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Fix another segfault on abrupt X connection shutdown. This should
[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 static void ssh_do_close(Ssh ssh);
519
520 struct rdpkt1_state_tag {
521 long len, pad, biglen, to_read;
522 unsigned long realcrc, gotcrc;
523 unsigned char *p;
524 int i;
525 int chunk;
526 };
527
528 struct rdpkt2_state_tag {
529 long len, pad, payload, packetlen, maclen;
530 int i;
531 int cipherblk;
532 unsigned long incoming_sequence;
533 };
534
535 struct ssh_tag {
536 const struct plug_function_table *fn;
537 /* the above field _must_ be first in the structure */
538
539 SHA_State exhash, exhashbase;
540
541 Socket s;
542
543 void *ldisc;
544 void *logctx;
545
546 unsigned char session_key[32];
547 int v1_compressing;
548 int v1_remote_protoflags;
549 int v1_local_protoflags;
550 int agentfwd_enabled;
551 int X11_fwd_enabled;
552 int remote_bugs;
553 const struct ssh_cipher *cipher;
554 void *v1_cipher_ctx;
555 void *crcda_ctx;
556 const struct ssh2_cipher *cscipher, *sccipher;
557 void *cs_cipher_ctx, *sc_cipher_ctx;
558 const struct ssh_mac *csmac, *scmac;
559 void *cs_mac_ctx, *sc_mac_ctx;
560 const struct ssh_compress *cscomp, *sccomp;
561 void *cs_comp_ctx, *sc_comp_ctx;
562 const struct ssh_kex *kex;
563 const struct ssh_signkey *hostkey;
564 unsigned char v2_session_id[20];
565 void *kex_ctx;
566
567 char *savedhost;
568 int savedport;
569 int send_ok;
570 int echoing, editing;
571
572 void *frontend;
573
574 int term_width, term_height;
575
576 tree234 *channels; /* indexed by local id */
577 struct ssh_channel *mainchan; /* primary session channel */
578 int exitcode;
579
580 tree234 *rportfwds;
581
582 enum {
583 SSH_STATE_PREPACKET,
584 SSH_STATE_BEFORE_SIZE,
585 SSH_STATE_INTERMED,
586 SSH_STATE_SESSION,
587 SSH_STATE_CLOSED
588 } state;
589
590 int size_needed, eof_needed;
591
592 struct Packet pktin;
593 struct Packet pktout;
594 unsigned char *deferred_send_data;
595 int deferred_len, deferred_size;
596
597 /*
598 * Gross hack: pscp will try to start SFTP but fall back to
599 * scp1 if that fails. This variable is the means by which
600 * scp.c can reach into the SSH code and find out which one it
601 * got.
602 */
603 int fallback_cmd;
604
605 /*
606 * Used for username and password input.
607 */
608 char *userpass_input_buffer;
609 int userpass_input_buflen;
610 int userpass_input_bufpos;
611 int userpass_input_echo;
612
613 char *portfwd_strptr;
614 int pkt_ctx;
615
616 void *x11auth;
617
618 int version;
619 int v1_throttle_count;
620 int overall_bufsize;
621 int throttled_all;
622 int v1_stdout_throttling;
623 int v2_outgoing_sequence;
624
625 int ssh1_rdpkt_crstate;
626 int ssh2_rdpkt_crstate;
627 int do_ssh_init_crstate;
628 int ssh_gotdata_crstate;
629 int ssh1_protocol_crstate;
630 int do_ssh1_login_crstate;
631 int do_ssh2_transport_crstate;
632 int do_ssh2_authconn_crstate;
633
634 void *do_ssh_init_state;
635 void *do_ssh1_login_state;
636 void *do_ssh2_transport_state;
637 void *do_ssh2_authconn_state;
638
639 struct rdpkt1_state_tag rdpkt1_state;
640 struct rdpkt2_state_tag rdpkt2_state;
641
642 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
643 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
644
645 /*
646 * We maintain a full _copy_ of a Config structure here, not
647 * merely a pointer to it. That way, when we're passed a new
648 * one for reconfiguration, we can check the differences and
649 * potentially reconfigure port forwardings etc in mid-session.
650 */
651 Config cfg;
652 };
653
654 #define logevent(s) logevent(ssh->frontend, s)
655
656 /* logevent, only printf-formatted. */
657 static void logeventf(Ssh ssh, char *fmt, ...)
658 {
659 va_list ap;
660 char *buf;
661
662 va_start(ap, fmt);
663 buf = dupvprintf(fmt, ap);
664 va_end(ap);
665 logevent(buf);
666 sfree(buf);
667 }
668
669 #define bombout(msg) \
670 do { \
671 char *text = dupprintf msg; \
672 ssh_do_close(ssh); \
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 crStop(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 crStop(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 crStop(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 crStop(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 crStop(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 crStop(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 crStop(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 crStop(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 crStop(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 void ssh_do_close(Ssh ssh)
2041 {
2042 int i;
2043 struct ssh_channel *c;
2044
2045 ssh->state = SSH_STATE_CLOSED;
2046 if (ssh->s) {
2047 sk_close(ssh->s);
2048 ssh->s = NULL;
2049 }
2050 /*
2051 * Now we must shut down any port and X forwardings going
2052 * through this connection.
2053 */
2054 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2055 switch (c->type) {
2056 case CHAN_X11:
2057 x11_close(c->u.x11.s);
2058 break;
2059 case CHAN_SOCKDATA:
2060 pfd_close(c->u.pfd.s);
2061 break;
2062 }
2063 del234(ssh->channels, c);
2064 if (ssh->version == 2)
2065 bufchain_clear(&c->v.v2.outbuffer);
2066 sfree(c);
2067 }
2068 }
2069
2070 static int ssh_closing(Plug plug, char *error_msg, int error_code,
2071 int calling_back)
2072 {
2073 Ssh ssh = (Ssh) plug;
2074 ssh_do_close(ssh);
2075 if (error_msg) {
2076 /* A socket error has occurred. */
2077 logevent(error_msg);
2078 connection_fatal(ssh->frontend, error_msg);
2079 } else {
2080 /* Otherwise, the remote side closed the connection normally. */
2081 }
2082 return 0;
2083 }
2084
2085 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2086 {
2087 Ssh ssh = (Ssh) plug;
2088 ssh_gotdata(ssh, (unsigned char *)data, len);
2089 if (ssh->state == SSH_STATE_CLOSED) {
2090 ssh_do_close(ssh);
2091 return 0;
2092 }
2093 return 1;
2094 }
2095
2096 static void ssh_sent(Plug plug, int bufsize)
2097 {
2098 Ssh ssh = (Ssh) plug;
2099 /*
2100 * If the send backlog on the SSH socket itself clears, we
2101 * should unthrottle the whole world if it was throttled.
2102 */
2103 if (bufsize < SSH_MAX_BACKLOG)
2104 ssh_throttle_all(ssh, 0, bufsize);
2105 }
2106
2107 /*
2108 * Connect to specified host and port.
2109 * Returns an error message, or NULL on success.
2110 * Also places the canonical host name into `realhost'. It must be
2111 * freed by the caller.
2112 */
2113 static char *connect_to_host(Ssh ssh, char *host, int port,
2114 char **realhost, int nodelay)
2115 {
2116 static const struct plug_function_table fn_table = {
2117 ssh_closing,
2118 ssh_receive,
2119 ssh_sent,
2120 NULL
2121 };
2122
2123 SockAddr addr;
2124 char *err;
2125
2126 ssh->savedhost = snewn(1 + strlen(host), char);
2127 if (!ssh->savedhost)
2128 fatalbox("Out of memory");
2129 strcpy(ssh->savedhost, host);
2130
2131 if (port < 0)
2132 port = 22; /* default ssh port */
2133 ssh->savedport = port;
2134
2135 /*
2136 * Try to find host.
2137 */
2138 logeventf(ssh, "Looking up host \"%s\"", host);
2139 addr = name_lookup(host, port, realhost, &ssh->cfg);
2140 if ((err = sk_addr_error(addr)) != NULL)
2141 return err;
2142
2143 /*
2144 * Open socket.
2145 */
2146 {
2147 char addrbuf[100];
2148 sk_getaddr(addr, addrbuf, 100);
2149 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2150 }
2151 ssh->fn = &fn_table;
2152 ssh->s = new_connection(addr, *realhost, port,
2153 0, 1, nodelay, (Plug) ssh, &ssh->cfg);
2154 if ((err = sk_socket_error(ssh->s)) != NULL) {
2155 ssh->s = NULL;
2156 return err;
2157 }
2158
2159 return NULL;
2160 }
2161
2162 /*
2163 * Throttle or unthrottle the SSH connection.
2164 */
2165 static void ssh1_throttle(Ssh ssh, int adjust)
2166 {
2167 int old_count = ssh->v1_throttle_count;
2168 ssh->v1_throttle_count += adjust;
2169 assert(ssh->v1_throttle_count >= 0);
2170 if (ssh->v1_throttle_count && !old_count) {
2171 sk_set_frozen(ssh->s, 1);
2172 } else if (!ssh->v1_throttle_count && old_count) {
2173 sk_set_frozen(ssh->s, 0);
2174 }
2175 }
2176
2177 /*
2178 * Throttle or unthrottle _all_ local data streams (for when sends
2179 * on the SSH connection itself back up).
2180 */
2181 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2182 {
2183 int i;
2184 struct ssh_channel *c;
2185
2186 if (enable == ssh->throttled_all)
2187 return;
2188 ssh->throttled_all = enable;
2189 ssh->overall_bufsize = bufsize;
2190 if (!ssh->channels)
2191 return;
2192 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2193 switch (c->type) {
2194 case CHAN_MAINSESSION:
2195 /*
2196 * This is treated separately, outside the switch.
2197 */
2198 break;
2199 case CHAN_X11:
2200 x11_override_throttle(c->u.x11.s, enable);
2201 break;
2202 case CHAN_AGENT:
2203 /* Agent channels require no buffer management. */
2204 break;
2205 case CHAN_SOCKDATA:
2206 pfd_override_throttle(c->u.pfd.s, enable);
2207 break;
2208 }
2209 }
2210 }
2211
2212 /*
2213 * Username and password input, abstracted off into routines
2214 * reusable in several places - even between SSH1 and SSH2.
2215 */
2216
2217 /* Set up a username or password input loop on a given buffer. */
2218 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2219 {
2220 ssh->userpass_input_buffer = buffer;
2221 ssh->userpass_input_buflen = buflen;
2222 ssh->userpass_input_bufpos = 0;
2223 ssh->userpass_input_echo = echo;
2224 }
2225
2226 /*
2227 * Process some terminal data in the course of username/password
2228 * input. Returns >0 for success (line of input returned in
2229 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2230 * for inconclusive (keep waiting for more input please).
2231 */
2232 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2233 {
2234 char c;
2235
2236 while (inlen--) {
2237 switch (c = *in++) {
2238 case 10:
2239 case 13:
2240 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2241 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2242 return +1;
2243 break;
2244 case 8:
2245 case 127:
2246 if (ssh->userpass_input_bufpos > 0) {
2247 if (ssh->userpass_input_echo)
2248 c_write_str(ssh, "\b \b");
2249 ssh->userpass_input_bufpos--;
2250 }
2251 break;
2252 case 21:
2253 case 27:
2254 while (ssh->userpass_input_bufpos > 0) {
2255 if (ssh->userpass_input_echo)
2256 c_write_str(ssh, "\b \b");
2257 ssh->userpass_input_bufpos--;
2258 }
2259 break;
2260 case 3:
2261 case 4:
2262 return -1;
2263 break;
2264 default:
2265 /*
2266 * This simplistic check for printability is disabled
2267 * when we're doing password input, because some people
2268 * have control characters in their passwords.o
2269 */
2270 if ((!ssh->userpass_input_echo ||
2271 (c >= ' ' && c <= '~') ||
2272 ((unsigned char) c >= 160))
2273 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2274 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2275 if (ssh->userpass_input_echo)
2276 c_write(ssh, &c, 1);
2277 }
2278 break;
2279 }
2280 }
2281 return 0;
2282 }
2283
2284 /*
2285 * Handle the key exchange and user authentication phases.
2286 */
2287 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2288 {
2289 int i, j;
2290 unsigned char cookie[8];
2291 struct RSAKey servkey, hostkey;
2292 struct MD5Context md5c;
2293 struct do_ssh1_login_state {
2294 int len;
2295 unsigned char *rsabuf, *keystr1, *keystr2;
2296 unsigned long supported_ciphers_mask, supported_auths_mask;
2297 int tried_publickey, tried_agent;
2298 int tis_auth_refused, ccard_auth_refused;
2299 unsigned char session_id[16];
2300 int cipher_type;
2301 char username[100];
2302 void *publickey_blob;
2303 int publickey_bloblen;
2304 char password[100];
2305 char prompt[200];
2306 int pos;
2307 char c;
2308 int pwpkt_type;
2309 unsigned char request[5], *response, *p;
2310 int responselen;
2311 int keyi, nkeys;
2312 int authed;
2313 struct RSAKey key;
2314 Bignum challenge;
2315 char *commentp;
2316 int commentlen;
2317 };
2318 crState(do_ssh1_login_state);
2319
2320 crBegin(ssh->do_ssh1_login_crstate);
2321
2322 if (!ispkt)
2323 crWaitUntil(ispkt);
2324
2325 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2326 bombout(("Public key packet not received"));
2327 crStop(0);
2328 }
2329
2330 logevent("Received public keys");
2331
2332 memcpy(cookie, ssh->pktin.body, 8);
2333
2334 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2335 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2336
2337 /*
2338 * Log the host key fingerprint.
2339 */
2340 {
2341 char logmsg[80];
2342 logevent("Host key fingerprint is:");
2343 strcpy(logmsg, " ");
2344 hostkey.comment = NULL;
2345 rsa_fingerprint(logmsg + strlen(logmsg),
2346 sizeof(logmsg) - strlen(logmsg), &hostkey);
2347 logevent(logmsg);
2348 }
2349
2350 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2351 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2352 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2353
2354 ssh->v1_local_protoflags =
2355 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2356 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2357
2358 MD5Init(&md5c);
2359 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2360 MD5Update(&md5c, s->keystr1, servkey.bytes);
2361 MD5Update(&md5c, ssh->pktin.body, 8);
2362 MD5Final(s->session_id, &md5c);
2363
2364 for (i = 0; i < 32; i++)
2365 ssh->session_key[i] = random_byte();
2366
2367 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2368
2369 s->rsabuf = snewn(s->len, unsigned char);
2370 if (!s->rsabuf)
2371 fatalbox("Out of memory");
2372
2373 /*
2374 * Verify the host key.
2375 */
2376 {
2377 /*
2378 * First format the key into a string.
2379 */
2380 int len = rsastr_len(&hostkey);
2381 char fingerprint[100];
2382 char *keystr = snewn(len, char);
2383 if (!keystr)
2384 fatalbox("Out of memory");
2385 rsastr_fmt(keystr, &hostkey);
2386 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2387 verify_ssh_host_key(ssh->frontend,
2388 ssh->savedhost, ssh->savedport, "rsa", keystr,
2389 fingerprint);
2390 sfree(keystr);
2391 }
2392
2393 for (i = 0; i < 32; i++) {
2394 s->rsabuf[i] = ssh->session_key[i];
2395 if (i < 16)
2396 s->rsabuf[i] ^= s->session_id[i];
2397 }
2398
2399 if (hostkey.bytes > servkey.bytes) {
2400 rsaencrypt(s->rsabuf, 32, &servkey);
2401 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2402 } else {
2403 rsaencrypt(s->rsabuf, 32, &hostkey);
2404 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2405 }
2406
2407 logevent("Encrypted session key");
2408
2409 {
2410 int cipher_chosen = 0, warn = 0;
2411 char *cipher_string = NULL;
2412 int i;
2413 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2414 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2415 if (next_cipher == CIPHER_WARN) {
2416 /* If/when we choose a cipher, warn about it */
2417 warn = 1;
2418 } else if (next_cipher == CIPHER_AES) {
2419 /* XXX Probably don't need to mention this. */
2420 logevent("AES not supported in SSH1, skipping");
2421 } else {
2422 switch (next_cipher) {
2423 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2424 cipher_string = "3DES"; break;
2425 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2426 cipher_string = "Blowfish"; break;
2427 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2428 cipher_string = "single-DES"; break;
2429 }
2430 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2431 cipher_chosen = 1;
2432 }
2433 }
2434 if (!cipher_chosen) {
2435 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2436 bombout(("Server violates SSH 1 protocol by not "
2437 "supporting 3DES encryption"));
2438 else
2439 /* shouldn't happen */
2440 bombout(("No supported ciphers found"));
2441 crStop(0);
2442 }
2443
2444 /* Warn about chosen cipher if necessary. */
2445 if (warn)
2446 askcipher(ssh->frontend, cipher_string, 0);
2447 }
2448
2449 switch (s->cipher_type) {
2450 case SSH_CIPHER_3DES:
2451 logevent("Using 3DES encryption");
2452 break;
2453 case SSH_CIPHER_DES:
2454 logevent("Using single-DES encryption");
2455 break;
2456 case SSH_CIPHER_BLOWFISH:
2457 logevent("Using Blowfish encryption");
2458 break;
2459 }
2460
2461 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2462 PKT_CHAR, s->cipher_type,
2463 PKT_DATA, cookie, 8,
2464 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2465 PKT_DATA, s->rsabuf, s->len,
2466 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2467
2468 logevent("Trying to enable encryption...");
2469
2470 sfree(s->rsabuf);
2471
2472 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2473 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2474 &ssh_3des);
2475 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2476 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2477 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2478
2479 ssh->crcda_ctx = crcda_make_context();
2480 logevent("Installing CRC compensation attack detector");
2481
2482 crWaitUntil(ispkt);
2483
2484 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2485 bombout(("Encryption not successfully enabled"));
2486 crStop(0);
2487 }
2488
2489 logevent("Successfully started encryption");
2490
2491 fflush(stdout);
2492 {
2493 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
2494 if (ssh_get_line && !ssh_getline_pw_only) {
2495 if (!ssh_get_line("login as: ",
2496 s->username, sizeof(s->username), FALSE)) {
2497 /*
2498 * get_line failed to get a username.
2499 * Terminate.
2500 */
2501 logevent("No username provided. Abandoning session.");
2502 ssh_closing((Plug)ssh, NULL, 0, 0);
2503 crStop(1);
2504 }
2505 } else {
2506 int ret; /* need not be kept over crReturn */
2507 c_write_str(ssh, "login as: ");
2508 ssh->send_ok = 1;
2509
2510 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2511 do {
2512 crWaitUntil(!ispkt);
2513 ret = process_userpass_input(ssh, in, inlen);
2514 } while (ret == 0);
2515 if (ret < 0)
2516 cleanup_exit(0);
2517 c_write_str(ssh, "\r\n");
2518 }
2519 } else {
2520 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2521 s->username[sizeof(s->username)-1] = '\0';
2522 }
2523
2524 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2525 {
2526 char userlog[22 + sizeof(s->username)];
2527 sprintf(userlog, "Sent username \"%s\"", s->username);
2528 logevent(userlog);
2529 if (flags & FLAG_INTERACTIVE &&
2530 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2531 strcat(userlog, "\r\n");
2532 c_write_str(ssh, userlog);
2533 }
2534 }
2535 }
2536
2537 crWaitUntil(ispkt);
2538
2539 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2540 /* We must not attempt PK auth. Pretend we've already tried it. */
2541 s->tried_publickey = s->tried_agent = 1;
2542 } else {
2543 s->tried_publickey = s->tried_agent = 0;
2544 }
2545 s->tis_auth_refused = s->ccard_auth_refused = 0;
2546 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2547 if (!filename_is_null(ssh->cfg.keyfile)) {
2548 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2549 &s->publickey_blob, &s->publickey_bloblen))
2550 s->publickey_blob = NULL;
2551 } else
2552 s->publickey_blob = NULL;
2553
2554 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2555 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2556
2557 if (agent_exists() && !s->tried_agent) {
2558 /*
2559 * Attempt RSA authentication using Pageant.
2560 */
2561 void *r;
2562
2563 s->authed = FALSE;
2564 s->tried_agent = 1;
2565 logevent("Pageant is running. Requesting keys.");
2566
2567 /* Request the keys held by the agent. */
2568 PUT_32BIT(s->request, 1);
2569 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2570 agent_query(s->request, 5, &r, &s->responselen);
2571 s->response = (unsigned char *) r;
2572 if (s->response && s->responselen >= 5 &&
2573 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2574 s->p = s->response + 5;
2575 s->nkeys = GET_32BIT(s->p);
2576 s->p += 4;
2577 {
2578 char buf[64];
2579 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2580 logevent(buf);
2581 }
2582 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2583 {
2584 char buf[64];
2585 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2586 logevent(buf);
2587 }
2588 if (s->publickey_blob &&
2589 !memcmp(s->p, s->publickey_blob,
2590 s->publickey_bloblen)) {
2591 logevent("This key matches configured key file");
2592 s->tried_publickey = 1;
2593 }
2594 s->p += 4;
2595 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2596 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2597 s->commentlen = GET_32BIT(s->p);
2598 s->p += 4;
2599 s->commentp = (char *)s->p;
2600 s->p += s->commentlen;
2601 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2602 PKT_BIGNUM, s->key.modulus, PKT_END);
2603 crWaitUntil(ispkt);
2604 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2605 logevent("Key refused");
2606 continue;
2607 }
2608 logevent("Received RSA challenge");
2609 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2610 {
2611 char *agentreq, *q, *ret;
2612 void *vret;
2613 int len, retlen;
2614 len = 1 + 4; /* message type, bit count */
2615 len += ssh1_bignum_length(s->key.exponent);
2616 len += ssh1_bignum_length(s->key.modulus);
2617 len += ssh1_bignum_length(s->challenge);
2618 len += 16; /* session id */
2619 len += 4; /* response format */
2620 agentreq = snewn(4 + len, char);
2621 PUT_32BIT(agentreq, len);
2622 q = agentreq + 4;
2623 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2624 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2625 q += 4;
2626 q += ssh1_write_bignum(q, s->key.exponent);
2627 q += ssh1_write_bignum(q, s->key.modulus);
2628 q += ssh1_write_bignum(q, s->challenge);
2629 memcpy(q, s->session_id, 16);
2630 q += 16;
2631 PUT_32BIT(q, 1); /* response format */
2632 agent_query(agentreq, len + 4, &vret, &retlen);
2633 ret = vret;
2634 sfree(agentreq);
2635 if (ret) {
2636 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2637 logevent("Sending Pageant's response");
2638 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2639 PKT_DATA, ret + 5, 16,
2640 PKT_END);
2641 sfree(ret);
2642 crWaitUntil(ispkt);
2643 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2644 logevent
2645 ("Pageant's response accepted");
2646 if (flags & FLAG_VERBOSE) {
2647 c_write_str(ssh, "Authenticated using"
2648 " RSA key \"");
2649 c_write(ssh, s->commentp,
2650 s->commentlen);
2651 c_write_str(ssh, "\" from agent\r\n");
2652 }
2653 s->authed = TRUE;
2654 } else
2655 logevent
2656 ("Pageant's response not accepted");
2657 } else {
2658 logevent
2659 ("Pageant failed to answer challenge");
2660 sfree(ret);
2661 }
2662 } else {
2663 logevent("No reply received from Pageant");
2664 }
2665 }
2666 freebn(s->key.exponent);
2667 freebn(s->key.modulus);
2668 freebn(s->challenge);
2669 if (s->authed)
2670 break;
2671 }
2672 }
2673 if (s->authed)
2674 break;
2675 }
2676 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
2677 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2678
2679 if (ssh->cfg.try_tis_auth &&
2680 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2681 !s->tis_auth_refused) {
2682 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2683 logevent("Requested TIS authentication");
2684 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2685 crWaitUntil(ispkt);
2686 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2687 logevent("TIS authentication declined");
2688 if (flags & FLAG_INTERACTIVE)
2689 c_write_str(ssh, "TIS authentication refused.\r\n");
2690 s->tis_auth_refused = 1;
2691 continue;
2692 } else {
2693 int challengelen = GET_32BIT(ssh->pktin.body);
2694 logevent("Received TIS challenge");
2695 if (challengelen > sizeof(s->prompt) - 1)
2696 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2697 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2698 /* Prompt heuristic comes from OpenSSH */
2699 strncpy(s->prompt + challengelen,
2700 memchr(s->prompt, '\n', challengelen) ?
2701 "": "\r\nResponse: ",
2702 (sizeof s->prompt) - challengelen);
2703 s->prompt[(sizeof s->prompt) - 1] = '\0';
2704 }
2705 }
2706 if (ssh->cfg.try_tis_auth &&
2707 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2708 !s->ccard_auth_refused) {
2709 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2710 logevent("Requested CryptoCard authentication");
2711 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2712 crWaitUntil(ispkt);
2713 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2714 logevent("CryptoCard authentication declined");
2715 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2716 s->ccard_auth_refused = 1;
2717 continue;
2718 } else {
2719 int challengelen = GET_32BIT(ssh->pktin.body);
2720 logevent("Received CryptoCard challenge");
2721 if (challengelen > sizeof(s->prompt) - 1)
2722 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2723 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2724 strncpy(s->prompt + challengelen,
2725 memchr(s->prompt, '\n', challengelen) ?
2726 "" : "\r\nResponse: ",
2727 sizeof(s->prompt) - challengelen);
2728 s->prompt[sizeof(s->prompt) - 1] = '\0';
2729 }
2730 }
2731 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2732 sprintf(s->prompt, "%.90s@%.90s's password: ",
2733 s->username, ssh->savedhost);
2734 }
2735 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2736 char *comment = NULL;
2737 int type;
2738 char msgbuf[256];
2739 if (flags & FLAG_VERBOSE)
2740 c_write_str(ssh, "Trying public key authentication.\r\n");
2741 logeventf(ssh, "Trying public key \"%s\"",
2742 filename_to_str(&ssh->cfg.keyfile));
2743 type = key_type(&ssh->cfg.keyfile);
2744 if (type != SSH_KEYTYPE_SSH1) {
2745 sprintf(msgbuf, "Key is of wrong type (%s)",
2746 key_type_to_str(type));
2747 logevent(msgbuf);
2748 c_write_str(ssh, msgbuf);
2749 c_write_str(ssh, "\r\n");
2750 s->tried_publickey = 1;
2751 continue;
2752 }
2753 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
2754 if (flags & FLAG_VERBOSE)
2755 c_write_str(ssh, "No passphrase required.\r\n");
2756 goto tryauth;
2757 }
2758 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2759 sfree(comment);
2760 }
2761
2762 /*
2763 * Show password prompt, having first obtained it via a TIS
2764 * or CryptoCard exchange if we're doing TIS or CryptoCard
2765 * authentication.
2766 */
2767 if (ssh_get_line) {
2768 if (!ssh_get_line(s->prompt, s->password,
2769 sizeof(s->password), TRUE)) {
2770 /*
2771 * get_line failed to get a password (for example
2772 * because one was supplied on the command line
2773 * which has already failed to work). Terminate.
2774 */
2775 send_packet(ssh, SSH1_MSG_DISCONNECT,
2776 PKT_STR, "No more passwords available to try",
2777 PKT_END);
2778 logevent("Unable to authenticate");
2779 connection_fatal(ssh->frontend, "Unable to authenticate");
2780 ssh_closing((Plug)ssh, NULL, 0, 0);
2781 crStop(1);
2782 }
2783 } else {
2784 /* Prompt may have come from server. We've munged it a bit, so
2785 * we know it to be zero-terminated at least once. */
2786 int ret; /* need not be saved over crReturn */
2787 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2788 s->pos = 0;
2789
2790 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2791 do {
2792 crWaitUntil(!ispkt);
2793 ret = process_userpass_input(ssh, in, inlen);
2794 } while (ret == 0);
2795 if (ret < 0)
2796 cleanup_exit(0);
2797 c_write_str(ssh, "\r\n");
2798 }
2799
2800 tryauth:
2801 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2802 /*
2803 * Try public key authentication with the specified
2804 * key file.
2805 */
2806 s->tried_publickey = 1;
2807
2808 {
2809 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password);
2810 if (ret == 0) {
2811 c_write_str(ssh, "Couldn't load private key from ");
2812 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
2813 c_write_str(ssh, ".\r\n");
2814 continue; /* go and try password */
2815 }
2816 if (ret == -1) {
2817 c_write_str(ssh, "Wrong passphrase.\r\n");
2818 s->tried_publickey = 0;
2819 continue; /* try again */
2820 }
2821 }
2822
2823 /*
2824 * Send a public key attempt.
2825 */
2826 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2827 PKT_BIGNUM, s->key.modulus, PKT_END);
2828
2829 crWaitUntil(ispkt);
2830 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2831 c_write_str(ssh, "Server refused our public key.\r\n");
2832 continue; /* go and try password */
2833 }
2834 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2835 bombout(("Bizarre response to offer of public key"));
2836 crStop(0);
2837 }
2838
2839 {
2840 int i;
2841 unsigned char buffer[32];
2842 Bignum challenge, response;
2843
2844 ssh1_read_bignum(ssh->pktin.body, &challenge);
2845 response = rsadecrypt(challenge, &s->key);
2846 freebn(s->key.private_exponent);/* burn the evidence */
2847
2848 for (i = 0; i < 32; i++) {
2849 buffer[i] = bignum_byte(response, 31 - i);
2850 }
2851
2852 MD5Init(&md5c);
2853 MD5Update(&md5c, buffer, 32);
2854 MD5Update(&md5c, s->session_id, 16);
2855 MD5Final(buffer, &md5c);
2856
2857 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2858 PKT_DATA, buffer, 16, PKT_END);
2859
2860 freebn(challenge);
2861 freebn(response);
2862 }
2863
2864 crWaitUntil(ispkt);
2865 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2866 if (flags & FLAG_VERBOSE)
2867 c_write_str(ssh, "Failed to authenticate with"
2868 " our public key.\r\n");
2869 continue; /* go and try password */
2870 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2871 bombout(("Bizarre response to RSA authentication response"));
2872 crStop(0);
2873 }
2874
2875 break; /* we're through! */
2876 } else {
2877 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2878 /*
2879 * Defence against traffic analysis: we send a
2880 * whole bunch of packets containing strings of
2881 * different lengths. One of these strings is the
2882 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2883 * The others are all random data in
2884 * SSH1_MSG_IGNORE packets. This way a passive
2885 * listener can't tell which is the password, and
2886 * hence can't deduce the password length.
2887 *
2888 * Anybody with a password length greater than 16
2889 * bytes is going to have enough entropy in their
2890 * password that a listener won't find it _that_
2891 * much help to know how long it is. So what we'll
2892 * do is:
2893 *
2894 * - if password length < 16, we send 15 packets
2895 * containing string lengths 1 through 15
2896 *
2897 * - otherwise, we let N be the nearest multiple
2898 * of 8 below the password length, and send 8
2899 * packets containing string lengths N through
2900 * N+7. This won't obscure the order of
2901 * magnitude of the password length, but it will
2902 * introduce a bit of extra uncertainty.
2903 *
2904 * A few servers (the old 1.2.18 through 1.2.22)
2905 * can't deal with SSH1_MSG_IGNORE. For these
2906 * servers, we need an alternative defence. We make
2907 * use of the fact that the password is interpreted
2908 * as a C string: so we can append a NUL, then some
2909 * random data.
2910 *
2911 * One server (a Cisco one) can deal with neither
2912 * SSH1_MSG_IGNORE _nor_ a padded password string.
2913 * For this server we are left with no defences
2914 * against password length sniffing.
2915 */
2916 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2917 /*
2918 * The server can deal with SSH1_MSG_IGNORE, so
2919 * we can use the primary defence.
2920 */
2921 int bottom, top, pwlen, i;
2922 char *randomstr;
2923
2924 pwlen = strlen(s->password);
2925 if (pwlen < 16) {
2926 bottom = 0; /* zero length passwords are OK! :-) */
2927 top = 15;
2928 } else {
2929 bottom = pwlen & ~7;
2930 top = bottom + 7;
2931 }
2932
2933 assert(pwlen >= bottom && pwlen <= top);
2934
2935 randomstr = snewn(top + 1, char);
2936
2937 for (i = bottom; i <= top; i++) {
2938 if (i == pwlen)
2939 defer_packet(ssh, s->pwpkt_type,
2940 PKT_STR, s->password, PKT_END);
2941 else {
2942 for (j = 0; j < i; j++) {
2943 do {
2944 randomstr[j] = random_byte();
2945 } while (randomstr[j] == '\0');
2946 }
2947 randomstr[i] = '\0';
2948 defer_packet(ssh, SSH1_MSG_IGNORE,
2949 PKT_STR, randomstr, PKT_END);
2950 }
2951 }
2952 logevent("Sending password with camouflage packets");
2953 ssh_pkt_defersend(ssh);
2954 }
2955 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2956 /*
2957 * The server can't deal with SSH1_MSG_IGNORE
2958 * but can deal with padded passwords, so we
2959 * can use the secondary defence.
2960 */
2961 char string[64];
2962 char *ss;
2963 int len;
2964
2965 len = strlen(s->password);
2966 if (len < sizeof(string)) {
2967 ss = string;
2968 strcpy(string, s->password);
2969 len++; /* cover the zero byte */
2970 while (len < sizeof(string)) {
2971 string[len++] = (char) random_byte();
2972 }
2973 } else {
2974 ss = s->password;
2975 }
2976 logevent("Sending length-padded password");
2977 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2978 PKT_DATA, ss, len, PKT_END);
2979 } else {
2980 /*
2981 * The server has _both_
2982 * BUG_CHOKES_ON_SSH1_IGNORE and
2983 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2984 * therefore nothing we can do.
2985 */
2986 int len;
2987 len = strlen(s->password);
2988 logevent("Sending unpadded password");
2989 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2990 PKT_DATA, s->password, len, PKT_END);
2991 }
2992 } else {
2993 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
2994 }
2995 }
2996 logevent("Sent password");
2997 memset(s->password, 0, strlen(s->password));
2998 crWaitUntil(ispkt);
2999 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3000 if (flags & FLAG_VERBOSE)
3001 c_write_str(ssh, "Access denied\r\n");
3002 logevent("Authentication refused");
3003 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3004 bombout(("Strange packet received, type %d", ssh->pktin.type));
3005 crStop(0);
3006 }
3007 }
3008
3009 logevent("Authentication successful");
3010
3011 crFinish(1);
3012 }
3013
3014 void sshfwd_close(struct ssh_channel *c)
3015 {
3016 Ssh ssh = c->ssh;
3017
3018 if (ssh->state != SSH_STATE_SESSION) {
3019 assert(ssh->state == SSH_STATE_CLOSED);
3020 return;
3021 }
3022
3023 if (c && !c->closes) {
3024 /*
3025 * If the channel's remoteid is -1, we have sent
3026 * CHANNEL_OPEN for this channel, but it hasn't even been
3027 * acknowledged by the server. So we must set a close flag
3028 * on it now, and then when the server acks the channel
3029 * open, we can close it then.
3030 */
3031 if (((int)c->remoteid) != -1) {
3032 if (ssh->version == 1) {
3033 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3034 PKT_END);
3035 } else {
3036 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3037 ssh2_pkt_adduint32(ssh, c->remoteid);
3038 ssh2_pkt_send(ssh);
3039 }
3040 }
3041 c->closes = 1; /* sent MSG_CLOSE */
3042 if (c->type == CHAN_X11) {
3043 c->u.x11.s = NULL;
3044 logevent("Forwarded X11 connection terminated");
3045 } else if (c->type == CHAN_SOCKDATA ||
3046 c->type == CHAN_SOCKDATA_DORMANT) {
3047 c->u.pfd.s = NULL;
3048 logevent("Forwarded port closed");
3049 }
3050 }
3051 }
3052
3053 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3054 {
3055 Ssh ssh = c->ssh;
3056
3057 if (ssh->state != SSH_STATE_SESSION) {
3058 assert(ssh->state == SSH_STATE_CLOSED);
3059 return 0;
3060 }
3061
3062 if (ssh->version == 1) {
3063 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3064 PKT_INT, c->remoteid,
3065 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
3066 /*
3067 * In SSH1 we can return 0 here - implying that forwarded
3068 * connections are never individually throttled - because
3069 * the only circumstance that can cause throttling will be
3070 * the whole SSH connection backing up, in which case
3071 * _everything_ will be throttled as a whole.
3072 */
3073 return 0;
3074 } else {
3075 ssh2_add_channel_data(c, buf, len);
3076 return ssh2_try_send(c);
3077 }
3078 }
3079
3080 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3081 {
3082 Ssh ssh = c->ssh;
3083
3084 if (ssh->state != SSH_STATE_SESSION) {
3085 assert(ssh->state == SSH_STATE_CLOSED);
3086 return;
3087 }
3088
3089 if (ssh->version == 1) {
3090 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3091 c->v.v1.throttling = 0;
3092 ssh1_throttle(ssh, -1);
3093 }
3094 } else {
3095 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3096 }
3097 }
3098
3099 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3100 {
3101 crBegin(ssh->ssh1_protocol_crstate);
3102
3103 random_init();
3104
3105 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3106 crReturnV;
3107 }
3108 if (ssh->state == SSH_STATE_CLOSED)
3109 crReturnV;
3110
3111 if (ssh->cfg.agentfwd && agent_exists()) {
3112 logevent("Requesting agent forwarding");
3113 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3114 do {
3115 crReturnV;
3116 } while (!ispkt);
3117 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3118 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3119 bombout(("Protocol confusion"));
3120 crStopV;
3121 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3122 logevent("Agent forwarding refused");
3123 } else {
3124 logevent("Agent forwarding enabled");
3125 ssh->agentfwd_enabled = TRUE;
3126 }
3127 }
3128
3129 if (ssh->cfg.x11_forward) {
3130 char proto[20], data[64];
3131 logevent("Requesting X11 forwarding");
3132 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3133 data, sizeof(data), ssh->cfg.x11_auth);
3134 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3135 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3136 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3137 PKT_STR, proto, PKT_STR, data,
3138 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3139 PKT_END);
3140 } else {
3141 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3142 PKT_STR, proto, PKT_STR, data, PKT_END);
3143 }
3144 do {
3145 crReturnV;
3146 } while (!ispkt);
3147 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3148 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3149 bombout(("Protocol confusion"));
3150 crStopV;
3151 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3152 logevent("X11 forwarding refused");
3153 } else {
3154 logevent("X11 forwarding enabled");
3155 ssh->X11_fwd_enabled = TRUE;
3156 }
3157 }
3158
3159 {
3160 char type;
3161 int n;
3162 int sport,dport,sserv,dserv;
3163 char sports[256], dports[256], saddr[256], host[256];
3164
3165 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3166 /* Add port forwardings. */
3167 ssh->portfwd_strptr = ssh->cfg.portfwd;
3168 while (*ssh->portfwd_strptr) {
3169 type = *ssh->portfwd_strptr++;
3170 saddr[0] = '\0';
3171 n = 0;
3172 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3173 if (*ssh->portfwd_strptr == ':') {
3174 /*
3175 * We've seen a colon in the middle of the
3176 * source port number. This means that
3177 * everything we've seen until now is the
3178 * source _address_, so we'll move it into
3179 * saddr and start sports from the beginning
3180 * again.
3181 */
3182 ssh->portfwd_strptr++;
3183 sports[n] = '\0';
3184 strcpy(saddr, sports);
3185 n = 0;
3186 }
3187 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3188 }
3189 sports[n] = 0;
3190 if (type != 'D') {
3191 if (*ssh->portfwd_strptr == '\t')
3192 ssh->portfwd_strptr++;
3193 n = 0;
3194 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3195 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3196 }
3197 host[n] = 0;
3198 if (*ssh->portfwd_strptr == ':')
3199 ssh->portfwd_strptr++;
3200 n = 0;
3201 while (*ssh->portfwd_strptr) {
3202 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3203 }
3204 dports[n] = 0;
3205 ssh->portfwd_strptr++;
3206 dport = atoi(dports);
3207 dserv = 0;
3208 if (dport == 0) {
3209 dserv = 1;
3210 dport = net_service_lookup(dports);
3211 if (!dport) {
3212 logeventf(ssh, "Service lookup failed for"
3213 " destination port \"%s\"", dports);
3214 }
3215 }
3216 } else {
3217 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3218 dport = dserv = -1;
3219 }
3220 sport = atoi(sports);
3221 sserv = 0;
3222 if (sport == 0) {
3223 sserv = 1;
3224 sport = net_service_lookup(sports);
3225 if (!sport) {
3226 logeventf(ssh, "Service lookup failed for source"
3227 " port \"%s\"", sports);
3228 }
3229 }
3230 if (sport && dport) {
3231 if (type == 'L') {
3232 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3233 sport, ssh, &ssh->cfg);
3234 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3235 " forwarding to %s:%.*s%.*s%d%.*s",
3236 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3237 (int)(*saddr?1:0), ":",
3238 (int)(sserv ? strlen(sports) : 0), sports,
3239 sserv, "(", sport, sserv, ")",
3240 host,
3241 (int)(dserv ? strlen(dports) : 0), dports,
3242 dserv, "(", dport, dserv, ")");
3243 } else if (type == 'D') {
3244 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
3245 sport, ssh, &ssh->cfg);
3246 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3247 " doing SOCKS dynamic forwarding",
3248 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3249 (int)(*saddr?1:0), ":",
3250 (int)(sserv ? strlen(sports) : 0), sports,
3251 sserv, "(", sport, sserv, ")");
3252 } else {
3253 struct ssh_rportfwd *pf;
3254 pf = snew(struct ssh_rportfwd);
3255 strcpy(pf->dhost, host);
3256 pf->dport = dport;
3257 if (saddr) {
3258 logeventf(ssh,
3259 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3260 saddr, sport);
3261 }
3262 if (add234(ssh->rportfwds, pf) != pf) {
3263 logeventf(ssh,
3264 "Duplicate remote port forwarding to %s:%d",
3265 host, dport);
3266 sfree(pf);
3267 } else {
3268 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3269 " forward to %s:%.*s%.*s%d%.*s",
3270 (int)(sserv ? strlen(sports) : 0), sports,
3271 sserv, "(", sport, sserv, ")",
3272 host,
3273 (int)(dserv ? strlen(dports) : 0), dports,
3274 dserv, "(", dport, dserv, ")");
3275 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3276 PKT_INT, sport,
3277 PKT_STR, host,
3278 PKT_INT, dport,
3279 PKT_END);
3280 do {
3281 crReturnV;
3282 } while (!ispkt);
3283 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3284 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3285 bombout(("Protocol confusion"));
3286 crStopV;
3287 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3288 c_write_str(ssh, "Server refused port"
3289 " forwarding\r\n");
3290 }
3291 logevent("Remote port forwarding enabled");
3292 }
3293 }
3294 }
3295 }
3296 }
3297
3298 if (!ssh->cfg.nopty) {
3299 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3300 PKT_STR, ssh->cfg.termtype,
3301 PKT_INT, ssh->term_height,
3302 PKT_INT, ssh->term_width,
3303 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3304 ssh->state = SSH_STATE_INTERMED;
3305 do {
3306 crReturnV;
3307 } while (!ispkt);
3308 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3309 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3310 bombout(("Protocol confusion"));
3311 crStopV;
3312 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3313 c_write_str(ssh, "Server refused to allocate pty\r\n");
3314 ssh->editing = ssh->echoing = 1;
3315 }
3316 logevent("Allocated pty");
3317 } else {
3318 ssh->editing = ssh->echoing = 1;
3319 }
3320
3321 if (ssh->cfg.compression) {
3322 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3323 do {
3324 crReturnV;
3325 } while (!ispkt);
3326 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3327 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3328 bombout(("Protocol confusion"));
3329 crStopV;
3330 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3331 c_write_str(ssh, "Server refused to compress\r\n");
3332 }
3333 logevent("Started compression");
3334 ssh->v1_compressing = TRUE;
3335 ssh->cs_comp_ctx = zlib_compress_init();
3336 logevent("Initialised zlib (RFC1950) compression");
3337 ssh->sc_comp_ctx = zlib_decompress_init();
3338 logevent("Initialised zlib (RFC1950) decompression");
3339 }
3340
3341 /*
3342 * Start the shell or command.
3343 *
3344 * Special case: if the first-choice command is an SSH2
3345 * subsystem (hence not usable here) and the second choice
3346 * exists, we fall straight back to that.
3347 */
3348 {
3349 char *cmd = ssh->cfg.remote_cmd_ptr;
3350
3351 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3352 cmd = ssh->cfg.remote_cmd_ptr2;
3353 ssh->fallback_cmd = TRUE;
3354 }
3355 if (*cmd)
3356 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3357 else
3358 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3359 logevent("Started session");
3360 }
3361
3362 ssh->state = SSH_STATE_SESSION;
3363 if (ssh->size_needed)
3364 ssh_size(ssh, ssh->term_width, ssh->term_height);
3365 if (ssh->eof_needed)
3366 ssh_special(ssh, TS_EOF);
3367
3368 if (ssh->ldisc)
3369 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3370 ssh->send_ok = 1;
3371 ssh->channels = newtree234(ssh_channelcmp);
3372 while (1) {
3373 crReturnV;
3374 if (ispkt) {
3375 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3376 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3377 long len = GET_32BIT(ssh->pktin.body);
3378 int bufsize =
3379 from_backend(ssh->frontend,
3380 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3381 (char *)(ssh->pktin.body) + 4, len);
3382 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3383 ssh->v1_stdout_throttling = 1;
3384 ssh1_throttle(ssh, +1);
3385 }
3386 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3387 ssh_closing((Plug)ssh, NULL, 0, 0);
3388 logevent("Received disconnect request");
3389 crStopV;
3390 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3391 /* Remote side is trying to open a channel to talk to our
3392 * X-Server. Give them back a local channel number. */
3393 struct ssh_channel *c;
3394
3395 logevent("Received X11 connect request");
3396 /* Refuse if X11 forwarding is disabled. */
3397 if (!ssh->X11_fwd_enabled) {
3398 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3399 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3400 logevent("Rejected X11 connect request");
3401 } else {
3402 c = snew(struct ssh_channel);
3403 c->ssh = ssh;
3404
3405 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3406 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3407 logevent("opening X11 forward connection failed");
3408 sfree(c);
3409 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3410 PKT_INT, GET_32BIT(ssh->pktin.body),
3411 PKT_END);
3412 } else {
3413 logevent
3414 ("opening X11 forward connection succeeded");
3415 c->remoteid = GET_32BIT(ssh->pktin.body);
3416 c->localid = alloc_channel_id(ssh);
3417 c->closes = 0;
3418 c->v.v1.throttling = 0;
3419 c->type = CHAN_X11; /* identify channel type */
3420 add234(ssh->channels, c);
3421 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3422 PKT_INT, c->remoteid, PKT_INT,
3423 c->localid, PKT_END);
3424 logevent("Opened X11 forward channel");
3425 }
3426 }
3427 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3428 /* Remote side is trying to open a channel to talk to our
3429 * agent. Give them back a local channel number. */
3430 struct ssh_channel *c;
3431
3432 /* Refuse if agent forwarding is disabled. */
3433 if (!ssh->agentfwd_enabled) {
3434 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3435 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3436 } else {
3437 c = snew(struct ssh_channel);
3438 c->ssh = ssh;
3439 c->remoteid = GET_32BIT(ssh->pktin.body);
3440 c->localid = alloc_channel_id(ssh);
3441 c->closes = 0;
3442 c->v.v1.throttling = 0;
3443 c->type = CHAN_AGENT; /* identify channel type */
3444 c->u.a.lensofar = 0;
3445 add234(ssh->channels, c);
3446 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3447 PKT_INT, c->remoteid, PKT_INT, c->localid,
3448 PKT_END);
3449 }
3450 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3451 /* Remote side is trying to open a channel to talk to a
3452 * forwarded port. Give them back a local channel number. */
3453 struct ssh_channel *c;
3454 struct ssh_rportfwd pf;
3455 int hostsize, port;
3456 char host[256], buf[1024];
3457 char *p, *h, *e;
3458 c = snew(struct ssh_channel);
3459 c->ssh = ssh;
3460
3461 hostsize = GET_32BIT(ssh->pktin.body+4);
3462 for (h = host, p = (char *)(ssh->pktin.body+8);
3463 hostsize != 0; hostsize--) {
3464 if (h+1 < host+sizeof(host))
3465 *h++ = *p;
3466 p++;
3467 }
3468 *h = 0;
3469 port = GET_32BIT(p);
3470
3471 strcpy(pf.dhost, host);
3472 pf.dport = port;
3473
3474 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3475 sprintf(buf, "Rejected remote port open request for %s:%d",
3476 host, port);
3477 logevent(buf);
3478 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3479 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3480 } else {
3481 sprintf(buf, "Received remote port open request for %s:%d",
3482 host, port);
3483 logevent(buf);
3484 e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg);
3485 if (e != NULL) {
3486 char buf[256];
3487 sprintf(buf, "Port open failed: %s", e);
3488 logevent(buf);
3489 sfree(c);
3490 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3491 PKT_INT, GET_32BIT(ssh->pktin.body),
3492 PKT_END);
3493 } else {
3494 c->remoteid = GET_32BIT(ssh->pktin.body);
3495 c->localid = alloc_channel_id(ssh);
3496 c->closes = 0;
3497 c->v.v1.throttling = 0;
3498 c->type = CHAN_SOCKDATA; /* identify channel type */
3499 add234(ssh->channels, c);
3500 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3501 PKT_INT, c->remoteid, PKT_INT,
3502 c->localid, PKT_END);
3503 logevent("Forwarded port opened successfully");
3504 }
3505 }
3506
3507 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3508 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3509 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3510 struct ssh_channel *c;
3511
3512 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3513 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3514 c->remoteid = localid;
3515 c->type = CHAN_SOCKDATA;
3516 c->v.v1.throttling = 0;
3517 pfd_confirm(c->u.pfd.s);
3518 }
3519
3520 if (c && c->closes) {
3521 /*
3522 * We have a pending close on this channel,
3523 * which we decided on before the server acked
3524 * the channel open. So now we know the
3525 * remoteid, we can close it again.
3526 */
3527 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3528 PKT_INT, c->remoteid, PKT_END);
3529 }
3530
3531 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3532 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3533 struct ssh_channel *c;
3534
3535 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3536 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3537 logevent("Forwarded connection refused by server");
3538 pfd_close(c->u.pfd.s);
3539 del234(ssh->channels, c);
3540 sfree(c);
3541 }
3542
3543 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3544 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3545 /* Remote side closes a channel. */
3546 unsigned i = GET_32BIT(ssh->pktin.body);
3547 struct ssh_channel *c;
3548 c = find234(ssh->channels, &i, ssh_channelfind);
3549 if (c && ((int)c->remoteid) != -1) {
3550 int closetype;
3551 closetype =
3552 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3553
3554 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3555 logevent("Forwarded X11 connection terminated");
3556 assert(c->u.x11.s != NULL);
3557 x11_close(c->u.x11.s);
3558 c->u.x11.s = NULL;
3559 }
3560 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3561 logevent("Forwarded port closed");
3562 assert(c->u.pfd.s != NULL);
3563 pfd_close(c->u.pfd.s);
3564 c->u.pfd.s = NULL;
3565 }
3566
3567 c->closes |= (closetype << 2); /* seen this message */
3568 if (!(c->closes & closetype)) {
3569 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3570 PKT_END);
3571 c->closes |= closetype; /* sent it too */
3572 }
3573
3574 if (c->closes == 15) {
3575 del234(ssh->channels, c);
3576 sfree(c);
3577 }
3578 } else {
3579 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3580 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3581 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3582 i));
3583 crStopV;
3584 }
3585 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3586 /* Data sent down one of our channels. */
3587 int i = GET_32BIT(ssh->pktin.body);
3588 int len = GET_32BIT(ssh->pktin.body + 4);
3589 unsigned char *p = ssh->pktin.body + 8;
3590 struct ssh_channel *c;
3591 c = find234(ssh->channels, &i, ssh_channelfind);
3592 if (c) {
3593 int bufsize = 0;
3594 switch (c->type) {
3595 case CHAN_X11:
3596 bufsize = x11_send(c->u.x11.s, (char *)p, len);
3597 break;
3598 case CHAN_SOCKDATA:
3599 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
3600 break;
3601 case CHAN_AGENT:
3602 /* Data for an agent message. Buffer it. */
3603 while (len > 0) {
3604 if (c->u.a.lensofar < 4) {
3605 int l = min(4 - c->u.a.lensofar, len);
3606 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3607 l);
3608 p += l;
3609 len -= l;
3610 c->u.a.lensofar += l;
3611 }
3612 if (c->u.a.lensofar == 4) {
3613 c->u.a.totallen =
3614 4 + GET_32BIT(c->u.a.msglen);
3615 c->u.a.message = snewn(c->u.a.totallen,
3616 unsigned char);
3617 memcpy(c->u.a.message, c->u.a.msglen, 4);
3618 }
3619 if (c->u.a.lensofar >= 4 && len > 0) {
3620 int l =
3621 min(c->u.a.totallen - c->u.a.lensofar,
3622 len);
3623 memcpy(c->u.a.message + c->u.a.lensofar, p,
3624 l);
3625 p += l;
3626 len -= l;
3627 c->u.a.lensofar += l;
3628 }
3629 if (c->u.a.lensofar == c->u.a.totallen) {
3630 void *reply, *sentreply;
3631 int replylen;
3632 agent_query(c->u.a.message,
3633 c->u.a.totallen, &reply,
3634 &replylen);
3635 if (reply)
3636 sentreply = reply;
3637 else {
3638 /* Fake SSH_AGENT_FAILURE. */
3639 sentreply = "\0\0\0\1\5";
3640 replylen = 5;
3641 }
3642 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3643 PKT_INT, c->remoteid,
3644 PKT_INT, replylen,
3645 PKT_DATA, sentreply, replylen,
3646 PKT_END);
3647 if (reply)
3648 sfree(reply);
3649 sfree(c->u.a.message);
3650 c->u.a.lensofar = 0;
3651 }
3652 }
3653 bufsize = 0; /* agent channels never back up */
3654 break;
3655 }
3656 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3657 c->v.v1.throttling = 1;
3658 ssh1_throttle(ssh, +1);
3659 }
3660 }
3661 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3662 /* may be from EXEC_SHELL on some servers */
3663 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3664 /* may be from EXEC_SHELL on some servers
3665 * if no pty is available or in other odd cases. Ignore */
3666 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3667 char buf[100];
3668 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3669 sprintf(buf, "Server sent command exit status %d",
3670 ssh->exitcode);
3671 logevent(buf);
3672 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3673 /*
3674 * In case `helpful' firewalls or proxies tack
3675 * extra human-readable text on the end of the
3676 * session which we might mistake for another
3677 * encrypted packet, we close the session once
3678 * we've sent EXIT_CONFIRMATION.
3679 */
3680 ssh_closing((Plug)ssh, NULL, 0, 0);
3681 crStopV;
3682 } else {
3683 bombout(("Strange packet received: type %d", ssh->pktin.type));
3684 crStopV;
3685 }
3686 } else {
3687 while (inlen > 0) {
3688 int len = min(inlen, 512);
3689 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3690 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3691 in += len;
3692 inlen -= len;
3693 }
3694 }
3695 }
3696
3697 crFinishV;
3698 }
3699
3700 /*
3701 * Utility routine for decoding comma-separated strings in KEXINIT.
3702 */
3703 static int in_commasep_string(char *needle, char *haystack, int haylen)
3704 {
3705 int needlen;
3706 if (!needle || !haystack) /* protect against null pointers */
3707 return 0;
3708 needlen = strlen(needle);
3709 while (1) {
3710 /*
3711 * Is it at the start of the string?
3712 */
3713 if (haylen >= needlen && /* haystack is long enough */
3714 !memcmp(needle, haystack, needlen) && /* initial match */
3715 (haylen == needlen || haystack[needlen] == ',')
3716 /* either , or EOS follows */
3717 )
3718 return 1;
3719 /*
3720 * If not, search for the next comma and resume after that.
3721 * If no comma found, terminate.
3722 */
3723 while (haylen > 0 && *haystack != ',')
3724 haylen--, haystack++;
3725 if (haylen == 0)
3726 return 0;
3727 haylen--, haystack++; /* skip over comma itself */
3728 }
3729 }
3730
3731 /*
3732 * SSH2 key creation method.
3733 */
3734 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3735 unsigned char *sessid, char chr,
3736 unsigned char *keyspace)
3737 {
3738 SHA_State s;
3739 /* First 20 bytes. */
3740 SHA_Init(&s);
3741 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3742 sha_mpint(&s, K);
3743 SHA_Bytes(&s, H, 20);
3744 SHA_Bytes(&s, &chr, 1);
3745 SHA_Bytes(&s, sessid, 20);
3746 SHA_Final(&s, keyspace);
3747 /* Next 20 bytes. */
3748 SHA_Init(&s);
3749 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3750 sha_mpint(&s, K);
3751 SHA_Bytes(&s, H, 20);
3752 SHA_Bytes(&s, keyspace, 20);
3753 SHA_Final(&s, keyspace + 20);
3754 }
3755
3756 /*
3757 * Handle the SSH2 transport layer.
3758 */
3759 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3760 {
3761 struct do_ssh2_transport_state {
3762 int nbits, pbits, warn;
3763 Bignum p, g, e, f, K;
3764 int kex_init_value, kex_reply_value;
3765 const struct ssh_mac **maclist;
3766 int nmacs;
3767 const struct ssh2_cipher *cscipher_tobe;
3768 const struct ssh2_cipher *sccipher_tobe;
3769 const struct ssh_mac *csmac_tobe;
3770 const struct ssh_mac *scmac_tobe;
3771 const struct ssh_compress *cscomp_tobe;
3772 const struct ssh_compress *sccomp_tobe;
3773 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3774 int hostkeylen, siglen;
3775 void *hkey; /* actual host key */
3776 unsigned char exchange_hash[20];
3777 int n_preferred_ciphers;
3778 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3779 const struct ssh_compress *preferred_comp;
3780 int first_kex;
3781 };
3782 crState(do_ssh2_transport_state);
3783
3784 crBegin(ssh->do_ssh2_transport_crstate);
3785
3786 s->cscipher_tobe = s->sccipher_tobe = NULL;
3787 s->csmac_tobe = s->scmac_tobe = NULL;
3788 s->cscomp_tobe = s->sccomp_tobe = NULL;
3789
3790 random_init();
3791 s->first_kex = 1;
3792
3793 {
3794 int i;
3795 /*
3796 * Set up the preferred ciphers. (NULL => warn below here)
3797 */
3798 s->n_preferred_ciphers = 0;
3799 for (i = 0; i < CIPHER_MAX; i++) {
3800 switch (ssh->cfg.ssh_cipherlist[i]) {
3801 case CIPHER_BLOWFISH:
3802 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3803 break;
3804 case CIPHER_DES:
3805 if (ssh->cfg.ssh2_des_cbc) {
3806 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3807 }
3808 break;
3809 case CIPHER_3DES:
3810 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3811 break;
3812 case CIPHER_AES:
3813 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3814 break;
3815 case CIPHER_WARN:
3816 /* Flag for later. Don't bother if it's the last in
3817 * the list. */
3818 if (i < CIPHER_MAX - 1) {
3819 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3820 }
3821 break;
3822 }
3823 }
3824 }
3825
3826 /*
3827 * Set up preferred compression.
3828 */
3829 if (ssh->cfg.compression)
3830 s->preferred_comp = &ssh_zlib;
3831 else
3832 s->preferred_comp = &ssh_comp_none;
3833
3834 /*
3835 * Be prepared to work around the buggy MAC problem.
3836 */
3837 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3838 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3839 else
3840 s->maclist = macs, s->nmacs = lenof(macs);
3841
3842 begin_key_exchange:
3843 {
3844 int i, j, cipherstr_started;
3845
3846 /*
3847 * Construct and send our key exchange packet.
3848 */
3849 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3850 for (i = 0; i < 16; i++)
3851 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3852 /* List key exchange algorithms. */
3853 ssh2_pkt_addstring_start(ssh);
3854 for (i = 0; i < lenof(kex_algs); i++) {
3855 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3856 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3857 continue;
3858 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3859 if (i < lenof(kex_algs) - 1)
3860 ssh2_pkt_addstring_str(ssh, ",");
3861 }
3862 /* List server host key algorithms. */
3863 ssh2_pkt_addstring_start(ssh);
3864 for (i = 0; i < lenof(hostkey_algs); i++) {
3865 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3866 if (i < lenof(hostkey_algs) - 1)
3867 ssh2_pkt_addstring_str(ssh, ",");
3868 }
3869 /* List client->server encryption algorithms. */
3870 ssh2_pkt_addstring_start(ssh);
3871 cipherstr_started = 0;
3872 for (i = 0; i < s->n_preferred_ciphers; i++) {
3873 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3874 if (!c) continue; /* warning flag */
3875 for (j = 0; j < c->nciphers; j++) {
3876 if (cipherstr_started)
3877 ssh2_pkt_addstring_str(ssh, ",");
3878 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3879 cipherstr_started = 1;
3880 }
3881 }
3882 /* List server->client encryption algorithms. */
3883 ssh2_pkt_addstring_start(ssh);
3884 cipherstr_started = 0;
3885 for (i = 0; i < s->n_preferred_ciphers; i++) {
3886 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3887 if (!c) continue; /* warning flag */
3888 for (j = 0; j < c->nciphers; j++) {
3889 if (cipherstr_started)
3890 ssh2_pkt_addstring_str(ssh, ",");
3891 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3892 cipherstr_started = 1;
3893 }
3894 }
3895 /* List client->server MAC algorithms. */
3896 ssh2_pkt_addstring_start(ssh);
3897 for (i = 0; i < s->nmacs; i++) {
3898 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3899 if (i < s->nmacs - 1)
3900 ssh2_pkt_addstring_str(ssh, ",");
3901 }
3902 /* List server->client MAC algorithms. */
3903 ssh2_pkt_addstring_start(ssh);
3904 for (i = 0; i < s->nmacs; i++) {
3905 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3906 if (i < s->nmacs - 1)
3907 ssh2_pkt_addstring_str(ssh, ",");
3908 }
3909 /* List client->server compression algorithms. */
3910 ssh2_pkt_addstring_start(ssh);
3911 for (i = 0; i < lenof(compressions) + 1; i++) {
3912 const struct ssh_compress *c =
3913 i == 0 ? s->preferred_comp : compressions[i - 1];
3914 ssh2_pkt_addstring_str(ssh, c->name);
3915 if (i < lenof(compressions))
3916 ssh2_pkt_addstring_str(ssh, ",");
3917 }
3918 /* List server->client compression algorithms. */
3919 ssh2_pkt_addstring_start(ssh);
3920 for (i = 0; i < lenof(compressions) + 1; i++) {
3921 const struct ssh_compress *c =
3922 i == 0 ? s->preferred_comp : compressions[i - 1];
3923 ssh2_pkt_addstring_str(ssh, c->name);
3924 if (i < lenof(compressions))
3925 ssh2_pkt_addstring_str(ssh, ",");
3926 }
3927 /* List client->server languages. Empty list. */
3928 ssh2_pkt_addstring_start(ssh);
3929 /* List server->client languages. Empty list. */
3930 ssh2_pkt_addstring_start(ssh);
3931 /* First KEX packet does _not_ follow, because we're not that brave. */
3932 ssh2_pkt_addbool(ssh, FALSE);
3933 /* Reserved. */
3934 ssh2_pkt_adduint32(ssh, 0);
3935 }
3936
3937 ssh->exhash = ssh->exhashbase;
3938 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
3939
3940 ssh2_pkt_send(ssh);
3941
3942 if (!ispkt)
3943 crWaitUntil(ispkt);
3944 if (ssh->pktin.length > 5)
3945 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
3946
3947 /*
3948 * Now examine the other side's KEXINIT to see what we're up
3949 * to.
3950 */
3951 {
3952 char *str;
3953 int i, j, len;
3954
3955 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3956 bombout(("expected key exchange packet from server"));
3957 crStop(0);
3958 }
3959 ssh->kex = NULL;
3960 ssh->hostkey = NULL;
3961 s->cscipher_tobe = NULL;
3962 s->sccipher_tobe = NULL;
3963 s->csmac_tobe = NULL;
3964 s->scmac_tobe = NULL;
3965 s->cscomp_tobe = NULL;
3966 s->sccomp_tobe = NULL;
3967 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3968 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3969 for (i = 0; i < lenof(kex_algs); i++) {
3970 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3971 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3972 continue;
3973 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3974 ssh->kex = kex_algs[i];
3975 break;
3976 }
3977 }
3978 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3979 for (i = 0; i < lenof(hostkey_algs); i++) {
3980 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3981 ssh->hostkey = hostkey_algs[i];
3982 break;
3983 }
3984 }
3985 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3986 s->warn = 0;
3987 for (i = 0; i < s->n_preferred_ciphers; i++) {
3988 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3989 if (!c) {
3990 s->warn = 1;
3991 } else {
3992 for (j = 0; j < c->nciphers; j++) {
3993 if (in_commasep_string(c->list[j]->name, str, len)) {
3994 s->cscipher_tobe = c->list[j];
3995 break;
3996 }
3997 }
3998 }
3999 if (s->cscipher_tobe) {
4000 if (s->warn)
4001 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
4002 break;
4003 }
4004 }
4005 if (!s->cscipher_tobe) {
4006 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4007 str ? str : "(null)"));
4008 crStop(0);
4009 }
4010
4011 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
4012 s->warn = 0;
4013 for (i = 0; i < s->n_preferred_ciphers; i++) {
4014 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4015 if (!c) {
4016 s->warn = 1;
4017 } else {
4018 for (j = 0; j < c->nciphers; j++) {
4019 if (in_commasep_string(c->list[j]->name, str, len)) {
4020 s->sccipher_tobe = c->list[j];
4021 break;
4022 }
4023 }
4024 }
4025 if (s->sccipher_tobe) {
4026 if (s->warn)
4027 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
4028 break;
4029 }
4030 }
4031 if (!s->sccipher_tobe) {
4032 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4033 str ? str : "(null)"));
4034 crStop(0);
4035 }
4036
4037 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
4038 for (i = 0; i < s->nmacs; i++) {
4039 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4040 s->csmac_tobe = s->maclist[i];
4041 break;
4042 }
4043 }
4044 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
4045 for (i = 0; i < s->nmacs; i++) {
4046 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4047 s->scmac_tobe = s->maclist[i];
4048 break;
4049 }
4050 }
4051 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
4052 for (i = 0; i < lenof(compressions) + 1; i++) {
4053 const struct ssh_compress *c =
4054 i == 0 ? s->preferred_comp : compressions[i - 1];
4055 if (in_commasep_string(c->name, str, len)) {
4056 s->cscomp_tobe = c;
4057 break;
4058 }
4059 }
4060 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
4061 for (i = 0; i < lenof(compressions) + 1; i++) {
4062 const struct ssh_compress *c =
4063 i == 0 ? s->preferred_comp : compressions[i - 1];
4064 if (in_commasep_string(c->name, str, len)) {
4065 s->sccomp_tobe = c;
4066 break;
4067 }
4068 }
4069 }
4070
4071 /*
4072 * Work out the number of bits of key we will need from the key
4073 * exchange. We start with the maximum key length of either
4074 * cipher...
4075 */
4076 {
4077 int csbits, scbits;
4078
4079 csbits = s->cscipher_tobe->keylen;
4080 scbits = s->sccipher_tobe->keylen;
4081 s->nbits = (csbits > scbits ? csbits : scbits);
4082 }
4083 /* The keys only have 160-bit entropy, since they're based on
4084 * a SHA-1 hash. So cap the key size at 160 bits. */
4085 if (s->nbits > 160)
4086 s->nbits = 160;
4087
4088 /*
4089 * If we're doing Diffie-Hellman group exchange, start by
4090 * requesting a group.
4091 */
4092 if (ssh->kex == &ssh_diffiehellman_gex) {
4093 logevent("Doing Diffie-Hellman group exchange");
4094 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4095 /*
4096 * Work out how big a DH group we will need to allow that
4097 * much data.
4098 */
4099 s->pbits = 512 << ((s->nbits - 1) / 64);
4100 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4101 ssh2_pkt_adduint32(ssh, s->pbits);
4102 ssh2_pkt_send(ssh);
4103
4104 crWaitUntil(ispkt);
4105 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4106 bombout(("expected key exchange group packet from server"));
4107 crStop(0);
4108 }
4109 s->p = ssh2_pkt_getmp(ssh);
4110 s->g = ssh2_pkt_getmp(ssh);
4111 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4112 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4113 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4114 } else {
4115 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4116 ssh->kex_ctx = dh_setup_group1();
4117 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4118 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4119 }
4120
4121 logevent("Doing Diffie-Hellman key exchange");
4122 /*
4123 * Now generate and send e for Diffie-Hellman.
4124 */
4125 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4126 ssh2_pkt_init(ssh, s->kex_init_value);
4127 ssh2_pkt_addmp(ssh, s->e);
4128 ssh2_pkt_send(ssh);
4129
4130 crWaitUntil(ispkt);
4131 if (ssh->pktin.type != s->kex_reply_value) {
4132 bombout(("expected key exchange reply packet from server"));
4133 crStop(0);
4134 }
4135 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4136 s->f = ssh2_pkt_getmp(ssh);
4137 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4138
4139 s->K = dh_find_K(ssh->kex_ctx, s->f);
4140
4141 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4142 if (ssh->kex == &ssh_diffiehellman_gex) {
4143 sha_uint32(&ssh->exhash, s->pbits);
4144 sha_mpint(&ssh->exhash, s->p);
4145 sha_mpint(&ssh->exhash, s->g);
4146 }
4147 sha_mpint(&ssh->exhash, s->e);
4148 sha_mpint(&ssh->exhash, s->f);
4149 sha_mpint(&ssh->exhash, s->K);
4150 SHA_Final(&ssh->exhash, s->exchange_hash);
4151
4152 dh_cleanup(ssh->kex_ctx);
4153 ssh->kex_ctx = NULL;
4154
4155 #if 0
4156 debug(("Exchange hash is:\n"));
4157 dmemdump(s->exchange_hash, 20);
4158 #endif
4159
4160 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4161 if (!s->hkey ||
4162 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4163 (char *)s->exchange_hash, 20)) {
4164 bombout(("Server's host key did not match the signature supplied"));
4165 crStop(0);
4166 }
4167
4168 /*
4169 * Authenticate remote host: verify host key. (We've already
4170 * checked the signature of the exchange hash.)
4171 */
4172 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4173 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4174 verify_ssh_host_key(ssh->frontend,
4175 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4176 s->keystr, s->fingerprint);
4177 if (s->first_kex) { /* don't bother logging this in rekeys */
4178 logevent("Host key fingerprint is:");
4179 logevent(s->fingerprint);
4180 }
4181 sfree(s->fingerprint);
4182 sfree(s->keystr);
4183 ssh->hostkey->freekey(s->hkey);
4184
4185 /*
4186 * Send SSH2_MSG_NEWKEYS.
4187 */
4188 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4189 ssh2_pkt_send(ssh);
4190
4191 /*
4192 * Expect SSH2_MSG_NEWKEYS from server.
4193 */
4194 crWaitUntil(ispkt);
4195 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4196 bombout(("expected new-keys packet from server"));
4197 crStop(0);
4198 }
4199
4200 /*
4201 * Create and initialise session keys.
4202 */
4203 if (ssh->cs_cipher_ctx)
4204 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4205 ssh->cscipher = s->cscipher_tobe;
4206 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4207
4208 if (ssh->sc_cipher_ctx)
4209 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4210 ssh->sccipher = s->sccipher_tobe;
4211 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4212
4213 if (ssh->cs_mac_ctx)
4214 ssh->csmac->free_context(ssh->cs_mac_ctx);
4215 ssh->csmac = s->csmac_tobe;
4216 ssh->cs_mac_ctx = ssh->csmac->make_context();
4217
4218 if (ssh->sc_mac_ctx)
4219 ssh->scmac->free_context(ssh->sc_mac_ctx);
4220 ssh->scmac = s->scmac_tobe;
4221 ssh->sc_mac_ctx = ssh->scmac->make_context();
4222
4223 if (ssh->cs_comp_ctx)
4224 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4225 ssh->cscomp = s->cscomp_tobe;
4226 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4227
4228 if (ssh->sc_comp_ctx)
4229 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4230 ssh->sccomp = s->sccomp_tobe;
4231 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4232
4233 /*
4234 * Set IVs after keys. Here we use the exchange hash from the
4235 * _first_ key exchange.
4236 */
4237 {
4238 unsigned char keyspace[40];
4239 if (s->first_kex)
4240 memcpy(ssh->v2_session_id, s->exchange_hash,
4241 sizeof(s->exchange_hash));
4242 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4243 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4244 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4245 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4246 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4247 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4248 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4249 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4250 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4251 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4252 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4253 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4254 }
4255 logeventf(ssh, "Initialised %.200s client->server encryption",
4256 ssh->cscipher->text_name);
4257 logeventf(ssh, "Initialised %.200s server->client encryption",
4258 ssh->sccipher->text_name);
4259 if (ssh->cscomp->text_name)
4260 logeventf(ssh, "Initialised %s compression",
4261 ssh->cscomp->text_name);
4262 if (ssh->sccomp->text_name)
4263 logeventf(ssh, "Initialised %s decompression",
4264 ssh->sccomp->text_name);
4265
4266 /*
4267 * If this is the first key exchange phase, we must pass the
4268 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4269 * wants to see it but because it will need time to initialise
4270 * itself before it sees an actual packet. In subsequent key
4271 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4272 * it would only confuse the layer above.
4273 */
4274 if (!s->first_kex) {
4275 crReturn(0);
4276 }
4277 s->first_kex = 0;
4278
4279 /*
4280 * Now we're encrypting. Begin returning 1 to the protocol main
4281 * function so that other things can run on top of the
4282 * transport. If we ever see a KEXINIT, we must go back to the
4283 * start.
4284 */
4285 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4286 crReturn(1);
4287 }
4288 logevent("Server initiated key re-exchange");
4289 goto begin_key_exchange;
4290
4291 crFinish(1);
4292 }
4293
4294 /*
4295 * Add data to an SSH2 channel output buffer.
4296 */
4297 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4298 int len)
4299 {
4300 bufchain_add(&c->v.v2.outbuffer, buf, len);
4301 }
4302
4303 /*
4304 * Attempt to send data on an SSH2 channel.
4305 */
4306 static int ssh2_try_send(struct ssh_channel *c)
4307 {
4308 Ssh ssh = c->ssh;
4309
4310 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4311 int len;
4312 void *data;
4313 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4314 if ((unsigned)len > c->v.v2.remwindow)
4315 len = c->v.v2.remwindow;
4316 if ((unsigned)len > c->v.v2.remmaxpkt)
4317 len = c->v.v2.remmaxpkt;
4318 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4319 ssh2_pkt_adduint32(ssh, c->remoteid);
4320 ssh2_pkt_addstring_start(ssh);
4321 ssh2_pkt_addstring_data(ssh, data, len);
4322 ssh2_pkt_send(ssh);
4323 bufchain_consume(&c->v.v2.outbuffer, len);
4324 c->v.v2.remwindow -= len;
4325 }
4326
4327 /*
4328 * After having sent as much data as we can, return the amount
4329 * still buffered.
4330 */
4331 return bufchain_size(&c->v.v2.outbuffer);
4332 }
4333
4334 /*
4335 * Potentially enlarge the window on an SSH2 channel.
4336 */
4337 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4338 {
4339 Ssh ssh = c->ssh;
4340
4341 /*
4342 * Never send WINDOW_ADJUST for a channel that the remote side
4343 * already thinks it's closed; there's no point, since it won't
4344 * be sending any more data anyway.
4345 */
4346 if (c->closes != 0)
4347 return;
4348
4349 if (newwin > c->v.v2.locwindow) {
4350 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4351 ssh2_pkt_adduint32(ssh, c->remoteid);
4352 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4353 ssh2_pkt_send(ssh);
4354 c->v.v2.locwindow = newwin;
4355 }
4356 }
4357
4358 /*
4359 * Handle the SSH2 userauth and connection layers.
4360 */
4361 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4362 {
4363 struct do_ssh2_authconn_state {
4364 enum {
4365 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4366 AUTH_PASSWORD,
4367 AUTH_KEYBOARD_INTERACTIVE
4368 } method;
4369 enum {
4370 AUTH_TYPE_NONE,
4371 AUTH_TYPE_PUBLICKEY,
4372 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4373 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4374 AUTH_TYPE_PASSWORD,
4375 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4376 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4377 } type;
4378 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4379 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4380 int kbd_inter_running;
4381 int we_are_in;
4382 int num_prompts, curr_prompt, echo;
4383 char username[100];
4384 int got_username;
4385 char pwprompt[200];
4386 char password[100];
4387 void *publickey_blob;
4388 int publickey_bloblen;
4389 unsigned char request[5], *response, *p;
4390 int responselen;
4391 int keyi, nkeys;
4392 int authed;
4393 char *pkblob, *alg, *commentp;
4394 int pklen, alglen, commentlen;
4395 int siglen, retlen, len;
4396 char *q, *agentreq, *ret;
4397 int try_send;
4398 };
4399 crState(do_ssh2_authconn_state);
4400
4401 crBegin(ssh->do_ssh2_authconn_crstate);
4402
4403 /*
4404 * Request userauth protocol, and await a response to it.
4405 */
4406 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4407 ssh2_pkt_addstring(ssh, "ssh-userauth");
4408 ssh2_pkt_send(ssh);
4409 crWaitUntilV(ispkt);
4410 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4411 bombout(("Server refused user authentication protocol"));
4412 crStopV;
4413 }
4414
4415 /*
4416 * We repeat this whole loop, including the username prompt,
4417 * until we manage a successful authentication. If the user
4418 * types the wrong _password_, they can be sent back to the
4419 * beginning to try another username, if this is configured on.
4420 * (If they specify a username in the config, they are never
4421 * asked, even if they do give a wrong password.)
4422 *
4423 * I think this best serves the needs of
4424 *
4425 * - the people who have no configuration, no keys, and just
4426 * want to try repeated (username,password) pairs until they
4427 * type both correctly
4428 *
4429 * - people who have keys and configuration but occasionally
4430 * need to fall back to passwords
4431 *
4432 * - people with a key held in Pageant, who might not have
4433 * logged in to a particular machine before; so they want to
4434 * type a username, and then _either_ their key will be
4435 * accepted, _or_ they will type a password. If they mistype
4436 * the username they will want to be able to get back and
4437 * retype it!
4438 */
4439 s->username[0] = '\0';
4440 s->got_username = FALSE;
4441 do {
4442 /*
4443 * Get a username.
4444 */
4445 if (s->got_username && !ssh->cfg.change_username) {
4446 /*
4447 * We got a username last time round this loop, and
4448 * with change_username turned off we don't try to get
4449 * it again.
4450 */
4451 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
4452 if (ssh_get_line && !ssh_getline_pw_only) {
4453 if (!ssh_get_line("login as: ",
4454 s->username, sizeof(s->username), FALSE)) {
4455 /*
4456 * get_line failed to get a username.
4457 * Terminate.
4458 */
4459 logevent("No username provided. Abandoning session.");
4460 ssh_closing((Plug)ssh, NULL, 0, 0);
4461 crStopV;
4462 }
4463 } else {
4464 int ret; /* need not be saved across crReturn */
4465 c_write_str(ssh, "login as: ");
4466 ssh->send_ok = 1;
4467 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4468 do {
4469 crWaitUntilV(!ispkt);
4470 ret = process_userpass_input(ssh, in, inlen);
4471 } while (ret == 0);
4472 if (ret < 0)
4473 cleanup_exit(0);
4474 c_write_str(ssh, "\r\n");
4475 }
4476 s->username[strcspn(s->username, "\n\r")] = '\0';
4477 } else {
4478 char *stuff;
4479 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
4480 s->username[sizeof(s->username)-1] = '\0';
4481 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4482 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4483 c_write_str(ssh, stuff);
4484 sfree(stuff);
4485 }
4486 }
4487 s->got_username = TRUE;
4488
4489 /*
4490 * Send an authentication request using method "none": (a)
4491 * just in case it succeeds, and (b) so that we know what
4492 * authentication methods we can usefully try next.
4493 */
4494 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4495
4496 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4497 ssh2_pkt_addstring(ssh, s->username);
4498 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4499 ssh2_pkt_addstring(ssh, "none"); /* method */
4500 ssh2_pkt_send(ssh);
4501 s->type = AUTH_TYPE_NONE;
4502 s->gotit = FALSE;
4503 s->we_are_in = FALSE;
4504
4505 s->tried_pubkey_config = FALSE;
4506 s->tried_agent = FALSE;
4507 s->tried_keyb_inter = FALSE;
4508 s->kbd_inter_running = FALSE;
4509 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4510 if (!filename_is_null(ssh->cfg.keyfile)) {
4511 int keytype;
4512 logeventf(ssh, "Reading private key file \"%.150s\"",
4513 filename_to_str(&ssh->cfg.keyfile));
4514 keytype = key_type(&ssh->cfg.keyfile);
4515 if (keytype == SSH_KEYTYPE_SSH2) {
4516 s->publickey_blob =
4517 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
4518 &s->publickey_bloblen);
4519 } else {
4520 char *msgbuf;
4521 logeventf(ssh, "Unable to use this key file (%s)",
4522 key_type_to_str(keytype));
4523 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4524 " (%s)\r\n",
4525 filename_to_str(&ssh->cfg.keyfile),
4526 key_type_to_str(keytype));
4527 c_write_str(ssh, msgbuf);
4528 sfree(msgbuf);
4529 s->publickey_blob = NULL;
4530 }
4531 } else
4532 s->publickey_blob = NULL;
4533
4534 while (1) {
4535 /*
4536 * Wait for the result of the last authentication request.
4537 */
4538 if (!s->gotit)
4539 crWaitUntilV(ispkt);
4540 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4541 char *banner;
4542 int size;
4543 /*
4544 * Don't show the banner if we're operating in
4545 * non-verbose non-interactive mode. (It's probably
4546 * a script, which means nobody will read the
4547 * banner _anyway_, and moreover the printing of
4548 * the banner will screw up processing on the
4549 * output of (say) plink.)
4550 */
4551 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4552 ssh2_pkt_getstring(ssh, &banner, &size);
4553 if (banner)
4554 c_write_untrusted(ssh, banner, size);
4555 }
4556 crWaitUntilV(ispkt);
4557 }
4558 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4559 logevent("Access granted");
4560 s->we_are_in = TRUE;
4561 break;
4562 }
4563
4564 if (s->kbd_inter_running &&
4565 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4566 /*
4567 * This is either a further set-of-prompts packet
4568 * in keyboard-interactive authentication, or it's
4569 * the same one and we came back here with `gotit'
4570 * set. In the former case, we must reset the
4571 * curr_prompt variable.
4572 */
4573 if (!s->gotit)
4574 s->curr_prompt = 0;
4575 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4576 bombout(("Strange packet received during authentication: type %d",
4577 ssh->pktin.type));
4578 crStopV;
4579 }
4580
4581 s->gotit = FALSE;
4582
4583 /*
4584 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4585 * we can look at the string in it and know what we can
4586 * helpfully try next.
4587 */
4588 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4589 char *methods;
4590 int methlen;
4591 ssh2_pkt_getstring(ssh, &methods, &methlen);
4592 s->kbd_inter_running = FALSE;
4593 if (!ssh2_pkt_getbool(ssh)) {
4594 /*
4595 * We have received an unequivocal Access
4596 * Denied. This can translate to a variety of
4597 * messages:
4598 *
4599 * - if we'd just tried "none" authentication,
4600 * it's not worth printing anything at all
4601 *
4602 * - if we'd just tried a public key _offer_,
4603 * the message should be "Server refused our
4604 * key" (or no message at all if the key
4605 * came from Pageant)
4606 *
4607 * - if we'd just tried anything else, the
4608 * message really should be "Access denied".
4609 *
4610 * Additionally, if we'd just tried password
4611 * authentication, we should break out of this
4612 * whole loop so as to go back to the username
4613 * prompt.
4614 */
4615 if (s->type == AUTH_TYPE_NONE) {
4616 /* do nothing */
4617 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4618 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4619 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4620 c_write_str(ssh, "Server refused our key\r\n");
4621 logevent("Server refused public key");
4622 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4623 /* server declined keyboard-interactive; ignore */
4624 } else {
4625 c_write_str(ssh, "Access denied\r\n");
4626 logevent("Access denied");
4627 if (s->type == AUTH_TYPE_PASSWORD) {
4628 s->we_are_in = FALSE;
4629 break;
4630 }
4631 }
4632 } else {
4633 c_write_str(ssh, "Further authentication required\r\n");
4634 logevent("Further authentication required");
4635 }
4636
4637 s->can_pubkey =
4638 in_commasep_string("publickey", methods, methlen);
4639 s->can_passwd =
4640 in_commasep_string("password", methods, methlen);
4641 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
4642 in_commasep_string("keyboard-interactive", methods, methlen);
4643 }
4644
4645 s->method = 0;
4646 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4647
4648 /*
4649 * Most password/passphrase prompts will be
4650 * non-echoing, so we set this to 0 by default.
4651 * Exception is that some keyboard-interactive prompts
4652 * can be echoing, in which case we'll set this to 1.
4653 */
4654 s->echo = 0;
4655
4656 if (!s->method && s->can_pubkey &&
4657 agent_exists() && !s->tried_agent) {
4658 /*
4659 * Attempt public-key authentication using Pageant.
4660 */
4661 void *r;
4662 s->authed = FALSE;
4663
4664 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4665 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4666
4667 s->tried_agent = TRUE;
4668
4669 logevent("Pageant is running. Requesting keys.");
4670
4671 /* Request the keys held by the agent. */
4672 PUT_32BIT(s->request, 1);
4673 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4674 agent_query(s->request, 5, &r, &s->responselen);
4675 s->response = (unsigned char *) r;
4676 if (s->response && s->responselen >= 5 &&
4677 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4678 s->p = s->response + 5;
4679 s->nkeys = GET_32BIT(s->p);
4680 s->p += 4;
4681 {
4682 char buf[64];
4683 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4684 logevent(buf);
4685 }
4686 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4687 void *vret;
4688
4689 {
4690 char buf[64];
4691 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4692 logevent(buf);
4693 }
4694 s->pklen = GET_32BIT(s->p);
4695 s->p += 4;
4696 if (s->publickey_blob &&
4697 s->pklen == s->publickey_bloblen &&
4698 !memcmp(s->p, s->publickey_blob,
4699 s->publickey_bloblen)) {
4700 logevent("This key matches configured key file");
4701 s->tried_pubkey_config = 1;
4702 }
4703 s->pkblob = (char *)s->p;
4704 s->p += s->pklen;
4705 s->alglen = GET_32BIT(s->pkblob);
4706 s->alg = s->pkblob + 4;
4707 s->commentlen = GET_32BIT(s->p);
4708 s->p += 4;
4709 s->commentp = (char *)s->p;
4710 s->p += s->commentlen;
4711 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4712 ssh2_pkt_addstring(ssh, s->username);
4713 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4714 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4715 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4716 ssh2_pkt_addstring_start(ssh);
4717 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4718 ssh2_pkt_addstring_start(ssh);
4719 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4720 ssh2_pkt_send(ssh);
4721
4722 crWaitUntilV(ispkt);
4723 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4724 logevent("Key refused");
4725 continue;
4726 }
4727
4728 if (flags & FLAG_VERBOSE) {
4729 c_write_str(ssh, "Authenticating with "
4730 "public key \"");
4731 c_write(ssh, s->commentp, s->commentlen);
4732 c_write_str(ssh, "\" from agent\r\n");
4733 }
4734
4735 /*
4736 * Server is willing to accept the key.
4737 * Construct a SIGN_REQUEST.
4738 */
4739 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4740 ssh2_pkt_addstring(ssh, s->username);
4741 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4742 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4743 ssh2_pkt_addbool(ssh, TRUE);
4744 ssh2_pkt_addstring_start(ssh);
4745 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4746 ssh2_pkt_addstring_start(ssh);
4747 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4748
4749 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4750 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4751 s->siglen -= 4;
4752 s->len = 1; /* message type */
4753 s->len += 4 + s->pklen; /* key blob */
4754 s->len += 4 + s->siglen; /* data to sign */
4755 s->len += 4; /* flags */
4756 s->agentreq = snewn(4 + s->len, char);
4757 PUT_32BIT(s->agentreq, s->len);
4758 s->q = s->agentreq + 4;
4759 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4760 PUT_32BIT(s->q, s->pklen);
4761 s->q += 4;
4762 memcpy(s->q, s->pkblob, s->pklen);
4763 s->q += s->pklen;
4764 PUT_32BIT(s->q, s->siglen);
4765 s->q += 4;
4766 /* Now the data to be signed... */
4767 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
4768 PUT_32BIT(s->q, 20);
4769 s->q += 4;
4770 }
4771 memcpy(s->q, ssh->v2_session_id, 20);
4772 s->q += 20;
4773 memcpy(s->q, ssh->pktout.data + 5,
4774 ssh->pktout.length - 5);
4775 s->q += ssh->pktout.length - 5;
4776 /* And finally the (zero) flags word. */
4777 PUT_32BIT(s->q, 0);
4778 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4779 s->ret = vret;
4780 sfree(s->agentreq);
4781 if (s->ret) {
4782 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4783 logevent("Sending Pageant's response");
4784 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4785 s->ret + 9,
4786 GET_32BIT(s->ret + 5));
4787 ssh2_pkt_send(ssh);
4788 s->authed = TRUE;
4789 break;
4790 } else {
4791 logevent
4792 ("Pageant failed to answer challenge");
4793 sfree(s->ret);
4794 }
4795 }
4796 }
4797 if (s->authed)
4798 continue;
4799 }
4800 }
4801
4802 if (!s->method && s->can_pubkey && s->publickey_blob
4803 && !s->tried_pubkey_config) {
4804 unsigned char *pub_blob;
4805 char *algorithm, *comment;
4806 int pub_blob_len;
4807
4808 s->tried_pubkey_config = TRUE;
4809
4810 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4811 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4812
4813 /*
4814 * Try the public key supplied in the configuration.
4815 *
4816 * First, offer the public blob to see if the server is
4817 * willing to accept it.
4818 */
4819 pub_blob =
4820 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
4821 &algorithm,
4822 &pub_blob_len);
4823 if (pub_blob) {
4824 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4825 ssh2_pkt_addstring(ssh, s->username);
4826 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4827 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4828 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4829 ssh2_pkt_addstring(ssh, algorithm);
4830 ssh2_pkt_addstring_start(ssh);
4831 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4832 pub_blob_len);
4833 ssh2_pkt_send(ssh);
4834 logevent("Offered public key"); /* FIXME */
4835
4836 crWaitUntilV(ispkt);
4837 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4838 s->gotit = TRUE;
4839 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4840 continue; /* key refused; give up on it */
4841 }
4842
4843 logevent("Offer of public key accepted");
4844 /*
4845 * Actually attempt a serious authentication using
4846 * the key.
4847 */
4848 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
4849 sprintf(s->pwprompt,
4850 "Passphrase for key \"%.100s\": ",
4851 comment);
4852 s->need_pw = TRUE;
4853 } else {
4854 s->need_pw = FALSE;
4855 }
4856 c_write_str(ssh, "Authenticating with public key \"");
4857 c_write_str(ssh, comment);
4858 c_write_str(ssh, "\"\r\n");
4859 s->method = AUTH_PUBLICKEY_FILE;
4860 }
4861 }
4862
4863 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4864 s->method = AUTH_KEYBOARD_INTERACTIVE;
4865 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4866 s->tried_keyb_inter = TRUE;
4867
4868 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4869 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4870
4871 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4872 ssh2_pkt_addstring(ssh, s->username);
4873 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4874 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4875 ssh2_pkt_addstring(ssh, ""); /* lang */
4876 ssh2_pkt_addstring(ssh, "");
4877 ssh2_pkt_send(ssh);
4878
4879 crWaitUntilV(ispkt);
4880 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4881 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4882 s->gotit = TRUE;
4883 logevent("Keyboard-interactive authentication refused");
4884 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4885 continue;
4886 }
4887
4888 s->kbd_inter_running = TRUE;
4889 s->curr_prompt = 0;
4890 }
4891
4892 if (s->kbd_inter_running) {
4893 s->method = AUTH_KEYBOARD_INTERACTIVE;
4894 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4895 s->tried_keyb_inter = TRUE;
4896
4897 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4898 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4899
4900 if (s->curr_prompt == 0) {
4901 /*
4902 * We've got a fresh USERAUTH_INFO_REQUEST.
4903 * Display header data, and start going through
4904 * the prompts.
4905 */
4906 char *name, *inst, *lang;
4907 int name_len, inst_len, lang_len;
4908
4909 ssh2_pkt_getstring(ssh, &name, &name_len);
4910 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4911 ssh2_pkt_getstring(ssh, &lang, &lang_len);
4912 if (name_len > 0) {
4913 c_write_untrusted(ssh, name, name_len);
4914 c_write_str(ssh, "\r\n");
4915 }
4916 if (inst_len > 0) {
4917 c_write_untrusted(ssh, inst, inst_len);
4918 c_write_str(ssh, "\r\n");
4919 }
4920 s->num_prompts = ssh2_pkt_getuint32(ssh);
4921 }
4922
4923 /*
4924 * If there are prompts remaining in the packet,
4925 * display one and get a response.
4926 */
4927 if (s->curr_prompt < s->num_prompts) {
4928 char *prompt;
4929 int prompt_len;
4930
4931 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
4932 if (prompt_len > 0) {
4933 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4934 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4935 prompt_len : sizeof(s->pwprompt)-1] = '\0';
4936 } else {
4937 strcpy(s->pwprompt,
4938 "<server failed to send prompt>: ");
4939 }
4940 s->echo = ssh2_pkt_getbool(ssh);
4941 s->need_pw = TRUE;
4942 } else
4943 s->need_pw = FALSE;
4944 }
4945
4946 if (!s->method && s->can_passwd) {
4947 s->method = AUTH_PASSWORD;
4948 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4949 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4950 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4951 ssh->savedhost);
4952 s->need_pw = TRUE;
4953 }
4954
4955 if (s->need_pw) {
4956 if (ssh_get_line) {
4957 if (!ssh_get_line(s->pwprompt, s->password,
4958 sizeof(s->password), TRUE)) {
4959 /*
4960 * get_line failed to get a password (for
4961 * example because one was supplied on the
4962 * command line which has already failed to
4963 * work). Terminate.
4964 */
4965 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4966 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4967 ssh2_pkt_addstring(ssh, "No more passwords available"
4968 " to try");
4969 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4970 ssh2_pkt_send(ssh);
4971 logevent("Unable to authenticate");
4972 connection_fatal(ssh->frontend,
4973 "Unable to authenticate");
4974 ssh_closing((Plug)ssh, NULL, 0, 0);
4975 crStopV;
4976 }
4977 } else {
4978 int ret; /* need not be saved across crReturn */
4979 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4980 ssh->send_ok = 1;
4981
4982 setup_userpass_input(ssh, s->password,
4983 sizeof(s->password), s->echo);
4984 do {
4985 crWaitUntilV(!ispkt);
4986 ret = process_userpass_input(ssh, in, inlen);
4987 } while (ret == 0);
4988 if (ret < 0)
4989 cleanup_exit(0);
4990 c_write_str(ssh, "\r\n");
4991 }
4992 }
4993
4994 if (s->method == AUTH_PUBLICKEY_FILE) {
4995 /*
4996 * We have our passphrase. Now try the actual authentication.
4997 */
4998 struct ssh2_userkey *key;
4999
5000 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password);
5001 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5002 if (key == SSH2_WRONG_PASSPHRASE) {
5003 c_write_str(ssh, "Wrong passphrase\r\n");
5004 s->tried_pubkey_config = FALSE;
5005 } else {
5006 c_write_str(ssh, "Unable to load private key\r\n");
5007 s->tried_pubkey_config = TRUE;
5008 }
5009 /* Send a spurious AUTH_NONE to return to the top. */
5010 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5011 ssh2_pkt_addstring(ssh, s->username);
5012 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5013 ssh2_pkt_addstring(ssh, "none"); /* method */
5014 ssh2_pkt_send(ssh);
5015 s->type = AUTH_TYPE_NONE;
5016 } else {
5017 unsigned char *pkblob, *sigblob, *sigdata;
5018 int pkblob_len, sigblob_len, sigdata_len;
5019 int p;
5020
5021 /*
5022 * We have loaded the private key and the server
5023 * has announced that it's willing to accept it.
5024 * Hallelujah. Generate a signature and send it.
5025 */
5026 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5027 ssh2_pkt_addstring(ssh, s->username);
5028 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5029 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5030 ssh2_pkt_addbool(ssh, TRUE);
5031 ssh2_pkt_addstring(ssh, key->alg->name);
5032 pkblob = key->alg->public_blob(key->data, &pkblob_len);
5033 ssh2_pkt_addstring_start(ssh);
5034 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
5035
5036 /*
5037 * The data to be signed is:
5038 *
5039 * string session-id
5040 *
5041 * followed by everything so far placed in the
5042 * outgoing packet.
5043 */
5044 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
5045 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5046 sigdata_len -= 4;
5047 sigdata = snewn(sigdata_len, unsigned char);
5048 p = 0;
5049 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5050 PUT_32BIT(sigdata+p, 20);
5051 p += 4;
5052 }
5053 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5054 memcpy(sigdata+p, ssh->pktout.data + 5,
5055 ssh->pktout.length - 5);
5056 p += ssh->pktout.length - 5;
5057 assert(p == sigdata_len);
5058 sigblob = key->alg->sign(key->data, (char *)sigdata,
5059 sigdata_len, &sigblob_len);
5060 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
5061 sigblob, sigblob_len);
5062 sfree(pkblob);
5063 sfree(sigblob);
5064 sfree(sigdata);
5065
5066 ssh2_pkt_send(ssh);
5067 s->type = AUTH_TYPE_PUBLICKEY;
5068 }
5069 } else if (s->method == AUTH_PASSWORD) {
5070 /*
5071 * We send the password packet lumped tightly together with
5072 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5073 * string long enough to make the total length of the two
5074 * packets constant. This should ensure that a passive
5075 * listener doing traffic analyis can't work out the length
5076 * of the password.
5077 *
5078 * For this to work, we need an assumption about the
5079 * maximum length of the password packet. I think 256 is
5080 * pretty conservative. Anyone using a password longer than
5081 * that probably doesn't have much to worry about from
5082 * people who find out how long their password is!
5083 */
5084 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5085 ssh2_pkt_addstring(ssh, s->username);
5086 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5087 ssh2_pkt_addstring(ssh, "password");
5088 ssh2_pkt_addbool(ssh, FALSE);
5089 ssh2_pkt_addstring(ssh, s->password);
5090 memset(s->password, 0, sizeof(s->password));
5091 ssh2_pkt_defer(ssh);
5092 /*
5093 * We'll include a string that's an exact multiple of the
5094 * cipher block size. If the cipher is NULL for some
5095 * reason, we don't do this trick at all because we gain
5096 * nothing by it.
5097 */
5098 if (ssh->cscipher) {
5099 int stringlen, i;
5100
5101 stringlen = (256 - ssh->deferred_len);
5102 stringlen += ssh->cscipher->blksize - 1;
5103 stringlen -= (stringlen % ssh->cscipher->blksize);
5104 if (ssh->cscomp) {
5105 /*
5106 * Temporarily disable actual compression,
5107 * so we can guarantee to get this string
5108 * exactly the length we want it. The
5109 * compression-disabling routine should
5110 * return an integer indicating how many
5111 * bytes we should adjust our string length
5112 * by.
5113 */
5114 stringlen -=
5115 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
5116 }
5117 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5118 ssh2_pkt_addstring_start(ssh);
5119 for (i = 0; i < stringlen; i++) {
5120 char c = (char) random_byte();
5121 ssh2_pkt_addstring_data(ssh, &c, 1);
5122 }
5123 ssh2_pkt_defer(ssh);
5124 }
5125 ssh_pkt_defersend(ssh);
5126 logevent("Sent password");
5127 s->type = AUTH_TYPE_PASSWORD;
5128 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5129 if (s->curr_prompt == 0) {
5130 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5131 ssh2_pkt_adduint32(ssh, s->num_prompts);
5132 }
5133 if (s->need_pw) { /* only add pw if we just got one! */
5134 ssh2_pkt_addstring(ssh, s->password);
5135 memset(s->password, 0, sizeof(s->password));
5136 s->curr_prompt++;
5137 }
5138 if (s->curr_prompt >= s->num_prompts) {
5139 ssh2_pkt_send(ssh);
5140 } else {
5141 /*
5142 * If there are prompts remaining, we set
5143 * `gotit' so that we won't attempt to get
5144 * another packet. Then we go back round the
5145 * loop and will end up retrieving another
5146 * prompt out of the existing packet. Funky or
5147 * what?
5148 */
5149 s->gotit = TRUE;
5150 }
5151 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5152 } else {
5153 c_write_str(ssh, "No supported authentication methods"
5154 " left to try!\r\n");
5155 logevent("No supported authentications offered."
5156 " Disconnecting");
5157 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5158 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5159 ssh2_pkt_addstring(ssh, "No supported authentication"
5160 " methods available");
5161 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5162 ssh2_pkt_send(ssh);
5163 ssh_closing((Plug)ssh, NULL, 0, 0);
5164 crStopV;
5165 }
5166 }
5167 } while (!s->we_are_in);
5168
5169 /*
5170 * Now we're authenticated for the connection protocol. The
5171 * connection protocol will automatically have started at this
5172 * point; there's no need to send SERVICE_REQUEST.
5173 */
5174
5175 /*
5176 * So now create a channel with a session in it.
5177 */
5178 ssh->channels = newtree234(ssh_channelcmp);
5179 ssh->mainchan = snew(struct ssh_channel);
5180 ssh->mainchan->ssh = ssh;
5181 ssh->mainchan->localid = alloc_channel_id(ssh);
5182 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5183 ssh2_pkt_addstring(ssh, "session");
5184 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5185 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5186 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5187 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5188 ssh2_pkt_send(ssh);
5189 crWaitUntilV(ispkt);
5190 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5191 bombout(("Server refused to open a session"));
5192 crStopV;
5193 /* FIXME: error data comes back in FAILURE packet */
5194 }
5195 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5196 bombout(("Server's channel confirmation cited wrong channel"));
5197 crStopV;
5198 }
5199 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5200 ssh->mainchan->type = CHAN_MAINSESSION;
5201 ssh->mainchan->closes = 0;
5202 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5203 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5204 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5205 add234(ssh->channels, ssh->mainchan);
5206 logevent("Opened channel for session");
5207
5208 /*
5209 * Potentially enable X11 forwarding.
5210 */
5211 if (ssh->cfg.x11_forward) {
5212 char proto[20], data[64];
5213 logevent("Requesting X11 forwarding");
5214 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5215 data, sizeof(data), ssh->cfg.x11_auth);
5216 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
5217 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5218 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5219 ssh2_pkt_addstring(ssh, "x11-req");
5220 ssh2_pkt_addbool(ssh, 1); /* want reply */
5221 ssh2_pkt_addbool(ssh, 0); /* many connections */
5222 ssh2_pkt_addstring(ssh, proto);
5223 ssh2_pkt_addstring(ssh, data);
5224 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
5225 ssh2_pkt_send(ssh);
5226
5227 do {
5228 crWaitUntilV(ispkt);
5229 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5230 unsigned i = ssh2_pkt_getuint32(ssh);
5231 struct ssh_channel *c;
5232 c = find234(ssh->channels, &i, ssh_channelfind);
5233 if (!c)
5234 continue; /* nonexistent channel */
5235 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5236 }
5237 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5238
5239 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5240 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5241 bombout(("Unexpected response to X11 forwarding request:"
5242 " packet type %d", ssh->pktin.type));
5243 crStopV;
5244 }
5245 logevent("X11 forwarding refused");
5246 } else {
5247 logevent("X11 forwarding enabled");
5248 ssh->X11_fwd_enabled = TRUE;
5249 }
5250 }
5251
5252 /*
5253 * Enable port forwardings.
5254 */
5255 {
5256 char type;
5257 int n;
5258 int sport,dport,sserv,dserv;
5259 char sports[256], dports[256], saddr[256], host[256];
5260
5261 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5262 /* Add port forwardings. */
5263 ssh->portfwd_strptr = ssh->cfg.portfwd;
5264 while (*ssh->portfwd_strptr) {
5265 type = *ssh->portfwd_strptr++;
5266 saddr[0] = '\0';
5267 n = 0;
5268 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5269 if (*ssh->portfwd_strptr == ':') {
5270 /*
5271 * We've seen a colon in the middle of the
5272 * source port number. This means that
5273 * everything we've seen until now is the
5274 * source _address_, so we'll move it into
5275 * saddr and start sports from the beginning
5276 * again.
5277 */
5278 ssh->portfwd_strptr++;
5279 sports[n] = '\0';
5280 strcpy(saddr, sports);
5281 n = 0;
5282 }
5283 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5284 }
5285 sports[n] = 0;
5286 if (type != 'D') {
5287 if (*ssh->portfwd_strptr == '\t')
5288 ssh->portfwd_strptr++;
5289 n = 0;
5290 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5291 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5292 }
5293 host[n] = 0;
5294 if (*ssh->portfwd_strptr == ':')
5295 ssh->portfwd_strptr++;
5296 n = 0;
5297 while (*ssh->portfwd_strptr) {
5298 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5299 }
5300 dports[n] = 0;
5301 ssh->portfwd_strptr++;
5302 dport = atoi(dports);
5303 dserv = 0;
5304 if (dport == 0) {
5305 dserv = 1;
5306 dport = net_service_lookup(dports);
5307 if (!dport) {
5308 logeventf(ssh, "Service lookup failed for destination"
5309 " port \"%s\"", dports);
5310 }
5311 }
5312 } else {
5313 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
5314 dport = dserv = -1;
5315 }
5316 sport = atoi(sports);
5317 sserv = 0;
5318 if (sport == 0) {
5319 sserv = 1;
5320 sport = net_service_lookup(sports);
5321 if (!sport) {
5322 logeventf(ssh, "Service lookup failed for source"
5323 " port \"%s\"", sports);
5324 }
5325 }
5326 if (sport && dport) {
5327 if (type == 'L') {
5328 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5329 sport, ssh, &ssh->cfg);
5330 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5331 " forwarding to %s:%.*s%.*s%d%.*s",
5332 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5333 (int)(*saddr?1:0), ":",
5334 (int)(sserv ? strlen(sports) : 0), sports,
5335 sserv, "(", sport, sserv, ")",
5336 host,
5337 (int)(dserv ? strlen(dports) : 0), dports,
5338 dserv, "(", dport, dserv, ")");
5339 } else if (type == 'D') {
5340 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
5341 sport, ssh, &ssh->cfg);
5342 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5343 " doing SOCKS dynamic forwarding",
5344 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5345 (int)(*saddr?1:0), ":",
5346 (int)(sserv ? strlen(sports) : 0), sports,
5347 sserv, "(", sport, sserv, ")");
5348 } else {
5349 struct ssh_rportfwd *pf;
5350 pf = snew(struct ssh_rportfwd);
5351 strcpy(pf->dhost, host);
5352 pf->dport = dport;
5353 pf->sport = sport;
5354 if (add234(ssh->rportfwds, pf) != pf) {
5355 logeventf(ssh, "Duplicate remote port forwarding"
5356 " to %s:%d", host, dport);
5357 sfree(pf);
5358 } else {
5359 logeventf(ssh, "Requesting remote port "
5360 "%.*s%.*s%.*s%.*s%d%.*s"
5361 " forward to %s:%.*s%.*s%d%.*s",
5362 (int)(*saddr?strlen(saddr):0),
5363 *saddr?saddr:NULL,
5364 (int)(*saddr?1:0), ":",
5365 (int)(sserv ? strlen(sports) : 0), sports,
5366 sserv, "(", sport, sserv, ")",
5367 host,
5368 (int)(dserv ? strlen(dports) : 0), dports,
5369 dserv, "(", dport, dserv, ")");
5370 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5371 ssh2_pkt_addstring(ssh, "tcpip-forward");
5372 ssh2_pkt_addbool(ssh, 1);/* want reply */
5373 if (*saddr)
5374 ssh2_pkt_addstring(ssh, saddr);
5375 if (ssh->cfg.rport_acceptall)
5376 ssh2_pkt_addstring(ssh, "0.0.0.0");
5377 else
5378 ssh2_pkt_addstring(ssh, "127.0.0.1");
5379 ssh2_pkt_adduint32(ssh, sport);
5380 ssh2_pkt_send(ssh);
5381
5382 do {
5383 crWaitUntilV(ispkt);
5384 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5385 unsigned i = ssh2_pkt_getuint32(ssh);
5386 struct ssh_channel *c;
5387 c = find234(ssh->channels, &i, ssh_channelfind);
5388 if (!c)
5389 continue;/* nonexistent channel */
5390 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5391 }
5392 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5393
5394 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5395 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5396 bombout(("Unexpected response to port "
5397 "forwarding request: packet type %d",
5398 ssh->pktin.type));
5399 crStopV;
5400 }
5401 logevent("Server refused this port forwarding");
5402 } else {
5403 logevent("Remote port forwarding enabled");
5404 }
5405 }
5406 }
5407 }
5408 }
5409 }
5410
5411 /*
5412 * Potentially enable agent forwarding.
5413 */
5414 if (ssh->cfg.agentfwd && agent_exists()) {
5415 logevent("Requesting OpenSSH-style agent forwarding");
5416 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5417 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5418 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5419 ssh2_pkt_addbool(ssh, 1); /* want reply */
5420 ssh2_pkt_send(ssh);
5421
5422 do {
5423 crWaitUntilV(ispkt);
5424 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5425 unsigned i = ssh2_pkt_getuint32(ssh);
5426 struct ssh_channel *c;
5427 c = find234(ssh->channels, &i, ssh_channelfind);
5428 if (!c)
5429 continue; /* nonexistent channel */
5430 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5431 }
5432 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5433
5434 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5435 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5436 bombout(("Unexpected response to agent forwarding request:"
5437 " packet type %d", ssh->pktin.type));
5438 crStopV;
5439 }
5440 logevent("Agent forwarding refused");
5441 } else {
5442 logevent("Agent forwarding enabled");
5443 ssh->agentfwd_enabled = TRUE;
5444 }
5445 }
5446
5447 /*
5448 * Now allocate a pty for the session.
5449 */
5450 if (!ssh->cfg.nopty) {
5451 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5452 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5453 ssh2_pkt_addstring(ssh, "pty-req");
5454 ssh2_pkt_addbool(ssh, 1); /* want reply */
5455 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
5456 ssh2_pkt_adduint32(ssh, ssh->term_width);
5457 ssh2_pkt_adduint32(ssh, ssh->term_height);
5458 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5459 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5460 ssh2_pkt_addstring_start(ssh);
5461 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5462 ssh2_pkt_send(ssh);
5463 ssh->state = SSH_STATE_INTERMED;
5464
5465 do {
5466 crWaitUntilV(ispkt);
5467 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5468 unsigned i = ssh2_pkt_getuint32(ssh);
5469 struct ssh_channel *c;
5470 c = find234(ssh->channels, &i, ssh_channelfind);
5471 if (!c)
5472 continue; /* nonexistent channel */
5473 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5474 }
5475 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5476
5477 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5478 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5479 bombout(("Unexpected response to pty request:"
5480 " packet type %d", ssh->pktin.type));
5481 crStopV;
5482 }
5483 c_write_str(ssh, "Server refused to allocate pty\r\n");
5484 ssh->editing = ssh->echoing = 1;
5485 } else {
5486 logevent("Allocated pty");
5487 }
5488 } else {
5489 ssh->editing = ssh->echoing = 1;
5490 }
5491
5492 /*
5493 * Start a shell or a remote command. We may have to attempt
5494 * this twice if the config data has provided a second choice
5495 * of command.
5496 */
5497 while (1) {
5498 int subsys;
5499 char *cmd;
5500
5501 if (ssh->fallback_cmd) {
5502 subsys = ssh->cfg.ssh_subsys2;
5503 cmd = ssh->cfg.remote_cmd_ptr2;
5504 } else {
5505 subsys = ssh->cfg.ssh_subsys;
5506 cmd = ssh->cfg.remote_cmd_ptr;
5507 }
5508
5509 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5510 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5511 if (subsys) {
5512 ssh2_pkt_addstring(ssh, "subsystem");
5513 ssh2_pkt_addbool(ssh, 1); /* want reply */
5514 ssh2_pkt_addstring(ssh, cmd);
5515 } else if (*cmd) {
5516 ssh2_pkt_addstring(ssh, "exec");
5517 ssh2_pkt_addbool(ssh, 1); /* want reply */
5518 ssh2_pkt_addstring(ssh, cmd);
5519 } else {
5520 ssh2_pkt_addstring(ssh, "shell");
5521 ssh2_pkt_addbool(ssh, 1); /* want reply */
5522 }
5523 ssh2_pkt_send(ssh);
5524 do {
5525 crWaitUntilV(ispkt);
5526 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5527 unsigned i = ssh2_pkt_getuint32(ssh);
5528 struct ssh_channel *c;
5529 c = find234(ssh->channels, &i, ssh_channelfind);
5530 if (!c)
5531 continue; /* nonexistent channel */
5532 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5533 }
5534 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5535 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5536 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5537 bombout(("Unexpected response to shell/command request:"
5538 " packet type %d", ssh->pktin.type));
5539 crStopV;
5540 }
5541 /*
5542 * We failed to start the command. If this is the
5543 * fallback command, we really are finished; if it's
5544 * not, and if the fallback command exists, try falling
5545 * back to it before complaining.
5546 */
5547 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
5548 logevent("Primary command failed; attempting fallback");
5549 ssh->fallback_cmd = TRUE;
5550 continue;
5551 }
5552 bombout(("Server refused to start a shell/command"));
5553 crStopV;
5554 } else {
5555 logevent("Started a shell/command");
5556 }
5557 break;
5558 }
5559
5560 ssh->state = SSH_STATE_SESSION;
5561 if (ssh->size_needed)
5562 ssh_size(ssh, ssh->term_width, ssh->term_height);
5563 if (ssh->eof_needed)
5564 ssh_special(ssh, TS_EOF);
5565
5566 /*
5567 * Transfer data!
5568 */
5569 if (ssh->ldisc)
5570 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5571 ssh->send_ok = 1;
5572 while (1) {
5573 crReturnV;
5574 s->try_send = FALSE;
5575 if (ispkt) {
5576 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5577 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5578 char *data;
5579 int length;
5580 unsigned i = ssh2_pkt_getuint32(ssh);
5581 struct ssh_channel *c;
5582 c = find234(ssh->channels, &i, ssh_channelfind);
5583 if (!c)
5584 continue; /* nonexistent channel */
5585 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5586 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5587 continue; /* extended but not stderr */
5588 ssh2_pkt_getstring(ssh, &data, &length);
5589 if (data) {
5590 int bufsize = 0;
5591 c->v.v2.locwindow -= length;
5592 switch (c->type) {
5593 case CHAN_MAINSESSION:
5594 bufsize =
5595 from_backend(ssh->frontend, ssh->pktin.type ==
5596 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5597 data, length);
5598 break;
5599 case CHAN_X11:
5600 bufsize = x11_send(c->u.x11.s, data, length);
5601 break;
5602 case CHAN_SOCKDATA:
5603 bufsize = pfd_send(c->u.pfd.s, data, length);
5604 break;
5605 case CHAN_AGENT:
5606 while (length > 0) {
5607 if (c->u.a.lensofar < 4) {
5608 int l = min(4 - c->u.a.lensofar, length);
5609 memcpy(c->u.a.msglen + c->u.a.lensofar,
5610 data, l);
5611 data += l;
5612 length -= l;
5613 c->u.a.lensofar += l;
5614 }
5615 if (c->u.a.lensofar == 4) {
5616 c->u.a.totallen =
5617 4 + GET_32BIT(c->u.a.msglen);
5618 c->u.a.message = snewn(c->u.a.totallen,
5619 unsigned char);
5620 memcpy(c->u.a.message, c->u.a.msglen, 4);
5621 }
5622 if (c->u.a.lensofar >= 4 && length > 0) {
5623 int l =
5624 min(c->u.a.totallen - c->u.a.lensofar,
5625 length);
5626 memcpy(c->u.a.message + c->u.a.lensofar,
5627 data, l);
5628 data += l;
5629 length -= l;
5630 c->u.a.lensofar += l;
5631 }
5632 if (c->u.a.lensofar == c->u.a.totallen) {
5633 void *reply, *sentreply;
5634 int replylen;
5635 agent_query(c->u.a.message,
5636 c->u.a.totallen, &reply,
5637 &replylen);
5638 if (reply)
5639 sentreply = reply;
5640 else {
5641 /* Fake SSH_AGENT_FAILURE. */
5642 sentreply = "\0\0\0\1\5";
5643 replylen = 5;
5644 }
5645 ssh2_add_channel_data(c, sentreply, replylen);
5646 s->try_send = TRUE;
5647 if (reply)
5648 sfree(reply);
5649 sfree(c->u.a.message);
5650 c->u.a.lensofar = 0;
5651 }
5652 }
5653 bufsize = 0;
5654 break;
5655 }
5656 /*
5657 * If we are not buffering too much data,
5658 * enlarge the window again at the remote side.
5659 */
5660 if (bufsize < OUR_V2_WINSIZE)
5661 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5662 }
5663 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5664 unsigned i = ssh2_pkt_getuint32(ssh);
5665 struct ssh_channel *c;
5666
5667 c = find234(ssh->channels, &i, ssh_channelfind);
5668 if (!c)
5669 continue; /* nonexistent channel */
5670
5671 if (c->type == CHAN_X11) {
5672 /*
5673 * Remote EOF on an X11 channel means we should
5674 * wrap up and close the channel ourselves.
5675 */
5676 x11_close(c->u.x11.s);
5677 sshfwd_close(c);
5678 } else if (c->type == CHAN_AGENT) {
5679 sshfwd_close(c);
5680 } else if (c->type == CHAN_SOCKDATA) {
5681 pfd_close(c->u.pfd.s);
5682 sshfwd_close(c);
5683 }
5684 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5685 unsigned i = ssh2_pkt_getuint32(ssh);
5686 struct ssh_channel *c;
5687
5688 c = find234(ssh->channels, &i, ssh_channelfind);
5689 if (!c || ((int)c->remoteid) == -1) {
5690 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5691 c ? "half-open" : "nonexistent", i));
5692 crStopV;
5693 }
5694 /* Do pre-close processing on the channel. */
5695 switch (c->type) {
5696 case CHAN_MAINSESSION:
5697 break; /* nothing to see here, move along */
5698 case CHAN_X11:
5699 if (c->u.x11.s != NULL)
5700 x11_close(c->u.x11.s);
5701 sshfwd_close(c);
5702 break;
5703 case CHAN_AGENT:
5704 sshfwd_close(c);
5705 break;
5706 case CHAN_SOCKDATA:
5707 if (c->u.pfd.s != NULL)
5708 pfd_close(c->u.pfd.s);
5709 sshfwd_close(c);
5710 break;
5711 }
5712 if (c->closes == 0) {
5713 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5714 ssh2_pkt_adduint32(ssh, c->remoteid);
5715 ssh2_pkt_send(ssh);
5716 }
5717 del234(ssh->channels, c);
5718 bufchain_clear(&c->v.v2.outbuffer);
5719 sfree(c);
5720
5721 /*
5722 * See if that was the last channel left open.
5723 */
5724 if (count234(ssh->channels) == 0) {
5725 logevent("All channels closed. Disconnecting");
5726 #if 0
5727 /*
5728 * We used to send SSH_MSG_DISCONNECT here,
5729 * because I'd believed that _every_ conforming
5730 * SSH2 connection had to end with a disconnect
5731 * being sent by at least one side; apparently
5732 * I was wrong and it's perfectly OK to
5733 * unceremoniously slam the connection shut
5734 * when you're done, and indeed OpenSSH feels
5735 * this is more polite than sending a
5736 * DISCONNECT. So now we don't.
5737 */
5738 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5739 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5740 ssh2_pkt_addstring(ssh, "All open channels closed");
5741 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5742 ssh2_pkt_send(ssh);
5743 #endif
5744 ssh_closing((Plug)ssh, NULL, 0, 0);
5745 crStopV;
5746 }
5747 continue; /* remote sends close; ignore (FIXME) */
5748 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5749 unsigned i = ssh2_pkt_getuint32(ssh);
5750 struct ssh_channel *c;
5751 c = find234(ssh->channels, &i, ssh_channelfind);
5752 if (!c || c->closes)
5753 continue; /* nonexistent or closing channel */
5754 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5755 s->try_send = TRUE;
5756 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5757 unsigned i = ssh2_pkt_getuint32(ssh);
5758 struct ssh_channel *c;
5759 c = find234(ssh->channels, &i, ssh_channelfind);
5760 if (!c)
5761 continue; /* nonexistent channel */
5762 if (c->type != CHAN_SOCKDATA_DORMANT)
5763 continue; /* dunno why they're confirming this */
5764 c->remoteid = ssh2_pkt_getuint32(ssh);
5765 c->type = CHAN_SOCKDATA;
5766 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5767 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5768 if (c->u.pfd.s)
5769 pfd_confirm(c->u.pfd.s);
5770 if (c->closes) {
5771 /*
5772 * We have a pending close on this channel,
5773 * which we decided on before the server acked
5774 * the channel open. So now we know the
5775 * remoteid, we can close it again.
5776 */
5777 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5778 ssh2_pkt_adduint32(ssh, c->remoteid);
5779 ssh2_pkt_send(ssh);
5780 }
5781 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5782 unsigned i = ssh2_pkt_getuint32(ssh);
5783 struct ssh_channel *c;
5784 c = find234(ssh->channels, &i, ssh_channelfind);
5785 if (!c)
5786 continue; /* nonexistent channel */
5787 if (c->type != CHAN_SOCKDATA_DORMANT)
5788 continue; /* dunno why they're failing this */
5789
5790 logevent("Forwarded connection refused by server");
5791
5792 pfd_close(c->u.pfd.s);
5793
5794 del234(ssh->channels, c);
5795 sfree(c);
5796 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5797 unsigned localid;
5798 char *type;
5799 int typelen, want_reply;
5800 struct ssh_channel *c;
5801
5802 localid = ssh2_pkt_getuint32(ssh);
5803 ssh2_pkt_getstring(ssh, &type, &typelen);
5804 want_reply = ssh2_pkt_getbool(ssh);
5805
5806 /*
5807 * First, check that the channel exists. Otherwise,
5808 * we can instantly disconnect with a rude message.
5809 */
5810 c = find234(ssh->channels, &localid, ssh_channelfind);
5811 if (!c) {
5812 char buf[80];
5813 sprintf(buf, "Received channel request for nonexistent"
5814 " channel %d", localid);
5815 logevent(buf);
5816 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5817 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5818 ssh2_pkt_addstring(ssh, buf);
5819 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5820 ssh2_pkt_send(ssh);
5821 connection_fatal(ssh->frontend, "%s", buf);
5822 ssh_closing((Plug)ssh, NULL, 0, 0);
5823 crStopV;
5824 }
5825
5826 /*
5827 * Having got the channel number, we now look at
5828 * the request type string to see if it's something
5829 * we recognise.
5830 */
5831 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5832 c == ssh->mainchan) {
5833 /* We recognise "exit-status" on the primary channel. */
5834 char buf[100];
5835 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5836 sprintf(buf, "Server sent command exit status %d",
5837 ssh->exitcode);
5838 logevent(buf);
5839 if (want_reply) {
5840 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5841 ssh2_pkt_adduint32(ssh, c->remoteid);
5842 ssh2_pkt_send(ssh);
5843 }
5844 } else {
5845 /*
5846 * This is a channel request we don't know
5847 * about, so we now either ignore the request
5848 * or respond with CHANNEL_FAILURE, depending
5849 * on want_reply.
5850 */
5851 if (want_reply) {
5852 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5853 ssh2_pkt_adduint32(ssh, c->remoteid);
5854 ssh2_pkt_send(ssh);
5855 }
5856 }
5857 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5858 char *type;
5859 int typelen, want_reply;
5860
5861 ssh2_pkt_getstring(ssh, &type, &typelen);
5862 want_reply = ssh2_pkt_getbool(ssh);
5863
5864 /*
5865 * We currently don't support any global requests
5866 * at all, so we either ignore the request or
5867 * respond with REQUEST_FAILURE, depending on
5868 * want_reply.
5869 */
5870 if (want_reply) {
5871 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5872 ssh2_pkt_send(ssh);
5873 }
5874 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5875 char *type;
5876 int typelen;
5877 char *peeraddr;
5878 int peeraddrlen;
5879 int peerport;
5880 char *error = NULL;
5881 struct ssh_channel *c;
5882 unsigned remid, winsize, pktsize;
5883 ssh2_pkt_getstring(ssh, &type, &typelen);
5884 c = snew(struct ssh_channel);
5885 c->ssh = ssh;
5886
5887 remid = ssh2_pkt_getuint32(ssh);
5888 winsize = ssh2_pkt_getuint32(ssh);
5889 pktsize = ssh2_pkt_getuint32(ssh);
5890
5891 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5892 char *addrstr;
5893
5894 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5895 addrstr = snewn(peeraddrlen+1, char);
5896 memcpy(addrstr, peeraddr, peeraddrlen);
5897 peeraddr[peeraddrlen] = '\0';
5898 peerport = ssh2_pkt_getuint32(ssh);
5899
5900 if (!ssh->X11_fwd_enabled)
5901 error = "X11 forwarding is not enabled";
5902 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5903 ssh->x11auth, addrstr, peerport,
5904 &ssh->cfg) != NULL) {
5905 error = "Unable to open an X11 connection";
5906 } else {
5907 c->type = CHAN_X11;
5908 }
5909
5910 sfree(addrstr);
5911 } else if (typelen == 15 &&
5912 !memcmp(type, "forwarded-tcpip", 15)) {
5913 struct ssh_rportfwd pf, *realpf;
5914 char *dummy;
5915 int dummylen;
5916 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5917 pf.sport = ssh2_pkt_getuint32(ssh);
5918 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5919 peerport = ssh2_pkt_getuint32(ssh);
5920 realpf = find234(ssh->rportfwds, &pf, NULL);
5921 if (realpf == NULL) {
5922 error = "Remote port is not recognised";
5923 } else {
5924 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5925 realpf->dport, c, &ssh->cfg);
5926 logeventf(ssh, "Received remote port open request"
5927 " for %s:%d", realpf->dhost, realpf->dport);
5928 if (e != NULL) {
5929 logeventf(ssh, "Port open failed: %s", e);
5930 error = "Port open failed";
5931 } else {
5932 logevent("Forwarded port opened successfully");
5933 c->type = CHAN_SOCKDATA;
5934 }
5935 }
5936 } else if (typelen == 22 &&
5937 !memcmp(type, "auth-agent@openssh.com", 3)) {
5938 if (!ssh->agentfwd_enabled)
5939 error = "Agent forwarding is not enabled";
5940 else {
5941 c->type = CHAN_AGENT; /* identify channel type */
5942 c->u.a.lensofar = 0;
5943 }
5944 } else {
5945 error = "Unsupported channel type requested";
5946 }
5947
5948 c->remoteid = remid;
5949 if (error) {
5950 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5951 ssh2_pkt_adduint32(ssh, c->remoteid);
5952 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5953 ssh2_pkt_addstring(ssh, error);
5954 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5955 ssh2_pkt_send(ssh);
5956 sfree(c);
5957 } else {
5958 c->localid = alloc_channel_id(ssh);
5959 c->closes = 0;
5960 c->v.v2.locwindow = OUR_V2_WINSIZE;
5961 c->v.v2.remwindow = winsize;
5962 c->v.v2.remmaxpkt = pktsize;
5963 bufchain_init(&c->v.v2.outbuffer);
5964 add234(ssh->channels, c);
5965 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5966 ssh2_pkt_adduint32(ssh, c->remoteid);
5967 ssh2_pkt_adduint32(ssh, c->localid);
5968 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5969 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5970 ssh2_pkt_send(ssh);
5971 }
5972 } else {
5973 bombout(("Strange packet received: type %d", ssh->pktin.type));
5974 crStopV;
5975 }
5976 } else {
5977 /*
5978 * We have spare data. Add it to the channel buffer.
5979 */
5980 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
5981 s->try_send = TRUE;
5982 }
5983 if (s->try_send) {
5984 int i;
5985 struct ssh_channel *c;
5986 /*
5987 * Try to send data on all channels if we can.
5988 */
5989 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5990 int bufsize;
5991 if (c->closes)
5992 continue; /* don't send on closing channels */
5993 bufsize = ssh2_try_send(c);
5994 if (bufsize == 0) {
5995 switch (c->type) {
5996 case CHAN_MAINSESSION:
5997 /* stdin need not receive an unthrottle
5998 * notification since it will be polled */
5999 break;
6000 case CHAN_X11:
6001 x11_unthrottle(c->u.x11.s);
6002 break;
6003 case CHAN_AGENT:
6004 /* agent sockets are request/response and need no
6005 * buffer management */
6006 break;
6007 case CHAN_SOCKDATA:
6008 pfd_unthrottle(c->u.pfd.s);
6009 break;
6010 }
6011 }
6012 }
6013 }
6014 }
6015
6016 crFinishV;
6017 }
6018
6019 /*
6020 * Handle the top-level SSH2 protocol.
6021 */
6022 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
6023 {
6024 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
6025 return;
6026 do_ssh2_authconn(ssh, in, inlen, ispkt);
6027 }
6028
6029 /*
6030 * Called to set up the connection.
6031 *
6032 * Returns an error message, or NULL on success.
6033 */
6034 static char *ssh_init(void *frontend_handle, void **backend_handle,
6035 Config *cfg,
6036 char *host, int port, char **realhost, int nodelay)
6037 {
6038 char *p;
6039 Ssh ssh;
6040
6041 ssh = snew(struct ssh_tag);
6042 ssh->cfg = *cfg; /* STRUCTURE COPY */
6043 ssh->version = 0; /* when not ready yet */
6044 ssh->s = NULL;
6045 ssh->cipher = NULL;
6046 ssh->v1_cipher_ctx = NULL;
6047 ssh->crcda_ctx = NULL;
6048 ssh->cscipher = NULL;
6049 ssh->cs_cipher_ctx = NULL;
6050 ssh->sccipher = NULL;
6051 ssh->sc_cipher_ctx = NULL;
6052 ssh->csmac = NULL;
6053 ssh->cs_mac_ctx = NULL;
6054 ssh->scmac = NULL;
6055 ssh->sc_mac_ctx = NULL;
6056 ssh->cscomp = NULL;
6057 ssh->cs_comp_ctx = NULL;
6058 ssh->sccomp = NULL;
6059 ssh->sc_comp_ctx = NULL;
6060 ssh->kex = NULL;
6061 ssh->kex_ctx = NULL;
6062 ssh->hostkey = NULL;
6063 ssh->exitcode = -1;
6064 ssh->state = SSH_STATE_PREPACKET;
6065 ssh->size_needed = FALSE;
6066 ssh->eof_needed = FALSE;
6067 ssh->ldisc = NULL;
6068 ssh->logctx = NULL;
6069 {
6070 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6071 ssh->pktin = ssh->pktout = empty;
6072 }
6073 ssh->deferred_send_data = NULL;
6074 ssh->deferred_len = 0;
6075 ssh->deferred_size = 0;
6076 ssh->fallback_cmd = 0;
6077 ssh->pkt_ctx = 0;
6078 ssh->x11auth = NULL;
6079 ssh->v1_compressing = FALSE;
6080 ssh->v2_outgoing_sequence = 0;
6081 ssh->ssh1_rdpkt_crstate = 0;
6082 ssh->ssh2_rdpkt_crstate = 0;
6083 ssh->do_ssh_init_crstate = 0;
6084 ssh->ssh_gotdata_crstate = 0;
6085 ssh->ssh1_protocol_crstate = 0;
6086 ssh->do_ssh1_login_crstate = 0;
6087 ssh->do_ssh2_transport_crstate = 0;
6088 ssh->do_ssh2_authconn_crstate = 0;
6089 ssh->do_ssh_init_state = NULL;
6090 ssh->do_ssh1_login_state = NULL;
6091 ssh->do_ssh2_transport_state = NULL;
6092 ssh->do_ssh2_authconn_state = NULL;
6093 ssh->mainchan = NULL;
6094 ssh->throttled_all = 0;
6095 ssh->v1_stdout_throttling = 0;
6096
6097 *backend_handle = ssh;
6098
6099 #ifdef MSCRYPTOAPI
6100 if (crypto_startup() == 0)
6101 return "Microsoft high encryption pack not installed!";
6102 #endif
6103
6104 ssh->frontend = frontend_handle;
6105 ssh->term_width = ssh->cfg.width;
6106 ssh->term_height = ssh->cfg.height;
6107
6108 ssh->channels = NULL;
6109 ssh->rportfwds = NULL;
6110
6111 ssh->send_ok = 0;
6112 ssh->editing = 0;
6113 ssh->echoing = 0;
6114 ssh->v1_throttle_count = 0;
6115 ssh->overall_bufsize = 0;
6116 ssh->fallback_cmd = 0;
6117
6118 ssh->protocol = NULL;
6119
6120 p = connect_to_host(ssh, host, port, realhost, nodelay);
6121 if (p != NULL)
6122 return p;
6123
6124 return NULL;
6125 }
6126
6127 static void ssh_free(void *handle)
6128 {
6129 Ssh ssh = (Ssh) handle;
6130 struct ssh_channel *c;
6131 struct ssh_rportfwd *pf;
6132
6133 if (ssh->v1_cipher_ctx)
6134 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6135 if (ssh->cs_cipher_ctx)
6136 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6137 if (ssh->sc_cipher_ctx)
6138 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6139 if (ssh->cs_mac_ctx)
6140 ssh->csmac->free_context(ssh->cs_mac_ctx);
6141 if (ssh->sc_mac_ctx)
6142 ssh->scmac->free_context(ssh->sc_mac_ctx);
6143 if (ssh->cs_comp_ctx)
6144 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6145 if (ssh->sc_comp_ctx)
6146 ssh->sccomp->compress_cleanup(ssh->sc_comp_ctx);
6147 if (ssh->kex_ctx)
6148 dh_cleanup(ssh->kex_ctx);
6149 sfree(ssh->savedhost);
6150
6151 if (ssh->channels) {
6152 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6153 switch (c->type) {
6154 case CHAN_X11:
6155 if (c->u.x11.s != NULL)
6156 x11_close(c->u.x11.s);
6157 break;
6158 case CHAN_SOCKDATA:
6159 if (c->u.pfd.s != NULL)
6160 pfd_close(c->u.pfd.s);
6161 break;
6162 }
6163 sfree(c);
6164 }
6165 freetree234(ssh->channels);
6166 }
6167
6168 if (ssh->rportfwds) {
6169 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6170 sfree(pf);
6171 freetree234(ssh->rportfwds);
6172 }
6173 sfree(ssh->deferred_send_data);
6174 if (ssh->x11auth)
6175 x11_free_auth(ssh->x11auth);
6176 sfree(ssh->do_ssh_init_state);
6177 sfree(ssh->do_ssh1_login_state);
6178 sfree(ssh->do_ssh2_transport_state);
6179 sfree(ssh->do_ssh2_authconn_state);
6180
6181 if (ssh->s)
6182 ssh_do_close(ssh);
6183 sfree(ssh);
6184 }
6185
6186 /*
6187 * Reconfigure the SSH backend.
6188 *
6189 * Currently, this function does nothing very useful. In future,
6190 * however, we could do some handy things with it. For example, we
6191 * could make the port forwarding configurer active in the Change
6192 * Settings box, and this routine could close down existing
6193 * forwardings and open up new ones in response to changes.
6194 */
6195 static void ssh_reconfig(void *handle, Config *cfg)
6196 {
6197 Ssh ssh = (Ssh) handle;
6198 ssh->cfg = *cfg; /* STRUCTURE COPY */
6199 }
6200
6201 /*
6202 * Called to send data down the Telnet connection.
6203 */
6204 static int ssh_send(void *handle, char *buf, int len)
6205 {
6206 Ssh ssh = (Ssh) handle;
6207
6208 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6209 return 0;
6210
6211 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
6212
6213 return ssh_sendbuffer(ssh);
6214 }
6215
6216 /*
6217 * Called to query the current amount of buffered stdin data.
6218 */
6219 static int ssh_sendbuffer(void *handle)
6220 {
6221 Ssh ssh = (Ssh) handle;
6222 int override_value;
6223
6224 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6225 return 0;
6226
6227 /*
6228 * If the SSH socket itself has backed up, add the total backup
6229 * size on that to any individual buffer on the stdin channel.
6230 */
6231 override_value = 0;
6232 if (ssh->throttled_all)
6233 override_value = ssh->overall_bufsize;
6234
6235 if (ssh->version == 1) {
6236 return override_value;
6237 } else if (ssh->version == 2) {
6238 if (!ssh->mainchan || ssh->mainchan->closes > 0)
6239 return override_value;
6240 else
6241 return (override_value +
6242 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
6243 }
6244
6245 return 0;
6246 }
6247
6248 /*
6249 * Called to set the size of the window from SSH's POV.
6250 */
6251 static void ssh_size(void *handle, int width, int height)
6252 {
6253 Ssh ssh = (Ssh) handle;
6254
6255 ssh->term_width = width;
6256 ssh->term_height = height;
6257
6258 switch (ssh->state) {
6259 case SSH_STATE_BEFORE_SIZE:
6260 case SSH_STATE_PREPACKET:
6261 case SSH_STATE_CLOSED:
6262 break; /* do nothing */
6263 case SSH_STATE_INTERMED:
6264 ssh->size_needed = TRUE; /* buffer for later */
6265 break;
6266 case SSH_STATE_SESSION:
6267 if (!ssh->cfg.nopty) {
6268 if (ssh->version == 1) {
6269 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6270 PKT_INT, ssh->term_height,
6271 PKT_INT, ssh->term_width,
6272 PKT_INT, 0, PKT_INT, 0, PKT_END);
6273 } else {
6274 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6275 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6276 ssh2_pkt_addstring(ssh, "window-change");
6277 ssh2_pkt_addbool(ssh, 0);
6278 ssh2_pkt_adduint32(ssh, ssh->term_width);
6279 ssh2_pkt_adduint32(ssh, ssh->term_height);
6280 ssh2_pkt_adduint32(ssh, 0);
6281 ssh2_pkt_adduint32(ssh, 0);
6282 ssh2_pkt_send(ssh);
6283 }
6284 }
6285 break;
6286 }
6287 }
6288
6289 /*
6290 * Return a list of the special codes that make sense in this
6291 * protocol.
6292 */
6293 static const struct telnet_special *ssh_get_specials(void *handle)
6294 {
6295 Ssh ssh = (Ssh) handle;
6296
6297 if (ssh->version == 1) {
6298 static const struct telnet_special ssh1_specials[] = {
6299 {"IGNORE message", TS_NOP},
6300 {NULL, 0}
6301 };
6302 return ssh1_specials;
6303 } else if (ssh->version == 2) {
6304 static const struct telnet_special ssh2_specials[] = {
6305 {"Break", TS_BRK},
6306 {"IGNORE message", TS_NOP},
6307 {NULL, 0}
6308 };
6309 return ssh2_specials;
6310 } else
6311 return NULL;
6312 }
6313
6314 /*
6315 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6316 * can send an EOF and collect resulting output (e.g. `plink
6317 * hostname sort').
6318 */
6319 static void ssh_special(void *handle, Telnet_Special code)
6320 {
6321 Ssh ssh = (Ssh) handle;
6322
6323 if (code == TS_EOF) {
6324 if (ssh->state != SSH_STATE_SESSION) {
6325 /*
6326 * Buffer the EOF in case we are pre-SESSION, so we can
6327 * send it as soon as we reach SESSION.
6328 */
6329 if (code == TS_EOF)
6330 ssh->eof_needed = TRUE;
6331 return;
6332 }
6333 if (ssh->version == 1) {
6334 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6335 } else {
6336 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6337 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6338 ssh2_pkt_send(ssh);
6339 }
6340 logevent("Sent EOF message");
6341 } else if (code == TS_PING || code == TS_NOP) {
6342 if (ssh->state == SSH_STATE_CLOSED
6343 || ssh->state == SSH_STATE_PREPACKET) return;
6344 if (ssh->version == 1) {
6345 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6346 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6347 } else {
6348 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6349 ssh2_pkt_addstring_start(ssh);
6350 ssh2_pkt_send(ssh);
6351 }
6352 } else if (code == TS_BRK) {
6353 if (ssh->state == SSH_STATE_CLOSED
6354 || ssh->state == SSH_STATE_PREPACKET) return;
6355 if (ssh->version == 1) {
6356 logevent("Unable to send BREAK signal in SSH1");
6357 } else {
6358 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6359 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6360 ssh2_pkt_addstring(ssh, "break");
6361 ssh2_pkt_addbool(ssh, 0);
6362 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6363 ssh2_pkt_send(ssh);
6364 }
6365 } else {
6366 /* do nothing */
6367 }
6368 }
6369
6370 void *new_sock_channel(void *handle, Socket s)
6371 {
6372 Ssh ssh = (Ssh) handle;
6373 struct ssh_channel *c;
6374 c = snew(struct ssh_channel);
6375 c->ssh = ssh;
6376
6377 if (c) {
6378 c->remoteid = -1; /* to be set when open confirmed */
6379 c->localid = alloc_channel_id(ssh);
6380 c->closes = 0;
6381 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6382 c->u.pfd.s = s;
6383 bufchain_init(&c->v.v2.outbuffer);
6384 add234(ssh->channels, c);
6385 }
6386 return c;
6387 }
6388
6389 /*
6390 * This is called when stdout/stderr (the entity to which
6391 * from_backend sends data) manages to clear some backlog.
6392 */
6393 static void ssh_unthrottle(void *handle, int bufsize)
6394 {
6395 Ssh ssh = (Ssh) handle;
6396 if (ssh->version == 1) {
6397 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6398 ssh->v1_stdout_throttling = 0;
6399 ssh1_throttle(ssh, -1);
6400 }
6401 } else {
6402 if (ssh->mainchan && ssh->mainchan->closes == 0)
6403 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6404 }
6405 }
6406
6407 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6408 {
6409 struct ssh_channel *c = (struct ssh_channel *)channel;
6410 Ssh ssh = c->ssh;
6411
6412 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6413
6414 if (ssh->version == 1) {
6415 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6416 PKT_INT, c->localid,
6417 PKT_STR, hostname,
6418 PKT_INT, port,
6419 //PKT_STR, <org:orgport>,
6420 PKT_END);
6421 } else {
6422 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6423 ssh2_pkt_addstring(ssh, "direct-tcpip");
6424 ssh2_pkt_adduint32(ssh, c->localid);
6425 c->v.v2.locwindow = OUR_V2_WINSIZE;
6426 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6427 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6428 ssh2_pkt_addstring(ssh, hostname);
6429 ssh2_pkt_adduint32(ssh, port);
6430 /*
6431 * We make up values for the originator data; partly it's
6432 * too much hassle to keep track, and partly I'm not
6433 * convinced the server should be told details like that
6434 * about my local network configuration.
6435 */
6436 ssh2_pkt_addstring(ssh, "client-side-connection");
6437 ssh2_pkt_adduint32(ssh, 0);
6438 ssh2_pkt_send(ssh);
6439 }
6440 }
6441
6442
6443 static Socket ssh_socket(void *handle)
6444 {
6445 Ssh ssh = (Ssh) handle;
6446 return ssh->s;
6447 }
6448
6449 static int ssh_sendok(void *handle)
6450 {
6451 Ssh ssh = (Ssh) handle;
6452 return ssh->send_ok;
6453 }
6454
6455 static int ssh_ldisc(void *handle, int option)
6456 {
6457 Ssh ssh = (Ssh) handle;
6458 if (option == LD_ECHO)
6459 return ssh->echoing;
6460 if (option == LD_EDIT)
6461 return ssh->editing;
6462 return FALSE;
6463 }
6464
6465 static void ssh_provide_ldisc(void *handle, void *ldisc)
6466 {
6467 Ssh ssh = (Ssh) handle;
6468 ssh->ldisc = ldisc;
6469 }
6470
6471 static void ssh_provide_logctx(void *handle, void *logctx)
6472 {
6473 Ssh ssh = (Ssh) handle;
6474 ssh->logctx = logctx;
6475 }
6476
6477 static int ssh_return_exitcode(void *handle)
6478 {
6479 Ssh ssh = (Ssh) handle;
6480 if (ssh->s != NULL)
6481 return -1;
6482 else
6483 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
6484 }
6485
6486 /*
6487 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6488 * that fails. This variable is the means by which scp.c can reach
6489 * into the SSH code and find out which one it got.
6490 */
6491 extern int ssh_fallback_cmd(void *handle)
6492 {
6493 Ssh ssh = (Ssh) handle;
6494 return ssh->fallback_cmd;
6495 }
6496
6497 Backend ssh_backend = {
6498 ssh_init,
6499 ssh_free,
6500 ssh_reconfig,
6501 ssh_send,
6502 ssh_sendbuffer,
6503 ssh_size,
6504 ssh_special,
6505 ssh_get_specials,
6506 ssh_socket,
6507 ssh_return_exitcode,
6508 ssh_sendok,
6509 ssh_ldisc,
6510 ssh_provide_ldisc,
6511 ssh_provide_logctx,
6512 ssh_unthrottle,
6513 22
6514 };
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator