1 /* $OpenBSD: ssh-agent.c,v 1.213 2016/05/02 08:49:03 djm 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/param.h> /* MIN MAX */
40 #include <sys/types.h>
41 #include <sys/param.h>
42 #include <sys/resource.h>
44 #include <sys/socket.h>
45 #ifdef HAVE_SYS_TIME_H
46 # include <sys/time.h>
51 #include "openbsd-compat/sys-queue.h"
54 #include <openssl/evp.h>
55 #include "openbsd-compat/openssl-compat.h"
88 #include "ssh-pkcs11.h"
100 struct sshbuf *input;
101 struct sshbuf *output;
102 struct sshbuf *request;
105 u_int sockets_alloc = 0;
106 SocketEntry *sockets = NULL;
108 typedef struct identity {
109 TAILQ_ENTRY(identity) next;
119 TAILQ_HEAD(idqueue, identity) idlist;
122 /* private key table, one per protocol version */
127 /* pid of shell == parent of agent */
128 pid_t parent_pid = -1;
129 time_t parent_alive_interval = 0;
131 /* pid of process for which cleanup_socket is applicable */
132 pid_t cleanup_pid = 0;
134 /* pathname and directory for AUTH_SOCKET */
135 char socket_name[PATH_MAX];
136 char socket_dir[PATH_MAX];
140 #define LOCK_SALT_SIZE 16
141 #define LOCK_ROUNDS 1
143 u_char lock_pwhash[LOCK_SIZE];
144 u_char lock_salt[LOCK_SALT_SIZE];
146 extern char *__progname;
148 /* Default lifetime in seconds (0 == forever) */
149 static long lifetime = 0;
151 static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
154 close_socket(SocketEntry *e)
158 e->type = AUTH_UNUSED;
159 sshbuf_free(e->input);
160 sshbuf_free(e->output);
161 sshbuf_free(e->request);
169 for (i = 0; i <=2; i++) {
170 TAILQ_INIT(&idtable[i].idlist);
171 idtable[i].nentries = 0;
175 /* return private key table for requested protocol version */
177 idtab_lookup(int version)
179 if (version < 1 || version > 2)
180 fatal("internal error, bad protocol version %d", version);
181 return &idtable[version];
185 free_identity(Identity *id)
187 sshkey_free(id->key);
193 /* return matching private key for given public key */
195 lookup_identity(struct sshkey *key, int version)
199 Idtab *tab = idtab_lookup(version);
200 TAILQ_FOREACH(id, &tab->idlist, next) {
201 if (sshkey_equal(key, id->key))
207 /* Check confirmation of keysign request */
209 confirm_key(Identity *id)
214 p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT);
216 ask_permission("Allow use of key %s?\nKey fingerprint %s.",
225 send_status(SocketEntry *e, int success)
229 if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
230 (r = sshbuf_put_u8(e->output, success ?
231 SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
232 fatal("%s: buffer error: %s", __func__, ssh_err(r));
235 /* send list of supported public keys to 'client' */
237 process_request_identities(SocketEntry *e, int version)
239 Idtab *tab = idtab_lookup(version);
244 if ((msg = sshbuf_new()) == NULL)
245 fatal("%s: sshbuf_new failed", __func__);
246 if ((r = sshbuf_put_u8(msg, (version == 1) ?
247 SSH_AGENT_RSA_IDENTITIES_ANSWER :
248 SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
249 (r = sshbuf_put_u32(msg, tab->nentries)) != 0)
250 fatal("%s: buffer error: %s", __func__, ssh_err(r));
251 TAILQ_FOREACH(id, &tab->idlist, next) {
252 if (id->key->type == KEY_RSA1) {
254 if ((r = sshbuf_put_u32(msg,
255 BN_num_bits(id->key->rsa->n))) != 0 ||
256 (r = sshbuf_put_bignum1(msg,
257 id->key->rsa->e)) != 0 ||
258 (r = sshbuf_put_bignum1(msg,
259 id->key->rsa->n)) != 0)
260 fatal("%s: buffer error: %s",
261 __func__, ssh_err(r));
267 if ((r = sshkey_to_blob(id->key, &blob, &blen)) != 0) {
268 error("%s: sshkey_to_blob: %s", __func__,
272 if ((r = sshbuf_put_string(msg, blob, blen)) != 0)
273 fatal("%s: buffer error: %s",
274 __func__, ssh_err(r));
277 if ((r = sshbuf_put_cstring(msg, id->comment)) != 0)
278 fatal("%s: buffer error: %s", __func__, ssh_err(r));
280 if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
281 fatal("%s: buffer error: %s", __func__, ssh_err(r));
288 process_authentication_challenge1(SocketEntry *e)
290 u_char buf[32], mdbuf[16], session_id[16];
296 struct ssh_digest_ctx *md;
299 if ((msg = sshbuf_new()) == NULL)
300 fatal("%s: sshbuf_new failed", __func__);
301 if ((key = sshkey_new(KEY_RSA1)) == NULL)
302 fatal("%s: sshkey_new failed", __func__);
303 if ((challenge = BN_new()) == NULL)
304 fatal("%s: BN_new failed", __func__);
306 if ((r = sshbuf_get_u32(e->request, NULL)) != 0 || /* ignored */
307 (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 ||
308 (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0 ||
309 (r = sshbuf_get_bignum1(e->request, challenge)))
310 fatal("%s: buffer error: %s", __func__, ssh_err(r));
312 /* Only protocol 1.1 is supported */
313 if (sshbuf_len(e->request) == 0)
315 if ((r = sshbuf_get(e->request, session_id, sizeof(session_id))) != 0 ||
316 (r = sshbuf_get_u32(e->request, &response_type)) != 0)
317 fatal("%s: buffer error: %s", __func__, ssh_err(r));
318 if (response_type != 1)
321 id = lookup_identity(key, 1);
322 if (id != NULL && (!id->confirm || confirm_key(id) == 0)) {
323 struct sshkey *private = id->key;
324 /* Decrypt the challenge using the private key. */
325 if ((r = rsa_private_decrypt(challenge, challenge,
326 private->rsa) != 0)) {
327 fatal("%s: rsa_public_encrypt: %s", __func__,
329 goto failure; /* XXX ? */
332 /* The response is MD5 of decrypted challenge plus session id */
333 len = BN_num_bytes(challenge);
334 if (len <= 0 || len > 32) {
335 logit("%s: bad challenge length %d", __func__, len);
339 BN_bn2bin(challenge, buf + 32 - len);
340 if ((md = ssh_digest_start(SSH_DIGEST_MD5)) == NULL ||
341 ssh_digest_update(md, buf, 32) < 0 ||
342 ssh_digest_update(md, session_id, 16) < 0 ||
343 ssh_digest_final(md, mdbuf, sizeof(mdbuf)) < 0)
344 fatal("%s: md5 failed", __func__);
347 /* Send the response. */
348 if ((r = sshbuf_put_u8(msg, SSH_AGENT_RSA_RESPONSE)) != 0 ||
349 (r = sshbuf_put(msg, mdbuf, sizeof(mdbuf))) != 0)
350 fatal("%s: buffer error: %s", __func__, ssh_err(r));
355 /* Unknown identity or protocol error. Send failure. */
356 if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
357 fatal("%s: buffer error: %s", __func__, ssh_err(r));
359 if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
360 fatal("%s: buffer error: %s", __func__, ssh_err(r));
362 BN_clear_free(challenge);
368 agent_decode_alg(struct sshkey *key, u_int flags)
370 if (key->type == KEY_RSA) {
371 if (flags & SSH_AGENT_RSA_SHA2_256)
372 return "rsa-sha2-256";
373 else if (flags & SSH_AGENT_RSA_SHA2_512)
374 return "rsa-sha2-512";
381 process_sign_request2(SocketEntry *e)
383 u_char *blob, *data, *signature = NULL;
384 size_t blen, dlen, slen = 0;
385 u_int compat = 0, flags;
391 if ((msg = sshbuf_new()) == NULL)
392 fatal("%s: sshbuf_new failed", __func__);
393 if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0 ||
394 (r = sshbuf_get_string(e->request, &data, &dlen)) != 0 ||
395 (r = sshbuf_get_u32(e->request, &flags)) != 0)
396 fatal("%s: buffer error: %s", __func__, ssh_err(r));
397 if (flags & SSH_AGENT_OLD_SIGNATURE)
398 compat = SSH_BUG_SIGBLOB;
399 if ((r = sshkey_from_blob(blob, blen, &key)) != 0) {
400 error("%s: cannot parse key blob: %s", __func__, ssh_err(r));
403 if ((id = lookup_identity(key, 2)) == NULL) {
404 verbose("%s: %s key not found", __func__, sshkey_type(key));
407 if (id->confirm && confirm_key(id) != 0) {
408 verbose("%s: user refused key", __func__);
411 if ((r = sshkey_sign(id->key, &signature, &slen,
412 data, dlen, agent_decode_alg(key, flags), compat)) != 0) {
413 error("%s: sshkey_sign: %s", __func__, ssh_err(r));
421 if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
422 (r = sshbuf_put_string(msg, signature, slen)) != 0)
423 fatal("%s: buffer error: %s", __func__, ssh_err(r));
424 } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
425 fatal("%s: buffer error: %s", __func__, ssh_err(r));
427 if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
428 fatal("%s: buffer error: %s", __func__, ssh_err(r));
438 process_remove_identity(SocketEntry *e, int version)
442 struct sshkey *key = NULL;
446 #endif /* WITH_SSH1 */
451 if ((key = sshkey_new(KEY_RSA1)) == NULL) {
452 error("%s: sshkey_new failed", __func__);
455 if ((r = sshbuf_get_u32(e->request, &bits)) != 0 ||
456 (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 ||
457 (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0)
458 fatal("%s: buffer error: %s", __func__, ssh_err(r));
460 if (bits != sshkey_size(key))
461 logit("Warning: identity keysize mismatch: "
462 "actual %u, announced %u",
463 sshkey_size(key), bits);
465 #endif /* WITH_SSH1 */
467 if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0)
468 fatal("%s: buffer error: %s", __func__, ssh_err(r));
469 if ((r = sshkey_from_blob(blob, blen, &key)) != 0)
470 error("%s: sshkey_from_blob failed: %s",
471 __func__, ssh_err(r));
476 Identity *id = lookup_identity(key, version);
479 * We have this key. Free the old key. Since we
480 * don't want to leave empty slots in the middle of
481 * the array, we actually free the key there and move
482 * all the entries between the empty slot and the end
485 Idtab *tab = idtab_lookup(version);
486 if (tab->nentries < 1)
487 fatal("process_remove_identity: "
488 "internal error: tab->nentries %d",
490 TAILQ_REMOVE(&tab->idlist, id, next);
497 send_status(e, success);
501 process_remove_all_identities(SocketEntry *e, int version)
503 Idtab *tab = idtab_lookup(version);
506 /* Loop over all identities and clear the keys. */
507 for (id = TAILQ_FIRST(&tab->idlist); id;
508 id = TAILQ_FIRST(&tab->idlist)) {
509 TAILQ_REMOVE(&tab->idlist, id, next);
513 /* Mark that there are no identities. */
520 /* removes expired keys and returns number of seconds until the next expiry */
524 time_t deadline = 0, now = monotime();
529 for (version = 1; version < 3; version++) {
530 tab = idtab_lookup(version);
531 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) {
532 nxt = TAILQ_NEXT(id, next);
535 if (now >= id->death) {
536 debug("expiring key '%s'", id->comment);
537 TAILQ_REMOVE(&tab->idlist, id, next);
541 deadline = (deadline == 0) ? id->death :
542 MIN(deadline, id->death);
545 if (deadline == 0 || deadline <= now)
548 return (deadline - now);
552 * XXX this and the corresponding serialisation function probably belongs
557 agent_decode_rsa1(struct sshbuf *m, struct sshkey **kp)
559 struct sshkey *k = NULL;
560 int r = SSH_ERR_INTERNAL_ERROR;
563 if ((k = sshkey_new_private(KEY_RSA1)) == NULL)
564 return SSH_ERR_ALLOC_FAIL;
566 if ((r = sshbuf_get_u32(m, NULL)) != 0 || /* ignored */
567 (r = sshbuf_get_bignum1(m, k->rsa->n)) != 0 ||
568 (r = sshbuf_get_bignum1(m, k->rsa->e)) != 0 ||
569 (r = sshbuf_get_bignum1(m, k->rsa->d)) != 0 ||
570 (r = sshbuf_get_bignum1(m, k->rsa->iqmp)) != 0 ||
571 /* SSH1 and SSL have p and q swapped */
572 (r = sshbuf_get_bignum1(m, k->rsa->q)) != 0 || /* p */
573 (r = sshbuf_get_bignum1(m, k->rsa->p)) != 0) /* q */
576 /* Generate additional parameters */
577 if ((r = rsa_generate_additional_parameters(k->rsa)) != 0)
579 /* enable blinding */
580 if (RSA_blinding_on(k->rsa, NULL) != 1) {
581 r = SSH_ERR_LIBCRYPTO_ERROR;
593 #endif /* WITH_SSH1 */
596 process_add_identity(SocketEntry *e, int version)
598 Idtab *tab = idtab_lookup(version);
600 int success = 0, confirm = 0;
602 char *comment = NULL;
604 struct sshkey *k = NULL;
606 int r = SSH_ERR_INTERNAL_ERROR;
611 r = agent_decode_rsa1(e->request, &k);
613 #endif /* WITH_SSH1 */
615 r = sshkey_private_deserialize(e->request, &k);
618 if (r != 0 || k == NULL ||
619 (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
620 error("%s: decode private key: %s", __func__, ssh_err(r));
624 while (sshbuf_len(e->request)) {
625 if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
626 error("%s: buffer error: %s", __func__, ssh_err(r));
630 case SSH_AGENT_CONSTRAIN_LIFETIME:
631 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
632 error("%s: bad lifetime constraint: %s",
633 __func__, ssh_err(r));
636 death = monotime() + seconds;
638 case SSH_AGENT_CONSTRAIN_CONFIRM:
642 error("%s: Unknown constraint %d", __func__, ctype);
644 sshbuf_reset(e->request);
652 if (lifetime && !death)
653 death = monotime() + lifetime;
654 if ((id = lookup_identity(k, version)) == NULL) {
655 id = xcalloc(1, sizeof(Identity));
657 TAILQ_INSERT_TAIL(&tab->idlist, id, next);
658 /* Increment the number of identities. */
664 id->comment = comment;
666 id->confirm = confirm;
668 send_status(e, success);
671 /* XXX todo: encrypt sensitive data with passphrase */
673 process_lock_agent(SocketEntry *e, int lock)
675 int r, success = 0, delay;
677 u_char passwdhash[LOCK_SIZE];
678 static u_int fail_count = 0;
681 if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
682 fatal("%s: buffer error: %s", __func__, ssh_err(r));
684 debug("empty password not supported");
685 } else if (locked && !lock) {
686 if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
687 passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
688 fatal("bcrypt_pbkdf");
689 if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
690 debug("agent unlocked");
693 explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
696 /* delay in 0.1s increments up to 10s */
697 if (fail_count < 100)
699 delay = 100000 * fail_count;
700 debug("unlock failed, delaying %0.1lf seconds",
701 (double)delay/1000000);
704 explicit_bzero(passwdhash, sizeof(passwdhash));
705 } else if (!locked && lock) {
706 debug("agent locked");
708 arc4random_buf(lock_salt, sizeof(lock_salt));
709 if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
710 lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
711 fatal("bcrypt_pbkdf");
714 explicit_bzero(passwd, pwlen);
716 send_status(e, success);
720 no_identities(SocketEntry *e, u_int type)
725 if ((msg = sshbuf_new()) == NULL)
726 fatal("%s: sshbuf_new failed", __func__);
727 if ((r = sshbuf_put_u8(msg,
728 (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ?
729 SSH_AGENT_RSA_IDENTITIES_ANSWER :
730 SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
731 (r = sshbuf_put_u32(msg, 0)) != 0 ||
732 (r = sshbuf_put_stringb(e->output, msg)) != 0)
733 fatal("%s: buffer error: %s", __func__, ssh_err(r));
739 process_add_smartcard_key(SocketEntry *e)
741 char *provider = NULL, *pin;
742 int r, i, version, count = 0, success = 0, confirm = 0;
746 struct sshkey **keys = NULL, *k;
750 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
751 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0)
752 fatal("%s: buffer error: %s", __func__, ssh_err(r));
754 while (sshbuf_len(e->request)) {
755 if ((r = sshbuf_get_u8(e->request, &type)) != 0)
756 fatal("%s: buffer error: %s", __func__, ssh_err(r));
758 case SSH_AGENT_CONSTRAIN_LIFETIME:
759 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0)
760 fatal("%s: buffer error: %s",
761 __func__, ssh_err(r));
762 death = monotime() + seconds;
764 case SSH_AGENT_CONSTRAIN_CONFIRM:
768 error("process_add_smartcard_key: "
769 "Unknown constraint type %d", type);
773 if (lifetime && !death)
774 death = monotime() + lifetime;
776 count = pkcs11_add_provider(provider, pin, &keys);
777 for (i = 0; i < count; i++) {
779 version = k->type == KEY_RSA1 ? 1 : 2;
780 tab = idtab_lookup(version);
781 if (lookup_identity(k, version) == NULL) {
782 id = xcalloc(1, sizeof(Identity));
784 id->provider = xstrdup(provider);
785 id->comment = xstrdup(provider); /* XXX */
787 id->confirm = confirm;
788 TAILQ_INSERT_TAIL(&tab->idlist, id, next);
800 send_status(e, success);
804 process_remove_smartcard_key(SocketEntry *e)
806 char *provider = NULL, *pin = NULL;
807 int r, version, success = 0;
811 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
812 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0)
813 fatal("%s: buffer error: %s", __func__, ssh_err(r));
816 for (version = 1; version < 3; version++) {
817 tab = idtab_lookup(version);
818 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) {
819 nxt = TAILQ_NEXT(id, next);
820 /* Skip file--based keys */
821 if (id->provider == NULL)
823 if (!strcmp(provider, id->provider)) {
824 TAILQ_REMOVE(&tab->idlist, id, next);
830 if (pkcs11_del_provider(provider) == 0)
833 error("process_remove_smartcard_key:"
834 " pkcs11_del_provider failed");
836 send_status(e, success);
838 #endif /* ENABLE_PKCS11 */
840 /* dispatch incoming messages */
843 process_message(SocketEntry *e)
850 if (sshbuf_len(e->input) < 5)
851 return; /* Incomplete message. */
852 cp = sshbuf_ptr(e->input);
853 msg_len = PEEK_U32(cp);
854 if (msg_len > 256 * 1024) {
858 if (sshbuf_len(e->input) < msg_len + 4)
861 /* move the current input to e->request */
862 sshbuf_reset(e->request);
863 if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
864 (r = sshbuf_get_u8(e->request, &type)) != 0)
865 fatal("%s: buffer error: %s", __func__, ssh_err(r));
867 /* check wheter agent is locked */
868 if (locked && type != SSH_AGENTC_UNLOCK) {
869 sshbuf_reset(e->request);
871 case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
872 case SSH2_AGENTC_REQUEST_IDENTITIES:
873 /* send empty lists */
874 no_identities(e, type);
877 /* send a fail message for all other request types */
883 debug("type %d", type);
885 case SSH_AGENTC_LOCK:
886 case SSH_AGENTC_UNLOCK:
887 process_lock_agent(e, type == SSH_AGENTC_LOCK);
891 case SSH_AGENTC_RSA_CHALLENGE:
892 process_authentication_challenge1(e);
894 case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
895 process_request_identities(e, 1);
897 case SSH_AGENTC_ADD_RSA_IDENTITY:
898 case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED:
899 process_add_identity(e, 1);
901 case SSH_AGENTC_REMOVE_RSA_IDENTITY:
902 process_remove_identity(e, 1);
905 case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
906 process_remove_all_identities(e, 1); /* safe for !WITH_SSH1 */
909 case SSH2_AGENTC_SIGN_REQUEST:
910 process_sign_request2(e);
912 case SSH2_AGENTC_REQUEST_IDENTITIES:
913 process_request_identities(e, 2);
915 case SSH2_AGENTC_ADD_IDENTITY:
916 case SSH2_AGENTC_ADD_ID_CONSTRAINED:
917 process_add_identity(e, 2);
919 case SSH2_AGENTC_REMOVE_IDENTITY:
920 process_remove_identity(e, 2);
922 case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
923 process_remove_all_identities(e, 2);
926 case SSH_AGENTC_ADD_SMARTCARD_KEY:
927 case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
928 process_add_smartcard_key(e);
930 case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
931 process_remove_smartcard_key(e);
933 #endif /* ENABLE_PKCS11 */
935 /* Unknown message. Respond with failure. */
936 error("Unknown message %d", type);
937 sshbuf_reset(e->request);
944 new_socket(sock_type type, int fd)
946 u_int i, old_alloc, new_alloc;
953 for (i = 0; i < sockets_alloc; i++)
954 if (sockets[i].type == AUTH_UNUSED) {
956 if ((sockets[i].input = sshbuf_new()) == NULL)
957 fatal("%s: sshbuf_new failed", __func__);
958 if ((sockets[i].output = sshbuf_new()) == NULL)
959 fatal("%s: sshbuf_new failed", __func__);
960 if ((sockets[i].request = sshbuf_new()) == NULL)
961 fatal("%s: sshbuf_new failed", __func__);
962 sockets[i].type = type;
965 old_alloc = sockets_alloc;
966 new_alloc = sockets_alloc + 10;
967 sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
968 for (i = old_alloc; i < new_alloc; i++)
969 sockets[i].type = AUTH_UNUSED;
970 sockets_alloc = new_alloc;
971 sockets[old_alloc].fd = fd;
972 if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
973 fatal("%s: sshbuf_new failed", __func__);
974 if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
975 fatal("%s: sshbuf_new failed", __func__);
976 if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
977 fatal("%s: sshbuf_new failed", __func__);
978 sockets[old_alloc].type = type;
982 prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp,
983 struct timeval **tvpp)
987 static struct timeval tv;
990 for (i = 0; i < sockets_alloc; i++) {
991 switch (sockets[i].type) {
993 case AUTH_CONNECTION:
994 n = MAX(n, sockets[i].fd);
999 fatal("Unknown socket type %d", sockets[i].type);
1004 sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1005 if (*fdrp == NULL || sz > *nallocp) {
1008 *fdrp = xmalloc(sz);
1009 *fdwp = xmalloc(sz);
1013 debug("XXX shrink: %d < %d", n, *fdl);
1015 memset(*fdrp, 0, sz);
1016 memset(*fdwp, 0, sz);
1018 for (i = 0; i < sockets_alloc; i++) {
1019 switch (sockets[i].type) {
1021 case AUTH_CONNECTION:
1022 FD_SET(sockets[i].fd, *fdrp);
1023 if (sshbuf_len(sockets[i].output) > 0)
1024 FD_SET(sockets[i].fd, *fdwp);
1030 deadline = reaper();
1031 if (parent_alive_interval != 0)
1032 deadline = (deadline == 0) ? parent_alive_interval :
1033 MIN(deadline, parent_alive_interval);
1034 if (deadline == 0) {
1037 tv.tv_sec = deadline;
1045 after_select(fd_set *readset, fd_set *writeset)
1047 struct sockaddr_un sunaddr;
1051 u_int i, orig_alloc;
1055 for (i = 0, orig_alloc = sockets_alloc; i < orig_alloc; i++)
1056 switch (sockets[i].type) {
1060 if (FD_ISSET(sockets[i].fd, readset)) {
1061 slen = sizeof(sunaddr);
1062 sock = accept(sockets[i].fd,
1063 (struct sockaddr *)&sunaddr, &slen);
1065 error("accept from AUTH_SOCKET: %s",
1069 if (getpeereid(sock, &euid, &egid) < 0) {
1070 error("getpeereid %d failed: %s",
1071 sock, strerror(errno));
1075 if ((euid != 0) && (getuid() != euid)) {
1076 error("uid mismatch: "
1077 "peer euid %u != uid %u",
1078 (u_int) euid, (u_int) getuid());
1082 new_socket(AUTH_CONNECTION, sock);
1085 case AUTH_CONNECTION:
1086 if (sshbuf_len(sockets[i].output) > 0 &&
1087 FD_ISSET(sockets[i].fd, writeset)) {
1088 len = write(sockets[i].fd,
1089 sshbuf_ptr(sockets[i].output),
1090 sshbuf_len(sockets[i].output));
1091 if (len == -1 && (errno == EAGAIN ||
1092 errno == EWOULDBLOCK ||
1096 close_socket(&sockets[i]);
1099 if ((r = sshbuf_consume(sockets[i].output,
1101 fatal("%s: buffer error: %s",
1102 __func__, ssh_err(r));
1104 if (FD_ISSET(sockets[i].fd, readset)) {
1105 len = read(sockets[i].fd, buf, sizeof(buf));
1106 if (len == -1 && (errno == EAGAIN ||
1107 errno == EWOULDBLOCK ||
1111 close_socket(&sockets[i]);
1114 if ((r = sshbuf_put(sockets[i].input,
1116 fatal("%s: buffer error: %s",
1117 __func__, ssh_err(r));
1118 explicit_bzero(buf, sizeof(buf));
1119 process_message(&sockets[i]);
1123 fatal("Unknown type %d", sockets[i].type);
1128 cleanup_socket(void)
1130 if (cleanup_pid != 0 && getpid() != cleanup_pid)
1132 debug("%s: cleanup", __func__);
1134 unlink(socket_name);
1148 cleanup_handler(int sig)
1151 #ifdef ENABLE_PKCS11
1158 check_parent_exists(void)
1161 * If our parent has exited then getppid() will return (pid_t)1,
1162 * so testing for that should be safe.
1164 if (parent_pid != -1 && getppid() != parent_pid) {
1165 /* printf("Parent has died - Authentication agent exiting.\n"); */
1175 "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
1176 " [-t life] [command [arg ...]]\n"
1177 " ssh-agent [-c | -s] -k\n");
1182 main(int ac, char **av)
1184 int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
1185 int sock, fd, ch, result, saved_errno;
1187 char *shell, *format, *pidstr, *agentsocket = NULL;
1188 fd_set *readsetp = NULL, *writesetp = NULL;
1189 #ifdef HAVE_SETRLIMIT
1193 extern char *optarg;
1195 char pidstrbuf[1 + 3 * sizeof pid];
1196 struct timeval *tvp = NULL;
1200 ssh_malloc_init(); /* must be called before any mallocs */
1201 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1209 platform_disable_tracing(0); /* strict=no */
1212 OpenSSL_add_all_algorithms();
1215 __progname = ssh_get_progname(av[0]);
1218 while ((ch = getopt(ac, av, "cDdksE:a:t:")) != -1) {
1221 fingerprint_hash = ssh_digest_alg_by_name(optarg);
1222 if (fingerprint_hash == -1)
1223 fatal("Invalid hash algorithm \"%s\"", optarg);
1239 if (d_flag || D_flag)
1244 if (d_flag || D_flag)
1249 agentsocket = optarg;
1252 if ((lifetime = convtime(optarg)) == -1) {
1253 fprintf(stderr, "Invalid lifetime\n");
1264 if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
1267 if (ac == 0 && !c_flag && !s_flag) {
1268 shell = getenv("SHELL");
1269 if (shell != NULL && (len = strlen(shell)) > 2 &&
1270 strncmp(shell + len - 3, "csh", 3) == 0)
1274 const char *errstr = NULL;
1276 pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1277 if (pidstr == NULL) {
1278 fprintf(stderr, "%s not set, cannot kill agent\n",
1279 SSH_AGENTPID_ENV_NAME);
1282 pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr);
1285 "%s=\"%s\", which is not a good PID: %s\n",
1286 SSH_AGENTPID_ENV_NAME, pidstr, errstr);
1289 if (kill(pid, SIGTERM) == -1) {
1293 format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1294 printf(format, SSH_AUTHSOCKET_ENV_NAME);
1295 printf(format, SSH_AGENTPID_ENV_NAME);
1296 printf("echo Agent pid %ld killed;\n", (long)pid);
1299 parent_pid = getpid();
1301 if (agentsocket == NULL) {
1302 /* Create private directory for agent socket */
1303 mktemp_proto(socket_dir, sizeof(socket_dir));
1304 if (mkdtemp(socket_dir) == NULL) {
1305 perror("mkdtemp: private socket dir");
1308 snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1311 /* Try to use specified agent socket */
1312 socket_dir[0] = '\0';
1313 strlcpy(socket_name, agentsocket, sizeof socket_name);
1317 * Create socket early so it will exist before command gets run from
1320 prev_mask = umask(0177);
1321 sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0);
1323 /* XXX - unix_listener() calls error() not perror() */
1324 *socket_name = '\0'; /* Don't unlink any existing file */
1330 * Fork, and have the parent execute the command, if any, or present
1331 * the socket data. The child continues as the authentication agent.
1333 if (D_flag || d_flag) {
1334 log_init(__progname,
1335 d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
1336 SYSLOG_FACILITY_AUTH, 1);
1337 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1338 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1339 SSH_AUTHSOCKET_ENV_NAME);
1340 printf("echo Agent pid %ld;\n", (long)parent_pid);
1349 if (pid != 0) { /* Parent - execute the given command. */
1351 snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1353 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1354 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1355 SSH_AUTHSOCKET_ENV_NAME);
1356 printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1357 SSH_AGENTPID_ENV_NAME);
1358 printf("echo Agent pid %ld;\n", (long)pid);
1361 if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1362 setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1371 log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1373 if (setsid() == -1) {
1374 error("setsid: %s", strerror(errno));
1379 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1380 /* XXX might close listen socket */
1381 (void)dup2(fd, STDIN_FILENO);
1382 (void)dup2(fd, STDOUT_FILENO);
1383 (void)dup2(fd, STDERR_FILENO);
1388 #ifdef HAVE_SETRLIMIT
1389 /* deny core dumps, since memory contains unencrypted private keys */
1390 rlim.rlim_cur = rlim.rlim_max = 0;
1391 if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
1392 error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1399 cleanup_pid = getpid();
1401 #ifdef ENABLE_PKCS11
1404 new_socket(AUTH_SOCKET, sock);
1406 parent_alive_interval = 10;
1408 signal(SIGPIPE, SIG_IGN);
1409 signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
1410 signal(SIGHUP, cleanup_handler);
1411 signal(SIGTERM, cleanup_handler);
1414 if (pledge("stdio cpath unix id proc exec", NULL) == -1)
1415 fatal("%s: pledge: %s", __progname, strerror(errno));
1416 platform_pledge_agent();
1419 prepare_select(&readsetp, &writesetp, &max_fd, &nalloc, &tvp);
1420 result = select(max_fd + 1, readsetp, writesetp, NULL, tvp);
1421 saved_errno = errno;
1422 if (parent_alive_interval != 0)
1423 check_parent_exists();
1424 (void) reaper(); /* remove expired keys */
1426 if (saved_errno == EINTR)
1428 fatal("select: %s", strerror(saved_errno));
1429 } else if (result > 0)
1430 after_select(readsetp, writesetp);