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[netbsd-mini2440.git] / crypto / external / bsd / openssh / dist / ssh-agent.c
blobbfd125236d5af1c0fc091e9b063527df59e4a859
1 /* $NetBSD: ssh-agent.c,v 1.1.1.2 2009/12/27 01:07:09 christos Exp $ */
2 /* $OpenBSD: ssh-agent.c,v 1.161 2009/03/23 19:38:04 tobias Exp $ */
3 /*
4 * Author: Tatu Ylonen <ylo@cs.hut.fi>
5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * All rights reserved
7 * The authentication agent program.
8 *
9 * As far as I am concerned, the code I have written for this software
10 * can be used freely for any purpose. Any derived versions of this
11 * software must be clearly marked as such, and if the derived work is
12 * incompatible with the protocol description in the RFC file, it must be
13 * called by a name other than "ssh" or "Secure Shell".
14 *
15 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 #include "includes.h"
39 __RCSID("$NetBSD: ssh-agent.c,v 1.3 2009/12/17 15:55:16 agc Exp $");
40 #include <sys/types.h>
41 #include <sys/time.h>
42 #include <sys/queue.h>
43 #include <sys/resource.h>
44 #include <sys/types.h>
45 #include <sys/socket.h>
46 #include <sys/un.h>
47 #include <sys/param.h>
48
49 #include <openssl/evp.h>
50 #include <openssl/md5.h>
51
52 #include <errno.h>
53 #include <fcntl.h>
54 #include <paths.h>
55 #include <signal.h>
56 #include <stdlib.h>
57 #include <stdio.h>
58 #include <string.h>
59 #include <time.h>
60 #include <unistd.h>
61
62 #include "xmalloc.h"
63 #include "ssh.h"
64 #include "rsa.h"
65 #include "buffer.h"
66 #include "key.h"
67 #include "authfd.h"
68 #include "compat.h"
69 #include "log.h"
70 #include "misc.h"
71 #include "getpeereid.h"
72
73 #ifdef SMARTCARD
74 #include "scard.h"
75 #endif
76
77 typedef enum {
78 AUTH_UNUSED,
79 AUTH_SOCKET,
80 AUTH_CONNECTION
81 } sock_type;
82
83 typedef struct {
84 int fd;
85 sock_type type;
86 Buffer input;
87 Buffer output;
88 Buffer request;
89 } SocketEntry;
90
91 u_int sockets_alloc = 0;
92 SocketEntry *sockets = NULL;
93
94 typedef struct identity {
95 TAILQ_ENTRY(identity) next;
96 Key *key;
97 char *comment;
98 u_int death;
99 u_int confirm;
100 } Identity;
101
102 typedef struct {
103 int nentries;
104 TAILQ_HEAD(idqueue, identity) idlist;
105 } Idtab;
106
107 /* private key table, one per protocol version */
108 Idtab idtable[3];
109
110 int max_fd = 0;
111
112 /* pid of shell == parent of agent */
113 pid_t parent_pid = -1;
114 u_int parent_alive_interval = 0;
115
116 /* pathname and directory for AUTH_SOCKET */
117 char socket_name[MAXPATHLEN];
118 char socket_dir[MAXPATHLEN];
119
120 /* locking */
121 int locked = 0;
122 char *lock_passwd = NULL;
123
124 extern char *__progname;
125
126 /* Default lifetime (0 == forever) */
127 static int lifetime = 0;
128
129 static void
130 close_socket(SocketEntry *e)
131 {
132 close(e->fd);
133 e->fd = -1;
134 e->type = AUTH_UNUSED;
135 buffer_free(&e->input);
136 buffer_free(&e->output);
137 buffer_free(&e->request);
138 }
139
140 static void
141 idtab_init(void)
142 {
143 int i;
144
145 for (i = 0; i <=2; i++) {
146 TAILQ_INIT(&idtable[i].idlist);
147 idtable[i].nentries = 0;
148 }
149 }
150
151 /* return private key table for requested protocol version */
152 static Idtab *
153 idtab_lookup(int version)
154 {
155 if (version < 1 || version > 2)
156 fatal("internal error, bad protocol version %d", version);
157 return &idtable[version];
158 }
159
160 static void
161 free_identity(Identity *id)
162 {
163 key_free(id->key);
164 xfree(id->comment);
165 xfree(id);
166 }
167
168 /* return matching private key for given public key */
169 static Identity *
170 lookup_identity(Key *key, int version)
171 {
172 Identity *id;
173
174 Idtab *tab = idtab_lookup(version);
175 TAILQ_FOREACH(id, &tab->idlist, next) {
176 if (key_equal(key, id->key))
177 return (id);
178 }
179 return (NULL);
180 }
181
182 /* Check confirmation of keysign request */
183 static int
184 confirm_key(Identity *id)
185 {
186 char *p;
187 int ret = -1;
188
189 p = key_fingerprint(id->key, SSH_FP_MD5, SSH_FP_HEX);
190 if (ask_permission("Allow use of key %s?\nKey fingerprint %s.",
191 id->comment, p))
192 ret = 0;
193 xfree(p);
194
195 return (ret);
196 }
197
198 /* send list of supported public keys to 'client' */
199 static void
200 process_request_identities(SocketEntry *e, int version)
201 {
202 Idtab *tab = idtab_lookup(version);
203 Identity *id;
204 Buffer msg;
205
206 buffer_init(&msg);
207 buffer_put_char(&msg, (version == 1) ?
208 SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
209 buffer_put_int(&msg, tab->nentries);
210 TAILQ_FOREACH(id, &tab->idlist, next) {
211 if (id->key->type == KEY_RSA1) {
212 buffer_put_int(&msg, BN_num_bits(id->key->rsa->n));
213 buffer_put_bignum(&msg, id->key->rsa->e);
214 buffer_put_bignum(&msg, id->key->rsa->n);
215 } else {
216 u_char *blob;
217 u_int blen;
218 key_to_blob(id->key, &blob, &blen);
219 buffer_put_string(&msg, blob, blen);
220 xfree(blob);
221 }
222 buffer_put_cstring(&msg, id->comment);
223 }
224 buffer_put_int(&e->output, buffer_len(&msg));
225 buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
226 buffer_free(&msg);
227 }
228
229 /* ssh1 only */
230 static void
231 process_authentication_challenge1(SocketEntry *e)
232 {
233 u_char buf[32], mdbuf[16], session_id[16];
234 u_int response_type;
235 BIGNUM *challenge;
236 Identity *id;
237 int i, len;
238 Buffer msg;
239 MD5_CTX md;
240 Key *key;
241
242 buffer_init(&msg);
243 key = key_new(KEY_RSA1);
244 if ((challenge = BN_new()) == NULL)
245 fatal("process_authentication_challenge1: BN_new failed");
246
247 (void) buffer_get_int(&e->request); /* ignored */
248 buffer_get_bignum(&e->request, key->rsa->e);
249 buffer_get_bignum(&e->request, key->rsa->n);
250 buffer_get_bignum(&e->request, challenge);
251
252 /* Only protocol 1.1 is supported */
253 if (buffer_len(&e->request) == 0)
254 goto failure;
255 buffer_get(&e->request, session_id, 16);
256 response_type = buffer_get_int(&e->request);
257 if (response_type != 1)
258 goto failure;
259
260 id = lookup_identity(key, 1);
261 if (id != NULL && (!id->confirm || confirm_key(id) == 0)) {
262 Key *private = id->key;
263 /* Decrypt the challenge using the private key. */
264 if (rsa_private_decrypt(challenge, challenge, private->rsa) <= 0)
265 goto failure;
266
267 /* The response is MD5 of decrypted challenge plus session id. */
268 len = BN_num_bytes(challenge);
269 if (len <= 0 || len > 32) {
270 logit("process_authentication_challenge: bad challenge length %d", len);
271 goto failure;
272 }
273 memset(buf, 0, 32);
274 BN_bn2bin(challenge, buf + 32 - len);
275 MD5_Init(&md);
276 MD5_Update(&md, buf, 32);
277 MD5_Update(&md, session_id, 16);
278 MD5_Final(mdbuf, &md);
279
280 /* Send the response. */
281 buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE);
282 for (i = 0; i < 16; i++)
283 buffer_put_char(&msg, mdbuf[i]);
284 goto send;
285 }
286
287 failure:
288 /* Unknown identity or protocol error. Send failure. */
289 buffer_put_char(&msg, SSH_AGENT_FAILURE);
290 send:
291 buffer_put_int(&e->output, buffer_len(&msg));
292 buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
293 key_free(key);
294 BN_clear_free(challenge);
295 buffer_free(&msg);
296 }
297
298 /* ssh2 only */
299 static void
300 process_sign_request2(SocketEntry *e)
301 {
302 u_char *blob, *data, *signature = NULL;
303 u_int blen, dlen, slen = 0;
304 extern int datafellows;
305 int odatafellows;
306 int ok = -1, flags;
307 Buffer msg;
308 Key *key;
309
310 odatafellows = datafellows;
311 datafellows = 0;
312
313 blob = buffer_get_string(&e->request, &blen);
314 data = buffer_get_string(&e->request, &dlen);
315
316 flags = buffer_get_int(&e->request);
317 if (flags & SSH_AGENT_OLD_SIGNATURE)
318 datafellows = SSH_BUG_SIGBLOB;
319
320 key = key_from_blob(blob, blen);
321 if (key != NULL) {
322 Identity *id = lookup_identity(key, 2);
323 if (id != NULL && (!id->confirm || confirm_key(id) == 0))
324 ok = key_sign(id->key, &signature, &slen, data, dlen);
325 key_free(key);
326 }
327 buffer_init(&msg);
328 if (ok == 0) {
329 buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE);
330 buffer_put_string(&msg, signature, slen);
331 } else {
332 buffer_put_char(&msg, SSH_AGENT_FAILURE);
333 }
334 buffer_put_int(&e->output, buffer_len(&msg));
335 buffer_append(&e->output, buffer_ptr(&msg),
336 buffer_len(&msg));
337 buffer_free(&msg);
338 xfree(data);
339 xfree(blob);
340 if (signature != NULL)
341 xfree(signature);
342 datafellows = odatafellows;
343 }
344
345 /* shared */
346 static void
347 process_remove_identity(SocketEntry *e, int version)
348 {
349 u_int blen, bits;
350 int success = 0;
351 Key *key = NULL;
352 u_char *blob;
353
354 switch (version) {
355 case 1:
356 key = key_new(KEY_RSA1);
357 bits = buffer_get_int(&e->request);
358 buffer_get_bignum(&e->request, key->rsa->e);
359 buffer_get_bignum(&e->request, key->rsa->n);
360
361 if (bits != key_size(key))
362 logit("Warning: identity keysize mismatch: actual %u, announced %u",
363 key_size(key), bits);
364 break;
365 case 2:
366 blob = buffer_get_string(&e->request, &blen);
367 key = key_from_blob(blob, blen);
368 xfree(blob);
369 break;
370 }
371 if (key != NULL) {
372 Identity *id = lookup_identity(key, version);
373 if (id != NULL) {
374 /*
375 * We have this key. Free the old key. Since we
376 * don't want to leave empty slots in the middle of
377 * the array, we actually free the key there and move
378 * all the entries between the empty slot and the end
379 * of the array.
380 */
381 Idtab *tab = idtab_lookup(version);
382 if (tab->nentries < 1)
383 fatal("process_remove_identity: "
384 "internal error: tab->nentries %d",
385 tab->nentries);
386 TAILQ_REMOVE(&tab->idlist, id, next);
387 free_identity(id);
388 tab->nentries--;
389 success = 1;
390 }
391 key_free(key);
392 }
393 buffer_put_int(&e->output, 1);
394 buffer_put_char(&e->output,
395 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
396 }
397
398 static void
399 process_remove_all_identities(SocketEntry *e, int version)
400 {
401 Idtab *tab = idtab_lookup(version);
402 Identity *id;
403
404 /* Loop over all identities and clear the keys. */
405 while ((id = TAILQ_FIRST(&tab->idlist)) != NULL) {
406 TAILQ_REMOVE(&tab->idlist, id, next);
407 free_identity(id);
408 }
409
410 /* Mark that there are no identities. */
411 tab->nentries = 0;
412
413 /* Send success. */
414 buffer_put_int(&e->output, 1);
415 buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
416 }
417
418 /* removes expired keys and returns number of seconds until the next expiry */
419 static u_int
420 reaper(void)
421 {
422 u_int deadline = 0, now = time(NULL);
423 Identity *id, *nxt;
424 int version;
425 Idtab *tab;
426
427 for (version = 1; version < 3; version++) {
428 tab = idtab_lookup(version);
429 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) {
430 nxt = TAILQ_NEXT(id, next);
431 if (id->death == 0)
432 continue;
433 if (now >= id->death) {
434 debug("expiring key '%s'", id->comment);
435 TAILQ_REMOVE(&tab->idlist, id, next);
436 free_identity(id);
437 tab->nentries--;
438 } else
439 deadline = (deadline == 0) ? id->death :
440 MIN(deadline, id->death);
441 }
442 }
443 if (deadline == 0 || deadline <= now)
444 return 0;
445 else
446 return (deadline - now);
447 }
448
449 static void
450 process_add_identity(SocketEntry *e, int version)
451 {
452 Idtab *tab = idtab_lookup(version);
453 Identity *id;
454 int type, success = 0, death = 0, confirm = 0;
455 char *type_name, *comment;
456 Key *k = NULL;
457
458 switch (version) {
459 case 1:
460 k = key_new_private(KEY_RSA1);
461 (void) buffer_get_int(&e->request); /* ignored */
462 buffer_get_bignum(&e->request, k->rsa->n);
463 buffer_get_bignum(&e->request, k->rsa->e);
464 buffer_get_bignum(&e->request, k->rsa->d);
465 buffer_get_bignum(&e->request, k->rsa->iqmp);
466
467 /* SSH and SSL have p and q swapped */
468 buffer_get_bignum(&e->request, k->rsa->q); /* p */
469 buffer_get_bignum(&e->request, k->rsa->p); /* q */
470
471 /* Generate additional parameters */
472 rsa_generate_additional_parameters(k->rsa);
473 break;
474 case 2:
475 type_name = buffer_get_string(&e->request, NULL);
476 type = key_type_from_name(type_name);
477 xfree(type_name);
478 switch (type) {
479 case KEY_DSA:
480 k = key_new_private(type);
481 buffer_get_bignum2(&e->request, k->dsa->p);
482 buffer_get_bignum2(&e->request, k->dsa->q);
483 buffer_get_bignum2(&e->request, k->dsa->g);
484 buffer_get_bignum2(&e->request, k->dsa->pub_key);
485 buffer_get_bignum2(&e->request, k->dsa->priv_key);
486 break;
487 case KEY_RSA:
488 k = key_new_private(type);
489 buffer_get_bignum2(&e->request, k->rsa->n);
490 buffer_get_bignum2(&e->request, k->rsa->e);
491 buffer_get_bignum2(&e->request, k->rsa->d);
492 buffer_get_bignum2(&e->request, k->rsa->iqmp);
493 buffer_get_bignum2(&e->request, k->rsa->p);
494 buffer_get_bignum2(&e->request, k->rsa->q);
495
496 /* Generate additional parameters */
497 rsa_generate_additional_parameters(k->rsa);
498 break;
499 default:
500 buffer_clear(&e->request);
501 goto send;
502 }
503 break;
504 }
505 /* enable blinding */
506 switch (k->type) {
507 case KEY_RSA:
508 case KEY_RSA1:
509 if (RSA_blinding_on(k->rsa, NULL) != 1) {
510 error("process_add_identity: RSA_blinding_on failed");
511 key_free(k);
512 goto send;
513 }
514 break;
515 }
516 comment = buffer_get_string(&e->request, NULL);
517 if (k == NULL) {
518 xfree(comment);
519 goto send;
520 }
521 while (buffer_len(&e->request)) {
522 switch ((type = buffer_get_char(&e->request))) {
523 case SSH_AGENT_CONSTRAIN_LIFETIME:
524 death = time(NULL) + buffer_get_int(&e->request);
525 break;
526 case SSH_AGENT_CONSTRAIN_CONFIRM:
527 confirm = 1;
528 break;
529 default:
530 error("process_add_identity: "
531 "Unknown constraint type %d", type);
532 xfree(comment);
533 key_free(k);
534 goto send;
535 }
536 }
537 success = 1;
538 if (lifetime && !death)
539 death = time(NULL) + lifetime;
540 if ((id = lookup_identity(k, version)) == NULL) {
541 id = xmalloc(sizeof(Identity));
542 id->key = k;
543 TAILQ_INSERT_TAIL(&tab->idlist, id, next);
544 /* Increment the number of identities. */
545 tab->nentries++;
546 } else {
547 key_free(k);
548 xfree(id->comment);
549 }
550 id->comment = comment;
551 id->death = death;
552 id->confirm = confirm;
553 send:
554 buffer_put_int(&e->output, 1);
555 buffer_put_char(&e->output,
556 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
557 }
558
559 /* XXX todo: encrypt sensitive data with passphrase */
560 static void
561 process_lock_agent(SocketEntry *e, int lock)
562 {
563 int success = 0;
564 char *passwd;
565
566 passwd = buffer_get_string(&e->request, NULL);
567 if (locked && !lock && strcmp(passwd, lock_passwd) == 0) {
568 locked = 0;
569 memset(lock_passwd, 0, strlen(lock_passwd));
570 xfree(lock_passwd);
571 lock_passwd = NULL;
572 success = 1;
573 } else if (!locked && lock) {
574 locked = 1;
575 lock_passwd = xstrdup(passwd);
576 success = 1;
577 }
578 memset(passwd, 0, strlen(passwd));
579 xfree(passwd);
580
581 buffer_put_int(&e->output, 1);
582 buffer_put_char(&e->output,
583 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
584 }
585
586 static void
587 no_identities(SocketEntry *e, u_int type)
588 {
589 Buffer msg;
590
591 buffer_init(&msg);
592 buffer_put_char(&msg,
593 (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ?
594 SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
595 buffer_put_int(&msg, 0);
596 buffer_put_int(&e->output, buffer_len(&msg));
597 buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
598 buffer_free(&msg);
599 }
600
601 #ifdef SMARTCARD
602 static void
603 process_add_smartcard_key(SocketEntry *e)
604 {
605 char *sc_reader_id = NULL, *pin;
606 int i, type, version, success = 0, death = 0, confirm = 0;
607 Key **keys, *k;
608 Identity *id;
609 Idtab *tab;
610
611 sc_reader_id = buffer_get_string(&e->request, NULL);
612 pin = buffer_get_string(&e->request, NULL);
613
614 while (buffer_len(&e->request)) {
615 switch ((type = buffer_get_char(&e->request))) {
616 case SSH_AGENT_CONSTRAIN_LIFETIME:
617 death = time(NULL) + buffer_get_int(&e->request);
618 break;
619 case SSH_AGENT_CONSTRAIN_CONFIRM:
620 confirm = 1;
621 break;
622 default:
623 error("process_add_smartcard_key: "
624 "Unknown constraint type %d", type);
625 xfree(sc_reader_id);
626 xfree(pin);
627 goto send;
628 }
629 }
630 if (lifetime && !death)
631 death = time(NULL) + lifetime;
632
633 keys = sc_get_keys(sc_reader_id, pin);
634 xfree(sc_reader_id);
635 xfree(pin);
636
637 if (keys == NULL || keys[0] == NULL) {
638 error("sc_get_keys failed");
639 goto send;
640 }
641 for (i = 0; keys[i] != NULL; i++) {
642 k = keys[i];
643 version = k->type == KEY_RSA1 ? 1 : 2;
644 tab = idtab_lookup(version);
645 if (lookup_identity(k, version) == NULL) {
646 id = xmalloc(sizeof(Identity));
647 id->key = k;
648 id->comment = sc_get_key_label(k);
649 id->death = death;
650 id->confirm = confirm;
651 TAILQ_INSERT_TAIL(&tab->idlist, id, next);
652 tab->nentries++;
653 success = 1;
654 } else {
655 key_free(k);
656 }
657 keys[i] = NULL;
658 }
659 xfree(keys);
660 send:
661 buffer_put_int(&e->output, 1);
662 buffer_put_char(&e->output,
663 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
664 }
665
666 static void
667 process_remove_smartcard_key(SocketEntry *e)
668 {
669 char *sc_reader_id = NULL, *pin;
670 int i, version, success = 0;
671 Key **keys, *k = NULL;
672 Identity *id;
673 Idtab *tab;
674
675 sc_reader_id = buffer_get_string(&e->request, NULL);
676 pin = buffer_get_string(&e->request, NULL);
677 keys = sc_get_keys(sc_reader_id, pin);
678 xfree(sc_reader_id);
679 xfree(pin);
680
681 if (keys == NULL || keys[0] == NULL) {
682 error("sc_get_keys failed");
683 goto send;
684 }
685 for (i = 0; keys[i] != NULL; i++) {
686 k = keys[i];
687 version = k->type == KEY_RSA1 ? 1 : 2;
688 if ((id = lookup_identity(k, version)) != NULL) {
689 tab = idtab_lookup(version);
690 TAILQ_REMOVE(&tab->idlist, id, next);
691 tab->nentries--;
692 free_identity(id);
693 success = 1;
694 }
695 key_free(k);
696 keys[i] = NULL;
697 }
698 xfree(keys);
699 send:
700 buffer_put_int(&e->output, 1);
701 buffer_put_char(&e->output,
702 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
703 }
704 #endif /* SMARTCARD */
705
706 /* dispatch incoming messages */
707
708 static void
709 process_message(SocketEntry *e)
710 {
711 u_int msg_len, type;
712 u_char *cp;
713
714 if (buffer_len(&e->input) < 5)
715 return; /* Incomplete message. */
716 cp = buffer_ptr(&e->input);
717 msg_len = get_u32(cp);
718 if (msg_len > 256 * 1024) {
719 close_socket(e);
720 return;
721 }
722 if (buffer_len(&e->input) < msg_len + 4)
723 return;
724
725 /* move the current input to e->request */
726 buffer_consume(&e->input, 4);
727 buffer_clear(&e->request);
728 buffer_append(&e->request, buffer_ptr(&e->input), msg_len);
729 buffer_consume(&e->input, msg_len);
730 type = buffer_get_char(&e->request);
731
732 /* check wheter agent is locked */
733 if (locked && type != SSH_AGENTC_UNLOCK) {
734 buffer_clear(&e->request);
735 switch (type) {
736 case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
737 case SSH2_AGENTC_REQUEST_IDENTITIES:
738 /* send empty lists */
739 no_identities(e, type);
740 break;
741 default:
742 /* send a fail message for all other request types */
743 buffer_put_int(&e->output, 1);
744 buffer_put_char(&e->output, SSH_AGENT_FAILURE);
745 }
746 return;
747 }
748
749 debug("type %d", type);
750 switch (type) {
751 case SSH_AGENTC_LOCK:
752 case SSH_AGENTC_UNLOCK:
753 process_lock_agent(e, type == SSH_AGENTC_LOCK);
754 break;
755 /* ssh1 */
756 case SSH_AGENTC_RSA_CHALLENGE:
757 process_authentication_challenge1(e);
758 break;
759 case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
760 process_request_identities(e, 1);
761 break;
762 case SSH_AGENTC_ADD_RSA_IDENTITY:
763 case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED:
764 process_add_identity(e, 1);
765 break;
766 case SSH_AGENTC_REMOVE_RSA_IDENTITY:
767 process_remove_identity(e, 1);
768 break;
769 case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
770 process_remove_all_identities(e, 1);
771 break;
772 /* ssh2 */
773 case SSH2_AGENTC_SIGN_REQUEST:
774 process_sign_request2(e);
775 break;
776 case SSH2_AGENTC_REQUEST_IDENTITIES:
777 process_request_identities(e, 2);
778 break;
779 case SSH2_AGENTC_ADD_IDENTITY:
780 case SSH2_AGENTC_ADD_ID_CONSTRAINED:
781 process_add_identity(e, 2);
782 break;
783 case SSH2_AGENTC_REMOVE_IDENTITY:
784 process_remove_identity(e, 2);
785 break;
786 case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
787 process_remove_all_identities(e, 2);
788 break;
789 #ifdef SMARTCARD
790 case SSH_AGENTC_ADD_SMARTCARD_KEY:
791 case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
792 process_add_smartcard_key(e);
793 break;
794 case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
795 process_remove_smartcard_key(e);
796 break;
797 #endif /* SMARTCARD */
798 default:
799 /* Unknown message. Respond with failure. */
800 error("Unknown message %d", type);
801 buffer_clear(&e->request);
802 buffer_put_int(&e->output, 1);
803 buffer_put_char(&e->output, SSH_AGENT_FAILURE);
804 break;
805 }
806 }
807
808 static void
809 new_socket(sock_type type, int fd)
810 {
811 u_int i, old_alloc, new_alloc;
812
813 set_nonblock(fd);
814
815 if (fd > max_fd)
816 max_fd = fd;
817
818 for (i = 0; i < sockets_alloc; i++)
819 if (sockets[i].type == AUTH_UNUSED) {
820 sockets[i].fd = fd;
821 buffer_init(&sockets[i].input);
822 buffer_init(&sockets[i].output);
823 buffer_init(&sockets[i].request);
824 sockets[i].type = type;
825 return;
826 }
827 old_alloc = sockets_alloc;
828 new_alloc = sockets_alloc + 10;
829 sockets = xrealloc(sockets, new_alloc, sizeof(sockets[0]));
830 for (i = old_alloc; i < new_alloc; i++)
831 sockets[i].type = AUTH_UNUSED;
832 sockets_alloc = new_alloc;
833 sockets[old_alloc].fd = fd;
834 buffer_init(&sockets[old_alloc].input);
835 buffer_init(&sockets[old_alloc].output);
836 buffer_init(&sockets[old_alloc].request);
837 sockets[old_alloc].type = type;
838 }
839
840 static int
841 prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp,
842 struct timeval **tvpp)
843 {
844 u_int i, sz, deadline;
845 int n = 0;
846 static struct timeval tv;
847
848 for (i = 0; i < sockets_alloc; i++) {
849 switch (sockets[i].type) {
850 case AUTH_SOCKET:
851 case AUTH_CONNECTION:
852 n = MAX(n, sockets[i].fd);
853 break;
854 case AUTH_UNUSED:
855 break;
856 default:
857 fatal("Unknown socket type %d", sockets[i].type);
858 break;
859 }
860 }
861
862 sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
863 if (*fdrp == NULL || sz > *nallocp) {
864 if (*fdrp)
865 xfree(*fdrp);
866 if (*fdwp)
867 xfree(*fdwp);
868 *fdrp = xmalloc(sz);
869 *fdwp = xmalloc(sz);
870 *nallocp = sz;
871 }
872 if (n < *fdl)
873 debug("XXX shrink: %d < %d", n, *fdl);
874 *fdl = n;
875 memset(*fdrp, 0, sz);
876 memset(*fdwp, 0, sz);
877
878 for (i = 0; i < sockets_alloc; i++) {
879 switch (sockets[i].type) {
880 case AUTH_SOCKET:
881 case AUTH_CONNECTION:
882 FD_SET(sockets[i].fd, *fdrp);
883 if (buffer_len(&sockets[i].output) > 0)
884 FD_SET(sockets[i].fd, *fdwp);
885 break;
886 default:
887 break;
888 }
889 }
890 deadline = reaper();
891 if (parent_alive_interval != 0)
892 deadline = (deadline == 0) ? parent_alive_interval :
893 MIN(deadline, parent_alive_interval);
894 if (deadline == 0) {
895 *tvpp = NULL;
896 } else {
897 tv.tv_sec = deadline;
898 tv.tv_usec = 0;
899 *tvpp = &tv;
900 }
901 return (1);
902 }
903
904 static void
905 after_select(fd_set *readset, fd_set *writeset)
906 {
907 struct sockaddr_un sunaddr;
908 socklen_t slen;
909 char buf[1024];
910 int len, sock;
911 u_int i;
912 uid_t euid;
913 gid_t egid;
914
915 for (i = 0; i < sockets_alloc; i++)
916 switch (sockets[i].type) {
917 case AUTH_UNUSED:
918 break;
919 case AUTH_SOCKET:
920 if (FD_ISSET(sockets[i].fd, readset)) {
921 slen = sizeof(sunaddr);
922 sock = accept(sockets[i].fd,
923 (struct sockaddr *)&sunaddr, &slen);
924 if (sock < 0) {
925 error("accept from AUTH_SOCKET: %s",
926 strerror(errno));
927 break;
928 }
929 if (getpeereid(sock, &euid, &egid) < 0) {
930 error("getpeereid %d failed: %s",
931 sock, strerror(errno));
932 close(sock);
933 break;
934 }
935 if ((euid != 0) && (getuid() != euid)) {
936 error("uid mismatch: "
937 "peer euid %u != uid %u",
938 (u_int) euid, (u_int) getuid());
939 close(sock);
940 break;
941 }
942 new_socket(AUTH_CONNECTION, sock);
943 }
944 break;
945 case AUTH_CONNECTION:
946 if (buffer_len(&sockets[i].output) > 0 &&
947 FD_ISSET(sockets[i].fd, writeset)) {
948 do {
949 len = write(sockets[i].fd,
950 buffer_ptr(&sockets[i].output),
951 buffer_len(&sockets[i].output));
952 if (len == -1 && (errno == EAGAIN ||
953 errno == EINTR))
954 continue;
955 break;
956 } while (1);
957 if (len <= 0) {
958 close_socket(&sockets[i]);
959 break;
960 }
961 buffer_consume(&sockets[i].output, len);
962 }
963 if (FD_ISSET(sockets[i].fd, readset)) {
964 do {
965 len = read(sockets[i].fd, buf, sizeof(buf));
966 if (len == -1 && (errno == EAGAIN ||
967 errno == EINTR))
968 continue;
969 break;
970 } while (1);
971 if (len <= 0) {
972 close_socket(&sockets[i]);
973 break;
974 }
975 buffer_append(&sockets[i].input, buf, len);
976 process_message(&sockets[i]);
977 }
978 break;
979 default:
980 fatal("Unknown type %d", sockets[i].type);
981 }
982 }
983
984 static void
985 cleanup_socket(void)
986 {
987 if (socket_name[0])
988 unlink(socket_name);
989 if (socket_dir[0])
990 rmdir(socket_dir);
991 }
992
993 void
994 cleanup_exit(int i)
995 {
996 cleanup_socket();
997 _exit(i);
998 }
999
1000 /*ARGSUSED*/
1001 static void
1002 cleanup_handler(int sig)
1003 {
1004 cleanup_socket();
1005 _exit(2);
1006 }
1007
1008 static void
1009 check_parent_exists(void)
1010 {
1011 if (parent_pid != -1 && kill(parent_pid, 0) < 0) {
1012 /* printf("Parent has died - Authentication agent exiting.\n"); */
1013 cleanup_socket();
1014 _exit(2);
1015 }
1016 }
1017
1018 static void
1019 usage(void)
1020 {
1021 fprintf(stderr, "usage: %s [options] [command [arg ...]]\n",
1022 __progname);
1023 fprintf(stderr, "Options:\n");
1024 fprintf(stderr, " -c Generate C-shell commands on stdout.\n");
1025 fprintf(stderr, " -s Generate Bourne shell commands on stdout.\n");
1026 fprintf(stderr, " -k Kill the current agent.\n");
1027 fprintf(stderr, " -d Debug mode.\n");
1028 fprintf(stderr, " -a socket Bind agent socket to given name.\n");
1029 fprintf(stderr, " -t life Default identity lifetime (seconds).\n");
1030 exit(1);
1031 }
1032
1033 int
1034 main(int ac, char **av)
1035 {
1036 int c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0;
1037 int sock, fd, ch, result, saved_errno;
1038 u_int nalloc;
1039 char *shell, *format, *pidstr, *agentsocket = NULL;
1040 fd_set *readsetp = NULL, *writesetp = NULL;
1041 struct sockaddr_un sunaddr;
1042 struct rlimit rlim;
1043 extern int optind;
1044 extern char *optarg;
1045 pid_t pid;
1046 char pidstrbuf[1 + 3 * sizeof pid];
1047 struct timeval *tvp = NULL;
1048 size_t len;
1049
1050 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1051 sanitise_stdfd();
1052
1053 /* drop */
1054 setegid(getgid());
1055 setgid(getgid());
1056
1057 SSLeay_add_all_algorithms();
1058
1059 while ((ch = getopt(ac, av, "cdksa:t:")) != -1) {
1060 switch (ch) {
1061 case 'c':
1062 if (s_flag)
1063 usage();
1064 c_flag++;
1065 break;
1066 case 'k':
1067 k_flag++;
1068 break;
1069 case 's':
1070 if (c_flag)
1071 usage();
1072 s_flag++;
1073 break;
1074 case 'd':
1075 if (d_flag)
1076 usage();
1077 d_flag++;
1078 break;
1079 case 'a':
1080 agentsocket = optarg;
1081 break;
1082 case 't':
1083 if ((lifetime = convtime(optarg)) == -1) {
1084 fprintf(stderr, "Invalid lifetime\n");
1085 usage();
1086 }
1087 break;
1088 default:
1089 usage();
1090 }
1091 }
1092 ac -= optind;
1093 av += optind;
1094
1095 if (ac > 0 && (c_flag || k_flag || s_flag || d_flag))
1096 usage();
1097
1098 if (ac == 0 && !c_flag && !s_flag) {
1099 shell = getenv("SHELL");
1100 if (shell != NULL && (len = strlen(shell)) > 2 &&
1101 strncmp(shell + len - 3, "csh", 3) == 0)
1102 c_flag = 1;
1103 }
1104 if (k_flag) {
1105 const char *errstr = NULL;
1106
1107 pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1108 if (pidstr == NULL) {
1109 fprintf(stderr, "%s not set, cannot kill agent\n",
1110 SSH_AGENTPID_ENV_NAME);
1111 exit(1);
1112 }
1113 pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1114 if (errstr) {
1115 fprintf(stderr,
1116 "%s=\"%s\", which is not a good PID: %s\n",
1117 SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1118 exit(1);
1119 }
1120 if (kill(pid, SIGTERM) == -1) {
1121 perror("kill");
1122 exit(1);
1123 }
1124 format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1125 printf(format, SSH_AUTHSOCKET_ENV_NAME);
1126 printf(format, SSH_AGENTPID_ENV_NAME);
1127 printf("echo Agent pid %ld killed;\n", (long)pid);
1128 exit(0);
1129 }
1130 parent_pid = getpid();
1131
1132 if (agentsocket == NULL) {
1133 /* Create private directory for agent socket */
1134 strlcpy(socket_dir, "/tmp/ssh-XXXXXXXXXX", sizeof socket_dir);
1135 if (mkdtemp(socket_dir) == NULL) {
1136 perror("mkdtemp: private socket dir");
1137 exit(1);
1138 }
1139 snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1140 (long)parent_pid);
1141 } else {
1142 /* Try to use specified agent socket */
1143 socket_dir[0] = '\0';
1144 strlcpy(socket_name, agentsocket, sizeof socket_name);
1145 }
1146
1147 /*
1148 * Create socket early so it will exist before command gets run from
1149 * the parent.
1150 */
1151 sock = socket(AF_UNIX, SOCK_STREAM, 0);
1152 if (sock < 0) {
1153 perror("socket");
1154 *socket_name = '\0'; /* Don't unlink any existing file */
1155 cleanup_exit(1);
1156 }
1157 memset(&sunaddr, 0, sizeof(sunaddr));
1158 sunaddr.sun_family = AF_UNIX;
1159 strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path));
1160 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
1161 perror("bind");
1162 *socket_name = '\0'; /* Don't unlink any existing file */
1163 cleanup_exit(1);
1164 }
1165 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1166 perror("listen");
1167 cleanup_exit(1);
1168 }
1169
1170 /*
1171 * Fork, and have the parent execute the command, if any, or present
1172 * the socket data. The child continues as the authentication agent.
1173 */
1174 if (d_flag) {
1175 log_init(__progname, SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 1);
1176 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1177 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1178 SSH_AUTHSOCKET_ENV_NAME);
1179 printf("echo Agent pid %ld;\n", (long)parent_pid);
1180 goto skip;
1181 }
1182 pid = fork();
1183 if (pid == -1) {
1184 perror("fork");
1185 cleanup_exit(1);
1186 }
1187 if (pid != 0) { /* Parent - execute the given command. */
1188 close(sock);
1189 snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1190 if (ac == 0) {
1191 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1192 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1193 SSH_AUTHSOCKET_ENV_NAME);
1194 printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1195 SSH_AGENTPID_ENV_NAME);
1196 printf("echo Agent pid %ld;\n", (long)pid);
1197 exit(0);
1198 }
1199 if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1200 setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1201 perror("setenv");
1202 exit(1);
1203 }
1204 execvp(av[0], av);
1205 perror(av[0]);
1206 exit(1);
1207 }
1208 /* child */
1209 log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1210
1211 if (setsid() == -1) {
1212 error("setsid: %s", strerror(errno));
1213 cleanup_exit(1);
1214 }
1215
1216 (void)chdir("/");
1217 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1218 /* XXX might close listen socket */
1219 (void)dup2(fd, STDIN_FILENO);
1220 (void)dup2(fd, STDOUT_FILENO);
1221 (void)dup2(fd, STDERR_FILENO);
1222 if (fd > 2)
1223 close(fd);
1224 }
1225
1226 /* deny core dumps, since memory contains unencrypted private keys */
1227 rlim.rlim_cur = rlim.rlim_max = 0;
1228 if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
1229 error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1230 cleanup_exit(1);
1231 }
1232
1233 skip:
1234 new_socket(AUTH_SOCKET, sock);
1235 if (ac > 0)
1236 parent_alive_interval = 10;
1237 idtab_init();
1238 if (!d_flag)
1239 signal(SIGINT, SIG_IGN);
1240 signal(SIGPIPE, SIG_IGN);
1241 signal(SIGHUP, cleanup_handler);
1242 signal(SIGTERM, cleanup_handler);
1243 nalloc = 0;
1244
1245 while (1) {
1246 prepare_select(&readsetp, &writesetp, &max_fd, &nalloc, &tvp);
1247 result = select(max_fd + 1, readsetp, writesetp, NULL, tvp);
1248 saved_errno = errno;
1249 if (parent_alive_interval != 0)
1250 check_parent_exists();
1251 (void) reaper(); /* remove expired keys */
1252 if (result < 0) {
1253 if (saved_errno == EINTR)
1254 continue;
1255 fatal("select: %s", strerror(saved_errno));
1256 } else if (result > 0)
1257 after_select(readsetp, writesetp);
1258 }
1259 /* NOTREACHED */
1260 }
NetBSD on the FriendlyARM MINI2440