1 /* $OpenBSD: ssh-agent.c,v 1.154 2007/02/28 00:55:30 dtucker Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * The authentication agent program.
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".
14 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
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.
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.
39 #include <sys/types.h>
40 #include <sys/param.h>
41 #include <sys/resource.h>
43 #include <sys/socket.h>
44 #ifdef HAVE_SYS_TIME_H
45 # include <sys/time.h>
50 #include "openbsd-compat/sys-queue.h"
52 #include <openssl/evp.h>
53 #include <openssl/md5.h>
82 #if defined(HAVE_SYS_PRCTL_H)
83 #include <sys/prctl.h> /* For prctl() and PR_SET_DUMPABLE */
100 u_int sockets_alloc
= 0;
101 SocketEntry
*sockets
= NULL
;
103 typedef struct identity
{
104 TAILQ_ENTRY(identity
) next
;
113 TAILQ_HEAD(idqueue
, identity
) idlist
;
116 /* private key table, one per protocol version */
121 /* pid of shell == parent of agent */
122 pid_t parent_pid
= -1;
124 /* pathname and directory for AUTH_SOCKET */
125 char socket_name
[MAXPATHLEN
];
126 char socket_dir
[MAXPATHLEN
];
130 char *lock_passwd
= NULL
;
132 extern char *__progname
;
134 /* Default lifetime (0 == forever) */
135 static int lifetime
= 0;
138 close_socket(SocketEntry
*e
)
142 e
->type
= AUTH_UNUSED
;
143 buffer_free(&e
->input
);
144 buffer_free(&e
->output
);
145 buffer_free(&e
->request
);
153 for (i
= 0; i
<=2; i
++) {
154 TAILQ_INIT(&idtable
[i
].idlist
);
155 idtable
[i
].nentries
= 0;
159 /* return private key table for requested protocol version */
161 idtab_lookup(int version
)
163 if (version
< 1 || version
> 2)
164 fatal("internal error, bad protocol version %d", version
);
165 return &idtable
[version
];
169 free_identity(Identity
*id
)
176 /* return matching private key for given public key */
178 lookup_identity(Key
*key
, int version
)
182 Idtab
*tab
= idtab_lookup(version
);
183 TAILQ_FOREACH(id
, &tab
->idlist
, next
) {
184 if (key_equal(key
, id
->key
))
190 /* Check confirmation of keysign request */
192 confirm_key(Identity
*id
)
197 p
= key_fingerprint(id
->key
, SSH_FP_MD5
, SSH_FP_HEX
);
198 if (ask_permission("Allow use of key %s?\nKey fingerprint %s.",
206 /* send list of supported public keys to 'client' */
208 process_request_identities(SocketEntry
*e
, int version
)
210 Idtab
*tab
= idtab_lookup(version
);
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
);
226 key_to_blob(id
->key
, &blob
, &blen
);
227 buffer_put_string(&msg
, blob
, blen
);
230 buffer_put_cstring(&msg
, id
->comment
);
232 buffer_put_int(&e
->output
, buffer_len(&msg
));
233 buffer_append(&e
->output
, buffer_ptr(&msg
), buffer_len(&msg
));
239 process_authentication_challenge1(SocketEntry
*e
)
241 u_char buf
[32], mdbuf
[16], session_id
[16];
251 key
= key_new(KEY_RSA1
);
252 if ((challenge
= BN_new()) == NULL
)
253 fatal("process_authentication_challenge1: BN_new failed");
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
);
260 /* Only protocol 1.1 is supported */
261 if (buffer_len(&e
->request
) == 0)
263 buffer_get(&e
->request
, session_id
, 16);
264 response_type
= buffer_get_int(&e
->request
);
265 if (response_type
!= 1)
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)
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
);
282 BN_bn2bin(challenge
, buf
+ 32 - len
);
284 MD5_Update(&md
, buf
, 32);
285 MD5_Update(&md
, session_id
, 16);
286 MD5_Final(mdbuf
, &md
);
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
]);
296 /* Unknown identity or protocol error. Send failure. */
297 buffer_put_char(&msg
, SSH_AGENT_FAILURE
);
299 buffer_put_int(&e
->output
, buffer_len(&msg
));
300 buffer_append(&e
->output
, buffer_ptr(&msg
), buffer_len(&msg
));
302 BN_clear_free(challenge
);
308 process_sign_request2(SocketEntry
*e
)
310 u_char
*blob
, *data
, *signature
= NULL
;
311 u_int blen
, dlen
, slen
= 0;
312 extern int datafellows
;
319 blob
= buffer_get_string(&e
->request
, &blen
);
320 data
= buffer_get_string(&e
->request
, &dlen
);
322 flags
= buffer_get_int(&e
->request
);
323 if (flags
& SSH_AGENT_OLD_SIGNATURE
)
324 datafellows
= SSH_BUG_SIGBLOB
;
326 key
= key_from_blob(blob
, blen
);
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
);
335 buffer_put_char(&msg
, SSH2_AGENT_SIGN_RESPONSE
);
336 buffer_put_string(&msg
, signature
, slen
);
338 buffer_put_char(&msg
, SSH_AGENT_FAILURE
);
340 buffer_put_int(&e
->output
, buffer_len(&msg
));
341 buffer_append(&e
->output
, buffer_ptr(&msg
),
346 if (signature
!= NULL
)
352 process_remove_identity(SocketEntry
*e
, int version
)
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
);
366 if (bits
!= key_size(key
))
367 logit("Warning: identity keysize mismatch: actual %u, announced %u",
368 key_size(key
), bits
);
371 blob
= buffer_get_string(&e
->request
, &blen
);
372 key
= key_from_blob(blob
, blen
);
377 Identity
*id
= lookup_identity(key
, version
);
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
386 Idtab
*tab
= idtab_lookup(version
);
387 if (tab
->nentries
< 1)
388 fatal("process_remove_identity: "
389 "internal error: tab->nentries %d",
391 TAILQ_REMOVE(&tab
->idlist
, id
, next
);
398 buffer_put_int(&e
->output
, 1);
399 buffer_put_char(&e
->output
,
400 success
? SSH_AGENT_SUCCESS
: SSH_AGENT_FAILURE
);
404 process_remove_all_identities(SocketEntry
*e
, int version
)
406 Idtab
*tab
= idtab_lookup(version
);
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
);
416 /* Mark that there are no identities. */
420 buffer_put_int(&e
->output
, 1);
421 buffer_put_char(&e
->output
, SSH_AGENT_SUCCESS
);
427 u_int now
= time(NULL
);
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
);
447 process_add_identity(SocketEntry
*e
, int version
)
449 Idtab
*tab
= idtab_lookup(version
);
450 int type
, success
= 0, death
= 0, confirm
= 0;
451 char *type_name
, *comment
;
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
);
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 */
467 /* Generate additional parameters */
468 rsa_generate_additional_parameters(k
->rsa
);
471 type_name
= buffer_get_string(&e
->request
, NULL
);
472 type
= key_type_from_name(type_name
);
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
);
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
);
492 /* Generate additional parameters */
493 rsa_generate_additional_parameters(k
->rsa
);
496 buffer_clear(&e
->request
);
501 /* enable blinding */
505 if (RSA_blinding_on(k
->rsa
, NULL
) != 1) {
506 error("process_add_identity: RSA_blinding_on failed");
512 comment
= buffer_get_string(&e
->request
, NULL
);
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
);
523 case SSH_AGENT_CONSTRAIN_CONFIRM
:
530 if (lifetime
&& !death
)
531 death
= time(NULL
) + lifetime
;
532 if (lookup_identity(k
, version
) == NULL
) {
533 Identity
*id
= xmalloc(sizeof(Identity
));
535 id
->comment
= comment
;
537 id
->confirm
= confirm
;
538 TAILQ_INSERT_TAIL(&tab
->idlist
, id
, next
);
539 /* Increment the number of identities. */
546 buffer_put_int(&e
->output
, 1);
547 buffer_put_char(&e
->output
,
548 success
? SSH_AGENT_SUCCESS
: SSH_AGENT_FAILURE
);
551 /* XXX todo: encrypt sensitive data with passphrase */
553 process_lock_agent(SocketEntry
*e
, int lock
)
558 passwd
= buffer_get_string(&e
->request
, NULL
);
559 if (locked
&& !lock
&& strcmp(passwd
, lock_passwd
) == 0) {
561 memset(lock_passwd
, 0, strlen(lock_passwd
));
565 } else if (!locked
&& lock
) {
567 lock_passwd
= xstrdup(passwd
);
570 memset(passwd
, 0, strlen(passwd
));
573 buffer_put_int(&e
->output
, 1);
574 buffer_put_char(&e
->output
,
575 success
? SSH_AGENT_SUCCESS
: SSH_AGENT_FAILURE
);
579 no_identities(SocketEntry
*e
, u_int type
)
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
));
595 process_add_smartcard_key (SocketEntry
*e
)
597 char *sc_reader_id
= NULL
, *pin
;
598 int i
, version
, success
= 0, death
= 0, confirm
= 0;
603 sc_reader_id
= buffer_get_string(&e
->request
, NULL
);
604 pin
= buffer_get_string(&e
->request
, NULL
);
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
);
611 case SSH_AGENT_CONSTRAIN_CONFIRM
:
618 if (lifetime
&& !death
)
619 death
= time(NULL
) + lifetime
;
621 keys
= sc_get_keys(sc_reader_id
, pin
);
625 if (keys
== NULL
|| keys
[0] == NULL
) {
626 error("sc_get_keys failed");
629 for (i
= 0; keys
[i
] != NULL
; 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
));
636 id
->comment
= sc_get_key_label(k
);
638 id
->confirm
= confirm
;
639 TAILQ_INSERT_TAIL(&tab
->idlist
, id
, next
);
649 buffer_put_int(&e
->output
, 1);
650 buffer_put_char(&e
->output
,
651 success
? SSH_AGENT_SUCCESS
: SSH_AGENT_FAILURE
);
655 process_remove_smartcard_key(SocketEntry
*e
)
657 char *sc_reader_id
= NULL
, *pin
;
658 int i
, version
, success
= 0;
659 Key
**keys
, *k
= NULL
;
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
);
669 if (keys
== NULL
|| keys
[0] == NULL
) {
670 error("sc_get_keys failed");
673 for (i
= 0; keys
[i
] != NULL
; 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
);
688 buffer_put_int(&e
->output
, 1);
689 buffer_put_char(&e
->output
,
690 success
? SSH_AGENT_SUCCESS
: SSH_AGENT_FAILURE
);
692 #endif /* SMARTCARD */
694 /* dispatch incoming messages */
697 process_message(SocketEntry
*e
)
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) {
710 if (buffer_len(&e
->input
) < msg_len
+ 4)
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
);
720 /* check wheter agent is locked */
721 if (locked
&& type
!= SSH_AGENTC_UNLOCK
) {
722 buffer_clear(&e
->request
);
724 case SSH_AGENTC_REQUEST_RSA_IDENTITIES
:
725 case SSH2_AGENTC_REQUEST_IDENTITIES
:
726 /* send empty lists */
727 no_identities(e
, type
);
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
);
737 debug("type %d", type
);
739 case SSH_AGENTC_LOCK
:
740 case SSH_AGENTC_UNLOCK
:
741 process_lock_agent(e
, type
== SSH_AGENTC_LOCK
);
744 case SSH_AGENTC_RSA_CHALLENGE
:
745 process_authentication_challenge1(e
);
747 case SSH_AGENTC_REQUEST_RSA_IDENTITIES
:
748 process_request_identities(e
, 1);
750 case SSH_AGENTC_ADD_RSA_IDENTITY
:
751 case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED
:
752 process_add_identity(e
, 1);
754 case SSH_AGENTC_REMOVE_RSA_IDENTITY
:
755 process_remove_identity(e
, 1);
757 case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES
:
758 process_remove_all_identities(e
, 1);
761 case SSH2_AGENTC_SIGN_REQUEST
:
762 process_sign_request2(e
);
764 case SSH2_AGENTC_REQUEST_IDENTITIES
:
765 process_request_identities(e
, 2);
767 case SSH2_AGENTC_ADD_IDENTITY
:
768 case SSH2_AGENTC_ADD_ID_CONSTRAINED
:
769 process_add_identity(e
, 2);
771 case SSH2_AGENTC_REMOVE_IDENTITY
:
772 process_remove_identity(e
, 2);
774 case SSH2_AGENTC_REMOVE_ALL_IDENTITIES
:
775 process_remove_all_identities(e
, 2);
778 case SSH_AGENTC_ADD_SMARTCARD_KEY
:
779 case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED
:
780 process_add_smartcard_key(e
);
782 case SSH_AGENTC_REMOVE_SMARTCARD_KEY
:
783 process_remove_smartcard_key(e
);
785 #endif /* SMARTCARD */
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
);
797 new_socket(sock_type type
, int fd
)
799 u_int i
, old_alloc
, new_alloc
;
806 for (i
= 0; i
< sockets_alloc
; i
++)
807 if (sockets
[i
].type
== AUTH_UNUSED
) {
809 buffer_init(&sockets
[i
].input
);
810 buffer_init(&sockets
[i
].output
);
811 buffer_init(&sockets
[i
].request
);
812 sockets
[i
].type
= type
;
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
;
829 prepare_select(fd_set
**fdrp
, fd_set
**fdwp
, int *fdl
, u_int
*nallocp
)
834 for (i
= 0; i
< sockets_alloc
; i
++) {
835 switch (sockets
[i
].type
) {
837 case AUTH_CONNECTION
:
838 n
= MAX(n
, sockets
[i
].fd
);
843 fatal("Unknown socket type %d", sockets
[i
].type
);
848 sz
= howmany(n
+1, NFDBITS
) * sizeof(fd_mask
);
849 if (*fdrp
== NULL
|| sz
> *nallocp
) {
859 debug("XXX shrink: %d < %d", n
, *fdl
);
861 memset(*fdrp
, 0, sz
);
862 memset(*fdwp
, 0, sz
);
864 for (i
= 0; i
< sockets_alloc
; i
++) {
865 switch (sockets
[i
].type
) {
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
);
880 after_select(fd_set
*readset
, fd_set
*writeset
)
882 struct sockaddr_un sunaddr
;
890 for (i
= 0; i
< sockets_alloc
; i
++)
891 switch (sockets
[i
].type
) {
895 if (FD_ISSET(sockets
[i
].fd
, readset
)) {
896 slen
= sizeof(sunaddr
);
897 sock
= accept(sockets
[i
].fd
,
898 (struct sockaddr
*)&sunaddr
, &slen
);
900 error("accept from AUTH_SOCKET: %s",
904 if (getpeereid(sock
, &euid
, &egid
) < 0) {
905 error("getpeereid %d failed: %s",
906 sock
, strerror(errno
));
910 if ((euid
!= 0) && (getuid() != euid
)) {
911 error("uid mismatch: "
912 "peer euid %u != uid %u",
913 (u_int
) euid
, (u_int
) getuid());
917 new_socket(AUTH_CONNECTION
, sock
);
920 case AUTH_CONNECTION
:
921 if (buffer_len(&sockets
[i
].output
) > 0 &&
922 FD_ISSET(sockets
[i
].fd
, writeset
)) {
924 len
= write(sockets
[i
].fd
,
925 buffer_ptr(&sockets
[i
].output
),
926 buffer_len(&sockets
[i
].output
));
927 if (len
== -1 && (errno
== EAGAIN
||
933 close_socket(&sockets
[i
]);
936 buffer_consume(&sockets
[i
].output
, len
);
938 if (FD_ISSET(sockets
[i
].fd
, readset
)) {
940 len
= read(sockets
[i
].fd
, buf
, sizeof(buf
));
941 if (len
== -1 && (errno
== EAGAIN
||
947 close_socket(&sockets
[i
]);
950 buffer_append(&sockets
[i
].input
, buf
, len
);
951 process_message(&sockets
[i
]);
955 fatal("Unknown type %d", sockets
[i
].type
);
977 cleanup_handler(int sig
)
985 check_parent_exists(int sig
)
987 int save_errno
= errno
;
989 if (parent_pid
!= -1 && kill(parent_pid
, 0) < 0) {
990 /* printf("Parent has died - Authentication agent exiting.\n"); */
991 cleanup_handler(sig
); /* safe */
993 mysignal(SIGALRM
, check_parent_exists
);
1001 fprintf(stderr
, "Usage: %s [options] [command [args ...]]\n",
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");
1014 main(int ac
, char **av
)
1016 int c_flag
= 0, d_flag
= 0, k_flag
= 0, s_flag
= 0;
1017 int sock
, fd
, ch
, result
, saved_errno
;
1019 char *shell
, *format
, *pidstr
, *agentsocket
= NULL
;
1020 fd_set
*readsetp
= NULL
, *writesetp
= NULL
;
1021 struct sockaddr_un sunaddr
;
1022 #ifdef HAVE_SETRLIMIT
1027 extern char *optarg
;
1029 char pidstrbuf
[1 + 3 * sizeof pid
];
1032 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1039 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
1040 /* Disable ptrace on Linux without sgid bit */
1041 prctl(PR_SET_DUMPABLE
, 0);
1044 SSLeay_add_all_algorithms();
1046 __progname
= ssh_get_progname(av
[0]);
1050 while ((ch
= getopt(ac
, av
, "cdksa:t:")) != -1) {
1071 agentsocket
= optarg
;
1074 if ((lifetime
= convtime(optarg
)) == -1) {
1075 fprintf(stderr
, "Invalid lifetime\n");
1086 if (ac
> 0 && (c_flag
|| k_flag
|| s_flag
|| d_flag
))
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)
1096 const char *errstr
= NULL
;
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
);
1104 pid
= (int)strtonum(pidstr
, 2, INT_MAX
, &errstr
);
1107 "%s=\"%s\", which is not a good PID: %s\n",
1108 SSH_AGENTPID_ENV_NAME
, pidstr
, errstr
);
1111 if (kill(pid
, SIGTERM
) == -1) {
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
);
1121 parent_pid
= getpid();
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");
1130 snprintf(socket_name
, sizeof socket_name
, "%s/agent.%ld", socket_dir
,
1133 /* Try to use specified agent socket */
1134 socket_dir
[0] = '\0';
1135 strlcpy(socket_name
, agentsocket
, sizeof socket_name
);
1139 * Create socket early so it will exist before command gets run from
1142 sock
= socket(AF_UNIX
, SOCK_STREAM
, 0);
1145 *socket_name
= '\0'; /* Don't unlink any existing file */
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) {
1154 *socket_name
= '\0'; /* Don't unlink any existing file */
1159 if (listen(sock
, SSH_LISTEN_BACKLOG
) < 0) {
1165 * Fork, and have the parent execute the command, if any, or present
1166 * the socket data. The child continues as the authentication agent.
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
);
1181 if (pid
!= 0) { /* Parent - execute the given command. */
1183 snprintf(pidstrbuf
, sizeof pidstrbuf
, "%ld", (long)pid
);
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
);
1193 if (setenv(SSH_AUTHSOCKET_ENV_NAME
, socket_name
, 1) == -1 ||
1194 setenv(SSH_AGENTPID_ENV_NAME
, pidstrbuf
, 1) == -1) {
1203 log_init(__progname
, SYSLOG_LEVEL_INFO
, SYSLOG_FACILITY_AUTH
, 0);
1205 if (setsid() == -1) {
1206 error("setsid: %s", strerror(errno
));
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
);
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
));
1230 new_socket(AUTH_SOCKET
, sock
);
1232 mysignal(SIGALRM
, check_parent_exists
);
1237 signal(SIGINT
, SIG_IGN
);
1238 signal(SIGPIPE
, SIG_IGN
);
1239 signal(SIGHUP
, cleanup_handler
);
1240 signal(SIGTERM
, cleanup_handler
);
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 */
1251 if (saved_errno
== EINTR
)
1253 fatal("select: %s", strerror(saved_errno
));
1254 } else if (result
> 0)
1255 after_select(readsetp
, writesetp
);