2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * The authentication agent program.
7 * As far as I am concerned, the code I have written for this software
8 * can be used freely for any purpose. Any derived versions of this
9 * software must be clearly marked as such, and if the derived work is
10 * incompatible with the protocol description in the RFC file, it must be
11 * called by a name other than "ssh" or "Secure Shell".
13 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 #include "openbsd-compat/sys-queue.h"
38 RCSID("$OpenBSD: ssh-agent.c,v 1.123 2005/09/13 23:40:07 djm Exp $");
40 #include <openssl/evp.h>
41 #include <openssl/md5.h>
59 #if defined(HAVE_SYS_PRCTL_H)
60 #include <sys/prctl.h> /* For prctl() and PR_SET_DUMPABLE */
77 u_int sockets_alloc = 0;
78 SocketEntry *sockets = NULL;
80 typedef struct identity {
81 TAILQ_ENTRY(identity) next;
90 TAILQ_HEAD(idqueue, identity) idlist;
93 /* private key table, one per protocol version */
98 /* pid of shell == parent of agent */
99 pid_t parent_pid = -1;
101 /* pathname and directory for AUTH_SOCKET */
102 char socket_name[1024];
103 char socket_dir[1024];
107 char *lock_passwd = NULL;
109 extern char *__progname;
111 /* Default lifetime (0 == forever) */
112 static int lifetime = 0;
115 close_socket(SocketEntry *e)
119 e->type = AUTH_UNUSED;
120 buffer_free(&e->input);
121 buffer_free(&e->output);
122 buffer_free(&e->request);
130 for (i = 0; i <=2; i++) {
131 TAILQ_INIT(&idtable[i].idlist);
132 idtable[i].nentries = 0;
136 /* return private key table for requested protocol version */
138 idtab_lookup(int version)
140 if (version < 1 || version > 2)
141 fatal("internal error, bad protocol version %d", version);
142 return &idtable[version];
146 free_identity(Identity *id)
153 /* return matching private key for given public key */
155 lookup_identity(Key *key, int version)
159 Idtab *tab = idtab_lookup(version);
160 TAILQ_FOREACH(id, &tab->idlist, next) {
161 if (key_equal(key, id->key))
167 /* Check confirmation of keysign request */
169 confirm_key(Identity *id)
174 p = key_fingerprint(id->key, SSH_FP_MD5, SSH_FP_HEX);
175 if (ask_permission("Allow use of key %s?\nKey fingerprint %s.",
183 /* send list of supported public keys to 'client' */
185 process_request_identities(SocketEntry *e, int version)
187 Idtab *tab = idtab_lookup(version);
192 buffer_put_char(&msg, (version == 1) ?
193 SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
194 buffer_put_int(&msg, tab->nentries);
195 TAILQ_FOREACH(id, &tab->idlist, next) {
196 if (id->key->type == KEY_RSA1) {
197 buffer_put_int(&msg, BN_num_bits(id->key->rsa->n));
198 buffer_put_bignum(&msg, id->key->rsa->e);
199 buffer_put_bignum(&msg, id->key->rsa->n);
203 key_to_blob(id->key, &blob, &blen);
204 buffer_put_string(&msg, blob, blen);
207 buffer_put_cstring(&msg, id->comment);
209 buffer_put_int(&e->output, buffer_len(&msg));
210 buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
216 process_authentication_challenge1(SocketEntry *e)
218 u_char buf[32], mdbuf[16], session_id[16];
228 key = key_new(KEY_RSA1);
229 if ((challenge = BN_new()) == NULL)
230 fatal("process_authentication_challenge1: BN_new failed");
232 (void) buffer_get_int(&e->request); /* ignored */
233 buffer_get_bignum(&e->request, key->rsa->e);
234 buffer_get_bignum(&e->request, key->rsa->n);
235 buffer_get_bignum(&e->request, challenge);
237 /* Only protocol 1.1 is supported */
238 if (buffer_len(&e->request) == 0)
240 buffer_get(&e->request, session_id, 16);
241 response_type = buffer_get_int(&e->request);
242 if (response_type != 1)
245 id = lookup_identity(key, 1);
246 if (id != NULL && (!id->confirm || confirm_key(id) == 0)) {
247 Key *private = id->key;
248 /* Decrypt the challenge using the private key. */
249 if (rsa_private_decrypt(challenge, challenge, private->rsa) <= 0)
252 /* The response is MD5 of decrypted challenge plus session id. */
253 len = BN_num_bytes(challenge);
254 if (len <= 0 || len > 32) {
255 logit("process_authentication_challenge: bad challenge length %d", len);
259 BN_bn2bin(challenge, buf + 32 - len);
261 MD5_Update(&md, buf, 32);
262 MD5_Update(&md, session_id, 16);
263 MD5_Final(mdbuf, &md);
265 /* Send the response. */
266 buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE);
267 for (i = 0; i < 16; i++)
268 buffer_put_char(&msg, mdbuf[i]);
273 /* Unknown identity or protocol error. Send failure. */
274 buffer_put_char(&msg, SSH_AGENT_FAILURE);
276 buffer_put_int(&e->output, buffer_len(&msg));
277 buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
279 BN_clear_free(challenge);
285 process_sign_request2(SocketEntry *e)
287 u_char *blob, *data, *signature = NULL;
288 u_int blen, dlen, slen = 0;
289 extern int datafellows;
296 blob = buffer_get_string(&e->request, &blen);
297 data = buffer_get_string(&e->request, &dlen);
299 flags = buffer_get_int(&e->request);
300 if (flags & SSH_AGENT_OLD_SIGNATURE)
301 datafellows = SSH_BUG_SIGBLOB;
303 key = key_from_blob(blob, blen);
305 Identity *id = lookup_identity(key, 2);
306 if (id != NULL && (!id->confirm || confirm_key(id) == 0))
307 ok = key_sign(id->key, &signature, &slen, data, dlen);
312 buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE);
313 buffer_put_string(&msg, signature, slen);
315 buffer_put_char(&msg, SSH_AGENT_FAILURE);
317 buffer_put_int(&e->output, buffer_len(&msg));
318 buffer_append(&e->output, buffer_ptr(&msg),
323 if (signature != NULL)
329 process_remove_identity(SocketEntry *e, int version)
338 key = key_new(KEY_RSA1);
339 bits = buffer_get_int(&e->request);
340 buffer_get_bignum(&e->request, key->rsa->e);
341 buffer_get_bignum(&e->request, key->rsa->n);
343 if (bits != key_size(key))
344 logit("Warning: identity keysize mismatch: actual %u, announced %u",
345 key_size(key), bits);
348 blob = buffer_get_string(&e->request, &blen);
349 key = key_from_blob(blob, blen);
354 Identity *id = lookup_identity(key, version);
357 * We have this key. Free the old key. Since we
358 * don\'t want to leave empty slots in the middle of
359 * the array, we actually free the key there and move
360 * all the entries between the empty slot and the end
363 Idtab *tab = idtab_lookup(version);
364 if (tab->nentries < 1)
365 fatal("process_remove_identity: "
366 "internal error: tab->nentries %d",
368 TAILQ_REMOVE(&tab->idlist, id, next);
375 buffer_put_int(&e->output, 1);
376 buffer_put_char(&e->output,
377 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
381 process_remove_all_identities(SocketEntry *e, int version)
383 Idtab *tab = idtab_lookup(version);
386 /* Loop over all identities and clear the keys. */
387 for (id = TAILQ_FIRST(&tab->idlist); id;
388 id = TAILQ_FIRST(&tab->idlist)) {
389 TAILQ_REMOVE(&tab->idlist, id, next);
393 /* Mark that there are no identities. */
397 buffer_put_int(&e->output, 1);
398 buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
404 u_int now = time(NULL);
409 for (version = 1; version < 3; version++) {
410 tab = idtab_lookup(version);
411 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) {
412 nxt = TAILQ_NEXT(id, next);
413 if (id->death != 0 && now >= id->death) {
414 TAILQ_REMOVE(&tab->idlist, id, next);
423 process_add_identity(SocketEntry *e, int version)
425 Idtab *tab = idtab_lookup(version);
426 int type, success = 0, death = 0, confirm = 0;
427 char *type_name, *comment;
432 k = key_new_private(KEY_RSA1);
433 (void) buffer_get_int(&e->request); /* ignored */
434 buffer_get_bignum(&e->request, k->rsa->n);
435 buffer_get_bignum(&e->request, k->rsa->e);
436 buffer_get_bignum(&e->request, k->rsa->d);
437 buffer_get_bignum(&e->request, k->rsa->iqmp);
439 /* SSH and SSL have p and q swapped */
440 buffer_get_bignum(&e->request, k->rsa->q); /* p */
441 buffer_get_bignum(&e->request, k->rsa->p); /* q */
443 /* Generate additional parameters */
444 rsa_generate_additional_parameters(k->rsa);
447 type_name = buffer_get_string(&e->request, NULL);
448 type = key_type_from_name(type_name);
452 k = key_new_private(type);
453 buffer_get_bignum2(&e->request, k->dsa->p);
454 buffer_get_bignum2(&e->request, k->dsa->q);
455 buffer_get_bignum2(&e->request, k->dsa->g);
456 buffer_get_bignum2(&e->request, k->dsa->pub_key);
457 buffer_get_bignum2(&e->request, k->dsa->priv_key);
460 k = key_new_private(type);
461 buffer_get_bignum2(&e->request, k->rsa->n);
462 buffer_get_bignum2(&e->request, k->rsa->e);
463 buffer_get_bignum2(&e->request, k->rsa->d);
464 buffer_get_bignum2(&e->request, k->rsa->iqmp);
465 buffer_get_bignum2(&e->request, k->rsa->p);
466 buffer_get_bignum2(&e->request, k->rsa->q);
468 /* Generate additional parameters */
469 rsa_generate_additional_parameters(k->rsa);
472 buffer_clear(&e->request);
477 /* enable blinding */
481 if (RSA_blinding_on(k->rsa, NULL) != 1) {
482 error("process_add_identity: RSA_blinding_on failed");
488 comment = buffer_get_string(&e->request, NULL);
494 while (buffer_len(&e->request)) {
495 switch (buffer_get_char(&e->request)) {
496 case SSH_AGENT_CONSTRAIN_LIFETIME:
497 death = time(NULL) + buffer_get_int(&e->request);
499 case SSH_AGENT_CONSTRAIN_CONFIRM:
506 if (lifetime && !death)
507 death = time(NULL) + lifetime;
508 if (lookup_identity(k, version) == NULL) {
509 Identity *id = xmalloc(sizeof(Identity));
511 id->comment = comment;
513 id->confirm = confirm;
514 TAILQ_INSERT_TAIL(&tab->idlist, id, next);
515 /* Increment the number of identities. */
522 buffer_put_int(&e->output, 1);
523 buffer_put_char(&e->output,
524 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
527 /* XXX todo: encrypt sensitive data with passphrase */
529 process_lock_agent(SocketEntry *e, int lock)
534 passwd = buffer_get_string(&e->request, NULL);
535 if (locked && !lock && strcmp(passwd, lock_passwd) == 0) {
537 memset(lock_passwd, 0, strlen(lock_passwd));
541 } else if (!locked && lock) {
543 lock_passwd = xstrdup(passwd);
546 memset(passwd, 0, strlen(passwd));
549 buffer_put_int(&e->output, 1);
550 buffer_put_char(&e->output,
551 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
555 no_identities(SocketEntry *e, u_int type)
560 buffer_put_char(&msg,
561 (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ?
562 SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
563 buffer_put_int(&msg, 0);
564 buffer_put_int(&e->output, buffer_len(&msg));
565 buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
571 process_add_smartcard_key (SocketEntry *e)
573 char *sc_reader_id = NULL, *pin;
574 int i, version, success = 0, death = 0, confirm = 0;
579 sc_reader_id = buffer_get_string(&e->request, NULL);
580 pin = buffer_get_string(&e->request, NULL);
582 while (buffer_len(&e->request)) {
583 switch (buffer_get_char(&e->request)) {
584 case SSH_AGENT_CONSTRAIN_LIFETIME:
585 death = time(NULL) + buffer_get_int(&e->request);
587 case SSH_AGENT_CONSTRAIN_CONFIRM:
594 if (lifetime && !death)
595 death = time(NULL) + lifetime;
597 keys = sc_get_keys(sc_reader_id, pin);
601 if (keys == NULL || keys[0] == NULL) {
602 error("sc_get_keys failed");
605 for (i = 0; keys[i] != NULL; i++) {
607 version = k->type == KEY_RSA1 ? 1 : 2;
608 tab = idtab_lookup(version);
609 if (lookup_identity(k, version) == NULL) {
610 id = xmalloc(sizeof(Identity));
612 id->comment = sc_get_key_label(k);
614 id->confirm = confirm;
615 TAILQ_INSERT_TAIL(&tab->idlist, id, next);
625 buffer_put_int(&e->output, 1);
626 buffer_put_char(&e->output,
627 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
631 process_remove_smartcard_key(SocketEntry *e)
633 char *sc_reader_id = NULL, *pin;
634 int i, version, success = 0;
635 Key **keys, *k = NULL;
639 sc_reader_id = buffer_get_string(&e->request, NULL);
640 pin = buffer_get_string(&e->request, NULL);
641 keys = sc_get_keys(sc_reader_id, pin);
645 if (keys == NULL || keys[0] == NULL) {
646 error("sc_get_keys failed");
649 for (i = 0; keys[i] != NULL; i++) {
651 version = k->type == KEY_RSA1 ? 1 : 2;
652 if ((id = lookup_identity(k, version)) != NULL) {
653 tab = idtab_lookup(version);
654 TAILQ_REMOVE(&tab->idlist, id, next);
664 buffer_put_int(&e->output, 1);
665 buffer_put_char(&e->output,
666 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
668 #endif /* SMARTCARD */
670 /* dispatch incoming messages */
673 process_message(SocketEntry *e)
681 if (buffer_len(&e->input) < 5)
682 return; /* Incomplete message. */
683 cp = buffer_ptr(&e->input);
684 msg_len = GET_32BIT(cp);
685 if (msg_len > 256 * 1024) {
689 if (buffer_len(&e->input) < msg_len + 4)
692 /* move the current input to e->request */
693 buffer_consume(&e->input, 4);
694 buffer_clear(&e->request);
695 buffer_append(&e->request, buffer_ptr(&e->input), msg_len);
696 buffer_consume(&e->input, msg_len);
697 type = buffer_get_char(&e->request);
699 /* check wheter agent is locked */
700 if (locked && type != SSH_AGENTC_UNLOCK) {
701 buffer_clear(&e->request);
703 case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
704 case SSH2_AGENTC_REQUEST_IDENTITIES:
705 /* send empty lists */
706 no_identities(e, type);
709 /* send a fail message for all other request types */
710 buffer_put_int(&e->output, 1);
711 buffer_put_char(&e->output, SSH_AGENT_FAILURE);
716 debug("type %d", type);
718 case SSH_AGENTC_LOCK:
719 case SSH_AGENTC_UNLOCK:
720 process_lock_agent(e, type == SSH_AGENTC_LOCK);
723 case SSH_AGENTC_RSA_CHALLENGE:
724 process_authentication_challenge1(e);
726 case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
727 process_request_identities(e, 1);
729 case SSH_AGENTC_ADD_RSA_IDENTITY:
730 case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED:
731 process_add_identity(e, 1);
733 case SSH_AGENTC_REMOVE_RSA_IDENTITY:
734 process_remove_identity(e, 1);
736 case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
737 process_remove_all_identities(e, 1);
740 case SSH2_AGENTC_SIGN_REQUEST:
741 process_sign_request2(e);
743 case SSH2_AGENTC_REQUEST_IDENTITIES:
744 process_request_identities(e, 2);
746 case SSH2_AGENTC_ADD_IDENTITY:
747 case SSH2_AGENTC_ADD_ID_CONSTRAINED:
748 process_add_identity(e, 2);
750 case SSH2_AGENTC_REMOVE_IDENTITY:
751 process_remove_identity(e, 2);
753 case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
754 process_remove_all_identities(e, 2);
757 case SSH_AGENTC_ADD_SMARTCARD_KEY:
758 case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
759 process_add_smartcard_key(e);
761 case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
762 process_remove_smartcard_key(e);
764 #endif /* SMARTCARD */
766 /* Unknown message. Respond with failure. */
767 error("Unknown message %d", type);
768 buffer_clear(&e->request);
769 buffer_put_int(&e->output, 1);
770 buffer_put_char(&e->output, SSH_AGENT_FAILURE);
776 new_socket(sock_type type, int fd)
778 u_int i, old_alloc, new_alloc;
785 for (i = 0; i < sockets_alloc; i++)
786 if (sockets[i].type == AUTH_UNUSED) {
788 buffer_init(&sockets[i].input);
789 buffer_init(&sockets[i].output);
790 buffer_init(&sockets[i].request);
791 sockets[i].type = type;
794 old_alloc = sockets_alloc;
795 new_alloc = sockets_alloc + 10;
797 sockets = xrealloc(sockets, new_alloc * sizeof(sockets[0]));
799 sockets = xmalloc(new_alloc * sizeof(sockets[0]));
800 for (i = old_alloc; i < new_alloc; i++)
801 sockets[i].type = AUTH_UNUSED;
802 sockets_alloc = new_alloc;
803 sockets[old_alloc].fd = fd;
804 buffer_init(&sockets[old_alloc].input);
805 buffer_init(&sockets[old_alloc].output);
806 buffer_init(&sockets[old_alloc].request);
807 sockets[old_alloc].type = type;
811 prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp)
816 for (i = 0; i < sockets_alloc; i++) {
817 switch (sockets[i].type) {
819 case AUTH_CONNECTION:
820 n = MAX(n, sockets[i].fd);
825 fatal("Unknown socket type %d", sockets[i].type);
830 sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
831 if (*fdrp == NULL || sz > *nallocp) {
841 debug("XXX shrink: %d < %d", n, *fdl);
843 memset(*fdrp, 0, sz);
844 memset(*fdwp, 0, sz);
846 for (i = 0; i < sockets_alloc; i++) {
847 switch (sockets[i].type) {
849 case AUTH_CONNECTION:
850 FD_SET(sockets[i].fd, *fdrp);
851 if (buffer_len(&sockets[i].output) > 0)
852 FD_SET(sockets[i].fd, *fdwp);
862 after_select(fd_set *readset, fd_set *writeset)
864 struct sockaddr_un sunaddr;
872 for (i = 0; i < sockets_alloc; i++)
873 switch (sockets[i].type) {
877 if (FD_ISSET(sockets[i].fd, readset)) {
878 slen = sizeof(sunaddr);
879 sock = accept(sockets[i].fd,
880 (struct sockaddr *) &sunaddr, &slen);
882 error("accept from AUTH_SOCKET: %s",
886 if (getpeereid(sock, &euid, &egid) < 0) {
887 error("getpeereid %d failed: %s",
888 sock, strerror(errno));
892 if ((euid != 0) && (getuid() != euid)) {
893 error("uid mismatch: "
894 "peer euid %u != uid %u",
895 (u_int) euid, (u_int) getuid());
899 new_socket(AUTH_CONNECTION, sock);
902 case AUTH_CONNECTION:
903 if (buffer_len(&sockets[i].output) > 0 &&
904 FD_ISSET(sockets[i].fd, writeset)) {
906 len = write(sockets[i].fd,
907 buffer_ptr(&sockets[i].output),
908 buffer_len(&sockets[i].output));
909 if (len == -1 && (errno == EAGAIN ||
915 close_socket(&sockets[i]);
918 buffer_consume(&sockets[i].output, len);
920 if (FD_ISSET(sockets[i].fd, readset)) {
922 len = read(sockets[i].fd, buf, sizeof(buf));
923 if (len == -1 && (errno == EAGAIN ||
929 close_socket(&sockets[i]);
932 buffer_append(&sockets[i].input, buf, len);
933 process_message(&sockets[i]);
937 fatal("Unknown type %d", sockets[i].type);
958 cleanup_handler(int sig)
965 check_parent_exists(int sig)
967 int save_errno = errno;
969 if (parent_pid != -1 && kill(parent_pid, 0) < 0) {
970 /* printf("Parent has died - Authentication agent exiting.\n"); */
971 cleanup_handler(sig); /* safe */
973 mysignal(SIGALRM, check_parent_exists);
981 fprintf(stderr, "Usage: %s [options] [command [args ...]]\n",
983 fprintf(stderr, "Options:\n");
984 fprintf(stderr, " -c Generate C-shell commands on stdout.\n");
985 fprintf(stderr, " -s Generate Bourne shell commands on stdout.\n");
986 fprintf(stderr, " -k Kill the current agent.\n");
987 fprintf(stderr, " -d Debug mode.\n");
988 fprintf(stderr, " -a socket Bind agent socket to given name.\n");
989 fprintf(stderr, " -t life Default identity lifetime (seconds).\n");
994 main(int ac, char **av)
996 int c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0;
999 char *shell, *format, *pidstr, *agentsocket = NULL;
1000 fd_set *readsetp = NULL, *writesetp = NULL;
1001 struct sockaddr_un sunaddr;
1002 #ifdef HAVE_SETRLIMIT
1007 extern char *optarg;
1009 char pidstrbuf[1 + 3 * sizeof pid];
1011 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1018 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
1019 /* Disable ptrace on Linux without sgid bit */
1020 prctl(PR_SET_DUMPABLE, 0);
1023 SSLeay_add_all_algorithms();
1025 __progname = ssh_get_progname(av[0]);
1029 while ((ch = getopt(ac, av, "cdksa:t:")) != -1) {
1050 agentsocket = optarg;
1053 if ((lifetime = convtime(optarg)) == -1) {
1054 fprintf(stderr, "Invalid lifetime\n");
1065 if (ac > 0 && (c_flag || k_flag || s_flag || d_flag))
1068 if (ac == 0 && !c_flag && !s_flag) {
1069 shell = getenv("SHELL");
1070 if (shell != NULL && strncmp(shell + strlen(shell) - 3, "csh", 3) == 0)
1074 pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1075 if (pidstr == NULL) {
1076 fprintf(stderr, "%s not set, cannot kill agent\n",
1077 SSH_AGENTPID_ENV_NAME);
1082 fprintf(stderr, "%s=\"%s\", which is not a good PID\n",
1083 SSH_AGENTPID_ENV_NAME, pidstr);
1086 if (kill(pid, SIGTERM) == -1) {
1090 format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1091 printf(format, SSH_AUTHSOCKET_ENV_NAME);
1092 printf(format, SSH_AGENTPID_ENV_NAME);
1093 printf("echo Agent pid %ld killed;\n", (long)pid);
1096 parent_pid = getpid();
1098 if (agentsocket == NULL) {
1099 /* Create private directory for agent socket */
1100 strlcpy(socket_dir, "/tmp/ssh-XXXXXXXXXX", sizeof socket_dir);
1101 if (mkdtemp(socket_dir) == NULL) {
1102 perror("mkdtemp: private socket dir");
1105 snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1108 /* Try to use specified agent socket */
1109 socket_dir[0] = '\0';
1110 strlcpy(socket_name, agentsocket, sizeof socket_name);
1114 * Create socket early so it will exist before command gets run from
1117 sock = socket(AF_UNIX, SOCK_STREAM, 0);
1120 *socket_name = '\0'; /* Don't unlink any existing file */
1123 memset(&sunaddr, 0, sizeof(sunaddr));
1124 sunaddr.sun_family = AF_UNIX;
1125 strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path));
1126 prev_mask = umask(0177);
1127 if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) {
1129 *socket_name = '\0'; /* Don't unlink any existing file */
1134 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1140 * Fork, and have the parent execute the command, if any, or present
1141 * the socket data. The child continues as the authentication agent.
1144 log_init(__progname, SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 1);
1145 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1146 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1147 SSH_AUTHSOCKET_ENV_NAME);
1148 printf("echo Agent pid %ld;\n", (long)parent_pid);
1156 if (pid != 0) { /* Parent - execute the given command. */
1158 snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1160 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1161 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1162 SSH_AUTHSOCKET_ENV_NAME);
1163 printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1164 SSH_AGENTPID_ENV_NAME);
1165 printf("echo Agent pid %ld;\n", (long)pid);
1168 if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1169 setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1178 log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1180 if (setsid() == -1) {
1181 error("setsid: %s", strerror(errno));
1186 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1187 /* XXX might close listen socket */
1188 (void)dup2(fd, STDIN_FILENO);
1189 (void)dup2(fd, STDOUT_FILENO);
1190 (void)dup2(fd, STDERR_FILENO);
1195 #ifdef HAVE_SETRLIMIT
1196 /* deny core dumps, since memory contains unencrypted private keys */
1197 rlim.rlim_cur = rlim.rlim_max = 0;
1198 if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
1199 error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1205 new_socket(AUTH_SOCKET, sock);
1207 mysignal(SIGALRM, check_parent_exists);
1212 signal(SIGINT, SIG_IGN);
1213 signal(SIGPIPE, SIG_IGN);
1214 signal(SIGHUP, cleanup_handler);
1215 signal(SIGTERM, cleanup_handler);
1219 prepare_select(&readsetp, &writesetp, &max_fd, &nalloc);
1220 if (select(max_fd + 1, readsetp, writesetp, NULL, NULL) < 0) {
1223 fatal("select: %s", strerror(errno));
1225 after_select(readsetp, writesetp);