1 /* $OpenBSD: ssh-agent.c,v 1.199 2015/03/04 21:12:59 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * The authentication agent program. 7 * 8 * As far as I am concerned, the code I have written for this software 9 * can be used freely for any purpose. Any derived versions of this 10 * software must be clearly marked as such, and if the derived work is 11 * incompatible with the protocol description in the RFC file, it must be 12 * called by a name other than "ssh" or "Secure Shell". 13 * 14 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 28 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 30 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 34 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 35 */ 36 37 #include "includes.h" 38 __RCSID("$FreeBSD$"); 39 40 #include <sys/param.h> /* MIN MAX */ 41 #include <sys/types.h> 42 #include <sys/param.h> 43 #include <sys/resource.h> 44 #include <sys/stat.h> 45 #include <sys/socket.h> 46 #ifdef HAVE_SYS_TIME_H 47 # include <sys/time.h> 48 #endif 49 #ifdef HAVE_SYS_UN_H 50 # include <sys/un.h> 51 #endif 52 #include "openbsd-compat/sys-queue.h" 53 54 #ifdef WITH_OPENSSL 55 #include <openssl/evp.h> 56 #include "openbsd-compat/openssl-compat.h" 57 #endif 58 59 #include <errno.h> 60 #include <fcntl.h> 61 #include <limits.h> 62 #ifdef HAVE_PATHS_H 63 # include <paths.h> 64 #endif 65 #include <signal.h> 66 #include <stdarg.h> 67 #include <stdio.h> 68 #include <stdlib.h> 69 #include <time.h> 70 #include <string.h> 71 #include <unistd.h> 72 73 #include "key.h" /* XXX for typedef */ 74 #include "buffer.h" /* XXX for typedef */ 75 76 #include "xmalloc.h" 77 #include "ssh.h" 78 #include "rsa.h" 79 #include "sshbuf.h" 80 #include "sshkey.h" 81 #include "authfd.h" 82 #include "compat.h" 83 #include "log.h" 84 #include "misc.h" 85 #include "digest.h" 86 #include "ssherr.h" 87 88 #ifdef ENABLE_PKCS11 89 #include "ssh-pkcs11.h" 90 #endif 91 92 #if defined(HAVE_SYS_PRCTL_H) 93 #include <sys/prctl.h> /* For prctl() and PR_SET_DUMPABLE */ 94 #endif 95 96 typedef enum { 97 AUTH_UNUSED, 98 AUTH_SOCKET, 99 AUTH_CONNECTION 100 } sock_type; 101 102 typedef struct { 103 int fd; 104 sock_type type; 105 struct sshbuf *input; 106 struct sshbuf *output; 107 struct sshbuf *request; 108 } SocketEntry; 109 110 u_int sockets_alloc = 0; 111 SocketEntry *sockets = NULL; 112 113 typedef struct identity { 114 TAILQ_ENTRY(identity) next; 115 struct sshkey *key; 116 char *comment; 117 char *provider; 118 time_t death; 119 u_int confirm; 120 } Identity; 121 122 typedef struct { 123 int nentries; 124 TAILQ_HEAD(idqueue, identity) idlist; 125 } Idtab; 126 127 /* private key table, one per protocol version */ 128 Idtab idtable[3]; 129 130 int max_fd = 0; 131 132 /* pid of shell == parent of agent */ 133 pid_t parent_pid = -1; 134 time_t parent_alive_interval = 0; 135 136 /* pid of process for which cleanup_socket is applicable */ 137 pid_t cleanup_pid = 0; 138 139 /* pathname and directory for AUTH_SOCKET */ 140 char socket_name[PATH_MAX]; 141 char socket_dir[PATH_MAX]; 142 143 /* locking */ 144 int locked = 0; 145 char *lock_passwd = NULL; 146 147 extern char *__progname; 148 149 /* Default lifetime in seconds (0 == forever) */ 150 static long lifetime = 0; 151 152 static int fingerprint_hash = SSH_FP_HASH_DEFAULT; 153 154 /* 155 * Client connection count; incremented in new_socket() and decremented in 156 * close_socket(). When it reaches 0, ssh-agent will exit. Since it is 157 * normally initialized to 1, it will never reach 0. However, if the -x 158 * option is specified, it is initialized to 0 in main(); in that case, 159 * ssh-agent will exit as soon as it has had at least one client but no 160 * longer has any. 161 */ 162 static int xcount = 1; 163 164 static void 165 close_socket(SocketEntry *e) 166 { 167 int last = 0; 168 169 if (e->type == AUTH_CONNECTION) { 170 debug("xcount %d -> %d", xcount, xcount - 1); 171 if (--xcount == 0) 172 last = 1; 173 } 174 close(e->fd); 175 e->fd = -1; 176 e->type = AUTH_UNUSED; 177 sshbuf_free(e->input); 178 sshbuf_free(e->output); 179 sshbuf_free(e->request); 180 if (last) 181 cleanup_exit(0); 182 } 183 184 static void 185 idtab_init(void) 186 { 187 int i; 188 189 for (i = 0; i <=2; i++) { 190 TAILQ_INIT(&idtable[i].idlist); 191 idtable[i].nentries = 0; 192 } 193 } 194 195 /* return private key table for requested protocol version */ 196 static Idtab * 197 idtab_lookup(int version) 198 { 199 if (version < 1 || version > 2) 200 fatal("internal error, bad protocol version %d", version); 201 return &idtable[version]; 202 } 203 204 static void 205 free_identity(Identity *id) 206 { 207 sshkey_free(id->key); 208 free(id->provider); 209 free(id->comment); 210 free(id); 211 } 212 213 /* return matching private key for given public key */ 214 static Identity * 215 lookup_identity(struct sshkey *key, int version) 216 { 217 Identity *id; 218 219 Idtab *tab = idtab_lookup(version); 220 TAILQ_FOREACH(id, &tab->idlist, next) { 221 if (sshkey_equal(key, id->key)) 222 return (id); 223 } 224 return (NULL); 225 } 226 227 /* Check confirmation of keysign request */ 228 static int 229 confirm_key(Identity *id) 230 { 231 char *p; 232 int ret = -1; 233 234 p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT); 235 if (p != NULL && 236 ask_permission("Allow use of key %s?\nKey fingerprint %s.", 237 id->comment, p)) 238 ret = 0; 239 free(p); 240 241 return (ret); 242 } 243 244 static void 245 send_status(SocketEntry *e, int success) 246 { 247 int r; 248 249 if ((r = sshbuf_put_u32(e->output, 1)) != 0 || 250 (r = sshbuf_put_u8(e->output, success ? 251 SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0) 252 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 253 } 254 255 /* send list of supported public keys to 'client' */ 256 static void 257 process_request_identities(SocketEntry *e, int version) 258 { 259 Idtab *tab = idtab_lookup(version); 260 Identity *id; 261 struct sshbuf *msg; 262 int r; 263 264 if ((msg = sshbuf_new()) == NULL) 265 fatal("%s: sshbuf_new failed", __func__); 266 if ((r = sshbuf_put_u8(msg, (version == 1) ? 267 SSH_AGENT_RSA_IDENTITIES_ANSWER : 268 SSH2_AGENT_IDENTITIES_ANSWER)) != 0 || 269 (r = sshbuf_put_u32(msg, tab->nentries)) != 0) 270 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 271 TAILQ_FOREACH(id, &tab->idlist, next) { 272 if (id->key->type == KEY_RSA1) { 273 #ifdef WITH_SSH1 274 if ((r = sshbuf_put_u32(msg, 275 BN_num_bits(id->key->rsa->n))) != 0 || 276 (r = sshbuf_put_bignum1(msg, 277 id->key->rsa->e)) != 0 || 278 (r = sshbuf_put_bignum1(msg, 279 id->key->rsa->n)) != 0) 280 fatal("%s: buffer error: %s", 281 __func__, ssh_err(r)); 282 #endif 283 } else { 284 u_char *blob; 285 size_t blen; 286 287 if ((r = sshkey_to_blob(id->key, &blob, &blen)) != 0) { 288 error("%s: sshkey_to_blob: %s", __func__, 289 ssh_err(r)); 290 continue; 291 } 292 if ((r = sshbuf_put_string(msg, blob, blen)) != 0) 293 fatal("%s: buffer error: %s", 294 __func__, ssh_err(r)); 295 free(blob); 296 } 297 if ((r = sshbuf_put_cstring(msg, id->comment)) != 0) 298 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 299 } 300 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 301 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 302 sshbuf_free(msg); 303 } 304 305 #ifdef WITH_SSH1 306 /* ssh1 only */ 307 static void 308 process_authentication_challenge1(SocketEntry *e) 309 { 310 u_char buf[32], mdbuf[16], session_id[16]; 311 u_int response_type; 312 BIGNUM *challenge; 313 Identity *id; 314 int r, len; 315 struct sshbuf *msg; 316 struct ssh_digest_ctx *md; 317 struct sshkey *key; 318 319 if ((msg = sshbuf_new()) == NULL) 320 fatal("%s: sshbuf_new failed", __func__); 321 if ((key = sshkey_new(KEY_RSA1)) == NULL) 322 fatal("%s: sshkey_new failed", __func__); 323 if ((challenge = BN_new()) == NULL) 324 fatal("%s: BN_new failed", __func__); 325 326 if ((r = sshbuf_get_u32(e->request, NULL)) != 0 || /* ignored */ 327 (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 || 328 (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0 || 329 (r = sshbuf_get_bignum1(e->request, challenge))) 330 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 331 332 /* Only protocol 1.1 is supported */ 333 if (sshbuf_len(e->request) == 0) 334 goto failure; 335 if ((r = sshbuf_get(e->request, session_id, sizeof(session_id))) != 0 || 336 (r = sshbuf_get_u32(e->request, &response_type)) != 0) 337 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 338 if (response_type != 1) 339 goto failure; 340 341 id = lookup_identity(key, 1); 342 if (id != NULL && (!id->confirm || confirm_key(id) == 0)) { 343 struct sshkey *private = id->key; 344 /* Decrypt the challenge using the private key. */ 345 if ((r = rsa_private_decrypt(challenge, challenge, 346 private->rsa) != 0)) { 347 fatal("%s: rsa_public_encrypt: %s", __func__, 348 ssh_err(r)); 349 goto failure; /* XXX ? */ 350 } 351 352 /* The response is MD5 of decrypted challenge plus session id */ 353 len = BN_num_bytes(challenge); 354 if (len <= 0 || len > 32) { 355 logit("%s: bad challenge length %d", __func__, len); 356 goto failure; 357 } 358 memset(buf, 0, 32); 359 BN_bn2bin(challenge, buf + 32 - len); 360 if ((md = ssh_digest_start(SSH_DIGEST_MD5)) == NULL || 361 ssh_digest_update(md, buf, 32) < 0 || 362 ssh_digest_update(md, session_id, 16) < 0 || 363 ssh_digest_final(md, mdbuf, sizeof(mdbuf)) < 0) 364 fatal("%s: md5 failed", __func__); 365 ssh_digest_free(md); 366 367 /* Send the response. */ 368 if ((r = sshbuf_put_u8(msg, SSH_AGENT_RSA_RESPONSE)) != 0 || 369 (r = sshbuf_put(msg, mdbuf, sizeof(mdbuf))) != 0) 370 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 371 goto send; 372 } 373 374 failure: 375 /* Unknown identity or protocol error. Send failure. */ 376 if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0) 377 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 378 send: 379 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 380 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 381 sshkey_free(key); 382 BN_clear_free(challenge); 383 sshbuf_free(msg); 384 } 385 #endif 386 387 /* ssh2 only */ 388 static void 389 process_sign_request2(SocketEntry *e) 390 { 391 u_char *blob, *data, *signature = NULL; 392 size_t blen, dlen, slen = 0; 393 u_int compat = 0, flags; 394 int r, ok = -1; 395 struct sshbuf *msg; 396 struct sshkey *key; 397 struct identity *id; 398 399 if ((msg = sshbuf_new()) == NULL) 400 fatal("%s: sshbuf_new failed", __func__); 401 if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0 || 402 (r = sshbuf_get_string(e->request, &data, &dlen)) != 0 || 403 (r = sshbuf_get_u32(e->request, &flags)) != 0) 404 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 405 if (flags & SSH_AGENT_OLD_SIGNATURE) 406 compat = SSH_BUG_SIGBLOB; 407 if ((r = sshkey_from_blob(blob, blen, &key)) != 0) { 408 error("%s: cannot parse key blob: %s", __func__, ssh_err(ok)); 409 goto send; 410 } 411 if ((id = lookup_identity(key, 2)) == NULL) { 412 verbose("%s: %s key not found", __func__, sshkey_type(key)); 413 goto send; 414 } 415 if (id->confirm && confirm_key(id) != 0) { 416 verbose("%s: user refused key", __func__); 417 goto send; 418 } 419 if ((r = sshkey_sign(id->key, &signature, &slen, 420 data, dlen, compat)) != 0) { 421 error("%s: sshkey_sign: %s", __func__, ssh_err(ok)); 422 goto send; 423 } 424 /* Success */ 425 ok = 0; 426 send: 427 sshkey_free(key); 428 if (ok == 0) { 429 if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 || 430 (r = sshbuf_put_string(msg, signature, slen)) != 0) 431 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 432 } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0) 433 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 434 435 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 436 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 437 438 sshbuf_free(msg); 439 free(data); 440 free(blob); 441 free(signature); 442 } 443 444 /* shared */ 445 static void 446 process_remove_identity(SocketEntry *e, int version) 447 { 448 size_t blen; 449 int r, success = 0; 450 struct sshkey *key = NULL; 451 u_char *blob; 452 #ifdef WITH_SSH1 453 u_int bits; 454 #endif /* WITH_SSH1 */ 455 456 switch (version) { 457 #ifdef WITH_SSH1 458 case 1: 459 if ((key = sshkey_new(KEY_RSA1)) == NULL) { 460 error("%s: sshkey_new failed", __func__); 461 return; 462 } 463 if ((r = sshbuf_get_u32(e->request, &bits)) != 0 || 464 (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 || 465 (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0) 466 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 467 468 if (bits != sshkey_size(key)) 469 logit("Warning: identity keysize mismatch: " 470 "actual %u, announced %u", 471 sshkey_size(key), bits); 472 break; 473 #endif /* WITH_SSH1 */ 474 case 2: 475 if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0) 476 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 477 if ((r = sshkey_from_blob(blob, blen, &key)) != 0) 478 error("%s: sshkey_from_blob failed: %s", 479 __func__, ssh_err(r)); 480 free(blob); 481 break; 482 } 483 if (key != NULL) { 484 Identity *id = lookup_identity(key, version); 485 if (id != NULL) { 486 /* 487 * We have this key. Free the old key. Since we 488 * don't want to leave empty slots in the middle of 489 * the array, we actually free the key there and move 490 * all the entries between the empty slot and the end 491 * of the array. 492 */ 493 Idtab *tab = idtab_lookup(version); 494 if (tab->nentries < 1) 495 fatal("process_remove_identity: " 496 "internal error: tab->nentries %d", 497 tab->nentries); 498 TAILQ_REMOVE(&tab->idlist, id, next); 499 free_identity(id); 500 tab->nentries--; 501 success = 1; 502 } 503 sshkey_free(key); 504 } 505 send_status(e, success); 506 } 507 508 static void 509 process_remove_all_identities(SocketEntry *e, int version) 510 { 511 Idtab *tab = idtab_lookup(version); 512 Identity *id; 513 514 /* Loop over all identities and clear the keys. */ 515 for (id = TAILQ_FIRST(&tab->idlist); id; 516 id = TAILQ_FIRST(&tab->idlist)) { 517 TAILQ_REMOVE(&tab->idlist, id, next); 518 free_identity(id); 519 } 520 521 /* Mark that there are no identities. */ 522 tab->nentries = 0; 523 524 /* Send success. */ 525 send_status(e, 1); 526 } 527 528 /* removes expired keys and returns number of seconds until the next expiry */ 529 static time_t 530 reaper(void) 531 { 532 time_t deadline = 0, now = monotime(); 533 Identity *id, *nxt; 534 int version; 535 Idtab *tab; 536 537 for (version = 1; version < 3; version++) { 538 tab = idtab_lookup(version); 539 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) { 540 nxt = TAILQ_NEXT(id, next); 541 if (id->death == 0) 542 continue; 543 if (now >= id->death) { 544 debug("expiring key '%s'", id->comment); 545 TAILQ_REMOVE(&tab->idlist, id, next); 546 free_identity(id); 547 tab->nentries--; 548 } else 549 deadline = (deadline == 0) ? id->death : 550 MIN(deadline, id->death); 551 } 552 } 553 if (deadline == 0 || deadline <= now) 554 return 0; 555 else 556 return (deadline - now); 557 } 558 559 /* 560 * XXX this and the corresponding serialisation function probably belongs 561 * in key.c 562 */ 563 #ifdef WITH_SSH1 564 static int 565 agent_decode_rsa1(struct sshbuf *m, struct sshkey **kp) 566 { 567 struct sshkey *k = NULL; 568 int r = SSH_ERR_INTERNAL_ERROR; 569 570 *kp = NULL; 571 if ((k = sshkey_new_private(KEY_RSA1)) == NULL) 572 return SSH_ERR_ALLOC_FAIL; 573 574 if ((r = sshbuf_get_u32(m, NULL)) != 0 || /* ignored */ 575 (r = sshbuf_get_bignum1(m, k->rsa->n)) != 0 || 576 (r = sshbuf_get_bignum1(m, k->rsa->e)) != 0 || 577 (r = sshbuf_get_bignum1(m, k->rsa->d)) != 0 || 578 (r = sshbuf_get_bignum1(m, k->rsa->iqmp)) != 0 || 579 /* SSH1 and SSL have p and q swapped */ 580 (r = sshbuf_get_bignum1(m, k->rsa->q)) != 0 || /* p */ 581 (r = sshbuf_get_bignum1(m, k->rsa->p)) != 0) /* q */ 582 goto out; 583 584 /* Generate additional parameters */ 585 if ((r = rsa_generate_additional_parameters(k->rsa)) != 0) 586 goto out; 587 /* enable blinding */ 588 if (RSA_blinding_on(k->rsa, NULL) != 1) { 589 r = SSH_ERR_LIBCRYPTO_ERROR; 590 goto out; 591 } 592 593 r = 0; /* success */ 594 out: 595 if (r == 0) 596 *kp = k; 597 else 598 sshkey_free(k); 599 return r; 600 } 601 #endif /* WITH_SSH1 */ 602 603 static void 604 process_add_identity(SocketEntry *e, int version) 605 { 606 Idtab *tab = idtab_lookup(version); 607 Identity *id; 608 int success = 0, confirm = 0; 609 u_int seconds; 610 char *comment = NULL; 611 time_t death = 0; 612 struct sshkey *k = NULL; 613 u_char ctype; 614 int r = SSH_ERR_INTERNAL_ERROR; 615 616 switch (version) { 617 #ifdef WITH_SSH1 618 case 1: 619 r = agent_decode_rsa1(e->request, &k); 620 break; 621 #endif /* WITH_SSH1 */ 622 case 2: 623 r = sshkey_private_deserialize(e->request, &k); 624 break; 625 } 626 if (r != 0 || k == NULL || 627 (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) { 628 error("%s: decode private key: %s", __func__, ssh_err(r)); 629 goto err; 630 } 631 632 while (sshbuf_len(e->request)) { 633 if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) { 634 error("%s: buffer error: %s", __func__, ssh_err(r)); 635 goto err; 636 } 637 switch (ctype) { 638 case SSH_AGENT_CONSTRAIN_LIFETIME: 639 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) { 640 error("%s: bad lifetime constraint: %s", 641 __func__, ssh_err(r)); 642 goto err; 643 } 644 death = monotime() + seconds; 645 break; 646 case SSH_AGENT_CONSTRAIN_CONFIRM: 647 confirm = 1; 648 break; 649 default: 650 error("%s: Unknown constraint %d", __func__, ctype); 651 err: 652 sshbuf_reset(e->request); 653 free(comment); 654 sshkey_free(k); 655 goto send; 656 } 657 } 658 659 success = 1; 660 if (lifetime && !death) 661 death = monotime() + lifetime; 662 if ((id = lookup_identity(k, version)) == NULL) { 663 id = xcalloc(1, sizeof(Identity)); 664 id->key = k; 665 TAILQ_INSERT_TAIL(&tab->idlist, id, next); 666 /* Increment the number of identities. */ 667 tab->nentries++; 668 } else { 669 sshkey_free(k); 670 free(id->comment); 671 } 672 id->comment = comment; 673 id->death = death; 674 id->confirm = confirm; 675 send: 676 send_status(e, success); 677 } 678 679 /* XXX todo: encrypt sensitive data with passphrase */ 680 static void 681 process_lock_agent(SocketEntry *e, int lock) 682 { 683 int r, success = 0; 684 char *passwd; 685 686 if ((r = sshbuf_get_cstring(e->request, &passwd, NULL)) != 0) 687 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 688 if (locked && !lock && strcmp(passwd, lock_passwd) == 0) { 689 locked = 0; 690 explicit_bzero(lock_passwd, strlen(lock_passwd)); 691 free(lock_passwd); 692 lock_passwd = NULL; 693 success = 1; 694 } else if (!locked && lock) { 695 locked = 1; 696 lock_passwd = xstrdup(passwd); 697 success = 1; 698 } 699 explicit_bzero(passwd, strlen(passwd)); 700 free(passwd); 701 send_status(e, success); 702 } 703 704 static void 705 no_identities(SocketEntry *e, u_int type) 706 { 707 struct sshbuf *msg; 708 int r; 709 710 if ((msg = sshbuf_new()) == NULL) 711 fatal("%s: sshbuf_new failed", __func__); 712 if ((r = sshbuf_put_u8(msg, 713 (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ? 714 SSH_AGENT_RSA_IDENTITIES_ANSWER : 715 SSH2_AGENT_IDENTITIES_ANSWER)) != 0 || 716 (r = sshbuf_put_u32(msg, 0)) != 0 || 717 (r = sshbuf_put_stringb(e->output, msg)) != 0) 718 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 719 sshbuf_free(msg); 720 } 721 722 #ifdef ENABLE_PKCS11 723 static void 724 process_add_smartcard_key(SocketEntry *e) 725 { 726 char *provider = NULL, *pin; 727 int r, i, version, count = 0, success = 0, confirm = 0; 728 u_int seconds; 729 time_t death = 0; 730 u_char type; 731 struct sshkey **keys = NULL, *k; 732 Identity *id; 733 Idtab *tab; 734 735 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 || 736 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) 737 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 738 739 while (sshbuf_len(e->request)) { 740 if ((r = sshbuf_get_u8(e->request, &type)) != 0) 741 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 742 switch (type) { 743 case SSH_AGENT_CONSTRAIN_LIFETIME: 744 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) 745 fatal("%s: buffer error: %s", 746 __func__, ssh_err(r)); 747 death = monotime() + seconds; 748 break; 749 case SSH_AGENT_CONSTRAIN_CONFIRM: 750 confirm = 1; 751 break; 752 default: 753 error("process_add_smartcard_key: " 754 "Unknown constraint type %d", type); 755 goto send; 756 } 757 } 758 if (lifetime && !death) 759 death = monotime() + lifetime; 760 761 count = pkcs11_add_provider(provider, pin, &keys); 762 for (i = 0; i < count; i++) { 763 k = keys[i]; 764 version = k->type == KEY_RSA1 ? 1 : 2; 765 tab = idtab_lookup(version); 766 if (lookup_identity(k, version) == NULL) { 767 id = xcalloc(1, sizeof(Identity)); 768 id->key = k; 769 id->provider = xstrdup(provider); 770 id->comment = xstrdup(provider); /* XXX */ 771 id->death = death; 772 id->confirm = confirm; 773 TAILQ_INSERT_TAIL(&tab->idlist, id, next); 774 tab->nentries++; 775 success = 1; 776 } else { 777 sshkey_free(k); 778 } 779 keys[i] = NULL; 780 } 781 send: 782 free(pin); 783 free(provider); 784 free(keys); 785 send_status(e, success); 786 } 787 788 static void 789 process_remove_smartcard_key(SocketEntry *e) 790 { 791 char *provider = NULL, *pin = NULL; 792 int r, version, success = 0; 793 Identity *id, *nxt; 794 Idtab *tab; 795 796 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 || 797 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) 798 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 799 free(pin); 800 801 for (version = 1; version < 3; version++) { 802 tab = idtab_lookup(version); 803 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) { 804 nxt = TAILQ_NEXT(id, next); 805 /* Skip file--based keys */ 806 if (id->provider == NULL) 807 continue; 808 if (!strcmp(provider, id->provider)) { 809 TAILQ_REMOVE(&tab->idlist, id, next); 810 free_identity(id); 811 tab->nentries--; 812 } 813 } 814 } 815 if (pkcs11_del_provider(provider) == 0) 816 success = 1; 817 else 818 error("process_remove_smartcard_key:" 819 " pkcs11_del_provider failed"); 820 free(provider); 821 send_status(e, success); 822 } 823 #endif /* ENABLE_PKCS11 */ 824 825 /* dispatch incoming messages */ 826 827 static void 828 process_message(SocketEntry *e) 829 { 830 u_int msg_len; 831 u_char type; 832 const u_char *cp; 833 int r; 834 835 if (sshbuf_len(e->input) < 5) 836 return; /* Incomplete message. */ 837 cp = sshbuf_ptr(e->input); 838 msg_len = PEEK_U32(cp); 839 if (msg_len > 256 * 1024) { 840 close_socket(e); 841 return; 842 } 843 if (sshbuf_len(e->input) < msg_len + 4) 844 return; 845 846 /* move the current input to e->request */ 847 sshbuf_reset(e->request); 848 if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 || 849 (r = sshbuf_get_u8(e->request, &type)) != 0) 850 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 851 852 /* check wheter agent is locked */ 853 if (locked && type != SSH_AGENTC_UNLOCK) { 854 sshbuf_reset(e->request); 855 switch (type) { 856 case SSH_AGENTC_REQUEST_RSA_IDENTITIES: 857 case SSH2_AGENTC_REQUEST_IDENTITIES: 858 /* send empty lists */ 859 no_identities(e, type); 860 break; 861 default: 862 /* send a fail message for all other request types */ 863 send_status(e, 0); 864 } 865 return; 866 } 867 868 debug("type %d", type); 869 switch (type) { 870 case SSH_AGENTC_LOCK: 871 case SSH_AGENTC_UNLOCK: 872 process_lock_agent(e, type == SSH_AGENTC_LOCK); 873 break; 874 #ifdef WITH_SSH1 875 /* ssh1 */ 876 case SSH_AGENTC_RSA_CHALLENGE: 877 process_authentication_challenge1(e); 878 break; 879 case SSH_AGENTC_REQUEST_RSA_IDENTITIES: 880 process_request_identities(e, 1); 881 break; 882 case SSH_AGENTC_ADD_RSA_IDENTITY: 883 case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED: 884 process_add_identity(e, 1); 885 break; 886 case SSH_AGENTC_REMOVE_RSA_IDENTITY: 887 process_remove_identity(e, 1); 888 break; 889 #endif 890 case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES: 891 process_remove_all_identities(e, 1); /* safe for !WITH_SSH1 */ 892 break; 893 /* ssh2 */ 894 case SSH2_AGENTC_SIGN_REQUEST: 895 process_sign_request2(e); 896 break; 897 case SSH2_AGENTC_REQUEST_IDENTITIES: 898 process_request_identities(e, 2); 899 break; 900 case SSH2_AGENTC_ADD_IDENTITY: 901 case SSH2_AGENTC_ADD_ID_CONSTRAINED: 902 process_add_identity(e, 2); 903 break; 904 case SSH2_AGENTC_REMOVE_IDENTITY: 905 process_remove_identity(e, 2); 906 break; 907 case SSH2_AGENTC_REMOVE_ALL_IDENTITIES: 908 process_remove_all_identities(e, 2); 909 break; 910 #ifdef ENABLE_PKCS11 911 case SSH_AGENTC_ADD_SMARTCARD_KEY: 912 case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED: 913 process_add_smartcard_key(e); 914 break; 915 case SSH_AGENTC_REMOVE_SMARTCARD_KEY: 916 process_remove_smartcard_key(e); 917 break; 918 #endif /* ENABLE_PKCS11 */ 919 default: 920 /* Unknown message. Respond with failure. */ 921 error("Unknown message %d", type); 922 sshbuf_reset(e->request); 923 send_status(e, 0); 924 break; 925 } 926 } 927 928 static void 929 new_socket(sock_type type, int fd) 930 { 931 u_int i, old_alloc, new_alloc; 932 933 if (type == AUTH_CONNECTION) { 934 debug("xcount %d -> %d", xcount, xcount + 1); 935 ++xcount; 936 } 937 set_nonblock(fd); 938 939 if (fd > max_fd) 940 max_fd = fd; 941 942 for (i = 0; i < sockets_alloc; i++) 943 if (sockets[i].type == AUTH_UNUSED) { 944 sockets[i].fd = fd; 945 if ((sockets[i].input = sshbuf_new()) == NULL) 946 fatal("%s: sshbuf_new failed", __func__); 947 if ((sockets[i].output = sshbuf_new()) == NULL) 948 fatal("%s: sshbuf_new failed", __func__); 949 if ((sockets[i].request = sshbuf_new()) == NULL) 950 fatal("%s: sshbuf_new failed", __func__); 951 sockets[i].type = type; 952 return; 953 } 954 old_alloc = sockets_alloc; 955 new_alloc = sockets_alloc + 10; 956 sockets = xrealloc(sockets, new_alloc, sizeof(sockets[0])); 957 for (i = old_alloc; i < new_alloc; i++) 958 sockets[i].type = AUTH_UNUSED; 959 sockets_alloc = new_alloc; 960 sockets[old_alloc].fd = fd; 961 if ((sockets[old_alloc].input = sshbuf_new()) == NULL) 962 fatal("%s: sshbuf_new failed", __func__); 963 if ((sockets[old_alloc].output = sshbuf_new()) == NULL) 964 fatal("%s: sshbuf_new failed", __func__); 965 if ((sockets[old_alloc].request = sshbuf_new()) == NULL) 966 fatal("%s: sshbuf_new failed", __func__); 967 sockets[old_alloc].type = type; 968 } 969 970 static int 971 prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp, 972 struct timeval **tvpp) 973 { 974 u_int i, sz; 975 int n = 0; 976 static struct timeval tv; 977 time_t deadline; 978 979 for (i = 0; i < sockets_alloc; i++) { 980 switch (sockets[i].type) { 981 case AUTH_SOCKET: 982 case AUTH_CONNECTION: 983 n = MAX(n, sockets[i].fd); 984 break; 985 case AUTH_UNUSED: 986 break; 987 default: 988 fatal("Unknown socket type %d", sockets[i].type); 989 break; 990 } 991 } 992 993 sz = howmany(n+1, NFDBITS) * sizeof(fd_mask); 994 if (*fdrp == NULL || sz > *nallocp) { 995 free(*fdrp); 996 free(*fdwp); 997 *fdrp = xmalloc(sz); 998 *fdwp = xmalloc(sz); 999 *nallocp = sz; 1000 } 1001 if (n < *fdl) 1002 debug("XXX shrink: %d < %d", n, *fdl); 1003 *fdl = n; 1004 memset(*fdrp, 0, sz); 1005 memset(*fdwp, 0, sz); 1006 1007 for (i = 0; i < sockets_alloc; i++) { 1008 switch (sockets[i].type) { 1009 case AUTH_SOCKET: 1010 case AUTH_CONNECTION: 1011 FD_SET(sockets[i].fd, *fdrp); 1012 if (sshbuf_len(sockets[i].output) > 0) 1013 FD_SET(sockets[i].fd, *fdwp); 1014 break; 1015 default: 1016 break; 1017 } 1018 } 1019 deadline = reaper(); 1020 if (parent_alive_interval != 0) 1021 deadline = (deadline == 0) ? parent_alive_interval : 1022 MIN(deadline, parent_alive_interval); 1023 if (deadline == 0) { 1024 *tvpp = NULL; 1025 } else { 1026 tv.tv_sec = deadline; 1027 tv.tv_usec = 0; 1028 *tvpp = &tv; 1029 } 1030 return (1); 1031 } 1032 1033 static void 1034 after_select(fd_set *readset, fd_set *writeset) 1035 { 1036 struct sockaddr_un sunaddr; 1037 socklen_t slen; 1038 char buf[1024]; 1039 int len, sock, r; 1040 u_int i, orig_alloc; 1041 uid_t euid; 1042 gid_t egid; 1043 1044 for (i = 0, orig_alloc = sockets_alloc; i < orig_alloc; i++) 1045 switch (sockets[i].type) { 1046 case AUTH_UNUSED: 1047 break; 1048 case AUTH_SOCKET: 1049 if (FD_ISSET(sockets[i].fd, readset)) { 1050 slen = sizeof(sunaddr); 1051 sock = accept(sockets[i].fd, 1052 (struct sockaddr *)&sunaddr, &slen); 1053 if (sock < 0) { 1054 error("accept from AUTH_SOCKET: %s", 1055 strerror(errno)); 1056 break; 1057 } 1058 if (getpeereid(sock, &euid, &egid) < 0) { 1059 error("getpeereid %d failed: %s", 1060 sock, strerror(errno)); 1061 close(sock); 1062 break; 1063 } 1064 if ((euid != 0) && (getuid() != euid)) { 1065 error("uid mismatch: " 1066 "peer euid %u != uid %u", 1067 (u_int) euid, (u_int) getuid()); 1068 close(sock); 1069 break; 1070 } 1071 new_socket(AUTH_CONNECTION, sock); 1072 } 1073 break; 1074 case AUTH_CONNECTION: 1075 if (sshbuf_len(sockets[i].output) > 0 && 1076 FD_ISSET(sockets[i].fd, writeset)) { 1077 len = write(sockets[i].fd, 1078 sshbuf_ptr(sockets[i].output), 1079 sshbuf_len(sockets[i].output)); 1080 if (len == -1 && (errno == EAGAIN || 1081 errno == EWOULDBLOCK || 1082 errno == EINTR)) 1083 continue; 1084 if (len <= 0) { 1085 close_socket(&sockets[i]); 1086 break; 1087 } 1088 if ((r = sshbuf_consume(sockets[i].output, 1089 len)) != 0) 1090 fatal("%s: buffer error: %s", 1091 __func__, ssh_err(r)); 1092 } 1093 if (FD_ISSET(sockets[i].fd, readset)) { 1094 len = read(sockets[i].fd, buf, sizeof(buf)); 1095 if (len == -1 && (errno == EAGAIN || 1096 errno == EWOULDBLOCK || 1097 errno == EINTR)) 1098 continue; 1099 if (len <= 0) { 1100 close_socket(&sockets[i]); 1101 break; 1102 } 1103 if ((r = sshbuf_put(sockets[i].input, 1104 buf, len)) != 0) 1105 fatal("%s: buffer error: %s", 1106 __func__, ssh_err(r)); 1107 explicit_bzero(buf, sizeof(buf)); 1108 process_message(&sockets[i]); 1109 } 1110 break; 1111 default: 1112 fatal("Unknown type %d", sockets[i].type); 1113 } 1114 } 1115 1116 static void 1117 cleanup_socket(void) 1118 { 1119 if (cleanup_pid != 0 && getpid() != cleanup_pid) 1120 return; 1121 debug("%s: cleanup", __func__); 1122 if (socket_name[0]) 1123 unlink(socket_name); 1124 if (socket_dir[0]) 1125 rmdir(socket_dir); 1126 } 1127 1128 void 1129 cleanup_exit(int i) 1130 { 1131 cleanup_socket(); 1132 _exit(i); 1133 } 1134 1135 /*ARGSUSED*/ 1136 static void 1137 cleanup_handler(int sig) 1138 { 1139 cleanup_socket(); 1140 #ifdef ENABLE_PKCS11 1141 pkcs11_terminate(); 1142 #endif 1143 _exit(2); 1144 } 1145 1146 static void 1147 check_parent_exists(void) 1148 { 1149 /* 1150 * If our parent has exited then getppid() will return (pid_t)1, 1151 * so testing for that should be safe. 1152 */ 1153 if (parent_pid != -1 && getppid() != parent_pid) { 1154 /* printf("Parent has died - Authentication agent exiting.\n"); */ 1155 cleanup_socket(); 1156 _exit(2); 1157 } 1158 } 1159 1160 static void 1161 usage(void) 1162 { 1163 fprintf(stderr, 1164 "usage: ssh-agent [-c | -s] [-d] [-a bind_address] [-E fingerprint_hash]\n" 1165 " [-t life] [command [arg ...]]\n" 1166 " ssh-agent [-c | -s] -k\n"); 1167 fprintf(stderr, " -x Exit when the last client disconnects.\n"); 1168 exit(1); 1169 } 1170 1171 int 1172 main(int ac, char **av) 1173 { 1174 int c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0; 1175 int sock, fd, ch, result, saved_errno; 1176 u_int nalloc; 1177 char *shell, *format, *pidstr, *agentsocket = NULL; 1178 fd_set *readsetp = NULL, *writesetp = NULL; 1179 #ifdef HAVE_SETRLIMIT 1180 struct rlimit rlim; 1181 #endif 1182 extern int optind; 1183 extern char *optarg; 1184 pid_t pid; 1185 char pidstrbuf[1 + 3 * sizeof pid]; 1186 struct timeval *tvp = NULL; 1187 size_t len; 1188 mode_t prev_mask; 1189 1190 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 1191 sanitise_stdfd(); 1192 1193 /* drop */ 1194 setegid(getgid()); 1195 setgid(getgid()); 1196 setuid(geteuid()); 1197 1198 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE) 1199 /* Disable ptrace on Linux without sgid bit */ 1200 prctl(PR_SET_DUMPABLE, 0); 1201 #endif 1202 1203 #ifdef WITH_OPENSSL 1204 OpenSSL_add_all_algorithms(); 1205 #endif 1206 1207 __progname = ssh_get_progname(av[0]); 1208 seed_rng(); 1209 1210 while ((ch = getopt(ac, av, "cdksE:a:t:x")) != -1) { 1211 switch (ch) { 1212 case 'E': 1213 fingerprint_hash = ssh_digest_alg_by_name(optarg); 1214 if (fingerprint_hash == -1) 1215 fatal("Invalid hash algorithm \"%s\"", optarg); 1216 break; 1217 case 'c': 1218 if (s_flag) 1219 usage(); 1220 c_flag++; 1221 break; 1222 case 'k': 1223 k_flag++; 1224 break; 1225 case 's': 1226 if (c_flag) 1227 usage(); 1228 s_flag++; 1229 break; 1230 case 'd': 1231 if (d_flag) 1232 usage(); 1233 d_flag++; 1234 break; 1235 case 'a': 1236 agentsocket = optarg; 1237 break; 1238 case 't': 1239 if ((lifetime = convtime(optarg)) == -1) { 1240 fprintf(stderr, "Invalid lifetime\n"); 1241 usage(); 1242 } 1243 break; 1244 case 'x': 1245 xcount = 0; 1246 break; 1247 default: 1248 usage(); 1249 } 1250 } 1251 ac -= optind; 1252 av += optind; 1253 1254 if (ac > 0 && (c_flag || k_flag || s_flag || d_flag)) 1255 usage(); 1256 1257 if (ac == 0 && !c_flag && !s_flag) { 1258 shell = getenv("SHELL"); 1259 if (shell != NULL && (len = strlen(shell)) > 2 && 1260 strncmp(shell + len - 3, "csh", 3) == 0) 1261 c_flag = 1; 1262 } 1263 if (k_flag) { 1264 const char *errstr = NULL; 1265 1266 pidstr = getenv(SSH_AGENTPID_ENV_NAME); 1267 if (pidstr == NULL) { 1268 fprintf(stderr, "%s not set, cannot kill agent\n", 1269 SSH_AGENTPID_ENV_NAME); 1270 exit(1); 1271 } 1272 pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr); 1273 if (errstr) { 1274 fprintf(stderr, 1275 "%s=\"%s\", which is not a good PID: %s\n", 1276 SSH_AGENTPID_ENV_NAME, pidstr, errstr); 1277 exit(1); 1278 } 1279 if (kill(pid, SIGTERM) == -1) { 1280 perror("kill"); 1281 exit(1); 1282 } 1283 format = c_flag ? "unsetenv %s;\n" : "unset %s;\n"; 1284 printf(format, SSH_AUTHSOCKET_ENV_NAME); 1285 printf(format, SSH_AGENTPID_ENV_NAME); 1286 printf("echo Agent pid %ld killed;\n", (long)pid); 1287 exit(0); 1288 } 1289 parent_pid = getpid(); 1290 1291 if (agentsocket == NULL) { 1292 /* Create private directory for agent socket */ 1293 mktemp_proto(socket_dir, sizeof(socket_dir)); 1294 if (mkdtemp(socket_dir) == NULL) { 1295 perror("mkdtemp: private socket dir"); 1296 exit(1); 1297 } 1298 snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir, 1299 (long)parent_pid); 1300 } else { 1301 /* Try to use specified agent socket */ 1302 socket_dir[0] = '\0'; 1303 strlcpy(socket_name, agentsocket, sizeof socket_name); 1304 } 1305 1306 /* 1307 * Create socket early so it will exist before command gets run from 1308 * the parent. 1309 */ 1310 prev_mask = umask(0177); 1311 sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0); 1312 if (sock < 0) { 1313 /* XXX - unix_listener() calls error() not perror() */ 1314 *socket_name = '\0'; /* Don't unlink any existing file */ 1315 cleanup_exit(1); 1316 } 1317 umask(prev_mask); 1318 1319 /* 1320 * Fork, and have the parent execute the command, if any, or present 1321 * the socket data. The child continues as the authentication agent. 1322 */ 1323 if (d_flag) { 1324 log_init(__progname, SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 1); 1325 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; 1326 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, 1327 SSH_AUTHSOCKET_ENV_NAME); 1328 printf("echo Agent pid %ld;\n", (long)parent_pid); 1329 goto skip; 1330 } 1331 pid = fork(); 1332 if (pid == -1) { 1333 perror("fork"); 1334 cleanup_exit(1); 1335 } 1336 if (pid != 0) { /* Parent - execute the given command. */ 1337 close(sock); 1338 snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid); 1339 if (ac == 0) { 1340 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; 1341 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, 1342 SSH_AUTHSOCKET_ENV_NAME); 1343 printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf, 1344 SSH_AGENTPID_ENV_NAME); 1345 printf("echo Agent pid %ld;\n", (long)pid); 1346 exit(0); 1347 } 1348 if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 || 1349 setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) { 1350 perror("setenv"); 1351 exit(1); 1352 } 1353 execvp(av[0], av); 1354 perror(av[0]); 1355 exit(1); 1356 } 1357 /* child */ 1358 log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0); 1359 1360 if (setsid() == -1) { 1361 error("setsid: %s", strerror(errno)); 1362 cleanup_exit(1); 1363 } 1364 1365 (void)chdir("/"); 1366 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { 1367 /* XXX might close listen socket */ 1368 (void)dup2(fd, STDIN_FILENO); 1369 (void)dup2(fd, STDOUT_FILENO); 1370 (void)dup2(fd, STDERR_FILENO); 1371 if (fd > 2) 1372 close(fd); 1373 } 1374 1375 #ifdef HAVE_SETRLIMIT 1376 /* deny core dumps, since memory contains unencrypted private keys */ 1377 rlim.rlim_cur = rlim.rlim_max = 0; 1378 if (setrlimit(RLIMIT_CORE, &rlim) < 0) { 1379 error("setrlimit RLIMIT_CORE: %s", strerror(errno)); 1380 cleanup_exit(1); 1381 } 1382 #endif 1383 1384 skip: 1385 1386 cleanup_pid = getpid(); 1387 1388 #ifdef ENABLE_PKCS11 1389 pkcs11_init(0); 1390 #endif 1391 new_socket(AUTH_SOCKET, sock); 1392 if (ac > 0) 1393 parent_alive_interval = 10; 1394 idtab_init(); 1395 signal(SIGPIPE, SIG_IGN); 1396 signal(SIGINT, d_flag ? cleanup_handler : SIG_IGN); 1397 signal(SIGHUP, cleanup_handler); 1398 signal(SIGTERM, cleanup_handler); 1399 nalloc = 0; 1400 1401 while (1) { 1402 prepare_select(&readsetp, &writesetp, &max_fd, &nalloc, &tvp); 1403 result = select(max_fd + 1, readsetp, writesetp, NULL, tvp); 1404 saved_errno = errno; 1405 if (parent_alive_interval != 0) 1406 check_parent_exists(); 1407 (void) reaper(); /* remove expired keys */ 1408 if (result < 0) { 1409 if (saved_errno == EINTR) 1410 continue; 1411 fatal("select: %s", strerror(saved_errno)); 1412 } else if (result > 0) 1413 after_select(readsetp, writesetp); 1414 } 1415 /* NOTREACHED */ 1416 } 1417