf));
1408a877 877}
878
ff3187f6 879static void ssh_free_packet(struct Packet *pkt)
880{
881 sfree(pkt->data);
882 sfree(pkt);
883}
884static struct Packet *ssh_new_packet(void)
885{
886 struct Packet *pkt = snew(struct Packet);
887
888 pkt->data = NULL;
889 pkt->maxlen = 0;
890 pkt->logmode = PKTLOG_EMIT;
891 pkt->nblanks = 0;
892 pkt->blanks = NULL;
893
894 return pkt;
895}
896
fb09bf1c 897/*
898 * Collect incoming data in the incoming packet buffer.
e5574168 899 * Decipher and verify the packet when it is completely read.
900 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 901 * Update the *data and *datalen variables.
ff3187f6 902 * Return a Packet structure when a packet is completed.
fb09bf1c 903 */
ff3187f6 904static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 905{
51470298 906 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 907
51470298 908 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 909
ff3187f6 910 st->pktin = ssh_new_packet();
911
912 st->pktin->type = 0;
913 st->pktin->length = 0;
374330e2 914
57476f6b 915 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 916 while ((*datalen) == 0)
ff3187f6 917 crReturn(NULL);
57476f6b 918 st->len = (st->len << 8) + **data;
fb09bf1c 919 (*data)++, (*datalen)--;
920 }
374330e2 921
57476f6b 922 st->pad = 8 - (st->len % 8);
923 st->biglen = st->len + st->pad;
ff3187f6 924 st->pktin->length = st->len - 5;
fb09bf1c 925
ae0500e5 926 if (st->biglen < 0) {
927 bombout(("Extremely large packet length from server suggests"
928 " data stream corruption"));
ff3187f6 929 ssh_free_packet(st->pktin);
930 crStop(NULL);
ae0500e5 931 }
932
ff3187f6 933 st->pktin->maxlen = st->biglen;
934 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 935
57476f6b 936 st->to_read = st->biglen;
ff3187f6 937 st->p = st->pktin->data;
57476f6b 938 while (st->to_read > 0) {
32874aea 939 st->chunk = st->to_read;
fb09bf1c 940 while ((*datalen) == 0)
ff3187f6 941 crReturn(NULL);
57476f6b 942 if (st->chunk > (*datalen))
943 st->chunk = (*datalen);
944 memcpy(st->p, *data, st->chunk);
945 *data += st->chunk;
946 *datalen -= st->chunk;
947 st->p += st->chunk;
948 st->to_read -= st->chunk;
fb09bf1c 949 }
374330e2 950
ff3187f6 951 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 952 st->biglen, NULL)) {
6b5cf8b4 953 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 954 ssh_free_packet(st->pktin);
955 crStop(NULL);
9a3a93a5 956 }
957
51470298 958 if (ssh->cipher)
ff3187f6 959 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 960
ff3187f6 961 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
962 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 963 if (st->gotcrc != st->realcrc) {
6b5cf8b4 964 bombout(("Incorrect CRC received on packet"));
ff3187f6 965 ssh_free_packet(st->pktin);
966 crStop(NULL);
fb09bf1c 967 }
572f871e 968
ff3187f6 969 st->pktin->body = st->pktin->data + st->pad + 1;
970 st->pktin->savedpos = 0;
4ba9b64b 971
51470298 972 if (ssh->v1_compressing) {
4ba9b64b 973 unsigned char *decompblk;
974 int decomplen;
36b8d9bb 975 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 976 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 977 &decompblk, &decomplen)) {
978 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 979 ssh_free_packet(st->pktin);
980 crStop(NULL);
36b8d9bb 981 }
4ba9b64b 982
ff3187f6 983 if (st->pktin->maxlen < st->pad + decomplen) {
984 st->pktin->maxlen = st->pad + decomplen;
985 st->pktin->data = sresize(st->pktin->data,
986 st->pktin->maxlen + APIEXTRA,
3d88e64d 987 unsigned char);
ff3187f6 988 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 989 }
990
ff3187f6 991 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 992 sfree(decompblk);
ff3187f6 993 st->pktin->length = decomplen - 1;
4ba9b64b 994 }
995
ff3187f6 996 st->pktin->type = st->pktin->body[-1];
00db133f 997
9a10ecf4 998 /*
999 * Log incoming packet, possibly omitting sensitive fields.
1000 */
1001 if (ssh->logctx) {
1002 int nblanks = 0;
1003 struct logblank_t blank;
1004 if (ssh->cfg.logomitdata) {
1005 int do_blank = FALSE, blank_prefix = 0;
1006 /* "Session data" packets - omit the data field */
ff3187f6 1007 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1008 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1009 do_blank = TRUE; blank_prefix = 0;
ff3187f6 1010 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
9a10ecf4 1011 do_blank = TRUE; blank_prefix = 4;
1012 }
1013 if (do_blank) {
1014 blank.offset = blank_prefix;
ff3187f6 1015 blank.len = st->pktin->length;
9a10ecf4 1016 blank.type = PKTLOG_OMIT;
1017 nblanks = 1;
1018 }
1019 }
a8327734 1020 log_packet(ssh->logctx,
ff3187f6 1021 PKT_INCOMING, st->pktin->type,
1022 ssh1_pkt_type(st->pktin->type),
1023 st->pktin->body, st->pktin->length,
9a10ecf4 1024 nblanks, &blank);
1025 }
00db133f 1026
ff3187f6 1027 crFinish(st->pktin);
fb09bf1c 1028}
1029
ff3187f6 1030static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1031{
51470298 1032 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1033
51470298 1034 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1035
ff3187f6 1036 st->pktin = ssh_new_packet();
1037
1038 st->pktin->type = 0;
1039 st->pktin->length = 0;
51470298 1040 if (ssh->sccipher)
1041 st->cipherblk = ssh->sccipher->blksize;
e5574168 1042 else
32874aea 1043 st->cipherblk = 8;
960e736a 1044 if (st->cipherblk < 8)
32874aea 1045 st->cipherblk = 8;
960e736a 1046
ff3187f6 1047 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
e5574168 1048
1049 /*
1050 * Acquire and decrypt the first block of the packet. This will
1051 * contain the length and padding details.
1052 */
32874aea 1053 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 1054 while ((*datalen) == 0)
ff3187f6 1055 crReturn(NULL);
1056 st->pktin->data[st->i] = *(*data)++;
32874aea 1057 (*datalen)--;
e5574168 1058 }
4252c9cc 1059
51470298 1060 if (ssh->sccipher)
371e569c 1061 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1062 st->pktin->data, st->cipherblk);
e5574168 1063
1064 /*
1065 * Now get the length and padding figures.
1066 */
ff3187f6 1067 st->len = GET_32BIT(st->pktin->data);
1068 st->pad = st->pktin->data[4];
e5574168 1069
1070 /*
717dc483 1071 * _Completely_ silly lengths should be stomped on before they
1072 * do us any more damage.
1073 */
1074 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
6b5cf8b4 1075 bombout(("Incoming packet was garbled on decryption"));
ff3187f6 1076 ssh_free_packet(st->pktin);
1077 crStop(NULL);
717dc483 1078 }
1079
1080 /*
e5574168 1081 * This enables us to deduce the payload length.
1082 */
960e736a 1083 st->payload = st->len - st->pad - 1;
e5574168 1084
ff3187f6 1085 st->pktin->length = st->payload + 5;
e5574168 1086
1087 /*
1088 * So now we can work out the total packet length.
1089 */
960e736a 1090 st->packetlen = st->len + 4;
51470298 1091 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 1092
1093 /*
ff3187f6 1094 * Allocate memory for the rest of the packet.
e5574168 1095 */
ff3187f6 1096 st->pktin->maxlen = st->packetlen + st->maclen;
1097 st->pktin->data = sresize(st->pktin->data,
1098 st->pktin->maxlen + APIEXTRA,
1099 unsigned char);
e5574168 1100
1101 /*
1102 * Read and decrypt the remainder of the packet.
1103 */
32874aea 1104 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1105 st->i++) {
e5574168 1106 while ((*datalen) == 0)
ff3187f6 1107 crReturn(NULL);
1108 st->pktin->data[st->i] = *(*data)++;
32874aea 1109 (*datalen)--;
e5574168 1110 }
1111 /* Decrypt everything _except_ the MAC. */
51470298 1112 if (ssh->sccipher)
371e569c 1113 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1114 st->pktin->data + st->cipherblk,
51470298 1115 st->packetlen - st->cipherblk);
e5574168 1116
9442dd57 1117 st->pktin->encrypted_len = st->packetlen;
1118
e5574168 1119 /*
1120 * Check the MAC.
1121 */
51470298 1122 if (ssh->scmac
ff3187f6 1123 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
51470298 1124 st->incoming_sequence)) {
6b5cf8b4 1125 bombout(("Incorrect MAC received on packet"));
ff3187f6 1126 ssh_free_packet(st->pktin);
1127 crStop(NULL);
8d5de777 1128 }
b09eaa88 1129
1130 st->pktin->sequence = st->incoming_sequence++;
e5574168 1131
4ba9b64b 1132 /*
1133 * Decompress packet payload.
1134 */
1135 {
1136 unsigned char *newpayload;
1137 int newlen;
51470298 1138 if (ssh->sccomp &&
5366aed8 1139 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1140 st->pktin->data + 5, st->pktin->length - 5,
51470298 1141 &newpayload, &newlen)) {
ff3187f6 1142 if (st->pktin->maxlen < newlen + 5) {
1143 st->pktin->maxlen = newlen + 5;
1144 st->pktin->data = sresize(st->pktin->data,
1145 st->pktin->maxlen + APIEXTRA,
3d88e64d 1146 unsigned char);
4ba9b64b 1147 }
ff3187f6 1148 st->pktin->length = 5 + newlen;
1149 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1150 sfree(newpayload);
4ba9b64b 1151 }
1152 }
1153
ff3187f6 1154 st->pktin->savedpos = 6;
1155 st->pktin->body = st->pktin->data;
1156 st->pktin->type = st->pktin->data[5];
e5574168 1157
9a10ecf4 1158 /*
1159 * Log incoming packet, possibly omitting sensitive fields.
1160 */
1161 if (ssh->logctx) {
1162 int nblanks = 0;
1163 struct logblank_t blank;
1164 if (ssh->cfg.logomitdata) {
1165 int do_blank = FALSE, blank_prefix = 0;
1166 /* "Session data" packets - omit the data field */
ff3187f6 1167 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1168 do_blank = TRUE; blank_prefix = 4;
ff3187f6 1169 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
9a10ecf4 1170 do_blank = TRUE; blank_prefix = 8;
1171 }
1172 if (do_blank) {
1173 blank.offset = blank_prefix;
ff3187f6 1174 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1175 blank.type = PKTLOG_OMIT;
1176 nblanks = 1;
1177 }
1178 }
ff3187f6 1179 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1180 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1181 st->pktin->data+6, st->pktin->length-6,
9a10ecf4 1182 nblanks, &blank);
1183 }
00db133f 1184
ff3187f6 1185 crFinish(st->pktin);
e5574168 1186}
1187
ff3187f6 1188static void ssh1_pktout_size(struct Packet *pkt, int len)
32874aea 1189{
374330e2 1190 int pad, biglen;
1191
1192 len += 5; /* type and CRC */
32874aea 1193 pad = 8 - (len % 8);
374330e2 1194 biglen = len + pad;
1195
ff3187f6 1196 pkt->length = len - 5;
1197 if (pkt->maxlen < biglen) {
1198 pkt->maxlen = biglen;
1199 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
374330e2 1200 }
ff3187f6 1201 pkt->body = pkt->data + 4 + pad + 1;
4ba9b64b 1202}
374330e2 1203
ff3187f6 1204static struct Packet *s_wrpkt_start(int type, int len)
32874aea 1205{
ff3187f6 1206 struct Packet *pkt = ssh_new_packet();
1207 ssh1_pktout_size(pkt, len);
1208 pkt->type = type;
9a10ecf4 1209 /* Initialise log omission state */
ff3187f6 1210 pkt->nblanks = 0;
1211 pkt->blanks = NULL;
1212 return pkt;
374330e2 1213}
1214
ff3187f6 1215static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
32874aea 1216{
fd7a4aad 1217 int pad, biglen, i;
374330e2 1218 unsigned long crc;
fd7a4aad 1219#ifdef __SC__
1220 /*
1221 * XXX various versions of SC (including 8.8.4) screw up the
1222 * register allocation in this function and use the same register
1223 * (D6) for len and as a temporary, with predictable results. The
1224 * following sledgehammer prevents this.
1225 */
1226 volatile
1227#endif
1228 int len;
374330e2 1229
ff3187f6 1230 pkt->body[-1] = pkt->type;
4ba9b64b 1231
a8327734 1232 if (ssh->logctx)
ff3187f6 1233 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1234 ssh1_pkt_type(pkt->type),
1235 pkt->body, pkt->length,
1236 pkt->nblanks, pkt->blanks);
1237 sfree(pkt->blanks); pkt->blanks = NULL;
1238 pkt->nblanks = 0;
00db133f 1239
51470298 1240 if (ssh->v1_compressing) {
4ba9b64b 1241 unsigned char *compblk;
1242 int complen;
5366aed8 1243 zlib_compress_block(ssh->cs_comp_ctx,
ff3187f6 1244 pkt->body - 1, pkt->length + 1,
4ba9b64b 1245 &compblk, &complen);
ff3187f6 1246 ssh1_pktout_size(pkt, complen - 1);
1247 memcpy(pkt->body - 1, compblk, complen);
dcbde236 1248 sfree(compblk);
4ba9b64b 1249 }
1250
ff3187f6 1251 len = pkt->length + 5; /* type and CRC */
32874aea 1252 pad = 8 - (len % 8);
374330e2 1253 biglen = len + pad;
1254
32874aea 1255 for (i = 0; i < pad; i++)
ff3187f6 1256 pkt->data[i + 4] = random_byte();
1257 crc = crc32_compute(pkt->data + 4, biglen - 4);
1258 PUT_32BIT(pkt->data + biglen, crc);
1259 PUT_32BIT(pkt->data, len);
374330e2 1260
51470298 1261 if (ssh->cipher)
ff3187f6 1262 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
374330e2 1263
32874aea 1264 return biglen + 4;
39065bed 1265}
1266
ff3187f6 1267static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1268{
5471d09a 1269 int len, backlog;
ff3187f6 1270 len = s_wrpkt_prepare(ssh, pkt);
1271 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1272 if (backlog > SSH_MAX_BACKLOG)
51470298 1273 ssh_throttle_all(ssh, 1, backlog);
39065bed 1274}
1275
ff3187f6 1276static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1277{
39065bed 1278 int len;
ff3187f6 1279 len = s_wrpkt_prepare(ssh, pkt);
51470298 1280 if (ssh->deferred_len + len > ssh->deferred_size) {
1281 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1282 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1283 ssh->deferred_size,
1284 unsigned char);
39065bed 1285 }
ff3187f6 1286 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1287 ssh->deferred_len += len;
374330e2 1288}
1289
fb09bf1c 1290/*
39065bed 1291 * Construct a packet with the specified contents.
fb09bf1c 1292 */
ff3187f6 1293static struct Packet *construct_packet(Ssh ssh, int pkttype,
1294 va_list ap1, va_list ap2)
fb09bf1c 1295{
fb09bf1c 1296 unsigned char *p, *argp, argchar;
1297 unsigned long argint;
1298 int pktlen, argtype, arglen;
7cca0d81 1299 Bignum bn;
ff3187f6 1300 struct Packet *pkt;
fb09bf1c 1301
1302 pktlen = 0;
39065bed 1303 while ((argtype = va_arg(ap1, int)) != PKT_END) {
fb09bf1c 1304 switch (argtype) {
1305 case PKT_INT:
39065bed 1306 (void) va_arg(ap1, int);
fb09bf1c 1307 pktlen += 4;
1308 break;
1309 case PKT_CHAR:
1ec39246 1310 (void) va_arg(ap1, int);
fb09bf1c 1311 pktlen++;
1312 break;
1313 case PKT_DATA:
39065bed 1314 (void) va_arg(ap1, unsigned char *);
1315 arglen = va_arg(ap1, int);
fb09bf1c 1316 pktlen += arglen;
1317 break;
1318 case PKT_STR:
39065bed 1319 argp = va_arg(ap1, unsigned char *);
d8baa528 1320 arglen = strlen((char *)argp);
fb09bf1c 1321 pktlen += 4 + arglen;
1322 break;
7cca0d81 1323 case PKT_BIGNUM:
39065bed 1324 bn = va_arg(ap1, Bignum);
32874aea 1325 pktlen += ssh1_bignum_length(bn);
7cca0d81 1326 break;
9a10ecf4 1327 case PKTT_PASSWORD:
1328 case PKTT_DATA:
1329 case PKTT_OTHER:
1330 /* ignore this pass */
1331 break;
fb09bf1c 1332 default:
1333 assert(0);
1334 }
1335 }
fb09bf1c 1336
ff3187f6 1337 pkt = s_wrpkt_start(pkttype, pktlen);
1338 p = pkt->body;
fb09bf1c 1339
39065bed 1340 while ((argtype = va_arg(ap2, int)) != PKT_END) {
ff3187f6 1341 int offset = p - pkt->body, len = 0;
fb09bf1c 1342 switch (argtype) {
9a10ecf4 1343 /* Actual fields in the packet */
fb09bf1c 1344 case PKT_INT:
39065bed 1345 argint = va_arg(ap2, int);
fb09bf1c 1346 PUT_32BIT(p, argint);
9a10ecf4 1347 len = 4;
fb09bf1c 1348 break;
1349 case PKT_CHAR:
1ec39246 1350 argchar = (unsigned char) va_arg(ap2, int);
fb09bf1c 1351 *p = argchar;
9a10ecf4 1352 len = 1;
fb09bf1c 1353 break;
1354 case PKT_DATA:
39065bed 1355 argp = va_arg(ap2, unsigned char *);
1356 arglen = va_arg(ap2, int);
fb09bf1c 1357 memcpy(p, argp, arglen);
9a10ecf4 1358 len = arglen;
fb09bf1c 1359 break;
1360 case PKT_STR:
39065bed 1361 argp = va_arg(ap2, unsigned char *);
d8baa528 1362 arglen = strlen((char *)argp);
fb09bf1c 1363 PUT_32BIT(p, arglen);
1364 memcpy(p + 4, argp, arglen);
9a10ecf4 1365 len = arglen + 4;
fb09bf1c 1366 break;
7cca0d81 1367 case PKT_BIGNUM:
39065bed 1368 bn = va_arg(ap2, Bignum);
9a10ecf4 1369 len = ssh1_write_bignum(p, bn);
1370 break;
1371 /* Tokens for modifications to packet logging */
1372 case PKTT_PASSWORD:
ff3187f6 1373 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1374 break;
1375 case PKTT_DATA:
ff3187f6 1376 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1377 break;
9a10ecf4 1378 case PKTT_OTHER:
ff3187f6 1379 end_log_omission(ssh, pkt);
9a10ecf4 1380 break;
1381 }
1382 p += len;
1383 /* Deal with logfile omission, if required. */
ff3187f6 1384 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1385 pkt->nblanks++;
1386 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1387 struct logblank_t);
1388 pkt->blanks[pkt->nblanks-1].offset = offset;
1389 pkt->blanks[pkt->nblanks-1].len = len;
1390 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
fb09bf1c 1391 }
1392 }
ff3187f6 1393
1394 return pkt;
39065bed 1395}
fb09bf1c 1396
51470298 1397static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1398{
ff3187f6 1399 struct Packet *pkt;
39065bed 1400 va_list ap1, ap2;
1401 va_start(ap1, pkttype);
1402 va_start(ap2, pkttype);
ff3187f6 1403 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1404 va_end(ap2);
1405 va_end(ap1);
1406 s_wrpkt(ssh, pkt);
1407 ssh_free_packet(pkt);
fb09bf1c 1408}
1409
51470298 1410static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1411{
ff3187f6 1412 struct Packet *pkt;
39065bed 1413 va_list ap1, ap2;
1414 va_start(ap1, pkttype);
1415 va_start(ap2, pkttype);
ff3187f6 1416 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1417 va_end(ap2);
1418 va_end(ap1);
1419 s_wrpkt_defer(ssh, pkt);
1420 ssh_free_packet(pkt);
39065bed 1421}
1422
32874aea 1423static int ssh_versioncmp(char *a, char *b)
1424{
9697bfd2 1425 char *ae, *be;
1426 unsigned long av, bv;
1427
43aa02a7 1428 av = strtoul(a, &ae, 10);
1429 bv = strtoul(b, &be, 10);
32874aea 1430 if (av != bv)
1431 return (av < bv ? -1 : +1);
1432 if (*ae == '.')
1433 ae++;
1434 if (*be == '.')
1435 be++;
43aa02a7 1436 av = strtoul(ae, &ae, 10);
1437 bv = strtoul(be, &be, 10);
32874aea 1438 if (av != bv)
1439 return (av < bv ? -1 : +1);
9697bfd2 1440 return 0;
1441}
1442
e5574168 1443/*
a92dd380 1444 * Utility routines for putting an SSH-protocol `string' and
1445 * `uint32' into a SHA state.
e5574168 1446 */
1447#include <stdio.h>
32874aea 1448static void sha_string(SHA_State * s, void *str, int len)
1449{
e5574168 1450 unsigned char lenblk[4];
e5574168 1451 PUT_32BIT(lenblk, len);
e5574168 1452 SHA_Bytes(s, lenblk, 4);
e5574168 1453 SHA_Bytes(s, str, len);
1454}
1455
32874aea 1456static void sha_uint32(SHA_State * s, unsigned i)
1457{
a92dd380 1458 unsigned char intblk[4];
1459 PUT_32BIT(intblk, i);
1460 SHA_Bytes(s, intblk, 4);
1461}
1462
7cca0d81 1463/*
1464 * SSH2 packet construction functions.
1465 */
ff3187f6 1466static void ssh2_pkt_ensure(struct Packet *pkt, int length)
32874aea 1467{
ff3187f6 1468 if (pkt->maxlen < length) {
1469 pkt->maxlen = length + 256;
1470 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
7cca0d81 1471 }
783415f8 1472}
ff3187f6 1473static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1474{
ff3187f6 1475 if (pkt->logmode != PKTLOG_EMIT) {
1476 pkt->nblanks++;
1477 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1478 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1479 pkt->blanks[pkt->nblanks-1].len = len;
1480 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1481 }
1482 pkt->length += len;
1483 ssh2_pkt_ensure(pkt, pkt->length);
1484 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1485}
ff3187f6 1486static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1487{
ff3187f6 1488 ssh2_pkt_adddata(pkt, &byte, 1);
7cca0d81 1489}
ff3187f6 1490static struct Packet *ssh2_pkt_init(int pkt_type)
32874aea 1491{
ff3187f6 1492 struct Packet *pkt = ssh_new_packet();
1493 pkt->length = 5;
1494 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1495 return pkt;
7cca0d81 1496}
ff3187f6 1497static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1498{
ff3187f6 1499 ssh2_pkt_adddata(pkt, &value, 1);
7cca0d81 1500}
ff3187f6 1501static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1502{
7cca0d81 1503 unsigned char x[4];
1504 PUT_32BIT(x, value);
ff3187f6 1505 ssh2_pkt_adddata(pkt, x, 4);
7cca0d81 1506}
ff3187f6 1507static void ssh2_pkt_addstring_start(struct Packet *pkt)
32874aea 1508{
ff3187f6 1509 ssh2_pkt_adduint32(pkt, 0);
1510 pkt->savedpos = pkt->length;
7cca0d81 1511}
ff3187f6 1512static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1513{
ff3187f6 1514 ssh2_pkt_adddata(pkt, data, strlen(data));
1515 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1516}
ff3187f6 1517static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1518{
ff3187f6 1519 ssh2_pkt_adddata(pkt, data, len);
1520 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1521}
ff3187f6 1522static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
32874aea 1523{
ff3187f6 1524 ssh2_pkt_addstring_start(pkt);
1525 ssh2_pkt_addstring_str(pkt, data);
7cca0d81 1526}
d8baa528 1527static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1528{
7cca0d81 1529 unsigned char *p;
32874aea 1530 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1531 p = snewn(n + 1, unsigned char);
7cca0d81 1532 if (!p)
32874aea 1533 fatalbox("out of memory");
7cca0d81 1534 p[0] = 0;
3709bfe9 1535 for (i = 1; i <= n; i++)
32874aea 1536 p[i] = bignum_byte(b, n - i);
7cca0d81 1537 i = 0;
32874aea 1538 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1539 i++;
1540 memmove(p, p + i, n + 1 - i);
1541 *len = n + 1 - i;
7cca0d81 1542 return p;
1543}
ff3187f6 1544static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1545{
7cca0d81 1546 unsigned char *p;
1547 int len;
1548 p = ssh2_mpint_fmt(b, &len);
ff3187f6 1549 ssh2_pkt_addstring_start(pkt);
1550 ssh2_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1551 sfree(p);
7cca0d81 1552}
b185170a 1553
1554/*
1555 * Construct an SSH2 final-form packet: compress it, encrypt it,
1556 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1557 * pkt->data. Total length is returned.
b185170a 1558 */
ff3187f6 1559static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1560{
7cca0d81 1561 int cipherblk, maclen, padding, i;
7cca0d81 1562
a8327734 1563 if (ssh->logctx)
ff3187f6 1564 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1565 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1566 pkt->data + 6, pkt->length - 6,
1567 pkt->nblanks, pkt->blanks);
1568 sfree(pkt->blanks); pkt->blanks = NULL;
1569 pkt->nblanks = 0;
00db133f 1570
7cca0d81 1571 /*
4ba9b64b 1572 * Compress packet payload.
1573 */
4ba9b64b 1574 {
1575 unsigned char *newpayload;
1576 int newlen;
51470298 1577 if (ssh->cscomp &&
ff3187f6 1578 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1579 pkt->length - 5,
51470298 1580 &newpayload, &newlen)) {
ff3187f6 1581 pkt->length = 5;
1582 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1583 sfree(newpayload);
4ba9b64b 1584 }
1585 }
1586
1587 /*
7cca0d81 1588 * Add padding. At least four bytes, and must also bring total
1589 * length (minus MAC) up to a multiple of the block size.
1590 */
51470298 1591 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1592 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1593 padding = 4;
32874aea 1594 padding +=
ff3187f6 1595 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
51470298 1596 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1597 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1598 pkt->data[4] = padding;
7cca0d81 1599 for (i = 0; i < padding; i++)
ff3187f6 1600 pkt->data[pkt->length + i] = random_byte();
1601 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1602 if (ssh->csmac)
ff3187f6 1603 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1604 pkt->length + padding,
51470298 1605 ssh->v2_outgoing_sequence);
1606 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1607
1608 if (ssh->cscipher)
371e569c 1609 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 1610 pkt->data, pkt->length + padding);
51470298 1611
9442dd57 1612 pkt->encrypted_len = pkt->length + padding;
1613
ff3187f6 1614 /* Ready-to-send packet starts at pkt->data. We return length. */
1615 return pkt->length + padding + maclen;
b185170a 1616}
1617
1618/*
590f6a5f 1619 * Routines called from the main SSH code to send packets. There
1620 * are quite a few of these, because we have two separate
1621 * mechanisms for delaying the sending of packets:
1622 *
1623 * - In order to send an IGNORE message and a password message in
1624 * a single fixed-length blob, we require the ability to
1625 * concatenate the encrypted forms of those two packets _into_ a
1626 * single blob and then pass it to our <network.h> transport
1627 * layer in one go. Hence, there's a deferment mechanism which
1628 * works after packet encryption.
1629 *
1630 * - In order to avoid sending any connection-layer messages
1631 * during repeat key exchange, we have to queue up any such
1632 * outgoing messages _before_ they are encrypted (and in
1633 * particular before they're allocated sequence numbers), and
1634 * then send them once we've finished.
1635 *
1636 * I call these mechanisms `defer' and `queue' respectively, so as
1637 * to distinguish them reasonably easily.
1638 *
1639 * The functions send_noqueue() and defer_noqueue() free the packet
1640 * structure they are passed. Every outgoing packet goes through
1641 * precisely one of these functions in its life; packets passed to
1642 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1643 * these or get queued, and then when the queue is later emptied
1644 * the packets are all passed to defer_noqueue().
b185170a 1645 */
590f6a5f 1646
1647/*
1648 * Send an SSH2 packet immediately, without queuing or deferring.
1649 */
1650static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1651{
5471d09a 1652 int len;
1653 int backlog;
ff3187f6 1654 len = ssh2_pkt_construct(ssh, pkt);
1655 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1656 if (backlog > SSH_MAX_BACKLOG)
51470298 1657 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1658
1659 ssh->outgoing_data_size += pkt->encrypted_len;
1660 if (!ssh->kex_in_progress &&
1661 ssh->outgoing_data_size > MAX_DATA_BEFORE_REKEY)
1662 do_ssh2_transport(ssh, "Initiating key re-exchange "
1663 "(too much data sent)", -1, NULL);
1664
ff3187f6 1665 ssh_free_packet(pkt);
b185170a 1666}
1667
1668/*
590f6a5f 1669 * Defer an SSH2 packet.
b185170a 1670 */
590f6a5f 1671static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1672{
ff3187f6 1673 int len = ssh2_pkt_construct(ssh, pkt);
51470298 1674 if (ssh->deferred_len + len > ssh->deferred_size) {
1675 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1676 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1677 ssh->deferred_size,
1678 unsigned char);
b185170a 1679 }
ff3187f6 1680 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1681 ssh->deferred_len += len;
9442dd57 1682 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 1683 ssh_free_packet(pkt);
b185170a 1684}
1685
1686/*
590f6a5f 1687 * Queue an SSH2 packet.
1688 */
1689static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1690{
1691 assert(ssh->queueing);
1692
1693 if (ssh->queuelen >= ssh->queuesize) {
1694 ssh->queuesize = ssh->queuelen + 32;
1695 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1696 }
1697
1698 ssh->queue[ssh->queuelen++] = pkt;
1699}
1700
1701/*
1702 * Either queue or send a packet, depending on whether queueing is
1703 * set.
1704 */
1705static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1706{
1707 if (ssh->queueing)
1708 ssh2_pkt_queue(ssh, pkt);
1709 else
1710 ssh2_pkt_send_noqueue(ssh, pkt);
1711}
1712
1713/*
1714 * Either queue or defer a packet, depending on whether queueing is
1715 * set.
1716 */
1717static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1718{
1719 if (ssh->queueing)
1720 ssh2_pkt_queue(ssh, pkt);
1721 else
1722 ssh2_pkt_defer_noqueue(ssh, pkt);
1723}
1724
1725/*
b185170a 1726 * Send the whole deferred data block constructed by
39065bed 1727 * ssh2_pkt_defer() or SSH1's defer_packet().
590f6a5f 1728 *
1729 * The expected use of the defer mechanism is that you call
1730 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1731 * not currently queueing, this simply sets up deferred_send_data
1732 * and then sends it. If we _are_ currently queueing, the calls to
1733 * ssh2_pkt_defer() put the deferred packets on to the queue
1734 * instead, and therefore ssh_pkt_defersend() has no deferred data
1735 * to send. Hence, there's no need to make it conditional on
1736 * ssh->queueing.
b185170a 1737 */
51470298 1738static void ssh_pkt_defersend(Ssh ssh)
32874aea 1739{
5471d09a 1740 int backlog;
d8baa528 1741 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1742 ssh->deferred_len);
51470298 1743 ssh->deferred_len = ssh->deferred_size = 0;
1744 sfree(ssh->deferred_send_data);
1745 ssh->deferred_send_data = NULL;
5471d09a 1746 if (backlog > SSH_MAX_BACKLOG)
51470298 1747 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1748
1749 ssh->outgoing_data_size += ssh->deferred_data_size;
1750 if (!ssh->kex_in_progress &&
1751 ssh->outgoing_data_size > MAX_DATA_BEFORE_REKEY)
1752 do_ssh2_transport(ssh, "Initiating key re-exchange "
1753 "(too much data sent)", -1, NULL);
1754 ssh->deferred_data_size = 0;
7cca0d81 1755}
1756
590f6a5f 1757/*
1758 * Send all queued SSH2 packets. We send them by means of
1759 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1760 * packets that needed to be lumped together.
1761 */
1762static void ssh2_pkt_queuesend(Ssh ssh)
1763{
1764 int i;
1765
1766 assert(!ssh->queueing);
1767
1768 for (i = 0; i < ssh->queuelen; i++)
1769 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1770 ssh->queuelen = 0;
1771
1772 ssh_pkt_defersend(ssh);
1773}
1774
7cca0d81 1775#if 0
32874aea 1776void bndebug(char *string, Bignum b)
1777{
7cca0d81 1778 unsigned char *p;
1779 int i, len;
1780 p = ssh2_mpint_fmt(b, &len);
1781 debug(("%s", string));
1782 for (i = 0; i < len; i++)
32874aea 1783 debug((" %02x", p[i]));
765c4200 1784 debug(("\n"));
dcbde236 1785 sfree(p);
7cca0d81 1786}
1787#endif
1788
32874aea 1789static void sha_mpint(SHA_State * s, Bignum b)
1790{
7cca0d81 1791 unsigned char *p;
1792 int len;
1793 p = ssh2_mpint_fmt(b, &len);
1794 sha_string(s, p, len);
dcbde236 1795 sfree(p);
7cca0d81 1796}
1797
1798/*
0016d70b 1799 * Packet decode functions for both SSH1 and SSH2.
7cca0d81 1800 */
ff3187f6 1801static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 1802{
7cca0d81 1803 unsigned long value;
ff3187f6 1804 if (pkt->length - pkt->savedpos < 4)
32874aea 1805 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1806 value = GET_32BIT(pkt->body + pkt->savedpos);
1807 pkt->savedpos += 4;
7cca0d81 1808 return value;
1809}
ff3187f6 1810static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 1811{
65a22376 1812 unsigned long value;
ff3187f6 1813 if (pkt->length - pkt->savedpos < 1)
32874aea 1814 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1815 value = pkt->body[pkt->savedpos] != 0;
1816 pkt->savedpos++;
65a22376 1817 return value;
1818}
ff3187f6 1819static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 1820{
57356d63 1821 int len;
7cca0d81 1822 *p = NULL;
45068b27 1823 *length = 0;
ff3187f6 1824 if (pkt->length - pkt->savedpos < 4)
32874aea 1825 return;
ff3187f6 1826 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 1827 if (len < 0)
1828 return;
1829 *length = len;
ff3187f6 1830 pkt->savedpos += 4;
1831 if (pkt->length - pkt->savedpos < *length)
32874aea 1832 return;
ff3187f6 1833 *p = (char *)(pkt->body + pkt->savedpos);
1834 pkt->savedpos += *length;
7cca0d81 1835}
ff3187f6 1836static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 1837{
ff3187f6 1838 if (pkt->length - pkt->savedpos < length)
0016d70b 1839 return NULL;
ff3187f6 1840 pkt->savedpos += length;
1841 return pkt->body + (pkt->savedpos - length);
0016d70b 1842}
ff3187f6 1843static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 1844 unsigned char **keystr)
1845{
1846 int j;
1847
ff3187f6 1848 j = makekey(pkt->body + pkt->savedpos,
1849 pkt->length - pkt->savedpos,
0016d70b 1850 key, keystr, 0);
1851
1852 if (j < 0)
1853 return FALSE;
1854
ff3187f6 1855 pkt->savedpos += j;
1856 assert(pkt->savedpos < pkt->length);
0016d70b 1857
1858 return TRUE;
1859}
ff3187f6 1860static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 1861{
1862 int j;
1863 Bignum b;
1864
ff3187f6 1865 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1866 pkt->length - pkt->savedpos, &b);
0016d70b 1867
1868 if (j < 0)
1869 return NULL;
1870
ff3187f6 1871 pkt->savedpos += j;
0016d70b 1872 return b;
1873}
ff3187f6 1874static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 1875{
7cca0d81 1876 char *p;
3709bfe9 1877 int length;
7cca0d81 1878 Bignum b;
1879
ff3187f6 1880 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 1881 if (!p)
32874aea 1882 return NULL;
ff3187f6 1883 if (p[0] & 0x80)
32874aea 1884 return NULL;
d8baa528 1885 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 1886 return b;
1887}
1888
7d503c31 1889/*
1dd353b5 1890 * Helper function to add an SSH2 signature blob to a packet.
1891 * Expects to be shown the public key blob as well as the signature
1892 * blob. Normally works just like ssh2_pkt_addstring, but will
1893 * fiddle with the signature packet if necessary for
1894 * BUG_SSH2_RSA_PADDING.
1895 */
ff3187f6 1896static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1897 void *pkblob_v, int pkblob_len,
1dd353b5 1898 void *sigblob_v, int sigblob_len)
1899{
1900 unsigned char *pkblob = (unsigned char *)pkblob_v;
1901 unsigned char *sigblob = (unsigned char *)sigblob_v;
1902
1903 /* dmemdump(pkblob, pkblob_len); */
1904 /* dmemdump(sigblob, sigblob_len); */
1905
1906 /*
1907 * See if this is in fact an ssh-rsa signature and a buggy
1908 * server; otherwise we can just do this the easy way.
1909 */
51470298 1910 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 1911 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1912 int pos, len, siglen;
1913
1914 /*
1915 * Find the byte length of the modulus.
1916 */
1917
1918 pos = 4+7; /* skip over "ssh-rsa" */
1919 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1920 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1921 pos += 4; /* find modulus itself */
1922 while (len > 0 && pkblob[pos] == 0)
1923 len--, pos++;
1924 /* debug(("modulus length is %d\n", len)); */
1925
1926 /*
1927 * Now find the signature integer.
1928 */
1929 pos = 4+7; /* skip over "ssh-rsa" */
1930 siglen = GET_32BIT(sigblob+pos);
1931 /* debug(("signature length is %d\n", siglen)); */
1932
1933 if (len != siglen) {
1934 unsigned char newlen[4];
ff3187f6 1935 ssh2_pkt_addstring_start(pkt);
1936 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 1937 /* dmemdump(sigblob, pos); */
1938 pos += 4; /* point to start of actual sig */
1939 PUT_32BIT(newlen, len);
ff3187f6 1940 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 1941 /* dmemdump(newlen, 4); */
1942 newlen[0] = 0;
1943 while (len-- > siglen) {
ff3187f6 1944 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 1945 /* dmemdump(newlen, 1); */
1946 }
ff3187f6 1947 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 1948 /* dmemdump(sigblob+pos, siglen); */
1949 return;
1950 }
1951
1952 /* Otherwise fall through and do it the easy way. */
1953 }
1954
ff3187f6 1955 ssh2_pkt_addstring_start(pkt);
1956 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 1957}
1958
1959/*
7d503c31 1960 * Examine the remote side's version string and compare it against
1961 * a list of known buggy implementations.
1962 */
51470298 1963static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 1964{
1965 char *imp; /* pointer to implementation part */
7d503c31 1966 imp = vstring;
1967 imp += strcspn(imp, "-");
bd358db1 1968 if (*imp) imp++;
7d503c31 1969 imp += strcspn(imp, "-");
bd358db1 1970 if (*imp) imp++;
7d503c31 1971
51470298 1972 ssh->remote_bugs = 0;
7d503c31 1973
5ecd7ad0 1974 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1975 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 1976 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1977 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 1978 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 1979 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 1980 /*
1981 * These versions don't support SSH1_MSG_IGNORE, so we have
1982 * to use a different defence against password length
1983 * sniffing.
1984 */
51470298 1985 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
32874aea 1986 logevent("We believe remote version has SSH1 ignore bug");
7d503c31 1987 }
1988
5ecd7ad0 1989 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1990 (ssh->cfg.sshbug_plainpw1 == AUTO &&
46ac09aa 1991 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 1992 /*
1993 * These versions need a plain password sent; they can't
1994 * handle having a null and a random length of data after
1995 * the password.
1996 */
51470298 1997 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
bd358db1 1998 logevent("We believe remote version needs a plain SSH1 password");
1999 }
2000
5ecd7ad0 2001 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2002 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 2003 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2004 /*
2005 * These versions apparently have no clue whatever about
2006 * RSA authentication and will panic and die if they see
2007 * an AUTH_RSA message.
2008 */
51470298 2009 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
0df73905 2010 logevent("We believe remote version can't handle RSA authentication");
2011 }
2012
5ecd7ad0 2013 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2014 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 2015 !wc_match("* VShell", imp) &&
831301f6 2016 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2017 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2018 wc_match("2.1 *", imp)))) {
32874aea 2019 /*
2020 * These versions have the HMAC bug.
2021 */
51470298 2022 ssh->remote_bugs |= BUG_SSH2_HMAC;
32874aea 2023 logevent("We believe remote version has SSH2 HMAC bug");
7d503c31 2024 }
1dd353b5 2025
5ecd7ad0 2026 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2027 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 2028 !wc_match("* VShell", imp) &&
2856a1b9 2029 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2030 /*
2031 * These versions have the key-derivation bug (failing to
2032 * include the literal shared secret in the hashes that
2033 * generate the keys).
2034 */
51470298 2035 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
088bde77 2036 logevent("We believe remote version has SSH2 key-derivation bug");
2037 }
2038
5ecd7ad0 2039 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2040 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 2041 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2042 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2043 /*
2044 * These versions have the SSH2 RSA padding bug.
2045 */
51470298 2046 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1dd353b5 2047 logevent("We believe remote version has SSH2 RSA padding bug");
2048 }
8e975795 2049
dda87a28 2050 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2051 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2052 wc_match("OpenSSH_2.[0-2]*", imp))) {
2053 /*
2054 * These versions have the SSH2 session-ID bug in
2055 * public-key authentication.
2056 */
2057 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2058 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2059 }
2060
5ecd7ad0 2061 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
8e975795 2062 /*
831301f6 2063 * User specified the SSH2 DH GEX bug.
8e975795 2064 */
51470298 2065 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
8e975795 2066 logevent("We believe remote version has SSH2 DH group exchange bug");
2067 }
7d503c31 2068}
2069
51470298 2070static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2071{
51470298 2072 struct do_ssh_init_state {
2073 int vslen;
2074 char version[10];
2075 char *vstring;
2076 int vstrsize;
2077 int i;
2078 int proto1, proto2;
2079 };
2080 crState(do_ssh_init_state);
374330e2 2081
51470298 2082 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2083
2084 /* Search for the string "SSH-" in the input. */
51470298 2085 s->i = 0;
8df7a775 2086 while (1) {
2087 static const int transS[] = { 1, 2, 2, 1 };
2088 static const int transH[] = { 0, 0, 3, 0 };
2089 static const int transminus[] = { 0, 0, 0, -1 };
32874aea 2090 if (c == 'S')
51470298 2091 s->i = transS[s->i];
32874aea 2092 else if (c == 'H')
51470298 2093 s->i = transH[s->i];
32874aea 2094 else if (c == '-')
51470298 2095 s->i = transminus[s->i];
32874aea 2096 else
51470298 2097 s->i = 0;
2098 if (s->i < 0)
8df7a775 2099 break;
2100 crReturn(1); /* get another character */
374330e2 2101 }
8df7a775 2102
51470298 2103 s->vstrsize = 16;
3d88e64d 2104 s->vstring = snewn(s->vstrsize, char);
51470298 2105 strcpy(s->vstring, "SSH-");
2106 s->vslen = 4;
2107 s->i = 0;
374330e2 2108 while (1) {
8df7a775 2109 crReturn(1); /* get another char */
51470298 2110 if (s->vslen >= s->vstrsize - 1) {
2111 s->vstrsize += 16;
3d88e64d 2112 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2113 }
51470298 2114 s->vstring[s->vslen++] = c;
2115 if (s->i >= 0) {
374330e2 2116 if (c == '-') {
51470298 2117 s->version[s->i] = '\0';
2118 s->i = -1;
2119 } else if (s->i < sizeof(s->version) - 1)
2120 s->version[s->i++] = c;
c4ffc4d0 2121 } else if (c == '\012')
374330e2 2122 break;
2123 }
2124
51470298 2125 ssh->agentfwd_enabled = FALSE;
2126 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2127
51470298 2128 s->vstring[s->vslen] = 0;
2129 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
2130 {
2131 char *vlog;
3d88e64d 2132 vlog = snewn(20 + s->vslen, char);
51470298 2133 sprintf(vlog, "Server version: %s", s->vstring);
2134 logevent(vlog);
2135 sfree(vlog);
2136 }
2137 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2138
adf799dd 2139 /*
38d228a2 2140 * Decide which SSH protocol version to support.
adf799dd 2141 */
38d228a2 2142
2143 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2144 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2145 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2146 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2147
86916870 2148 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2149 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2150 crStop(0);
38d228a2 2151 }
86916870 2152 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2153 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2154 crStop(0);
38d228a2 2155 }
2156
86916870 2157 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
32874aea 2158 /*
38d228a2 2159 * Use v2 protocol.
32874aea 2160 */
2161 char verstring[80], vlog[100];
2162 sprintf(verstring, "SSH-2.0-%s", sshver);
51470298 2163 SHA_Init(&ssh->exhashbase);
32874aea 2164 /*
2165 * Hash our version string and their version string.
2166 */
51470298 2167 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
2168 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
32874aea 2169 sprintf(vlog, "We claim version: %s", verstring);
2170 logevent(vlog);
c4ffc4d0 2171 strcat(verstring, "\012");
32874aea 2172 logevent("Using SSH protocol version 2");
51470298 2173 sk_write(ssh->s, verstring, strlen(verstring));
2174 ssh->protocol = ssh2_protocol;
b09eaa88 2175 ssh2_protocol_setup(ssh);
51470298 2176 ssh->version = 2;
2177 ssh->s_rdpkt = ssh2_rdpkt;
e5574168 2178 } else {
32874aea 2179 /*
38d228a2 2180 * Use v1 protocol.
32874aea 2181 */
2182 char verstring[80], vlog[100];
2183 sprintf(verstring, "SSH-%s-%s",
51470298 2184 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
32874aea 2185 sshver);
2186 sprintf(vlog, "We claim version: %s", verstring);
2187 logevent(vlog);
c4ffc4d0 2188 strcat(verstring, "\012");
759712a6 2189
32874aea 2190 logevent("Using SSH protocol version 1");
51470298 2191 sk_write(ssh->s, verstring, strlen(verstring));
2192 ssh->protocol = ssh1_protocol;
b09eaa88 2193 ssh1_protocol_setup(ssh);
51470298 2194 ssh->version = 1;
2195 ssh->s_rdpkt = ssh1_rdpkt;
e5574168 2196 }
125105d1 2197 update_specials_menu(ssh->frontend);
51470298 2198 ssh->state = SSH_STATE_BEFORE_SIZE;
39934deb 2199 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
8df7a775 2200
51470298 2201 sfree(s->vstring);
50526e47 2202
8df7a775 2203 crFinish(0);
2204}
2205
51470298 2206static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2207{
51470298 2208 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2209
2210 /*
2211 * To begin with, feed the characters one by one to the
2212 * protocol initialisation / selection function do_ssh_init().
2213 * When that returns 0, we're done with the initial greeting
2214 * exchange and can move on to packet discipline.
2215 */
2216 while (1) {
51470298 2217 int ret; /* need not be kept across crReturn */
8df7a775 2218 if (datalen == 0)
2219 crReturnV; /* more data please */
51470298 2220 ret = do_ssh_init(ssh, *data);
32874aea 2221 data++;
2222 datalen--;
8df7a775 2223 if (ret == 0)
2224 break;
2225 }
2226
2227 /*
2228 * We emerge from that loop when the initial negotiation is
2229 * over and we have selected an s_rdpkt function. Now pass
2230 * everything to s_rdpkt, and then pass the resulting packets
2231 * to the proper protocol handler.
2232 */
2233 if (datalen == 0)
2234 crReturnV;
2235 while (1) {
2236 while (datalen > 0) {
ff3187f6 2237 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2238 if (pktin) {
2239 ssh->protocol(ssh, NULL, 0, pktin);
2240 ssh_free_packet(pktin);
8df7a775 2241 }
ff3187f6 2242 if (ssh->state == SSH_STATE_CLOSED)
2243 return;
8df7a775 2244 }
2245 crReturnV;
2246 }
2247 crFinishV;
2248}
2249
36f94d1f 2250static void ssh_do_close(Ssh ssh)
32874aea 2251{
36f94d1f 2252 int i;
2253 struct ssh_channel *c;
2254
51470298 2255 ssh->state = SSH_STATE_CLOSED;
2256 if (ssh->s) {
2257 sk_close(ssh->s);
2258 ssh->s = NULL;
39934deb 2259 notify_remote_exit(ssh->frontend);
f3ab576e 2260 }
36f94d1f 2261 /*
2262 * Now we must shut down any port and X forwardings going
2263 * through this connection.
2264 */
74a98066 2265 if (ssh->channels) {
2266 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2267 switch (c->type) {
2268 case CHAN_X11:
2269 x11_close(c->u.x11.s);
2270 break;
2271 case CHAN_SOCKDATA:
2272 pfd_close(c->u.pfd.s);
2273 break;
2274 }
2275 del234(ssh->channels, c);
2276 if (ssh->version == 2)
2277 bufchain_clear(&c->v.v2.outbuffer);
2278 sfree(c);
36f94d1f 2279 }
36f94d1f 2280 }
2281}
2282
cbe2d68f 2283static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2284 int calling_back)
2285{
2286 Ssh ssh = (Ssh) plug;
2287 ssh_do_close(ssh);
7e78000d 2288 if (error_msg) {
32874aea 2289 /* A socket error has occurred. */
247308b5 2290 logevent(error_msg);
971bcc0a 2291 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2292 } else {
2293 /* Otherwise, the remote side closed the connection normally. */
8df7a775 2294 }
7e78000d 2295 return 0;
2296}
2297
32874aea 2298static int ssh_receive(Plug plug, int urgent, char *data, int len)
2299{
51470298 2300 Ssh ssh = (Ssh) plug;
d8baa528 2301 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2302 if (ssh->state == SSH_STATE_CLOSED) {
36f94d1f 2303 ssh_do_close(ssh);
32874aea 2304 return 0;
3257deae 2305 }
fef97f43 2306 return 1;
374330e2 2307}
2308
5471d09a 2309static void ssh_sent(Plug plug, int bufsize)
2310{
51470298 2311 Ssh ssh = (Ssh) plug;
5471d09a 2312 /*
2313 * If the send backlog on the SSH socket itself clears, we
2314 * should unthrottle the whole world if it was throttled.
2315 */
2316 if (bufsize < SSH_MAX_BACKLOG)
51470298 2317 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2318}
2319
fb09bf1c 2320/*
8df7a775 2321 * Connect to specified host and port.
2322 * Returns an error message, or NULL on success.
6e1ebb76 2323 * Also places the canonical host name into `realhost'. It must be
2324 * freed by the caller.
8df7a775 2325 */
cbe2d68f 2326static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2327 char **realhost, int nodelay, int keepalive)
8df7a775 2328{
51470298 2329 static const struct plug_function_table fn_table = {
7e78000d 2330 ssh_closing,
5471d09a 2331 ssh_receive,
2332 ssh_sent,
2333 NULL
51470298 2334 };
7e78000d 2335
8df7a775 2336 SockAddr addr;
cbe2d68f 2337 const char *err;
8df7a775 2338
3d88e64d 2339 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2340 if (!ssh->savedhost)
8df7a775 2341 fatalbox("Out of memory");
51470298 2342 strcpy(ssh->savedhost, host);
8df7a775 2343
2344 if (port < 0)
2345 port = 22; /* default ssh port */
51470298 2346 ssh->savedport = port;
8df7a775 2347
2348 /*
2349 * Try to find host.
2350 */
57356d63 2351 logeventf(ssh, "Looking up host \"%s\"", host);
e8fa8f62 2352 addr = name_lookup(host, port, realhost, &ssh->cfg);
170c1e6e 2353 if ((err = sk_addr_error(addr)) != NULL) {
2354 sk_addr_free(addr);
8df7a775 2355 return err;
170c1e6e 2356 }
8df7a775 2357
8df7a775 2358 /*
2359 * Open socket.
2360 */
3ad9d396 2361 {
57356d63 2362 char addrbuf[100];
3ad9d396 2363 sk_getaddr(addr, addrbuf, 100);
57356d63 2364 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
3ad9d396 2365 }
51470298 2366 ssh->fn = &fn_table;
e8fa8f62 2367 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2368 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2369 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2370 ssh->s = NULL;
39934deb 2371 notify_remote_exit(ssh->frontend);
8df7a775 2372 return err;
67c4ba2e 2373 }
8df7a775 2374
8df7a775 2375 return NULL;
2376}
2377
2378/*
5471d09a 2379 * Throttle or unthrottle the SSH connection.
2380 */
51470298 2381static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2382{
51470298 2383 int old_count = ssh->v1_throttle_count;
2384 ssh->v1_throttle_count += adjust;
2385 assert(ssh->v1_throttle_count >= 0);
2386 if (ssh->v1_throttle_count && !old_count) {
2387 sk_set_frozen(ssh->s, 1);
2388 } else if (!ssh->v1_throttle_count && old_count) {
2389 sk_set_frozen(ssh->s, 0);
5471d09a 2390 }
2391}
2392
2393/*
2394 * Throttle or unthrottle _all_ local data streams (for when sends
2395 * on the SSH connection itself back up).
2396 */
51470298 2397static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2398{
2399 int i;
2400 struct ssh_channel *c;
2401
51470298 2402 if (enable == ssh->throttled_all)
5471d09a 2403 return;
51470298 2404 ssh->throttled_all = enable;
2405 ssh->overall_bufsize = bufsize;
2406 if (!ssh->channels)
5471d09a 2407 return;
51470298 2408 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2409 switch (c->type) {
2410 case CHAN_MAINSESSION:
2411 /*
2412 * This is treated separately, outside the switch.
2413 */
2414 break;
2415 case CHAN_X11:
2416 x11_override_throttle(c->u.x11.s, enable);
2417 break;
2418 case CHAN_AGENT:
2419 /* Agent channels require no buffer management. */
2420 break;
2421 case CHAN_SOCKDATA:
36f94d1f 2422 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2423 break;
2424 }
2425 }
2426}
2427
2428/*
51470298 2429 * Username and password input, abstracted off into routines
2430 * reusable in several places - even between SSH1 and SSH2.
0405e71f 2431 */
0405e71f 2432
2433/* Set up a username or password input loop on a given buffer. */
ae9ae89f 2434static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
0405e71f 2435{
51470298 2436 ssh->userpass_input_buffer = buffer;
2437 ssh->userpass_input_buflen = buflen;
2438 ssh->userpass_input_bufpos = 0;
2439 ssh->userpass_input_echo = echo;
0405e71f 2440}
2441
2442/*
2443 * Process some terminal data in the course of username/password
2444 * input. Returns >0 for success (line of input returned in
2445 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2446 * for inconclusive (keep waiting for more input please).
2447 */
ae9ae89f 2448static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
0405e71f 2449{
2450 char c;
2451
2452 while (inlen--) {
2453 switch (c = *in++) {
2454 case 10:
2455 case 13:
51470298 2456 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2457 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
0405e71f 2458 return +1;
2459 break;
2460 case 8:
2461 case 127:
51470298 2462 if (ssh->userpass_input_bufpos > 0) {
2463 if (ssh->userpass_input_echo)
2464 c_write_str(ssh, "\b \b");
2465 ssh->userpass_input_bufpos--;
0405e71f 2466 }
2467 break;
2468 case 21:
2469 case 27:
51470298 2470 while (ssh->userpass_input_bufpos > 0) {
2471 if (ssh->userpass_input_echo)
2472 c_write_str(ssh, "\b \b");
2473 ssh->userpass_input_bufpos--;
0405e71f 2474 }
2475 break;
2476 case 3:
2477 case 4:
2478 return -1;
2479 break;
2480 default:
4692a14a 2481 /*
2482 * This simplistic check for printability is disabled
2483 * when we're doing password input, because some people
2484 * have control characters in their passwords.o
2485 */
2486 if ((!ssh->userpass_input_echo ||
2487 (c >= ' ' && c <= '~') ||
0405e71f 2488 ((unsigned char) c >= 160))
51470298 2489 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2490 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2491 if (ssh->userpass_input_echo)
2492 c_write(ssh, &c, 1);
0405e71f 2493 }
2494 break;
2495 }
2496 }
2497 return 0;
2498}
2499
f11d78f2 2500static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2501{
2502 Ssh ssh = (Ssh) sshv;
2503
2504 ssh->agent_response = reply;
2505 ssh->agent_response_len = replylen;
2506
2507 if (ssh->version == 1)
ff3187f6 2508 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2509 else
ff3187f6 2510 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2511}
2512
f11d78f2 2513static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2514{
2515 struct ssh_channel *c = (struct ssh_channel *)cv;
2516 Ssh ssh = c->ssh;
2517 void *sentreply = reply;
2518
2519 if (!sentreply) {
2520 /* Fake SSH_AGENT_FAILURE. */
2521 sentreply = "\0\0\0\1\5";
2522 replylen = 5;
2523 }
2524 if (ssh->version == 2) {
2525 ssh2_add_channel_data(c, sentreply, replylen);
2526 ssh2_try_send(c);
2527 } else {
2528 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2529 PKT_INT, c->remoteid,
9a10ecf4 2530 PKTT_DATA,
839f10db 2531 PKT_INT, replylen,
2532 PKT_DATA, sentreply, replylen,
9a10ecf4 2533 PKTT_OTHER,
839f10db 2534 PKT_END);
2535 }
2536 if (reply)
2537 sfree(reply);
2538}
2539
0405e71f 2540/*
fb09bf1c 2541 * Handle the key exchange and user authentication phases.
2542 */
ff3187f6 2543static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2544 struct Packet *pktin)
fb09bf1c 2545{
0016d70b 2546 int i, j, ret;
2547 unsigned char cookie[8], *ptr;
374330e2 2548 struct RSAKey servkey, hostkey;
2549 struct MD5Context md5c;
51470298 2550 struct do_ssh1_login_state {
2551 int len;
2552 unsigned char *rsabuf, *keystr1, *keystr2;
2553 unsigned long supported_ciphers_mask, supported_auths_mask;
2554 int tried_publickey, tried_agent;
2555 int tis_auth_refused, ccard_auth_refused;
2556 unsigned char session_id[16];
2557 int cipher_type;
2558 char username[100];
2559 void *publickey_blob;
2560 int publickey_bloblen;
2561 char password[100];
2562 char prompt[200];
2563 int pos;
2564 char c;
2565 int pwpkt_type;
2566 unsigned char request[5], *response, *p;
2567 int responselen;
2568 int keyi, nkeys;
2569 int authed;
2570 struct RSAKey key;
2571 Bignum challenge;
2572 char *commentp;
2573 int commentlen;
2574 };
2575 crState(do_ssh1_login_state);
2576
2577 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2578
ff3187f6 2579 if (!pktin)
2580 crWaitUntil(pktin);
374330e2 2581
ff3187f6 2582 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2583 bombout(("Public key packet not received"));
7ffdbc1a 2584 crStop(0);
8d5de777 2585 }
374330e2 2586
c5e9c988 2587 logevent("Received public keys");
374330e2 2588
ff3187f6 2589 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2590 if (!ptr) {
2591 bombout(("SSH1 public key packet stopped before random cookie"));
2592 crStop(0);
2593 }
2594 memcpy(cookie, ptr, 8);
374330e2 2595
ff3187f6 2596 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2597 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
ae0500e5 2598 bombout(("Failed to read SSH1 public keys from public key packet"));
0016d70b 2599 crStop(0);
2600 }
374330e2 2601
c5e9c988 2602 /*
1c2a93c4 2603 * Log the host key fingerprint.
c5e9c988 2604 */
c5e9c988 2605 {
2606 char logmsg[80];
1c2a93c4 2607 logevent("Host key fingerprint is:");
c5e9c988 2608 strcpy(logmsg, " ");
32874aea 2609 hostkey.comment = NULL;
2610 rsa_fingerprint(logmsg + strlen(logmsg),
2611 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2612 logevent(logmsg);
2613 }
2614
ff3187f6 2615 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2616 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2617 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2618
51470298 2619 ssh->v1_local_protoflags =
2620 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2621 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2622
c5e9c988 2623 MD5Init(&md5c);
51470298 2624 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2625 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2626 MD5Update(&md5c, cookie, 8);
51470298 2627 MD5Final(s->session_id, &md5c);
374330e2 2628
32874aea 2629 for (i = 0; i < 32; i++)
51470298 2630 ssh->session_key[i] = random_byte();
374330e2 2631
0016d70b 2632 /*
2633 * Verify that the `bits' and `bytes' parameters match.
2634 */
2635 if (hostkey.bits > hostkey.bytes * 8 ||
2636 servkey.bits > servkey.bytes * 8) {
2637 bombout(("SSH1 public keys were badly formatted"));
2638 crStop(0);
2639 }
2640
51470298 2641 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2642
3d88e64d 2643 s->rsabuf = snewn(s->len, unsigned char);
51470298 2644 if (!s->rsabuf)
374330e2 2645 fatalbox("Out of memory");
2646
89ee5268 2647 /*
2648 * Verify the host key.
2649 */
2650 {
32874aea 2651 /*
2652 * First format the key into a string.
2653 */
2654 int len = rsastr_len(&hostkey);
2655 char fingerprint[100];
3d88e64d 2656 char *keystr = snewn(len, char);
32874aea 2657 if (!keystr)
2658 fatalbox("Out of memory");
2659 rsastr_fmt(keystr, &hostkey);
2660 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
a8327734 2661 verify_ssh_host_key(ssh->frontend,
2662 ssh->savedhost, ssh->savedport, "rsa", keystr,
32874aea 2663 fingerprint);
2664 sfree(keystr);
2665 }
2666
2667 for (i = 0; i < 32; i++) {
51470298 2668 s->rsabuf[i] = ssh->session_key[i];
374330e2 2669 if (i < 16)
51470298 2670 s->rsabuf[i] ^= s->session_id[i];
374330e2 2671 }
2672
2673 if (hostkey.bytes > servkey.bytes) {
0016d70b 2674 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2675 if (ret)
2676 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2677 } else {
0016d70b 2678 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2679 if (ret)
2680 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2681 }
2682 if (!ret) {
2683 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2684 crStop(0);
374330e2 2685 }
2686
c5e9c988 2687 logevent("Encrypted session key");
2688
ca20bfcf 2689 {
2690 int cipher_chosen = 0, warn = 0;
2691 char *cipher_string = NULL;
51470298 2692 int i;
ca20bfcf 2693 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 2694 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 2695 if (next_cipher == CIPHER_WARN) {
2696 /* If/when we choose a cipher, warn about it */
2697 warn = 1;
2698 } else if (next_cipher == CIPHER_AES) {
2699 /* XXX Probably don't need to mention this. */
2700 logevent("AES not supported in SSH1, skipping");
2701 } else {
2702 switch (next_cipher) {
51470298 2703 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 2704 cipher_string = "3DES"; break;
51470298 2705 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 2706 cipher_string = "Blowfish"; break;
51470298 2707 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 2708 cipher_string = "single-DES"; break;
2709 }
51470298 2710 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 2711 cipher_chosen = 1;
2712 }
2713 }
2714 if (!cipher_chosen) {
51470298 2715 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
6b5cf8b4 2716 bombout(("Server violates SSH 1 protocol by not "
ca20bfcf 2717 "supporting 3DES encryption"));
2718 else
2719 /* shouldn't happen */
6b5cf8b4 2720 bombout(("No supported ciphers found"));
7ffdbc1a 2721 crStop(0);
a99a05c0 2722 }
ca20bfcf 2723
2724 /* Warn about chosen cipher if necessary. */
2725 if (warn)
a8327734 2726 askcipher(ssh->frontend, cipher_string, 0);
bea1ef5f 2727 }
ca20bfcf 2728
51470298 2729 switch (s->cipher_type) {
32874aea 2730 case SSH_CIPHER_3DES:
2731 logevent("Using 3DES encryption");
2732 break;
2733 case SSH_CIPHER_DES:
2734 logevent("Using single-DES encryption");
2735 break;
2736 case SSH_CIPHER_BLOWFISH:
2737 logevent("Using Blowfish encryption");
2738 break;
c5e9c988 2739 }
bea1ef5f 2740
51470298 2741 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2742 PKT_CHAR, s->cipher_type,
32874aea 2743 PKT_DATA, cookie, 8,
51470298 2744 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2745 PKT_DATA, s->rsabuf, s->len,
2746 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 2747
c5e9c988 2748 logevent("Trying to enable encryption...");
374330e2 2749
51470298 2750 sfree(s->rsabuf);
374330e2 2751
51470298 2752 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2753 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2754 &ssh_3des);
371e569c 2755 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2756 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 2757 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 2758
0183b242 2759 ssh->crcda_ctx = crcda_make_context();
2760 logevent("Installing CRC compensation attack detector");
2761
679539d7 2762 if (servkey.modulus) {
2763 sfree(servkey.modulus);
2764 servkey.modulus = NULL;
2765 }
2766 if (servkey.exponent) {
2767 sfree(servkey.exponent);
2768 servkey.exponent = NULL;
2769 }
2770 if (hostkey.modulus) {
2771 sfree(hostkey.modulus);
2772 hostkey.modulus = NULL;
2773 }
2774 if (hostkey.exponent) {
2775 sfree(hostkey.exponent);
2776 hostkey.exponent = NULL;
2777 }
ff3187f6 2778 crWaitUntil(pktin);
374330e2 2779
ff3187f6 2780 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 2781 bombout(("Encryption not successfully enabled"));
7ffdbc1a 2782 crStop(0);
8d5de777 2783 }
374330e2 2784
c5e9c988 2785 logevent("Successfully started encryption");
2786
374330e2 2787 fflush(stdout);
2788 {
aa09f7d0 2789 if (!*ssh->cfg.username) {
c0a81592 2790 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 2791 if (!ssh_get_line("login as: ",
51470298 2792 s->username, sizeof(s->username), FALSE)) {
32874aea 2793 /*
2794 * get_line failed to get a username.
2795 * Terminate.
2796 */
2797 logevent("No username provided. Abandoning session.");
3bb2f322 2798 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 2799 crStop(1);
32874aea 2800 }
2801 } else {
51470298 2802 int ret; /* need not be kept over crReturn */
2803 c_write_str(ssh, "login as: ");
2804 ssh->send_ok = 1;
0405e71f 2805
51470298 2806 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 2807 do {
ff3187f6 2808 crWaitUntil(!pktin);
51470298 2809 ret = process_userpass_input(ssh, in, inlen);
0405e71f 2810 } while (ret == 0);
2811 if (ret < 0)
2812 cleanup_exit(0);
51470298 2813 c_write_str(ssh, "\r\n");
32874aea 2814 }
2815 } else {
86916870 2816 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 2817 s->username[sizeof(s->username)-1] = '\0';
374330e2 2818 }
fb09bf1c 2819
51470298 2820 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 2821 {
51470298 2822 char userlog[22 + sizeof(s->username)];
2823 sprintf(userlog, "Sent username \"%s\"", s->username);
c5e9c988 2824 logevent(userlog);
32874aea 2825 if (flags & FLAG_INTERACTIVE &&
2826 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3c8e959b 2827 strcat(userlog, "\r\n");
51470298 2828 c_write_str(ssh, userlog);
3c8e959b 2829 }
c5e9c988 2830 }
374330e2 2831 }
2832
ff3187f6 2833 crWaitUntil(pktin);
374330e2 2834
51470298 2835 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 2836 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 2837 s->tried_publickey = s->tried_agent = 1;
0df73905 2838 } else {
51470298 2839 s->tried_publickey = s->tried_agent = 0;
0df73905 2840 }
51470298 2841 s->tis_auth_refused = s->ccard_auth_refused = 0;
86916870 2842 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 2843 if (!filename_is_null(ssh->cfg.keyfile)) {
2844 if (!rsakey_pubblob(&ssh->cfg.keyfile,
222d54dc 2845 &s->publickey_blob, &s->publickey_bloblen, NULL))
51470298 2846 s->publickey_blob = NULL;
396778f1 2847 } else
51470298 2848 s->publickey_blob = NULL;
7cca0d81 2849
ff3187f6 2850 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 2851 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 2852
51470298 2853 if (agent_exists() && !s->tried_agent) {
32874aea 2854 /*
2855 * Attempt RSA authentication using Pageant.
2856 */
32874aea 2857 void *r;
2858
51470298 2859 s->authed = FALSE;
2860 s->tried_agent = 1;
32874aea 2861 logevent("Pageant is running. Requesting keys.");
2862
2863 /* Request the keys held by the agent. */
51470298 2864 PUT_32BIT(s->request, 1);
2865 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 2866 if (!agent_query(s->request, 5, &r, &s->responselen,
2867 ssh_agent_callback, ssh)) {
2868 do {
2869 crReturn(0);
ff3187f6 2870 if (pktin) {
839f10db 2871 bombout(("Unexpected data from server while waiting"
2872 " for agent response"));
2873 crStop(0);
2874 }
ff3187f6 2875 } while (pktin || inlen > 0);
839f10db 2876 r = ssh->agent_response;
2877 s->responselen = ssh->agent_response_len;
2878 }
51470298 2879 s->response = (unsigned char *) r;
2880 if (s->response && s->responselen >= 5 &&
2881 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2882 s->p = s->response + 5;
2883 s->nkeys = GET_32BIT(s->p);
2884 s->p += 4;
32874aea 2885 {
2886 char buf[64];
51470298 2887 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
32874aea 2888 logevent(buf);
2889 }
51470298 2890 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
32874aea 2891 {
2892 char buf[64];
51470298 2893 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 2894 logevent(buf);
2895 }
51470298 2896 if (s->publickey_blob &&
2897 !memcmp(s->p, s->publickey_blob,
2898 s->publickey_bloblen)) {
396778f1 2899 logevent("This key matches configured key file");
51470298 2900 s->tried_publickey = 1;
396778f1 2901 }
51470298 2902 s->p += 4;
0016d70b 2903 {
2904 int n, ok = FALSE;
2905 do { /* do while (0) to make breaking easy */
2906 n = ssh1_read_bignum
2907 (s->p, s->responselen-(s->p-s->response),
2908 &s->key.exponent);
2909 if (n < 0)
2910 break;
2911 s->p += n;
2912 n = ssh1_read_bignum
2913 (s->p, s->responselen-(s->p-s->response),
2914 &s->key.modulus);
2915 if (n < 0)
2916 break;
2917 s->p += n;
2918 if (s->responselen - (s->p-s->response) < 4)
2919 break;
2920 s->commentlen = GET_32BIT(s->p);
2921 s->p += 4;
2922 if (s->responselen - (s->p-s->response) <
2923 s->commentlen)
2924 break;
2925 s->commentp = (char *)s->p;
2926 s->p += s->commentlen;
2927 ok = TRUE;
2928 } while (0);
2929 if (!ok) {
2930 logevent("Pageant key list packet was truncated");
2931 break;
2932 }
2933 }
51470298 2934 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2935 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 2936 crWaitUntil(pktin);
2937 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 2938 logevent("Key refused");
2939 continue;
2940 }
2941 logevent("Received RSA challenge");
ff3187f6 2942 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 2943 bombout(("Server's RSA challenge was badly formatted"));
2944 crStop(0);
2945 }
2946
32874aea 2947 {
2948 char *agentreq, *q, *ret;
2d466ffd 2949 void *vret;
32874aea 2950 int len, retlen;
2951 len = 1 + 4; /* message type, bit count */
51470298 2952 len += ssh1_bignum_length(s->key.exponent);
2953 len += ssh1_bignum_length(s->key.modulus);
2954 len += ssh1_bignum_length(s->challenge);
32874aea 2955 len += 16; /* session id */
2956 len += 4; /* response format */
3d88e64d 2957 agentreq = snewn(4 + len, char);
32874aea 2958 PUT_32BIT(agentreq, len);
2959 q = agentreq + 4;
2960 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 2961 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 2962 q += 4;
51470298 2963 q += ssh1_write_bignum(q, s->key.exponent);
2964 q += ssh1_write_bignum(q, s->key.modulus);
2965 q += ssh1_write_bignum(q, s->challenge);
2966 memcpy(q, s->session_id, 16);
32874aea 2967 q += 16;
2968 PUT_32BIT(q, 1); /* response format */
839f10db 2969 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2970 ssh_agent_callback, ssh)) {
2971 sfree(agentreq);
2972 do {
2973 crReturn(0);
ff3187f6 2974 if (pktin) {
839f10db 2975 bombout(("Unexpected data from server"
2976 " while waiting for agent"
2977 " response"));
2978 crStop(0);
2979 }
ff3187f6 2980 } while (pktin || inlen > 0);
839f10db 2981 vret = ssh->agent_response;
2982 retlen = ssh->agent_response_len;
2983 } else
2984 sfree(agentreq);
2d466ffd 2985 ret = vret;
32874aea 2986 if (ret) {
2987 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2988 logevent("Sending Pageant's response");
51470298 2989 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 2990 PKT_DATA, ret + 5, 16,
2991 PKT_END);
2992 sfree(ret);
ff3187f6 2993 crWaitUntil(pktin);
2994 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 2995 logevent
2996 ("Pageant's response accepted");
2997 if (flags & FLAG_VERBOSE) {
51470298 2998 c_write_str(ssh, "Authenticated using"
2999 " RSA key \"");
3000 c_write(ssh, s->commentp,
3001 s->commentlen);
3002 c_write_str(ssh, "\" from agent\r\n");
32874aea 3003 }
51470298 3004 s->authed = TRUE;
32874aea 3005 } else
3006 logevent
3007 ("Pageant's response not accepted");
3008 } else {
3009 logevent
3010 ("Pageant failed to answer challenge");
3011 sfree(ret);
3012 }
3013 } else {
3014 logevent("No reply received from Pageant");
3015 }
3016 }
51470298 3017 freebn(s->key.exponent);
3018 freebn(s->key.modulus);
3019 freebn(s->challenge);
3020 if (s->authed)
32874aea 3021 break;
3022 }
29b1d0b3 3023 sfree(s->response);
32874aea 3024 }
51470298 3025 if (s->authed)
32874aea 3026 break;
3027 }
9a30e26b 3028 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
51470298 3029 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
32874aea 3030
86916870 3031 if (ssh->cfg.try_tis_auth &&
51470298 3032 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3033 !s->tis_auth_refused) {
3034 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3035 logevent("Requested TIS authentication");
51470298 3036 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3037 crWaitUntil(pktin);
3038 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3039 logevent("TIS authentication declined");
3040 if (flags & FLAG_INTERACTIVE)
51470298 3041 c_write_str(ssh, "TIS authentication refused.\r\n");
3042 s->tis_auth_refused = 1;
614a20a0 3043 continue;
32874aea 3044 } else {
0016d70b 3045 char *challenge;
3046 int challengelen;
3047
ff3187f6 3048 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3049 if (!challenge) {
3050 bombout(("TIS challenge packet was badly formed"));
3051 crStop(0);
3052 }
32874aea 3053 logevent("Received TIS challenge");
51470298 3054 if (challengelen > sizeof(s->prompt) - 1)
3055 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3056 memcpy(s->prompt, challenge, challengelen);
614a20a0 3057 /* Prompt heuristic comes from OpenSSH */
51470298 3058 strncpy(s->prompt + challengelen,
3059 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3060 "": "\r\nResponse: ",
51470298 3061 (sizeof s->prompt) - challengelen);
3062 s->prompt[(sizeof s->prompt) - 1] = '\0';
32874aea 3063 }
3064 }
86916870 3065 if (ssh->cfg.try_tis_auth &&
51470298 3066 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3067 !s->ccard_auth_refused) {
3068 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3069 logevent("Requested CryptoCard authentication");
51470298 3070 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3071 crWaitUntil(pktin);
3072 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3073 logevent("CryptoCard authentication declined");
51470298 3074 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3075 s->ccard_auth_refused = 1;
614a20a0 3076 continue;
32874aea 3077 } else {
0016d70b 3078 char *challenge;
3079 int challengelen;
3080
ff3187f6 3081 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3082 if (!challenge) {
3083 bombout(("CryptoCard challenge packet was badly formed"));
3084 crStop(0);
3085 }
32874aea 3086 logevent("Received CryptoCard challenge");
51470298 3087 if (challengelen > sizeof(s->prompt) - 1)
3088 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
0016d70b 3089 memcpy(s->prompt, challenge, challengelen);
51470298 3090 strncpy(s->prompt + challengelen,
3091 memchr(s->prompt, '\n', challengelen) ?
614a20a0 3092 "" : "\r\nResponse: ",
51470298 3093 sizeof(s->prompt) - challengelen);
3094 s->prompt[sizeof(s->prompt) - 1] = '\0';
32874aea 3095 }
3096 }
51470298 3097 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3098 sprintf(s->prompt, "%.90s@%.90s's password: ",
3099 s->username, ssh->savedhost);
32874aea 3100 }
51470298 3101 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3102 char *comment = NULL;
231ee168 3103 int type;
3104 char msgbuf[256];
32874aea 3105 if (flags & FLAG_VERBOSE)
51470298 3106 c_write_str(ssh, "Trying public key authentication.\r\n");
6c6d9ed9 3107 logeventf(ssh, "Trying public key \"%s\"",
3108 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 3109 type = key_type(&ssh->cfg.keyfile);
231ee168 3110 if (type != SSH_KEYTYPE_SSH1) {
3111 sprintf(msgbuf, "Key is of wrong type (%s)",
3112 key_type_to_str(type));
3113 logevent(msgbuf);
51470298 3114 c_write_str(ssh, msgbuf);
3115 c_write_str(ssh, "\r\n");
3116 s->tried_publickey = 1;
231ee168 3117 continue;
3118 }
9a30e26b 3119 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
32874aea 3120 if (flags & FLAG_VERBOSE)
51470298 3121 c_write_str(ssh, "No passphrase required.\r\n");
32874aea 3122 goto tryauth;
3123 }
51470298 3124 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
32874aea 3125 sfree(comment);
3126 }
a52f067e 3127
614a20a0 3128 /*
3129 * Show password prompt, having first obtained it via a TIS
3130 * or CryptoCard exchange if we're doing TIS or CryptoCard
3131 * authentication.
3132 */
fa17a66e 3133 if (ssh_get_line) {
51470298 3134 if (!ssh_get_line(s->prompt, s->password,
3135 sizeof(s->password), TRUE)) {
32874aea 3136 /*
3137 * get_line failed to get a password (for example
3138 * because one was supplied on the command line
3139 * which has already failed to work). Terminate.
3140 */
51470298 3141 send_packet(ssh, SSH1_MSG_DISCONNECT,
2bc6a386 3142 PKT_STR, "No more passwords available to try",
3143 PKT_END);
247308b5 3144 logevent("Unable to authenticate");
a8327734 3145 connection_fatal(ssh->frontend, "Unable to authenticate");
3bb2f322 3146 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 3147 crStop(1);
32874aea 3148 }
fb09bf1c 3149 } else {
614a20a0 3150 /* Prompt may have come from server. We've munged it a bit, so
3151 * we know it to be zero-terminated at least once. */
51470298 3152 int ret; /* need not be saved over crReturn */
3153 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3154 s->pos = 0;
0405e71f 3155
51470298 3156 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
0405e71f 3157 do {
ff3187f6 3158 crWaitUntil(!pktin);
51470298 3159 ret = process_userpass_input(ssh, in, inlen);
0405e71f 3160 } while (ret == 0);
3161 if (ret < 0)
3162 cleanup_exit(0);
51470298 3163 c_write_str(ssh, "\r\n");
32874aea 3164 }
3165
3166 tryauth:
51470298 3167 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
32874aea 3168 /*
3169 * Try public key authentication with the specified
3170 * key file.
3171 */
51470298 3172 s->tried_publickey = 1;
3173
3174 {
222d54dc 3175 const char *error = NULL;
3176 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3177 &error);
51470298 3178 if (ret == 0) {
3179 c_write_str(ssh, "Couldn't load private key from ");
9fab77dc 3180 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
222d54dc 3181 c_write_str(ssh, " (");
3182 c_write_str(ssh, error);
3183 c_write_str(ssh, ").\r\n");
51470298 3184 continue; /* go and try password */
3185 }
3186 if (ret == -1) {
3187 c_write_str(ssh, "Wrong passphrase.\r\n");
3188 s->tried_publickey = 0;
3189 continue; /* try again */
3190 }
32874aea 3191 }
3192
3193 /*
3194 * Send a public key attempt.
3195 */
51470298 3196 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3197 PKT_BIGNUM, s->key.modulus, PKT_END);
32874aea 3198
ff3187f6 3199 crWaitUntil(pktin);
3200 if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3201 c_write_str(ssh, "Server refused our public key.\r\n");
32874aea 3202 continue; /* go and try password */
3203 }
ff3187f6 3204 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
6b5cf8b4 3205 bombout(("Bizarre response to offer of public key"));
7ffdbc1a 3206 crStop(0);
32874aea 3207 }
32874aea 3208
51470298 3209 {
3210 int i;
3211 unsigned char buffer[32];
3212 Bignum challenge, response;
3213
ff3187f6 3214 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3215 bombout(("Server's RSA challenge was badly formatted"));
3216 crStop(0);
3217 }
51470298 3218 response = rsadecrypt(challenge, &s->key);
3219 freebn(s->key.private_exponent);/* burn the evidence */
32874aea 3220
51470298 3221 for (i = 0; i < 32; i++) {
3222 buffer[i] = bignum_byte(response, 31 - i);
3223 }
3224
3225 MD5Init(&md5c);
3226 MD5Update(&md5c, buffer, 32);
3227 MD5Update(&md5c, s->session_id, 16);
3228 MD5Final(buffer, &md5c);
32874aea 3229
51470298 3230 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3231 PKT_DATA, buffer, 16, PKT_END);
3232
3233 freebn(challenge);
3234 freebn(response);
3235 }
32874aea 3236
ff3187f6 3237 crWaitUntil(pktin);
3238 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3239 if (flags & FLAG_VERBOSE)
51470298 3240 c_write_str(ssh, "Failed to authenticate with"
3241 " our public key.\r\n");
32874aea 3242 continue; /* go and try password */
ff3187f6 3243 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3244 bombout(("Bizarre response to RSA authentication response"));
7ffdbc1a 3245 crStop(0);
32874aea 3246 }
3247
3248 break; /* we're through! */
3249 } else {
51470298 3250 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3251 /*
3252 * Defence against traffic analysis: we send a
3253 * whole bunch of packets containing strings of
3254 * different lengths. One of these strings is the
3255 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3256 * The others are all random data in
3257 * SSH1_MSG_IGNORE packets. This way a passive
3258 * listener can't tell which is the password, and
3259 * hence can't deduce the password length.
3260 *
3261 * Anybody with a password length greater than 16
3262 * bytes is going to have enough entropy in their
3263 * password that a listener won't find it _that_
3264 * much help to know how long it is. So what we'll
3265 * do is:
3266 *
3267 * - if password length < 16, we send 15 packets
3268 * containing string lengths 1 through 15
3269 *
3270 * - otherwise, we let N be the nearest multiple
3271 * of 8 below the password length, and send 8
3272 * packets containing string lengths N through
3273 * N+7. This won't obscure the order of
3274 * magnitude of the password length, but it will
3275 * introduce a bit of extra uncertainty.
3276 *
3277 * A few servers (the old 1.2.18 through 1.2.22)
3278 * can't deal with SSH1_MSG_IGNORE. For these
3279 * servers, we need an alternative defence. We make
3280 * use of the fact that the password is interpreted
3281 * as a C string: so we can append a NUL, then some
3282 * random data.
bd358db1 3283 *
3284 * One server (a Cisco one) can deal with neither
3285 * SSH1_MSG_IGNORE _nor_ a padded password string.
3286 * For this server we are left with no defences
3287 * against password length sniffing.
32874aea 3288 */
51470298 3289 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
b17c8428 3290 /*
3291 * The server can deal with SSH1_MSG_IGNORE, so
3292 * we can use the primary defence.
3293 */
32874aea 3294 int bottom, top, pwlen, i;
3295 char *randomstr;
3296
51470298 3297 pwlen = strlen(s->password);
32874aea 3298 if (pwlen < 16) {
3299 bottom = 0; /* zero length passwords are OK! :-) */
3300 top = 15;
3301 } else {
3302 bottom = pwlen & ~7;
3303 top = bottom + 7;
3304 }
3305
3306 assert(pwlen >= bottom && pwlen <= top);
3307
3d88e64d 3308 randomstr = snewn(top + 1, char);
32874aea 3309
3310 for (i = bottom; i <= top; i++) {
9a10ecf4 3311 if (i == pwlen) {
51470298 3312 defer_packet(ssh, s->pwpkt_type,
9a10ecf4 3313 PKTT_PASSWORD, PKT_STR, s->password,
3314 PKTT_OTHER, PKT_END);
3315 } else {
32874aea 3316 for (j = 0; j < i; j++) {
3317 do {
3318 randomstr[j] = random_byte();
3319 } while (randomstr[j] == '\0');
3320 }
3321 randomstr[i] = '\0';
51470298 3322 defer_packet(ssh, SSH1_MSG_IGNORE,
32874aea 3323 PKT_STR, randomstr, PKT_END);
3324 }
3325 }
bd358db1 3326 logevent("Sending password with camouflage packets");
51470298 3327 ssh_pkt_defersend(ssh);
679539d7 3328 sfree(randomstr);
bd358db1 3329 }
51470298 3330 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
b17c8428 3331 /*
3332 * The server can't deal with SSH1_MSG_IGNORE
3333 * but can deal with padded passwords, so we
3334 * can use the secondary defence.
3335 */
bd358db1 3336 char string[64];
51470298 3337 char *ss;
bd358db1 3338 int len;
3339
51470298 3340 len = strlen(s->password);
bd358db1 3341 if (len < sizeof(string)) {
51470298 3342 ss = string;
3343 strcpy(string, s->password);
bd358db1 3344 len++; /* cover the zero byte */
3345 while (len < sizeof(string)) {
3346 string[len++] = (char) random_byte();
3347 }
3348 } else {
51470298 3349 ss = s->password;
bd358db1 3350 }
3351 logevent("Sending length-padded password");
9a10ecf4 3352 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3353 PKT_INT, len, PKT_DATA, ss, len,
3354 PKTT_OTHER, PKT_END);
bd358db1 3355 } else {
3356 /*
3357 * The server has _both_
3358 * BUG_CHOKES_ON_SSH1_IGNORE and
3359 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3360 * therefore nothing we can do.
3361 */
3362 int len;
51470298 3363 len = strlen(s->password);
bd358db1 3364 logevent("Sending unpadded password");
9a10ecf4 3365 send_packet(ssh, s->pwpkt_type,
3366 PKTT_PASSWORD, PKT_INT, len,
3367 PKT_DATA, s->password, len,
3368 PKTT_OTHER, PKT_END);
32874aea 3369 }
3370 } else {
9a10ecf4 3371 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3372 PKT_STR, s->password, PKTT_OTHER, PKT_END);
32874aea 3373 }
3374 }
c5e9c988 3375 logevent("Sent password");
51470298 3376 memset(s->password, 0, strlen(s->password));
ff3187f6 3377 crWaitUntil(pktin);
3378 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3379 if (flags & FLAG_VERBOSE)
51470298 3380 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3381 logevent("Authentication refused");
ff3187f6 3382 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3383 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3384 crStop(0);
374330e2 3385 }
3386 }
3387
c5e9c988 3388 logevent("Authentication successful");
3389
fb09bf1c 3390 crFinish(1);
3391}
3392
32874aea 3393void sshfwd_close(struct ssh_channel *c)
3394{
51470298 3395 Ssh ssh = c->ssh;
3396
36f94d1f 3397 if (ssh->state != SSH_STATE_SESSION) {
3398 assert(ssh->state == SSH_STATE_CLOSED);
3399 return;
3400 }
3401
80e48603 3402 if (c && !c->closes) {
4ed34d25 3403 /*
3404 * If the channel's remoteid is -1, we have sent
3405 * CHANNEL_OPEN for this channel, but it hasn't even been
3406 * acknowledged by the server. So we must set a close flag
3407 * on it now, and then when the server acks the channel
3408 * open, we can close it then.
3409 */
36cac739 3410 if (((int)c->remoteid) != -1) {
51470298 3411 if (ssh->version == 1) {
3412 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3413 PKT_END);
3414 } else {
ff3187f6 3415 struct Packet *pktout;
3416 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3417 ssh2_pkt_adduint32(pktout, c->remoteid);
3418 ssh2_pkt_send(ssh, pktout);
4ed34d25 3419 }
32874aea 3420 }
0357890f 3421 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3422 if (c->type == CHAN_X11) {
3423 c->u.x11.s = NULL;
d74d141c 3424 logevent("Forwarded X11 connection terminated");
4ed34d25 3425 } else if (c->type == CHAN_SOCKDATA ||
3426 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3427 c->u.pfd.s = NULL;
3428 logevent("Forwarded port closed");
32874aea 3429 }
3430 }
3431}
3432
5471d09a 3433int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3434{
51470298 3435 Ssh ssh = c->ssh;
3436
36f94d1f 3437 if (ssh->state != SSH_STATE_SESSION) {
3438 assert(ssh->state == SSH_STATE_CLOSED);
3439 return 0;
3440 }
3441
51470298 3442 if (ssh->version == 1) {
3443 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3444 PKT_INT, c->remoteid,
9a10ecf4 3445 PKTT_DATA,
3446 PKT_INT, len, PKT_DATA, buf, len,
3447 PKTT_OTHER, PKT_END);
5471d09a 3448 /*
3449 * In SSH1 we can return 0 here - implying that forwarded
3450 * connections are never individually throttled - because
3451 * the only circumstance that can cause throttling will be
3452 * the whole SSH connection backing up, in which case
3453 * _everything_ will be throttled as a whole.
3454 */
3455 return 0;
783415f8 3456 } else {
32874aea 3457 ssh2_add_channel_data(c, buf, len);
5471d09a 3458 return ssh2_try_send(c);
3459 }
3460}
3461
3462void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3463{
51470298 3464 Ssh ssh = c->ssh;
3465
36f94d1f 3466 if (ssh->state != SSH_STATE_SESSION) {
3467 assert(ssh->state == SSH_STATE_CLOSED);
3468 return;
3469 }
3470
51470298 3471 if (ssh->version == 1) {
5471d09a 3472 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3473 c->v.v1.throttling = 0;
51470298 3474 ssh1_throttle(ssh, -1);
5471d09a 3475 }
3476 } else {
3477 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3478 }
9c964e85 3479}
3480
51df0ab5 3481static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
3482{
3483 char *string;
3484 int stringlen, bufsize;
3485
3486 ssh_pkt_getstring(pktin, &string, &stringlen);
3487 if (string == NULL) {
3488 bombout(("Incoming terminal data packet was badly formed"));
3489 return;
3490 }
3491
3492 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
3493 string, stringlen);
3494 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3495 ssh->v1_stdout_throttling = 1;
3496 ssh1_throttle(ssh, +1);
3497 }
3498}
3499
3500static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
3501{
3502 /* Remote side is trying to open a channel to talk to our
3503 * X-Server. Give them back a local channel number. */
3504 struct ssh_channel *c;
3505 int remoteid = ssh_pkt_getuint32(pktin);
3506
3507 logevent("Received X11 connect request");
3508 /* Refuse if X11 forwarding is disabled. */
3509 if (!ssh->X11_fwd_enabled) {
3510 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3511 PKT_INT, remoteid, PKT_END);
3512 logevent("Rejected X11 connect request");
3513 } else {
3514 c = snew(struct ssh_channel);
3515 c->ssh = ssh;
3516
3517 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3518 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3519 logevent("Opening X11 forward connection failed");
3520 sfree(c);
3521 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3522 PKT_INT, remoteid, PKT_END);
3523 } else {
3524 logevent
3525 ("Opening X11 forward connection succeeded");
3526 c->remoteid = remoteid;
3527 c->localid = alloc_channel_id(ssh);
3528 c->closes = 0;
3529 c->v.v1.throttling = 0;
3530 c->type = CHAN_X11; /* identify channel type */
3531 add234(ssh->channels, c);
3532 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3533 PKT_INT, c->remoteid, PKT_INT,
3534 c->localid, PKT_END);
3535 logevent("Opened X11 forward channel");
3536 }
3537 }
3538}
3539
3540static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
3541{
3542 /* Remote side is trying to open a channel to talk to our
3543 * agent. Give them back a local channel number. */
3544 struct ssh_channel *c;
3545 int remoteid = ssh_pkt_getuint32(pktin);
3546
3547 /* Refuse if agent forwarding is disabled. */
3548 if (!ssh->agentfwd_enabled) {
3549 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3550 PKT_INT, remoteid, PKT_END);
3551 } else {
3552 c = snew(struct ssh_channel);
3553 c->ssh = ssh;
3554 c->remoteid = remoteid;
3555 c->localid = alloc_channel_id(ssh);
3556 c->closes = 0;
3557 c->v.v1.throttling = 0;
3558 c->type = CHAN_AGENT; /* identify channel type */
3559 c->u.a.lensofar = 0;
3560 add234(ssh->channels, c);
3561 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3562 PKT_INT, c->remoteid, PKT_INT, c->localid,
3563 PKT_END);
3564 }
3565}
3566
3567static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
3568{
3569 /* Remote side is trying to open a channel to talk to a
3570 * forwarded port. Give them back a local channel number. */
3571 struct ssh_channel *c;
3572 struct ssh_rportfwd pf;
3573 int remoteid;
3574 int hostsize, port;
3575 char *host, buf[1024];
3576 const char *e;
3577 c = snew(struct ssh_channel);
3578 c->ssh = ssh;
3579
3580 remoteid = ssh_pkt_getuint32(pktin);
3581 ssh_pkt_getstring(pktin, &host, &hostsize);
3582 port = ssh_pkt_getuint32(pktin);
3583
3584 if (hostsize >= lenof(pf.dhost))
3585 hostsize = lenof(pf.dhost)-1;
3586 memcpy(pf.dhost, host, hostsize);
3587 pf.dhost[hostsize] = '\0';
3588 pf.dport = port;
3589
3590 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3591 sprintf(buf, "Rejected remote port open request for %s:%d",
3592 pf.dhost, port);
3593 logevent(buf);
3594 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3595 PKT_INT, remoteid, PKT_END);
3596 } else {
3597 sprintf(buf, "Received remote port open request for %s:%d",
3598 pf.dhost, port);
3599 logevent(buf);
3600 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3601 c, &ssh->cfg);
3602 if (e != NULL) {
3603 char buf[256];
3604 sprintf(buf, "Port open failed: %s", e);
3605 logevent(buf);
3606 sfree(c);
3607 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3608 PKT_INT, remoteid, PKT_END);
3609 } else {
3610 c->remoteid = remoteid;
3611 c->localid = alloc_channel_id(ssh);
3612 c->closes = 0;
3613 c->v.v1.throttling = 0;
3614 c->type = CHAN_SOCKDATA; /* identify channel type */
3615 add234(ssh->channels, c);
3616 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3617 PKT_INT, c->remoteid, PKT_INT,
3618 c->localid, PKT_END);
3619 logevent("Forwarded port opened successfully");
3620 }
3621 }
3622}
3623
3624static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
3625{
3626 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3627 unsigned int localid = ssh_pkt_getuint32(pktin);
3628 struct ssh_channel *c;
3629
3630 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3631 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3632 c->remoteid = localid;
3633 c->type = CHAN_SOCKDATA;
3634 c->v.v1.throttling = 0;
3635 pfd_confirm(c->u.pfd.s);
3636 }
3637
3638 if (c && c->closes) {
3639 /*
3640 * We have a pending close on this channel,
3641 * which we decided on before the server acked
3642 * the channel open. So now we know the
3643 * remoteid, we can close it again.
3644 */
3645 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3646 PKT_INT, c->remoteid, PKT_END);
3647 }
3648}
3649
3650static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
3651{
3652 unsigned int remoteid = ssh_pkt_getuint32(pktin);
3653 struct ssh_channel *c;
3654
3655 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3656 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3657 logevent("Forwarded connection refused by server");
3658 pfd_close(c->u.pfd.s);
3659 del234(ssh->channels, c);
3660 sfree(c);
3661 }
3662}
3663
3664static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
3665{
3666 /* Remote side closes a channel. */
3667 unsigned i = ssh_pkt_getuint32(pktin);
3668 struct ssh_channel *c;
3669 c = find234(ssh->channels, &i, ssh_channelfind);
3670 if (c && ((int)c->remoteid) != -1) {
3671 int closetype;
3672 closetype =
3673 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3674
3675 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3676 logevent("Forwarded X11 connection terminated");
3677 assert(c->u.x11.s != NULL);
3678 x11_close(c->u.x11.s);
3679 c->u.x11.s = NULL;
3680 }
3681 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3682 logevent("Forwarded port closed");
3683 assert(c->u.pfd.s != NULL);
3684 pfd_close(c->u.pfd.s);
3685 c->u.pfd.s = NULL;
3686 }
3687
3688 c->closes |= (closetype << 2); /* seen this message */
3689 if (!(c->closes & closetype)) {
3690 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
3691 PKT_END);
3692 c->closes |= closetype; /* sent it too */
3693 }
3694
3695 if (c->closes == 15) {
3696 del234(ssh->channels, c);
3697 sfree(c);
3698 }
3699 } else {
3700 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3701 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3702 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3703 i));
3704 }
3705}
3706
3707static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
3708{
3709 /* Data sent down one of our channels. */
3710 int i = ssh_pkt_getuint32(pktin);
3711 char *p;
3712 int len;
3713 struct ssh_channel *c;
3714
3715 ssh_pkt_getstring(pktin, &p, &len);
3716
3717 c = find234(ssh->channels, &i, ssh_channelfind);
3718 if (c) {
3719 int bufsize = 0;
3720 switch (c->type) {
3721 case CHAN_X11:
3722 bufsize = x11_send(c->u.x11.s, p, len);
3723 break;
3724 case CHAN_SOCKDATA:
3725 bufsize = pfd_send(c->u.pfd.s, p, len);
3726 break;
3727 case CHAN_AGENT:
3728 /* Data for an agent message. Buffer it. */
3729 while (len > 0) {
3730 if (c->u.a.lensofar < 4) {
3731 int l = min(4 - c->u.a.lensofar, len);
3732 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3733 l);
3734 p += l;
3735 len -= l;
3736 c->u.a.lensofar += l;
3737 }
3738 if (c->u.a.lensofar == 4) {
3739 c->u.a.totallen =
3740 4 + GET_32BIT(c->u.a.msglen);
3741 c->u.a.message = snewn(c->u.a.totallen,
3742 unsigned char);
3743 memcpy(c->u.a.message, c->u.a.msglen, 4);
3744 }
3745 if (c->u.a.lensofar >= 4 && len > 0) {
3746 int l =
3747 min(c->u.a.totallen - c->u.a.lensofar,
3748 len);
3749 memcpy(c->u.a.message + c->u.a.lensofar, p,
3750 l);
3751 p += l;
3752 len -= l;
3753 c->u.a.lensofar += l;
3754 }
3755 if (c->u.a.lensofar == c->u.a.totallen) {
3756 void *reply;
3757 int replylen;
3758 if (agent_query(c->u.a.message,
3759 c->u.a.totallen,
3760 &reply, &replylen,
3761 ssh_agentf_callback, c))
3762 ssh_agentf_callback(c, reply, replylen);
3763 sfree(c->u.a.message);
3764 c->u.a.lensofar = 0;
3765 }
3766 }
3767 bufsize = 0; /* agent channels never back up */
3768 break;
3769 }
3770 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3771 c->v.v1.throttling = 1;
3772 ssh1_throttle(ssh, +1);
3773 }
3774 }
3775}
3776
3777static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
3778{
3779 char buf[100];
3780 ssh->exitcode = ssh_pkt_getuint32(pktin);
3781 sprintf(buf, "Server sent command exit status %d",
3782 ssh->exitcode);
3783 logevent(buf);
3784 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3785 /*
3786 * In case `helpful' firewalls or proxies tack
3787 * extra human-readable text on the end of the
3788 * session which we might mistake for another
3789 * encrypted packet, we close the session once
3790 * we've sent EXIT_CONFIRMATION.
3791 */
3792 ssh_closing((Plug)ssh, NULL, 0, 0);
3793}
3794
b09eaa88 3795static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
3796 struct Packet *pktin)
32874aea 3797{
b09eaa88 3798 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 3799
51df0ab5 3800 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
3801 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
3802 ssh1_smsg_stdout_stderr_data;
3803
3804 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
3805 ssh1_msg_channel_open_confirmation;
3806 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
3807 ssh1_msg_channel_open_failure;
3808 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
3809 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
3810 ssh1_msg_channel_close;
3811 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
3812 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
3813
86916870 3814 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 3815 logevent("Requesting agent forwarding");
51470298 3816 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 3817 do {
3818 crReturnV;
ff3187f6 3819 } while (!pktin);
3820 if (pktin->type != SSH1_SMSG_SUCCESS
3821 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3822 bombout(("Protocol confusion"));
7ffdbc1a 3823 crStopV;
ff3187f6 3824 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3825 logevent("Agent forwarding refused");
3826 } else {
3827 logevent("Agent forwarding enabled");
51470298 3828 ssh->agentfwd_enabled = TRUE;
51df0ab5 3829 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 3830 }
dacbd0e8 3831 }
3832
86916870 3833 if (ssh->cfg.x11_forward) {
32874aea 3834 char proto[20], data[64];
3835 logevent("Requesting X11 forwarding");
302121de 3836 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 3837 data, sizeof(data), ssh->cfg.x11_auth);
3838 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
51470298 3839 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3840 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3841 PKT_STR, proto, PKT_STR, data,
86916870 3842 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 3843 PKT_END);
32874aea 3844 } else {
51470298 3845 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
32874aea 3846 PKT_STR, proto, PKT_STR, data, PKT_END);
3847 }
3848 do {
3849 crReturnV;
ff3187f6 3850 } while (!pktin);
3851 if (pktin->type != SSH1_SMSG_SUCCESS
3852 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 3853 bombout(("Protocol confusion"));
7ffdbc1a 3854 crStopV;
ff3187f6 3855 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3856 logevent("X11 forwarding refused");
3857 } else {
3858 logevent("X11 forwarding enabled");
51470298 3859 ssh->X11_fwd_enabled = TRUE;
51df0ab5 3860 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 3861 }
3862 }
3863
d74d141c 3864 {
9bf696b1 3865 char type;
d74d141c 3866 int n;
a4fc0d74 3867 int sport,dport,sserv,dserv;
6ee9b735 3868 char sports[256], dports[256], saddr[256], host[256];
d74d141c 3869
51470298 3870 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
d74d141c 3871 /* Add port forwardings. */
86916870 3872 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 3873 while (*ssh->portfwd_strptr) {
3874 type = *ssh->portfwd_strptr++;
6ee9b735 3875 saddr[0] = '\0';
d74d141c 3876 n = 0;
6ee9b735 3877 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3878 if (*ssh->portfwd_strptr == ':') {
3879 /*
3880 * We've seen a colon in the middle of the
3881 * source port number. This means that
3882 * everything we've seen until now is the
3883 * source _address_, so we'll move it into
3884 * saddr and start sports from the beginning
3885 * again.
3886 */
3887 ssh->portfwd_strptr++;
3888 sports[n] = '\0';
3889 strcpy(saddr, sports);
3890 n = 0;
3891 }
3892 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3893 }
d74d141c 3894 sports[n] = 0;
820ebe3b 3895 if (type != 'D') {
3896 if (*ssh->portfwd_strptr == '\t')
3897 ssh->portfwd_strptr++;
3898 n = 0;
3899 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3900 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3901 }
3902 host[n] = 0;
3903 if (*ssh->portfwd_strptr == ':')
3904 ssh->portfwd_strptr++;
3905 n = 0;
3906 while (*ssh->portfwd_strptr) {
3907 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3908 }
3909 dports[n] = 0;
51470298 3910 ssh->portfwd_strptr++;
820ebe3b 3911 dport = atoi(dports);
3912 dserv = 0;
3913 if (dport == 0) {
3914 dserv = 1;
3915 dport = net_service_lookup(dports);
3916 if (!dport) {
3917 logeventf(ssh, "Service lookup failed for"
3918 " destination port \"%s\"", dports);
3919 }
a4fc0d74 3920 }
820ebe3b 3921 } else {
3922 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 3923 dport = dserv = -1;
7d5b0f4d 3924 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
a4fc0d74 3925 }
d74d141c 3926 sport = atoi(sports);
a4fc0d74 3927 sserv = 0;
3928 if (sport == 0) {
3929 sserv = 1;
68a49acb 3930 sport = net_service_lookup(sports);
3931 if (!sport) {
57356d63 3932 logeventf(ssh, "Service lookup failed for source"
3933 " port \"%s\"", sports);
a4fc0d74 3934 }
3935 }
d74d141c 3936 if (sport && dport) {
94ab1ddf 3937 /* Set up a description of the source port. */
c61c9cdf 3938 static char *sportdesc;
3939 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
94ab1ddf 3940 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3941 (int)(*saddr?1:0), ":",
3942 (int)(sserv ? strlen(sports) : 0), sports,
3943 sserv, "(", sport, sserv, ")");
d74d141c 3944 if (type == 'L') {
94ab1ddf 3945 /* Verbose description of the destination port */
3946 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
3947 host,
3948 (int)(dserv ? strlen(dports) : 0), dports,
3949 dserv, "(", dport, dserv, ")");
3950 const char *err = pfd_addforward(host, dport,
3951 *saddr ? saddr : NULL,
3952 sport, ssh, &ssh->cfg);
3953 if (err) {
3954 logeventf(ssh, "Local port %s forward to %s"
3955 " failed: %s", sportdesc, dportdesc, err);
3956 } else {
3957 logeventf(ssh, "Local port %s forwarding to %s",
3958 sportdesc, dportdesc);
3959 }
3960 sfree(dportdesc);
820ebe3b 3961 } else if (type == 'D') {
94ab1ddf 3962 const char *err = pfd_addforward(NULL, -1,
3963 *saddr ? saddr : NULL,
3964 sport, ssh, &ssh->cfg);
3965 if (err) {
3966 logeventf(ssh, "Local port %s SOCKS dynamic forward"
3967 " setup failed: %s", sportdesc, err);
3968 } else {
3969 logeventf(ssh, "Local port %s doing SOCKS"
3970 " dynamic forwarding", sportdesc);
3971 }
d74d141c 3972 } else {
3973 struct ssh_rportfwd *pf;
3d88e64d 3974 pf = snew(struct ssh_rportfwd);
bc240b21 3975 strcpy(pf->dhost, host);
3976 pf->dport = dport;
0cd494d7 3977 if (*saddr) {
6ee9b735 3978 logeventf(ssh,
3979 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3980 saddr, sport);
3981 }
51470298 3982 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 3983 logeventf(ssh,
3984 "Duplicate remote port forwarding to %s:%d",
3985 host, dport);
bc240b21 3986 sfree(pf);
d74d141c 3987 } else {
57356d63 3988 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3989 " forward to %s:%.*s%.*s%d%.*s",
3990 (int)(sserv ? strlen(sports) : 0), sports,
3991 sserv, "(", sport, sserv, ")",
3992 host,
3993 (int)(dserv ? strlen(dports) : 0), dports,
3994 dserv, "(", dport, dserv, ")");
51470298 3995 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
d74d141c 3996 PKT_INT, sport,
3997 PKT_STR, host,
3998 PKT_INT, dport,
3999 PKT_END);
9bf696b1 4000 do {
4001 crReturnV;
ff3187f6 4002 } while (!pktin);
4003 if (pktin->type != SSH1_SMSG_SUCCESS
4004 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4005 bombout(("Protocol confusion"));
7ffdbc1a 4006 crStopV;
ff3187f6 4007 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4008 c_write_str(ssh, "Server refused port"
4009 " forwarding\r\n");
51df0ab5 4010 logevent("Server refused this port forwarding");
4011 } else {
4012 logevent("Remote port forwarding enabled");
4013 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] =
4014 ssh1_msg_port_open;
9bf696b1 4015 }
d74d141c 4016 }
4017 }
94ab1ddf 4018 sfree(sportdesc);
d74d141c 4019 }
4020 }
4021 }
4022
86916870 4023 if (!ssh->cfg.nopty) {
a5dd8467 4024 /* Unpick the terminal-speed string. */
4025 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4026 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4027 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4028 /* Send the pty request. */
51470298 4029 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
86916870 4030 PKT_STR, ssh->cfg.termtype,
51470298 4031 PKT_INT, ssh->term_height,
4032 PKT_INT, ssh->term_width,
a5dd8467 4033 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
db219738 4034 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4035 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
a5dd8467 4036 PKT_CHAR, 0, PKT_END);
51470298 4037 ssh->state = SSH_STATE_INTERMED;
32874aea 4038 do {
4039 crReturnV;
ff3187f6 4040 } while (!pktin);
4041 if (pktin->type != SSH1_SMSG_SUCCESS
4042 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4043 bombout(("Protocol confusion"));
7ffdbc1a 4044 crStopV;
ff3187f6 4045 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4046 c_write_str(ssh, "Server refused to allocate pty\r\n");
4047 ssh->editing = ssh->echoing = 1;
32874aea 4048 }
a5dd8467 4049 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4050 ssh->ospeed, ssh->ispeed);
0965bee0 4051 } else {
51470298 4052 ssh->editing = ssh->echoing = 1;
374330e2 4053 }
4054
86916870 4055 if (ssh->cfg.compression) {
51470298 4056 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4057 do {
4058 crReturnV;
ff3187f6 4059 } while (!pktin);
4060 if (pktin->type != SSH1_SMSG_SUCCESS
4061 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4062 bombout(("Protocol confusion"));
7ffdbc1a 4063 crStopV;
ff3187f6 4064 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4065 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4066 }
4ba9b64b 4067 logevent("Started compression");
51470298 4068 ssh->v1_compressing = TRUE;
5366aed8 4069 ssh->cs_comp_ctx = zlib_compress_init();
4070 logevent("Initialised zlib (RFC1950) compression");
4071 ssh->sc_comp_ctx = zlib_decompress_init();
4072 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4073 }
4074
fd5e5847 4075 /*
4076 * Start the shell or command.
4077 *
4078 * Special case: if the first-choice command is an SSH2
4079 * subsystem (hence not usable here) and the second choice
4080 * exists, we fall straight back to that.
4081 */
4082 {
86916870 4083 char *cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 4084
86916870 4085 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4086 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 4087 ssh->fallback_cmd = TRUE;
fd5e5847 4088 }
4089 if (*cmd)
51470298 4090 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 4091 else
51470298 4092 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 4093 logevent("Started session");
4094 }
374330e2 4095
51470298 4096 ssh->state = SSH_STATE_SESSION;
4097 if (ssh->size_needed)
4098 ssh_size(ssh, ssh->term_width, ssh->term_height);
4099 if (ssh->eof_needed)
4100 ssh_special(ssh, TS_EOF);
374330e2 4101
b9d7bcad 4102 if (ssh->ldisc)
4103 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 4104 ssh->send_ok = 1;
4105 ssh->channels = newtree234(ssh_channelcmp);
374330e2 4106 while (1) {
d74d141c 4107
51df0ab5 4108 /*
4109 * By this point, most incoming packets are already being
4110 * handled by the dispatch table, and we need only pay
4111 * attention to the unusual ones.
4112 */
0357890f 4113
51df0ab5 4114 crReturnV;
4115 if (pktin) {
4116 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4117 /* may be from EXEC_SHELL on some servers */
ff3187f6 4118 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 4119 /* may be from EXEC_SHELL on some servers
374330e2 4120 * if no pty is available or in other odd cases. Ignore */
374330e2 4121 } else {
ff3187f6 4122 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 4123 crStopV;
374330e2 4124 }
4125 } else {
8df7a775 4126 while (inlen > 0) {
4127 int len = min(inlen, 512);
9a10ecf4 4128 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4129 PKT_INT, len, PKT_DATA, in, len,
4130 PKTT_OTHER, PKT_END);
8df7a775 4131 in += len;
4132 inlen -= len;
4133 }
374330e2 4134 }
4135 }
4136
4137 crFinishV;
4138}
4139
4140/*
b09eaa88 4141 * Handle the top-level SSH2 protocol.
4142 */
4143static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4144{
4145 char *buf, *msg;
4146 int msglen;
4147
4148 ssh_pkt_getstring(pktin, &msg, &msglen);
4149 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4150 logevent(buf);
4151 sfree(buf);
4152}
4153
4154static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4155{
4156 /* log reason code in disconnect message */
4157 char *msg;
4158 int msglen;
4159
4160 ssh_pkt_getstring(pktin, &msg, &msglen);
4161 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4162}
4163
4164void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4165{
4166 /* Do nothing, because we're ignoring it! Duhh. */
4167}
4168
4169static void ssh1_protocol_setup(Ssh ssh)
4170{
4171 int i;
4172
4173 /*
4174 * Most messages are handled by the coroutines.
4175 */
4176 for (i = 0; i < 256; i++)
4177 ssh->packet_dispatch[i] = NULL;
4178
4179 /*
4180 * These special message types we install handlers for.
4181 */
4182 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4183 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4184 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4185}
4186
4187static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4188 struct Packet *pktin)
4189{
4190 if (ssh->state == SSH_STATE_CLOSED)
4191 return;
4192
4193 if (pktin && ssh->packet_dispatch[pktin->type]) {
4194 ssh->packet_dispatch[pktin->type](ssh, pktin);
4195 return;
4196 }
4197
4198 if (!ssh->protocol_initial_phase_done) {
4199 if (do_ssh1_login(ssh, in, inlen, pktin))
4200 ssh->protocol_initial_phase_done = TRUE;
4201 else
4202 return;
4203 }
4204
4205 do_ssh1_connection(ssh, in, inlen, pktin);
4206}
4207
4208/*
e5574168 4209 * Utility routine for decoding comma-separated strings in KEXINIT.
4210 */
32874aea 4211static int in_commasep_string(char *needle, char *haystack, int haylen)
4212{
57356d63 4213 int needlen;
4214 if (!needle || !haystack) /* protect against null pointers */
4215 return 0;
4216 needlen = strlen(needle);
e5574168 4217 while (1) {
32874aea 4218 /*
4219 * Is it at the start of the string?
4220 */
4221 if (haylen >= needlen && /* haystack is long enough */
4222 !memcmp(needle, haystack, needlen) && /* initial match */
4223 (haylen == needlen || haystack[needlen] == ',')
4224 /* either , or EOS follows */
4225 )
4226 return 1;
4227 /*
4228 * If not, search for the next comma and resume after that.
4229 * If no comma found, terminate.
4230 */
4231 while (haylen > 0 && *haystack != ',')
4232 haylen--, haystack++;
4233 if (haylen == 0)
4234 return 0;
4235 haylen--, haystack++; /* skip over comma itself */
e5574168 4236 }
4237}
4238
4239/*
d39f364a 4240 * SSH2 key creation method.
4241 */
d8baa528 4242static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4243 unsigned char *sessid, char chr,
4244 unsigned char *keyspace)
32874aea 4245{
d39f364a 4246 SHA_State s;
4247 /* First 20 bytes. */
4248 SHA_Init(&s);
51470298 4249 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4250 sha_mpint(&s, K);
d39f364a 4251 SHA_Bytes(&s, H, 20);
4252 SHA_Bytes(&s, &chr, 1);
5e0d7cb8 4253 SHA_Bytes(&s, sessid, 20);
d39f364a 4254 SHA_Final(&s, keyspace);
4255 /* Next 20 bytes. */
4256 SHA_Init(&s);
51470298 4257 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
088bde77 4258 sha_mpint(&s, K);
d39f364a 4259 SHA_Bytes(&s, H, 20);
4260 SHA_Bytes(&s, keyspace, 20);
32874aea 4261 SHA_Final(&s, keyspace + 20);
d39f364a 4262}
4263
4264/*
7cca0d81 4265 * Handle the SSH2 transport layer.
e5574168 4266 */
ff3187f6 4267static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4268 struct Packet *pktin)
e5574168 4269{
51470298 4270 struct do_ssh2_transport_state {
4271 int nbits, pbits, warn;
4272 Bignum p, g, e, f, K;
4273 int kex_init_value, kex_reply_value;
4274 const struct ssh_mac **maclist;
4275 int nmacs;
4276 const struct ssh2_cipher *cscipher_tobe;
4277 const struct ssh2_cipher *sccipher_tobe;
4278 const struct ssh_mac *csmac_tobe;
4279 const struct ssh_mac *scmac_tobe;
4280 const struct ssh_compress *cscomp_tobe;
4281 const struct ssh_compress *sccomp_tobe;
4282 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4283 int hostkeylen, siglen;
4284 void *hkey; /* actual host key */
4285 unsigned char exchange_hash[20];
4286 int n_preferred_ciphers;
4287 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4288 const struct ssh_compress *preferred_comp;
4289 int first_kex;
ff3187f6 4290 struct Packet *pktout;
51470298 4291 };
4292 crState(do_ssh2_transport_state);
4293
4294 crBegin(ssh->do_ssh2_transport_crstate);
4295
4296 s->cscipher_tobe = s->sccipher_tobe = NULL;
4297 s->csmac_tobe = s->scmac_tobe = NULL;
4298 s->cscomp_tobe = s->sccomp_tobe = NULL;
4299
51470298 4300 s->first_kex = 1;
e5574168 4301
51470298 4302 {
4303 int i;
4304 /*
4305 * Set up the preferred ciphers. (NULL => warn below here)
4306 */
4307 s->n_preferred_ciphers = 0;
4308 for (i = 0; i < CIPHER_MAX; i++) {
86916870 4309 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 4310 case CIPHER_BLOWFISH:
4311 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4312 break;
4313 case CIPHER_DES:
86916870 4314 if (ssh->cfg.ssh2_des_cbc) {
51470298 4315 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4316 }
4317 break;
4318 case CIPHER_3DES:
4319 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4320 break;
4321 case CIPHER_AES:
4322 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4323 break;
4324 case CIPHER_WARN:
4325 /* Flag for later. Don't bother if it's the last in
4326 * the list. */
4327 if (i < CIPHER_MAX - 1) {
4328 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4329 }
4330 break;
ca20bfcf 4331 }
ca20bfcf 4332 }
5e8358ad 4333 }
ca20bfcf 4334
4335 /*
4336 * Set up preferred compression.
4337 */
86916870 4338 if (ssh->cfg.compression)
51470298 4339 s->preferred_comp = &ssh_zlib;
4ba9b64b 4340 else
51470298 4341 s->preferred_comp = &ssh_comp_none;
5e8358ad 4342
7591b9ff 4343 /*
4344 * Be prepared to work around the buggy MAC problem.
4345 */
51470298 4346 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4347 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
7591b9ff 4348 else
51470298 4349 s->maclist = macs, s->nmacs = lenof(macs);
7591b9ff 4350
32874aea 4351 begin_key_exchange:
51470298 4352 {
4353 int i, j, cipherstr_started;
4354
4355 /*
590f6a5f 4356 * Enable queueing of outgoing auth- or connection-layer
4357 * packets while we are in the middle of a key exchange.
4358 */
4359 ssh->queueing = TRUE;
4360
4361 /*
9442dd57 4362 * Flag that KEX is in progress.
4363 */
4364 ssh->kex_in_progress = TRUE;
4365
4366 /*
51470298 4367 * Construct and send our key exchange packet.
4368 */
ff3187f6 4369 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 4370 for (i = 0; i < 16; i++)
ff3187f6 4371 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 4372 /* List key exchange algorithms. */
ff3187f6 4373 ssh2_pkt_addstring_start(s->pktout);
51470298 4374 for (i = 0; i < lenof(kex_algs); i++) {
4375 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4376 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4377 continue;
ff3187f6 4378 ssh2_pkt_addstring_str(s->pktout, kex_algs[i]->name);
51470298 4379 if (i < lenof(kex_algs) - 1)
ff3187f6 4380 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4381 }
51470298 4382 /* List server host key algorithms. */
ff3187f6 4383 ssh2_pkt_addstring_start(s->pktout);
51470298 4384 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 4385 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 4386 if (i < lenof(hostkey_algs) - 1)
ff3187f6 4387 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 4388 }
51470298 4389 /* List client->server encryption algorithms. */
ff3187f6 4390 ssh2_pkt_addstring_start(s->pktout);
51470298 4391 cipherstr_started = 0;
4392 for (i = 0; i < s->n_preferred_ciphers; i++) {
4393 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4394 if (!c) continue; /* warning flag */
4395 for (j = 0; j < c->nciphers; j++) {
4396 if (cipherstr_started)
ff3187f6 4397 ssh2_pkt_addstring_str(s->pktout, ",");
4398 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
51470298 4399 cipherstr_started = 1;
4400 }
4401 }
4402 /* List server->client encryption algorithms. */
ff3187f6 4403 ssh2_pkt_addstring_start(s->pktout);
51470298 4404 cipherstr_started = 0;
4405 for (i = 0; i < s->n_preferred_ciphers; i++) {
4406 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4407 if (!c) continue; /* warning flag */
4408 for (j = 0; j < c->nciphers; j++) {
4409 if (cipherstr_started)
ff3187f6 4410 ssh2_pkt_addstring_str(s->pktout, ",");
4411 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
51470298 4412 cipherstr_started = 1;
4413 }
4414 }
4415 /* List client->server MAC algorithms. */
ff3187f6 4416 ssh2_pkt_addstring_start(s->pktout);
51470298 4417 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4418 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4419 if (i < s->nmacs - 1)
ff3187f6 4420 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4421 }
4422 /* List server->client MAC algorithms. */
ff3187f6 4423 ssh2_pkt_addstring_start(s->pktout);
51470298 4424 for (i = 0; i < s->nmacs; i++) {
ff3187f6 4425 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 4426 if (i < s->nmacs - 1)
ff3187f6 4427 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 4428 }
4429 /* List client->server compression algorithms. */
ff3187f6 4430 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4431 assert(lenof(compressions) > 1);
ff3187f6 4432 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4433 for (i = 0; i < lenof(compressions); i++) {
4434 const struct ssh_compress *c = compressions[i];
4435 if (c != s->preferred_comp) {
ff3187f6 4436 ssh2_pkt_addstring_str(s->pktout, ",");
4437 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4438 }
51470298 4439 }
4440 /* List server->client compression algorithms. */
ff3187f6 4441 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 4442 assert(lenof(compressions) > 1);
ff3187f6 4443 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 4444 for (i = 0; i < lenof(compressions); i++) {
4445 const struct ssh_compress *c = compressions[i];
4446 if (c != s->preferred_comp) {
ff3187f6 4447 ssh2_pkt_addstring_str(s->pktout, ",");
4448 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 4449 }
51470298 4450 }
4451 /* List client->server languages. Empty list. */
ff3187f6 4452 ssh2_pkt_addstring_start(s->pktout);
51470298 4453 /* List server->client languages. Empty list. */
ff3187f6 4454 ssh2_pkt_addstring_start(s->pktout);
51470298 4455 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 4456 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 4457 /* Reserved. */
ff3187f6 4458 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 4459 }
0db56f73 4460
51470298 4461 ssh->exhash = ssh->exhashbase;
ff3187f6 4462 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
0db56f73 4463
590f6a5f 4464 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4465
ff3187f6 4466 if (!pktin)
4467 crWaitUntil(pktin);
4468 if (pktin->length > 5)
4469 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
e5574168 4470
4471 /*
4472 * Now examine the other side's KEXINIT to see what we're up
4473 * to.
4474 */
51470298 4475 {
4476 char *str;
4477 int i, j, len;
4478
ff3187f6 4479 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 4480 bombout(("expected key exchange packet from server"));
7ffdbc1a 4481 crStop(0);
32874aea 4482 }
51470298 4483 ssh->kex = NULL;
4484 ssh->hostkey = NULL;
4485 s->cscipher_tobe = NULL;
4486 s->sccipher_tobe = NULL;
4487 s->csmac_tobe = NULL;
4488 s->scmac_tobe = NULL;
4489 s->cscomp_tobe = NULL;
4490 s->sccomp_tobe = NULL;
ff3187f6 4491 pktin->savedpos += 16; /* skip garbage cookie */
4492 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
51470298 4493 for (i = 0; i < lenof(kex_algs); i++) {
4494 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4495 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4496 continue;
4497 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4498 ssh->kex = kex_algs[i];
4499 break;
4500 }
32874aea 4501 }
ff3187f6 4502 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 4503 for (i = 0; i < lenof(hostkey_algs); i++) {
4504 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4505 ssh->hostkey = hostkey_algs[i];
4506 break;
4507 }
4508 }
ff3187f6 4509 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 4510 s->warn = 0;
4511 for (i = 0; i < s->n_preferred_ciphers; i++) {
4512 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4513 if (!c) {
4514 s->warn = 1;
4515 } else {
4516 for (j = 0; j < c->nciphers; j++) {
4517 if (in_commasep_string(c->list[j]->name, str, len)) {
4518 s->cscipher_tobe = c->list[j];
4519 break;
4520 }
ca20bfcf 4521 }
32874aea 4522 }
51470298 4523 if (s->cscipher_tobe) {
4524 if (s->warn)
a8327734 4525 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
51470298 4526 break;
4527 }
32874aea 4528 }
51470298 4529 if (!s->cscipher_tobe) {
6b5cf8b4 4530 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 4531 str ? str : "(null)"));
7ffdbc1a 4532 crStop(0);
ca20bfcf 4533 }
0ef8f407 4534
ff3187f6 4535 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 4536 s->warn = 0;
4537 for (i = 0; i < s->n_preferred_ciphers; i++) {
4538 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4539 if (!c) {
4540 s->warn = 1;
4541 } else {
4542 for (j = 0; j < c->nciphers; j++) {
4543 if (in_commasep_string(c->list[j]->name, str, len)) {
4544 s->sccipher_tobe = c->list[j];
4545 break;
4546 }
ca20bfcf 4547 }
32874aea 4548 }
51470298 4549 if (s->sccipher_tobe) {
4550 if (s->warn)
a8327734 4551 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
51470298 4552 break;
4553 }
32874aea 4554 }
51470298 4555 if (!s->sccipher_tobe) {
6b5cf8b4 4556 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 4557 str ? str : "(null)"));
7ffdbc1a 4558 crStop(0);
ca20bfcf 4559 }
0ef8f407 4560
ff3187f6 4561 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 4562 for (i = 0; i < s->nmacs; i++) {
4563 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4564 s->csmac_tobe = s->maclist[i];
4565 break;
4566 }
32874aea 4567 }
ff3187f6 4568 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 4569 for (i = 0; i < s->nmacs; i++) {
4570 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4571 s->scmac_tobe = s->maclist[i];
4572 break;
4573 }
32874aea 4574 }
ff3187f6 4575 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 4576 for (i = 0; i < lenof(compressions) + 1; i++) {
4577 const struct ssh_compress *c =
4578 i == 0 ? s->preferred_comp : compressions[i - 1];
4579 if (in_commasep_string(c->name, str, len)) {
4580 s->cscomp_tobe = c;
4581 break;
4582 }
32874aea 4583 }
ff3187f6 4584 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 4585 for (i = 0; i < lenof(compressions) + 1; i++) {
4586 const struct ssh_compress *c =
4587 i == 0 ? s->preferred_comp : compressions[i - 1];
4588 if (in_commasep_string(c->name, str, len)) {
4589 s->sccomp_tobe = c;
4590 break;
4591 }
32874aea 4592 }
e5574168 4593 }
e5574168 4594
4595 /*
7bd5a860 4596 * Work out the number of bits of key we will need from the key
4597 * exchange. We start with the maximum key length of either
4598 * cipher...
4599 */
4600 {
32874aea 4601 int csbits, scbits;
7bd5a860 4602
51470298 4603 csbits = s->cscipher_tobe->keylen;
4604 scbits = s->sccipher_tobe->keylen;
4605 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 4606 }
4607 /* The keys only have 160-bit entropy, since they're based on
4608 * a SHA-1 hash. So cap the key size at 160 bits. */
51470298 4609 if (s->nbits > 160)
4610 s->nbits = 160;
7bd5a860 4611
4612 /*
a92dd380 4613 * If we're doing Diffie-Hellman group exchange, start by
4614 * requesting a group.
e5574168 4615 */
51470298 4616 if (ssh->kex == &ssh_diffiehellman_gex) {
32874aea 4617 logevent("Doing Diffie-Hellman group exchange");
51470298 4618 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 4619 /*
4620 * Work out how big a DH group we will need to allow that
4621 * much data.
7bd5a860 4622 */
51470298 4623 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 4624 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
4625 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 4626 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 4627
ff3187f6 4628 crWaitUntil(pktin);
4629 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 4630 bombout(("expected key exchange group packet from server"));
7ffdbc1a 4631 crStop(0);
32874aea 4632 }
ff3187f6 4633 s->p = ssh2_pkt_getmp(pktin);
4634 s->g = ssh2_pkt_getmp(pktin);
4635 if (!s->p || !s->g) {
4636 bombout(("unable to read mp-ints from incoming group packet"));
4637 crStop(0);
4638 }
27cd7fc2 4639 ssh->kex_ctx = dh_setup_group(s->p, s->g);
51470298 4640 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4641 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 4642 } else {
51470298 4643 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
27cd7fc2 4644 ssh->kex_ctx = dh_setup_group1();
51470298 4645 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4646 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
8d5de777 4647 }
e5574168 4648
a92dd380 4649 logevent("Doing Diffie-Hellman key exchange");
e5574168 4650 /*
a92dd380 4651 * Now generate and send e for Diffie-Hellman.
e5574168 4652 */
27cd7fc2 4653 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 4654 s->pktout = ssh2_pkt_init(s->kex_init_value);
4655 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 4656 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 4657
ff3187f6 4658 crWaitUntil(pktin);
4659 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 4660 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 4661 crStop(0);
7cca0d81 4662 }
ff3187f6 4663 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
4664 s->f = ssh2_pkt_getmp(pktin);
4665 if (!s->f) {
4666 bombout(("unable to parse key exchange reply packet"));
4667 crStop(0);
4668 }
4669 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 4670
27cd7fc2 4671 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 4672
51470298 4673 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4674 if (ssh->kex == &ssh_diffiehellman_gex) {
4675 sha_uint32(&ssh->exhash, s->pbits);
4676 sha_mpint(&ssh->exhash, s->p);
4677 sha_mpint(&ssh->exhash, s->g);
a92dd380 4678 }
51470298 4679 sha_mpint(&ssh->exhash, s->e);
4680 sha_mpint(&ssh->exhash, s->f);
4681 sha_mpint(&ssh->exhash, s->K);
4682 SHA_Final(&ssh->exhash, s->exchange_hash);
e5574168 4683
27cd7fc2 4684 dh_cleanup(ssh->kex_ctx);
fabd1805 4685 ssh->kex_ctx = NULL;
3709bfe9 4686
7cca0d81 4687#if 0
765c4200 4688 debug(("Exchange hash is:\n"));
51470298 4689 dmemdump(s->exchange_hash, 20);
7cca0d81 4690#endif
4691
51470298 4692 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4693 if (!s->hkey ||
4694 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
d8baa528 4695 (char *)s->exchange_hash, 20)) {
6b5cf8b4 4696 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 4697 crStop(0);
8d5de777 4698 }
e5574168 4699
4700 /*
7cca0d81 4701 * Authenticate remote host: verify host key. (We've already
4702 * checked the signature of the exchange hash.)
e5574168 4703 */
51470298 4704 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4705 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
a8327734 4706 verify_ssh_host_key(ssh->frontend,
4707 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
51470298 4708 s->keystr, s->fingerprint);
4709 if (s->first_kex) { /* don't bother logging this in rekeys */
5e0d7cb8 4710 logevent("Host key fingerprint is:");
51470298 4711 logevent(s->fingerprint);
5e0d7cb8 4712 }
51470298 4713 sfree(s->fingerprint);
4714 sfree(s->keystr);
4715 ssh->hostkey->freekey(s->hkey);
d39f364a 4716
4717 /*
9442dd57 4718 * The exchange hash from the very first key exchange is also
4719 * the session id, used in session key construction and
4720 * authentication.
4721 */
4722 if (s->first_kex)
4723 memcpy(ssh->v2_session_id, s->exchange_hash,
4724 sizeof(s->exchange_hash));
4725
4726 /*
7cca0d81 4727 * Send SSH2_MSG_NEWKEYS.
d39f364a 4728 */
ff3187f6 4729 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 4730 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 4731 ssh->outgoing_data_size = 0; /* start counting from here */
4732
4733 /*
4734 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 4735 * client-to-server session keys.
9442dd57 4736 */
4737 if (ssh->cs_cipher_ctx)
4738 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4739 ssh->cscipher = s->cscipher_tobe;
4740 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4741
4742 if (ssh->cs_mac_ctx)
4743 ssh->csmac->free_context(ssh->cs_mac_ctx);
4744 ssh->csmac = s->csmac_tobe;
4745 ssh->cs_mac_ctx = ssh->csmac->make_context();
4746
4747 if (ssh->cs_comp_ctx)
4748 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4749 ssh->cscomp = s->cscomp_tobe;
4750 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4751
4752 /*
4753 * Set IVs on client-to-server keys. Here we use the exchange
4754 * hash from the _first_ key exchange.
4755 */
4756 {
4757 unsigned char keyspace[40];
4758 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4759 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4760 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4761 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4762 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4763 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4764 }
4765
4766 logeventf(ssh, "Initialised %.200s client->server encryption",
4767 ssh->cscipher->text_name);
4768 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
4769 ssh->csmac->text_name);
4770 if (ssh->cscomp->text_name)
4771 logeventf(ssh, "Initialised %s compression",
4772 ssh->cscomp->text_name);
590f6a5f 4773
4774 /*
4775 * Now our end of the key exchange is complete, we can send all
4776 * our queued higher-layer packets.
4777 */
4778 ssh->queueing = FALSE;
4779 ssh2_pkt_queuesend(ssh);
d39f364a 4780
4781 /*
8406eaf9 4782 * Expect SSH2_MSG_NEWKEYS from server.
4783 */
ff3187f6 4784 crWaitUntil(pktin);
4785 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 4786 bombout(("expected new-keys packet from server"));
7ffdbc1a 4787 crStop(0);
8406eaf9 4788 }
9442dd57 4789 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 4790
4791 /*
9442dd57 4792 * We've seen server NEWKEYS, so create and initialise
4793 * server-to-client session keys.
d39f364a 4794 */
371e569c 4795 if (ssh->sc_cipher_ctx)
4796 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 4797 ssh->sccipher = s->sccipher_tobe;
371e569c 4798 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 4799
e0e1a00d 4800 if (ssh->sc_mac_ctx)
4801 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 4802 ssh->scmac = s->scmac_tobe;
e0e1a00d 4803 ssh->sc_mac_ctx = ssh->scmac->make_context();
4804
5366aed8 4805 if (ssh->sc_comp_ctx)
4806 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 4807 ssh->sccomp = s->sccomp_tobe;
5366aed8 4808 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4809
d39f364a 4810 /*
9442dd57 4811 * Set IVs on server-to-client keys. Here we use the exchange
4812 * hash from the _first_ key exchange.
d39f364a 4813 */
51470298 4814 {
4815 unsigned char keyspace[40];
51470298 4816 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
371e569c 4817 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
51470298 4818 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
371e569c 4819 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
51470298 4820 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
e0e1a00d 4821 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 4822 }
57356d63 4823 logeventf(ssh, "Initialised %.200s server->client encryption",
4824 ssh->sccipher->text_name);
6c135243 4825 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
4826 ssh->scmac->text_name);
57356d63 4827 if (ssh->sccomp->text_name)
4828 logeventf(ssh, "Initialised %s decompression",
4829 ssh->sccomp->text_name);
9442dd57 4830
4831 /*
4832 * Free key exchange data.
4833 */
679539d7 4834 freebn(s->f);
679539d7 4835 freebn(s->K);
b3949e7e 4836 if (ssh->kex == &ssh_diffiehellman_gex) {
4837 freebn(s->g);
4838 freebn(s->p);
4839 }
d39f364a 4840
033b4cef 4841 /*
9442dd57 4842 * Key exchange is over. Schedule a timer for our next rekey.
4843 */
4844 ssh->kex_in_progress = FALSE;
4845 ssh->next_rekey = schedule_timer(REKEY_TIMEOUT, ssh2_timer, ssh);
4846
4847 /*
0db56f73 4848 * If this is the first key exchange phase, we must pass the
4849 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4850 * wants to see it but because it will need time to initialise
4851 * itself before it sees an actual packet. In subsequent key
4852 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4853 * it would only confuse the layer above.
4854 */
51470298 4855 if (!s->first_kex) {
b09eaa88 4856 crReturn(1);
0db56f73 4857 }
51470298 4858 s->first_kex = 0;
0db56f73 4859
4860 /*
7cca0d81 4861 * Now we're encrypting. Begin returning 1 to the protocol main
4862 * function so that other things can run on top of the
4863 * transport. If we ever see a KEXINIT, we must go back to the
4864 * start.
9442dd57 4865 *
4866 * We _also_ go back to the start if we see pktin==NULL and
4867 * inlen==-1, because this is a special signal meaning
4868 * `initiate client-driven rekey', and `in' contains a message
4869 * giving the reason for the rekey.
033b4cef 4870 */
9442dd57 4871 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
4872 (!pktin && inlen == -1))) {
32874aea 4873 crReturn(1);
e96adf72 4874 }
9442dd57 4875 if (pktin) {
4876 logevent("Server initiated key re-exchange");
4877 } else {
4878 logevent((char *)in);
4879 }
7cca0d81 4880 goto begin_key_exchange;
e5574168 4881
4882 crFinish(1);
4883}
4884
7cca0d81 4885/*
783415f8 4886 * Add data to an SSH2 channel output buffer.
4887 */
32874aea 4888static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4889 int len)
4890{
5471d09a 4891 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 4892}
4893
4894/*
4895 * Attempt to send data on an SSH2 channel.
4896 */
5471d09a 4897static int ssh2_try_send(struct ssh_channel *c)
32874aea 4898{
51470298 4899 Ssh ssh = c->ssh;
ff3187f6 4900 struct Packet *pktout;
51470298 4901
5471d09a 4902 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4903 int len;
4904 void *data;
4905 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4906 if ((unsigned)len > c->v.v2.remwindow)
4907 len = c->v.v2.remwindow;
4908 if ((unsigned)len > c->v.v2.remmaxpkt)
4909 len = c->v.v2.remmaxpkt;
ff3187f6 4910 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
4911 ssh2_pkt_adduint32(pktout, c->remoteid);
4912 dont_log_data(ssh, pktout, PKTLOG_OMIT);
4913 ssh2_pkt_addstring_start(pktout);
4914 ssh2_pkt_addstring_data(pktout, data, len);
4915 end_log_omission(ssh, pktout);
4916 ssh2_pkt_send(ssh, pktout);
5471d09a 4917 bufchain_consume(&c->v.v2.outbuffer, len);
4918 c->v.v2.remwindow -= len;
4919 }
4920
4921 /*
4922 * After having sent as much data as we can, return the amount
4923 * still buffered.
4924 */
4925 return bufchain_size(&c->v.v2.outbuffer);
4926}
4927
4928/*
4929 * Potentially enlarge the window on an SSH2 channel.
4930 */
4931static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4932{
51470298 4933 Ssh ssh = c->ssh;
4934
6b69f42e 4935 /*
4936 * Never send WINDOW_ADJUST for a channel that the remote side
4937 * already thinks it's closed; there's no point, since it won't
4938 * be sending any more data anyway.
4939 */
4940 if (c->closes != 0)
4941 return;
4942
5471d09a 4943 if (newwin > c->v.v2.locwindow) {
ff3187f6 4944 struct Packet *pktout;
4945
4946 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4947 ssh2_pkt_adduint32(pktout, c->remoteid);
4948 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
4949 ssh2_pkt_send(ssh, pktout);
5471d09a 4950 c->v.v2.locwindow = newwin;
783415f8 4951 }
4952}
4953
51df0ab5 4954static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 4955{
4956 unsigned i = ssh_pkt_getuint32(pktin);
4957 struct ssh_channel *c;
4958 c = find234(ssh->channels, &i, ssh_channelfind);
4959 if (c && !c->closes)
4960 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
4961}
4962
51df0ab5 4963static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
4964{
4965 char *data;
4966 int length;
4967 unsigned i = ssh_pkt_getuint32(pktin);
4968 struct ssh_channel *c;
4969 c = find234(ssh->channels, &i, ssh_channelfind);
4970 if (!c)
4971 return; /* nonexistent channel */
4972 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
4973 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
4974 return; /* extended but not stderr */
4975 ssh_pkt_getstring(pktin, &data, &length);
4976 if (data) {
4977 int bufsize = 0;
4978 c->v.v2.locwindow -= length;
4979 switch (c->type) {
4980 case CHAN_MAINSESSION:
4981 bufsize =
4982 from_backend(ssh->frontend, pktin->type ==
4983 SSH2_MSG_CHANNEL_EXTENDED_DATA,
4984 data, length);
4985 break;
4986 case CHAN_X11:
4987 bufsize = x11_send(c->u.x11.s, data, length);
4988 break;
4989 case CHAN_SOCKDATA:
4990 bufsize = pfd_send(c->u.pfd.s, data, length);
4991 break;
4992 case CHAN_AGENT:
4993 while (length > 0) {
4994 if (c->u.a.lensofar < 4) {
4995 int l = min(4 - c->u.a.lensofar, length);
4996 memcpy(c->u.a.msglen + c->u.a.lensofar,
4997 data, l);
4998 data += l;
4999 length -= l;
5000 c->u.a.lensofar += l;
5001 }
5002 if (c->u.a.lensofar == 4) {
5003 c->u.a.totallen =
5004 4 + GET_32BIT(c->u.a.msglen);
5005 c->u.a.message = snewn(c->u.a.totallen,
5006 unsigned char);
5007 memcpy(c->u.a.message, c->u.a.msglen, 4);
5008 }
5009 if (c->u.a.lensofar >= 4 && length > 0) {
5010 int l =
5011 min(c->u.a.totallen - c->u.a.lensofar,
5012 length);
5013 memcpy(c->u.a.message + c->u.a.lensofar,
5014 data, l);
5015 data += l;
5016 length -= l;
5017 c->u.a.lensofar += l;
5018 }
5019 if (c->u.a.lensofar == c->u.a.totallen) {
5020 void *reply;
5021 int replylen;
5022 if (agent_query(c->u.a.message,
5023 c->u.a.totallen,
5024 &reply, &replylen,
5025 ssh_agentf_callback, c))
5026 ssh_agentf_callback(c, reply, replylen);
5027 sfree(c->u.a.message);
5028 c->u.a.lensofar = 0;
5029 }
5030 }
5031 bufsize = 0;
5032 break;
5033 }
5034 /*
5035 * If we are not buffering too much data,
5036 * enlarge the window again at the remote side.
5037 */
5038 if (bufsize < OUR_V2_WINSIZE)
5039 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5040 }
5041}
5042
5043static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5044{
5045 unsigned i = ssh_pkt_getuint32(pktin);
5046 struct ssh_channel *c;
5047
5048 c = find234(ssh->channels, &i, ssh_channelfind);
5049 if (!c)
5050 return; /* nonexistent channel */
5051
5052 if (c->type == CHAN_X11) {
5053 /*
5054 * Remote EOF on an X11 channel means we should
5055 * wrap up and close the channel ourselves.
5056 */
5057 x11_close(c->u.x11.s);
5058 sshfwd_close(c);
5059 } else if (c->type == CHAN_AGENT) {
5060 sshfwd_close(c);
5061 } else if (c->type == CHAN_SOCKDATA) {
5062 pfd_close(c->u.pfd.s);
5063 sshfwd_close(c);
5064 }
5065}
5066
5067static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5068{
5069 unsigned i = ssh_pkt_getuint32(pktin);
5070 struct ssh_channel *c;
5071 struct Packet *pktout;
5072
5073 c = find234(ssh->channels, &i, ssh_channelfind);
5074 if (!c || ((int)c->remoteid) == -1) {
5075 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5076 c ? "half-open" : "nonexistent", i));
5077 return;
5078 }
5079 /* Do pre-close processing on the channel. */
5080 switch (c->type) {
5081 case CHAN_MAINSESSION:
5082 ssh->mainchan = NULL;
5083 update_specials_menu(ssh->frontend);
5084 break;
5085 case CHAN_X11:
5086 if (c->u.x11.s != NULL)
5087 x11_close(c->u.x11.s);
5088 sshfwd_close(c);
5089 break;
5090 case CHAN_AGENT:
5091 sshfwd_close(c);
5092 break;
5093 case CHAN_SOCKDATA:
5094 if (c->u.pfd.s != NULL)
5095 pfd_close(c->u.pfd.s);
5096 sshfwd_close(c);
5097 break;
5098 }
5099 if (c->closes == 0) {
5100 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5101 ssh2_pkt_adduint32(pktout, c->remoteid);
5102 ssh2_pkt_send(ssh, pktout);
5103 }
5104 del234(ssh->channels, c);
5105 bufchain_clear(&c->v.v2.outbuffer);
5106 sfree(c);
5107
5108 /*
5109 * See if that was the last channel left open.
5110 * (This is only our termination condition if we're
5111 * not running in -N mode.)
5112 */
5113 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5114 logevent("All channels closed. Disconnecting");
5115#if 0
5116 /*
5117 * We used to send SSH_MSG_DISCONNECT here,
5118 * because I'd believed that _every_ conforming
5119 * SSH2 connection had to end with a disconnect
5120 * being sent by at least one side; apparently
5121 * I was wrong and it's perfectly OK to
5122 * unceremoniously slam the connection shut
5123 * when you're done, and indeed OpenSSH feels
5124 * this is more polite than sending a
5125 * DISCONNECT. So now we don't.
5126 */
5127 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5128 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5129 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5130 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5131 ssh2_pkt_send_noqueue(ssh, s->pktout);
5132#endif
5133 ssh_closing((Plug)ssh, NULL, 0, 0);
5134 }
5135}
5136
5137static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5138{
5139 unsigned i = ssh_pkt_getuint32(pktin);
5140 struct ssh_channel *c;
5141 struct Packet *pktout;
5142
5143 c = find234(ssh->channels, &i, ssh_channelfind);
5144 if (!c)
5145 return; /* nonexistent channel */
5146 if (c->type != CHAN_SOCKDATA_DORMANT)
5147 return; /* dunno why they're confirming this */
5148 c->remoteid = ssh_pkt_getuint32(pktin);
5149 c->type = CHAN_SOCKDATA;
5150 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5151 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5152 if (c->u.pfd.s)
5153 pfd_confirm(c->u.pfd.s);
5154 if (c->closes) {
5155 /*
5156 * We have a pending close on this channel,
5157 * which we decided on before the server acked
5158 * the channel open. So now we know the
5159 * remoteid, we can close it again.
5160 */
5161 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5162 ssh2_pkt_adduint32(pktout, c->remoteid);
5163 ssh2_pkt_send(ssh, pktout);
5164 }
5165}
5166
5167static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5168{
5169 static const char *const reasons[] = {
5170 "<unknown reason code>",
5171 "Administratively prohibited",
5172 "Connect failed",
5173 "Unknown channel type",
5174 "Resource shortage",
5175 };
5176 unsigned i = ssh_pkt_getuint32(pktin);
5177 unsigned reason_code;
5178 char *reason_string;
5179 int reason_length;
5180 char *message;
5181 struct ssh_channel *c;
5182 c = find234(ssh->channels, &i, ssh_channelfind);
5183 if (!c)
5184 return; /* nonexistent channel */
5185 if (c->type != CHAN_SOCKDATA_DORMANT)
5186 return; /* dunno why they're failing this */
5187
5188 reason_code = ssh_pkt_getuint32(pktin);
5189 if (reason_code >= lenof(reasons))
5190 reason_code = 0; /* ensure reasons[reason_code] in range */
5191 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5192 message = dupprintf("Forwarded connection refused by"
5193 " server: %s [%.*s]", reasons[reason_code],
5194 reason_length, reason_string);
5195 logevent(message);
5196 sfree(message);
5197
5198 pfd_close(c->u.pfd.s);
5199
5200 del234(ssh->channels, c);
5201 sfree(c);
5202}
5203
5204static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5205{
5206 unsigned localid;
5207 char *type;
5208 int typelen, want_reply;
5209 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5210 struct ssh_channel *c;
5211 struct Packet *pktout;
5212
5213 localid = ssh_pkt_getuint32(pktin);
5214 ssh_pkt_getstring(pktin, &type, &typelen);
5215 want_reply = ssh2_pkt_getbool(pktin);
5216
5217 /*
5218 * First, check that the channel exists. Otherwise,
5219 * we can instantly disconnect with a rude message.
5220 */
5221 c = find234(ssh->channels, &localid, ssh_channelfind);
5222 if (!c) {
5223 char buf[80];
5224 sprintf(buf, "Received channel request for nonexistent"
5225 " channel %d", localid);
5226 logevent(buf);
5227 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5228 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5229 ssh2_pkt_addstring(pktout, buf);
5230 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5231 ssh2_pkt_send_noqueue(ssh, pktout);
5232 connection_fatal(ssh->frontend, "%s", buf);
5233 ssh_closing((Plug)ssh, NULL, 0, 0);
5234 return;
5235 }
5236
5237 /*
5238 * Having got the channel number, we now look at
5239 * the request type string to see if it's something
5240 * we recognise.
5241 */
5242 if (c == ssh->mainchan) {
5243 /*
5244 * We recognise "exit-status" and "exit-signal" on
5245 * the primary channel.
5246 */
5247 if (typelen == 11 &&
5248 !memcmp(type, "exit-status", 11)) {
5249
5250 ssh->exitcode = ssh_pkt_getuint32(pktin);
5251 logeventf(ssh, "Server sent command exit status %d",
5252 ssh->exitcode);
5253 reply = SSH2_MSG_CHANNEL_SUCCESS;
5254
5255 } else if (typelen == 11 &&
5256 !memcmp(type, "exit-signal", 11)) {
5257
5258 int is_plausible = TRUE, is_int = FALSE;
5259 char *fmt_sig = "", *fmt_msg = "";
5260 char *msg;
5261 int msglen = 0, core = FALSE;
5262 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5263 * provide an `int' for the signal, despite its
5264 * having been a `string' in the drafts since at
5265 * least 2001. (Fixed in session.c 1.147.) Try to
5266 * infer which we can safely parse it as. */
5267 {
5268 unsigned char *p = pktin->body +
5269 pktin->savedpos;
5270 long len = pktin->length - pktin->savedpos;
5271 unsigned long num = GET_32BIT(p); /* what is it? */
5272 /* If it's 0, it hardly matters; assume string */
5273 if (num == 0) {
5274 is_int = FALSE;
5275 } else {
5276 int maybe_int = FALSE, maybe_str = FALSE;
5277#define CHECK_HYPOTHESIS(offset, result) \
5278 do { \
5279 long q = offset; \
5280 if (q >= 0 && q+4 <= len) { \
5281 q = q + 4 + GET_32BIT(p+q); \
5282 if (q >= 0 && q+4 <= len && \
5283 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5284 result = TRUE; \
5285 } \
5286 } while(0)
5287 CHECK_HYPOTHESIS(4+1, maybe_int);
5288 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5289#undef CHECK_HYPOTHESIS
5290 if (maybe_int && !maybe_str)
5291 is_int = TRUE;
5292 else if (!maybe_int && maybe_str)
5293 is_int = FALSE;
5294 else
5295 /* Crikey. Either or neither. Panic. */
5296 is_plausible = FALSE;
5297 }
5298 }
5299 if (is_plausible) {
5300 if (is_int) {
5301 /* Old non-standard OpenSSH. */
5302 int signum = ssh_pkt_getuint32(pktin);
5303 fmt_sig = dupprintf(" %d", signum);
5304 } else {
5305 /* As per the drafts. */
5306 char *sig;
5307 int siglen;
5308 ssh_pkt_getstring(pktin, &sig, &siglen);
5309 /* Signal name isn't supposed to be blank, but
5310 * let's cope gracefully if it is. */
5311 if (siglen) {
5312 fmt_sig = dupprintf(" \"%.*s\"",
5313 siglen, sig);
5314 }
5315 }
5316 core = ssh2_pkt_getbool(pktin);
5317 ssh_pkt_getstring(pktin, &msg, &msglen);
5318 if (msglen) {
5319 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5320 }
5321 /* ignore lang tag */
5322 } /* else don't attempt to parse */
5323 logeventf(ssh, "Server exited on signal%s%s%s",
5324 fmt_sig, core ? " (core dumped)" : "",
5325 fmt_msg);
5326 if (*fmt_sig) sfree(fmt_sig);
5327 if (*fmt_msg) sfree(fmt_msg);
5328 reply = SSH2_MSG_CHANNEL_SUCCESS;
5329
5330 }
5331 } else {
5332 /*
5333 * This is a channel request we don't know
5334 * about, so we now either ignore the request
5335 * or respond with CHANNEL_FAILURE, depending
5336 * on want_reply.
5337 */
5338 reply = SSH2_MSG_CHANNEL_FAILURE;
5339 }
5340 if (want_reply) {
5341 pktout = ssh2_pkt_init(reply);
5342 ssh2_pkt_adduint32(pktout, c->remoteid);
5343 ssh2_pkt_send(ssh, pktout);
5344 }
5345}
5346
5347static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5348{
5349 char *type;
5350 int typelen, want_reply;
5351 struct Packet *pktout;
5352
5353 ssh_pkt_getstring(pktin, &type, &typelen);
5354 want_reply = ssh2_pkt_getbool(pktin);
5355
5356 /*
5357 * We currently don't support any global requests
5358 * at all, so we either ignore the request or
5359 * respond with REQUEST_FAILURE, depending on
5360 * want_reply.
5361 */
5362 if (want_reply) {
5363 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5364 ssh2_pkt_send(ssh, pktout);
5365 }
5366}
5367
5368static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5369{
5370 char *type;
5371 int typelen;
5372 char *peeraddr;
5373 int peeraddrlen;
5374 int peerport;
5375 char *error = NULL;
5376 struct ssh_channel *c;
5377 unsigned remid, winsize, pktsize;
5378 struct Packet *pktout;
5379
5380 ssh_pkt_getstring(pktin, &type, &typelen);
5381 c = snew(struct ssh_channel);
5382 c->ssh = ssh;
5383
5384 remid = ssh_pkt_getuint32(pktin);
5385 winsize = ssh_pkt_getuint32(pktin);
5386 pktsize = ssh_pkt_getuint32(pktin);
5387
5388 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5389 char *addrstr;
5390
5391 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5392 addrstr = snewn(peeraddrlen+1, char);
5393 memcpy(addrstr, peeraddr, peeraddrlen);
5394 addrstr[peeraddrlen] = '\0';
5395 peerport = ssh_pkt_getuint32(pktin);
5396
5397 logeventf(ssh, "Received X11 connect request from %s:%d",
5398 addrstr, peerport);
5399
5400 if (!ssh->X11_fwd_enabled)
5401 error = "X11 forwarding is not enabled";
5402 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5403 ssh->x11auth, addrstr, peerport,
5404 &ssh->cfg) != NULL) {
5405 error = "Unable to open an X11 connection";
5406 } else {
5407 logevent("Opening X11 forward connection succeeded");
5408 c->type = CHAN_X11;
5409 }
5410
5411 sfree(addrstr);
5412 } else if (typelen == 15 &&
5413 !memcmp(type, "forwarded-tcpip", 15)) {
5414 struct ssh_rportfwd pf, *realpf;
5415 char *dummy;
5416 int dummylen;
5417 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5418 pf.sport = ssh_pkt_getuint32(pktin);
5419 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5420 peerport = ssh_pkt_getuint32(pktin);
5421 realpf = find234(ssh->rportfwds, &pf, NULL);
5422 logeventf(ssh, "Received remote port %d open request "
5423 "from %s:%d", pf.sport, peeraddr, peerport);
5424 if (realpf == NULL) {
5425 error = "Remote port is not recognised";
5426 } else {
5427 const char *e = pfd_newconnect(&c->u.pfd.s,
5428 realpf->dhost,
5429 realpf->dport, c,
5430 &ssh->cfg);
5431 logeventf(ssh, "Attempting to forward remote port to "
5432 "%s:%d", realpf->dhost, realpf->dport);
5433 if (e != NULL) {
5434 logeventf(ssh, "Port open failed: %s", e);
5435 error = "Port open failed";
5436 } else {
5437 logevent("Forwarded port opened successfully");
5438 c->type = CHAN_SOCKDATA;
5439 }
5440 }
5441 } else if (typelen == 22 &&
5442 !memcmp(type, "auth-agent@openssh.com", 3)) {
5443 if (!ssh->agentfwd_enabled)
5444 error = "Agent forwarding is not enabled";
5445 else {
5446 c->type = CHAN_AGENT; /* identify channel type */
5447 c->u.a.lensofar = 0;
5448 }
5449 } else {
5450 error = "Unsupported channel type requested";
5451 }
5452
5453 c->remoteid = remid;
5454 if (error) {
5455 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5456 ssh2_pkt_adduint32(pktout, c->remoteid);
5457 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5458 ssh2_pkt_addstring(pktout, error);
5459 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5460 ssh2_pkt_send(ssh, pktout);
5461 logeventf(ssh, "Rejected channel open: %s", error);
5462 sfree(c);
5463 } else {
5464 c->localid = alloc_channel_id(ssh);
5465 c->closes = 0;
5466 c->v.v2.locwindow = OUR_V2_WINSIZE;
5467 c->v.v2.remwindow = winsize;
5468 c->v.v2.remmaxpkt = pktsize;
5469 bufchain_init(&c->v.v2.outbuffer);
5470 add234(ssh->channels, c);
5471 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5472 ssh2_pkt_adduint32(pktout, c->remoteid);
5473 ssh2_pkt_adduint32(pktout, c->localid);
5474 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5475 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5476 ssh2_pkt_send(ssh, pktout);
5477 }
5478}
5479
783415f8 5480/*
7cca0d81 5481 * Handle the SSH2 userauth and connection layers.
5482 */
ff3187f6 5483static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5484 struct Packet *pktin)
7cca0d81 5485{
51470298 5486 struct do_ssh2_authconn_state {
5487 enum {
5488 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5489 AUTH_PASSWORD,
5490 AUTH_KEYBOARD_INTERACTIVE
5491 } method;
5492 enum {
5493 AUTH_TYPE_NONE,
5494 AUTH_TYPE_PUBLICKEY,
5495 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5496 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5497 AUTH_TYPE_PASSWORD,
5498 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5499 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5500 } type;
5501 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
5502 int tried_pubkey_config, tried_agent, tried_keyb_inter;
5503 int kbd_inter_running;
5504 int we_are_in;
5505 int num_prompts, curr_prompt, echo;
5506 char username[100];
5507 int got_username;
85fdbe25 5508 char pwprompt[512];
51470298 5509 char password[100];
5510 void *publickey_blob;
5511 int publickey_bloblen;
5512 unsigned char request[5], *response, *p;
5513 int responselen;
5514 int keyi, nkeys;
5515 int authed;
5516 char *pkblob, *alg, *commentp;
5517 int pklen, alglen, commentlen;
5518 int siglen, retlen, len;
5519 char *q, *agentreq, *ret;
5520 int try_send;
73feed4f 5521 int num_env, env_left, env_ok;
ff3187f6 5522 struct Packet *pktout;
51470298 5523 };
5524 crState(do_ssh2_authconn_state);
5525
5526 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 5527
7cca0d81 5528 /*
5529 * Request userauth protocol, and await a response to it.
5530 */
ff3187f6 5531 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
5532 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
5533 ssh2_pkt_send(ssh, s->pktout);
5534 crWaitUntilV(pktin);
5535 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6b5cf8b4 5536 bombout(("Server refused user authentication protocol"));
7ffdbc1a 5537 crStopV;
8d5de777 5538 }
7cca0d81 5539
5540 /*
1408a877 5541 * We repeat this whole loop, including the username prompt,
5542 * until we manage a successful authentication. If the user
51470298 5543 * types the wrong _password_, they can be sent back to the
5544 * beginning to try another username, if this is configured on.
5545 * (If they specify a username in the config, they are never
5546 * asked, even if they do give a wrong password.)
1408a877 5547 *
5548 * I think this best serves the needs of
5549 *
5550 * - the people who have no configuration, no keys, and just
5551 * want to try repeated (username,password) pairs until they
5552 * type both correctly
5553 *
5554 * - people who have keys and configuration but occasionally
5555 * need to fall back to passwords
5556 *
5557 * - people with a key held in Pageant, who might not have
5558 * logged in to a particular machine before; so they want to
5559 * type a username, and then _either_ their key will be
5560 * accepted, _or_ they will type a password. If they mistype
5561 * the username they will want to be able to get back and
5562 * retype it!
7cca0d81 5563 */
51470298 5564 s->username[0] = '\0';
5565 s->got_username = FALSE;
1408a877 5566 do {
1408a877 5567 /*
5568 * Get a username.
5569 */
86916870 5570 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 5571 /*
5572 * We got a username last time round this loop, and
5573 * with change_username turned off we don't try to get
5574 * it again.
5575 */
aa09f7d0 5576 } else if (!*ssh->cfg.username) {
c0a81592 5577 if (ssh_get_line && !ssh_getline_pw_only) {
32874aea 5578 if (!ssh_get_line("login as: ",
51470298 5579 s->username, sizeof(s->username), FALSE)) {
32874aea 5580 /*
5581 * get_line failed to get a username.
5582 * Terminate.
5583 */
5584 logevent("No username provided. Abandoning session.");
3bb2f322 5585 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 5586 crStopV;
32874aea 5587 }
5588 } else {
51470298 5589 int ret; /* need not be saved across crReturn */
5590 c_write_str(ssh, "login as: ");
5591 ssh->send_ok = 1;
5592 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
0405e71f 5593 do {
ff3187f6 5594 crWaitUntilV(!pktin);
51470298 5595 ret = process_userpass_input(ssh, in, inlen);
0405e71f 5596 } while (ret == 0);
5597 if (ret < 0)
5598 cleanup_exit(0);
4ca0c9d1 5599 c_write_str(ssh, "\r\n");
32874aea 5600 }
51470298 5601 s->username[strcspn(s->username, "\n\r")] = '\0';
7cca0d81 5602 } else {
57356d63 5603 char *stuff;
86916870 5604 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 5605 s->username[sizeof(s->username)-1] = '\0';
65a22376 5606 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 5607 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 5608 c_write_str(ssh, stuff);
57356d63 5609 sfree(stuff);
7cca0d81 5610 }
5611 }
51470298 5612 s->got_username = TRUE;
7cca0d81 5613
65a22376 5614 /*
1408a877 5615 * Send an authentication request using method "none": (a)
5616 * just in case it succeeds, and (b) so that we know what
5617 * authentication methods we can usefully try next.
65a22376 5618 */
51470298 5619 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5620
ff3187f6 5621 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5622 ssh2_pkt_addstring(s->pktout, s->username);
5623 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
5624 ssh2_pkt_addstring(s->pktout, "none"); /* method */
5625 ssh2_pkt_send(ssh, s->pktout);
51470298 5626 s->type = AUTH_TYPE_NONE;
5627 s->gotit = FALSE;
5628 s->we_are_in = FALSE;
5629
5630 s->tried_pubkey_config = FALSE;
5631 s->tried_agent = FALSE;
5632 s->tried_keyb_inter = FALSE;
5633 s->kbd_inter_running = FALSE;
86916870 5634 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
9a30e26b 5635 if (!filename_is_null(ssh->cfg.keyfile)) {
231ee168 5636 int keytype;
6c6d9ed9 5637 logeventf(ssh, "Reading private key file \"%.150s\"",
5638 filename_to_str(&ssh->cfg.keyfile));
9a30e26b 5639 keytype = key_type(&ssh->cfg.keyfile);
51470298 5640 if (keytype == SSH_KEYTYPE_SSH2) {
5641 s->publickey_blob =
9a30e26b 5642 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
222d54dc 5643 &s->publickey_bloblen, NULL);
51470298 5644 } else {
57356d63 5645 char *msgbuf;
c2ad7d0d 5646 logeventf(ssh, "Unable to use this key file (%s)",
a8327734 5647 key_type_to_str(keytype));
57356d63 5648 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6c6d9ed9 5649 " (%s)\r\n",
5650 filename_to_str(&ssh->cfg.keyfile),
57356d63 5651 key_type_to_str(keytype));
51470298 5652 c_write_str(ssh, msgbuf);
57356d63 5653 sfree(msgbuf);
51470298 5654 s->publickey_blob = NULL;
231ee168 5655 }
396778f1 5656 } else
51470298 5657 s->publickey_blob = NULL;
65a22376 5658
1408a877 5659 while (1) {
5660 /*
5661 * Wait for the result of the last authentication request.
5662 */
51470298 5663 if (!s->gotit)
ff3187f6 5664 crWaitUntilV(pktin);
5665 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
32874aea 5666 char *banner;
5667 int size;
5668 /*
5669 * Don't show the banner if we're operating in
5670 * non-verbose non-interactive mode. (It's probably
5671 * a script, which means nobody will read the
5672 * banner _anyway_, and moreover the printing of
5673 * the banner will screw up processing on the
5674 * output of (say) plink.)
5675 */
5676 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
ff3187f6 5677 ssh_pkt_getstring(pktin, &banner, &size);
32874aea 5678 if (banner)
51470298 5679 c_write_untrusted(ssh, banner, size);
32874aea 5680 }
ff3187f6 5681 crWaitUntilV(pktin);
1408a877 5682 }
ff3187f6 5683 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 5684 logevent("Access granted");
51470298 5685 s->we_are_in = TRUE;
1408a877 5686 break;
5687 }
65a22376 5688
51470298 5689 if (s->kbd_inter_running &&
ff3187f6 5690 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
b3186d64 5691 /*
45068b27 5692 * This is either a further set-of-prompts packet
5693 * in keyboard-interactive authentication, or it's
5694 * the same one and we came back here with `gotit'
5695 * set. In the former case, we must reset the
5696 * curr_prompt variable.
b3186d64 5697 */
51470298 5698 if (!s->gotit)
5699 s->curr_prompt = 0;
ff3187f6 5700 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6b5cf8b4 5701 bombout(("Strange packet received during authentication: type %d",
ff3187f6 5702 pktin->type));
7ffdbc1a 5703 crStopV;
65a22376 5704 }
5705
51470298 5706 s->gotit = FALSE;
65a22376 5707
1408a877 5708 /*
5709 * OK, we're now sitting on a USERAUTH_FAILURE message, so
5710 * we can look at the string in it and know what we can
5711 * helpfully try next.
5712 */
ff3187f6 5713 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 5714 char *methods;
5715 int methlen;
ff3187f6 5716 ssh_pkt_getstring(pktin, &methods, &methlen);
51470298 5717 s->kbd_inter_running = FALSE;
ff3187f6 5718 if (!ssh2_pkt_getbool(pktin)) {
1408a877 5719 /*
5720 * We have received an unequivocal Access
5721 * Denied. This can translate to a variety of
5722 * messages:
5723 *
5724 * - if we'd just tried "none" authentication,
5725 * it's not worth printing anything at all
5726 *
5727 * - if we'd just tried a public key _offer_,
5728 * the message should be "Server refused our
5729 * key" (or no message at all if the key
5730 * came from Pageant)
5731 *
5732 * - if we'd just tried anything else, the
5733 * message really should be "Access denied".
5734 *
5735 * Additionally, if we'd just tried password
5736 * authentication, we should break out of this
5737 * whole loop so as to go back to the username
91f57d1f 5738 * prompt (iff we're configured to allow
5739 * username change attempts).
1408a877 5740 */
51470298 5741 if (s->type == AUTH_TYPE_NONE) {
1408a877 5742 /* do nothing */
51470298 5743 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
5744 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
5745 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
5746 c_write_str(ssh, "Server refused our key\r\n");
1408a877 5747 logevent("Server refused public key");
51470298 5748 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 5749 /* server declined keyboard-interactive; ignore */
1408a877 5750 } else {
51470298 5751 c_write_str(ssh, "Access denied\r\n");
1408a877 5752 logevent("Access denied");
91f57d1f 5753 if (s->type == AUTH_TYPE_PASSWORD &&
5754 ssh->cfg.change_username) {
6c9dce7c 5755 /* XXX perhaps we should allow
5756 * keyboard-interactive to do this too? */
51470298 5757 s->we_are_in = FALSE;
1408a877 5758 break;
5759 }
5760 }
5761 } else {
51470298 5762 c_write_str(ssh, "Further authentication required\r\n");
1408a877 5763 logevent("Further authentication required");
5764 }
65a22376 5765
51470298 5766 s->can_pubkey =
32874aea 5767 in_commasep_string("publickey", methods, methlen);
51470298 5768 s->can_passwd =
32874aea 5769 in_commasep_string("password", methods, methlen);
86916870 5770 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 5771 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 5772 }
65a22376 5773
51470298 5774 s->method = 0;
5775 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
954a9540 5776 s->need_pw = FALSE;
65a22376 5777
0405e71f 5778 /*
5779 * Most password/passphrase prompts will be
5780 * non-echoing, so we set this to 0 by default.
5781 * Exception is that some keyboard-interactive prompts
5782 * can be echoing, in which case we'll set this to 1.
5783 */
51470298 5784 s->echo = 0;
0405e71f 5785
51470298 5786 if (!s->method && s->can_pubkey &&
5787 agent_exists() && !s->tried_agent) {
1983e559 5788 /*
5789 * Attempt public-key authentication using Pageant.
5790 */
1983e559 5791 void *r;
51470298 5792 s->authed = FALSE;
1983e559 5793
51470298 5794 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5795 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 5796
51470298 5797 s->tried_agent = TRUE;
1983e559 5798
5799 logevent("Pageant is running. Requesting keys.");
5800
5801 /* Request the keys held by the agent. */
51470298 5802 PUT_32BIT(s->request, 1);
5803 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
839f10db 5804 if (!agent_query(s->request, 5, &r, &s->responselen,
5805 ssh_agent_callback, ssh)) {
5806 do {
5807 crReturnV;
ff3187f6 5808 if (pktin) {
839f10db 5809 bombout(("Unexpected data from server while"
5810 " waiting for agent response"));
5811 crStopV;
5812 }
ff3187f6 5813 } while (pktin || inlen > 0);
839f10db 5814 r = ssh->agent_response;
5815 s->responselen = ssh->agent_response_len;
5816 }
51470298 5817 s->response = (unsigned char *) r;
5818 if (s->response && s->responselen >= 5 &&
5819 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
5820 s->p = s->response + 5;
5821 s->nkeys = GET_32BIT(s->p);
5822 s->p += 4;
32874aea 5823 {
5824 char buf[64];
51470298 5825 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
32874aea 5826 logevent(buf);
5827 }
51470298 5828 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2d466ffd 5829 void *vret;
1983e559 5830
32874aea 5831 {
5832 char buf[64];
51470298 5833 sprintf(buf, "Trying Pageant key #%d", s->keyi);
32874aea 5834 logevent(buf);
5835 }
51470298 5836 s->pklen = GET_32BIT(s->p);
5837 s->p += 4;
5838 if (s->publickey_blob &&
5839 s->pklen == s->publickey_bloblen &&
5840 !memcmp(s->p, s->publickey_blob,
5841 s->publickey_bloblen)) {
396778f1 5842 logevent("This key matches configured key file");
51470298 5843 s->tried_pubkey_config = 1;
396778f1 5844 }
d8baa528 5845 s->pkblob = (char *)s->p;
51470298 5846 s->p += s->pklen;
5847 s->alglen = GET_32BIT(s->pkblob);
5848 s->alg = s->pkblob + 4;
5849 s->commentlen = GET_32BIT(s->p);
5850 s->p += 4;
d8baa528 5851 s->commentp = (char *)s->p;
51470298 5852 s->p += s->commentlen;
ff3187f6 5853 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5854 ssh2_pkt_addstring(s->pktout, s->username);
5855 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5856 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5857 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
5858 ssh2_pkt_addstring_start(s->pktout);
5859 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5860 ssh2_pkt_addstring_start(s->pktout);
5861 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5862 ssh2_pkt_send(ssh, s->pktout);
5863
5864 crWaitUntilV(pktin);
5865 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 5866 logevent("Key refused");
5867 continue;
5868 }
5869
32874aea 5870 if (flags & FLAG_VERBOSE) {
51470298 5871 c_write_str(ssh, "Authenticating with "
5872 "public key \"");
5873 c_write(ssh, s->commentp, s->commentlen);
5874 c_write_str(ssh, "\" from agent\r\n");
32874aea 5875 }
1983e559 5876
5877 /*
5878 * Server is willing to accept the key.
5879 * Construct a SIGN_REQUEST.
5880 */
ff3187f6 5881 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5882 ssh2_pkt_addstring(s->pktout, s->username);
5883 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5884 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5885 ssh2_pkt_addbool(s->pktout, TRUE);
5886 ssh2_pkt_addstring_start(s->pktout);
5887 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
5888 ssh2_pkt_addstring_start(s->pktout);
5889 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
5890
5891 s->siglen = s->pktout->length - 5 + 4 + 20;
dda87a28 5892 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5893 s->siglen -= 4;
51470298 5894 s->len = 1; /* message type */
5895 s->len += 4 + s->pklen; /* key blob */
5896 s->len += 4 + s->siglen; /* data to sign */
5897 s->len += 4; /* flags */
3d88e64d 5898 s->agentreq = snewn(4 + s->len, char);
51470298 5899 PUT_32BIT(s->agentreq, s->len);
5900 s->q = s->agentreq + 4;
5901 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
5902 PUT_32BIT(s->q, s->pklen);
5903 s->q += 4;
5904 memcpy(s->q, s->pkblob, s->pklen);
5905 s->q += s->pklen;
5906 PUT_32BIT(s->q, s->siglen);
5907 s->q += 4;
1983e559 5908 /* Now the data to be signed... */
dda87a28 5909 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5910 PUT_32BIT(s->q, 20);
5911 s->q += 4;
5912 }
51470298 5913 memcpy(s->q, ssh->v2_session_id, 20);
5914 s->q += 20;
ff3187f6 5915 memcpy(s->q, s->pktout->data + 5,
5916 s->pktout->length - 5);
5917 s->q += s->pktout->length - 5;
1983e559 5918 /* And finally the (zero) flags word. */
51470298 5919 PUT_32BIT(s->q, 0);
839f10db 5920 if (!agent_query(s->agentreq, s->len + 4,
5921 &vret, &s->retlen,
5922 ssh_agent_callback, ssh)) {
5923 do {
5924 crReturnV;
ff3187f6 5925 if (pktin) {
839f10db 5926 bombout(("Unexpected data from server"
5927 " while waiting for agent"
5928 " response"));
5929 crStopV;
5930 }
ff3187f6 5931 } while (pktin || inlen > 0);
839f10db 5932 vret = ssh->agent_response;
5933 s->retlen = ssh->agent_response_len;
5934 }
51470298 5935 s->ret = vret;
5936 sfree(s->agentreq);
5937 if (s->ret) {
5938 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
1983e559 5939 logevent("Sending Pageant's response");
ff3187f6 5940 ssh2_add_sigblob(ssh, s->pktout,
5941 s->pkblob, s->pklen,
51470298 5942 s->ret + 9,
5943 GET_32BIT(s->ret + 5));
ff3187f6 5944 ssh2_pkt_send(ssh, s->pktout);
51470298 5945 s->authed = TRUE;
1983e559 5946 break;
5947 } else {
32874aea 5948 logevent
5949 ("Pageant failed to answer challenge");
51470298 5950 sfree(s->ret);
1983e559 5951 }
5952 }
5953 }
51470298 5954 if (s->authed)
1983e559 5955 continue;
5956 }
29b1d0b3 5957 sfree(s->response);
1983e559 5958 }
5959
51470298 5960 if (!s->method && s->can_pubkey && s->publickey_blob
5961 && !s->tried_pubkey_config) {
1408a877 5962 unsigned char *pub_blob;
5963 char *algorithm, *comment;
5964 int pub_blob_len;
65a22376 5965
51470298 5966 s->tried_pubkey_config = TRUE;
65a22376 5967
51470298 5968 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5969 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 5970
65a22376 5971 /*
1408a877 5972 * Try the public key supplied in the configuration.
5973 *
5974 * First, offer the public blob to see if the server is
5975 * willing to accept it.
65a22376 5976 */
d8baa528 5977 pub_blob =
9a30e26b 5978 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
d8baa528 5979 &algorithm,
222d54dc 5980 &pub_blob_len,
5981 NULL);
1408a877 5982 if (pub_blob) {
ff3187f6 5983 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
5984 ssh2_pkt_addstring(s->pktout, s->username);
5985 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
5986 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
5987 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
5988 ssh2_pkt_addstring(s->pktout, algorithm);
5989 ssh2_pkt_addstring_start(s->pktout);
5990 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
d8baa528 5991 pub_blob_len);
ff3187f6 5992 ssh2_pkt_send(ssh, s->pktout);
a03c9f9c 5993 logevent("Offered public key");
1408a877 5994
ff3187f6 5995 crWaitUntilV(pktin);
5996 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
51470298 5997 s->gotit = TRUE;
5998 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
32874aea 5999 continue; /* key refused; give up on it */
1408a877 6000 }
65a22376 6001
1408a877 6002 logevent("Offer of public key accepted");
65a22376 6003 /*
1408a877 6004 * Actually attempt a serious authentication using
6005 * the key.
65a22376 6006 */
9a30e26b 6007 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
51470298 6008 sprintf(s->pwprompt,
32874aea 6009 "Passphrase for key \"%.100s\": ",
6010 comment);
51470298 6011 s->need_pw = TRUE;
1408a877 6012 } else {
51470298 6013 s->need_pw = FALSE;
1408a877 6014 }
4e520718 6015 if (flags & FLAG_VERBOSE) {
6016 c_write_str(ssh, "Authenticating with public key \"");
6017 c_write_str(ssh, comment);
6018 c_write_str(ssh, "\"\r\n");
6019 }
51470298 6020 s->method = AUTH_PUBLICKEY_FILE;
65a22376 6021 }
1408a877 6022 }
6023
51470298 6024 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
6025 s->method = AUTH_KEYBOARD_INTERACTIVE;
6026 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6027 s->tried_keyb_inter = TRUE;
af659722 6028
51470298 6029 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6030 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6031
ff3187f6 6032 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6033 ssh2_pkt_addstring(s->pktout, s->username);
6034 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6035 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6036 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6037 ssh2_pkt_addstring(s->pktout, "");
6038 ssh2_pkt_send(ssh, s->pktout);
6039
6040 crWaitUntilV(pktin);
6041 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6042 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
51470298 6043 s->gotit = TRUE;
af659722 6044 logevent("Keyboard-interactive authentication refused");
51470298 6045 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
af659722 6046 continue;
6047 }
6048
51470298 6049 s->kbd_inter_running = TRUE;
6050 s->curr_prompt = 0;
af659722 6051 }
6052
51470298 6053 if (s->kbd_inter_running) {
6054 s->method = AUTH_KEYBOARD_INTERACTIVE;
6055 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6056 s->tried_keyb_inter = TRUE;
af659722 6057
51470298 6058 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6059 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
00db133f 6060
51470298 6061 if (s->curr_prompt == 0) {
45068b27 6062 /*
6063 * We've got a fresh USERAUTH_INFO_REQUEST.
6064 * Display header data, and start going through
6065 * the prompts.
6066 */
6067 char *name, *inst, *lang;
6068 int name_len, inst_len, lang_len;
6069
ff3187f6 6070 ssh_pkt_getstring(pktin, &name, &name_len);
6071 ssh_pkt_getstring(pktin, &inst, &inst_len);
6072 ssh_pkt_getstring(pktin, &lang, &lang_len);
45068b27 6073 if (name_len > 0) {
51470298 6074 c_write_untrusted(ssh, name, name_len);
6075 c_write_str(ssh, "\r\n");
45068b27 6076 }
6077 if (inst_len > 0) {
51470298 6078 c_write_untrusted(ssh, inst, inst_len);
6079 c_write_str(ssh, "\r\n");
45068b27 6080 }
ff3187f6 6081 s->num_prompts = ssh_pkt_getuint32(pktin);
45068b27 6082 }
af659722 6083
45068b27 6084 /*
6085 * If there are prompts remaining in the packet,
6086 * display one and get a response.
6087 */
51470298 6088 if (s->curr_prompt < s->num_prompts) {
45068b27 6089 char *prompt;
6090 int prompt_len;
af659722 6091
ff3187f6 6092 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
45068b27 6093 if (prompt_len > 0) {
85fdbe25 6094 static const char trunc[] = "<prompt truncated>: ";
6095 static const int prlen = sizeof(s->pwprompt) -
6096 lenof(trunc);
6097 if (prompt_len > prlen) {
6098 memcpy(s->pwprompt, prompt, prlen);
6099 strcpy(s->pwprompt + prlen, trunc);
6100 } else {
6101 memcpy(s->pwprompt, prompt, prompt_len);
6102 s->pwprompt[prompt_len] = '\0';
6103 }
45068b27 6104 } else {
51470298 6105 strcpy(s->pwprompt,
45068b27 6106 "<server failed to send prompt>: ");
6107 }
ff3187f6 6108 s->echo = ssh2_pkt_getbool(pktin);
51470298 6109 s->need_pw = TRUE;
45068b27 6110 } else
51470298 6111 s->need_pw = FALSE;
af659722 6112 }
6113
51470298 6114 if (!s->method && s->can_passwd) {
6115 s->method = AUTH_PASSWORD;
6116 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6117 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6118 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6119 ssh->savedhost);
6120 s->need_pw = TRUE;
1408a877 6121 }
6122
51470298 6123 if (s->need_pw) {
fa17a66e 6124 if (ssh_get_line) {
51470298 6125 if (!ssh_get_line(s->pwprompt, s->password,
6126 sizeof(s->password), TRUE)) {
1408a877 6127 /*
fa17a66e 6128 * get_line failed to get a password (for
6129 * example because one was supplied on the
6130 * command line which has already failed to
6131 * work). Terminate.
1408a877 6132 */
ff3187f6 6133 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6134 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6135 ssh2_pkt_addstring(s->pktout, "No more passwords available"
51470298 6136 " to try");
ff3187f6 6137 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6138 ssh2_pkt_send_noqueue(ssh, s->pktout);
247308b5 6139 logevent("Unable to authenticate");
a8327734 6140 connection_fatal(ssh->frontend,
6141 "Unable to authenticate");
3bb2f322 6142 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6143 crStopV;
1408a877 6144 }
6145 } else {
51470298 6146 int ret; /* need not be saved across crReturn */
6147 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6148 ssh->send_ok = 1;
1408a877 6149
51470298 6150 setup_userpass_input(ssh, s->password,
6151 sizeof(s->password), s->echo);
0405e71f 6152 do {
ff3187f6 6153 crWaitUntilV(!pktin);
51470298 6154 ret = process_userpass_input(ssh, in, inlen);
0405e71f 6155 } while (ret == 0);
6156 if (ret < 0)
6157 cleanup_exit(0);
51470298 6158 c_write_str(ssh, "\r\n");
65a22376 6159 }
65a22376 6160 }
65a22376 6161
51470298 6162 if (s->method == AUTH_PUBLICKEY_FILE) {
1408a877 6163 /*
6164 * We have our passphrase. Now try the actual authentication.
6165 */
6166 struct ssh2_userkey *key;
222d54dc 6167 const char *error = NULL;
65a22376 6168
222d54dc 6169 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6170 &error);
1408a877 6171 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6172 if (key == SSH2_WRONG_PASSPHRASE) {
51470298 6173 c_write_str(ssh, "Wrong passphrase\r\n");
6174 s->tried_pubkey_config = FALSE;
1408a877 6175 } else {
222d54dc 6176 c_write_str(ssh, "Unable to load private key (");
6177 c_write_str(ssh, error);
6178 c_write_str(ssh, ")\r\n");
51470298 6179 s->tried_pubkey_config = TRUE;
1408a877 6180 }
6181 /* Send a spurious AUTH_NONE to return to the top. */
ff3187f6 6182 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6183 ssh2_pkt_addstring(s->pktout, s->username);
6184 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6185 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6186 ssh2_pkt_send(ssh, s->pktout);
51470298 6187 s->type = AUTH_TYPE_NONE;
1408a877 6188 } else {
1dd353b5 6189 unsigned char *pkblob, *sigblob, *sigdata;
6190 int pkblob_len, sigblob_len, sigdata_len;
dda87a28 6191 int p;
65a22376 6192
1408a877 6193 /*
6194 * We have loaded the private key and the server
6195 * has announced that it's willing to accept it.
6196 * Hallelujah. Generate a signature and send it.
6197 */
ff3187f6 6198 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6199 ssh2_pkt_addstring(s->pktout, s->username);
6200 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6201 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6202 ssh2_pkt_addbool(s->pktout, TRUE);
6203 ssh2_pkt_addstring(s->pktout, key->alg->name);
1dd353b5 6204 pkblob = key->alg->public_blob(key->data, &pkblob_len);
ff3187f6 6205 ssh2_pkt_addstring_start(s->pktout);
6206 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
1408a877 6207
6208 /*
6209 * The data to be signed is:
6210 *
6211 * string session-id
6212 *
6213 * followed by everything so far placed in the
6214 * outgoing packet.
6215 */
ff3187f6 6216 sigdata_len = s->pktout->length - 5 + 4 + 20;
dda87a28 6217 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6218 sigdata_len -= 4;
92d60585 6219 sigdata = snewn(sigdata_len, unsigned char);
dda87a28 6220 p = 0;
6221 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6222 PUT_32BIT(sigdata+p, 20);
6223 p += 4;
6224 }
6225 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
ff3187f6 6226 memcpy(sigdata+p, s->pktout->data + 5,
6227 s->pktout->length - 5);
6228 p += s->pktout->length - 5;
dda87a28 6229 assert(p == sigdata_len);
d8baa528 6230 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 6231 sigdata_len, &sigblob_len);
ff3187f6 6232 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 6233 sigblob, sigblob_len);
6234 sfree(pkblob);
6235 sfree(sigblob);
1408a877 6236 sfree(sigdata);
6237
ff3187f6 6238 ssh2_pkt_send(ssh, s->pktout);
51470298 6239 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 6240 key->alg->freekey(key->data);
1408a877 6241 }
51470298 6242 } else if (s->method == AUTH_PASSWORD) {
65a22376 6243 /*
1408a877 6244 * We send the password packet lumped tightly together with
6245 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6246 * string long enough to make the total length of the two
6247 * packets constant. This should ensure that a passive
6248 * listener doing traffic analyis can't work out the length
6249 * of the password.
6250 *
6251 * For this to work, we need an assumption about the
6252 * maximum length of the password packet. I think 256 is
6253 * pretty conservative. Anyone using a password longer than
6254 * that probably doesn't have much to worry about from
6255 * people who find out how long their password is!
65a22376 6256 */
ff3187f6 6257 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6258 ssh2_pkt_addstring(s->pktout, s->username);
6259 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6260 ssh2_pkt_addstring(s->pktout, "password");
6261 ssh2_pkt_addbool(s->pktout, FALSE);
6262 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6263 ssh2_pkt_addstring(s->pktout, s->password);
1409c1b3 6264 memset(s->password, 0, sizeof(s->password));
ff3187f6 6265 end_log_omission(ssh, s->pktout);
6266 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6267 /*
1408a877 6268 * We'll include a string that's an exact multiple of the
6269 * cipher block size. If the cipher is NULL for some
6270 * reason, we don't do this trick at all because we gain
6271 * nothing by it.
65a22376 6272 */
51470298 6273 if (ssh->cscipher) {
32874aea 6274 int stringlen, i;
6275
51470298 6276 stringlen = (256 - ssh->deferred_len);
6277 stringlen += ssh->cscipher->blksize - 1;
6278 stringlen -= (stringlen % ssh->cscipher->blksize);
6279 if (ssh->cscomp) {
32874aea 6280 /*
6281 * Temporarily disable actual compression,
6282 * so we can guarantee to get this string
6283 * exactly the length we want it. The
6284 * compression-disabling routine should
6285 * return an integer indicating how many
6286 * bytes we should adjust our string length
6287 * by.
6288 */
5366aed8 6289 stringlen -=
6290 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
32874aea 6291 }
ff3187f6 6292 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6293 ssh2_pkt_addstring_start(s->pktout);
6e9e9520 6294 for (i = 0; i < stringlen; i++) {
32874aea 6295 char c = (char) random_byte();
ff3187f6 6296 ssh2_pkt_addstring_data(s->pktout, &c, 1);
65a22376 6297 }
ff3187f6 6298 ssh2_pkt_defer(ssh, s->pktout);
65a22376 6299 }
51470298 6300 ssh_pkt_defersend(ssh);
0d43337a 6301 logevent("Sent password");
51470298 6302 s->type = AUTH_TYPE_PASSWORD;
6303 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6304 if (s->curr_prompt == 0) {
ff3187f6 6305 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6306 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
45068b27 6307 }
51470298 6308 if (s->need_pw) { /* only add pw if we just got one! */
ff3187f6 6309 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6310 ssh2_pkt_addstring(s->pktout, s->password);
51470298 6311 memset(s->password, 0, sizeof(s->password));
ff3187f6 6312 end_log_omission(ssh, s->pktout);
51470298 6313 s->curr_prompt++;
45068b27 6314 }
51470298 6315 if (s->curr_prompt >= s->num_prompts) {
ff3187f6 6316 ssh2_pkt_send(ssh, s->pktout);
45068b27 6317 } else {
6318 /*
6319 * If there are prompts remaining, we set
6320 * `gotit' so that we won't attempt to get
6321 * another packet. Then we go back round the
6322 * loop and will end up retrieving another
6323 * prompt out of the existing packet. Funky or
6324 * what?
6325 */
51470298 6326 s->gotit = TRUE;
45068b27 6327 }
51470298 6328 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
1408a877 6329 } else {
51470298 6330 c_write_str(ssh, "No supported authentication methods"
6331 " left to try!\r\n");
6332 logevent("No supported authentications offered."
6333 " Disconnecting");
ff3187f6 6334 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6335 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6336 ssh2_pkt_addstring(s->pktout, "No supported authentication"
51470298 6337 " methods available");
ff3187f6 6338 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
590f6a5f 6339 ssh2_pkt_send_noqueue(ssh, s->pktout);
3bb2f322 6340 ssh_closing((Plug)ssh, NULL, 0, 0);
7ffdbc1a 6341 crStopV;
65a22376 6342 }
65a22376 6343 }
51470298 6344 } while (!s->we_are_in);
7cca0d81 6345
6346 /*
6347 * Now we're authenticated for the connection protocol. The
6348 * connection protocol will automatically have started at this
6349 * point; there's no need to send SERVICE_REQUEST.
6350 */
6351
0ed48730 6352 ssh->channels = newtree234(ssh_channelcmp);
6353
7cca0d81 6354 /*
b09eaa88 6355 * Set up handlers for some connection protocol messages, so we
6356 * don't have to handle them repeatedly in this coroutine.
6357 */
6358 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6359 ssh2_msg_channel_window_adjust;
51df0ab5 6360 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6361 ssh2_msg_global_request;
b09eaa88 6362
6363 /*
0ed48730 6364 * Create the main session channel.
7cca0d81 6365 */
0ed48730 6366 if (!ssh->cfg.ssh_no_shell) {
6367 ssh->mainchan = snew(struct ssh_channel);
6368 ssh->mainchan->ssh = ssh;
6369 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 6370 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6371 ssh2_pkt_addstring(s->pktout, "session");
6372 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 6373 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 6374 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6375 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6376 ssh2_pkt_send(ssh, s->pktout);
6377 crWaitUntilV(pktin);
6378 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 6379 bombout(("Server refused to open a session"));
6380 crStopV;
6381 /* FIXME: error data comes back in FAILURE packet */
6382 }
ff3187f6 6383 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 6384 bombout(("Server's channel confirmation cited wrong channel"));
6385 crStopV;
6386 }
ff3187f6 6387 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
0ed48730 6388 ssh->mainchan->type = CHAN_MAINSESSION;
6389 ssh->mainchan->closes = 0;
ff3187f6 6390 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6391 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 6392 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6393 add234(ssh->channels, ssh->mainchan);
62638676 6394 update_specials_menu(ssh->frontend);
0ed48730 6395 logevent("Opened channel for session");
6396 } else
6397 ssh->mainchan = NULL;
7cca0d81 6398
6399 /*
51df0ab5 6400 * Now we have a channel, make dispatch table entries for
6401 * general channel-based messages.
6402 */
6403 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6404 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6405 ssh2_msg_channel_data;
6406 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6407 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6408 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6409 ssh2_msg_channel_open_confirmation;
6410 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6411 ssh2_msg_channel_open_failure;
6412 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6413 ssh2_msg_channel_request;
6414 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6415 ssh2_msg_channel_open;
6416
6417 /*
783415f8 6418 * Potentially enable X11 forwarding.
6419 */
0ed48730 6420 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 6421 char proto[20], data[64];
6422 logevent("Requesting X11 forwarding");
302121de 6423 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 6424 data, sizeof(data), ssh->cfg.x11_auth);
6425 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 6426 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6427 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6428 ssh2_pkt_addstring(s->pktout, "x11-req");
6429 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6430 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6431 ssh2_pkt_addstring(s->pktout, proto);
6432 ssh2_pkt_addstring(s->pktout, data);
6433 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6434 ssh2_pkt_send(ssh, s->pktout);
32874aea 6435
b09eaa88 6436 crWaitUntilV(pktin);
32874aea 6437
ff3187f6 6438 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6439 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6440 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 6441 " packet type %d", pktin->type));
7ffdbc1a 6442 crStopV;
32874aea 6443 }
6444 logevent("X11 forwarding refused");
6445 } else {
6446 logevent("X11 forwarding enabled");
51470298 6447 ssh->X11_fwd_enabled = TRUE;
32874aea 6448 }
783415f8 6449 }
6450
6451 /*
bc240b21 6452 * Enable port forwardings.
6453 */
6454 {
bc240b21 6455 char type;
6456 int n;
a4fc0d74 6457 int sport,dport,sserv,dserv;
6ee9b735 6458 char sports[256], dports[256], saddr[256], host[256];
bc240b21 6459
51470298 6460 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
bc240b21 6461 /* Add port forwardings. */
86916870 6462 ssh->portfwd_strptr = ssh->cfg.portfwd;
51470298 6463 while (*ssh->portfwd_strptr) {
6464 type = *ssh->portfwd_strptr++;
6ee9b735 6465 saddr[0] = '\0';
bc240b21 6466 n = 0;
6ee9b735 6467 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
6468 if (*ssh->portfwd_strptr == ':') {
6469 /*
6470 * We've seen a colon in the middle of the
6471 * source port number. This means that
6472 * everything we've seen until now is the
6473 * source _address_, so we'll move it into
6474 * saddr and start sports from the beginning
6475 * again.
6476 */
6477 ssh->portfwd_strptr++;
6478 sports[n] = '\0';
6479 strcpy(saddr, sports);
6480 n = 0;
6481 }
6482 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
6483 }
bc240b21 6484 sports[n] = 0;
820ebe3b 6485 if (type != 'D') {
6486 if (*ssh->portfwd_strptr == '\t')
6487 ssh->portfwd_strptr++;
6488 n = 0;
6489 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
6490 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
6491 }
6492 host[n] = 0;
6493 if (*ssh->portfwd_strptr == ':')
6494 ssh->portfwd_strptr++;
6495 n = 0;
6496 while (*ssh->portfwd_strptr) {
6497 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
6498 }
6499 dports[n] = 0;
51470298 6500 ssh->portfwd_strptr++;
820ebe3b 6501 dport = atoi(dports);
6502 dserv = 0;
6503 if (dport == 0) {
6504 dserv = 1;
6505 dport = net_service_lookup(dports);
6506 if (!dport) {
6507 logeventf(ssh, "Service lookup failed for destination"
6508 " port \"%s\"", dports);
6509 }
a4fc0d74 6510 }
820ebe3b 6511 } else {
6512 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
7ffdbc1a 6513 dport = dserv = -1;
7d5b0f4d 6514 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
a4fc0d74 6515 }
bc240b21 6516 sport = atoi(sports);
a4fc0d74 6517 sserv = 0;
6518 if (sport == 0) {
6519 sserv = 1;
68a49acb 6520 sport = net_service_lookup(sports);
6521 if (!sport) {
57356d63 6522 logeventf(ssh, "Service lookup failed for source"
6523 " port \"%s\"", sports);
a4fc0d74 6524 }
6525 }
bc240b21 6526 if (sport && dport) {
94ab1ddf 6527 /* Set up a description of the source port. */
49b8f9c4 6528 static char *sportdesc;
6529 sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
94ab1ddf 6530 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
6531 (int)(*saddr?1:0), ":",
6532 (int)(sserv ? strlen(sports) : 0), sports,
6533 sserv, "(", sport, sserv, ")");
bc240b21 6534 if (type == 'L') {
94ab1ddf 6535 /* Verbose description of the destination port */
6536 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
6537 host,
6538 (int)(dserv ? strlen(dports) : 0), dports,
6539 dserv, "(", dport, dserv, ")");
6540 const char *err = pfd_addforward(host, dport,
6541 *saddr ? saddr : NULL,
6542 sport, ssh, &ssh->cfg);
6543 if (err) {
6544 logeventf(ssh, "Local port %s forward to %s"
6545 " failed: %s", sportdesc, dportdesc, err);
6546 } else {
6547 logeventf(ssh, "Local port %s forwarding to %s",
6548 sportdesc, dportdesc);
6549 }
6550 sfree(dportdesc);
820ebe3b 6551 } else if (type == 'D') {
94ab1ddf 6552 const char *err = pfd_addforward(NULL, -1,
6553 *saddr ? saddr : NULL,
6554 sport, ssh, &ssh->cfg);
6555 if (err) {
6556 logeventf(ssh, "Local port %s SOCKS dynamic forward"
6557 " setup failed: %s", sportdesc, err);
6558 } else {
6559 logeventf(ssh, "Local port %s doing SOCKS"
6560 " dynamic forwarding", sportdesc);
6561 }
bc240b21 6562 } else {
6563 struct ssh_rportfwd *pf;
3d88e64d 6564 pf = snew(struct ssh_rportfwd);
bc240b21 6565 strcpy(pf->dhost, host);
6566 pf->dport = dport;
6567 pf->sport = sport;
51470298 6568 if (add234(ssh->rportfwds, pf) != pf) {
57356d63 6569 logeventf(ssh, "Duplicate remote port forwarding"
6570 " to %s:%d", host, dport);
bc240b21 6571 sfree(pf);
6572 } else {
94ab1ddf 6573 logeventf(ssh, "Requesting remote port %s"
57356d63 6574 " forward to %s:%.*s%.*s%d%.*s",
94ab1ddf 6575 sportdesc,
57356d63 6576 host,
6577 (int)(dserv ? strlen(dports) : 0), dports,
6578 dserv, "(", dport, dserv, ")");
ff3187f6 6579 s->pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
6580 ssh2_pkt_addstring(s->pktout, "tcpip-forward");
6581 ssh2_pkt_addbool(s->pktout, 1);/* want reply */
49b8f9c4 6582 if (*saddr) {
ff3187f6 6583 ssh2_pkt_addstring(s->pktout, saddr);
49b8f9c4 6584 } else if (ssh->cfg.rport_acceptall) {
ff3187f6 6585 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
49b8f9c4 6586 } else {
ff3187f6 6587 ssh2_pkt_addstring(s->pktout, "127.0.0.1");
49b8f9c4 6588 }
ff3187f6 6589 ssh2_pkt_adduint32(s->pktout, sport);
6590 ssh2_pkt_send(ssh, s->pktout);
bc240b21 6591
b09eaa88 6592 crWaitUntilV(pktin);
bc240b21 6593
ff3187f6 6594 if (pktin->type != SSH2_MSG_REQUEST_SUCCESS) {
6595 if (pktin->type != SSH2_MSG_REQUEST_FAILURE) {
6b5cf8b4 6596 bombout(("Unexpected response to port "
c9886e66 6597 "forwarding request: packet type %d",
ff3187f6 6598 pktin->type));
7ffdbc1a 6599 crStopV;
bc240b21 6600 }
6601 logevent("Server refused this port forwarding");
6602 } else {
6603 logevent("Remote port forwarding enabled");
6604 }
6605 }
6606 }
94ab1ddf 6607 sfree(sportdesc);
bc240b21 6608 }
6609 }
6610 }
6611
6612 /*
36c2a3e9 6613 * Potentially enable agent forwarding.
6614 */
0ed48730 6615 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 6616 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 6617 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6618 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6619 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6620 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6621 ssh2_pkt_send(ssh, s->pktout);
32874aea 6622
b09eaa88 6623 crWaitUntilV(pktin);
32874aea 6624
ff3187f6 6625 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6626 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6627 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 6628 " packet type %d", pktin->type));
7ffdbc1a 6629 crStopV;
32874aea 6630 }
6631 logevent("Agent forwarding refused");
6632 } else {
6633 logevent("Agent forwarding enabled");
51470298 6634 ssh->agentfwd_enabled = TRUE;
32874aea 6635 }
36c2a3e9 6636 }
6637
6638 /*
7cca0d81 6639 * Now allocate a pty for the session.
6640 */
0ed48730 6641 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 6642 /* Unpick the terminal-speed string. */
6643 /* XXX perhaps we should allow no speeds to be sent. */
db219738 6644 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6645 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 6646 /* Build the pty request. */
ff3187f6 6647 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6648 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6649 ssh2_pkt_addstring(s->pktout, "pty-req");
6650 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6651 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6652 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6653 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6654 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6655 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6656 ssh2_pkt_addstring_start(s->pktout);
6657 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6658 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6659 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6660 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6661 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6662 ssh2_pkt_send(ssh, s->pktout);
51470298 6663 ssh->state = SSH_STATE_INTERMED;
32874aea 6664
b09eaa88 6665 crWaitUntilV(pktin);
32874aea 6666
ff3187f6 6667 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6668 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6669 bombout(("Unexpected response to pty request:"
ff3187f6 6670 " packet type %d", pktin->type));
7ffdbc1a 6671 crStopV;
32874aea 6672 }
51470298 6673 c_write_str(ssh, "Server refused to allocate pty\r\n");
6674 ssh->editing = ssh->echoing = 1;
32874aea 6675 } else {
a5dd8467 6676 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 6677 ssh->ospeed, ssh->ispeed);
32874aea 6678 }
0965bee0 6679 } else {
51470298 6680 ssh->editing = ssh->echoing = 1;
7cca0d81 6681 }
6682
6683 /*
73feed4f 6684 * Send environment variables.
6685 *
6686 * Simplest thing here is to send all the requests at once, and
6687 * then wait for a whole bunch of successes or failures.
6688 */
6689 if (ssh->mainchan && *ssh->cfg.environmt) {
6690 char *e = ssh->cfg.environmt;
6691 char *var, *varend, *val;
6692
6693 s->num_env = 0;
6694
6695 while (*e) {
6696 var = e;
6697 while (*e && *e != '\t') e++;
6698 varend = e;
6699 if (*e == '\t') e++;
6700 val = e;
6701 while (*e) e++;
6702 e++;
6703
ff3187f6 6704 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6705 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6706 ssh2_pkt_addstring(s->pktout, "env");
6707 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6708 ssh2_pkt_addstring_start(s->pktout);
6709 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
6710 ssh2_pkt_addstring(s->pktout, val);
6711 ssh2_pkt_send(ssh, s->pktout);
73feed4f 6712
6713 s->num_env++;
6714 }
6715
6716 logeventf(ssh, "Sent %d environment variables", s->num_env);
6717
6718 s->env_ok = 0;
6719 s->env_left = s->num_env;
6720
6721 while (s->env_left > 0) {
b09eaa88 6722 crWaitUntilV(pktin);
73feed4f 6723
ff3187f6 6724 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6725 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 6726 bombout(("Unexpected response to environment request:"
ff3187f6 6727 " packet type %d", pktin->type));
73feed4f 6728 crStopV;
6729 }
6730 } else {
6731 s->env_ok++;
6732 }
6733
6734 s->env_left--;
6735 }
6736
6737 if (s->env_ok == s->num_env) {
6738 logevent("All environment variables successfully set");
6739 } else if (s->env_ok == 0) {
6740 logevent("All environment variables refused");
6741 c_write_str(ssh, "Server refused to set environment variables\r\n");
6742 } else {
6743 logeventf(ssh, "%d environment variables refused",
6744 s->num_env - s->env_ok);
6745 c_write_str(ssh, "Server refused to set all environment variables\r\n");
6746 }
6747 }
6748
6749 /*
fd5e5847 6750 * Start a shell or a remote command. We may have to attempt
6751 * this twice if the config data has provided a second choice
6752 * of command.
7cca0d81 6753 */
0ed48730 6754 if (ssh->mainchan) while (1) {
fd5e5847 6755 int subsys;
6756 char *cmd;
6757
51470298 6758 if (ssh->fallback_cmd) {
86916870 6759 subsys = ssh->cfg.ssh_subsys2;
6760 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 6761 } else {
86916870 6762 subsys = ssh->cfg.ssh_subsys;
6763 cmd = ssh->cfg.remote_cmd_ptr;
fd5e5847 6764 }
6765
ff3187f6 6766 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6767 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 6768 if (subsys) {
ff3187f6 6769 ssh2_pkt_addstring(s->pktout, "subsystem");
6770 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6771 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 6772 } else if (*cmd) {
ff3187f6 6773 ssh2_pkt_addstring(s->pktout, "exec");
6774 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6775 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 6776 } else {
ff3187f6 6777 ssh2_pkt_addstring(s->pktout, "shell");
6778 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 6779 }
ff3187f6 6780 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 6781
6782 crWaitUntilV(pktin);
6783
ff3187f6 6784 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6785 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 6786 bombout(("Unexpected response to shell/command request:"
ff3187f6 6787 " packet type %d", pktin->type));
7ffdbc1a 6788 crStopV;
fd5e5847 6789 }
6790 /*
6791 * We failed to start the command. If this is the
6792 * fallback command, we really are finished; if it's
6793 * not, and if the fallback command exists, try falling
6794 * back to it before complaining.
6795 */
86916870 6796 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 6797 logevent("Primary command failed; attempting fallback");
51470298 6798 ssh->fallback_cmd = TRUE;
fd5e5847 6799 continue;
6800 }
6b5cf8b4 6801 bombout(("Server refused to start a shell/command"));
7ffdbc1a 6802 crStopV;
fd5e5847 6803 } else {
6804 logevent("Started a shell/command");
32874aea 6805 }
fd5e5847 6806 break;
7cca0d81 6807 }
6808
51470298 6809 ssh->state = SSH_STATE_SESSION;
6810 if (ssh->size_needed)
6811 ssh_size(ssh, ssh->term_width, ssh->term_height);
6812 if (ssh->eof_needed)
6813 ssh_special(ssh, TS_EOF);
6e48c3fe 6814
7cca0d81 6815 /*
6816 * Transfer data!
6817 */
b9d7bcad 6818 if (ssh->ldisc)
6819 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 6820 if (ssh->mainchan)
6821 ssh->send_ok = 1;
7cca0d81 6822 while (1) {
e5574168 6823 crReturnV;
51470298 6824 s->try_send = FALSE;
ff3187f6 6825 if (pktin) {
2b7540a7 6826
51df0ab5 6827 /*
6828 * _All_ the connection-layer packets we expect to
6829 * receive are now handled by the dispatch table.
6830 * Anything that reaches here must be bogus.
6831 */
32874aea 6832
51df0ab5 6833 bombout(("Strange packet received: type %d", pktin->type));
6834 crStopV;
0ed48730 6835 } else if (ssh->mainchan) {
32874aea 6836 /*
6837 * We have spare data. Add it to the channel buffer.
6838 */
d8baa528 6839 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 6840 s->try_send = TRUE;
32874aea 6841 }
51470298 6842 if (s->try_send) {
32874aea 6843 int i;
6844 struct ssh_channel *c;
6845 /*
6846 * Try to send data on all channels if we can.
6847 */
51470298 6848 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
a6253970 6849 int bufsize;
6850 if (c->closes)
6851 continue; /* don't send on closing channels */
6852 bufsize = ssh2_try_send(c);
5471d09a 6853 if (bufsize == 0) {
6854 switch (c->type) {
6855 case CHAN_MAINSESSION:
6856 /* stdin need not receive an unthrottle
6857 * notification since it will be polled */
6858 break;
6859 case CHAN_X11:
6860 x11_unthrottle(c->u.x11.s);
6861 break;
6862 case CHAN_AGENT:
6863 /* agent sockets are request/response and need no
6864 * buffer management */
6865 break;
6866 case CHAN_SOCKDATA:
6867 pfd_unthrottle(c->u.pfd.s);
6868 break;
6869 }
6870 }
6871 }
7cca0d81 6872 }
e5574168 6873 }
6874
6875 crFinishV;
6876}
6877
6878/*
b09eaa88 6879 * Handlers for SSH2 messages that might arrive at any moment.
6880 */
6881void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
6882{
6883 /* log reason code in disconnect message */
6884 char *buf, *msg;
6885 int nowlen, reason, msglen;
6886
6887 reason = ssh_pkt_getuint32(pktin);
6888 ssh_pkt_getstring(pktin, &msg, &msglen);
6889
6890 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
6891 buf = dupprintf("Received disconnect message (%s)",
6892 ssh2_disconnect_reasons[reason]);
6893 } else {
6894 buf = dupprintf("Received disconnect message (unknown"
6895 " type %d)", reason);
6896 }
6897 logevent(buf);
6898 sfree(buf);
6899 buf = dupprintf("Disconnection message text: %n%.*s",
6900 &nowlen, msglen, msg);
6901 logevent(buf);
6902 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
6903 reason,
6904 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
6905 ssh2_disconnect_reasons[reason] : "unknown",
6906 buf+nowlen));
6907 sfree(buf);
6908}
6909
6910void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
6911{
6912 /* log the debug message */
6913 char *buf, *msg;
6914 int msglen;
6915 int always_display;
6916
6917 /* XXX maybe we should actually take notice of this */
6918 always_display = ssh2_pkt_getbool(pktin);
6919 ssh_pkt_getstring(pktin, &msg, &msglen);
6920
6921 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
6922 logevent(buf);
6923 sfree(buf);
6924}
6925
6926void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
6927{
6928 struct Packet *pktout;
6929 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
6930 ssh2_pkt_adduint32(pktout, pktin->sequence);
6931 /*
6932 * UNIMPLEMENTED messages MUST appear in the same order as the
6933 * messages they respond to. Hence, never queue them.
6934 */
6935 ssh2_pkt_send_noqueue(ssh, pktout);
6936}
6937
6938/*
7cca0d81 6939 * Handle the top-level SSH2 protocol.
6940 */
b09eaa88 6941static void ssh2_protocol_setup(Ssh ssh)
6942{
6943 int i;
6944
6945 /*
6946 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
6947 */
6948 for (i = 0; i < 256; i++)
6949 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
6950
6951 /*
6952 * Any message we actually understand, we set to NULL so that
6953 * the coroutines will get it.
6954 */
6955 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
6956 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
6957 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
6958 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
6959 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
6960 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
6961 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
6962 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
6963 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
6964 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
6965 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
6966 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
6967 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
6968 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
6969 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
6970 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
6971 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
6972 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
6973 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
6974 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
6975 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
6976 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
6977 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
6978 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
6979 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
6980 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
6981 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
6982 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
6983 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
6984 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
6985 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
6986 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
6987 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
6988
6989 /*
6990 * These special message types we install handlers for.
6991 */
6992 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
6993 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
6994 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
6995}
6996
9442dd57 6997static void ssh2_timer(void *ctx, long now)
6998{
6999 Ssh ssh = (Ssh)ctx;
7000
7001 if (!ssh->kex_in_progress &&
7002 now - ssh->next_rekey >= 0) {
7003 do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
7004 -1, NULL);
7005 }
7006}
7007
ff3187f6 7008static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7009 struct Packet *pktin)
7cca0d81 7010{
b09eaa88 7011 if (ssh->state == SSH_STATE_CLOSED)
7012 return;
7013
9442dd57 7014 if (pktin) {
7015 ssh->incoming_data_size += pktin->encrypted_len;
7016 if (!ssh->kex_in_progress &&
7017 ssh->incoming_data_size > MAX_DATA_BEFORE_REKEY)
7018 do_ssh2_transport(ssh, "Initiating key re-exchange "
7019 "(too much data received)", -1, NULL);
7020 }
7021
b09eaa88 7022 if (pktin && ssh->packet_dispatch[pktin->type]) {
7023 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 7024 return;
b09eaa88 7025 }
7026
7027 if (!ssh->protocol_initial_phase_done ||
7028 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7029 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7030 !ssh->protocol_initial_phase_done) {
7031 ssh->protocol_initial_phase_done = TRUE;
7032 /*
7033 * Allow authconn to initialise itself.
7034 */
7035 do_ssh2_authconn(ssh, NULL, 0, NULL);
7036 }
7037 } else {
7038 do_ssh2_authconn(ssh, in, inlen, pktin);
7039 }
7cca0d81 7040}
7041
7042/*
8df7a775 7043 * Called to set up the connection.
374330e2 7044 *
7045 * Returns an error message, or NULL on success.
374330e2 7046 */
cbe2d68f 7047static const char *ssh_init(void *frontend_handle, void **backend_handle,
7048 Config *cfg,
79bf227b 7049 char *host, int port, char **realhost, int nodelay,
7050 int keepalive)
32874aea 7051{
cbe2d68f 7052 const char *p;
51470298 7053 Ssh ssh;
7054
3d88e64d 7055 ssh = snew(struct ssh_tag);
86916870 7056 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 7057 ssh->version = 0; /* when not ready yet */
51470298 7058 ssh->s = NULL;
7059 ssh->cipher = NULL;
371e569c 7060 ssh->v1_cipher_ctx = NULL;
0183b242 7061 ssh->crcda_ctx = NULL;
51470298 7062 ssh->cscipher = NULL;
371e569c 7063 ssh->cs_cipher_ctx = NULL;
51470298 7064 ssh->sccipher = NULL;
371e569c 7065 ssh->sc_cipher_ctx = NULL;
51470298 7066 ssh->csmac = NULL;
a8327734 7067 ssh->cs_mac_ctx = NULL;
51470298 7068 ssh->scmac = NULL;
e0e1a00d 7069 ssh->sc_mac_ctx = NULL;
51470298 7070 ssh->cscomp = NULL;
5366aed8 7071 ssh->cs_comp_ctx = NULL;
51470298 7072 ssh->sccomp = NULL;
5366aed8 7073 ssh->sc_comp_ctx = NULL;
51470298 7074 ssh->kex = NULL;
389aa499 7075 ssh->kex_ctx = NULL;
51470298 7076 ssh->hostkey = NULL;
7077 ssh->exitcode = -1;
7078 ssh->state = SSH_STATE_PREPACKET;
7079 ssh->size_needed = FALSE;
7080 ssh->eof_needed = FALSE;
b9d7bcad 7081 ssh->ldisc = NULL;
a8327734 7082 ssh->logctx = NULL;
51470298 7083 ssh->deferred_send_data = NULL;
7084 ssh->deferred_len = 0;
7085 ssh->deferred_size = 0;
7086 ssh->fallback_cmd = 0;
7087 ssh->pkt_ctx = 0;
302121de 7088 ssh->x11auth = NULL;
be738459 7089 ssh->v1_compressing = FALSE;
51470298 7090 ssh->v2_outgoing_sequence = 0;
7091 ssh->ssh1_rdpkt_crstate = 0;
7092 ssh->ssh2_rdpkt_crstate = 0;
7093 ssh->do_ssh_init_crstate = 0;
7094 ssh->ssh_gotdata_crstate = 0;
b09eaa88 7095 ssh->do_ssh1_connection_crstate = 0;
51470298 7096 ssh->do_ssh1_login_crstate = 0;
7097 ssh->do_ssh2_transport_crstate = 0;
7098 ssh->do_ssh2_authconn_crstate = 0;
7099 ssh->do_ssh_init_state = NULL;
7100 ssh->do_ssh1_login_state = NULL;
7101 ssh->do_ssh2_transport_state = NULL;
7102 ssh->do_ssh2_authconn_state = NULL;
6571dbfd 7103 ssh->mainchan = NULL;
968d2d92 7104 ssh->throttled_all = 0;
7105 ssh->v1_stdout_throttling = 0;
590f6a5f 7106 ssh->queue = NULL;
7107 ssh->queuelen = ssh->queuesize = 0;
7108 ssh->queueing = FALSE;
51470298 7109
7110 *backend_handle = ssh;
32874aea 7111
8f203108 7112#ifdef MSCRYPTOAPI
32874aea 7113 if (crypto_startup() == 0)
8f203108 7114 return "Microsoft high encryption pack not installed!";
7115#endif
374330e2 7116
51470298 7117 ssh->frontend = frontend_handle;
86916870 7118 ssh->term_width = ssh->cfg.width;
7119 ssh->term_height = ssh->cfg.height;
887035a5 7120
fabd1805 7121 ssh->channels = NULL;
7122 ssh->rportfwds = NULL;
7123
51470298 7124 ssh->send_ok = 0;
7125 ssh->editing = 0;
7126 ssh->echoing = 0;
7127 ssh->v1_throttle_count = 0;
7128 ssh->overall_bufsize = 0;
7129 ssh->fallback_cmd = 0;
8df7a775 7130
3648d4c5 7131 ssh->protocol = NULL;
7132
b09eaa88 7133 ssh->protocol_initial_phase_done = FALSE;
7134
39934deb 7135 ssh->pinger = NULL;
7136
9442dd57 7137 ssh->incoming_data_size = ssh->outgoing_data_size =
7138 ssh->deferred_data_size = 0L;
7139 ssh->kex_in_progress = FALSE;
7140
79bf227b 7141 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 7142 if (p != NULL)
7143 return p;
374330e2 7144
5d17ccfc 7145 random_ref();
7146
374330e2 7147 return NULL;
7148}
7149
fabd1805 7150static void ssh_free(void *handle)
7151{
7152 Ssh ssh = (Ssh) handle;
7153 struct ssh_channel *c;
7154 struct ssh_rportfwd *pf;
7155
7156 if (ssh->v1_cipher_ctx)
7157 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7158 if (ssh->cs_cipher_ctx)
7159 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7160 if (ssh->sc_cipher_ctx)
7161 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7162 if (ssh->cs_mac_ctx)
7163 ssh->csmac->free_context(ssh->cs_mac_ctx);
7164 if (ssh->sc_mac_ctx)
7165 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 7166 if (ssh->cs_comp_ctx) {
7167 if (ssh->cscomp)
7168 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7169 else
7170 zlib_compress_cleanup(ssh->cs_comp_ctx);
7171 }
7172 if (ssh->sc_comp_ctx) {
7173 if (ssh->sccomp)
7174 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7175 else
7176 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7177 }
fabd1805 7178 if (ssh->kex_ctx)
7179 dh_cleanup(ssh->kex_ctx);
7180 sfree(ssh->savedhost);
7181
590f6a5f 7182 while (ssh->queuelen-- > 0)
7183 ssh_free_packet(ssh->queue[ssh->queuelen]);
7184 sfree(ssh->queue);
7185
fabd1805 7186 if (ssh->channels) {
7187 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7188 switch (c->type) {
7189 case CHAN_X11:
7190 if (c->u.x11.s != NULL)
7191 x11_close(c->u.x11.s);
7192 break;
7193 case CHAN_SOCKDATA:
7194 if (c->u.pfd.s != NULL)
7195 pfd_close(c->u.pfd.s);
7196 break;
7197 }
7198 sfree(c);
7199 }
7200 freetree234(ssh->channels);
7201 }
7202
7203 if (ssh->rportfwds) {
7204 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7205 sfree(pf);
7206 freetree234(ssh->rportfwds);
7207 }
7208 sfree(ssh->deferred_send_data);
7209 if (ssh->x11auth)
7210 x11_free_auth(ssh->x11auth);
7211 sfree(ssh->do_ssh_init_state);
7212 sfree(ssh->do_ssh1_login_state);
7213 sfree(ssh->do_ssh2_transport_state);
7214 sfree(ssh->do_ssh2_authconn_state);
679539d7 7215 if (ssh->crcda_ctx) {
7216 crcda_free_context(ssh->crcda_ctx);
7217 ssh->crcda_ctx = NULL;
7218 }
fabd1805 7219 if (ssh->s)
36f94d1f 7220 ssh_do_close(ssh);
9442dd57 7221 expire_timer_context(ssh);
fabd1805 7222 sfree(ssh);
39934deb 7223 if (ssh->pinger)
7224 pinger_free(ssh->pinger);
5d17ccfc 7225
7226 random_unref();
fabd1805 7227}
7228
374330e2 7229/*
86916870 7230 * Reconfigure the SSH backend.
7231 *
7232 * Currently, this function does nothing very useful. In future,
7233 * however, we could do some handy things with it. For example, we
7234 * could make the port forwarding configurer active in the Change
7235 * Settings box, and this routine could close down existing
7236 * forwardings and open up new ones in response to changes.
7237 */
7238static void ssh_reconfig(void *handle, Config *cfg)
7239{
7240 Ssh ssh = (Ssh) handle;
39934deb 7241 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
86916870 7242 ssh->cfg = *cfg; /* STRUCTURE COPY */
7243}
7244
7245/*
374330e2 7246 * Called to send data down the Telnet connection.
7247 */
51470298 7248static int ssh_send(void *handle, char *buf, int len)
32874aea 7249{
51470298 7250 Ssh ssh = (Ssh) handle;
7251
7252 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7253 return 0;
374330e2 7254
d8baa528 7255 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 7256
51470298 7257 return ssh_sendbuffer(ssh);
5471d09a 7258}
7259
7260/*
7261 * Called to query the current amount of buffered stdin data.
7262 */
51470298 7263static int ssh_sendbuffer(void *handle)
5471d09a 7264{
51470298 7265 Ssh ssh = (Ssh) handle;
5471d09a 7266 int override_value;
7267
51470298 7268 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 7269 return 0;
7270
7271 /*
7272 * If the SSH socket itself has backed up, add the total backup
7273 * size on that to any individual buffer on the stdin channel.
7274 */
7275 override_value = 0;
51470298 7276 if (ssh->throttled_all)
7277 override_value = ssh->overall_bufsize;
5471d09a 7278
51470298 7279 if (ssh->version == 1) {
5471d09a 7280 return override_value;
51470298 7281 } else if (ssh->version == 2) {
7282 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 7283 return override_value;
7284 else
51470298 7285 return (override_value +
7286 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 7287 }
7288
7289 return 0;
374330e2 7290}
7291
7292/*
6e48c3fe 7293 * Called to set the size of the window from SSH's POV.
374330e2 7294 */
51470298 7295static void ssh_size(void *handle, int width, int height)
32874aea 7296{
51470298 7297 Ssh ssh = (Ssh) handle;
ff3187f6 7298 struct Packet *pktout;
51470298 7299
7300 ssh->term_width = width;
7301 ssh->term_height = height;
f278d6f8 7302
51470298 7303 switch (ssh->state) {
374330e2 7304 case SSH_STATE_BEFORE_SIZE:
3687d221 7305 case SSH_STATE_PREPACKET:
21248260 7306 case SSH_STATE_CLOSED:
374330e2 7307 break; /* do nothing */
7308 case SSH_STATE_INTERMED:
51470298 7309 ssh->size_needed = TRUE; /* buffer for later */
374330e2 7310 break;
7311 case SSH_STATE_SESSION:
86916870 7312 if (!ssh->cfg.nopty) {
51470298 7313 if (ssh->version == 1) {
7314 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7315 PKT_INT, ssh->term_height,
7316 PKT_INT, ssh->term_width,
32874aea 7317 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 7318 } else if (ssh->mainchan) {
ff3187f6 7319 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7320 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7321 ssh2_pkt_addstring(pktout, "window-change");
7322 ssh2_pkt_addbool(pktout, 0);
7323 ssh2_pkt_adduint32(pktout, ssh->term_width);
7324 ssh2_pkt_adduint32(pktout, ssh->term_height);
7325 ssh2_pkt_adduint32(pktout, 0);
7326 ssh2_pkt_adduint32(pktout, 0);
7327 ssh2_pkt_send(ssh, pktout);
32874aea 7328 }
7329 }
7330 break;
374330e2 7331 }
7332}
7333
7334/*
125105d1 7335 * Return a list of the special codes that make sense in this
7336 * protocol.
7337 */
7338static const struct telnet_special *ssh_get_specials(void *handle)
7339{
62638676 7340 static const struct telnet_special ignore_special[] = {
7341 {"IGNORE message", TS_NOP},
9442dd57 7342 {"Repeat key exchange", TS_REKEY},
62638676 7343 };
7344 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 7345 {NULL, TS_SEP},
7346 {"Break", TS_BRK},
7347 /* These are the signal names defined by draft-ietf-secsh-connect-19.
7348 * They include all the ISO C signals, but are a subset of the POSIX
7349 * required signals. */
7350 {"SIGINT (Interrupt)", TS_SIGINT},
7351 {"SIGTERM (Terminate)", TS_SIGTERM},
7352 {"SIGKILL (Kill)", TS_SIGKILL},
7353 {"SIGQUIT (Quit)", TS_SIGQUIT},
7354 {"SIGHUP (Hangup)", TS_SIGHUP},
7355 {"More signals", TS_SUBMENU},
7356 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7357 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7358 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7359 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7360 {NULL, TS_EXITMENU}
62638676 7361 };
7362 static const struct telnet_special specials_end[] = {
6f2d0cde 7363 {NULL, TS_EXITMENU}
62638676 7364 };
7365 static struct telnet_special ssh_specials[lenof(ignore_special) +
7366 lenof(ssh2_session_specials) +
7367 lenof(specials_end)];
125105d1 7368 Ssh ssh = (Ssh) handle;
62638676 7369 int i = 0;
7370#define ADD_SPECIALS(name) \
7371 do { \
7372 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7373 memcpy(&ssh_specials[i], name, sizeof name); \
7374 i += lenof(name); \
7375 } while(0)
125105d1 7376
7377 if (ssh->version == 1) {
62638676 7378 /* Don't bother offering IGNORE if we've decided the remote
7379 * won't cope with it, since we wouldn't bother sending it if
7380 * asked anyway. */
7381 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7382 ADD_SPECIALS(ignore_special);
125105d1 7383 } else if (ssh->version == 2) {
62638676 7384 ADD_SPECIALS(ignore_special);
7385 if (ssh->mainchan)
7386 ADD_SPECIALS(ssh2_session_specials);
7387 } /* else we're not ready yet */
7388
7389 if (i) {
7390 ADD_SPECIALS(specials_end);
7391 return ssh_specials;
7392 } else {
125105d1 7393 return NULL;
62638676 7394 }
7395#undef ADD_SPECIALS
125105d1 7396}
7397
7398/*
6abbf9e3 7399 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7400 * can send an EOF and collect resulting output (e.g. `plink
7401 * hostname sort').
374330e2 7402 */
51470298 7403static void ssh_special(void *handle, Telnet_Special code)
32874aea 7404{
51470298 7405 Ssh ssh = (Ssh) handle;
ff3187f6 7406 struct Packet *pktout;
51470298 7407
6abbf9e3 7408 if (code == TS_EOF) {
51470298 7409 if (ssh->state != SSH_STATE_SESSION) {
32874aea 7410 /*
7411 * Buffer the EOF in case we are pre-SESSION, so we can
7412 * send it as soon as we reach SESSION.
7413 */
7414 if (code == TS_EOF)
51470298 7415 ssh->eof_needed = TRUE;
32874aea 7416 return;
7417 }
51470298 7418 if (ssh->version == 1) {
7419 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 7420 } else if (ssh->mainchan) {
ff3187f6 7421 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7422 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7423 ssh2_pkt_send(ssh, pktout);
32874aea 7424 }
7425 logevent("Sent EOF message");
125105d1 7426 } else if (code == TS_PING || code == TS_NOP) {
51470298 7427 if (ssh->state == SSH_STATE_CLOSED
7428 || ssh->state == SSH_STATE_PREPACKET) return;
7429 if (ssh->version == 1) {
7430 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7431 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 7432 } else {
ff3187f6 7433 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7434 ssh2_pkt_addstring_start(pktout);
590f6a5f 7435 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 7436 }
9442dd57 7437 } else if (code == TS_REKEY) {
7438 if (!ssh->kex_in_progress && ssh->version == 2) {
7439 do_ssh2_transport(ssh, "Initiating key re-exchange at"
7440 " user request", -1, NULL);
7441 }
125105d1 7442 } else if (code == TS_BRK) {
7443 if (ssh->state == SSH_STATE_CLOSED
7444 || ssh->state == SSH_STATE_PREPACKET) return;
7445 if (ssh->version == 1) {
7446 logevent("Unable to send BREAK signal in SSH1");
0ed48730 7447 } else if (ssh->mainchan) {
ff3187f6 7448 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7449 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7450 ssh2_pkt_addstring(pktout, "break");
7451 ssh2_pkt_addbool(pktout, 0);
7452 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7453 ssh2_pkt_send(ssh, pktout);
125105d1 7454 }
6abbf9e3 7455 } else {
6f2d0cde 7456 /* Is is a POSIX signal? */
7457 char *signame = NULL;
7458 if (code == TS_SIGABRT) signame = "ABRT";
7459 if (code == TS_SIGALRM) signame = "ALRM";
7460 if (code == TS_SIGFPE) signame = "FPE";
7461 if (code == TS_SIGHUP) signame = "HUP";
7462 if (code == TS_SIGILL) signame = "ILL";
7463 if (code == TS_SIGINT) signame = "INT";
7464 if (code == TS_SIGKILL) signame = "KILL";
7465 if (code == TS_SIGPIPE) signame = "PIPE";
7466 if (code == TS_SIGQUIT) signame = "QUIT";
7467 if (code == TS_SIGSEGV) signame = "SEGV";
7468 if (code == TS_SIGTERM) signame = "TERM";
7469 if (code == TS_SIGUSR1) signame = "USR1";
7470 if (code == TS_SIGUSR2) signame = "USR2";
7471 /* The SSH-2 protocol does in principle support arbitrary named
7472 * signals, including signame@domain, but we don't support those. */
7473 if (signame) {
7474 /* It's a signal. */
7475 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 7476 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7477 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7478 ssh2_pkt_addstring(pktout, "signal");
7479 ssh2_pkt_addbool(pktout, 0);
7480 ssh2_pkt_addstring(pktout, signame);
7481 ssh2_pkt_send(ssh, pktout);
6f2d0cde 7482 logeventf(ssh, "Sent signal SIG%s", signame);
7483 }
7484 } else {
7485 /* Never heard of it. Do nothing */
7486 }
6abbf9e3 7487 }
374330e2 7488}
7489
51470298 7490void *new_sock_channel(void *handle, Socket s)
d74d141c 7491{
51470298 7492 Ssh ssh = (Ssh) handle;
d74d141c 7493 struct ssh_channel *c;
3d88e64d 7494 c = snew(struct ssh_channel);
51470298 7495 c->ssh = ssh;
d74d141c 7496
7497 if (c) {
bc240b21 7498 c->remoteid = -1; /* to be set when open confirmed */
51470298 7499 c->localid = alloc_channel_id(ssh);
d74d141c 7500 c->closes = 0;
bc240b21 7501 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 7502 c->u.pfd.s = s;
013dd8c0 7503 bufchain_init(&c->v.v2.outbuffer);
51470298 7504 add234(ssh->channels, c);
d74d141c 7505 }
7506 return c;
7507}
7508
5471d09a 7509/*
7510 * This is called when stdout/stderr (the entity to which
7511 * from_backend sends data) manages to clear some backlog.
7512 */
ae9ae89f 7513static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 7514{
51470298 7515 Ssh ssh = (Ssh) handle;
7516 if (ssh->version == 1) {
7517 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7518 ssh->v1_stdout_throttling = 0;
7519 ssh1_throttle(ssh, -1);
5471d09a 7520 }
7521 } else {
51470298 7522 if (ssh->mainchan && ssh->mainchan->closes == 0)
7523 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 7524 }
7525}
7526
6b78788a 7527void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 7528{
7529 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 7530 Ssh ssh = c->ssh;
ff3187f6 7531 struct Packet *pktout;
d74d141c 7532
57356d63 7533 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 7534
51470298 7535 if (ssh->version == 1) {
7536 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 7537 PKT_INT, c->localid,
7538 PKT_STR, hostname,
7539 PKT_INT, port,
7540 //PKT_STR, <org:orgport>,
7541 PKT_END);
7542 } else {
ff3187f6 7543 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7544 ssh2_pkt_addstring(pktout, "direct-tcpip");
7545 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 7546 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7547 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7548 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7549 ssh2_pkt_addstring(pktout, hostname);
7550 ssh2_pkt_adduint32(pktout, port);
bc240b21 7551 /*
7552 * We make up values for the originator data; partly it's
7553 * too much hassle to keep track, and partly I'm not
7554 * convinced the server should be told details like that
7555 * about my local network configuration.
7556 */
ff3187f6 7557 ssh2_pkt_addstring(pktout, "client-side-connection");
7558 ssh2_pkt_adduint32(pktout, 0);
7559 ssh2_pkt_send(ssh, pktout);
bc240b21 7560 }
d74d141c 7561}
7562
51470298 7563static Socket ssh_socket(void *handle)
32874aea 7564{
51470298 7565 Ssh ssh = (Ssh) handle;
7566 return ssh->s;
32874aea 7567}
8ccc75b0 7568
51470298 7569static int ssh_sendok(void *handle)
32874aea 7570{
51470298 7571 Ssh ssh = (Ssh) handle;
7572 return ssh->send_ok;
32874aea 7573}
fb09bf1c 7574
51470298 7575static int ssh_ldisc(void *handle, int option)
32874aea 7576{
51470298 7577 Ssh ssh = (Ssh) handle;
32874aea 7578 if (option == LD_ECHO)
51470298 7579 return ssh->echoing;
32874aea 7580 if (option == LD_EDIT)
51470298 7581 return ssh->editing;
0965bee0 7582 return FALSE;
7583}
7584
b9d7bcad 7585static void ssh_provide_ldisc(void *handle, void *ldisc)
7586{
7587 Ssh ssh = (Ssh) handle;
7588 ssh->ldisc = ldisc;
7589}
7590
a8327734 7591static void ssh_provide_logctx(void *handle, void *logctx)
7592{
7593 Ssh ssh = (Ssh) handle;
7594 ssh->logctx = logctx;
7595}
7596
51470298 7597static int ssh_return_exitcode(void *handle)
7598{
7599 Ssh ssh = (Ssh) handle;
3bb2f322 7600 if (ssh->s != NULL)
7601 return -1;
7602 else
7603 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 7604}
7605
7606/*
7607 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7608 * that fails. This variable is the means by which scp.c can reach
7609 * into the SSH code and find out which one it got.
7610 */
7611extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 7612{
51470298 7613 Ssh ssh = (Ssh) handle;
7614 return ssh->fallback_cmd;
d8d6c7e5 7615}
7616
374330e2 7617Backend ssh_backend = {
7618 ssh_init,
fabd1805 7619 ssh_free,
86916870 7620 ssh_reconfig,
374330e2 7621 ssh_send,
5471d09a 7622 ssh_sendbuffer,
374330e2 7623 ssh_size,
4017be6d 7624 ssh_special,
125105d1 7625 ssh_get_specials,
8ccc75b0 7626 ssh_socket,
d8d6c7e5 7627 ssh_return_exitcode,
97db3be4 7628 ssh_sendok,
0965bee0 7629 ssh_ldisc,
b9d7bcad 7630 ssh_provide_ldisc,
a8327734 7631 ssh_provide_logctx,
5471d09a 7632 ssh_unthrottle,
97db3be4 7633 22
bc240b21 7634};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator