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1 | /* | |
2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
5 | * The authentication agent program. | |
6 | * | |
7 | * As far as I am concerned, the code I have written for this software | |
8 | * can be used freely for any purpose. Any derived versions of this | |
9 | * software must be clearly marked as such, and if the derived work is | |
10 | * incompatible with the protocol description in the RFC file, it must be | |
11 | * called by a name other than "ssh" or "Secure Shell". | |
12 | * | |
13 | * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. | |
14 | * | |
15 | * Redistribution and use in source and binary forms, with or without | |
16 | * modification, are permitted provided that the following conditions | |
17 | * are met: | |
18 | * 1. Redistributions of source code must retain the above copyright | |
19 | * notice, this list of conditions and the following disclaimer. | |
20 | * 2. Redistributions in binary form must reproduce the above copyright | |
21 | * notice, this list of conditions and the following disclaimer in the | |
22 | * documentation and/or other materials provided with the distribution. | |
23 | * | |
24 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
25 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
26 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
27 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
28 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
29 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
30 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
31 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
32 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
33 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
34 | */ | |
35 | ||
36 | #include "includes.h" | |
37 | #include "openbsd-compat/fake-queue.h" | |
38 | RCSID("$OpenBSD: ssh-agent.c,v 1.87 2002/06/05 16:48:54 markus Exp $"); | |
39 | ||
40 | #include <openssl/evp.h> | |
41 | #include <openssl/md5.h> | |
42 | ||
43 | #include "ssh.h" | |
44 | #include "rsa.h" | |
45 | #include "buffer.h" | |
46 | #include "bufaux.h" | |
47 | #include "xmalloc.h" | |
48 | #include "getput.h" | |
49 | #include "key.h" | |
50 | #include "authfd.h" | |
51 | #include "compat.h" | |
52 | #include "log.h" | |
53 | ||
54 | #ifdef SMARTCARD | |
55 | #include "scard.h" | |
56 | #endif | |
57 | ||
58 | typedef enum { | |
59 | AUTH_UNUSED, | |
60 | AUTH_SOCKET, | |
61 | AUTH_CONNECTION | |
62 | } sock_type; | |
63 | ||
64 | typedef struct { | |
65 | int fd; | |
66 | sock_type type; | |
67 | Buffer input; | |
68 | Buffer output; | |
69 | Buffer request; | |
70 | } SocketEntry; | |
71 | ||
72 | u_int sockets_alloc = 0; | |
73 | SocketEntry *sockets = NULL; | |
74 | ||
75 | typedef struct identity { | |
76 | TAILQ_ENTRY(identity) next; | |
77 | Key *key; | |
78 | char *comment; | |
79 | } Identity; | |
80 | ||
81 | typedef struct { | |
82 | int nentries; | |
83 | TAILQ_HEAD(idqueue, identity) idlist; | |
84 | } Idtab; | |
85 | ||
86 | /* private key table, one per protocol version */ | |
87 | Idtab idtable[3]; | |
88 | ||
89 | int max_fd = 0; | |
90 | ||
91 | /* pid of shell == parent of agent */ | |
92 | pid_t parent_pid = -1; | |
93 | ||
94 | /* pathname and directory for AUTH_SOCKET */ | |
95 | char socket_name[1024]; | |
96 | char socket_dir[1024]; | |
97 | ||
98 | #ifdef HAVE___PROGNAME | |
99 | extern char *__progname; | |
100 | #else | |
101 | char *__progname; | |
102 | #endif | |
103 | ||
104 | static void | |
105 | idtab_init(void) | |
106 | { | |
107 | int i; | |
108 | for (i = 0; i <=2; i++) { | |
109 | TAILQ_INIT(&idtable[i].idlist); | |
110 | idtable[i].nentries = 0; | |
111 | } | |
112 | } | |
113 | ||
114 | /* return private key table for requested protocol version */ | |
115 | static Idtab * | |
116 | idtab_lookup(int version) | |
117 | { | |
118 | if (version < 1 || version > 2) | |
119 | fatal("internal error, bad protocol version %d", version); | |
120 | return &idtable[version]; | |
121 | } | |
122 | ||
123 | /* return matching private key for given public key */ | |
124 | static Identity * | |
125 | lookup_identity(Key *key, int version) | |
126 | { | |
127 | Identity *id; | |
128 | ||
129 | Idtab *tab = idtab_lookup(version); | |
130 | TAILQ_FOREACH(id, &tab->idlist, next) { | |
131 | if (key_equal(key, id->key)) | |
132 | return (id); | |
133 | } | |
134 | return (NULL); | |
135 | } | |
136 | ||
137 | static void | |
138 | free_identity(Identity *id) | |
139 | { | |
140 | key_free(id->key); | |
141 | xfree(id->comment); | |
142 | xfree(id); | |
143 | } | |
144 | ||
145 | /* send list of supported public keys to 'client' */ | |
146 | static void | |
147 | process_request_identities(SocketEntry *e, int version) | |
148 | { | |
149 | Idtab *tab = idtab_lookup(version); | |
150 | Buffer msg; | |
151 | Identity *id; | |
152 | ||
153 | buffer_init(&msg); | |
154 | buffer_put_char(&msg, (version == 1) ? | |
155 | SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER); | |
156 | buffer_put_int(&msg, tab->nentries); | |
157 | TAILQ_FOREACH(id, &tab->idlist, next) { | |
158 | if (id->key->type == KEY_RSA1) { | |
159 | buffer_put_int(&msg, BN_num_bits(id->key->rsa->n)); | |
160 | buffer_put_bignum(&msg, id->key->rsa->e); | |
161 | buffer_put_bignum(&msg, id->key->rsa->n); | |
162 | } else { | |
163 | u_char *blob; | |
164 | u_int blen; | |
165 | key_to_blob(id->key, &blob, &blen); | |
166 | buffer_put_string(&msg, blob, blen); | |
167 | xfree(blob); | |
168 | } | |
169 | buffer_put_cstring(&msg, id->comment); | |
170 | } | |
171 | buffer_put_int(&e->output, buffer_len(&msg)); | |
172 | buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg)); | |
173 | buffer_free(&msg); | |
174 | } | |
175 | ||
176 | /* ssh1 only */ | |
177 | static void | |
178 | process_authentication_challenge1(SocketEntry *e) | |
179 | { | |
180 | Identity *id; | |
181 | Key *key; | |
182 | BIGNUM *challenge; | |
183 | int i, len; | |
184 | Buffer msg; | |
185 | MD5_CTX md; | |
186 | u_char buf[32], mdbuf[16], session_id[16]; | |
187 | u_int response_type; | |
188 | ||
189 | buffer_init(&msg); | |
190 | key = key_new(KEY_RSA1); | |
191 | if ((challenge = BN_new()) == NULL) | |
192 | fatal("process_authentication_challenge1: BN_new failed"); | |
193 | ||
194 | buffer_get_int(&e->request); /* ignored */ | |
195 | buffer_get_bignum(&e->request, key->rsa->e); | |
196 | buffer_get_bignum(&e->request, key->rsa->n); | |
197 | buffer_get_bignum(&e->request, challenge); | |
198 | ||
199 | /* Only protocol 1.1 is supported */ | |
200 | if (buffer_len(&e->request) == 0) | |
201 | goto failure; | |
202 | buffer_get(&e->request, session_id, 16); | |
203 | response_type = buffer_get_int(&e->request); | |
204 | if (response_type != 1) | |
205 | goto failure; | |
206 | ||
207 | id = lookup_identity(key, 1); | |
208 | if (id != NULL) { | |
209 | Key *private = id->key; | |
210 | /* Decrypt the challenge using the private key. */ | |
211 | if (rsa_private_decrypt(challenge, challenge, private->rsa) <= 0) | |
212 | goto failure; | |
213 | ||
214 | /* The response is MD5 of decrypted challenge plus session id. */ | |
215 | len = BN_num_bytes(challenge); | |
216 | if (len <= 0 || len > 32) { | |
217 | log("process_authentication_challenge: bad challenge length %d", len); | |
218 | goto failure; | |
219 | } | |
220 | memset(buf, 0, 32); | |
221 | BN_bn2bin(challenge, buf + 32 - len); | |
222 | MD5_Init(&md); | |
223 | MD5_Update(&md, buf, 32); | |
224 | MD5_Update(&md, session_id, 16); | |
225 | MD5_Final(mdbuf, &md); | |
226 | ||
227 | /* Send the response. */ | |
228 | buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE); | |
229 | for (i = 0; i < 16; i++) | |
230 | buffer_put_char(&msg, mdbuf[i]); | |
231 | goto send; | |
232 | } | |
233 | ||
234 | failure: | |
235 | /* Unknown identity or protocol error. Send failure. */ | |
236 | buffer_put_char(&msg, SSH_AGENT_FAILURE); | |
237 | send: | |
238 | buffer_put_int(&e->output, buffer_len(&msg)); | |
239 | buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg)); | |
240 | key_free(key); | |
241 | BN_clear_free(challenge); | |
242 | buffer_free(&msg); | |
243 | } | |
244 | ||
245 | /* ssh2 only */ | |
246 | static void | |
247 | process_sign_request2(SocketEntry *e) | |
248 | { | |
249 | extern int datafellows; | |
250 | Key *key; | |
251 | u_char *blob, *data, *signature = NULL; | |
252 | u_int blen, dlen, slen = 0; | |
253 | int flags; | |
254 | Buffer msg; | |
255 | int ok = -1; | |
256 | ||
257 | datafellows = 0; | |
258 | ||
259 | blob = buffer_get_string(&e->request, &blen); | |
260 | data = buffer_get_string(&e->request, &dlen); | |
261 | ||
262 | flags = buffer_get_int(&e->request); | |
263 | if (flags & SSH_AGENT_OLD_SIGNATURE) | |
264 | datafellows = SSH_BUG_SIGBLOB; | |
265 | ||
266 | key = key_from_blob(blob, blen); | |
267 | if (key != NULL) { | |
268 | Identity *id = lookup_identity(key, 2); | |
269 | if (id != NULL) | |
270 | ok = key_sign(id->key, &signature, &slen, data, dlen); | |
271 | } | |
272 | key_free(key); | |
273 | buffer_init(&msg); | |
274 | if (ok == 0) { | |
275 | buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE); | |
276 | buffer_put_string(&msg, signature, slen); | |
277 | } else { | |
278 | buffer_put_char(&msg, SSH_AGENT_FAILURE); | |
279 | } | |
280 | buffer_put_int(&e->output, buffer_len(&msg)); | |
281 | buffer_append(&e->output, buffer_ptr(&msg), | |
282 | buffer_len(&msg)); | |
283 | buffer_free(&msg); | |
284 | xfree(data); | |
285 | xfree(blob); | |
286 | if (signature != NULL) | |
287 | xfree(signature); | |
288 | } | |
289 | ||
290 | /* shared */ | |
291 | static void | |
292 | process_remove_identity(SocketEntry *e, int version) | |
293 | { | |
294 | Key *key = NULL; | |
295 | u_char *blob; | |
296 | u_int blen; | |
297 | u_int bits; | |
298 | int success = 0; | |
299 | ||
300 | switch (version) { | |
301 | case 1: | |
302 | key = key_new(KEY_RSA1); | |
303 | bits = buffer_get_int(&e->request); | |
304 | buffer_get_bignum(&e->request, key->rsa->e); | |
305 | buffer_get_bignum(&e->request, key->rsa->n); | |
306 | ||
307 | if (bits != key_size(key)) | |
308 | log("Warning: identity keysize mismatch: actual %d, announced %d", | |
309 | key_size(key), bits); | |
310 | break; | |
311 | case 2: | |
312 | blob = buffer_get_string(&e->request, &blen); | |
313 | key = key_from_blob(blob, blen); | |
314 | xfree(blob); | |
315 | break; | |
316 | } | |
317 | if (key != NULL) { | |
318 | Identity *id = lookup_identity(key, version); | |
319 | if (id != NULL) { | |
320 | /* | |
321 | * We have this key. Free the old key. Since we | |
322 | * don\'t want to leave empty slots in the middle of | |
323 | * the array, we actually free the key there and move | |
324 | * all the entries between the empty slot and the end | |
325 | * of the array. | |
326 | */ | |
327 | Idtab *tab = idtab_lookup(version); | |
328 | if (tab->nentries < 1) | |
329 | fatal("process_remove_identity: " | |
330 | "internal error: tab->nentries %d", | |
331 | tab->nentries); | |
332 | TAILQ_REMOVE(&tab->idlist, id, next); | |
333 | free_identity(id); | |
334 | tab->nentries--; | |
335 | success = 1; | |
336 | } | |
337 | key_free(key); | |
338 | } | |
339 | buffer_put_int(&e->output, 1); | |
340 | buffer_put_char(&e->output, | |
341 | success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE); | |
342 | } | |
343 | ||
344 | static void | |
345 | process_remove_all_identities(SocketEntry *e, int version) | |
346 | { | |
347 | Idtab *tab = idtab_lookup(version); | |
348 | Identity *id; | |
349 | ||
350 | /* Loop over all identities and clear the keys. */ | |
351 | for (id = TAILQ_FIRST(&tab->idlist); id; | |
352 | id = TAILQ_FIRST(&tab->idlist)) { | |
353 | TAILQ_REMOVE(&tab->idlist, id, next); | |
354 | free_identity(id); | |
355 | } | |
356 | ||
357 | /* Mark that there are no identities. */ | |
358 | tab->nentries = 0; | |
359 | ||
360 | /* Send success. */ | |
361 | buffer_put_int(&e->output, 1); | |
362 | buffer_put_char(&e->output, SSH_AGENT_SUCCESS); | |
363 | return; | |
364 | } | |
365 | ||
366 | static void | |
367 | process_add_identity(SocketEntry *e, int version) | |
368 | { | |
369 | Key *k = NULL; | |
370 | char *type_name; | |
371 | char *comment; | |
372 | int type, success = 0; | |
373 | Idtab *tab = idtab_lookup(version); | |
374 | ||
375 | switch (version) { | |
376 | case 1: | |
377 | k = key_new_private(KEY_RSA1); | |
378 | buffer_get_int(&e->request); /* ignored */ | |
379 | buffer_get_bignum(&e->request, k->rsa->n); | |
380 | buffer_get_bignum(&e->request, k->rsa->e); | |
381 | buffer_get_bignum(&e->request, k->rsa->d); | |
382 | buffer_get_bignum(&e->request, k->rsa->iqmp); | |
383 | ||
384 | /* SSH and SSL have p and q swapped */ | |
385 | buffer_get_bignum(&e->request, k->rsa->q); /* p */ | |
386 | buffer_get_bignum(&e->request, k->rsa->p); /* q */ | |
387 | ||
388 | /* Generate additional parameters */ | |
389 | rsa_generate_additional_parameters(k->rsa); | |
390 | break; | |
391 | case 2: | |
392 | type_name = buffer_get_string(&e->request, NULL); | |
393 | type = key_type_from_name(type_name); | |
394 | xfree(type_name); | |
395 | switch (type) { | |
396 | case KEY_DSA: | |
397 | k = key_new_private(type); | |
398 | buffer_get_bignum2(&e->request, k->dsa->p); | |
399 | buffer_get_bignum2(&e->request, k->dsa->q); | |
400 | buffer_get_bignum2(&e->request, k->dsa->g); | |
401 | buffer_get_bignum2(&e->request, k->dsa->pub_key); | |
402 | buffer_get_bignum2(&e->request, k->dsa->priv_key); | |
403 | break; | |
404 | case KEY_RSA: | |
405 | k = key_new_private(type); | |
406 | buffer_get_bignum2(&e->request, k->rsa->n); | |
407 | buffer_get_bignum2(&e->request, k->rsa->e); | |
408 | buffer_get_bignum2(&e->request, k->rsa->d); | |
409 | buffer_get_bignum2(&e->request, k->rsa->iqmp); | |
410 | buffer_get_bignum2(&e->request, k->rsa->p); | |
411 | buffer_get_bignum2(&e->request, k->rsa->q); | |
412 | ||
413 | /* Generate additional parameters */ | |
414 | rsa_generate_additional_parameters(k->rsa); | |
415 | break; | |
416 | default: | |
417 | buffer_clear(&e->request); | |
418 | goto send; | |
419 | } | |
420 | break; | |
421 | } | |
422 | comment = buffer_get_string(&e->request, NULL); | |
423 | if (k == NULL) { | |
424 | xfree(comment); | |
425 | goto send; | |
426 | } | |
427 | success = 1; | |
428 | if (lookup_identity(k, version) == NULL) { | |
429 | Identity *id = xmalloc(sizeof(Identity)); | |
430 | id->key = k; | |
431 | id->comment = comment; | |
432 | TAILQ_INSERT_TAIL(&tab->idlist, id, next); | |
433 | /* Increment the number of identities. */ | |
434 | tab->nentries++; | |
435 | } else { | |
436 | key_free(k); | |
437 | xfree(comment); | |
438 | } | |
439 | send: | |
440 | buffer_put_int(&e->output, 1); | |
441 | buffer_put_char(&e->output, | |
442 | success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE); | |
443 | } | |
444 | ||
445 | ||
446 | #ifdef SMARTCARD | |
447 | static void | |
448 | process_add_smartcard_key (SocketEntry *e) | |
449 | { | |
450 | Identity *id; | |
451 | Idtab *tab; | |
452 | Key **keys, *k; | |
453 | char *sc_reader_id = NULL, *pin; | |
454 | int i, version, success = 0; | |
455 | ||
456 | sc_reader_id = buffer_get_string(&e->request, NULL); | |
457 | pin = buffer_get_string(&e->request, NULL); | |
458 | keys = sc_get_keys(sc_reader_id, pin); | |
459 | xfree(sc_reader_id); | |
460 | xfree(pin); | |
461 | ||
462 | if (keys == NULL || keys[0] == NULL) { | |
463 | error("sc_get_keys failed"); | |
464 | goto send; | |
465 | } | |
466 | for (i = 0; keys[i] != NULL; i++) { | |
467 | k = keys[i]; | |
468 | version = k->type == KEY_RSA1 ? 1 : 2; | |
469 | tab = idtab_lookup(version); | |
470 | if (lookup_identity(k, version) == NULL) { | |
471 | id = xmalloc(sizeof(Identity)); | |
472 | id->key = k; | |
473 | id->comment = xstrdup("smartcard key"); | |
474 | TAILQ_INSERT_TAIL(&tab->idlist, id, next); | |
475 | tab->nentries++; | |
476 | success = 1; | |
477 | } else { | |
478 | key_free(k); | |
479 | } | |
480 | keys[i] = NULL; | |
481 | } | |
482 | xfree(keys); | |
483 | send: | |
484 | buffer_put_int(&e->output, 1); | |
485 | buffer_put_char(&e->output, | |
486 | success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE); | |
487 | } | |
488 | ||
489 | static void | |
490 | process_remove_smartcard_key(SocketEntry *e) | |
491 | { | |
492 | Identity *id; | |
493 | Idtab *tab; | |
494 | Key **keys, *k = NULL; | |
495 | char *sc_reader_id = NULL, *pin; | |
496 | int i, version, success = 0; | |
497 | ||
498 | sc_reader_id = buffer_get_string(&e->request, NULL); | |
499 | pin = buffer_get_string(&e->request, NULL); | |
500 | keys = sc_get_keys(sc_reader_id, pin); | |
501 | xfree(sc_reader_id); | |
502 | xfree(pin); | |
503 | ||
504 | if (keys == NULL || keys[0] == NULL) { | |
505 | error("sc_get_keys failed"); | |
506 | goto send; | |
507 | } | |
508 | for (i = 0; keys[i] != NULL; i++) { | |
509 | k = keys[i]; | |
510 | version = k->type == KEY_RSA1 ? 1 : 2; | |
511 | if ((id = lookup_identity(k, version)) != NULL) { | |
512 | tab = idtab_lookup(version); | |
513 | TAILQ_REMOVE(&tab->idlist, id, next); | |
514 | tab->nentries--; | |
515 | free_identity(id); | |
516 | success = 1; | |
517 | } | |
518 | key_free(k); | |
519 | keys[i] = NULL; | |
520 | } | |
521 | xfree(keys); | |
522 | send: | |
523 | buffer_put_int(&e->output, 1); | |
524 | buffer_put_char(&e->output, | |
525 | success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE); | |
526 | } | |
527 | #endif /* SMARTCARD */ | |
528 | ||
529 | /* dispatch incoming messages */ | |
530 | ||
531 | static void | |
532 | process_message(SocketEntry *e) | |
533 | { | |
534 | u_int msg_len; | |
535 | u_int type; | |
536 | u_char *cp; | |
537 | if (buffer_len(&e->input) < 5) | |
538 | return; /* Incomplete message. */ | |
539 | cp = buffer_ptr(&e->input); | |
540 | msg_len = GET_32BIT(cp); | |
541 | if (msg_len > 256 * 1024) { | |
542 | shutdown(e->fd, SHUT_RDWR); | |
543 | close(e->fd); | |
544 | e->type = AUTH_UNUSED; | |
545 | buffer_free(&e->input); | |
546 | buffer_free(&e->output); | |
547 | buffer_free(&e->request); | |
548 | return; | |
549 | } | |
550 | if (buffer_len(&e->input) < msg_len + 4) | |
551 | return; | |
552 | ||
553 | /* move the current input to e->request */ | |
554 | buffer_consume(&e->input, 4); | |
555 | buffer_clear(&e->request); | |
556 | buffer_append(&e->request, buffer_ptr(&e->input), msg_len); | |
557 | buffer_consume(&e->input, msg_len); | |
558 | type = buffer_get_char(&e->request); | |
559 | ||
560 | debug("type %d", type); | |
561 | switch (type) { | |
562 | /* ssh1 */ | |
563 | case SSH_AGENTC_RSA_CHALLENGE: | |
564 | process_authentication_challenge1(e); | |
565 | break; | |
566 | case SSH_AGENTC_REQUEST_RSA_IDENTITIES: | |
567 | process_request_identities(e, 1); | |
568 | break; | |
569 | case SSH_AGENTC_ADD_RSA_IDENTITY: | |
570 | process_add_identity(e, 1); | |
571 | break; | |
572 | case SSH_AGENTC_REMOVE_RSA_IDENTITY: | |
573 | process_remove_identity(e, 1); | |
574 | break; | |
575 | case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES: | |
576 | process_remove_all_identities(e, 1); | |
577 | break; | |
578 | /* ssh2 */ | |
579 | case SSH2_AGENTC_SIGN_REQUEST: | |
580 | process_sign_request2(e); | |
581 | break; | |
582 | case SSH2_AGENTC_REQUEST_IDENTITIES: | |
583 | process_request_identities(e, 2); | |
584 | break; | |
585 | case SSH2_AGENTC_ADD_IDENTITY: | |
586 | process_add_identity(e, 2); | |
587 | break; | |
588 | case SSH2_AGENTC_REMOVE_IDENTITY: | |
589 | process_remove_identity(e, 2); | |
590 | break; | |
591 | case SSH2_AGENTC_REMOVE_ALL_IDENTITIES: | |
592 | process_remove_all_identities(e, 2); | |
593 | break; | |
594 | #ifdef SMARTCARD | |
595 | case SSH_AGENTC_ADD_SMARTCARD_KEY: | |
596 | process_add_smartcard_key(e); | |
597 | break; | |
598 | case SSH_AGENTC_REMOVE_SMARTCARD_KEY: | |
599 | process_remove_smartcard_key(e); | |
600 | break; | |
601 | #endif /* SMARTCARD */ | |
602 | default: | |
603 | /* Unknown message. Respond with failure. */ | |
604 | error("Unknown message %d", type); | |
605 | buffer_clear(&e->request); | |
606 | buffer_put_int(&e->output, 1); | |
607 | buffer_put_char(&e->output, SSH_AGENT_FAILURE); | |
608 | break; | |
609 | } | |
610 | } | |
611 | ||
612 | static void | |
613 | new_socket(sock_type type, int fd) | |
614 | { | |
615 | u_int i, old_alloc; | |
616 | if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) | |
617 | error("fcntl O_NONBLOCK: %s", strerror(errno)); | |
618 | ||
619 | if (fd > max_fd) | |
620 | max_fd = fd; | |
621 | ||
622 | for (i = 0; i < sockets_alloc; i++) | |
623 | if (sockets[i].type == AUTH_UNUSED) { | |
624 | sockets[i].fd = fd; | |
625 | sockets[i].type = type; | |
626 | buffer_init(&sockets[i].input); | |
627 | buffer_init(&sockets[i].output); | |
628 | buffer_init(&sockets[i].request); | |
629 | return; | |
630 | } | |
631 | old_alloc = sockets_alloc; | |
632 | sockets_alloc += 10; | |
633 | if (sockets) | |
634 | sockets = xrealloc(sockets, sockets_alloc * sizeof(sockets[0])); | |
635 | else | |
636 | sockets = xmalloc(sockets_alloc * sizeof(sockets[0])); | |
637 | for (i = old_alloc; i < sockets_alloc; i++) | |
638 | sockets[i].type = AUTH_UNUSED; | |
639 | sockets[old_alloc].type = type; | |
640 | sockets[old_alloc].fd = fd; | |
641 | buffer_init(&sockets[old_alloc].input); | |
642 | buffer_init(&sockets[old_alloc].output); | |
643 | buffer_init(&sockets[old_alloc].request); | |
644 | } | |
645 | ||
646 | static int | |
647 | prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, int *nallocp) | |
648 | { | |
649 | u_int i, sz; | |
650 | int n = 0; | |
651 | ||
652 | for (i = 0; i < sockets_alloc; i++) { | |
653 | switch (sockets[i].type) { | |
654 | case AUTH_SOCKET: | |
655 | case AUTH_CONNECTION: | |
656 | n = MAX(n, sockets[i].fd); | |
657 | break; | |
658 | case AUTH_UNUSED: | |
659 | break; | |
660 | default: | |
661 | fatal("Unknown socket type %d", sockets[i].type); | |
662 | break; | |
663 | } | |
664 | } | |
665 | ||
666 | sz = howmany(n+1, NFDBITS) * sizeof(fd_mask); | |
667 | if (*fdrp == NULL || sz > *nallocp) { | |
668 | if (*fdrp) | |
669 | xfree(*fdrp); | |
670 | if (*fdwp) | |
671 | xfree(*fdwp); | |
672 | *fdrp = xmalloc(sz); | |
673 | *fdwp = xmalloc(sz); | |
674 | *nallocp = sz; | |
675 | } | |
676 | if (n < *fdl) | |
677 | debug("XXX shrink: %d < %d", n, *fdl); | |
678 | *fdl = n; | |
679 | memset(*fdrp, 0, sz); | |
680 | memset(*fdwp, 0, sz); | |
681 | ||
682 | for (i = 0; i < sockets_alloc; i++) { | |
683 | switch (sockets[i].type) { | |
684 | case AUTH_SOCKET: | |
685 | case AUTH_CONNECTION: | |
686 | FD_SET(sockets[i].fd, *fdrp); | |
687 | if (buffer_len(&sockets[i].output) > 0) | |
688 | FD_SET(sockets[i].fd, *fdwp); | |
689 | break; | |
690 | default: | |
691 | break; | |
692 | } | |
693 | } | |
694 | return (1); | |
695 | } | |
696 | ||
697 | static void | |
698 | after_select(fd_set *readset, fd_set *writeset) | |
699 | { | |
700 | u_int i; | |
701 | int len, sock; | |
702 | socklen_t slen; | |
703 | char buf[1024]; | |
704 | struct sockaddr_un sunaddr; | |
705 | ||
706 | for (i = 0; i < sockets_alloc; i++) | |
707 | switch (sockets[i].type) { | |
708 | case AUTH_UNUSED: | |
709 | break; | |
710 | case AUTH_SOCKET: | |
711 | if (FD_ISSET(sockets[i].fd, readset)) { | |
712 | slen = sizeof(sunaddr); | |
713 | sock = accept(sockets[i].fd, | |
714 | (struct sockaddr *) &sunaddr, &slen); | |
715 | if (sock < 0) { | |
716 | error("accept from AUTH_SOCKET: %s", | |
717 | strerror(errno)); | |
718 | break; | |
719 | } | |
720 | new_socket(AUTH_CONNECTION, sock); | |
721 | } | |
722 | break; | |
723 | case AUTH_CONNECTION: | |
724 | if (buffer_len(&sockets[i].output) > 0 && | |
725 | FD_ISSET(sockets[i].fd, writeset)) { | |
726 | do { | |
727 | len = write(sockets[i].fd, | |
728 | buffer_ptr(&sockets[i].output), | |
729 | buffer_len(&sockets[i].output)); | |
730 | if (len == -1 && (errno == EAGAIN || | |
731 | errno == EINTR)) | |
732 | continue; | |
733 | break; | |
734 | } while (1); | |
735 | if (len <= 0) { | |
736 | shutdown(sockets[i].fd, SHUT_RDWR); | |
737 | close(sockets[i].fd); | |
738 | sockets[i].type = AUTH_UNUSED; | |
739 | buffer_free(&sockets[i].input); | |
740 | buffer_free(&sockets[i].output); | |
741 | buffer_free(&sockets[i].request); | |
742 | break; | |
743 | } | |
744 | buffer_consume(&sockets[i].output, len); | |
745 | } | |
746 | if (FD_ISSET(sockets[i].fd, readset)) { | |
747 | do { | |
748 | len = read(sockets[i].fd, buf, sizeof(buf)); | |
749 | if (len == -1 && (errno == EAGAIN || | |
750 | errno == EINTR)) | |
751 | continue; | |
752 | break; | |
753 | } while (1); | |
754 | if (len <= 0) { | |
755 | shutdown(sockets[i].fd, SHUT_RDWR); | |
756 | close(sockets[i].fd); | |
757 | sockets[i].type = AUTH_UNUSED; | |
758 | buffer_free(&sockets[i].input); | |
759 | buffer_free(&sockets[i].output); | |
760 | buffer_free(&sockets[i].request); | |
761 | break; | |
762 | } | |
763 | buffer_append(&sockets[i].input, buf, len); | |
764 | process_message(&sockets[i]); | |
765 | } | |
766 | break; | |
767 | default: | |
768 | fatal("Unknown type %d", sockets[i].type); | |
769 | } | |
770 | } | |
771 | ||
772 | static void | |
773 | cleanup_socket(void *p) | |
774 | { | |
775 | if (socket_name[0]) | |
776 | unlink(socket_name); | |
777 | if (socket_dir[0]) | |
778 | rmdir(socket_dir); | |
779 | } | |
780 | ||
781 | static void | |
782 | cleanup_exit(int i) | |
783 | { | |
784 | cleanup_socket(NULL); | |
785 | exit(i); | |
786 | } | |
787 | ||
788 | static void | |
789 | cleanup_handler(int sig) | |
790 | { | |
791 | cleanup_socket(NULL); | |
792 | _exit(2); | |
793 | } | |
794 | ||
795 | static void | |
796 | check_parent_exists(int sig) | |
797 | { | |
798 | int save_errno = errno; | |
799 | ||
800 | if (parent_pid != -1 && kill(parent_pid, 0) < 0) { | |
801 | /* printf("Parent has died - Authentication agent exiting.\n"); */ | |
802 | cleanup_handler(sig); /* safe */ | |
803 | } | |
804 | signal(SIGALRM, check_parent_exists); | |
805 | alarm(10); | |
806 | errno = save_errno; | |
807 | } | |
808 | ||
809 | static void | |
810 | usage(void) | |
811 | { | |
812 | fprintf(stderr, "Usage: %s [options] [command [args ...]]\n", | |
813 | __progname); | |
814 | fprintf(stderr, "Options:\n"); | |
815 | fprintf(stderr, " -c Generate C-shell commands on stdout.\n"); | |
816 | fprintf(stderr, " -s Generate Bourne shell commands on stdout.\n"); | |
817 | fprintf(stderr, " -k Kill the current agent.\n"); | |
818 | fprintf(stderr, " -d Debug mode.\n"); | |
819 | fprintf(stderr, " -a socket Bind agent socket to given name.\n"); | |
820 | exit(1); | |
821 | } | |
822 | ||
823 | int | |
824 | main(int ac, char **av) | |
825 | { | |
826 | int sock, c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0, ch, nalloc; | |
827 | struct sockaddr_un sunaddr; | |
828 | #ifdef HAVE_SETRLIMIT | |
829 | struct rlimit rlim; | |
830 | #endif | |
831 | #ifdef HAVE_CYGWIN | |
832 | int prev_mask; | |
833 | #endif | |
834 | pid_t pid; | |
835 | char *shell, *format, *pidstr, pidstrbuf[1 + 3 * sizeof pid]; | |
836 | char *agentsocket = NULL; | |
837 | extern int optind; | |
838 | fd_set *readsetp = NULL, *writesetp = NULL; | |
839 | ||
840 | SSLeay_add_all_algorithms(); | |
841 | ||
842 | __progname = get_progname(av[0]); | |
843 | init_rng(); | |
844 | seed_rng(); | |
845 | ||
846 | #ifdef __GNU_LIBRARY__ | |
847 | while ((ch = getopt(ac, av, "+cdksa:")) != -1) { | |
848 | #else /* __GNU_LIBRARY__ */ | |
849 | while ((ch = getopt(ac, av, "cdksa:")) != -1) { | |
850 | #endif /* __GNU_LIBRARY__ */ | |
851 | switch (ch) { | |
852 | case 'c': | |
853 | if (s_flag) | |
854 | usage(); | |
855 | c_flag++; | |
856 | break; | |
857 | case 'k': | |
858 | k_flag++; | |
859 | break; | |
860 | case 's': | |
861 | if (c_flag) | |
862 | usage(); | |
863 | s_flag++; | |
864 | break; | |
865 | case 'd': | |
866 | if (d_flag) | |
867 | usage(); | |
868 | d_flag++; | |
869 | break; | |
870 | case 'a': | |
871 | agentsocket = optarg; | |
872 | break; | |
873 | default: | |
874 | usage(); | |
875 | } | |
876 | } | |
877 | ac -= optind; | |
878 | av += optind; | |
879 | ||
880 | if (ac > 0 && (c_flag || k_flag || s_flag || d_flag)) | |
881 | usage(); | |
882 | ||
883 | if (ac == 0 && !c_flag && !s_flag) { | |
884 | shell = getenv("SHELL"); | |
885 | if (shell != NULL && strncmp(shell + strlen(shell) - 3, "csh", 3) == 0) | |
886 | c_flag = 1; | |
887 | } | |
888 | if (k_flag) { | |
889 | pidstr = getenv(SSH_AGENTPID_ENV_NAME); | |
890 | if (pidstr == NULL) { | |
891 | fprintf(stderr, "%s not set, cannot kill agent\n", | |
892 | SSH_AGENTPID_ENV_NAME); | |
893 | exit(1); | |
894 | } | |
895 | pid = atoi(pidstr); | |
896 | if (pid < 1) { | |
897 | fprintf(stderr, "%s=\"%s\", which is not a good PID\n", | |
898 | SSH_AGENTPID_ENV_NAME, pidstr); | |
899 | exit(1); | |
900 | } | |
901 | if (kill(pid, SIGTERM) == -1) { | |
902 | perror("kill"); | |
903 | exit(1); | |
904 | } | |
905 | format = c_flag ? "unsetenv %s;\n" : "unset %s;\n"; | |
906 | printf(format, SSH_AUTHSOCKET_ENV_NAME); | |
907 | printf(format, SSH_AGENTPID_ENV_NAME); | |
908 | printf("echo Agent pid %d killed;\n", pid); | |
909 | exit(0); | |
910 | } | |
911 | parent_pid = getpid(); | |
912 | ||
913 | if (agentsocket == NULL) { | |
914 | /* Create private directory for agent socket */ | |
915 | strlcpy(socket_dir, "/tmp/ssh-XXXXXXXX", sizeof socket_dir); | |
916 | if (mkdtemp(socket_dir) == NULL) { | |
917 | perror("mkdtemp: private socket dir"); | |
918 | exit(1); | |
919 | } | |
920 | snprintf(socket_name, sizeof socket_name, "%s/agent.%d", socket_dir, | |
921 | parent_pid); | |
922 | } else { | |
923 | /* Try to use specified agent socket */ | |
924 | socket_dir[0] = '\0'; | |
925 | strlcpy(socket_name, agentsocket, sizeof socket_name); | |
926 | } | |
927 | ||
928 | /* | |
929 | * Create socket early so it will exist before command gets run from | |
930 | * the parent. | |
931 | */ | |
932 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
933 | if (sock < 0) { | |
934 | perror("socket"); | |
935 | cleanup_exit(1); | |
936 | } | |
937 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
938 | sunaddr.sun_family = AF_UNIX; | |
939 | strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path)); | |
940 | #ifdef HAVE_CYGWIN | |
941 | prev_mask = umask(0177); | |
942 | #endif | |
943 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) { | |
944 | perror("bind"); | |
945 | #ifdef HAVE_CYGWIN | |
946 | umask(prev_mask); | |
947 | #endif | |
948 | cleanup_exit(1); | |
949 | } | |
950 | #ifdef HAVE_CYGWIN | |
951 | umask(prev_mask); | |
952 | #endif | |
953 | if (listen(sock, 5) < 0) { | |
954 | perror("listen"); | |
955 | cleanup_exit(1); | |
956 | } | |
957 | ||
958 | /* | |
959 | * Fork, and have the parent execute the command, if any, or present | |
960 | * the socket data. The child continues as the authentication agent. | |
961 | */ | |
962 | if (d_flag) { | |
963 | log_init(__progname, SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 1); | |
964 | format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; | |
965 | printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, | |
966 | SSH_AUTHSOCKET_ENV_NAME); | |
967 | printf("echo Agent pid %d;\n", parent_pid); | |
968 | goto skip; | |
969 | } | |
970 | pid = fork(); | |
971 | if (pid == -1) { | |
972 | perror("fork"); | |
973 | cleanup_exit(1); | |
974 | } | |
975 | if (pid != 0) { /* Parent - execute the given command. */ | |
976 | close(sock); | |
977 | snprintf(pidstrbuf, sizeof pidstrbuf, "%d", pid); | |
978 | if (ac == 0) { | |
979 | format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; | |
980 | printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, | |
981 | SSH_AUTHSOCKET_ENV_NAME); | |
982 | printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf, | |
983 | SSH_AGENTPID_ENV_NAME); | |
984 | printf("echo Agent pid %d;\n", pid); | |
985 | exit(0); | |
986 | } | |
987 | if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 || | |
988 | setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) { | |
989 | perror("setenv"); | |
990 | exit(1); | |
991 | } | |
992 | execvp(av[0], av); | |
993 | perror(av[0]); | |
994 | exit(1); | |
995 | } | |
996 | /* child */ | |
997 | log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0); | |
998 | ||
999 | if (setsid() == -1) { | |
1000 | error("setsid: %s", strerror(errno)); | |
1001 | cleanup_exit(1); | |
1002 | } | |
1003 | ||
1004 | (void)chdir("/"); | |
1005 | close(0); | |
1006 | close(1); | |
1007 | close(2); | |
1008 | ||
1009 | #ifdef HAVE_SETRLIMIT | |
1010 | /* deny core dumps, since memory contains unencrypted private keys */ | |
1011 | rlim.rlim_cur = rlim.rlim_max = 0; | |
1012 | if (setrlimit(RLIMIT_CORE, &rlim) < 0) { | |
1013 | error("setrlimit RLIMIT_CORE: %s", strerror(errno)); | |
1014 | cleanup_exit(1); | |
1015 | } | |
1016 | #endif | |
1017 | ||
1018 | skip: | |
1019 | fatal_add_cleanup(cleanup_socket, NULL); | |
1020 | new_socket(AUTH_SOCKET, sock); | |
1021 | if (ac > 0) { | |
1022 | signal(SIGALRM, check_parent_exists); | |
1023 | alarm(10); | |
1024 | } | |
1025 | idtab_init(); | |
1026 | if (!d_flag) | |
1027 | signal(SIGINT, SIG_IGN); | |
1028 | signal(SIGPIPE, SIG_IGN); | |
1029 | signal(SIGHUP, cleanup_handler); | |
1030 | signal(SIGTERM, cleanup_handler); | |
1031 | nalloc = 0; | |
1032 | ||
1033 | while (1) { | |
1034 | prepare_select(&readsetp, &writesetp, &max_fd, &nalloc); | |
1035 | if (select(max_fd + 1, readsetp, writesetp, NULL, NULL) < 0) { | |
1036 | if (errno == EINTR) | |
1037 | continue; | |
1038 | fatal("select: %s", strerror(errno)); | |
1039 | } | |
1040 | after_select(readsetp, writesetp); | |
1041 | } | |
1042 | /* NOTREACHED */ | |
1043 | } |