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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 1.103 2002/09/10 20:24:47 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 | u_int death; | |
80 | } Identity; | |
81 | ||
82 | typedef struct { | |
83 | int nentries; | |
84 | TAILQ_HEAD(idqueue, identity) idlist; | |
85 | } Idtab; | |
86 | ||
87 | /* private key table, one per protocol version */ | |
88 | Idtab idtable[3]; | |
89 | ||
90 | int max_fd = 0; | |
91 | ||
92 | /* pid of shell == parent of agent */ | |
93 | pid_t parent_pid = -1; | |
94 | ||
95 | /* pathname and directory for AUTH_SOCKET */ | |
96 | char socket_name[1024]; | |
97 | char socket_dir[1024]; | |
98 | ||
99 | /* locking */ | |
100 | int locked = 0; | |
101 | char *lock_passwd = NULL; | |
102 | ||
103 | #ifdef HAVE___PROGNAME | |
104 | extern char *__progname; | |
105 | #else | |
106 | char *__progname; | |
107 | #endif | |
108 | ||
109 | static void | |
110 | close_socket(SocketEntry *e) | |
111 | { | |
112 | close(e->fd); | |
113 | e->fd = -1; | |
114 | e->type = AUTH_UNUSED; | |
115 | buffer_free(&e->input); | |
116 | buffer_free(&e->output); | |
117 | buffer_free(&e->request); | |
118 | } | |
119 | ||
120 | static void | |
121 | idtab_init(void) | |
122 | { | |
123 | int i; | |
124 | ||
125 | for (i = 0; i <=2; i++) { | |
126 | TAILQ_INIT(&idtable[i].idlist); | |
127 | idtable[i].nentries = 0; | |
128 | } | |
129 | } | |
130 | ||
131 | /* return private key table for requested protocol version */ | |
132 | static Idtab * | |
133 | idtab_lookup(int version) | |
134 | { | |
135 | if (version < 1 || version > 2) | |
136 | fatal("internal error, bad protocol version %d", version); | |
137 | return &idtable[version]; | |
138 | } | |
139 | ||
140 | static void | |
141 | free_identity(Identity *id) | |
142 | { | |
143 | key_free(id->key); | |
144 | xfree(id->comment); | |
145 | xfree(id); | |
146 | } | |
147 | ||
148 | /* return matching private key for given public key */ | |
149 | static Identity * | |
150 | lookup_identity(Key *key, int version) | |
151 | { | |
152 | Identity *id; | |
153 | ||
154 | Idtab *tab = idtab_lookup(version); | |
155 | TAILQ_FOREACH(id, &tab->idlist, next) { | |
156 | if (key_equal(key, id->key)) | |
157 | return (id); | |
158 | } | |
159 | return (NULL); | |
160 | } | |
161 | ||
162 | /* send list of supported public keys to 'client' */ | |
163 | static void | |
164 | process_request_identities(SocketEntry *e, int version) | |
165 | { | |
166 | Idtab *tab = idtab_lookup(version); | |
167 | Identity *id; | |
168 | Buffer msg; | |
169 | ||
170 | buffer_init(&msg); | |
171 | buffer_put_char(&msg, (version == 1) ? | |
172 | SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER); | |
173 | buffer_put_int(&msg, tab->nentries); | |
174 | TAILQ_FOREACH(id, &tab->idlist, next) { | |
175 | if (id->key->type == KEY_RSA1) { | |
176 | buffer_put_int(&msg, BN_num_bits(id->key->rsa->n)); | |
177 | buffer_put_bignum(&msg, id->key->rsa->e); | |
178 | buffer_put_bignum(&msg, id->key->rsa->n); | |
179 | } else { | |
180 | u_char *blob; | |
181 | u_int blen; | |
182 | key_to_blob(id->key, &blob, &blen); | |
183 | buffer_put_string(&msg, blob, blen); | |
184 | xfree(blob); | |
185 | } | |
186 | buffer_put_cstring(&msg, id->comment); | |
187 | } | |
188 | buffer_put_int(&e->output, buffer_len(&msg)); | |
189 | buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg)); | |
190 | buffer_free(&msg); | |
191 | } | |
192 | ||
193 | /* ssh1 only */ | |
194 | static void | |
195 | process_authentication_challenge1(SocketEntry *e) | |
196 | { | |
197 | u_char buf[32], mdbuf[16], session_id[16]; | |
198 | u_int response_type; | |
199 | BIGNUM *challenge; | |
200 | Identity *id; | |
201 | int i, len; | |
202 | Buffer msg; | |
203 | MD5_CTX md; | |
204 | Key *key; | |
205 | ||
206 | buffer_init(&msg); | |
207 | key = key_new(KEY_RSA1); | |
208 | if ((challenge = BN_new()) == NULL) | |
209 | fatal("process_authentication_challenge1: BN_new failed"); | |
210 | ||
211 | (void) buffer_get_int(&e->request); /* ignored */ | |
212 | buffer_get_bignum(&e->request, key->rsa->e); | |
213 | buffer_get_bignum(&e->request, key->rsa->n); | |
214 | buffer_get_bignum(&e->request, challenge); | |
215 | ||
216 | /* Only protocol 1.1 is supported */ | |
217 | if (buffer_len(&e->request) == 0) | |
218 | goto failure; | |
219 | buffer_get(&e->request, session_id, 16); | |
220 | response_type = buffer_get_int(&e->request); | |
221 | if (response_type != 1) | |
222 | goto failure; | |
223 | ||
224 | id = lookup_identity(key, 1); | |
225 | if (id != NULL) { | |
226 | Key *private = id->key; | |
227 | /* Decrypt the challenge using the private key. */ | |
228 | if (rsa_private_decrypt(challenge, challenge, private->rsa) <= 0) | |
229 | goto failure; | |
230 | ||
231 | /* The response is MD5 of decrypted challenge plus session id. */ | |
232 | len = BN_num_bytes(challenge); | |
233 | if (len <= 0 || len > 32) { | |
234 | log("process_authentication_challenge: bad challenge length %d", len); | |
235 | goto failure; | |
236 | } | |
237 | memset(buf, 0, 32); | |
238 | BN_bn2bin(challenge, buf + 32 - len); | |
239 | MD5_Init(&md); | |
240 | MD5_Update(&md, buf, 32); | |
241 | MD5_Update(&md, session_id, 16); | |
242 | MD5_Final(mdbuf, &md); | |
243 | ||
244 | /* Send the response. */ | |
245 | buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE); | |
246 | for (i = 0; i < 16; i++) | |
247 | buffer_put_char(&msg, mdbuf[i]); | |
248 | goto send; | |
249 | } | |
250 | ||
251 | failure: | |
252 | /* Unknown identity or protocol error. Send failure. */ | |
253 | buffer_put_char(&msg, SSH_AGENT_FAILURE); | |
254 | send: | |
255 | buffer_put_int(&e->output, buffer_len(&msg)); | |
256 | buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg)); | |
257 | key_free(key); | |
258 | BN_clear_free(challenge); | |
259 | buffer_free(&msg); | |
260 | } | |
261 | ||
262 | /* ssh2 only */ | |
263 | static void | |
264 | process_sign_request2(SocketEntry *e) | |
265 | { | |
266 | u_char *blob, *data, *signature = NULL; | |
267 | u_int blen, dlen, slen = 0; | |
268 | extern int datafellows; | |
269 | int ok = -1, flags; | |
270 | Buffer msg; | |
271 | Key *key; | |
272 | ||
273 | datafellows = 0; | |
274 | ||
275 | blob = buffer_get_string(&e->request, &blen); | |
276 | data = buffer_get_string(&e->request, &dlen); | |
277 | ||
278 | flags = buffer_get_int(&e->request); | |
279 | if (flags & SSH_AGENT_OLD_SIGNATURE) | |
280 | datafellows = SSH_BUG_SIGBLOB; | |
281 | ||
282 | key = key_from_blob(blob, blen); | |
283 | if (key != NULL) { | |
284 | Identity *id = lookup_identity(key, 2); | |
285 | if (id != NULL) | |
286 | ok = key_sign(id->key, &signature, &slen, data, dlen); | |
287 | } | |
288 | key_free(key); | |
289 | buffer_init(&msg); | |
290 | if (ok == 0) { | |
291 | buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE); | |
292 | buffer_put_string(&msg, signature, slen); | |
293 | } else { | |
294 | buffer_put_char(&msg, SSH_AGENT_FAILURE); | |
295 | } | |
296 | buffer_put_int(&e->output, buffer_len(&msg)); | |
297 | buffer_append(&e->output, buffer_ptr(&msg), | |
298 | buffer_len(&msg)); | |
299 | buffer_free(&msg); | |
300 | xfree(data); | |
301 | xfree(blob); | |
302 | if (signature != NULL) | |
303 | xfree(signature); | |
304 | } | |
305 | ||
306 | /* shared */ | |
307 | static void | |
308 | process_remove_identity(SocketEntry *e, int version) | |
309 | { | |
310 | u_int blen, bits; | |
311 | int success = 0; | |
312 | Key *key = NULL; | |
313 | u_char *blob; | |
314 | ||
315 | switch (version) { | |
316 | case 1: | |
317 | key = key_new(KEY_RSA1); | |
318 | bits = buffer_get_int(&e->request); | |
319 | buffer_get_bignum(&e->request, key->rsa->e); | |
320 | buffer_get_bignum(&e->request, key->rsa->n); | |
321 | ||
322 | if (bits != key_size(key)) | |
323 | log("Warning: identity keysize mismatch: actual %u, announced %u", | |
324 | key_size(key), bits); | |
325 | break; | |
326 | case 2: | |
327 | blob = buffer_get_string(&e->request, &blen); | |
328 | key = key_from_blob(blob, blen); | |
329 | xfree(blob); | |
330 | break; | |
331 | } | |
332 | if (key != NULL) { | |
333 | Identity *id = lookup_identity(key, version); | |
334 | if (id != NULL) { | |
335 | /* | |
336 | * We have this key. Free the old key. Since we | |
337 | * don\'t want to leave empty slots in the middle of | |
338 | * the array, we actually free the key there and move | |
339 | * all the entries between the empty slot and the end | |
340 | * of the array. | |
341 | */ | |
342 | Idtab *tab = idtab_lookup(version); | |
343 | if (tab->nentries < 1) | |
344 | fatal("process_remove_identity: " | |
345 | "internal error: tab->nentries %d", | |
346 | tab->nentries); | |
347 | TAILQ_REMOVE(&tab->idlist, id, next); | |
348 | free_identity(id); | |
349 | tab->nentries--; | |
350 | success = 1; | |
351 | } | |
352 | key_free(key); | |
353 | } | |
354 | buffer_put_int(&e->output, 1); | |
355 | buffer_put_char(&e->output, | |
356 | success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE); | |
357 | } | |
358 | ||
359 | static void | |
360 | process_remove_all_identities(SocketEntry *e, int version) | |
361 | { | |
362 | Idtab *tab = idtab_lookup(version); | |
363 | Identity *id; | |
364 | ||
365 | /* Loop over all identities and clear the keys. */ | |
366 | for (id = TAILQ_FIRST(&tab->idlist); id; | |
367 | id = TAILQ_FIRST(&tab->idlist)) { | |
368 | TAILQ_REMOVE(&tab->idlist, id, next); | |
369 | free_identity(id); | |
370 | } | |
371 | ||
372 | /* Mark that there are no identities. */ | |
373 | tab->nentries = 0; | |
374 | ||
375 | /* Send success. */ | |
376 | buffer_put_int(&e->output, 1); | |
377 | buffer_put_char(&e->output, SSH_AGENT_SUCCESS); | |
378 | } | |
379 | ||
380 | static void | |
381 | reaper(void) | |
382 | { | |
383 | u_int now = time(NULL); | |
384 | Identity *id, *nxt; | |
385 | int version; | |
386 | Idtab *tab; | |
387 | ||
388 | for (version = 1; version < 3; version++) { | |
389 | tab = idtab_lookup(version); | |
390 | for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) { | |
391 | nxt = TAILQ_NEXT(id, next); | |
392 | if (id->death != 0 && now >= id->death) { | |
393 | TAILQ_REMOVE(&tab->idlist, id, next); | |
394 | free_identity(id); | |
395 | tab->nentries--; | |
396 | } | |
397 | } | |
398 | } | |
399 | } | |
400 | ||
401 | static void | |
402 | process_add_identity(SocketEntry *e, int version) | |
403 | { | |
404 | Idtab *tab = idtab_lookup(version); | |
405 | int type, success = 0, death = 0; | |
406 | char *type_name, *comment; | |
407 | Key *k = NULL; | |
408 | ||
409 | switch (version) { | |
410 | case 1: | |
411 | k = key_new_private(KEY_RSA1); | |
412 | (void) buffer_get_int(&e->request); /* ignored */ | |
413 | buffer_get_bignum(&e->request, k->rsa->n); | |
414 | buffer_get_bignum(&e->request, k->rsa->e); | |
415 | buffer_get_bignum(&e->request, k->rsa->d); | |
416 | buffer_get_bignum(&e->request, k->rsa->iqmp); | |
417 | ||
418 | /* SSH and SSL have p and q swapped */ | |
419 | buffer_get_bignum(&e->request, k->rsa->q); /* p */ | |
420 | buffer_get_bignum(&e->request, k->rsa->p); /* q */ | |
421 | ||
422 | /* Generate additional parameters */ | |
423 | rsa_generate_additional_parameters(k->rsa); | |
424 | break; | |
425 | case 2: | |
426 | type_name = buffer_get_string(&e->request, NULL); | |
427 | type = key_type_from_name(type_name); | |
428 | xfree(type_name); | |
429 | switch (type) { | |
430 | case KEY_DSA: | |
431 | k = key_new_private(type); | |
432 | buffer_get_bignum2(&e->request, k->dsa->p); | |
433 | buffer_get_bignum2(&e->request, k->dsa->q); | |
434 | buffer_get_bignum2(&e->request, k->dsa->g); | |
435 | buffer_get_bignum2(&e->request, k->dsa->pub_key); | |
436 | buffer_get_bignum2(&e->request, k->dsa->priv_key); | |
437 | break; | |
438 | case KEY_RSA: | |
439 | k = key_new_private(type); | |
440 | buffer_get_bignum2(&e->request, k->rsa->n); | |
441 | buffer_get_bignum2(&e->request, k->rsa->e); | |
442 | buffer_get_bignum2(&e->request, k->rsa->d); | |
443 | buffer_get_bignum2(&e->request, k->rsa->iqmp); | |
444 | buffer_get_bignum2(&e->request, k->rsa->p); | |
445 | buffer_get_bignum2(&e->request, k->rsa->q); | |
446 | ||
447 | /* Generate additional parameters */ | |
448 | rsa_generate_additional_parameters(k->rsa); | |
449 | break; | |
450 | default: | |
451 | buffer_clear(&e->request); | |
452 | goto send; | |
453 | } | |
454 | break; | |
455 | } | |
456 | comment = buffer_get_string(&e->request, NULL); | |
457 | if (k == NULL) { | |
458 | xfree(comment); | |
459 | goto send; | |
460 | } | |
461 | success = 1; | |
462 | while (buffer_len(&e->request)) { | |
463 | switch (buffer_get_char(&e->request)) { | |
464 | case SSH_AGENT_CONSTRAIN_LIFETIME: | |
465 | death = time(NULL) + buffer_get_int(&e->request); | |
466 | break; | |
467 | default: | |
468 | break; | |
469 | } | |
470 | } | |
471 | if (lookup_identity(k, version) == NULL) { | |
472 | Identity *id = xmalloc(sizeof(Identity)); | |
473 | id->key = k; | |
474 | id->comment = comment; | |
475 | id->death = death; | |
476 | TAILQ_INSERT_TAIL(&tab->idlist, id, next); | |
477 | /* Increment the number of identities. */ | |
478 | tab->nentries++; | |
479 | } else { | |
480 | key_free(k); | |
481 | xfree(comment); | |
482 | } | |
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 | /* XXX todo: encrypt sensitive data with passphrase */ | |
490 | static void | |
491 | process_lock_agent(SocketEntry *e, int lock) | |
492 | { | |
493 | int success = 0; | |
494 | char *passwd; | |
495 | ||
496 | passwd = buffer_get_string(&e->request, NULL); | |
497 | if (locked && !lock && strcmp(passwd, lock_passwd) == 0) { | |
498 | locked = 0; | |
499 | memset(lock_passwd, 0, strlen(lock_passwd)); | |
500 | xfree(lock_passwd); | |
501 | lock_passwd = NULL; | |
502 | success = 1; | |
503 | } else if (!locked && lock) { | |
504 | locked = 1; | |
505 | lock_passwd = xstrdup(passwd); | |
506 | success = 1; | |
507 | } | |
508 | memset(passwd, 0, strlen(passwd)); | |
509 | xfree(passwd); | |
510 | ||
511 | buffer_put_int(&e->output, 1); | |
512 | buffer_put_char(&e->output, | |
513 | success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE); | |
514 | } | |
515 | ||
516 | static void | |
517 | no_identities(SocketEntry *e, u_int type) | |
518 | { | |
519 | Buffer msg; | |
520 | ||
521 | buffer_init(&msg); | |
522 | buffer_put_char(&msg, | |
523 | (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ? | |
524 | SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER); | |
525 | buffer_put_int(&msg, 0); | |
526 | buffer_put_int(&e->output, buffer_len(&msg)); | |
527 | buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg)); | |
528 | buffer_free(&msg); | |
529 | } | |
530 | ||
531 | #ifdef SMARTCARD | |
532 | static void | |
533 | process_add_smartcard_key (SocketEntry *e) | |
534 | { | |
535 | char *sc_reader_id = NULL, *pin; | |
536 | int i, version, success = 0; | |
537 | Key **keys, *k; | |
538 | Identity *id; | |
539 | Idtab *tab; | |
540 | ||
541 | sc_reader_id = buffer_get_string(&e->request, NULL); | |
542 | pin = buffer_get_string(&e->request, NULL); | |
543 | keys = sc_get_keys(sc_reader_id, pin); | |
544 | xfree(sc_reader_id); | |
545 | xfree(pin); | |
546 | ||
547 | if (keys == NULL || keys[0] == NULL) { | |
548 | error("sc_get_keys failed"); | |
549 | goto send; | |
550 | } | |
551 | for (i = 0; keys[i] != NULL; i++) { | |
552 | k = keys[i]; | |
553 | version = k->type == KEY_RSA1 ? 1 : 2; | |
554 | tab = idtab_lookup(version); | |
555 | if (lookup_identity(k, version) == NULL) { | |
556 | id = xmalloc(sizeof(Identity)); | |
557 | id->key = k; | |
558 | id->comment = xstrdup("smartcard key"); | |
559 | id->death = 0; | |
560 | TAILQ_INSERT_TAIL(&tab->idlist, id, next); | |
561 | tab->nentries++; | |
562 | success = 1; | |
563 | } else { | |
564 | key_free(k); | |
565 | } | |
566 | keys[i] = NULL; | |
567 | } | |
568 | xfree(keys); | |
569 | send: | |
570 | buffer_put_int(&e->output, 1); | |
571 | buffer_put_char(&e->output, | |
572 | success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE); | |
573 | } | |
574 | ||
575 | static void | |
576 | process_remove_smartcard_key(SocketEntry *e) | |
577 | { | |
578 | char *sc_reader_id = NULL, *pin; | |
579 | int i, version, success = 0; | |
580 | Key **keys, *k = NULL; | |
581 | Identity *id; | |
582 | Idtab *tab; | |
583 | ||
584 | sc_reader_id = buffer_get_string(&e->request, NULL); | |
585 | pin = buffer_get_string(&e->request, NULL); | |
586 | keys = sc_get_keys(sc_reader_id, pin); | |
587 | xfree(sc_reader_id); | |
588 | xfree(pin); | |
589 | ||
590 | if (keys == NULL || keys[0] == NULL) { | |
591 | error("sc_get_keys failed"); | |
592 | goto send; | |
593 | } | |
594 | for (i = 0; keys[i] != NULL; i++) { | |
595 | k = keys[i]; | |
596 | version = k->type == KEY_RSA1 ? 1 : 2; | |
597 | if ((id = lookup_identity(k, version)) != NULL) { | |
598 | tab = idtab_lookup(version); | |
599 | TAILQ_REMOVE(&tab->idlist, id, next); | |
600 | tab->nentries--; | |
601 | free_identity(id); | |
602 | success = 1; | |
603 | } | |
604 | key_free(k); | |
605 | keys[i] = NULL; | |
606 | } | |
607 | xfree(keys); | |
608 | send: | |
609 | buffer_put_int(&e->output, 1); | |
610 | buffer_put_char(&e->output, | |
611 | success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE); | |
612 | } | |
613 | #endif /* SMARTCARD */ | |
614 | ||
615 | /* dispatch incoming messages */ | |
616 | ||
617 | static void | |
618 | process_message(SocketEntry *e) | |
619 | { | |
620 | u_int msg_len, type; | |
621 | u_char *cp; | |
622 | ||
623 | /* kill dead keys */ | |
624 | reaper(); | |
625 | ||
626 | if (buffer_len(&e->input) < 5) | |
627 | return; /* Incomplete message. */ | |
628 | cp = buffer_ptr(&e->input); | |
629 | msg_len = GET_32BIT(cp); | |
630 | if (msg_len > 256 * 1024) { | |
631 | close_socket(e); | |
632 | return; | |
633 | } | |
634 | if (buffer_len(&e->input) < msg_len + 4) | |
635 | return; | |
636 | ||
637 | /* move the current input to e->request */ | |
638 | buffer_consume(&e->input, 4); | |
639 | buffer_clear(&e->request); | |
640 | buffer_append(&e->request, buffer_ptr(&e->input), msg_len); | |
641 | buffer_consume(&e->input, msg_len); | |
642 | type = buffer_get_char(&e->request); | |
643 | ||
644 | /* check wheter agent is locked */ | |
645 | if (locked && type != SSH_AGENTC_UNLOCK) { | |
646 | buffer_clear(&e->request); | |
647 | switch (type) { | |
648 | case SSH_AGENTC_REQUEST_RSA_IDENTITIES: | |
649 | case SSH2_AGENTC_REQUEST_IDENTITIES: | |
650 | /* send empty lists */ | |
651 | no_identities(e, type); | |
652 | break; | |
653 | default: | |
654 | /* send a fail message for all other request types */ | |
655 | buffer_put_int(&e->output, 1); | |
656 | buffer_put_char(&e->output, SSH_AGENT_FAILURE); | |
657 | } | |
658 | return; | |
659 | } | |
660 | ||
661 | debug("type %d", type); | |
662 | switch (type) { | |
663 | case SSH_AGENTC_LOCK: | |
664 | case SSH_AGENTC_UNLOCK: | |
665 | process_lock_agent(e, type == SSH_AGENTC_LOCK); | |
666 | break; | |
667 | /* ssh1 */ | |
668 | case SSH_AGENTC_RSA_CHALLENGE: | |
669 | process_authentication_challenge1(e); | |
670 | break; | |
671 | case SSH_AGENTC_REQUEST_RSA_IDENTITIES: | |
672 | process_request_identities(e, 1); | |
673 | break; | |
674 | case SSH_AGENTC_ADD_RSA_IDENTITY: | |
675 | case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED: | |
676 | process_add_identity(e, 1); | |
677 | break; | |
678 | case SSH_AGENTC_REMOVE_RSA_IDENTITY: | |
679 | process_remove_identity(e, 1); | |
680 | break; | |
681 | case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES: | |
682 | process_remove_all_identities(e, 1); | |
683 | break; | |
684 | /* ssh2 */ | |
685 | case SSH2_AGENTC_SIGN_REQUEST: | |
686 | process_sign_request2(e); | |
687 | break; | |
688 | case SSH2_AGENTC_REQUEST_IDENTITIES: | |
689 | process_request_identities(e, 2); | |
690 | break; | |
691 | case SSH2_AGENTC_ADD_IDENTITY: | |
692 | case SSH2_AGENTC_ADD_ID_CONSTRAINED: | |
693 | process_add_identity(e, 2); | |
694 | break; | |
695 | case SSH2_AGENTC_REMOVE_IDENTITY: | |
696 | process_remove_identity(e, 2); | |
697 | break; | |
698 | case SSH2_AGENTC_REMOVE_ALL_IDENTITIES: | |
699 | process_remove_all_identities(e, 2); | |
700 | break; | |
701 | #ifdef SMARTCARD | |
702 | case SSH_AGENTC_ADD_SMARTCARD_KEY: | |
703 | process_add_smartcard_key(e); | |
704 | break; | |
705 | case SSH_AGENTC_REMOVE_SMARTCARD_KEY: | |
706 | process_remove_smartcard_key(e); | |
707 | break; | |
708 | #endif /* SMARTCARD */ | |
709 | default: | |
710 | /* Unknown message. Respond with failure. */ | |
711 | error("Unknown message %d", type); | |
712 | buffer_clear(&e->request); | |
713 | buffer_put_int(&e->output, 1); | |
714 | buffer_put_char(&e->output, SSH_AGENT_FAILURE); | |
715 | break; | |
716 | } | |
717 | } | |
718 | ||
719 | static void | |
720 | new_socket(sock_type type, int fd) | |
721 | { | |
722 | u_int i, old_alloc; | |
723 | ||
724 | if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) | |
725 | error("fcntl O_NONBLOCK: %s", strerror(errno)); | |
726 | ||
727 | if (fd > max_fd) | |
728 | max_fd = fd; | |
729 | ||
730 | for (i = 0; i < sockets_alloc; i++) | |
731 | if (sockets[i].type == AUTH_UNUSED) { | |
732 | sockets[i].fd = fd; | |
733 | sockets[i].type = type; | |
734 | buffer_init(&sockets[i].input); | |
735 | buffer_init(&sockets[i].output); | |
736 | buffer_init(&sockets[i].request); | |
737 | return; | |
738 | } | |
739 | old_alloc = sockets_alloc; | |
740 | sockets_alloc += 10; | |
741 | if (sockets) | |
742 | sockets = xrealloc(sockets, sockets_alloc * sizeof(sockets[0])); | |
743 | else | |
744 | sockets = xmalloc(sockets_alloc * sizeof(sockets[0])); | |
745 | for (i = old_alloc; i < sockets_alloc; i++) | |
746 | sockets[i].type = AUTH_UNUSED; | |
747 | sockets[old_alloc].type = type; | |
748 | sockets[old_alloc].fd = fd; | |
749 | buffer_init(&sockets[old_alloc].input); | |
750 | buffer_init(&sockets[old_alloc].output); | |
751 | buffer_init(&sockets[old_alloc].request); | |
752 | } | |
753 | ||
754 | static int | |
755 | prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, int *nallocp) | |
756 | { | |
757 | u_int i, sz; | |
758 | int n = 0; | |
759 | ||
760 | for (i = 0; i < sockets_alloc; i++) { | |
761 | switch (sockets[i].type) { | |
762 | case AUTH_SOCKET: | |
763 | case AUTH_CONNECTION: | |
764 | n = MAX(n, sockets[i].fd); | |
765 | break; | |
766 | case AUTH_UNUSED: | |
767 | break; | |
768 | default: | |
769 | fatal("Unknown socket type %d", sockets[i].type); | |
770 | break; | |
771 | } | |
772 | } | |
773 | ||
774 | sz = howmany(n+1, NFDBITS) * sizeof(fd_mask); | |
775 | if (*fdrp == NULL || sz > *nallocp) { | |
776 | if (*fdrp) | |
777 | xfree(*fdrp); | |
778 | if (*fdwp) | |
779 | xfree(*fdwp); | |
780 | *fdrp = xmalloc(sz); | |
781 | *fdwp = xmalloc(sz); | |
782 | *nallocp = sz; | |
783 | } | |
784 | if (n < *fdl) | |
785 | debug("XXX shrink: %d < %d", n, *fdl); | |
786 | *fdl = n; | |
787 | memset(*fdrp, 0, sz); | |
788 | memset(*fdwp, 0, sz); | |
789 | ||
790 | for (i = 0; i < sockets_alloc; i++) { | |
791 | switch (sockets[i].type) { | |
792 | case AUTH_SOCKET: | |
793 | case AUTH_CONNECTION: | |
794 | FD_SET(sockets[i].fd, *fdrp); | |
795 | if (buffer_len(&sockets[i].output) > 0) | |
796 | FD_SET(sockets[i].fd, *fdwp); | |
797 | break; | |
798 | default: | |
799 | break; | |
800 | } | |
801 | } | |
802 | return (1); | |
803 | } | |
804 | ||
805 | static void | |
806 | after_select(fd_set *readset, fd_set *writeset) | |
807 | { | |
808 | struct sockaddr_un sunaddr; | |
809 | socklen_t slen; | |
810 | char buf[1024]; | |
811 | int len, sock; | |
812 | u_int i; | |
813 | uid_t euid; | |
814 | gid_t egid; | |
815 | ||
816 | for (i = 0; i < sockets_alloc; i++) | |
817 | switch (sockets[i].type) { | |
818 | case AUTH_UNUSED: | |
819 | break; | |
820 | case AUTH_SOCKET: | |
821 | if (FD_ISSET(sockets[i].fd, readset)) { | |
822 | slen = sizeof(sunaddr); | |
823 | sock = accept(sockets[i].fd, | |
824 | (struct sockaddr *) &sunaddr, &slen); | |
825 | if (sock < 0) { | |
826 | error("accept from AUTH_SOCKET: %s", | |
827 | strerror(errno)); | |
828 | break; | |
829 | } | |
830 | if (getpeereid(sock, &euid, &egid) < 0) { | |
831 | error("getpeereid %d failed: %s", | |
832 | sock, strerror(errno)); | |
833 | close(sock); | |
834 | break; | |
835 | } | |
836 | if (getuid() != euid) { | |
837 | error("uid mismatch: " | |
838 | "peer euid %d != uid %d", | |
839 | (int) euid, (int) getuid()); | |
840 | close(sock); | |
841 | break; | |
842 | } | |
843 | new_socket(AUTH_CONNECTION, sock); | |
844 | } | |
845 | break; | |
846 | case AUTH_CONNECTION: | |
847 | if (buffer_len(&sockets[i].output) > 0 && | |
848 | FD_ISSET(sockets[i].fd, writeset)) { | |
849 | do { | |
850 | len = write(sockets[i].fd, | |
851 | buffer_ptr(&sockets[i].output), | |
852 | buffer_len(&sockets[i].output)); | |
853 | if (len == -1 && (errno == EAGAIN || | |
854 | errno == EINTR)) | |
855 | continue; | |
856 | break; | |
857 | } while (1); | |
858 | if (len <= 0) { | |
859 | close_socket(&sockets[i]); | |
860 | break; | |
861 | } | |
862 | buffer_consume(&sockets[i].output, len); | |
863 | } | |
864 | if (FD_ISSET(sockets[i].fd, readset)) { | |
865 | do { | |
866 | len = read(sockets[i].fd, buf, sizeof(buf)); | |
867 | if (len == -1 && (errno == EAGAIN || | |
868 | errno == EINTR)) | |
869 | continue; | |
870 | break; | |
871 | } while (1); | |
872 | if (len <= 0) { | |
873 | close_socket(&sockets[i]); | |
874 | break; | |
875 | } | |
876 | buffer_append(&sockets[i].input, buf, len); | |
877 | process_message(&sockets[i]); | |
878 | } | |
879 | break; | |
880 | default: | |
881 | fatal("Unknown type %d", sockets[i].type); | |
882 | } | |
883 | } | |
884 | ||
885 | static void | |
886 | cleanup_socket(void *p) | |
887 | { | |
888 | if (socket_name[0]) | |
889 | unlink(socket_name); | |
890 | if (socket_dir[0]) | |
891 | rmdir(socket_dir); | |
892 | } | |
893 | ||
894 | static void | |
895 | cleanup_exit(int i) | |
896 | { | |
897 | cleanup_socket(NULL); | |
898 | exit(i); | |
899 | } | |
900 | ||
901 | static void | |
902 | cleanup_handler(int sig) | |
903 | { | |
904 | cleanup_socket(NULL); | |
905 | _exit(2); | |
906 | } | |
907 | ||
908 | static void | |
909 | check_parent_exists(int sig) | |
910 | { | |
911 | int save_errno = errno; | |
912 | ||
913 | if (parent_pid != -1 && kill(parent_pid, 0) < 0) { | |
914 | /* printf("Parent has died - Authentication agent exiting.\n"); */ | |
915 | cleanup_handler(sig); /* safe */ | |
916 | } | |
917 | signal(SIGALRM, check_parent_exists); | |
918 | alarm(10); | |
919 | errno = save_errno; | |
920 | } | |
921 | ||
922 | static void | |
923 | usage(void) | |
924 | { | |
925 | fprintf(stderr, "Usage: %s [options] [command [args ...]]\n", | |
926 | __progname); | |
927 | fprintf(stderr, "Options:\n"); | |
928 | fprintf(stderr, " -c Generate C-shell commands on stdout.\n"); | |
929 | fprintf(stderr, " -s Generate Bourne shell commands on stdout.\n"); | |
930 | fprintf(stderr, " -k Kill the current agent.\n"); | |
931 | fprintf(stderr, " -d Debug mode.\n"); | |
932 | fprintf(stderr, " -a socket Bind agent socket to given name.\n"); | |
933 | exit(1); | |
934 | } | |
935 | ||
936 | int | |
937 | main(int ac, char **av) | |
938 | { | |
939 | int sock, c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0, ch, nalloc; | |
940 | char *shell, *format, *pidstr, *agentsocket = NULL; | |
941 | fd_set *readsetp = NULL, *writesetp = NULL; | |
942 | struct sockaddr_un sunaddr; | |
943 | #ifdef HAVE_SETRLIMIT | |
944 | struct rlimit rlim; | |
945 | #endif | |
946 | #ifdef HAVE_CYGWIN | |
947 | int prev_mask; | |
948 | #endif | |
949 | extern int optind; | |
950 | extern char *optarg; | |
951 | pid_t pid; | |
952 | char pidstrbuf[1 + 3 * sizeof pid]; | |
953 | ||
954 | /* drop */ | |
955 | setegid(getgid()); | |
956 | setgid(getgid()); | |
957 | ||
958 | SSLeay_add_all_algorithms(); | |
959 | ||
960 | __progname = get_progname(av[0]); | |
961 | init_rng(); | |
962 | seed_rng(); | |
963 | ||
964 | while ((ch = getopt(ac, av, "cdksa:")) != -1) { | |
965 | switch (ch) { | |
966 | case 'c': | |
967 | if (s_flag) | |
968 | usage(); | |
969 | c_flag++; | |
970 | break; | |
971 | case 'k': | |
972 | k_flag++; | |
973 | break; | |
974 | case 's': | |
975 | if (c_flag) | |
976 | usage(); | |
977 | s_flag++; | |
978 | break; | |
979 | case 'd': | |
980 | if (d_flag) | |
981 | usage(); | |
982 | d_flag++; | |
983 | break; | |
984 | case 'a': | |
985 | agentsocket = optarg; | |
986 | break; | |
987 | default: | |
988 | usage(); | |
989 | } | |
990 | } | |
991 | ac -= optind; | |
992 | av += optind; | |
993 | ||
994 | if (ac > 0 && (c_flag || k_flag || s_flag || d_flag)) | |
995 | usage(); | |
996 | ||
997 | if (ac == 0 && !c_flag && !s_flag) { | |
998 | shell = getenv("SHELL"); | |
999 | if (shell != NULL && strncmp(shell + strlen(shell) - 3, "csh", 3) == 0) | |
1000 | c_flag = 1; | |
1001 | } | |
1002 | if (k_flag) { | |
1003 | pidstr = getenv(SSH_AGENTPID_ENV_NAME); | |
1004 | if (pidstr == NULL) { | |
1005 | fprintf(stderr, "%s not set, cannot kill agent\n", | |
1006 | SSH_AGENTPID_ENV_NAME); | |
1007 | exit(1); | |
1008 | } | |
1009 | pid = atoi(pidstr); | |
1010 | if (pid < 1) { | |
1011 | fprintf(stderr, "%s=\"%s\", which is not a good PID\n", | |
1012 | SSH_AGENTPID_ENV_NAME, pidstr); | |
1013 | exit(1); | |
1014 | } | |
1015 | if (kill(pid, SIGTERM) == -1) { | |
1016 | perror("kill"); | |
1017 | exit(1); | |
1018 | } | |
1019 | format = c_flag ? "unsetenv %s;\n" : "unset %s;\n"; | |
1020 | printf(format, SSH_AUTHSOCKET_ENV_NAME); | |
1021 | printf(format, SSH_AGENTPID_ENV_NAME); | |
1022 | printf("echo Agent pid %ld killed;\n", (long)pid); | |
1023 | exit(0); | |
1024 | } | |
1025 | parent_pid = getpid(); | |
1026 | ||
1027 | if (agentsocket == NULL) { | |
1028 | /* Create private directory for agent socket */ | |
1029 | strlcpy(socket_dir, "/tmp/ssh-XXXXXXXX", sizeof socket_dir); | |
1030 | if (mkdtemp(socket_dir) == NULL) { | |
1031 | perror("mkdtemp: private socket dir"); | |
1032 | exit(1); | |
1033 | } | |
1034 | snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir, | |
1035 | (long)parent_pid); | |
1036 | } else { | |
1037 | /* Try to use specified agent socket */ | |
1038 | socket_dir[0] = '\0'; | |
1039 | strlcpy(socket_name, agentsocket, sizeof socket_name); | |
1040 | } | |
1041 | ||
1042 | /* | |
1043 | * Create socket early so it will exist before command gets run from | |
1044 | * the parent. | |
1045 | */ | |
1046 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
1047 | if (sock < 0) { | |
1048 | perror("socket"); | |
1049 | cleanup_exit(1); | |
1050 | } | |
1051 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
1052 | sunaddr.sun_family = AF_UNIX; | |
1053 | strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path)); | |
1054 | #ifdef HAVE_CYGWIN | |
1055 | prev_mask = umask(0177); | |
1056 | #endif | |
1057 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) { | |
1058 | perror("bind"); | |
1059 | #ifdef HAVE_CYGWIN | |
1060 | umask(prev_mask); | |
1061 | #endif | |
1062 | cleanup_exit(1); | |
1063 | } | |
1064 | #ifdef HAVE_CYGWIN | |
1065 | umask(prev_mask); | |
1066 | #endif | |
1067 | if (listen(sock, 128) < 0) { | |
1068 | perror("listen"); | |
1069 | cleanup_exit(1); | |
1070 | } | |
1071 | ||
1072 | /* | |
1073 | * Fork, and have the parent execute the command, if any, or present | |
1074 | * the socket data. The child continues as the authentication agent. | |
1075 | */ | |
1076 | if (d_flag) { | |
1077 | log_init(__progname, SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 1); | |
1078 | format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; | |
1079 | printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, | |
1080 | SSH_AUTHSOCKET_ENV_NAME); | |
1081 | printf("echo Agent pid %ld;\n", (long)parent_pid); | |
1082 | goto skip; | |
1083 | } | |
1084 | pid = fork(); | |
1085 | if (pid == -1) { | |
1086 | perror("fork"); | |
1087 | cleanup_exit(1); | |
1088 | } | |
1089 | if (pid != 0) { /* Parent - execute the given command. */ | |
1090 | close(sock); | |
1091 | snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid); | |
1092 | if (ac == 0) { | |
1093 | format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; | |
1094 | printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, | |
1095 | SSH_AUTHSOCKET_ENV_NAME); | |
1096 | printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf, | |
1097 | SSH_AGENTPID_ENV_NAME); | |
1098 | printf("echo Agent pid %ld;\n", (long)pid); | |
1099 | exit(0); | |
1100 | } | |
1101 | if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 || | |
1102 | setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) { | |
1103 | perror("setenv"); | |
1104 | exit(1); | |
1105 | } | |
1106 | execvp(av[0], av); | |
1107 | perror(av[0]); | |
1108 | exit(1); | |
1109 | } | |
1110 | /* child */ | |
1111 | log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0); | |
1112 | ||
1113 | if (setsid() == -1) { | |
1114 | error("setsid: %s", strerror(errno)); | |
1115 | cleanup_exit(1); | |
1116 | } | |
1117 | ||
1118 | (void)chdir("/"); | |
1119 | close(0); | |
1120 | close(1); | |
1121 | close(2); | |
1122 | ||
1123 | #ifdef HAVE_SETRLIMIT | |
1124 | /* deny core dumps, since memory contains unencrypted private keys */ | |
1125 | rlim.rlim_cur = rlim.rlim_max = 0; | |
1126 | if (setrlimit(RLIMIT_CORE, &rlim) < 0) { | |
1127 | error("setrlimit RLIMIT_CORE: %s", strerror(errno)); | |
1128 | cleanup_exit(1); | |
1129 | } | |
1130 | #endif | |
1131 | ||
1132 | skip: | |
1133 | fatal_add_cleanup(cleanup_socket, NULL); | |
1134 | new_socket(AUTH_SOCKET, sock); | |
1135 | if (ac > 0) { | |
1136 | signal(SIGALRM, check_parent_exists); | |
1137 | alarm(10); | |
1138 | } | |
1139 | idtab_init(); | |
1140 | if (!d_flag) | |
1141 | signal(SIGINT, SIG_IGN); | |
1142 | signal(SIGPIPE, SIG_IGN); | |
1143 | signal(SIGHUP, cleanup_handler); | |
1144 | signal(SIGTERM, cleanup_handler); | |
1145 | nalloc = 0; | |
1146 | ||
1147 | while (1) { | |
1148 | prepare_select(&readsetp, &writesetp, &max_fd, &nalloc); | |
1149 | if (select(max_fd + 1, readsetp, writesetp, NULL, NULL) < 0) { | |
1150 | if (errno == EINTR) | |
1151 | continue; | |
1152 | fatal("select: %s", strerror(errno)); | |
1153 | } | |
1154 | after_select(readsetp, writesetp); | |
1155 | } | |
1156 | /* NOTREACHED */ | |
1157 | } |