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Switched back to using pthread_create versus lwp_create.
[dragonfly/vkernel-mp.git] / crypto / openssh-4 / ssh-agent.c
bloba3a867c33b70e7a191c1608eb862f11b7ed34988
1 /* $OpenBSD: ssh-agent.c,v 1.154 2007/02/28 00:55:30 dtucker Exp $ */
2 /*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
6 * The authentication agent program.
7 *
8 * As far as I am concerned, the code I have written for this software
9 * can be used freely for any purpose. Any derived versions of this
10 * software must be clearly marked as such, and if the derived work is
11 * incompatible with the protocol description in the RFC file, it must be
12 * called by a name other than "ssh" or "Secure Shell".
13 *
14 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 */
36
37 #include "includes.h"
38
39 #include <sys/types.h>
40 #include <sys/param.h>
41 #include <sys/resource.h>
42 #include <sys/stat.h>
43 #include <sys/socket.h>
44 #ifdef HAVE_SYS_TIME_H
45 # include <sys/time.h>
46 #endif
47 #ifdef HAVE_SYS_UN_H
48 # include <sys/un.h>
49 #endif
50 #include "openbsd-compat/sys-queue.h"
51
52 #include <openssl/evp.h>
53 #include <openssl/md5.h>
54
55 #include <errno.h>
56 #include <fcntl.h>
57 #ifdef HAVE_PATHS_H
58 # include <paths.h>
59 #endif
60 #include <signal.h>
61 #include <stdarg.h>
62 #include <stdio.h>
63 #include <stdlib.h>
64 #include <time.h>
65 #include <string.h>
66 #include <unistd.h>
67
68 #include "xmalloc.h"
69 #include "ssh.h"
70 #include "rsa.h"
71 #include "buffer.h"
72 #include "key.h"
73 #include "authfd.h"
74 #include "compat.h"
75 #include "log.h"
76 #include "misc.h"
77
78 #ifdef SMARTCARD
79 #include "scard.h"
80 #endif
81
82 #if defined(HAVE_SYS_PRCTL_H)
83 #include <sys/prctl.h> /* For prctl() and PR_SET_DUMPABLE */
84 #endif
85
86 typedef enum {
87 AUTH_UNUSED,
88 AUTH_SOCKET,
89 AUTH_CONNECTION
90 } sock_type;
91
92 typedef struct {
93 int fd;
94 sock_type type;
95 Buffer input;
96 Buffer output;
97 Buffer request;
98 } SocketEntry;
99
100 u_int sockets_alloc = 0;
101 SocketEntry *sockets = NULL;
102
103 typedef struct identity {
104 TAILQ_ENTRY(identity) next;
105 Key *key;
106 char *comment;
107 u_int death;
108 u_int confirm;
109 } Identity;
110
111 typedef struct {
112 int nentries;
113 TAILQ_HEAD(idqueue, identity) idlist;
114 } Idtab;
115
116 /* private key table, one per protocol version */
117 Idtab idtable[3];
118
119 int max_fd = 0;
120
121 /* pid of shell == parent of agent */
122 pid_t parent_pid = -1;
123
124 /* pathname and directory for AUTH_SOCKET */
125 char socket_name[MAXPATHLEN];
126 char socket_dir[MAXPATHLEN];
127
128 /* locking */
129 int locked = 0;
130 char *lock_passwd = NULL;
131
132 extern char *__progname;
133
134 /* Default lifetime (0 == forever) */
135 static int lifetime = 0;
136
137 static void
138 close_socket(SocketEntry *e)
139 {
140 close(e->fd);
141 e->fd = -1;
142 e->type = AUTH_UNUSED;
143 buffer_free(&e->input);
144 buffer_free(&e->output);
145 buffer_free(&e->request);
146 }
147
148 static void
149 idtab_init(void)
150 {
151 int i;
152
153 for (i = 0; i <=2; i++) {
154 TAILQ_INIT(&idtable[i].idlist);
155 idtable[i].nentries = 0;
156 }
157 }
158
159 /* return private key table for requested protocol version */
160 static Idtab *
161 idtab_lookup(int version)
162 {
163 if (version < 1 || version > 2)
164 fatal("internal error, bad protocol version %d", version);
165 return &idtable[version];
166 }
167
168 static void
169 free_identity(Identity *id)
170 {
171 key_free(id->key);
172 xfree(id->comment);
173 xfree(id);
174 }
175
176 /* return matching private key for given public key */
177 static Identity *
178 lookup_identity(Key *key, int version)
179 {
180 Identity *id;
181
182 Idtab *tab = idtab_lookup(version);
183 TAILQ_FOREACH(id, &tab->idlist, next) {
184 if (key_equal(key, id->key))
185 return (id);
186 }
187 return (NULL);
188 }
189
190 /* Check confirmation of keysign request */
191 static int
192 confirm_key(Identity *id)
193 {
194 char *p;
195 int ret = -1;
196
197 p = key_fingerprint(id->key, SSH_FP_MD5, SSH_FP_HEX);
198 if (ask_permission("Allow use of key %s?\nKey fingerprint %s.",
199 id->comment, p))
200 ret = 0;
201 xfree(p);
202
203 return (ret);
204 }
205
206 /* send list of supported public keys to 'client' */
207 static void
208 process_request_identities(SocketEntry *e, int version)
209 {
210 Idtab *tab = idtab_lookup(version);
211 Identity *id;
212 Buffer msg;
213
214 buffer_init(&msg);
215 buffer_put_char(&msg, (version == 1) ?
216 SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
217 buffer_put_int(&msg, tab->nentries);
218 TAILQ_FOREACH(id, &tab->idlist, next) {
219 if (id->key->type == KEY_RSA1) {
220 buffer_put_int(&msg, BN_num_bits(id->key->rsa->n));
221 buffer_put_bignum(&msg, id->key->rsa->e);
222 buffer_put_bignum(&msg, id->key->rsa->n);
223 } else {
224 u_char *blob;
225 u_int blen;
226 key_to_blob(id->key, &blob, &blen);
227 buffer_put_string(&msg, blob, blen);
228 xfree(blob);
229 }
230 buffer_put_cstring(&msg, id->comment);
231 }
232 buffer_put_int(&e->output, buffer_len(&msg));
233 buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
234 buffer_free(&msg);
235 }
236
237 /* ssh1 only */
238 static void
239 process_authentication_challenge1(SocketEntry *e)
240 {
241 u_char buf[32], mdbuf[16], session_id[16];
242 u_int response_type;
243 BIGNUM *challenge;
244 Identity *id;
245 int i, len;
246 Buffer msg;
247 MD5_CTX md;
248 Key *key;
249
250 buffer_init(&msg);
251 key = key_new(KEY_RSA1);
252 if ((challenge = BN_new()) == NULL)
253 fatal("process_authentication_challenge1: BN_new failed");
254
255 (void) buffer_get_int(&e->request); /* ignored */
256 buffer_get_bignum(&e->request, key->rsa->e);
257 buffer_get_bignum(&e->request, key->rsa->n);
258 buffer_get_bignum(&e->request, challenge);
259
260 /* Only protocol 1.1 is supported */
261 if (buffer_len(&e->request) == 0)
262 goto failure;
263 buffer_get(&e->request, session_id, 16);
264 response_type = buffer_get_int(&e->request);
265 if (response_type != 1)
266 goto failure;
267
268 id = lookup_identity(key, 1);
269 if (id != NULL && (!id->confirm || confirm_key(id) == 0)) {
270 Key *private = id->key;
271 /* Decrypt the challenge using the private key. */
272 if (rsa_private_decrypt(challenge, challenge, private->rsa) <= 0)
273 goto failure;
274
275 /* The response is MD5 of decrypted challenge plus session id. */
276 len = BN_num_bytes(challenge);
277 if (len <= 0 || len > 32) {
278 logit("process_authentication_challenge: bad challenge length %d", len);
279 goto failure;
280 }
281 memset(buf, 0, 32);
282 BN_bn2bin(challenge, buf + 32 - len);
283 MD5_Init(&md);
284 MD5_Update(&md, buf, 32);
285 MD5_Update(&md, session_id, 16);
286 MD5_Final(mdbuf, &md);
287
288 /* Send the response. */
289 buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE);
290 for (i = 0; i < 16; i++)
291 buffer_put_char(&msg, mdbuf[i]);
292 goto send;
293 }
294
295 failure:
296 /* Unknown identity or protocol error. Send failure. */
297 buffer_put_char(&msg, SSH_AGENT_FAILURE);
298 send:
299 buffer_put_int(&e->output, buffer_len(&msg));
300 buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
301 key_free(key);
302 BN_clear_free(challenge);
303 buffer_free(&msg);
304 }
305
306 /* ssh2 only */
307 static void
308 process_sign_request2(SocketEntry *e)
309 {
310 u_char *blob, *data, *signature = NULL;
311 u_int blen, dlen, slen = 0;
312 extern int datafellows;
313 int ok = -1, flags;
314 Buffer msg;
315 Key *key;
316
317 datafellows = 0;
318
319 blob = buffer_get_string(&e->request, &blen);
320 data = buffer_get_string(&e->request, &dlen);
321
322 flags = buffer_get_int(&e->request);
323 if (flags & SSH_AGENT_OLD_SIGNATURE)
324 datafellows = SSH_BUG_SIGBLOB;
325
326 key = key_from_blob(blob, blen);
327 if (key != NULL) {
328 Identity *id = lookup_identity(key, 2);
329 if (id != NULL && (!id->confirm || confirm_key(id) == 0))
330 ok = key_sign(id->key, &signature, &slen, data, dlen);
331 key_free(key);
332 }
333 buffer_init(&msg);
334 if (ok == 0) {
335 buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE);
336 buffer_put_string(&msg, signature, slen);
337 } else {
338 buffer_put_char(&msg, SSH_AGENT_FAILURE);
339 }
340 buffer_put_int(&e->output, buffer_len(&msg));
341 buffer_append(&e->output, buffer_ptr(&msg),
342 buffer_len(&msg));
343 buffer_free(&msg);
344 xfree(data);
345 xfree(blob);
346 if (signature != NULL)
347 xfree(signature);
348 }
349
350 /* shared */
351 static void
352 process_remove_identity(SocketEntry *e, int version)
353 {
354 u_int blen, bits;
355 int success = 0;
356 Key *key = NULL;
357 u_char *blob;
358
359 switch (version) {
360 case 1:
361 key = key_new(KEY_RSA1);
362 bits = buffer_get_int(&e->request);
363 buffer_get_bignum(&e->request, key->rsa->e);
364 buffer_get_bignum(&e->request, key->rsa->n);
365
366 if (bits != key_size(key))
367 logit("Warning: identity keysize mismatch: actual %u, announced %u",
368 key_size(key), bits);
369 break;
370 case 2:
371 blob = buffer_get_string(&e->request, &blen);
372 key = key_from_blob(blob, blen);
373 xfree(blob);
374 break;
375 }
376 if (key != NULL) {
377 Identity *id = lookup_identity(key, version);
378 if (id != NULL) {
379 /*
380 * We have this key. Free the old key. Since we
381 * don't want to leave empty slots in the middle of
382 * the array, we actually free the key there and move
383 * all the entries between the empty slot and the end
384 * of the array.
385 */
386 Idtab *tab = idtab_lookup(version);
387 if (tab->nentries < 1)
388 fatal("process_remove_identity: "
389 "internal error: tab->nentries %d",
390 tab->nentries);
391 TAILQ_REMOVE(&tab->idlist, id, next);
392 free_identity(id);
393 tab->nentries--;
394 success = 1;
395 }
396 key_free(key);
397 }
398 buffer_put_int(&e->output, 1);
399 buffer_put_char(&e->output,
400 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
401 }
402
403 static void
404 process_remove_all_identities(SocketEntry *e, int version)
405 {
406 Idtab *tab = idtab_lookup(version);
407 Identity *id;
408
409 /* Loop over all identities and clear the keys. */
410 for (id = TAILQ_FIRST(&tab->idlist); id;
411 id = TAILQ_FIRST(&tab->idlist)) {
412 TAILQ_REMOVE(&tab->idlist, id, next);
413 free_identity(id);
414 }
415
416 /* Mark that there are no identities. */
417 tab->nentries = 0;
418
419 /* Send success. */
420 buffer_put_int(&e->output, 1);
421 buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
422 }
423
424 static void
425 reaper(void)
426 {
427 u_int now = time(NULL);
428 Identity *id, *nxt;
429 int version;
430 Idtab *tab;
431
432 for (version = 1; version < 3; version++) {
433 tab = idtab_lookup(version);
434 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) {
435 nxt = TAILQ_NEXT(id, next);
436 if (id->death != 0 && now >= id->death) {
437 debug("expiring key '%s'", id->comment);
438 TAILQ_REMOVE(&tab->idlist, id, next);
439 free_identity(id);
440 tab->nentries--;
441 }
442 }
443 }
444 }
445
446 static void
447 process_add_identity(SocketEntry *e, int version)
448 {
449 Idtab *tab = idtab_lookup(version);
450 int type, success = 0, death = 0, confirm = 0;
451 char *type_name, *comment;
452 Key *k = NULL;
453
454 switch (version) {
455 case 1:
456 k = key_new_private(KEY_RSA1);
457 (void) buffer_get_int(&e->request); /* ignored */
458 buffer_get_bignum(&e->request, k->rsa->n);
459 buffer_get_bignum(&e->request, k->rsa->e);
460 buffer_get_bignum(&e->request, k->rsa->d);
461 buffer_get_bignum(&e->request, k->rsa->iqmp);
462
463 /* SSH and SSL have p and q swapped */
464 buffer_get_bignum(&e->request, k->rsa->q); /* p */
465 buffer_get_bignum(&e->request, k->rsa->p); /* q */
466
467 /* Generate additional parameters */
468 rsa_generate_additional_parameters(k->rsa);
469 break;
470 case 2:
471 type_name = buffer_get_string(&e->request, NULL);
472 type = key_type_from_name(type_name);
473 xfree(type_name);
474 switch (type) {
475 case KEY_DSA:
476 k = key_new_private(type);
477 buffer_get_bignum2(&e->request, k->dsa->p);
478 buffer_get_bignum2(&e->request, k->dsa->q);
479 buffer_get_bignum2(&e->request, k->dsa->g);
480 buffer_get_bignum2(&e->request, k->dsa->pub_key);
481 buffer_get_bignum2(&e->request, k->dsa->priv_key);
482 break;
483 case KEY_RSA:
484 k = key_new_private(type);
485 buffer_get_bignum2(&e->request, k->rsa->n);
486 buffer_get_bignum2(&e->request, k->rsa->e);
487 buffer_get_bignum2(&e->request, k->rsa->d);
488 buffer_get_bignum2(&e->request, k->rsa->iqmp);
489 buffer_get_bignum2(&e->request, k->rsa->p);
490 buffer_get_bignum2(&e->request, k->rsa->q);
491
492 /* Generate additional parameters */
493 rsa_generate_additional_parameters(k->rsa);
494 break;
495 default:
496 buffer_clear(&e->request);
497 goto send;
498 }
499 break;
500 }
501 /* enable blinding */
502 switch (k->type) {
503 case KEY_RSA:
504 case KEY_RSA1:
505 if (RSA_blinding_on(k->rsa, NULL) != 1) {
506 error("process_add_identity: RSA_blinding_on failed");
507 key_free(k);
508 goto send;
509 }
510 break;
511 }
512 comment = buffer_get_string(&e->request, NULL);
513 if (k == NULL) {
514 xfree(comment);
515 goto send;
516 }
517 success = 1;
518 while (buffer_len(&e->request)) {
519 switch (buffer_get_char(&e->request)) {
520 case SSH_AGENT_CONSTRAIN_LIFETIME:
521 death = time(NULL) + buffer_get_int(&e->request);
522 break;
523 case SSH_AGENT_CONSTRAIN_CONFIRM:
524 confirm = 1;
525 break;
526 default:
527 break;
528 }
529 }
530 if (lifetime && !death)
531 death = time(NULL) + lifetime;
532 if (lookup_identity(k, version) == NULL) {
533 Identity *id = xmalloc(sizeof(Identity));
534 id->key = k;
535 id->comment = comment;
536 id->death = death;
537 id->confirm = confirm;
538 TAILQ_INSERT_TAIL(&tab->idlist, id, next);
539 /* Increment the number of identities. */
540 tab->nentries++;
541 } else {
542 key_free(k);
543 xfree(comment);
544 }
545 send:
546 buffer_put_int(&e->output, 1);
547 buffer_put_char(&e->output,
548 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
549 }
550
551 /* XXX todo: encrypt sensitive data with passphrase */
552 static void
553 process_lock_agent(SocketEntry *e, int lock)
554 {
555 int success = 0;
556 char *passwd;
557
558 passwd = buffer_get_string(&e->request, NULL);
559 if (locked && !lock && strcmp(passwd, lock_passwd) == 0) {
560 locked = 0;
561 memset(lock_passwd, 0, strlen(lock_passwd));
562 xfree(lock_passwd);
563 lock_passwd = NULL;
564 success = 1;
565 } else if (!locked && lock) {
566 locked = 1;
567 lock_passwd = xstrdup(passwd);
568 success = 1;
569 }
570 memset(passwd, 0, strlen(passwd));
571 xfree(passwd);
572
573 buffer_put_int(&e->output, 1);
574 buffer_put_char(&e->output,
575 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
576 }
577
578 static void
579 no_identities(SocketEntry *e, u_int type)
580 {
581 Buffer msg;
582
583 buffer_init(&msg);
584 buffer_put_char(&msg,
585 (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ?
586 SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
587 buffer_put_int(&msg, 0);
588 buffer_put_int(&e->output, buffer_len(&msg));
589 buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
590 buffer_free(&msg);
591 }
592
593 #ifdef SMARTCARD
594 static void
595 process_add_smartcard_key (SocketEntry *e)
596 {
597 char *sc_reader_id = NULL, *pin;
598 int i, version, success = 0, death = 0, confirm = 0;
599 Key **keys, *k;
600 Identity *id;
601 Idtab *tab;
602
603 sc_reader_id = buffer_get_string(&e->request, NULL);
604 pin = buffer_get_string(&e->request, NULL);
605
606 while (buffer_len(&e->request)) {
607 switch (buffer_get_char(&e->request)) {
608 case SSH_AGENT_CONSTRAIN_LIFETIME:
609 death = time(NULL) + buffer_get_int(&e->request);
610 break;
611 case SSH_AGENT_CONSTRAIN_CONFIRM:
612 confirm = 1;
613 break;
614 default:
615 break;
616 }
617 }
618 if (lifetime && !death)
619 death = time(NULL) + lifetime;
620
621 keys = sc_get_keys(sc_reader_id, pin);
622 xfree(sc_reader_id);
623 xfree(pin);
624
625 if (keys == NULL || keys[0] == NULL) {
626 error("sc_get_keys failed");
627 goto send;
628 }
629 for (i = 0; keys[i] != NULL; i++) {
630 k = keys[i];
631 version = k->type == KEY_RSA1 ? 1 : 2;
632 tab = idtab_lookup(version);
633 if (lookup_identity(k, version) == NULL) {
634 id = xmalloc(sizeof(Identity));
635 id->key = k;
636 id->comment = sc_get_key_label(k);
637 id->death = death;
638 id->confirm = confirm;
639 TAILQ_INSERT_TAIL(&tab->idlist, id, next);
640 tab->nentries++;
641 success = 1;
642 } else {
643 key_free(k);
644 }
645 keys[i] = NULL;
646 }
647 xfree(keys);
648 send:
649 buffer_put_int(&e->output, 1);
650 buffer_put_char(&e->output,
651 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
652 }
653
654 static void
655 process_remove_smartcard_key(SocketEntry *e)
656 {
657 char *sc_reader_id = NULL, *pin;
658 int i, version, success = 0;
659 Key **keys, *k = NULL;
660 Identity *id;
661 Idtab *tab;
662
663 sc_reader_id = buffer_get_string(&e->request, NULL);
664 pin = buffer_get_string(&e->request, NULL);
665 keys = sc_get_keys(sc_reader_id, pin);
666 xfree(sc_reader_id);
667 xfree(pin);
668
669 if (keys == NULL || keys[0] == NULL) {
670 error("sc_get_keys failed");
671 goto send;
672 }
673 for (i = 0; keys[i] != NULL; i++) {
674 k = keys[i];
675 version = k->type == KEY_RSA1 ? 1 : 2;
676 if ((id = lookup_identity(k, version)) != NULL) {
677 tab = idtab_lookup(version);
678 TAILQ_REMOVE(&tab->idlist, id, next);
679 tab->nentries--;
680 free_identity(id);
681 success = 1;
682 }
683 key_free(k);
684 keys[i] = NULL;
685 }
686 xfree(keys);
687 send:
688 buffer_put_int(&e->output, 1);
689 buffer_put_char(&e->output,
690 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
691 }
692 #endif /* SMARTCARD */
693
694 /* dispatch incoming messages */
695
696 static void
697 process_message(SocketEntry *e)
698 {
699 u_int msg_len, type;
700 u_char *cp;
701
702 if (buffer_len(&e->input) < 5)
703 return; /* Incomplete message. */
704 cp = buffer_ptr(&e->input);
705 msg_len = get_u32(cp);
706 if (msg_len > 256 * 1024) {
707 close_socket(e);
708 return;
709 }
710 if (buffer_len(&e->input) < msg_len + 4)
711 return;
712
713 /* move the current input to e->request */
714 buffer_consume(&e->input, 4);
715 buffer_clear(&e->request);
716 buffer_append(&e->request, buffer_ptr(&e->input), msg_len);
717 buffer_consume(&e->input, msg_len);
718 type = buffer_get_char(&e->request);
719
720 /* check wheter agent is locked */
721 if (locked && type != SSH_AGENTC_UNLOCK) {
722 buffer_clear(&e->request);
723 switch (type) {
724 case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
725 case SSH2_AGENTC_REQUEST_IDENTITIES:
726 /* send empty lists */
727 no_identities(e, type);
728 break;
729 default:
730 /* send a fail message for all other request types */
731 buffer_put_int(&e->output, 1);
732 buffer_put_char(&e->output, SSH_AGENT_FAILURE);
733 }
734 return;
735 }
736
737 debug("type %d", type);
738 switch (type) {
739 case SSH_AGENTC_LOCK:
740 case SSH_AGENTC_UNLOCK:
741 process_lock_agent(e, type == SSH_AGENTC_LOCK);
742 break;
743 /* ssh1 */
744 case SSH_AGENTC_RSA_CHALLENGE:
745 process_authentication_challenge1(e);
746 break;
747 case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
748 process_request_identities(e, 1);
749 break;
750 case SSH_AGENTC_ADD_RSA_IDENTITY:
751 case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED:
752 process_add_identity(e, 1);
753 break;
754 case SSH_AGENTC_REMOVE_RSA_IDENTITY:
755 process_remove_identity(e, 1);
756 break;
757 case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
758 process_remove_all_identities(e, 1);
759 break;
760 /* ssh2 */
761 case SSH2_AGENTC_SIGN_REQUEST:
762 process_sign_request2(e);
763 break;
764 case SSH2_AGENTC_REQUEST_IDENTITIES:
765 process_request_identities(e, 2);
766 break;
767 case SSH2_AGENTC_ADD_IDENTITY:
768 case SSH2_AGENTC_ADD_ID_CONSTRAINED:
769 process_add_identity(e, 2);
770 break;
771 case SSH2_AGENTC_REMOVE_IDENTITY:
772 process_remove_identity(e, 2);
773 break;
774 case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
775 process_remove_all_identities(e, 2);
776 break;
777 #ifdef SMARTCARD
778 case SSH_AGENTC_ADD_SMARTCARD_KEY:
779 case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
780 process_add_smartcard_key(e);
781 break;
782 case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
783 process_remove_smartcard_key(e);
784 break;
785 #endif /* SMARTCARD */
786 default:
787 /* Unknown message. Respond with failure. */
788 error("Unknown message %d", type);
789 buffer_clear(&e->request);
790 buffer_put_int(&e->output, 1);
791 buffer_put_char(&e->output, SSH_AGENT_FAILURE);
792 break;
793 }
794 }
795
796 static void
797 new_socket(sock_type type, int fd)
798 {
799 u_int i, old_alloc, new_alloc;
800
801 set_nonblock(fd);
802
803 if (fd > max_fd)
804 max_fd = fd;
805
806 for (i = 0; i < sockets_alloc; i++)
807 if (sockets[i].type == AUTH_UNUSED) {
808 sockets[i].fd = fd;
809 buffer_init(&sockets[i].input);
810 buffer_init(&sockets[i].output);
811 buffer_init(&sockets[i].request);
812 sockets[i].type = type;
813 return;
814 }
815 old_alloc = sockets_alloc;
816 new_alloc = sockets_alloc + 10;
817 sockets = xrealloc(sockets, new_alloc, sizeof(sockets[0]));
818 for (i = old_alloc; i < new_alloc; i++)
819 sockets[i].type = AUTH_UNUSED;
820 sockets_alloc = new_alloc;
821 sockets[old_alloc].fd = fd;
822 buffer_init(&sockets[old_alloc].input);
823 buffer_init(&sockets[old_alloc].output);
824 buffer_init(&sockets[old_alloc].request);
825 sockets[old_alloc].type = type;
826 }
827
828 static int
829 prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp)
830 {
831 u_int i, sz;
832 int n = 0;
833
834 for (i = 0; i < sockets_alloc; i++) {
835 switch (sockets[i].type) {
836 case AUTH_SOCKET:
837 case AUTH_CONNECTION:
838 n = MAX(n, sockets[i].fd);
839 break;
840 case AUTH_UNUSED:
841 break;
842 default:
843 fatal("Unknown socket type %d", sockets[i].type);
844 break;
845 }
846 }
847
848 sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
849 if (*fdrp == NULL || sz > *nallocp) {
850 if (*fdrp)
851 xfree(*fdrp);
852 if (*fdwp)
853 xfree(*fdwp);
854 *fdrp = xmalloc(sz);
855 *fdwp = xmalloc(sz);
856 *nallocp = sz;
857 }
858 if (n < *fdl)
859 debug("XXX shrink: %d < %d", n, *fdl);
860 *fdl = n;
861 memset(*fdrp, 0, sz);
862 memset(*fdwp, 0, sz);
863
864 for (i = 0; i < sockets_alloc; i++) {
865 switch (sockets[i].type) {
866 case AUTH_SOCKET:
867 case AUTH_CONNECTION:
868 FD_SET(sockets[i].fd, *fdrp);
869 if (buffer_len(&sockets[i].output) > 0)
870 FD_SET(sockets[i].fd, *fdwp);
871 break;
872 default:
873 break;
874 }
875 }
876 return (1);
877 }
878
879 static void
880 after_select(fd_set *readset, fd_set *writeset)
881 {
882 struct sockaddr_un sunaddr;
883 socklen_t slen;
884 char buf[1024];
885 int len, sock;
886 u_int i;
887 uid_t euid;
888 gid_t egid;
889
890 for (i = 0; i < sockets_alloc; i++)
891 switch (sockets[i].type) {
892 case AUTH_UNUSED:
893 break;
894 case AUTH_SOCKET:
895 if (FD_ISSET(sockets[i].fd, readset)) {
896 slen = sizeof(sunaddr);
897 sock = accept(sockets[i].fd,
898 (struct sockaddr *)&sunaddr, &slen);
899 if (sock < 0) {
900 error("accept from AUTH_SOCKET: %s",
901 strerror(errno));
902 break;
903 }
904 if (getpeereid(sock, &euid, &egid) < 0) {
905 error("getpeereid %d failed: %s",
906 sock, strerror(errno));
907 close(sock);
908 break;
909 }
910 if ((euid != 0) && (getuid() != euid)) {
911 error("uid mismatch: "
912 "peer euid %u != uid %u",
913 (u_int) euid, (u_int) getuid());
914 close(sock);
915 break;
916 }
917 new_socket(AUTH_CONNECTION, sock);
918 }
919 break;
920 case AUTH_CONNECTION:
921 if (buffer_len(&sockets[i].output) > 0 &&
922 FD_ISSET(sockets[i].fd, writeset)) {
923 do {
924 len = write(sockets[i].fd,
925 buffer_ptr(&sockets[i].output),
926 buffer_len(&sockets[i].output));
927 if (len == -1 && (errno == EAGAIN ||
928 errno == EINTR))
929 continue;
930 break;
931 } while (1);
932 if (len <= 0) {
933 close_socket(&sockets[i]);
934 break;
935 }
936 buffer_consume(&sockets[i].output, len);
937 }
938 if (FD_ISSET(sockets[i].fd, readset)) {
939 do {
940 len = read(sockets[i].fd, buf, sizeof(buf));
941 if (len == -1 && (errno == EAGAIN ||
942 errno == EINTR))
943 continue;
944 break;
945 } while (1);
946 if (len <= 0) {
947 close_socket(&sockets[i]);
948 break;
949 }
950 buffer_append(&sockets[i].input, buf, len);
951 process_message(&sockets[i]);
952 }
953 break;
954 default:
955 fatal("Unknown type %d", sockets[i].type);
956 }
957 }
958
959 static void
960 cleanup_socket(void)
961 {
962 if (socket_name[0])
963 unlink(socket_name);
964 if (socket_dir[0])
965 rmdir(socket_dir);
966 }
967
968 void
969 cleanup_exit(int i)
970 {
971 cleanup_socket();
972 _exit(i);
973 }
974
975 /*ARGSUSED*/
976 static void
977 cleanup_handler(int sig)
978 {
979 cleanup_socket();
980 _exit(2);
981 }
982
983 /*ARGSUSED*/
984 static void
985 check_parent_exists(int sig)
986 {
987 int save_errno = errno;
988
989 if (parent_pid != -1 && kill(parent_pid, 0) < 0) {
990 /* printf("Parent has died - Authentication agent exiting.\n"); */
991 cleanup_handler(sig); /* safe */
992 }
993 mysignal(SIGALRM, check_parent_exists);
994 alarm(10);
995 errno = save_errno;
996 }
997
998 static void
999 usage(void)
1000 {
1001 fprintf(stderr, "Usage: %s [options] [command [args ...]]\n",
1002 __progname);
1003 fprintf(stderr, "Options:\n");
1004 fprintf(stderr, " -c Generate C-shell commands on stdout.\n");
1005 fprintf(stderr, " -s Generate Bourne shell commands on stdout.\n");
1006 fprintf(stderr, " -k Kill the current agent.\n");
1007 fprintf(stderr, " -d Debug mode.\n");
1008 fprintf(stderr, " -a socket Bind agent socket to given name.\n");
1009 fprintf(stderr, " -t life Default identity lifetime (seconds).\n");
1010 exit(1);
1011 }
1012
1013 int
1014 main(int ac, char **av)
1015 {
1016 int c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0;
1017 int sock, fd, ch, result, saved_errno;
1018 u_int nalloc;
1019 char *shell, *format, *pidstr, *agentsocket = NULL;
1020 fd_set *readsetp = NULL, *writesetp = NULL;
1021 struct sockaddr_un sunaddr;
1022 #ifdef HAVE_SETRLIMIT
1023 struct rlimit rlim;
1024 #endif
1025 int prev_mask;
1026 extern int optind;
1027 extern char *optarg;
1028 pid_t pid;
1029 char pidstrbuf[1 + 3 * sizeof pid];
1030 struct timeval tv;
1031
1032 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1033 sanitise_stdfd();
1034
1035 /* drop */
1036 setegid(getgid());
1037 setgid(getgid());
1038
1039 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
1040 /* Disable ptrace on Linux without sgid bit */
1041 prctl(PR_SET_DUMPABLE, 0);
1042 #endif
1043
1044 SSLeay_add_all_algorithms();
1045
1046 __progname = ssh_get_progname(av[0]);
1047 init_rng();
1048 seed_rng();
1049
1050 while ((ch = getopt(ac, av, "cdksa:t:")) != -1) {
1051 switch (ch) {
1052 case 'c':
1053 if (s_flag)
1054 usage();
1055 c_flag++;
1056 break;
1057 case 'k':
1058 k_flag++;
1059 break;
1060 case 's':
1061 if (c_flag)
1062 usage();
1063 s_flag++;
1064 break;
1065 case 'd':
1066 if (d_flag)
1067 usage();
1068 d_flag++;
1069 break;
1070 case 'a':
1071 agentsocket = optarg;
1072 break;
1073 case 't':
1074 if ((lifetime = convtime(optarg)) == -1) {
1075 fprintf(stderr, "Invalid lifetime\n");
1076 usage();
1077 }
1078 break;
1079 default:
1080 usage();
1081 }
1082 }
1083 ac -= optind;
1084 av += optind;
1085
1086 if (ac > 0 && (c_flag || k_flag || s_flag || d_flag))
1087 usage();
1088
1089 if (ac == 0 && !c_flag && !s_flag) {
1090 shell = getenv("SHELL");
1091 if (shell != NULL &&
1092 strncmp(shell + strlen(shell) - 3, "csh", 3) == 0)
1093 c_flag = 1;
1094 }
1095 if (k_flag) {
1096 const char *errstr = NULL;
1097
1098 pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1099 if (pidstr == NULL) {
1100 fprintf(stderr, "%s not set, cannot kill agent\n",
1101 SSH_AGENTPID_ENV_NAME);
1102 exit(1);
1103 }
1104 pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1105 if (errstr) {
1106 fprintf(stderr,
1107 "%s=\"%s\", which is not a good PID: %s\n",
1108 SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1109 exit(1);
1110 }
1111 if (kill(pid, SIGTERM) == -1) {
1112 perror("kill");
1113 exit(1);
1114 }
1115 format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1116 printf(format, SSH_AUTHSOCKET_ENV_NAME);
1117 printf(format, SSH_AGENTPID_ENV_NAME);
1118 printf("echo Agent pid %ld killed;\n", (long)pid);
1119 exit(0);
1120 }
1121 parent_pid = getpid();
1122
1123 if (agentsocket == NULL) {
1124 /* Create private directory for agent socket */
1125 strlcpy(socket_dir, "/tmp/ssh-XXXXXXXXXX", sizeof socket_dir);
1126 if (mkdtemp(socket_dir) == NULL) {
1127 perror("mkdtemp: private socket dir");
1128 exit(1);
1129 }
1130 snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1131 (long)parent_pid);
1132 } else {
1133 /* Try to use specified agent socket */
1134 socket_dir[0] = '\0';
1135 strlcpy(socket_name, agentsocket, sizeof socket_name);
1136 }
1137
1138 /*
1139 * Create socket early so it will exist before command gets run from
1140 * the parent.
1141 */
1142 sock = socket(AF_UNIX, SOCK_STREAM, 0);
1143 if (sock < 0) {
1144 perror("socket");
1145 *socket_name = '\0'; /* Don't unlink any existing file */
1146 cleanup_exit(1);
1147 }
1148 memset(&sunaddr, 0, sizeof(sunaddr));
1149 sunaddr.sun_family = AF_UNIX;
1150 strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path));
1151 prev_mask = umask(0177);
1152 if (bind(sock, (struct sockaddr *) &sunaddr, sizeof(sunaddr)) < 0) {
1153 perror("bind");
1154 *socket_name = '\0'; /* Don't unlink any existing file */
1155 umask(prev_mask);
1156 cleanup_exit(1);
1157 }
1158 umask(prev_mask);
1159 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1160 perror("listen");
1161 cleanup_exit(1);
1162 }
1163
1164 /*
1165 * Fork, and have the parent execute the command, if any, or present
1166 * the socket data. The child continues as the authentication agent.
1167 */
1168 if (d_flag) {
1169 log_init(__progname, SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 1);
1170 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1171 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1172 SSH_AUTHSOCKET_ENV_NAME);
1173 printf("echo Agent pid %ld;\n", (long)parent_pid);
1174 goto skip;
1175 }
1176 pid = fork();
1177 if (pid == -1) {
1178 perror("fork");
1179 cleanup_exit(1);
1180 }
1181 if (pid != 0) { /* Parent - execute the given command. */
1182 close(sock);
1183 snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1184 if (ac == 0) {
1185 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1186 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1187 SSH_AUTHSOCKET_ENV_NAME);
1188 printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1189 SSH_AGENTPID_ENV_NAME);
1190 printf("echo Agent pid %ld;\n", (long)pid);
1191 exit(0);
1192 }
1193 if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1194 setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1195 perror("setenv");
1196 exit(1);
1197 }
1198 execvp(av[0], av);
1199 perror(av[0]);
1200 exit(1);
1201 }
1202 /* child */
1203 log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1204
1205 if (setsid() == -1) {
1206 error("setsid: %s", strerror(errno));
1207 cleanup_exit(1);
1208 }
1209
1210 (void)chdir("/");
1211 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1212 /* XXX might close listen socket */
1213 (void)dup2(fd, STDIN_FILENO);
1214 (void)dup2(fd, STDOUT_FILENO);
1215 (void)dup2(fd, STDERR_FILENO);
1216 if (fd > 2)
1217 close(fd);
1218 }
1219
1220 #ifdef HAVE_SETRLIMIT
1221 /* deny core dumps, since memory contains unencrypted private keys */
1222 rlim.rlim_cur = rlim.rlim_max = 0;
1223 if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
1224 error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1225 cleanup_exit(1);
1226 }
1227 #endif
1228
1229 skip:
1230 new_socket(AUTH_SOCKET, sock);
1231 if (ac > 0) {
1232 mysignal(SIGALRM, check_parent_exists);
1233 alarm(10);
1234 }
1235 idtab_init();
1236 if (!d_flag)
1237 signal(SIGINT, SIG_IGN);
1238 signal(SIGPIPE, SIG_IGN);
1239 signal(SIGHUP, cleanup_handler);
1240 signal(SIGTERM, cleanup_handler);
1241 nalloc = 0;
1242
1243 while (1) {
1244 tv.tv_sec = 10;
1245 tv.tv_usec = 0;
1246 prepare_select(&readsetp, &writesetp, &max_fd, &nalloc);
1247 result = select(max_fd + 1, readsetp, writesetp, NULL, &tv);
1248 saved_errno = errno;
1249 reaper(); /* remove expired keys */
1250 if (result < 0) {
1251 if (saved_errno == EINTR)
1252 continue;
1253 fatal("select: %s", strerror(saved_errno));
1254 } else if (result > 0)
1255 after_select(readsetp, writesetp);
1256 }
1257 /* NOTREACHED */
1258 }
DragonFly vkernel multiprocessor port