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Dynamic port forwarding by means of a local SOCKS server. Fully
[u/mdw/putty] / ssh.c
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <stdarg.h>
4 #include <assert.h>
5
6 #include "putty.h"
7 #include "tree234.h"
8 #include "ssh.h"
9
10 #ifndef FALSE
11 #define FALSE 0
12 #endif
13 #ifndef TRUE
14 #define TRUE 1
15 #endif
16
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 */
63 /* Mask for protoflags we will echo back to server if seen */
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 */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
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
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
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 */
129
130 static 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 };
148
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 */
153
154 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
155
156 /*
157 * Various remote-bug flags.
158 */
159 #define BUG_CHOKES_ON_SSH1_IGNORE 1
160 #define BUG_SSH2_HMAC 2
161 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
162 #define BUG_CHOKES_ON_RSA 8
163 #define BUG_SSH2_RSA_PADDING 16
164 #define BUG_SSH2_DERIVEKEY 32
165 #define BUG_SSH2_DH_GEX 64
166 #define BUG_SSH2_PK_SESSIONID 128
167
168 #define translate(x) if (type == x) return #x
169 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
170 static char *ssh1_pkt_type(int type)
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 }
215 static char *ssh2_pkt_type(int pkt_ctx, int type)
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
257
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
270 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
271
272 /*
273 * Coroutine mechanics for the sillier bits of the code. If these
274 * macros look impenetrable to you, you might find it helpful to
275 * read
276 *
277 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
278 *
279 * which explains the theory behind these macros.
280 *
281 * In particular, if you are getting `case expression not constant'
282 * errors when building with MS Visual Studio, this is because MS's
283 * Edit and Continue debugging feature causes their compiler to
284 * violate ANSI C. To disable Edit and Continue debugging:
285 *
286 * - right-click ssh.c in the FileView
287 * - click Settings
288 * - select the C/C++ tab and the General category
289 * - under `Debug info:', select anything _other_ than `Program
290 * Database for Edit and Continue'.
291 */
292 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
293 #define crState(t) \
294 struct t *s; \
295 if (!ssh->t) ssh->t = snew(struct t); \
296 s = ssh->t;
297 #define crFinish(z) } *crLine = 0; return (z); }
298 #define crFinishV } *crLine = 0; return; }
299 #define crReturn(z) \
300 do {\
301 *crLine =__LINE__; return (z); case __LINE__:;\
302 } while (0)
303 #define crReturnV \
304 do {\
305 *crLine=__LINE__; return; case __LINE__:;\
306 } while (0)
307 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
308 #define crStopV do{ *crLine = 0; return; }while(0)
309 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
310 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
311
312 typedef struct ssh_tag *Ssh;
313
314 static void ssh2_pkt_init(Ssh, int pkt_type);
315 static void ssh2_pkt_addbool(Ssh, unsigned char value);
316 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
317 static void ssh2_pkt_addstring_start(Ssh);
318 static void ssh2_pkt_addstring_str(Ssh, char *data);
319 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
320 static void ssh2_pkt_addstring(Ssh, char *data);
321 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
322 static void ssh2_pkt_addmp(Ssh, Bignum b);
323 static int ssh2_pkt_construct(Ssh);
324 static void ssh2_pkt_send(Ssh);
325
326 /*
327 * Buffer management constants. There are several of these for
328 * various different purposes:
329 *
330 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
331 * on a local data stream before we throttle the whole SSH
332 * connection (in SSH1 only). Throttling the whole connection is
333 * pretty drastic so we set this high in the hope it won't
334 * happen very often.
335 *
336 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
337 * on the SSH connection itself before we defensively throttle
338 * _all_ local data streams. This is pretty drastic too (though
339 * thankfully unlikely in SSH2 since the window mechanism should
340 * ensure that the server never has any need to throttle its end
341 * of the connection), so we set this high as well.
342 *
343 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
344 * channels.
345 */
346
347 #define SSH1_BUFFER_LIMIT 32768
348 #define SSH_MAX_BACKLOG 32768
349 #define OUR_V2_WINSIZE 16384
350
351 const static struct ssh_kex *kex_algs[] = {
352 &ssh_diffiehellman_gex,
353 &ssh_diffiehellman
354 };
355
356 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
357
358 static void *nullmac_make_context(void)
359 {
360 return NULL;
361 }
362 static void nullmac_free_context(void *handle)
363 {
364 }
365 static void nullmac_key(void *handle, unsigned char *key)
366 {
367 }
368 static void nullmac_generate(void *handle, unsigned char *blk, int len,
369 unsigned long seq)
370 {
371 }
372 static int nullmac_verify(void *handle, unsigned char *blk, int len,
373 unsigned long seq)
374 {
375 return 1;
376 }
377 const static struct ssh_mac ssh_mac_none = {
378 nullmac_make_context, nullmac_free_context, nullmac_key,
379 nullmac_generate, nullmac_verify, "none", 0
380 };
381 const static struct ssh_mac *macs[] = {
382 &ssh_sha1, &ssh_md5, &ssh_mac_none
383 };
384 const static struct ssh_mac *buggymacs[] = {
385 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
386 };
387
388 static void *ssh_comp_none_init(void)
389 {
390 return NULL;
391 }
392 static void ssh_comp_none_cleanup(void *handle)
393 {
394 }
395 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
396 unsigned char **outblock, int *outlen)
397 {
398 return 0;
399 }
400 static int ssh_comp_none_disable(void *handle)
401 {
402 return 0;
403 }
404 const static struct ssh_compress ssh_comp_none = {
405 "none",
406 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
407 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
408 ssh_comp_none_disable, NULL
409 };
410 extern const struct ssh_compress ssh_zlib;
411 const static struct ssh_compress *compressions[] = {
412 &ssh_zlib, &ssh_comp_none
413 };
414
415 enum { /* channel types */
416 CHAN_MAINSESSION,
417 CHAN_X11,
418 CHAN_AGENT,
419 CHAN_SOCKDATA,
420 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
421 };
422
423 /*
424 * 2-3-4 tree storing channels.
425 */
426 struct ssh_channel {
427 Ssh ssh; /* pointer back to main context */
428 unsigned remoteid, localid;
429 int type;
430 /*
431 * In SSH1, this value contains four bits:
432 *
433 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
434 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
435 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
436 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
437 *
438 * A channel is completely finished with when all four bits are set.
439 */
440 int closes;
441 union {
442 struct ssh1_data_channel {
443 int throttling;
444 } v1;
445 struct ssh2_data_channel {
446 bufchain outbuffer;
447 unsigned remwindow, remmaxpkt;
448 unsigned locwindow;
449 } v2;
450 } v;
451 union {
452 struct ssh_agent_channel {
453 unsigned char *message;
454 unsigned char msglen[4];
455 int lensofar, totallen;
456 } a;
457 struct ssh_x11_channel {
458 Socket s;
459 } x11;
460 struct ssh_pfd_channel {
461 Socket s;
462 } pfd;
463 } u;
464 };
465
466 /*
467 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
468 * 2 use this structure in different ways, reflecting SSH 2's
469 * altogether saner approach to port forwarding.
470 *
471 * In SSH 1, you arrange a remote forwarding by sending the server
472 * the remote port number, and the local destination host:port.
473 * When a connection comes in, the server sends you back that
474 * host:port pair, and you connect to it. This is a ready-made
475 * security hole if you're not on the ball: a malicious server
476 * could send you back _any_ host:port pair, so if you trustingly
477 * connect to the address it gives you then you've just opened the
478 * entire inside of your corporate network just by connecting
479 * through it to a dodgy SSH server. Hence, we must store a list of
480 * host:port pairs we _are_ trying to forward to, and reject a
481 * connection request from the server if it's not in the list.
482 *
483 * In SSH 2, each side of the connection minds its own business and
484 * doesn't send unnecessary information to the other. You arrange a
485 * remote forwarding by sending the server just the remote port
486 * number. When a connection comes in, the server tells you which
487 * of its ports was connected to; and _you_ have to remember what
488 * local host:port pair went with that port number.
489 *
490 * Hence: in SSH 1 this structure stores host:port pairs we intend
491 * to allow connections to, and is indexed by those host:port
492 * pairs. In SSH 2 it stores a mapping from source port to
493 * destination host:port pair, and is indexed by source port.
494 */
495 struct ssh_rportfwd {
496 unsigned sport, dport;
497 char dhost[256];
498 };
499
500 struct Packet {
501 long length;
502 int type;
503 unsigned char *data;
504 unsigned char *body;
505 long savedpos;
506 long maxlen;
507 };
508
509 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
510 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
511 static void ssh_size(void *handle, int width, int height);
512 static void ssh_special(void *handle, Telnet_Special);
513 static int ssh2_try_send(struct ssh_channel *c);
514 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
515 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
516 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
517 static int ssh_sendbuffer(void *handle);
518
519 struct rdpkt1_state_tag {
520 long len, pad, biglen, to_read;
521 unsigned long realcrc, gotcrc;
522 unsigned char *p;
523 int i;
524 int chunk;
525 };
526
527 struct rdpkt2_state_tag {
528 long len, pad, payload, packetlen, maclen;
529 int i;
530 int cipherblk;
531 unsigned long incoming_sequence;
532 };
533
534 struct ssh_tag {
535 const struct plug_function_table *fn;
536 /* the above field _must_ be first in the structure */
537
538 SHA_State exhash, exhashbase;
539
540 Socket s;
541
542 void *ldisc;
543 void *logctx;
544
545 unsigned char session_key[32];
546 int v1_compressing;
547 int v1_remote_protoflags;
548 int v1_local_protoflags;
549 int agentfwd_enabled;
550 int X11_fwd_enabled;
551 int remote_bugs;
552 const struct ssh_cipher *cipher;
553 void *v1_cipher_ctx;
554 void *crcda_ctx;
555 const struct ssh2_cipher *cscipher, *sccipher;
556 void *cs_cipher_ctx, *sc_cipher_ctx;
557 const struct ssh_mac *csmac, *scmac;
558 void *cs_mac_ctx, *sc_mac_ctx;
559 const struct ssh_compress *cscomp, *sccomp;
560 void *cs_comp_ctx, *sc_comp_ctx;
561 const struct ssh_kex *kex;
562 const struct ssh_signkey *hostkey;
563 unsigned char v2_session_id[20];
564 void *kex_ctx;
565
566 char *savedhost;
567 int savedport;
568 int send_ok;
569 int echoing, editing;
570
571 void *frontend;
572
573 int term_width, term_height;
574
575 tree234 *channels; /* indexed by local id */
576 struct ssh_channel *mainchan; /* primary session channel */
577 int exitcode;
578
579 tree234 *rportfwds;
580
581 enum {
582 SSH_STATE_PREPACKET,
583 SSH_STATE_BEFORE_SIZE,
584 SSH_STATE_INTERMED,
585 SSH_STATE_SESSION,
586 SSH_STATE_CLOSED
587 } state;
588
589 int size_needed, eof_needed;
590
591 struct Packet pktin;
592 struct Packet pktout;
593 unsigned char *deferred_send_data;
594 int deferred_len, deferred_size;
595
596 /*
597 * Gross hack: pscp will try to start SFTP but fall back to
598 * scp1 if that fails. This variable is the means by which
599 * scp.c can reach into the SSH code and find out which one it
600 * got.
601 */
602 int fallback_cmd;
603
604 /*
605 * Used for username and password input.
606 */
607 char *userpass_input_buffer;
608 int userpass_input_buflen;
609 int userpass_input_bufpos;
610 int userpass_input_echo;
611
612 char *portfwd_strptr;
613 int pkt_ctx;
614
615 void *x11auth;
616
617 int version;
618 int v1_throttle_count;
619 int overall_bufsize;
620 int throttled_all;
621 int v1_stdout_throttling;
622 int v2_outgoing_sequence;
623
624 int ssh1_rdpkt_crstate;
625 int ssh2_rdpkt_crstate;
626 int do_ssh_init_crstate;
627 int ssh_gotdata_crstate;
628 int ssh1_protocol_crstate;
629 int do_ssh1_login_crstate;
630 int do_ssh2_transport_crstate;
631 int do_ssh2_authconn_crstate;
632
633 void *do_ssh_init_state;
634 void *do_ssh1_login_state;
635 void *do_ssh2_transport_state;
636 void *do_ssh2_authconn_state;
637
638 struct rdpkt1_state_tag rdpkt1_state;
639 struct rdpkt2_state_tag rdpkt2_state;
640
641 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
642 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
643
644 /*
645 * We maintain a full _copy_ of a Config structure here, not
646 * merely a pointer to it. That way, when we're passed a new
647 * one for reconfiguration, we can check the differences and
648 * potentially reconfigure port forwardings etc in mid-session.
649 */
650 Config cfg;
651 };
652
653 #define logevent(s) logevent(ssh->frontend, s)
654
655 /* logevent, only printf-formatted. */
656 static void logeventf(Ssh ssh, char *fmt, ...)
657 {
658 va_list ap;
659 char *buf;
660
661 va_start(ap, fmt);
662 buf = dupvprintf(fmt, ap);
663 va_end(ap);
664 logevent(buf);
665 sfree(buf);
666 }
667
668 #define bombout(msg) \
669 do { \
670 char *text = dupprintf msg; \
671 ssh->state = SSH_STATE_CLOSED; \
672 if (ssh->s) { sk_close(ssh->s); ssh->s = NULL; } \
673 logevent(text); \
674 connection_fatal(ssh->frontend, "%s", text); \
675 sfree(text); \
676 } while (0)
677
678 static int ssh_channelcmp(void *av, void *bv)
679 {
680 struct ssh_channel *a = (struct ssh_channel *) av;
681 struct ssh_channel *b = (struct ssh_channel *) bv;
682 if (a->localid < b->localid)
683 return -1;
684 if (a->localid > b->localid)
685 return +1;
686 return 0;
687 }
688 static int ssh_channelfind(void *av, void *bv)
689 {
690 unsigned *a = (unsigned *) av;
691 struct ssh_channel *b = (struct ssh_channel *) bv;
692 if (*a < b->localid)
693 return -1;
694 if (*a > b->localid)
695 return +1;
696 return 0;
697 }
698
699 static int ssh_rportcmp_ssh1(void *av, void *bv)
700 {
701 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
702 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
703 int i;
704 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
705 return i < 0 ? -1 : +1;
706 if (a->dport > b->dport)
707 return +1;
708 if (a->dport < b->dport)
709 return -1;
710 return 0;
711 }
712
713 static int ssh_rportcmp_ssh2(void *av, void *bv)
714 {
715 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
716 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
717
718 if (a->sport > b->sport)
719 return +1;
720 if (a->sport < b->sport)
721 return -1;
722 return 0;
723 }
724
725 static int alloc_channel_id(Ssh ssh)
726 {
727 const unsigned CHANNEL_NUMBER_OFFSET = 256;
728 unsigned low, high, mid;
729 int tsize;
730 struct ssh_channel *c;
731
732 /*
733 * First-fit allocation of channel numbers: always pick the
734 * lowest unused one. To do this, binary-search using the
735 * counted B-tree to find the largest channel ID which is in a
736 * contiguous sequence from the beginning. (Precisely
737 * everything in that sequence must have ID equal to its tree
738 * index plus CHANNEL_NUMBER_OFFSET.)
739 */
740 tsize = count234(ssh->channels);
741
742 low = -1;
743 high = tsize;
744 while (high - low > 1) {
745 mid = (high + low) / 2;
746 c = index234(ssh->channels, mid);
747 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
748 low = mid; /* this one is fine */
749 else
750 high = mid; /* this one is past it */
751 }
752 /*
753 * Now low points to either -1, or the tree index of the
754 * largest ID in the initial sequence.
755 */
756 {
757 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
758 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
759 }
760 return low + 1 + CHANNEL_NUMBER_OFFSET;
761 }
762
763 static void c_write(Ssh ssh, const char *buf, int len)
764 {
765 if ((flags & FLAG_STDERR)) {
766 int i;
767 for (i = 0; i < len; i++)
768 if (buf[i] != '\r')
769 fputc(buf[i], stderr);
770 return;
771 }
772 from_backend(ssh->frontend, 1, buf, len);
773 }
774
775 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
776 {
777 int i;
778 for (i = 0; i < len; i++) {
779 if (buf[i] == '\n')
780 c_write(ssh, "\r\n", 2);
781 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
782 c_write(ssh, buf + i, 1);
783 }
784 }
785
786 static void c_write_str(Ssh ssh, const char *buf)
787 {
788 c_write(ssh, buf, strlen(buf));
789 }
790
791 /*
792 * Collect incoming data in the incoming packet buffer.
793 * Decipher and verify the packet when it is completely read.
794 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
795 * Update the *data and *datalen variables.
796 * Return the additional nr of bytes needed, or 0 when
797 * a complete packet is available.
798 */
799 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
800 {
801 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
802
803 crBegin(ssh->ssh1_rdpkt_crstate);
804
805 next_packet:
806
807 ssh->pktin.type = 0;
808 ssh->pktin.length = 0;
809
810 for (st->i = st->len = 0; st->i < 4; st->i++) {
811 while ((*datalen) == 0)
812 crReturn(4 - st->i);
813 st->len = (st->len << 8) + **data;
814 (*data)++, (*datalen)--;
815 }
816
817 st->pad = 8 - (st->len % 8);
818 st->biglen = st->len + st->pad;
819 ssh->pktin.length = st->len - 5;
820
821 if (ssh->pktin.maxlen < st->biglen) {
822 ssh->pktin.maxlen = st->biglen;
823 ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA,
824 unsigned char);
825 }
826
827 st->to_read = st->biglen;
828 st->p = ssh->pktin.data;
829 while (st->to_read > 0) {
830 st->chunk = st->to_read;
831 while ((*datalen) == 0)
832 crReturn(st->to_read);
833 if (st->chunk > (*datalen))
834 st->chunk = (*datalen);
835 memcpy(st->p, *data, st->chunk);
836 *data += st->chunk;
837 *datalen -= st->chunk;
838 st->p += st->chunk;
839 st->to_read -= st->chunk;
840 }
841
842 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
843 st->biglen, NULL)) {
844 bombout(("Network attack (CRC compensation) detected!"));
845 crReturn(0);
846 }
847
848 if (ssh->cipher)
849 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
850
851 st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
852 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
853 if (st->gotcrc != st->realcrc) {
854 bombout(("Incorrect CRC received on packet"));
855 crReturn(0);
856 }
857
858 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
859
860 if (ssh->v1_compressing) {
861 unsigned char *decompblk;
862 int decomplen;
863 zlib_decompress_block(ssh->sc_comp_ctx,
864 ssh->pktin.body - 1, ssh->pktin.length + 1,
865 &decompblk, &decomplen);
866
867 if (ssh->pktin.maxlen < st->pad + decomplen) {
868 ssh->pktin.maxlen = st->pad + decomplen;
869 ssh->pktin.data = sresize(ssh->pktin.data,
870 ssh->pktin.maxlen + APIEXTRA,
871 unsigned char);
872 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
873 }
874
875 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
876 sfree(decompblk);
877 ssh->pktin.length = decomplen - 1;
878 }
879
880 ssh->pktin.type = ssh->pktin.body[-1];
881
882 if (ssh->logctx)
883 log_packet(ssh->logctx,
884 PKT_INCOMING, ssh->pktin.type,
885 ssh1_pkt_type(ssh->pktin.type),
886 ssh->pktin.body, ssh->pktin.length);
887
888 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
889 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
890 ssh->pktin.type == SSH1_MSG_DEBUG ||
891 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
892 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
893 long stringlen = GET_32BIT(ssh->pktin.body);
894 if (stringlen + 4 != ssh->pktin.length) {
895 bombout(("Received data packet with bogus string length"));
896 crReturn(0);
897 }
898 }
899
900 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
901 /* log debug message */
902 char buf[512];
903 int stringlen = GET_32BIT(ssh->pktin.body);
904 strcpy(buf, "Remote debug message: ");
905 if (stringlen > 480)
906 stringlen = 480;
907 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
908 buf[8 + stringlen] = '\0';
909 logevent(buf);
910 goto next_packet;
911 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
912 /* do nothing */
913 goto next_packet;
914 }
915
916 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
917 /* log reason code in disconnect message */
918 char buf[256];
919 unsigned msglen = GET_32BIT(ssh->pktin.body);
920 unsigned nowlen;
921 strcpy(buf, "Remote sent disconnect: ");
922 nowlen = strlen(buf);
923 if (msglen > sizeof(buf) - nowlen - 1)
924 msglen = sizeof(buf) - nowlen - 1;
925 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
926 buf[nowlen + msglen] = '\0';
927 /* logevent(buf); (this is now done within the bombout macro) */
928 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
929 crReturn(0);
930 }
931
932 crFinish(0);
933 }
934
935 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
936 {
937 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
938
939 crBegin(ssh->ssh2_rdpkt_crstate);
940
941 next_packet:
942 ssh->pktin.type = 0;
943 ssh->pktin.length = 0;
944 if (ssh->sccipher)
945 st->cipherblk = ssh->sccipher->blksize;
946 else
947 st->cipherblk = 8;
948 if (st->cipherblk < 8)
949 st->cipherblk = 8;
950
951 if (ssh->pktin.maxlen < st->cipherblk) {
952 ssh->pktin.maxlen = st->cipherblk;
953 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
954 unsigned char);
955 }
956
957 /*
958 * Acquire and decrypt the first block of the packet. This will
959 * contain the length and padding details.
960 */
961 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
962 while ((*datalen) == 0)
963 crReturn(st->cipherblk - st->i);
964 ssh->pktin.data[st->i] = *(*data)++;
965 (*datalen)--;
966 }
967
968 if (ssh->sccipher)
969 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
970 ssh->pktin.data, st->cipherblk);
971
972 /*
973 * Now get the length and padding figures.
974 */
975 st->len = GET_32BIT(ssh->pktin.data);
976 st->pad = ssh->pktin.data[4];
977
978 /*
979 * _Completely_ silly lengths should be stomped on before they
980 * do us any more damage.
981 */
982 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
983 bombout(("Incoming packet was garbled on decryption"));
984 crReturn(0);
985 }
986
987 /*
988 * This enables us to deduce the payload length.
989 */
990 st->payload = st->len - st->pad - 1;
991
992 ssh->pktin.length = st->payload + 5;
993
994 /*
995 * So now we can work out the total packet length.
996 */
997 st->packetlen = st->len + 4;
998 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
999
1000 /*
1001 * Adjust memory allocation if packet is too big.
1002 */
1003 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1004 ssh->pktin.maxlen = st->packetlen + st->maclen;
1005 ssh->pktin.data = sresize(ssh->pktin.data,
1006 ssh->pktin.maxlen + APIEXTRA,
1007 unsigned char);
1008 }
1009
1010 /*
1011 * Read and decrypt the remainder of the packet.
1012 */
1013 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1014 st->i++) {
1015 while ((*datalen) == 0)
1016 crReturn(st->packetlen + st->maclen - st->i);
1017 ssh->pktin.data[st->i] = *(*data)++;
1018 (*datalen)--;
1019 }
1020 /* Decrypt everything _except_ the MAC. */
1021 if (ssh->sccipher)
1022 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1023 ssh->pktin.data + st->cipherblk,
1024 st->packetlen - st->cipherblk);
1025
1026 /*
1027 * Check the MAC.
1028 */
1029 if (ssh->scmac
1030 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1031 st->incoming_sequence)) {
1032 bombout(("Incorrect MAC received on packet"));
1033 crReturn(0);
1034 }
1035 st->incoming_sequence++; /* whether or not we MACed */
1036
1037 /*
1038 * Decompress packet payload.
1039 */
1040 {
1041 unsigned char *newpayload;
1042 int newlen;
1043 if (ssh->sccomp &&
1044 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1045 ssh->pktin.data + 5, ssh->pktin.length - 5,
1046 &newpayload, &newlen)) {
1047 if (ssh->pktin.maxlen < newlen + 5) {
1048 ssh->pktin.maxlen = newlen + 5;
1049 ssh->pktin.data = sresize(ssh->pktin.data,
1050 ssh->pktin.maxlen + APIEXTRA,
1051 unsigned char);
1052 }
1053 ssh->pktin.length = 5 + newlen;
1054 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1055 sfree(newpayload);
1056 }
1057 }
1058
1059 ssh->pktin.savedpos = 6;
1060 ssh->pktin.type = ssh->pktin.data[5];
1061
1062 if (ssh->logctx)
1063 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1064 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1065 ssh->pktin.data+6, ssh->pktin.length-6);
1066
1067 switch (ssh->pktin.type) {
1068 /*
1069 * These packets we must handle instantly.
1070 */
1071 case SSH2_MSG_DISCONNECT:
1072 {
1073 /* log reason code in disconnect message */
1074 char *buf;
1075 int nowlen;
1076 int reason = GET_32BIT(ssh->pktin.data + 6);
1077 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1078
1079 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1080 buf = dupprintf("Received disconnect message (%s)",
1081 ssh2_disconnect_reasons[reason]);
1082 } else {
1083 buf = dupprintf("Received disconnect message (unknown"
1084 " type %d)", reason);
1085 }
1086 logevent(buf);
1087 sfree(buf);
1088 buf = dupprintf("Disconnection message text: %n%.*s",
1089 &nowlen, msglen, ssh->pktin.data + 14);
1090 logevent(buf);
1091 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1092 reason,
1093 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1094 ssh2_disconnect_reasons[reason] : "unknown",
1095 buf+nowlen));
1096 sfree(buf);
1097 crReturn(0);
1098 }
1099 break;
1100 case SSH2_MSG_IGNORE:
1101 goto next_packet;
1102 case SSH2_MSG_DEBUG:
1103 {
1104 /* log the debug message */
1105 char buf[512];
1106 /* int display = ssh->pktin.body[6]; */
1107 int stringlen = GET_32BIT(ssh->pktin.data+7);
1108 int prefix;
1109 strcpy(buf, "Remote debug message: ");
1110 prefix = strlen(buf);
1111 if (stringlen > (int)(sizeof(buf)-prefix-1))
1112 stringlen = sizeof(buf)-prefix-1;
1113 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1114 buf[prefix + stringlen] = '\0';
1115 logevent(buf);
1116 }
1117 goto next_packet; /* FIXME: print the debug message */
1118
1119 /*
1120 * These packets we need do nothing about here.
1121 */
1122 case SSH2_MSG_UNIMPLEMENTED:
1123 case SSH2_MSG_SERVICE_REQUEST:
1124 case SSH2_MSG_SERVICE_ACCEPT:
1125 case SSH2_MSG_KEXINIT:
1126 case SSH2_MSG_NEWKEYS:
1127 case SSH2_MSG_KEXDH_INIT:
1128 case SSH2_MSG_KEXDH_REPLY:
1129 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1130 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1131 case SSH2_MSG_KEX_DH_GEX_INIT:
1132 case SSH2_MSG_KEX_DH_GEX_REPLY:
1133 case SSH2_MSG_USERAUTH_REQUEST:
1134 case SSH2_MSG_USERAUTH_FAILURE:
1135 case SSH2_MSG_USERAUTH_SUCCESS:
1136 case SSH2_MSG_USERAUTH_BANNER:
1137 case SSH2_MSG_USERAUTH_PK_OK:
1138 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1139 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1140 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1141 case SSH2_MSG_GLOBAL_REQUEST:
1142 case SSH2_MSG_REQUEST_SUCCESS:
1143 case SSH2_MSG_REQUEST_FAILURE:
1144 case SSH2_MSG_CHANNEL_OPEN:
1145 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1146 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1147 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1148 case SSH2_MSG_CHANNEL_DATA:
1149 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1150 case SSH2_MSG_CHANNEL_EOF:
1151 case SSH2_MSG_CHANNEL_CLOSE:
1152 case SSH2_MSG_CHANNEL_REQUEST:
1153 case SSH2_MSG_CHANNEL_SUCCESS:
1154 case SSH2_MSG_CHANNEL_FAILURE:
1155 break;
1156
1157 /*
1158 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1159 */
1160 default:
1161 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1162 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1163 ssh2_pkt_send(ssh);
1164 break;
1165 }
1166
1167 crFinish(0);
1168 }
1169
1170 static void ssh1_pktout_size(Ssh ssh, int len)
1171 {
1172 int pad, biglen;
1173
1174 len += 5; /* type and CRC */
1175 pad = 8 - (len % 8);
1176 biglen = len + pad;
1177
1178 ssh->pktout.length = len - 5;
1179 if (ssh->pktout.maxlen < biglen) {
1180 ssh->pktout.maxlen = biglen;
1181 #ifdef MSCRYPTOAPI
1182 /* Allocate enough buffer space for extra block
1183 * for MS CryptEncrypt() */
1184 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1185 unsigned char);
1186 #else
1187 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1188 unsigned char);
1189 #endif
1190 }
1191 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1192 }
1193
1194 static void s_wrpkt_start(Ssh ssh, int type, int len)
1195 {
1196 ssh1_pktout_size(ssh, len);
1197 ssh->pktout.type = type;
1198 }
1199
1200 static int s_wrpkt_prepare(Ssh ssh)
1201 {
1202 int pad, biglen, i;
1203 unsigned long crc;
1204 #ifdef __SC__
1205 /*
1206 * XXX various versions of SC (including 8.8.4) screw up the
1207 * register allocation in this function and use the same register
1208 * (D6) for len and as a temporary, with predictable results. The
1209 * following sledgehammer prevents this.
1210 */
1211 volatile
1212 #endif
1213 int len;
1214
1215 ssh->pktout.body[-1] = ssh->pktout.type;
1216
1217 if (ssh->logctx)
1218 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1219 ssh1_pkt_type(ssh->pktout.type),
1220 ssh->pktout.body, ssh->pktout.length);
1221
1222 if (ssh->v1_compressing) {
1223 unsigned char *compblk;
1224 int complen;
1225 zlib_compress_block(ssh->cs_comp_ctx,
1226 ssh->pktout.body - 1, ssh->pktout.length + 1,
1227 &compblk, &complen);
1228 ssh1_pktout_size(ssh, complen - 1);
1229 memcpy(ssh->pktout.body - 1, compblk, complen);
1230 sfree(compblk);
1231 }
1232
1233 len = ssh->pktout.length + 5; /* type and CRC */
1234 pad = 8 - (len % 8);
1235 biglen = len + pad;
1236
1237 for (i = 0; i < pad; i++)
1238 ssh->pktout.data[i + 4] = random_byte();
1239 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1240 PUT_32BIT(ssh->pktout.data + biglen, crc);
1241 PUT_32BIT(ssh->pktout.data, len);
1242
1243 if (ssh->cipher)
1244 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1245
1246 return biglen + 4;
1247 }
1248
1249 static void s_wrpkt(Ssh ssh)
1250 {
1251 int len, backlog;
1252 len = s_wrpkt_prepare(ssh);
1253 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1254 if (backlog > SSH_MAX_BACKLOG)
1255 ssh_throttle_all(ssh, 1, backlog);
1256 }
1257
1258 static void s_wrpkt_defer(Ssh ssh)
1259 {
1260 int len;
1261 len = s_wrpkt_prepare(ssh);
1262 if (ssh->deferred_len + len > ssh->deferred_size) {
1263 ssh->deferred_size = ssh->deferred_len + len + 128;
1264 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1265 ssh->deferred_size,
1266 unsigned char);
1267 }
1268 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1269 ssh->deferred_len += len;
1270 }
1271
1272 /*
1273 * Construct a packet with the specified contents.
1274 */
1275 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1276 {
1277 unsigned char *p, *argp, argchar;
1278 unsigned long argint;
1279 int pktlen, argtype, arglen;
1280 Bignum bn;
1281
1282 pktlen = 0;
1283 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1284 switch (argtype) {
1285 case PKT_INT:
1286 (void) va_arg(ap1, int);
1287 pktlen += 4;
1288 break;
1289 case PKT_CHAR:
1290 (void) va_arg(ap1, int);
1291 pktlen++;
1292 break;
1293 case PKT_DATA:
1294 (void) va_arg(ap1, unsigned char *);
1295 arglen = va_arg(ap1, int);
1296 pktlen += arglen;
1297 break;
1298 case PKT_STR:
1299 argp = va_arg(ap1, unsigned char *);
1300 arglen = strlen((char *)argp);
1301 pktlen += 4 + arglen;
1302 break;
1303 case PKT_BIGNUM:
1304 bn = va_arg(ap1, Bignum);
1305 pktlen += ssh1_bignum_length(bn);
1306 break;
1307 default:
1308 assert(0);
1309 }
1310 }
1311
1312 s_wrpkt_start(ssh, pkttype, pktlen);
1313 p = ssh->pktout.body;
1314
1315 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1316 switch (argtype) {
1317 case PKT_INT:
1318 argint = va_arg(ap2, int);
1319 PUT_32BIT(p, argint);
1320 p += 4;
1321 break;
1322 case PKT_CHAR:
1323 argchar = (unsigned char) va_arg(ap2, int);
1324 *p = argchar;
1325 p++;
1326 break;
1327 case PKT_DATA:
1328 argp = va_arg(ap2, unsigned char *);
1329 arglen = va_arg(ap2, int);
1330 memcpy(p, argp, arglen);
1331 p += arglen;
1332 break;
1333 case PKT_STR:
1334 argp = va_arg(ap2, unsigned char *);
1335 arglen = strlen((char *)argp);
1336 PUT_32BIT(p, arglen);
1337 memcpy(p + 4, argp, arglen);
1338 p += 4 + arglen;
1339 break;
1340 case PKT_BIGNUM:
1341 bn = va_arg(ap2, Bignum);
1342 p += ssh1_write_bignum(p, bn);
1343 break;
1344 }
1345 }
1346 }
1347
1348 static void send_packet(Ssh ssh, int pkttype, ...)
1349 {
1350 va_list ap1, ap2;
1351 va_start(ap1, pkttype);
1352 va_start(ap2, pkttype);
1353 construct_packet(ssh, pkttype, ap1, ap2);
1354 s_wrpkt(ssh);
1355 }
1356
1357 static void defer_packet(Ssh ssh, int pkttype, ...)
1358 {
1359 va_list ap1, ap2;
1360 va_start(ap1, pkttype);
1361 va_start(ap2, pkttype);
1362 construct_packet(ssh, pkttype, ap1, ap2);
1363 s_wrpkt_defer(ssh);
1364 }
1365
1366 static int ssh_versioncmp(char *a, char *b)
1367 {
1368 char *ae, *be;
1369 unsigned long av, bv;
1370
1371 av = strtoul(a, &ae, 10);
1372 bv = strtoul(b, &be, 10);
1373 if (av != bv)
1374 return (av < bv ? -1 : +1);
1375 if (*ae == '.')
1376 ae++;
1377 if (*be == '.')
1378 be++;
1379 av = strtoul(ae, &ae, 10);
1380 bv = strtoul(be, &be, 10);
1381 if (av != bv)
1382 return (av < bv ? -1 : +1);
1383 return 0;
1384 }
1385
1386 /*
1387 * Utility routines for putting an SSH-protocol `string' and
1388 * `uint32' into a SHA state.
1389 */
1390 #include <stdio.h>
1391 static void sha_string(SHA_State * s, void *str, int len)
1392 {
1393 unsigned char lenblk[4];
1394 PUT_32BIT(lenblk, len);
1395 SHA_Bytes(s, lenblk, 4);
1396 SHA_Bytes(s, str, len);
1397 }
1398
1399 static void sha_uint32(SHA_State * s, unsigned i)
1400 {
1401 unsigned char intblk[4];
1402 PUT_32BIT(intblk, i);
1403 SHA_Bytes(s, intblk, 4);
1404 }
1405
1406 /*
1407 * SSH2 packet construction functions.
1408 */
1409 static void ssh2_pkt_ensure(Ssh ssh, int length)
1410 {
1411 if (ssh->pktout.maxlen < length) {
1412 ssh->pktout.maxlen = length + 256;
1413 ssh->pktout.data = sresize(ssh->pktout.data,
1414 ssh->pktout.maxlen + APIEXTRA,
1415 unsigned char);
1416 if (!ssh->pktout.data)
1417 fatalbox("Out of memory");
1418 }
1419 }
1420 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1421 {
1422 ssh->pktout.length += len;
1423 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1424 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1425 }
1426 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1427 {
1428 ssh2_pkt_adddata(ssh, &byte, 1);
1429 }
1430 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1431 {
1432 ssh->pktout.length = 5;
1433 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1434 }
1435 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1436 {
1437 ssh2_pkt_adddata(ssh, &value, 1);
1438 }
1439 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1440 {
1441 unsigned char x[4];
1442 PUT_32BIT(x, value);
1443 ssh2_pkt_adddata(ssh, x, 4);
1444 }
1445 static void ssh2_pkt_addstring_start(Ssh ssh)
1446 {
1447 ssh2_pkt_adduint32(ssh, 0);
1448 ssh->pktout.savedpos = ssh->pktout.length;
1449 }
1450 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1451 {
1452 ssh2_pkt_adddata(ssh, data, strlen(data));
1453 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1454 ssh->pktout.length - ssh->pktout.savedpos);
1455 }
1456 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1457 {
1458 ssh2_pkt_adddata(ssh, data, len);
1459 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1460 ssh->pktout.length - ssh->pktout.savedpos);
1461 }
1462 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1463 {
1464 ssh2_pkt_addstring_start(ssh);
1465 ssh2_pkt_addstring_str(ssh, data);
1466 }
1467 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1468 {
1469 unsigned char *p;
1470 int i, n = (bignum_bitcount(b) + 7) / 8;
1471 p = snewn(n + 1, unsigned char);
1472 if (!p)
1473 fatalbox("out of memory");
1474 p[0] = 0;
1475 for (i = 1; i <= n; i++)
1476 p[i] = bignum_byte(b, n - i);
1477 i = 0;
1478 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1479 i++;
1480 memmove(p, p + i, n + 1 - i);
1481 *len = n + 1 - i;
1482 return p;
1483 }
1484 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1485 {
1486 unsigned char *p;
1487 int len;
1488 p = ssh2_mpint_fmt(b, &len);
1489 ssh2_pkt_addstring_start(ssh);
1490 ssh2_pkt_addstring_data(ssh, (char *)p, len);
1491 sfree(p);
1492 }
1493
1494 /*
1495 * Construct an SSH2 final-form packet: compress it, encrypt it,
1496 * put the MAC on it. Final packet, ready to be sent, is stored in
1497 * ssh->pktout.data. Total length is returned.
1498 */
1499 static int ssh2_pkt_construct(Ssh ssh)
1500 {
1501 int cipherblk, maclen, padding, i;
1502
1503 if (ssh->logctx)
1504 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1505 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1506 ssh->pktout.data + 6, ssh->pktout.length - 6);
1507
1508 /*
1509 * Compress packet payload.
1510 */
1511 {
1512 unsigned char *newpayload;
1513 int newlen;
1514 if (ssh->cscomp &&
1515 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1516 ssh->pktout.length - 5,
1517 &newpayload, &newlen)) {
1518 ssh->pktout.length = 5;
1519 ssh2_pkt_adddata(ssh, newpayload, newlen);
1520 sfree(newpayload);
1521 }
1522 }
1523
1524 /*
1525 * Add padding. At least four bytes, and must also bring total
1526 * length (minus MAC) up to a multiple of the block size.
1527 */
1528 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1529 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1530 padding = 4;
1531 padding +=
1532 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1533 maclen = ssh->csmac ? ssh->csmac->len : 0;
1534 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1535 ssh->pktout.data[4] = padding;
1536 for (i = 0; i < padding; i++)
1537 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1538 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1539 if (ssh->csmac)
1540 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1541 ssh->pktout.length + padding,
1542 ssh->v2_outgoing_sequence);
1543 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1544
1545 if (ssh->cscipher)
1546 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1547 ssh->pktout.data, ssh->pktout.length + padding);
1548
1549 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1550 return ssh->pktout.length + padding + maclen;
1551 }
1552
1553 /*
1554 * Construct and send an SSH2 packet immediately.
1555 */
1556 static void ssh2_pkt_send(Ssh ssh)
1557 {
1558 int len;
1559 int backlog;
1560 len = ssh2_pkt_construct(ssh);
1561 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1562 if (backlog > SSH_MAX_BACKLOG)
1563 ssh_throttle_all(ssh, 1, backlog);
1564 }
1565
1566 /*
1567 * Construct an SSH2 packet and add it to a deferred data block.
1568 * Useful for sending multiple packets in a single sk_write() call,
1569 * to prevent a traffic-analysing listener from being able to work
1570 * out the length of any particular packet (such as the password
1571 * packet).
1572 *
1573 * Note that because SSH2 sequence-numbers its packets, this can
1574 * NOT be used as an m4-style `defer' allowing packets to be
1575 * constructed in one order and sent in another.
1576 */
1577 static void ssh2_pkt_defer(Ssh ssh)
1578 {
1579 int len = ssh2_pkt_construct(ssh);
1580 if (ssh->deferred_len + len > ssh->deferred_size) {
1581 ssh->deferred_size = ssh->deferred_len + len + 128;
1582 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1583 ssh->deferred_size,
1584 unsigned char);
1585 }
1586 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1587 ssh->deferred_len += len;
1588 }
1589
1590 /*
1591 * Send the whole deferred data block constructed by
1592 * ssh2_pkt_defer() or SSH1's defer_packet().
1593 */
1594 static void ssh_pkt_defersend(Ssh ssh)
1595 {
1596 int backlog;
1597 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1598 ssh->deferred_len);
1599 ssh->deferred_len = ssh->deferred_size = 0;
1600 sfree(ssh->deferred_send_data);
1601 ssh->deferred_send_data = NULL;
1602 if (backlog > SSH_MAX_BACKLOG)
1603 ssh_throttle_all(ssh, 1, backlog);
1604 }
1605
1606 #if 0
1607 void bndebug(char *string, Bignum b)
1608 {
1609 unsigned char *p;
1610 int i, len;
1611 p = ssh2_mpint_fmt(b, &len);
1612 debug(("%s", string));
1613 for (i = 0; i < len; i++)
1614 debug((" %02x", p[i]));
1615 debug(("\n"));
1616 sfree(p);
1617 }
1618 #endif
1619
1620 static void sha_mpint(SHA_State * s, Bignum b)
1621 {
1622 unsigned char *p;
1623 int len;
1624 p = ssh2_mpint_fmt(b, &len);
1625 sha_string(s, p, len);
1626 sfree(p);
1627 }
1628
1629 /*
1630 * SSH2 packet decode functions.
1631 */
1632 static unsigned long ssh2_pkt_getuint32(Ssh ssh)
1633 {
1634 unsigned long value;
1635 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1636 return 0; /* arrgh, no way to decline (FIXME?) */
1637 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1638 ssh->pktin.savedpos += 4;
1639 return value;
1640 }
1641 static int ssh2_pkt_getbool(Ssh ssh)
1642 {
1643 unsigned long value;
1644 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1645 return 0; /* arrgh, no way to decline (FIXME?) */
1646 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1647 ssh->pktin.savedpos++;
1648 return value;
1649 }
1650 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
1651 {
1652 int len;
1653 *p = NULL;
1654 *length = 0;
1655 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1656 return;
1657 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1658 if (len < 0)
1659 return;
1660 *length = len;
1661 ssh->pktin.savedpos += 4;
1662 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1663 return;
1664 *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos);
1665 ssh->pktin.savedpos += *length;
1666 }
1667 static Bignum ssh2_pkt_getmp(Ssh ssh)
1668 {
1669 char *p;
1670 int length;
1671 Bignum b;
1672
1673 ssh2_pkt_getstring(ssh, &p, &length);
1674 if (!p)
1675 return NULL;
1676 if (p[0] & 0x80) {
1677 bombout(("internal error: Can't handle negative mpints"));
1678 return NULL;
1679 }
1680 b = bignum_from_bytes((unsigned char *)p, length);
1681 return b;
1682 }
1683
1684 /*
1685 * Helper function to add an SSH2 signature blob to a packet.
1686 * Expects to be shown the public key blob as well as the signature
1687 * blob. Normally works just like ssh2_pkt_addstring, but will
1688 * fiddle with the signature packet if necessary for
1689 * BUG_SSH2_RSA_PADDING.
1690 */
1691 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1692 void *sigblob_v, int sigblob_len)
1693 {
1694 unsigned char *pkblob = (unsigned char *)pkblob_v;
1695 unsigned char *sigblob = (unsigned char *)sigblob_v;
1696
1697 /* dmemdump(pkblob, pkblob_len); */
1698 /* dmemdump(sigblob, sigblob_len); */
1699
1700 /*
1701 * See if this is in fact an ssh-rsa signature and a buggy
1702 * server; otherwise we can just do this the easy way.
1703 */
1704 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1705 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1706 int pos, len, siglen;
1707
1708 /*
1709 * Find the byte length of the modulus.
1710 */
1711
1712 pos = 4+7; /* skip over "ssh-rsa" */
1713 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1714 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1715 pos += 4; /* find modulus itself */
1716 while (len > 0 && pkblob[pos] == 0)
1717 len--, pos++;
1718 /* debug(("modulus length is %d\n", len)); */
1719
1720 /*
1721 * Now find the signature integer.
1722 */
1723 pos = 4+7; /* skip over "ssh-rsa" */
1724 siglen = GET_32BIT(sigblob+pos);
1725 /* debug(("signature length is %d\n", siglen)); */
1726
1727 if (len != siglen) {
1728 unsigned char newlen[4];
1729 ssh2_pkt_addstring_start(ssh);
1730 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1731 /* dmemdump(sigblob, pos); */
1732 pos += 4; /* point to start of actual sig */
1733 PUT_32BIT(newlen, len);
1734 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1735 /* dmemdump(newlen, 4); */
1736 newlen[0] = 0;
1737 while (len-- > siglen) {
1738 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1739 /* dmemdump(newlen, 1); */
1740 }
1741 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1742 /* dmemdump(sigblob+pos, siglen); */
1743 return;
1744 }
1745
1746 /* Otherwise fall through and do it the easy way. */
1747 }
1748
1749 ssh2_pkt_addstring_start(ssh);
1750 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1751 }
1752
1753 /*
1754 * Examine the remote side's version string and compare it against
1755 * a list of known buggy implementations.
1756 */
1757 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1758 {
1759 char *imp; /* pointer to implementation part */
1760 imp = vstring;
1761 imp += strcspn(imp, "-");
1762 if (*imp) imp++;
1763 imp += strcspn(imp, "-");
1764 if (*imp) imp++;
1765
1766 ssh->remote_bugs = 0;
1767
1768 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1769 (ssh->cfg.sshbug_ignore1 == AUTO &&
1770 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1771 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1772 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
1773 /*
1774 * These versions don't support SSH1_MSG_IGNORE, so we have
1775 * to use a different defence against password length
1776 * sniffing.
1777 */
1778 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1779 logevent("We believe remote version has SSH1 ignore bug");
1780 }
1781
1782 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1783 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1784 (!strcmp(imp, "Cisco-1.25")))) {
1785 /*
1786 * These versions need a plain password sent; they can't
1787 * handle having a null and a random length of data after
1788 * the password.
1789 */
1790 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1791 logevent("We believe remote version needs a plain SSH1 password");
1792 }
1793
1794 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1795 (ssh->cfg.sshbug_rsa1 == AUTO &&
1796 (!strcmp(imp, "Cisco-1.25")))) {
1797 /*
1798 * These versions apparently have no clue whatever about
1799 * RSA authentication and will panic and die if they see
1800 * an AUTH_RSA message.
1801 */
1802 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1803 logevent("We believe remote version can't handle RSA authentication");
1804 }
1805
1806 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1807 (ssh->cfg.sshbug_hmac2 == AUTO &&
1808 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1809 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1810 wc_match("2.1 *", imp)))) {
1811 /*
1812 * These versions have the HMAC bug.
1813 */
1814 ssh->remote_bugs |= BUG_SSH2_HMAC;
1815 logevent("We believe remote version has SSH2 HMAC bug");
1816 }
1817
1818 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
1819 (ssh->cfg.sshbug_derivekey2 == AUTO &&
1820 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
1821 /*
1822 * These versions have the key-derivation bug (failing to
1823 * include the literal shared secret in the hashes that
1824 * generate the keys).
1825 */
1826 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1827 logevent("We believe remote version has SSH2 key-derivation bug");
1828 }
1829
1830 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
1831 (ssh->cfg.sshbug_rsapad2 == AUTO &&
1832 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1833 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1834 /*
1835 * These versions have the SSH2 RSA padding bug.
1836 */
1837 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1838 logevent("We believe remote version has SSH2 RSA padding bug");
1839 }
1840
1841 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
1842 (ssh->cfg.sshbug_pksessid2 == AUTO &&
1843 wc_match("OpenSSH_2.[0-2]*", imp))) {
1844 /*
1845 * These versions have the SSH2 session-ID bug in
1846 * public-key authentication.
1847 */
1848 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
1849 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1850 }
1851
1852 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
1853 /*
1854 * User specified the SSH2 DH GEX bug.
1855 */
1856 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1857 logevent("We believe remote version has SSH2 DH group exchange bug");
1858 }
1859 }
1860
1861 static int do_ssh_init(Ssh ssh, unsigned char c)
1862 {
1863 struct do_ssh_init_state {
1864 int vslen;
1865 char version[10];
1866 char *vstring;
1867 int vstrsize;
1868 int i;
1869 int proto1, proto2;
1870 };
1871 crState(do_ssh_init_state);
1872
1873 crBegin(ssh->do_ssh_init_crstate);
1874
1875 /* Search for the string "SSH-" in the input. */
1876 s->i = 0;
1877 while (1) {
1878 static const int transS[] = { 1, 2, 2, 1 };
1879 static const int transH[] = { 0, 0, 3, 0 };
1880 static const int transminus[] = { 0, 0, 0, -1 };
1881 if (c == 'S')
1882 s->i = transS[s->i];
1883 else if (c == 'H')
1884 s->i = transH[s->i];
1885 else if (c == '-')
1886 s->i = transminus[s->i];
1887 else
1888 s->i = 0;
1889 if (s->i < 0)
1890 break;
1891 crReturn(1); /* get another character */
1892 }
1893
1894 s->vstrsize = 16;
1895 s->vstring = snewn(s->vstrsize, char);
1896 strcpy(s->vstring, "SSH-");
1897 s->vslen = 4;
1898 s->i = 0;
1899 while (1) {
1900 crReturn(1); /* get another char */
1901 if (s->vslen >= s->vstrsize - 1) {
1902 s->vstrsize += 16;
1903 s->vstring = sresize(s->vstring, s->vstrsize, char);
1904 }
1905 s->vstring[s->vslen++] = c;
1906 if (s->i >= 0) {
1907 if (c == '-') {
1908 s->version[s->i] = '\0';
1909 s->i = -1;
1910 } else if (s->i < sizeof(s->version) - 1)
1911 s->version[s->i++] = c;
1912 } else if (c == '\012')
1913 break;
1914 }
1915
1916 ssh->agentfwd_enabled = FALSE;
1917 ssh->rdpkt2_state.incoming_sequence = 0;
1918
1919 s->vstring[s->vslen] = 0;
1920 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1921 {
1922 char *vlog;
1923 vlog = snewn(20 + s->vslen, char);
1924 sprintf(vlog, "Server version: %s", s->vstring);
1925 logevent(vlog);
1926 sfree(vlog);
1927 }
1928 ssh_detect_bugs(ssh, s->vstring);
1929
1930 /*
1931 * Decide which SSH protocol version to support.
1932 */
1933
1934 /* Anything strictly below "2.0" means protocol 1 is supported. */
1935 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1936 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1937 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1938
1939 if (ssh->cfg.sshprot == 0 && !s->proto1) {
1940 bombout(("SSH protocol version 1 required by user but not provided by server"));
1941 crReturn(0);
1942 }
1943 if (ssh->cfg.sshprot == 3 && !s->proto2) {
1944 bombout(("SSH protocol version 2 required by user but not provided by server"));
1945 crReturn(0);
1946 }
1947
1948 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
1949 /*
1950 * Use v2 protocol.
1951 */
1952 char verstring[80], vlog[100];
1953 sprintf(verstring, "SSH-2.0-%s", sshver);
1954 SHA_Init(&ssh->exhashbase);
1955 /*
1956 * Hash our version string and their version string.
1957 */
1958 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1959 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
1960 sprintf(vlog, "We claim version: %s", verstring);
1961 logevent(vlog);
1962 strcat(verstring, "\012");
1963 logevent("Using SSH protocol version 2");
1964 sk_write(ssh->s, verstring, strlen(verstring));
1965 ssh->protocol = ssh2_protocol;
1966 ssh->version = 2;
1967 ssh->s_rdpkt = ssh2_rdpkt;
1968 } else {
1969 /*
1970 * Use v1 protocol.
1971 */
1972 char verstring[80], vlog[100];
1973 sprintf(verstring, "SSH-%s-%s",
1974 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
1975 sshver);
1976 sprintf(vlog, "We claim version: %s", verstring);
1977 logevent(vlog);
1978 strcat(verstring, "\012");
1979
1980 logevent("Using SSH protocol version 1");
1981 sk_write(ssh->s, verstring, strlen(verstring));
1982 ssh->protocol = ssh1_protocol;
1983 ssh->version = 1;
1984 ssh->s_rdpkt = ssh1_rdpkt;
1985 }
1986 update_specials_menu(ssh->frontend);
1987 ssh->state = SSH_STATE_BEFORE_SIZE;
1988
1989 sfree(s->vstring);
1990
1991 crFinish(0);
1992 }
1993
1994 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
1995 {
1996 crBegin(ssh->ssh_gotdata_crstate);
1997
1998 /*
1999 * To begin with, feed the characters one by one to the
2000 * protocol initialisation / selection function do_ssh_init().
2001 * When that returns 0, we're done with the initial greeting
2002 * exchange and can move on to packet discipline.
2003 */
2004 while (1) {
2005 int ret; /* need not be kept across crReturn */
2006 if (datalen == 0)
2007 crReturnV; /* more data please */
2008 ret = do_ssh_init(ssh, *data);
2009 data++;
2010 datalen--;
2011 if (ret == 0)
2012 break;
2013 }
2014
2015 /*
2016 * We emerge from that loop when the initial negotiation is
2017 * over and we have selected an s_rdpkt function. Now pass
2018 * everything to s_rdpkt, and then pass the resulting packets
2019 * to the proper protocol handler.
2020 */
2021 if (datalen == 0)
2022 crReturnV;
2023 while (1) {
2024 while (datalen > 0) {
2025 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2026 if (ssh->state == SSH_STATE_CLOSED) {
2027 return;
2028 }
2029 ssh->protocol(ssh, NULL, 0, 1);
2030 if (ssh->state == SSH_STATE_CLOSED) {
2031 return;
2032 }
2033 }
2034 }
2035 crReturnV;
2036 }
2037 crFinishV;
2038 }
2039
2040 static int ssh_closing(Plug plug, char *error_msg, int error_code,
2041 int calling_back)
2042 {
2043 Ssh ssh = (Ssh) plug;
2044 ssh->state = SSH_STATE_CLOSED;
2045 if (ssh->s) {
2046 sk_close(ssh->s);
2047 ssh->s = NULL;
2048 }
2049 if (error_msg) {
2050 /* A socket error has occurred. */
2051 logevent(error_msg);
2052 connection_fatal(ssh->frontend, error_msg);
2053 } else {
2054 /* Otherwise, the remote side closed the connection normally. */
2055 }
2056 return 0;
2057 }
2058
2059 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2060 {
2061 Ssh ssh = (Ssh) plug;
2062 ssh_gotdata(ssh, (unsigned char *)data, len);
2063 if (ssh->state == SSH_STATE_CLOSED) {
2064 if (ssh->s) {
2065 sk_close(ssh->s);
2066 ssh->s = NULL;
2067 }
2068 return 0;
2069 }
2070 return 1;
2071 }
2072
2073 static void ssh_sent(Plug plug, int bufsize)
2074 {
2075 Ssh ssh = (Ssh) plug;
2076 /*
2077 * If the send backlog on the SSH socket itself clears, we
2078 * should unthrottle the whole world if it was throttled.
2079 */
2080 if (bufsize < SSH_MAX_BACKLOG)
2081 ssh_throttle_all(ssh, 0, bufsize);
2082 }
2083
2084 /*
2085 * Connect to specified host and port.
2086 * Returns an error message, or NULL on success.
2087 * Also places the canonical host name into `realhost'. It must be
2088 * freed by the caller.
2089 */
2090 static char *connect_to_host(Ssh ssh, char *host, int port,
2091 char **realhost, int nodelay)
2092 {
2093 static const struct plug_function_table fn_table = {
2094 ssh_closing,
2095 ssh_receive,
2096 ssh_sent,
2097 NULL
2098 };
2099
2100 SockAddr addr;
2101 char *err;
2102
2103 ssh->savedhost = snewn(1 + strlen(host), char);
2104 if (!ssh->savedhost)
2105 fatalbox("Out of memory");
2106 strcpy(ssh->savedhost, host);
2107
2108 if (port < 0)
2109 port = 22; /* default ssh port */
2110 ssh->savedport = port;
2111
2112 /*
2113 * Try to find host.
2114 */
2115 logeventf(ssh, "Looking up host \"%s\"", host);
2116 addr = name_lookup(host, port, realhost, &ssh->cfg);
2117 if ((err = sk_addr_error(addr)) != NULL)
2118 return err;
2119
2120 /*
2121 * Open socket.
2122 */
2123 {
2124 char addrbuf[100];
2125 sk_getaddr(addr, addrbuf, 100);
2126 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2127 }
2128 ssh->fn = &fn_table;
2129 ssh->s = new_connection(addr, *realhost, port,
2130 0, 1, nodelay, (Plug) ssh, &ssh->cfg);
2131 if ((err = sk_socket_error(ssh->s)) != NULL) {
2132 ssh->s = NULL;
2133 return err;
2134 }
2135
2136 return NULL;
2137 }
2138
2139 /*
2140 * Throttle or unthrottle the SSH connection.
2141 */
2142 static void ssh1_throttle(Ssh ssh, int adjust)
2143 {
2144 int old_count = ssh->v1_throttle_count;
2145 ssh->v1_throttle_count += adjust;
2146 assert(ssh->v1_throttle_count >= 0);
2147 if (ssh->v1_throttle_count && !old_count) {
2148 sk_set_frozen(ssh->s, 1);
2149 } else if (!ssh->v1_throttle_count && old_count) {
2150 sk_set_frozen(ssh->s, 0);
2151 }
2152 }
2153
2154 /*
2155 * Throttle or unthrottle _all_ local data streams (for when sends
2156 * on the SSH connection itself back up).
2157 */
2158 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2159 {
2160 int i;
2161 struct ssh_channel *c;
2162
2163 if (enable == ssh->throttled_all)
2164 return;
2165 ssh->throttled_all = enable;
2166 ssh->overall_bufsize = bufsize;
2167 if (!ssh->channels)
2168 return;
2169 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2170 switch (c->type) {
2171 case CHAN_MAINSESSION:
2172 /*
2173 * This is treated separately, outside the switch.
2174 */
2175 break;
2176 case CHAN_X11:
2177 x11_override_throttle(c->u.x11.s, enable);
2178 break;
2179 case CHAN_AGENT:
2180 /* Agent channels require no buffer management. */
2181 break;
2182 case CHAN_SOCKDATA:
2183 pfd_override_throttle(c->u.x11.s, enable);
2184 break;
2185 }
2186 }
2187 }
2188
2189 /*
2190 * Username and password input, abstracted off into routines
2191 * reusable in several places - even between SSH1 and SSH2.
2192 */
2193
2194 /* Set up a username or password input loop on a given buffer. */
2195 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2196 {
2197 ssh->userpass_input_buffer = buffer;
2198 ssh->userpass_input_buflen = buflen;
2199 ssh->userpass_input_bufpos = 0;
2200 ssh->userpass_input_echo = echo;
2201 }
2202
2203 /*
2204 * Process some terminal data in the course of username/password
2205 * input. Returns >0 for success (line of input returned in
2206 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2207 * for inconclusive (keep waiting for more input please).
2208 */
2209 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2210 {
2211 char c;
2212
2213 while (inlen--) {
2214 switch (c = *in++) {
2215 case 10:
2216 case 13:
2217 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2218 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2219 return +1;
2220 break;
2221 case 8:
2222 case 127:
2223 if (ssh->userpass_input_bufpos > 0) {
2224 if (ssh->userpass_input_echo)
2225 c_write_str(ssh, "\b \b");
2226 ssh->userpass_input_bufpos--;
2227 }
2228 break;
2229 case 21:
2230 case 27:
2231 while (ssh->userpass_input_bufpos > 0) {
2232 if (ssh->userpass_input_echo)
2233 c_write_str(ssh, "\b \b");
2234 ssh->userpass_input_bufpos--;
2235 }
2236 break;
2237 case 3:
2238 case 4:
2239 return -1;
2240 break;
2241 default:
2242 /*
2243 * This simplistic check for printability is disabled
2244 * when we're doing password input, because some people
2245 * have control characters in their passwords.o
2246 */
2247 if ((!ssh->userpass_input_echo ||
2248 (c >= ' ' && c <= '~') ||
2249 ((unsigned char) c >= 160))
2250 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2251 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2252 if (ssh->userpass_input_echo)
2253 c_write(ssh, &c, 1);
2254 }
2255 break;
2256 }
2257 }
2258 return 0;
2259 }
2260
2261 /*
2262 * Handle the key exchange and user authentication phases.
2263 */
2264 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2265 {
2266 int i, j;
2267 unsigned char cookie[8];
2268 struct RSAKey servkey, hostkey;
2269 struct MD5Context md5c;
2270 struct do_ssh1_login_state {
2271 int len;
2272 unsigned char *rsabuf, *keystr1, *keystr2;
2273 unsigned long supported_ciphers_mask, supported_auths_mask;
2274 int tried_publickey, tried_agent;
2275 int tis_auth_refused, ccard_auth_refused;
2276 unsigned char session_id[16];
2277 int cipher_type;
2278 char username[100];
2279 void *publickey_blob;
2280 int publickey_bloblen;
2281 char password[100];
2282 char prompt[200];
2283 int pos;
2284 char c;
2285 int pwpkt_type;
2286 unsigned char request[5], *response, *p;
2287 int responselen;
2288 int keyi, nkeys;
2289 int authed;
2290 struct RSAKey key;
2291 Bignum challenge;
2292 char *commentp;
2293 int commentlen;
2294 };
2295 crState(do_ssh1_login_state);
2296
2297 crBegin(ssh->do_ssh1_login_crstate);
2298
2299 if (!ispkt)
2300 crWaitUntil(ispkt);
2301
2302 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2303 bombout(("Public key packet not received"));
2304 crReturn(0);
2305 }
2306
2307 logevent("Received public keys");
2308
2309 memcpy(cookie, ssh->pktin.body, 8);
2310
2311 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2312 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2313
2314 /*
2315 * Log the host key fingerprint.
2316 */
2317 {
2318 char logmsg[80];
2319 logevent("Host key fingerprint is:");
2320 strcpy(logmsg, " ");
2321 hostkey.comment = NULL;
2322 rsa_fingerprint(logmsg + strlen(logmsg),
2323 sizeof(logmsg) - strlen(logmsg), &hostkey);
2324 logevent(logmsg);
2325 }
2326
2327 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2328 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2329 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2330
2331 ssh->v1_local_protoflags =
2332 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2333 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2334
2335 MD5Init(&md5c);
2336 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2337 MD5Update(&md5c, s->keystr1, servkey.bytes);
2338 MD5Update(&md5c, ssh->pktin.body, 8);
2339 MD5Final(s->session_id, &md5c);
2340
2341 for (i = 0; i < 32; i++)
2342 ssh->session_key[i] = random_byte();
2343
2344 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2345
2346 s->rsabuf = snewn(s->len, unsigned char);
2347 if (!s->rsabuf)
2348 fatalbox("Out of memory");
2349
2350 /*
2351 * Verify the host key.
2352 */
2353 {
2354 /*
2355 * First format the key into a string.
2356 */
2357 int len = rsastr_len(&hostkey);
2358 char fingerprint[100];
2359 char *keystr = snewn(len, char);
2360 if (!keystr)
2361 fatalbox("Out of memory");
2362 rsastr_fmt(keystr, &hostkey);
2363 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2364 verify_ssh_host_key(ssh->frontend,
2365 ssh->savedhost, ssh->savedport, "rsa", keystr,
2366 fingerprint);
2367 sfree(keystr);
2368 }
2369
2370 for (i = 0; i < 32; i++) {
2371 s->rsabuf[i] = ssh->session_key[i];
2372 if (i < 16)
2373 s->rsabuf[i] ^= s->session_id[i];
2374 }
2375
2376 if (hostkey.bytes > servkey.bytes) {
2377 rsaencrypt(s->rsabuf, 32, &servkey);
2378 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2379 } else {
2380 rsaencrypt(s->rsabuf, 32, &hostkey);
2381 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2382 }
2383
2384 logevent("Encrypted session key");
2385
2386 {
2387 int cipher_chosen = 0, warn = 0;
2388 char *cipher_string = NULL;
2389 int i;
2390 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2391 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2392 if (next_cipher == CIPHER_WARN) {
2393 /* If/when we choose a cipher, warn about it */
2394 warn = 1;
2395 } else if (next_cipher == CIPHER_AES) {
2396 /* XXX Probably don't need to mention this. */
2397 logevent("AES not supported in SSH1, skipping");
2398 } else {
2399 switch (next_cipher) {
2400 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2401 cipher_string = "3DES"; break;
2402 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2403 cipher_string = "Blowfish"; break;
2404 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2405 cipher_string = "single-DES"; break;
2406 }
2407 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2408 cipher_chosen = 1;
2409 }
2410 }
2411 if (!cipher_chosen) {
2412 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2413 bombout(("Server violates SSH 1 protocol by not "
2414 "supporting 3DES encryption"));
2415 else
2416 /* shouldn't happen */
2417 bombout(("No supported ciphers found"));
2418 crReturn(0);
2419 }
2420
2421 /* Warn about chosen cipher if necessary. */
2422 if (warn)
2423 askcipher(ssh->frontend, cipher_string, 0);
2424 }
2425
2426 switch (s->cipher_type) {
2427 case SSH_CIPHER_3DES:
2428 logevent("Using 3DES encryption");
2429 break;
2430 case SSH_CIPHER_DES:
2431 logevent("Using single-DES encryption");
2432 break;
2433 case SSH_CIPHER_BLOWFISH:
2434 logevent("Using Blowfish encryption");
2435 break;
2436 }
2437
2438 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2439 PKT_CHAR, s->cipher_type,
2440 PKT_DATA, cookie, 8,
2441 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2442 PKT_DATA, s->rsabuf, s->len,
2443 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2444
2445 logevent("Trying to enable encryption...");
2446
2447 sfree(s->rsabuf);
2448
2449 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2450 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2451 &ssh_3des);
2452 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2453 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2454 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2455
2456 ssh->crcda_ctx = crcda_make_context();
2457 logevent("Installing CRC compensation attack detector");
2458
2459 crWaitUntil(ispkt);
2460
2461 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2462 bombout(("Encryption not successfully enabled"));
2463 crReturn(0);
2464 }
2465
2466 logevent("Successfully started encryption");
2467
2468 fflush(stdout);
2469 {
2470 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
2471 if (ssh_get_line && !ssh_getline_pw_only) {
2472 if (!ssh_get_line("login as: ",
2473 s->username, sizeof(s->username), FALSE)) {
2474 /*
2475 * get_line failed to get a username.
2476 * Terminate.
2477 */
2478 logevent("No username provided. Abandoning session.");
2479 ssh_closing((Plug)ssh, NULL, 0, 0);
2480 crReturn(1);
2481 }
2482 } else {
2483 int ret; /* need not be kept over crReturn */
2484 c_write_str(ssh, "login as: ");
2485 ssh->send_ok = 1;
2486
2487 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2488 do {
2489 crWaitUntil(!ispkt);
2490 ret = process_userpass_input(ssh, in, inlen);
2491 } while (ret == 0);
2492 if (ret < 0)
2493 cleanup_exit(0);
2494 c_write_str(ssh, "\r\n");
2495 }
2496 } else {
2497 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2498 s->username[sizeof(s->username)-1] = '\0';
2499 }
2500
2501 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2502 {
2503 char userlog[22 + sizeof(s->username)];
2504 sprintf(userlog, "Sent username \"%s\"", s->username);
2505 logevent(userlog);
2506 if (flags & FLAG_INTERACTIVE &&
2507 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2508 strcat(userlog, "\r\n");
2509 c_write_str(ssh, userlog);
2510 }
2511 }
2512 }
2513
2514 crWaitUntil(ispkt);
2515
2516 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2517 /* We must not attempt PK auth. Pretend we've already tried it. */
2518 s->tried_publickey = s->tried_agent = 1;
2519 } else {
2520 s->tried_publickey = s->tried_agent = 0;
2521 }
2522 s->tis_auth_refused = s->ccard_auth_refused = 0;
2523 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2524 if (!filename_is_null(ssh->cfg.keyfile)) {
2525 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2526 &s->publickey_blob, &s->publickey_bloblen))
2527 s->publickey_blob = NULL;
2528 } else
2529 s->publickey_blob = NULL;
2530
2531 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2532 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2533
2534 if (agent_exists() && !s->tried_agent) {
2535 /*
2536 * Attempt RSA authentication using Pageant.
2537 */
2538 void *r;
2539
2540 s->authed = FALSE;
2541 s->tried_agent = 1;
2542 logevent("Pageant is running. Requesting keys.");
2543
2544 /* Request the keys held by the agent. */
2545 PUT_32BIT(s->request, 1);
2546 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2547 agent_query(s->request, 5, &r, &s->responselen);
2548 s->response = (unsigned char *) r;
2549 if (s->response && s->responselen >= 5 &&
2550 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2551 s->p = s->response + 5;
2552 s->nkeys = GET_32BIT(s->p);
2553 s->p += 4;
2554 {
2555 char buf[64];
2556 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2557 logevent(buf);
2558 }
2559 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2560 {
2561 char buf[64];
2562 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2563 logevent(buf);
2564 }
2565 if (s->publickey_blob &&
2566 !memcmp(s->p, s->publickey_blob,
2567 s->publickey_bloblen)) {
2568 logevent("This key matches configured key file");
2569 s->tried_publickey = 1;
2570 }
2571 s->p += 4;
2572 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2573 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2574 s->commentlen = GET_32BIT(s->p);
2575 s->p += 4;
2576 s->commentp = (char *)s->p;
2577 s->p += s->commentlen;
2578 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2579 PKT_BIGNUM, s->key.modulus, PKT_END);
2580 crWaitUntil(ispkt);
2581 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2582 logevent("Key refused");
2583 continue;
2584 }
2585 logevent("Received RSA challenge");
2586 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2587 {
2588 char *agentreq, *q, *ret;
2589 void *vret;
2590 int len, retlen;
2591 len = 1 + 4; /* message type, bit count */
2592 len += ssh1_bignum_length(s->key.exponent);
2593 len += ssh1_bignum_length(s->key.modulus);
2594 len += ssh1_bignum_length(s->challenge);
2595 len += 16; /* session id */
2596 len += 4; /* response format */
2597 agentreq = snewn(4 + len, char);
2598 PUT_32BIT(agentreq, len);
2599 q = agentreq + 4;
2600 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2601 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2602 q += 4;
2603 q += ssh1_write_bignum(q, s->key.exponent);
2604 q += ssh1_write_bignum(q, s->key.modulus);
2605 q += ssh1_write_bignum(q, s->challenge);
2606 memcpy(q, s->session_id, 16);
2607 q += 16;
2608 PUT_32BIT(q, 1); /* response format */
2609 agent_query(agentreq, len + 4, &vret, &retlen);
2610 ret = vret;
2611 sfree(agentreq);
2612 if (ret) {
2613 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2614 logevent("Sending Pageant's response");
2615 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2616 PKT_DATA, ret + 5, 16,
2617 PKT_END);
2618 sfree(ret);
2619 crWaitUntil(ispkt);
2620 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2621 logevent
2622 ("Pageant's response accepted");
2623 if (flags & FLAG_VERBOSE) {
2624 c_write_str(ssh, "Authenticated using"
2625 " RSA key \"");
2626 c_write(ssh, s->commentp,
2627 s->commentlen);
2628 c_write_str(ssh, "\" from agent\r\n");
2629 }
2630 s->authed = TRUE;
2631 } else
2632 logevent
2633 ("Pageant's response not accepted");
2634 } else {
2635 logevent
2636 ("Pageant failed to answer challenge");
2637 sfree(ret);
2638 }
2639 } else {
2640 logevent("No reply received from Pageant");
2641 }
2642 }
2643 freebn(s->key.exponent);
2644 freebn(s->key.modulus);
2645 freebn(s->challenge);
2646 if (s->authed)
2647 break;
2648 }
2649 }
2650 if (s->authed)
2651 break;
2652 }
2653 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
2654 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2655
2656 if (ssh->cfg.try_tis_auth &&
2657 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2658 !s->tis_auth_refused) {
2659 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2660 logevent("Requested TIS authentication");
2661 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2662 crWaitUntil(ispkt);
2663 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2664 logevent("TIS authentication declined");
2665 if (flags & FLAG_INTERACTIVE)
2666 c_write_str(ssh, "TIS authentication refused.\r\n");
2667 s->tis_auth_refused = 1;
2668 continue;
2669 } else {
2670 int challengelen = GET_32BIT(ssh->pktin.body);
2671 logevent("Received TIS challenge");
2672 if (challengelen > sizeof(s->prompt) - 1)
2673 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2674 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2675 /* Prompt heuristic comes from OpenSSH */
2676 strncpy(s->prompt + challengelen,
2677 memchr(s->prompt, '\n', challengelen) ?
2678 "": "\r\nResponse: ",
2679 (sizeof s->prompt) - challengelen);
2680 s->prompt[(sizeof s->prompt) - 1] = '\0';
2681 }
2682 }
2683 if (ssh->cfg.try_tis_auth &&
2684 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2685 !s->ccard_auth_refused) {
2686 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2687 logevent("Requested CryptoCard authentication");
2688 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2689 crWaitUntil(ispkt);
2690 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2691 logevent("CryptoCard authentication declined");
2692 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2693 s->ccard_auth_refused = 1;
2694 continue;
2695 } else {
2696 int challengelen = GET_32BIT(ssh->pktin.body);
2697 logevent("Received CryptoCard challenge");
2698 if (challengelen > sizeof(s->prompt) - 1)
2699 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2700 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2701 strncpy(s->prompt + challengelen,
2702 memchr(s->prompt, '\n', challengelen) ?
2703 "" : "\r\nResponse: ",
2704 sizeof(s->prompt) - challengelen);
2705 s->prompt[sizeof(s->prompt) - 1] = '\0';
2706 }
2707 }
2708 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2709 sprintf(s->prompt, "%.90s@%.90s's password: ",
2710 s->username, ssh->savedhost);
2711 }
2712 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2713 char *comment = NULL;
2714 int type;
2715 char msgbuf[256];
2716 if (flags & FLAG_VERBOSE)
2717 c_write_str(ssh, "Trying public key authentication.\r\n");
2718 logeventf(ssh, "Trying public key \"%s\"",
2719 filename_to_str(&ssh->cfg.keyfile));
2720 type = key_type(&ssh->cfg.keyfile);
2721 if (type != SSH_KEYTYPE_SSH1) {
2722 sprintf(msgbuf, "Key is of wrong type (%s)",
2723 key_type_to_str(type));
2724 logevent(msgbuf);
2725 c_write_str(ssh, msgbuf);
2726 c_write_str(ssh, "\r\n");
2727 s->tried_publickey = 1;
2728 continue;
2729 }
2730 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
2731 if (flags & FLAG_VERBOSE)
2732 c_write_str(ssh, "No passphrase required.\r\n");
2733 goto tryauth;
2734 }
2735 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2736 sfree(comment);
2737 }
2738
2739 /*
2740 * Show password prompt, having first obtained it via a TIS
2741 * or CryptoCard exchange if we're doing TIS or CryptoCard
2742 * authentication.
2743 */
2744 if (ssh_get_line) {
2745 if (!ssh_get_line(s->prompt, s->password,
2746 sizeof(s->password), TRUE)) {
2747 /*
2748 * get_line failed to get a password (for example
2749 * because one was supplied on the command line
2750 * which has already failed to work). Terminate.
2751 */
2752 send_packet(ssh, SSH1_MSG_DISCONNECT,
2753 PKT_STR, "No more passwords available to try",
2754 PKT_END);
2755 logevent("Unable to authenticate");
2756 connection_fatal(ssh->frontend, "Unable to authenticate");
2757 ssh_closing((Plug)ssh, NULL, 0, 0);
2758 crReturn(1);
2759 }
2760 } else {
2761 /* Prompt may have come from server. We've munged it a bit, so
2762 * we know it to be zero-terminated at least once. */
2763 int ret; /* need not be saved over crReturn */
2764 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2765 s->pos = 0;
2766
2767 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2768 do {
2769 crWaitUntil(!ispkt);
2770 ret = process_userpass_input(ssh, in, inlen);
2771 } while (ret == 0);
2772 if (ret < 0)
2773 cleanup_exit(0);
2774 c_write_str(ssh, "\r\n");
2775 }
2776
2777 tryauth:
2778 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2779 /*
2780 * Try public key authentication with the specified
2781 * key file.
2782 */
2783 s->tried_publickey = 1;
2784
2785 {
2786 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password);
2787 if (ret == 0) {
2788 c_write_str(ssh, "Couldn't load private key from ");
2789 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
2790 c_write_str(ssh, ".\r\n");
2791 continue; /* go and try password */
2792 }
2793 if (ret == -1) {
2794 c_write_str(ssh, "Wrong passphrase.\r\n");
2795 s->tried_publickey = 0;
2796 continue; /* try again */
2797 }
2798 }
2799
2800 /*
2801 * Send a public key attempt.
2802 */
2803 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2804 PKT_BIGNUM, s->key.modulus, PKT_END);
2805
2806 crWaitUntil(ispkt);
2807 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2808 c_write_str(ssh, "Server refused our public key.\r\n");
2809 continue; /* go and try password */
2810 }
2811 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2812 bombout(("Bizarre response to offer of public key"));
2813 crReturn(0);
2814 }
2815
2816 {
2817 int i;
2818 unsigned char buffer[32];
2819 Bignum challenge, response;
2820
2821 ssh1_read_bignum(ssh->pktin.body, &challenge);
2822 response = rsadecrypt(challenge, &s->key);
2823 freebn(s->key.private_exponent);/* burn the evidence */
2824
2825 for (i = 0; i < 32; i++) {
2826 buffer[i] = bignum_byte(response, 31 - i);
2827 }
2828
2829 MD5Init(&md5c);
2830 MD5Update(&md5c, buffer, 32);
2831 MD5Update(&md5c, s->session_id, 16);
2832 MD5Final(buffer, &md5c);
2833
2834 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2835 PKT_DATA, buffer, 16, PKT_END);
2836
2837 freebn(challenge);
2838 freebn(response);
2839 }
2840
2841 crWaitUntil(ispkt);
2842 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2843 if (flags & FLAG_VERBOSE)
2844 c_write_str(ssh, "Failed to authenticate with"
2845 " our public key.\r\n");
2846 continue; /* go and try password */
2847 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2848 bombout(("Bizarre response to RSA authentication response"));
2849 crReturn(0);
2850 }
2851
2852 break; /* we're through! */
2853 } else {
2854 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2855 /*
2856 * Defence against traffic analysis: we send a
2857 * whole bunch of packets containing strings of
2858 * different lengths. One of these strings is the
2859 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2860 * The others are all random data in
2861 * SSH1_MSG_IGNORE packets. This way a passive
2862 * listener can't tell which is the password, and
2863 * hence can't deduce the password length.
2864 *
2865 * Anybody with a password length greater than 16
2866 * bytes is going to have enough entropy in their
2867 * password that a listener won't find it _that_
2868 * much help to know how long it is. So what we'll
2869 * do is:
2870 *
2871 * - if password length < 16, we send 15 packets
2872 * containing string lengths 1 through 15
2873 *
2874 * - otherwise, we let N be the nearest multiple
2875 * of 8 below the password length, and send 8
2876 * packets containing string lengths N through
2877 * N+7. This won't obscure the order of
2878 * magnitude of the password length, but it will
2879 * introduce a bit of extra uncertainty.
2880 *
2881 * A few servers (the old 1.2.18 through 1.2.22)
2882 * can't deal with SSH1_MSG_IGNORE. For these
2883 * servers, we need an alternative defence. We make
2884 * use of the fact that the password is interpreted
2885 * as a C string: so we can append a NUL, then some
2886 * random data.
2887 *
2888 * One server (a Cisco one) can deal with neither
2889 * SSH1_MSG_IGNORE _nor_ a padded password string.
2890 * For this server we are left with no defences
2891 * against password length sniffing.
2892 */
2893 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2894 /*
2895 * The server can deal with SSH1_MSG_IGNORE, so
2896 * we can use the primary defence.
2897 */
2898 int bottom, top, pwlen, i;
2899 char *randomstr;
2900
2901 pwlen = strlen(s->password);
2902 if (pwlen < 16) {
2903 bottom = 0; /* zero length passwords are OK! :-) */
2904 top = 15;
2905 } else {
2906 bottom = pwlen & ~7;
2907 top = bottom + 7;
2908 }
2909
2910 assert(pwlen >= bottom && pwlen <= top);
2911
2912 randomstr = snewn(top + 1, char);
2913
2914 for (i = bottom; i <= top; i++) {
2915 if (i == pwlen)
2916 defer_packet(ssh, s->pwpkt_type,
2917 PKT_STR, s->password, PKT_END);
2918 else {
2919 for (j = 0; j < i; j++) {
2920 do {
2921 randomstr[j] = random_byte();
2922 } while (randomstr[j] == '\0');
2923 }
2924 randomstr[i] = '\0';
2925 defer_packet(ssh, SSH1_MSG_IGNORE,
2926 PKT_STR, randomstr, PKT_END);
2927 }
2928 }
2929 logevent("Sending password with camouflage packets");
2930 ssh_pkt_defersend(ssh);
2931 }
2932 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2933 /*
2934 * The server can't deal with SSH1_MSG_IGNORE
2935 * but can deal with padded passwords, so we
2936 * can use the secondary defence.
2937 */
2938 char string[64];
2939 char *ss;
2940 int len;
2941
2942 len = strlen(s->password);
2943 if (len < sizeof(string)) {
2944 ss = string;
2945 strcpy(string, s->password);
2946 len++; /* cover the zero byte */
2947 while (len < sizeof(string)) {
2948 string[len++] = (char) random_byte();
2949 }
2950 } else {
2951 ss = s->password;
2952 }
2953 logevent("Sending length-padded password");
2954 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2955 PKT_DATA, ss, len, PKT_END);
2956 } else {
2957 /*
2958 * The server has _both_
2959 * BUG_CHOKES_ON_SSH1_IGNORE and
2960 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2961 * therefore nothing we can do.
2962 */
2963 int len;
2964 len = strlen(s->password);
2965 logevent("Sending unpadded password");
2966 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2967 PKT_DATA, s->password, len, PKT_END);
2968 }
2969 } else {
2970 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
2971 }
2972 }
2973 logevent("Sent password");
2974 memset(s->password, 0, strlen(s->password));
2975 crWaitUntil(ispkt);
2976 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2977 if (flags & FLAG_VERBOSE)
2978 c_write_str(ssh, "Access denied\r\n");
2979 logevent("Authentication refused");
2980 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2981 bombout(("Strange packet received, type %d", ssh->pktin.type));
2982 crReturn(0);
2983 }
2984 }
2985
2986 logevent("Authentication successful");
2987
2988 crFinish(1);
2989 }
2990
2991 void sshfwd_close(struct ssh_channel *c)
2992 {
2993 Ssh ssh = c->ssh;
2994
2995 if (c && !c->closes) {
2996 /*
2997 * If the channel's remoteid is -1, we have sent
2998 * CHANNEL_OPEN for this channel, but it hasn't even been
2999 * acknowledged by the server. So we must set a close flag
3000 * on it now, and then when the server acks the channel
3001 * open, we can close it then.
3002 */
3003 if (((int)c->remoteid) != -1) {
3004 if (ssh->version == 1) {
3005 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3006 PKT_END);
3007 } else {
3008 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3009 ssh2_pkt_adduint32(ssh, c->remoteid);
3010 ssh2_pkt_send(ssh);
3011 }
3012 }
3013 c->closes = 1; /* sent MSG_CLOSE */
3014 if (c->type == CHAN_X11) {
3015 c->u.x11.s = NULL;
3016 logevent("Forwarded X11 connection terminated");
3017 } else if (c->type == CHAN_SOCKDATA ||
3018 c->type == CHAN_SOCKDATA_DORMANT) {
3019 c->u.pfd.s = NULL;
3020 logevent("Forwarded port closed");
3021 }
3022 }
3023 }
3024
3025 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3026 {
3027 Ssh ssh = c->ssh;
3028
3029 if (ssh->version == 1) {
3030 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3031 PKT_INT, c->remoteid,
3032 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
3033 /*
3034 * In SSH1 we can return 0 here - implying that forwarded
3035 * connections are never individually throttled - because
3036 * the only circumstance that can cause throttling will be
3037 * the whole SSH connection backing up, in which case
3038 * _everything_ will be throttled as a whole.
3039 */
3040 return 0;
3041 } else {
3042 ssh2_add_channel_data(c, buf, len);
3043 return ssh2_try_send(c);
3044 }
3045 }
3046
3047 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3048 {
3049 Ssh ssh = c->ssh;
3050
3051 if (ssh->version == 1) {
3052 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3053 c->v.v1.throttling = 0;
3054 ssh1_throttle(ssh, -1);
3055 }
3056 } else {
3057 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3058 }
3059 }
3060
3061 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3062 {
3063 crBegin(ssh->ssh1_protocol_crstate);
3064
3065 random_init();
3066
3067 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3068 crReturnV;
3069 }
3070 if (ssh->state == SSH_STATE_CLOSED)
3071 crReturnV;
3072
3073 if (ssh->cfg.agentfwd && agent_exists()) {
3074 logevent("Requesting agent forwarding");
3075 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3076 do {
3077 crReturnV;
3078 } while (!ispkt);
3079 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3080 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3081 bombout(("Protocol confusion"));
3082 crReturnV;
3083 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3084 logevent("Agent forwarding refused");
3085 } else {
3086 logevent("Agent forwarding enabled");
3087 ssh->agentfwd_enabled = TRUE;
3088 }
3089 }
3090
3091 if (ssh->cfg.x11_forward) {
3092 char proto[20], data[64];
3093 logevent("Requesting X11 forwarding");
3094 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3095 data, sizeof(data), ssh->cfg.x11_auth);
3096 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3097 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3098 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3099 PKT_STR, proto, PKT_STR, data,
3100 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3101 PKT_END);
3102 } else {
3103 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3104 PKT_STR, proto, PKT_STR, data, PKT_END);
3105 }
3106 do {
3107 crReturnV;
3108 } while (!ispkt);
3109 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3110 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3111 bombout(("Protocol confusion"));
3112 crReturnV;
3113 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3114 logevent("X11 forwarding refused");
3115 } else {
3116 logevent("X11 forwarding enabled");
3117 ssh->X11_fwd_enabled = TRUE;
3118 }
3119 }
3120
3121 {
3122 char type;
3123 int n;
3124 int sport,dport,sserv,dserv;
3125 char sports[256], dports[256], saddr[256], host[256];
3126
3127 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3128 /* Add port forwardings. */
3129 ssh->portfwd_strptr = ssh->cfg.portfwd;
3130 while (*ssh->portfwd_strptr) {
3131 type = *ssh->portfwd_strptr++;
3132 saddr[0] = '\0';
3133 n = 0;
3134 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3135 if (*ssh->portfwd_strptr == ':') {
3136 /*
3137 * We've seen a colon in the middle of the
3138 * source port number. This means that
3139 * everything we've seen until now is the
3140 * source _address_, so we'll move it into
3141 * saddr and start sports from the beginning
3142 * again.
3143 */
3144 ssh->portfwd_strptr++;
3145 sports[n] = '\0';
3146 strcpy(saddr, sports);
3147 n = 0;
3148 }
3149 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3150 }
3151 sports[n] = 0;
3152 if (type != 'D') {
3153 if (*ssh->portfwd_strptr == '\t')
3154 ssh->portfwd_strptr++;
3155 n = 0;
3156 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3157 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3158 }
3159 host[n] = 0;
3160 if (*ssh->portfwd_strptr == ':')
3161 ssh->portfwd_strptr++;
3162 n = 0;
3163 while (*ssh->portfwd_strptr) {
3164 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3165 }
3166 dports[n] = 0;
3167 ssh->portfwd_strptr++;
3168 dport = atoi(dports);
3169 dserv = 0;
3170 if (dport == 0) {
3171 dserv = 1;
3172 dport = net_service_lookup(dports);
3173 if (!dport) {
3174 logeventf(ssh, "Service lookup failed for"
3175 " destination port \"%s\"", dports);
3176 }
3177 }
3178 } else {
3179 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3180 }
3181 sport = atoi(sports);
3182 sserv = 0;
3183 if (sport == 0) {
3184 sserv = 1;
3185 sport = net_service_lookup(sports);
3186 if (!sport) {
3187 logeventf(ssh, "Service lookup failed for source"
3188 " port \"%s\"", sports);
3189 }
3190 }
3191 if (sport && dport) {
3192 if (type == 'L') {
3193 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3194 sport, ssh, &ssh->cfg);
3195 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3196 " forwarding to %s:%.*s%.*s%d%.*s",
3197 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3198 (int)(*saddr?1:0), ":",
3199 (int)(sserv ? strlen(sports) : 0), sports,
3200 sserv, "(", sport, sserv, ")",
3201 host,
3202 (int)(dserv ? strlen(dports) : 0), dports,
3203 dserv, "(", dport, dserv, ")");
3204 } else if (type == 'D') {
3205 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
3206 sport, ssh, &ssh->cfg);
3207 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3208 " doing SOCKS dynamic forwarding",
3209 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3210 (int)(*saddr?1:0), ":",
3211 (int)(sserv ? strlen(sports) : 0), sports,
3212 sserv, "(", sport, sserv, ")");
3213 } else {
3214 struct ssh_rportfwd *pf;
3215 pf = snew(struct ssh_rportfwd);
3216 strcpy(pf->dhost, host);
3217 pf->dport = dport;
3218 if (saddr) {
3219 logeventf(ssh,
3220 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3221 saddr, sport);
3222 }
3223 if (add234(ssh->rportfwds, pf) != pf) {
3224 logeventf(ssh,
3225 "Duplicate remote port forwarding to %s:%d",
3226 host, dport);
3227 sfree(pf);
3228 } else {
3229 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3230 " forward to %s:%.*s%.*s%d%.*s",
3231 (int)(sserv ? strlen(sports) : 0), sports,
3232 sserv, "(", sport, sserv, ")",
3233 host,
3234 (int)(dserv ? strlen(dports) : 0), dports,
3235 dserv, "(", dport, dserv, ")");
3236 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3237 PKT_INT, sport,
3238 PKT_STR, host,
3239 PKT_INT, dport,
3240 PKT_END);
3241 do {
3242 crReturnV;
3243 } while (!ispkt);
3244 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3245 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3246 bombout(("Protocol confusion"));
3247 crReturnV;
3248 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3249 c_write_str(ssh, "Server refused port"
3250 " forwarding\r\n");
3251 }
3252 logevent("Remote port forwarding enabled");
3253 }
3254 }
3255 }
3256 }
3257 }
3258
3259 if (!ssh->cfg.nopty) {
3260 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3261 PKT_STR, ssh->cfg.termtype,
3262 PKT_INT, ssh->term_height,
3263 PKT_INT, ssh->term_width,
3264 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3265 ssh->state = SSH_STATE_INTERMED;
3266 do {
3267 crReturnV;
3268 } while (!ispkt);
3269 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3270 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3271 bombout(("Protocol confusion"));
3272 crReturnV;
3273 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3274 c_write_str(ssh, "Server refused to allocate pty\r\n");
3275 ssh->editing = ssh->echoing = 1;
3276 }
3277 logevent("Allocated pty");
3278 } else {
3279 ssh->editing = ssh->echoing = 1;
3280 }
3281
3282 if (ssh->cfg.compression) {
3283 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3284 do {
3285 crReturnV;
3286 } while (!ispkt);
3287 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3288 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3289 bombout(("Protocol confusion"));
3290 crReturnV;
3291 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3292 c_write_str(ssh, "Server refused to compress\r\n");
3293 }
3294 logevent("Started compression");
3295 ssh->v1_compressing = TRUE;
3296 ssh->cs_comp_ctx = zlib_compress_init();
3297 logevent("Initialised zlib (RFC1950) compression");
3298 ssh->sc_comp_ctx = zlib_decompress_init();
3299 logevent("Initialised zlib (RFC1950) decompression");
3300 }
3301
3302 /*
3303 * Start the shell or command.
3304 *
3305 * Special case: if the first-choice command is an SSH2
3306 * subsystem (hence not usable here) and the second choice
3307 * exists, we fall straight back to that.
3308 */
3309 {
3310 char *cmd = ssh->cfg.remote_cmd_ptr;
3311
3312 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3313 cmd = ssh->cfg.remote_cmd_ptr2;
3314 ssh->fallback_cmd = TRUE;
3315 }
3316 if (*cmd)
3317 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3318 else
3319 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3320 logevent("Started session");
3321 }
3322
3323 ssh->state = SSH_STATE_SESSION;
3324 if (ssh->size_needed)
3325 ssh_size(ssh, ssh->term_width, ssh->term_height);
3326 if (ssh->eof_needed)
3327 ssh_special(ssh, TS_EOF);
3328
3329 if (ssh->ldisc)
3330 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3331 ssh->send_ok = 1;
3332 ssh->channels = newtree234(ssh_channelcmp);
3333 while (1) {
3334 crReturnV;
3335 if (ispkt) {
3336 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3337 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3338 long len = GET_32BIT(ssh->pktin.body);
3339 int bufsize =
3340 from_backend(ssh->frontend,
3341 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3342 (char *)(ssh->pktin.body) + 4, len);
3343 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3344 ssh->v1_stdout_throttling = 1;
3345 ssh1_throttle(ssh, +1);
3346 }
3347 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3348 ssh_closing((Plug)ssh, NULL, 0, 0);
3349 logevent("Received disconnect request");
3350 crReturnV;
3351 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3352 /* Remote side is trying to open a channel to talk to our
3353 * X-Server. Give them back a local channel number. */
3354 struct ssh_channel *c;
3355
3356 logevent("Received X11 connect request");
3357 /* Refuse if X11 forwarding is disabled. */
3358 if (!ssh->X11_fwd_enabled) {
3359 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3360 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3361 logevent("Rejected X11 connect request");
3362 } else {
3363 c = snew(struct ssh_channel);
3364 c->ssh = ssh;
3365
3366 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3367 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3368 logevent("opening X11 forward connection failed");
3369 sfree(c);
3370 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3371 PKT_INT, GET_32BIT(ssh->pktin.body),
3372 PKT_END);
3373 } else {
3374 logevent
3375 ("opening X11 forward connection succeeded");
3376 c->remoteid = GET_32BIT(ssh->pktin.body);
3377 c->localid = alloc_channel_id(ssh);
3378 c->closes = 0;
3379 c->v.v1.throttling = 0;
3380 c->type = CHAN_X11; /* identify channel type */
3381 add234(ssh->channels, c);
3382 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3383 PKT_INT, c->remoteid, PKT_INT,
3384 c->localid, PKT_END);
3385 logevent("Opened X11 forward channel");
3386 }
3387 }
3388 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3389 /* Remote side is trying to open a channel to talk to our
3390 * agent. Give them back a local channel number. */
3391 struct ssh_channel *c;
3392
3393 /* Refuse if agent forwarding is disabled. */
3394 if (!ssh->agentfwd_enabled) {
3395 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3396 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3397 } else {
3398 c = snew(struct ssh_channel);
3399 c->ssh = ssh;
3400 c->remoteid = GET_32BIT(ssh->pktin.body);
3401 c->localid = alloc_channel_id(ssh);
3402 c->closes = 0;
3403 c->v.v1.throttling = 0;
3404 c->type = CHAN_AGENT; /* identify channel type */
3405 c->u.a.lensofar = 0;
3406 add234(ssh->channels, c);
3407 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3408 PKT_INT, c->remoteid, PKT_INT, c->localid,
3409 PKT_END);
3410 }
3411 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3412 /* Remote side is trying to open a channel to talk to a
3413 * forwarded port. Give them back a local channel number. */
3414 struct ssh_channel *c;
3415 struct ssh_rportfwd pf;
3416 int hostsize, port;
3417 char host[256], buf[1024];
3418 char *p, *h, *e;
3419 c = snew(struct ssh_channel);
3420 c->ssh = ssh;
3421
3422 hostsize = GET_32BIT(ssh->pktin.body+4);
3423 for (h = host, p = (char *)(ssh->pktin.body+8);
3424 hostsize != 0; hostsize--) {
3425 if (h+1 < host+sizeof(host))
3426 *h++ = *p;
3427 p++;
3428 }
3429 *h = 0;
3430 port = GET_32BIT(p);
3431
3432 strcpy(pf.dhost, host);
3433 pf.dport = port;
3434
3435 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3436 sprintf(buf, "Rejected remote port open request for %s:%d",
3437 host, port);
3438 logevent(buf);
3439 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3440 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3441 } else {
3442 sprintf(buf, "Received remote port open request for %s:%d",
3443 host, port);
3444 logevent(buf);
3445 e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg);
3446 if (e != NULL) {
3447 char buf[256];
3448 sprintf(buf, "Port open failed: %s", e);
3449 logevent(buf);
3450 sfree(c);
3451 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3452 PKT_INT, GET_32BIT(ssh->pktin.body),
3453 PKT_END);
3454 } else {
3455 c->remoteid = GET_32BIT(ssh->pktin.body);
3456 c->localid = alloc_channel_id(ssh);
3457 c->closes = 0;
3458 c->v.v1.throttling = 0;
3459 c->type = CHAN_SOCKDATA; /* identify channel type */
3460 add234(ssh->channels, c);
3461 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3462 PKT_INT, c->remoteid, PKT_INT,
3463 c->localid, PKT_END);
3464 logevent("Forwarded port opened successfully");
3465 }
3466 }
3467
3468 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3469 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3470 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3471 struct ssh_channel *c;
3472
3473 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3474 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3475 c->remoteid = localid;
3476 c->type = CHAN_SOCKDATA;
3477 c->v.v1.throttling = 0;
3478 pfd_confirm(c->u.pfd.s);
3479 }
3480
3481 if (c && c->closes) {
3482 /*
3483 * We have a pending close on this channel,
3484 * which we decided on before the server acked
3485 * the channel open. So now we know the
3486 * remoteid, we can close it again.
3487 */
3488 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3489 PKT_INT, c->remoteid, PKT_END);
3490 }
3491
3492 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3493 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3494 struct ssh_channel *c;
3495
3496 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3497 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3498 logevent("Forwarded connection refused by server");
3499 pfd_close(c->u.pfd.s);
3500 del234(ssh->channels, c);
3501 sfree(c);
3502 }
3503
3504 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3505 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3506 /* Remote side closes a channel. */
3507 unsigned i = GET_32BIT(ssh->pktin.body);
3508 struct ssh_channel *c;
3509 c = find234(ssh->channels, &i, ssh_channelfind);
3510 if (c && ((int)c->remoteid) != -1) {
3511 int closetype;
3512 closetype =
3513 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3514
3515 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3516 logevent("Forwarded X11 connection terminated");
3517 assert(c->u.x11.s != NULL);
3518 x11_close(c->u.x11.s);
3519 c->u.x11.s = NULL;
3520 }
3521 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3522 logevent("Forwarded port closed");
3523 assert(c->u.pfd.s != NULL);
3524 pfd_close(c->u.pfd.s);
3525 c->u.pfd.s = NULL;
3526 }
3527
3528 c->closes |= (closetype << 2); /* seen this message */
3529 if (!(c->closes & closetype)) {
3530 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3531 PKT_END);
3532 c->closes |= closetype; /* sent it too */
3533 }
3534
3535 if (c->closes == 15) {
3536 del234(ssh->channels, c);
3537 sfree(c);
3538 }
3539 } else {
3540 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3541 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3542 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3543 i));
3544 }
3545 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3546 /* Data sent down one of our channels. */
3547 int i = GET_32BIT(ssh->pktin.body);
3548 int len = GET_32BIT(ssh->pktin.body + 4);
3549 unsigned char *p = ssh->pktin.body + 8;
3550 struct ssh_channel *c;
3551 c = find234(ssh->channels, &i, ssh_channelfind);
3552 if (c) {
3553 int bufsize;
3554 switch (c->type) {
3555 case CHAN_X11:
3556 bufsize = x11_send(c->u.x11.s, (char *)p, len);
3557 break;
3558 case CHAN_SOCKDATA:
3559 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
3560 break;
3561 case CHAN_AGENT:
3562 /* Data for an agent message. Buffer it. */
3563 while (len > 0) {
3564 if (c->u.a.lensofar < 4) {
3565 int l = min(4 - c->u.a.lensofar, len);
3566 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3567 l);
3568 p += l;
3569 len -= l;
3570 c->u.a.lensofar += l;
3571 }
3572 if (c->u.a.lensofar == 4) {
3573 c->u.a.totallen =
3574 4 + GET_32BIT(c->u.a.msglen);
3575 c->u.a.message = snewn(c->u.a.totallen,
3576 unsigned char);
3577 memcpy(c->u.a.message, c->u.a.msglen, 4);
3578 }
3579 if (c->u.a.lensofar >= 4 && len > 0) {
3580 int l =
3581 min(c->u.a.totallen - c->u.a.lensofar,
3582 len);
3583 memcpy(c->u.a.message + c->u.a.lensofar, p,
3584 l);
3585 p += l;
3586 len -= l;
3587 c->u.a.lensofar += l;
3588 }
3589 if (c->u.a.lensofar == c->u.a.totallen) {
3590 void *reply, *sentreply;
3591 int replylen;
3592 agent_query(c->u.a.message,
3593 c->u.a.totallen, &reply,
3594 &replylen);
3595 if (reply)
3596 sentreply = reply;
3597 else {
3598 /* Fake SSH_AGENT_FAILURE. */
3599 sentreply = "\0\0\0\1\5";
3600 replylen = 5;
3601 }
3602 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3603 PKT_INT, c->remoteid,
3604 PKT_INT, replylen,
3605 PKT_DATA, sentreply, replylen,
3606 PKT_END);
3607 if (reply)
3608 sfree(reply);
3609 sfree(c->u.a.message);
3610 c->u.a.lensofar = 0;
3611 }
3612 }
3613 bufsize = 0; /* agent channels never back up */
3614 break;
3615 }
3616 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3617 c->v.v1.throttling = 1;
3618 ssh1_throttle(ssh, +1);
3619 }
3620 }
3621 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3622 /* may be from EXEC_SHELL on some servers */
3623 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3624 /* may be from EXEC_SHELL on some servers
3625 * if no pty is available or in other odd cases. Ignore */
3626 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3627 char buf[100];
3628 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3629 sprintf(buf, "Server sent command exit status %d",
3630 ssh->exitcode);
3631 logevent(buf);
3632 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3633 /*
3634 * In case `helpful' firewalls or proxies tack
3635 * extra human-readable text on the end of the
3636 * session which we might mistake for another
3637 * encrypted packet, we close the session once
3638 * we've sent EXIT_CONFIRMATION.
3639 */
3640 ssh_closing((Plug)ssh, NULL, 0, 0);
3641 crReturnV;
3642 } else {
3643 bombout(("Strange packet received: type %d", ssh->pktin.type));
3644 crReturnV;
3645 }
3646 } else {
3647 while (inlen > 0) {
3648 int len = min(inlen, 512);
3649 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3650 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3651 in += len;
3652 inlen -= len;
3653 }
3654 }
3655 }
3656
3657 crFinishV;
3658 }
3659
3660 /*
3661 * Utility routine for decoding comma-separated strings in KEXINIT.
3662 */
3663 static int in_commasep_string(char *needle, char *haystack, int haylen)
3664 {
3665 int needlen;
3666 if (!needle || !haystack) /* protect against null pointers */
3667 return 0;
3668 needlen = strlen(needle);
3669 while (1) {
3670 /*
3671 * Is it at the start of the string?
3672 */
3673 if (haylen >= needlen && /* haystack is long enough */
3674 !memcmp(needle, haystack, needlen) && /* initial match */
3675 (haylen == needlen || haystack[needlen] == ',')
3676 /* either , or EOS follows */
3677 )
3678 return 1;
3679 /*
3680 * If not, search for the next comma and resume after that.
3681 * If no comma found, terminate.
3682 */
3683 while (haylen > 0 && *haystack != ',')
3684 haylen--, haystack++;
3685 if (haylen == 0)
3686 return 0;
3687 haylen--, haystack++; /* skip over comma itself */
3688 }
3689 }
3690
3691 /*
3692 * SSH2 key creation method.
3693 */
3694 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3695 unsigned char *sessid, char chr,
3696 unsigned char *keyspace)
3697 {
3698 SHA_State s;
3699 /* First 20 bytes. */
3700 SHA_Init(&s);
3701 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3702 sha_mpint(&s, K);
3703 SHA_Bytes(&s, H, 20);
3704 SHA_Bytes(&s, &chr, 1);
3705 SHA_Bytes(&s, sessid, 20);
3706 SHA_Final(&s, keyspace);
3707 /* Next 20 bytes. */
3708 SHA_Init(&s);
3709 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3710 sha_mpint(&s, K);
3711 SHA_Bytes(&s, H, 20);
3712 SHA_Bytes(&s, keyspace, 20);
3713 SHA_Final(&s, keyspace + 20);
3714 }
3715
3716 /*
3717 * Handle the SSH2 transport layer.
3718 */
3719 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3720 {
3721 struct do_ssh2_transport_state {
3722 int nbits, pbits, warn;
3723 Bignum p, g, e, f, K;
3724 int kex_init_value, kex_reply_value;
3725 const struct ssh_mac **maclist;
3726 int nmacs;
3727 const struct ssh2_cipher *cscipher_tobe;
3728 const struct ssh2_cipher *sccipher_tobe;
3729 const struct ssh_mac *csmac_tobe;
3730 const struct ssh_mac *scmac_tobe;
3731 const struct ssh_compress *cscomp_tobe;
3732 const struct ssh_compress *sccomp_tobe;
3733 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3734 int hostkeylen, siglen;
3735 void *hkey; /* actual host key */
3736 unsigned char exchange_hash[20];
3737 int n_preferred_ciphers;
3738 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3739 const struct ssh_compress *preferred_comp;
3740 int first_kex;
3741 };
3742 crState(do_ssh2_transport_state);
3743
3744 crBegin(ssh->do_ssh2_transport_crstate);
3745
3746 s->cscipher_tobe = s->sccipher_tobe = NULL;
3747 s->csmac_tobe = s->scmac_tobe = NULL;
3748 s->cscomp_tobe = s->sccomp_tobe = NULL;
3749
3750 random_init();
3751 s->first_kex = 1;
3752
3753 {
3754 int i;
3755 /*
3756 * Set up the preferred ciphers. (NULL => warn below here)
3757 */
3758 s->n_preferred_ciphers = 0;
3759 for (i = 0; i < CIPHER_MAX; i++) {
3760 switch (ssh->cfg.ssh_cipherlist[i]) {
3761 case CIPHER_BLOWFISH:
3762 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3763 break;
3764 case CIPHER_DES:
3765 if (ssh->cfg.ssh2_des_cbc) {
3766 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3767 }
3768 break;
3769 case CIPHER_3DES:
3770 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3771 break;
3772 case CIPHER_AES:
3773 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3774 break;
3775 case CIPHER_WARN:
3776 /* Flag for later. Don't bother if it's the last in
3777 * the list. */
3778 if (i < CIPHER_MAX - 1) {
3779 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3780 }
3781 break;
3782 }
3783 }
3784 }
3785
3786 /*
3787 * Set up preferred compression.
3788 */
3789 if (ssh->cfg.compression)
3790 s->preferred_comp = &ssh_zlib;
3791 else
3792 s->preferred_comp = &ssh_comp_none;
3793
3794 /*
3795 * Be prepared to work around the buggy MAC problem.
3796 */
3797 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3798 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3799 else
3800 s->maclist = macs, s->nmacs = lenof(macs);
3801
3802 begin_key_exchange:
3803 {
3804 int i, j, cipherstr_started;
3805
3806 /*
3807 * Construct and send our key exchange packet.
3808 */
3809 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3810 for (i = 0; i < 16; i++)
3811 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3812 /* List key exchange algorithms. */
3813 ssh2_pkt_addstring_start(ssh);
3814 for (i = 0; i < lenof(kex_algs); i++) {
3815 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3816 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3817 continue;
3818 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3819 if (i < lenof(kex_algs) - 1)
3820 ssh2_pkt_addstring_str(ssh, ",");
3821 }
3822 /* List server host key algorithms. */
3823 ssh2_pkt_addstring_start(ssh);
3824 for (i = 0; i < lenof(hostkey_algs); i++) {
3825 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3826 if (i < lenof(hostkey_algs) - 1)
3827 ssh2_pkt_addstring_str(ssh, ",");
3828 }
3829 /* List client->server encryption algorithms. */
3830 ssh2_pkt_addstring_start(ssh);
3831 cipherstr_started = 0;
3832 for (i = 0; i < s->n_preferred_ciphers; i++) {
3833 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3834 if (!c) continue; /* warning flag */
3835 for (j = 0; j < c->nciphers; j++) {
3836 if (cipherstr_started)
3837 ssh2_pkt_addstring_str(ssh, ",");
3838 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3839 cipherstr_started = 1;
3840 }
3841 }
3842 /* List server->client encryption algorithms. */
3843 ssh2_pkt_addstring_start(ssh);
3844 cipherstr_started = 0;
3845 for (i = 0; i < s->n_preferred_ciphers; i++) {
3846 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3847 if (!c) continue; /* warning flag */
3848 for (j = 0; j < c->nciphers; j++) {
3849 if (cipherstr_started)
3850 ssh2_pkt_addstring_str(ssh, ",");
3851 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3852 cipherstr_started = 1;
3853 }
3854 }
3855 /* List client->server MAC algorithms. */
3856 ssh2_pkt_addstring_start(ssh);
3857 for (i = 0; i < s->nmacs; i++) {
3858 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3859 if (i < s->nmacs - 1)
3860 ssh2_pkt_addstring_str(ssh, ",");
3861 }
3862 /* List server->client MAC algorithms. */
3863 ssh2_pkt_addstring_start(ssh);
3864 for (i = 0; i < s->nmacs; i++) {
3865 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3866 if (i < s->nmacs - 1)
3867 ssh2_pkt_addstring_str(ssh, ",");
3868 }
3869 /* List client->server compression algorithms. */
3870 ssh2_pkt_addstring_start(ssh);
3871 for (i = 0; i < lenof(compressions) + 1; i++) {
3872 const struct ssh_compress *c =
3873 i == 0 ? s->preferred_comp : compressions[i - 1];
3874 ssh2_pkt_addstring_str(ssh, c->name);
3875 if (i < lenof(compressions))
3876 ssh2_pkt_addstring_str(ssh, ",");
3877 }
3878 /* List server->client compression algorithms. */
3879 ssh2_pkt_addstring_start(ssh);
3880 for (i = 0; i < lenof(compressions) + 1; i++) {
3881 const struct ssh_compress *c =
3882 i == 0 ? s->preferred_comp : compressions[i - 1];
3883 ssh2_pkt_addstring_str(ssh, c->name);
3884 if (i < lenof(compressions))
3885 ssh2_pkt_addstring_str(ssh, ",");
3886 }
3887 /* List client->server languages. Empty list. */
3888 ssh2_pkt_addstring_start(ssh);
3889 /* List server->client languages. Empty list. */
3890 ssh2_pkt_addstring_start(ssh);
3891 /* First KEX packet does _not_ follow, because we're not that brave. */
3892 ssh2_pkt_addbool(ssh, FALSE);
3893 /* Reserved. */
3894 ssh2_pkt_adduint32(ssh, 0);
3895 }
3896
3897 ssh->exhash = ssh->exhashbase;
3898 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
3899
3900 ssh2_pkt_send(ssh);
3901
3902 if (!ispkt)
3903 crWaitUntil(ispkt);
3904 if (ssh->pktin.length > 5)
3905 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
3906
3907 /*
3908 * Now examine the other side's KEXINIT to see what we're up
3909 * to.
3910 */
3911 {
3912 char *str;
3913 int i, j, len;
3914
3915 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3916 bombout(("expected key exchange packet from server"));
3917 crReturn(0);
3918 }
3919 ssh->kex = NULL;
3920 ssh->hostkey = NULL;
3921 s->cscipher_tobe = NULL;
3922 s->sccipher_tobe = NULL;
3923 s->csmac_tobe = NULL;
3924 s->scmac_tobe = NULL;
3925 s->cscomp_tobe = NULL;
3926 s->sccomp_tobe = NULL;
3927 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3928 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3929 for (i = 0; i < lenof(kex_algs); i++) {
3930 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3931 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3932 continue;
3933 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3934 ssh->kex = kex_algs[i];
3935 break;
3936 }
3937 }
3938 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3939 for (i = 0; i < lenof(hostkey_algs); i++) {
3940 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3941 ssh->hostkey = hostkey_algs[i];
3942 break;
3943 }
3944 }
3945 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3946 s->warn = 0;
3947 for (i = 0; i < s->n_preferred_ciphers; i++) {
3948 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3949 if (!c) {
3950 s->warn = 1;
3951 } else {
3952 for (j = 0; j < c->nciphers; j++) {
3953 if (in_commasep_string(c->list[j]->name, str, len)) {
3954 s->cscipher_tobe = c->list[j];
3955 break;
3956 }
3957 }
3958 }
3959 if (s->cscipher_tobe) {
3960 if (s->warn)
3961 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
3962 break;
3963 }
3964 }
3965 if (!s->cscipher_tobe) {
3966 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
3967 str ? str : "(null)"));
3968 crReturn(0);
3969 }
3970
3971 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3972 s->warn = 0;
3973 for (i = 0; i < s->n_preferred_ciphers; i++) {
3974 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3975 if (!c) {
3976 s->warn = 1;
3977 } else {
3978 for (j = 0; j < c->nciphers; j++) {
3979 if (in_commasep_string(c->list[j]->name, str, len)) {
3980 s->sccipher_tobe = c->list[j];
3981 break;
3982 }
3983 }
3984 }
3985 if (s->sccipher_tobe) {
3986 if (s->warn)
3987 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
3988 break;
3989 }
3990 }
3991 if (!s->sccipher_tobe) {
3992 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
3993 str ? str : "(null)"));
3994 crReturn(0);
3995 }
3996
3997 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3998 for (i = 0; i < s->nmacs; i++) {
3999 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4000 s->csmac_tobe = s->maclist[i];
4001 break;
4002 }
4003 }
4004 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
4005 for (i = 0; i < s->nmacs; i++) {
4006 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4007 s->scmac_tobe = s->maclist[i];
4008 break;
4009 }
4010 }
4011 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
4012 for (i = 0; i < lenof(compressions) + 1; i++) {
4013 const struct ssh_compress *c =
4014 i == 0 ? s->preferred_comp : compressions[i - 1];
4015 if (in_commasep_string(c->name, str, len)) {
4016 s->cscomp_tobe = c;
4017 break;
4018 }
4019 }
4020 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
4021 for (i = 0; i < lenof(compressions) + 1; i++) {
4022 const struct ssh_compress *c =
4023 i == 0 ? s->preferred_comp : compressions[i - 1];
4024 if (in_commasep_string(c->name, str, len)) {
4025 s->sccomp_tobe = c;
4026 break;
4027 }
4028 }
4029 }
4030
4031 /*
4032 * Work out the number of bits of key we will need from the key
4033 * exchange. We start with the maximum key length of either
4034 * cipher...
4035 */
4036 {
4037 int csbits, scbits;
4038
4039 csbits = s->cscipher_tobe->keylen;
4040 scbits = s->sccipher_tobe->keylen;
4041 s->nbits = (csbits > scbits ? csbits : scbits);
4042 }
4043 /* The keys only have 160-bit entropy, since they're based on
4044 * a SHA-1 hash. So cap the key size at 160 bits. */
4045 if (s->nbits > 160)
4046 s->nbits = 160;
4047
4048 /*
4049 * If we're doing Diffie-Hellman group exchange, start by
4050 * requesting a group.
4051 */
4052 if (ssh->kex == &ssh_diffiehellman_gex) {
4053 logevent("Doing Diffie-Hellman group exchange");
4054 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4055 /*
4056 * Work out how big a DH group we will need to allow that
4057 * much data.
4058 */
4059 s->pbits = 512 << ((s->nbits - 1) / 64);
4060 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4061 ssh2_pkt_adduint32(ssh, s->pbits);
4062 ssh2_pkt_send(ssh);
4063
4064 crWaitUntil(ispkt);
4065 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4066 bombout(("expected key exchange group packet from server"));
4067 crReturn(0);
4068 }
4069 s->p = ssh2_pkt_getmp(ssh);
4070 s->g = ssh2_pkt_getmp(ssh);
4071 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4072 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4073 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4074 } else {
4075 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4076 ssh->kex_ctx = dh_setup_group1();
4077 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4078 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4079 }
4080
4081 logevent("Doing Diffie-Hellman key exchange");
4082 /*
4083 * Now generate and send e for Diffie-Hellman.
4084 */
4085 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4086 ssh2_pkt_init(ssh, s->kex_init_value);
4087 ssh2_pkt_addmp(ssh, s->e);
4088 ssh2_pkt_send(ssh);
4089
4090 crWaitUntil(ispkt);
4091 if (ssh->pktin.type != s->kex_reply_value) {
4092 bombout(("expected key exchange reply packet from server"));
4093 crReturn(0);
4094 }
4095 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4096 s->f = ssh2_pkt_getmp(ssh);
4097 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4098
4099 s->K = dh_find_K(ssh->kex_ctx, s->f);
4100
4101 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4102 if (ssh->kex == &ssh_diffiehellman_gex) {
4103 sha_uint32(&ssh->exhash, s->pbits);
4104 sha_mpint(&ssh->exhash, s->p);
4105 sha_mpint(&ssh->exhash, s->g);
4106 }
4107 sha_mpint(&ssh->exhash, s->e);
4108 sha_mpint(&ssh->exhash, s->f);
4109 sha_mpint(&ssh->exhash, s->K);
4110 SHA_Final(&ssh->exhash, s->exchange_hash);
4111
4112 dh_cleanup(ssh->kex_ctx);
4113 ssh->kex_ctx = NULL;
4114
4115 #if 0
4116 debug(("Exchange hash is:\n"));
4117 dmemdump(s->exchange_hash, 20);
4118 #endif
4119
4120 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4121 if (!s->hkey ||
4122 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4123 (char *)s->exchange_hash, 20)) {
4124 bombout(("Server's host key did not match the signature supplied"));
4125 crReturn(0);
4126 }
4127
4128 /*
4129 * Authenticate remote host: verify host key. (We've already
4130 * checked the signature of the exchange hash.)
4131 */
4132 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4133 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4134 verify_ssh_host_key(ssh->frontend,
4135 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4136 s->keystr, s->fingerprint);
4137 if (s->first_kex) { /* don't bother logging this in rekeys */
4138 logevent("Host key fingerprint is:");
4139 logevent(s->fingerprint);
4140 }
4141 sfree(s->fingerprint);
4142 sfree(s->keystr);
4143 ssh->hostkey->freekey(s->hkey);
4144
4145 /*
4146 * Send SSH2_MSG_NEWKEYS.
4147 */
4148 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4149 ssh2_pkt_send(ssh);
4150
4151 /*
4152 * Expect SSH2_MSG_NEWKEYS from server.
4153 */
4154 crWaitUntil(ispkt);
4155 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4156 bombout(("expected new-keys packet from server"));
4157 crReturn(0);
4158 }
4159
4160 /*
4161 * Create and initialise session keys.
4162 */
4163 if (ssh->cs_cipher_ctx)
4164 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4165 ssh->cscipher = s->cscipher_tobe;
4166 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4167
4168 if (ssh->sc_cipher_ctx)
4169 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4170 ssh->sccipher = s->sccipher_tobe;
4171 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4172
4173 if (ssh->cs_mac_ctx)
4174 ssh->csmac->free_context(ssh->cs_mac_ctx);
4175 ssh->csmac = s->csmac_tobe;
4176 ssh->cs_mac_ctx = ssh->csmac->make_context();
4177
4178 if (ssh->sc_mac_ctx)
4179 ssh->scmac->free_context(ssh->sc_mac_ctx);
4180 ssh->scmac = s->scmac_tobe;
4181 ssh->sc_mac_ctx = ssh->scmac->make_context();
4182
4183 if (ssh->cs_comp_ctx)
4184 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4185 ssh->cscomp = s->cscomp_tobe;
4186 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4187
4188 if (ssh->sc_comp_ctx)
4189 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4190 ssh->sccomp = s->sccomp_tobe;
4191 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4192
4193 /*
4194 * Set IVs after keys. Here we use the exchange hash from the
4195 * _first_ key exchange.
4196 */
4197 {
4198 unsigned char keyspace[40];
4199 if (s->first_kex)
4200 memcpy(ssh->v2_session_id, s->exchange_hash,
4201 sizeof(s->exchange_hash));
4202 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4203 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4204 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4205 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4206 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4207 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4208 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4209 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4210 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4211 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4212 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4213 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4214 }
4215 logeventf(ssh, "Initialised %.200s client->server encryption",
4216 ssh->cscipher->text_name);
4217 logeventf(ssh, "Initialised %.200s server->client encryption",
4218 ssh->sccipher->text_name);
4219 if (ssh->cscomp->text_name)
4220 logeventf(ssh, "Initialised %s compression",
4221 ssh->cscomp->text_name);
4222 if (ssh->sccomp->text_name)
4223 logeventf(ssh, "Initialised %s decompression",
4224 ssh->sccomp->text_name);
4225
4226 /*
4227 * If this is the first key exchange phase, we must pass the
4228 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4229 * wants to see it but because it will need time to initialise
4230 * itself before it sees an actual packet. In subsequent key
4231 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4232 * it would only confuse the layer above.
4233 */
4234 if (!s->first_kex) {
4235 crReturn(0);
4236 }
4237 s->first_kex = 0;
4238
4239 /*
4240 * Now we're encrypting. Begin returning 1 to the protocol main
4241 * function so that other things can run on top of the
4242 * transport. If we ever see a KEXINIT, we must go back to the
4243 * start.
4244 */
4245 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4246 crReturn(1);
4247 }
4248 logevent("Server initiated key re-exchange");
4249 goto begin_key_exchange;
4250
4251 crFinish(1);
4252 }
4253
4254 /*
4255 * Add data to an SSH2 channel output buffer.
4256 */
4257 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4258 int len)
4259 {
4260 bufchain_add(&c->v.v2.outbuffer, buf, len);
4261 }
4262
4263 /*
4264 * Attempt to send data on an SSH2 channel.
4265 */
4266 static int ssh2_try_send(struct ssh_channel *c)
4267 {
4268 Ssh ssh = c->ssh;
4269
4270 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4271 int len;
4272 void *data;
4273 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4274 if ((unsigned)len > c->v.v2.remwindow)
4275 len = c->v.v2.remwindow;
4276 if ((unsigned)len > c->v.v2.remmaxpkt)
4277 len = c->v.v2.remmaxpkt;
4278 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4279 ssh2_pkt_adduint32(ssh, c->remoteid);
4280 ssh2_pkt_addstring_start(ssh);
4281 ssh2_pkt_addstring_data(ssh, data, len);
4282 ssh2_pkt_send(ssh);
4283 bufchain_consume(&c->v.v2.outbuffer, len);
4284 c->v.v2.remwindow -= len;
4285 }
4286
4287 /*
4288 * After having sent as much data as we can, return the amount
4289 * still buffered.
4290 */
4291 return bufchain_size(&c->v.v2.outbuffer);
4292 }
4293
4294 /*
4295 * Potentially enlarge the window on an SSH2 channel.
4296 */
4297 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4298 {
4299 Ssh ssh = c->ssh;
4300
4301 /*
4302 * Never send WINDOW_ADJUST for a channel that the remote side
4303 * already thinks it's closed; there's no point, since it won't
4304 * be sending any more data anyway.
4305 */
4306 if (c->closes != 0)
4307 return;
4308
4309 if (newwin > c->v.v2.locwindow) {
4310 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4311 ssh2_pkt_adduint32(ssh, c->remoteid);
4312 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4313 ssh2_pkt_send(ssh);
4314 c->v.v2.locwindow = newwin;
4315 }
4316 }
4317
4318 /*
4319 * Handle the SSH2 userauth and connection layers.
4320 */
4321 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4322 {
4323 struct do_ssh2_authconn_state {
4324 enum {
4325 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4326 AUTH_PASSWORD,
4327 AUTH_KEYBOARD_INTERACTIVE
4328 } method;
4329 enum {
4330 AUTH_TYPE_NONE,
4331 AUTH_TYPE_PUBLICKEY,
4332 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4333 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4334 AUTH_TYPE_PASSWORD,
4335 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4336 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4337 } type;
4338 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4339 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4340 int kbd_inter_running;
4341 int we_are_in;
4342 int num_prompts, curr_prompt, echo;
4343 char username[100];
4344 int got_username;
4345 char pwprompt[200];
4346 char password[100];
4347 void *publickey_blob;
4348 int publickey_bloblen;
4349 unsigned char request[5], *response, *p;
4350 int responselen;
4351 int keyi, nkeys;
4352 int authed;
4353 char *pkblob, *alg, *commentp;
4354 int pklen, alglen, commentlen;
4355 int siglen, retlen, len;
4356 char *q, *agentreq, *ret;
4357 int try_send;
4358 };
4359 crState(do_ssh2_authconn_state);
4360
4361 crBegin(ssh->do_ssh2_authconn_crstate);
4362
4363 /*
4364 * Request userauth protocol, and await a response to it.
4365 */
4366 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4367 ssh2_pkt_addstring(ssh, "ssh-userauth");
4368 ssh2_pkt_send(ssh);
4369 crWaitUntilV(ispkt);
4370 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4371 bombout(("Server refused user authentication protocol"));
4372 crReturnV;
4373 }
4374
4375 /*
4376 * We repeat this whole loop, including the username prompt,
4377 * until we manage a successful authentication. If the user
4378 * types the wrong _password_, they can be sent back to the
4379 * beginning to try another username, if this is configured on.
4380 * (If they specify a username in the config, they are never
4381 * asked, even if they do give a wrong password.)
4382 *
4383 * I think this best serves the needs of
4384 *
4385 * - the people who have no configuration, no keys, and just
4386 * want to try repeated (username,password) pairs until they
4387 * type both correctly
4388 *
4389 * - people who have keys and configuration but occasionally
4390 * need to fall back to passwords
4391 *
4392 * - people with a key held in Pageant, who might not have
4393 * logged in to a particular machine before; so they want to
4394 * type a username, and then _either_ their key will be
4395 * accepted, _or_ they will type a password. If they mistype
4396 * the username they will want to be able to get back and
4397 * retype it!
4398 */
4399 s->username[0] = '\0';
4400 s->got_username = FALSE;
4401 do {
4402 /*
4403 * Get a username.
4404 */
4405 if (s->got_username && !ssh->cfg.change_username) {
4406 /*
4407 * We got a username last time round this loop, and
4408 * with change_username turned off we don't try to get
4409 * it again.
4410 */
4411 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
4412 if (ssh_get_line && !ssh_getline_pw_only) {
4413 if (!ssh_get_line("login as: ",
4414 s->username, sizeof(s->username), FALSE)) {
4415 /*
4416 * get_line failed to get a username.
4417 * Terminate.
4418 */
4419 logevent("No username provided. Abandoning session.");
4420 ssh_closing((Plug)ssh, NULL, 0, 0);
4421 crReturnV;
4422 }
4423 } else {
4424 int ret; /* need not be saved across crReturn */
4425 c_write_str(ssh, "login as: ");
4426 ssh->send_ok = 1;
4427 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4428 do {
4429 crWaitUntilV(!ispkt);
4430 ret = process_userpass_input(ssh, in, inlen);
4431 } while (ret == 0);
4432 if (ret < 0)
4433 cleanup_exit(0);
4434 c_write_str(ssh, "\r\n");
4435 }
4436 s->username[strcspn(s->username, "\n\r")] = '\0';
4437 } else {
4438 char *stuff;
4439 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
4440 s->username[sizeof(s->username)-1] = '\0';
4441 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4442 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4443 c_write_str(ssh, stuff);
4444 sfree(stuff);
4445 }
4446 }
4447 s->got_username = TRUE;
4448
4449 /*
4450 * Send an authentication request using method "none": (a)
4451 * just in case it succeeds, and (b) so that we know what
4452 * authentication methods we can usefully try next.
4453 */
4454 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4455
4456 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4457 ssh2_pkt_addstring(ssh, s->username);
4458 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4459 ssh2_pkt_addstring(ssh, "none"); /* method */
4460 ssh2_pkt_send(ssh);
4461 s->type = AUTH_TYPE_NONE;
4462 s->gotit = FALSE;
4463 s->we_are_in = FALSE;
4464
4465 s->tried_pubkey_config = FALSE;
4466 s->tried_agent = FALSE;
4467 s->tried_keyb_inter = FALSE;
4468 s->kbd_inter_running = FALSE;
4469 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4470 if (!filename_is_null(ssh->cfg.keyfile)) {
4471 int keytype;
4472 logeventf(ssh, "Reading private key file \"%.150s\"",
4473 filename_to_str(&ssh->cfg.keyfile));
4474 keytype = key_type(&ssh->cfg.keyfile);
4475 if (keytype == SSH_KEYTYPE_SSH2) {
4476 s->publickey_blob =
4477 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
4478 &s->publickey_bloblen);
4479 } else {
4480 char *msgbuf;
4481 logeventf(ssh, "Unable to use this key file (%s)",
4482 key_type_to_str(keytype));
4483 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4484 " (%s)\r\n",
4485 filename_to_str(&ssh->cfg.keyfile),
4486 key_type_to_str(keytype));
4487 c_write_str(ssh, msgbuf);
4488 sfree(msgbuf);
4489 s->publickey_blob = NULL;
4490 }
4491 } else
4492 s->publickey_blob = NULL;
4493
4494 while (1) {
4495 /*
4496 * Wait for the result of the last authentication request.
4497 */
4498 if (!s->gotit)
4499 crWaitUntilV(ispkt);
4500 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4501 char *banner;
4502 int size;
4503 /*
4504 * Don't show the banner if we're operating in
4505 * non-verbose non-interactive mode. (It's probably
4506 * a script, which means nobody will read the
4507 * banner _anyway_, and moreover the printing of
4508 * the banner will screw up processing on the
4509 * output of (say) plink.)
4510 */
4511 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4512 ssh2_pkt_getstring(ssh, &banner, &size);
4513 if (banner)
4514 c_write_untrusted(ssh, banner, size);
4515 }
4516 crWaitUntilV(ispkt);
4517 }
4518 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4519 logevent("Access granted");
4520 s->we_are_in = TRUE;
4521 break;
4522 }
4523
4524 if (s->kbd_inter_running &&
4525 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4526 /*
4527 * This is either a further set-of-prompts packet
4528 * in keyboard-interactive authentication, or it's
4529 * the same one and we came back here with `gotit'
4530 * set. In the former case, we must reset the
4531 * curr_prompt variable.
4532 */
4533 if (!s->gotit)
4534 s->curr_prompt = 0;
4535 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4536 bombout(("Strange packet received during authentication: type %d",
4537 ssh->pktin.type));
4538 crReturnV;
4539 }
4540
4541 s->gotit = FALSE;
4542
4543 /*
4544 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4545 * we can look at the string in it and know what we can
4546 * helpfully try next.
4547 */
4548 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4549 char *methods;
4550 int methlen;
4551 ssh2_pkt_getstring(ssh, &methods, &methlen);
4552 s->kbd_inter_running = FALSE;
4553 if (!ssh2_pkt_getbool(ssh)) {
4554 /*
4555 * We have received an unequivocal Access
4556 * Denied. This can translate to a variety of
4557 * messages:
4558 *
4559 * - if we'd just tried "none" authentication,
4560 * it's not worth printing anything at all
4561 *
4562 * - if we'd just tried a public key _offer_,
4563 * the message should be "Server refused our
4564 * key" (or no message at all if the key
4565 * came from Pageant)
4566 *
4567 * - if we'd just tried anything else, the
4568 * message really should be "Access denied".
4569 *
4570 * Additionally, if we'd just tried password
4571 * authentication, we should break out of this
4572 * whole loop so as to go back to the username
4573 * prompt.
4574 */
4575 if (s->type == AUTH_TYPE_NONE) {
4576 /* do nothing */
4577 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4578 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4579 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4580 c_write_str(ssh, "Server refused our key\r\n");
4581 logevent("Server refused public key");
4582 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4583 /* server declined keyboard-interactive; ignore */
4584 } else {
4585 c_write_str(ssh, "Access denied\r\n");
4586 logevent("Access denied");
4587 if (s->type == AUTH_TYPE_PASSWORD) {
4588 s->we_are_in = FALSE;
4589 break;
4590 }
4591 }
4592 } else {
4593 c_write_str(ssh, "Further authentication required\r\n");
4594 logevent("Further authentication required");
4595 }
4596
4597 s->can_pubkey =
4598 in_commasep_string("publickey", methods, methlen);
4599 s->can_passwd =
4600 in_commasep_string("password", methods, methlen);
4601 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
4602 in_commasep_string("keyboard-interactive", methods, methlen);
4603 }
4604
4605 s->method = 0;
4606 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4607
4608 /*
4609 * Most password/passphrase prompts will be
4610 * non-echoing, so we set this to 0 by default.
4611 * Exception is that some keyboard-interactive prompts
4612 * can be echoing, in which case we'll set this to 1.
4613 */
4614 s->echo = 0;
4615
4616 if (!s->method && s->can_pubkey &&
4617 agent_exists() && !s->tried_agent) {
4618 /*
4619 * Attempt public-key authentication using Pageant.
4620 */
4621 void *r;
4622 s->authed = FALSE;
4623
4624 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4625 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4626
4627 s->tried_agent = TRUE;
4628
4629 logevent("Pageant is running. Requesting keys.");
4630
4631 /* Request the keys held by the agent. */
4632 PUT_32BIT(s->request, 1);
4633 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4634 agent_query(s->request, 5, &r, &s->responselen);
4635 s->response = (unsigned char *) r;
4636 if (s->response && s->responselen >= 5 &&
4637 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4638 s->p = s->response + 5;
4639 s->nkeys = GET_32BIT(s->p);
4640 s->p += 4;
4641 {
4642 char buf[64];
4643 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4644 logevent(buf);
4645 }
4646 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4647 void *vret;
4648
4649 {
4650 char buf[64];
4651 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4652 logevent(buf);
4653 }
4654 s->pklen = GET_32BIT(s->p);
4655 s->p += 4;
4656 if (s->publickey_blob &&
4657 s->pklen == s->publickey_bloblen &&
4658 !memcmp(s->p, s->publickey_blob,
4659 s->publickey_bloblen)) {
4660 logevent("This key matches configured key file");
4661 s->tried_pubkey_config = 1;
4662 }
4663 s->pkblob = (char *)s->p;
4664 s->p += s->pklen;
4665 s->alglen = GET_32BIT(s->pkblob);
4666 s->alg = s->pkblob + 4;
4667 s->commentlen = GET_32BIT(s->p);
4668 s->p += 4;
4669 s->commentp = (char *)s->p;
4670 s->p += s->commentlen;
4671 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4672 ssh2_pkt_addstring(ssh, s->username);
4673 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4674 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4675 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4676 ssh2_pkt_addstring_start(ssh);
4677 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4678 ssh2_pkt_addstring_start(ssh);
4679 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4680 ssh2_pkt_send(ssh);
4681
4682 crWaitUntilV(ispkt);
4683 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4684 logevent("Key refused");
4685 continue;
4686 }
4687
4688 if (flags & FLAG_VERBOSE) {
4689 c_write_str(ssh, "Authenticating with "
4690 "public key \"");
4691 c_write(ssh, s->commentp, s->commentlen);
4692 c_write_str(ssh, "\" from agent\r\n");
4693 }
4694
4695 /*
4696 * Server is willing to accept the key.
4697 * Construct a SIGN_REQUEST.
4698 */
4699 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4700 ssh2_pkt_addstring(ssh, s->username);
4701 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4702 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4703 ssh2_pkt_addbool(ssh, TRUE);
4704 ssh2_pkt_addstring_start(ssh);
4705 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4706 ssh2_pkt_addstring_start(ssh);
4707 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4708
4709 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4710 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4711 s->siglen -= 4;
4712 s->len = 1; /* message type */
4713 s->len += 4 + s->pklen; /* key blob */
4714 s->len += 4 + s->siglen; /* data to sign */
4715 s->len += 4; /* flags */
4716 s->agentreq = snewn(4 + s->len, char);
4717 PUT_32BIT(s->agentreq, s->len);
4718 s->q = s->agentreq + 4;
4719 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4720 PUT_32BIT(s->q, s->pklen);
4721 s->q += 4;
4722 memcpy(s->q, s->pkblob, s->pklen);
4723 s->q += s->pklen;
4724 PUT_32BIT(s->q, s->siglen);
4725 s->q += 4;
4726 /* Now the data to be signed... */
4727 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
4728 PUT_32BIT(s->q, 20);
4729 s->q += 4;
4730 }
4731 memcpy(s->q, ssh->v2_session_id, 20);
4732 s->q += 20;
4733 memcpy(s->q, ssh->pktout.data + 5,
4734 ssh->pktout.length - 5);
4735 s->q += ssh->pktout.length - 5;
4736 /* And finally the (zero) flags word. */
4737 PUT_32BIT(s->q, 0);
4738 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4739 s->ret = vret;
4740 sfree(s->agentreq);
4741 if (s->ret) {
4742 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4743 logevent("Sending Pageant's response");
4744 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4745 s->ret + 9,
4746 GET_32BIT(s->ret + 5));
4747 ssh2_pkt_send(ssh);
4748 s->authed = TRUE;
4749 break;
4750 } else {
4751 logevent
4752 ("Pageant failed to answer challenge");
4753 sfree(s->ret);
4754 }
4755 }
4756 }
4757 if (s->authed)
4758 continue;
4759 }
4760 }
4761
4762 if (!s->method && s->can_pubkey && s->publickey_blob
4763 && !s->tried_pubkey_config) {
4764 unsigned char *pub_blob;
4765 char *algorithm, *comment;
4766 int pub_blob_len;
4767
4768 s->tried_pubkey_config = TRUE;
4769
4770 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4771 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4772
4773 /*
4774 * Try the public key supplied in the configuration.
4775 *
4776 * First, offer the public blob to see if the server is
4777 * willing to accept it.
4778 */
4779 pub_blob =
4780 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
4781 &algorithm,
4782 &pub_blob_len);
4783 if (pub_blob) {
4784 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4785 ssh2_pkt_addstring(ssh, s->username);
4786 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4787 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4788 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4789 ssh2_pkt_addstring(ssh, algorithm);
4790 ssh2_pkt_addstring_start(ssh);
4791 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4792 pub_blob_len);
4793 ssh2_pkt_send(ssh);
4794 logevent("Offered public key"); /* FIXME */
4795
4796 crWaitUntilV(ispkt);
4797 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4798 s->gotit = TRUE;
4799 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4800 continue; /* key refused; give up on it */
4801 }
4802
4803 logevent("Offer of public key accepted");
4804 /*
4805 * Actually attempt a serious authentication using
4806 * the key.
4807 */
4808 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
4809 sprintf(s->pwprompt,
4810 "Passphrase for key \"%.100s\": ",
4811 comment);
4812 s->need_pw = TRUE;
4813 } else {
4814 s->need_pw = FALSE;
4815 }
4816 c_write_str(ssh, "Authenticating with public key \"");
4817 c_write_str(ssh, comment);
4818 c_write_str(ssh, "\"\r\n");
4819 s->method = AUTH_PUBLICKEY_FILE;
4820 }
4821 }
4822
4823 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4824 s->method = AUTH_KEYBOARD_INTERACTIVE;
4825 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4826 s->tried_keyb_inter = TRUE;
4827
4828 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4829 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4830
4831 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4832 ssh2_pkt_addstring(ssh, s->username);
4833 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4834 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4835 ssh2_pkt_addstring(ssh, ""); /* lang */
4836 ssh2_pkt_addstring(ssh, "");
4837 ssh2_pkt_send(ssh);
4838
4839 crWaitUntilV(ispkt);
4840 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4841 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4842 s->gotit = TRUE;
4843 logevent("Keyboard-interactive authentication refused");
4844 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4845 continue;
4846 }
4847
4848 s->kbd_inter_running = TRUE;
4849 s->curr_prompt = 0;
4850 }
4851
4852 if (s->kbd_inter_running) {
4853 s->method = AUTH_KEYBOARD_INTERACTIVE;
4854 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4855 s->tried_keyb_inter = TRUE;
4856
4857 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4858 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4859
4860 if (s->curr_prompt == 0) {
4861 /*
4862 * We've got a fresh USERAUTH_INFO_REQUEST.
4863 * Display header data, and start going through
4864 * the prompts.
4865 */
4866 char *name, *inst, *lang;
4867 int name_len, inst_len, lang_len;
4868
4869 ssh2_pkt_getstring(ssh, &name, &name_len);
4870 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4871 ssh2_pkt_getstring(ssh, &lang, &lang_len);
4872 if (name_len > 0) {
4873 c_write_untrusted(ssh, name, name_len);
4874 c_write_str(ssh, "\r\n");
4875 }
4876 if (inst_len > 0) {
4877 c_write_untrusted(ssh, inst, inst_len);
4878 c_write_str(ssh, "\r\n");
4879 }
4880 s->num_prompts = ssh2_pkt_getuint32(ssh);
4881 }
4882
4883 /*
4884 * If there are prompts remaining in the packet,
4885 * display one and get a response.
4886 */
4887 if (s->curr_prompt < s->num_prompts) {
4888 char *prompt;
4889 int prompt_len;
4890
4891 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
4892 if (prompt_len > 0) {
4893 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4894 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4895 prompt_len : sizeof(s->pwprompt)-1] = '\0';
4896 } else {
4897 strcpy(s->pwprompt,
4898 "<server failed to send prompt>: ");
4899 }
4900 s->echo = ssh2_pkt_getbool(ssh);
4901 s->need_pw = TRUE;
4902 } else
4903 s->need_pw = FALSE;
4904 }
4905
4906 if (!s->method && s->can_passwd) {
4907 s->method = AUTH_PASSWORD;
4908 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4909 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4910 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4911 ssh->savedhost);
4912 s->need_pw = TRUE;
4913 }
4914
4915 if (s->need_pw) {
4916 if (ssh_get_line) {
4917 if (!ssh_get_line(s->pwprompt, s->password,
4918 sizeof(s->password), TRUE)) {
4919 /*
4920 * get_line failed to get a password (for
4921 * example because one was supplied on the
4922 * command line which has already failed to
4923 * work). Terminate.
4924 */
4925 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4926 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4927 ssh2_pkt_addstring(ssh, "No more passwords available"
4928 " to try");
4929 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4930 ssh2_pkt_send(ssh);
4931 logevent("Unable to authenticate");
4932 connection_fatal(ssh->frontend,
4933 "Unable to authenticate");
4934 ssh_closing((Plug)ssh, NULL, 0, 0);
4935 crReturnV;
4936 }
4937 } else {
4938 int ret; /* need not be saved across crReturn */
4939 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4940 ssh->send_ok = 1;
4941
4942 setup_userpass_input(ssh, s->password,
4943 sizeof(s->password), s->echo);
4944 do {
4945 crWaitUntilV(!ispkt);
4946 ret = process_userpass_input(ssh, in, inlen);
4947 } while (ret == 0);
4948 if (ret < 0)
4949 cleanup_exit(0);
4950 c_write_str(ssh, "\r\n");
4951 }
4952 }
4953
4954 if (s->method == AUTH_PUBLICKEY_FILE) {
4955 /*
4956 * We have our passphrase. Now try the actual authentication.
4957 */
4958 struct ssh2_userkey *key;
4959
4960 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password);
4961 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4962 if (key == SSH2_WRONG_PASSPHRASE) {
4963 c_write_str(ssh, "Wrong passphrase\r\n");
4964 s->tried_pubkey_config = FALSE;
4965 } else {
4966 c_write_str(ssh, "Unable to load private key\r\n");
4967 s->tried_pubkey_config = TRUE;
4968 }
4969 /* Send a spurious AUTH_NONE to return to the top. */
4970 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4971 ssh2_pkt_addstring(ssh, s->username);
4972 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4973 ssh2_pkt_addstring(ssh, "none"); /* method */
4974 ssh2_pkt_send(ssh);
4975 s->type = AUTH_TYPE_NONE;
4976 } else {
4977 unsigned char *pkblob, *sigblob, *sigdata;
4978 int pkblob_len, sigblob_len, sigdata_len;
4979 int p;
4980
4981 /*
4982 * We have loaded the private key and the server
4983 * has announced that it's willing to accept it.
4984 * Hallelujah. Generate a signature and send it.
4985 */
4986 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4987 ssh2_pkt_addstring(ssh, s->username);
4988 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4989 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4990 ssh2_pkt_addbool(ssh, TRUE);
4991 ssh2_pkt_addstring(ssh, key->alg->name);
4992 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4993 ssh2_pkt_addstring_start(ssh);
4994 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
4995
4996 /*
4997 * The data to be signed is:
4998 *
4999 * string session-id
5000 *
5001 * followed by everything so far placed in the
5002 * outgoing packet.
5003 */
5004 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
5005 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5006 sigdata_len -= 4;
5007 sigdata = snewn(sigdata_len, unsigned char);
5008 p = 0;
5009 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5010 PUT_32BIT(sigdata+p, 20);
5011 p += 4;
5012 }
5013 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5014 memcpy(sigdata+p, ssh->pktout.data + 5,
5015 ssh->pktout.length - 5);
5016 p += ssh->pktout.length - 5;
5017 assert(p == sigdata_len);
5018 sigblob = key->alg->sign(key->data, (char *)sigdata,
5019 sigdata_len, &sigblob_len);
5020 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
5021 sigblob, sigblob_len);
5022 sfree(pkblob);
5023 sfree(sigblob);
5024 sfree(sigdata);
5025
5026 ssh2_pkt_send(ssh);
5027 s->type = AUTH_TYPE_PUBLICKEY;
5028 }
5029 } else if (s->method == AUTH_PASSWORD) {
5030 /*
5031 * We send the password packet lumped tightly together with
5032 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5033 * string long enough to make the total length of the two
5034 * packets constant. This should ensure that a passive
5035 * listener doing traffic analyis can't work out the length
5036 * of the password.
5037 *
5038 * For this to work, we need an assumption about the
5039 * maximum length of the password packet. I think 256 is
5040 * pretty conservative. Anyone using a password longer than
5041 * that probably doesn't have much to worry about from
5042 * people who find out how long their password is!
5043 */
5044 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5045 ssh2_pkt_addstring(ssh, s->username);
5046 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5047 ssh2_pkt_addstring(ssh, "password");
5048 ssh2_pkt_addbool(ssh, FALSE);
5049 ssh2_pkt_addstring(ssh, s->password);
5050 memset(s->password, 0, sizeof(s->password));
5051 ssh2_pkt_defer(ssh);
5052 /*
5053 * We'll include a string that's an exact multiple of the
5054 * cipher block size. If the cipher is NULL for some
5055 * reason, we don't do this trick at all because we gain
5056 * nothing by it.
5057 */
5058 if (ssh->cscipher) {
5059 int stringlen, i;
5060
5061 stringlen = (256 - ssh->deferred_len);
5062 stringlen += ssh->cscipher->blksize - 1;
5063 stringlen -= (stringlen % ssh->cscipher->blksize);
5064 if (ssh->cscomp) {
5065 /*
5066 * Temporarily disable actual compression,
5067 * so we can guarantee to get this string
5068 * exactly the length we want it. The
5069 * compression-disabling routine should
5070 * return an integer indicating how many
5071 * bytes we should adjust our string length
5072 * by.
5073 */
5074 stringlen -=
5075 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
5076 }
5077 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5078 ssh2_pkt_addstring_start(ssh);
5079 for (i = 0; i < stringlen; i++) {
5080 char c = (char) random_byte();
5081 ssh2_pkt_addstring_data(ssh, &c, 1);
5082 }
5083 ssh2_pkt_defer(ssh);
5084 }
5085 ssh_pkt_defersend(ssh);
5086 logevent("Sent password");
5087 s->type = AUTH_TYPE_PASSWORD;
5088 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5089 if (s->curr_prompt == 0) {
5090 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5091 ssh2_pkt_adduint32(ssh, s->num_prompts);
5092 }
5093 if (s->need_pw) { /* only add pw if we just got one! */
5094 ssh2_pkt_addstring(ssh, s->password);
5095 memset(s->password, 0, sizeof(s->password));
5096 s->curr_prompt++;
5097 }
5098 if (s->curr_prompt >= s->num_prompts) {
5099 ssh2_pkt_send(ssh);
5100 } else {
5101 /*
5102 * If there are prompts remaining, we set
5103 * `gotit' so that we won't attempt to get
5104 * another packet. Then we go back round the
5105 * loop and will end up retrieving another
5106 * prompt out of the existing packet. Funky or
5107 * what?
5108 */
5109 s->gotit = TRUE;
5110 }
5111 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5112 } else {
5113 c_write_str(ssh, "No supported authentication methods"
5114 " left to try!\r\n");
5115 logevent("No supported authentications offered."
5116 " Disconnecting");
5117 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5118 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5119 ssh2_pkt_addstring(ssh, "No supported authentication"
5120 " methods available");
5121 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5122 ssh2_pkt_send(ssh);
5123 ssh_closing((Plug)ssh, NULL, 0, 0);
5124 crReturnV;
5125 }
5126 }
5127 } while (!s->we_are_in);
5128
5129 /*
5130 * Now we're authenticated for the connection protocol. The
5131 * connection protocol will automatically have started at this
5132 * point; there's no need to send SERVICE_REQUEST.
5133 */
5134
5135 /*
5136 * So now create a channel with a session in it.
5137 */
5138 ssh->channels = newtree234(ssh_channelcmp);
5139 ssh->mainchan = snew(struct ssh_channel);
5140 ssh->mainchan->ssh = ssh;
5141 ssh->mainchan->localid = alloc_channel_id(ssh);
5142 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5143 ssh2_pkt_addstring(ssh, "session");
5144 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5145 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5146 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5147 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5148 ssh2_pkt_send(ssh);
5149 crWaitUntilV(ispkt);
5150 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5151 bombout(("Server refused to open a session"));
5152 crReturnV;
5153 /* FIXME: error data comes back in FAILURE packet */
5154 }
5155 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5156 bombout(("Server's channel confirmation cited wrong channel"));
5157 crReturnV;
5158 }
5159 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5160 ssh->mainchan->type = CHAN_MAINSESSION;
5161 ssh->mainchan->closes = 0;
5162 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5163 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5164 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5165 add234(ssh->channels, ssh->mainchan);
5166 logevent("Opened channel for session");
5167
5168 /*
5169 * Potentially enable X11 forwarding.
5170 */
5171 if (ssh->cfg.x11_forward) {
5172 char proto[20], data[64];
5173 logevent("Requesting X11 forwarding");
5174 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5175 data, sizeof(data), ssh->cfg.x11_auth);
5176 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
5177 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5178 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5179 ssh2_pkt_addstring(ssh, "x11-req");
5180 ssh2_pkt_addbool(ssh, 1); /* want reply */
5181 ssh2_pkt_addbool(ssh, 0); /* many connections */
5182 ssh2_pkt_addstring(ssh, proto);
5183 ssh2_pkt_addstring(ssh, data);
5184 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
5185 ssh2_pkt_send(ssh);
5186
5187 do {
5188 crWaitUntilV(ispkt);
5189 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5190 unsigned i = ssh2_pkt_getuint32(ssh);
5191 struct ssh_channel *c;
5192 c = find234(ssh->channels, &i, ssh_channelfind);
5193 if (!c)
5194 continue; /* nonexistent channel */
5195 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5196 }
5197 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5198
5199 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5200 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5201 bombout(("Unexpected response to X11 forwarding request:"
5202 " packet type %d", ssh->pktin.type));
5203 crReturnV;
5204 }
5205 logevent("X11 forwarding refused");
5206 } else {
5207 logevent("X11 forwarding enabled");
5208 ssh->X11_fwd_enabled = TRUE;
5209 }
5210 }
5211
5212 /*
5213 * Enable port forwardings.
5214 */
5215 {
5216 char type;
5217 int n;
5218 int sport,dport,sserv,dserv;
5219 char sports[256], dports[256], saddr[256], host[256];
5220
5221 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5222 /* Add port forwardings. */
5223 ssh->portfwd_strptr = ssh->cfg.portfwd;
5224 while (*ssh->portfwd_strptr) {
5225 type = *ssh->portfwd_strptr++;
5226 saddr[0] = '\0';
5227 n = 0;
5228 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5229 if (*ssh->portfwd_strptr == ':') {
5230 /*
5231 * We've seen a colon in the middle of the
5232 * source port number. This means that
5233 * everything we've seen until now is the
5234 * source _address_, so we'll move it into
5235 * saddr and start sports from the beginning
5236 * again.
5237 */
5238 ssh->portfwd_strptr++;
5239 sports[n] = '\0';
5240 strcpy(saddr, sports);
5241 n = 0;
5242 }
5243 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5244 }
5245 sports[n] = 0;
5246 if (type != 'D') {
5247 if (*ssh->portfwd_strptr == '\t')
5248 ssh->portfwd_strptr++;
5249 n = 0;
5250 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5251 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5252 }
5253 host[n] = 0;
5254 if (*ssh->portfwd_strptr == ':')
5255 ssh->portfwd_strptr++;
5256 n = 0;
5257 while (*ssh->portfwd_strptr) {
5258 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5259 }
5260 dports[n] = 0;
5261 ssh->portfwd_strptr++;
5262 dport = atoi(dports);
5263 dserv = 0;
5264 if (dport == 0) {
5265 dserv = 1;
5266 dport = net_service_lookup(dports);
5267 if (!dport) {
5268 logeventf(ssh, "Service lookup failed for destination"
5269 " port \"%s\"", dports);
5270 }
5271 }
5272 } else {
5273 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
5274 }
5275 sport = atoi(sports);
5276 sserv = 0;
5277 if (sport == 0) {
5278 sserv = 1;
5279 sport = net_service_lookup(sports);
5280 if (!sport) {
5281 logeventf(ssh, "Service lookup failed for source"
5282 " port \"%s\"", sports);
5283 }
5284 }
5285 if (sport && dport) {
5286 if (type == 'L') {
5287 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5288 sport, ssh, &ssh->cfg);
5289 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5290 " forwarding to %s:%.*s%.*s%d%.*s",
5291 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5292 (int)(*saddr?1:0), ":",
5293 (int)(sserv ? strlen(sports) : 0), sports,
5294 sserv, "(", sport, sserv, ")",
5295 host,
5296 (int)(dserv ? strlen(dports) : 0), dports,
5297 dserv, "(", dport, dserv, ")");
5298 } else if (type == 'D') {
5299 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
5300 sport, ssh, &ssh->cfg);
5301 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5302 " doing SOCKS dynamic forwarding",
5303 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5304 (int)(*saddr?1:0), ":",
5305 (int)(sserv ? strlen(sports) : 0), sports,
5306 sserv, "(", sport, sserv, ")");
5307 } else {
5308 struct ssh_rportfwd *pf;
5309 pf = snew(struct ssh_rportfwd);
5310 strcpy(pf->dhost, host);
5311 pf->dport = dport;
5312 pf->sport = sport;
5313 if (add234(ssh->rportfwds, pf) != pf) {
5314 logeventf(ssh, "Duplicate remote port forwarding"
5315 " to %s:%d", host, dport);
5316 sfree(pf);
5317 } else {
5318 logeventf(ssh, "Requesting remote port "
5319 "%.*s%.*s%.*s%.*s%d%.*s"
5320 " forward to %s:%.*s%.*s%d%.*s",
5321 (int)(*saddr?strlen(saddr):0),
5322 *saddr?saddr:NULL,
5323 (int)(*saddr?1:0), ":",
5324 (int)(sserv ? strlen(sports) : 0), sports,
5325 sserv, "(", sport, sserv, ")",
5326 host,
5327 (int)(dserv ? strlen(dports) : 0), dports,
5328 dserv, "(", dport, dserv, ")");
5329 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5330 ssh2_pkt_addstring(ssh, "tcpip-forward");
5331 ssh2_pkt_addbool(ssh, 1);/* want reply */
5332 if (*saddr)
5333 ssh2_pkt_addstring(ssh, saddr);
5334 if (ssh->cfg.rport_acceptall)
5335 ssh2_pkt_addstring(ssh, "0.0.0.0");
5336 else
5337 ssh2_pkt_addstring(ssh, "127.0.0.1");
5338 ssh2_pkt_adduint32(ssh, sport);
5339 ssh2_pkt_send(ssh);
5340
5341 do {
5342 crWaitUntilV(ispkt);
5343 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5344 unsigned i = ssh2_pkt_getuint32(ssh);
5345 struct ssh_channel *c;
5346 c = find234(ssh->channels, &i, ssh_channelfind);
5347 if (!c)
5348 continue;/* nonexistent channel */
5349 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5350 }
5351 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5352
5353 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5354 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5355 bombout(("Unexpected response to port "
5356 "forwarding request: packet type %d",
5357 ssh->pktin.type));
5358 crReturnV;
5359 }
5360 logevent("Server refused this port forwarding");
5361 } else {
5362 logevent("Remote port forwarding enabled");
5363 }
5364 }
5365 }
5366 }
5367 }
5368 }
5369
5370 /*
5371 * Potentially enable agent forwarding.
5372 */
5373 if (ssh->cfg.agentfwd && agent_exists()) {
5374 logevent("Requesting OpenSSH-style agent forwarding");
5375 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5376 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5377 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5378 ssh2_pkt_addbool(ssh, 1); /* want reply */
5379 ssh2_pkt_send(ssh);
5380
5381 do {
5382 crWaitUntilV(ispkt);
5383 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5384 unsigned i = ssh2_pkt_getuint32(ssh);
5385 struct ssh_channel *c;
5386 c = find234(ssh->channels, &i, ssh_channelfind);
5387 if (!c)
5388 continue; /* nonexistent channel */
5389 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5390 }
5391 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5392
5393 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5394 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5395 bombout(("Unexpected response to agent forwarding request:"
5396 " packet type %d", ssh->pktin.type));
5397 crReturnV;
5398 }
5399 logevent("Agent forwarding refused");
5400 } else {
5401 logevent("Agent forwarding enabled");
5402 ssh->agentfwd_enabled = TRUE;
5403 }
5404 }
5405
5406 /*
5407 * Now allocate a pty for the session.
5408 */
5409 if (!ssh->cfg.nopty) {
5410 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5411 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5412 ssh2_pkt_addstring(ssh, "pty-req");
5413 ssh2_pkt_addbool(ssh, 1); /* want reply */
5414 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
5415 ssh2_pkt_adduint32(ssh, ssh->term_width);
5416 ssh2_pkt_adduint32(ssh, ssh->term_height);
5417 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5418 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5419 ssh2_pkt_addstring_start(ssh);
5420 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5421 ssh2_pkt_send(ssh);
5422 ssh->state = SSH_STATE_INTERMED;
5423
5424 do {
5425 crWaitUntilV(ispkt);
5426 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5427 unsigned i = ssh2_pkt_getuint32(ssh);
5428 struct ssh_channel *c;
5429 c = find234(ssh->channels, &i, ssh_channelfind);
5430 if (!c)
5431 continue; /* nonexistent channel */
5432 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5433 }
5434 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5435
5436 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5437 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5438 bombout(("Unexpected response to pty request:"
5439 " packet type %d", ssh->pktin.type));
5440 crReturnV;
5441 }
5442 c_write_str(ssh, "Server refused to allocate pty\r\n");
5443 ssh->editing = ssh->echoing = 1;
5444 } else {
5445 logevent("Allocated pty");
5446 }
5447 } else {
5448 ssh->editing = ssh->echoing = 1;
5449 }
5450
5451 /*
5452 * Start a shell or a remote command. We may have to attempt
5453 * this twice if the config data has provided a second choice
5454 * of command.
5455 */
5456 while (1) {
5457 int subsys;
5458 char *cmd;
5459
5460 if (ssh->fallback_cmd) {
5461 subsys = ssh->cfg.ssh_subsys2;
5462 cmd = ssh->cfg.remote_cmd_ptr2;
5463 } else {
5464 subsys = ssh->cfg.ssh_subsys;
5465 cmd = ssh->cfg.remote_cmd_ptr;
5466 }
5467
5468 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5469 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5470 if (subsys) {
5471 ssh2_pkt_addstring(ssh, "subsystem");
5472 ssh2_pkt_addbool(ssh, 1); /* want reply */
5473 ssh2_pkt_addstring(ssh, cmd);
5474 } else if (*cmd) {
5475 ssh2_pkt_addstring(ssh, "exec");
5476 ssh2_pkt_addbool(ssh, 1); /* want reply */
5477 ssh2_pkt_addstring(ssh, cmd);
5478 } else {
5479 ssh2_pkt_addstring(ssh, "shell");
5480 ssh2_pkt_addbool(ssh, 1); /* want reply */
5481 }
5482 ssh2_pkt_send(ssh);
5483 do {
5484 crWaitUntilV(ispkt);
5485 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5486 unsigned i = ssh2_pkt_getuint32(ssh);
5487 struct ssh_channel *c;
5488 c = find234(ssh->channels, &i, ssh_channelfind);
5489 if (!c)
5490 continue; /* nonexistent channel */
5491 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5492 }
5493 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5494 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5495 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5496 bombout(("Unexpected response to shell/command request:"
5497 " packet type %d", ssh->pktin.type));
5498 crReturnV;
5499 }
5500 /*
5501 * We failed to start the command. If this is the
5502 * fallback command, we really are finished; if it's
5503 * not, and if the fallback command exists, try falling
5504 * back to it before complaining.
5505 */
5506 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
5507 logevent("Primary command failed; attempting fallback");
5508 ssh->fallback_cmd = TRUE;
5509 continue;
5510 }
5511 bombout(("Server refused to start a shell/command"));
5512 crReturnV;
5513 } else {
5514 logevent("Started a shell/command");
5515 }
5516 break;
5517 }
5518
5519 ssh->state = SSH_STATE_SESSION;
5520 if (ssh->size_needed)
5521 ssh_size(ssh, ssh->term_width, ssh->term_height);
5522 if (ssh->eof_needed)
5523 ssh_special(ssh, TS_EOF);
5524
5525 /*
5526 * Transfer data!
5527 */
5528 if (ssh->ldisc)
5529 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5530 ssh->send_ok = 1;
5531 while (1) {
5532 crReturnV;
5533 s->try_send = FALSE;
5534 if (ispkt) {
5535 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5536 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5537 char *data;
5538 int length;
5539 unsigned i = ssh2_pkt_getuint32(ssh);
5540 struct ssh_channel *c;
5541 c = find234(ssh->channels, &i, ssh_channelfind);
5542 if (!c)
5543 continue; /* nonexistent channel */
5544 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5545 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5546 continue; /* extended but not stderr */
5547 ssh2_pkt_getstring(ssh, &data, &length);
5548 if (data) {
5549 int bufsize;
5550 c->v.v2.locwindow -= length;
5551 switch (c->type) {
5552 case CHAN_MAINSESSION:
5553 bufsize =
5554 from_backend(ssh->frontend, ssh->pktin.type ==
5555 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5556 data, length);
5557 break;
5558 case CHAN_X11:
5559 bufsize = x11_send(c->u.x11.s, data, length);
5560 break;
5561 case CHAN_SOCKDATA:
5562 bufsize = pfd_send(c->u.pfd.s, data, length);
5563 break;
5564 case CHAN_AGENT:
5565 while (length > 0) {
5566 if (c->u.a.lensofar < 4) {
5567 int l = min(4 - c->u.a.lensofar, length);
5568 memcpy(c->u.a.msglen + c->u.a.lensofar,
5569 data, l);
5570 data += l;
5571 length -= l;
5572 c->u.a.lensofar += l;
5573 }
5574 if (c->u.a.lensofar == 4) {
5575 c->u.a.totallen =
5576 4 + GET_32BIT(c->u.a.msglen);
5577 c->u.a.message = snewn(c->u.a.totallen,
5578 unsigned char);
5579 memcpy(c->u.a.message, c->u.a.msglen, 4);
5580 }
5581 if (c->u.a.lensofar >= 4 && length > 0) {
5582 int l =
5583 min(c->u.a.totallen - c->u.a.lensofar,
5584 length);
5585 memcpy(c->u.a.message + c->u.a.lensofar,
5586 data, l);
5587 data += l;
5588 length -= l;
5589 c->u.a.lensofar += l;
5590 }
5591 if (c->u.a.lensofar == c->u.a.totallen) {
5592 void *reply, *sentreply;
5593 int replylen;
5594 agent_query(c->u.a.message,
5595 c->u.a.totallen, &reply,
5596 &replylen);
5597 if (reply)
5598 sentreply = reply;
5599 else {
5600 /* Fake SSH_AGENT_FAILURE. */
5601 sentreply = "\0\0\0\1\5";
5602 replylen = 5;
5603 }
5604 ssh2_add_channel_data(c, sentreply, replylen);
5605 s->try_send = TRUE;
5606 if (reply)
5607 sfree(reply);
5608 sfree(c->u.a.message);
5609 c->u.a.lensofar = 0;
5610 }
5611 }
5612 bufsize = 0;
5613 break;
5614 }
5615 /*
5616 * If we are not buffering too much data,
5617 * enlarge the window again at the remote side.
5618 */
5619 if (bufsize < OUR_V2_WINSIZE)
5620 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5621 }
5622 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5623 unsigned i = ssh2_pkt_getuint32(ssh);
5624 struct ssh_channel *c;
5625
5626 c = find234(ssh->channels, &i, ssh_channelfind);
5627 if (!c)
5628 continue; /* nonexistent channel */
5629
5630 if (c->type == CHAN_X11) {
5631 /*
5632 * Remote EOF on an X11 channel means we should
5633 * wrap up and close the channel ourselves.
5634 */
5635 x11_close(c->u.x11.s);
5636 sshfwd_close(c);
5637 } else if (c->type == CHAN_AGENT) {
5638 sshfwd_close(c);
5639 } else if (c->type == CHAN_SOCKDATA) {
5640 pfd_close(c->u.pfd.s);
5641 sshfwd_close(c);
5642 }
5643 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5644 unsigned i = ssh2_pkt_getuint32(ssh);
5645 struct ssh_channel *c;
5646
5647 c = find234(ssh->channels, &i, ssh_channelfind);
5648 if (!c || ((int)c->remoteid) == -1) {
5649 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5650 c ? "half-open" : "nonexistent", i));
5651 }
5652 /* Do pre-close processing on the channel. */
5653 switch (c->type) {
5654 case CHAN_MAINSESSION:
5655 break; /* nothing to see here, move along */
5656 case CHAN_X11:
5657 if (c->u.x11.s != NULL)
5658 x11_close(c->u.x11.s);
5659 sshfwd_close(c);
5660 break;
5661 case CHAN_AGENT:
5662 sshfwd_close(c);
5663 break;
5664 case CHAN_SOCKDATA:
5665 if (c->u.pfd.s != NULL)
5666 pfd_close(c->u.pfd.s);
5667 sshfwd_close(c);
5668 break;
5669 }
5670 if (c->closes == 0) {
5671 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5672 ssh2_pkt_adduint32(ssh, c->remoteid);
5673 ssh2_pkt_send(ssh);
5674 }
5675 del234(ssh->channels, c);
5676 bufchain_clear(&c->v.v2.outbuffer);
5677 sfree(c);
5678
5679 /*
5680 * See if that was the last channel left open.
5681 */
5682 if (count234(ssh->channels) == 0) {
5683 logevent("All channels closed. Disconnecting");
5684 #if 0
5685 /*
5686 * We used to send SSH_MSG_DISCONNECT here,
5687 * because I'd believed that _every_ conforming
5688 * SSH2 connection had to end with a disconnect
5689 * being sent by at least one side; apparently
5690 * I was wrong and it's perfectly OK to
5691 * unceremoniously slam the connection shut
5692 * when you're done, and indeed OpenSSH feels
5693 * this is more polite than sending a
5694 * DISCONNECT. So now we don't.
5695 */
5696 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5697 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5698 ssh2_pkt_addstring(ssh, "All open channels closed");
5699 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5700 ssh2_pkt_send(ssh);
5701 #endif
5702 ssh_closing((Plug)ssh, NULL, 0, 0);
5703 crReturnV;
5704 }
5705 continue; /* remote sends close; ignore (FIXME) */
5706 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5707 unsigned i = ssh2_pkt_getuint32(ssh);
5708 struct ssh_channel *c;
5709 c = find234(ssh->channels, &i, ssh_channelfind);
5710 if (!c || c->closes)
5711 continue; /* nonexistent or closing channel */
5712 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5713 s->try_send = TRUE;
5714 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5715 unsigned i = ssh2_pkt_getuint32(ssh);
5716 struct ssh_channel *c;
5717 c = find234(ssh->channels, &i, ssh_channelfind);
5718 if (!c)
5719 continue; /* nonexistent channel */
5720 if (c->type != CHAN_SOCKDATA_DORMANT)
5721 continue; /* dunno why they're confirming this */
5722 c->remoteid = ssh2_pkt_getuint32(ssh);
5723 c->type = CHAN_SOCKDATA;
5724 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5725 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5726 if (c->u.pfd.s)
5727 pfd_confirm(c->u.pfd.s);
5728 if (c->closes) {
5729 /*
5730 * We have a pending close on this channel,
5731 * which we decided on before the server acked
5732 * the channel open. So now we know the
5733 * remoteid, we can close it again.
5734 */
5735 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5736 ssh2_pkt_adduint32(ssh, c->remoteid);
5737 ssh2_pkt_send(ssh);
5738 }
5739 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5740 unsigned i = ssh2_pkt_getuint32(ssh);
5741 struct ssh_channel *c;
5742 c = find234(ssh->channels, &i, ssh_channelfind);
5743 if (!c)
5744 continue; /* nonexistent channel */
5745 if (c->type != CHAN_SOCKDATA_DORMANT)
5746 continue; /* dunno why they're failing this */
5747
5748 logevent("Forwarded connection refused by server");
5749
5750 pfd_close(c->u.pfd.s);
5751
5752 del234(ssh->channels, c);
5753 sfree(c);
5754 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5755 unsigned localid;
5756 char *type;
5757 int typelen, want_reply;
5758 struct ssh_channel *c;
5759
5760 localid = ssh2_pkt_getuint32(ssh);
5761 ssh2_pkt_getstring(ssh, &type, &typelen);
5762 want_reply = ssh2_pkt_getbool(ssh);
5763
5764 /*
5765 * First, check that the channel exists. Otherwise,
5766 * we can instantly disconnect with a rude message.
5767 */
5768 c = find234(ssh->channels, &localid, ssh_channelfind);
5769 if (!c) {
5770 char buf[80];
5771 sprintf(buf, "Received channel request for nonexistent"
5772 " channel %d", localid);
5773 logevent(buf);
5774 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5775 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5776 ssh2_pkt_addstring(ssh, buf);
5777 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5778 ssh2_pkt_send(ssh);
5779 connection_fatal(ssh->frontend, "%s", buf);
5780 ssh_closing((Plug)ssh, NULL, 0, 0);
5781 crReturnV;
5782 }
5783
5784 /*
5785 * Having got the channel number, we now look at
5786 * the request type string to see if it's something
5787 * we recognise.
5788 */
5789 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5790 c == ssh->mainchan) {
5791 /* We recognise "exit-status" on the primary channel. */
5792 char buf[100];
5793 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5794 sprintf(buf, "Server sent command exit status %d",
5795 ssh->exitcode);
5796 logevent(buf);
5797 if (want_reply) {
5798 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5799 ssh2_pkt_adduint32(ssh, c->remoteid);
5800 ssh2_pkt_send(ssh);
5801 }
5802 } else {
5803 /*
5804 * This is a channel request we don't know
5805 * about, so we now either ignore the request
5806 * or respond with CHANNEL_FAILURE, depending
5807 * on want_reply.
5808 */
5809 if (want_reply) {
5810 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5811 ssh2_pkt_adduint32(ssh, c->remoteid);
5812 ssh2_pkt_send(ssh);
5813 }
5814 }
5815 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5816 char *type;
5817 int typelen, want_reply;
5818
5819 ssh2_pkt_getstring(ssh, &type, &typelen);
5820 want_reply = ssh2_pkt_getbool(ssh);
5821
5822 /*
5823 * We currently don't support any global requests
5824 * at all, so we either ignore the request or
5825 * respond with REQUEST_FAILURE, depending on
5826 * want_reply.
5827 */
5828 if (want_reply) {
5829 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5830 ssh2_pkt_send(ssh);
5831 }
5832 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5833 char *type;
5834 int typelen;
5835 char *peeraddr;
5836 int peeraddrlen;
5837 int port;
5838 char *error = NULL;
5839 struct ssh_channel *c;
5840 unsigned remid, winsize, pktsize;
5841 ssh2_pkt_getstring(ssh, &type, &typelen);
5842 c = snew(struct ssh_channel);
5843 c->ssh = ssh;
5844
5845 remid = ssh2_pkt_getuint32(ssh);
5846 winsize = ssh2_pkt_getuint32(ssh);
5847 pktsize = ssh2_pkt_getuint32(ssh);
5848 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5849 port = ssh2_pkt_getuint32(ssh);
5850
5851 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5852 char *addrstr = snewn(peeraddrlen+1, char);
5853 memcpy(addrstr, peeraddr, peeraddrlen);
5854 peeraddr[peeraddrlen] = '\0';
5855
5856 if (!ssh->X11_fwd_enabled)
5857 error = "X11 forwarding is not enabled";
5858 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5859 ssh->x11auth, addrstr, port,
5860 &ssh->cfg) != NULL) {
5861 error = "Unable to open an X11 connection";
5862 } else {
5863 c->type = CHAN_X11;
5864 }
5865
5866 sfree(addrstr);
5867 } else if (typelen == 15 &&
5868 !memcmp(type, "forwarded-tcpip", 15)) {
5869 struct ssh_rportfwd pf, *realpf;
5870 char *dummy;
5871 int dummylen;
5872 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5873 pf.sport = ssh2_pkt_getuint32(ssh);
5874 realpf = find234(ssh->rportfwds, &pf, NULL);
5875 if (realpf == NULL) {
5876 error = "Remote port is not recognised";
5877 } else {
5878 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5879 realpf->dport, c, &ssh->cfg);
5880 logeventf(ssh, "Received remote port open request"
5881 " for %s:%d", realpf->dhost, realpf->dport);
5882 if (e != NULL) {
5883 logeventf(ssh, "Port open failed: %s", e);
5884 error = "Port open failed";
5885 } else {
5886 logevent("Forwarded port opened successfully");
5887 c->type = CHAN_SOCKDATA;
5888 }
5889 }
5890 } else if (typelen == 22 &&
5891 !memcmp(type, "auth-agent@openssh.com", 3)) {
5892 if (!ssh->agentfwd_enabled)
5893 error = "Agent forwarding is not enabled";
5894 else {
5895 c->type = CHAN_AGENT; /* identify channel type */
5896 c->u.a.lensofar = 0;
5897 }
5898 } else {
5899 error = "Unsupported channel type requested";
5900 }
5901
5902 c->remoteid = remid;
5903 if (error) {
5904 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5905 ssh2_pkt_adduint32(ssh, c->remoteid);
5906 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5907 ssh2_pkt_addstring(ssh, error);
5908 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5909 ssh2_pkt_send(ssh);
5910 sfree(c);
5911 } else {
5912 c->localid = alloc_channel_id(ssh);
5913 c->closes = 0;
5914 c->v.v2.locwindow = OUR_V2_WINSIZE;
5915 c->v.v2.remwindow = winsize;
5916 c->v.v2.remmaxpkt = pktsize;
5917 bufchain_init(&c->v.v2.outbuffer);
5918 add234(ssh->channels, c);
5919 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5920 ssh2_pkt_adduint32(ssh, c->remoteid);
5921 ssh2_pkt_adduint32(ssh, c->localid);
5922 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5923 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5924 ssh2_pkt_send(ssh);
5925 }
5926 } else {
5927 bombout(("Strange packet received: type %d", ssh->pktin.type));
5928 crReturnV;
5929 }
5930 } else {
5931 /*
5932 * We have spare data. Add it to the channel buffer.
5933 */
5934 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
5935 s->try_send = TRUE;
5936 }
5937 if (s->try_send) {
5938 int i;
5939 struct ssh_channel *c;
5940 /*
5941 * Try to send data on all channels if we can.
5942 */
5943 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5944 int bufsize;
5945 if (c->closes)
5946 continue; /* don't send on closing channels */
5947 bufsize = ssh2_try_send(c);
5948 if (bufsize == 0) {
5949 switch (c->type) {
5950 case CHAN_MAINSESSION:
5951 /* stdin need not receive an unthrottle
5952 * notification since it will be polled */
5953 break;
5954 case CHAN_X11:
5955 x11_unthrottle(c->u.x11.s);
5956 break;
5957 case CHAN_AGENT:
5958 /* agent sockets are request/response and need no
5959 * buffer management */
5960 break;
5961 case CHAN_SOCKDATA:
5962 pfd_unthrottle(c->u.pfd.s);
5963 break;
5964 }
5965 }
5966 }
5967 }
5968 }
5969
5970 crFinishV;
5971 }
5972
5973 /*
5974 * Handle the top-level SSH2 protocol.
5975 */
5976 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
5977 {
5978 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
5979 return;
5980 do_ssh2_authconn(ssh, in, inlen, ispkt);
5981 }
5982
5983 /*
5984 * Called to set up the connection.
5985 *
5986 * Returns an error message, or NULL on success.
5987 */
5988 static char *ssh_init(void *frontend_handle, void **backend_handle,
5989 Config *cfg,
5990 char *host, int port, char **realhost, int nodelay)
5991 {
5992 char *p;
5993 Ssh ssh;
5994
5995 ssh = snew(struct ssh_tag);
5996 ssh->cfg = *cfg; /* STRUCTURE COPY */
5997 ssh->version = 0; /* when not ready yet */
5998 ssh->s = NULL;
5999 ssh->cipher = NULL;
6000 ssh->v1_cipher_ctx = NULL;
6001 ssh->crcda_ctx = NULL;
6002 ssh->cscipher = NULL;
6003 ssh->cs_cipher_ctx = NULL;
6004 ssh->sccipher = NULL;
6005 ssh->sc_cipher_ctx = NULL;
6006 ssh->csmac = NULL;
6007 ssh->cs_mac_ctx = NULL;
6008 ssh->scmac = NULL;
6009 ssh->sc_mac_ctx = NULL;
6010 ssh->cscomp = NULL;
6011 ssh->cs_comp_ctx = NULL;
6012 ssh->sccomp = NULL;
6013 ssh->sc_comp_ctx = NULL;
6014 ssh->kex = NULL;
6015 ssh->kex_ctx = NULL;
6016 ssh->hostkey = NULL;
6017 ssh->exitcode = -1;
6018 ssh->state = SSH_STATE_PREPACKET;
6019 ssh->size_needed = FALSE;
6020 ssh->eof_needed = FALSE;
6021 ssh->ldisc = NULL;
6022 ssh->logctx = NULL;
6023 {
6024 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6025 ssh->pktin = ssh->pktout = empty;
6026 }
6027 ssh->deferred_send_data = NULL;
6028 ssh->deferred_len = 0;
6029 ssh->deferred_size = 0;
6030 ssh->fallback_cmd = 0;
6031 ssh->pkt_ctx = 0;
6032 ssh->x11auth = NULL;
6033 ssh->v1_compressing = FALSE;
6034 ssh->v2_outgoing_sequence = 0;
6035 ssh->ssh1_rdpkt_crstate = 0;
6036 ssh->ssh2_rdpkt_crstate = 0;
6037 ssh->do_ssh_init_crstate = 0;
6038 ssh->ssh_gotdata_crstate = 0;
6039 ssh->ssh1_protocol_crstate = 0;
6040 ssh->do_ssh1_login_crstate = 0;
6041 ssh->do_ssh2_transport_crstate = 0;
6042 ssh->do_ssh2_authconn_crstate = 0;
6043 ssh->do_ssh_init_state = NULL;
6044 ssh->do_ssh1_login_state = NULL;
6045 ssh->do_ssh2_transport_state = NULL;
6046 ssh->do_ssh2_authconn_state = NULL;
6047 ssh->mainchan = NULL;
6048 ssh->throttled_all = 0;
6049 ssh->v1_stdout_throttling = 0;
6050
6051 *backend_handle = ssh;
6052
6053 #ifdef MSCRYPTOAPI
6054 if (crypto_startup() == 0)
6055 return "Microsoft high encryption pack not installed!";
6056 #endif
6057
6058 ssh->frontend = frontend_handle;
6059 ssh->term_width = ssh->cfg.width;
6060 ssh->term_height = ssh->cfg.height;
6061
6062 ssh->channels = NULL;
6063 ssh->rportfwds = NULL;
6064
6065 ssh->send_ok = 0;
6066 ssh->editing = 0;
6067 ssh->echoing = 0;
6068 ssh->v1_throttle_count = 0;
6069 ssh->overall_bufsize = 0;
6070 ssh->fallback_cmd = 0;
6071
6072 ssh->protocol = NULL;
6073
6074 p = connect_to_host(ssh, host, port, realhost, nodelay);
6075 if (p != NULL)
6076 return p;
6077
6078 return NULL;
6079 }
6080
6081 static void ssh_free(void *handle)
6082 {
6083 Ssh ssh = (Ssh) handle;
6084 struct ssh_channel *c;
6085 struct ssh_rportfwd *pf;
6086
6087 if (ssh->v1_cipher_ctx)
6088 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6089 if (ssh->cs_cipher_ctx)
6090 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6091 if (ssh->sc_cipher_ctx)
6092 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6093 if (ssh->cs_mac_ctx)
6094 ssh->csmac->free_context(ssh->cs_mac_ctx);
6095 if (ssh->sc_mac_ctx)
6096 ssh->scmac->free_context(ssh->sc_mac_ctx);
6097 if (ssh->cs_comp_ctx)
6098 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6099 if (ssh->sc_comp_ctx)
6100 ssh->sccomp->compress_cleanup(ssh->sc_comp_ctx);
6101 if (ssh->kex_ctx)
6102 dh_cleanup(ssh->kex_ctx);
6103 sfree(ssh->savedhost);
6104
6105 if (ssh->channels) {
6106 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6107 switch (c->type) {
6108 case CHAN_X11:
6109 if (c->u.x11.s != NULL)
6110 x11_close(c->u.x11.s);
6111 break;
6112 case CHAN_SOCKDATA:
6113 if (c->u.pfd.s != NULL)
6114 pfd_close(c->u.pfd.s);
6115 break;
6116 }
6117 sfree(c);
6118 }
6119 freetree234(ssh->channels);
6120 }
6121
6122 if (ssh->rportfwds) {
6123 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6124 sfree(pf);
6125 freetree234(ssh->rportfwds);
6126 }
6127 sfree(ssh->deferred_send_data);
6128 if (ssh->x11auth)
6129 x11_free_auth(ssh->x11auth);
6130 sfree(ssh->do_ssh_init_state);
6131 sfree(ssh->do_ssh1_login_state);
6132 sfree(ssh->do_ssh2_transport_state);
6133 sfree(ssh->do_ssh2_authconn_state);
6134
6135 if (ssh->s)
6136 sk_close(ssh->s);
6137 sfree(ssh);
6138 }
6139
6140 /*
6141 * Reconfigure the SSH backend.
6142 *
6143 * Currently, this function does nothing very useful. In future,
6144 * however, we could do some handy things with it. For example, we
6145 * could make the port forwarding configurer active in the Change
6146 * Settings box, and this routine could close down existing
6147 * forwardings and open up new ones in response to changes.
6148 */
6149 static void ssh_reconfig(void *handle, Config *cfg)
6150 {
6151 Ssh ssh = (Ssh) handle;
6152 ssh->cfg = *cfg; /* STRUCTURE COPY */
6153 }
6154
6155 /*
6156 * Called to send data down the Telnet connection.
6157 */
6158 static int ssh_send(void *handle, char *buf, int len)
6159 {
6160 Ssh ssh = (Ssh) handle;
6161
6162 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6163 return 0;
6164
6165 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
6166
6167 return ssh_sendbuffer(ssh);
6168 }
6169
6170 /*
6171 * Called to query the current amount of buffered stdin data.
6172 */
6173 static int ssh_sendbuffer(void *handle)
6174 {
6175 Ssh ssh = (Ssh) handle;
6176 int override_value;
6177
6178 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6179 return 0;
6180
6181 /*
6182 * If the SSH socket itself has backed up, add the total backup
6183 * size on that to any individual buffer on the stdin channel.
6184 */
6185 override_value = 0;
6186 if (ssh->throttled_all)
6187 override_value = ssh->overall_bufsize;
6188
6189 if (ssh->version == 1) {
6190 return override_value;
6191 } else if (ssh->version == 2) {
6192 if (!ssh->mainchan || ssh->mainchan->closes > 0)
6193 return override_value;
6194 else
6195 return (override_value +
6196 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
6197 }
6198
6199 return 0;
6200 }
6201
6202 /*
6203 * Called to set the size of the window from SSH's POV.
6204 */
6205 static void ssh_size(void *handle, int width, int height)
6206 {
6207 Ssh ssh = (Ssh) handle;
6208
6209 ssh->term_width = width;
6210 ssh->term_height = height;
6211
6212 switch (ssh->state) {
6213 case SSH_STATE_BEFORE_SIZE:
6214 case SSH_STATE_PREPACKET:
6215 case SSH_STATE_CLOSED:
6216 break; /* do nothing */
6217 case SSH_STATE_INTERMED:
6218 ssh->size_needed = TRUE; /* buffer for later */
6219 break;
6220 case SSH_STATE_SESSION:
6221 if (!ssh->cfg.nopty) {
6222 if (ssh->version == 1) {
6223 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6224 PKT_INT, ssh->term_height,
6225 PKT_INT, ssh->term_width,
6226 PKT_INT, 0, PKT_INT, 0, PKT_END);
6227 } else {
6228 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6229 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6230 ssh2_pkt_addstring(ssh, "window-change");
6231 ssh2_pkt_addbool(ssh, 0);
6232 ssh2_pkt_adduint32(ssh, ssh->term_width);
6233 ssh2_pkt_adduint32(ssh, ssh->term_height);
6234 ssh2_pkt_adduint32(ssh, 0);
6235 ssh2_pkt_adduint32(ssh, 0);
6236 ssh2_pkt_send(ssh);
6237 }
6238 }
6239 break;
6240 }
6241 }
6242
6243 /*
6244 * Return a list of the special codes that make sense in this
6245 * protocol.
6246 */
6247 static const struct telnet_special *ssh_get_specials(void *handle)
6248 {
6249 Ssh ssh = (Ssh) handle;
6250
6251 if (ssh->version == 1) {
6252 static const struct telnet_special ssh1_specials[] = {
6253 {"IGNORE message", TS_NOP},
6254 {NULL, 0}
6255 };
6256 return ssh1_specials;
6257 } else if (ssh->version == 2) {
6258 static const struct telnet_special ssh2_specials[] = {
6259 {"Break", TS_BRK},
6260 {"IGNORE message", TS_NOP},
6261 {NULL, 0}
6262 };
6263 return ssh2_specials;
6264 } else
6265 return NULL;
6266 }
6267
6268 /*
6269 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6270 * can send an EOF and collect resulting output (e.g. `plink
6271 * hostname sort').
6272 */
6273 static void ssh_special(void *handle, Telnet_Special code)
6274 {
6275 Ssh ssh = (Ssh) handle;
6276
6277 if (code == TS_EOF) {
6278 if (ssh->state != SSH_STATE_SESSION) {
6279 /*
6280 * Buffer the EOF in case we are pre-SESSION, so we can
6281 * send it as soon as we reach SESSION.
6282 */
6283 if (code == TS_EOF)
6284 ssh->eof_needed = TRUE;
6285 return;
6286 }
6287 if (ssh->version == 1) {
6288 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6289 } else {
6290 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6291 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6292 ssh2_pkt_send(ssh);
6293 }
6294 logevent("Sent EOF message");
6295 } else if (code == TS_PING || code == TS_NOP) {
6296 if (ssh->state == SSH_STATE_CLOSED
6297 || ssh->state == SSH_STATE_PREPACKET) return;
6298 if (ssh->version == 1) {
6299 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6300 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6301 } else {
6302 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6303 ssh2_pkt_addstring_start(ssh);
6304 ssh2_pkt_send(ssh);
6305 }
6306 } else if (code == TS_BRK) {
6307 if (ssh->state == SSH_STATE_CLOSED
6308 || ssh->state == SSH_STATE_PREPACKET) return;
6309 if (ssh->version == 1) {
6310 logevent("Unable to send BREAK signal in SSH1");
6311 } else {
6312 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6313 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6314 ssh2_pkt_addstring(ssh, "break");
6315 ssh2_pkt_addbool(ssh, 0);
6316 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6317 ssh2_pkt_send(ssh);
6318 }
6319 } else {
6320 /* do nothing */
6321 }
6322 }
6323
6324 void *new_sock_channel(void *handle, Socket s)
6325 {
6326 Ssh ssh = (Ssh) handle;
6327 struct ssh_channel *c;
6328 c = snew(struct ssh_channel);
6329 c->ssh = ssh;
6330
6331 if (c) {
6332 c->remoteid = -1; /* to be set when open confirmed */
6333 c->localid = alloc_channel_id(ssh);
6334 c->closes = 0;
6335 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6336 c->u.pfd.s = s;
6337 bufchain_init(&c->v.v2.outbuffer);
6338 add234(ssh->channels, c);
6339 }
6340 return c;
6341 }
6342
6343 /*
6344 * This is called when stdout/stderr (the entity to which
6345 * from_backend sends data) manages to clear some backlog.
6346 */
6347 static void ssh_unthrottle(void *handle, int bufsize)
6348 {
6349 Ssh ssh = (Ssh) handle;
6350 if (ssh->version == 1) {
6351 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6352 ssh->v1_stdout_throttling = 0;
6353 ssh1_throttle(ssh, -1);
6354 }
6355 } else {
6356 if (ssh->mainchan && ssh->mainchan->closes == 0)
6357 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6358 }
6359 }
6360
6361 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6362 {
6363 struct ssh_channel *c = (struct ssh_channel *)channel;
6364 Ssh ssh = c->ssh;
6365
6366 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6367
6368 if (ssh->version == 1) {
6369 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6370 PKT_INT, c->localid,
6371 PKT_STR, hostname,
6372 PKT_INT, port,
6373 //PKT_STR, <org:orgport>,
6374 PKT_END);
6375 } else {
6376 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6377 ssh2_pkt_addstring(ssh, "direct-tcpip");
6378 ssh2_pkt_adduint32(ssh, c->localid);
6379 c->v.v2.locwindow = OUR_V2_WINSIZE;
6380 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6381 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6382 ssh2_pkt_addstring(ssh, hostname);
6383 ssh2_pkt_adduint32(ssh, port);
6384 /*
6385 * We make up values for the originator data; partly it's
6386 * too much hassle to keep track, and partly I'm not
6387 * convinced the server should be told details like that
6388 * about my local network configuration.
6389 */
6390 ssh2_pkt_addstring(ssh, "client-side-connection");
6391 ssh2_pkt_adduint32(ssh, 0);
6392 ssh2_pkt_send(ssh);
6393 }
6394 }
6395
6396
6397 static Socket ssh_socket(void *handle)
6398 {
6399 Ssh ssh = (Ssh) handle;
6400 return ssh->s;
6401 }
6402
6403 static int ssh_sendok(void *handle)
6404 {
6405 Ssh ssh = (Ssh) handle;
6406 return ssh->send_ok;
6407 }
6408
6409 static int ssh_ldisc(void *handle, int option)
6410 {
6411 Ssh ssh = (Ssh) handle;
6412 if (option == LD_ECHO)
6413 return ssh->echoing;
6414 if (option == LD_EDIT)
6415 return ssh->editing;
6416 return FALSE;
6417 }
6418
6419 static void ssh_provide_ldisc(void *handle, void *ldisc)
6420 {
6421 Ssh ssh = (Ssh) handle;
6422 ssh->ldisc = ldisc;
6423 }
6424
6425 static void ssh_provide_logctx(void *handle, void *logctx)
6426 {
6427 Ssh ssh = (Ssh) handle;
6428 ssh->logctx = logctx;
6429 }
6430
6431 static int ssh_return_exitcode(void *handle)
6432 {
6433 Ssh ssh = (Ssh) handle;
6434 if (ssh->s != NULL)
6435 return -1;
6436 else
6437 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
6438 }
6439
6440 /*
6441 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6442 * that fails. This variable is the means by which scp.c can reach
6443 * into the SSH code and find out which one it got.
6444 */
6445 extern int ssh_fallback_cmd(void *handle)
6446 {
6447 Ssh ssh = (Ssh) handle;
6448 return ssh->fallback_cmd;
6449 }
6450
6451 Backend ssh_backend = {
6452 ssh_init,
6453 ssh_free,
6454 ssh_reconfig,
6455 ssh_send,
6456 ssh_sendbuffer,
6457 ssh_size,
6458 ssh_special,
6459 ssh_get_specials,
6460 ssh_socket,
6461 ssh_return_exitcode,
6462 ssh_sendok,
6463 ssh_ldisc,
6464 ssh_provide_ldisc,
6465 ssh_provide_logctx,
6466 ssh_unthrottle,
6467 22
6468 };
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator