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Introduced wrapper macros snew(), snewn() and sresize() for the
[u/mdw/putty] / ssh.c
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <stdarg.h>
4 #include <assert.h>
5
6 #include "putty.h"
7 #include "tree234.h"
8 #include "ssh.h"
9
10 #ifndef FALSE
11 #define FALSE 0
12 #endif
13 #ifndef TRUE
14 #define TRUE 1
15 #endif
16
17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
58
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
61
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
65
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
102
103 /*
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
106 */
107 #define SSH2_PKTCTX_DHGROUP1 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_PUBLICKEY 0x0010
110 #define SSH2_PKTCTX_PASSWORD 0x0020
111 #define SSH2_PKTCTX_KBDINTER 0x0040
112 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
113
114 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
129
130 static const char *const ssh2_disconnect_reasons[] = {
131 NULL,
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
147 };
148
149 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
153
154 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
155
156 /*
157 * Various remote-bug flags.
158 */
159 #define BUG_CHOKES_ON_SSH1_IGNORE 1
160 #define BUG_SSH2_HMAC 2
161 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
162 #define BUG_CHOKES_ON_RSA 8
163 #define BUG_SSH2_RSA_PADDING 16
164 #define BUG_SSH2_DERIVEKEY 32
165 #define BUG_SSH2_DH_GEX 64
166 #define BUG_SSH2_PK_SESSIONID 128
167
168 #define translate(x) if (type == x) return #x
169 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
170 static char *ssh1_pkt_type(int type)
171 {
172 translate(SSH1_MSG_DISCONNECT);
173 translate(SSH1_SMSG_PUBLIC_KEY);
174 translate(SSH1_CMSG_SESSION_KEY);
175 translate(SSH1_CMSG_USER);
176 translate(SSH1_CMSG_AUTH_RSA);
177 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
178 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
179 translate(SSH1_CMSG_AUTH_PASSWORD);
180 translate(SSH1_CMSG_REQUEST_PTY);
181 translate(SSH1_CMSG_WINDOW_SIZE);
182 translate(SSH1_CMSG_EXEC_SHELL);
183 translate(SSH1_CMSG_EXEC_CMD);
184 translate(SSH1_SMSG_SUCCESS);
185 translate(SSH1_SMSG_FAILURE);
186 translate(SSH1_CMSG_STDIN_DATA);
187 translate(SSH1_SMSG_STDOUT_DATA);
188 translate(SSH1_SMSG_STDERR_DATA);
189 translate(SSH1_CMSG_EOF);
190 translate(SSH1_SMSG_EXIT_STATUS);
191 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
192 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
193 translate(SSH1_MSG_CHANNEL_DATA);
194 translate(SSH1_MSG_CHANNEL_CLOSE);
195 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
196 translate(SSH1_SMSG_X11_OPEN);
197 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
198 translate(SSH1_MSG_PORT_OPEN);
199 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
200 translate(SSH1_SMSG_AGENT_OPEN);
201 translate(SSH1_MSG_IGNORE);
202 translate(SSH1_CMSG_EXIT_CONFIRMATION);
203 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
204 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
205 translate(SSH1_MSG_DEBUG);
206 translate(SSH1_CMSG_REQUEST_COMPRESSION);
207 translate(SSH1_CMSG_AUTH_TIS);
208 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
209 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
210 translate(SSH1_CMSG_AUTH_CCARD);
211 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
212 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
213 return "unknown";
214 }
215 static char *ssh2_pkt_type(int pkt_ctx, int type)
216 {
217 translate(SSH2_MSG_DISCONNECT);
218 translate(SSH2_MSG_IGNORE);
219 translate(SSH2_MSG_UNIMPLEMENTED);
220 translate(SSH2_MSG_DEBUG);
221 translate(SSH2_MSG_SERVICE_REQUEST);
222 translate(SSH2_MSG_SERVICE_ACCEPT);
223 translate(SSH2_MSG_KEXINIT);
224 translate(SSH2_MSG_NEWKEYS);
225 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
226 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
227 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
231 translate(SSH2_MSG_USERAUTH_REQUEST);
232 translate(SSH2_MSG_USERAUTH_FAILURE);
233 translate(SSH2_MSG_USERAUTH_SUCCESS);
234 translate(SSH2_MSG_USERAUTH_BANNER);
235 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
236 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
237 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
238 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
239 translate(SSH2_MSG_GLOBAL_REQUEST);
240 translate(SSH2_MSG_REQUEST_SUCCESS);
241 translate(SSH2_MSG_REQUEST_FAILURE);
242 translate(SSH2_MSG_CHANNEL_OPEN);
243 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
244 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
245 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
246 translate(SSH2_MSG_CHANNEL_DATA);
247 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
248 translate(SSH2_MSG_CHANNEL_EOF);
249 translate(SSH2_MSG_CHANNEL_CLOSE);
250 translate(SSH2_MSG_CHANNEL_REQUEST);
251 translate(SSH2_MSG_CHANNEL_SUCCESS);
252 translate(SSH2_MSG_CHANNEL_FAILURE);
253 return "unknown";
254 }
255 #undef translate
256 #undef translatec
257
258 #define GET_32BIT(cp) \
259 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
260 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
261 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
262 ((unsigned long)(unsigned char)(cp)[3]))
263
264 #define PUT_32BIT(cp, value) { \
265 (cp)[0] = (unsigned char)((value) >> 24); \
266 (cp)[1] = (unsigned char)((value) >> 16); \
267 (cp)[2] = (unsigned char)((value) >> 8); \
268 (cp)[3] = (unsigned char)(value); }
269
270 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
271
272 /*
273 * Coroutine mechanics for the sillier bits of the code. If these
274 * macros look impenetrable to you, you might find it helpful to
275 * read
276 *
277 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
278 *
279 * which explains the theory behind these macros.
280 *
281 * In particular, if you are getting `case expression not constant'
282 * errors when building with MS Visual Studio, this is because MS's
283 * Edit and Continue debugging feature causes their compiler to
284 * violate ANSI C. To disable Edit and Continue debugging:
285 *
286 * - right-click ssh.c in the FileView
287 * - click Settings
288 * - select the C/C++ tab and the General category
289 * - under `Debug info:', select anything _other_ than `Program
290 * Database for Edit and Continue'.
291 */
292 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
293 #define crState(t) \
294 struct t *s; \
295 if (!ssh->t) ssh->t = snew(struct t); \
296 s = ssh->t;
297 #define crFinish(z) } *crLine = 0; return (z); }
298 #define crFinishV } *crLine = 0; return; }
299 #define crReturn(z) \
300 do {\
301 *crLine =__LINE__; return (z); case __LINE__:;\
302 } while (0)
303 #define crReturnV \
304 do {\
305 *crLine=__LINE__; return; case __LINE__:;\
306 } while (0)
307 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
308 #define crStopV do{ *crLine = 0; return; }while(0)
309 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
310 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
311
312 typedef struct ssh_tag *Ssh;
313
314 static void ssh2_pkt_init(Ssh, int pkt_type);
315 static void ssh2_pkt_addbool(Ssh, unsigned char value);
316 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
317 static void ssh2_pkt_addstring_start(Ssh);
318 static void ssh2_pkt_addstring_str(Ssh, char *data);
319 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
320 static void ssh2_pkt_addstring(Ssh, char *data);
321 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
322 static void ssh2_pkt_addmp(Ssh, Bignum b);
323 static int ssh2_pkt_construct(Ssh);
324 static void ssh2_pkt_send(Ssh);
325
326 /*
327 * Buffer management constants. There are several of these for
328 * various different purposes:
329 *
330 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
331 * on a local data stream before we throttle the whole SSH
332 * connection (in SSH1 only). Throttling the whole connection is
333 * pretty drastic so we set this high in the hope it won't
334 * happen very often.
335 *
336 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
337 * on the SSH connection itself before we defensively throttle
338 * _all_ local data streams. This is pretty drastic too (though
339 * thankfully unlikely in SSH2 since the window mechanism should
340 * ensure that the server never has any need to throttle its end
341 * of the connection), so we set this high as well.
342 *
343 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
344 * channels.
345 */
346
347 #define SSH1_BUFFER_LIMIT 32768
348 #define SSH_MAX_BACKLOG 32768
349 #define OUR_V2_WINSIZE 16384
350
351 const static struct ssh_kex *kex_algs[] = {
352 &ssh_diffiehellman_gex,
353 &ssh_diffiehellman
354 };
355
356 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
357
358 static void *nullmac_make_context(void)
359 {
360 return NULL;
361 }
362 static void nullmac_free_context(void *handle)
363 {
364 }
365 static void nullmac_key(void *handle, unsigned char *key)
366 {
367 }
368 static void nullmac_generate(void *handle, unsigned char *blk, int len,
369 unsigned long seq)
370 {
371 }
372 static int nullmac_verify(void *handle, unsigned char *blk, int len,
373 unsigned long seq)
374 {
375 return 1;
376 }
377 const static struct ssh_mac ssh_mac_none = {
378 nullmac_make_context, nullmac_free_context, nullmac_key,
379 nullmac_generate, nullmac_verify, "none", 0
380 };
381 const static struct ssh_mac *macs[] = {
382 &ssh_sha1, &ssh_md5, &ssh_mac_none
383 };
384 const static struct ssh_mac *buggymacs[] = {
385 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
386 };
387
388 static void *ssh_comp_none_init(void)
389 {
390 return NULL;
391 }
392 static void ssh_comp_none_cleanup(void *handle)
393 {
394 }
395 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
396 unsigned char **outblock, int *outlen)
397 {
398 return 0;
399 }
400 static int ssh_comp_none_disable(void *handle)
401 {
402 return 0;
403 }
404 const static struct ssh_compress ssh_comp_none = {
405 "none",
406 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
407 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
408 ssh_comp_none_disable, NULL
409 };
410 extern const struct ssh_compress ssh_zlib;
411 const static struct ssh_compress *compressions[] = {
412 &ssh_zlib, &ssh_comp_none
413 };
414
415 enum { /* channel types */
416 CHAN_MAINSESSION,
417 CHAN_X11,
418 CHAN_AGENT,
419 CHAN_SOCKDATA,
420 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
421 };
422
423 /*
424 * 2-3-4 tree storing channels.
425 */
426 struct ssh_channel {
427 Ssh ssh; /* pointer back to main context */
428 unsigned remoteid, localid;
429 int type;
430 /*
431 * In SSH1, this value contains four bits:
432 *
433 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
434 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
435 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
436 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
437 *
438 * A channel is completely finished with when all four bits are set.
439 */
440 int closes;
441 union {
442 struct ssh1_data_channel {
443 int throttling;
444 } v1;
445 struct ssh2_data_channel {
446 bufchain outbuffer;
447 unsigned remwindow, remmaxpkt;
448 unsigned locwindow;
449 } v2;
450 } v;
451 union {
452 struct ssh_agent_channel {
453 unsigned char *message;
454 unsigned char msglen[4];
455 int lensofar, totallen;
456 } a;
457 struct ssh_x11_channel {
458 Socket s;
459 } x11;
460 struct ssh_pfd_channel {
461 Socket s;
462 } pfd;
463 } u;
464 };
465
466 /*
467 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
468 * 2 use this structure in different ways, reflecting SSH 2's
469 * altogether saner approach to port forwarding.
470 *
471 * In SSH 1, you arrange a remote forwarding by sending the server
472 * the remote port number, and the local destination host:port.
473 * When a connection comes in, the server sends you back that
474 * host:port pair, and you connect to it. This is a ready-made
475 * security hole if you're not on the ball: a malicious server
476 * could send you back _any_ host:port pair, so if you trustingly
477 * connect to the address it gives you then you've just opened the
478 * entire inside of your corporate network just by connecting
479 * through it to a dodgy SSH server. Hence, we must store a list of
480 * host:port pairs we _are_ trying to forward to, and reject a
481 * connection request from the server if it's not in the list.
482 *
483 * In SSH 2, each side of the connection minds its own business and
484 * doesn't send unnecessary information to the other. You arrange a
485 * remote forwarding by sending the server just the remote port
486 * number. When a connection comes in, the server tells you which
487 * of its ports was connected to; and _you_ have to remember what
488 * local host:port pair went with that port number.
489 *
490 * Hence: in SSH 1 this structure stores host:port pairs we intend
491 * to allow connections to, and is indexed by those host:port
492 * pairs. In SSH 2 it stores a mapping from source port to
493 * destination host:port pair, and is indexed by source port.
494 */
495 struct ssh_rportfwd {
496 unsigned sport, dport;
497 char dhost[256];
498 };
499
500 struct Packet {
501 long length;
502 int type;
503 unsigned char *data;
504 unsigned char *body;
505 long savedpos;
506 long maxlen;
507 };
508
509 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
510 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
511 static void ssh_size(void *handle, int width, int height);
512 static void ssh_special(void *handle, Telnet_Special);
513 static int ssh2_try_send(struct ssh_channel *c);
514 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
515 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
516 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
517 static int ssh_sendbuffer(void *handle);
518
519 struct rdpkt1_state_tag {
520 long len, pad, biglen, to_read;
521 unsigned long realcrc, gotcrc;
522 unsigned char *p;
523 int i;
524 int chunk;
525 };
526
527 struct rdpkt2_state_tag {
528 long len, pad, payload, packetlen, maclen;
529 int i;
530 int cipherblk;
531 unsigned long incoming_sequence;
532 };
533
534 struct ssh_tag {
535 const struct plug_function_table *fn;
536 /* the above field _must_ be first in the structure */
537
538 SHA_State exhash, exhashbase;
539
540 Socket s;
541
542 void *ldisc;
543 void *logctx;
544
545 unsigned char session_key[32];
546 int v1_compressing;
547 int v1_remote_protoflags;
548 int v1_local_protoflags;
549 int agentfwd_enabled;
550 int X11_fwd_enabled;
551 int remote_bugs;
552 const struct ssh_cipher *cipher;
553 void *v1_cipher_ctx;
554 void *crcda_ctx;
555 const struct ssh2_cipher *cscipher, *sccipher;
556 void *cs_cipher_ctx, *sc_cipher_ctx;
557 const struct ssh_mac *csmac, *scmac;
558 void *cs_mac_ctx, *sc_mac_ctx;
559 const struct ssh_compress *cscomp, *sccomp;
560 void *cs_comp_ctx, *sc_comp_ctx;
561 const struct ssh_kex *kex;
562 const struct ssh_signkey *hostkey;
563 unsigned char v2_session_id[20];
564 void *kex_ctx;
565
566 char *savedhost;
567 int savedport;
568 int send_ok;
569 int echoing, editing;
570
571 void *frontend;
572
573 int term_width, term_height;
574
575 tree234 *channels; /* indexed by local id */
576 struct ssh_channel *mainchan; /* primary session channel */
577 int exitcode;
578
579 tree234 *rportfwds;
580
581 enum {
582 SSH_STATE_PREPACKET,
583 SSH_STATE_BEFORE_SIZE,
584 SSH_STATE_INTERMED,
585 SSH_STATE_SESSION,
586 SSH_STATE_CLOSED
587 } state;
588
589 int size_needed, eof_needed;
590
591 struct Packet pktin;
592 struct Packet pktout;
593 unsigned char *deferred_send_data;
594 int deferred_len, deferred_size;
595
596 /*
597 * Gross hack: pscp will try to start SFTP but fall back to
598 * scp1 if that fails. This variable is the means by which
599 * scp.c can reach into the SSH code and find out which one it
600 * got.
601 */
602 int fallback_cmd;
603
604 /*
605 * Used for username and password input.
606 */
607 char *userpass_input_buffer;
608 int userpass_input_buflen;
609 int userpass_input_bufpos;
610 int userpass_input_echo;
611
612 char *portfwd_strptr;
613 int pkt_ctx;
614
615 void *x11auth;
616
617 int version;
618 int v1_throttle_count;
619 int overall_bufsize;
620 int throttled_all;
621 int v1_stdout_throttling;
622 int v2_outgoing_sequence;
623
624 int ssh1_rdpkt_crstate;
625 int ssh2_rdpkt_crstate;
626 int do_ssh_init_crstate;
627 int ssh_gotdata_crstate;
628 int ssh1_protocol_crstate;
629 int do_ssh1_login_crstate;
630 int do_ssh2_transport_crstate;
631 int do_ssh2_authconn_crstate;
632
633 void *do_ssh_init_state;
634 void *do_ssh1_login_state;
635 void *do_ssh2_transport_state;
636 void *do_ssh2_authconn_state;
637
638 struct rdpkt1_state_tag rdpkt1_state;
639 struct rdpkt2_state_tag rdpkt2_state;
640
641 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
642 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
643
644 /*
645 * We maintain a full _copy_ of a Config structure here, not
646 * merely a pointer to it. That way, when we're passed a new
647 * one for reconfiguration, we can check the differences and
648 * potentially reconfigure port forwardings etc in mid-session.
649 */
650 Config cfg;
651 };
652
653 #define logevent(s) logevent(ssh->frontend, s)
654
655 /* logevent, only printf-formatted. */
656 static void logeventf(Ssh ssh, char *fmt, ...)
657 {
658 va_list ap;
659 char *buf;
660
661 va_start(ap, fmt);
662 buf = dupvprintf(fmt, ap);
663 va_end(ap);
664 logevent(buf);
665 sfree(buf);
666 }
667
668 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
669 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
670 logeventf msg, connection_fatal msg )
671
672 static int ssh_channelcmp(void *av, void *bv)
673 {
674 struct ssh_channel *a = (struct ssh_channel *) av;
675 struct ssh_channel *b = (struct ssh_channel *) bv;
676 if (a->localid < b->localid)
677 return -1;
678 if (a->localid > b->localid)
679 return +1;
680 return 0;
681 }
682 static int ssh_channelfind(void *av, void *bv)
683 {
684 unsigned *a = (unsigned *) av;
685 struct ssh_channel *b = (struct ssh_channel *) bv;
686 if (*a < b->localid)
687 return -1;
688 if (*a > b->localid)
689 return +1;
690 return 0;
691 }
692
693 static int ssh_rportcmp_ssh1(void *av, void *bv)
694 {
695 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
696 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
697 int i;
698 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
699 return i < 0 ? -1 : +1;
700 if (a->dport > b->dport)
701 return +1;
702 if (a->dport < b->dport)
703 return -1;
704 return 0;
705 }
706
707 static int ssh_rportcmp_ssh2(void *av, void *bv)
708 {
709 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
710 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
711
712 if (a->sport > b->sport)
713 return +1;
714 if (a->sport < b->sport)
715 return -1;
716 return 0;
717 }
718
719 static int alloc_channel_id(Ssh ssh)
720 {
721 const unsigned CHANNEL_NUMBER_OFFSET = 256;
722 unsigned low, high, mid;
723 int tsize;
724 struct ssh_channel *c;
725
726 /*
727 * First-fit allocation of channel numbers: always pick the
728 * lowest unused one. To do this, binary-search using the
729 * counted B-tree to find the largest channel ID which is in a
730 * contiguous sequence from the beginning. (Precisely
731 * everything in that sequence must have ID equal to its tree
732 * index plus CHANNEL_NUMBER_OFFSET.)
733 */
734 tsize = count234(ssh->channels);
735
736 low = -1;
737 high = tsize;
738 while (high - low > 1) {
739 mid = (high + low) / 2;
740 c = index234(ssh->channels, mid);
741 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
742 low = mid; /* this one is fine */
743 else
744 high = mid; /* this one is past it */
745 }
746 /*
747 * Now low points to either -1, or the tree index of the
748 * largest ID in the initial sequence.
749 */
750 {
751 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
752 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
753 }
754 return low + 1 + CHANNEL_NUMBER_OFFSET;
755 }
756
757 static void c_write(Ssh ssh, const char *buf, int len)
758 {
759 if ((flags & FLAG_STDERR)) {
760 int i;
761 for (i = 0; i < len; i++)
762 if (buf[i] != '\r')
763 fputc(buf[i], stderr);
764 return;
765 }
766 from_backend(ssh->frontend, 1, buf, len);
767 }
768
769 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
770 {
771 int i;
772 for (i = 0; i < len; i++) {
773 if (buf[i] == '\n')
774 c_write(ssh, "\r\n", 2);
775 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
776 c_write(ssh, buf + i, 1);
777 }
778 }
779
780 static void c_write_str(Ssh ssh, const char *buf)
781 {
782 c_write(ssh, buf, strlen(buf));
783 }
784
785 /*
786 * Collect incoming data in the incoming packet buffer.
787 * Decipher and verify the packet when it is completely read.
788 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
789 * Update the *data and *datalen variables.
790 * Return the additional nr of bytes needed, or 0 when
791 * a complete packet is available.
792 */
793 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
794 {
795 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
796
797 crBegin(ssh->ssh1_rdpkt_crstate);
798
799 next_packet:
800
801 ssh->pktin.type = 0;
802 ssh->pktin.length = 0;
803
804 for (st->i = st->len = 0; st->i < 4; st->i++) {
805 while ((*datalen) == 0)
806 crReturn(4 - st->i);
807 st->len = (st->len << 8) + **data;
808 (*data)++, (*datalen)--;
809 }
810
811 st->pad = 8 - (st->len % 8);
812 st->biglen = st->len + st->pad;
813 ssh->pktin.length = st->len - 5;
814
815 if (ssh->pktin.maxlen < st->biglen) {
816 ssh->pktin.maxlen = st->biglen;
817 ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA,
818 unsigned char);
819 }
820
821 st->to_read = st->biglen;
822 st->p = ssh->pktin.data;
823 while (st->to_read > 0) {
824 st->chunk = st->to_read;
825 while ((*datalen) == 0)
826 crReturn(st->to_read);
827 if (st->chunk > (*datalen))
828 st->chunk = (*datalen);
829 memcpy(st->p, *data, st->chunk);
830 *data += st->chunk;
831 *datalen -= st->chunk;
832 st->p += st->chunk;
833 st->to_read -= st->chunk;
834 }
835
836 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
837 st->biglen, NULL)) {
838 bombout((ssh,"Network attack (CRC compensation) detected!"));
839 crReturn(0);
840 }
841
842 if (ssh->cipher)
843 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
844
845 st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
846 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
847 if (st->gotcrc != st->realcrc) {
848 bombout((ssh,"Incorrect CRC received on packet"));
849 crReturn(0);
850 }
851
852 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
853
854 if (ssh->v1_compressing) {
855 unsigned char *decompblk;
856 int decomplen;
857 zlib_decompress_block(ssh->sc_comp_ctx,
858 ssh->pktin.body - 1, ssh->pktin.length + 1,
859 &decompblk, &decomplen);
860
861 if (ssh->pktin.maxlen < st->pad + decomplen) {
862 ssh->pktin.maxlen = st->pad + decomplen;
863 ssh->pktin.data = sresize(ssh->pktin.data,
864 ssh->pktin.maxlen + APIEXTRA,
865 unsigned char);
866 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
867 }
868
869 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
870 sfree(decompblk);
871 ssh->pktin.length = decomplen - 1;
872 }
873
874 ssh->pktin.type = ssh->pktin.body[-1];
875
876 if (ssh->logctx)
877 log_packet(ssh->logctx,
878 PKT_INCOMING, ssh->pktin.type,
879 ssh1_pkt_type(ssh->pktin.type),
880 ssh->pktin.body, ssh->pktin.length);
881
882 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
883 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
884 ssh->pktin.type == SSH1_MSG_DEBUG ||
885 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
886 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
887 long stringlen = GET_32BIT(ssh->pktin.body);
888 if (stringlen + 4 != ssh->pktin.length) {
889 bombout((ssh,"Received data packet with bogus string length"));
890 crReturn(0);
891 }
892 }
893
894 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
895 /* log debug message */
896 char buf[512];
897 int stringlen = GET_32BIT(ssh->pktin.body);
898 strcpy(buf, "Remote debug message: ");
899 if (stringlen > 480)
900 stringlen = 480;
901 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
902 buf[8 + stringlen] = '\0';
903 logevent(buf);
904 goto next_packet;
905 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
906 /* do nothing */
907 goto next_packet;
908 }
909
910 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
911 /* log reason code in disconnect message */
912 char buf[256];
913 unsigned msglen = GET_32BIT(ssh->pktin.body);
914 unsigned nowlen;
915 strcpy(buf, "Remote sent disconnect: ");
916 nowlen = strlen(buf);
917 if (msglen > sizeof(buf) - nowlen - 1)
918 msglen = sizeof(buf) - nowlen - 1;
919 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
920 buf[nowlen + msglen] = '\0';
921 /* logevent(buf); (this is now done within the bombout macro) */
922 bombout((ssh,"Server sent disconnect message:\n\"%s\"", buf+nowlen));
923 crReturn(0);
924 }
925
926 crFinish(0);
927 }
928
929 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
930 {
931 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
932
933 crBegin(ssh->ssh2_rdpkt_crstate);
934
935 next_packet:
936 ssh->pktin.type = 0;
937 ssh->pktin.length = 0;
938 if (ssh->sccipher)
939 st->cipherblk = ssh->sccipher->blksize;
940 else
941 st->cipherblk = 8;
942 if (st->cipherblk < 8)
943 st->cipherblk = 8;
944
945 if (ssh->pktin.maxlen < st->cipherblk) {
946 ssh->pktin.maxlen = st->cipherblk;
947 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
948 unsigned char);
949 }
950
951 /*
952 * Acquire and decrypt the first block of the packet. This will
953 * contain the length and padding details.
954 */
955 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
956 while ((*datalen) == 0)
957 crReturn(st->cipherblk - st->i);
958 ssh->pktin.data[st->i] = *(*data)++;
959 (*datalen)--;
960 }
961
962 if (ssh->sccipher)
963 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
964 ssh->pktin.data, st->cipherblk);
965
966 /*
967 * Now get the length and padding figures.
968 */
969 st->len = GET_32BIT(ssh->pktin.data);
970 st->pad = ssh->pktin.data[4];
971
972 /*
973 * _Completely_ silly lengths should be stomped on before they
974 * do us any more damage.
975 */
976 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
977 bombout((ssh,"Incoming packet was garbled on decryption"));
978 crReturn(0);
979 }
980
981 /*
982 * This enables us to deduce the payload length.
983 */
984 st->payload = st->len - st->pad - 1;
985
986 ssh->pktin.length = st->payload + 5;
987
988 /*
989 * So now we can work out the total packet length.
990 */
991 st->packetlen = st->len + 4;
992 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
993
994 /*
995 * Adjust memory allocation if packet is too big.
996 */
997 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
998 ssh->pktin.maxlen = st->packetlen + st->maclen;
999 ssh->pktin.data = sresize(ssh->pktin.data,
1000 ssh->pktin.maxlen + APIEXTRA,
1001 unsigned char);
1002 }
1003
1004 /*
1005 * Read and decrypt the remainder of the packet.
1006 */
1007 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1008 st->i++) {
1009 while ((*datalen) == 0)
1010 crReturn(st->packetlen + st->maclen - st->i);
1011 ssh->pktin.data[st->i] = *(*data)++;
1012 (*datalen)--;
1013 }
1014 /* Decrypt everything _except_ the MAC. */
1015 if (ssh->sccipher)
1016 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1017 ssh->pktin.data + st->cipherblk,
1018 st->packetlen - st->cipherblk);
1019
1020 /*
1021 * Check the MAC.
1022 */
1023 if (ssh->scmac
1024 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1025 st->incoming_sequence)) {
1026 bombout((ssh,"Incorrect MAC received on packet"));
1027 crReturn(0);
1028 }
1029 st->incoming_sequence++; /* whether or not we MACed */
1030
1031 /*
1032 * Decompress packet payload.
1033 */
1034 {
1035 unsigned char *newpayload;
1036 int newlen;
1037 if (ssh->sccomp &&
1038 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1039 ssh->pktin.data + 5, ssh->pktin.length - 5,
1040 &newpayload, &newlen)) {
1041 if (ssh->pktin.maxlen < newlen + 5) {
1042 ssh->pktin.maxlen = newlen + 5;
1043 ssh->pktin.data = sresize(ssh->pktin.data,
1044 ssh->pktin.maxlen + APIEXTRA,
1045 unsigned char);
1046 }
1047 ssh->pktin.length = 5 + newlen;
1048 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1049 sfree(newpayload);
1050 }
1051 }
1052
1053 ssh->pktin.savedpos = 6;
1054 ssh->pktin.type = ssh->pktin.data[5];
1055
1056 if (ssh->logctx)
1057 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1058 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1059 ssh->pktin.data+6, ssh->pktin.length-6);
1060
1061 switch (ssh->pktin.type) {
1062 /*
1063 * These packets we must handle instantly.
1064 */
1065 case SSH2_MSG_DISCONNECT:
1066 {
1067 /* log reason code in disconnect message */
1068 char *buf;
1069 int nowlen;
1070 int reason = GET_32BIT(ssh->pktin.data + 6);
1071 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1072
1073 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1074 buf = dupprintf("Received disconnect message (%s)",
1075 ssh2_disconnect_reasons[reason]);
1076 } else {
1077 buf = dupprintf("Received disconnect message (unknown"
1078 " type %d)", reason);
1079 }
1080 logevent(buf);
1081 sfree(buf);
1082 buf = dupprintf("Disconnection message text: %n%.*s",
1083 &nowlen, msglen, ssh->pktin.data + 14);
1084 logevent(buf);
1085 bombout((ssh,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1086 reason,
1087 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1088 ssh2_disconnect_reasons[reason] : "unknown",
1089 buf+nowlen));
1090 sfree(buf);
1091 crReturn(0);
1092 }
1093 break;
1094 case SSH2_MSG_IGNORE:
1095 goto next_packet;
1096 case SSH2_MSG_DEBUG:
1097 {
1098 /* log the debug message */
1099 char buf[512];
1100 /* int display = ssh->pktin.body[6]; */
1101 int stringlen = GET_32BIT(ssh->pktin.data+7);
1102 int prefix;
1103 strcpy(buf, "Remote debug message: ");
1104 prefix = strlen(buf);
1105 if (stringlen > (int)(sizeof(buf)-prefix-1))
1106 stringlen = sizeof(buf)-prefix-1;
1107 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1108 buf[prefix + stringlen] = '\0';
1109 logevent(buf);
1110 }
1111 goto next_packet; /* FIXME: print the debug message */
1112
1113 /*
1114 * These packets we need do nothing about here.
1115 */
1116 case SSH2_MSG_UNIMPLEMENTED:
1117 case SSH2_MSG_SERVICE_REQUEST:
1118 case SSH2_MSG_SERVICE_ACCEPT:
1119 case SSH2_MSG_KEXINIT:
1120 case SSH2_MSG_NEWKEYS:
1121 case SSH2_MSG_KEXDH_INIT:
1122 case SSH2_MSG_KEXDH_REPLY:
1123 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1124 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1125 case SSH2_MSG_KEX_DH_GEX_INIT:
1126 case SSH2_MSG_KEX_DH_GEX_REPLY:
1127 case SSH2_MSG_USERAUTH_REQUEST:
1128 case SSH2_MSG_USERAUTH_FAILURE:
1129 case SSH2_MSG_USERAUTH_SUCCESS:
1130 case SSH2_MSG_USERAUTH_BANNER:
1131 case SSH2_MSG_USERAUTH_PK_OK:
1132 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1133 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1134 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1135 case SSH2_MSG_GLOBAL_REQUEST:
1136 case SSH2_MSG_REQUEST_SUCCESS:
1137 case SSH2_MSG_REQUEST_FAILURE:
1138 case SSH2_MSG_CHANNEL_OPEN:
1139 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1140 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1141 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1142 case SSH2_MSG_CHANNEL_DATA:
1143 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1144 case SSH2_MSG_CHANNEL_EOF:
1145 case SSH2_MSG_CHANNEL_CLOSE:
1146 case SSH2_MSG_CHANNEL_REQUEST:
1147 case SSH2_MSG_CHANNEL_SUCCESS:
1148 case SSH2_MSG_CHANNEL_FAILURE:
1149 break;
1150
1151 /*
1152 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1153 */
1154 default:
1155 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1156 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1157 ssh2_pkt_send(ssh);
1158 break;
1159 }
1160
1161 crFinish(0);
1162 }
1163
1164 static void ssh1_pktout_size(Ssh ssh, int len)
1165 {
1166 int pad, biglen;
1167
1168 len += 5; /* type and CRC */
1169 pad = 8 - (len % 8);
1170 biglen = len + pad;
1171
1172 ssh->pktout.length = len - 5;
1173 if (ssh->pktout.maxlen < biglen) {
1174 ssh->pktout.maxlen = biglen;
1175 #ifdef MSCRYPTOAPI
1176 /* Allocate enough buffer space for extra block
1177 * for MS CryptEncrypt() */
1178 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1179 unsigned char);
1180 #else
1181 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1182 unsigned char);
1183 #endif
1184 }
1185 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1186 }
1187
1188 static void s_wrpkt_start(Ssh ssh, int type, int len)
1189 {
1190 ssh1_pktout_size(ssh, len);
1191 ssh->pktout.type = type;
1192 }
1193
1194 static int s_wrpkt_prepare(Ssh ssh)
1195 {
1196 int pad, biglen, i;
1197 unsigned long crc;
1198 #ifdef __SC__
1199 /*
1200 * XXX various versions of SC (including 8.8.4) screw up the
1201 * register allocation in this function and use the same register
1202 * (D6) for len and as a temporary, with predictable results. The
1203 * following sledgehammer prevents this.
1204 */
1205 volatile
1206 #endif
1207 int len;
1208
1209 ssh->pktout.body[-1] = ssh->pktout.type;
1210
1211 if (ssh->logctx)
1212 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1213 ssh1_pkt_type(ssh->pktout.type),
1214 ssh->pktout.body, ssh->pktout.length);
1215
1216 if (ssh->v1_compressing) {
1217 unsigned char *compblk;
1218 int complen;
1219 zlib_compress_block(ssh->cs_comp_ctx,
1220 ssh->pktout.body - 1, ssh->pktout.length + 1,
1221 &compblk, &complen);
1222 ssh1_pktout_size(ssh, complen - 1);
1223 memcpy(ssh->pktout.body - 1, compblk, complen);
1224 sfree(compblk);
1225 }
1226
1227 len = ssh->pktout.length + 5; /* type and CRC */
1228 pad = 8 - (len % 8);
1229 biglen = len + pad;
1230
1231 for (i = 0; i < pad; i++)
1232 ssh->pktout.data[i + 4] = random_byte();
1233 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1234 PUT_32BIT(ssh->pktout.data + biglen, crc);
1235 PUT_32BIT(ssh->pktout.data, len);
1236
1237 if (ssh->cipher)
1238 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1239
1240 return biglen + 4;
1241 }
1242
1243 static void s_wrpkt(Ssh ssh)
1244 {
1245 int len, backlog;
1246 len = s_wrpkt_prepare(ssh);
1247 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1248 if (backlog > SSH_MAX_BACKLOG)
1249 ssh_throttle_all(ssh, 1, backlog);
1250 }
1251
1252 static void s_wrpkt_defer(Ssh ssh)
1253 {
1254 int len;
1255 len = s_wrpkt_prepare(ssh);
1256 if (ssh->deferred_len + len > ssh->deferred_size) {
1257 ssh->deferred_size = ssh->deferred_len + len + 128;
1258 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1259 ssh->deferred_size,
1260 unsigned char);
1261 }
1262 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1263 ssh->deferred_len += len;
1264 }
1265
1266 /*
1267 * Construct a packet with the specified contents.
1268 */
1269 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1270 {
1271 unsigned char *p, *argp, argchar;
1272 unsigned long argint;
1273 int pktlen, argtype, arglen;
1274 Bignum bn;
1275
1276 pktlen = 0;
1277 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1278 switch (argtype) {
1279 case PKT_INT:
1280 (void) va_arg(ap1, int);
1281 pktlen += 4;
1282 break;
1283 case PKT_CHAR:
1284 (void) va_arg(ap1, int);
1285 pktlen++;
1286 break;
1287 case PKT_DATA:
1288 (void) va_arg(ap1, unsigned char *);
1289 arglen = va_arg(ap1, int);
1290 pktlen += arglen;
1291 break;
1292 case PKT_STR:
1293 argp = va_arg(ap1, unsigned char *);
1294 arglen = strlen((char *)argp);
1295 pktlen += 4 + arglen;
1296 break;
1297 case PKT_BIGNUM:
1298 bn = va_arg(ap1, Bignum);
1299 pktlen += ssh1_bignum_length(bn);
1300 break;
1301 default:
1302 assert(0);
1303 }
1304 }
1305
1306 s_wrpkt_start(ssh, pkttype, pktlen);
1307 p = ssh->pktout.body;
1308
1309 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1310 switch (argtype) {
1311 case PKT_INT:
1312 argint = va_arg(ap2, int);
1313 PUT_32BIT(p, argint);
1314 p += 4;
1315 break;
1316 case PKT_CHAR:
1317 argchar = (unsigned char) va_arg(ap2, int);
1318 *p = argchar;
1319 p++;
1320 break;
1321 case PKT_DATA:
1322 argp = va_arg(ap2, unsigned char *);
1323 arglen = va_arg(ap2, int);
1324 memcpy(p, argp, arglen);
1325 p += arglen;
1326 break;
1327 case PKT_STR:
1328 argp = va_arg(ap2, unsigned char *);
1329 arglen = strlen((char *)argp);
1330 PUT_32BIT(p, arglen);
1331 memcpy(p + 4, argp, arglen);
1332 p += 4 + arglen;
1333 break;
1334 case PKT_BIGNUM:
1335 bn = va_arg(ap2, Bignum);
1336 p += ssh1_write_bignum(p, bn);
1337 break;
1338 }
1339 }
1340 }
1341
1342 static void send_packet(Ssh ssh, int pkttype, ...)
1343 {
1344 va_list ap1, ap2;
1345 va_start(ap1, pkttype);
1346 va_start(ap2, pkttype);
1347 construct_packet(ssh, pkttype, ap1, ap2);
1348 s_wrpkt(ssh);
1349 }
1350
1351 static void defer_packet(Ssh ssh, int pkttype, ...)
1352 {
1353 va_list ap1, ap2;
1354 va_start(ap1, pkttype);
1355 va_start(ap2, pkttype);
1356 construct_packet(ssh, pkttype, ap1, ap2);
1357 s_wrpkt_defer(ssh);
1358 }
1359
1360 static int ssh_versioncmp(char *a, char *b)
1361 {
1362 char *ae, *be;
1363 unsigned long av, bv;
1364
1365 av = strtoul(a, &ae, 10);
1366 bv = strtoul(b, &be, 10);
1367 if (av != bv)
1368 return (av < bv ? -1 : +1);
1369 if (*ae == '.')
1370 ae++;
1371 if (*be == '.')
1372 be++;
1373 av = strtoul(ae, &ae, 10);
1374 bv = strtoul(be, &be, 10);
1375 if (av != bv)
1376 return (av < bv ? -1 : +1);
1377 return 0;
1378 }
1379
1380 /*
1381 * Utility routines for putting an SSH-protocol `string' and
1382 * `uint32' into a SHA state.
1383 */
1384 #include <stdio.h>
1385 static void sha_string(SHA_State * s, void *str, int len)
1386 {
1387 unsigned char lenblk[4];
1388 PUT_32BIT(lenblk, len);
1389 SHA_Bytes(s, lenblk, 4);
1390 SHA_Bytes(s, str, len);
1391 }
1392
1393 static void sha_uint32(SHA_State * s, unsigned i)
1394 {
1395 unsigned char intblk[4];
1396 PUT_32BIT(intblk, i);
1397 SHA_Bytes(s, intblk, 4);
1398 }
1399
1400 /*
1401 * SSH2 packet construction functions.
1402 */
1403 static void ssh2_pkt_ensure(Ssh ssh, int length)
1404 {
1405 if (ssh->pktout.maxlen < length) {
1406 ssh->pktout.maxlen = length + 256;
1407 ssh->pktout.data = sresize(ssh->pktout.data,
1408 ssh->pktout.maxlen + APIEXTRA,
1409 unsigned char);
1410 if (!ssh->pktout.data)
1411 fatalbox("Out of memory");
1412 }
1413 }
1414 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1415 {
1416 ssh->pktout.length += len;
1417 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1418 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1419 }
1420 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1421 {
1422 ssh2_pkt_adddata(ssh, &byte, 1);
1423 }
1424 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1425 {
1426 ssh->pktout.length = 5;
1427 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1428 }
1429 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1430 {
1431 ssh2_pkt_adddata(ssh, &value, 1);
1432 }
1433 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1434 {
1435 unsigned char x[4];
1436 PUT_32BIT(x, value);
1437 ssh2_pkt_adddata(ssh, x, 4);
1438 }
1439 static void ssh2_pkt_addstring_start(Ssh ssh)
1440 {
1441 ssh2_pkt_adduint32(ssh, 0);
1442 ssh->pktout.savedpos = ssh->pktout.length;
1443 }
1444 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1445 {
1446 ssh2_pkt_adddata(ssh, data, strlen(data));
1447 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1448 ssh->pktout.length - ssh->pktout.savedpos);
1449 }
1450 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1451 {
1452 ssh2_pkt_adddata(ssh, data, len);
1453 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1454 ssh->pktout.length - ssh->pktout.savedpos);
1455 }
1456 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1457 {
1458 ssh2_pkt_addstring_start(ssh);
1459 ssh2_pkt_addstring_str(ssh, data);
1460 }
1461 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1462 {
1463 unsigned char *p;
1464 int i, n = (bignum_bitcount(b) + 7) / 8;
1465 p = snewn(n + 1, unsigned char);
1466 if (!p)
1467 fatalbox("out of memory");
1468 p[0] = 0;
1469 for (i = 1; i <= n; i++)
1470 p[i] = bignum_byte(b, n - i);
1471 i = 0;
1472 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1473 i++;
1474 memmove(p, p + i, n + 1 - i);
1475 *len = n + 1 - i;
1476 return p;
1477 }
1478 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1479 {
1480 unsigned char *p;
1481 int len;
1482 p = ssh2_mpint_fmt(b, &len);
1483 ssh2_pkt_addstring_start(ssh);
1484 ssh2_pkt_addstring_data(ssh, (char *)p, len);
1485 sfree(p);
1486 }
1487
1488 /*
1489 * Construct an SSH2 final-form packet: compress it, encrypt it,
1490 * put the MAC on it. Final packet, ready to be sent, is stored in
1491 * ssh->pktout.data. Total length is returned.
1492 */
1493 static int ssh2_pkt_construct(Ssh ssh)
1494 {
1495 int cipherblk, maclen, padding, i;
1496
1497 if (ssh->logctx)
1498 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1499 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1500 ssh->pktout.data + 6, ssh->pktout.length - 6);
1501
1502 /*
1503 * Compress packet payload.
1504 */
1505 {
1506 unsigned char *newpayload;
1507 int newlen;
1508 if (ssh->cscomp &&
1509 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1510 ssh->pktout.length - 5,
1511 &newpayload, &newlen)) {
1512 ssh->pktout.length = 5;
1513 ssh2_pkt_adddata(ssh, newpayload, newlen);
1514 sfree(newpayload);
1515 }
1516 }
1517
1518 /*
1519 * Add padding. At least four bytes, and must also bring total
1520 * length (minus MAC) up to a multiple of the block size.
1521 */
1522 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1523 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1524 padding = 4;
1525 padding +=
1526 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1527 maclen = ssh->csmac ? ssh->csmac->len : 0;
1528 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1529 ssh->pktout.data[4] = padding;
1530 for (i = 0; i < padding; i++)
1531 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1532 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1533 if (ssh->csmac)
1534 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1535 ssh->pktout.length + padding,
1536 ssh->v2_outgoing_sequence);
1537 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1538
1539 if (ssh->cscipher)
1540 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1541 ssh->pktout.data, ssh->pktout.length + padding);
1542
1543 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1544 return ssh->pktout.length + padding + maclen;
1545 }
1546
1547 /*
1548 * Construct and send an SSH2 packet immediately.
1549 */
1550 static void ssh2_pkt_send(Ssh ssh)
1551 {
1552 int len;
1553 int backlog;
1554 len = ssh2_pkt_construct(ssh);
1555 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1556 if (backlog > SSH_MAX_BACKLOG)
1557 ssh_throttle_all(ssh, 1, backlog);
1558 }
1559
1560 /*
1561 * Construct an SSH2 packet and add it to a deferred data block.
1562 * Useful for sending multiple packets in a single sk_write() call,
1563 * to prevent a traffic-analysing listener from being able to work
1564 * out the length of any particular packet (such as the password
1565 * packet).
1566 *
1567 * Note that because SSH2 sequence-numbers its packets, this can
1568 * NOT be used as an m4-style `defer' allowing packets to be
1569 * constructed in one order and sent in another.
1570 */
1571 static void ssh2_pkt_defer(Ssh ssh)
1572 {
1573 int len = ssh2_pkt_construct(ssh);
1574 if (ssh->deferred_len + len > ssh->deferred_size) {
1575 ssh->deferred_size = ssh->deferred_len + len + 128;
1576 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1577 ssh->deferred_size,
1578 unsigned char);
1579 }
1580 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1581 ssh->deferred_len += len;
1582 }
1583
1584 /*
1585 * Send the whole deferred data block constructed by
1586 * ssh2_pkt_defer() or SSH1's defer_packet().
1587 */
1588 static void ssh_pkt_defersend(Ssh ssh)
1589 {
1590 int backlog;
1591 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1592 ssh->deferred_len);
1593 ssh->deferred_len = ssh->deferred_size = 0;
1594 sfree(ssh->deferred_send_data);
1595 ssh->deferred_send_data = NULL;
1596 if (backlog > SSH_MAX_BACKLOG)
1597 ssh_throttle_all(ssh, 1, backlog);
1598 }
1599
1600 #if 0
1601 void bndebug(char *string, Bignum b)
1602 {
1603 unsigned char *p;
1604 int i, len;
1605 p = ssh2_mpint_fmt(b, &len);
1606 debug(("%s", string));
1607 for (i = 0; i < len; i++)
1608 debug((" %02x", p[i]));
1609 debug(("\n"));
1610 sfree(p);
1611 }
1612 #endif
1613
1614 static void sha_mpint(SHA_State * s, Bignum b)
1615 {
1616 unsigned char *p;
1617 int len;
1618 p = ssh2_mpint_fmt(b, &len);
1619 sha_string(s, p, len);
1620 sfree(p);
1621 }
1622
1623 /*
1624 * SSH2 packet decode functions.
1625 */
1626 static unsigned long ssh2_pkt_getuint32(Ssh ssh)
1627 {
1628 unsigned long value;
1629 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1630 return 0; /* arrgh, no way to decline (FIXME?) */
1631 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1632 ssh->pktin.savedpos += 4;
1633 return value;
1634 }
1635 static int ssh2_pkt_getbool(Ssh ssh)
1636 {
1637 unsigned long value;
1638 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1639 return 0; /* arrgh, no way to decline (FIXME?) */
1640 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1641 ssh->pktin.savedpos++;
1642 return value;
1643 }
1644 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
1645 {
1646 int len;
1647 *p = NULL;
1648 *length = 0;
1649 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1650 return;
1651 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1652 if (len < 0)
1653 return;
1654 *length = len;
1655 ssh->pktin.savedpos += 4;
1656 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1657 return;
1658 *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos);
1659 ssh->pktin.savedpos += *length;
1660 }
1661 static Bignum ssh2_pkt_getmp(Ssh ssh)
1662 {
1663 char *p;
1664 int length;
1665 Bignum b;
1666
1667 ssh2_pkt_getstring(ssh, &p, &length);
1668 if (!p)
1669 return NULL;
1670 if (p[0] & 0x80) {
1671 bombout((ssh,"internal error: Can't handle negative mpints"));
1672 return NULL;
1673 }
1674 b = bignum_from_bytes((unsigned char *)p, length);
1675 return b;
1676 }
1677
1678 /*
1679 * Helper function to add an SSH2 signature blob to a packet.
1680 * Expects to be shown the public key blob as well as the signature
1681 * blob. Normally works just like ssh2_pkt_addstring, but will
1682 * fiddle with the signature packet if necessary for
1683 * BUG_SSH2_RSA_PADDING.
1684 */
1685 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1686 void *sigblob_v, int sigblob_len)
1687 {
1688 unsigned char *pkblob = (unsigned char *)pkblob_v;
1689 unsigned char *sigblob = (unsigned char *)sigblob_v;
1690
1691 /* dmemdump(pkblob, pkblob_len); */
1692 /* dmemdump(sigblob, sigblob_len); */
1693
1694 /*
1695 * See if this is in fact an ssh-rsa signature and a buggy
1696 * server; otherwise we can just do this the easy way.
1697 */
1698 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1699 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1700 int pos, len, siglen;
1701
1702 /*
1703 * Find the byte length of the modulus.
1704 */
1705
1706 pos = 4+7; /* skip over "ssh-rsa" */
1707 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1708 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1709 pos += 4; /* find modulus itself */
1710 while (len > 0 && pkblob[pos] == 0)
1711 len--, pos++;
1712 /* debug(("modulus length is %d\n", len)); */
1713
1714 /*
1715 * Now find the signature integer.
1716 */
1717 pos = 4+7; /* skip over "ssh-rsa" */
1718 siglen = GET_32BIT(sigblob+pos);
1719 /* debug(("signature length is %d\n", siglen)); */
1720
1721 if (len != siglen) {
1722 unsigned char newlen[4];
1723 ssh2_pkt_addstring_start(ssh);
1724 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1725 /* dmemdump(sigblob, pos); */
1726 pos += 4; /* point to start of actual sig */
1727 PUT_32BIT(newlen, len);
1728 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1729 /* dmemdump(newlen, 4); */
1730 newlen[0] = 0;
1731 while (len-- > siglen) {
1732 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1733 /* dmemdump(newlen, 1); */
1734 }
1735 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1736 /* dmemdump(sigblob+pos, siglen); */
1737 return;
1738 }
1739
1740 /* Otherwise fall through and do it the easy way. */
1741 }
1742
1743 ssh2_pkt_addstring_start(ssh);
1744 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1745 }
1746
1747 /*
1748 * Examine the remote side's version string and compare it against
1749 * a list of known buggy implementations.
1750 */
1751 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1752 {
1753 char *imp; /* pointer to implementation part */
1754 imp = vstring;
1755 imp += strcspn(imp, "-");
1756 if (*imp) imp++;
1757 imp += strcspn(imp, "-");
1758 if (*imp) imp++;
1759
1760 ssh->remote_bugs = 0;
1761
1762 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1763 (ssh->cfg.sshbug_ignore1 == AUTO &&
1764 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1765 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1766 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
1767 /*
1768 * These versions don't support SSH1_MSG_IGNORE, so we have
1769 * to use a different defence against password length
1770 * sniffing.
1771 */
1772 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1773 logevent("We believe remote version has SSH1 ignore bug");
1774 }
1775
1776 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1777 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1778 (!strcmp(imp, "Cisco-1.25")))) {
1779 /*
1780 * These versions need a plain password sent; they can't
1781 * handle having a null and a random length of data after
1782 * the password.
1783 */
1784 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1785 logevent("We believe remote version needs a plain SSH1 password");
1786 }
1787
1788 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1789 (ssh->cfg.sshbug_rsa1 == AUTO &&
1790 (!strcmp(imp, "Cisco-1.25")))) {
1791 /*
1792 * These versions apparently have no clue whatever about
1793 * RSA authentication and will panic and die if they see
1794 * an AUTH_RSA message.
1795 */
1796 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1797 logevent("We believe remote version can't handle RSA authentication");
1798 }
1799
1800 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1801 (ssh->cfg.sshbug_hmac2 == AUTO &&
1802 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1803 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1804 wc_match("2.1 *", imp)))) {
1805 /*
1806 * These versions have the HMAC bug.
1807 */
1808 ssh->remote_bugs |= BUG_SSH2_HMAC;
1809 logevent("We believe remote version has SSH2 HMAC bug");
1810 }
1811
1812 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
1813 (ssh->cfg.sshbug_derivekey2 == AUTO &&
1814 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
1815 /*
1816 * These versions have the key-derivation bug (failing to
1817 * include the literal shared secret in the hashes that
1818 * generate the keys).
1819 */
1820 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1821 logevent("We believe remote version has SSH2 key-derivation bug");
1822 }
1823
1824 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
1825 (ssh->cfg.sshbug_rsapad2 == AUTO &&
1826 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1827 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1828 /*
1829 * These versions have the SSH2 RSA padding bug.
1830 */
1831 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1832 logevent("We believe remote version has SSH2 RSA padding bug");
1833 }
1834
1835 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
1836 (ssh->cfg.sshbug_pksessid2 == AUTO &&
1837 wc_match("OpenSSH_2.[0-2]*", imp))) {
1838 /*
1839 * These versions have the SSH2 session-ID bug in
1840 * public-key authentication.
1841 */
1842 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
1843 logevent("We believe remote version has SSH2 public-key-session-ID bug");
1844 }
1845
1846 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
1847 /*
1848 * User specified the SSH2 DH GEX bug.
1849 */
1850 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1851 logevent("We believe remote version has SSH2 DH group exchange bug");
1852 }
1853 }
1854
1855 static int do_ssh_init(Ssh ssh, unsigned char c)
1856 {
1857 struct do_ssh_init_state {
1858 int vslen;
1859 char version[10];
1860 char *vstring;
1861 int vstrsize;
1862 int i;
1863 int proto1, proto2;
1864 };
1865 crState(do_ssh_init_state);
1866
1867 crBegin(ssh->do_ssh_init_crstate);
1868
1869 /* Search for the string "SSH-" in the input. */
1870 s->i = 0;
1871 while (1) {
1872 static const int transS[] = { 1, 2, 2, 1 };
1873 static const int transH[] = { 0, 0, 3, 0 };
1874 static const int transminus[] = { 0, 0, 0, -1 };
1875 if (c == 'S')
1876 s->i = transS[s->i];
1877 else if (c == 'H')
1878 s->i = transH[s->i];
1879 else if (c == '-')
1880 s->i = transminus[s->i];
1881 else
1882 s->i = 0;
1883 if (s->i < 0)
1884 break;
1885 crReturn(1); /* get another character */
1886 }
1887
1888 s->vstrsize = 16;
1889 s->vstring = snewn(s->vstrsize, char);
1890 strcpy(s->vstring, "SSH-");
1891 s->vslen = 4;
1892 s->i = 0;
1893 while (1) {
1894 crReturn(1); /* get another char */
1895 if (s->vslen >= s->vstrsize - 1) {
1896 s->vstrsize += 16;
1897 s->vstring = sresize(s->vstring, s->vstrsize, char);
1898 }
1899 s->vstring[s->vslen++] = c;
1900 if (s->i >= 0) {
1901 if (c == '-') {
1902 s->version[s->i] = '\0';
1903 s->i = -1;
1904 } else if (s->i < sizeof(s->version) - 1)
1905 s->version[s->i++] = c;
1906 } else if (c == '\012')
1907 break;
1908 }
1909
1910 ssh->agentfwd_enabled = FALSE;
1911 ssh->rdpkt2_state.incoming_sequence = 0;
1912
1913 s->vstring[s->vslen] = 0;
1914 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1915 {
1916 char *vlog;
1917 vlog = snewn(20 + s->vslen, char);
1918 sprintf(vlog, "Server version: %s", s->vstring);
1919 logevent(vlog);
1920 sfree(vlog);
1921 }
1922 ssh_detect_bugs(ssh, s->vstring);
1923
1924 /*
1925 * Decide which SSH protocol version to support.
1926 */
1927
1928 /* Anything strictly below "2.0" means protocol 1 is supported. */
1929 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1930 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1931 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1932
1933 if (ssh->cfg.sshprot == 0 && !s->proto1) {
1934 bombout((ssh,"SSH protocol version 1 required by user but not provided by server"));
1935 crReturn(0);
1936 }
1937 if (ssh->cfg.sshprot == 3 && !s->proto2) {
1938 bombout((ssh,"SSH protocol version 2 required by user but not provided by server"));
1939 crReturn(0);
1940 }
1941
1942 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
1943 /*
1944 * Use v2 protocol.
1945 */
1946 char verstring[80], vlog[100];
1947 sprintf(verstring, "SSH-2.0-%s", sshver);
1948 SHA_Init(&ssh->exhashbase);
1949 /*
1950 * Hash our version string and their version string.
1951 */
1952 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1953 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
1954 sprintf(vlog, "We claim version: %s", verstring);
1955 logevent(vlog);
1956 strcat(verstring, "\012");
1957 logevent("Using SSH protocol version 2");
1958 sk_write(ssh->s, verstring, strlen(verstring));
1959 ssh->protocol = ssh2_protocol;
1960 ssh->version = 2;
1961 ssh->s_rdpkt = ssh2_rdpkt;
1962 } else {
1963 /*
1964 * Use v1 protocol.
1965 */
1966 char verstring[80], vlog[100];
1967 sprintf(verstring, "SSH-%s-%s",
1968 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
1969 sshver);
1970 sprintf(vlog, "We claim version: %s", verstring);
1971 logevent(vlog);
1972 strcat(verstring, "\012");
1973
1974 logevent("Using SSH protocol version 1");
1975 sk_write(ssh->s, verstring, strlen(verstring));
1976 ssh->protocol = ssh1_protocol;
1977 ssh->version = 1;
1978 ssh->s_rdpkt = ssh1_rdpkt;
1979 }
1980 ssh->state = SSH_STATE_BEFORE_SIZE;
1981
1982 sfree(s->vstring);
1983
1984 crFinish(0);
1985 }
1986
1987 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
1988 {
1989 crBegin(ssh->ssh_gotdata_crstate);
1990
1991 /*
1992 * To begin with, feed the characters one by one to the
1993 * protocol initialisation / selection function do_ssh_init().
1994 * When that returns 0, we're done with the initial greeting
1995 * exchange and can move on to packet discipline.
1996 */
1997 while (1) {
1998 int ret; /* need not be kept across crReturn */
1999 if (datalen == 0)
2000 crReturnV; /* more data please */
2001 ret = do_ssh_init(ssh, *data);
2002 data++;
2003 datalen--;
2004 if (ret == 0)
2005 break;
2006 }
2007
2008 /*
2009 * We emerge from that loop when the initial negotiation is
2010 * over and we have selected an s_rdpkt function. Now pass
2011 * everything to s_rdpkt, and then pass the resulting packets
2012 * to the proper protocol handler.
2013 */
2014 if (datalen == 0)
2015 crReturnV;
2016 while (1) {
2017 while (datalen > 0) {
2018 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2019 if (ssh->state == SSH_STATE_CLOSED) {
2020 return;
2021 }
2022 ssh->protocol(ssh, NULL, 0, 1);
2023 if (ssh->state == SSH_STATE_CLOSED) {
2024 return;
2025 }
2026 }
2027 }
2028 crReturnV;
2029 }
2030 crFinishV;
2031 }
2032
2033 static int ssh_closing(Plug plug, char *error_msg, int error_code,
2034 int calling_back)
2035 {
2036 Ssh ssh = (Ssh) plug;
2037 ssh->state = SSH_STATE_CLOSED;
2038 if (ssh->s) {
2039 sk_close(ssh->s);
2040 ssh->s = NULL;
2041 }
2042 if (error_msg) {
2043 /* A socket error has occurred. */
2044 logevent(error_msg);
2045 connection_fatal(ssh->frontend, error_msg);
2046 } else {
2047 /* Otherwise, the remote side closed the connection normally. */
2048 }
2049 return 0;
2050 }
2051
2052 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2053 {
2054 Ssh ssh = (Ssh) plug;
2055 ssh_gotdata(ssh, (unsigned char *)data, len);
2056 if (ssh->state == SSH_STATE_CLOSED) {
2057 if (ssh->s) {
2058 sk_close(ssh->s);
2059 ssh->s = NULL;
2060 }
2061 return 0;
2062 }
2063 return 1;
2064 }
2065
2066 static void ssh_sent(Plug plug, int bufsize)
2067 {
2068 Ssh ssh = (Ssh) plug;
2069 /*
2070 * If the send backlog on the SSH socket itself clears, we
2071 * should unthrottle the whole world if it was throttled.
2072 */
2073 if (bufsize < SSH_MAX_BACKLOG)
2074 ssh_throttle_all(ssh, 0, bufsize);
2075 }
2076
2077 /*
2078 * Connect to specified host and port.
2079 * Returns an error message, or NULL on success.
2080 * Also places the canonical host name into `realhost'. It must be
2081 * freed by the caller.
2082 */
2083 static char *connect_to_host(Ssh ssh, char *host, int port,
2084 char **realhost, int nodelay)
2085 {
2086 static const struct plug_function_table fn_table = {
2087 ssh_closing,
2088 ssh_receive,
2089 ssh_sent,
2090 NULL
2091 };
2092
2093 SockAddr addr;
2094 char *err;
2095
2096 ssh->savedhost = snewn(1 + strlen(host), char);
2097 if (!ssh->savedhost)
2098 fatalbox("Out of memory");
2099 strcpy(ssh->savedhost, host);
2100
2101 if (port < 0)
2102 port = 22; /* default ssh port */
2103 ssh->savedport = port;
2104
2105 /*
2106 * Try to find host.
2107 */
2108 logeventf(ssh, "Looking up host \"%s\"", host);
2109 addr = name_lookup(host, port, realhost, &ssh->cfg);
2110 if ((err = sk_addr_error(addr)) != NULL)
2111 return err;
2112
2113 /*
2114 * Open socket.
2115 */
2116 {
2117 char addrbuf[100];
2118 sk_getaddr(addr, addrbuf, 100);
2119 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2120 }
2121 ssh->fn = &fn_table;
2122 ssh->s = new_connection(addr, *realhost, port,
2123 0, 1, nodelay, (Plug) ssh, &ssh->cfg);
2124 if ((err = sk_socket_error(ssh->s)) != NULL) {
2125 ssh->s = NULL;
2126 return err;
2127 }
2128
2129 return NULL;
2130 }
2131
2132 /*
2133 * Throttle or unthrottle the SSH connection.
2134 */
2135 static void ssh1_throttle(Ssh ssh, int adjust)
2136 {
2137 int old_count = ssh->v1_throttle_count;
2138 ssh->v1_throttle_count += adjust;
2139 assert(ssh->v1_throttle_count >= 0);
2140 if (ssh->v1_throttle_count && !old_count) {
2141 sk_set_frozen(ssh->s, 1);
2142 } else if (!ssh->v1_throttle_count && old_count) {
2143 sk_set_frozen(ssh->s, 0);
2144 }
2145 }
2146
2147 /*
2148 * Throttle or unthrottle _all_ local data streams (for when sends
2149 * on the SSH connection itself back up).
2150 */
2151 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2152 {
2153 int i;
2154 struct ssh_channel *c;
2155
2156 if (enable == ssh->throttled_all)
2157 return;
2158 ssh->throttled_all = enable;
2159 ssh->overall_bufsize = bufsize;
2160 if (!ssh->channels)
2161 return;
2162 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2163 switch (c->type) {
2164 case CHAN_MAINSESSION:
2165 /*
2166 * This is treated separately, outside the switch.
2167 */
2168 break;
2169 case CHAN_X11:
2170 x11_override_throttle(c->u.x11.s, enable);
2171 break;
2172 case CHAN_AGENT:
2173 /* Agent channels require no buffer management. */
2174 break;
2175 case CHAN_SOCKDATA:
2176 pfd_override_throttle(c->u.x11.s, enable);
2177 break;
2178 }
2179 }
2180 }
2181
2182 /*
2183 * Username and password input, abstracted off into routines
2184 * reusable in several places - even between SSH1 and SSH2.
2185 */
2186
2187 /* Set up a username or password input loop on a given buffer. */
2188 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2189 {
2190 ssh->userpass_input_buffer = buffer;
2191 ssh->userpass_input_buflen = buflen;
2192 ssh->userpass_input_bufpos = 0;
2193 ssh->userpass_input_echo = echo;
2194 }
2195
2196 /*
2197 * Process some terminal data in the course of username/password
2198 * input. Returns >0 for success (line of input returned in
2199 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2200 * for inconclusive (keep waiting for more input please).
2201 */
2202 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2203 {
2204 char c;
2205
2206 while (inlen--) {
2207 switch (c = *in++) {
2208 case 10:
2209 case 13:
2210 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2211 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2212 return +1;
2213 break;
2214 case 8:
2215 case 127:
2216 if (ssh->userpass_input_bufpos > 0) {
2217 if (ssh->userpass_input_echo)
2218 c_write_str(ssh, "\b \b");
2219 ssh->userpass_input_bufpos--;
2220 }
2221 break;
2222 case 21:
2223 case 27:
2224 while (ssh->userpass_input_bufpos > 0) {
2225 if (ssh->userpass_input_echo)
2226 c_write_str(ssh, "\b \b");
2227 ssh->userpass_input_bufpos--;
2228 }
2229 break;
2230 case 3:
2231 case 4:
2232 return -1;
2233 break;
2234 default:
2235 /*
2236 * This simplistic check for printability is disabled
2237 * when we're doing password input, because some people
2238 * have control characters in their passwords.o
2239 */
2240 if ((!ssh->userpass_input_echo ||
2241 (c >= ' ' && c <= '~') ||
2242 ((unsigned char) c >= 160))
2243 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2244 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2245 if (ssh->userpass_input_echo)
2246 c_write(ssh, &c, 1);
2247 }
2248 break;
2249 }
2250 }
2251 return 0;
2252 }
2253
2254 /*
2255 * Handle the key exchange and user authentication phases.
2256 */
2257 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2258 {
2259 int i, j;
2260 unsigned char cookie[8];
2261 struct RSAKey servkey, hostkey;
2262 struct MD5Context md5c;
2263 struct do_ssh1_login_state {
2264 int len;
2265 unsigned char *rsabuf, *keystr1, *keystr2;
2266 unsigned long supported_ciphers_mask, supported_auths_mask;
2267 int tried_publickey, tried_agent;
2268 int tis_auth_refused, ccard_auth_refused;
2269 unsigned char session_id[16];
2270 int cipher_type;
2271 char username[100];
2272 void *publickey_blob;
2273 int publickey_bloblen;
2274 char password[100];
2275 char prompt[200];
2276 int pos;
2277 char c;
2278 int pwpkt_type;
2279 unsigned char request[5], *response, *p;
2280 int responselen;
2281 int keyi, nkeys;
2282 int authed;
2283 struct RSAKey key;
2284 Bignum challenge;
2285 char *commentp;
2286 int commentlen;
2287 };
2288 crState(do_ssh1_login_state);
2289
2290 crBegin(ssh->do_ssh1_login_crstate);
2291
2292 if (!ispkt)
2293 crWaitUntil(ispkt);
2294
2295 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2296 bombout((ssh,"Public key packet not received"));
2297 crReturn(0);
2298 }
2299
2300 logevent("Received public keys");
2301
2302 memcpy(cookie, ssh->pktin.body, 8);
2303
2304 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2305 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2306
2307 /*
2308 * Log the host key fingerprint.
2309 */
2310 {
2311 char logmsg[80];
2312 logevent("Host key fingerprint is:");
2313 strcpy(logmsg, " ");
2314 hostkey.comment = NULL;
2315 rsa_fingerprint(logmsg + strlen(logmsg),
2316 sizeof(logmsg) - strlen(logmsg), &hostkey);
2317 logevent(logmsg);
2318 }
2319
2320 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2321 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2322 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2323
2324 ssh->v1_local_protoflags =
2325 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2326 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2327
2328 MD5Init(&md5c);
2329 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2330 MD5Update(&md5c, s->keystr1, servkey.bytes);
2331 MD5Update(&md5c, ssh->pktin.body, 8);
2332 MD5Final(s->session_id, &md5c);
2333
2334 for (i = 0; i < 32; i++)
2335 ssh->session_key[i] = random_byte();
2336
2337 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2338
2339 s->rsabuf = snewn(s->len, unsigned char);
2340 if (!s->rsabuf)
2341 fatalbox("Out of memory");
2342
2343 /*
2344 * Verify the host key.
2345 */
2346 {
2347 /*
2348 * First format the key into a string.
2349 */
2350 int len = rsastr_len(&hostkey);
2351 char fingerprint[100];
2352 char *keystr = snewn(len, char);
2353 if (!keystr)
2354 fatalbox("Out of memory");
2355 rsastr_fmt(keystr, &hostkey);
2356 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2357 verify_ssh_host_key(ssh->frontend,
2358 ssh->savedhost, ssh->savedport, "rsa", keystr,
2359 fingerprint);
2360 sfree(keystr);
2361 }
2362
2363 for (i = 0; i < 32; i++) {
2364 s->rsabuf[i] = ssh->session_key[i];
2365 if (i < 16)
2366 s->rsabuf[i] ^= s->session_id[i];
2367 }
2368
2369 if (hostkey.bytes > servkey.bytes) {
2370 rsaencrypt(s->rsabuf, 32, &servkey);
2371 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2372 } else {
2373 rsaencrypt(s->rsabuf, 32, &hostkey);
2374 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2375 }
2376
2377 logevent("Encrypted session key");
2378
2379 {
2380 int cipher_chosen = 0, warn = 0;
2381 char *cipher_string = NULL;
2382 int i;
2383 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2384 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2385 if (next_cipher == CIPHER_WARN) {
2386 /* If/when we choose a cipher, warn about it */
2387 warn = 1;
2388 } else if (next_cipher == CIPHER_AES) {
2389 /* XXX Probably don't need to mention this. */
2390 logevent("AES not supported in SSH1, skipping");
2391 } else {
2392 switch (next_cipher) {
2393 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2394 cipher_string = "3DES"; break;
2395 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2396 cipher_string = "Blowfish"; break;
2397 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2398 cipher_string = "single-DES"; break;
2399 }
2400 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2401 cipher_chosen = 1;
2402 }
2403 }
2404 if (!cipher_chosen) {
2405 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2406 bombout((ssh,"Server violates SSH 1 protocol by not "
2407 "supporting 3DES encryption"));
2408 else
2409 /* shouldn't happen */
2410 bombout((ssh,"No supported ciphers found"));
2411 crReturn(0);
2412 }
2413
2414 /* Warn about chosen cipher if necessary. */
2415 if (warn)
2416 askcipher(ssh->frontend, cipher_string, 0);
2417 }
2418
2419 switch (s->cipher_type) {
2420 case SSH_CIPHER_3DES:
2421 logevent("Using 3DES encryption");
2422 break;
2423 case SSH_CIPHER_DES:
2424 logevent("Using single-DES encryption");
2425 break;
2426 case SSH_CIPHER_BLOWFISH:
2427 logevent("Using Blowfish encryption");
2428 break;
2429 }
2430
2431 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2432 PKT_CHAR, s->cipher_type,
2433 PKT_DATA, cookie, 8,
2434 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2435 PKT_DATA, s->rsabuf, s->len,
2436 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2437
2438 logevent("Trying to enable encryption...");
2439
2440 sfree(s->rsabuf);
2441
2442 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2443 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2444 &ssh_3des);
2445 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2446 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2447 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2448
2449 ssh->crcda_ctx = crcda_make_context();
2450 logevent("Installing CRC compensation attack detector");
2451
2452 crWaitUntil(ispkt);
2453
2454 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2455 bombout((ssh,"Encryption not successfully enabled"));
2456 crReturn(0);
2457 }
2458
2459 logevent("Successfully started encryption");
2460
2461 fflush(stdout);
2462 {
2463 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
2464 if (ssh_get_line && !ssh_getline_pw_only) {
2465 if (!ssh_get_line("login as: ",
2466 s->username, sizeof(s->username), FALSE)) {
2467 /*
2468 * get_line failed to get a username.
2469 * Terminate.
2470 */
2471 logevent("No username provided. Abandoning session.");
2472 ssh->state = SSH_STATE_CLOSED;
2473 crReturn(1);
2474 }
2475 } else {
2476 int ret; /* need not be kept over crReturn */
2477 c_write_str(ssh, "login as: ");
2478 ssh->send_ok = 1;
2479
2480 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2481 do {
2482 crWaitUntil(!ispkt);
2483 ret = process_userpass_input(ssh, in, inlen);
2484 } while (ret == 0);
2485 if (ret < 0)
2486 cleanup_exit(0);
2487 c_write_str(ssh, "\r\n");
2488 }
2489 } else {
2490 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2491 s->username[sizeof(s->username)-1] = '\0';
2492 }
2493
2494 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2495 {
2496 char userlog[22 + sizeof(s->username)];
2497 sprintf(userlog, "Sent username \"%s\"", s->username);
2498 logevent(userlog);
2499 if (flags & FLAG_INTERACTIVE &&
2500 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2501 strcat(userlog, "\r\n");
2502 c_write_str(ssh, userlog);
2503 }
2504 }
2505 }
2506
2507 crWaitUntil(ispkt);
2508
2509 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2510 /* We must not attempt PK auth. Pretend we've already tried it. */
2511 s->tried_publickey = s->tried_agent = 1;
2512 } else {
2513 s->tried_publickey = s->tried_agent = 0;
2514 }
2515 s->tis_auth_refused = s->ccard_auth_refused = 0;
2516 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2517 if (!filename_is_null(ssh->cfg.keyfile)) {
2518 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2519 &s->publickey_blob, &s->publickey_bloblen))
2520 s->publickey_blob = NULL;
2521 } else
2522 s->publickey_blob = NULL;
2523
2524 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2525 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2526
2527 if (agent_exists() && !s->tried_agent) {
2528 /*
2529 * Attempt RSA authentication using Pageant.
2530 */
2531 void *r;
2532
2533 s->authed = FALSE;
2534 s->tried_agent = 1;
2535 logevent("Pageant is running. Requesting keys.");
2536
2537 /* Request the keys held by the agent. */
2538 PUT_32BIT(s->request, 1);
2539 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2540 agent_query(s->request, 5, &r, &s->responselen);
2541 s->response = (unsigned char *) r;
2542 if (s->response && s->responselen >= 5 &&
2543 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2544 s->p = s->response + 5;
2545 s->nkeys = GET_32BIT(s->p);
2546 s->p += 4;
2547 {
2548 char buf[64];
2549 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2550 logevent(buf);
2551 }
2552 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2553 {
2554 char buf[64];
2555 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2556 logevent(buf);
2557 }
2558 if (s->publickey_blob &&
2559 !memcmp(s->p, s->publickey_blob,
2560 s->publickey_bloblen)) {
2561 logevent("This key matches configured key file");
2562 s->tried_publickey = 1;
2563 }
2564 s->p += 4;
2565 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2566 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2567 s->commentlen = GET_32BIT(s->p);
2568 s->p += 4;
2569 s->commentp = (char *)s->p;
2570 s->p += s->commentlen;
2571 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2572 PKT_BIGNUM, s->key.modulus, PKT_END);
2573 crWaitUntil(ispkt);
2574 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2575 logevent("Key refused");
2576 continue;
2577 }
2578 logevent("Received RSA challenge");
2579 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2580 {
2581 char *agentreq, *q, *ret;
2582 void *vret;
2583 int len, retlen;
2584 len = 1 + 4; /* message type, bit count */
2585 len += ssh1_bignum_length(s->key.exponent);
2586 len += ssh1_bignum_length(s->key.modulus);
2587 len += ssh1_bignum_length(s->challenge);
2588 len += 16; /* session id */
2589 len += 4; /* response format */
2590 agentreq = snewn(4 + len, char);
2591 PUT_32BIT(agentreq, len);
2592 q = agentreq + 4;
2593 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2594 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2595 q += 4;
2596 q += ssh1_write_bignum(q, s->key.exponent);
2597 q += ssh1_write_bignum(q, s->key.modulus);
2598 q += ssh1_write_bignum(q, s->challenge);
2599 memcpy(q, s->session_id, 16);
2600 q += 16;
2601 PUT_32BIT(q, 1); /* response format */
2602 agent_query(agentreq, len + 4, &vret, &retlen);
2603 ret = vret;
2604 sfree(agentreq);
2605 if (ret) {
2606 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2607 logevent("Sending Pageant's response");
2608 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2609 PKT_DATA, ret + 5, 16,
2610 PKT_END);
2611 sfree(ret);
2612 crWaitUntil(ispkt);
2613 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2614 logevent
2615 ("Pageant's response accepted");
2616 if (flags & FLAG_VERBOSE) {
2617 c_write_str(ssh, "Authenticated using"
2618 " RSA key \"");
2619 c_write(ssh, s->commentp,
2620 s->commentlen);
2621 c_write_str(ssh, "\" from agent\r\n");
2622 }
2623 s->authed = TRUE;
2624 } else
2625 logevent
2626 ("Pageant's response not accepted");
2627 } else {
2628 logevent
2629 ("Pageant failed to answer challenge");
2630 sfree(ret);
2631 }
2632 } else {
2633 logevent("No reply received from Pageant");
2634 }
2635 }
2636 freebn(s->key.exponent);
2637 freebn(s->key.modulus);
2638 freebn(s->challenge);
2639 if (s->authed)
2640 break;
2641 }
2642 }
2643 if (s->authed)
2644 break;
2645 }
2646 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
2647 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2648
2649 if (ssh->cfg.try_tis_auth &&
2650 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2651 !s->tis_auth_refused) {
2652 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2653 logevent("Requested TIS authentication");
2654 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2655 crWaitUntil(ispkt);
2656 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2657 logevent("TIS authentication declined");
2658 if (flags & FLAG_INTERACTIVE)
2659 c_write_str(ssh, "TIS authentication refused.\r\n");
2660 s->tis_auth_refused = 1;
2661 continue;
2662 } else {
2663 int challengelen = GET_32BIT(ssh->pktin.body);
2664 logevent("Received TIS challenge");
2665 if (challengelen > sizeof(s->prompt) - 1)
2666 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2667 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2668 /* Prompt heuristic comes from OpenSSH */
2669 strncpy(s->prompt + challengelen,
2670 memchr(s->prompt, '\n', challengelen) ?
2671 "": "\r\nResponse: ",
2672 (sizeof s->prompt) - challengelen);
2673 s->prompt[(sizeof s->prompt) - 1] = '\0';
2674 }
2675 }
2676 if (ssh->cfg.try_tis_auth &&
2677 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2678 !s->ccard_auth_refused) {
2679 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2680 logevent("Requested CryptoCard authentication");
2681 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2682 crWaitUntil(ispkt);
2683 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2684 logevent("CryptoCard authentication declined");
2685 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2686 s->ccard_auth_refused = 1;
2687 continue;
2688 } else {
2689 int challengelen = GET_32BIT(ssh->pktin.body);
2690 logevent("Received CryptoCard challenge");
2691 if (challengelen > sizeof(s->prompt) - 1)
2692 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2693 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2694 strncpy(s->prompt + challengelen,
2695 memchr(s->prompt, '\n', challengelen) ?
2696 "" : "\r\nResponse: ",
2697 sizeof(s->prompt) - challengelen);
2698 s->prompt[sizeof(s->prompt) - 1] = '\0';
2699 }
2700 }
2701 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2702 sprintf(s->prompt, "%.90s@%.90s's password: ",
2703 s->username, ssh->savedhost);
2704 }
2705 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2706 char *comment = NULL;
2707 int type;
2708 char msgbuf[256];
2709 if (flags & FLAG_VERBOSE)
2710 c_write_str(ssh, "Trying public key authentication.\r\n");
2711 logeventf(ssh, "Trying public key \"%s\"",
2712 filename_to_str(&ssh->cfg.keyfile));
2713 type = key_type(&ssh->cfg.keyfile);
2714 if (type != SSH_KEYTYPE_SSH1) {
2715 sprintf(msgbuf, "Key is of wrong type (%s)",
2716 key_type_to_str(type));
2717 logevent(msgbuf);
2718 c_write_str(ssh, msgbuf);
2719 c_write_str(ssh, "\r\n");
2720 s->tried_publickey = 1;
2721 continue;
2722 }
2723 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
2724 if (flags & FLAG_VERBOSE)
2725 c_write_str(ssh, "No passphrase required.\r\n");
2726 goto tryauth;
2727 }
2728 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2729 sfree(comment);
2730 }
2731
2732 /*
2733 * Show password prompt, having first obtained it via a TIS
2734 * or CryptoCard exchange if we're doing TIS or CryptoCard
2735 * authentication.
2736 */
2737 if (ssh_get_line) {
2738 if (!ssh_get_line(s->prompt, s->password,
2739 sizeof(s->password), TRUE)) {
2740 /*
2741 * get_line failed to get a password (for example
2742 * because one was supplied on the command line
2743 * which has already failed to work). Terminate.
2744 */
2745 send_packet(ssh, SSH1_MSG_DISCONNECT,
2746 PKT_STR, "No more passwords available to try",
2747 PKT_END);
2748 logevent("Unable to authenticate");
2749 connection_fatal(ssh->frontend, "Unable to authenticate");
2750 ssh->state = SSH_STATE_CLOSED;
2751 crReturn(1);
2752 }
2753 } else {
2754 /* Prompt may have come from server. We've munged it a bit, so
2755 * we know it to be zero-terminated at least once. */
2756 int ret; /* need not be saved over crReturn */
2757 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2758 s->pos = 0;
2759
2760 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2761 do {
2762 crWaitUntil(!ispkt);
2763 ret = process_userpass_input(ssh, in, inlen);
2764 } while (ret == 0);
2765 if (ret < 0)
2766 cleanup_exit(0);
2767 c_write_str(ssh, "\r\n");
2768 }
2769
2770 tryauth:
2771 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2772 /*
2773 * Try public key authentication with the specified
2774 * key file.
2775 */
2776 s->tried_publickey = 1;
2777
2778 {
2779 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password);
2780 if (ret == 0) {
2781 c_write_str(ssh, "Couldn't load private key from ");
2782 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
2783 c_write_str(ssh, ".\r\n");
2784 continue; /* go and try password */
2785 }
2786 if (ret == -1) {
2787 c_write_str(ssh, "Wrong passphrase.\r\n");
2788 s->tried_publickey = 0;
2789 continue; /* try again */
2790 }
2791 }
2792
2793 /*
2794 * Send a public key attempt.
2795 */
2796 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2797 PKT_BIGNUM, s->key.modulus, PKT_END);
2798
2799 crWaitUntil(ispkt);
2800 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2801 c_write_str(ssh, "Server refused our public key.\r\n");
2802 continue; /* go and try password */
2803 }
2804 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2805 bombout((ssh,"Bizarre response to offer of public key"));
2806 crReturn(0);
2807 }
2808
2809 {
2810 int i;
2811 unsigned char buffer[32];
2812 Bignum challenge, response;
2813
2814 ssh1_read_bignum(ssh->pktin.body, &challenge);
2815 response = rsadecrypt(challenge, &s->key);
2816 freebn(s->key.private_exponent);/* burn the evidence */
2817
2818 for (i = 0; i < 32; i++) {
2819 buffer[i] = bignum_byte(response, 31 - i);
2820 }
2821
2822 MD5Init(&md5c);
2823 MD5Update(&md5c, buffer, 32);
2824 MD5Update(&md5c, s->session_id, 16);
2825 MD5Final(buffer, &md5c);
2826
2827 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2828 PKT_DATA, buffer, 16, PKT_END);
2829
2830 freebn(challenge);
2831 freebn(response);
2832 }
2833
2834 crWaitUntil(ispkt);
2835 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2836 if (flags & FLAG_VERBOSE)
2837 c_write_str(ssh, "Failed to authenticate with"
2838 " our public key.\r\n");
2839 continue; /* go and try password */
2840 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2841 bombout((ssh,"Bizarre response to RSA authentication response"));
2842 crReturn(0);
2843 }
2844
2845 break; /* we're through! */
2846 } else {
2847 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2848 /*
2849 * Defence against traffic analysis: we send a
2850 * whole bunch of packets containing strings of
2851 * different lengths. One of these strings is the
2852 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2853 * The others are all random data in
2854 * SSH1_MSG_IGNORE packets. This way a passive
2855 * listener can't tell which is the password, and
2856 * hence can't deduce the password length.
2857 *
2858 * Anybody with a password length greater than 16
2859 * bytes is going to have enough entropy in their
2860 * password that a listener won't find it _that_
2861 * much help to know how long it is. So what we'll
2862 * do is:
2863 *
2864 * - if password length < 16, we send 15 packets
2865 * containing string lengths 1 through 15
2866 *
2867 * - otherwise, we let N be the nearest multiple
2868 * of 8 below the password length, and send 8
2869 * packets containing string lengths N through
2870 * N+7. This won't obscure the order of
2871 * magnitude of the password length, but it will
2872 * introduce a bit of extra uncertainty.
2873 *
2874 * A few servers (the old 1.2.18 through 1.2.22)
2875 * can't deal with SSH1_MSG_IGNORE. For these
2876 * servers, we need an alternative defence. We make
2877 * use of the fact that the password is interpreted
2878 * as a C string: so we can append a NUL, then some
2879 * random data.
2880 *
2881 * One server (a Cisco one) can deal with neither
2882 * SSH1_MSG_IGNORE _nor_ a padded password string.
2883 * For this server we are left with no defences
2884 * against password length sniffing.
2885 */
2886 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2887 /*
2888 * The server can deal with SSH1_MSG_IGNORE, so
2889 * we can use the primary defence.
2890 */
2891 int bottom, top, pwlen, i;
2892 char *randomstr;
2893
2894 pwlen = strlen(s->password);
2895 if (pwlen < 16) {
2896 bottom = 0; /* zero length passwords are OK! :-) */
2897 top = 15;
2898 } else {
2899 bottom = pwlen & ~7;
2900 top = bottom + 7;
2901 }
2902
2903 assert(pwlen >= bottom && pwlen <= top);
2904
2905 randomstr = snewn(top + 1, char);
2906
2907 for (i = bottom; i <= top; i++) {
2908 if (i == pwlen)
2909 defer_packet(ssh, s->pwpkt_type,
2910 PKT_STR, s->password, PKT_END);
2911 else {
2912 for (j = 0; j < i; j++) {
2913 do {
2914 randomstr[j] = random_byte();
2915 } while (randomstr[j] == '\0');
2916 }
2917 randomstr[i] = '\0';
2918 defer_packet(ssh, SSH1_MSG_IGNORE,
2919 PKT_STR, randomstr, PKT_END);
2920 }
2921 }
2922 logevent("Sending password with camouflage packets");
2923 ssh_pkt_defersend(ssh);
2924 }
2925 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2926 /*
2927 * The server can't deal with SSH1_MSG_IGNORE
2928 * but can deal with padded passwords, so we
2929 * can use the secondary defence.
2930 */
2931 char string[64];
2932 char *ss;
2933 int len;
2934
2935 len = strlen(s->password);
2936 if (len < sizeof(string)) {
2937 ss = string;
2938 strcpy(string, s->password);
2939 len++; /* cover the zero byte */
2940 while (len < sizeof(string)) {
2941 string[len++] = (char) random_byte();
2942 }
2943 } else {
2944 ss = s->password;
2945 }
2946 logevent("Sending length-padded password");
2947 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2948 PKT_DATA, ss, len, PKT_END);
2949 } else {
2950 /*
2951 * The server has _both_
2952 * BUG_CHOKES_ON_SSH1_IGNORE and
2953 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2954 * therefore nothing we can do.
2955 */
2956 int len;
2957 len = strlen(s->password);
2958 logevent("Sending unpadded password");
2959 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2960 PKT_DATA, s->password, len, PKT_END);
2961 }
2962 } else {
2963 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
2964 }
2965 }
2966 logevent("Sent password");
2967 memset(s->password, 0, strlen(s->password));
2968 crWaitUntil(ispkt);
2969 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2970 if (flags & FLAG_VERBOSE)
2971 c_write_str(ssh, "Access denied\r\n");
2972 logevent("Authentication refused");
2973 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2974 bombout((ssh,"Strange packet received, type %d", ssh->pktin.type));
2975 crReturn(0);
2976 }
2977 }
2978
2979 logevent("Authentication successful");
2980
2981 crFinish(1);
2982 }
2983
2984 void sshfwd_close(struct ssh_channel *c)
2985 {
2986 Ssh ssh = c->ssh;
2987
2988 if (c && !c->closes) {
2989 /*
2990 * If the channel's remoteid is -1, we have sent
2991 * CHANNEL_OPEN for this channel, but it hasn't even been
2992 * acknowledged by the server. So we must set a close flag
2993 * on it now, and then when the server acks the channel
2994 * open, we can close it then.
2995 */
2996 if (((int)c->remoteid) != -1) {
2997 if (ssh->version == 1) {
2998 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2999 PKT_END);
3000 } else {
3001 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3002 ssh2_pkt_adduint32(ssh, c->remoteid);
3003 ssh2_pkt_send(ssh);
3004 }
3005 }
3006 c->closes = 1; /* sent MSG_CLOSE */
3007 if (c->type == CHAN_X11) {
3008 c->u.x11.s = NULL;
3009 logevent("Forwarded X11 connection terminated");
3010 } else if (c->type == CHAN_SOCKDATA ||
3011 c->type == CHAN_SOCKDATA_DORMANT) {
3012 c->u.pfd.s = NULL;
3013 logevent("Forwarded port closed");
3014 }
3015 }
3016 }
3017
3018 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3019 {
3020 Ssh ssh = c->ssh;
3021
3022 if (ssh->version == 1) {
3023 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3024 PKT_INT, c->remoteid,
3025 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
3026 /*
3027 * In SSH1 we can return 0 here - implying that forwarded
3028 * connections are never individually throttled - because
3029 * the only circumstance that can cause throttling will be
3030 * the whole SSH connection backing up, in which case
3031 * _everything_ will be throttled as a whole.
3032 */
3033 return 0;
3034 } else {
3035 ssh2_add_channel_data(c, buf, len);
3036 return ssh2_try_send(c);
3037 }
3038 }
3039
3040 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3041 {
3042 Ssh ssh = c->ssh;
3043
3044 if (ssh->version == 1) {
3045 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3046 c->v.v1.throttling = 0;
3047 ssh1_throttle(ssh, -1);
3048 }
3049 } else {
3050 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3051 }
3052 }
3053
3054 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3055 {
3056 crBegin(ssh->ssh1_protocol_crstate);
3057
3058 random_init();
3059
3060 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3061 crReturnV;
3062 }
3063 if (ssh->state == SSH_STATE_CLOSED)
3064 crReturnV;
3065
3066 if (ssh->cfg.agentfwd && agent_exists()) {
3067 logevent("Requesting agent forwarding");
3068 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3069 do {
3070 crReturnV;
3071 } while (!ispkt);
3072 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3073 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3074 bombout((ssh,"Protocol confusion"));
3075 crReturnV;
3076 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3077 logevent("Agent forwarding refused");
3078 } else {
3079 logevent("Agent forwarding enabled");
3080 ssh->agentfwd_enabled = TRUE;
3081 }
3082 }
3083
3084 if (ssh->cfg.x11_forward) {
3085 char proto[20], data[64];
3086 logevent("Requesting X11 forwarding");
3087 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3088 data, sizeof(data), ssh->cfg.x11_auth);
3089 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3090 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3091 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3092 PKT_STR, proto, PKT_STR, data,
3093 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3094 PKT_END);
3095 } else {
3096 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3097 PKT_STR, proto, PKT_STR, data, PKT_END);
3098 }
3099 do {
3100 crReturnV;
3101 } while (!ispkt);
3102 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3103 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3104 bombout((ssh,"Protocol confusion"));
3105 crReturnV;
3106 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3107 logevent("X11 forwarding refused");
3108 } else {
3109 logevent("X11 forwarding enabled");
3110 ssh->X11_fwd_enabled = TRUE;
3111 }
3112 }
3113
3114 {
3115 char type;
3116 int n;
3117 int sport,dport,sserv,dserv;
3118 char sports[256], dports[256], saddr[256], host[256];
3119
3120 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3121 /* Add port forwardings. */
3122 ssh->portfwd_strptr = ssh->cfg.portfwd;
3123 while (*ssh->portfwd_strptr) {
3124 type = *ssh->portfwd_strptr++;
3125 saddr[0] = '\0';
3126 n = 0;
3127 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3128 if (*ssh->portfwd_strptr == ':') {
3129 /*
3130 * We've seen a colon in the middle of the
3131 * source port number. This means that
3132 * everything we've seen until now is the
3133 * source _address_, so we'll move it into
3134 * saddr and start sports from the beginning
3135 * again.
3136 */
3137 ssh->portfwd_strptr++;
3138 sports[n] = '\0';
3139 strcpy(saddr, sports);
3140 n = 0;
3141 }
3142 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3143 }
3144 sports[n] = 0;
3145 if (*ssh->portfwd_strptr == '\t')
3146 ssh->portfwd_strptr++;
3147 n = 0;
3148 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3149 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3150 }
3151 host[n] = 0;
3152 if (*ssh->portfwd_strptr == ':')
3153 ssh->portfwd_strptr++;
3154 n = 0;
3155 while (*ssh->portfwd_strptr) {
3156 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3157 }
3158 dports[n] = 0;
3159 ssh->portfwd_strptr++;
3160 dport = atoi(dports);
3161 dserv = 0;
3162 if (dport == 0) {
3163 dserv = 1;
3164 dport = net_service_lookup(dports);
3165 if (!dport) {
3166 logeventf(ssh, "Service lookup failed for"
3167 " destination port \"%s\"", dports);
3168 }
3169 }
3170 sport = atoi(sports);
3171 sserv = 0;
3172 if (sport == 0) {
3173 sserv = 1;
3174 sport = net_service_lookup(sports);
3175 if (!sport) {
3176 logeventf(ssh, "Service lookup failed for source"
3177 " port \"%s\"", sports);
3178 }
3179 }
3180 if (sport && dport) {
3181 if (type == 'L') {
3182 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3183 sport, ssh, &ssh->cfg);
3184 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3185 " forwarding to %s:%.*s%.*s%d%.*s",
3186 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3187 (int)(*saddr?1:0), ":",
3188 (int)(sserv ? strlen(sports) : 0), sports,
3189 sserv, "(", sport, sserv, ")",
3190 host,
3191 (int)(dserv ? strlen(dports) : 0), dports,
3192 dserv, "(", dport, dserv, ")");
3193 } else {
3194 struct ssh_rportfwd *pf;
3195 pf = snew(struct ssh_rportfwd);
3196 strcpy(pf->dhost, host);
3197 pf->dport = dport;
3198 if (saddr) {
3199 logeventf(ssh,
3200 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3201 saddr, sport);
3202 }
3203 if (add234(ssh->rportfwds, pf) != pf) {
3204 logeventf(ssh,
3205 "Duplicate remote port forwarding to %s:%d",
3206 host, dport);
3207 sfree(pf);
3208 } else {
3209 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3210 " forward to %s:%.*s%.*s%d%.*s",
3211 (int)(sserv ? strlen(sports) : 0), sports,
3212 sserv, "(", sport, sserv, ")",
3213 host,
3214 (int)(dserv ? strlen(dports) : 0), dports,
3215 dserv, "(", dport, dserv, ")");
3216 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3217 PKT_INT, sport,
3218 PKT_STR, host,
3219 PKT_INT, dport,
3220 PKT_END);
3221 do {
3222 crReturnV;
3223 } while (!ispkt);
3224 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3225 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3226 bombout((ssh,"Protocol confusion"));
3227 crReturnV;
3228 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3229 c_write_str(ssh, "Server refused port"
3230 " forwarding\r\n");
3231 }
3232 logevent("Remote port forwarding enabled");
3233 }
3234 }
3235 }
3236 }
3237 }
3238
3239 if (!ssh->cfg.nopty) {
3240 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3241 PKT_STR, ssh->cfg.termtype,
3242 PKT_INT, ssh->term_height,
3243 PKT_INT, ssh->term_width,
3244 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3245 ssh->state = SSH_STATE_INTERMED;
3246 do {
3247 crReturnV;
3248 } while (!ispkt);
3249 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3250 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3251 bombout((ssh,"Protocol confusion"));
3252 crReturnV;
3253 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3254 c_write_str(ssh, "Server refused to allocate pty\r\n");
3255 ssh->editing = ssh->echoing = 1;
3256 }
3257 logevent("Allocated pty");
3258 } else {
3259 ssh->editing = ssh->echoing = 1;
3260 }
3261
3262 if (ssh->cfg.compression) {
3263 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3264 do {
3265 crReturnV;
3266 } while (!ispkt);
3267 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3268 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3269 bombout((ssh,"Protocol confusion"));
3270 crReturnV;
3271 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3272 c_write_str(ssh, "Server refused to compress\r\n");
3273 }
3274 logevent("Started compression");
3275 ssh->v1_compressing = TRUE;
3276 ssh->cs_comp_ctx = zlib_compress_init();
3277 logevent("Initialised zlib (RFC1950) compression");
3278 ssh->sc_comp_ctx = zlib_decompress_init();
3279 logevent("Initialised zlib (RFC1950) decompression");
3280 }
3281
3282 /*
3283 * Start the shell or command.
3284 *
3285 * Special case: if the first-choice command is an SSH2
3286 * subsystem (hence not usable here) and the second choice
3287 * exists, we fall straight back to that.
3288 */
3289 {
3290 char *cmd = ssh->cfg.remote_cmd_ptr;
3291
3292 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3293 cmd = ssh->cfg.remote_cmd_ptr2;
3294 ssh->fallback_cmd = TRUE;
3295 }
3296 if (*cmd)
3297 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3298 else
3299 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3300 logevent("Started session");
3301 }
3302
3303 ssh->state = SSH_STATE_SESSION;
3304 if (ssh->size_needed)
3305 ssh_size(ssh, ssh->term_width, ssh->term_height);
3306 if (ssh->eof_needed)
3307 ssh_special(ssh, TS_EOF);
3308
3309 if (ssh->ldisc)
3310 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3311 ssh->send_ok = 1;
3312 ssh->channels = newtree234(ssh_channelcmp);
3313 while (1) {
3314 crReturnV;
3315 if (ispkt) {
3316 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3317 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3318 long len = GET_32BIT(ssh->pktin.body);
3319 int bufsize =
3320 from_backend(ssh->frontend,
3321 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3322 (char *)(ssh->pktin.body) + 4, len);
3323 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3324 ssh->v1_stdout_throttling = 1;
3325 ssh1_throttle(ssh, +1);
3326 }
3327 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3328 ssh->state = SSH_STATE_CLOSED;
3329 logevent("Received disconnect request");
3330 crReturnV;
3331 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3332 /* Remote side is trying to open a channel to talk to our
3333 * X-Server. Give them back a local channel number. */
3334 struct ssh_channel *c;
3335
3336 logevent("Received X11 connect request");
3337 /* Refuse if X11 forwarding is disabled. */
3338 if (!ssh->X11_fwd_enabled) {
3339 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3340 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3341 logevent("Rejected X11 connect request");
3342 } else {
3343 c = snew(struct ssh_channel);
3344 c->ssh = ssh;
3345
3346 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3347 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3348 logevent("opening X11 forward connection failed");
3349 sfree(c);
3350 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3351 PKT_INT, GET_32BIT(ssh->pktin.body),
3352 PKT_END);
3353 } else {
3354 logevent
3355 ("opening X11 forward connection succeeded");
3356 c->remoteid = GET_32BIT(ssh->pktin.body);
3357 c->localid = alloc_channel_id(ssh);
3358 c->closes = 0;
3359 c->v.v1.throttling = 0;
3360 c->type = CHAN_X11; /* identify channel type */
3361 add234(ssh->channels, c);
3362 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3363 PKT_INT, c->remoteid, PKT_INT,
3364 c->localid, PKT_END);
3365 logevent("Opened X11 forward channel");
3366 }
3367 }
3368 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3369 /* Remote side is trying to open a channel to talk to our
3370 * agent. Give them back a local channel number. */
3371 struct ssh_channel *c;
3372
3373 /* Refuse if agent forwarding is disabled. */
3374 if (!ssh->agentfwd_enabled) {
3375 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3376 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3377 } else {
3378 c = snew(struct ssh_channel);
3379 c->ssh = ssh;
3380 c->remoteid = GET_32BIT(ssh->pktin.body);
3381 c->localid = alloc_channel_id(ssh);
3382 c->closes = 0;
3383 c->v.v1.throttling = 0;
3384 c->type = CHAN_AGENT; /* identify channel type */
3385 c->u.a.lensofar = 0;
3386 add234(ssh->channels, c);
3387 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3388 PKT_INT, c->remoteid, PKT_INT, c->localid,
3389 PKT_END);
3390 }
3391 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3392 /* Remote side is trying to open a channel to talk to a
3393 * forwarded port. Give them back a local channel number. */
3394 struct ssh_channel *c;
3395 struct ssh_rportfwd pf;
3396 int hostsize, port;
3397 char host[256], buf[1024];
3398 char *p, *h, *e;
3399 c = snew(struct ssh_channel);
3400 c->ssh = ssh;
3401
3402 hostsize = GET_32BIT(ssh->pktin.body+4);
3403 for (h = host, p = (char *)(ssh->pktin.body+8);
3404 hostsize != 0; hostsize--) {
3405 if (h+1 < host+sizeof(host))
3406 *h++ = *p;
3407 p++;
3408 }
3409 *h = 0;
3410 port = GET_32BIT(p);
3411
3412 strcpy(pf.dhost, host);
3413 pf.dport = port;
3414
3415 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3416 sprintf(buf, "Rejected remote port open request for %s:%d",
3417 host, port);
3418 logevent(buf);
3419 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3420 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3421 } else {
3422 sprintf(buf, "Received remote port open request for %s:%d",
3423 host, port);
3424 logevent(buf);
3425 e = pfd_newconnect(&c->u.pfd.s, host, port, c, &ssh->cfg);
3426 if (e != NULL) {
3427 char buf[256];
3428 sprintf(buf, "Port open failed: %s", e);
3429 logevent(buf);
3430 sfree(c);
3431 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3432 PKT_INT, GET_32BIT(ssh->pktin.body),
3433 PKT_END);
3434 } else {
3435 c->remoteid = GET_32BIT(ssh->pktin.body);
3436 c->localid = alloc_channel_id(ssh);
3437 c->closes = 0;
3438 c->v.v1.throttling = 0;
3439 c->type = CHAN_SOCKDATA; /* identify channel type */
3440 add234(ssh->channels, c);
3441 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3442 PKT_INT, c->remoteid, PKT_INT,
3443 c->localid, PKT_END);
3444 logevent("Forwarded port opened successfully");
3445 }
3446 }
3447
3448 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3449 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3450 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3451 struct ssh_channel *c;
3452
3453 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3454 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3455 c->remoteid = localid;
3456 c->type = CHAN_SOCKDATA;
3457 c->v.v1.throttling = 0;
3458 pfd_confirm(c->u.pfd.s);
3459 }
3460
3461 if (c && c->closes) {
3462 /*
3463 * We have a pending close on this channel,
3464 * which we decided on before the server acked
3465 * the channel open. So now we know the
3466 * remoteid, we can close it again.
3467 */
3468 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3469 PKT_INT, c->remoteid, PKT_END);
3470 }
3471
3472 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3473 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3474 struct ssh_channel *c;
3475
3476 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3477 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3478 logevent("Forwarded connection refused by server");
3479 pfd_close(c->u.pfd.s);
3480 del234(ssh->channels, c);
3481 sfree(c);
3482 }
3483
3484 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3485 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3486 /* Remote side closes a channel. */
3487 unsigned i = GET_32BIT(ssh->pktin.body);
3488 struct ssh_channel *c;
3489 c = find234(ssh->channels, &i, ssh_channelfind);
3490 if (c && ((int)c->remoteid) != -1) {
3491 int closetype;
3492 closetype =
3493 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3494
3495 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3496 logevent("Forwarded X11 connection terminated");
3497 assert(c->u.x11.s != NULL);
3498 x11_close(c->u.x11.s);
3499 c->u.x11.s = NULL;
3500 }
3501 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3502 logevent("Forwarded port closed");
3503 assert(c->u.pfd.s != NULL);
3504 pfd_close(c->u.pfd.s);
3505 c->u.pfd.s = NULL;
3506 }
3507
3508 c->closes |= (closetype << 2); /* seen this message */
3509 if (!(c->closes & closetype)) {
3510 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3511 PKT_END);
3512 c->closes |= closetype; /* sent it too */
3513 }
3514
3515 if (c->closes == 15) {
3516 del234(ssh->channels, c);
3517 sfree(c);
3518 }
3519 } else {
3520 bombout((ssh,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3521 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3522 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3523 i));
3524 }
3525 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3526 /* Data sent down one of our channels. */
3527 int i = GET_32BIT(ssh->pktin.body);
3528 int len = GET_32BIT(ssh->pktin.body + 4);
3529 unsigned char *p = ssh->pktin.body + 8;
3530 struct ssh_channel *c;
3531 c = find234(ssh->channels, &i, ssh_channelfind);
3532 if (c) {
3533 int bufsize;
3534 switch (c->type) {
3535 case CHAN_X11:
3536 bufsize = x11_send(c->u.x11.s, (char *)p, len);
3537 break;
3538 case CHAN_SOCKDATA:
3539 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
3540 break;
3541 case CHAN_AGENT:
3542 /* Data for an agent message. Buffer it. */
3543 while (len > 0) {
3544 if (c->u.a.lensofar < 4) {
3545 int l = min(4 - c->u.a.lensofar, len);
3546 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3547 l);
3548 p += l;
3549 len -= l;
3550 c->u.a.lensofar += l;
3551 }
3552 if (c->u.a.lensofar == 4) {
3553 c->u.a.totallen =
3554 4 + GET_32BIT(c->u.a.msglen);
3555 c->u.a.message = snewn(c->u.a.totallen,
3556 unsigned char);
3557 memcpy(c->u.a.message, c->u.a.msglen, 4);
3558 }
3559 if (c->u.a.lensofar >= 4 && len > 0) {
3560 int l =
3561 min(c->u.a.totallen - c->u.a.lensofar,
3562 len);
3563 memcpy(c->u.a.message + c->u.a.lensofar, p,
3564 l);
3565 p += l;
3566 len -= l;
3567 c->u.a.lensofar += l;
3568 }
3569 if (c->u.a.lensofar == c->u.a.totallen) {
3570 void *reply, *sentreply;
3571 int replylen;
3572 agent_query(c->u.a.message,
3573 c->u.a.totallen, &reply,
3574 &replylen);
3575 if (reply)
3576 sentreply = reply;
3577 else {
3578 /* Fake SSH_AGENT_FAILURE. */
3579 sentreply = "\0\0\0\1\5";
3580 replylen = 5;
3581 }
3582 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3583 PKT_INT, c->remoteid,
3584 PKT_INT, replylen,
3585 PKT_DATA, sentreply, replylen,
3586 PKT_END);
3587 if (reply)
3588 sfree(reply);
3589 sfree(c->u.a.message);
3590 c->u.a.lensofar = 0;
3591 }
3592 }
3593 bufsize = 0; /* agent channels never back up */
3594 break;
3595 }
3596 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3597 c->v.v1.throttling = 1;
3598 ssh1_throttle(ssh, +1);
3599 }
3600 }
3601 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3602 /* may be from EXEC_SHELL on some servers */
3603 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3604 /* may be from EXEC_SHELL on some servers
3605 * if no pty is available or in other odd cases. Ignore */
3606 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3607 char buf[100];
3608 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3609 sprintf(buf, "Server sent command exit status %d",
3610 ssh->exitcode);
3611 logevent(buf);
3612 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3613 /*
3614 * In case `helpful' firewalls or proxies tack
3615 * extra human-readable text on the end of the
3616 * session which we might mistake for another
3617 * encrypted packet, we close the session once
3618 * we've sent EXIT_CONFIRMATION.
3619 */
3620 ssh->state = SSH_STATE_CLOSED;
3621 crReturnV;
3622 } else {
3623 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
3624 crReturnV;
3625 }
3626 } else {
3627 while (inlen > 0) {
3628 int len = min(inlen, 512);
3629 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3630 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3631 in += len;
3632 inlen -= len;
3633 }
3634 }
3635 }
3636
3637 crFinishV;
3638 }
3639
3640 /*
3641 * Utility routine for decoding comma-separated strings in KEXINIT.
3642 */
3643 static int in_commasep_string(char *needle, char *haystack, int haylen)
3644 {
3645 int needlen;
3646 if (!needle || !haystack) /* protect against null pointers */
3647 return 0;
3648 needlen = strlen(needle);
3649 while (1) {
3650 /*
3651 * Is it at the start of the string?
3652 */
3653 if (haylen >= needlen && /* haystack is long enough */
3654 !memcmp(needle, haystack, needlen) && /* initial match */
3655 (haylen == needlen || haystack[needlen] == ',')
3656 /* either , or EOS follows */
3657 )
3658 return 1;
3659 /*
3660 * If not, search for the next comma and resume after that.
3661 * If no comma found, terminate.
3662 */
3663 while (haylen > 0 && *haystack != ',')
3664 haylen--, haystack++;
3665 if (haylen == 0)
3666 return 0;
3667 haylen--, haystack++; /* skip over comma itself */
3668 }
3669 }
3670
3671 /*
3672 * SSH2 key creation method.
3673 */
3674 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3675 unsigned char *sessid, char chr,
3676 unsigned char *keyspace)
3677 {
3678 SHA_State s;
3679 /* First 20 bytes. */
3680 SHA_Init(&s);
3681 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3682 sha_mpint(&s, K);
3683 SHA_Bytes(&s, H, 20);
3684 SHA_Bytes(&s, &chr, 1);
3685 SHA_Bytes(&s, sessid, 20);
3686 SHA_Final(&s, keyspace);
3687 /* Next 20 bytes. */
3688 SHA_Init(&s);
3689 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3690 sha_mpint(&s, K);
3691 SHA_Bytes(&s, H, 20);
3692 SHA_Bytes(&s, keyspace, 20);
3693 SHA_Final(&s, keyspace + 20);
3694 }
3695
3696 /*
3697 * Handle the SSH2 transport layer.
3698 */
3699 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3700 {
3701 struct do_ssh2_transport_state {
3702 int nbits, pbits, warn;
3703 Bignum p, g, e, f, K;
3704 int kex_init_value, kex_reply_value;
3705 const struct ssh_mac **maclist;
3706 int nmacs;
3707 const struct ssh2_cipher *cscipher_tobe;
3708 const struct ssh2_cipher *sccipher_tobe;
3709 const struct ssh_mac *csmac_tobe;
3710 const struct ssh_mac *scmac_tobe;
3711 const struct ssh_compress *cscomp_tobe;
3712 const struct ssh_compress *sccomp_tobe;
3713 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3714 int hostkeylen, siglen;
3715 void *hkey; /* actual host key */
3716 unsigned char exchange_hash[20];
3717 int n_preferred_ciphers;
3718 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3719 const struct ssh_compress *preferred_comp;
3720 int first_kex;
3721 };
3722 crState(do_ssh2_transport_state);
3723
3724 crBegin(ssh->do_ssh2_transport_crstate);
3725
3726 s->cscipher_tobe = s->sccipher_tobe = NULL;
3727 s->csmac_tobe = s->scmac_tobe = NULL;
3728 s->cscomp_tobe = s->sccomp_tobe = NULL;
3729
3730 random_init();
3731 s->first_kex = 1;
3732
3733 {
3734 int i;
3735 /*
3736 * Set up the preferred ciphers. (NULL => warn below here)
3737 */
3738 s->n_preferred_ciphers = 0;
3739 for (i = 0; i < CIPHER_MAX; i++) {
3740 switch (ssh->cfg.ssh_cipherlist[i]) {
3741 case CIPHER_BLOWFISH:
3742 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3743 break;
3744 case CIPHER_DES:
3745 if (ssh->cfg.ssh2_des_cbc) {
3746 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3747 }
3748 break;
3749 case CIPHER_3DES:
3750 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3751 break;
3752 case CIPHER_AES:
3753 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3754 break;
3755 case CIPHER_WARN:
3756 /* Flag for later. Don't bother if it's the last in
3757 * the list. */
3758 if (i < CIPHER_MAX - 1) {
3759 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3760 }
3761 break;
3762 }
3763 }
3764 }
3765
3766 /*
3767 * Set up preferred compression.
3768 */
3769 if (ssh->cfg.compression)
3770 s->preferred_comp = &ssh_zlib;
3771 else
3772 s->preferred_comp = &ssh_comp_none;
3773
3774 /*
3775 * Be prepared to work around the buggy MAC problem.
3776 */
3777 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3778 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3779 else
3780 s->maclist = macs, s->nmacs = lenof(macs);
3781
3782 begin_key_exchange:
3783 {
3784 int i, j, cipherstr_started;
3785
3786 /*
3787 * Construct and send our key exchange packet.
3788 */
3789 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3790 for (i = 0; i < 16; i++)
3791 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3792 /* List key exchange algorithms. */
3793 ssh2_pkt_addstring_start(ssh);
3794 for (i = 0; i < lenof(kex_algs); i++) {
3795 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3796 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3797 continue;
3798 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3799 if (i < lenof(kex_algs) - 1)
3800 ssh2_pkt_addstring_str(ssh, ",");
3801 }
3802 /* List server host key algorithms. */
3803 ssh2_pkt_addstring_start(ssh);
3804 for (i = 0; i < lenof(hostkey_algs); i++) {
3805 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3806 if (i < lenof(hostkey_algs) - 1)
3807 ssh2_pkt_addstring_str(ssh, ",");
3808 }
3809 /* List client->server encryption algorithms. */
3810 ssh2_pkt_addstring_start(ssh);
3811 cipherstr_started = 0;
3812 for (i = 0; i < s->n_preferred_ciphers; i++) {
3813 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3814 if (!c) continue; /* warning flag */
3815 for (j = 0; j < c->nciphers; j++) {
3816 if (cipherstr_started)
3817 ssh2_pkt_addstring_str(ssh, ",");
3818 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3819 cipherstr_started = 1;
3820 }
3821 }
3822 /* List server->client encryption algorithms. */
3823 ssh2_pkt_addstring_start(ssh);
3824 cipherstr_started = 0;
3825 for (i = 0; i < s->n_preferred_ciphers; i++) {
3826 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3827 if (!c) continue; /* warning flag */
3828 for (j = 0; j < c->nciphers; j++) {
3829 if (cipherstr_started)
3830 ssh2_pkt_addstring_str(ssh, ",");
3831 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3832 cipherstr_started = 1;
3833 }
3834 }
3835 /* List client->server MAC algorithms. */
3836 ssh2_pkt_addstring_start(ssh);
3837 for (i = 0; i < s->nmacs; i++) {
3838 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3839 if (i < s->nmacs - 1)
3840 ssh2_pkt_addstring_str(ssh, ",");
3841 }
3842 /* List server->client MAC algorithms. */
3843 ssh2_pkt_addstring_start(ssh);
3844 for (i = 0; i < s->nmacs; i++) {
3845 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3846 if (i < s->nmacs - 1)
3847 ssh2_pkt_addstring_str(ssh, ",");
3848 }
3849 /* List client->server compression algorithms. */
3850 ssh2_pkt_addstring_start(ssh);
3851 for (i = 0; i < lenof(compressions) + 1; i++) {
3852 const struct ssh_compress *c =
3853 i == 0 ? s->preferred_comp : compressions[i - 1];
3854 ssh2_pkt_addstring_str(ssh, c->name);
3855 if (i < lenof(compressions))
3856 ssh2_pkt_addstring_str(ssh, ",");
3857 }
3858 /* List server->client compression algorithms. */
3859 ssh2_pkt_addstring_start(ssh);
3860 for (i = 0; i < lenof(compressions) + 1; i++) {
3861 const struct ssh_compress *c =
3862 i == 0 ? s->preferred_comp : compressions[i - 1];
3863 ssh2_pkt_addstring_str(ssh, c->name);
3864 if (i < lenof(compressions))
3865 ssh2_pkt_addstring_str(ssh, ",");
3866 }
3867 /* List client->server languages. Empty list. */
3868 ssh2_pkt_addstring_start(ssh);
3869 /* List server->client languages. Empty list. */
3870 ssh2_pkt_addstring_start(ssh);
3871 /* First KEX packet does _not_ follow, because we're not that brave. */
3872 ssh2_pkt_addbool(ssh, FALSE);
3873 /* Reserved. */
3874 ssh2_pkt_adduint32(ssh, 0);
3875 }
3876
3877 ssh->exhash = ssh->exhashbase;
3878 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
3879
3880 ssh2_pkt_send(ssh);
3881
3882 if (!ispkt)
3883 crWaitUntil(ispkt);
3884 if (ssh->pktin.length > 5)
3885 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
3886
3887 /*
3888 * Now examine the other side's KEXINIT to see what we're up
3889 * to.
3890 */
3891 {
3892 char *str;
3893 int i, j, len;
3894
3895 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3896 bombout((ssh,"expected key exchange packet from server"));
3897 crReturn(0);
3898 }
3899 ssh->kex = NULL;
3900 ssh->hostkey = NULL;
3901 s->cscipher_tobe = NULL;
3902 s->sccipher_tobe = NULL;
3903 s->csmac_tobe = NULL;
3904 s->scmac_tobe = NULL;
3905 s->cscomp_tobe = NULL;
3906 s->sccomp_tobe = NULL;
3907 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3908 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3909 for (i = 0; i < lenof(kex_algs); i++) {
3910 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3911 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3912 continue;
3913 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3914 ssh->kex = kex_algs[i];
3915 break;
3916 }
3917 }
3918 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3919 for (i = 0; i < lenof(hostkey_algs); i++) {
3920 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3921 ssh->hostkey = hostkey_algs[i];
3922 break;
3923 }
3924 }
3925 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3926 s->warn = 0;
3927 for (i = 0; i < s->n_preferred_ciphers; i++) {
3928 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3929 if (!c) {
3930 s->warn = 1;
3931 } else {
3932 for (j = 0; j < c->nciphers; j++) {
3933 if (in_commasep_string(c->list[j]->name, str, len)) {
3934 s->cscipher_tobe = c->list[j];
3935 break;
3936 }
3937 }
3938 }
3939 if (s->cscipher_tobe) {
3940 if (s->warn)
3941 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
3942 break;
3943 }
3944 }
3945 if (!s->cscipher_tobe) {
3946 bombout((ssh,"Couldn't agree a client-to-server cipher (available: %s)",
3947 str ? str : "(null)"));
3948 crReturn(0);
3949 }
3950
3951 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3952 s->warn = 0;
3953 for (i = 0; i < s->n_preferred_ciphers; i++) {
3954 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3955 if (!c) {
3956 s->warn = 1;
3957 } else {
3958 for (j = 0; j < c->nciphers; j++) {
3959 if (in_commasep_string(c->list[j]->name, str, len)) {
3960 s->sccipher_tobe = c->list[j];
3961 break;
3962 }
3963 }
3964 }
3965 if (s->sccipher_tobe) {
3966 if (s->warn)
3967 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
3968 break;
3969 }
3970 }
3971 if (!s->sccipher_tobe) {
3972 bombout((ssh,"Couldn't agree a server-to-client cipher (available: %s)",
3973 str ? str : "(null)"));
3974 crReturn(0);
3975 }
3976
3977 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3978 for (i = 0; i < s->nmacs; i++) {
3979 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3980 s->csmac_tobe = s->maclist[i];
3981 break;
3982 }
3983 }
3984 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
3985 for (i = 0; i < s->nmacs; i++) {
3986 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3987 s->scmac_tobe = s->maclist[i];
3988 break;
3989 }
3990 }
3991 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
3992 for (i = 0; i < lenof(compressions) + 1; i++) {
3993 const struct ssh_compress *c =
3994 i == 0 ? s->preferred_comp : compressions[i - 1];
3995 if (in_commasep_string(c->name, str, len)) {
3996 s->cscomp_tobe = c;
3997 break;
3998 }
3999 }
4000 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
4001 for (i = 0; i < lenof(compressions) + 1; i++) {
4002 const struct ssh_compress *c =
4003 i == 0 ? s->preferred_comp : compressions[i - 1];
4004 if (in_commasep_string(c->name, str, len)) {
4005 s->sccomp_tobe = c;
4006 break;
4007 }
4008 }
4009 }
4010
4011 /*
4012 * Work out the number of bits of key we will need from the key
4013 * exchange. We start with the maximum key length of either
4014 * cipher...
4015 */
4016 {
4017 int csbits, scbits;
4018
4019 csbits = s->cscipher_tobe->keylen;
4020 scbits = s->sccipher_tobe->keylen;
4021 s->nbits = (csbits > scbits ? csbits : scbits);
4022 }
4023 /* The keys only have 160-bit entropy, since they're based on
4024 * a SHA-1 hash. So cap the key size at 160 bits. */
4025 if (s->nbits > 160)
4026 s->nbits = 160;
4027
4028 /*
4029 * If we're doing Diffie-Hellman group exchange, start by
4030 * requesting a group.
4031 */
4032 if (ssh->kex == &ssh_diffiehellman_gex) {
4033 logevent("Doing Diffie-Hellman group exchange");
4034 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4035 /*
4036 * Work out how big a DH group we will need to allow that
4037 * much data.
4038 */
4039 s->pbits = 512 << ((s->nbits - 1) / 64);
4040 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4041 ssh2_pkt_adduint32(ssh, s->pbits);
4042 ssh2_pkt_send(ssh);
4043
4044 crWaitUntil(ispkt);
4045 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4046 bombout((ssh,"expected key exchange group packet from server"));
4047 crReturn(0);
4048 }
4049 s->p = ssh2_pkt_getmp(ssh);
4050 s->g = ssh2_pkt_getmp(ssh);
4051 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4052 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4053 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4054 } else {
4055 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4056 ssh->kex_ctx = dh_setup_group1();
4057 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4058 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4059 }
4060
4061 logevent("Doing Diffie-Hellman key exchange");
4062 /*
4063 * Now generate and send e for Diffie-Hellman.
4064 */
4065 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4066 ssh2_pkt_init(ssh, s->kex_init_value);
4067 ssh2_pkt_addmp(ssh, s->e);
4068 ssh2_pkt_send(ssh);
4069
4070 crWaitUntil(ispkt);
4071 if (ssh->pktin.type != s->kex_reply_value) {
4072 bombout((ssh,"expected key exchange reply packet from server"));
4073 crReturn(0);
4074 }
4075 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4076 s->f = ssh2_pkt_getmp(ssh);
4077 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4078
4079 s->K = dh_find_K(ssh->kex_ctx, s->f);
4080
4081 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4082 if (ssh->kex == &ssh_diffiehellman_gex) {
4083 sha_uint32(&ssh->exhash, s->pbits);
4084 sha_mpint(&ssh->exhash, s->p);
4085 sha_mpint(&ssh->exhash, s->g);
4086 }
4087 sha_mpint(&ssh->exhash, s->e);
4088 sha_mpint(&ssh->exhash, s->f);
4089 sha_mpint(&ssh->exhash, s->K);
4090 SHA_Final(&ssh->exhash, s->exchange_hash);
4091
4092 dh_cleanup(ssh->kex_ctx);
4093 ssh->kex_ctx = NULL;
4094
4095 #if 0
4096 debug(("Exchange hash is:\n"));
4097 dmemdump(s->exchange_hash, 20);
4098 #endif
4099
4100 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4101 if (!s->hkey ||
4102 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4103 (char *)s->exchange_hash, 20)) {
4104 bombout((ssh,"Server's host key did not match the signature supplied"));
4105 crReturn(0);
4106 }
4107
4108 /*
4109 * Authenticate remote host: verify host key. (We've already
4110 * checked the signature of the exchange hash.)
4111 */
4112 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4113 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4114 verify_ssh_host_key(ssh->frontend,
4115 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4116 s->keystr, s->fingerprint);
4117 if (s->first_kex) { /* don't bother logging this in rekeys */
4118 logevent("Host key fingerprint is:");
4119 logevent(s->fingerprint);
4120 }
4121 sfree(s->fingerprint);
4122 sfree(s->keystr);
4123 ssh->hostkey->freekey(s->hkey);
4124
4125 /*
4126 * Send SSH2_MSG_NEWKEYS.
4127 */
4128 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4129 ssh2_pkt_send(ssh);
4130
4131 /*
4132 * Expect SSH2_MSG_NEWKEYS from server.
4133 */
4134 crWaitUntil(ispkt);
4135 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4136 bombout((ssh,"expected new-keys packet from server"));
4137 crReturn(0);
4138 }
4139
4140 /*
4141 * Create and initialise session keys.
4142 */
4143 if (ssh->cs_cipher_ctx)
4144 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4145 ssh->cscipher = s->cscipher_tobe;
4146 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4147
4148 if (ssh->sc_cipher_ctx)
4149 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4150 ssh->sccipher = s->sccipher_tobe;
4151 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4152
4153 if (ssh->cs_mac_ctx)
4154 ssh->csmac->free_context(ssh->cs_mac_ctx);
4155 ssh->csmac = s->csmac_tobe;
4156 ssh->cs_mac_ctx = ssh->csmac->make_context();
4157
4158 if (ssh->sc_mac_ctx)
4159 ssh->scmac->free_context(ssh->sc_mac_ctx);
4160 ssh->scmac = s->scmac_tobe;
4161 ssh->sc_mac_ctx = ssh->scmac->make_context();
4162
4163 if (ssh->cs_comp_ctx)
4164 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4165 ssh->cscomp = s->cscomp_tobe;
4166 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4167
4168 if (ssh->sc_comp_ctx)
4169 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4170 ssh->sccomp = s->sccomp_tobe;
4171 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4172
4173 /*
4174 * Set IVs after keys. Here we use the exchange hash from the
4175 * _first_ key exchange.
4176 */
4177 {
4178 unsigned char keyspace[40];
4179 if (s->first_kex)
4180 memcpy(ssh->v2_session_id, s->exchange_hash,
4181 sizeof(s->exchange_hash));
4182 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4183 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4184 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4185 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4186 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4187 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4188 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4189 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4190 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4191 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4192 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4193 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4194 }
4195 logeventf(ssh, "Initialised %.200s client->server encryption",
4196 ssh->cscipher->text_name);
4197 logeventf(ssh, "Initialised %.200s server->client encryption",
4198 ssh->sccipher->text_name);
4199 if (ssh->cscomp->text_name)
4200 logeventf(ssh, "Initialised %s compression",
4201 ssh->cscomp->text_name);
4202 if (ssh->sccomp->text_name)
4203 logeventf(ssh, "Initialised %s decompression",
4204 ssh->sccomp->text_name);
4205
4206 /*
4207 * If this is the first key exchange phase, we must pass the
4208 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4209 * wants to see it but because it will need time to initialise
4210 * itself before it sees an actual packet. In subsequent key
4211 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4212 * it would only confuse the layer above.
4213 */
4214 if (!s->first_kex) {
4215 crReturn(0);
4216 }
4217 s->first_kex = 0;
4218
4219 /*
4220 * Now we're encrypting. Begin returning 1 to the protocol main
4221 * function so that other things can run on top of the
4222 * transport. If we ever see a KEXINIT, we must go back to the
4223 * start.
4224 */
4225 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4226 crReturn(1);
4227 }
4228 logevent("Server initiated key re-exchange");
4229 goto begin_key_exchange;
4230
4231 crFinish(1);
4232 }
4233
4234 /*
4235 * Add data to an SSH2 channel output buffer.
4236 */
4237 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4238 int len)
4239 {
4240 bufchain_add(&c->v.v2.outbuffer, buf, len);
4241 }
4242
4243 /*
4244 * Attempt to send data on an SSH2 channel.
4245 */
4246 static int ssh2_try_send(struct ssh_channel *c)
4247 {
4248 Ssh ssh = c->ssh;
4249
4250 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4251 int len;
4252 void *data;
4253 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4254 if ((unsigned)len > c->v.v2.remwindow)
4255 len = c->v.v2.remwindow;
4256 if ((unsigned)len > c->v.v2.remmaxpkt)
4257 len = c->v.v2.remmaxpkt;
4258 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4259 ssh2_pkt_adduint32(ssh, c->remoteid);
4260 ssh2_pkt_addstring_start(ssh);
4261 ssh2_pkt_addstring_data(ssh, data, len);
4262 ssh2_pkt_send(ssh);
4263 bufchain_consume(&c->v.v2.outbuffer, len);
4264 c->v.v2.remwindow -= len;
4265 }
4266
4267 /*
4268 * After having sent as much data as we can, return the amount
4269 * still buffered.
4270 */
4271 return bufchain_size(&c->v.v2.outbuffer);
4272 }
4273
4274 /*
4275 * Potentially enlarge the window on an SSH2 channel.
4276 */
4277 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4278 {
4279 Ssh ssh = c->ssh;
4280
4281 /*
4282 * Never send WINDOW_ADJUST for a channel that the remote side
4283 * already thinks it's closed; there's no point, since it won't
4284 * be sending any more data anyway.
4285 */
4286 if (c->closes != 0)
4287 return;
4288
4289 if (newwin > c->v.v2.locwindow) {
4290 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4291 ssh2_pkt_adduint32(ssh, c->remoteid);
4292 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4293 ssh2_pkt_send(ssh);
4294 c->v.v2.locwindow = newwin;
4295 }
4296 }
4297
4298 /*
4299 * Handle the SSH2 userauth and connection layers.
4300 */
4301 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4302 {
4303 struct do_ssh2_authconn_state {
4304 enum {
4305 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4306 AUTH_PASSWORD,
4307 AUTH_KEYBOARD_INTERACTIVE
4308 } method;
4309 enum {
4310 AUTH_TYPE_NONE,
4311 AUTH_TYPE_PUBLICKEY,
4312 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4313 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4314 AUTH_TYPE_PASSWORD,
4315 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4316 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4317 } type;
4318 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4319 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4320 int kbd_inter_running;
4321 int we_are_in;
4322 int num_prompts, curr_prompt, echo;
4323 char username[100];
4324 int got_username;
4325 char pwprompt[200];
4326 char password[100];
4327 void *publickey_blob;
4328 int publickey_bloblen;
4329 unsigned char request[5], *response, *p;
4330 int responselen;
4331 int keyi, nkeys;
4332 int authed;
4333 char *pkblob, *alg, *commentp;
4334 int pklen, alglen, commentlen;
4335 int siglen, retlen, len;
4336 char *q, *agentreq, *ret;
4337 int try_send;
4338 };
4339 crState(do_ssh2_authconn_state);
4340
4341 crBegin(ssh->do_ssh2_authconn_crstate);
4342
4343 /*
4344 * Request userauth protocol, and await a response to it.
4345 */
4346 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4347 ssh2_pkt_addstring(ssh, "ssh-userauth");
4348 ssh2_pkt_send(ssh);
4349 crWaitUntilV(ispkt);
4350 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4351 bombout((ssh,"Server refused user authentication protocol"));
4352 crReturnV;
4353 }
4354
4355 /*
4356 * We repeat this whole loop, including the username prompt,
4357 * until we manage a successful authentication. If the user
4358 * types the wrong _password_, they can be sent back to the
4359 * beginning to try another username, if this is configured on.
4360 * (If they specify a username in the config, they are never
4361 * asked, even if they do give a wrong password.)
4362 *
4363 * I think this best serves the needs of
4364 *
4365 * - the people who have no configuration, no keys, and just
4366 * want to try repeated (username,password) pairs until they
4367 * type both correctly
4368 *
4369 * - people who have keys and configuration but occasionally
4370 * need to fall back to passwords
4371 *
4372 * - people with a key held in Pageant, who might not have
4373 * logged in to a particular machine before; so they want to
4374 * type a username, and then _either_ their key will be
4375 * accepted, _or_ they will type a password. If they mistype
4376 * the username they will want to be able to get back and
4377 * retype it!
4378 */
4379 s->username[0] = '\0';
4380 s->got_username = FALSE;
4381 do {
4382 /*
4383 * Get a username.
4384 */
4385 if (s->got_username && !ssh->cfg.change_username) {
4386 /*
4387 * We got a username last time round this loop, and
4388 * with change_username turned off we don't try to get
4389 * it again.
4390 */
4391 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
4392 if (ssh_get_line && !ssh_getline_pw_only) {
4393 if (!ssh_get_line("login as: ",
4394 s->username, sizeof(s->username), FALSE)) {
4395 /*
4396 * get_line failed to get a username.
4397 * Terminate.
4398 */
4399 logevent("No username provided. Abandoning session.");
4400 ssh->state = SSH_STATE_CLOSED;
4401 crReturnV;
4402 }
4403 } else {
4404 int ret; /* need not be saved across crReturn */
4405 c_write_str(ssh, "login as: ");
4406 ssh->send_ok = 1;
4407 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4408 do {
4409 crWaitUntilV(!ispkt);
4410 ret = process_userpass_input(ssh, in, inlen);
4411 } while (ret == 0);
4412 if (ret < 0)
4413 cleanup_exit(0);
4414 c_write_str(ssh, "\r\n");
4415 }
4416 s->username[strcspn(s->username, "\n\r")] = '\0';
4417 } else {
4418 char *stuff;
4419 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
4420 s->username[sizeof(s->username)-1] = '\0';
4421 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4422 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4423 c_write_str(ssh, stuff);
4424 sfree(stuff);
4425 }
4426 }
4427 s->got_username = TRUE;
4428
4429 /*
4430 * Send an authentication request using method "none": (a)
4431 * just in case it succeeds, and (b) so that we know what
4432 * authentication methods we can usefully try next.
4433 */
4434 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4435
4436 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4437 ssh2_pkt_addstring(ssh, s->username);
4438 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4439 ssh2_pkt_addstring(ssh, "none"); /* method */
4440 ssh2_pkt_send(ssh);
4441 s->type = AUTH_TYPE_NONE;
4442 s->gotit = FALSE;
4443 s->we_are_in = FALSE;
4444
4445 s->tried_pubkey_config = FALSE;
4446 s->tried_agent = FALSE;
4447 s->tried_keyb_inter = FALSE;
4448 s->kbd_inter_running = FALSE;
4449 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4450 if (!filename_is_null(ssh->cfg.keyfile)) {
4451 int keytype;
4452 logeventf(ssh, "Reading private key file \"%.150s\"",
4453 filename_to_str(&ssh->cfg.keyfile));
4454 keytype = key_type(&ssh->cfg.keyfile);
4455 if (keytype == SSH_KEYTYPE_SSH2) {
4456 s->publickey_blob =
4457 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
4458 &s->publickey_bloblen);
4459 } else {
4460 char *msgbuf;
4461 logeventf(ssh, "Unable to use this key file (%s)",
4462 key_type_to_str(keytype));
4463 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4464 " (%s)\r\n",
4465 filename_to_str(&ssh->cfg.keyfile),
4466 key_type_to_str(keytype));
4467 c_write_str(ssh, msgbuf);
4468 sfree(msgbuf);
4469 s->publickey_blob = NULL;
4470 }
4471 } else
4472 s->publickey_blob = NULL;
4473
4474 while (1) {
4475 /*
4476 * Wait for the result of the last authentication request.
4477 */
4478 if (!s->gotit)
4479 crWaitUntilV(ispkt);
4480 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4481 char *banner;
4482 int size;
4483 /*
4484 * Don't show the banner if we're operating in
4485 * non-verbose non-interactive mode. (It's probably
4486 * a script, which means nobody will read the
4487 * banner _anyway_, and moreover the printing of
4488 * the banner will screw up processing on the
4489 * output of (say) plink.)
4490 */
4491 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4492 ssh2_pkt_getstring(ssh, &banner, &size);
4493 if (banner)
4494 c_write_untrusted(ssh, banner, size);
4495 }
4496 crWaitUntilV(ispkt);
4497 }
4498 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4499 logevent("Access granted");
4500 s->we_are_in = TRUE;
4501 break;
4502 }
4503
4504 if (s->kbd_inter_running &&
4505 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4506 /*
4507 * This is either a further set-of-prompts packet
4508 * in keyboard-interactive authentication, or it's
4509 * the same one and we came back here with `gotit'
4510 * set. In the former case, we must reset the
4511 * curr_prompt variable.
4512 */
4513 if (!s->gotit)
4514 s->curr_prompt = 0;
4515 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4516 bombout((ssh,"Strange packet received during authentication: type %d",
4517 ssh->pktin.type));
4518 crReturnV;
4519 }
4520
4521 s->gotit = FALSE;
4522
4523 /*
4524 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4525 * we can look at the string in it and know what we can
4526 * helpfully try next.
4527 */
4528 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4529 char *methods;
4530 int methlen;
4531 ssh2_pkt_getstring(ssh, &methods, &methlen);
4532 s->kbd_inter_running = FALSE;
4533 if (!ssh2_pkt_getbool(ssh)) {
4534 /*
4535 * We have received an unequivocal Access
4536 * Denied. This can translate to a variety of
4537 * messages:
4538 *
4539 * - if we'd just tried "none" authentication,
4540 * it's not worth printing anything at all
4541 *
4542 * - if we'd just tried a public key _offer_,
4543 * the message should be "Server refused our
4544 * key" (or no message at all if the key
4545 * came from Pageant)
4546 *
4547 * - if we'd just tried anything else, the
4548 * message really should be "Access denied".
4549 *
4550 * Additionally, if we'd just tried password
4551 * authentication, we should break out of this
4552 * whole loop so as to go back to the username
4553 * prompt.
4554 */
4555 if (s->type == AUTH_TYPE_NONE) {
4556 /* do nothing */
4557 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4558 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4559 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4560 c_write_str(ssh, "Server refused our key\r\n");
4561 logevent("Server refused public key");
4562 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4563 /* server declined keyboard-interactive; ignore */
4564 } else {
4565 c_write_str(ssh, "Access denied\r\n");
4566 logevent("Access denied");
4567 if (s->type == AUTH_TYPE_PASSWORD) {
4568 s->we_are_in = FALSE;
4569 break;
4570 }
4571 }
4572 } else {
4573 c_write_str(ssh, "Further authentication required\r\n");
4574 logevent("Further authentication required");
4575 }
4576
4577 s->can_pubkey =
4578 in_commasep_string("publickey", methods, methlen);
4579 s->can_passwd =
4580 in_commasep_string("password", methods, methlen);
4581 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
4582 in_commasep_string("keyboard-interactive", methods, methlen);
4583 }
4584
4585 s->method = 0;
4586 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4587
4588 /*
4589 * Most password/passphrase prompts will be
4590 * non-echoing, so we set this to 0 by default.
4591 * Exception is that some keyboard-interactive prompts
4592 * can be echoing, in which case we'll set this to 1.
4593 */
4594 s->echo = 0;
4595
4596 if (!s->method && s->can_pubkey &&
4597 agent_exists() && !s->tried_agent) {
4598 /*
4599 * Attempt public-key authentication using Pageant.
4600 */
4601 void *r;
4602 s->authed = FALSE;
4603
4604 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4605 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4606
4607 s->tried_agent = TRUE;
4608
4609 logevent("Pageant is running. Requesting keys.");
4610
4611 /* Request the keys held by the agent. */
4612 PUT_32BIT(s->request, 1);
4613 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4614 agent_query(s->request, 5, &r, &s->responselen);
4615 s->response = (unsigned char *) r;
4616 if (s->response && s->responselen >= 5 &&
4617 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4618 s->p = s->response + 5;
4619 s->nkeys = GET_32BIT(s->p);
4620 s->p += 4;
4621 {
4622 char buf[64];
4623 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4624 logevent(buf);
4625 }
4626 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4627 void *vret;
4628
4629 {
4630 char buf[64];
4631 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4632 logevent(buf);
4633 }
4634 s->pklen = GET_32BIT(s->p);
4635 s->p += 4;
4636 if (s->publickey_blob &&
4637 s->pklen == s->publickey_bloblen &&
4638 !memcmp(s->p, s->publickey_blob,
4639 s->publickey_bloblen)) {
4640 logevent("This key matches configured key file");
4641 s->tried_pubkey_config = 1;
4642 }
4643 s->pkblob = (char *)s->p;
4644 s->p += s->pklen;
4645 s->alglen = GET_32BIT(s->pkblob);
4646 s->alg = s->pkblob + 4;
4647 s->commentlen = GET_32BIT(s->p);
4648 s->p += 4;
4649 s->commentp = (char *)s->p;
4650 s->p += s->commentlen;
4651 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4652 ssh2_pkt_addstring(ssh, s->username);
4653 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4654 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4655 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4656 ssh2_pkt_addstring_start(ssh);
4657 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4658 ssh2_pkt_addstring_start(ssh);
4659 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4660 ssh2_pkt_send(ssh);
4661
4662 crWaitUntilV(ispkt);
4663 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4664 logevent("Key refused");
4665 continue;
4666 }
4667
4668 if (flags & FLAG_VERBOSE) {
4669 c_write_str(ssh, "Authenticating with "
4670 "public key \"");
4671 c_write(ssh, s->commentp, s->commentlen);
4672 c_write_str(ssh, "\" from agent\r\n");
4673 }
4674
4675 /*
4676 * Server is willing to accept the key.
4677 * Construct a SIGN_REQUEST.
4678 */
4679 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4680 ssh2_pkt_addstring(ssh, s->username);
4681 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4682 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4683 ssh2_pkt_addbool(ssh, TRUE);
4684 ssh2_pkt_addstring_start(ssh);
4685 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4686 ssh2_pkt_addstring_start(ssh);
4687 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4688
4689 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4690 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4691 s->siglen -= 4;
4692 s->len = 1; /* message type */
4693 s->len += 4 + s->pklen; /* key blob */
4694 s->len += 4 + s->siglen; /* data to sign */
4695 s->len += 4; /* flags */
4696 s->agentreq = snewn(4 + s->len, char);
4697 PUT_32BIT(s->agentreq, s->len);
4698 s->q = s->agentreq + 4;
4699 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4700 PUT_32BIT(s->q, s->pklen);
4701 s->q += 4;
4702 memcpy(s->q, s->pkblob, s->pklen);
4703 s->q += s->pklen;
4704 PUT_32BIT(s->q, s->siglen);
4705 s->q += 4;
4706 /* Now the data to be signed... */
4707 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
4708 PUT_32BIT(s->q, 20);
4709 s->q += 4;
4710 }
4711 memcpy(s->q, ssh->v2_session_id, 20);
4712 s->q += 20;
4713 memcpy(s->q, ssh->pktout.data + 5,
4714 ssh->pktout.length - 5);
4715 s->q += ssh->pktout.length - 5;
4716 /* And finally the (zero) flags word. */
4717 PUT_32BIT(s->q, 0);
4718 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4719 s->ret = vret;
4720 sfree(s->agentreq);
4721 if (s->ret) {
4722 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4723 logevent("Sending Pageant's response");
4724 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4725 s->ret + 9,
4726 GET_32BIT(s->ret + 5));
4727 ssh2_pkt_send(ssh);
4728 s->authed = TRUE;
4729 break;
4730 } else {
4731 logevent
4732 ("Pageant failed to answer challenge");
4733 sfree(s->ret);
4734 }
4735 }
4736 }
4737 if (s->authed)
4738 continue;
4739 }
4740 }
4741
4742 if (!s->method && s->can_pubkey && s->publickey_blob
4743 && !s->tried_pubkey_config) {
4744 unsigned char *pub_blob;
4745 char *algorithm, *comment;
4746 int pub_blob_len;
4747
4748 s->tried_pubkey_config = TRUE;
4749
4750 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4751 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4752
4753 /*
4754 * Try the public key supplied in the configuration.
4755 *
4756 * First, offer the public blob to see if the server is
4757 * willing to accept it.
4758 */
4759 pub_blob =
4760 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
4761 &algorithm,
4762 &pub_blob_len);
4763 if (pub_blob) {
4764 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4765 ssh2_pkt_addstring(ssh, s->username);
4766 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4767 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4768 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4769 ssh2_pkt_addstring(ssh, algorithm);
4770 ssh2_pkt_addstring_start(ssh);
4771 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4772 pub_blob_len);
4773 ssh2_pkt_send(ssh);
4774 logevent("Offered public key"); /* FIXME */
4775
4776 crWaitUntilV(ispkt);
4777 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4778 s->gotit = TRUE;
4779 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4780 continue; /* key refused; give up on it */
4781 }
4782
4783 logevent("Offer of public key accepted");
4784 /*
4785 * Actually attempt a serious authentication using
4786 * the key.
4787 */
4788 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
4789 sprintf(s->pwprompt,
4790 "Passphrase for key \"%.100s\": ",
4791 comment);
4792 s->need_pw = TRUE;
4793 } else {
4794 s->need_pw = FALSE;
4795 }
4796 c_write_str(ssh, "Authenticating with public key \"");
4797 c_write_str(ssh, comment);
4798 c_write_str(ssh, "\"\r\n");
4799 s->method = AUTH_PUBLICKEY_FILE;
4800 }
4801 }
4802
4803 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4804 s->method = AUTH_KEYBOARD_INTERACTIVE;
4805 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4806 s->tried_keyb_inter = TRUE;
4807
4808 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4809 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4810
4811 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4812 ssh2_pkt_addstring(ssh, s->username);
4813 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4814 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4815 ssh2_pkt_addstring(ssh, ""); /* lang */
4816 ssh2_pkt_addstring(ssh, "");
4817 ssh2_pkt_send(ssh);
4818
4819 crWaitUntilV(ispkt);
4820 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4821 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4822 s->gotit = TRUE;
4823 logevent("Keyboard-interactive authentication refused");
4824 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4825 continue;
4826 }
4827
4828 s->kbd_inter_running = TRUE;
4829 s->curr_prompt = 0;
4830 }
4831
4832 if (s->kbd_inter_running) {
4833 s->method = AUTH_KEYBOARD_INTERACTIVE;
4834 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4835 s->tried_keyb_inter = TRUE;
4836
4837 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4838 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4839
4840 if (s->curr_prompt == 0) {
4841 /*
4842 * We've got a fresh USERAUTH_INFO_REQUEST.
4843 * Display header data, and start going through
4844 * the prompts.
4845 */
4846 char *name, *inst, *lang;
4847 int name_len, inst_len, lang_len;
4848
4849 ssh2_pkt_getstring(ssh, &name, &name_len);
4850 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4851 ssh2_pkt_getstring(ssh, &lang, &lang_len);
4852 if (name_len > 0) {
4853 c_write_untrusted(ssh, name, name_len);
4854 c_write_str(ssh, "\r\n");
4855 }
4856 if (inst_len > 0) {
4857 c_write_untrusted(ssh, inst, inst_len);
4858 c_write_str(ssh, "\r\n");
4859 }
4860 s->num_prompts = ssh2_pkt_getuint32(ssh);
4861 }
4862
4863 /*
4864 * If there are prompts remaining in the packet,
4865 * display one and get a response.
4866 */
4867 if (s->curr_prompt < s->num_prompts) {
4868 char *prompt;
4869 int prompt_len;
4870
4871 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
4872 if (prompt_len > 0) {
4873 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4874 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4875 prompt_len : sizeof(s->pwprompt)-1] = '\0';
4876 } else {
4877 strcpy(s->pwprompt,
4878 "<server failed to send prompt>: ");
4879 }
4880 s->echo = ssh2_pkt_getbool(ssh);
4881 s->need_pw = TRUE;
4882 } else
4883 s->need_pw = FALSE;
4884 }
4885
4886 if (!s->method && s->can_passwd) {
4887 s->method = AUTH_PASSWORD;
4888 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4889 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4890 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4891 ssh->savedhost);
4892 s->need_pw = TRUE;
4893 }
4894
4895 if (s->need_pw) {
4896 if (ssh_get_line) {
4897 if (!ssh_get_line(s->pwprompt, s->password,
4898 sizeof(s->password), TRUE)) {
4899 /*
4900 * get_line failed to get a password (for
4901 * example because one was supplied on the
4902 * command line which has already failed to
4903 * work). Terminate.
4904 */
4905 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4906 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4907 ssh2_pkt_addstring(ssh, "No more passwords available"
4908 " to try");
4909 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4910 ssh2_pkt_send(ssh);
4911 logevent("Unable to authenticate");
4912 connection_fatal(ssh->frontend,
4913 "Unable to authenticate");
4914 ssh->state = SSH_STATE_CLOSED;
4915 crReturnV;
4916 }
4917 } else {
4918 int ret; /* need not be saved across crReturn */
4919 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4920 ssh->send_ok = 1;
4921
4922 setup_userpass_input(ssh, s->password,
4923 sizeof(s->password), s->echo);
4924 do {
4925 crWaitUntilV(!ispkt);
4926 ret = process_userpass_input(ssh, in, inlen);
4927 } while (ret == 0);
4928 if (ret < 0)
4929 cleanup_exit(0);
4930 c_write_str(ssh, "\r\n");
4931 }
4932 }
4933
4934 if (s->method == AUTH_PUBLICKEY_FILE) {
4935 /*
4936 * We have our passphrase. Now try the actual authentication.
4937 */
4938 struct ssh2_userkey *key;
4939
4940 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password);
4941 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4942 if (key == SSH2_WRONG_PASSPHRASE) {
4943 c_write_str(ssh, "Wrong passphrase\r\n");
4944 s->tried_pubkey_config = FALSE;
4945 } else {
4946 c_write_str(ssh, "Unable to load private key\r\n");
4947 s->tried_pubkey_config = TRUE;
4948 }
4949 /* Send a spurious AUTH_NONE to return to the top. */
4950 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4951 ssh2_pkt_addstring(ssh, s->username);
4952 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4953 ssh2_pkt_addstring(ssh, "none"); /* method */
4954 ssh2_pkt_send(ssh);
4955 s->type = AUTH_TYPE_NONE;
4956 } else {
4957 unsigned char *pkblob, *sigblob, *sigdata;
4958 int pkblob_len, sigblob_len, sigdata_len;
4959 int p;
4960
4961 /*
4962 * We have loaded the private key and the server
4963 * has announced that it's willing to accept it.
4964 * Hallelujah. Generate a signature and send it.
4965 */
4966 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4967 ssh2_pkt_addstring(ssh, s->username);
4968 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4969 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4970 ssh2_pkt_addbool(ssh, TRUE);
4971 ssh2_pkt_addstring(ssh, key->alg->name);
4972 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4973 ssh2_pkt_addstring_start(ssh);
4974 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
4975
4976 /*
4977 * The data to be signed is:
4978 *
4979 * string session-id
4980 *
4981 * followed by everything so far placed in the
4982 * outgoing packet.
4983 */
4984 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
4985 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
4986 sigdata_len -= 4;
4987 sigdata = snewn(sigdata_len, char);
4988 p = 0;
4989 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
4990 PUT_32BIT(sigdata+p, 20);
4991 p += 4;
4992 }
4993 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
4994 memcpy(sigdata+p, ssh->pktout.data + 5,
4995 ssh->pktout.length - 5);
4996 p += ssh->pktout.length - 5;
4997 assert(p == sigdata_len);
4998 sigblob = key->alg->sign(key->data, (char *)sigdata,
4999 sigdata_len, &sigblob_len);
5000 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
5001 sigblob, sigblob_len);
5002 sfree(pkblob);
5003 sfree(sigblob);
5004 sfree(sigdata);
5005
5006 ssh2_pkt_send(ssh);
5007 s->type = AUTH_TYPE_PUBLICKEY;
5008 }
5009 } else if (s->method == AUTH_PASSWORD) {
5010 /*
5011 * We send the password packet lumped tightly together with
5012 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5013 * string long enough to make the total length of the two
5014 * packets constant. This should ensure that a passive
5015 * listener doing traffic analyis can't work out the length
5016 * of the password.
5017 *
5018 * For this to work, we need an assumption about the
5019 * maximum length of the password packet. I think 256 is
5020 * pretty conservative. Anyone using a password longer than
5021 * that probably doesn't have much to worry about from
5022 * people who find out how long their password is!
5023 */
5024 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5025 ssh2_pkt_addstring(ssh, s->username);
5026 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5027 ssh2_pkt_addstring(ssh, "password");
5028 ssh2_pkt_addbool(ssh, FALSE);
5029 ssh2_pkt_addstring(ssh, s->password);
5030 memset(s->password, 0, sizeof(s->password));
5031 ssh2_pkt_defer(ssh);
5032 /*
5033 * We'll include a string that's an exact multiple of the
5034 * cipher block size. If the cipher is NULL for some
5035 * reason, we don't do this trick at all because we gain
5036 * nothing by it.
5037 */
5038 if (ssh->cscipher) {
5039 int stringlen, i;
5040
5041 stringlen = (256 - ssh->deferred_len);
5042 stringlen += ssh->cscipher->blksize - 1;
5043 stringlen -= (stringlen % ssh->cscipher->blksize);
5044 if (ssh->cscomp) {
5045 /*
5046 * Temporarily disable actual compression,
5047 * so we can guarantee to get this string
5048 * exactly the length we want it. The
5049 * compression-disabling routine should
5050 * return an integer indicating how many
5051 * bytes we should adjust our string length
5052 * by.
5053 */
5054 stringlen -=
5055 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
5056 }
5057 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5058 ssh2_pkt_addstring_start(ssh);
5059 for (i = 0; i < stringlen; i++) {
5060 char c = (char) random_byte();
5061 ssh2_pkt_addstring_data(ssh, &c, 1);
5062 }
5063 ssh2_pkt_defer(ssh);
5064 }
5065 ssh_pkt_defersend(ssh);
5066 logevent("Sent password");
5067 s->type = AUTH_TYPE_PASSWORD;
5068 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5069 if (s->curr_prompt == 0) {
5070 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5071 ssh2_pkt_adduint32(ssh, s->num_prompts);
5072 }
5073 if (s->need_pw) { /* only add pw if we just got one! */
5074 ssh2_pkt_addstring(ssh, s->password);
5075 memset(s->password, 0, sizeof(s->password));
5076 s->curr_prompt++;
5077 }
5078 if (s->curr_prompt >= s->num_prompts) {
5079 ssh2_pkt_send(ssh);
5080 } else {
5081 /*
5082 * If there are prompts remaining, we set
5083 * `gotit' so that we won't attempt to get
5084 * another packet. Then we go back round the
5085 * loop and will end up retrieving another
5086 * prompt out of the existing packet. Funky or
5087 * what?
5088 */
5089 s->gotit = TRUE;
5090 }
5091 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5092 } else {
5093 c_write_str(ssh, "No supported authentication methods"
5094 " left to try!\r\n");
5095 logevent("No supported authentications offered."
5096 " Disconnecting");
5097 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5098 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5099 ssh2_pkt_addstring(ssh, "No supported authentication"
5100 " methods available");
5101 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5102 ssh2_pkt_send(ssh);
5103 ssh->state = SSH_STATE_CLOSED;
5104 crReturnV;
5105 }
5106 }
5107 } while (!s->we_are_in);
5108
5109 /*
5110 * Now we're authenticated for the connection protocol. The
5111 * connection protocol will automatically have started at this
5112 * point; there's no need to send SERVICE_REQUEST.
5113 */
5114
5115 /*
5116 * So now create a channel with a session in it.
5117 */
5118 ssh->channels = newtree234(ssh_channelcmp);
5119 ssh->mainchan = snew(struct ssh_channel);
5120 ssh->mainchan->ssh = ssh;
5121 ssh->mainchan->localid = alloc_channel_id(ssh);
5122 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5123 ssh2_pkt_addstring(ssh, "session");
5124 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5125 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5126 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5127 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5128 ssh2_pkt_send(ssh);
5129 crWaitUntilV(ispkt);
5130 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5131 bombout((ssh,"Server refused to open a session"));
5132 crReturnV;
5133 /* FIXME: error data comes back in FAILURE packet */
5134 }
5135 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5136 bombout((ssh,"Server's channel confirmation cited wrong channel"));
5137 crReturnV;
5138 }
5139 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5140 ssh->mainchan->type = CHAN_MAINSESSION;
5141 ssh->mainchan->closes = 0;
5142 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5143 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5144 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5145 add234(ssh->channels, ssh->mainchan);
5146 logevent("Opened channel for session");
5147
5148 /*
5149 * Potentially enable X11 forwarding.
5150 */
5151 if (ssh->cfg.x11_forward) {
5152 char proto[20], data[64];
5153 logevent("Requesting X11 forwarding");
5154 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5155 data, sizeof(data), ssh->cfg.x11_auth);
5156 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
5157 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5158 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5159 ssh2_pkt_addstring(ssh, "x11-req");
5160 ssh2_pkt_addbool(ssh, 1); /* want reply */
5161 ssh2_pkt_addbool(ssh, 0); /* many connections */
5162 ssh2_pkt_addstring(ssh, proto);
5163 ssh2_pkt_addstring(ssh, data);
5164 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
5165 ssh2_pkt_send(ssh);
5166
5167 do {
5168 crWaitUntilV(ispkt);
5169 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5170 unsigned i = ssh2_pkt_getuint32(ssh);
5171 struct ssh_channel *c;
5172 c = find234(ssh->channels, &i, ssh_channelfind);
5173 if (!c)
5174 continue; /* nonexistent channel */
5175 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5176 }
5177 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5178
5179 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5180 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5181 bombout((ssh,"Unexpected response to X11 forwarding request:"
5182 " packet type %d", ssh->pktin.type));
5183 crReturnV;
5184 }
5185 logevent("X11 forwarding refused");
5186 } else {
5187 logevent("X11 forwarding enabled");
5188 ssh->X11_fwd_enabled = TRUE;
5189 }
5190 }
5191
5192 /*
5193 * Enable port forwardings.
5194 */
5195 {
5196 char type;
5197 int n;
5198 int sport,dport,sserv,dserv;
5199 char sports[256], dports[256], saddr[256], host[256];
5200
5201 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5202 /* Add port forwardings. */
5203 ssh->portfwd_strptr = ssh->cfg.portfwd;
5204 while (*ssh->portfwd_strptr) {
5205 type = *ssh->portfwd_strptr++;
5206 saddr[0] = '\0';
5207 n = 0;
5208 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5209 if (*ssh->portfwd_strptr == ':') {
5210 /*
5211 * We've seen a colon in the middle of the
5212 * source port number. This means that
5213 * everything we've seen until now is the
5214 * source _address_, so we'll move it into
5215 * saddr and start sports from the beginning
5216 * again.
5217 */
5218 ssh->portfwd_strptr++;
5219 sports[n] = '\0';
5220 strcpy(saddr, sports);
5221 n = 0;
5222 }
5223 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5224 }
5225 sports[n] = 0;
5226 if (*ssh->portfwd_strptr == '\t')
5227 ssh->portfwd_strptr++;
5228 n = 0;
5229 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5230 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5231 }
5232 host[n] = 0;
5233 if (*ssh->portfwd_strptr == ':')
5234 ssh->portfwd_strptr++;
5235 n = 0;
5236 while (*ssh->portfwd_strptr) {
5237 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5238 }
5239 dports[n] = 0;
5240 ssh->portfwd_strptr++;
5241 dport = atoi(dports);
5242 dserv = 0;
5243 if (dport == 0) {
5244 dserv = 1;
5245 dport = net_service_lookup(dports);
5246 if (!dport) {
5247 logeventf(ssh, "Service lookup failed for destination"
5248 " port \"%s\"", dports);
5249 }
5250 }
5251 sport = atoi(sports);
5252 sserv = 0;
5253 if (sport == 0) {
5254 sserv = 1;
5255 sport = net_service_lookup(sports);
5256 if (!sport) {
5257 logeventf(ssh, "Service lookup failed for source"
5258 " port \"%s\"", sports);
5259 }
5260 }
5261 if (sport && dport) {
5262 if (type == 'L') {
5263 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5264 sport, ssh, &ssh->cfg);
5265 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5266 " forwarding to %s:%.*s%.*s%d%.*s",
5267 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5268 (int)(*saddr?1:0), ":",
5269 (int)(sserv ? strlen(sports) : 0), sports,
5270 sserv, "(", sport, sserv, ")",
5271 host,
5272 (int)(dserv ? strlen(dports) : 0), dports,
5273 dserv, "(", dport, dserv, ")");
5274 } else {
5275 struct ssh_rportfwd *pf;
5276 pf = snew(struct ssh_rportfwd);
5277 strcpy(pf->dhost, host);
5278 pf->dport = dport;
5279 pf->sport = sport;
5280 if (add234(ssh->rportfwds, pf) != pf) {
5281 logeventf(ssh, "Duplicate remote port forwarding"
5282 " to %s:%d", host, dport);
5283 sfree(pf);
5284 } else {
5285 logeventf(ssh, "Requesting remote port "
5286 "%.*s%.*s%.*s%.*s%d%.*s"
5287 " forward to %s:%.*s%.*s%d%.*s",
5288 (int)(*saddr?strlen(saddr):0),
5289 *saddr?saddr:NULL,
5290 (int)(*saddr?1:0), ":",
5291 (int)(sserv ? strlen(sports) : 0), sports,
5292 sserv, "(", sport, sserv, ")",
5293 host,
5294 (int)(dserv ? strlen(dports) : 0), dports,
5295 dserv, "(", dport, dserv, ")");
5296 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5297 ssh2_pkt_addstring(ssh, "tcpip-forward");
5298 ssh2_pkt_addbool(ssh, 1);/* want reply */
5299 if (*saddr)
5300 ssh2_pkt_addstring(ssh, saddr);
5301 if (ssh->cfg.rport_acceptall)
5302 ssh2_pkt_addstring(ssh, "0.0.0.0");
5303 else
5304 ssh2_pkt_addstring(ssh, "127.0.0.1");
5305 ssh2_pkt_adduint32(ssh, sport);
5306 ssh2_pkt_send(ssh);
5307
5308 do {
5309 crWaitUntilV(ispkt);
5310 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5311 unsigned i = ssh2_pkt_getuint32(ssh);
5312 struct ssh_channel *c;
5313 c = find234(ssh->channels, &i, ssh_channelfind);
5314 if (!c)
5315 continue;/* nonexistent channel */
5316 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5317 }
5318 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5319
5320 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5321 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5322 bombout((ssh,"Unexpected response to port "
5323 "forwarding request: packet type %d",
5324 ssh->pktin.type));
5325 crReturnV;
5326 }
5327 logevent("Server refused this port forwarding");
5328 } else {
5329 logevent("Remote port forwarding enabled");
5330 }
5331 }
5332 }
5333 }
5334 }
5335 }
5336
5337 /*
5338 * Potentially enable agent forwarding.
5339 */
5340 if (ssh->cfg.agentfwd && agent_exists()) {
5341 logevent("Requesting OpenSSH-style agent forwarding");
5342 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5343 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5344 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5345 ssh2_pkt_addbool(ssh, 1); /* want reply */
5346 ssh2_pkt_send(ssh);
5347
5348 do {
5349 crWaitUntilV(ispkt);
5350 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5351 unsigned i = ssh2_pkt_getuint32(ssh);
5352 struct ssh_channel *c;
5353 c = find234(ssh->channels, &i, ssh_channelfind);
5354 if (!c)
5355 continue; /* nonexistent channel */
5356 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5357 }
5358 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5359
5360 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5361 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5362 bombout((ssh,"Unexpected response to agent forwarding request:"
5363 " packet type %d", ssh->pktin.type));
5364 crReturnV;
5365 }
5366 logevent("Agent forwarding refused");
5367 } else {
5368 logevent("Agent forwarding enabled");
5369 ssh->agentfwd_enabled = TRUE;
5370 }
5371 }
5372
5373 /*
5374 * Now allocate a pty for the session.
5375 */
5376 if (!ssh->cfg.nopty) {
5377 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5378 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5379 ssh2_pkt_addstring(ssh, "pty-req");
5380 ssh2_pkt_addbool(ssh, 1); /* want reply */
5381 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
5382 ssh2_pkt_adduint32(ssh, ssh->term_width);
5383 ssh2_pkt_adduint32(ssh, ssh->term_height);
5384 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5385 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5386 ssh2_pkt_addstring_start(ssh);
5387 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5388 ssh2_pkt_send(ssh);
5389 ssh->state = SSH_STATE_INTERMED;
5390
5391 do {
5392 crWaitUntilV(ispkt);
5393 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5394 unsigned i = ssh2_pkt_getuint32(ssh);
5395 struct ssh_channel *c;
5396 c = find234(ssh->channels, &i, ssh_channelfind);
5397 if (!c)
5398 continue; /* nonexistent channel */
5399 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5400 }
5401 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5402
5403 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5404 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5405 bombout((ssh,"Unexpected response to pty request:"
5406 " packet type %d", ssh->pktin.type));
5407 crReturnV;
5408 }
5409 c_write_str(ssh, "Server refused to allocate pty\r\n");
5410 ssh->editing = ssh->echoing = 1;
5411 } else {
5412 logevent("Allocated pty");
5413 }
5414 } else {
5415 ssh->editing = ssh->echoing = 1;
5416 }
5417
5418 /*
5419 * Start a shell or a remote command. We may have to attempt
5420 * this twice if the config data has provided a second choice
5421 * of command.
5422 */
5423 while (1) {
5424 int subsys;
5425 char *cmd;
5426
5427 if (ssh->fallback_cmd) {
5428 subsys = ssh->cfg.ssh_subsys2;
5429 cmd = ssh->cfg.remote_cmd_ptr2;
5430 } else {
5431 subsys = ssh->cfg.ssh_subsys;
5432 cmd = ssh->cfg.remote_cmd_ptr;
5433 }
5434
5435 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5436 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5437 if (subsys) {
5438 ssh2_pkt_addstring(ssh, "subsystem");
5439 ssh2_pkt_addbool(ssh, 1); /* want reply */
5440 ssh2_pkt_addstring(ssh, cmd);
5441 } else if (*cmd) {
5442 ssh2_pkt_addstring(ssh, "exec");
5443 ssh2_pkt_addbool(ssh, 1); /* want reply */
5444 ssh2_pkt_addstring(ssh, cmd);
5445 } else {
5446 ssh2_pkt_addstring(ssh, "shell");
5447 ssh2_pkt_addbool(ssh, 1); /* want reply */
5448 }
5449 ssh2_pkt_send(ssh);
5450 do {
5451 crWaitUntilV(ispkt);
5452 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5453 unsigned i = ssh2_pkt_getuint32(ssh);
5454 struct ssh_channel *c;
5455 c = find234(ssh->channels, &i, ssh_channelfind);
5456 if (!c)
5457 continue; /* nonexistent channel */
5458 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5459 }
5460 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5461 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5462 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5463 bombout((ssh,"Unexpected response to shell/command request:"
5464 " packet type %d", ssh->pktin.type));
5465 crReturnV;
5466 }
5467 /*
5468 * We failed to start the command. If this is the
5469 * fallback command, we really are finished; if it's
5470 * not, and if the fallback command exists, try falling
5471 * back to it before complaining.
5472 */
5473 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
5474 logevent("Primary command failed; attempting fallback");
5475 ssh->fallback_cmd = TRUE;
5476 continue;
5477 }
5478 bombout((ssh,"Server refused to start a shell/command"));
5479 crReturnV;
5480 } else {
5481 logevent("Started a shell/command");
5482 }
5483 break;
5484 }
5485
5486 ssh->state = SSH_STATE_SESSION;
5487 if (ssh->size_needed)
5488 ssh_size(ssh, ssh->term_width, ssh->term_height);
5489 if (ssh->eof_needed)
5490 ssh_special(ssh, TS_EOF);
5491
5492 /*
5493 * Transfer data!
5494 */
5495 if (ssh->ldisc)
5496 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5497 ssh->send_ok = 1;
5498 while (1) {
5499 crReturnV;
5500 s->try_send = FALSE;
5501 if (ispkt) {
5502 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5503 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5504 char *data;
5505 int length;
5506 unsigned i = ssh2_pkt_getuint32(ssh);
5507 struct ssh_channel *c;
5508 c = find234(ssh->channels, &i, ssh_channelfind);
5509 if (!c)
5510 continue; /* nonexistent channel */
5511 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5512 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5513 continue; /* extended but not stderr */
5514 ssh2_pkt_getstring(ssh, &data, &length);
5515 if (data) {
5516 int bufsize;
5517 c->v.v2.locwindow -= length;
5518 switch (c->type) {
5519 case CHAN_MAINSESSION:
5520 bufsize =
5521 from_backend(ssh->frontend, ssh->pktin.type ==
5522 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5523 data, length);
5524 break;
5525 case CHAN_X11:
5526 bufsize = x11_send(c->u.x11.s, data, length);
5527 break;
5528 case CHAN_SOCKDATA:
5529 bufsize = pfd_send(c->u.pfd.s, data, length);
5530 break;
5531 case CHAN_AGENT:
5532 while (length > 0) {
5533 if (c->u.a.lensofar < 4) {
5534 int l = min(4 - c->u.a.lensofar, length);
5535 memcpy(c->u.a.msglen + c->u.a.lensofar,
5536 data, l);
5537 data += l;
5538 length -= l;
5539 c->u.a.lensofar += l;
5540 }
5541 if (c->u.a.lensofar == 4) {
5542 c->u.a.totallen =
5543 4 + GET_32BIT(c->u.a.msglen);
5544 c->u.a.message = snewn(c->u.a.totallen,
5545 unsigned char);
5546 memcpy(c->u.a.message, c->u.a.msglen, 4);
5547 }
5548 if (c->u.a.lensofar >= 4 && length > 0) {
5549 int l =
5550 min(c->u.a.totallen - c->u.a.lensofar,
5551 length);
5552 memcpy(c->u.a.message + c->u.a.lensofar,
5553 data, l);
5554 data += l;
5555 length -= l;
5556 c->u.a.lensofar += l;
5557 }
5558 if (c->u.a.lensofar == c->u.a.totallen) {
5559 void *reply, *sentreply;
5560 int replylen;
5561 agent_query(c->u.a.message,
5562 c->u.a.totallen, &reply,
5563 &replylen);
5564 if (reply)
5565 sentreply = reply;
5566 else {
5567 /* Fake SSH_AGENT_FAILURE. */
5568 sentreply = "\0\0\0\1\5";
5569 replylen = 5;
5570 }
5571 ssh2_add_channel_data(c, sentreply, replylen);
5572 s->try_send = TRUE;
5573 if (reply)
5574 sfree(reply);
5575 sfree(c->u.a.message);
5576 c->u.a.lensofar = 0;
5577 }
5578 }
5579 bufsize = 0;
5580 break;
5581 }
5582 /*
5583 * If we are not buffering too much data,
5584 * enlarge the window again at the remote side.
5585 */
5586 if (bufsize < OUR_V2_WINSIZE)
5587 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5588 }
5589 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5590 unsigned i = ssh2_pkt_getuint32(ssh);
5591 struct ssh_channel *c;
5592
5593 c = find234(ssh->channels, &i, ssh_channelfind);
5594 if (!c)
5595 continue; /* nonexistent channel */
5596
5597 if (c->type == CHAN_X11) {
5598 /*
5599 * Remote EOF on an X11 channel means we should
5600 * wrap up and close the channel ourselves.
5601 */
5602 x11_close(c->u.x11.s);
5603 sshfwd_close(c);
5604 } else if (c->type == CHAN_AGENT) {
5605 sshfwd_close(c);
5606 } else if (c->type == CHAN_SOCKDATA) {
5607 pfd_close(c->u.pfd.s);
5608 sshfwd_close(c);
5609 }
5610 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5611 unsigned i = ssh2_pkt_getuint32(ssh);
5612 struct ssh_channel *c;
5613
5614 c = find234(ssh->channels, &i, ssh_channelfind);
5615 if (!c || ((int)c->remoteid) == -1) {
5616 bombout((ssh,"Received CHANNEL_CLOSE for %s channel %d\n",
5617 c ? "half-open" : "nonexistent", i));
5618 }
5619 /* Do pre-close processing on the channel. */
5620 switch (c->type) {
5621 case CHAN_MAINSESSION:
5622 break; /* nothing to see here, move along */
5623 case CHAN_X11:
5624 if (c->u.x11.s != NULL)
5625 x11_close(c->u.x11.s);
5626 sshfwd_close(c);
5627 break;
5628 case CHAN_AGENT:
5629 sshfwd_close(c);
5630 break;
5631 case CHAN_SOCKDATA:
5632 if (c->u.pfd.s != NULL)
5633 pfd_close(c->u.pfd.s);
5634 sshfwd_close(c);
5635 break;
5636 }
5637 if (c->closes == 0) {
5638 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5639 ssh2_pkt_adduint32(ssh, c->remoteid);
5640 ssh2_pkt_send(ssh);
5641 }
5642 del234(ssh->channels, c);
5643 bufchain_clear(&c->v.v2.outbuffer);
5644 sfree(c);
5645
5646 /*
5647 * See if that was the last channel left open.
5648 */
5649 if (count234(ssh->channels) == 0) {
5650 #if 0
5651 /*
5652 * We used to send SSH_MSG_DISCONNECT here,
5653 * because I'd believed that _every_ conforming
5654 * SSH2 connection had to end with a disconnect
5655 * being sent by at least one side; apparently
5656 * I was wrong and it's perfectly OK to
5657 * unceremoniously slam the connection shut
5658 * when you're done, and indeed OpenSSH feels
5659 * this is more polite than sending a
5660 * DISCONNECT. So now we don't.
5661 */
5662 logevent("All channels closed. Disconnecting");
5663 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5664 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5665 ssh2_pkt_addstring(ssh, "All open channels closed");
5666 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5667 ssh2_pkt_send(ssh);
5668 #endif
5669 ssh->state = SSH_STATE_CLOSED;
5670 crReturnV;
5671 }
5672 continue; /* remote sends close; ignore (FIXME) */
5673 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5674 unsigned i = ssh2_pkt_getuint32(ssh);
5675 struct ssh_channel *c;
5676 c = find234(ssh->channels, &i, ssh_channelfind);
5677 if (!c || c->closes)
5678 continue; /* nonexistent or closing channel */
5679 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5680 s->try_send = TRUE;
5681 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5682 unsigned i = ssh2_pkt_getuint32(ssh);
5683 struct ssh_channel *c;
5684 c = find234(ssh->channels, &i, ssh_channelfind);
5685 if (!c)
5686 continue; /* nonexistent channel */
5687 if (c->type != CHAN_SOCKDATA_DORMANT)
5688 continue; /* dunno why they're confirming this */
5689 c->remoteid = ssh2_pkt_getuint32(ssh);
5690 c->type = CHAN_SOCKDATA;
5691 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5692 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5693 if (c->u.pfd.s)
5694 pfd_confirm(c->u.pfd.s);
5695 if (c->closes) {
5696 /*
5697 * We have a pending close on this channel,
5698 * which we decided on before the server acked
5699 * the channel open. So now we know the
5700 * remoteid, we can close it again.
5701 */
5702 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5703 ssh2_pkt_adduint32(ssh, c->remoteid);
5704 ssh2_pkt_send(ssh);
5705 }
5706 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5707 unsigned i = ssh2_pkt_getuint32(ssh);
5708 struct ssh_channel *c;
5709 c = find234(ssh->channels, &i, ssh_channelfind);
5710 if (!c)
5711 continue; /* nonexistent channel */
5712 if (c->type != CHAN_SOCKDATA_DORMANT)
5713 continue; /* dunno why they're failing this */
5714
5715 logevent("Forwarded connection refused by server");
5716
5717 pfd_close(c->u.pfd.s);
5718
5719 del234(ssh->channels, c);
5720 sfree(c);
5721 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5722 unsigned localid;
5723 char *type;
5724 int typelen, want_reply;
5725 struct ssh_channel *c;
5726
5727 localid = ssh2_pkt_getuint32(ssh);
5728 ssh2_pkt_getstring(ssh, &type, &typelen);
5729 want_reply = ssh2_pkt_getbool(ssh);
5730
5731 /*
5732 * First, check that the channel exists. Otherwise,
5733 * we can instantly disconnect with a rude message.
5734 */
5735 c = find234(ssh->channels, &localid, ssh_channelfind);
5736 if (!c) {
5737 char buf[80];
5738 sprintf(buf, "Received channel request for nonexistent"
5739 " channel %d", localid);
5740 logevent(buf);
5741 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5742 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5743 ssh2_pkt_addstring(ssh, buf);
5744 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5745 ssh2_pkt_send(ssh);
5746 connection_fatal("%s", buf);
5747 ssh->state = SSH_STATE_CLOSED;
5748 crReturnV;
5749 }
5750
5751 /*
5752 * Having got the channel number, we now look at
5753 * the request type string to see if it's something
5754 * we recognise.
5755 */
5756 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5757 c == ssh->mainchan) {
5758 /* We recognise "exit-status" on the primary channel. */
5759 char buf[100];
5760 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5761 sprintf(buf, "Server sent command exit status %d",
5762 ssh->exitcode);
5763 logevent(buf);
5764 if (want_reply) {
5765 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5766 ssh2_pkt_adduint32(ssh, c->remoteid);
5767 ssh2_pkt_send(ssh);
5768 }
5769 } else {
5770 /*
5771 * This is a channel request we don't know
5772 * about, so we now either ignore the request
5773 * or respond with CHANNEL_FAILURE, depending
5774 * on want_reply.
5775 */
5776 if (want_reply) {
5777 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5778 ssh2_pkt_adduint32(ssh, c->remoteid);
5779 ssh2_pkt_send(ssh);
5780 }
5781 }
5782 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5783 char *type;
5784 int typelen, want_reply;
5785
5786 ssh2_pkt_getstring(ssh, &type, &typelen);
5787 want_reply = ssh2_pkt_getbool(ssh);
5788
5789 /*
5790 * We currently don't support any global requests
5791 * at all, so we either ignore the request or
5792 * respond with REQUEST_FAILURE, depending on
5793 * want_reply.
5794 */
5795 if (want_reply) {
5796 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5797 ssh2_pkt_send(ssh);
5798 }
5799 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5800 char *type;
5801 int typelen;
5802 char *peeraddr;
5803 int peeraddrlen;
5804 int port;
5805 char *error = NULL;
5806 struct ssh_channel *c;
5807 unsigned remid, winsize, pktsize;
5808 ssh2_pkt_getstring(ssh, &type, &typelen);
5809 c = snew(struct ssh_channel);
5810 c->ssh = ssh;
5811
5812 remid = ssh2_pkt_getuint32(ssh);
5813 winsize = ssh2_pkt_getuint32(ssh);
5814 pktsize = ssh2_pkt_getuint32(ssh);
5815 ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
5816 port = ssh2_pkt_getuint32(ssh);
5817
5818 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5819 char *addrstr = snewn(peeraddrlen+1, char);
5820 memcpy(addrstr, peeraddr, peeraddrlen);
5821 peeraddr[peeraddrlen] = '\0';
5822
5823 if (!ssh->X11_fwd_enabled)
5824 error = "X11 forwarding is not enabled";
5825 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5826 ssh->x11auth, addrstr, port,
5827 &ssh->cfg) != NULL) {
5828 error = "Unable to open an X11 connection";
5829 } else {
5830 c->type = CHAN_X11;
5831 }
5832
5833 sfree(addrstr);
5834 } else if (typelen == 15 &&
5835 !memcmp(type, "forwarded-tcpip", 15)) {
5836 struct ssh_rportfwd pf, *realpf;
5837 char *dummy;
5838 int dummylen;
5839 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5840 pf.sport = ssh2_pkt_getuint32(ssh);
5841 realpf = find234(ssh->rportfwds, &pf, NULL);
5842 if (realpf == NULL) {
5843 error = "Remote port is not recognised";
5844 } else {
5845 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5846 realpf->dport, c, &ssh->cfg);
5847 logeventf(ssh, "Received remote port open request"
5848 " for %s:%d", realpf->dhost, realpf->dport);
5849 if (e != NULL) {
5850 logeventf(ssh, "Port open failed: %s", e);
5851 error = "Port open failed";
5852 } else {
5853 logevent("Forwarded port opened successfully");
5854 c->type = CHAN_SOCKDATA;
5855 }
5856 }
5857 } else if (typelen == 22 &&
5858 !memcmp(type, "auth-agent@openssh.com", 3)) {
5859 if (!ssh->agentfwd_enabled)
5860 error = "Agent forwarding is not enabled";
5861 else {
5862 c->type = CHAN_AGENT; /* identify channel type */
5863 c->u.a.lensofar = 0;
5864 }
5865 } else {
5866 error = "Unsupported channel type requested";
5867 }
5868
5869 c->remoteid = remid;
5870 if (error) {
5871 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5872 ssh2_pkt_adduint32(ssh, c->remoteid);
5873 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5874 ssh2_pkt_addstring(ssh, error);
5875 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5876 ssh2_pkt_send(ssh);
5877 sfree(c);
5878 } else {
5879 c->localid = alloc_channel_id(ssh);
5880 c->closes = 0;
5881 c->v.v2.locwindow = OUR_V2_WINSIZE;
5882 c->v.v2.remwindow = winsize;
5883 c->v.v2.remmaxpkt = pktsize;
5884 bufchain_init(&c->v.v2.outbuffer);
5885 add234(ssh->channels, c);
5886 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5887 ssh2_pkt_adduint32(ssh, c->remoteid);
5888 ssh2_pkt_adduint32(ssh, c->localid);
5889 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5890 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5891 ssh2_pkt_send(ssh);
5892 }
5893 } else {
5894 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
5895 crReturnV;
5896 }
5897 } else {
5898 /*
5899 * We have spare data. Add it to the channel buffer.
5900 */
5901 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
5902 s->try_send = TRUE;
5903 }
5904 if (s->try_send) {
5905 int i;
5906 struct ssh_channel *c;
5907 /*
5908 * Try to send data on all channels if we can.
5909 */
5910 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5911 int bufsize;
5912 if (c->closes)
5913 continue; /* don't send on closing channels */
5914 bufsize = ssh2_try_send(c);
5915 if (bufsize == 0) {
5916 switch (c->type) {
5917 case CHAN_MAINSESSION:
5918 /* stdin need not receive an unthrottle
5919 * notification since it will be polled */
5920 break;
5921 case CHAN_X11:
5922 x11_unthrottle(c->u.x11.s);
5923 break;
5924 case CHAN_AGENT:
5925 /* agent sockets are request/response and need no
5926 * buffer management */
5927 break;
5928 case CHAN_SOCKDATA:
5929 pfd_unthrottle(c->u.pfd.s);
5930 break;
5931 }
5932 }
5933 }
5934 }
5935 }
5936
5937 crFinishV;
5938 }
5939
5940 /*
5941 * Handle the top-level SSH2 protocol.
5942 */
5943 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
5944 {
5945 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
5946 return;
5947 do_ssh2_authconn(ssh, in, inlen, ispkt);
5948 }
5949
5950 /*
5951 * Called to set up the connection.
5952 *
5953 * Returns an error message, or NULL on success.
5954 */
5955 static char *ssh_init(void *frontend_handle, void **backend_handle,
5956 Config *cfg,
5957 char *host, int port, char **realhost, int nodelay)
5958 {
5959 char *p;
5960 Ssh ssh;
5961
5962 ssh = snew(struct ssh_tag);
5963 ssh->cfg = *cfg; /* STRUCTURE COPY */
5964 ssh->s = NULL;
5965 ssh->cipher = NULL;
5966 ssh->v1_cipher_ctx = NULL;
5967 ssh->crcda_ctx = NULL;
5968 ssh->cscipher = NULL;
5969 ssh->cs_cipher_ctx = NULL;
5970 ssh->sccipher = NULL;
5971 ssh->sc_cipher_ctx = NULL;
5972 ssh->csmac = NULL;
5973 ssh->cs_mac_ctx = NULL;
5974 ssh->scmac = NULL;
5975 ssh->sc_mac_ctx = NULL;
5976 ssh->cscomp = NULL;
5977 ssh->cs_comp_ctx = NULL;
5978 ssh->sccomp = NULL;
5979 ssh->sc_comp_ctx = NULL;
5980 ssh->kex = NULL;
5981 ssh->kex_ctx = NULL;
5982 ssh->hostkey = NULL;
5983 ssh->exitcode = -1;
5984 ssh->state = SSH_STATE_PREPACKET;
5985 ssh->size_needed = FALSE;
5986 ssh->eof_needed = FALSE;
5987 ssh->ldisc = NULL;
5988 ssh->logctx = NULL;
5989 {
5990 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
5991 ssh->pktin = ssh->pktout = empty;
5992 }
5993 ssh->deferred_send_data = NULL;
5994 ssh->deferred_len = 0;
5995 ssh->deferred_size = 0;
5996 ssh->fallback_cmd = 0;
5997 ssh->pkt_ctx = 0;
5998 ssh->x11auth = NULL;
5999 ssh->v1_compressing = FALSE;
6000 ssh->v2_outgoing_sequence = 0;
6001 ssh->ssh1_rdpkt_crstate = 0;
6002 ssh->ssh2_rdpkt_crstate = 0;
6003 ssh->do_ssh_init_crstate = 0;
6004 ssh->ssh_gotdata_crstate = 0;
6005 ssh->ssh1_protocol_crstate = 0;
6006 ssh->do_ssh1_login_crstate = 0;
6007 ssh->do_ssh2_transport_crstate = 0;
6008 ssh->do_ssh2_authconn_crstate = 0;
6009 ssh->do_ssh_init_state = NULL;
6010 ssh->do_ssh1_login_state = NULL;
6011 ssh->do_ssh2_transport_state = NULL;
6012 ssh->do_ssh2_authconn_state = NULL;
6013 ssh->mainchan = NULL;
6014 ssh->throttled_all = 0;
6015 ssh->v1_stdout_throttling = 0;
6016
6017 *backend_handle = ssh;
6018
6019 #ifdef MSCRYPTOAPI
6020 if (crypto_startup() == 0)
6021 return "Microsoft high encryption pack not installed!";
6022 #endif
6023
6024 ssh->frontend = frontend_handle;
6025 ssh->term_width = ssh->cfg.width;
6026 ssh->term_height = ssh->cfg.height;
6027
6028 ssh->channels = NULL;
6029 ssh->rportfwds = NULL;
6030
6031 ssh->send_ok = 0;
6032 ssh->editing = 0;
6033 ssh->echoing = 0;
6034 ssh->v1_throttle_count = 0;
6035 ssh->overall_bufsize = 0;
6036 ssh->fallback_cmd = 0;
6037
6038 ssh->protocol = NULL;
6039
6040 p = connect_to_host(ssh, host, port, realhost, nodelay);
6041 if (p != NULL)
6042 return p;
6043
6044 return NULL;
6045 }
6046
6047 static void ssh_free(void *handle)
6048 {
6049 Ssh ssh = (Ssh) handle;
6050 struct ssh_channel *c;
6051 struct ssh_rportfwd *pf;
6052
6053 if (ssh->v1_cipher_ctx)
6054 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6055 if (ssh->cs_cipher_ctx)
6056 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6057 if (ssh->sc_cipher_ctx)
6058 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6059 if (ssh->cs_mac_ctx)
6060 ssh->csmac->free_context(ssh->cs_mac_ctx);
6061 if (ssh->sc_mac_ctx)
6062 ssh->scmac->free_context(ssh->sc_mac_ctx);
6063 if (ssh->cs_comp_ctx)
6064 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6065 if (ssh->sc_comp_ctx)
6066 ssh->sccomp->compress_cleanup(ssh->sc_comp_ctx);
6067 if (ssh->kex_ctx)
6068 dh_cleanup(ssh->kex_ctx);
6069 sfree(ssh->savedhost);
6070
6071 if (ssh->channels) {
6072 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6073 switch (c->type) {
6074 case CHAN_X11:
6075 if (c->u.x11.s != NULL)
6076 x11_close(c->u.x11.s);
6077 break;
6078 case CHAN_SOCKDATA:
6079 if (c->u.pfd.s != NULL)
6080 pfd_close(c->u.pfd.s);
6081 break;
6082 }
6083 sfree(c);
6084 }
6085 freetree234(ssh->channels);
6086 }
6087
6088 if (ssh->rportfwds) {
6089 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6090 sfree(pf);
6091 freetree234(ssh->rportfwds);
6092 }
6093 sfree(ssh->deferred_send_data);
6094 if (ssh->x11auth)
6095 x11_free_auth(ssh->x11auth);
6096 sfree(ssh->do_ssh_init_state);
6097 sfree(ssh->do_ssh1_login_state);
6098 sfree(ssh->do_ssh2_transport_state);
6099 sfree(ssh->do_ssh2_authconn_state);
6100
6101 if (ssh->s)
6102 sk_close(ssh->s);
6103 sfree(ssh);
6104 }
6105
6106 /*
6107 * Reconfigure the SSH backend.
6108 *
6109 * Currently, this function does nothing very useful. In future,
6110 * however, we could do some handy things with it. For example, we
6111 * could make the port forwarding configurer active in the Change
6112 * Settings box, and this routine could close down existing
6113 * forwardings and open up new ones in response to changes.
6114 */
6115 static void ssh_reconfig(void *handle, Config *cfg)
6116 {
6117 Ssh ssh = (Ssh) handle;
6118 ssh->cfg = *cfg; /* STRUCTURE COPY */
6119 }
6120
6121 /*
6122 * Called to send data down the Telnet connection.
6123 */
6124 static int ssh_send(void *handle, char *buf, int len)
6125 {
6126 Ssh ssh = (Ssh) handle;
6127
6128 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6129 return 0;
6130
6131 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
6132
6133 return ssh_sendbuffer(ssh);
6134 }
6135
6136 /*
6137 * Called to query the current amount of buffered stdin data.
6138 */
6139 static int ssh_sendbuffer(void *handle)
6140 {
6141 Ssh ssh = (Ssh) handle;
6142 int override_value;
6143
6144 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6145 return 0;
6146
6147 /*
6148 * If the SSH socket itself has backed up, add the total backup
6149 * size on that to any individual buffer on the stdin channel.
6150 */
6151 override_value = 0;
6152 if (ssh->throttled_all)
6153 override_value = ssh->overall_bufsize;
6154
6155 if (ssh->version == 1) {
6156 return override_value;
6157 } else if (ssh->version == 2) {
6158 if (!ssh->mainchan || ssh->mainchan->closes > 0)
6159 return override_value;
6160 else
6161 return (override_value +
6162 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
6163 }
6164
6165 return 0;
6166 }
6167
6168 /*
6169 * Called to set the size of the window from SSH's POV.
6170 */
6171 static void ssh_size(void *handle, int width, int height)
6172 {
6173 Ssh ssh = (Ssh) handle;
6174
6175 ssh->term_width = width;
6176 ssh->term_height = height;
6177
6178 switch (ssh->state) {
6179 case SSH_STATE_BEFORE_SIZE:
6180 case SSH_STATE_PREPACKET:
6181 case SSH_STATE_CLOSED:
6182 break; /* do nothing */
6183 case SSH_STATE_INTERMED:
6184 ssh->size_needed = TRUE; /* buffer for later */
6185 break;
6186 case SSH_STATE_SESSION:
6187 if (!ssh->cfg.nopty) {
6188 if (ssh->version == 1) {
6189 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6190 PKT_INT, ssh->term_height,
6191 PKT_INT, ssh->term_width,
6192 PKT_INT, 0, PKT_INT, 0, PKT_END);
6193 } else {
6194 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6195 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6196 ssh2_pkt_addstring(ssh, "window-change");
6197 ssh2_pkt_addbool(ssh, 0);
6198 ssh2_pkt_adduint32(ssh, ssh->term_width);
6199 ssh2_pkt_adduint32(ssh, ssh->term_height);
6200 ssh2_pkt_adduint32(ssh, 0);
6201 ssh2_pkt_adduint32(ssh, 0);
6202 ssh2_pkt_send(ssh);
6203 }
6204 }
6205 break;
6206 }
6207 }
6208
6209 /*
6210 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6211 * can send an EOF and collect resulting output (e.g. `plink
6212 * hostname sort').
6213 */
6214 static void ssh_special(void *handle, Telnet_Special code)
6215 {
6216 Ssh ssh = (Ssh) handle;
6217
6218 if (code == TS_EOF) {
6219 if (ssh->state != SSH_STATE_SESSION) {
6220 /*
6221 * Buffer the EOF in case we are pre-SESSION, so we can
6222 * send it as soon as we reach SESSION.
6223 */
6224 if (code == TS_EOF)
6225 ssh->eof_needed = TRUE;
6226 return;
6227 }
6228 if (ssh->version == 1) {
6229 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6230 } else {
6231 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6232 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6233 ssh2_pkt_send(ssh);
6234 }
6235 logevent("Sent EOF message");
6236 } else if (code == TS_PING) {
6237 if (ssh->state == SSH_STATE_CLOSED
6238 || ssh->state == SSH_STATE_PREPACKET) return;
6239 if (ssh->version == 1) {
6240 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6241 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6242 } else {
6243 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6244 ssh2_pkt_addstring_start(ssh);
6245 ssh2_pkt_send(ssh);
6246 }
6247 } else {
6248 /* do nothing */
6249 }
6250 }
6251
6252 void *new_sock_channel(void *handle, Socket s)
6253 {
6254 Ssh ssh = (Ssh) handle;
6255 struct ssh_channel *c;
6256 c = snew(struct ssh_channel);
6257 c->ssh = ssh;
6258
6259 if (c) {
6260 c->remoteid = -1; /* to be set when open confirmed */
6261 c->localid = alloc_channel_id(ssh);
6262 c->closes = 0;
6263 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6264 c->u.pfd.s = s;
6265 bufchain_init(&c->v.v2.outbuffer);
6266 add234(ssh->channels, c);
6267 }
6268 return c;
6269 }
6270
6271 /*
6272 * This is called when stdout/stderr (the entity to which
6273 * from_backend sends data) manages to clear some backlog.
6274 */
6275 static void ssh_unthrottle(void *handle, int bufsize)
6276 {
6277 Ssh ssh = (Ssh) handle;
6278 if (ssh->version == 1) {
6279 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6280 ssh->v1_stdout_throttling = 0;
6281 ssh1_throttle(ssh, -1);
6282 }
6283 } else {
6284 if (ssh->mainchan && ssh->mainchan->closes == 0)
6285 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6286 }
6287 }
6288
6289 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6290 {
6291 struct ssh_channel *c = (struct ssh_channel *)channel;
6292 Ssh ssh = c->ssh;
6293
6294 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6295
6296 if (ssh->version == 1) {
6297 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6298 PKT_INT, c->localid,
6299 PKT_STR, hostname,
6300 PKT_INT, port,
6301 //PKT_STR, <org:orgport>,
6302 PKT_END);
6303 } else {
6304 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6305 ssh2_pkt_addstring(ssh, "direct-tcpip");
6306 ssh2_pkt_adduint32(ssh, c->localid);
6307 c->v.v2.locwindow = OUR_V2_WINSIZE;
6308 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6309 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6310 ssh2_pkt_addstring(ssh, hostname);
6311 ssh2_pkt_adduint32(ssh, port);
6312 /*
6313 * We make up values for the originator data; partly it's
6314 * too much hassle to keep track, and partly I'm not
6315 * convinced the server should be told details like that
6316 * about my local network configuration.
6317 */
6318 ssh2_pkt_addstring(ssh, "client-side-connection");
6319 ssh2_pkt_adduint32(ssh, 0);
6320 ssh2_pkt_send(ssh);
6321 }
6322 }
6323
6324
6325 static Socket ssh_socket(void *handle)
6326 {
6327 Ssh ssh = (Ssh) handle;
6328 return ssh->s;
6329 }
6330
6331 static int ssh_sendok(void *handle)
6332 {
6333 Ssh ssh = (Ssh) handle;
6334 return ssh->send_ok;
6335 }
6336
6337 static int ssh_ldisc(void *handle, int option)
6338 {
6339 Ssh ssh = (Ssh) handle;
6340 if (option == LD_ECHO)
6341 return ssh->echoing;
6342 if (option == LD_EDIT)
6343 return ssh->editing;
6344 return FALSE;
6345 }
6346
6347 static void ssh_provide_ldisc(void *handle, void *ldisc)
6348 {
6349 Ssh ssh = (Ssh) handle;
6350 ssh->ldisc = ldisc;
6351 }
6352
6353 static void ssh_provide_logctx(void *handle, void *logctx)
6354 {
6355 Ssh ssh = (Ssh) handle;
6356 ssh->logctx = logctx;
6357 }
6358
6359 static int ssh_return_exitcode(void *handle)
6360 {
6361 Ssh ssh = (Ssh) handle;
6362 return ssh->exitcode;
6363 }
6364
6365 /*
6366 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6367 * that fails. This variable is the means by which scp.c can reach
6368 * into the SSH code and find out which one it got.
6369 */
6370 extern int ssh_fallback_cmd(void *handle)
6371 {
6372 Ssh ssh = (Ssh) handle;
6373 return ssh->fallback_cmd;
6374 }
6375
6376 Backend ssh_backend = {
6377 ssh_init,
6378 ssh_free,
6379 ssh_reconfig,
6380 ssh_send,
6381 ssh_sendbuffer,
6382 ssh_size,
6383 ssh_special,
6384 ssh_socket,
6385 ssh_return_exitcode,
6386 ssh_sendok,
6387 ssh_ldisc,
6388 ssh_provide_ldisc,
6389 ssh_provide_logctx,
6390 ssh_unthrottle,
6391 22
6392 };
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator