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Support for non-ISO-8859-1 X keysyms. So in particular, pterm in a
[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 if (ssh->channels) {
2055 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2056 switch (c->type) {
2057 case CHAN_X11:
2058 x11_close(c->u.x11.s);
2059 break;
2060 case CHAN_SOCKDATA:
2061 pfd_close(c->u.pfd.s);
2062 break;
2063 }
2064 del234(ssh->channels, c);
2065 if (ssh->version == 2)
2066 bufchain_clear(&c->v.v2.outbuffer);
2067 sfree(c);
2068 }
2069 }
2070 }
2071
2072 static int ssh_closing(Plug plug, char *error_msg, int error_code,
2073 int calling_back)
2074 {
2075 Ssh ssh = (Ssh) plug;
2076 ssh_do_close(ssh);
2077 if (error_msg) {
2078 /* A socket error has occurred. */
2079 logevent(error_msg);
2080 connection_fatal(ssh->frontend, error_msg);
2081 } else {
2082 /* Otherwise, the remote side closed the connection normally. */
2083 }
2084 return 0;
2085 }
2086
2087 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2088 {
2089 Ssh ssh = (Ssh) plug;
2090 ssh_gotdata(ssh, (unsigned char *)data, len);
2091 if (ssh->state == SSH_STATE_CLOSED) {
2092 ssh_do_close(ssh);
2093 return 0;
2094 }
2095 return 1;
2096 }
2097
2098 static void ssh_sent(Plug plug, int bufsize)
2099 {
2100 Ssh ssh = (Ssh) plug;
2101 /*
2102 * If the send backlog on the SSH socket itself clears, we
2103 * should unthrottle the whole world if it was throttled.
2104 */
2105 if (bufsize < SSH_MAX_BACKLOG)
2106 ssh_throttle_all(ssh, 0, bufsize);
2107 }
2108
2109 /*
2110 * Connect to specified host and port.
2111 * Returns an error message, or NULL on success.
2112 * Also places the canonical host name into `realhost'. It must be
2113 * freed by the caller.
2114 */
2115 static char *connect_to_host(Ssh ssh, char *host, int port,
2116 char **realhost, int nodelay)
2117 {
2118 static const struct plug_function_table fn_table = {
2119 ssh_closing,
2120 ssh_receive,
2121 ssh_sent,
2122 NULL
2123 };
2124
2125 SockAddr addr;
2126 char *err;
2127
2128 ssh->savedhost = snewn(1 + strlen(host), char);
2129 if (!ssh->savedhost)
2130 fatalbox("Out of memory");
2131 strcpy(ssh->savedhost, host);
2132
2133 if (port < 0)
2134 port = 22; /* default ssh port */
2135 ssh->savedport = port;
2136
2137 /*
2138 * Try to find host.
2139 */
2140 logeventf(ssh, "Looking up host \"%s\"", host);
2141 addr = name_lookup(host, port, realhost, &ssh->cfg);
2142 if ((err = sk_addr_error(addr)) != NULL)
2143 return err;
2144
2145 /*
2146 * Open socket.
2147 */
2148 {
2149 char addrbuf[100];
2150 sk_getaddr(addr, addrbuf, 100);
2151 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2152 }
2153 ssh->fn = &fn_table;
2154 ssh->s = new_connection(addr, *realhost, port,
2155 0, 1, nodelay, (Plug) ssh, &ssh->cfg);
2156 if ((err = sk_socket_error(ssh->s)) != NULL) {
2157 ssh->s = NULL;
2158 return err;
2159 }
2160
2161 return NULL;
2162 }
2163
2164 /*
2165 * Throttle or unthrottle the SSH connection.
2166 */
2167 static void ssh1_throttle(Ssh ssh, int adjust)
2168 {
2169 int old_count = ssh->v1_throttle_count;
2170 ssh->v1_throttle_count += adjust;
2171 assert(ssh->v1_throttle_count >= 0);
2172 if (ssh->v1_throttle_count && !old_count) {
2173 sk_set_frozen(ssh->s, 1);
2174 } else if (!ssh->v1_throttle_count && old_count) {
2175 sk_set_frozen(ssh->s, 0);
2176 }
2177 }
2178
2179 /*
2180 * Throttle or unthrottle _all_ local data streams (for when sends
2181 * on the SSH connection itself back up).
2182 */
2183 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2184 {
2185 int i;
2186 struct ssh_channel *c;
2187
2188 if (enable == ssh->throttled_all)
2189 return;
2190 ssh->throttled_all = enable;
2191 ssh->overall_bufsize = bufsize;
2192 if (!ssh->channels)
2193 return;
2194 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2195 switch (c->type) {
2196 case CHAN_MAINSESSION:
2197 /*
2198 * This is treated separately, outside the switch.
2199 */
2200 break;
2201 case CHAN_X11:
2202 x11_override_throttle(c->u.x11.s, enable);
2203 break;
2204 case CHAN_AGENT:
2205 /* Agent channels require no buffer management. */
2206 break;
2207 case CHAN_SOCKDATA:
2208 pfd_override_throttle(c->u.pfd.s, enable);
2209 break;
2210 }
2211 }
2212 }
2213
2214 /*
2215 * Username and password input, abstracted off into routines
2216 * reusable in several places - even between SSH1 and SSH2.
2217 */
2218
2219 /* Set up a username or password input loop on a given buffer. */
2220 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2221 {
2222 ssh->userpass_input_buffer = buffer;
2223 ssh->userpass_input_buflen = buflen;
2224 ssh->userpass_input_bufpos = 0;
2225 ssh->userpass_input_echo = echo;
2226 }
2227
2228 /*
2229 * Process some terminal data in the course of username/password
2230 * input. Returns >0 for success (line of input returned in
2231 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2232 * for inconclusive (keep waiting for more input please).
2233 */
2234 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2235 {
2236 char c;
2237
2238 while (inlen--) {
2239 switch (c = *in++) {
2240 case 10:
2241 case 13:
2242 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2243 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2244 return +1;
2245 break;
2246 case 8:
2247 case 127:
2248 if (ssh->userpass_input_bufpos > 0) {
2249 if (ssh->userpass_input_echo)
2250 c_write_str(ssh, "\b \b");
2251 ssh->userpass_input_bufpos--;
2252 }
2253 break;
2254 case 21:
2255 case 27:
2256 while (ssh->userpass_input_bufpos > 0) {
2257 if (ssh->userpass_input_echo)
2258 c_write_str(ssh, "\b \b");
2259 ssh->userpass_input_bufpos--;
2260 }
2261 break;
2262 case 3:
2263 case 4:
2264 return -1;
2265 break;
2266 default:
2267 /*
2268 * This simplistic check for printability is disabled
2269 * when we're doing password input, because some people
2270 * have control characters in their passwords.o
2271 */
2272 if ((!ssh->userpass_input_echo ||
2273 (c >= ' ' && c <= '~') ||
2274 ((unsigned char) c >= 160))
2275 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2276 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2277 if (ssh->userpass_input_echo)
2278 c_write(ssh, &c, 1);
2279 }
2280 break;
2281 }
2282 }
2283 return 0;
2284 }
2285
2286 /*
2287 * Handle the key exchange and user authentication phases.
2288 */
2289 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2290 {
2291 int i, j;
2292 unsigned char cookie[8];
2293 struct RSAKey servkey, hostkey;
2294 struct MD5Context md5c;
2295 struct do_ssh1_login_state {
2296 int len;
2297 unsigned char *rsabuf, *keystr1, *keystr2;
2298 unsigned long supported_ciphers_mask, supported_auths_mask;
2299 int tried_publickey, tried_agent;
2300 int tis_auth_refused, ccard_auth_refused;
2301 unsigned char session_id[16];
2302 int cipher_type;
2303 char username[100];
2304 void *publickey_blob;
2305 int publickey_bloblen;
2306 char password[100];
2307 char prompt[200];
2308 int pos;
2309 char c;
2310 int pwpkt_type;
2311 unsigned char request[5], *response, *p;
2312 int responselen;
2313 int keyi, nkeys;
2314 int authed;
2315 struct RSAKey key;
2316 Bignum challenge;
2317 char *commentp;
2318 int commentlen;
2319 };
2320 crState(do_ssh1_login_state);
2321
2322 crBegin(ssh->do_ssh1_login_crstate);
2323
2324 if (!ispkt)
2325 crWaitUntil(ispkt);
2326
2327 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2328 bombout(("Public key packet not received"));
2329 crStop(0);
2330 }
2331
2332 logevent("Received public keys");
2333
2334 memcpy(cookie, ssh->pktin.body, 8);
2335
2336 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2337 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2338
2339 /*
2340 * Log the host key fingerprint.
2341 */
2342 {
2343 char logmsg[80];
2344 logevent("Host key fingerprint is:");
2345 strcpy(logmsg, " ");
2346 hostkey.comment = NULL;
2347 rsa_fingerprint(logmsg + strlen(logmsg),
2348 sizeof(logmsg) - strlen(logmsg), &hostkey);
2349 logevent(logmsg);
2350 }
2351
2352 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2353 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2354 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2355
2356 ssh->v1_local_protoflags =
2357 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2358 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2359
2360 MD5Init(&md5c);
2361 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2362 MD5Update(&md5c, s->keystr1, servkey.bytes);
2363 MD5Update(&md5c, ssh->pktin.body, 8);
2364 MD5Final(s->session_id, &md5c);
2365
2366 for (i = 0; i < 32; i++)
2367 ssh->session_key[i] = random_byte();
2368
2369 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2370
2371 s->rsabuf = snewn(s->len, unsigned char);
2372 if (!s->rsabuf)
2373 fatalbox("Out of memory");
2374
2375 /*
2376 * Verify the host key.
2377 */
2378 {
2379 /*
2380 * First format the key into a string.
2381 */
2382 int len = rsastr_len(&hostkey);
2383 char fingerprint[100];
2384 char *keystr = snewn(len, char);
2385 if (!keystr)
2386 fatalbox("Out of memory");
2387 rsastr_fmt(keystr, &hostkey);
2388 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2389 verify_ssh_host_key(ssh->frontend,
2390 ssh->savedhost, ssh->savedport, "rsa", keystr,
2391 fingerprint);
2392 sfree(keystr);
2393 }
2394
2395 for (i = 0; i < 32; i++) {
2396 s->rsabuf[i] = ssh->session_key[i];
2397 if (i < 16)
2398 s->rsabuf[i] ^= s->session_id[i];
2399 }
2400
2401 if (hostkey.bytes > servkey.bytes) {
2402 rsaencrypt(s->rsabuf, 32, &servkey);
2403 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2404 } else {
2405 rsaencrypt(s->rsabuf, 32, &hostkey);
2406 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2407 }
2408
2409 logevent("Encrypted session key");
2410
2411 {
2412 int cipher_chosen = 0, warn = 0;
2413 char *cipher_string = NULL;
2414 int i;
2415 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2416 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2417 if (next_cipher == CIPHER_WARN) {
2418 /* If/when we choose a cipher, warn about it */
2419 warn = 1;
2420 } else if (next_cipher == CIPHER_AES) {
2421 /* XXX Probably don't need to mention this. */
2422 logevent("AES not supported in SSH1, skipping");
2423 } else {
2424 switch (next_cipher) {
2425 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2426 cipher_string = "3DES"; break;
2427 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2428 cipher_string = "Blowfish"; break;
2429 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2430 cipher_string = "single-DES"; break;
2431 }
2432 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2433 cipher_chosen = 1;
2434 }
2435 }
2436 if (!cipher_chosen) {
2437 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2438 bombout(("Server violates SSH 1 protocol by not "
2439 "supporting 3DES encryption"));
2440 else
2441 /* shouldn't happen */
2442 bombout(("No supported ciphers found"));
2443 crStop(0);
2444 }
2445
2446 /* Warn about chosen cipher if necessary. */
2447 if (warn)
2448 askcipher(ssh->frontend, cipher_string, 0);
2449 }
2450
2451 switch (s->cipher_type) {
2452 case SSH_CIPHER_3DES:
2453 logevent("Using 3DES encryption");
2454 break;
2455 case SSH_CIPHER_DES:
2456 logevent("Using single-DES encryption");
2457 break;
2458 case SSH_CIPHER_BLOWFISH:
2459 logevent("Using Blowfish encryption");
2460 break;
2461 }
2462
2463 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2464 PKT_CHAR, s->cipher_type,
2465 PKT_DATA, cookie, 8,
2466 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2467 PKT_DATA, s->rsabuf, s->len,
2468 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2469
2470 logevent("Trying to enable encryption...");
2471
2472 sfree(s->rsabuf);
2473
2474 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2475 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2476 &ssh_3des);
2477 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2478 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2479 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2480
2481 ssh->crcda_ctx = crcda_make_context();
2482 logevent("Installing CRC compensation attack detector");
2483
2484 crWaitUntil(ispkt);
2485
2486 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2487 bombout(("Encryption not successfully enabled"));
2488 crStop(0);
2489 }
2490
2491 logevent("Successfully started encryption");
2492
2493 fflush(stdout);
2494 {
2495 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
2496 if (ssh_get_line && !ssh_getline_pw_only) {
2497 if (!ssh_get_line("login as: ",
2498 s->username, sizeof(s->username), FALSE)) {
2499 /*
2500 * get_line failed to get a username.
2501 * Terminate.
2502 */
2503 logevent("No username provided. Abandoning session.");
2504 ssh_closing((Plug)ssh, NULL, 0, 0);
2505 crStop(1);
2506 }
2507 } else {
2508 int ret; /* need not be kept over crReturn */
2509 c_write_str(ssh, "login as: ");
2510 ssh->send_ok = 1;
2511
2512 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2513 do {
2514 crWaitUntil(!ispkt);
2515 ret = process_userpass_input(ssh, in, inlen);
2516 } while (ret == 0);
2517 if (ret < 0)
2518 cleanup_exit(0);
2519 c_write_str(ssh, "\r\n");
2520 }
2521 } else {
2522 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2523 s->username[sizeof(s->username)-1] = '\0';
2524 }
2525
2526 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2527 {
2528 char userlog[22 + sizeof(s->username)];
2529 sprintf(userlog, "Sent username \"%s\"", s->username);
2530 logevent(userlog);
2531 if (flags & FLAG_INTERACTIVE &&
2532 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2533 strcat(userlog, "\r\n");
2534 c_write_str(ssh, userlog);
2535 }
2536 }
2537 }
2538
2539 crWaitUntil(ispkt);
2540
2541 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2542 /* We must not attempt PK auth. Pretend we've already tried it. */
2543 s->tried_publickey = s->tried_agent = 1;
2544 } else {
2545 s->tried_publickey = s->tried_agent = 0;
2546 }
2547 s->tis_auth_refused = s->ccard_auth_refused = 0;
2548 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2549 if (!filename_is_null(ssh->cfg.keyfile)) {
2550 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2551 &s->publickey_blob, &s->publickey_bloblen))
2552 s->publickey_blob = NULL;
2553 } else
2554 s->publickey_blob = NULL;
2555
2556 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2557 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2558
2559 if (agent_exists() && !s->tried_agent) {
2560 /*
2561 * Attempt RSA authentication using Pageant.
2562 */
2563 void *r;
2564
2565 s->authed = FALSE;
2566 s->tried_agent = 1;
2567 logevent("Pageant is running. Requesting keys.");
2568
2569 /* Request the keys held by the agent. */
2570 PUT_32BIT(s->request, 1);
2571 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2572 agent_query(s->request, 5, &r, &s->responselen);
2573 s->response = (unsigned char *) r;
2574 if (s->response && s->responselen >= 5 &&
2575 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2576 s->p = s->response + 5;
2577 s->nkeys = GET_32BIT(s->p);
2578 s->p += 4;
2579 {
2580 char buf[64];
2581 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2582 logevent(buf);
2583 }
2584 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2585 {
2586 char buf[64];
2587 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2588 logevent(buf);
2589 }
2590 if (s->publickey_blob &&
2591 !memcmp(s->p, s->publickey_blob,
2592 s->publickey_bloblen)) {
2593 logevent("This key matches configured key file");
2594 s->tried_publickey = 1;
2595 }
2596 s->p += 4;
2597 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2598 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2599 s->commentlen = GET_32BIT(s->p);
2600 s->p += 4;
2601 s->commentp = (char *)s->p;
2602 s->p += s->commentlen;
2603 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2604 PKT_BIGNUM, s->key.modulus, PKT_END);
2605 crWaitUntil(ispkt);
2606 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2607 logevent("Key refused");
2608 continue;
2609 }
2610 logevent("Received RSA challenge");
2611 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2612 {
2613 char *agentreq, *q, *ret;
2614 void *vret;
2615 int len, retlen;
2616 len = 1 + 4; /* message type, bit count */
2617 len += ssh1_bignum_length(s->key.exponent);
2618 len += ssh1_bignum_length(s->key.modulus);
2619 len += ssh1_bignum_length(s->challenge);
2620 len += 16; /* session id */
2621 len += 4; /* response format */
2622 agentreq = snewn(4 + len, char);
2623 PUT_32BIT(agentreq, len);
2624 q = agentreq + 4;
2625 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2626 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2627 q += 4;
2628 q += ssh1_write_bignum(q, s->key.exponent);
2629 q += ssh1_write_bignum(q, s->key.modulus);
2630 q += ssh1_write_bignum(q, s->challenge);
2631 memcpy(q, s->session_id, 16);
2632 q += 16;
2633 PUT_32BIT(q, 1); /* response format */
2634 agent_query(agentreq, len + 4, &vret, &retlen);
2635 ret = vret;
2636 sfree(agentreq);
2637 if (ret) {
2638 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2639 logevent("Sending Pageant's response");
2640 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2641 PKT_DATA, ret + 5, 16,
2642 PKT_END);
2643 sfree(ret);
2644 crWaitUntil(ispkt);
2645 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2646 logevent
2647 ("Pageant's response accepted");
2648 if (flags & FLAG_VERBOSE) {
2649 c_write_str(ssh, "Authenticated using"
2650 " RSA key \"");
2651 c_write(ssh, s->commentp,
2652 s->commentlen);
2653 c_write_str(ssh, "\" from agent\r\n");
2654 }
2655 s->authed = TRUE;
2656 } else
2657 logevent
2658 ("Pageant's response not accepted");
2659 } else {
2660 logevent
2661 ("Pageant failed to answer challenge");
2662 sfree(ret);
2663 }
2664 } else {
2665 logevent("No reply received from Pageant");
2666 }
2667 }
2668 freebn(s->key.exponent);
2669 freebn(s->key.modulus);
2670 freebn(s->challenge);
2671 if (s->authed)
2672 break;
2673 }
2674 }
2675 if (s->authed)
2676 break;
2677 }
2678 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
2679 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2680
2681 if (ssh->cfg.try_tis_auth &&
2682 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2683 !s->tis_auth_refused) {
2684 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2685 logevent("Requested TIS authentication");
2686 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2687 crWaitUntil(ispkt);
2688 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2689 logevent("TIS authentication declined");
2690 if (flags & FLAG_INTERACTIVE)
2691 c_write_str(ssh, "TIS authentication refused.\r\n");
2692 s->tis_auth_refused = 1;
2693 continue;
2694 } else {
2695 int challengelen = GET_32BIT(ssh->pktin.body);
2696 logevent("Received TIS challenge");
2697 if (challengelen > sizeof(s->prompt) - 1)
2698 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2699 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2700 /* Prompt heuristic comes from OpenSSH */
2701 strncpy(s->prompt + challengelen,
2702 memchr(s->prompt, '\n', challengelen) ?
2703 "": "\r\nResponse: ",
2704 (sizeof s->prompt) - challengelen);
2705 s->prompt[(sizeof s->prompt) - 1] = '\0';
2706 }
2707 }
2708 if (ssh->cfg.try_tis_auth &&
2709 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2710 !s->ccard_auth_refused) {
2711 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2712 logevent("Requested CryptoCard authentication");
2713 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2714 crWaitUntil(ispkt);
2715 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2716 logevent("CryptoCard authentication declined");
2717 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2718 s->ccard_auth_refused = 1;
2719 continue;
2720 } else {
2721 int challengelen = GET_32BIT(ssh->pktin.body);
2722 logevent("Received CryptoCard challenge");
2723 if (challengelen > sizeof(s->prompt) - 1)
2724 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2725 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2726 strncpy(s->prompt + challengelen,
2727 memchr(s->prompt, '\n', challengelen) ?
2728 "" : "\r\nResponse: ",
2729 sizeof(s->prompt) - challengelen);
2730 s->prompt[sizeof(s->prompt) - 1] = '\0';
2731 }
2732 }
2733 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2734 sprintf(s->prompt, "%.90s@%.90s's password: ",
2735 s->username, ssh->savedhost);
2736 }
2737 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2738 char *comment = NULL;
2739 int type;
2740 char msgbuf[256];
2741 if (flags & FLAG_VERBOSE)
2742 c_write_str(ssh, "Trying public key authentication.\r\n");
2743 logeventf(ssh, "Trying public key \"%s\"",
2744 filename_to_str(&ssh->cfg.keyfile));
2745 type = key_type(&ssh->cfg.keyfile);
2746 if (type != SSH_KEYTYPE_SSH1) {
2747 sprintf(msgbuf, "Key is of wrong type (%s)",
2748 key_type_to_str(type));
2749 logevent(msgbuf);
2750 c_write_str(ssh, msgbuf);
2751 c_write_str(ssh, "\r\n");
2752 s->tried_publickey = 1;
2753 continue;
2754 }
2755 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
2756 if (flags & FLAG_VERBOSE)
2757 c_write_str(ssh, "No passphrase required.\r\n");
2758 goto tryauth;
2759 }
2760 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2761 sfree(comment);
2762 }
2763
2764 /*
2765 * Show password prompt, having first obtained it via a TIS
2766 * or CryptoCard exchange if we're doing TIS or CryptoCard
2767 * authentication.
2768 */
2769 if (ssh_get_line) {
2770 if (!ssh_get_line(s->prompt, s->password,
2771 sizeof(s->password), TRUE)) {
2772 /*
2773 * get_line failed to get a password (for example
2774 * because one was supplied on the command line
2775 * which has already failed to work). Terminate.
2776 */
2777 send_packet(ssh, SSH1_MSG_DISCONNECT,
2778 PKT_STR, "No more passwords available to try",
2779 PKT_END);
2780 logevent("Unable to authenticate");
2781 connection_fatal(ssh->frontend, "Unable to authenticate");
2782 ssh_closing((Plug)ssh, NULL, 0, 0);
2783 crStop(1);
2784 }
2785 } else {
2786 /* Prompt may have come from server. We've munged it a bit, so
2787 * we know it to be zero-terminated at least once. */
2788 int ret; /* need not be saved over crReturn */
2789 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2790 s->pos = 0;
2791
2792 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2793 do {
2794 crWaitUntil(!ispkt);
2795 ret = process_userpass_input(ssh, in, inlen);
2796 } while (ret == 0);
2797 if (ret < 0)
2798 cleanup_exit(0);
2799 c_write_str(ssh, "\r\n");
2800 }
2801
2802 tryauth:
2803 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2804 /*
2805 * Try public key authentication with the specified
2806 * key file.
2807 */
2808 s->tried_publickey = 1;
2809
2810 {
2811 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password);
2812 if (ret == 0) {
2813 c_write_str(ssh, "Couldn't load private key from ");
2814 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
2815 c_write_str(ssh, ".\r\n");
2816 continue; /* go and try password */
2817 }
2818 if (ret == -1) {
2819 c_write_str(ssh, "Wrong passphrase.\r\n");
2820 s->tried_publickey = 0;
2821 continue; /* try again */
2822 }
2823 }
2824
2825 /*
2826 * Send a public key attempt.
2827 */
2828 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2829 PKT_BIGNUM, s->key.modulus, PKT_END);
2830
2831 crWaitUntil(ispkt);
2832 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2833 c_write_str(ssh, "Server refused our public key.\r\n");
2834 continue; /* go and try password */
2835 }
2836 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2837 bombout(("Bizarre response to offer of public key"));
2838 crStop(0);
2839 }
2840
2841 {
2842 int i;
2843 unsigned char buffer[32];
2844 Bignum challenge, response;
2845
2846 ssh1_read_bignum(ssh->pktin.body, &challenge);
2847 response = rsadecrypt(challenge, &s->key);
2848 freebn(s->key.private_exponent);/* burn the evidence */
2849
2850 for (i = 0; i < 32; i++) {
2851 buffer[i] = bignum_byte(response, 31 - i);
2852 }
2853
2854 MD5Init(&md5c);
2855 MD5Update(&md5c, buffer, 32);
2856 MD5Update(&md5c, s->session_id, 16);
2857 MD5Final(buffer, &md5c);
2858
2859 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2860 PKT_DATA, buffer, 16, PKT_END);
2861
2862 freebn(challenge);
2863 freebn(response);
2864 }
2865
2866 crWaitUntil(ispkt);
2867 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2868 if (flags & FLAG_VERBOSE)
2869 c_write_str(ssh, "Failed to authenticate with"
2870 " our public key.\r\n");
2871 continue; /* go and try password */
2872 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2873 bombout(("Bizarre response to RSA authentication response"));
2874 crStop(0);
2875 }
2876
2877 break; /* we're through! */
2878 } else {
2879 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2880 /*
2881 * Defence against traffic analysis: we send a
2882 * whole bunch of packets containing strings of
2883 * different lengths. One of these strings is the
2884 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2885 * The others are all random data in
2886 * SSH1_MSG_IGNORE packets. This way a passive
2887 * listener can't tell which is the password, and
2888 * hence can't deduce the password length.
2889 *
2890 * Anybody with a password length greater than 16
2891 * bytes is going to have enough entropy in their
2892 * password that a listener won't find it _that_
2893 * much help to know how long it is. So what we'll
2894 * do is:
2895 *
2896 * - if password length < 16, we send 15 packets
2897 * containing string lengths 1 through 15
2898 *
2899 * - otherwise, we let N be the nearest multiple
2900 * of 8 below the password length, and send 8
2901 * packets containing string lengths N through
2902 * N+7. This won't obscure the order of
2903 * magnitude of the password length, but it will
2904 * introduce a bit of extra uncertainty.
2905 *
2906 * A few servers (the old 1.2.18 through 1.2.22)
2907 * can't deal with SSH1_MSG_IGNORE. For these
2908 * servers, we need an alternative defence. We make
2909 * use of the fact that the password is interpreted
2910 * as a C string: so we can append a NUL, then some
2911 * random data.
2912 *
2913 * One server (a Cisco one) can deal with neither
2914 * SSH1_MSG_IGNORE _nor_ a padded password string.
2915 * For this server we are left with no defences
2916 * against password length sniffing.
2917 */
2918 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2919 /*
2920 * The server can deal with SSH1_MSG_IGNORE, so
2921 * we can use the primary defence.
2922 */
2923 int bottom, top, pwlen, i;
2924 char *randomstr;
2925
2926 pwlen = strlen(s->password);
2927 if (pwlen < 16) {
2928 bottom = 0; /* zero length passwords are OK! :-) */
2929 top = 15;
2930 } else {
2931 bottom = pwlen & ~7;
2932 top = bottom + 7;
2933 }
2934
2935 assert(pwlen >= bottom && pwlen <= top);
2936
2937 randomstr = snewn(top + 1, char);
2938
2939 for (i = bottom; i <= top; i++) {
2940 if (i == pwlen)
2941 defer_packet(ssh, s->pwpkt_type,
2942 PKT_STR, s->password, PKT_END);
2943 else {
2944 for (j = 0; j < i; j++) {
2945 do {
2946 randomstr[j] = random_byte();
2947 } while (randomstr[j] == '\0');
2948 }
2949 randomstr[i] = '\0';
2950 defer_packet(ssh, SSH1_MSG_IGNORE,
2951 PKT_STR, randomstr, PKT_END);
2952 }
2953 }
2954 logevent("Sending password with camouflage packets");
2955 ssh_pkt_defersend(ssh);
2956 }
2957 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2958 /*
2959 * The server can't deal with SSH1_MSG_IGNORE
2960 * but can deal with padded passwords, so we
2961 * can use the secondary defence.
2962 */
2963 char string[64];
2964 char *ss;
2965 int len;
2966
2967 len = strlen(s->password);
2968 if (len < sizeof(string)) {
2969 ss = string;
2970 strcpy(string, s->password);
2971 len++; /* cover the zero byte */
2972 while (len < sizeof(string)) {
2973 string[len++] = (char) random_byte();
2974 }
2975 } else {
2976 ss = s->password;
2977 }
2978 logevent("Sending length-padded password");
2979 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2980 PKT_DATA, ss, len, PKT_END);
2981 } else {
2982 /*
2983 * The server has _both_
2984 * BUG_CHOKES_ON_SSH1_IGNORE and
2985 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2986 * therefore nothing we can do.
2987 */
2988 int len;
2989 len = strlen(s->password);
2990 logevent("Sending unpadded password");
2991 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2992 PKT_DATA, s->password, len, PKT_END);
2993 }
2994 } else {
2995 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
2996 }
2997 }
2998 logevent("Sent password");
2999 memset(s->password, 0, strlen(s->password));
3000 crWaitUntil(ispkt);
3001 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3002 if (flags & FLAG_VERBOSE)
3003 c_write_str(ssh, "Access denied\r\n");
3004 logevent("Authentication refused");
3005 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3006 bombout(("Strange packet received, type %d", ssh->pktin.type));
3007 crStop(0);
3008 }
3009 }
3010
3011 logevent("Authentication successful");
3012
3013 crFinish(1);
3014 }
3015
3016 void sshfwd_close(struct ssh_channel *c)
3017 {
3018 Ssh ssh = c->ssh;
3019
3020 if (ssh->state != SSH_STATE_SESSION) {
3021 assert(ssh->state == SSH_STATE_CLOSED);
3022 return;
3023 }
3024
3025 if (c && !c->closes) {
3026 /*
3027 * If the channel's remoteid is -1, we have sent
3028 * CHANNEL_OPEN for this channel, but it hasn't even been
3029 * acknowledged by the server. So we must set a close flag
3030 * on it now, and then when the server acks the channel
3031 * open, we can close it then.
3032 */
3033 if (((int)c->remoteid) != -1) {
3034 if (ssh->version == 1) {
3035 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3036 PKT_END);
3037 } else {
3038 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3039 ssh2_pkt_adduint32(ssh, c->remoteid);
3040 ssh2_pkt_send(ssh);
3041 }
3042 }
3043 c->closes = 1; /* sent MSG_CLOSE */
3044 if (c->type == CHAN_X11) {
3045 c->u.x11.s = NULL;
3046 logevent("Forwarded X11 connection terminated");
3047 } else if (c->type == CHAN_SOCKDATA ||
3048 c->type == CHAN_SOCKDATA_DORMANT) {
3049 c->u.pfd.s = NULL;
3050 logevent("Forwarded port closed");
3051 }
3052 }
3053 }
3054
3055 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3056 {
3057 Ssh ssh = c->ssh;
3058
3059 if (ssh->state != SSH_STATE_SESSION) {
3060 assert(ssh->state == SSH_STATE_CLOSED);
3061 return 0;
3062 }
3063
3064 if (ssh->version == 1) {
3065 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3066 PKT_INT, c->remoteid,
3067 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
3068 /*
3069 * In SSH1 we can return 0 here - implying that forwarded
3070 * connections are never individually throttled - because
3071 * the only circumstance that can cause throttling will be
3072 * the whole SSH connection backing up, in which case
3073 * _everything_ will be throttled as a whole.
3074 */
3075 return 0;
3076 } else {
3077 ssh2_add_channel_data(c, buf, len);
3078 return ssh2_try_send(c);
3079 }
3080 }
3081
3082 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3083 {
3084 Ssh ssh = c->ssh;
3085
3086 if (ssh->state != SSH_STATE_SESSION) {
3087 assert(ssh->state == SSH_STATE_CLOSED);
3088 return;
3089 }
3090
3091 if (ssh->version == 1) {
3092 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3093 c->v.v1.throttling = 0;
3094 ssh1_throttle(ssh, -1);
3095 }
3096 } else {
3097 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3098 }
3099 }
3100
3101 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3102 {
3103 crBegin(ssh->ssh1_protocol_crstate);
3104
3105 random_init();
3106
3107 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3108 crReturnV;
3109 }
3110 if (ssh->state == SSH_STATE_CLOSED)
3111 crReturnV;
3112
3113 if (ssh->cfg.agentfwd && agent_exists()) {
3114 logevent("Requesting agent forwarding");
3115 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3116 do {
3117 crReturnV;
3118 } while (!ispkt);
3119 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3120 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3121 bombout(("Protocol confusion"));
3122 crStopV;
3123 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3124 logevent("Agent forwarding refused");
3125 } else {
3126 logevent("Agent forwarding enabled");
3127 ssh->agentfwd_enabled = TRUE;
3128 }
3129 }
3130
3131 if (ssh->cfg.x11_forward) {
3132 char proto[20], data[64];
3133 logevent("Requesting X11 forwarding");
3134 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3135 data, sizeof(data), ssh->cfg.x11_auth);
3136 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3137 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3138 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3139 PKT_STR, proto, PKT_STR, data,
3140 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3141 PKT_END);
3142 } else {
3143 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3144 PKT_STR, proto, PKT_STR, data, PKT_END);
3145 }
3146 do {
3147 crReturnV;
3148 } while (!ispkt);
3149 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3150 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3151 bombout(("Protocol confusion"));
3152 crStopV;
3153 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3154 logevent("X11 forwarding refused");
3155 } else {
3156 logevent("X11 forwarding enabled");
3157 ssh->X11_fwd_enabled = TRUE;
3158 }
3159 }
3160
3161 {
3162 char type;
3163 int n;
3164 int sport,dport,sserv,dserv;
3165 char sports[256], dports[256], saddr[256], host[256];
3166
3167 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3168 /* Add port forwardings. */
3169 ssh->portfwd_strptr = ssh->cfg.portfwd;
3170 while (*ssh->portfwd_strptr) {
3171 type = *ssh->portfwd_strptr++;
3172 saddr[0] = '\0';
3173 n = 0;
3174 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3175 if (*ssh->portfwd_strptr == ':') {
3176 /*
3177 * We've seen a colon in the middle of the
3178 * source port number. This means that
3179 * everything we've seen until now is the
3180 * source _address_, so we'll move it into
3181 * saddr and start sports from the beginning
3182 * again.
3183 */
3184 ssh->portfwd_strptr++;
3185 sports[n] = '\0';
3186 strcpy(saddr, sports);
3187 n = 0;
3188 }
3189 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3190 }
3191 sports[n] = 0;
3192 if (type != 'D') {
3193 if (*ssh->portfwd_strptr == '\t')
3194 ssh->portfwd_strptr++;
3195 n = 0;
3196 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3197 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3198 }
3199 host[n] = 0;
3200 if (*ssh->portfwd_strptr == ':')
3201 ssh->portfwd_strptr++;
3202 n = 0;
3203 while (*ssh->portfwd_strptr) {
3204 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3205 }
3206 dports[n] = 0;
3207 ssh->portfwd_strptr++;
3208 dport = atoi(dports);
3209 dserv = 0;
3210 if (dport == 0) {
3211 dserv = 1;
3212 dport = net_service_lookup(dports);
3213 if (!dport) {
3214 logeventf(ssh, "Service lookup failed for"
3215 " destination port \"%s\"", dports);
3216 }
3217 }
3218 } else {
3219 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3220 dport = dserv = -1;
3221 }
3222 sport = atoi(sports);
3223 sserv = 0;
3224 if (sport == 0) {
3225 sserv = 1;
3226 sport = net_service_lookup(sports);
3227 if (!sport) {
3228 logeventf(ssh, "Service lookup failed for source"
3229 " port \"%s\"", sports);
3230 }
3231 }
3232 if (sport && dport) {
3233 if (type == 'L') {
3234 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3235 sport, ssh, &ssh->cfg);
3236 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3237 " forwarding to %s:%.*s%.*s%d%.*s",
3238 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3239 (int)(*saddr?1:0), ":",
3240 (int)(sserv ? strlen(sports) : 0), sports,
3241 sserv, "(", sport, sserv, ")",
3242 host,
3243 (int)(dserv ? strlen(dports) : 0), dports,
3244 dserv, "(", dport, dserv, ")");
3245 } else if (type == 'D') {
3246 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
3247 sport, ssh, &ssh->cfg);
3248 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3249 " doing SOCKS dynamic forwarding",
3250 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3251 (int)(*saddr?1:0), ":",
3252 (int)(sserv ? strlen(sports) : 0), sports,
3253 sserv, "(", sport, sserv, ")");
3254 } else {
3255 struct ssh_rportfwd *pf;
3256 pf = snew(struct ssh_rportfwd);
3257 strcpy(pf->dhost, host);
3258 pf->dport = dport;
3259 if (saddr) {
3260 logeventf(ssh,
3261 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3262 saddr, sport);
3263 }
3264 if (add234(ssh->rportfwds, pf) != pf) {
3265 logeventf(ssh,
3266 "Duplicate remote port forwarding to %s:%d",
3267 host, dport);
3268 sfree(pf);
3269 } else {
3270 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3271 " forward to %s:%.*s%.*s%d%.*s",
3272 (int)(sserv ? strlen(sports) : 0), sports,
3273 sserv, "(", sport, sserv, ")",
3274 host,
3275 (int)(dserv ? strlen(dports) : 0), dports,
3276 dserv, "(", dport, dserv, ")");
3277 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3278 PKT_INT, sport,
3279 PKT_STR, host,
3280 PKT_INT, dport,
3281 PKT_END);
3282 do {
3283 crReturnV;
3284 } while (!ispkt);
3285 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3286 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3287 bombout(("Protocol confusion"));
3288 crStopV;
3289 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3290 c_write_str(ssh, "Server refused port"
3291 " forwarding\r\n");
3292 }
3293 logevent("Remote port forwarding enabled");
3294 }
3295 }
3296 }
3297 }
3298 }
3299
3300 if (!ssh->cfg.nopty) {
3301 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3302 PKT_STR, ssh->cfg.termtype,
3303 PKT_INT, ssh->term_height,
3304 PKT_INT, ssh->term_width,
3305 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3306 ssh->state = SSH_STATE_INTERMED;
3307 do {
3308 crReturnV;
3309 } while (!ispkt);
3310 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3311 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3312 bombout(("Protocol confusion"));
3313 crStopV;
3314 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3315 c_write_str(ssh, "Server refused to allocate pty\r\n");
3316 ssh->editing = ssh->echoing = 1;
3317 }
3318 logevent("Allocated pty");
3319 } else {
3320 ssh->editing = ssh->echoing = 1;
3321 }
3322
3323 if (ssh->cfg.compression) {
3324 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3325 do {
3326 crReturnV;
3327 } while (!ispkt);
3328 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3329 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3330 bombout(("Protocol confusion"));
3331 crStopV;
3332 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3333 c_write_str(ssh, "Server refused to compress\r\n");
3334 }
3335 logevent("Started compression");
3336 ssh->v1_compressing = TRUE;
3337 ssh->cs_comp_ctx = zlib_compress_init();
3338 logevent("Initialised zlib (RFC1950) compression");
3339 ssh->sc_comp_ctx = zlib_decompress_init();
3340 logevent("Initialised zlib (RFC1950) decompression");
3341 }
3342
3343 /*
3344 * Start the shell or command.
3345 *
3346 * Special case: if the first-choice command is an SSH2
3347 * subsystem (hence not usable here) and the second choice
3348 * exists, we fall straight back to that.
3349 */
3350 {
3351 char *cmd = ssh->cfg.remote_cmd_ptr;
3352
3353 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3354 cmd = ssh->cfg.remote_cmd_ptr2;
3355 ssh->fallback_cmd = TRUE;
3356 }
3357 if (*cmd)
3358 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3359 else
3360 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3361 logevent("Started session");
3362 }
3363
3364 ssh->state = SSH_STATE_SESSION;
3365 if (ssh->size_needed)
3366 ssh_size(ssh, ssh->term_width, ssh->term_height);
3367 if (ssh->eof_needed)
3368 ssh_special(ssh, TS_EOF);
3369
3370 if (ssh->ldisc)
3371 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3372 ssh->send_ok = 1;
3373 ssh->channels = newtree234(ssh_channelcmp);
3374 while (1) {
3375 crReturnV;
3376 if (ispkt) {
3377 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3378 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3379 long len = GET_32BIT(ssh->pktin.body);
3380 int bufsize =
3381 from_backend(ssh->frontend,
3382 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3383 (char *)(ssh->pktin.body) + 4, len);
3384 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3385 ssh->v1_stdout_throttling = 1;
3386 ssh1_throttle(ssh, +1);
3387 }
3388 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3389 ssh_closing((Plug)ssh, NULL, 0, 0);
3390 logevent("Received disconnect request");
3391 crStopV;
3392 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3393 /* Remote side is trying to open a channel to talk to our
3394 * X-Server. Give them back a local channel number. */
3395 struct ssh_channel *c;
3396
3397 logevent("Received X11 connect request");
3398 /* Refuse if X11 forwarding is disabled. */
3399 if (!ssh->X11_fwd_enabled) {
3400 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3401 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3402 logevent("Rejected X11 connect request");
3403 } else {
3404 c = snew(struct ssh_channel);
3405 c->ssh = ssh;
3406
3407 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3408 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3409 logevent("opening X11 forward connection failed");
3410 sfree(c);
3411 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3412 PKT_INT, GET_32BIT(ssh->pktin.body),
3413 PKT_END);
3414 } else {
3415 logevent
3416 ("opening X11 forward connection succeeded");
3417 c->remoteid = GET_32BIT(ssh->pktin.body);
3418 c->localid = alloc_channel_id(ssh);
3419 c->closes = 0;
3420 c->v.v1.throttling = 0;
3421 c->type = CHAN_X11; /* identify channel type */
3422 add234(ssh->channels, c);
3423 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3424 PKT_INT, c->remoteid, PKT_INT,
3425 c->localid, PKT_END);
3426 logevent("Opened X11 forward channel");
3427 }
3428 }
3429 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3430 /* Remote side is trying to open a channel to talk to our
3431 * agent. Give them back a local channel number. */
3432 struct ssh_channel *c;
3433
3434 /* Refuse if agent forwarding is disabled. */
3435 if (!ssh->agentfwd_enabled) {
3436 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3437 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3438 } else {
3439 c = snew(struct ssh_channel);
3440 c->ssh = ssh;
3441 c->remoteid = GET_32BIT(ssh->pktin.body);
3442 c->localid = alloc_channel_id(ssh);
3443 c->closes = 0;
3444 c->v.v1.throttling = 0;
3445 c->type = CHAN_AGENT; /* identify channel type */
3446 c->u.a.lensofar = 0;
3447 add234(ssh->channels, c);
3448 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3449 PKT_INT, c->remoteid, PKT_INT, c->localid,
3450 PKT_END);
3451 }
3452 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3453 /* Remote side is trying to open a channel to talk to a
3454 * forwarded port. Give them back a local channel number. */
3455 struct ssh_channel *c;
3456 struct ssh_rportfwd pf;
3457 int hostsize, port;
3458 char host[256], buf[1024];
3459 char *p, *h, *e;
3460 c = snew(struct ssh_channel);
3461 c->ssh = ssh;
3462
3463 hostsize = GET_32BIT(ssh->pktin.body+4);
3464 for (h = host, p = (char *)(ssh->pktin.body+8);
3465 hostsize != 0; hostsize--) {
3466 if (h+1 < host+sizeof(host))
3467 *h++ = *p;
3468 p++;
3469 }
3470 *h = 0;
3471 port = GET_32BIT(p);
3472
3473 strcpy(pf.dhost, host);
3474 pf.dport = port;
3475
3476 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3477 sprintf(buf, "Rejected remote port open request for %s:%d",
3478 host, port);
3479 logevent(buf);
3480 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3481 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3482 } else {
3483 sprintf(buf, "Received remote port open request for %s:%d",
3484 host, port);
3485 logevent(buf);
3486 e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg);
3487 if (e != NULL) {
3488 char buf[256];
3489 sprintf(buf, "Port open failed: %s", e);
3490 logevent(buf);
3491 sfree(c);
3492 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3493 PKT_INT, GET_32BIT(ssh->pktin.body),
3494 PKT_END);
3495 } else {
3496 c->remoteid = GET_32BIT(ssh->pktin.body);
3497 c->localid = alloc_channel_id(ssh);
3498 c->closes = 0;
3499 c->v.v1.throttling = 0;
3500 c->type = CHAN_SOCKDATA; /* identify channel type */
3501 add234(ssh->channels, c);
3502 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3503 PKT_INT, c->remoteid, PKT_INT,
3504 c->localid, PKT_END);
3505 logevent("Forwarded port opened successfully");
3506 }
3507 }
3508
3509 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3510 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3511 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3512 struct ssh_channel *c;
3513
3514 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3515 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3516 c->remoteid = localid;
3517 c->type = CHAN_SOCKDATA;
3518 c->v.v1.throttling = 0;
3519 pfd_confirm(c->u.pfd.s);
3520 }
3521
3522 if (c && c->closes) {
3523 /*
3524 * We have a pending close on this channel,
3525 * which we decided on before the server acked
3526 * the channel open. So now we know the
3527 * remoteid, we can close it again.
3528 */
3529 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3530 PKT_INT, c->remoteid, PKT_END);
3531 }
3532
3533 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3534 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3535 struct ssh_channel *c;
3536
3537 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3538 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3539 logevent("Forwarded connection refused by server");
3540 pfd_close(c->u.pfd.s);
3541 del234(ssh->channels, c);
3542 sfree(c);
3543 }
3544
3545 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3546 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3547 /* Remote side closes a channel. */
3548 unsigned i = GET_32BIT(ssh->pktin.body);
3549 struct ssh_channel *c;
3550 c = find234(ssh->channels, &i, ssh_channelfind);
3551 if (c && ((int)c->remoteid) != -1) {
3552 int closetype;
3553 closetype =
3554 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3555
3556 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3557 logevent("Forwarded X11 connection terminated");
3558 assert(c->u.x11.s != NULL);
3559 x11_close(c->u.x11.s);
3560 c->u.x11.s = NULL;
3561 }
3562 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3563 logevent("Forwarded port closed");
3564 assert(c->u.pfd.s != NULL);
3565 pfd_close(c->u.pfd.s);
3566 c->u.pfd.s = NULL;
3567 }
3568
3569 c->closes |= (closetype << 2); /* seen this message */
3570 if (!(c->closes & closetype)) {
3571 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3572 PKT_END);
3573 c->closes |= closetype; /* sent it too */
3574 }
3575
3576 if (c->closes == 15) {
3577 del234(ssh->channels, c);
3578 sfree(c);
3579 }
3580 } else {
3581 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3582 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3583 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3584 i));
3585 crStopV;
3586 }
3587 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3588 /* Data sent down one of our channels. */
3589 int i = GET_32BIT(ssh->pktin.body);
3590 int len = GET_32BIT(ssh->pktin.body + 4);
3591 unsigned char *p = ssh->pktin.body + 8;
3592 struct ssh_channel *c;
3593 c = find234(ssh->channels, &i, ssh_channelfind);
3594 if (c) {
3595 int bufsize = 0;
3596 switch (c->type) {
3597 case CHAN_X11:
3598 bufsize = x11_send(c->u.x11.s, (char *)p, len);
3599 break;
3600 case CHAN_SOCKDATA:
3601 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
3602 break;
3603 case CHAN_AGENT:
3604 /* Data for an agent message. Buffer it. */
3605 while (len > 0) {
3606 if (c->u.a.lensofar < 4) {
3607 int l = min(4 - c->u.a.lensofar, len);
3608 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3609 l);
3610 p += l;
3611 len -= l;
3612 c->u.a.lensofar += l;
3613 }
3614 if (c->u.a.lensofar == 4) {
3615 c->u.a.totallen =
3616 4 + GET_32BIT(c->u.a.msglen);
3617 c->u.a.message = snewn(c->u.a.totallen,
3618 unsigned char);
3619 memcpy(c->u.a.message, c->u.a.msglen, 4);
3620 }
3621 if (c->u.a.lensofar >= 4 && len > 0) {
3622 int l =
3623 min(c->u.a.totallen - c->u.a.lensofar,
3624 len);
3625 memcpy(c->u.a.message + c->u.a.lensofar, p,
3626 l);
3627 p += l;
3628 len -= l;
3629 c->u.a.lensofar += l;
3630 }
3631 if (c->u.a.lensofar == c->u.a.totallen) {
3632 void *reply, *sentreply;
3633 int replylen;
3634 agent_query(c->u.a.message,
3635 c->u.a.totallen, &reply,
3636 &replylen);
3637 if (reply)
3638 sentreply = reply;
3639 else {
3640 /* Fake SSH_AGENT_FAILURE. */
3641 sentreply = "\0\0\0\1\5";
3642 replylen = 5;
3643 }
3644 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3645 PKT_INT, c->remoteid,
3646 PKT_INT, replylen,
3647 PKT_DATA, sentreply, replylen,
3648 PKT_END);
3649 if (reply)
3650 sfree(reply);
3651 sfree(c->u.a.message);
3652 c->u.a.lensofar = 0;
3653 }
3654 }
3655 bufsize = 0; /* agent channels never back up */
3656 break;
3657 }
3658 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3659 c->v.v1.throttling = 1;
3660 ssh1_throttle(ssh, +1);
3661 }
3662 }
3663 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3664 /* may be from EXEC_SHELL on some servers */
3665 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3666 /* may be from EXEC_SHELL on some servers
3667 * if no pty is available or in other odd cases. Ignore */
3668 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3669 char buf[100];
3670 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3671 sprintf(buf, "Server sent command exit status %d",
3672 ssh->exitcode);
3673 logevent(buf);
3674 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3675 /*
3676 * In case `helpful' firewalls or proxies tack
3677 * extra human-readable text on the end of the
3678 * session which we might mistake for another
3679 * encrypted packet, we close the session once
3680 * we've sent EXIT_CONFIRMATION.
3681 */
3682 ssh_closing((Plug)ssh, NULL, 0, 0);
3683 crStopV;
3684 } else {
3685 bombout(("Strange packet received: type %d", ssh->pktin.type));
3686 crStopV;
3687 }
3688 } else {
3689 while (inlen > 0) {
3690 int len = min(inlen, 512);
3691 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3692 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3693 in += len;
3694 inlen -= len;
3695 }
3696 }
3697 }
3698
3699 crFinishV;
3700 }
3701
3702 /*
3703 * Utility routine for decoding comma-separated strings in KEXINIT.
3704 */
3705 static int in_commasep_string(char *needle, char *haystack, int haylen)
3706 {
3707 int needlen;
3708 if (!needle || !haystack) /* protect against null pointers */
3709 return 0;
3710 needlen = strlen(needle);
3711 while (1) {
3712 /*
3713 * Is it at the start of the string?
3714 */
3715 if (haylen >= needlen && /* haystack is long enough */
3716 !memcmp(needle, haystack, needlen) && /* initial match */
3717 (haylen == needlen || haystack[needlen] == ',')
3718 /* either , or EOS follows */
3719 )
3720 return 1;
3721 /*
3722 * If not, search for the next comma and resume after that.
3723 * If no comma found, terminate.
3724 */
3725 while (haylen > 0 && *haystack != ',')
3726 haylen--, haystack++;
3727 if (haylen == 0)
3728 return 0;
3729 haylen--, haystack++; /* skip over comma itself */
3730 }
3731 }
3732
3733 /*
3734 * SSH2 key creation method.
3735 */
3736 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3737 unsigned char *sessid, char chr,
3738 unsigned char *keyspace)
3739 {
3740 SHA_State s;
3741 /* First 20 bytes. */
3742 SHA_Init(&s);
3743 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3744 sha_mpint(&s, K);
3745 SHA_Bytes(&s, H, 20);
3746 SHA_Bytes(&s, &chr, 1);
3747 SHA_Bytes(&s, sessid, 20);
3748 SHA_Final(&s, keyspace);
3749 /* Next 20 bytes. */
3750 SHA_Init(&s);
3751 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3752 sha_mpint(&s, K);
3753 SHA_Bytes(&s, H, 20);
3754 SHA_Bytes(&s, keyspace, 20);
3755 SHA_Final(&s, keyspace + 20);
3756 }
3757
3758 /*
3759 * Handle the SSH2 transport layer.
3760 */
3761 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3762 {
3763 struct do_ssh2_transport_state {
3764 int nbits, pbits, warn;
3765 Bignum p, g, e, f, K;
3766 int kex_init_value, kex_reply_value;
3767 const struct ssh_mac **maclist;
3768 int nmacs;
3769 const struct ssh2_cipher *cscipher_tobe;
3770 const struct ssh2_cipher *sccipher_tobe;
3771 const struct ssh_mac *csmac_tobe;
3772 const struct ssh_mac *scmac_tobe;
3773 const struct ssh_compress *cscomp_tobe;
3774 const struct ssh_compress *sccomp_tobe;
3775 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3776 int hostkeylen, siglen;
3777 void *hkey; /* actual host key */
3778 unsigned char exchange_hash[20];
3779 int n_preferred_ciphers;
3780 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3781 const struct ssh_compress *preferred_comp;
3782 int first_kex;
3783 };
3784 crState(do_ssh2_transport_state);
3785
3786 crBegin(ssh->do_ssh2_transport_crstate);
3787
3788 s->cscipher_tobe = s->sccipher_tobe = NULL;
3789 s->csmac_tobe = s->scmac_tobe = NULL;
3790 s->cscomp_tobe = s->sccomp_tobe = NULL;
3791
3792 random_init();
3793 s->first_kex = 1;
3794
3795 {
3796 int i;
3797 /*
3798 * Set up the preferred ciphers. (NULL => warn below here)
3799 */
3800 s->n_preferred_ciphers = 0;
3801 for (i = 0; i < CIPHER_MAX; i++) {
3802 switch (ssh->cfg.ssh_cipherlist[i]) {
3803 case CIPHER_BLOWFISH:
3804 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3805 break;
3806 case CIPHER_DES:
3807 if (ssh->cfg.ssh2_des_cbc) {
3808 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3809 }
3810 break;
3811 case CIPHER_3DES:
3812 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3813 break;
3814 case CIPHER_AES:
3815 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3816 break;
3817 case CIPHER_WARN:
3818 /* Flag for later. Don't bother if it's the last in
3819 * the list. */
3820 if (i < CIPHER_MAX - 1) {
3821 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3822 }
3823 break;
3824 }
3825 }
3826 }
3827
3828 /*
3829 * Set up preferred compression.
3830 */
3831 if (ssh->cfg.compression)
3832 s->preferred_comp = &ssh_zlib;
3833 else
3834 s->preferred_comp = &ssh_comp_none;
3835
3836 /*
3837 * Be prepared to work around the buggy MAC problem.
3838 */
3839 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3840 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3841 else
3842 s->maclist = macs, s->nmacs = lenof(macs);
3843
3844 begin_key_exchange:
3845 {
3846 int i, j, cipherstr_started;
3847
3848 /*
3849 * Construct and send our key exchange packet.
3850 */
3851 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3852 for (i = 0; i < 16; i++)
3853 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3854 /* List key exchange algorithms. */
3855 ssh2_pkt_addstring_start(ssh);
3856 for (i = 0; i < lenof(kex_algs); i++) {
3857 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3858 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3859 continue;
3860 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3861 if (i < lenof(kex_algs) - 1)
3862 ssh2_pkt_addstring_str(ssh, ",");
3863 }
3864 /* List server host key algorithms. */
3865 ssh2_pkt_addstring_start(ssh);
3866 for (i = 0; i < lenof(hostkey_algs); i++) {
3867 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3868 if (i < lenof(hostkey_algs) - 1)
3869 ssh2_pkt_addstring_str(ssh, ",");
3870 }
3871 /* List client->server encryption algorithms. */
3872 ssh2_pkt_addstring_start(ssh);
3873 cipherstr_started = 0;
3874 for (i = 0; i < s->n_preferred_ciphers; i++) {
3875 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3876 if (!c) continue; /* warning flag */
3877 for (j = 0; j < c->nciphers; j++) {
3878 if (cipherstr_started)
3879 ssh2_pkt_addstring_str(ssh, ",");
3880 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3881 cipherstr_started = 1;
3882 }
3883 }
3884 /* List server->client encryption algorithms. */
3885 ssh2_pkt_addstring_start(ssh);
3886 cipherstr_started = 0;
3887 for (i = 0; i < s->n_preferred_ciphers; i++) {
3888 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3889 if (!c) continue; /* warning flag */
3890 for (j = 0; j < c->nciphers; j++) {
3891 if (cipherstr_started)
3892 ssh2_pkt_addstring_str(ssh, ",");
3893 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3894 cipherstr_started = 1;
3895 }
3896 }
3897 /* List client->server MAC algorithms. */
3898 ssh2_pkt_addstring_start(ssh);
3899 for (i = 0; i < s->nmacs; i++) {
3900 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3901 if (i < s->nmacs - 1)
3902 ssh2_pkt_addstring_str(ssh, ",");
3903 }
3904 /* List server->client MAC algorithms. */
3905 ssh2_pkt_addstring_start(ssh);
3906 for (i = 0; i < s->nmacs; i++) {
3907 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3908 if (i < s->nmacs - 1)
3909 ssh2_pkt_addstring_str(ssh, ",");
3910 }
3911 /* List client->server compression algorithms. */
3912 ssh2_pkt_addstring_start(ssh);
3913 for (i = 0; i < lenof(compressions) + 1; i++) {
3914 const struct ssh_compress *c =
3915 i == 0 ? s->preferred_comp : compressions[i - 1];
3916 ssh2_pkt_addstring_str(ssh, c->name);
3917 if (i < lenof(compressions))
3918 ssh2_pkt_addstring_str(ssh, ",");
3919 }
3920 /* List server->client compression algorithms. */
3921 ssh2_pkt_addstring_start(ssh);
3922 for (i = 0; i < lenof(compressions) + 1; i++) {
3923 const struct ssh_compress *c =
3924 i == 0 ? s->preferred_comp : compressions[i - 1];
3925 ssh2_pkt_addstring_str(ssh, c->name);
3926 if (i < lenof(compressions))
3927 ssh2_pkt_addstring_str(ssh, ",");
3928 }
3929 /* List client->server languages. Empty list. */
3930 ssh2_pkt_addstring_start(ssh);
3931 /* List server->client languages. Empty list. */
3932 ssh2_pkt_addstring_start(ssh);
3933 /* First KEX packet does _not_ follow, because we're not that brave. */
3934 ssh2_pkt_addbool(ssh, FALSE);
3935 /* Reserved. */
3936 ssh2_pkt_adduint32(ssh, 0);
3937 }
3938
3939 ssh->exhash = ssh->exhashbase;
3940 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
3941
3942 ssh2_pkt_send(ssh);
3943
3944 if (!ispkt)
3945 crWaitUntil(ispkt);
3946 if (ssh->pktin.length > 5)
3947 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
3948
3949 /*
3950 * Now examine the other side's KEXINIT to see what we're up
3951 * to.
3952 */
3953 {
3954 char *str;
3955 int i, j, len;
3956
3957 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3958 bombout(("expected key exchange packet from server"));
3959 crStop(0);
3960 }
3961 ssh->kex = NULL;
3962 ssh->hostkey = NULL;
3963 s->cscipher_tobe = NULL;
3964 s->sccipher_tobe = NULL;
3965 s->csmac_tobe = NULL;
3966 s->scmac_tobe = NULL;
3967 s->cscomp_tobe = NULL;
3968 s->sccomp_tobe = NULL;
3969 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3970 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3971 for (i = 0; i < lenof(kex_algs); i++) {
3972 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3973 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3974 continue;
3975 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3976 ssh->kex = kex_algs[i];
3977 break;
3978 }
3979 }
3980 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3981 for (i = 0; i < lenof(hostkey_algs); i++) {
3982 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3983 ssh->hostkey = hostkey_algs[i];
3984 break;
3985 }
3986 }
3987 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3988 s->warn = 0;
3989 for (i = 0; i < s->n_preferred_ciphers; i++) {
3990 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3991 if (!c) {
3992 s->warn = 1;
3993 } else {
3994 for (j = 0; j < c->nciphers; j++) {
3995 if (in_commasep_string(c->list[j]->name, str, len)) {
3996 s->cscipher_tobe = c->list[j];
3997 break;
3998 }
3999 }
4000 }
4001 if (s->cscipher_tobe) {
4002 if (s->warn)
4003 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
4004 break;
4005 }
4006 }
4007 if (!s->cscipher_tobe) {
4008 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4009 str ? str : "(null)"));
4010 crStop(0);
4011 }
4012
4013 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
4014 s->warn = 0;
4015 for (i = 0; i < s->n_preferred_ciphers; i++) {
4016 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4017 if (!c) {
4018 s->warn = 1;
4019 } else {
4020 for (j = 0; j < c->nciphers; j++) {
4021 if (in_commasep_string(c->list[j]->name, str, len)) {
4022 s->sccipher_tobe = c->list[j];
4023 break;
4024 }
4025 }
4026 }
4027 if (s->sccipher_tobe) {
4028 if (s->warn)
4029 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
4030 break;
4031 }
4032 }
4033 if (!s->sccipher_tobe) {
4034 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4035 str ? str : "(null)"));
4036 crStop(0);
4037 }
4038
4039 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
4040 for (i = 0; i < s->nmacs; i++) {
4041 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4042 s->csmac_tobe = s->maclist[i];
4043 break;
4044 }
4045 }
4046 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
4047 for (i = 0; i < s->nmacs; i++) {
4048 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4049 s->scmac_tobe = s->maclist[i];
4050 break;
4051 }
4052 }
4053 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
4054 for (i = 0; i < lenof(compressions) + 1; i++) {
4055 const struct ssh_compress *c =
4056 i == 0 ? s->preferred_comp : compressions[i - 1];
4057 if (in_commasep_string(c->name, str, len)) {
4058 s->cscomp_tobe = c;
4059 break;
4060 }
4061 }
4062 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
4063 for (i = 0; i < lenof(compressions) + 1; i++) {
4064 const struct ssh_compress *c =
4065 i == 0 ? s->preferred_comp : compressions[i - 1];
4066 if (in_commasep_string(c->name, str, len)) {
4067 s->sccomp_tobe = c;
4068 break;
4069 }
4070 }
4071 }
4072
4073 /*
4074 * Work out the number of bits of key we will need from the key
4075 * exchange. We start with the maximum key length of either
4076 * cipher...
4077 */
4078 {
4079 int csbits, scbits;
4080
4081 csbits = s->cscipher_tobe->keylen;
4082 scbits = s->sccipher_tobe->keylen;
4083 s->nbits = (csbits > scbits ? csbits : scbits);
4084 }
4085 /* The keys only have 160-bit entropy, since they're based on
4086 * a SHA-1 hash. So cap the key size at 160 bits. */
4087 if (s->nbits > 160)
4088 s->nbits = 160;
4089
4090 /*
4091 * If we're doing Diffie-Hellman group exchange, start by
4092 * requesting a group.
4093 */
4094 if (ssh->kex == &ssh_diffiehellman_gex) {
4095 logevent("Doing Diffie-Hellman group exchange");
4096 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4097 /*
4098 * Work out how big a DH group we will need to allow that
4099 * much data.
4100 */
4101 s->pbits = 512 << ((s->nbits - 1) / 64);
4102 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4103 ssh2_pkt_adduint32(ssh, s->pbits);
4104 ssh2_pkt_send(ssh);
4105
4106 crWaitUntil(ispkt);
4107 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4108 bombout(("expected key exchange group packet from server"));
4109 crStop(0);
4110 }
4111 s->p = ssh2_pkt_getmp(ssh);
4112 s->g = ssh2_pkt_getmp(ssh);
4113 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4114 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4115 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4116 } else {
4117 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4118 ssh->kex_ctx = dh_setup_group1();
4119 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4120 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4121 }
4122
4123 logevent("Doing Diffie-Hellman key exchange");
4124 /*
4125 * Now generate and send e for Diffie-Hellman.
4126 */
4127 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4128 ssh2_pkt_init(ssh, s->kex_init_value);
4129 ssh2_pkt_addmp(ssh, s->e);
4130 ssh2_pkt_send(ssh);
4131
4132 crWaitUntil(ispkt);
4133 if (ssh->pktin.type != s->kex_reply_value) {
4134 bombout(("expected key exchange reply packet from server"));
4135 crStop(0);
4136 }
4137 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4138 s->f = ssh2_pkt_getmp(ssh);
4139 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4140
4141 s->K = dh_find_K(ssh->kex_ctx, s->f);
4142
4143 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4144 if (ssh->kex == &ssh_diffiehellman_gex) {
4145 sha_uint32(&ssh->exhash, s->pbits);
4146 sha_mpint(&ssh->exhash, s->p);
4147 sha_mpint(&ssh->exhash, s->g);
4148 }
4149 sha_mpint(&ssh->exhash, s->e);
4150 sha_mpint(&ssh->exhash, s->f);
4151 sha_mpint(&ssh->exhash, s->K);
4152 SHA_Final(&ssh->exhash, s->exchange_hash);
4153
4154 dh_cleanup(ssh->kex_ctx);
4155 ssh->kex_ctx = NULL;
4156
4157 #if 0
4158 debug(("Exchange hash is:\n"));
4159 dmemdump(s->exchange_hash, 20);
4160 #endif
4161
4162 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4163 if (!s->hkey ||
4164 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4165 (char *)s->exchange_hash, 20)) {
4166 bombout(("Server's host key did not match the signature supplied"));
4167 crStop(0);
4168 }
4169
4170 /*
4171 * Authenticate remote host: verify host key. (We've already
4172 * checked the signature of the exchange hash.)
4173 */
4174 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4175 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4176 verify_ssh_host_key(ssh->frontend,
4177 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4178 s->keystr, s->fingerprint);
4179 if (s->first_kex) { /* don't bother logging this in rekeys */
4180 logevent("Host key fingerprint is:");
4181 logevent(s->fingerprint);
4182 }
4183 sfree(s->fingerprint);
4184 sfree(s->keystr);
4185 ssh->hostkey->freekey(s->hkey);
4186
4187 /*
4188 * Send SSH2_MSG_NEWKEYS.
4189 */
4190 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4191 ssh2_pkt_send(ssh);
4192
4193 /*
4194 * Expect SSH2_MSG_NEWKEYS from server.
4195 */
4196 crWaitUntil(ispkt);
4197 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4198 bombout(("expected new-keys packet from server"));
4199 crStop(0);
4200 }
4201
4202 /*
4203 * Create and initialise session keys.
4204 */
4205 if (ssh->cs_cipher_ctx)
4206 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4207 ssh->cscipher = s->cscipher_tobe;
4208 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4209
4210 if (ssh->sc_cipher_ctx)
4211 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4212 ssh->sccipher = s->sccipher_tobe;
4213 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4214
4215 if (ssh->cs_mac_ctx)
4216 ssh->csmac->free_context(ssh->cs_mac_ctx);
4217 ssh->csmac = s->csmac_tobe;
4218 ssh->cs_mac_ctx = ssh->csmac->make_context();
4219
4220 if (ssh->sc_mac_ctx)
4221 ssh->scmac->free_context(ssh->sc_mac_ctx);
4222 ssh->scmac = s->scmac_tobe;
4223 ssh->sc_mac_ctx = ssh->scmac->make_context();
4224
4225 if (ssh->cs_comp_ctx)
4226 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4227 ssh->cscomp = s->cscomp_tobe;
4228 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4229
4230 if (ssh->sc_comp_ctx)
4231 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4232 ssh->sccomp = s->sccomp_tobe;
4233 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4234
4235 /*
4236 * Set IVs after keys. Here we use the exchange hash from the
4237 * _first_ key exchange.
4238 */
4239 {
4240 unsigned char keyspace[40];
4241 if (s->first_kex)
4242 memcpy(ssh->v2_session_id, s->exchange_hash,
4243 sizeof(s->exchange_hash));
4244 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4245 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4246 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4247 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4248 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4249 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4250 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4251 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4252 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4253 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4254 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4255 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4256 }
4257 logeventf(ssh, "Initialised %.200s client->server encryption",
4258 ssh->cscipher->text_name);
4259 logeventf(ssh, "Initialised %.200s server->client encryption",
4260 ssh->sccipher->text_name);
4261 if (ssh->cscomp->text_name)
4262 logeventf(ssh, "Initialised %s compression",
4263 ssh->cscomp->text_name);
4264 if (ssh->sccomp->text_name)
4265 logeventf(ssh, "Initialised %s decompression",
4266 ssh->sccomp->text_name);
4267
4268 /*
4269 * If this is the first key exchange phase, we must pass the
4270 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4271 * wants to see it but because it will need time to initialise
4272 * itself before it sees an actual packet. In subsequent key
4273 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4274 * it would only confuse the layer above.
4275 */
4276 if (!s->first_kex) {
4277 crReturn(0);
4278 }
4279 s->first_kex = 0;
4280
4281 /*
4282 * Now we're encrypting. Begin returning 1 to the protocol main
4283 * function so that other things can run on top of the
4284 * transport. If we ever see a KEXINIT, we must go back to the
4285 * start.
4286 */
4287 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4288 crReturn(1);
4289 }
4290 logevent("Server initiated key re-exchange");
4291 goto begin_key_exchange;
4292
4293 crFinish(1);
4294 }
4295
4296 /*
4297 * Add data to an SSH2 channel output buffer.
4298 */
4299 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4300 int len)
4301 {
4302 bufchain_add(&c->v.v2.outbuffer, buf, len);
4303 }
4304
4305 /*
4306 * Attempt to send data on an SSH2 channel.
4307 */
4308 static int ssh2_try_send(struct ssh_channel *c)
4309 {
4310 Ssh ssh = c->ssh;
4311
4312 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4313 int len;
4314 void *data;
4315 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4316 if ((unsigned)len > c->v.v2.remwindow)
4317 len = c->v.v2.remwindow;
4318 if ((unsigned)len > c->v.v2.remmaxpkt)
4319 len = c->v.v2.remmaxpkt;
4320 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4321 ssh2_pkt_adduint32(ssh, c->remoteid);
4322 ssh2_pkt_addstring_start(ssh);
4323 ssh2_pkt_addstring_data(ssh, data, len);
4324 ssh2_pkt_send(ssh);
4325 bufchain_consume(&c->v.v2.outbuffer, len);
4326 c->v.v2.remwindow -= len;
4327 }
4328
4329 /*
4330 * After having sent as much data as we can, return the amount
4331 * still buffered.
4332 */
4333 return bufchain_size(&c->v.v2.outbuffer);
4334 }
4335
4336 /*
4337 * Potentially enlarge the window on an SSH2 channel.
4338 */
4339 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4340 {
4341 Ssh ssh = c->ssh;
4342
4343 /*
4344 * Never send WINDOW_ADJUST for a channel that the remote side
4345 * already thinks it's closed; there's no point, since it won't
4346 * be sending any more data anyway.
4347 */
4348 if (c->closes != 0)
4349 return;
4350
4351 if (newwin > c->v.v2.locwindow) {
4352 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4353 ssh2_pkt_adduint32(ssh, c->remoteid);
4354 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4355 ssh2_pkt_send(ssh);
4356 c->v.v2.locwindow = newwin;
4357 }
4358 }
4359
4360 /*
4361 * Handle the SSH2 userauth and connection layers.
4362 */
4363 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4364 {
4365 struct do_ssh2_authconn_state {
4366 enum {
4367 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4368 AUTH_PASSWORD,
4369 AUTH_KEYBOARD_INTERACTIVE
4370 } method;
4371 enum {
4372 AUTH_TYPE_NONE,
4373 AUTH_TYPE_PUBLICKEY,
4374 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4375 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4376 AUTH_TYPE_PASSWORD,
4377 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4378 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4379 } type;
4380 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4381 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4382 int kbd_inter_running;
4383 int we_are_in;
4384 int num_prompts, curr_prompt, echo;
4385 char username[100];
4386 int got_username;
4387 char pwprompt[200];
4388 char password[100];
4389 void *publickey_blob;
4390 int publickey_bloblen;
4391 unsigned char request[5], *response, *p;
4392 int responselen;
4393 int keyi, nkeys;
4394 int authed;
4395 char *pkblob, *alg, *commentp;
4396 int pklen, alglen, commentlen;
4397 int siglen, retlen, len;
4398 char *q, *agentreq, *ret;
4399 int try_send;
4400 };
4401 crState(do_ssh2_authconn_state);
4402
4403 crBegin(ssh->do_ssh2_authconn_crstate);
4404
4405 /*
4406 * Request userauth protocol, and await a response to it.
4407 */
4408 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4409 ssh2_pkt_addstring(ssh, "ssh-userauth");
4410 ssh2_pkt_send(ssh);
4411 crWaitUntilV(ispkt);
4412 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4413 bombout(("Server refused user authentication protocol"));
4414 crStopV;
4415 }
4416
4417 /*
4418 * We repeat this whole loop, including the username prompt,
4419 * until we manage a successful authentication. If the user
4420 * types the wrong _password_, they can be sent back to the
4421 * beginning to try another username, if this is configured on.
4422 * (If they specify a username in the config, they are never
4423 * asked, even if they do give a wrong password.)
4424 *
4425 * I think this best serves the needs of
4426 *
4427 * - the people who have no configuration, no keys, and just
4428 * want to try repeated (username,password) pairs until they
4429 * type both correctly
4430 *
4431 * - people who have keys and configuration but occasionally
4432 * need to fall back to passwords
4433 *
4434 * - people with a key held in Pageant, who might not have
4435 * logged in to a particular machine before; so they want to
4436 * type a username, and then _either_ their key will be
4437 * accepted, _or_ they will type a password. If they mistype
4438 * the username they will want to be able to get back and
4439 * retype it!
4440 */
4441 s->username[0] = '\0';
4442 s->got_username = FALSE;
4443 do {
4444 /*
4445 * Get a username.
4446 */
4447 if (s->got_username && !ssh->cfg.change_username) {
4448 /*
4449 * We got a username last time round this loop, and
4450 * with change_username turned off we don't try to get
4451 * it again.
4452 */
4453 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
4454 if (ssh_get_line && !ssh_getline_pw_only) {
4455 if (!ssh_get_line("login as: ",
4456 s->username, sizeof(s->username), FALSE)) {
4457 /*
4458 * get_line failed to get a username.
4459 * Terminate.
4460 */
4461 logevent("No username provided. Abandoning session.");
4462 ssh_closing((Plug)ssh, NULL, 0, 0);
4463 crStopV;
4464 }
4465 } else {
4466 int ret; /* need not be saved across crReturn */
4467 c_write_str(ssh, "login as: ");
4468 ssh->send_ok = 1;
4469 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4470 do {
4471 crWaitUntilV(!ispkt);
4472 ret = process_userpass_input(ssh, in, inlen);
4473 } while (ret == 0);
4474 if (ret < 0)
4475 cleanup_exit(0);
4476 c_write_str(ssh, "\r\n");
4477 }
4478 s->username[strcspn(s->username, "\n\r")] = '\0';
4479 } else {
4480 char *stuff;
4481 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
4482 s->username[sizeof(s->username)-1] = '\0';
4483 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4484 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4485 c_write_str(ssh, stuff);
4486 sfree(stuff);
4487 }
4488 }
4489 s->got_username = TRUE;
4490
4491 /*
4492 * Send an authentication request using method "none": (a)
4493 * just in case it succeeds, and (b) so that we know what
4494 * authentication methods we can usefully try next.
4495 */
4496 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4497
4498 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4499 ssh2_pkt_addstring(ssh, s->username);
4500 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4501 ssh2_pkt_addstring(ssh, "none"); /* method */
4502 ssh2_pkt_send(ssh);
4503 s->type = AUTH_TYPE_NONE;
4504 s->gotit = FALSE;
4505 s->we_are_in = FALSE;
4506
4507 s->tried_pubkey_config = FALSE;
4508 s->tried_agent = FALSE;
4509 s->tried_keyb_inter = FALSE;
4510 s->kbd_inter_running = FALSE;
4511 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4512 if (!filename_is_null(ssh->cfg.keyfile)) {
4513 int keytype;
4514 logeventf(ssh, "Reading private key file \"%.150s\"",
4515 filename_to_str(&ssh->cfg.keyfile));
4516 keytype = key_type(&ssh->cfg.keyfile);
4517 if (keytype == SSH_KEYTYPE_SSH2) {
4518 s->publickey_blob =
4519 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
4520 &s->publickey_bloblen);
4521 } else {
4522 char *msgbuf;
4523 logeventf(ssh, "Unable to use this key file (%s)",
4524 key_type_to_str(keytype));
4525 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4526 " (%s)\r\n",
4527 filename_to_str(&ssh->cfg.keyfile),
4528 key_type_to_str(keytype));
4529 c_write_str(ssh, msgbuf);
4530 sfree(msgbuf);
4531 s->publickey_blob = NULL;
4532 }
4533 } else
4534 s->publickey_blob = NULL;
4535
4536 while (1) {
4537 /*
4538 * Wait for the result of the last authentication request.
4539 */
4540 if (!s->gotit)
4541 crWaitUntilV(ispkt);
4542 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4543 char *banner;
4544 int size;
4545 /*
4546 * Don't show the banner if we're operating in
4547 * non-verbose non-interactive mode. (It's probably
4548 * a script, which means nobody will read the
4549 * banner _anyway_, and moreover the printing of
4550 * the banner will screw up processing on the
4551 * output of (say) plink.)
4552 */
4553 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4554 ssh2_pkt_getstring(ssh, &banner, &size);
4555 if (banner)
4556 c_write_untrusted(ssh, banner, size);
4557 }
4558 crWaitUntilV(ispkt);
4559 }
4560 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4561 logevent("Access granted");
4562 s->we_are_in = TRUE;
4563 break;
4564 }
4565
4566 if (s->kbd_inter_running &&
4567 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4568 /*
4569 * This is either a further set-of-prompts packet
4570 * in keyboard-interactive authentication, or it's
4571 * the same one and we came back here with `gotit'
4572 * set. In the former case, we must reset the
4573 * curr_prompt variable.
4574 */
4575 if (!s->gotit)
4576 s->curr_prompt = 0;
4577 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4578 bombout(("Strange packet received during authentication: type %d",
4579 ssh->pktin.type));
4580 crStopV;
4581 }
4582
4583 s->gotit = FALSE;
4584
4585 /*
4586 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4587 * we can look at the string in it and know what we can
4588 * helpfully try next.
4589 */
4590 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4591 char *methods;
4592 int methlen;
4593 ssh2_pkt_getstring(ssh, &methods, &methlen);
4594 s->kbd_inter_running = FALSE;
4595 if (!ssh2_pkt_getbool(ssh)) {
4596 /*
4597 * We have received an unequivocal Access
4598 * Denied. This can translate to a variety of
4599 * messages:
4600 *
4601 * - if we'd just tried "none" authentication,
4602 * it's not worth printing anything at all
4603 *
4604 * - if we'd just tried a public key _offer_,
4605 * the message should be "Server refused our
4606 * key" (or no message at all if the key
4607 * came from Pageant)
4608 *
4609 * - if we'd just tried anything else, the
4610 * message really should be "Access denied".
4611 *
4612 * Additionally, if we'd just tried password
4613 * authentication, we should break out of this
4614 * whole loop so as to go back to the username
4615 * prompt.
4616 */
4617 if (s->type == AUTH_TYPE_NONE) {
4618 /* do nothing */
4619 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4620 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4621 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4622 c_write_str(ssh, "Server refused our key\r\n");
4623 logevent("Server refused public key");
4624 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4625 /* server declined keyboard-interactive; ignore */
4626 } else {
4627 c_write_str(ssh, "Access denied\r\n");
4628 logevent("Access denied");
4629 if (s->type == AUTH_TYPE_PASSWORD) {
4630 s->we_are_in = FALSE;
4631 break;
4632 }
4633 }
4634 } else {
4635 c_write_str(ssh, "Further authentication required\r\n");
4636 logevent("Further authentication required");
4637 }
4638
4639 s->can_pubkey =
4640 in_commasep_string("publickey", methods, methlen);
4641 s->can_passwd =
4642 in_commasep_string("password", methods, methlen);
4643 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
4644 in_commasep_string("keyboard-interactive", methods, methlen);
4645 }
4646
4647 s->method = 0;
4648 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4649
4650 /*
4651 * Most password/passphrase prompts will be
4652 * non-echoing, so we set this to 0 by default.
4653 * Exception is that some keyboard-interactive prompts
4654 * can be echoing, in which case we'll set this to 1.
4655 */
4656 s->echo = 0;
4657
4658 if (!s->method && s->can_pubkey &&
4659 agent_exists() && !s->tried_agent) {
4660 /*
4661 * Attempt public-key authentication using Pageant.
4662 */
4663 void *r;
4664 s->authed = FALSE;
4665
4666 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4667 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4668
4669 s->tried_agent = TRUE;
4670
4671 logevent("Pageant is running. Requesting keys.");
4672
4673 /* Request the keys held by the agent. */
4674 PUT_32BIT(s->request, 1);
4675 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4676 agent_query(s->request, 5, &r, &s->responselen);
4677 s->response = (unsigned char *) r;
4678 if (s->response && s->responselen >= 5 &&
4679 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4680 s->p = s->response + 5;
4681 s->nkeys = GET_32BIT(s->p);
4682 s->p += 4;
4683 {
4684 char buf[64];
4685 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4686 logevent(buf);
4687 }
4688 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4689 void *vret;
4690
4691 {
4692 char buf[64];
4693 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4694 logevent(buf);
4695 }
4696 s->pklen = GET_32BIT(s->p);
4697 s->p += 4;
4698 if (s->publickey_blob &&
4699 s->pklen == s->publickey_bloblen &&
4700 !memcmp(s->p, s->publickey_blob,
4701 s->publickey_bloblen)) {
4702 logevent("This key matches configured key file");
4703 s->tried_pubkey_config = 1;
4704 }
4705 s->pkblob = (char *)s->p;
4706 s->p += s->pklen;
4707 s->alglen = GET_32BIT(s->pkblob);
4708 s->alg = s->pkblob + 4;
4709 s->commentlen = GET_32BIT(s->p);
4710 s->p += 4;
4711 s->commentp = (char *)s->p;
4712 s->p += s->commentlen;
4713 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4714 ssh2_pkt_addstring(ssh, s->username);
4715 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4716 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4717 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4718 ssh2_pkt_addstring_start(ssh);
4719 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4720 ssh2_pkt_addstring_start(ssh);
4721 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4722 ssh2_pkt_send(ssh);
4723
4724 crWaitUntilV(ispkt);
4725 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4726 logevent("Key refused");
4727 continue;
4728 }
4729
4730 if (flags & FLAG_VERBOSE) {
4731 c_write_str(ssh, "Authenticating with "
4732 "public key \"");
4733 c_write(ssh, s->commentp, s->commentlen);
4734 c_write_str(ssh, "\" from agent\r\n");
4735 }
4736
4737 /*
4738 * Server is willing to accept the key.
4739 * Construct a SIGN_REQUEST.
4740 */
4741 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4742 ssh2_pkt_addstring(ssh, s->username);
4743 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4744 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4745 ssh2_pkt_addbool(ssh, TRUE);
4746 ssh2_pkt_addstring_start(ssh);
4747 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4748 ssh2_pkt_addstring_start(ssh);
4749 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4750
4751 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4752 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4753 s->siglen -= 4;
4754 s->len = 1; /* message type */
4755 s->len += 4 + s->pklen; /* key blob */
4756 s->len += 4 + s->siglen; /* data to sign */
4757 s->len += 4; /* flags */
4758 s->agentreq = snewn(4 + s->len, char);
4759 PUT_32BIT(s->agentreq, s->len);
4760 s->q = s->agentreq + 4;
4761 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4762 PUT_32BIT(s->q, s->pklen);
4763 s->q += 4;
4764 memcpy(s->q, s->pkblob, s->pklen);
4765 s->q += s->pklen;
4766 PUT_32BIT(s->q, s->siglen);
4767 s->q += 4;
4768 /* Now the data to be signed... */
4769 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
4770 PUT_32BIT(s->q, 20);
4771 s->q += 4;
4772 }
4773 memcpy(s->q, ssh->v2_session_id, 20);
4774 s->q += 20;
4775 memcpy(s->q, ssh->pktout.data + 5,
4776 ssh->pktout.length - 5);
4777 s->q += ssh->pktout.length - 5;
4778 /* And finally the (zero) flags word. */
4779 PUT_32BIT(s->q, 0);
4780 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4781 s->ret = vret;
4782 sfree(s->agentreq);
4783 if (s->ret) {
4784 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4785 logevent("Sending Pageant's response");
4786 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4787 s->ret + 9,
4788 GET_32BIT(s->ret + 5));
4789 ssh2_pkt_send(ssh);
4790 s->authed = TRUE;
4791 break;
4792 } else {
4793 logevent
4794 ("Pageant failed to answer challenge");
4795 sfree(s->ret);
4796 }
4797 }
4798 }
4799 if (s->authed)
4800 continue;
4801 }
4802 }
4803
4804 if (!s->method && s->can_pubkey && s->publickey_blob
4805 && !s->tried_pubkey_config) {
4806 unsigned char *pub_blob;
4807 char *algorithm, *comment;
4808 int pub_blob_len;
4809
4810 s->tried_pubkey_config = TRUE;
4811
4812 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4813 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4814
4815 /*
4816 * Try the public key supplied in the configuration.
4817 *
4818 * First, offer the public blob to see if the server is
4819 * willing to accept it.
4820 */
4821 pub_blob =
4822 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
4823 &algorithm,
4824 &pub_blob_len);
4825 if (pub_blob) {
4826 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4827 ssh2_pkt_addstring(ssh, s->username);
4828 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4829 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4830 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4831 ssh2_pkt_addstring(ssh, algorithm);
4832 ssh2_pkt_addstring_start(ssh);
4833 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4834 pub_blob_len);
4835 ssh2_pkt_send(ssh);
4836 logevent("Offered public key"); /* FIXME */
4837
4838 crWaitUntilV(ispkt);
4839 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4840 s->gotit = TRUE;
4841 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4842 continue; /* key refused; give up on it */
4843 }
4844
4845 logevent("Offer of public key accepted");
4846 /*
4847 * Actually attempt a serious authentication using
4848 * the key.
4849 */
4850 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
4851 sprintf(s->pwprompt,
4852 "Passphrase for key \"%.100s\": ",
4853 comment);
4854 s->need_pw = TRUE;
4855 } else {
4856 s->need_pw = FALSE;
4857 }
4858 c_write_str(ssh, "Authenticating with public key \"");
4859 c_write_str(ssh, comment);
4860 c_write_str(ssh, "\"\r\n");
4861 s->method = AUTH_PUBLICKEY_FILE;
4862 }
4863 }
4864
4865 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4866 s->method = AUTH_KEYBOARD_INTERACTIVE;
4867 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4868 s->tried_keyb_inter = TRUE;
4869
4870 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4871 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4872
4873 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4874 ssh2_pkt_addstring(ssh, s->username);
4875 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4876 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4877 ssh2_pkt_addstring(ssh, ""); /* lang */
4878 ssh2_pkt_addstring(ssh, "");
4879 ssh2_pkt_send(ssh);
4880
4881 crWaitUntilV(ispkt);
4882 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4883 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4884 s->gotit = TRUE;
4885 logevent("Keyboard-interactive authentication refused");
4886 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4887 continue;
4888 }
4889
4890 s->kbd_inter_running = TRUE;
4891 s->curr_prompt = 0;
4892 }
4893
4894 if (s->kbd_inter_running) {
4895 s->method = AUTH_KEYBOARD_INTERACTIVE;
4896 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4897 s->tried_keyb_inter = TRUE;
4898
4899 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4900 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4901
4902 if (s->curr_prompt == 0) {
4903 /*
4904 * We've got a fresh USERAUTH_INFO_REQUEST.
4905 * Display header data, and start going through
4906 * the prompts.
4907 */
4908 char *name, *inst, *lang;
4909 int name_len, inst_len, lang_len;
4910
4911 ssh2_pkt_getstring(ssh, &name, &name_len);
4912 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4913 ssh2_pkt_getstring(ssh, &lang, &lang_len);
4914 if (name_len > 0) {
4915 c_write_untrusted(ssh, name, name_len);
4916 c_write_str(ssh, "\r\n");
4917 }
4918 if (inst_len > 0) {
4919 c_write_untrusted(ssh, inst, inst_len);
4920 c_write_str(ssh, "\r\n");
4921 }
4922 s->num_prompts = ssh2_pkt_getuint32(ssh);
4923 }
4924
4925 /*
4926 * If there are prompts remaining in the packet,
4927 * display one and get a response.
4928 */
4929 if (s->curr_prompt < s->num_prompts) {
4930 char *prompt;
4931 int prompt_len;
4932
4933 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
4934 if (prompt_len > 0) {
4935 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4936 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4937 prompt_len : sizeof(s->pwprompt)-1] = '\0';
4938 } else {
4939 strcpy(s->pwprompt,
4940 "<server failed to send prompt>: ");
4941 }
4942 s->echo = ssh2_pkt_getbool(ssh);
4943 s->need_pw = TRUE;
4944 } else
4945 s->need_pw = FALSE;
4946 }
4947
4948 if (!s->method && s->can_passwd) {
4949 s->method = AUTH_PASSWORD;
4950 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4951 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4952 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4953 ssh->savedhost);
4954 s->need_pw = TRUE;
4955 }
4956
4957 if (s->need_pw) {
4958 if (ssh_get_line) {
4959 if (!ssh_get_line(s->pwprompt, s->password,
4960 sizeof(s->password), TRUE)) {
4961 /*
4962 * get_line failed to get a password (for
4963 * example because one was supplied on the
4964 * command line which has already failed to
4965 * work). Terminate.
4966 */
4967 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4968 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4969 ssh2_pkt_addstring(ssh, "No more passwords available"
4970 " to try");
4971 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4972 ssh2_pkt_send(ssh);
4973 logevent("Unable to authenticate");
4974 connection_fatal(ssh->frontend,
4975 "Unable to authenticate");
4976 ssh_closing((Plug)ssh, NULL, 0, 0);
4977 crStopV;
4978 }
4979 } else {
4980 int ret; /* need not be saved across crReturn */
4981 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4982 ssh->send_ok = 1;
4983
4984 setup_userpass_input(ssh, s->password,
4985 sizeof(s->password), s->echo);
4986 do {
4987 crWaitUntilV(!ispkt);
4988 ret = process_userpass_input(ssh, in, inlen);
4989 } while (ret == 0);
4990 if (ret < 0)
4991 cleanup_exit(0);
4992 c_write_str(ssh, "\r\n");
4993 }
4994 }
4995
4996 if (s->method == AUTH_PUBLICKEY_FILE) {
4997 /*
4998 * We have our passphrase. Now try the actual authentication.
4999 */
5000 struct ssh2_userkey *key;
5001
5002 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password);
5003 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5004 if (key == SSH2_WRONG_PASSPHRASE) {
5005 c_write_str(ssh, "Wrong passphrase\r\n");
5006 s->tried_pubkey_config = FALSE;
5007 } else {
5008 c_write_str(ssh, "Unable to load private key\r\n");
5009 s->tried_pubkey_config = TRUE;
5010 }
5011 /* Send a spurious AUTH_NONE to return to the top. */
5012 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5013 ssh2_pkt_addstring(ssh, s->username);
5014 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5015 ssh2_pkt_addstring(ssh, "none"); /* method */
5016 ssh2_pkt_send(ssh);
5017 s->type = AUTH_TYPE_NONE;
5018 } else {
5019 unsigned char *pkblob, *sigblob, *sigdata;
5020 int pkblob_len, sigblob_len, sigdata_len;
5021 int p;
5022
5023 /*
5024 * We have loaded the private key and the server
5025 * has announced that it's willing to accept it.
5026 * Hallelujah. Generate a signature and send it.
5027 */
5028 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5029 ssh2_pkt_addstring(ssh, s->username);
5030 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5031 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5032 ssh2_pkt_addbool(ssh, TRUE);
5033 ssh2_pkt_addstring(ssh, key->alg->name);
5034 pkblob = key->alg->public_blob(key->data, &pkblob_len);
5035 ssh2_pkt_addstring_start(ssh);
5036 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
5037
5038 /*
5039 * The data to be signed is:
5040 *
5041 * string session-id
5042 *
5043 * followed by everything so far placed in the
5044 * outgoing packet.
5045 */
5046 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
5047 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5048 sigdata_len -= 4;
5049 sigdata = snewn(sigdata_len, unsigned char);
5050 p = 0;
5051 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5052 PUT_32BIT(sigdata+p, 20);
5053 p += 4;
5054 }
5055 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5056 memcpy(sigdata+p, ssh->pktout.data + 5,
5057 ssh->pktout.length - 5);
5058 p += ssh->pktout.length - 5;
5059 assert(p == sigdata_len);
5060 sigblob = key->alg->sign(key->data, (char *)sigdata,
5061 sigdata_len, &sigblob_len);
5062 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
5063 sigblob, sigblob_len);
5064 sfree(pkblob);
5065 sfree(sigblob);
5066 sfree(sigdata);
5067
5068 ssh2_pkt_send(ssh);
5069 s->type = AUTH_TYPE_PUBLICKEY;
5070 }
5071 } else if (s->method == AUTH_PASSWORD) {
5072 /*
5073 * We send the password packet lumped tightly together with
5074 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5075 * string long enough to make the total length of the two
5076 * packets constant. This should ensure that a passive
5077 * listener doing traffic analyis can't work out the length
5078 * of the password.
5079 *
5080 * For this to work, we need an assumption about the
5081 * maximum length of the password packet. I think 256 is
5082 * pretty conservative. Anyone using a password longer than
5083 * that probably doesn't have much to worry about from
5084 * people who find out how long their password is!
5085 */
5086 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5087 ssh2_pkt_addstring(ssh, s->username);
5088 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5089 ssh2_pkt_addstring(ssh, "password");
5090 ssh2_pkt_addbool(ssh, FALSE);
5091 ssh2_pkt_addstring(ssh, s->password);
5092 memset(s->password, 0, sizeof(s->password));
5093 ssh2_pkt_defer(ssh);
5094 /*
5095 * We'll include a string that's an exact multiple of the
5096 * cipher block size. If the cipher is NULL for some
5097 * reason, we don't do this trick at all because we gain
5098 * nothing by it.
5099 */
5100 if (ssh->cscipher) {
5101 int stringlen, i;
5102
5103 stringlen = (256 - ssh->deferred_len);
5104 stringlen += ssh->cscipher->blksize - 1;
5105 stringlen -= (stringlen % ssh->cscipher->blksize);
5106 if (ssh->cscomp) {
5107 /*
5108 * Temporarily disable actual compression,
5109 * so we can guarantee to get this string
5110 * exactly the length we want it. The
5111 * compression-disabling routine should
5112 * return an integer indicating how many
5113 * bytes we should adjust our string length
5114 * by.
5115 */
5116 stringlen -=
5117 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
5118 }
5119 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5120 ssh2_pkt_addstring_start(ssh);
5121 for (i = 0; i < stringlen; i++) {
5122 char c = (char) random_byte();
5123 ssh2_pkt_addstring_data(ssh, &c, 1);
5124 }
5125 ssh2_pkt_defer(ssh);
5126 }
5127 ssh_pkt_defersend(ssh);
5128 logevent("Sent password");
5129 s->type = AUTH_TYPE_PASSWORD;
5130 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5131 if (s->curr_prompt == 0) {
5132 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5133 ssh2_pkt_adduint32(ssh, s->num_prompts);
5134 }
5135 if (s->need_pw) { /* only add pw if we just got one! */
5136 ssh2_pkt_addstring(ssh, s->password);
5137 memset(s->password, 0, sizeof(s->password));
5138 s->curr_prompt++;
5139 }
5140 if (s->curr_prompt >= s->num_prompts) {
5141 ssh2_pkt_send(ssh);
5142 } else {
5143 /*
5144 * If there are prompts remaining, we set
5145 * `gotit' so that we won't attempt to get
5146 * another packet. Then we go back round the
5147 * loop and will end up retrieving another
5148 * prompt out of the existing packet. Funky or
5149 * what?
5150 */
5151 s->gotit = TRUE;
5152 }
5153 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5154 } else {
5155 c_write_str(ssh, "No supported authentication methods"
5156 " left to try!\r\n");
5157 logevent("No supported authentications offered."
5158 " Disconnecting");
5159 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5160 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5161 ssh2_pkt_addstring(ssh, "No supported authentication"
5162 " methods available");
5163 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5164 ssh2_pkt_send(ssh);
5165 ssh_closing((Plug)ssh, NULL, 0, 0);
5166 crStopV;
5167 }
5168 }
5169 } while (!s->we_are_in);
5170
5171 /*
5172 * Now we're authenticated for the connection protocol. The
5173 * connection protocol will automatically have started at this
5174 * point; there's no need to send SERVICE_REQUEST.
5175 */
5176
5177 /*
5178 * So now create a channel with a session in it.
5179 */
5180 ssh->channels = newtree234(ssh_channelcmp);
5181 ssh->mainchan = snew(struct ssh_channel);
5182 ssh->mainchan->ssh = ssh;
5183 ssh->mainchan->localid = alloc_channel_id(ssh);
5184 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5185 ssh2_pkt_addstring(ssh, "session");
5186 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5187 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5188 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5189 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5190 ssh2_pkt_send(ssh);
5191 crWaitUntilV(ispkt);
5192 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5193 bombout(("Server refused to open a session"));
5194 crStopV;
5195 /* FIXME: error data comes back in FAILURE packet */
5196 }
5197 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5198 bombout(("Server's channel confirmation cited wrong channel"));
5199 crStopV;
5200 }
5201 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5202 ssh->mainchan->type = CHAN_MAINSESSION;
5203 ssh->mainchan->closes = 0;
5204 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5205 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5206 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5207 add234(ssh->channels, ssh->mainchan);
5208 logevent("Opened channel for session");
5209
5210 /*
5211 * Potentially enable X11 forwarding.
5212 */
5213 if (ssh->cfg.x11_forward) {
5214 char proto[20], data[64];
5215 logevent("Requesting X11 forwarding");
5216 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5217 data, sizeof(data), ssh->cfg.x11_auth);
5218 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
5219 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5220 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5221 ssh2_pkt_addstring(ssh, "x11-req");
5222 ssh2_pkt_addbool(ssh, 1); /* want reply */
5223 ssh2_pkt_addbool(ssh, 0); /* many connections */
5224 ssh2_pkt_addstring(ssh, proto);
5225 ssh2_pkt_addstring(ssh, data);
5226 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
5227 ssh2_pkt_send(ssh);
5228
5229 do {
5230 crWaitUntilV(ispkt);
5231 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5232 unsigned i = ssh2_pkt_getuint32(ssh);
5233 struct ssh_channel *c;
5234 c = find234(ssh->channels, &i, ssh_channelfind);
5235 if (!c)
5236 continue; /* nonexistent channel */
5237 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5238 }
5239 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5240
5241 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5242 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5243 bombout(("Unexpected response to X11 forwarding request:"
5244 " packet type %d", ssh->pktin.type));
5245 crStopV;
5246 }
5247 logevent("X11 forwarding refused");
5248 } else {
5249 logevent("X11 forwarding enabled");
5250 ssh->X11_fwd_enabled = TRUE;
5251 }
5252 }
5253
5254 /*
5255 * Enable port forwardings.
5256 */
5257 {
5258 char type;
5259 int n;
5260 int sport,dport,sserv,dserv;
5261 char sports[256], dports[256], saddr[256], host[256];
5262
5263 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5264 /* Add port forwardings. */
5265 ssh->portfwd_strptr = ssh->cfg.portfwd;
5266 while (*ssh->portfwd_strptr) {
5267 type = *ssh->portfwd_strptr++;
5268 saddr[0] = '\0';
5269 n = 0;
5270 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5271 if (*ssh->portfwd_strptr == ':') {
5272 /*
5273 * We've seen a colon in the middle of the
5274 * source port number. This means that
5275 * everything we've seen until now is the
5276 * source _address_, so we'll move it into
5277 * saddr and start sports from the beginning
5278 * again.
5279 */
5280 ssh->portfwd_strptr++;
5281 sports[n] = '\0';
5282 strcpy(saddr, sports);
5283 n = 0;
5284 }
5285 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5286 }
5287 sports[n] = 0;
5288 if (type != 'D') {
5289 if (*ssh->portfwd_strptr == '\t')
5290 ssh->portfwd_strptr++;
5291 n = 0;
5292 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5293 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5294 }
5295 host[n] = 0;
5296 if (*ssh->portfwd_strptr == ':')
5297 ssh->portfwd_strptr++;
5298 n = 0;
5299 while (*ssh->portfwd_strptr) {
5300 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5301 }
5302 dports[n] = 0;
5303 ssh->portfwd_strptr++;
5304 dport = atoi(dports);
5305 dserv = 0;
5306 if (dport == 0) {
5307 dserv = 1;
5308 dport = net_service_lookup(dports);
5309 if (!dport) {
5310 logeventf(ssh, "Service lookup failed for destination"
5311 " port \"%s\"", dports);
5312 }
5313 }
5314 } else {
5315 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
5316 dport = dserv = -1;
5317 }
5318 sport = atoi(sports);
5319 sserv = 0;
5320 if (sport == 0) {
5321 sserv = 1;
5322 sport = net_service_lookup(sports);
5323 if (!sport) {
5324 logeventf(ssh, "Service lookup failed for source"
5325 " port \"%s\"", sports);
5326 }
5327 }
5328 if (sport && dport) {
5329 if (type == 'L') {
5330 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5331 sport, ssh, &ssh->cfg);
5332 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5333 " forwarding to %s:%.*s%.*s%d%.*s",
5334 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5335 (int)(*saddr?1:0), ":",
5336 (int)(sserv ? strlen(sports) : 0), sports,
5337 sserv, "(", sport, sserv, ")",
5338 host,
5339 (int)(dserv ? strlen(dports) : 0), dports,
5340 dserv, "(", dport, dserv, ")");
5341 } else if (type == 'D') {
5342 pfd_addforward(NULL, -1, *saddr ? saddr : NULL,
5343 sport, ssh, &ssh->cfg);
5344 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5345 " doing SOCKS dynamic forwarding",
5346 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5347 (int)(*saddr?1:0), ":",
5348 (int)(sserv ? strlen(sports) : 0), sports,
5349 sserv, "(", sport, sserv, ")");
5350 } else {
5351 struct ssh_rportfwd *pf;
5352 pf = snew(struct ssh_rportfwd);
5353 strcpy(pf->dhost, host);
5354 pf->dport = dport;
5355 pf->sport = sport;
5356 if (add234(ssh->rportfwds, pf) != pf) {
5357 logeventf(ssh, "Duplicate remote port forwarding"
5358 " to %s:%d", host, dport);
5359 sfree(pf);
5360 } else {
5361 logeventf(ssh, "Requesting remote port "
5362 "%.*s%.*s%.*s%.*s%d%.*s"
5363 " forward to %s:%.*s%.*s%d%.*s",
5364 (int)(*saddr?strlen(saddr):0),
5365 *saddr?saddr:NULL,
5366 (int)(*saddr?1:0), ":",
5367 (int)(sserv ? strlen(sports) : 0), sports,
5368 sserv, "(", sport, sserv, ")",
5369 host,
5370 (int)(dserv ? strlen(dports) : 0), dports,
5371 dserv, "(", dport, dserv, ")");
5372 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5373 ssh2_pkt_addstring(ssh, "tcpip-forward");
5374 ssh2_pkt_addbool(ssh, 1);/* want reply */
5375 if (*saddr)
5376 ssh2_pkt_addstring(ssh, saddr);
5377 if (ssh->cfg.rport_acceptall)
5378 ssh2_pkt_addstring(ssh, "0.0.0.0");
5379 else
5380 ssh2_pkt_addstring(ssh, "127.0.0.1");
5381 ssh2_pkt_adduint32(ssh, sport);
5382 ssh2_pkt_send(ssh);
5383
5384 do {
5385 crWaitUntilV(ispkt);
5386 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5387 unsigned i = ssh2_pkt_getuint32(ssh);
5388 struct ssh_channel *c;
5389 c = find234(ssh->channels, &i, ssh_channelfind);
5390 if (!c)
5391 continue;/* nonexistent channel */
5392 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5393 }
5394 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5395
5396 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5397 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5398 bombout(("Unexpected response to port "
5399 "forwarding request: packet type %d",
5400 ssh->pktin.type));
5401 crStopV;
5402 }
5403 logevent("Server refused this port forwarding");
5404 } else {
5405 logevent("Remote port forwarding enabled");
5406 }
5407 }
5408 }
5409 }
5410 }
5411 }
5412
5413 /*
5414 * Potentially enable agent forwarding.
5415 */
5416 if (ssh->cfg.agentfwd && agent_exists()) {
5417 logevent("Requesting OpenSSH-style agent forwarding");
5418 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5419 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5420 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5421 ssh2_pkt_addbool(ssh, 1); /* want reply */
5422 ssh2_pkt_send(ssh);
5423
5424 do {
5425 crWaitUntilV(ispkt);
5426 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5427 unsigned i = ssh2_pkt_getuint32(ssh);
5428 struct ssh_channel *c;
5429 c = find234(ssh->channels, &i, ssh_channelfind);
5430 if (!c)
5431 continue; /* nonexistent channel */
5432 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5433 }
5434 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5435
5436 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5437 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5438 bombout(("Unexpected response to agent forwarding request:"
5439 " packet type %d", ssh->pktin.type));
5440 crStopV;
5441 }
5442 logevent("Agent forwarding refused");
5443 } else {
5444 logevent("Agent forwarding enabled");
5445 ssh->agentfwd_enabled = TRUE;
5446 }
5447 }
5448
5449 /*
5450 * Now allocate a pty for the session.
5451 */
5452 if (!ssh->cfg.nopty) {
5453 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5454 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5455 ssh2_pkt_addstring(ssh, "pty-req");
5456 ssh2_pkt_addbool(ssh, 1); /* want reply */
5457 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
5458 ssh2_pkt_adduint32(ssh, ssh->term_width);
5459 ssh2_pkt_adduint32(ssh, ssh->term_height);
5460 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5461 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5462 ssh2_pkt_addstring_start(ssh);
5463 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5464 ssh2_pkt_send(ssh);
5465 ssh->state = SSH_STATE_INTERMED;
5466
5467 do {
5468 crWaitUntilV(ispkt);
5469 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5470 unsigned i = ssh2_pkt_getuint32(ssh);
5471 struct ssh_channel *c;
5472 c = find234(ssh->channels, &i, ssh_channelfind);
5473 if (!c)
5474 continue; /* nonexistent channel */
5475 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5476 }
5477 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5478
5479 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5480 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5481 bombout(("Unexpected response to pty request:"
5482 " packet type %d", ssh->pktin.type));
5483 crStopV;
5484 }
5485 c_write_str(ssh, "Server refused to allocate pty\r\n");
5486 ssh->editing = ssh->echoing = 1;
5487 } else {
5488 logevent("Allocated pty");
5489 }
5490 } else {
5491 ssh->editing = ssh->echoing = 1;
5492 }
5493
5494 /*
5495 * Start a shell or a remote command. We may have to attempt
5496 * this twice if the config data has provided a second choice
5497 * of command.
5498 */
5499 while (1) {
5500 int subsys;
5501 char *cmd;
5502
5503 if (ssh->fallback_cmd) {
5504 subsys = ssh->cfg.ssh_subsys2;
5505 cmd = ssh->cfg.remote_cmd_ptr2;
5506 } else {
5507 subsys = ssh->cfg.ssh_subsys;
5508 cmd = ssh->cfg.remote_cmd_ptr;
5509 }
5510
5511 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5512 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5513 if (subsys) {
5514 ssh2_pkt_addstring(ssh, "subsystem");
5515 ssh2_pkt_addbool(ssh, 1); /* want reply */
5516 ssh2_pkt_addstring(ssh, cmd);
5517 } else if (*cmd) {
5518 ssh2_pkt_addstring(ssh, "exec");
5519 ssh2_pkt_addbool(ssh, 1); /* want reply */
5520 ssh2_pkt_addstring(ssh, cmd);
5521 } else {
5522 ssh2_pkt_addstring(ssh, "shell");
5523 ssh2_pkt_addbool(ssh, 1); /* want reply */
5524 }
5525 ssh2_pkt_send(ssh);
5526 do {
5527 crWaitUntilV(ispkt);
5528 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5529 unsigned i = ssh2_pkt_getuint32(ssh);
5530 struct ssh_channel *c;
5531 c = find234(ssh->channels, &i, ssh_channelfind);
5532 if (!c)
5533 continue; /* nonexistent channel */
5534 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5535 }
5536 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5537 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5538 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5539 bombout(("Unexpected response to shell/command request:"
5540 " packet type %d", ssh->pktin.type));
5541 crStopV;
5542 }
5543 /*
5544 * We failed to start the command. If this is the
5545 * fallback command, we really are finished; if it's
5546 * not, and if the fallback command exists, try falling
5547 * back to it before complaining.
5548 */
5549 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
5550 logevent("Primary command failed; attempting fallback");
5551 ssh->fallback_cmd = TRUE;
5552 continue;
5553 }
5554 bombout(("Server refused to start a shell/command"));
5555 crStopV;
5556 } else {
5557 logevent("Started a shell/command");
5558 }
5559 break;
5560 }
5561
5562 ssh->state = SSH_STATE_SESSION;
5563 if (ssh->size_needed)
5564 ssh_size(ssh, ssh->term_width, ssh->term_height);
5565 if (ssh->eof_needed)
5566 ssh_special(ssh, TS_EOF);
5567
5568 /*
5569 * Transfer data!
5570 */
5571 if (ssh->ldisc)
5572 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5573 ssh->send_ok = 1;
5574 while (1) {
5575 crReturnV;
5576 s->try_send = FALSE;
5577 if (ispkt) {
5578 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5579 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5580 char *data;
5581 int length;
5582 unsigned i = ssh2_pkt_getuint32(ssh);
5583 struct ssh_channel *c;
5584 c = find234(ssh->channels, &i, ssh_channelfind);
5585 if (!c)
5586 continue; /* nonexistent channel */
5587 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5588 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5589 continue; /* extended but not stderr */
5590 ssh2_pkt_getstring(ssh, &data, &length);
5591 if (data) {
5592 int bufsize = 0;
5593 c->v.v2.locwindow -= length;
5594 switch (c->type) {
5595 case CHAN_MAINSESSION:
5596 bufsize =
5597 from_backend(ssh->frontend, ssh->pktin.type ==
5598 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5599 data, length);
5600 break;
5601 case CHAN_X11:
5602 bufsize = x11_send(c->u.x11.s, data, length);
5603 break;
5604 case CHAN_SOCKDATA:
5605 bufsize = pfd_send(c->u.pfd.s, data, length);
5606 break;
5607 case CHAN_AGENT:
5608 while (length > 0) {
5609 if (c->u.a.lensofar < 4) {
5610 int l = min(4 - c->u.a.lensofar, length);
5611 memcpy(c->u.a.msglen + c->u.a.lensofar,
5612 data, l);
5613 data += l;
5614 length -= l;
5615 c->u.a.lensofar += l;
5616 }
5617 if (c->u.a.lensofar == 4) {
5618 c->u.a.totallen =
5619 4 + GET_32BIT(c->u.a.msglen);
5620 c->u.a.message = snewn(c->u.a.totallen,
5621 unsigned char);
5622 memcpy(c->u.a.message, c->u.a.msglen, 4);
5623 }
5624 if (c->u.a.lensofar >= 4 && length > 0) {
5625 int l =
5626 min(c->u.a.totallen - c->u.a.lensofar,
5627 length);
5628 memcpy(c->u.a.message + c->u.a.lensofar,
5629 data, l);
5630 data += l;
5631 length -= l;
5632 c->u.a.lensofar += l;
5633 }
5634 if (c->u.a.lensofar == c->u.a.totallen) {
5635 void *reply, *sentreply;
5636 int replylen;
5637 agent_query(c->u.a.message,
5638 c->u.a.totallen, &reply,
5639 &replylen);
5640 if (reply)
5641 sentreply = reply;
5642 else {
5643 /* Fake SSH_AGENT_FAILURE. */
5644 sentreply = "\0\0\0\1\5";
5645 replylen = 5;
5646 }
5647 ssh2_add_channel_data(c, sentreply, replylen);
5648 s->try_send = TRUE;
5649 if (reply)
5650 sfree(reply);
5651 sfree(c->u.a.message);
5652 c->u.a.lensofar = 0;
5653 }
5654 }
5655 bufsize = 0;
5656 break;
5657 }
5658 /*
5659 * If we are not buffering too much data,
5660 * enlarge the window again at the remote side.
5661 */
5662 if (bufsize < OUR_V2_WINSIZE)
5663 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5664 }
5665 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5666 unsigned i = ssh2_pkt_getuint32(ssh);
5667 struct ssh_channel *c;
5668
5669 c = find234(ssh->channels, &i, ssh_channelfind);
5670 if (!c)
5671 continue; /* nonexistent channel */
5672
5673 if (c->type == CHAN_X11) {
5674 /*
5675 * Remote EOF on an X11 channel means we should
5676 * wrap up and close the channel ourselves.
5677 */
5678 x11_close(c->u.x11.s);
5679 sshfwd_close(c);
5680 } else if (c->type == CHAN_AGENT) {
5681 sshfwd_close(c);
5682 } else if (c->type == CHAN_SOCKDATA) {
5683 pfd_close(c->u.pfd.s);
5684 sshfwd_close(c);
5685 }
5686 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5687 unsigned i = ssh2_pkt_getuint32(ssh);
5688 struct ssh_channel *c;
5689
5690 c = find234(ssh->channels, &i, ssh_channelfind);
5691 if (!c || ((int)c->remoteid) == -1) {
5692 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5693 c ? "half-open" : "nonexistent", i));
5694 crStopV;
5695 }
5696 /* Do pre-close processing on the channel. */
5697 switch (c->type) {
5698 case CHAN_MAINSESSION:
5699 break; /* nothing to see here, move along */
5700 case CHAN_X11:
5701 if (c->u.x11.s != NULL)
5702 x11_close(c->u.x11.s);
5703 sshfwd_close(c);
5704 break;
5705 case CHAN_AGENT:
5706 sshfwd_close(c);
5707 break;
5708 case CHAN_SOCKDATA:
5709 if (c->u.pfd.s != NULL)
5710 pfd_close(c->u.pfd.s);
5711 sshfwd_close(c);
5712 break;
5713 }
5714 if (c->closes == 0) {
5715 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5716 ssh2_pkt_adduint32(ssh, c->remoteid);
5717 ssh2_pkt_send(ssh);
5718 }
5719 del234(ssh->channels, c);
5720 bufchain_clear(&c->v.v2.outbuffer);
5721 sfree(c);
5722
5723 /*
5724 * See if that was the last channel left open.
5725 */
5726 if (count234(ssh->channels) == 0) {
5727 logevent("All channels closed. Disconnecting");
5728 #if 0
5729 /*
5730 * We used to send SSH_MSG_DISCONNECT here,
5731 * because I'd believed that _every_ conforming
5732 * SSH2 connection had to end with a disconnect
5733 * being sent by at least one side; apparently
5734 * I was wrong and it's perfectly OK to
5735 * unceremoniously slam the connection shut
5736 * when you're done, and indeed OpenSSH feels
5737 * this is more polite than sending a
5738 * DISCONNECT. So now we don't.
5739 */
5740 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5741 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5742 ssh2_pkt_addstring(ssh, "All open channels closed");
5743 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5744 ssh2_pkt_send(ssh);
5745 #endif
5746 ssh_closing((Plug)ssh, NULL, 0, 0);
5747 crStopV;
5748 }
5749 continue; /* remote sends close; ignore (FIXME) */
5750 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5751 unsigned i = ssh2_pkt_getuint32(ssh);
5752 struct ssh_channel *c;
5753 c = find234(ssh->channels, &i, ssh_channelfind);
5754 if (!c || c->closes)
5755 continue; /* nonexistent or closing channel */
5756 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5757 s->try_send = TRUE;
5758 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5759 unsigned i = ssh2_pkt_getuint32(ssh);
5760 struct ssh_channel *c;
5761 c = find234(ssh->channels, &i, ssh_channelfind);
5762 if (!c)
5763 continue; /* nonexistent channel */
5764 if (c->type != CHAN_SOCKDATA_DORMANT)
5765 continue; /* dunno why they're confirming this */
5766 c->remoteid = ssh2_pkt_getuint32(ssh);
5767 c->type = CHAN_SOCKDATA;
5768 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5769 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5770 if (c->u.pfd.s)
5771 pfd_confirm(c->u.pfd.s);
5772 if (c->closes) {
5773 /*
5774 * We have a pending close on this channel,
5775 * which we decided on before the server acked
5776 * the channel open. So now we know the
5777 * remoteid, we can close it again.
5778 */
5779 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5780 ssh2_pkt_adduint32(ssh, c->remoteid);
5781 ssh2_pkt_send(ssh);
5782 }
5783 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5784 unsigned i = ssh2_pkt_getuint32(ssh);
5785 struct ssh_channel *c;
5786 c = find234(ssh->channels, &i, ssh_channelfind);
5787 if (!c)
5788 continue; /* nonexistent channel */
5789 if (c->type != CHAN_SOCKDATA_DORMANT)
5790 continue; /* dunno why they're failing this */
5791
5792 logevent("Forwarded connection refused by server");
5793
5794 pfd_close(c->u.pfd.s);
5795
5796 del234(ssh->channels, c);
5797 sfree(c);
5798 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5799 unsigned localid;
5800 char *type;
5801 int typelen, want_reply;
5802 struct ssh_channel *c;
5803
5804 localid = ssh2_pkt_getuint32(ssh);
5805 ssh2_pkt_getstring(ssh, &type, &typelen);
5806 want_reply = ssh2_pkt_getbool(ssh);
5807
5808 /*
5809 * First, check that the channel exists. Otherwise,
5810 * we can instantly disconnect with a rude message.
5811 */
5812 c = find234(ssh->channels, &localid, ssh_channelfind);
5813 if (!c) {
5814 char buf[80];
5815 sprintf(buf, "Received channel request for nonexistent"
5816 " channel %d", localid);
5817 logevent(buf);
5818 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5819 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5820 ssh2_pkt_addstring(ssh, buf);
5821 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5822 ssh2_pkt_send(ssh);
5823 connection_fatal(ssh->frontend, "%s", buf);
5824 ssh_closing((Plug)ssh, NULL, 0, 0);
5825 crStopV;
5826 }
5827
5828 /*
5829 * Having got the channel number, we now look at
5830 * the request type string to see if it's something
5831 * we recognise.
5832 */
5833 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5834 c == ssh->mainchan) {
5835 /* We recognise "exit-status" on the primary channel. */
5836 char buf[100];
5837 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5838 sprintf(buf, "Server sent command exit status %d",
5839 ssh->exitcode);
5840 logevent(buf);
5841 if (want_reply) {
5842 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5843 ssh2_pkt_adduint32(ssh, c->remoteid);
5844 ssh2_pkt_send(ssh);
5845 }
5846 } else {
5847 /*
5848 * This is a channel request we don't know
5849 * about, so we now either ignore the request
5850 * or respond with CHANNEL_FAILURE, depending
5851 * on want_reply.
5852 */
5853 if (want_reply) {
5854 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5855 ssh2_pkt_adduint32(ssh, c->remoteid);
5856 ssh2_pkt_send(ssh);
5857 }
5858 }
5859 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5860 char *type;
5861 int typelen, want_reply;
5862
5863 ssh2_pkt_getstring(ssh, &type, &typelen);
5864 want_reply = ssh2_pkt_getbool(ssh);
5865
5866 /*
5867 * We currently don't support any global requests
5868 * at all, so we either ignore the request or
5869 * respond with REQUEST_FAILURE, depending on
5870 * want_reply.
5871 */
5872 if (want_reply) {
5873 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5874 ssh2_pkt_send(ssh);
5875 }
5876 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5877 char *type;
5878 int typelen;
5879 char *peeraddr;
5880 int peeraddrlen;
5881 int peerport;
5882 char *error = NULL;
5883 struct ssh_channel *c;
5884 unsigned remid, winsize, pktsize;
5885 ssh2_pkt_getstring(ssh, &type, &typelen);
5886 c = snew(struct ssh_channel);
5887 c->ssh = ssh;
5888
5889 remid = ssh2_pkt_getuint32(ssh);
5890 winsize = ssh2_pkt_getuint32(ssh);
5891 pktsize = ssh2_pkt_getuint32(ssh);
5892
5893 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5894 char *addrstr;
5895
5896 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5897 addrstr = snewn(peeraddrlen+1, char);
5898 memcpy(addrstr, peeraddr, peeraddrlen);
5899 peeraddr[peeraddrlen] = '\0';
5900 peerport = ssh2_pkt_getuint32(ssh);
5901
5902 if (!ssh->X11_fwd_enabled)
5903 error = "X11 forwarding is not enabled";
5904 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5905 ssh->x11auth, addrstr, peerport,
5906 &ssh->cfg) != NULL) {
5907 error = "Unable to open an X11 connection";
5908 } else {
5909 c->type = CHAN_X11;
5910 }
5911
5912 sfree(addrstr);
5913 } else if (typelen == 15 &&
5914 !memcmp(type, "forwarded-tcpip", 15)) {
5915 struct ssh_rportfwd pf, *realpf;
5916 char *dummy;
5917 int dummylen;
5918 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5919 pf.sport = ssh2_pkt_getuint32(ssh);
5920 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5921 peerport = ssh2_pkt_getuint32(ssh);
5922 realpf = find234(ssh->rportfwds, &pf, NULL);
5923 if (realpf == NULL) {
5924 error = "Remote port is not recognised";
5925 } else {
5926 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5927 realpf->dport, c, &ssh->cfg);
5928 logeventf(ssh, "Received remote port open request"
5929 " for %s:%d", realpf->dhost, realpf->dport);
5930 if (e != NULL) {
5931 logeventf(ssh, "Port open failed: %s", e);
5932 error = "Port open failed";
5933 } else {
5934 logevent("Forwarded port opened successfully");
5935 c->type = CHAN_SOCKDATA;
5936 }
5937 }
5938 } else if (typelen == 22 &&
5939 !memcmp(type, "auth-agent@openssh.com", 3)) {
5940 if (!ssh->agentfwd_enabled)
5941 error = "Agent forwarding is not enabled";
5942 else {
5943 c->type = CHAN_AGENT; /* identify channel type */
5944 c->u.a.lensofar = 0;
5945 }
5946 } else {
5947 error = "Unsupported channel type requested";
5948 }
5949
5950 c->remoteid = remid;
5951 if (error) {
5952 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5953 ssh2_pkt_adduint32(ssh, c->remoteid);
5954 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5955 ssh2_pkt_addstring(ssh, error);
5956 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5957 ssh2_pkt_send(ssh);
5958 sfree(c);
5959 } else {
5960 c->localid = alloc_channel_id(ssh);
5961 c->closes = 0;
5962 c->v.v2.locwindow = OUR_V2_WINSIZE;
5963 c->v.v2.remwindow = winsize;
5964 c->v.v2.remmaxpkt = pktsize;
5965 bufchain_init(&c->v.v2.outbuffer);
5966 add234(ssh->channels, c);
5967 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5968 ssh2_pkt_adduint32(ssh, c->remoteid);
5969 ssh2_pkt_adduint32(ssh, c->localid);
5970 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5971 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5972 ssh2_pkt_send(ssh);
5973 }
5974 } else {
5975 bombout(("Strange packet received: type %d", ssh->pktin.type));
5976 crStopV;
5977 }
5978 } else {
5979 /*
5980 * We have spare data. Add it to the channel buffer.
5981 */
5982 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
5983 s->try_send = TRUE;
5984 }
5985 if (s->try_send) {
5986 int i;
5987 struct ssh_channel *c;
5988 /*
5989 * Try to send data on all channels if we can.
5990 */
5991 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5992 int bufsize;
5993 if (c->closes)
5994 continue; /* don't send on closing channels */
5995 bufsize = ssh2_try_send(c);
5996 if (bufsize == 0) {
5997 switch (c->type) {
5998 case CHAN_MAINSESSION:
5999 /* stdin need not receive an unthrottle
6000 * notification since it will be polled */
6001 break;
6002 case CHAN_X11:
6003 x11_unthrottle(c->u.x11.s);
6004 break;
6005 case CHAN_AGENT:
6006 /* agent sockets are request/response and need no
6007 * buffer management */
6008 break;
6009 case CHAN_SOCKDATA:
6010 pfd_unthrottle(c->u.pfd.s);
6011 break;
6012 }
6013 }
6014 }
6015 }
6016 }
6017
6018 crFinishV;
6019 }
6020
6021 /*
6022 * Handle the top-level SSH2 protocol.
6023 */
6024 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
6025 {
6026 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
6027 return;
6028 do_ssh2_authconn(ssh, in, inlen, ispkt);
6029 }
6030
6031 /*
6032 * Called to set up the connection.
6033 *
6034 * Returns an error message, or NULL on success.
6035 */
6036 static char *ssh_init(void *frontend_handle, void **backend_handle,
6037 Config *cfg,
6038 char *host, int port, char **realhost, int nodelay)
6039 {
6040 char *p;
6041 Ssh ssh;
6042
6043 ssh = snew(struct ssh_tag);
6044 ssh->cfg = *cfg; /* STRUCTURE COPY */
6045 ssh->version = 0; /* when not ready yet */
6046 ssh->s = NULL;
6047 ssh->cipher = NULL;
6048 ssh->v1_cipher_ctx = NULL;
6049 ssh->crcda_ctx = NULL;
6050 ssh->cscipher = NULL;
6051 ssh->cs_cipher_ctx = NULL;
6052 ssh->sccipher = NULL;
6053 ssh->sc_cipher_ctx = NULL;
6054 ssh->csmac = NULL;
6055 ssh->cs_mac_ctx = NULL;
6056 ssh->scmac = NULL;
6057 ssh->sc_mac_ctx = NULL;
6058 ssh->cscomp = NULL;
6059 ssh->cs_comp_ctx = NULL;
6060 ssh->sccomp = NULL;
6061 ssh->sc_comp_ctx = NULL;
6062 ssh->kex = NULL;
6063 ssh->kex_ctx = NULL;
6064 ssh->hostkey = NULL;
6065 ssh->exitcode = -1;
6066 ssh->state = SSH_STATE_PREPACKET;
6067 ssh->size_needed = FALSE;
6068 ssh->eof_needed = FALSE;
6069 ssh->ldisc = NULL;
6070 ssh->logctx = NULL;
6071 {
6072 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6073 ssh->pktin = ssh->pktout = empty;
6074 }
6075 ssh->deferred_send_data = NULL;
6076 ssh->deferred_len = 0;
6077 ssh->deferred_size = 0;
6078 ssh->fallback_cmd = 0;
6079 ssh->pkt_ctx = 0;
6080 ssh->x11auth = NULL;
6081 ssh->v1_compressing = FALSE;
6082 ssh->v2_outgoing_sequence = 0;
6083 ssh->ssh1_rdpkt_crstate = 0;
6084 ssh->ssh2_rdpkt_crstate = 0;
6085 ssh->do_ssh_init_crstate = 0;
6086 ssh->ssh_gotdata_crstate = 0;
6087 ssh->ssh1_protocol_crstate = 0;
6088 ssh->do_ssh1_login_crstate = 0;
6089 ssh->do_ssh2_transport_crstate = 0;
6090 ssh->do_ssh2_authconn_crstate = 0;
6091 ssh->do_ssh_init_state = NULL;
6092 ssh->do_ssh1_login_state = NULL;
6093 ssh->do_ssh2_transport_state = NULL;
6094 ssh->do_ssh2_authconn_state = NULL;
6095 ssh->mainchan = NULL;
6096 ssh->throttled_all = 0;
6097 ssh->v1_stdout_throttling = 0;
6098
6099 *backend_handle = ssh;
6100
6101 #ifdef MSCRYPTOAPI
6102 if (crypto_startup() == 0)
6103 return "Microsoft high encryption pack not installed!";
6104 #endif
6105
6106 ssh->frontend = frontend_handle;
6107 ssh->term_width = ssh->cfg.width;
6108 ssh->term_height = ssh->cfg.height;
6109
6110 ssh->channels = NULL;
6111 ssh->rportfwds = NULL;
6112
6113 ssh->send_ok = 0;
6114 ssh->editing = 0;
6115 ssh->echoing = 0;
6116 ssh->v1_throttle_count = 0;
6117 ssh->overall_bufsize = 0;
6118 ssh->fallback_cmd = 0;
6119
6120 ssh->protocol = NULL;
6121
6122 p = connect_to_host(ssh, host, port, realhost, nodelay);
6123 if (p != NULL)
6124 return p;
6125
6126 return NULL;
6127 }
6128
6129 static void ssh_free(void *handle)
6130 {
6131 Ssh ssh = (Ssh) handle;
6132 struct ssh_channel *c;
6133 struct ssh_rportfwd *pf;
6134
6135 if (ssh->v1_cipher_ctx)
6136 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6137 if (ssh->cs_cipher_ctx)
6138 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6139 if (ssh->sc_cipher_ctx)
6140 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6141 if (ssh->cs_mac_ctx)
6142 ssh->csmac->free_context(ssh->cs_mac_ctx);
6143 if (ssh->sc_mac_ctx)
6144 ssh->scmac->free_context(ssh->sc_mac_ctx);
6145 if (ssh->cs_comp_ctx)
6146 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6147 if (ssh->sc_comp_ctx)
6148 ssh->sccomp->compress_cleanup(ssh->sc_comp_ctx);
6149 if (ssh->kex_ctx)
6150 dh_cleanup(ssh->kex_ctx);
6151 sfree(ssh->savedhost);
6152
6153 if (ssh->channels) {
6154 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6155 switch (c->type) {
6156 case CHAN_X11:
6157 if (c->u.x11.s != NULL)
6158 x11_close(c->u.x11.s);
6159 break;
6160 case CHAN_SOCKDATA:
6161 if (c->u.pfd.s != NULL)
6162 pfd_close(c->u.pfd.s);
6163 break;
6164 }
6165 sfree(c);
6166 }
6167 freetree234(ssh->channels);
6168 }
6169
6170 if (ssh->rportfwds) {
6171 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6172 sfree(pf);
6173 freetree234(ssh->rportfwds);
6174 }
6175 sfree(ssh->deferred_send_data);
6176 if (ssh->x11auth)
6177 x11_free_auth(ssh->x11auth);
6178 sfree(ssh->do_ssh_init_state);
6179 sfree(ssh->do_ssh1_login_state);
6180 sfree(ssh->do_ssh2_transport_state);
6181 sfree(ssh->do_ssh2_authconn_state);
6182
6183 if (ssh->s)
6184 ssh_do_close(ssh);
6185 sfree(ssh);
6186 }
6187
6188 /*
6189 * Reconfigure the SSH backend.
6190 *
6191 * Currently, this function does nothing very useful. In future,
6192 * however, we could do some handy things with it. For example, we
6193 * could make the port forwarding configurer active in the Change
6194 * Settings box, and this routine could close down existing
6195 * forwardings and open up new ones in response to changes.
6196 */
6197 static void ssh_reconfig(void *handle, Config *cfg)
6198 {
6199 Ssh ssh = (Ssh) handle;
6200 ssh->cfg = *cfg; /* STRUCTURE COPY */
6201 }
6202
6203 /*
6204 * Called to send data down the Telnet connection.
6205 */
6206 static int ssh_send(void *handle, char *buf, int len)
6207 {
6208 Ssh ssh = (Ssh) handle;
6209
6210 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6211 return 0;
6212
6213 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
6214
6215 return ssh_sendbuffer(ssh);
6216 }
6217
6218 /*
6219 * Called to query the current amount of buffered stdin data.
6220 */
6221 static int ssh_sendbuffer(void *handle)
6222 {
6223 Ssh ssh = (Ssh) handle;
6224 int override_value;
6225
6226 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6227 return 0;
6228
6229 /*
6230 * If the SSH socket itself has backed up, add the total backup
6231 * size on that to any individual buffer on the stdin channel.
6232 */
6233 override_value = 0;
6234 if (ssh->throttled_all)
6235 override_value = ssh->overall_bufsize;
6236
6237 if (ssh->version == 1) {
6238 return override_value;
6239 } else if (ssh->version == 2) {
6240 if (!ssh->mainchan || ssh->mainchan->closes > 0)
6241 return override_value;
6242 else
6243 return (override_value +
6244 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
6245 }
6246
6247 return 0;
6248 }
6249
6250 /*
6251 * Called to set the size of the window from SSH's POV.
6252 */
6253 static void ssh_size(void *handle, int width, int height)
6254 {
6255 Ssh ssh = (Ssh) handle;
6256
6257 ssh->term_width = width;
6258 ssh->term_height = height;
6259
6260 switch (ssh->state) {
6261 case SSH_STATE_BEFORE_SIZE:
6262 case SSH_STATE_PREPACKET:
6263 case SSH_STATE_CLOSED:
6264 break; /* do nothing */
6265 case SSH_STATE_INTERMED:
6266 ssh->size_needed = TRUE; /* buffer for later */
6267 break;
6268 case SSH_STATE_SESSION:
6269 if (!ssh->cfg.nopty) {
6270 if (ssh->version == 1) {
6271 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6272 PKT_INT, ssh->term_height,
6273 PKT_INT, ssh->term_width,
6274 PKT_INT, 0, PKT_INT, 0, PKT_END);
6275 } else {
6276 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6277 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6278 ssh2_pkt_addstring(ssh, "window-change");
6279 ssh2_pkt_addbool(ssh, 0);
6280 ssh2_pkt_adduint32(ssh, ssh->term_width);
6281 ssh2_pkt_adduint32(ssh, ssh->term_height);
6282 ssh2_pkt_adduint32(ssh, 0);
6283 ssh2_pkt_adduint32(ssh, 0);
6284 ssh2_pkt_send(ssh);
6285 }
6286 }
6287 break;
6288 }
6289 }
6290
6291 /*
6292 * Return a list of the special codes that make sense in this
6293 * protocol.
6294 */
6295 static const struct telnet_special *ssh_get_specials(void *handle)
6296 {
6297 Ssh ssh = (Ssh) handle;
6298
6299 if (ssh->version == 1) {
6300 static const struct telnet_special ssh1_specials[] = {
6301 {"IGNORE message", TS_NOP},
6302 {NULL, 0}
6303 };
6304 return ssh1_specials;
6305 } else if (ssh->version == 2) {
6306 static const struct telnet_special ssh2_specials[] = {
6307 {"Break", TS_BRK},
6308 {"IGNORE message", TS_NOP},
6309 {NULL, 0}
6310 };
6311 return ssh2_specials;
6312 } else
6313 return NULL;
6314 }
6315
6316 /*
6317 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6318 * can send an EOF and collect resulting output (e.g. `plink
6319 * hostname sort').
6320 */
6321 static void ssh_special(void *handle, Telnet_Special code)
6322 {
6323 Ssh ssh = (Ssh) handle;
6324
6325 if (code == TS_EOF) {
6326 if (ssh->state != SSH_STATE_SESSION) {
6327 /*
6328 * Buffer the EOF in case we are pre-SESSION, so we can
6329 * send it as soon as we reach SESSION.
6330 */
6331 if (code == TS_EOF)
6332 ssh->eof_needed = TRUE;
6333 return;
6334 }
6335 if (ssh->version == 1) {
6336 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6337 } else {
6338 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6339 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6340 ssh2_pkt_send(ssh);
6341 }
6342 logevent("Sent EOF message");
6343 } else if (code == TS_PING || code == TS_NOP) {
6344 if (ssh->state == SSH_STATE_CLOSED
6345 || ssh->state == SSH_STATE_PREPACKET) return;
6346 if (ssh->version == 1) {
6347 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6348 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6349 } else {
6350 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6351 ssh2_pkt_addstring_start(ssh);
6352 ssh2_pkt_send(ssh);
6353 }
6354 } else if (code == TS_BRK) {
6355 if (ssh->state == SSH_STATE_CLOSED
6356 || ssh->state == SSH_STATE_PREPACKET) return;
6357 if (ssh->version == 1) {
6358 logevent("Unable to send BREAK signal in SSH1");
6359 } else {
6360 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6361 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6362 ssh2_pkt_addstring(ssh, "break");
6363 ssh2_pkt_addbool(ssh, 0);
6364 ssh2_pkt_adduint32(ssh, 0); /* default break length */
6365 ssh2_pkt_send(ssh);
6366 }
6367 } else {
6368 /* do nothing */
6369 }
6370 }
6371
6372 void *new_sock_channel(void *handle, Socket s)
6373 {
6374 Ssh ssh = (Ssh) handle;
6375 struct ssh_channel *c;
6376 c = snew(struct ssh_channel);
6377 c->ssh = ssh;
6378
6379 if (c) {
6380 c->remoteid = -1; /* to be set when open confirmed */
6381 c->localid = alloc_channel_id(ssh);
6382 c->closes = 0;
6383 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6384 c->u.pfd.s = s;
6385 bufchain_init(&c->v.v2.outbuffer);
6386 add234(ssh->channels, c);
6387 }
6388 return c;
6389 }
6390
6391 /*
6392 * This is called when stdout/stderr (the entity to which
6393 * from_backend sends data) manages to clear some backlog.
6394 */
6395 static void ssh_unthrottle(void *handle, int bufsize)
6396 {
6397 Ssh ssh = (Ssh) handle;
6398 if (ssh->version == 1) {
6399 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6400 ssh->v1_stdout_throttling = 0;
6401 ssh1_throttle(ssh, -1);
6402 }
6403 } else {
6404 if (ssh->mainchan && ssh->mainchan->closes == 0)
6405 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6406 }
6407 }
6408
6409 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6410 {
6411 struct ssh_channel *c = (struct ssh_channel *)channel;
6412 Ssh ssh = c->ssh;
6413
6414 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6415
6416 if (ssh->version == 1) {
6417 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6418 PKT_INT, c->localid,
6419 PKT_STR, hostname,
6420 PKT_INT, port,
6421 //PKT_STR, <org:orgport>,
6422 PKT_END);
6423 } else {
6424 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6425 ssh2_pkt_addstring(ssh, "direct-tcpip");
6426 ssh2_pkt_adduint32(ssh, c->localid);
6427 c->v.v2.locwindow = OUR_V2_WINSIZE;
6428 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6429 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6430 ssh2_pkt_addstring(ssh, hostname);
6431 ssh2_pkt_adduint32(ssh, port);
6432 /*
6433 * We make up values for the originator data; partly it's
6434 * too much hassle to keep track, and partly I'm not
6435 * convinced the server should be told details like that
6436 * about my local network configuration.
6437 */
6438 ssh2_pkt_addstring(ssh, "client-side-connection");
6439 ssh2_pkt_adduint32(ssh, 0);
6440 ssh2_pkt_send(ssh);
6441 }
6442 }
6443
6444
6445 static Socket ssh_socket(void *handle)
6446 {
6447 Ssh ssh = (Ssh) handle;
6448 return ssh->s;
6449 }
6450
6451 static int ssh_sendok(void *handle)
6452 {
6453 Ssh ssh = (Ssh) handle;
6454 return ssh->send_ok;
6455 }
6456
6457 static int ssh_ldisc(void *handle, int option)
6458 {
6459 Ssh ssh = (Ssh) handle;
6460 if (option == LD_ECHO)
6461 return ssh->echoing;
6462 if (option == LD_EDIT)
6463 return ssh->editing;
6464 return FALSE;
6465 }
6466
6467 static void ssh_provide_ldisc(void *handle, void *ldisc)
6468 {
6469 Ssh ssh = (Ssh) handle;
6470 ssh->ldisc = ldisc;
6471 }
6472
6473 static void ssh_provide_logctx(void *handle, void *logctx)
6474 {
6475 Ssh ssh = (Ssh) handle;
6476 ssh->logctx = logctx;
6477 }
6478
6479 static int ssh_return_exitcode(void *handle)
6480 {
6481 Ssh ssh = (Ssh) handle;
6482 if (ssh->s != NULL)
6483 return -1;
6484 else
6485 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
6486 }
6487
6488 /*
6489 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6490 * that fails. This variable is the means by which scp.c can reach
6491 * into the SSH code and find out which one it got.
6492 */
6493 extern int ssh_fallback_cmd(void *handle)
6494 {
6495 Ssh ssh = (Ssh) handle;
6496 return ssh->fallback_cmd;
6497 }
6498
6499 Backend ssh_backend = {
6500 ssh_init,
6501 ssh_free,
6502 ssh_reconfig,
6503 ssh_send,
6504 ssh_sendbuffer,
6505 ssh_size,
6506 ssh_special,
6507 ssh_get_specials,
6508 ssh_socket,
6509 ssh_return_exitcode,
6510 ssh_sendok,
6511 ssh_ldisc,
6512 ssh_provide_ldisc,
6513 ssh_provide_logctx,
6514 ssh_unthrottle,
6515 22
6516 };
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator