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Good grief! I should create the `htmldoc' subdir in the release tree
[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 /* Enumeration values for fields in SSH-1 packets */
271 enum {
272 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
273 /* These values are for communicating relevant semantics of
274 * fields to the packet logging code. */
275 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
276 };
277
278 /*
279 * Coroutine mechanics for the sillier bits of the code. If these
280 * macros look impenetrable to you, you might find it helpful to
281 * read
282 *
283 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
284 *
285 * which explains the theory behind these macros.
286 *
287 * In particular, if you are getting `case expression not constant'
288 * errors when building with MS Visual Studio, this is because MS's
289 * Edit and Continue debugging feature causes their compiler to
290 * violate ANSI C. To disable Edit and Continue debugging:
291 *
292 * - right-click ssh.c in the FileView
293 * - click Settings
294 * - select the C/C++ tab and the General category
295 * - under `Debug info:', select anything _other_ than `Program
296 * Database for Edit and Continue'.
297 */
298 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
299 #define crState(t) \
300 struct t *s; \
301 if (!ssh->t) ssh->t = snew(struct t); \
302 s = ssh->t;
303 #define crFinish(z) } *crLine = 0; return (z); }
304 #define crFinishV } *crLine = 0; return; }
305 #define crReturn(z) \
306 do {\
307 *crLine =__LINE__; return (z); case __LINE__:;\
308 } while (0)
309 #define crReturnV \
310 do {\
311 *crLine=__LINE__; return; case __LINE__:;\
312 } while (0)
313 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
314 #define crStopV do{ *crLine = 0; return; }while(0)
315 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
316 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
317
318 typedef struct ssh_tag *Ssh;
319
320 static void ssh2_pkt_init(Ssh, int pkt_type);
321 static void ssh2_pkt_addbool(Ssh, unsigned char value);
322 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
323 static void ssh2_pkt_addstring_start(Ssh);
324 static void ssh2_pkt_addstring_str(Ssh, char *data);
325 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
326 static void ssh2_pkt_addstring(Ssh, char *data);
327 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
328 static void ssh2_pkt_addmp(Ssh, Bignum b);
329 static int ssh2_pkt_construct(Ssh);
330 static void ssh2_pkt_send(Ssh);
331 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt);
332 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt);
333
334 /*
335 * Buffer management constants. There are several of these for
336 * various different purposes:
337 *
338 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
339 * on a local data stream before we throttle the whole SSH
340 * connection (in SSH1 only). Throttling the whole connection is
341 * pretty drastic so we set this high in the hope it won't
342 * happen very often.
343 *
344 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
345 * on the SSH connection itself before we defensively throttle
346 * _all_ local data streams. This is pretty drastic too (though
347 * thankfully unlikely in SSH2 since the window mechanism should
348 * ensure that the server never has any need to throttle its end
349 * of the connection), so we set this high as well.
350 *
351 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
352 * channels.
353 */
354
355 #define SSH1_BUFFER_LIMIT 32768
356 #define SSH_MAX_BACKLOG 32768
357 #define OUR_V2_WINSIZE 16384
358
359 const static struct ssh_kex *kex_algs[] = {
360 &ssh_diffiehellman_gex,
361 &ssh_diffiehellman
362 };
363
364 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
365
366 static void *nullmac_make_context(void)
367 {
368 return NULL;
369 }
370 static void nullmac_free_context(void *handle)
371 {
372 }
373 static void nullmac_key(void *handle, unsigned char *key)
374 {
375 }
376 static void nullmac_generate(void *handle, unsigned char *blk, int len,
377 unsigned long seq)
378 {
379 }
380 static int nullmac_verify(void *handle, unsigned char *blk, int len,
381 unsigned long seq)
382 {
383 return 1;
384 }
385 const static struct ssh_mac ssh_mac_none = {
386 nullmac_make_context, nullmac_free_context, nullmac_key,
387 nullmac_generate, nullmac_verify, "none", 0
388 };
389 const static struct ssh_mac *macs[] = {
390 &ssh_sha1, &ssh_md5, &ssh_mac_none
391 };
392 const static struct ssh_mac *buggymacs[] = {
393 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
394 };
395
396 static void *ssh_comp_none_init(void)
397 {
398 return NULL;
399 }
400 static void ssh_comp_none_cleanup(void *handle)
401 {
402 }
403 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
404 unsigned char **outblock, int *outlen)
405 {
406 return 0;
407 }
408 static int ssh_comp_none_disable(void *handle)
409 {
410 return 0;
411 }
412 const static struct ssh_compress ssh_comp_none = {
413 "none",
414 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
415 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
416 ssh_comp_none_disable, NULL
417 };
418 extern const struct ssh_compress ssh_zlib;
419 const static struct ssh_compress *compressions[] = {
420 &ssh_zlib, &ssh_comp_none
421 };
422
423 enum { /* channel types */
424 CHAN_MAINSESSION,
425 CHAN_X11,
426 CHAN_AGENT,
427 CHAN_SOCKDATA,
428 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
429 };
430
431 /*
432 * 2-3-4 tree storing channels.
433 */
434 struct ssh_channel {
435 Ssh ssh; /* pointer back to main context */
436 unsigned remoteid, localid;
437 int type;
438 /*
439 * In SSH1, this value contains four bits:
440 *
441 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
442 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
443 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
444 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
445 *
446 * A channel is completely finished with when all four bits are set.
447 */
448 int closes;
449 union {
450 struct ssh1_data_channel {
451 int throttling;
452 } v1;
453 struct ssh2_data_channel {
454 bufchain outbuffer;
455 unsigned remwindow, remmaxpkt;
456 unsigned locwindow;
457 } v2;
458 } v;
459 union {
460 struct ssh_agent_channel {
461 unsigned char *message;
462 unsigned char msglen[4];
463 unsigned lensofar, totallen;
464 } a;
465 struct ssh_x11_channel {
466 Socket s;
467 } x11;
468 struct ssh_pfd_channel {
469 Socket s;
470 } pfd;
471 } u;
472 };
473
474 /*
475 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
476 * 2 use this structure in different ways, reflecting SSH 2's
477 * altogether saner approach to port forwarding.
478 *
479 * In SSH 1, you arrange a remote forwarding by sending the server
480 * the remote port number, and the local destination host:port.
481 * When a connection comes in, the server sends you back that
482 * host:port pair, and you connect to it. This is a ready-made
483 * security hole if you're not on the ball: a malicious server
484 * could send you back _any_ host:port pair, so if you trustingly
485 * connect to the address it gives you then you've just opened the
486 * entire inside of your corporate network just by connecting
487 * through it to a dodgy SSH server. Hence, we must store a list of
488 * host:port pairs we _are_ trying to forward to, and reject a
489 * connection request from the server if it's not in the list.
490 *
491 * In SSH 2, each side of the connection minds its own business and
492 * doesn't send unnecessary information to the other. You arrange a
493 * remote forwarding by sending the server just the remote port
494 * number. When a connection comes in, the server tells you which
495 * of its ports was connected to; and _you_ have to remember what
496 * local host:port pair went with that port number.
497 *
498 * Hence: in SSH 1 this structure stores host:port pairs we intend
499 * to allow connections to, and is indexed by those host:port
500 * pairs. In SSH 2 it stores a mapping from source port to
501 * destination host:port pair, and is indexed by source port.
502 */
503 struct ssh_rportfwd {
504 unsigned sport, dport;
505 char dhost[256];
506 };
507
508 struct Packet {
509 long length;
510 int type;
511 unsigned char *data;
512 unsigned char *body;
513 long savedpos;
514 long maxlen;
515 };
516
517 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
518 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
519 static void ssh_size(void *handle, int width, int height);
520 static void ssh_special(void *handle, Telnet_Special);
521 static int ssh2_try_send(struct ssh_channel *c);
522 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
523 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
524 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
525 static int ssh_sendbuffer(void *handle);
526 static void ssh_do_close(Ssh ssh);
527 static unsigned long ssh_pkt_getuint32(Ssh ssh);
528 static void ssh_pkt_getstring(Ssh ssh, char **p, int *length);
529
530 struct rdpkt1_state_tag {
531 long len, pad, biglen, to_read;
532 unsigned long realcrc, gotcrc;
533 unsigned char *p;
534 int i;
535 int chunk;
536 };
537
538 struct rdpkt2_state_tag {
539 long len, pad, payload, packetlen, maclen;
540 int i;
541 int cipherblk;
542 unsigned long incoming_sequence;
543 };
544
545 struct ssh_tag {
546 const struct plug_function_table *fn;
547 /* the above field _must_ be first in the structure */
548
549 SHA_State exhash, exhashbase;
550
551 Socket s;
552
553 void *ldisc;
554 void *logctx;
555
556 unsigned char session_key[32];
557 int v1_compressing;
558 int v1_remote_protoflags;
559 int v1_local_protoflags;
560 int agentfwd_enabled;
561 int X11_fwd_enabled;
562 int remote_bugs;
563 const struct ssh_cipher *cipher;
564 void *v1_cipher_ctx;
565 void *crcda_ctx;
566 const struct ssh2_cipher *cscipher, *sccipher;
567 void *cs_cipher_ctx, *sc_cipher_ctx;
568 const struct ssh_mac *csmac, *scmac;
569 void *cs_mac_ctx, *sc_mac_ctx;
570 const struct ssh_compress *cscomp, *sccomp;
571 void *cs_comp_ctx, *sc_comp_ctx;
572 const struct ssh_kex *kex;
573 const struct ssh_signkey *hostkey;
574 unsigned char v2_session_id[20];
575 void *kex_ctx;
576
577 char *savedhost;
578 int savedport;
579 int send_ok;
580 int echoing, editing;
581
582 void *frontend;
583
584 int ospeed, ispeed; /* temporaries */
585 int term_width, term_height;
586
587 tree234 *channels; /* indexed by local id */
588 struct ssh_channel *mainchan; /* primary session channel */
589 int exitcode;
590
591 tree234 *rportfwds;
592
593 enum {
594 SSH_STATE_PREPACKET,
595 SSH_STATE_BEFORE_SIZE,
596 SSH_STATE_INTERMED,
597 SSH_STATE_SESSION,
598 SSH_STATE_CLOSED
599 } state;
600
601 int size_needed, eof_needed;
602
603 struct Packet pktin;
604 struct Packet pktout;
605 unsigned char *deferred_send_data;
606 int deferred_len, deferred_size;
607
608 /*
609 * State associated with packet logging
610 */
611 int pktout_logmode;
612 int pktout_nblanks;
613 struct logblank_t *pktout_blanks;
614
615 /*
616 * Gross hack: pscp will try to start SFTP but fall back to
617 * scp1 if that fails. This variable is the means by which
618 * scp.c can reach into the SSH code and find out which one it
619 * got.
620 */
621 int fallback_cmd;
622
623 /*
624 * Used for username and password input.
625 */
626 char *userpass_input_buffer;
627 int userpass_input_buflen;
628 int userpass_input_bufpos;
629 int userpass_input_echo;
630
631 char *portfwd_strptr;
632 int pkt_ctx;
633
634 void *x11auth;
635
636 int version;
637 int v1_throttle_count;
638 int overall_bufsize;
639 int throttled_all;
640 int v1_stdout_throttling;
641 int v2_outgoing_sequence;
642
643 int ssh1_rdpkt_crstate;
644 int ssh2_rdpkt_crstate;
645 int do_ssh_init_crstate;
646 int ssh_gotdata_crstate;
647 int ssh1_protocol_crstate;
648 int do_ssh1_login_crstate;
649 int do_ssh2_transport_crstate;
650 int do_ssh2_authconn_crstate;
651
652 void *do_ssh_init_state;
653 void *do_ssh1_login_state;
654 void *do_ssh2_transport_state;
655 void *do_ssh2_authconn_state;
656
657 struct rdpkt1_state_tag rdpkt1_state;
658 struct rdpkt2_state_tag rdpkt2_state;
659
660 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
661 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
662
663 /*
664 * We maintain a full _copy_ of a Config structure here, not
665 * merely a pointer to it. That way, when we're passed a new
666 * one for reconfiguration, we can check the differences and
667 * potentially reconfigure port forwardings etc in mid-session.
668 */
669 Config cfg;
670
671 /*
672 * Used to transfer data back from async agent callbacks.
673 */
674 void *agent_response;
675 int agent_response_len;
676 };
677
678 #define logevent(s) logevent(ssh->frontend, s)
679
680 /* logevent, only printf-formatted. */
681 static void logeventf(Ssh ssh, const char *fmt, ...)
682 {
683 va_list ap;
684 char *buf;
685
686 va_start(ap, fmt);
687 buf = dupvprintf(fmt, ap);
688 va_end(ap);
689 logevent(buf);
690 sfree(buf);
691 }
692
693 #define bombout(msg) \
694 do { \
695 char *text = dupprintf msg; \
696 ssh_do_close(ssh); \
697 logevent(text); \
698 connection_fatal(ssh->frontend, "%s", text); \
699 sfree(text); \
700 } while (0)
701
702 /* Functions to leave bits out of the SSH packet log file. */
703
704 static void dont_log_password(Ssh ssh, int blanktype)
705 {
706 if (ssh->cfg.logomitpass)
707 ssh->pktout_logmode = blanktype;
708 }
709
710 static void dont_log_data(Ssh ssh, int blanktype)
711 {
712 if (ssh->cfg.logomitdata)
713 ssh->pktout_logmode = blanktype;
714 }
715
716 static void end_log_omission(Ssh ssh)
717 {
718 ssh->pktout_logmode = PKTLOG_EMIT;
719 }
720
721 static int ssh_channelcmp(void *av, void *bv)
722 {
723 struct ssh_channel *a = (struct ssh_channel *) av;
724 struct ssh_channel *b = (struct ssh_channel *) bv;
725 if (a->localid < b->localid)
726 return -1;
727 if (a->localid > b->localid)
728 return +1;
729 return 0;
730 }
731 static int ssh_channelfind(void *av, void *bv)
732 {
733 unsigned *a = (unsigned *) av;
734 struct ssh_channel *b = (struct ssh_channel *) bv;
735 if (*a < b->localid)
736 return -1;
737 if (*a > b->localid)
738 return +1;
739 return 0;
740 }
741
742 static int ssh_rportcmp_ssh1(void *av, void *bv)
743 {
744 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
745 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
746 int i;
747 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
748 return i < 0 ? -1 : +1;
749 if (a->dport > b->dport)
750 return +1;
751 if (a->dport < b->dport)
752 return -1;
753 return 0;
754 }
755
756 static int ssh_rportcmp_ssh2(void *av, void *bv)
757 {
758 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
759 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
760
761 if (a->sport > b->sport)
762 return +1;
763 if (a->sport < b->sport)
764 return -1;
765 return 0;
766 }
767
768 static int alloc_channel_id(Ssh ssh)
769 {
770 const unsigned CHANNEL_NUMBER_OFFSET = 256;
771 unsigned low, high, mid;
772 int tsize;
773 struct ssh_channel *c;
774
775 /*
776 * First-fit allocation of channel numbers: always pick the
777 * lowest unused one. To do this, binary-search using the
778 * counted B-tree to find the largest channel ID which is in a
779 * contiguous sequence from the beginning. (Precisely
780 * everything in that sequence must have ID equal to its tree
781 * index plus CHANNEL_NUMBER_OFFSET.)
782 */
783 tsize = count234(ssh->channels);
784
785 low = -1;
786 high = tsize;
787 while (high - low > 1) {
788 mid = (high + low) / 2;
789 c = index234(ssh->channels, mid);
790 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
791 low = mid; /* this one is fine */
792 else
793 high = mid; /* this one is past it */
794 }
795 /*
796 * Now low points to either -1, or the tree index of the
797 * largest ID in the initial sequence.
798 */
799 {
800 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
801 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
802 }
803 return low + 1 + CHANNEL_NUMBER_OFFSET;
804 }
805
806 static void c_write(Ssh ssh, const char *buf, int len)
807 {
808 if ((flags & FLAG_STDERR)) {
809 int i;
810 for (i = 0; i < len; i++)
811 if (buf[i] != '\r')
812 fputc(buf[i], stderr);
813 return;
814 }
815 from_backend(ssh->frontend, 1, buf, len);
816 }
817
818 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
819 {
820 int i;
821 for (i = 0; i < len; i++) {
822 if (buf[i] == '\n')
823 c_write(ssh, "\r\n", 2);
824 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
825 c_write(ssh, buf + i, 1);
826 }
827 }
828
829 static void c_write_str(Ssh ssh, const char *buf)
830 {
831 c_write(ssh, buf, strlen(buf));
832 }
833
834 /*
835 * Collect incoming data in the incoming packet buffer.
836 * Decipher and verify the packet when it is completely read.
837 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
838 * Update the *data and *datalen variables.
839 * Return the additional nr of bytes needed, or 0 when
840 * a complete packet is available.
841 */
842 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
843 {
844 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
845
846 crBegin(ssh->ssh1_rdpkt_crstate);
847
848 next_packet:
849
850 ssh->pktin.type = 0;
851 ssh->pktin.length = 0;
852
853 for (st->i = st->len = 0; st->i < 4; st->i++) {
854 while ((*datalen) == 0)
855 crReturn(4 - st->i);
856 st->len = (st->len << 8) + **data;
857 (*data)++, (*datalen)--;
858 }
859
860 st->pad = 8 - (st->len % 8);
861 st->biglen = st->len + st->pad;
862 ssh->pktin.length = st->len - 5;
863
864 if (st->biglen < 0) {
865 bombout(("Extremely large packet length from server suggests"
866 " data stream corruption"));
867 crStop(0);
868 }
869
870 if (ssh->pktin.maxlen < st->biglen) {
871 ssh->pktin.maxlen = st->biglen;
872 ssh->pktin.data = sresize(ssh->pktin.data, st->biglen + APIEXTRA,
873 unsigned char);
874 }
875
876 st->to_read = st->biglen;
877 st->p = ssh->pktin.data;
878 while (st->to_read > 0) {
879 st->chunk = st->to_read;
880 while ((*datalen) == 0)
881 crReturn(st->to_read);
882 if (st->chunk > (*datalen))
883 st->chunk = (*datalen);
884 memcpy(st->p, *data, st->chunk);
885 *data += st->chunk;
886 *datalen -= st->chunk;
887 st->p += st->chunk;
888 st->to_read -= st->chunk;
889 }
890
891 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
892 st->biglen, NULL)) {
893 bombout(("Network attack (CRC compensation) detected!"));
894 crStop(0);
895 }
896
897 if (ssh->cipher)
898 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
899
900 st->realcrc = crc32_compute(ssh->pktin.data, st->biglen - 4);
901 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
902 if (st->gotcrc != st->realcrc) {
903 bombout(("Incorrect CRC received on packet"));
904 crStop(0);
905 }
906
907 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
908 ssh->pktin.savedpos = 0;
909
910 if (ssh->v1_compressing) {
911 unsigned char *decompblk;
912 int decomplen;
913 if (!zlib_decompress_block(ssh->sc_comp_ctx,
914 ssh->pktin.body - 1, ssh->pktin.length + 1,
915 &decompblk, &decomplen)) {
916 bombout(("Zlib decompression encountered invalid data"));
917 crStop(0);
918 }
919
920 if (ssh->pktin.maxlen < st->pad + decomplen) {
921 ssh->pktin.maxlen = st->pad + decomplen;
922 ssh->pktin.data = sresize(ssh->pktin.data,
923 ssh->pktin.maxlen + APIEXTRA,
924 unsigned char);
925 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
926 }
927
928 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
929 sfree(decompblk);
930 ssh->pktin.length = decomplen - 1;
931 }
932
933 ssh->pktin.type = ssh->pktin.body[-1];
934
935 /*
936 * Log incoming packet, possibly omitting sensitive fields.
937 */
938 if (ssh->logctx) {
939 int nblanks = 0;
940 struct logblank_t blank;
941 if (ssh->cfg.logomitdata) {
942 int do_blank = FALSE, blank_prefix = 0;
943 /* "Session data" packets - omit the data field */
944 if ((ssh->pktin.type == SSH1_SMSG_STDOUT_DATA) ||
945 (ssh->pktin.type == SSH1_SMSG_STDERR_DATA)) {
946 do_blank = TRUE; blank_prefix = 0;
947 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
948 do_blank = TRUE; blank_prefix = 4;
949 }
950 if (do_blank) {
951 blank.offset = blank_prefix;
952 blank.len = ssh->pktin.length;
953 blank.type = PKTLOG_OMIT;
954 nblanks = 1;
955 }
956 }
957 log_packet(ssh->logctx,
958 PKT_INCOMING, ssh->pktin.type,
959 ssh1_pkt_type(ssh->pktin.type),
960 ssh->pktin.body, ssh->pktin.length,
961 nblanks, &blank);
962 }
963
964 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
965 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
966 ssh->pktin.type == SSH1_MSG_DEBUG ||
967 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
968 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
969 long stringlen = GET_32BIT(ssh->pktin.body);
970 if (stringlen + 4 != ssh->pktin.length) {
971 bombout(("Received data packet with bogus string length"));
972 crStop(0);
973 }
974 }
975
976 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
977 char *buf, *msg;
978 int msglen;
979
980 ssh_pkt_getstring(ssh, &msg, &msglen);
981 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
982 logevent(buf);
983 sfree(buf);
984
985 goto next_packet;
986 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
987 /* do nothing */
988 goto next_packet;
989 }
990
991 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
992 /* log reason code in disconnect message */
993 char *msg;
994 int msglen;
995
996 ssh_pkt_getstring(ssh, &msg, &msglen);
997
998 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
999 crStop(0);
1000 }
1001
1002 crFinish(0);
1003 }
1004
1005 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1006 {
1007 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1008
1009 crBegin(ssh->ssh2_rdpkt_crstate);
1010
1011 next_packet:
1012 ssh->pktin.type = 0;
1013 ssh->pktin.length = 0;
1014 if (ssh->sccipher)
1015 st->cipherblk = ssh->sccipher->blksize;
1016 else
1017 st->cipherblk = 8;
1018 if (st->cipherblk < 8)
1019 st->cipherblk = 8;
1020
1021 if (ssh->pktin.maxlen < st->cipherblk) {
1022 ssh->pktin.maxlen = st->cipherblk;
1023 ssh->pktin.data = sresize(ssh->pktin.data, st->cipherblk + APIEXTRA,
1024 unsigned char);
1025 }
1026
1027 /*
1028 * Acquire and decrypt the first block of the packet. This will
1029 * contain the length and padding details.
1030 */
1031 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1032 while ((*datalen) == 0)
1033 crReturn(st->cipherblk - st->i);
1034 ssh->pktin.data[st->i] = *(*data)++;
1035 (*datalen)--;
1036 }
1037
1038 if (ssh->sccipher)
1039 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1040 ssh->pktin.data, st->cipherblk);
1041
1042 /*
1043 * Now get the length and padding figures.
1044 */
1045 st->len = GET_32BIT(ssh->pktin.data);
1046 st->pad = ssh->pktin.data[4];
1047
1048 /*
1049 * _Completely_ silly lengths should be stomped on before they
1050 * do us any more damage.
1051 */
1052 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1053 bombout(("Incoming packet was garbled on decryption"));
1054 crStop(0);
1055 }
1056
1057 /*
1058 * This enables us to deduce the payload length.
1059 */
1060 st->payload = st->len - st->pad - 1;
1061
1062 ssh->pktin.length = st->payload + 5;
1063
1064 /*
1065 * So now we can work out the total packet length.
1066 */
1067 st->packetlen = st->len + 4;
1068 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1069
1070 /*
1071 * Adjust memory allocation if packet is too big.
1072 */
1073 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
1074 ssh->pktin.maxlen = st->packetlen + st->maclen;
1075 ssh->pktin.data = sresize(ssh->pktin.data,
1076 ssh->pktin.maxlen + APIEXTRA,
1077 unsigned char);
1078 }
1079
1080 /*
1081 * Read and decrypt the remainder of the packet.
1082 */
1083 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1084 st->i++) {
1085 while ((*datalen) == 0)
1086 crReturn(st->packetlen + st->maclen - st->i);
1087 ssh->pktin.data[st->i] = *(*data)++;
1088 (*datalen)--;
1089 }
1090 /* Decrypt everything _except_ the MAC. */
1091 if (ssh->sccipher)
1092 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1093 ssh->pktin.data + st->cipherblk,
1094 st->packetlen - st->cipherblk);
1095
1096 /*
1097 * Check the MAC.
1098 */
1099 if (ssh->scmac
1100 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1101 st->incoming_sequence)) {
1102 bombout(("Incorrect MAC received on packet"));
1103 crStop(0);
1104 }
1105 st->incoming_sequence++; /* whether or not we MACed */
1106
1107 /*
1108 * Decompress packet payload.
1109 */
1110 {
1111 unsigned char *newpayload;
1112 int newlen;
1113 if (ssh->sccomp &&
1114 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1115 ssh->pktin.data + 5, ssh->pktin.length - 5,
1116 &newpayload, &newlen)) {
1117 if (ssh->pktin.maxlen < newlen + 5) {
1118 ssh->pktin.maxlen = newlen + 5;
1119 ssh->pktin.data = sresize(ssh->pktin.data,
1120 ssh->pktin.maxlen + APIEXTRA,
1121 unsigned char);
1122 }
1123 ssh->pktin.length = 5 + newlen;
1124 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1125 sfree(newpayload);
1126 }
1127 }
1128
1129 ssh->pktin.savedpos = 6;
1130 ssh->pktin.body = ssh->pktin.data;
1131 ssh->pktin.type = ssh->pktin.data[5];
1132
1133 /*
1134 * Log incoming packet, possibly omitting sensitive fields.
1135 */
1136 if (ssh->logctx) {
1137 int nblanks = 0;
1138 struct logblank_t blank;
1139 if (ssh->cfg.logomitdata) {
1140 int do_blank = FALSE, blank_prefix = 0;
1141 /* "Session data" packets - omit the data field */
1142 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA) {
1143 do_blank = TRUE; blank_prefix = 4;
1144 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1145 do_blank = TRUE; blank_prefix = 8;
1146 }
1147 if (do_blank) {
1148 blank.offset = blank_prefix;
1149 blank.len = (ssh->pktin.length-6) - blank_prefix;
1150 blank.type = PKTLOG_OMIT;
1151 nblanks = 1;
1152 }
1153 }
1154 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1155 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1156 ssh->pktin.data+6, ssh->pktin.length-6,
1157 nblanks, &blank);
1158 }
1159
1160 switch (ssh->pktin.type) {
1161 /*
1162 * These packets we must handle instantly.
1163 */
1164 case SSH2_MSG_DISCONNECT:
1165 {
1166 /* log reason code in disconnect message */
1167 char *buf, *msg;
1168 int nowlen, reason, msglen;
1169
1170 reason = ssh_pkt_getuint32(ssh);
1171 ssh_pkt_getstring(ssh, &msg, &msglen);
1172
1173 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1174 buf = dupprintf("Received disconnect message (%s)",
1175 ssh2_disconnect_reasons[reason]);
1176 } else {
1177 buf = dupprintf("Received disconnect message (unknown"
1178 " type %d)", reason);
1179 }
1180 logevent(buf);
1181 sfree(buf);
1182 buf = dupprintf("Disconnection message text: %n%.*s",
1183 &nowlen, msglen, msg);
1184 logevent(buf);
1185 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1186 reason,
1187 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1188 ssh2_disconnect_reasons[reason] : "unknown",
1189 buf+nowlen));
1190 sfree(buf);
1191 crStop(0);
1192 }
1193 break;
1194 case SSH2_MSG_IGNORE:
1195 goto next_packet;
1196 case SSH2_MSG_DEBUG:
1197 {
1198 /* log the debug message */
1199 char *buf, *msg;
1200 int msglen;
1201
1202 ssh_pkt_getstring(ssh, &msg, &msglen);
1203
1204 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
1205 logevent(buf);
1206 sfree(buf);
1207 }
1208 goto next_packet;
1209
1210 /*
1211 * These packets we need do nothing about here.
1212 */
1213 case SSH2_MSG_UNIMPLEMENTED:
1214 case SSH2_MSG_SERVICE_REQUEST:
1215 case SSH2_MSG_SERVICE_ACCEPT:
1216 case SSH2_MSG_KEXINIT:
1217 case SSH2_MSG_NEWKEYS:
1218 case SSH2_MSG_KEXDH_INIT:
1219 case SSH2_MSG_KEXDH_REPLY:
1220 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1221 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1222 case SSH2_MSG_KEX_DH_GEX_INIT:
1223 case SSH2_MSG_KEX_DH_GEX_REPLY:
1224 case SSH2_MSG_USERAUTH_REQUEST:
1225 case SSH2_MSG_USERAUTH_FAILURE:
1226 case SSH2_MSG_USERAUTH_SUCCESS:
1227 case SSH2_MSG_USERAUTH_BANNER:
1228 case SSH2_MSG_USERAUTH_PK_OK:
1229 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1230 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1231 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1232 case SSH2_MSG_GLOBAL_REQUEST:
1233 case SSH2_MSG_REQUEST_SUCCESS:
1234 case SSH2_MSG_REQUEST_FAILURE:
1235 case SSH2_MSG_CHANNEL_OPEN:
1236 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1237 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1238 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1239 case SSH2_MSG_CHANNEL_DATA:
1240 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1241 case SSH2_MSG_CHANNEL_EOF:
1242 case SSH2_MSG_CHANNEL_CLOSE:
1243 case SSH2_MSG_CHANNEL_REQUEST:
1244 case SSH2_MSG_CHANNEL_SUCCESS:
1245 case SSH2_MSG_CHANNEL_FAILURE:
1246 break;
1247
1248 /*
1249 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1250 */
1251 default:
1252 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1253 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1254 ssh2_pkt_send(ssh);
1255 break;
1256 }
1257
1258 crFinish(0);
1259 }
1260
1261 static void ssh1_pktout_size(Ssh ssh, int len)
1262 {
1263 int pad, biglen;
1264
1265 len += 5; /* type and CRC */
1266 pad = 8 - (len % 8);
1267 biglen = len + pad;
1268
1269 ssh->pktout.length = len - 5;
1270 if (ssh->pktout.maxlen < biglen) {
1271 ssh->pktout.maxlen = biglen;
1272 #ifdef MSCRYPTOAPI
1273 /* Allocate enough buffer space for extra block
1274 * for MS CryptEncrypt() */
1275 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 12,
1276 unsigned char);
1277 #else
1278 ssh->pktout.data = sresize(ssh->pktout.data, biglen + 4,
1279 unsigned char);
1280 #endif
1281 }
1282 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1283 }
1284
1285 static void s_wrpkt_start(Ssh ssh, int type, int len)
1286 {
1287 ssh1_pktout_size(ssh, len);
1288 ssh->pktout.type = type;
1289 /* Initialise log omission state */
1290 ssh->pktout_nblanks = 0;
1291 ssh->pktout_blanks = NULL;
1292 }
1293
1294 static int s_wrpkt_prepare(Ssh ssh)
1295 {
1296 int pad, biglen, i;
1297 unsigned long crc;
1298 #ifdef __SC__
1299 /*
1300 * XXX various versions of SC (including 8.8.4) screw up the
1301 * register allocation in this function and use the same register
1302 * (D6) for len and as a temporary, with predictable results. The
1303 * following sledgehammer prevents this.
1304 */
1305 volatile
1306 #endif
1307 int len;
1308
1309 ssh->pktout.body[-1] = ssh->pktout.type;
1310
1311 if (ssh->logctx)
1312 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1313 ssh1_pkt_type(ssh->pktout.type),
1314 ssh->pktout.body, ssh->pktout.length,
1315 ssh->pktout_nblanks, ssh->pktout_blanks);
1316 sfree(ssh->pktout_blanks); ssh->pktout_blanks = NULL;
1317 ssh->pktout_nblanks = 0;
1318
1319 if (ssh->v1_compressing) {
1320 unsigned char *compblk;
1321 int complen;
1322 zlib_compress_block(ssh->cs_comp_ctx,
1323 ssh->pktout.body - 1, ssh->pktout.length + 1,
1324 &compblk, &complen);
1325 ssh1_pktout_size(ssh, complen - 1);
1326 memcpy(ssh->pktout.body - 1, compblk, complen);
1327 sfree(compblk);
1328 }
1329
1330 len = ssh->pktout.length + 5; /* type and CRC */
1331 pad = 8 - (len % 8);
1332 biglen = len + pad;
1333
1334 for (i = 0; i < pad; i++)
1335 ssh->pktout.data[i + 4] = random_byte();
1336 crc = crc32_compute(ssh->pktout.data + 4, biglen - 4);
1337 PUT_32BIT(ssh->pktout.data + biglen, crc);
1338 PUT_32BIT(ssh->pktout.data, len);
1339
1340 if (ssh->cipher)
1341 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1342
1343 return biglen + 4;
1344 }
1345
1346 static void s_wrpkt(Ssh ssh)
1347 {
1348 int len, backlog;
1349 len = s_wrpkt_prepare(ssh);
1350 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1351 if (backlog > SSH_MAX_BACKLOG)
1352 ssh_throttle_all(ssh, 1, backlog);
1353 }
1354
1355 static void s_wrpkt_defer(Ssh ssh)
1356 {
1357 int len;
1358 len = s_wrpkt_prepare(ssh);
1359 if (ssh->deferred_len + len > ssh->deferred_size) {
1360 ssh->deferred_size = ssh->deferred_len + len + 128;
1361 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1362 ssh->deferred_size,
1363 unsigned char);
1364 }
1365 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1366 ssh->deferred_len += len;
1367 }
1368
1369 /*
1370 * Construct a packet with the specified contents.
1371 */
1372 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1373 {
1374 unsigned char *p, *argp, argchar;
1375 unsigned long argint;
1376 int pktlen, argtype, arglen;
1377 Bignum bn;
1378
1379 pktlen = 0;
1380 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1381 switch (argtype) {
1382 case PKT_INT:
1383 (void) va_arg(ap1, int);
1384 pktlen += 4;
1385 break;
1386 case PKT_CHAR:
1387 (void) va_arg(ap1, int);
1388 pktlen++;
1389 break;
1390 case PKT_DATA:
1391 (void) va_arg(ap1, unsigned char *);
1392 arglen = va_arg(ap1, int);
1393 pktlen += arglen;
1394 break;
1395 case PKT_STR:
1396 argp = va_arg(ap1, unsigned char *);
1397 arglen = strlen((char *)argp);
1398 pktlen += 4 + arglen;
1399 break;
1400 case PKT_BIGNUM:
1401 bn = va_arg(ap1, Bignum);
1402 pktlen += ssh1_bignum_length(bn);
1403 break;
1404 case PKTT_PASSWORD:
1405 case PKTT_DATA:
1406 case PKTT_OTHER:
1407 /* ignore this pass */
1408 break;
1409 default:
1410 assert(0);
1411 }
1412 }
1413
1414 s_wrpkt_start(ssh, pkttype, pktlen);
1415 p = ssh->pktout.body;
1416
1417 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1418 int offset = p - ssh->pktout.body, len = 0;
1419 switch (argtype) {
1420 /* Actual fields in the packet */
1421 case PKT_INT:
1422 argint = va_arg(ap2, int);
1423 PUT_32BIT(p, argint);
1424 len = 4;
1425 break;
1426 case PKT_CHAR:
1427 argchar = (unsigned char) va_arg(ap2, int);
1428 *p = argchar;
1429 len = 1;
1430 break;
1431 case PKT_DATA:
1432 argp = va_arg(ap2, unsigned char *);
1433 arglen = va_arg(ap2, int);
1434 memcpy(p, argp, arglen);
1435 len = arglen;
1436 break;
1437 case PKT_STR:
1438 argp = va_arg(ap2, unsigned char *);
1439 arglen = strlen((char *)argp);
1440 PUT_32BIT(p, arglen);
1441 memcpy(p + 4, argp, arglen);
1442 len = arglen + 4;
1443 break;
1444 case PKT_BIGNUM:
1445 bn = va_arg(ap2, Bignum);
1446 len = ssh1_write_bignum(p, bn);
1447 break;
1448 /* Tokens for modifications to packet logging */
1449 case PKTT_PASSWORD:
1450 dont_log_password(ssh, PKTLOG_BLANK);
1451 break;
1452 case PKTT_DATA:
1453 dont_log_data(ssh, PKTLOG_OMIT);
1454 break;
1455 case PKTT_OTHER:
1456 end_log_omission(ssh);
1457 break;
1458 }
1459 p += len;
1460 /* Deal with logfile omission, if required. */
1461 if (len && (ssh->pktout_logmode != PKTLOG_EMIT)) {
1462 ssh->pktout_nblanks++;
1463 ssh->pktout_blanks = sresize(ssh->pktout_blanks,
1464 ssh->pktout_nblanks,
1465 struct logblank_t);
1466 ssh->pktout_blanks[ssh->pktout_nblanks-1].offset = offset;
1467 ssh->pktout_blanks[ssh->pktout_nblanks-1].len = len;
1468 ssh->pktout_blanks[ssh->pktout_nblanks-1].type =
1469 ssh->pktout_logmode;
1470 }
1471 }
1472 }
1473
1474 static void send_packet(Ssh ssh, int pkttype, ...)
1475 {
1476 va_list ap1, ap2;
1477 va_start(ap1, pkttype);
1478 va_start(ap2, pkttype);
1479 construct_packet(ssh, pkttype, ap1, ap2);
1480 s_wrpkt(ssh);
1481 }
1482
1483 static void defer_packet(Ssh ssh, int pkttype, ...)
1484 {
1485 va_list ap1, ap2;
1486 va_start(ap1, pkttype);
1487 va_start(ap2, pkttype);
1488 construct_packet(ssh, pkttype, ap1, ap2);
1489 s_wrpkt_defer(ssh);
1490 }
1491
1492 static int ssh_versioncmp(char *a, char *b)
1493 {
1494 char *ae, *be;
1495 unsigned long av, bv;
1496
1497 av = strtoul(a, &ae, 10);
1498 bv = strtoul(b, &be, 10);
1499 if (av != bv)
1500 return (av < bv ? -1 : +1);
1501 if (*ae == '.')
1502 ae++;
1503 if (*be == '.')
1504 be++;
1505 av = strtoul(ae, &ae, 10);
1506 bv = strtoul(be, &be, 10);
1507 if (av != bv)
1508 return (av < bv ? -1 : +1);
1509 return 0;
1510 }
1511
1512 /*
1513 * Utility routines for putting an SSH-protocol `string' and
1514 * `uint32' into a SHA state.
1515 */
1516 #include <stdio.h>
1517 static void sha_string(SHA_State * s, void *str, int len)
1518 {
1519 unsigned char lenblk[4];
1520 PUT_32BIT(lenblk, len);
1521 SHA_Bytes(s, lenblk, 4);
1522 SHA_Bytes(s, str, len);
1523 }
1524
1525 static void sha_uint32(SHA_State * s, unsigned i)
1526 {
1527 unsigned char intblk[4];
1528 PUT_32BIT(intblk, i);
1529 SHA_Bytes(s, intblk, 4);
1530 }
1531
1532 /*
1533 * SSH2 packet construction functions.
1534 */
1535 static void ssh2_pkt_ensure(Ssh ssh, int length)
1536 {
1537 if (ssh->pktout.maxlen < length) {
1538 ssh->pktout.maxlen = length + 256;
1539 ssh->pktout.data = sresize(ssh->pktout.data,
1540 ssh->pktout.maxlen + APIEXTRA,
1541 unsigned char);
1542 if (!ssh->pktout.data)
1543 fatalbox("Out of memory");
1544 }
1545 }
1546 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1547 {
1548 if (ssh->pktout_logmode != PKTLOG_EMIT) {
1549 ssh->pktout_nblanks++;
1550 ssh->pktout_blanks = sresize(ssh->pktout_blanks, ssh->pktout_nblanks,
1551 struct logblank_t);
1552 ssh->pktout_blanks[ssh->pktout_nblanks-1].offset =
1553 ssh->pktout.length - 6;
1554 ssh->pktout_blanks[ssh->pktout_nblanks-1].len = len;
1555 ssh->pktout_blanks[ssh->pktout_nblanks-1].type = ssh->pktout_logmode;
1556 }
1557 ssh->pktout.length += len;
1558 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1559 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1560 }
1561 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1562 {
1563 ssh2_pkt_adddata(ssh, &byte, 1);
1564 }
1565 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1566 {
1567 ssh->pktout.length = 5;
1568 ssh->pktout_nblanks = 0; ssh->pktout_blanks = NULL;
1569 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1570 }
1571 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1572 {
1573 ssh2_pkt_adddata(ssh, &value, 1);
1574 }
1575 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1576 {
1577 unsigned char x[4];
1578 PUT_32BIT(x, value);
1579 ssh2_pkt_adddata(ssh, x, 4);
1580 }
1581 static void ssh2_pkt_addstring_start(Ssh ssh)
1582 {
1583 ssh2_pkt_adduint32(ssh, 0);
1584 ssh->pktout.savedpos = ssh->pktout.length;
1585 }
1586 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1587 {
1588 ssh2_pkt_adddata(ssh, data, strlen(data));
1589 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1590 ssh->pktout.length - ssh->pktout.savedpos);
1591 }
1592 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1593 {
1594 ssh2_pkt_adddata(ssh, data, len);
1595 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1596 ssh->pktout.length - ssh->pktout.savedpos);
1597 }
1598 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1599 {
1600 ssh2_pkt_addstring_start(ssh);
1601 ssh2_pkt_addstring_str(ssh, data);
1602 }
1603 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1604 {
1605 unsigned char *p;
1606 int i, n = (bignum_bitcount(b) + 7) / 8;
1607 p = snewn(n + 1, unsigned char);
1608 if (!p)
1609 fatalbox("out of memory");
1610 p[0] = 0;
1611 for (i = 1; i <= n; i++)
1612 p[i] = bignum_byte(b, n - i);
1613 i = 0;
1614 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1615 i++;
1616 memmove(p, p + i, n + 1 - i);
1617 *len = n + 1 - i;
1618 return p;
1619 }
1620 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1621 {
1622 unsigned char *p;
1623 int len;
1624 p = ssh2_mpint_fmt(b, &len);
1625 ssh2_pkt_addstring_start(ssh);
1626 ssh2_pkt_addstring_data(ssh, (char *)p, len);
1627 sfree(p);
1628 }
1629
1630 /*
1631 * Construct an SSH2 final-form packet: compress it, encrypt it,
1632 * put the MAC on it. Final packet, ready to be sent, is stored in
1633 * ssh->pktout.data. Total length is returned.
1634 */
1635 static int ssh2_pkt_construct(Ssh ssh)
1636 {
1637 int cipherblk, maclen, padding, i;
1638
1639 if (ssh->logctx)
1640 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1641 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1642 ssh->pktout.data + 6, ssh->pktout.length - 6,
1643 ssh->pktout_nblanks, ssh->pktout_blanks);
1644 sfree(ssh->pktout_blanks); ssh->pktout_blanks = NULL;
1645 ssh->pktout_nblanks = 0;
1646
1647 /*
1648 * Compress packet payload.
1649 */
1650 {
1651 unsigned char *newpayload;
1652 int newlen;
1653 if (ssh->cscomp &&
1654 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1655 ssh->pktout.length - 5,
1656 &newpayload, &newlen)) {
1657 ssh->pktout.length = 5;
1658 ssh2_pkt_adddata(ssh, newpayload, newlen);
1659 sfree(newpayload);
1660 }
1661 }
1662
1663 /*
1664 * Add padding. At least four bytes, and must also bring total
1665 * length (minus MAC) up to a multiple of the block size.
1666 */
1667 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1668 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1669 padding = 4;
1670 padding +=
1671 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1672 maclen = ssh->csmac ? ssh->csmac->len : 0;
1673 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1674 ssh->pktout.data[4] = padding;
1675 for (i = 0; i < padding; i++)
1676 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1677 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1678 if (ssh->csmac)
1679 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1680 ssh->pktout.length + padding,
1681 ssh->v2_outgoing_sequence);
1682 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1683
1684 if (ssh->cscipher)
1685 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1686 ssh->pktout.data, ssh->pktout.length + padding);
1687
1688 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1689 return ssh->pktout.length + padding + maclen;
1690 }
1691
1692 /*
1693 * Construct and send an SSH2 packet immediately.
1694 */
1695 static void ssh2_pkt_send(Ssh ssh)
1696 {
1697 int len;
1698 int backlog;
1699 len = ssh2_pkt_construct(ssh);
1700 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1701 if (backlog > SSH_MAX_BACKLOG)
1702 ssh_throttle_all(ssh, 1, backlog);
1703 }
1704
1705 /*
1706 * Construct an SSH2 packet and add it to a deferred data block.
1707 * Useful for sending multiple packets in a single sk_write() call,
1708 * to prevent a traffic-analysing listener from being able to work
1709 * out the length of any particular packet (such as the password
1710 * packet).
1711 *
1712 * Note that because SSH2 sequence-numbers its packets, this can
1713 * NOT be used as an m4-style `defer' allowing packets to be
1714 * constructed in one order and sent in another.
1715 */
1716 static void ssh2_pkt_defer(Ssh ssh)
1717 {
1718 int len = ssh2_pkt_construct(ssh);
1719 if (ssh->deferred_len + len > ssh->deferred_size) {
1720 ssh->deferred_size = ssh->deferred_len + len + 128;
1721 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1722 ssh->deferred_size,
1723 unsigned char);
1724 }
1725 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1726 ssh->deferred_len += len;
1727 }
1728
1729 /*
1730 * Send the whole deferred data block constructed by
1731 * ssh2_pkt_defer() or SSH1's defer_packet().
1732 */
1733 static void ssh_pkt_defersend(Ssh ssh)
1734 {
1735 int backlog;
1736 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1737 ssh->deferred_len);
1738 ssh->deferred_len = ssh->deferred_size = 0;
1739 sfree(ssh->deferred_send_data);
1740 ssh->deferred_send_data = NULL;
1741 if (backlog > SSH_MAX_BACKLOG)
1742 ssh_throttle_all(ssh, 1, backlog);
1743 }
1744
1745 #if 0
1746 void bndebug(char *string, Bignum b)
1747 {
1748 unsigned char *p;
1749 int i, len;
1750 p = ssh2_mpint_fmt(b, &len);
1751 debug(("%s", string));
1752 for (i = 0; i < len; i++)
1753 debug((" %02x", p[i]));
1754 debug(("\n"));
1755 sfree(p);
1756 }
1757 #endif
1758
1759 static void sha_mpint(SHA_State * s, Bignum b)
1760 {
1761 unsigned char *p;
1762 int len;
1763 p = ssh2_mpint_fmt(b, &len);
1764 sha_string(s, p, len);
1765 sfree(p);
1766 }
1767
1768 /*
1769 * Packet decode functions for both SSH1 and SSH2.
1770 */
1771 static unsigned long ssh_pkt_getuint32(Ssh ssh)
1772 {
1773 unsigned long value;
1774 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1775 return 0; /* arrgh, no way to decline (FIXME?) */
1776 value = GET_32BIT(ssh->pktin.body + ssh->pktin.savedpos);
1777 ssh->pktin.savedpos += 4;
1778 return value;
1779 }
1780 static int ssh2_pkt_getbool(Ssh ssh)
1781 {
1782 unsigned long value;
1783 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1784 return 0; /* arrgh, no way to decline (FIXME?) */
1785 value = ssh->pktin.body[ssh->pktin.savedpos] != 0;
1786 ssh->pktin.savedpos++;
1787 return value;
1788 }
1789 static void ssh_pkt_getstring(Ssh ssh, char **p, int *length)
1790 {
1791 int len;
1792 *p = NULL;
1793 *length = 0;
1794 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1795 return;
1796 len = GET_32BIT(ssh->pktin.body + ssh->pktin.savedpos);
1797 if (len < 0)
1798 return;
1799 *length = len;
1800 ssh->pktin.savedpos += 4;
1801 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1802 return;
1803 *p = (char *)(ssh->pktin.body + ssh->pktin.savedpos);
1804 ssh->pktin.savedpos += *length;
1805 }
1806 static void *ssh_pkt_getdata(Ssh ssh, int length)
1807 {
1808 if (ssh->pktin.length - ssh->pktin.savedpos < length)
1809 return NULL;
1810 ssh->pktin.savedpos += length;
1811 return ssh->pktin.body + (ssh->pktin.savedpos - length);
1812 }
1813 static int ssh1_pkt_getrsakey(Ssh ssh, struct RSAKey *key,
1814 unsigned char **keystr)
1815 {
1816 int j;
1817
1818 j = makekey(ssh->pktin.body + ssh->pktin.savedpos,
1819 ssh->pktin.length - ssh->pktin.savedpos,
1820 key, keystr, 0);
1821
1822 if (j < 0)
1823 return FALSE;
1824
1825 ssh->pktin.savedpos += j;
1826 assert(ssh->pktin.savedpos < ssh->pktin.length);
1827
1828 return TRUE;
1829 }
1830 static Bignum ssh1_pkt_getmp(Ssh ssh)
1831 {
1832 int j;
1833 Bignum b;
1834
1835 j = ssh1_read_bignum(ssh->pktin.body + ssh->pktin.savedpos,
1836 ssh->pktin.length - ssh->pktin.savedpos, &b);
1837
1838 if (j < 0)
1839 return NULL;
1840
1841 ssh->pktin.savedpos += j;
1842 return b;
1843 }
1844 static Bignum ssh2_pkt_getmp(Ssh ssh)
1845 {
1846 char *p;
1847 int length;
1848 Bignum b;
1849
1850 ssh_pkt_getstring(ssh, &p, &length);
1851 if (!p)
1852 return NULL;
1853 if (p[0] & 0x80) {
1854 bombout(("internal error: Can't handle negative mpints"));
1855 return NULL;
1856 }
1857 b = bignum_from_bytes((unsigned char *)p, length);
1858 return b;
1859 }
1860
1861 /*
1862 * Helper function to add an SSH2 signature blob to a packet.
1863 * Expects to be shown the public key blob as well as the signature
1864 * blob. Normally works just like ssh2_pkt_addstring, but will
1865 * fiddle with the signature packet if necessary for
1866 * BUG_SSH2_RSA_PADDING.
1867 */
1868 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1869 void *sigblob_v, int sigblob_len)
1870 {
1871 unsigned char *pkblob = (unsigned char *)pkblob_v;
1872 unsigned char *sigblob = (unsigned char *)sigblob_v;
1873
1874 /* dmemdump(pkblob, pkblob_len); */
1875 /* dmemdump(sigblob, sigblob_len); */
1876
1877 /*
1878 * See if this is in fact an ssh-rsa signature and a buggy
1879 * server; otherwise we can just do this the easy way.
1880 */
1881 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1882 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1883 int pos, len, siglen;
1884
1885 /*
1886 * Find the byte length of the modulus.
1887 */
1888
1889 pos = 4+7; /* skip over "ssh-rsa" */
1890 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1891 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1892 pos += 4; /* find modulus itself */
1893 while (len > 0 && pkblob[pos] == 0)
1894 len--, pos++;
1895 /* debug(("modulus length is %d\n", len)); */
1896
1897 /*
1898 * Now find the signature integer.
1899 */
1900 pos = 4+7; /* skip over "ssh-rsa" */
1901 siglen = GET_32BIT(sigblob+pos);
1902 /* debug(("signature length is %d\n", siglen)); */
1903
1904 if (len != siglen) {
1905 unsigned char newlen[4];
1906 ssh2_pkt_addstring_start(ssh);
1907 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1908 /* dmemdump(sigblob, pos); */
1909 pos += 4; /* point to start of actual sig */
1910 PUT_32BIT(newlen, len);
1911 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1912 /* dmemdump(newlen, 4); */
1913 newlen[0] = 0;
1914 while (len-- > siglen) {
1915 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1916 /* dmemdump(newlen, 1); */
1917 }
1918 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1919 /* dmemdump(sigblob+pos, siglen); */
1920 return;
1921 }
1922
1923 /* Otherwise fall through and do it the easy way. */
1924 }
1925
1926 ssh2_pkt_addstring_start(ssh);
1927 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1928 }
1929
1930 /*
1931 * Examine the remote side's version string and compare it against
1932 * a list of known buggy implementations.
1933 */
1934 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1935 {
1936 char *imp; /* pointer to implementation part */
1937 imp = vstring;
1938 imp += strcspn(imp, "-");
1939 if (*imp) imp++;
1940 imp += strcspn(imp, "-");
1941 if (*imp) imp++;
1942
1943 ssh->remote_bugs = 0;
1944
1945 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
1946 (ssh->cfg.sshbug_ignore1 == AUTO &&
1947 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1948 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1949 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
1950 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
1951 /*
1952 * These versions don't support SSH1_MSG_IGNORE, so we have
1953 * to use a different defence against password length
1954 * sniffing.
1955 */
1956 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1957 logevent("We believe remote version has SSH1 ignore bug");
1958 }
1959
1960 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
1961 (ssh->cfg.sshbug_plainpw1 == AUTO &&
1962 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
1963 /*
1964 * These versions need a plain password sent; they can't
1965 * handle having a null and a random length of data after
1966 * the password.
1967 */
1968 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1969 logevent("We believe remote version needs a plain SSH1 password");
1970 }
1971
1972 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
1973 (ssh->cfg.sshbug_rsa1 == AUTO &&
1974 (!strcmp(imp, "Cisco-1.25")))) {
1975 /*
1976 * These versions apparently have no clue whatever about
1977 * RSA authentication and will panic and die if they see
1978 * an AUTH_RSA message.
1979 */
1980 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1981 logevent("We believe remote version can't handle RSA authentication");
1982 }
1983
1984 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
1985 (ssh->cfg.sshbug_hmac2 == AUTO &&
1986 !wc_match("* VShell", imp) &&
1987 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1988 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1989 wc_match("2.1 *", imp)))) {
1990 /*
1991 * These versions have the HMAC bug.
1992 */
1993 ssh->remote_bugs |= BUG_SSH2_HMAC;
1994 logevent("We believe remote version has SSH2 HMAC bug");
1995 }
1996
1997 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
1998 (ssh->cfg.sshbug_derivekey2 == AUTO &&
1999 !wc_match("* VShell", imp) &&
2000 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2001 /*
2002 * These versions have the key-derivation bug (failing to
2003 * include the literal shared secret in the hashes that
2004 * generate the keys).
2005 */
2006 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2007 logevent("We believe remote version has SSH2 key-derivation bug");
2008 }
2009
2010 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2011 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2012 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2013 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2014 /*
2015 * These versions have the SSH2 RSA padding bug.
2016 */
2017 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2018 logevent("We believe remote version has SSH2 RSA padding bug");
2019 }
2020
2021 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2022 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2023 wc_match("OpenSSH_2.[0-2]*", imp))) {
2024 /*
2025 * These versions have the SSH2 session-ID bug in
2026 * public-key authentication.
2027 */
2028 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2029 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2030 }
2031
2032 if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
2033 /*
2034 * User specified the SSH2 DH GEX bug.
2035 */
2036 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
2037 logevent("We believe remote version has SSH2 DH group exchange bug");
2038 }
2039 }
2040
2041 static int do_ssh_init(Ssh ssh, unsigned char c)
2042 {
2043 struct do_ssh_init_state {
2044 int vslen;
2045 char version[10];
2046 char *vstring;
2047 int vstrsize;
2048 int i;
2049 int proto1, proto2;
2050 };
2051 crState(do_ssh_init_state);
2052
2053 crBegin(ssh->do_ssh_init_crstate);
2054
2055 /* Search for the string "SSH-" in the input. */
2056 s->i = 0;
2057 while (1) {
2058 static const int transS[] = { 1, 2, 2, 1 };
2059 static const int transH[] = { 0, 0, 3, 0 };
2060 static const int transminus[] = { 0, 0, 0, -1 };
2061 if (c == 'S')
2062 s->i = transS[s->i];
2063 else if (c == 'H')
2064 s->i = transH[s->i];
2065 else if (c == '-')
2066 s->i = transminus[s->i];
2067 else
2068 s->i = 0;
2069 if (s->i < 0)
2070 break;
2071 crReturn(1); /* get another character */
2072 }
2073
2074 s->vstrsize = 16;
2075 s->vstring = snewn(s->vstrsize, char);
2076 strcpy(s->vstring, "SSH-");
2077 s->vslen = 4;
2078 s->i = 0;
2079 while (1) {
2080 crReturn(1); /* get another char */
2081 if (s->vslen >= s->vstrsize - 1) {
2082 s->vstrsize += 16;
2083 s->vstring = sresize(s->vstring, s->vstrsize, char);
2084 }
2085 s->vstring[s->vslen++] = c;
2086 if (s->i >= 0) {
2087 if (c == '-') {
2088 s->version[s->i] = '\0';
2089 s->i = -1;
2090 } else if (s->i < sizeof(s->version) - 1)
2091 s->version[s->i++] = c;
2092 } else if (c == '\012')
2093 break;
2094 }
2095
2096 ssh->agentfwd_enabled = FALSE;
2097 ssh->rdpkt2_state.incoming_sequence = 0;
2098
2099 s->vstring[s->vslen] = 0;
2100 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
2101 {
2102 char *vlog;
2103 vlog = snewn(20 + s->vslen, char);
2104 sprintf(vlog, "Server version: %s", s->vstring);
2105 logevent(vlog);
2106 sfree(vlog);
2107 }
2108 ssh_detect_bugs(ssh, s->vstring);
2109
2110 /*
2111 * Decide which SSH protocol version to support.
2112 */
2113
2114 /* Anything strictly below "2.0" means protocol 1 is supported. */
2115 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2116 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2117 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2118
2119 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2120 bombout(("SSH protocol version 1 required by user but not provided by server"));
2121 crStop(0);
2122 }
2123 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2124 bombout(("SSH protocol version 2 required by user but not provided by server"));
2125 crStop(0);
2126 }
2127
2128 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2129 /*
2130 * Use v2 protocol.
2131 */
2132 char verstring[80], vlog[100];
2133 sprintf(verstring, "SSH-2.0-%s", sshver);
2134 SHA_Init(&ssh->exhashbase);
2135 /*
2136 * Hash our version string and their version string.
2137 */
2138 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
2139 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
2140 sprintf(vlog, "We claim version: %s", verstring);
2141 logevent(vlog);
2142 strcat(verstring, "\012");
2143 logevent("Using SSH protocol version 2");
2144 sk_write(ssh->s, verstring, strlen(verstring));
2145 ssh->protocol = ssh2_protocol;
2146 ssh->version = 2;
2147 ssh->s_rdpkt = ssh2_rdpkt;
2148 } else {
2149 /*
2150 * Use v1 protocol.
2151 */
2152 char verstring[80], vlog[100];
2153 sprintf(verstring, "SSH-%s-%s",
2154 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
2155 sshver);
2156 sprintf(vlog, "We claim version: %s", verstring);
2157 logevent(vlog);
2158 strcat(verstring, "\012");
2159
2160 logevent("Using SSH protocol version 1");
2161 sk_write(ssh->s, verstring, strlen(verstring));
2162 ssh->protocol = ssh1_protocol;
2163 ssh->version = 1;
2164 ssh->s_rdpkt = ssh1_rdpkt;
2165 }
2166 update_specials_menu(ssh->frontend);
2167 ssh->state = SSH_STATE_BEFORE_SIZE;
2168
2169 sfree(s->vstring);
2170
2171 crFinish(0);
2172 }
2173
2174 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2175 {
2176 crBegin(ssh->ssh_gotdata_crstate);
2177
2178 /*
2179 * To begin with, feed the characters one by one to the
2180 * protocol initialisation / selection function do_ssh_init().
2181 * When that returns 0, we're done with the initial greeting
2182 * exchange and can move on to packet discipline.
2183 */
2184 while (1) {
2185 int ret; /* need not be kept across crReturn */
2186 if (datalen == 0)
2187 crReturnV; /* more data please */
2188 ret = do_ssh_init(ssh, *data);
2189 data++;
2190 datalen--;
2191 if (ret == 0)
2192 break;
2193 }
2194
2195 /*
2196 * We emerge from that loop when the initial negotiation is
2197 * over and we have selected an s_rdpkt function. Now pass
2198 * everything to s_rdpkt, and then pass the resulting packets
2199 * to the proper protocol handler.
2200 */
2201 if (datalen == 0)
2202 crReturnV;
2203 while (1) {
2204 while (datalen > 0) {
2205 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
2206 if (ssh->state == SSH_STATE_CLOSED) {
2207 return;
2208 }
2209 ssh->protocol(ssh, NULL, 0, 1);
2210 if (ssh->state == SSH_STATE_CLOSED) {
2211 return;
2212 }
2213 }
2214 }
2215 crReturnV;
2216 }
2217 crFinishV;
2218 }
2219
2220 static void ssh_do_close(Ssh ssh)
2221 {
2222 int i;
2223 struct ssh_channel *c;
2224
2225 ssh->state = SSH_STATE_CLOSED;
2226 if (ssh->s) {
2227 sk_close(ssh->s);
2228 ssh->s = NULL;
2229 }
2230 /*
2231 * Now we must shut down any port and X forwardings going
2232 * through this connection.
2233 */
2234 if (ssh->channels) {
2235 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2236 switch (c->type) {
2237 case CHAN_X11:
2238 x11_close(c->u.x11.s);
2239 break;
2240 case CHAN_SOCKDATA:
2241 pfd_close(c->u.pfd.s);
2242 break;
2243 }
2244 del234(ssh->channels, c);
2245 if (ssh->version == 2)
2246 bufchain_clear(&c->v.v2.outbuffer);
2247 sfree(c);
2248 }
2249 }
2250 }
2251
2252 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2253 int calling_back)
2254 {
2255 Ssh ssh = (Ssh) plug;
2256 ssh_do_close(ssh);
2257 if (error_msg) {
2258 /* A socket error has occurred. */
2259 logevent(error_msg);
2260 connection_fatal(ssh->frontend, "%s", error_msg);
2261 } else {
2262 /* Otherwise, the remote side closed the connection normally. */
2263 }
2264 return 0;
2265 }
2266
2267 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2268 {
2269 Ssh ssh = (Ssh) plug;
2270 ssh_gotdata(ssh, (unsigned char *)data, len);
2271 if (ssh->state == SSH_STATE_CLOSED) {
2272 ssh_do_close(ssh);
2273 return 0;
2274 }
2275 return 1;
2276 }
2277
2278 static void ssh_sent(Plug plug, int bufsize)
2279 {
2280 Ssh ssh = (Ssh) plug;
2281 /*
2282 * If the send backlog on the SSH socket itself clears, we
2283 * should unthrottle the whole world if it was throttled.
2284 */
2285 if (bufsize < SSH_MAX_BACKLOG)
2286 ssh_throttle_all(ssh, 0, bufsize);
2287 }
2288
2289 /*
2290 * Connect to specified host and port.
2291 * Returns an error message, or NULL on success.
2292 * Also places the canonical host name into `realhost'. It must be
2293 * freed by the caller.
2294 */
2295 static const char *connect_to_host(Ssh ssh, char *host, int port,
2296 char **realhost, int nodelay, int keepalive)
2297 {
2298 static const struct plug_function_table fn_table = {
2299 ssh_closing,
2300 ssh_receive,
2301 ssh_sent,
2302 NULL
2303 };
2304
2305 SockAddr addr;
2306 const char *err;
2307
2308 ssh->savedhost = snewn(1 + strlen(host), char);
2309 if (!ssh->savedhost)
2310 fatalbox("Out of memory");
2311 strcpy(ssh->savedhost, host);
2312
2313 if (port < 0)
2314 port = 22; /* default ssh port */
2315 ssh->savedport = port;
2316
2317 /*
2318 * Try to find host.
2319 */
2320 logeventf(ssh, "Looking up host \"%s\"", host);
2321 addr = name_lookup(host, port, realhost, &ssh->cfg);
2322 if ((err = sk_addr_error(addr)) != NULL) {
2323 sk_addr_free(addr);
2324 return err;
2325 }
2326
2327 /*
2328 * Open socket.
2329 */
2330 {
2331 char addrbuf[100];
2332 sk_getaddr(addr, addrbuf, 100);
2333 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2334 }
2335 ssh->fn = &fn_table;
2336 ssh->s = new_connection(addr, *realhost, port,
2337 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2338 if ((err = sk_socket_error(ssh->s)) != NULL) {
2339 ssh->s = NULL;
2340 return err;
2341 }
2342
2343 return NULL;
2344 }
2345
2346 /*
2347 * Throttle or unthrottle the SSH connection.
2348 */
2349 static void ssh1_throttle(Ssh ssh, int adjust)
2350 {
2351 int old_count = ssh->v1_throttle_count;
2352 ssh->v1_throttle_count += adjust;
2353 assert(ssh->v1_throttle_count >= 0);
2354 if (ssh->v1_throttle_count && !old_count) {
2355 sk_set_frozen(ssh->s, 1);
2356 } else if (!ssh->v1_throttle_count && old_count) {
2357 sk_set_frozen(ssh->s, 0);
2358 }
2359 }
2360
2361 /*
2362 * Throttle or unthrottle _all_ local data streams (for when sends
2363 * on the SSH connection itself back up).
2364 */
2365 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2366 {
2367 int i;
2368 struct ssh_channel *c;
2369
2370 if (enable == ssh->throttled_all)
2371 return;
2372 ssh->throttled_all = enable;
2373 ssh->overall_bufsize = bufsize;
2374 if (!ssh->channels)
2375 return;
2376 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2377 switch (c->type) {
2378 case CHAN_MAINSESSION:
2379 /*
2380 * This is treated separately, outside the switch.
2381 */
2382 break;
2383 case CHAN_X11:
2384 x11_override_throttle(c->u.x11.s, enable);
2385 break;
2386 case CHAN_AGENT:
2387 /* Agent channels require no buffer management. */
2388 break;
2389 case CHAN_SOCKDATA:
2390 pfd_override_throttle(c->u.pfd.s, enable);
2391 break;
2392 }
2393 }
2394 }
2395
2396 /*
2397 * Username and password input, abstracted off into routines
2398 * reusable in several places - even between SSH1 and SSH2.
2399 */
2400
2401 /* Set up a username or password input loop on a given buffer. */
2402 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2403 {
2404 ssh->userpass_input_buffer = buffer;
2405 ssh->userpass_input_buflen = buflen;
2406 ssh->userpass_input_bufpos = 0;
2407 ssh->userpass_input_echo = echo;
2408 }
2409
2410 /*
2411 * Process some terminal data in the course of username/password
2412 * input. Returns >0 for success (line of input returned in
2413 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2414 * for inconclusive (keep waiting for more input please).
2415 */
2416 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2417 {
2418 char c;
2419
2420 while (inlen--) {
2421 switch (c = *in++) {
2422 case 10:
2423 case 13:
2424 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2425 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2426 return +1;
2427 break;
2428 case 8:
2429 case 127:
2430 if (ssh->userpass_input_bufpos > 0) {
2431 if (ssh->userpass_input_echo)
2432 c_write_str(ssh, "\b \b");
2433 ssh->userpass_input_bufpos--;
2434 }
2435 break;
2436 case 21:
2437 case 27:
2438 while (ssh->userpass_input_bufpos > 0) {
2439 if (ssh->userpass_input_echo)
2440 c_write_str(ssh, "\b \b");
2441 ssh->userpass_input_bufpos--;
2442 }
2443 break;
2444 case 3:
2445 case 4:
2446 return -1;
2447 break;
2448 default:
2449 /*
2450 * This simplistic check for printability is disabled
2451 * when we're doing password input, because some people
2452 * have control characters in their passwords.o
2453 */
2454 if ((!ssh->userpass_input_echo ||
2455 (c >= ' ' && c <= '~') ||
2456 ((unsigned char) c >= 160))
2457 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2458 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2459 if (ssh->userpass_input_echo)
2460 c_write(ssh, &c, 1);
2461 }
2462 break;
2463 }
2464 }
2465 return 0;
2466 }
2467
2468 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2469 {
2470 Ssh ssh = (Ssh) sshv;
2471
2472 ssh->agent_response = reply;
2473 ssh->agent_response_len = replylen;
2474
2475 if (ssh->version == 1)
2476 do_ssh1_login(ssh, NULL, -1, 0);
2477 else
2478 do_ssh2_authconn(ssh, NULL, -1, 0);
2479 }
2480
2481 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2482 {
2483 struct ssh_channel *c = (struct ssh_channel *)cv;
2484 Ssh ssh = c->ssh;
2485 void *sentreply = reply;
2486
2487 if (!sentreply) {
2488 /* Fake SSH_AGENT_FAILURE. */
2489 sentreply = "\0\0\0\1\5";
2490 replylen = 5;
2491 }
2492 if (ssh->version == 2) {
2493 ssh2_add_channel_data(c, sentreply, replylen);
2494 ssh2_try_send(c);
2495 } else {
2496 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2497 PKT_INT, c->remoteid,
2498 PKTT_DATA,
2499 PKT_INT, replylen,
2500 PKT_DATA, sentreply, replylen,
2501 PKTT_OTHER,
2502 PKT_END);
2503 }
2504 if (reply)
2505 sfree(reply);
2506 }
2507
2508 /*
2509 * Handle the key exchange and user authentication phases.
2510 */
2511 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2512 {
2513 int i, j, ret;
2514 unsigned char cookie[8], *ptr;
2515 struct RSAKey servkey, hostkey;
2516 struct MD5Context md5c;
2517 struct do_ssh1_login_state {
2518 int len;
2519 unsigned char *rsabuf, *keystr1, *keystr2;
2520 unsigned long supported_ciphers_mask, supported_auths_mask;
2521 int tried_publickey, tried_agent;
2522 int tis_auth_refused, ccard_auth_refused;
2523 unsigned char session_id[16];
2524 int cipher_type;
2525 char username[100];
2526 void *publickey_blob;
2527 int publickey_bloblen;
2528 char password[100];
2529 char prompt[200];
2530 int pos;
2531 char c;
2532 int pwpkt_type;
2533 unsigned char request[5], *response, *p;
2534 int responselen;
2535 int keyi, nkeys;
2536 int authed;
2537 struct RSAKey key;
2538 Bignum challenge;
2539 char *commentp;
2540 int commentlen;
2541 };
2542 crState(do_ssh1_login_state);
2543
2544 crBegin(ssh->do_ssh1_login_crstate);
2545
2546 if (!ispkt)
2547 crWaitUntil(ispkt);
2548
2549 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2550 bombout(("Public key packet not received"));
2551 crStop(0);
2552 }
2553
2554 logevent("Received public keys");
2555
2556 ptr = ssh_pkt_getdata(ssh, 8);
2557 if (!ptr) {
2558 bombout(("SSH1 public key packet stopped before random cookie"));
2559 crStop(0);
2560 }
2561 memcpy(cookie, ptr, 8);
2562
2563 if (!ssh1_pkt_getrsakey(ssh, &servkey, &s->keystr1) ||
2564 !ssh1_pkt_getrsakey(ssh, &hostkey, &s->keystr2)) {
2565 bombout(("Failed to read SSH1 public keys from public key packet"));
2566 crStop(0);
2567 }
2568
2569 /*
2570 * Log the host key fingerprint.
2571 */
2572 {
2573 char logmsg[80];
2574 logevent("Host key fingerprint is:");
2575 strcpy(logmsg, " ");
2576 hostkey.comment = NULL;
2577 rsa_fingerprint(logmsg + strlen(logmsg),
2578 sizeof(logmsg) - strlen(logmsg), &hostkey);
2579 logevent(logmsg);
2580 }
2581
2582 ssh->v1_remote_protoflags = ssh_pkt_getuint32(ssh);
2583 s->supported_ciphers_mask = ssh_pkt_getuint32(ssh);
2584 s->supported_auths_mask = ssh_pkt_getuint32(ssh);
2585
2586 ssh->v1_local_protoflags =
2587 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2588 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2589
2590 MD5Init(&md5c);
2591 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2592 MD5Update(&md5c, s->keystr1, servkey.bytes);
2593 MD5Update(&md5c, cookie, 8);
2594 MD5Final(s->session_id, &md5c);
2595
2596 for (i = 0; i < 32; i++)
2597 ssh->session_key[i] = random_byte();
2598
2599 /*
2600 * Verify that the `bits' and `bytes' parameters match.
2601 */
2602 if (hostkey.bits > hostkey.bytes * 8 ||
2603 servkey.bits > servkey.bytes * 8) {
2604 bombout(("SSH1 public keys were badly formatted"));
2605 crStop(0);
2606 }
2607
2608 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2609
2610 s->rsabuf = snewn(s->len, unsigned char);
2611 if (!s->rsabuf)
2612 fatalbox("Out of memory");
2613
2614 /*
2615 * Verify the host key.
2616 */
2617 {
2618 /*
2619 * First format the key into a string.
2620 */
2621 int len = rsastr_len(&hostkey);
2622 char fingerprint[100];
2623 char *keystr = snewn(len, char);
2624 if (!keystr)
2625 fatalbox("Out of memory");
2626 rsastr_fmt(keystr, &hostkey);
2627 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2628 verify_ssh_host_key(ssh->frontend,
2629 ssh->savedhost, ssh->savedport, "rsa", keystr,
2630 fingerprint);
2631 sfree(keystr);
2632 }
2633
2634 for (i = 0; i < 32; i++) {
2635 s->rsabuf[i] = ssh->session_key[i];
2636 if (i < 16)
2637 s->rsabuf[i] ^= s->session_id[i];
2638 }
2639
2640 if (hostkey.bytes > servkey.bytes) {
2641 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2642 if (ret)
2643 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2644 } else {
2645 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2646 if (ret)
2647 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2648 }
2649 if (!ret) {
2650 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2651 crStop(0);
2652 }
2653
2654 logevent("Encrypted session key");
2655
2656 {
2657 int cipher_chosen = 0, warn = 0;
2658 char *cipher_string = NULL;
2659 int i;
2660 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2661 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2662 if (next_cipher == CIPHER_WARN) {
2663 /* If/when we choose a cipher, warn about it */
2664 warn = 1;
2665 } else if (next_cipher == CIPHER_AES) {
2666 /* XXX Probably don't need to mention this. */
2667 logevent("AES not supported in SSH1, skipping");
2668 } else {
2669 switch (next_cipher) {
2670 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2671 cipher_string = "3DES"; break;
2672 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2673 cipher_string = "Blowfish"; break;
2674 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2675 cipher_string = "single-DES"; break;
2676 }
2677 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2678 cipher_chosen = 1;
2679 }
2680 }
2681 if (!cipher_chosen) {
2682 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2683 bombout(("Server violates SSH 1 protocol by not "
2684 "supporting 3DES encryption"));
2685 else
2686 /* shouldn't happen */
2687 bombout(("No supported ciphers found"));
2688 crStop(0);
2689 }
2690
2691 /* Warn about chosen cipher if necessary. */
2692 if (warn)
2693 askcipher(ssh->frontend, cipher_string, 0);
2694 }
2695
2696 switch (s->cipher_type) {
2697 case SSH_CIPHER_3DES:
2698 logevent("Using 3DES encryption");
2699 break;
2700 case SSH_CIPHER_DES:
2701 logevent("Using single-DES encryption");
2702 break;
2703 case SSH_CIPHER_BLOWFISH:
2704 logevent("Using Blowfish encryption");
2705 break;
2706 }
2707
2708 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2709 PKT_CHAR, s->cipher_type,
2710 PKT_DATA, cookie, 8,
2711 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2712 PKT_DATA, s->rsabuf, s->len,
2713 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2714
2715 logevent("Trying to enable encryption...");
2716
2717 sfree(s->rsabuf);
2718
2719 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2720 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2721 &ssh_3des);
2722 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2723 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2724 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2725
2726 ssh->crcda_ctx = crcda_make_context();
2727 logevent("Installing CRC compensation attack detector");
2728
2729 if (servkey.modulus) {
2730 sfree(servkey.modulus);
2731 servkey.modulus = NULL;
2732 }
2733 if (servkey.exponent) {
2734 sfree(servkey.exponent);
2735 servkey.exponent = NULL;
2736 }
2737 if (hostkey.modulus) {
2738 sfree(hostkey.modulus);
2739 hostkey.modulus = NULL;
2740 }
2741 if (hostkey.exponent) {
2742 sfree(hostkey.exponent);
2743 hostkey.exponent = NULL;
2744 }
2745 crWaitUntil(ispkt);
2746
2747 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2748 bombout(("Encryption not successfully enabled"));
2749 crStop(0);
2750 }
2751
2752 logevent("Successfully started encryption");
2753
2754 fflush(stdout);
2755 {
2756 if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
2757 if (ssh_get_line && !ssh_getline_pw_only) {
2758 if (!ssh_get_line("login as: ",
2759 s->username, sizeof(s->username), FALSE)) {
2760 /*
2761 * get_line failed to get a username.
2762 * Terminate.
2763 */
2764 logevent("No username provided. Abandoning session.");
2765 ssh_closing((Plug)ssh, NULL, 0, 0);
2766 crStop(1);
2767 }
2768 } else {
2769 int ret; /* need not be kept over crReturn */
2770 c_write_str(ssh, "login as: ");
2771 ssh->send_ok = 1;
2772
2773 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2774 do {
2775 crWaitUntil(!ispkt);
2776 ret = process_userpass_input(ssh, in, inlen);
2777 } while (ret == 0);
2778 if (ret < 0)
2779 cleanup_exit(0);
2780 c_write_str(ssh, "\r\n");
2781 }
2782 } else {
2783 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2784 s->username[sizeof(s->username)-1] = '\0';
2785 }
2786
2787 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2788 {
2789 char userlog[22 + sizeof(s->username)];
2790 sprintf(userlog, "Sent username \"%s\"", s->username);
2791 logevent(userlog);
2792 if (flags & FLAG_INTERACTIVE &&
2793 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2794 strcat(userlog, "\r\n");
2795 c_write_str(ssh, userlog);
2796 }
2797 }
2798 }
2799
2800 crWaitUntil(ispkt);
2801
2802 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2803 /* We must not attempt PK auth. Pretend we've already tried it. */
2804 s->tried_publickey = s->tried_agent = 1;
2805 } else {
2806 s->tried_publickey = s->tried_agent = 0;
2807 }
2808 s->tis_auth_refused = s->ccard_auth_refused = 0;
2809 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2810 if (!filename_is_null(ssh->cfg.keyfile)) {
2811 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2812 &s->publickey_blob, &s->publickey_bloblen, NULL))
2813 s->publickey_blob = NULL;
2814 } else
2815 s->publickey_blob = NULL;
2816
2817 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2818 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2819
2820 if (agent_exists() && !s->tried_agent) {
2821 /*
2822 * Attempt RSA authentication using Pageant.
2823 */
2824 void *r;
2825
2826 s->authed = FALSE;
2827 s->tried_agent = 1;
2828 logevent("Pageant is running. Requesting keys.");
2829
2830 /* Request the keys held by the agent. */
2831 PUT_32BIT(s->request, 1);
2832 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2833 if (!agent_query(s->request, 5, &r, &s->responselen,
2834 ssh_agent_callback, ssh)) {
2835 do {
2836 crReturn(0);
2837 if (ispkt) {
2838 bombout(("Unexpected data from server while waiting"
2839 " for agent response"));
2840 crStop(0);
2841 }
2842 } while (ispkt || inlen > 0);
2843 r = ssh->agent_response;
2844 s->responselen = ssh->agent_response_len;
2845 }
2846 s->response = (unsigned char *) r;
2847 if (s->response && s->responselen >= 5 &&
2848 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2849 s->p = s->response + 5;
2850 s->nkeys = GET_32BIT(s->p);
2851 s->p += 4;
2852 {
2853 char buf[64];
2854 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2855 logevent(buf);
2856 }
2857 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2858 {
2859 char buf[64];
2860 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2861 logevent(buf);
2862 }
2863 if (s->publickey_blob &&
2864 !memcmp(s->p, s->publickey_blob,
2865 s->publickey_bloblen)) {
2866 logevent("This key matches configured key file");
2867 s->tried_publickey = 1;
2868 }
2869 s->p += 4;
2870 {
2871 int n, ok = FALSE;
2872 do { /* do while (0) to make breaking easy */
2873 n = ssh1_read_bignum
2874 (s->p, s->responselen-(s->p-s->response),
2875 &s->key.exponent);
2876 if (n < 0)
2877 break;
2878 s->p += n;
2879 n = ssh1_read_bignum
2880 (s->p, s->responselen-(s->p-s->response),
2881 &s->key.modulus);
2882 if (n < 0)
2883 break;
2884 s->p += n;
2885 if (s->responselen - (s->p-s->response) < 4)
2886 break;
2887 s->commentlen = GET_32BIT(s->p);
2888 s->p += 4;
2889 if (s->responselen - (s->p-s->response) <
2890 s->commentlen)
2891 break;
2892 s->commentp = (char *)s->p;
2893 s->p += s->commentlen;
2894 ok = TRUE;
2895 } while (0);
2896 if (!ok) {
2897 logevent("Pageant key list packet was truncated");
2898 break;
2899 }
2900 }
2901 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2902 PKT_BIGNUM, s->key.modulus, PKT_END);
2903 crWaitUntil(ispkt);
2904 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2905 logevent("Key refused");
2906 continue;
2907 }
2908 logevent("Received RSA challenge");
2909 if ((s->challenge = ssh1_pkt_getmp(ssh)) == NULL) {
2910 bombout(("Server's RSA challenge was badly formatted"));
2911 crStop(0);
2912 }
2913
2914 {
2915 char *agentreq, *q, *ret;
2916 void *vret;
2917 int len, retlen;
2918 len = 1 + 4; /* message type, bit count */
2919 len += ssh1_bignum_length(s->key.exponent);
2920 len += ssh1_bignum_length(s->key.modulus);
2921 len += ssh1_bignum_length(s->challenge);
2922 len += 16; /* session id */
2923 len += 4; /* response format */
2924 agentreq = snewn(4 + len, char);
2925 PUT_32BIT(agentreq, len);
2926 q = agentreq + 4;
2927 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2928 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2929 q += 4;
2930 q += ssh1_write_bignum(q, s->key.exponent);
2931 q += ssh1_write_bignum(q, s->key.modulus);
2932 q += ssh1_write_bignum(q, s->challenge);
2933 memcpy(q, s->session_id, 16);
2934 q += 16;
2935 PUT_32BIT(q, 1); /* response format */
2936 if (!agent_query(agentreq, len + 4, &vret, &retlen,
2937 ssh_agent_callback, ssh)) {
2938 sfree(agentreq);
2939 do {
2940 crReturn(0);
2941 if (ispkt) {
2942 bombout(("Unexpected data from server"
2943 " while waiting for agent"
2944 " response"));
2945 crStop(0);
2946 }
2947 } while (ispkt || inlen > 0);
2948 vret = ssh->agent_response;
2949 retlen = ssh->agent_response_len;
2950 } else
2951 sfree(agentreq);
2952 ret = vret;
2953 if (ret) {
2954 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2955 logevent("Sending Pageant's response");
2956 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2957 PKT_DATA, ret + 5, 16,
2958 PKT_END);
2959 sfree(ret);
2960 crWaitUntil(ispkt);
2961 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2962 logevent
2963 ("Pageant's response accepted");
2964 if (flags & FLAG_VERBOSE) {
2965 c_write_str(ssh, "Authenticated using"
2966 " RSA key \"");
2967 c_write(ssh, s->commentp,
2968 s->commentlen);
2969 c_write_str(ssh, "\" from agent\r\n");
2970 }
2971 s->authed = TRUE;
2972 } else
2973 logevent
2974 ("Pageant's response not accepted");
2975 } else {
2976 logevent
2977 ("Pageant failed to answer challenge");
2978 sfree(ret);
2979 }
2980 } else {
2981 logevent("No reply received from Pageant");
2982 }
2983 }
2984 freebn(s->key.exponent);
2985 freebn(s->key.modulus);
2986 freebn(s->challenge);
2987 if (s->authed)
2988 break;
2989 }
2990 sfree(s->response);
2991 }
2992 if (s->authed)
2993 break;
2994 }
2995 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
2996 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2997
2998 if (ssh->cfg.try_tis_auth &&
2999 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3000 !s->tis_auth_refused) {
3001 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3002 logevent("Requested TIS authentication");
3003 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3004 crWaitUntil(ispkt);
3005 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3006 logevent("TIS authentication declined");
3007 if (flags & FLAG_INTERACTIVE)
3008 c_write_str(ssh, "TIS authentication refused.\r\n");
3009 s->tis_auth_refused = 1;
3010 continue;
3011 } else {
3012 char *challenge;
3013 int challengelen;
3014
3015 ssh_pkt_getstring(ssh, &challenge, &challengelen);
3016 if (!challenge) {
3017 bombout(("TIS challenge packet was badly formed"));
3018 crStop(0);
3019 }
3020 logevent("Received TIS challenge");
3021 if (challengelen > sizeof(s->prompt) - 1)
3022 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3023 memcpy(s->prompt, challenge, challengelen);
3024 /* Prompt heuristic comes from OpenSSH */
3025 strncpy(s->prompt + challengelen,
3026 memchr(s->prompt, '\n', challengelen) ?
3027 "": "\r\nResponse: ",
3028 (sizeof s->prompt) - challengelen);
3029 s->prompt[(sizeof s->prompt) - 1] = '\0';
3030 }
3031 }
3032 if (ssh->cfg.try_tis_auth &&
3033 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3034 !s->ccard_auth_refused) {
3035 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3036 logevent("Requested CryptoCard authentication");
3037 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3038 crWaitUntil(ispkt);
3039 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3040 logevent("CryptoCard authentication declined");
3041 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3042 s->ccard_auth_refused = 1;
3043 continue;
3044 } else {
3045 char *challenge;
3046 int challengelen;
3047
3048 ssh_pkt_getstring(ssh, &challenge, &challengelen);
3049 if (!challenge) {
3050 bombout(("CryptoCard challenge packet was badly formed"));
3051 crStop(0);
3052 }
3053 logevent("Received CryptoCard challenge");
3054 if (challengelen > sizeof(s->prompt) - 1)
3055 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3056 memcpy(s->prompt, challenge, challengelen);
3057 strncpy(s->prompt + challengelen,
3058 memchr(s->prompt, '\n', challengelen) ?
3059 "" : "\r\nResponse: ",
3060 sizeof(s->prompt) - challengelen);
3061 s->prompt[sizeof(s->prompt) - 1] = '\0';
3062 }
3063 }
3064 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3065 sprintf(s->prompt, "%.90s@%.90s's password: ",
3066 s->username, ssh->savedhost);
3067 }
3068 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3069 char *comment = NULL;
3070 int type;
3071 char msgbuf[256];
3072 if (flags & FLAG_VERBOSE)
3073 c_write_str(ssh, "Trying public key authentication.\r\n");
3074 logeventf(ssh, "Trying public key \"%s\"",
3075 filename_to_str(&ssh->cfg.keyfile));
3076 type = key_type(&ssh->cfg.keyfile);
3077 if (type != SSH_KEYTYPE_SSH1) {
3078 sprintf(msgbuf, "Key is of wrong type (%s)",
3079 key_type_to_str(type));
3080 logevent(msgbuf);
3081 c_write_str(ssh, msgbuf);
3082 c_write_str(ssh, "\r\n");
3083 s->tried_publickey = 1;
3084 continue;
3085 }
3086 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3087 if (flags & FLAG_VERBOSE)
3088 c_write_str(ssh, "No passphrase required.\r\n");
3089 goto tryauth;
3090 }
3091 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3092 sfree(comment);
3093 }
3094
3095 /*
3096 * Show password prompt, having first obtained it via a TIS
3097 * or CryptoCard exchange if we're doing TIS or CryptoCard
3098 * authentication.
3099 */
3100 if (ssh_get_line) {
3101 if (!ssh_get_line(s->prompt, s->password,
3102 sizeof(s->password), TRUE)) {
3103 /*
3104 * get_line failed to get a password (for example
3105 * because one was supplied on the command line
3106 * which has already failed to work). Terminate.
3107 */
3108 send_packet(ssh, SSH1_MSG_DISCONNECT,
3109 PKT_STR, "No more passwords available to try",
3110 PKT_END);
3111 logevent("Unable to authenticate");
3112 connection_fatal(ssh->frontend, "Unable to authenticate");
3113 ssh_closing((Plug)ssh, NULL, 0, 0);
3114 crStop(1);
3115 }
3116 } else {
3117 /* Prompt may have come from server. We've munged it a bit, so
3118 * we know it to be zero-terminated at least once. */
3119 int ret; /* need not be saved over crReturn */
3120 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3121 s->pos = 0;
3122
3123 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3124 do {
3125 crWaitUntil(!ispkt);
3126 ret = process_userpass_input(ssh, in, inlen);
3127 } while (ret == 0);
3128 if (ret < 0)
3129 cleanup_exit(0);
3130 c_write_str(ssh, "\r\n");
3131 }
3132
3133 tryauth:
3134 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3135 /*
3136 * Try public key authentication with the specified
3137 * key file.
3138 */
3139 s->tried_publickey = 1;
3140
3141 {
3142 const char *error = NULL;
3143 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3144 &error);
3145 if (ret == 0) {
3146 c_write_str(ssh, "Couldn't load private key from ");
3147 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3148 c_write_str(ssh, " (");
3149 c_write_str(ssh, error);
3150 c_write_str(ssh, ").\r\n");
3151 continue; /* go and try password */
3152 }
3153 if (ret == -1) {
3154 c_write_str(ssh, "Wrong passphrase.\r\n");
3155 s->tried_publickey = 0;
3156 continue; /* try again */
3157 }
3158 }
3159
3160 /*
3161 * Send a public key attempt.
3162 */
3163 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3164 PKT_BIGNUM, s->key.modulus, PKT_END);
3165
3166 crWaitUntil(ispkt);
3167 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3168 c_write_str(ssh, "Server refused our public key.\r\n");
3169 continue; /* go and try password */
3170 }
3171 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3172 bombout(("Bizarre response to offer of public key"));
3173 crStop(0);
3174 }
3175
3176 {
3177 int i;
3178 unsigned char buffer[32];
3179 Bignum challenge, response;
3180
3181 if ((challenge = ssh1_pkt_getmp(ssh)) == NULL) {
3182 bombout(("Server's RSA challenge was badly formatted"));
3183 crStop(0);
3184 }
3185 response = rsadecrypt(challenge, &s->key);
3186 freebn(s->key.private_exponent);/* burn the evidence */
3187
3188 for (i = 0; i < 32; i++) {
3189 buffer[i] = bignum_byte(response, 31 - i);
3190 }
3191
3192 MD5Init(&md5c);
3193 MD5Update(&md5c, buffer, 32);
3194 MD5Update(&md5c, s->session_id, 16);
3195 MD5Final(buffer, &md5c);
3196
3197 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3198 PKT_DATA, buffer, 16, PKT_END);
3199
3200 freebn(challenge);
3201 freebn(response);
3202 }
3203
3204 crWaitUntil(ispkt);
3205 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3206 if (flags & FLAG_VERBOSE)
3207 c_write_str(ssh, "Failed to authenticate with"
3208 " our public key.\r\n");
3209 continue; /* go and try password */
3210 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3211 bombout(("Bizarre response to RSA authentication response"));
3212 crStop(0);
3213 }
3214
3215 break; /* we're through! */
3216 } else {
3217 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3218 /*
3219 * Defence against traffic analysis: we send a
3220 * whole bunch of packets containing strings of
3221 * different lengths. One of these strings is the
3222 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3223 * The others are all random data in
3224 * SSH1_MSG_IGNORE packets. This way a passive
3225 * listener can't tell which is the password, and
3226 * hence can't deduce the password length.
3227 *
3228 * Anybody with a password length greater than 16
3229 * bytes is going to have enough entropy in their
3230 * password that a listener won't find it _that_
3231 * much help to know how long it is. So what we'll
3232 * do is:
3233 *
3234 * - if password length < 16, we send 15 packets
3235 * containing string lengths 1 through 15
3236 *
3237 * - otherwise, we let N be the nearest multiple
3238 * of 8 below the password length, and send 8
3239 * packets containing string lengths N through
3240 * N+7. This won't obscure the order of
3241 * magnitude of the password length, but it will
3242 * introduce a bit of extra uncertainty.
3243 *
3244 * A few servers (the old 1.2.18 through 1.2.22)
3245 * can't deal with SSH1_MSG_IGNORE. For these
3246 * servers, we need an alternative defence. We make
3247 * use of the fact that the password is interpreted
3248 * as a C string: so we can append a NUL, then some
3249 * random data.
3250 *
3251 * One server (a Cisco one) can deal with neither
3252 * SSH1_MSG_IGNORE _nor_ a padded password string.
3253 * For this server we are left with no defences
3254 * against password length sniffing.
3255 */
3256 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3257 /*
3258 * The server can deal with SSH1_MSG_IGNORE, so
3259 * we can use the primary defence.
3260 */
3261 int bottom, top, pwlen, i;
3262 char *randomstr;
3263
3264 pwlen = strlen(s->password);
3265 if (pwlen < 16) {
3266 bottom = 0; /* zero length passwords are OK! :-) */
3267 top = 15;
3268 } else {
3269 bottom = pwlen & ~7;
3270 top = bottom + 7;
3271 }
3272
3273 assert(pwlen >= bottom && pwlen <= top);
3274
3275 randomstr = snewn(top + 1, char);
3276
3277 for (i = bottom; i <= top; i++) {
3278 if (i == pwlen) {
3279 defer_packet(ssh, s->pwpkt_type,
3280 PKTT_PASSWORD, PKT_STR, s->password,
3281 PKTT_OTHER, PKT_END);
3282 } else {
3283 for (j = 0; j < i; j++) {
3284 do {
3285 randomstr[j] = random_byte();
3286 } while (randomstr[j] == '\0');
3287 }
3288 randomstr[i] = '\0';
3289 defer_packet(ssh, SSH1_MSG_IGNORE,
3290 PKT_STR, randomstr, PKT_END);
3291 }
3292 }
3293 logevent("Sending password with camouflage packets");
3294 ssh_pkt_defersend(ssh);
3295 sfree(randomstr);
3296 }
3297 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3298 /*
3299 * The server can't deal with SSH1_MSG_IGNORE
3300 * but can deal with padded passwords, so we
3301 * can use the secondary defence.
3302 */
3303 char string[64];
3304 char *ss;
3305 int len;
3306
3307 len = strlen(s->password);
3308 if (len < sizeof(string)) {
3309 ss = string;
3310 strcpy(string, s->password);
3311 len++; /* cover the zero byte */
3312 while (len < sizeof(string)) {
3313 string[len++] = (char) random_byte();
3314 }
3315 } else {
3316 ss = s->password;
3317 }
3318 logevent("Sending length-padded password");
3319 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3320 PKT_INT, len, PKT_DATA, ss, len,
3321 PKTT_OTHER, PKT_END);
3322 } else {
3323 /*
3324 * The server has _both_
3325 * BUG_CHOKES_ON_SSH1_IGNORE and
3326 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3327 * therefore nothing we can do.
3328 */
3329 int len;
3330 len = strlen(s->password);
3331 logevent("Sending unpadded password");
3332 send_packet(ssh, s->pwpkt_type,
3333 PKTT_PASSWORD, PKT_INT, len,
3334 PKT_DATA, s->password, len,
3335 PKTT_OTHER, PKT_END);
3336 }
3337 } else {
3338 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3339 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3340 }
3341 }
3342 logevent("Sent password");
3343 memset(s->password, 0, strlen(s->password));
3344 crWaitUntil(ispkt);
3345 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3346 if (flags & FLAG_VERBOSE)
3347 c_write_str(ssh, "Access denied\r\n");
3348 logevent("Authentication refused");
3349 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
3350 bombout(("Strange packet received, type %d", ssh->pktin.type));
3351 crStop(0);
3352 }
3353 }
3354
3355 logevent("Authentication successful");
3356
3357 crFinish(1);
3358 }
3359
3360 void sshfwd_close(struct ssh_channel *c)
3361 {
3362 Ssh ssh = c->ssh;
3363
3364 if (ssh->state != SSH_STATE_SESSION) {
3365 assert(ssh->state == SSH_STATE_CLOSED);
3366 return;
3367 }
3368
3369 if (c && !c->closes) {
3370 /*
3371 * If the channel's remoteid is -1, we have sent
3372 * CHANNEL_OPEN for this channel, but it hasn't even been
3373 * acknowledged by the server. So we must set a close flag
3374 * on it now, and then when the server acks the channel
3375 * open, we can close it then.
3376 */
3377 if (((int)c->remoteid) != -1) {
3378 if (ssh->version == 1) {
3379 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3380 PKT_END);
3381 } else {
3382 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
3383 ssh2_pkt_adduint32(ssh, c->remoteid);
3384 ssh2_pkt_send(ssh);
3385 }
3386 }
3387 c->closes = 1; /* sent MSG_CLOSE */
3388 if (c->type == CHAN_X11) {
3389 c->u.x11.s = NULL;
3390 logevent("Forwarded X11 connection terminated");
3391 } else if (c->type == CHAN_SOCKDATA ||
3392 c->type == CHAN_SOCKDATA_DORMANT) {
3393 c->u.pfd.s = NULL;
3394 logevent("Forwarded port closed");
3395 }
3396 }
3397 }
3398
3399 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3400 {
3401 Ssh ssh = c->ssh;
3402
3403 if (ssh->state != SSH_STATE_SESSION) {
3404 assert(ssh->state == SSH_STATE_CLOSED);
3405 return 0;
3406 }
3407
3408 if (ssh->version == 1) {
3409 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3410 PKT_INT, c->remoteid,
3411 PKTT_DATA,
3412 PKT_INT, len, PKT_DATA, buf, len,
3413 PKTT_OTHER, PKT_END);
3414 /*
3415 * In SSH1 we can return 0 here - implying that forwarded
3416 * connections are never individually throttled - because
3417 * the only circumstance that can cause throttling will be
3418 * the whole SSH connection backing up, in which case
3419 * _everything_ will be throttled as a whole.
3420 */
3421 return 0;
3422 } else {
3423 ssh2_add_channel_data(c, buf, len);
3424 return ssh2_try_send(c);
3425 }
3426 }
3427
3428 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3429 {
3430 Ssh ssh = c->ssh;
3431
3432 if (ssh->state != SSH_STATE_SESSION) {
3433 assert(ssh->state == SSH_STATE_CLOSED);
3434 return;
3435 }
3436
3437 if (ssh->version == 1) {
3438 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3439 c->v.v1.throttling = 0;
3440 ssh1_throttle(ssh, -1);
3441 }
3442 } else {
3443 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3444 }
3445 }
3446
3447 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3448 {
3449 crBegin(ssh->ssh1_protocol_crstate);
3450
3451 random_init();
3452
3453 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3454 crReturnV;
3455 }
3456 if (ssh->state == SSH_STATE_CLOSED)
3457 crReturnV;
3458
3459 if (ssh->cfg.agentfwd && agent_exists()) {
3460 logevent("Requesting agent forwarding");
3461 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3462 do {
3463 crReturnV;
3464 } while (!ispkt);
3465 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3466 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3467 bombout(("Protocol confusion"));
3468 crStopV;
3469 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3470 logevent("Agent forwarding refused");
3471 } else {
3472 logevent("Agent forwarding enabled");
3473 ssh->agentfwd_enabled = TRUE;
3474 }
3475 }
3476
3477 if (ssh->cfg.x11_forward) {
3478 char proto[20], data[64];
3479 logevent("Requesting X11 forwarding");
3480 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3481 data, sizeof(data), ssh->cfg.x11_auth);
3482 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
3483 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3484 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3485 PKT_STR, proto, PKT_STR, data,
3486 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
3487 PKT_END);
3488 } else {
3489 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3490 PKT_STR, proto, PKT_STR, data, PKT_END);
3491 }
3492 do {
3493 crReturnV;
3494 } while (!ispkt);
3495 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3496 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3497 bombout(("Protocol confusion"));
3498 crStopV;
3499 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3500 logevent("X11 forwarding refused");
3501 } else {
3502 logevent("X11 forwarding enabled");
3503 ssh->X11_fwd_enabled = TRUE;
3504 }
3505 }
3506
3507 {
3508 char type;
3509 int n;
3510 int sport,dport,sserv,dserv;
3511 char sports[256], dports[256], saddr[256], host[256];
3512
3513 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3514 /* Add port forwardings. */
3515 ssh->portfwd_strptr = ssh->cfg.portfwd;
3516 while (*ssh->portfwd_strptr) {
3517 type = *ssh->portfwd_strptr++;
3518 saddr[0] = '\0';
3519 n = 0;
3520 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3521 if (*ssh->portfwd_strptr == ':') {
3522 /*
3523 * We've seen a colon in the middle of the
3524 * source port number. This means that
3525 * everything we've seen until now is the
3526 * source _address_, so we'll move it into
3527 * saddr and start sports from the beginning
3528 * again.
3529 */
3530 ssh->portfwd_strptr++;
3531 sports[n] = '\0';
3532 strcpy(saddr, sports);
3533 n = 0;
3534 }
3535 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3536 }
3537 sports[n] = 0;
3538 if (type != 'D') {
3539 if (*ssh->portfwd_strptr == '\t')
3540 ssh->portfwd_strptr++;
3541 n = 0;
3542 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3543 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3544 }
3545 host[n] = 0;
3546 if (*ssh->portfwd_strptr == ':')
3547 ssh->portfwd_strptr++;
3548 n = 0;
3549 while (*ssh->portfwd_strptr) {
3550 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3551 }
3552 dports[n] = 0;
3553 ssh->portfwd_strptr++;
3554 dport = atoi(dports);
3555 dserv = 0;
3556 if (dport == 0) {
3557 dserv = 1;
3558 dport = net_service_lookup(dports);
3559 if (!dport) {
3560 logeventf(ssh, "Service lookup failed for"
3561 " destination port \"%s\"", dports);
3562 }
3563 }
3564 } else {
3565 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
3566 dport = dserv = -1;
3567 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
3568 }
3569 sport = atoi(sports);
3570 sserv = 0;
3571 if (sport == 0) {
3572 sserv = 1;
3573 sport = net_service_lookup(sports);
3574 if (!sport) {
3575 logeventf(ssh, "Service lookup failed for source"
3576 " port \"%s\"", sports);
3577 }
3578 }
3579 if (sport && dport) {
3580 /* Set up a description of the source port. */
3581 char *sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
3582 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3583 (int)(*saddr?1:0), ":",
3584 (int)(sserv ? strlen(sports) : 0), sports,
3585 sserv, "(", sport, sserv, ")");
3586 if (type == 'L') {
3587 /* Verbose description of the destination port */
3588 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
3589 host,
3590 (int)(dserv ? strlen(dports) : 0), dports,
3591 dserv, "(", dport, dserv, ")");
3592 const char *err = pfd_addforward(host, dport,
3593 *saddr ? saddr : NULL,
3594 sport, ssh, &ssh->cfg);
3595 if (err) {
3596 logeventf(ssh, "Local port %s forward to %s"
3597 " failed: %s", sportdesc, dportdesc, err);
3598 } else {
3599 logeventf(ssh, "Local port %s forwarding to %s",
3600 sportdesc, dportdesc);
3601 }
3602 sfree(dportdesc);
3603 } else if (type == 'D') {
3604 const char *err = pfd_addforward(NULL, -1,
3605 *saddr ? saddr : NULL,
3606 sport, ssh, &ssh->cfg);
3607 if (err) {
3608 logeventf(ssh, "Local port %s SOCKS dynamic forward"
3609 " setup failed: %s", sportdesc, err);
3610 } else {
3611 logeventf(ssh, "Local port %s doing SOCKS"
3612 " dynamic forwarding", sportdesc);
3613 }
3614 } else {
3615 struct ssh_rportfwd *pf;
3616 pf = snew(struct ssh_rportfwd);
3617 strcpy(pf->dhost, host);
3618 pf->dport = dport;
3619 if (*saddr) {
3620 logeventf(ssh,
3621 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3622 saddr, sport);
3623 }
3624 if (add234(ssh->rportfwds, pf) != pf) {
3625 logeventf(ssh,
3626 "Duplicate remote port forwarding to %s:%d",
3627 host, dport);
3628 sfree(pf);
3629 } else {
3630 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3631 " forward to %s:%.*s%.*s%d%.*s",
3632 (int)(sserv ? strlen(sports) : 0), sports,
3633 sserv, "(", sport, sserv, ")",
3634 host,
3635 (int)(dserv ? strlen(dports) : 0), dports,
3636 dserv, "(", dport, dserv, ")");
3637 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3638 PKT_INT, sport,
3639 PKT_STR, host,
3640 PKT_INT, dport,
3641 PKT_END);
3642 do {
3643 crReturnV;
3644 } while (!ispkt);
3645 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3646 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3647 bombout(("Protocol confusion"));
3648 crStopV;
3649 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3650 c_write_str(ssh, "Server refused port"
3651 " forwarding\r\n");
3652 }
3653 logevent("Remote port forwarding enabled");
3654 }
3655 }
3656 sfree(sportdesc);
3657 }
3658 }
3659 }
3660
3661 if (!ssh->cfg.nopty) {
3662 /* Unpick the terminal-speed string. */
3663 /* XXX perhaps we should allow no speeds to be sent. */
3664 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
3665 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
3666 /* Send the pty request. */
3667 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3668 PKT_STR, ssh->cfg.termtype,
3669 PKT_INT, ssh->term_height,
3670 PKT_INT, ssh->term_width,
3671 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
3672 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
3673 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
3674 PKT_CHAR, 0, PKT_END);
3675 ssh->state = SSH_STATE_INTERMED;
3676 do {
3677 crReturnV;
3678 } while (!ispkt);
3679 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3680 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3681 bombout(("Protocol confusion"));
3682 crStopV;
3683 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3684 c_write_str(ssh, "Server refused to allocate pty\r\n");
3685 ssh->editing = ssh->echoing = 1;
3686 }
3687 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
3688 ssh->ospeed, ssh->ispeed);
3689 } else {
3690 ssh->editing = ssh->echoing = 1;
3691 }
3692
3693 if (ssh->cfg.compression) {
3694 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3695 do {
3696 crReturnV;
3697 } while (!ispkt);
3698 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3699 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3700 bombout(("Protocol confusion"));
3701 crStopV;
3702 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3703 c_write_str(ssh, "Server refused to compress\r\n");
3704 }
3705 logevent("Started compression");
3706 ssh->v1_compressing = TRUE;
3707 ssh->cs_comp_ctx = zlib_compress_init();
3708 logevent("Initialised zlib (RFC1950) compression");
3709 ssh->sc_comp_ctx = zlib_decompress_init();
3710 logevent("Initialised zlib (RFC1950) decompression");
3711 }
3712
3713 /*
3714 * Start the shell or command.
3715 *
3716 * Special case: if the first-choice command is an SSH2
3717 * subsystem (hence not usable here) and the second choice
3718 * exists, we fall straight back to that.
3719 */
3720 {
3721 char *cmd = ssh->cfg.remote_cmd_ptr;
3722
3723 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
3724 cmd = ssh->cfg.remote_cmd_ptr2;
3725 ssh->fallback_cmd = TRUE;
3726 }
3727 if (*cmd)
3728 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3729 else
3730 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3731 logevent("Started session");
3732 }
3733
3734 ssh->state = SSH_STATE_SESSION;
3735 if (ssh->size_needed)
3736 ssh_size(ssh, ssh->term_width, ssh->term_height);
3737 if (ssh->eof_needed)
3738 ssh_special(ssh, TS_EOF);
3739
3740 if (ssh->ldisc)
3741 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3742 ssh->send_ok = 1;
3743 ssh->channels = newtree234(ssh_channelcmp);
3744 while (1) {
3745 crReturnV;
3746 if (ispkt) {
3747 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3748 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3749 char *string;
3750 int stringlen, bufsize;
3751
3752 ssh_pkt_getstring(ssh, &string, &stringlen);
3753 if (string == NULL) {
3754 bombout(("Incoming terminal data packet was badly formed"));
3755 crStopV;
3756 }
3757
3758 bufsize =
3759 from_backend(ssh->frontend,
3760 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3761 string, stringlen);
3762 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3763 ssh->v1_stdout_throttling = 1;
3764 ssh1_throttle(ssh, +1);
3765 }
3766 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3767 ssh_closing((Plug)ssh, NULL, 0, 0);
3768 logevent("Received disconnect request");
3769 crStopV;
3770 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3771 /* Remote side is trying to open a channel to talk to our
3772 * X-Server. Give them back a local channel number. */
3773 struct ssh_channel *c;
3774 int remoteid = ssh_pkt_getuint32(ssh);
3775
3776 logevent("Received X11 connect request");
3777 /* Refuse if X11 forwarding is disabled. */
3778 if (!ssh->X11_fwd_enabled) {
3779 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3780 PKT_INT, remoteid, PKT_END);
3781 logevent("Rejected X11 connect request");
3782 } else {
3783 c = snew(struct ssh_channel);
3784 c->ssh = ssh;
3785
3786 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
3787 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
3788 logevent("Opening X11 forward connection failed");
3789 sfree(c);
3790 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3791 PKT_INT, remoteid, PKT_END);
3792 } else {
3793 logevent
3794 ("Opening X11 forward connection succeeded");
3795 c->remoteid = remoteid;
3796 c->localid = alloc_channel_id(ssh);
3797 c->closes = 0;
3798 c->v.v1.throttling = 0;
3799 c->type = CHAN_X11; /* identify channel type */
3800 add234(ssh->channels, c);
3801 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3802 PKT_INT, c->remoteid, PKT_INT,
3803 c->localid, PKT_END);
3804 logevent("Opened X11 forward channel");
3805 }
3806 }
3807 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3808 /* Remote side is trying to open a channel to talk to our
3809 * agent. Give them back a local channel number. */
3810 struct ssh_channel *c;
3811 int remoteid = ssh_pkt_getuint32(ssh);
3812
3813 /* Refuse if agent forwarding is disabled. */
3814 if (!ssh->agentfwd_enabled) {
3815 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3816 PKT_INT, remoteid, PKT_END);
3817 } else {
3818 c = snew(struct ssh_channel);
3819 c->ssh = ssh;
3820 c->remoteid = remoteid;
3821 c->localid = alloc_channel_id(ssh);
3822 c->closes = 0;
3823 c->v.v1.throttling = 0;
3824 c->type = CHAN_AGENT; /* identify channel type */
3825 c->u.a.lensofar = 0;
3826 add234(ssh->channels, c);
3827 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3828 PKT_INT, c->remoteid, PKT_INT, c->localid,
3829 PKT_END);
3830 }
3831 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3832 /* Remote side is trying to open a channel to talk to a
3833 * forwarded port. Give them back a local channel number. */
3834 struct ssh_channel *c;
3835 struct ssh_rportfwd pf;
3836 int remoteid;
3837 int hostsize, port;
3838 char *host, buf[1024];
3839 const char *e;
3840 c = snew(struct ssh_channel);
3841 c->ssh = ssh;
3842
3843 remoteid = ssh_pkt_getuint32(ssh);
3844 ssh_pkt_getstring(ssh, &host, &hostsize);
3845 port = ssh_pkt_getuint32(ssh);
3846
3847 if (hostsize >= lenof(pf.dhost))
3848 hostsize = lenof(pf.dhost)-1;
3849 memcpy(pf.dhost, host, hostsize);
3850 pf.dhost[hostsize] = '\0';
3851 pf.dport = port;
3852
3853 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3854 sprintf(buf, "Rejected remote port open request for %s:%d",
3855 pf.dhost, port);
3856 logevent(buf);
3857 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3858 PKT_INT, remoteid, PKT_END);
3859 } else {
3860 sprintf(buf, "Received remote port open request for %s:%d",
3861 pf.dhost, port);
3862 logevent(buf);
3863 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
3864 c, &ssh->cfg);
3865 if (e != NULL) {
3866 char buf[256];
3867 sprintf(buf, "Port open failed: %s", e);
3868 logevent(buf);
3869 sfree(c);
3870 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3871 PKT_INT, remoteid, PKT_END);
3872 } else {
3873 c->remoteid = remoteid;
3874 c->localid = alloc_channel_id(ssh);
3875 c->closes = 0;
3876 c->v.v1.throttling = 0;
3877 c->type = CHAN_SOCKDATA; /* identify channel type */
3878 add234(ssh->channels, c);
3879 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3880 PKT_INT, c->remoteid, PKT_INT,
3881 c->localid, PKT_END);
3882 logevent("Forwarded port opened successfully");
3883 }
3884 }
3885
3886 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3887 unsigned int remoteid = ssh_pkt_getuint32(ssh);
3888 unsigned int localid = ssh_pkt_getuint32(ssh);
3889 struct ssh_channel *c;
3890
3891 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3892 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3893 c->remoteid = localid;
3894 c->type = CHAN_SOCKDATA;
3895 c->v.v1.throttling = 0;
3896 pfd_confirm(c->u.pfd.s);
3897 }
3898
3899 if (c && c->closes) {
3900 /*
3901 * We have a pending close on this channel,
3902 * which we decided on before the server acked
3903 * the channel open. So now we know the
3904 * remoteid, we can close it again.
3905 */
3906 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3907 PKT_INT, c->remoteid, PKT_END);
3908 }
3909
3910 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3911 unsigned int remoteid = ssh_pkt_getuint32(ssh);
3912 struct ssh_channel *c;
3913
3914 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3915 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3916 logevent("Forwarded connection refused by server");
3917 pfd_close(c->u.pfd.s);
3918 del234(ssh->channels, c);
3919 sfree(c);
3920 }
3921
3922 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3923 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3924 /* Remote side closes a channel. */
3925 unsigned i = ssh_pkt_getuint32(ssh);
3926 struct ssh_channel *c;
3927 c = find234(ssh->channels, &i, ssh_channelfind);
3928 if (c && ((int)c->remoteid) != -1) {
3929 int closetype;
3930 closetype =
3931 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3932
3933 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3934 logevent("Forwarded X11 connection terminated");
3935 assert(c->u.x11.s != NULL);
3936 x11_close(c->u.x11.s);
3937 c->u.x11.s = NULL;
3938 }
3939 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3940 logevent("Forwarded port closed");
3941 assert(c->u.pfd.s != NULL);
3942 pfd_close(c->u.pfd.s);
3943 c->u.pfd.s = NULL;
3944 }
3945
3946 c->closes |= (closetype << 2); /* seen this message */
3947 if (!(c->closes & closetype)) {
3948 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3949 PKT_END);
3950 c->closes |= closetype; /* sent it too */
3951 }
3952
3953 if (c->closes == 15) {
3954 del234(ssh->channels, c);
3955 sfree(c);
3956 }
3957 } else {
3958 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3959 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3960 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3961 i));
3962 crStopV;
3963 }
3964 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3965 /* Data sent down one of our channels. */
3966 int i = ssh_pkt_getuint32(ssh);
3967 char *p;
3968 int len;
3969 struct ssh_channel *c;
3970
3971 ssh_pkt_getstring(ssh, &p, &len);
3972
3973 c = find234(ssh->channels, &i, ssh_channelfind);
3974 if (c) {
3975 int bufsize = 0;
3976 switch (c->type) {
3977 case CHAN_X11:
3978 bufsize = x11_send(c->u.x11.s, p, len);
3979 break;
3980 case CHAN_SOCKDATA:
3981 bufsize = pfd_send(c->u.pfd.s, p, len);
3982 break;
3983 case CHAN_AGENT:
3984 /* Data for an agent message. Buffer it. */
3985 while (len > 0) {
3986 if (c->u.a.lensofar < 4) {
3987 int l = min(4 - c->u.a.lensofar, len);
3988 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3989 l);
3990 p += l;
3991 len -= l;
3992 c->u.a.lensofar += l;
3993 }
3994 if (c->u.a.lensofar == 4) {
3995 c->u.a.totallen =
3996 4 + GET_32BIT(c->u.a.msglen);
3997 c->u.a.message = snewn(c->u.a.totallen,
3998 unsigned char);
3999 memcpy(c->u.a.message, c->u.a.msglen, 4);
4000 }
4001 if (c->u.a.lensofar >= 4 && len > 0) {
4002 int l =
4003 min(c->u.a.totallen - c->u.a.lensofar,
4004 len);
4005 memcpy(c->u.a.message + c->u.a.lensofar, p,
4006 l);
4007 p += l;
4008 len -= l;
4009 c->u.a.lensofar += l;
4010 }
4011 if (c->u.a.lensofar == c->u.a.totallen) {
4012 void *reply;
4013 int replylen;
4014 if (agent_query(c->u.a.message,
4015 c->u.a.totallen,
4016 &reply, &replylen,
4017 ssh_agentf_callback, c))
4018 ssh_agentf_callback(c, reply, replylen);
4019 sfree(c->u.a.message);
4020 c->u.a.lensofar = 0;
4021 }
4022 }
4023 bufsize = 0; /* agent channels never back up */
4024 break;
4025 }
4026 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4027 c->v.v1.throttling = 1;
4028 ssh1_throttle(ssh, +1);
4029 }
4030 }
4031 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
4032 /* may be from EXEC_SHELL on some servers */
4033 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
4034 /* may be from EXEC_SHELL on some servers
4035 * if no pty is available or in other odd cases. Ignore */
4036 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
4037 char buf[100];
4038 ssh->exitcode = ssh_pkt_getuint32(ssh);
4039 sprintf(buf, "Server sent command exit status %d",
4040 ssh->exitcode);
4041 logevent(buf);
4042 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4043 /*
4044 * In case `helpful' firewalls or proxies tack
4045 * extra human-readable text on the end of the
4046 * session which we might mistake for another
4047 * encrypted packet, we close the session once
4048 * we've sent EXIT_CONFIRMATION.
4049 */
4050 ssh_closing((Plug)ssh, NULL, 0, 0);
4051 crStopV;
4052 } else {
4053 bombout(("Strange packet received: type %d", ssh->pktin.type));
4054 crStopV;
4055 }
4056 } else {
4057 while (inlen > 0) {
4058 int len = min(inlen, 512);
4059 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4060 PKT_INT, len, PKT_DATA, in, len,
4061 PKTT_OTHER, PKT_END);
4062 in += len;
4063 inlen -= len;
4064 }
4065 }
4066 }
4067
4068 crFinishV;
4069 }
4070
4071 /*
4072 * Utility routine for decoding comma-separated strings in KEXINIT.
4073 */
4074 static int in_commasep_string(char *needle, char *haystack, int haylen)
4075 {
4076 int needlen;
4077 if (!needle || !haystack) /* protect against null pointers */
4078 return 0;
4079 needlen = strlen(needle);
4080 while (1) {
4081 /*
4082 * Is it at the start of the string?
4083 */
4084 if (haylen >= needlen && /* haystack is long enough */
4085 !memcmp(needle, haystack, needlen) && /* initial match */
4086 (haylen == needlen || haystack[needlen] == ',')
4087 /* either , or EOS follows */
4088 )
4089 return 1;
4090 /*
4091 * If not, search for the next comma and resume after that.
4092 * If no comma found, terminate.
4093 */
4094 while (haylen > 0 && *haystack != ',')
4095 haylen--, haystack++;
4096 if (haylen == 0)
4097 return 0;
4098 haylen--, haystack++; /* skip over comma itself */
4099 }
4100 }
4101
4102 /*
4103 * SSH2 key creation method.
4104 */
4105 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4106 unsigned char *sessid, char chr,
4107 unsigned char *keyspace)
4108 {
4109 SHA_State s;
4110 /* First 20 bytes. */
4111 SHA_Init(&s);
4112 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4113 sha_mpint(&s, K);
4114 SHA_Bytes(&s, H, 20);
4115 SHA_Bytes(&s, &chr, 1);
4116 SHA_Bytes(&s, sessid, 20);
4117 SHA_Final(&s, keyspace);
4118 /* Next 20 bytes. */
4119 SHA_Init(&s);
4120 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4121 sha_mpint(&s, K);
4122 SHA_Bytes(&s, H, 20);
4123 SHA_Bytes(&s, keyspace, 20);
4124 SHA_Final(&s, keyspace + 20);
4125 }
4126
4127 /*
4128 * Handle the SSH2 transport layer.
4129 */
4130 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4131 {
4132 struct do_ssh2_transport_state {
4133 int nbits, pbits, warn;
4134 Bignum p, g, e, f, K;
4135 int kex_init_value, kex_reply_value;
4136 const struct ssh_mac **maclist;
4137 int nmacs;
4138 const struct ssh2_cipher *cscipher_tobe;
4139 const struct ssh2_cipher *sccipher_tobe;
4140 const struct ssh_mac *csmac_tobe;
4141 const struct ssh_mac *scmac_tobe;
4142 const struct ssh_compress *cscomp_tobe;
4143 const struct ssh_compress *sccomp_tobe;
4144 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4145 int hostkeylen, siglen;
4146 void *hkey; /* actual host key */
4147 unsigned char exchange_hash[20];
4148 int n_preferred_ciphers;
4149 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4150 const struct ssh_compress *preferred_comp;
4151 int first_kex;
4152 };
4153 crState(do_ssh2_transport_state);
4154
4155 crBegin(ssh->do_ssh2_transport_crstate);
4156
4157 s->cscipher_tobe = s->sccipher_tobe = NULL;
4158 s->csmac_tobe = s->scmac_tobe = NULL;
4159 s->cscomp_tobe = s->sccomp_tobe = NULL;
4160
4161 random_init();
4162 s->first_kex = 1;
4163
4164 {
4165 int i;
4166 /*
4167 * Set up the preferred ciphers. (NULL => warn below here)
4168 */
4169 s->n_preferred_ciphers = 0;
4170 for (i = 0; i < CIPHER_MAX; i++) {
4171 switch (ssh->cfg.ssh_cipherlist[i]) {
4172 case CIPHER_BLOWFISH:
4173 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4174 break;
4175 case CIPHER_DES:
4176 if (ssh->cfg.ssh2_des_cbc) {
4177 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4178 }
4179 break;
4180 case CIPHER_3DES:
4181 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4182 break;
4183 case CIPHER_AES:
4184 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4185 break;
4186 case CIPHER_WARN:
4187 /* Flag for later. Don't bother if it's the last in
4188 * the list. */
4189 if (i < CIPHER_MAX - 1) {
4190 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4191 }
4192 break;
4193 }
4194 }
4195 }
4196
4197 /*
4198 * Set up preferred compression.
4199 */
4200 if (ssh->cfg.compression)
4201 s->preferred_comp = &ssh_zlib;
4202 else
4203 s->preferred_comp = &ssh_comp_none;
4204
4205 /*
4206 * Be prepared to work around the buggy MAC problem.
4207 */
4208 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4209 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4210 else
4211 s->maclist = macs, s->nmacs = lenof(macs);
4212
4213 begin_key_exchange:
4214 {
4215 int i, j, cipherstr_started;
4216
4217 /*
4218 * Construct and send our key exchange packet.
4219 */
4220 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
4221 for (i = 0; i < 16; i++)
4222 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
4223 /* List key exchange algorithms. */
4224 ssh2_pkt_addstring_start(ssh);
4225 for (i = 0; i < lenof(kex_algs); i++) {
4226 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4227 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4228 continue;
4229 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
4230 if (i < lenof(kex_algs) - 1)
4231 ssh2_pkt_addstring_str(ssh, ",");
4232 }
4233 /* List server host key algorithms. */
4234 ssh2_pkt_addstring_start(ssh);
4235 for (i = 0; i < lenof(hostkey_algs); i++) {
4236 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
4237 if (i < lenof(hostkey_algs) - 1)
4238 ssh2_pkt_addstring_str(ssh, ",");
4239 }
4240 /* List client->server encryption algorithms. */
4241 ssh2_pkt_addstring_start(ssh);
4242 cipherstr_started = 0;
4243 for (i = 0; i < s->n_preferred_ciphers; i++) {
4244 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4245 if (!c) continue; /* warning flag */
4246 for (j = 0; j < c->nciphers; j++) {
4247 if (cipherstr_started)
4248 ssh2_pkt_addstring_str(ssh, ",");
4249 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
4250 cipherstr_started = 1;
4251 }
4252 }
4253 /* List server->client encryption algorithms. */
4254 ssh2_pkt_addstring_start(ssh);
4255 cipherstr_started = 0;
4256 for (i = 0; i < s->n_preferred_ciphers; i++) {
4257 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4258 if (!c) continue; /* warning flag */
4259 for (j = 0; j < c->nciphers; j++) {
4260 if (cipherstr_started)
4261 ssh2_pkt_addstring_str(ssh, ",");
4262 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
4263 cipherstr_started = 1;
4264 }
4265 }
4266 /* List client->server MAC algorithms. */
4267 ssh2_pkt_addstring_start(ssh);
4268 for (i = 0; i < s->nmacs; i++) {
4269 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
4270 if (i < s->nmacs - 1)
4271 ssh2_pkt_addstring_str(ssh, ",");
4272 }
4273 /* List server->client MAC algorithms. */
4274 ssh2_pkt_addstring_start(ssh);
4275 for (i = 0; i < s->nmacs; i++) {
4276 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
4277 if (i < s->nmacs - 1)
4278 ssh2_pkt_addstring_str(ssh, ",");
4279 }
4280 /* List client->server compression algorithms. */
4281 ssh2_pkt_addstring_start(ssh);
4282 assert(lenof(compressions) > 1);
4283 ssh2_pkt_addstring_str(ssh, s->preferred_comp->name);
4284 for (i = 0; i < lenof(compressions); i++) {
4285 const struct ssh_compress *c = compressions[i];
4286 if (c != s->preferred_comp) {
4287 ssh2_pkt_addstring_str(ssh, ",");
4288 ssh2_pkt_addstring_str(ssh, c->name);
4289 }
4290 }
4291 /* List server->client compression algorithms. */
4292 ssh2_pkt_addstring_start(ssh);
4293 assert(lenof(compressions) > 1);
4294 ssh2_pkt_addstring_str(ssh, s->preferred_comp->name);
4295 for (i = 0; i < lenof(compressions); i++) {
4296 const struct ssh_compress *c = compressions[i];
4297 if (c != s->preferred_comp) {
4298 ssh2_pkt_addstring_str(ssh, ",");
4299 ssh2_pkt_addstring_str(ssh, c->name);
4300 }
4301 }
4302 /* List client->server languages. Empty list. */
4303 ssh2_pkt_addstring_start(ssh);
4304 /* List server->client languages. Empty list. */
4305 ssh2_pkt_addstring_start(ssh);
4306 /* First KEX packet does _not_ follow, because we're not that brave. */
4307 ssh2_pkt_addbool(ssh, FALSE);
4308 /* Reserved. */
4309 ssh2_pkt_adduint32(ssh, 0);
4310 }
4311
4312 ssh->exhash = ssh->exhashbase;
4313 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
4314
4315 ssh2_pkt_send(ssh);
4316
4317 if (!ispkt)
4318 crWaitUntil(ispkt);
4319 if (ssh->pktin.length > 5)
4320 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
4321
4322 /*
4323 * Now examine the other side's KEXINIT to see what we're up
4324 * to.
4325 */
4326 {
4327 char *str;
4328 int i, j, len;
4329
4330 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
4331 bombout(("expected key exchange packet from server"));
4332 crStop(0);
4333 }
4334 ssh->kex = NULL;
4335 ssh->hostkey = NULL;
4336 s->cscipher_tobe = NULL;
4337 s->sccipher_tobe = NULL;
4338 s->csmac_tobe = NULL;
4339 s->scmac_tobe = NULL;
4340 s->cscomp_tobe = NULL;
4341 s->sccomp_tobe = NULL;
4342 ssh->pktin.savedpos += 16; /* skip garbage cookie */
4343 ssh_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
4344 for (i = 0; i < lenof(kex_algs); i++) {
4345 if (kex_algs[i] == &ssh_diffiehellman_gex &&
4346 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
4347 continue;
4348 if (in_commasep_string(kex_algs[i]->name, str, len)) {
4349 ssh->kex = kex_algs[i];
4350 break;
4351 }
4352 }
4353 ssh_pkt_getstring(ssh, &str, &len); /* host key algorithms */
4354 for (i = 0; i < lenof(hostkey_algs); i++) {
4355 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4356 ssh->hostkey = hostkey_algs[i];
4357 break;
4358 }
4359 }
4360 ssh_pkt_getstring(ssh, &str, &len); /* client->server cipher */
4361 s->warn = 0;
4362 for (i = 0; i < s->n_preferred_ciphers; i++) {
4363 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4364 if (!c) {
4365 s->warn = 1;
4366 } else {
4367 for (j = 0; j < c->nciphers; j++) {
4368 if (in_commasep_string(c->list[j]->name, str, len)) {
4369 s->cscipher_tobe = c->list[j];
4370 break;
4371 }
4372 }
4373 }
4374 if (s->cscipher_tobe) {
4375 if (s->warn)
4376 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
4377 break;
4378 }
4379 }
4380 if (!s->cscipher_tobe) {
4381 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4382 str ? str : "(null)"));
4383 crStop(0);
4384 }
4385
4386 ssh_pkt_getstring(ssh, &str, &len); /* server->client cipher */
4387 s->warn = 0;
4388 for (i = 0; i < s->n_preferred_ciphers; i++) {
4389 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4390 if (!c) {
4391 s->warn = 1;
4392 } else {
4393 for (j = 0; j < c->nciphers; j++) {
4394 if (in_commasep_string(c->list[j]->name, str, len)) {
4395 s->sccipher_tobe = c->list[j];
4396 break;
4397 }
4398 }
4399 }
4400 if (s->sccipher_tobe) {
4401 if (s->warn)
4402 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
4403 break;
4404 }
4405 }
4406 if (!s->sccipher_tobe) {
4407 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4408 str ? str : "(null)"));
4409 crStop(0);
4410 }
4411
4412 ssh_pkt_getstring(ssh, &str, &len); /* client->server mac */
4413 for (i = 0; i < s->nmacs; i++) {
4414 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4415 s->csmac_tobe = s->maclist[i];
4416 break;
4417 }
4418 }
4419 ssh_pkt_getstring(ssh, &str, &len); /* server->client mac */
4420 for (i = 0; i < s->nmacs; i++) {
4421 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4422 s->scmac_tobe = s->maclist[i];
4423 break;
4424 }
4425 }
4426 ssh_pkt_getstring(ssh, &str, &len); /* client->server compression */
4427 for (i = 0; i < lenof(compressions) + 1; i++) {
4428 const struct ssh_compress *c =
4429 i == 0 ? s->preferred_comp : compressions[i - 1];
4430 if (in_commasep_string(c->name, str, len)) {
4431 s->cscomp_tobe = c;
4432 break;
4433 }
4434 }
4435 ssh_pkt_getstring(ssh, &str, &len); /* server->client compression */
4436 for (i = 0; i < lenof(compressions) + 1; i++) {
4437 const struct ssh_compress *c =
4438 i == 0 ? s->preferred_comp : compressions[i - 1];
4439 if (in_commasep_string(c->name, str, len)) {
4440 s->sccomp_tobe = c;
4441 break;
4442 }
4443 }
4444 }
4445
4446 /*
4447 * Work out the number of bits of key we will need from the key
4448 * exchange. We start with the maximum key length of either
4449 * cipher...
4450 */
4451 {
4452 int csbits, scbits;
4453
4454 csbits = s->cscipher_tobe->keylen;
4455 scbits = s->sccipher_tobe->keylen;
4456 s->nbits = (csbits > scbits ? csbits : scbits);
4457 }
4458 /* The keys only have 160-bit entropy, since they're based on
4459 * a SHA-1 hash. So cap the key size at 160 bits. */
4460 if (s->nbits > 160)
4461 s->nbits = 160;
4462
4463 /*
4464 * If we're doing Diffie-Hellman group exchange, start by
4465 * requesting a group.
4466 */
4467 if (ssh->kex == &ssh_diffiehellman_gex) {
4468 logevent("Doing Diffie-Hellman group exchange");
4469 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
4470 /*
4471 * Work out how big a DH group we will need to allow that
4472 * much data.
4473 */
4474 s->pbits = 512 << ((s->nbits - 1) / 64);
4475 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
4476 ssh2_pkt_adduint32(ssh, s->pbits);
4477 ssh2_pkt_send(ssh);
4478
4479 crWaitUntil(ispkt);
4480 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
4481 bombout(("expected key exchange group packet from server"));
4482 crStop(0);
4483 }
4484 s->p = ssh2_pkt_getmp(ssh);
4485 s->g = ssh2_pkt_getmp(ssh);
4486 ssh->kex_ctx = dh_setup_group(s->p, s->g);
4487 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
4488 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4489 } else {
4490 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4491 ssh->kex_ctx = dh_setup_group1();
4492 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4493 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4494 }
4495
4496 logevent("Doing Diffie-Hellman key exchange");
4497 /*
4498 * Now generate and send e for Diffie-Hellman.
4499 */
4500 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4501 ssh2_pkt_init(ssh, s->kex_init_value);
4502 ssh2_pkt_addmp(ssh, s->e);
4503 ssh2_pkt_send(ssh);
4504
4505 crWaitUntil(ispkt);
4506 if (ssh->pktin.type != s->kex_reply_value) {
4507 bombout(("expected key exchange reply packet from server"));
4508 crStop(0);
4509 }
4510 ssh_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4511 s->f = ssh2_pkt_getmp(ssh);
4512 ssh_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4513
4514 s->K = dh_find_K(ssh->kex_ctx, s->f);
4515
4516 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4517 if (ssh->kex == &ssh_diffiehellman_gex) {
4518 sha_uint32(&ssh->exhash, s->pbits);
4519 sha_mpint(&ssh->exhash, s->p);
4520 sha_mpint(&ssh->exhash, s->g);
4521 }
4522 sha_mpint(&ssh->exhash, s->e);
4523 sha_mpint(&ssh->exhash, s->f);
4524 sha_mpint(&ssh->exhash, s->K);
4525 SHA_Final(&ssh->exhash, s->exchange_hash);
4526
4527 dh_cleanup(ssh->kex_ctx);
4528 ssh->kex_ctx = NULL;
4529
4530 #if 0
4531 debug(("Exchange hash is:\n"));
4532 dmemdump(s->exchange_hash, 20);
4533 #endif
4534
4535 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4536 if (!s->hkey ||
4537 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4538 (char *)s->exchange_hash, 20)) {
4539 bombout(("Server's host key did not match the signature supplied"));
4540 crStop(0);
4541 }
4542
4543 /*
4544 * Authenticate remote host: verify host key. (We've already
4545 * checked the signature of the exchange hash.)
4546 */
4547 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4548 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4549 verify_ssh_host_key(ssh->frontend,
4550 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4551 s->keystr, s->fingerprint);
4552 if (s->first_kex) { /* don't bother logging this in rekeys */
4553 logevent("Host key fingerprint is:");
4554 logevent(s->fingerprint);
4555 }
4556 sfree(s->fingerprint);
4557 sfree(s->keystr);
4558 ssh->hostkey->freekey(s->hkey);
4559
4560 /*
4561 * Send SSH2_MSG_NEWKEYS.
4562 */
4563 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4564 ssh2_pkt_send(ssh);
4565
4566 /*
4567 * Expect SSH2_MSG_NEWKEYS from server.
4568 */
4569 crWaitUntil(ispkt);
4570 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4571 bombout(("expected new-keys packet from server"));
4572 crStop(0);
4573 }
4574
4575 /*
4576 * Create and initialise session keys.
4577 */
4578 if (ssh->cs_cipher_ctx)
4579 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4580 ssh->cscipher = s->cscipher_tobe;
4581 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4582
4583 if (ssh->sc_cipher_ctx)
4584 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4585 ssh->sccipher = s->sccipher_tobe;
4586 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4587
4588 if (ssh->cs_mac_ctx)
4589 ssh->csmac->free_context(ssh->cs_mac_ctx);
4590 ssh->csmac = s->csmac_tobe;
4591 ssh->cs_mac_ctx = ssh->csmac->make_context();
4592
4593 if (ssh->sc_mac_ctx)
4594 ssh->scmac->free_context(ssh->sc_mac_ctx);
4595 ssh->scmac = s->scmac_tobe;
4596 ssh->sc_mac_ctx = ssh->scmac->make_context();
4597
4598 if (ssh->cs_comp_ctx)
4599 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4600 ssh->cscomp = s->cscomp_tobe;
4601 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4602
4603 if (ssh->sc_comp_ctx)
4604 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4605 ssh->sccomp = s->sccomp_tobe;
4606 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4607
4608 /*
4609 * Set IVs after keys. Here we use the exchange hash from the
4610 * _first_ key exchange.
4611 */
4612 {
4613 unsigned char keyspace[40];
4614 if (s->first_kex)
4615 memcpy(ssh->v2_session_id, s->exchange_hash,
4616 sizeof(s->exchange_hash));
4617 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4618 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4619 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4620 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4621 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4622 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4623 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4624 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4625 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4626 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4627 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4628 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4629 }
4630 logeventf(ssh, "Initialised %.200s client->server encryption",
4631 ssh->cscipher->text_name);
4632 logeventf(ssh, "Initialised %.200s server->client encryption",
4633 ssh->sccipher->text_name);
4634 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
4635 ssh->csmac->text_name);
4636 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
4637 ssh->scmac->text_name);
4638 if (ssh->cscomp->text_name)
4639 logeventf(ssh, "Initialised %s compression",
4640 ssh->cscomp->text_name);
4641 if (ssh->sccomp->text_name)
4642 logeventf(ssh, "Initialised %s decompression",
4643 ssh->sccomp->text_name);
4644 freebn(s->f);
4645 freebn(s->K);
4646 if (ssh->kex == &ssh_diffiehellman_gex) {
4647 freebn(s->g);
4648 freebn(s->p);
4649 }
4650
4651 /*
4652 * If this is the first key exchange phase, we must pass the
4653 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4654 * wants to see it but because it will need time to initialise
4655 * itself before it sees an actual packet. In subsequent key
4656 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4657 * it would only confuse the layer above.
4658 */
4659 if (!s->first_kex) {
4660 crReturn(0);
4661 }
4662 s->first_kex = 0;
4663
4664 /*
4665 * Now we're encrypting. Begin returning 1 to the protocol main
4666 * function so that other things can run on top of the
4667 * transport. If we ever see a KEXINIT, we must go back to the
4668 * start.
4669 */
4670 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4671 crReturn(1);
4672 }
4673 logevent("Server initiated key re-exchange");
4674 goto begin_key_exchange;
4675
4676 crFinish(1);
4677 }
4678
4679 /*
4680 * Add data to an SSH2 channel output buffer.
4681 */
4682 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4683 int len)
4684 {
4685 bufchain_add(&c->v.v2.outbuffer, buf, len);
4686 }
4687
4688 /*
4689 * Attempt to send data on an SSH2 channel.
4690 */
4691 static int ssh2_try_send(struct ssh_channel *c)
4692 {
4693 Ssh ssh = c->ssh;
4694
4695 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4696 int len;
4697 void *data;
4698 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4699 if ((unsigned)len > c->v.v2.remwindow)
4700 len = c->v.v2.remwindow;
4701 if ((unsigned)len > c->v.v2.remmaxpkt)
4702 len = c->v.v2.remmaxpkt;
4703 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4704 ssh2_pkt_adduint32(ssh, c->remoteid);
4705 dont_log_data(ssh, PKTLOG_OMIT);
4706 ssh2_pkt_addstring_start(ssh);
4707 ssh2_pkt_addstring_data(ssh, data, len);
4708 end_log_omission(ssh);
4709 ssh2_pkt_send(ssh);
4710 bufchain_consume(&c->v.v2.outbuffer, len);
4711 c->v.v2.remwindow -= len;
4712 }
4713
4714 /*
4715 * After having sent as much data as we can, return the amount
4716 * still buffered.
4717 */
4718 return bufchain_size(&c->v.v2.outbuffer);
4719 }
4720
4721 /*
4722 * Potentially enlarge the window on an SSH2 channel.
4723 */
4724 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4725 {
4726 Ssh ssh = c->ssh;
4727
4728 /*
4729 * Never send WINDOW_ADJUST for a channel that the remote side
4730 * already thinks it's closed; there's no point, since it won't
4731 * be sending any more data anyway.
4732 */
4733 if (c->closes != 0)
4734 return;
4735
4736 if (newwin > c->v.v2.locwindow) {
4737 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4738 ssh2_pkt_adduint32(ssh, c->remoteid);
4739 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4740 ssh2_pkt_send(ssh);
4741 c->v.v2.locwindow = newwin;
4742 }
4743 }
4744
4745 /*
4746 * Handle the SSH2 userauth and connection layers.
4747 */
4748 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4749 {
4750 struct do_ssh2_authconn_state {
4751 enum {
4752 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4753 AUTH_PASSWORD,
4754 AUTH_KEYBOARD_INTERACTIVE
4755 } method;
4756 enum {
4757 AUTH_TYPE_NONE,
4758 AUTH_TYPE_PUBLICKEY,
4759 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4760 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4761 AUTH_TYPE_PASSWORD,
4762 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4763 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4764 } type;
4765 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4766 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4767 int kbd_inter_running;
4768 int we_are_in;
4769 int num_prompts, curr_prompt, echo;
4770 char username[100];
4771 int got_username;
4772 char pwprompt[512];
4773 char password[100];
4774 void *publickey_blob;
4775 int publickey_bloblen;
4776 unsigned char request[5], *response, *p;
4777 int responselen;
4778 int keyi, nkeys;
4779 int authed;
4780 char *pkblob, *alg, *commentp;
4781 int pklen, alglen, commentlen;
4782 int siglen, retlen, len;
4783 char *q, *agentreq, *ret;
4784 int try_send;
4785 int num_env, env_left, env_ok;
4786 };
4787 crState(do_ssh2_authconn_state);
4788
4789 crBegin(ssh->do_ssh2_authconn_crstate);
4790
4791 /*
4792 * Request userauth protocol, and await a response to it.
4793 */
4794 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4795 ssh2_pkt_addstring(ssh, "ssh-userauth");
4796 ssh2_pkt_send(ssh);
4797 crWaitUntilV(ispkt);
4798 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4799 bombout(("Server refused user authentication protocol"));
4800 crStopV;
4801 }
4802
4803 /*
4804 * We repeat this whole loop, including the username prompt,
4805 * until we manage a successful authentication. If the user
4806 * types the wrong _password_, they can be sent back to the
4807 * beginning to try another username, if this is configured on.
4808 * (If they specify a username in the config, they are never
4809 * asked, even if they do give a wrong password.)
4810 *
4811 * I think this best serves the needs of
4812 *
4813 * - the people who have no configuration, no keys, and just
4814 * want to try repeated (username,password) pairs until they
4815 * type both correctly
4816 *
4817 * - people who have keys and configuration but occasionally
4818 * need to fall back to passwords
4819 *
4820 * - people with a key held in Pageant, who might not have
4821 * logged in to a particular machine before; so they want to
4822 * type a username, and then _either_ their key will be
4823 * accepted, _or_ they will type a password. If they mistype
4824 * the username they will want to be able to get back and
4825 * retype it!
4826 */
4827 s->username[0] = '\0';
4828 s->got_username = FALSE;
4829 do {
4830 /*
4831 * Get a username.
4832 */
4833 if (s->got_username && !ssh->cfg.change_username) {
4834 /*
4835 * We got a username last time round this loop, and
4836 * with change_username turned off we don't try to get
4837 * it again.
4838 */
4839 } else if ((flags & FLAG_INTERACTIVE) && !*ssh->cfg.username) {
4840 if (ssh_get_line && !ssh_getline_pw_only) {
4841 if (!ssh_get_line("login as: ",
4842 s->username, sizeof(s->username), FALSE)) {
4843 /*
4844 * get_line failed to get a username.
4845 * Terminate.
4846 */
4847 logevent("No username provided. Abandoning session.");
4848 ssh_closing((Plug)ssh, NULL, 0, 0);
4849 crStopV;
4850 }
4851 } else {
4852 int ret; /* need not be saved across crReturn */
4853 c_write_str(ssh, "login as: ");
4854 ssh->send_ok = 1;
4855 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4856 do {
4857 crWaitUntilV(!ispkt);
4858 ret = process_userpass_input(ssh, in, inlen);
4859 } while (ret == 0);
4860 if (ret < 0)
4861 cleanup_exit(0);
4862 c_write_str(ssh, "\r\n");
4863 }
4864 s->username[strcspn(s->username, "\n\r")] = '\0';
4865 } else {
4866 char *stuff;
4867 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
4868 s->username[sizeof(s->username)-1] = '\0';
4869 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4870 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4871 c_write_str(ssh, stuff);
4872 sfree(stuff);
4873 }
4874 }
4875 s->got_username = TRUE;
4876
4877 /*
4878 * Send an authentication request using method "none": (a)
4879 * just in case it succeeds, and (b) so that we know what
4880 * authentication methods we can usefully try next.
4881 */
4882 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4883
4884 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4885 ssh2_pkt_addstring(ssh, s->username);
4886 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4887 ssh2_pkt_addstring(ssh, "none"); /* method */
4888 ssh2_pkt_send(ssh);
4889 s->type = AUTH_TYPE_NONE;
4890 s->gotit = FALSE;
4891 s->we_are_in = FALSE;
4892
4893 s->tried_pubkey_config = FALSE;
4894 s->tried_agent = FALSE;
4895 s->tried_keyb_inter = FALSE;
4896 s->kbd_inter_running = FALSE;
4897 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
4898 if (!filename_is_null(ssh->cfg.keyfile)) {
4899 int keytype;
4900 logeventf(ssh, "Reading private key file \"%.150s\"",
4901 filename_to_str(&ssh->cfg.keyfile));
4902 keytype = key_type(&ssh->cfg.keyfile);
4903 if (keytype == SSH_KEYTYPE_SSH2) {
4904 s->publickey_blob =
4905 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
4906 &s->publickey_bloblen, NULL);
4907 } else {
4908 char *msgbuf;
4909 logeventf(ssh, "Unable to use this key file (%s)",
4910 key_type_to_str(keytype));
4911 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4912 " (%s)\r\n",
4913 filename_to_str(&ssh->cfg.keyfile),
4914 key_type_to_str(keytype));
4915 c_write_str(ssh, msgbuf);
4916 sfree(msgbuf);
4917 s->publickey_blob = NULL;
4918 }
4919 } else
4920 s->publickey_blob = NULL;
4921
4922 while (1) {
4923 /*
4924 * Wait for the result of the last authentication request.
4925 */
4926 if (!s->gotit)
4927 crWaitUntilV(ispkt);
4928 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4929 char *banner;
4930 int size;
4931 /*
4932 * Don't show the banner if we're operating in
4933 * non-verbose non-interactive mode. (It's probably
4934 * a script, which means nobody will read the
4935 * banner _anyway_, and moreover the printing of
4936 * the banner will screw up processing on the
4937 * output of (say) plink.)
4938 */
4939 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4940 ssh_pkt_getstring(ssh, &banner, &size);
4941 if (banner)
4942 c_write_untrusted(ssh, banner, size);
4943 }
4944 crWaitUntilV(ispkt);
4945 }
4946 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4947 logevent("Access granted");
4948 s->we_are_in = TRUE;
4949 break;
4950 }
4951
4952 if (s->kbd_inter_running &&
4953 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4954 /*
4955 * This is either a further set-of-prompts packet
4956 * in keyboard-interactive authentication, or it's
4957 * the same one and we came back here with `gotit'
4958 * set. In the former case, we must reset the
4959 * curr_prompt variable.
4960 */
4961 if (!s->gotit)
4962 s->curr_prompt = 0;
4963 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4964 bombout(("Strange packet received during authentication: type %d",
4965 ssh->pktin.type));
4966 crStopV;
4967 }
4968
4969 s->gotit = FALSE;
4970
4971 /*
4972 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4973 * we can look at the string in it and know what we can
4974 * helpfully try next.
4975 */
4976 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4977 char *methods;
4978 int methlen;
4979 ssh_pkt_getstring(ssh, &methods, &methlen);
4980 s->kbd_inter_running = FALSE;
4981 if (!ssh2_pkt_getbool(ssh)) {
4982 /*
4983 * We have received an unequivocal Access
4984 * Denied. This can translate to a variety of
4985 * messages:
4986 *
4987 * - if we'd just tried "none" authentication,
4988 * it's not worth printing anything at all
4989 *
4990 * - if we'd just tried a public key _offer_,
4991 * the message should be "Server refused our
4992 * key" (or no message at all if the key
4993 * came from Pageant)
4994 *
4995 * - if we'd just tried anything else, the
4996 * message really should be "Access denied".
4997 *
4998 * Additionally, if we'd just tried password
4999 * authentication, we should break out of this
5000 * whole loop so as to go back to the username
5001 * prompt.
5002 */
5003 if (s->type == AUTH_TYPE_NONE) {
5004 /* do nothing */
5005 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
5006 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
5007 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
5008 c_write_str(ssh, "Server refused our key\r\n");
5009 logevent("Server refused public key");
5010 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
5011 /* server declined keyboard-interactive; ignore */
5012 } else {
5013 c_write_str(ssh, "Access denied\r\n");
5014 logevent("Access denied");
5015 if (s->type == AUTH_TYPE_PASSWORD) {
5016 s->we_are_in = FALSE;
5017 break;
5018 }
5019 }
5020 } else {
5021 c_write_str(ssh, "Further authentication required\r\n");
5022 logevent("Further authentication required");
5023 }
5024
5025 s->can_pubkey =
5026 in_commasep_string("publickey", methods, methlen);
5027 s->can_passwd =
5028 in_commasep_string("password", methods, methlen);
5029 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
5030 in_commasep_string("keyboard-interactive", methods, methlen);
5031 }
5032
5033 s->method = 0;
5034 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5035 s->need_pw = FALSE;
5036
5037 /*
5038 * Most password/passphrase prompts will be
5039 * non-echoing, so we set this to 0 by default.
5040 * Exception is that some keyboard-interactive prompts
5041 * can be echoing, in which case we'll set this to 1.
5042 */
5043 s->echo = 0;
5044
5045 if (!s->method && s->can_pubkey &&
5046 agent_exists() && !s->tried_agent) {
5047 /*
5048 * Attempt public-key authentication using Pageant.
5049 */
5050 void *r;
5051 s->authed = FALSE;
5052
5053 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5054 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
5055
5056 s->tried_agent = TRUE;
5057
5058 logevent("Pageant is running. Requesting keys.");
5059
5060 /* Request the keys held by the agent. */
5061 PUT_32BIT(s->request, 1);
5062 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
5063 if (!agent_query(s->request, 5, &r, &s->responselen,
5064 ssh_agent_callback, ssh)) {
5065 do {
5066 crReturnV;
5067 if (ispkt) {
5068 bombout(("Unexpected data from server while"
5069 " waiting for agent response"));
5070 crStopV;
5071 }
5072 } while (ispkt || inlen > 0);
5073 r = ssh->agent_response;
5074 s->responselen = ssh->agent_response_len;
5075 }
5076 s->response = (unsigned char *) r;
5077 if (s->response && s->responselen >= 5 &&
5078 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
5079 s->p = s->response + 5;
5080 s->nkeys = GET_32BIT(s->p);
5081 s->p += 4;
5082 {
5083 char buf[64];
5084 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
5085 logevent(buf);
5086 }
5087 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
5088 void *vret;
5089
5090 {
5091 char buf[64];
5092 sprintf(buf, "Trying Pageant key #%d", s->keyi);
5093 logevent(buf);
5094 }
5095 s->pklen = GET_32BIT(s->p);
5096 s->p += 4;
5097 if (s->publickey_blob &&
5098 s->pklen == s->publickey_bloblen &&
5099 !memcmp(s->p, s->publickey_blob,
5100 s->publickey_bloblen)) {
5101 logevent("This key matches configured key file");
5102 s->tried_pubkey_config = 1;
5103 }
5104 s->pkblob = (char *)s->p;
5105 s->p += s->pklen;
5106 s->alglen = GET_32BIT(s->pkblob);
5107 s->alg = s->pkblob + 4;
5108 s->commentlen = GET_32BIT(s->p);
5109 s->p += 4;
5110 s->commentp = (char *)s->p;
5111 s->p += s->commentlen;
5112 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5113 ssh2_pkt_addstring(ssh, s->username);
5114 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5115 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5116 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
5117 ssh2_pkt_addstring_start(ssh);
5118 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
5119 ssh2_pkt_addstring_start(ssh);
5120 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
5121 ssh2_pkt_send(ssh);
5122
5123 crWaitUntilV(ispkt);
5124 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
5125 logevent("Key refused");
5126 continue;
5127 }
5128
5129 if (flags & FLAG_VERBOSE) {
5130 c_write_str(ssh, "Authenticating with "
5131 "public key \"");
5132 c_write(ssh, s->commentp, s->commentlen);
5133 c_write_str(ssh, "\" from agent\r\n");
5134 }
5135
5136 /*
5137 * Server is willing to accept the key.
5138 * Construct a SIGN_REQUEST.
5139 */
5140 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5141 ssh2_pkt_addstring(ssh, s->username);
5142 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5143 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5144 ssh2_pkt_addbool(ssh, TRUE);
5145 ssh2_pkt_addstring_start(ssh);
5146 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
5147 ssh2_pkt_addstring_start(ssh);
5148 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
5149
5150 s->siglen = ssh->pktout.length - 5 + 4 + 20;
5151 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5152 s->siglen -= 4;
5153 s->len = 1; /* message type */
5154 s->len += 4 + s->pklen; /* key blob */
5155 s->len += 4 + s->siglen; /* data to sign */
5156 s->len += 4; /* flags */
5157 s->agentreq = snewn(4 + s->len, char);
5158 PUT_32BIT(s->agentreq, s->len);
5159 s->q = s->agentreq + 4;
5160 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
5161 PUT_32BIT(s->q, s->pklen);
5162 s->q += 4;
5163 memcpy(s->q, s->pkblob, s->pklen);
5164 s->q += s->pklen;
5165 PUT_32BIT(s->q, s->siglen);
5166 s->q += 4;
5167 /* Now the data to be signed... */
5168 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5169 PUT_32BIT(s->q, 20);
5170 s->q += 4;
5171 }
5172 memcpy(s->q, ssh->v2_session_id, 20);
5173 s->q += 20;
5174 memcpy(s->q, ssh->pktout.data + 5,
5175 ssh->pktout.length - 5);
5176 s->q += ssh->pktout.length - 5;
5177 /* And finally the (zero) flags word. */
5178 PUT_32BIT(s->q, 0);
5179 if (!agent_query(s->agentreq, s->len + 4,
5180 &vret, &s->retlen,
5181 ssh_agent_callback, ssh)) {
5182 do {
5183 crReturnV;
5184 if (ispkt) {
5185 bombout(("Unexpected data from server"
5186 " while waiting for agent"
5187 " response"));
5188 crStopV;
5189 }
5190 } while (ispkt || inlen > 0);
5191 vret = ssh->agent_response;
5192 s->retlen = ssh->agent_response_len;
5193 }
5194 s->ret = vret;
5195 sfree(s->agentreq);
5196 if (s->ret) {
5197 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
5198 logevent("Sending Pageant's response");
5199 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
5200 s->ret + 9,
5201 GET_32BIT(s->ret + 5));
5202 ssh2_pkt_send(ssh);
5203 s->authed = TRUE;
5204 break;
5205 } else {
5206 logevent
5207 ("Pageant failed to answer challenge");
5208 sfree(s->ret);
5209 }
5210 }
5211 }
5212 if (s->authed)
5213 continue;
5214 }
5215 sfree(s->response);
5216 }
5217
5218 if (!s->method && s->can_pubkey && s->publickey_blob
5219 && !s->tried_pubkey_config) {
5220 unsigned char *pub_blob;
5221 char *algorithm, *comment;
5222 int pub_blob_len;
5223
5224 s->tried_pubkey_config = TRUE;
5225
5226 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5227 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
5228
5229 /*
5230 * Try the public key supplied in the configuration.
5231 *
5232 * First, offer the public blob to see if the server is
5233 * willing to accept it.
5234 */
5235 pub_blob =
5236 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
5237 &algorithm,
5238 &pub_blob_len,
5239 NULL);
5240 if (pub_blob) {
5241 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5242 ssh2_pkt_addstring(ssh, s->username);
5243 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5244 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5245 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
5246 ssh2_pkt_addstring(ssh, algorithm);
5247 ssh2_pkt_addstring_start(ssh);
5248 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
5249 pub_blob_len);
5250 ssh2_pkt_send(ssh);
5251 logevent("Offered public key");
5252
5253 crWaitUntilV(ispkt);
5254 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
5255 s->gotit = TRUE;
5256 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
5257 continue; /* key refused; give up on it */
5258 }
5259
5260 logevent("Offer of public key accepted");
5261 /*
5262 * Actually attempt a serious authentication using
5263 * the key.
5264 */
5265 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
5266 sprintf(s->pwprompt,
5267 "Passphrase for key \"%.100s\": ",
5268 comment);
5269 s->need_pw = TRUE;
5270 } else {
5271 s->need_pw = FALSE;
5272 }
5273 if (flags & FLAG_VERBOSE) {
5274 c_write_str(ssh, "Authenticating with public key \"");
5275 c_write_str(ssh, comment);
5276 c_write_str(ssh, "\"\r\n");
5277 }
5278 s->method = AUTH_PUBLICKEY_FILE;
5279 }
5280 }
5281
5282 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
5283 s->method = AUTH_KEYBOARD_INTERACTIVE;
5284 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5285 s->tried_keyb_inter = TRUE;
5286
5287 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5288 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
5289
5290 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5291 ssh2_pkt_addstring(ssh, s->username);
5292 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5293 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
5294 ssh2_pkt_addstring(ssh, ""); /* lang */
5295 ssh2_pkt_addstring(ssh, "");
5296 ssh2_pkt_send(ssh);
5297
5298 crWaitUntilV(ispkt);
5299 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
5300 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
5301 s->gotit = TRUE;
5302 logevent("Keyboard-interactive authentication refused");
5303 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
5304 continue;
5305 }
5306
5307 s->kbd_inter_running = TRUE;
5308 s->curr_prompt = 0;
5309 }
5310
5311 if (s->kbd_inter_running) {
5312 s->method = AUTH_KEYBOARD_INTERACTIVE;
5313 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5314 s->tried_keyb_inter = TRUE;
5315
5316 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5317 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
5318
5319 if (s->curr_prompt == 0) {
5320 /*
5321 * We've got a fresh USERAUTH_INFO_REQUEST.
5322 * Display header data, and start going through
5323 * the prompts.
5324 */
5325 char *name, *inst, *lang;
5326 int name_len, inst_len, lang_len;
5327
5328 ssh_pkt_getstring(ssh, &name, &name_len);
5329 ssh_pkt_getstring(ssh, &inst, &inst_len);
5330 ssh_pkt_getstring(ssh, &lang, &lang_len);
5331 if (name_len > 0) {
5332 c_write_untrusted(ssh, name, name_len);
5333 c_write_str(ssh, "\r\n");
5334 }
5335 if (inst_len > 0) {
5336 c_write_untrusted(ssh, inst, inst_len);
5337 c_write_str(ssh, "\r\n");
5338 }
5339 s->num_prompts = ssh_pkt_getuint32(ssh);
5340 }
5341
5342 /*
5343 * If there are prompts remaining in the packet,
5344 * display one and get a response.
5345 */
5346 if (s->curr_prompt < s->num_prompts) {
5347 char *prompt;
5348 int prompt_len;
5349
5350 ssh_pkt_getstring(ssh, &prompt, &prompt_len);
5351 if (prompt_len > 0) {
5352 static const char trunc[] = "<prompt truncated>: ";
5353 static const int prlen = sizeof(s->pwprompt) -
5354 lenof(trunc);
5355 if (prompt_len > prlen) {
5356 memcpy(s->pwprompt, prompt, prlen);
5357 strcpy(s->pwprompt + prlen, trunc);
5358 } else {
5359 memcpy(s->pwprompt, prompt, prompt_len);
5360 s->pwprompt[prompt_len] = '\0';
5361 }
5362 } else {
5363 strcpy(s->pwprompt,
5364 "<server failed to send prompt>: ");
5365 }
5366 s->echo = ssh2_pkt_getbool(ssh);
5367 s->need_pw = TRUE;
5368 } else
5369 s->need_pw = FALSE;
5370 }
5371
5372 if (!s->method && s->can_passwd) {
5373 s->method = AUTH_PASSWORD;
5374 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
5375 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
5376 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
5377 ssh->savedhost);
5378 s->need_pw = TRUE;
5379 }
5380
5381 if (s->need_pw) {
5382 if (ssh_get_line) {
5383 if (!ssh_get_line(s->pwprompt, s->password,
5384 sizeof(s->password), TRUE)) {
5385 /*
5386 * get_line failed to get a password (for
5387 * example because one was supplied on the
5388 * command line which has already failed to
5389 * work). Terminate.
5390 */
5391 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5392 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
5393 ssh2_pkt_addstring(ssh, "No more passwords available"
5394 " to try");
5395 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5396 ssh2_pkt_send(ssh);
5397 logevent("Unable to authenticate");
5398 connection_fatal(ssh->frontend,
5399 "Unable to authenticate");
5400 ssh_closing((Plug)ssh, NULL, 0, 0);
5401 crStopV;
5402 }
5403 } else {
5404 int ret; /* need not be saved across crReturn */
5405 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
5406 ssh->send_ok = 1;
5407
5408 setup_userpass_input(ssh, s->password,
5409 sizeof(s->password), s->echo);
5410 do {
5411 crWaitUntilV(!ispkt);
5412 ret = process_userpass_input(ssh, in, inlen);
5413 } while (ret == 0);
5414 if (ret < 0)
5415 cleanup_exit(0);
5416 c_write_str(ssh, "\r\n");
5417 }
5418 }
5419
5420 if (s->method == AUTH_PUBLICKEY_FILE) {
5421 /*
5422 * We have our passphrase. Now try the actual authentication.
5423 */
5424 struct ssh2_userkey *key;
5425 const char *error = NULL;
5426
5427 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
5428 &error);
5429 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
5430 if (key == SSH2_WRONG_PASSPHRASE) {
5431 c_write_str(ssh, "Wrong passphrase\r\n");
5432 s->tried_pubkey_config = FALSE;
5433 } else {
5434 c_write_str(ssh, "Unable to load private key (");
5435 c_write_str(ssh, error);
5436 c_write_str(ssh, ")\r\n");
5437 s->tried_pubkey_config = TRUE;
5438 }
5439 /* Send a spurious AUTH_NONE to return to the top. */
5440 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5441 ssh2_pkt_addstring(ssh, s->username);
5442 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5443 ssh2_pkt_addstring(ssh, "none"); /* method */
5444 ssh2_pkt_send(ssh);
5445 s->type = AUTH_TYPE_NONE;
5446 } else {
5447 unsigned char *pkblob, *sigblob, *sigdata;
5448 int pkblob_len, sigblob_len, sigdata_len;
5449 int p;
5450
5451 /*
5452 * We have loaded the private key and the server
5453 * has announced that it's willing to accept it.
5454 * Hallelujah. Generate a signature and send it.
5455 */
5456 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5457 ssh2_pkt_addstring(ssh, s->username);
5458 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5459 ssh2_pkt_addstring(ssh, "publickey"); /* method */
5460 ssh2_pkt_addbool(ssh, TRUE);
5461 ssh2_pkt_addstring(ssh, key->alg->name);
5462 pkblob = key->alg->public_blob(key->data, &pkblob_len);
5463 ssh2_pkt_addstring_start(ssh);
5464 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
5465
5466 /*
5467 * The data to be signed is:
5468 *
5469 * string session-id
5470 *
5471 * followed by everything so far placed in the
5472 * outgoing packet.
5473 */
5474 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
5475 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
5476 sigdata_len -= 4;
5477 sigdata = snewn(sigdata_len, unsigned char);
5478 p = 0;
5479 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
5480 PUT_32BIT(sigdata+p, 20);
5481 p += 4;
5482 }
5483 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
5484 memcpy(sigdata+p, ssh->pktout.data + 5,
5485 ssh->pktout.length - 5);
5486 p += ssh->pktout.length - 5;
5487 assert(p == sigdata_len);
5488 sigblob = key->alg->sign(key->data, (char *)sigdata,
5489 sigdata_len, &sigblob_len);
5490 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
5491 sigblob, sigblob_len);
5492 sfree(pkblob);
5493 sfree(sigblob);
5494 sfree(sigdata);
5495
5496 ssh2_pkt_send(ssh);
5497 s->type = AUTH_TYPE_PUBLICKEY;
5498 key->alg->freekey(key->data);
5499 }
5500 } else if (s->method == AUTH_PASSWORD) {
5501 /*
5502 * We send the password packet lumped tightly together with
5503 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
5504 * string long enough to make the total length of the two
5505 * packets constant. This should ensure that a passive
5506 * listener doing traffic analyis can't work out the length
5507 * of the password.
5508 *
5509 * For this to work, we need an assumption about the
5510 * maximum length of the password packet. I think 256 is
5511 * pretty conservative. Anyone using a password longer than
5512 * that probably doesn't have much to worry about from
5513 * people who find out how long their password is!
5514 */
5515 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
5516 ssh2_pkt_addstring(ssh, s->username);
5517 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
5518 ssh2_pkt_addstring(ssh, "password");
5519 ssh2_pkt_addbool(ssh, FALSE);
5520 dont_log_password(ssh, PKTLOG_BLANK);
5521 ssh2_pkt_addstring(ssh, s->password);
5522 memset(s->password, 0, sizeof(s->password));
5523 end_log_omission(ssh);
5524 ssh2_pkt_defer(ssh);
5525 /*
5526 * We'll include a string that's an exact multiple of the
5527 * cipher block size. If the cipher is NULL for some
5528 * reason, we don't do this trick at all because we gain
5529 * nothing by it.
5530 */
5531 if (ssh->cscipher) {
5532 int stringlen, i;
5533
5534 stringlen = (256 - ssh->deferred_len);
5535 stringlen += ssh->cscipher->blksize - 1;
5536 stringlen -= (stringlen % ssh->cscipher->blksize);
5537 if (ssh->cscomp) {
5538 /*
5539 * Temporarily disable actual compression,
5540 * so we can guarantee to get this string
5541 * exactly the length we want it. The
5542 * compression-disabling routine should
5543 * return an integer indicating how many
5544 * bytes we should adjust our string length
5545 * by.
5546 */
5547 stringlen -=
5548 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
5549 }
5550 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5551 ssh2_pkt_addstring_start(ssh);
5552 for (i = 0; i < stringlen; i++) {
5553 char c = (char) random_byte();
5554 ssh2_pkt_addstring_data(ssh, &c, 1);
5555 }
5556 ssh2_pkt_defer(ssh);
5557 }
5558 ssh_pkt_defersend(ssh);
5559 logevent("Sent password");
5560 s->type = AUTH_TYPE_PASSWORD;
5561 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
5562 if (s->curr_prompt == 0) {
5563 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
5564 ssh2_pkt_adduint32(ssh, s->num_prompts);
5565 }
5566 if (s->need_pw) { /* only add pw if we just got one! */
5567 dont_log_password(ssh, PKTLOG_BLANK);
5568 ssh2_pkt_addstring(ssh, s->password);
5569 memset(s->password, 0, sizeof(s->password));
5570 end_log_omission(ssh);
5571 s->curr_prompt++;
5572 }
5573 if (s->curr_prompt >= s->num_prompts) {
5574 ssh2_pkt_send(ssh);
5575 } else {
5576 /*
5577 * If there are prompts remaining, we set
5578 * `gotit' so that we won't attempt to get
5579 * another packet. Then we go back round the
5580 * loop and will end up retrieving another
5581 * prompt out of the existing packet. Funky or
5582 * what?
5583 */
5584 s->gotit = TRUE;
5585 }
5586 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5587 } else {
5588 c_write_str(ssh, "No supported authentication methods"
5589 " left to try!\r\n");
5590 logevent("No supported authentications offered."
5591 " Disconnecting");
5592 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5593 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5594 ssh2_pkt_addstring(ssh, "No supported authentication"
5595 " methods available");
5596 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5597 ssh2_pkt_send(ssh);
5598 ssh_closing((Plug)ssh, NULL, 0, 0);
5599 crStopV;
5600 }
5601 }
5602 } while (!s->we_are_in);
5603
5604 /*
5605 * Now we're authenticated for the connection protocol. The
5606 * connection protocol will automatically have started at this
5607 * point; there's no need to send SERVICE_REQUEST.
5608 */
5609
5610 ssh->channels = newtree234(ssh_channelcmp);
5611
5612 /*
5613 * Create the main session channel.
5614 */
5615 if (!ssh->cfg.ssh_no_shell) {
5616 ssh->mainchan = snew(struct ssh_channel);
5617 ssh->mainchan->ssh = ssh;
5618 ssh->mainchan->localid = alloc_channel_id(ssh);
5619 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5620 ssh2_pkt_addstring(ssh, "session");
5621 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5622 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5623 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5624 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5625 ssh2_pkt_send(ssh);
5626 crWaitUntilV(ispkt);
5627 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5628 bombout(("Server refused to open a session"));
5629 crStopV;
5630 /* FIXME: error data comes back in FAILURE packet */
5631 }
5632 if (ssh_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5633 bombout(("Server's channel confirmation cited wrong channel"));
5634 crStopV;
5635 }
5636 ssh->mainchan->remoteid = ssh_pkt_getuint32(ssh);
5637 ssh->mainchan->type = CHAN_MAINSESSION;
5638 ssh->mainchan->closes = 0;
5639 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(ssh);
5640 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(ssh);
5641 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5642 add234(ssh->channels, ssh->mainchan);
5643 update_specials_menu(ssh->frontend);
5644 logevent("Opened channel for session");
5645 } else
5646 ssh->mainchan = NULL;
5647
5648 /*
5649 * Potentially enable X11 forwarding.
5650 */
5651 if (ssh->mainchan && ssh->cfg.x11_forward) {
5652 char proto[20], data[64];
5653 logevent("Requesting X11 forwarding");
5654 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5655 data, sizeof(data), ssh->cfg.x11_auth);
5656 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
5657 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5658 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5659 ssh2_pkt_addstring(ssh, "x11-req");
5660 ssh2_pkt_addbool(ssh, 1); /* want reply */
5661 ssh2_pkt_addbool(ssh, 0); /* many connections */
5662 ssh2_pkt_addstring(ssh, proto);
5663 ssh2_pkt_addstring(ssh, data);
5664 ssh2_pkt_adduint32(ssh, x11_get_screen_number(ssh->cfg.x11_display));
5665 ssh2_pkt_send(ssh);
5666
5667 do {
5668 crWaitUntilV(ispkt);
5669 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5670 unsigned i = ssh_pkt_getuint32(ssh);
5671 struct ssh_channel *c;
5672 c = find234(ssh->channels, &i, ssh_channelfind);
5673 if (!c)
5674 continue; /* nonexistent channel */
5675 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5676 }
5677 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5678
5679 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5680 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5681 bombout(("Unexpected response to X11 forwarding request:"
5682 " packet type %d", ssh->pktin.type));
5683 crStopV;
5684 }
5685 logevent("X11 forwarding refused");
5686 } else {
5687 logevent("X11 forwarding enabled");
5688 ssh->X11_fwd_enabled = TRUE;
5689 }
5690 }
5691
5692 /*
5693 * Enable port forwardings.
5694 */
5695 {
5696 char type;
5697 int n;
5698 int sport,dport,sserv,dserv;
5699 char sports[256], dports[256], saddr[256], host[256];
5700
5701 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5702 /* Add port forwardings. */
5703 ssh->portfwd_strptr = ssh->cfg.portfwd;
5704 while (*ssh->portfwd_strptr) {
5705 type = *ssh->portfwd_strptr++;
5706 saddr[0] = '\0';
5707 n = 0;
5708 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5709 if (*ssh->portfwd_strptr == ':') {
5710 /*
5711 * We've seen a colon in the middle of the
5712 * source port number. This means that
5713 * everything we've seen until now is the
5714 * source _address_, so we'll move it into
5715 * saddr and start sports from the beginning
5716 * again.
5717 */
5718 ssh->portfwd_strptr++;
5719 sports[n] = '\0';
5720 strcpy(saddr, sports);
5721 n = 0;
5722 }
5723 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5724 }
5725 sports[n] = 0;
5726 if (type != 'D') {
5727 if (*ssh->portfwd_strptr == '\t')
5728 ssh->portfwd_strptr++;
5729 n = 0;
5730 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5731 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5732 }
5733 host[n] = 0;
5734 if (*ssh->portfwd_strptr == ':')
5735 ssh->portfwd_strptr++;
5736 n = 0;
5737 while (*ssh->portfwd_strptr) {
5738 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5739 }
5740 dports[n] = 0;
5741 ssh->portfwd_strptr++;
5742 dport = atoi(dports);
5743 dserv = 0;
5744 if (dport == 0) {
5745 dserv = 1;
5746 dport = net_service_lookup(dports);
5747 if (!dport) {
5748 logeventf(ssh, "Service lookup failed for destination"
5749 " port \"%s\"", dports);
5750 }
5751 }
5752 } else {
5753 while (*ssh->portfwd_strptr) ssh->portfwd_strptr++;
5754 dport = dserv = -1;
5755 ssh->portfwd_strptr++; /* eat the NUL and move to next one */
5756 }
5757 sport = atoi(sports);
5758 sserv = 0;
5759 if (sport == 0) {
5760 sserv = 1;
5761 sport = net_service_lookup(sports);
5762 if (!sport) {
5763 logeventf(ssh, "Service lookup failed for source"
5764 " port \"%s\"", sports);
5765 }
5766 }
5767 if (sport && dport) {
5768 /* Set up a description of the source port. */
5769 char *sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
5770 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5771 (int)(*saddr?1:0), ":",
5772 (int)(sserv ? strlen(sports) : 0), sports,
5773 sserv, "(", sport, sserv, ")");
5774 if (type == 'L') {
5775 /* Verbose description of the destination port */
5776 char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
5777 host,
5778 (int)(dserv ? strlen(dports) : 0), dports,
5779 dserv, "(", dport, dserv, ")");
5780 const char *err = pfd_addforward(host, dport,
5781 *saddr ? saddr : NULL,
5782 sport, ssh, &ssh->cfg);
5783 if (err) {
5784 logeventf(ssh, "Local port %s forward to %s"
5785 " failed: %s", sportdesc, dportdesc, err);
5786 } else {
5787 logeventf(ssh, "Local port %s forwarding to %s",
5788 sportdesc, dportdesc);
5789 }
5790 sfree(dportdesc);
5791 } else if (type == 'D') {
5792 const char *err = pfd_addforward(NULL, -1,
5793 *saddr ? saddr : NULL,
5794 sport, ssh, &ssh->cfg);
5795 if (err) {
5796 logeventf(ssh, "Local port %s SOCKS dynamic forward"
5797 " setup failed: %s", sportdesc, err);
5798 } else {
5799 logeventf(ssh, "Local port %s doing SOCKS"
5800 " dynamic forwarding", sportdesc);
5801 }
5802 } else {
5803 struct ssh_rportfwd *pf;
5804 pf = snew(struct ssh_rportfwd);
5805 strcpy(pf->dhost, host);
5806 pf->dport = dport;
5807 pf->sport = sport;
5808 if (add234(ssh->rportfwds, pf) != pf) {
5809 logeventf(ssh, "Duplicate remote port forwarding"
5810 " to %s:%d", host, dport);
5811 sfree(pf);
5812 } else {
5813 logeventf(ssh, "Requesting remote port %s"
5814 " forward to %s:%.*s%.*s%d%.*s",
5815 sportdesc,
5816 host,
5817 (int)(dserv ? strlen(dports) : 0), dports,
5818 dserv, "(", dport, dserv, ")");
5819 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5820 ssh2_pkt_addstring(ssh, "tcpip-forward");
5821 ssh2_pkt_addbool(ssh, 1);/* want reply */
5822 if (*saddr)
5823 ssh2_pkt_addstring(ssh, saddr);
5824 if (ssh->cfg.rport_acceptall)
5825 ssh2_pkt_addstring(ssh, "0.0.0.0");
5826 else
5827 ssh2_pkt_addstring(ssh, "127.0.0.1");
5828 ssh2_pkt_adduint32(ssh, sport);
5829 ssh2_pkt_send(ssh);
5830
5831 do {
5832 crWaitUntilV(ispkt);
5833 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5834 unsigned i = ssh_pkt_getuint32(ssh);
5835 struct ssh_channel *c;
5836 c = find234(ssh->channels, &i, ssh_channelfind);
5837 if (!c)
5838 continue;/* nonexistent channel */
5839 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5840 }
5841 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5842
5843 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5844 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5845 bombout(("Unexpected response to port "
5846 "forwarding request: packet type %d",
5847 ssh->pktin.type));
5848 crStopV;
5849 }
5850 logevent("Server refused this port forwarding");
5851 } else {
5852 logevent("Remote port forwarding enabled");
5853 }
5854 }
5855 }
5856 sfree(sportdesc);
5857 }
5858 }
5859 }
5860
5861 /*
5862 * Potentially enable agent forwarding.
5863 */
5864 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
5865 logevent("Requesting OpenSSH-style agent forwarding");
5866 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5867 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5868 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5869 ssh2_pkt_addbool(ssh, 1); /* want reply */
5870 ssh2_pkt_send(ssh);
5871
5872 do {
5873 crWaitUntilV(ispkt);
5874 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5875 unsigned i = ssh_pkt_getuint32(ssh);
5876 struct ssh_channel *c;
5877 c = find234(ssh->channels, &i, ssh_channelfind);
5878 if (!c)
5879 continue; /* nonexistent channel */
5880 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5881 }
5882 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5883
5884 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5885 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5886 bombout(("Unexpected response to agent forwarding request:"
5887 " packet type %d", ssh->pktin.type));
5888 crStopV;
5889 }
5890 logevent("Agent forwarding refused");
5891 } else {
5892 logevent("Agent forwarding enabled");
5893 ssh->agentfwd_enabled = TRUE;
5894 }
5895 }
5896
5897 /*
5898 * Now allocate a pty for the session.
5899 */
5900 if (ssh->mainchan && !ssh->cfg.nopty) {
5901 /* Unpick the terminal-speed string. */
5902 /* XXX perhaps we should allow no speeds to be sent. */
5903 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5904 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
5905 /* Build the pty request. */
5906 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5907 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5908 ssh2_pkt_addstring(ssh, "pty-req");
5909 ssh2_pkt_addbool(ssh, 1); /* want reply */
5910 ssh2_pkt_addstring(ssh, ssh->cfg.termtype);
5911 ssh2_pkt_adduint32(ssh, ssh->term_width);
5912 ssh2_pkt_adduint32(ssh, ssh->term_height);
5913 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5914 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5915 ssh2_pkt_addstring_start(ssh);
5916 ssh2_pkt_addbyte(ssh, 128); /* TTY_OP_ISPEED */
5917 ssh2_pkt_adduint32(ssh, ssh->ispeed);
5918 ssh2_pkt_addbyte(ssh, 129); /* TTY_OP_OSPEED */
5919 ssh2_pkt_adduint32(ssh, ssh->ospeed);
5920 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END */
5921 ssh2_pkt_send(ssh);
5922 ssh->state = SSH_STATE_INTERMED;
5923
5924 do {
5925 crWaitUntilV(ispkt);
5926 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5927 unsigned i = ssh_pkt_getuint32(ssh);
5928 struct ssh_channel *c;
5929 c = find234(ssh->channels, &i, ssh_channelfind);
5930 if (!c)
5931 continue; /* nonexistent channel */
5932 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
5933 }
5934 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5935
5936 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5937 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5938 bombout(("Unexpected response to pty request:"
5939 " packet type %d", ssh->pktin.type));
5940 crStopV;
5941 }
5942 c_write_str(ssh, "Server refused to allocate pty\r\n");
5943 ssh->editing = ssh->echoing = 1;
5944 } else {
5945 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5946 ssh->ospeed, ssh->ispeed);
5947 }
5948 } else {
5949 ssh->editing = ssh->echoing = 1;
5950 }
5951
5952 /*
5953 * Send environment variables.
5954 *
5955 * Simplest thing here is to send all the requests at once, and
5956 * then wait for a whole bunch of successes or failures.
5957 */
5958 if (ssh->mainchan && *ssh->cfg.environmt) {
5959 char *e = ssh->cfg.environmt;
5960 char *var, *varend, *val;
5961
5962 s->num_env = 0;
5963
5964 while (*e) {
5965 var = e;
5966 while (*e && *e != '\t') e++;
5967 varend = e;
5968 if (*e == '\t') e++;
5969 val = e;
5970 while (*e) e++;
5971 e++;
5972
5973 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5974 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5975 ssh2_pkt_addstring(ssh, "env");
5976 ssh2_pkt_addbool(ssh, 1); /* want reply */
5977 ssh2_pkt_addstring_start(ssh);
5978 ssh2_pkt_addstring_data(ssh, var, varend-var);
5979 ssh2_pkt_addstring(ssh, val);
5980 ssh2_pkt_send(ssh);
5981
5982 s->num_env++;
5983 }
5984
5985 logeventf(ssh, "Sent %d environment variables", s->num_env);
5986
5987 s->env_ok = 0;
5988 s->env_left = s->num_env;
5989
5990 while (s->env_left > 0) {
5991 do {
5992 crWaitUntilV(ispkt);
5993 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5994 unsigned i = ssh_pkt_getuint32(ssh);
5995 struct ssh_channel *c;
5996 c = find234(ssh->channels, &i, ssh_channelfind);
5997 if (!c)
5998 continue; /* nonexistent channel */
5999 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
6000 }
6001 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6002
6003 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
6004 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6005 bombout(("Unexpected response to environment request:"
6006 " packet type %d", ssh->pktin.type));
6007 crStopV;
6008 }
6009 } else {
6010 s->env_ok++;
6011 }
6012
6013 s->env_left--;
6014 }
6015
6016 if (s->env_ok == s->num_env) {
6017 logevent("All environment variables successfully set");
6018 } else if (s->env_ok == 0) {
6019 logevent("All environment variables refused");
6020 c_write_str(ssh, "Server refused to set environment variables\r\n");
6021 } else {
6022 logeventf(ssh, "%d environment variables refused",
6023 s->num_env - s->env_ok);
6024 c_write_str(ssh, "Server refused to set all environment variables\r\n");
6025 }
6026 }
6027
6028 /*
6029 * Start a shell or a remote command. We may have to attempt
6030 * this twice if the config data has provided a second choice
6031 * of command.
6032 */
6033 if (ssh->mainchan) while (1) {
6034 int subsys;
6035 char *cmd;
6036
6037 if (ssh->fallback_cmd) {
6038 subsys = ssh->cfg.ssh_subsys2;
6039 cmd = ssh->cfg.remote_cmd_ptr2;
6040 } else {
6041 subsys = ssh->cfg.ssh_subsys;
6042 cmd = ssh->cfg.remote_cmd_ptr;
6043 }
6044
6045 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6046 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
6047 if (subsys) {
6048 ssh2_pkt_addstring(ssh, "subsystem");
6049 ssh2_pkt_addbool(ssh, 1); /* want reply */
6050 ssh2_pkt_addstring(ssh, cmd);
6051 } else if (*cmd) {
6052 ssh2_pkt_addstring(ssh, "exec");
6053 ssh2_pkt_addbool(ssh, 1); /* want reply */
6054 ssh2_pkt_addstring(ssh, cmd);
6055 } else {
6056 ssh2_pkt_addstring(ssh, "shell");
6057 ssh2_pkt_addbool(ssh, 1); /* want reply */
6058 }
6059 ssh2_pkt_send(ssh);
6060 do {
6061 crWaitUntilV(ispkt);
6062 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
6063 unsigned i = ssh_pkt_getuint32(ssh);
6064 struct ssh_channel *c;
6065 c = find234(ssh->channels, &i, ssh_channelfind);
6066 if (!c)
6067 continue; /* nonexistent channel */
6068 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
6069 }
6070 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6071 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
6072 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
6073 bombout(("Unexpected response to shell/command request:"
6074 " packet type %d", ssh->pktin.type));
6075 crStopV;
6076 }
6077 /*
6078 * We failed to start the command. If this is the
6079 * fallback command, we really are finished; if it's
6080 * not, and if the fallback command exists, try falling
6081 * back to it before complaining.
6082 */
6083 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
6084 logevent("Primary command failed; attempting fallback");
6085 ssh->fallback_cmd = TRUE;
6086 continue;
6087 }
6088 bombout(("Server refused to start a shell/command"));
6089 crStopV;
6090 } else {
6091 logevent("Started a shell/command");
6092 }
6093 break;
6094 }
6095
6096 ssh->state = SSH_STATE_SESSION;
6097 if (ssh->size_needed)
6098 ssh_size(ssh, ssh->term_width, ssh->term_height);
6099 if (ssh->eof_needed)
6100 ssh_special(ssh, TS_EOF);
6101
6102 /*
6103 * Transfer data!
6104 */
6105 if (ssh->ldisc)
6106 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
6107 if (ssh->mainchan)
6108 ssh->send_ok = 1;
6109 while (1) {
6110 crReturnV;
6111 s->try_send = FALSE;
6112 if (ispkt) {
6113 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
6114 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
6115 char *data;
6116 int length;
6117 unsigned i = ssh_pkt_getuint32(ssh);
6118 struct ssh_channel *c;
6119 c = find234(ssh->channels, &i, ssh_channelfind);
6120 if (!c)
6121 continue; /* nonexistent channel */
6122 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6123 ssh_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
6124 continue; /* extended but not stderr */
6125 ssh_pkt_getstring(ssh, &data, &length);
6126 if (data) {
6127 int bufsize = 0;
6128 c->v.v2.locwindow -= length;
6129 switch (c->type) {
6130 case CHAN_MAINSESSION:
6131 bufsize =
6132 from_backend(ssh->frontend, ssh->pktin.type ==
6133 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6134 data, length);
6135 break;
6136 case CHAN_X11:
6137 bufsize = x11_send(c->u.x11.s, data, length);
6138 break;
6139 case CHAN_SOCKDATA:
6140 bufsize = pfd_send(c->u.pfd.s, data, length);
6141 break;
6142 case CHAN_AGENT:
6143 while (length > 0) {
6144 if (c->u.a.lensofar < 4) {
6145 int l = min(4 - c->u.a.lensofar, length);
6146 memcpy(c->u.a.msglen + c->u.a.lensofar,
6147 data, l);
6148 data += l;
6149 length -= l;
6150 c->u.a.lensofar += l;
6151 }
6152 if (c->u.a.lensofar == 4) {
6153 c->u.a.totallen =
6154 4 + GET_32BIT(c->u.a.msglen);
6155 c->u.a.message = snewn(c->u.a.totallen,
6156 unsigned char);
6157 memcpy(c->u.a.message, c->u.a.msglen, 4);
6158 }
6159 if (c->u.a.lensofar >= 4 && length > 0) {
6160 int l =
6161 min(c->u.a.totallen - c->u.a.lensofar,
6162 length);
6163 memcpy(c->u.a.message + c->u.a.lensofar,
6164 data, l);
6165 data += l;
6166 length -= l;
6167 c->u.a.lensofar += l;
6168 }
6169 if (c->u.a.lensofar == c->u.a.totallen) {
6170 void *reply;
6171 int replylen;
6172 if (agent_query(c->u.a.message,
6173 c->u.a.totallen,
6174 &reply, &replylen,
6175 ssh_agentf_callback, c))
6176 ssh_agentf_callback(c, reply, replylen);
6177 sfree(c->u.a.message);
6178 c->u.a.lensofar = 0;
6179 }
6180 }
6181 bufsize = 0;
6182 break;
6183 }
6184 /*
6185 * If we are not buffering too much data,
6186 * enlarge the window again at the remote side.
6187 */
6188 if (bufsize < OUR_V2_WINSIZE)
6189 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
6190 }
6191 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
6192 unsigned i = ssh_pkt_getuint32(ssh);
6193 struct ssh_channel *c;
6194
6195 c = find234(ssh->channels, &i, ssh_channelfind);
6196 if (!c)
6197 continue; /* nonexistent channel */
6198
6199 if (c->type == CHAN_X11) {
6200 /*
6201 * Remote EOF on an X11 channel means we should
6202 * wrap up and close the channel ourselves.
6203 */
6204 x11_close(c->u.x11.s);
6205 sshfwd_close(c);
6206 } else if (c->type == CHAN_AGENT) {
6207 sshfwd_close(c);
6208 } else if (c->type == CHAN_SOCKDATA) {
6209 pfd_close(c->u.pfd.s);
6210 sshfwd_close(c);
6211 }
6212 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
6213 unsigned i = ssh_pkt_getuint32(ssh);
6214 struct ssh_channel *c;
6215
6216 c = find234(ssh->channels, &i, ssh_channelfind);
6217 if (!c || ((int)c->remoteid) == -1) {
6218 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6219 c ? "half-open" : "nonexistent", i));
6220 crStopV;
6221 }
6222 /* Do pre-close processing on the channel. */
6223 switch (c->type) {
6224 case CHAN_MAINSESSION:
6225 ssh->mainchan = NULL;
6226 update_specials_menu(ssh->frontend);
6227 break;
6228 case CHAN_X11:
6229 if (c->u.x11.s != NULL)
6230 x11_close(c->u.x11.s);
6231 sshfwd_close(c);
6232 break;
6233 case CHAN_AGENT:
6234 sshfwd_close(c);
6235 break;
6236 case CHAN_SOCKDATA:
6237 if (c->u.pfd.s != NULL)
6238 pfd_close(c->u.pfd.s);
6239 sshfwd_close(c);
6240 break;
6241 }
6242 if (c->closes == 0) {
6243 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
6244 ssh2_pkt_adduint32(ssh, c->remoteid);
6245 ssh2_pkt_send(ssh);
6246 }
6247 del234(ssh->channels, c);
6248 bufchain_clear(&c->v.v2.outbuffer);
6249 sfree(c);
6250
6251 /*
6252 * See if that was the last channel left open.
6253 * (This is only our termination condition if we're
6254 * not running in -N mode.)
6255 */
6256 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6257 logevent("All channels closed. Disconnecting");
6258 #if 0
6259 /*
6260 * We used to send SSH_MSG_DISCONNECT here,
6261 * because I'd believed that _every_ conforming
6262 * SSH2 connection had to end with a disconnect
6263 * being sent by at least one side; apparently
6264 * I was wrong and it's perfectly OK to
6265 * unceremoniously slam the connection shut
6266 * when you're done, and indeed OpenSSH feels
6267 * this is more polite than sending a
6268 * DISCONNECT. So now we don't.
6269 */
6270 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
6271 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
6272 ssh2_pkt_addstring(ssh, "All open channels closed");
6273 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6274 ssh2_pkt_send(ssh);
6275 #endif
6276 ssh_closing((Plug)ssh, NULL, 0, 0);
6277 crStopV;
6278 }
6279 continue; /* remote sends close; ignore (FIXME) */
6280 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
6281 unsigned i = ssh_pkt_getuint32(ssh);
6282 struct ssh_channel *c;
6283 c = find234(ssh->channels, &i, ssh_channelfind);
6284 if (!c || c->closes)
6285 continue; /* nonexistent or closing channel */
6286 c->v.v2.remwindow += ssh_pkt_getuint32(ssh);
6287 s->try_send = TRUE;
6288 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6289 unsigned i = ssh_pkt_getuint32(ssh);
6290 struct ssh_channel *c;
6291 c = find234(ssh->channels, &i, ssh_channelfind);
6292 if (!c)
6293 continue; /* nonexistent channel */
6294 if (c->type != CHAN_SOCKDATA_DORMANT)
6295 continue; /* dunno why they're confirming this */
6296 c->remoteid = ssh_pkt_getuint32(ssh);
6297 c->type = CHAN_SOCKDATA;
6298 c->v.v2.remwindow = ssh_pkt_getuint32(ssh);
6299 c->v.v2.remmaxpkt = ssh_pkt_getuint32(ssh);
6300 if (c->u.pfd.s)
6301 pfd_confirm(c->u.pfd.s);
6302 if (c->closes) {
6303 /*
6304 * We have a pending close on this channel,
6305 * which we decided on before the server acked
6306 * the channel open. So now we know the
6307 * remoteid, we can close it again.
6308 */
6309 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
6310 ssh2_pkt_adduint32(ssh, c->remoteid);
6311 ssh2_pkt_send(ssh);
6312 }
6313 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
6314 static const char *const reasons[] = {
6315 "<unknown reason code>",
6316 "Administratively prohibited",
6317 "Connect failed",
6318 "Unknown channel type",
6319 "Resource shortage",
6320 };
6321 unsigned i = ssh_pkt_getuint32(ssh);
6322 unsigned reason_code;
6323 char *reason_string;
6324 int reason_length;
6325 char *message;
6326 struct ssh_channel *c;
6327 c = find234(ssh->channels, &i, ssh_channelfind);
6328 if (!c)
6329 continue; /* nonexistent channel */
6330 if (c->type != CHAN_SOCKDATA_DORMANT)
6331 continue; /* dunno why they're failing this */
6332
6333 reason_code = ssh_pkt_getuint32(ssh);
6334 if (reason_code >= lenof(reasons))
6335 reason_code = 0; /* ensure reasons[reason_code] in range */
6336 ssh_pkt_getstring(ssh, &reason_string, &reason_length);
6337 message = dupprintf("Forwarded connection refused by"
6338 " server: %s [%.*s]", reasons[reason_code],
6339 reason_length, reason_string);
6340 logevent(message);
6341 sfree(message);
6342
6343 pfd_close(c->u.pfd.s);
6344
6345 del234(ssh->channels, c);
6346 sfree(c);
6347 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
6348 unsigned localid;
6349 char *type;
6350 int typelen, want_reply;
6351 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6352 struct ssh_channel *c;
6353
6354 localid = ssh_pkt_getuint32(ssh);
6355 ssh_pkt_getstring(ssh, &type, &typelen);
6356 want_reply = ssh2_pkt_getbool(ssh);
6357
6358 /*
6359 * First, check that the channel exists. Otherwise,
6360 * we can instantly disconnect with a rude message.
6361 */
6362 c = find234(ssh->channels, &localid, ssh_channelfind);
6363 if (!c) {
6364 char buf[80];
6365 sprintf(buf, "Received channel request for nonexistent"
6366 " channel %d", localid);
6367 logevent(buf);
6368 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
6369 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
6370 ssh2_pkt_addstring(ssh, buf);
6371 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6372 ssh2_pkt_send(ssh);
6373 connection_fatal(ssh->frontend, "%s", buf);
6374 ssh_closing((Plug)ssh, NULL, 0, 0);
6375 crStopV;
6376 }
6377
6378 /*
6379 * Having got the channel number, we now look at
6380 * the request type string to see if it's something
6381 * we recognise.
6382 */
6383 if (c == ssh->mainchan) {
6384 /*
6385 * We recognise "exit-status" and "exit-signal" on
6386 * the primary channel.
6387 */
6388 if (typelen == 11 &&
6389 !memcmp(type, "exit-status", 11)) {
6390
6391 ssh->exitcode = ssh_pkt_getuint32(ssh);
6392 logeventf(ssh, "Server sent command exit status %d",
6393 ssh->exitcode);
6394 reply = SSH2_MSG_CHANNEL_SUCCESS;
6395
6396 } else if (typelen == 11 &&
6397 !memcmp(type, "exit-signal", 11)) {
6398
6399 int is_plausible = TRUE, is_int = FALSE;
6400 char *fmt_sig = "", *fmt_msg = "";
6401 char *msg;
6402 int msglen = 0, core = FALSE;
6403 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6404 * provide an `int' for the signal, despite its
6405 * having been a `string' in the drafts since at
6406 * least 2001. (Fixed in session.c 1.147.) Try to
6407 * infer which we can safely parse it as. */
6408 {
6409 unsigned char *p = ssh->pktin.body +
6410 ssh->pktin.savedpos;
6411 long len = ssh->pktin.length - ssh->pktin.savedpos;
6412 unsigned long num = GET_32BIT(p); /* what is it? */
6413 /* If it's 0, it hardly matters; assume string */
6414 if (num == 0) {
6415 is_int = FALSE;
6416 } else {
6417 int maybe_int = FALSE, maybe_str = FALSE;
6418 #define CHECK_HYPOTHESIS(offset, result) \
6419 do { \
6420 long q = offset; \
6421 if (q >= 0 && q+4 <= len) { \
6422 q = q + 4 + GET_32BIT(p+q); \
6423 if (q >= 0 && q+4 <= len && \
6424 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
6425 result = TRUE; \
6426 } \
6427 } while(0)
6428 CHECK_HYPOTHESIS(4+1, maybe_int);
6429 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6430 #undef CHECK_HYPOTHESIS
6431 if (maybe_int && !maybe_str)
6432 is_int = TRUE;
6433 else if (!maybe_int && maybe_str)
6434 is_int = FALSE;
6435 else
6436 /* Crikey. Either or neither. Panic. */
6437 is_plausible = FALSE;
6438 }
6439 }
6440 if (is_plausible) {
6441 if (is_int) {
6442 /* Old non-standard OpenSSH. */
6443 int signum = ssh_pkt_getuint32(ssh);
6444 fmt_sig = dupprintf(" %d", signum);
6445 } else {
6446 /* As per the drafts. */
6447 char *sig;
6448 int siglen;
6449 ssh_pkt_getstring(ssh, &sig, &siglen);
6450 /* Signal name isn't supposed to be blank, but
6451 * let's cope gracefully if it is. */
6452 if (siglen) {
6453 fmt_sig = dupprintf(" \"%.*s\"",
6454 siglen, sig);
6455 }
6456 }
6457 core = ssh2_pkt_getbool(ssh);
6458 ssh_pkt_getstring(ssh, &msg, &msglen);
6459 if (msglen) {
6460 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6461 }
6462 /* ignore lang tag */
6463 } /* else don't attempt to parse */
6464 logeventf(ssh, "Server exited on signal%s%s%s",
6465 fmt_sig, core ? " (core dumped)" : "",
6466 fmt_msg);
6467 if (*fmt_sig) sfree(fmt_sig);
6468 if (*fmt_msg) sfree(fmt_msg);
6469 reply = SSH2_MSG_CHANNEL_SUCCESS;
6470
6471 }
6472 } else {
6473 /*
6474 * This is a channel request we don't know
6475 * about, so we now either ignore the request
6476 * or respond with CHANNEL_FAILURE, depending
6477 * on want_reply.
6478 */
6479 reply = SSH2_MSG_CHANNEL_FAILURE;
6480 }
6481 if (want_reply) {
6482 ssh2_pkt_init(ssh, reply);
6483 ssh2_pkt_adduint32(ssh, c->remoteid);
6484 ssh2_pkt_send(ssh);
6485 }
6486 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
6487 char *type;
6488 int typelen, want_reply;
6489
6490 ssh_pkt_getstring(ssh, &type, &typelen);
6491 want_reply = ssh2_pkt_getbool(ssh);
6492
6493 /*
6494 * We currently don't support any global requests
6495 * at all, so we either ignore the request or
6496 * respond with REQUEST_FAILURE, depending on
6497 * want_reply.
6498 */
6499 if (want_reply) {
6500 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
6501 ssh2_pkt_send(ssh);
6502 }
6503 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
6504 char *type;
6505 int typelen;
6506 char *peeraddr;
6507 int peeraddrlen;
6508 int peerport;
6509 char *error = NULL;
6510 struct ssh_channel *c;
6511 unsigned remid, winsize, pktsize;
6512 ssh_pkt_getstring(ssh, &type, &typelen);
6513 c = snew(struct ssh_channel);
6514 c->ssh = ssh;
6515
6516 remid = ssh_pkt_getuint32(ssh);
6517 winsize = ssh_pkt_getuint32(ssh);
6518 pktsize = ssh_pkt_getuint32(ssh);
6519
6520 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6521 char *addrstr;
6522
6523 ssh_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6524 addrstr = snewn(peeraddrlen+1, char);
6525 memcpy(addrstr, peeraddr, peeraddrlen);
6526 addrstr[peeraddrlen] = '\0';
6527 peerport = ssh_pkt_getuint32(ssh);
6528
6529 logeventf(ssh, "Received X11 connect request from %s:%d",
6530 addrstr, peerport);
6531
6532 if (!ssh->X11_fwd_enabled)
6533 error = "X11 forwarding is not enabled";
6534 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6535 ssh->x11auth, addrstr, peerport,
6536 &ssh->cfg) != NULL) {
6537 error = "Unable to open an X11 connection";
6538 } else {
6539 logevent("Opening X11 forward connection succeeded");
6540 c->type = CHAN_X11;
6541 }
6542
6543 sfree(addrstr);
6544 } else if (typelen == 15 &&
6545 !memcmp(type, "forwarded-tcpip", 15)) {
6546 struct ssh_rportfwd pf, *realpf;
6547 char *dummy;
6548 int dummylen;
6549 ssh_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
6550 pf.sport = ssh_pkt_getuint32(ssh);
6551 ssh_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
6552 peerport = ssh_pkt_getuint32(ssh);
6553 realpf = find234(ssh->rportfwds, &pf, NULL);
6554 logeventf(ssh, "Received remote port %d open request "
6555 "from %s:%d", pf.sport, peeraddr, peerport);
6556 if (realpf == NULL) {
6557 error = "Remote port is not recognised";
6558 } else {
6559 const char *e = pfd_newconnect(&c->u.pfd.s,
6560 realpf->dhost,
6561 realpf->dport, c,
6562 &ssh->cfg);
6563 logeventf(ssh, "Attempting to forward remote port to "
6564 "%s:%d", realpf->dhost, realpf->dport);
6565 if (e != NULL) {
6566 logeventf(ssh, "Port open failed: %s", e);
6567 error = "Port open failed";
6568 } else {
6569 logevent("Forwarded port opened successfully");
6570 c->type = CHAN_SOCKDATA;
6571 }
6572 }
6573 } else if (typelen == 22 &&
6574 !memcmp(type, "auth-agent@openssh.com", 3)) {
6575 if (!ssh->agentfwd_enabled)
6576 error = "Agent forwarding is not enabled";
6577 else {
6578 c->type = CHAN_AGENT; /* identify channel type */
6579 c->u.a.lensofar = 0;
6580 }
6581 } else {
6582 error = "Unsupported channel type requested";
6583 }
6584
6585 c->remoteid = remid;
6586 if (error) {
6587 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
6588 ssh2_pkt_adduint32(ssh, c->remoteid);
6589 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
6590 ssh2_pkt_addstring(ssh, error);
6591 ssh2_pkt_addstring(ssh, "en"); /* language tag */
6592 ssh2_pkt_send(ssh);
6593 logeventf(ssh, "Rejected channel open: %s", error);
6594 sfree(c);
6595 } else {
6596 c->localid = alloc_channel_id(ssh);
6597 c->closes = 0;
6598 c->v.v2.locwindow = OUR_V2_WINSIZE;
6599 c->v.v2.remwindow = winsize;
6600 c->v.v2.remmaxpkt = pktsize;
6601 bufchain_init(&c->v.v2.outbuffer);
6602 add234(ssh->channels, c);
6603 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6604 ssh2_pkt_adduint32(ssh, c->remoteid);
6605 ssh2_pkt_adduint32(ssh, c->localid);
6606 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
6607 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6608 ssh2_pkt_send(ssh);
6609 }
6610 } else {
6611 bombout(("Strange packet received: type %d", ssh->pktin.type));
6612 crStopV;
6613 }
6614 } else if (ssh->mainchan) {
6615 /*
6616 * We have spare data. Add it to the channel buffer.
6617 */
6618 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
6619 s->try_send = TRUE;
6620 }
6621 if (s->try_send) {
6622 int i;
6623 struct ssh_channel *c;
6624 /*
6625 * Try to send data on all channels if we can.
6626 */
6627 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
6628 int bufsize;
6629 if (c->closes)
6630 continue; /* don't send on closing channels */
6631 bufsize = ssh2_try_send(c);
6632 if (bufsize == 0) {
6633 switch (c->type) {
6634 case CHAN_MAINSESSION:
6635 /* stdin need not receive an unthrottle
6636 * notification since it will be polled */
6637 break;
6638 case CHAN_X11:
6639 x11_unthrottle(c->u.x11.s);
6640 break;
6641 case CHAN_AGENT:
6642 /* agent sockets are request/response and need no
6643 * buffer management */
6644 break;
6645 case CHAN_SOCKDATA:
6646 pfd_unthrottle(c->u.pfd.s);
6647 break;
6648 }
6649 }
6650 }
6651 }
6652 }
6653
6654 crFinishV;
6655 }
6656
6657 /*
6658 * Handle the top-level SSH2 protocol.
6659 */
6660 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
6661 {
6662 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
6663 return;
6664 do_ssh2_authconn(ssh, in, inlen, ispkt);
6665 }
6666
6667 /*
6668 * Called to set up the connection.
6669 *
6670 * Returns an error message, or NULL on success.
6671 */
6672 static const char *ssh_init(void *frontend_handle, void **backend_handle,
6673 Config *cfg,
6674 char *host, int port, char **realhost, int nodelay,
6675 int keepalive)
6676 {
6677 const char *p;
6678 Ssh ssh;
6679
6680 ssh = snew(struct ssh_tag);
6681 ssh->cfg = *cfg; /* STRUCTURE COPY */
6682 ssh->version = 0; /* when not ready yet */
6683 ssh->s = NULL;
6684 ssh->cipher = NULL;
6685 ssh->v1_cipher_ctx = NULL;
6686 ssh->crcda_ctx = NULL;
6687 ssh->cscipher = NULL;
6688 ssh->cs_cipher_ctx = NULL;
6689 ssh->sccipher = NULL;
6690 ssh->sc_cipher_ctx = NULL;
6691 ssh->csmac = NULL;
6692 ssh->cs_mac_ctx = NULL;
6693 ssh->scmac = NULL;
6694 ssh->sc_mac_ctx = NULL;
6695 ssh->cscomp = NULL;
6696 ssh->cs_comp_ctx = NULL;
6697 ssh->sccomp = NULL;
6698 ssh->sc_comp_ctx = NULL;
6699 ssh->kex = NULL;
6700 ssh->kex_ctx = NULL;
6701 ssh->hostkey = NULL;
6702 ssh->exitcode = -1;
6703 ssh->state = SSH_STATE_PREPACKET;
6704 ssh->size_needed = FALSE;
6705 ssh->eof_needed = FALSE;
6706 ssh->ldisc = NULL;
6707 ssh->logctx = NULL;
6708 {
6709 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
6710 ssh->pktin = ssh->pktout = empty;
6711 }
6712 ssh->deferred_send_data = NULL;
6713 ssh->deferred_len = 0;
6714 ssh->deferred_size = 0;
6715 ssh->pktout_logmode = PKTLOG_EMIT;
6716 ssh->pktout_nblanks = 0;
6717 ssh->pktout_blanks = NULL;
6718 ssh->fallback_cmd = 0;
6719 ssh->pkt_ctx = 0;
6720 ssh->x11auth = NULL;
6721 ssh->v1_compressing = FALSE;
6722 ssh->v2_outgoing_sequence = 0;
6723 ssh->ssh1_rdpkt_crstate = 0;
6724 ssh->ssh2_rdpkt_crstate = 0;
6725 ssh->do_ssh_init_crstate = 0;
6726 ssh->ssh_gotdata_crstate = 0;
6727 ssh->ssh1_protocol_crstate = 0;
6728 ssh->do_ssh1_login_crstate = 0;
6729 ssh->do_ssh2_transport_crstate = 0;
6730 ssh->do_ssh2_authconn_crstate = 0;
6731 ssh->do_ssh_init_state = NULL;
6732 ssh->do_ssh1_login_state = NULL;
6733 ssh->do_ssh2_transport_state = NULL;
6734 ssh->do_ssh2_authconn_state = NULL;
6735 ssh->mainchan = NULL;
6736 ssh->throttled_all = 0;
6737 ssh->v1_stdout_throttling = 0;
6738
6739 *backend_handle = ssh;
6740
6741 #ifdef MSCRYPTOAPI
6742 if (crypto_startup() == 0)
6743 return "Microsoft high encryption pack not installed!";
6744 #endif
6745
6746 ssh->frontend = frontend_handle;
6747 ssh->term_width = ssh->cfg.width;
6748 ssh->term_height = ssh->cfg.height;
6749
6750 ssh->channels = NULL;
6751 ssh->rportfwds = NULL;
6752
6753 ssh->send_ok = 0;
6754 ssh->editing = 0;
6755 ssh->echoing = 0;
6756 ssh->v1_throttle_count = 0;
6757 ssh->overall_bufsize = 0;
6758 ssh->fallback_cmd = 0;
6759
6760 ssh->protocol = NULL;
6761
6762 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
6763 if (p != NULL)
6764 return p;
6765
6766 return NULL;
6767 }
6768
6769 static void ssh_free(void *handle)
6770 {
6771 Ssh ssh = (Ssh) handle;
6772 struct ssh_channel *c;
6773 struct ssh_rportfwd *pf;
6774
6775 if (ssh->v1_cipher_ctx)
6776 ssh->cipher->free_context(ssh->v1_cipher_ctx);
6777 if (ssh->cs_cipher_ctx)
6778 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6779 if (ssh->sc_cipher_ctx)
6780 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6781 if (ssh->cs_mac_ctx)
6782 ssh->csmac->free_context(ssh->cs_mac_ctx);
6783 if (ssh->sc_mac_ctx)
6784 ssh->scmac->free_context(ssh->sc_mac_ctx);
6785 if (ssh->cs_comp_ctx) {
6786 if (ssh->cscomp)
6787 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6788 else
6789 zlib_compress_cleanup(ssh->cs_comp_ctx);
6790 }
6791 if (ssh->sc_comp_ctx) {
6792 if (ssh->sccomp)
6793 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6794 else
6795 zlib_decompress_cleanup(ssh->sc_comp_ctx);
6796 }
6797 if (ssh->kex_ctx)
6798 dh_cleanup(ssh->kex_ctx);
6799 sfree(ssh->savedhost);
6800
6801 if (ssh->channels) {
6802 while ((c = delpos234(ssh->channels, 0)) != NULL) {
6803 switch (c->type) {
6804 case CHAN_X11:
6805 if (c->u.x11.s != NULL)
6806 x11_close(c->u.x11.s);
6807 break;
6808 case CHAN_SOCKDATA:
6809 if (c->u.pfd.s != NULL)
6810 pfd_close(c->u.pfd.s);
6811 break;
6812 }
6813 sfree(c);
6814 }
6815 freetree234(ssh->channels);
6816 }
6817
6818 if (ssh->rportfwds) {
6819 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
6820 sfree(pf);
6821 freetree234(ssh->rportfwds);
6822 }
6823 sfree(ssh->deferred_send_data);
6824 if (ssh->x11auth)
6825 x11_free_auth(ssh->x11auth);
6826 sfree(ssh->do_ssh_init_state);
6827 sfree(ssh->do_ssh1_login_state);
6828 sfree(ssh->do_ssh2_transport_state);
6829 sfree(ssh->do_ssh2_authconn_state);
6830 if (ssh->pktout.data) {
6831 sfree(ssh->pktout.data);
6832 ssh->pktout.data = NULL;
6833 }
6834 if (ssh->pktin.data) {
6835 sfree(ssh->pktin.data);
6836 ssh->pktin.data = NULL;
6837 }
6838 if (ssh->crcda_ctx) {
6839 crcda_free_context(ssh->crcda_ctx);
6840 ssh->crcda_ctx = NULL;
6841 }
6842 if (ssh->s)
6843 ssh_do_close(ssh);
6844 sfree(ssh);
6845 }
6846
6847 /*
6848 * Reconfigure the SSH backend.
6849 *
6850 * Currently, this function does nothing very useful. In future,
6851 * however, we could do some handy things with it. For example, we
6852 * could make the port forwarding configurer active in the Change
6853 * Settings box, and this routine could close down existing
6854 * forwardings and open up new ones in response to changes.
6855 */
6856 static void ssh_reconfig(void *handle, Config *cfg)
6857 {
6858 Ssh ssh = (Ssh) handle;
6859 ssh->cfg = *cfg; /* STRUCTURE COPY */
6860 }
6861
6862 /*
6863 * Called to send data down the Telnet connection.
6864 */
6865 static int ssh_send(void *handle, char *buf, int len)
6866 {
6867 Ssh ssh = (Ssh) handle;
6868
6869 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6870 return 0;
6871
6872 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
6873
6874 return ssh_sendbuffer(ssh);
6875 }
6876
6877 /*
6878 * Called to query the current amount of buffered stdin data.
6879 */
6880 static int ssh_sendbuffer(void *handle)
6881 {
6882 Ssh ssh = (Ssh) handle;
6883 int override_value;
6884
6885 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
6886 return 0;
6887
6888 /*
6889 * If the SSH socket itself has backed up, add the total backup
6890 * size on that to any individual buffer on the stdin channel.
6891 */
6892 override_value = 0;
6893 if (ssh->throttled_all)
6894 override_value = ssh->overall_bufsize;
6895
6896 if (ssh->version == 1) {
6897 return override_value;
6898 } else if (ssh->version == 2) {
6899 if (!ssh->mainchan || ssh->mainchan->closes > 0)
6900 return override_value;
6901 else
6902 return (override_value +
6903 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
6904 }
6905
6906 return 0;
6907 }
6908
6909 /*
6910 * Called to set the size of the window from SSH's POV.
6911 */
6912 static void ssh_size(void *handle, int width, int height)
6913 {
6914 Ssh ssh = (Ssh) handle;
6915
6916 ssh->term_width = width;
6917 ssh->term_height = height;
6918
6919 switch (ssh->state) {
6920 case SSH_STATE_BEFORE_SIZE:
6921 case SSH_STATE_PREPACKET:
6922 case SSH_STATE_CLOSED:
6923 break; /* do nothing */
6924 case SSH_STATE_INTERMED:
6925 ssh->size_needed = TRUE; /* buffer for later */
6926 break;
6927 case SSH_STATE_SESSION:
6928 if (!ssh->cfg.nopty) {
6929 if (ssh->version == 1) {
6930 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6931 PKT_INT, ssh->term_height,
6932 PKT_INT, ssh->term_width,
6933 PKT_INT, 0, PKT_INT, 0, PKT_END);
6934 } else if (ssh->mainchan) {
6935 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6936 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6937 ssh2_pkt_addstring(ssh, "window-change");
6938 ssh2_pkt_addbool(ssh, 0);
6939 ssh2_pkt_adduint32(ssh, ssh->term_width);
6940 ssh2_pkt_adduint32(ssh, ssh->term_height);
6941 ssh2_pkt_adduint32(ssh, 0);
6942 ssh2_pkt_adduint32(ssh, 0);
6943 ssh2_pkt_send(ssh);
6944 }
6945 }
6946 break;
6947 }
6948 }
6949
6950 /*
6951 * Return a list of the special codes that make sense in this
6952 * protocol.
6953 */
6954 static const struct telnet_special *ssh_get_specials(void *handle)
6955 {
6956 static const struct telnet_special ignore_special[] = {
6957 {"IGNORE message", TS_NOP},
6958 };
6959 static const struct telnet_special ssh2_session_specials[] = {
6960 {NULL, TS_SEP},
6961 {"Break", TS_BRK},
6962 /* These are the signal names defined by draft-ietf-secsh-connect-19.
6963 * They include all the ISO C signals, but are a subset of the POSIX
6964 * required signals. */
6965 {"SIGINT (Interrupt)", TS_SIGINT},
6966 {"SIGTERM (Terminate)", TS_SIGTERM},
6967 {"SIGKILL (Kill)", TS_SIGKILL},
6968 {"SIGQUIT (Quit)", TS_SIGQUIT},
6969 {"SIGHUP (Hangup)", TS_SIGHUP},
6970 {"More signals", TS_SUBMENU},
6971 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
6972 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
6973 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
6974 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
6975 {NULL, TS_EXITMENU}
6976 };
6977 static const struct telnet_special specials_end[] = {
6978 {NULL, TS_EXITMENU}
6979 };
6980 static struct telnet_special ssh_specials[lenof(ignore_special) +
6981 lenof(ssh2_session_specials) +
6982 lenof(specials_end)];
6983 Ssh ssh = (Ssh) handle;
6984 int i = 0;
6985 #define ADD_SPECIALS(name) \
6986 do { \
6987 assert((i + lenof(name)) <= lenof(ssh_specials)); \
6988 memcpy(&ssh_specials[i], name, sizeof name); \
6989 i += lenof(name); \
6990 } while(0)
6991
6992 if (ssh->version == 1) {
6993 /* Don't bother offering IGNORE if we've decided the remote
6994 * won't cope with it, since we wouldn't bother sending it if
6995 * asked anyway. */
6996 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6997 ADD_SPECIALS(ignore_special);
6998 } else if (ssh->version == 2) {
6999 /* XXX add rekey, when implemented */
7000 ADD_SPECIALS(ignore_special);
7001 if (ssh->mainchan)
7002 ADD_SPECIALS(ssh2_session_specials);
7003 } /* else we're not ready yet */
7004
7005 if (i) {
7006 ADD_SPECIALS(specials_end);
7007 return ssh_specials;
7008 } else {
7009 return NULL;
7010 }
7011 #undef ADD_SPECIALS
7012 }
7013
7014 /*
7015 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7016 * can send an EOF and collect resulting output (e.g. `plink
7017 * hostname sort').
7018 */
7019 static void ssh_special(void *handle, Telnet_Special code)
7020 {
7021 Ssh ssh = (Ssh) handle;
7022
7023 if (code == TS_EOF) {
7024 if (ssh->state != SSH_STATE_SESSION) {
7025 /*
7026 * Buffer the EOF in case we are pre-SESSION, so we can
7027 * send it as soon as we reach SESSION.
7028 */
7029 if (code == TS_EOF)
7030 ssh->eof_needed = TRUE;
7031 return;
7032 }
7033 if (ssh->version == 1) {
7034 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
7035 } else if (ssh->mainchan) {
7036 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
7037 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
7038 ssh2_pkt_send(ssh);
7039 }
7040 logevent("Sent EOF message");
7041 } else if (code == TS_PING || code == TS_NOP) {
7042 if (ssh->state == SSH_STATE_CLOSED
7043 || ssh->state == SSH_STATE_PREPACKET) return;
7044 if (ssh->version == 1) {
7045 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7046 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
7047 } else {
7048 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
7049 ssh2_pkt_addstring_start(ssh);
7050 ssh2_pkt_send(ssh);
7051 }
7052 } else if (code == TS_BRK) {
7053 if (ssh->state == SSH_STATE_CLOSED
7054 || ssh->state == SSH_STATE_PREPACKET) return;
7055 if (ssh->version == 1) {
7056 logevent("Unable to send BREAK signal in SSH1");
7057 } else if (ssh->mainchan) {
7058 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
7059 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
7060 ssh2_pkt_addstring(ssh, "break");
7061 ssh2_pkt_addbool(ssh, 0);
7062 ssh2_pkt_adduint32(ssh, 0); /* default break length */
7063 ssh2_pkt_send(ssh);
7064 }
7065 } else {
7066 /* Is is a POSIX signal? */
7067 char *signame = NULL;
7068 if (code == TS_SIGABRT) signame = "ABRT";
7069 if (code == TS_SIGALRM) signame = "ALRM";
7070 if (code == TS_SIGFPE) signame = "FPE";
7071 if (code == TS_SIGHUP) signame = "HUP";
7072 if (code == TS_SIGILL) signame = "ILL";
7073 if (code == TS_SIGINT) signame = "INT";
7074 if (code == TS_SIGKILL) signame = "KILL";
7075 if (code == TS_SIGPIPE) signame = "PIPE";
7076 if (code == TS_SIGQUIT) signame = "QUIT";
7077 if (code == TS_SIGSEGV) signame = "SEGV";
7078 if (code == TS_SIGTERM) signame = "TERM";
7079 if (code == TS_SIGUSR1) signame = "USR1";
7080 if (code == TS_SIGUSR2) signame = "USR2";
7081 /* The SSH-2 protocol does in principle support arbitrary named
7082 * signals, including signame@domain, but we don't support those. */
7083 if (signame) {
7084 /* It's a signal. */
7085 if (ssh->version == 2 && ssh->mainchan) {
7086 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
7087 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
7088 ssh2_pkt_addstring(ssh, "signal");
7089 ssh2_pkt_addbool(ssh, 0);
7090 ssh2_pkt_addstring(ssh, signame);
7091 ssh2_pkt_send(ssh);
7092 logeventf(ssh, "Sent signal SIG%s", signame);
7093 }
7094 } else {
7095 /* Never heard of it. Do nothing */
7096 }
7097 }
7098 }
7099
7100 void *new_sock_channel(void *handle, Socket s)
7101 {
7102 Ssh ssh = (Ssh) handle;
7103 struct ssh_channel *c;
7104 c = snew(struct ssh_channel);
7105 c->ssh = ssh;
7106
7107 if (c) {
7108 c->remoteid = -1; /* to be set when open confirmed */
7109 c->localid = alloc_channel_id(ssh);
7110 c->closes = 0;
7111 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
7112 c->u.pfd.s = s;
7113 bufchain_init(&c->v.v2.outbuffer);
7114 add234(ssh->channels, c);
7115 }
7116 return c;
7117 }
7118
7119 /*
7120 * This is called when stdout/stderr (the entity to which
7121 * from_backend sends data) manages to clear some backlog.
7122 */
7123 static void ssh_unthrottle(void *handle, int bufsize)
7124 {
7125 Ssh ssh = (Ssh) handle;
7126 if (ssh->version == 1) {
7127 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7128 ssh->v1_stdout_throttling = 0;
7129 ssh1_throttle(ssh, -1);
7130 }
7131 } else {
7132 if (ssh->mainchan && ssh->mainchan->closes == 0)
7133 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
7134 }
7135 }
7136
7137 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
7138 {
7139 struct ssh_channel *c = (struct ssh_channel *)channel;
7140 Ssh ssh = c->ssh;
7141
7142 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
7143
7144 if (ssh->version == 1) {
7145 send_packet(ssh, SSH1_MSG_PORT_OPEN,
7146 PKT_INT, c->localid,
7147 PKT_STR, hostname,
7148 PKT_INT, port,
7149 //PKT_STR, <org:orgport>,
7150 PKT_END);
7151 } else {
7152 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
7153 ssh2_pkt_addstring(ssh, "direct-tcpip");
7154 ssh2_pkt_adduint32(ssh, c->localid);
7155 c->v.v2.locwindow = OUR_V2_WINSIZE;
7156 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
7157 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
7158 ssh2_pkt_addstring(ssh, hostname);
7159 ssh2_pkt_adduint32(ssh, port);
7160 /*
7161 * We make up values for the originator data; partly it's
7162 * too much hassle to keep track, and partly I'm not
7163 * convinced the server should be told details like that
7164 * about my local network configuration.
7165 */
7166 ssh2_pkt_addstring(ssh, "client-side-connection");
7167 ssh2_pkt_adduint32(ssh, 0);
7168 ssh2_pkt_send(ssh);
7169 }
7170 }
7171
7172
7173 static Socket ssh_socket(void *handle)
7174 {
7175 Ssh ssh = (Ssh) handle;
7176 return ssh->s;
7177 }
7178
7179 static int ssh_sendok(void *handle)
7180 {
7181 Ssh ssh = (Ssh) handle;
7182 return ssh->send_ok;
7183 }
7184
7185 static int ssh_ldisc(void *handle, int option)
7186 {
7187 Ssh ssh = (Ssh) handle;
7188 if (option == LD_ECHO)
7189 return ssh->echoing;
7190 if (option == LD_EDIT)
7191 return ssh->editing;
7192 return FALSE;
7193 }
7194
7195 static void ssh_provide_ldisc(void *handle, void *ldisc)
7196 {
7197 Ssh ssh = (Ssh) handle;
7198 ssh->ldisc = ldisc;
7199 }
7200
7201 static void ssh_provide_logctx(void *handle, void *logctx)
7202 {
7203 Ssh ssh = (Ssh) handle;
7204 ssh->logctx = logctx;
7205 }
7206
7207 static int ssh_return_exitcode(void *handle)
7208 {
7209 Ssh ssh = (Ssh) handle;
7210 if (ssh->s != NULL)
7211 return -1;
7212 else
7213 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
7214 }
7215
7216 /*
7217 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7218 * that fails. This variable is the means by which scp.c can reach
7219 * into the SSH code and find out which one it got.
7220 */
7221 extern int ssh_fallback_cmd(void *handle)
7222 {
7223 Ssh ssh = (Ssh) handle;
7224 return ssh->fallback_cmd;
7225 }
7226
7227 Backend ssh_backend = {
7228 ssh_init,
7229 ssh_free,
7230 ssh_reconfig,
7231 ssh_send,
7232 ssh_sendbuffer,
7233 ssh_size,
7234 ssh_special,
7235 ssh_get_specials,
7236 ssh_socket,
7237 ssh_return_exitcode,
7238 ssh_sendok,
7239 ssh_ldisc,
7240 ssh_provide_ldisc,
7241 ssh_provide_logctx,
7242 ssh_unthrottle,
7243 22
7244 };
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator