1 /* $NetBSD: ssh-agent.c,v 1.24 2018/08/26 07:46:36 christos Exp $ */ 2 /* $OpenBSD: ssh-agent.c,v 1.231 2018/05/11 03:38:51 djm Exp $ */ 3 4 /* 5 * Author: Tatu Ylonen <ylo@cs.hut.fi> 6 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 7 * All rights reserved 8 * The authentication agent program. 9 * 10 * As far as I am concerned, the code I have written for this software 11 * can be used freely for any purpose. Any derived versions of this 12 * software must be clearly marked as such, and if the derived work is 13 * incompatible with the protocol description in the RFC file, it must be 14 * called by a name other than "ssh" or "Secure Shell". 15 * 16 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 28 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 29 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 30 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 31 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 32 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 33 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 34 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 36 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include "includes.h" 40 __RCSID("$NetBSD: ssh-agent.c,v 1.24 2018/08/26 07:46:36 christos Exp $"); 41 42 #include <sys/param.h> /* MIN MAX */ 43 #include <sys/types.h> 44 #include <sys/time.h> 45 #include <sys/queue.h> 46 #include <sys/resource.h> 47 #include <sys/socket.h> 48 #include <sys/stat.h> 49 #include <sys/un.h> 50 51 #ifdef WITH_OPENSSL 52 #include <openssl/evp.h> 53 #endif 54 55 #include <errno.h> 56 #include <fcntl.h> 57 #include <paths.h> 58 #include <poll.h> 59 #include <signal.h> 60 #include <stdlib.h> 61 #include <stdio.h> 62 #include <string.h> 63 #include <limits.h> 64 #include <time.h> 65 #include <unistd.h> 66 #include <util.h> 67 68 #include "xmalloc.h" 69 #include "ssh.h" 70 #include "sshbuf.h" 71 #include "sshkey.h" 72 #include "authfd.h" 73 #include "compat.h" 74 #include "log.h" 75 #include "misc.h" 76 #include "getpeereid.h" 77 #include "digest.h" 78 #include "ssherr.h" 79 #include "match.h" 80 81 #ifdef ENABLE_PKCS11 82 #include "ssh-pkcs11.h" 83 #endif 84 85 #ifndef DEFAULT_PKCS11_WHITELIST 86 # define DEFAULT_PKCS11_WHITELIST "/usr/lib*/*,/usr/pkg/lib*/*" 87 #endif 88 89 /* Maximum accepted message length */ 90 #define AGENT_MAX_LEN (256*1024) 91 92 typedef enum { 93 AUTH_UNUSED, 94 AUTH_SOCKET, 95 AUTH_CONNECTION 96 } sock_type; 97 98 typedef struct { 99 int fd; 100 sock_type type; 101 struct sshbuf *input; 102 struct sshbuf *output; 103 struct sshbuf *request; 104 } SocketEntry; 105 106 u_int sockets_alloc = 0; 107 SocketEntry *sockets = NULL; 108 109 typedef struct identity { 110 TAILQ_ENTRY(identity) next; 111 struct sshkey *key; 112 char *comment; 113 char *provider; 114 time_t death; 115 u_int confirm; 116 } Identity; 117 118 struct idtable { 119 int nentries; 120 TAILQ_HEAD(idqueue, identity) idlist; 121 }; 122 123 /* private key table */ 124 struct idtable *idtab; 125 126 int max_fd = 0; 127 128 /* pid of shell == parent of agent */ 129 pid_t parent_pid = -1; 130 time_t parent_alive_interval = 0; 131 132 /* pid of process for which cleanup_socket is applicable */ 133 pid_t cleanup_pid = 0; 134 135 /* pathname and directory for AUTH_SOCKET */ 136 char socket_name[PATH_MAX]; 137 char socket_dir[PATH_MAX]; 138 139 /* PKCS#11 path whitelist */ 140 static char *pkcs11_whitelist; 141 142 /* locking */ 143 #define LOCK_SIZE 32 144 #define LOCK_SALT_SIZE 16 145 #define LOCK_ROUNDS 1 146 int locked = 0; 147 u_char lock_pwhash[LOCK_SIZE]; 148 u_char lock_salt[LOCK_SALT_SIZE]; 149 150 extern char *__progname; 151 152 /* Default lifetime in seconds (0 == forever) */ 153 static long lifetime = 0; 154 155 static int fingerprint_hash = SSH_FP_HASH_DEFAULT; 156 157 static void 158 close_socket(SocketEntry *e) 159 { 160 close(e->fd); 161 e->fd = -1; 162 e->type = AUTH_UNUSED; 163 sshbuf_free(e->input); 164 sshbuf_free(e->output); 165 sshbuf_free(e->request); 166 } 167 168 static void 169 idtab_init(void) 170 { 171 idtab = xcalloc(1, sizeof(*idtab)); 172 TAILQ_INIT(&idtab->idlist); 173 idtab->nentries = 0; 174 } 175 176 static void 177 free_identity(Identity *id) 178 { 179 sshkey_free(id->key); 180 free(id->provider); 181 free(id->comment); 182 free(id); 183 } 184 185 /* return matching private key for given public key */ 186 static Identity * 187 lookup_identity(struct sshkey *key) 188 { 189 Identity *id; 190 191 TAILQ_FOREACH(id, &idtab->idlist, next) { 192 if (sshkey_equal(key, id->key)) 193 return (id); 194 } 195 return (NULL); 196 } 197 198 /* Check confirmation of keysign request */ 199 static int 200 confirm_key(Identity *id) 201 { 202 char *p; 203 int ret = -1; 204 205 p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT); 206 if (p != NULL && 207 ask_permission("Allow use of key %s?\nKey fingerprint %s.", 208 id->comment, p)) 209 ret = 0; 210 free(p); 211 212 return (ret); 213 } 214 215 static void 216 send_status(SocketEntry *e, int success) 217 { 218 int r; 219 220 if ((r = sshbuf_put_u32(e->output, 1)) != 0 || 221 (r = sshbuf_put_u8(e->output, success ? 222 SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0) 223 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 224 } 225 226 /* send list of supported public keys to 'client' */ 227 static void 228 process_request_identities(SocketEntry *e) 229 { 230 Identity *id; 231 struct sshbuf *msg; 232 int r; 233 234 if ((msg = sshbuf_new()) == NULL) 235 fatal("%s: sshbuf_new failed", __func__); 236 if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 || 237 (r = sshbuf_put_u32(msg, idtab->nentries)) != 0) 238 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 239 TAILQ_FOREACH(id, &idtab->idlist, next) { 240 if ((r = sshkey_puts_opts(id->key, msg, SSHKEY_SERIALIZE_INFO)) 241 != 0 || 242 (r = sshbuf_put_cstring(msg, id->comment)) != 0) { 243 error("%s: put key/comment: %s", __func__, 244 ssh_err(r)); 245 continue; 246 } 247 } 248 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 249 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 250 sshbuf_free(msg); 251 } 252 253 254 static const char * 255 agent_decode_alg(struct sshkey *key, u_int flags) 256 { 257 if (key->type == KEY_RSA) { 258 if (flags & SSH_AGENT_RSA_SHA2_256) 259 return "rsa-sha2-256"; 260 else if (flags & SSH_AGENT_RSA_SHA2_512) 261 return "rsa-sha2-512"; 262 } 263 return NULL; 264 } 265 266 /* ssh2 only */ 267 static void 268 process_sign_request2(SocketEntry *e) 269 { 270 const u_char *data; 271 u_char *signature = NULL; 272 size_t dlen, slen = 0; 273 u_int compat = 0, flags; 274 int r, ok = -1; 275 struct sshbuf *msg; 276 struct sshkey *key = NULL; 277 struct identity *id; 278 279 if ((msg = sshbuf_new()) == NULL) 280 fatal("%s: sshbuf_new failed", __func__); 281 if ((r = sshkey_froms(e->request, &key)) != 0 || 282 (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 || 283 (r = sshbuf_get_u32(e->request, &flags)) != 0) { 284 error("%s: couldn't parse request: %s", __func__, ssh_err(r)); 285 goto send; 286 } 287 288 if ((id = lookup_identity(key)) == NULL) { 289 verbose("%s: %s key not found", __func__, sshkey_type(key)); 290 goto send; 291 } 292 if (id->confirm && confirm_key(id) != 0) { 293 verbose("%s: user refused key", __func__); 294 goto send; 295 } 296 if ((r = sshkey_sign(id->key, &signature, &slen, 297 data, dlen, agent_decode_alg(key, flags), compat)) != 0) { 298 error("%s: sshkey_sign: %s", __func__, ssh_err(r)); 299 goto send; 300 } 301 /* Success */ 302 ok = 0; 303 send: 304 sshkey_free(key); 305 if (ok == 0) { 306 if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 || 307 (r = sshbuf_put_string(msg, signature, slen)) != 0) 308 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 309 } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0) 310 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 311 312 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 313 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 314 315 sshbuf_free(msg); 316 free(signature); 317 } 318 319 /* shared */ 320 static void 321 process_remove_identity(SocketEntry *e) 322 { 323 int r, success = 0; 324 struct sshkey *key = NULL; 325 Identity *id; 326 327 if ((r = sshkey_froms(e->request, &key)) != 0) { 328 error("%s: get key: %s", __func__, ssh_err(r)); 329 goto done; 330 } 331 if ((id = lookup_identity(key)) == NULL) { 332 debug("%s: key not found", __func__); 333 goto done; 334 } 335 /* We have this key, free it. */ 336 if (idtab->nentries < 1) 337 fatal("%s: internal error: nentries %d", 338 __func__, idtab->nentries); 339 TAILQ_REMOVE(&idtab->idlist, id, next); 340 free_identity(id); 341 idtab->nentries--; 342 sshkey_free(key); 343 success = 1; 344 done: 345 send_status(e, success); 346 } 347 348 static void 349 process_remove_all_identities(SocketEntry *e) 350 { 351 Identity *id; 352 353 /* Loop over all identities and clear the keys. */ 354 for (id = TAILQ_FIRST(&idtab->idlist); id; 355 id = TAILQ_FIRST(&idtab->idlist)) { 356 TAILQ_REMOVE(&idtab->idlist, id, next); 357 free_identity(id); 358 } 359 360 /* Mark that there are no identities. */ 361 idtab->nentries = 0; 362 363 /* Send success. */ 364 send_status(e, 1); 365 } 366 367 /* removes expired keys and returns number of seconds until the next expiry */ 368 static time_t 369 reaper(void) 370 { 371 time_t deadline = 0, now = monotime(); 372 Identity *id, *nxt; 373 374 for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) { 375 nxt = TAILQ_NEXT(id, next); 376 if (id->death == 0) 377 continue; 378 if (now >= id->death) { 379 debug("expiring key '%s'", id->comment); 380 TAILQ_REMOVE(&idtab->idlist, id, next); 381 free_identity(id); 382 idtab->nentries--; 383 } else 384 deadline = (deadline == 0) ? id->death : 385 MINIMUM(deadline, id->death); 386 } 387 if (deadline == 0 || deadline <= now) 388 return 0; 389 else 390 return (deadline - now); 391 } 392 393 static void 394 process_add_identity(SocketEntry *e) 395 { 396 Identity *id; 397 int success = 0, confirm = 0; 398 u_int seconds, maxsign; 399 char *comment = NULL; 400 time_t death = 0; 401 struct sshkey *k = NULL; 402 u_char ctype; 403 int r = SSH_ERR_INTERNAL_ERROR; 404 405 if ((r = sshkey_private_deserialize(e->request, &k)) != 0 || 406 k == NULL || 407 (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) { 408 error("%s: decode private key: %s", __func__, ssh_err(r)); 409 goto err; 410 } 411 412 while (sshbuf_len(e->request)) { 413 if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) { 414 error("%s: buffer error: %s", __func__, ssh_err(r)); 415 goto err; 416 } 417 switch (ctype) { 418 case SSH_AGENT_CONSTRAIN_LIFETIME: 419 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) { 420 error("%s: bad lifetime constraint: %s", 421 __func__, ssh_err(r)); 422 goto err; 423 } 424 death = monotime() + seconds; 425 break; 426 case SSH_AGENT_CONSTRAIN_CONFIRM: 427 confirm = 1; 428 break; 429 case SSH_AGENT_CONSTRAIN_MAXSIGN: 430 if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) { 431 error("%s: bad maxsign constraint: %s", 432 __func__, ssh_err(r)); 433 goto err; 434 } 435 if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) { 436 error("%s: cannot enable maxsign: %s", 437 __func__, ssh_err(r)); 438 goto err; 439 } 440 break; 441 default: 442 error("%s: Unknown constraint %d", __func__, ctype); 443 err: 444 sshbuf_reset(e->request); 445 free(comment); 446 sshkey_free(k); 447 goto send; 448 } 449 } 450 451 success = 1; 452 if (lifetime && !death) 453 death = monotime() + lifetime; 454 if ((id = lookup_identity(k)) == NULL) { 455 id = xcalloc(1, sizeof(Identity)); 456 TAILQ_INSERT_TAIL(&idtab->idlist, id, next); 457 /* Increment the number of identities. */ 458 idtab->nentries++; 459 } else { 460 /* key state might have been updated */ 461 sshkey_free(id->key); 462 free(id->comment); 463 } 464 id->key = k; 465 id->comment = comment; 466 id->death = death; 467 id->confirm = confirm; 468 send: 469 send_status(e, success); 470 } 471 472 /* XXX todo: encrypt sensitive data with passphrase */ 473 static void 474 process_lock_agent(SocketEntry *e, int lock) 475 { 476 int r, success = 0, delay; 477 char *passwd; 478 u_char passwdhash[LOCK_SIZE]; 479 static u_int fail_count = 0; 480 size_t pwlen; 481 482 /* 483 * This is deliberately fatal: the user has requested that we lock, 484 * but we can't parse their request properly. The only safe thing to 485 * do is abort. 486 */ 487 if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0) 488 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 489 if (pwlen == 0) { 490 debug("empty password not supported"); 491 } else if (locked && !lock) { 492 if (bcrypt_pbkdf(passwd, pwlen, (uint8_t *)lock_salt, sizeof(lock_salt), 493 (uint8_t *)passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0) 494 fatal("bcrypt_pbkdf"); 495 if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) { 496 debug("agent unlocked"); 497 locked = 0; 498 fail_count = 0; 499 explicit_bzero(lock_pwhash, sizeof(lock_pwhash)); 500 success = 1; 501 } else { 502 /* delay in 0.1s increments up to 10s */ 503 if (fail_count < 100) 504 fail_count++; 505 delay = 100000 * fail_count; 506 debug("unlock failed, delaying %0.1lf seconds", 507 (double)delay/1000000); 508 usleep(delay); 509 } 510 explicit_bzero(passwdhash, sizeof(passwdhash)); 511 } else if (!locked && lock) { 512 debug("agent locked"); 513 locked = 1; 514 arc4random_buf(lock_salt, sizeof(lock_salt)); 515 if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt), 516 lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0) 517 fatal("bcrypt_pbkdf"); 518 success = 1; 519 } 520 explicit_bzero(passwd, pwlen); 521 free(passwd); 522 send_status(e, success); 523 } 524 525 static void 526 no_identities(SocketEntry *e) 527 { 528 struct sshbuf *msg; 529 int r; 530 531 if ((msg = sshbuf_new()) == NULL) 532 fatal("%s: sshbuf_new failed", __func__); 533 if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 || 534 (r = sshbuf_put_u32(msg, 0)) != 0 || 535 (r = sshbuf_put_stringb(e->output, msg)) != 0) 536 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 537 sshbuf_free(msg); 538 } 539 540 #ifdef ENABLE_PKCS11 541 static void 542 process_add_smartcard_key(SocketEntry *e) 543 { 544 char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX]; 545 int r, i, count = 0, success = 0, confirm = 0; 546 u_int seconds; 547 time_t death = 0; 548 u_char type; 549 struct sshkey **keys = NULL, *k; 550 Identity *id; 551 552 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 || 553 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) { 554 error("%s: buffer error: %s", __func__, ssh_err(r)); 555 goto send; 556 } 557 558 while (sshbuf_len(e->request)) { 559 if ((r = sshbuf_get_u8(e->request, &type)) != 0) { 560 error("%s: buffer error: %s", __func__, ssh_err(r)); 561 goto send; 562 } 563 switch (type) { 564 case SSH_AGENT_CONSTRAIN_LIFETIME: 565 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) { 566 error("%s: buffer error: %s", 567 __func__, ssh_err(r)); 568 goto send; 569 } 570 death = monotime() + seconds; 571 break; 572 case SSH_AGENT_CONSTRAIN_CONFIRM: 573 confirm = 1; 574 break; 575 default: 576 error("%s: Unknown constraint type %d", __func__, type); 577 goto send; 578 } 579 } 580 if (realpath(provider, canonical_provider) == NULL) { 581 verbose("failed PKCS#11 add of \"%.100s\": realpath: %s", 582 provider, strerror(errno)); 583 goto send; 584 } 585 if (match_pattern_list(canonical_provider, pkcs11_whitelist, 0) != 1) { 586 verbose("refusing PKCS#11 add of \"%.100s\": " 587 "provider not whitelisted", canonical_provider); 588 goto send; 589 } 590 debug("%s: add %.100s", __func__, canonical_provider); 591 if (lifetime && !death) 592 death = monotime() + lifetime; 593 594 count = pkcs11_add_provider(canonical_provider, pin, &keys); 595 for (i = 0; i < count; i++) { 596 k = keys[i]; 597 if (lookup_identity(k) == NULL) { 598 id = xcalloc(1, sizeof(Identity)); 599 id->key = k; 600 id->provider = xstrdup(canonical_provider); 601 id->comment = xstrdup(canonical_provider); /* XXX */ 602 id->death = death; 603 id->confirm = confirm; 604 TAILQ_INSERT_TAIL(&idtab->idlist, id, next); 605 idtab->nentries++; 606 success = 1; 607 } else { 608 sshkey_free(k); 609 } 610 keys[i] = NULL; 611 } 612 send: 613 free(pin); 614 free(provider); 615 free(keys); 616 send_status(e, success); 617 } 618 619 static void 620 process_remove_smartcard_key(SocketEntry *e) 621 { 622 char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX]; 623 int r, success = 0; 624 Identity *id, *nxt; 625 626 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 || 627 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) { 628 error("%s: buffer error: %s", __func__, ssh_err(r)); 629 goto send; 630 } 631 free(pin); 632 633 if (realpath(provider, canonical_provider) == NULL) { 634 verbose("failed PKCS#11 add of \"%.100s\": realpath: %s", 635 provider, strerror(errno)); 636 goto send; 637 } 638 639 debug("%s: remove %.100s", __func__, canonical_provider); 640 for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) { 641 nxt = TAILQ_NEXT(id, next); 642 /* Skip file--based keys */ 643 if (id->provider == NULL) 644 continue; 645 if (!strcmp(canonical_provider, id->provider)) { 646 TAILQ_REMOVE(&idtab->idlist, id, next); 647 free_identity(id); 648 idtab->nentries--; 649 } 650 } 651 if (pkcs11_del_provider(canonical_provider) == 0) 652 success = 1; 653 else 654 error("%s: pkcs11_del_provider failed", __func__); 655 send: 656 free(provider); 657 send_status(e, success); 658 } 659 #endif /* ENABLE_PKCS11 */ 660 661 /* dispatch incoming messages */ 662 663 static int 664 process_message(u_int socknum) 665 { 666 u_int msg_len; 667 u_char type; 668 const u_char *cp; 669 int r; 670 SocketEntry *e; 671 672 if (socknum >= sockets_alloc) { 673 fatal("%s: socket number %u >= allocated %u", 674 __func__, socknum, sockets_alloc); 675 } 676 e = &sockets[socknum]; 677 678 if (sshbuf_len(e->input) < 5) 679 return 0; /* Incomplete message header. */ 680 cp = sshbuf_ptr(e->input); 681 msg_len = PEEK_U32(cp); 682 if (msg_len > AGENT_MAX_LEN) { 683 debug("%s: socket %u (fd=%d) message too long %u > %u", 684 __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN); 685 return -1; 686 } 687 if (sshbuf_len(e->input) < msg_len + 4) 688 return 0; /* Incomplete message body. */ 689 690 /* move the current input to e->request */ 691 sshbuf_reset(e->request); 692 if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 || 693 (r = sshbuf_get_u8(e->request, &type)) != 0) { 694 if (r == SSH_ERR_MESSAGE_INCOMPLETE || 695 r == SSH_ERR_STRING_TOO_LARGE) { 696 debug("%s: buffer error: %s", __func__, ssh_err(r)); 697 return -1; 698 } 699 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 700 } 701 702 debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type); 703 704 /* check whether agent is locked */ 705 if (locked && type != SSH_AGENTC_UNLOCK) { 706 sshbuf_reset(e->request); 707 switch (type) { 708 case SSH2_AGENTC_REQUEST_IDENTITIES: 709 /* send empty lists */ 710 no_identities(e); 711 break; 712 default: 713 /* send a fail message for all other request types */ 714 send_status(e, 0); 715 } 716 return 0; 717 } 718 719 switch (type) { 720 case SSH_AGENTC_LOCK: 721 case SSH_AGENTC_UNLOCK: 722 process_lock_agent(e, type == SSH_AGENTC_LOCK); 723 break; 724 case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES: 725 process_remove_all_identities(e); /* safe for !WITH_SSH1 */ 726 break; 727 /* ssh2 */ 728 case SSH2_AGENTC_SIGN_REQUEST: 729 process_sign_request2(e); 730 break; 731 case SSH2_AGENTC_REQUEST_IDENTITIES: 732 process_request_identities(e); 733 break; 734 case SSH2_AGENTC_ADD_IDENTITY: 735 case SSH2_AGENTC_ADD_ID_CONSTRAINED: 736 process_add_identity(e); 737 break; 738 case SSH2_AGENTC_REMOVE_IDENTITY: 739 process_remove_identity(e); 740 break; 741 case SSH2_AGENTC_REMOVE_ALL_IDENTITIES: 742 process_remove_all_identities(e); 743 break; 744 #ifdef ENABLE_PKCS11 745 case SSH_AGENTC_ADD_SMARTCARD_KEY: 746 case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED: 747 process_add_smartcard_key(e); 748 break; 749 case SSH_AGENTC_REMOVE_SMARTCARD_KEY: 750 process_remove_smartcard_key(e); 751 break; 752 #endif /* ENABLE_PKCS11 */ 753 default: 754 /* Unknown message. Respond with failure. */ 755 error("Unknown message %d", type); 756 sshbuf_reset(e->request); 757 send_status(e, 0); 758 break; 759 } 760 return 0; 761 } 762 763 static void 764 new_socket(sock_type type, int fd) 765 { 766 u_int i, old_alloc, new_alloc; 767 768 set_nonblock(fd); 769 770 if (fd > max_fd) 771 max_fd = fd; 772 773 for (i = 0; i < sockets_alloc; i++) 774 if (sockets[i].type == AUTH_UNUSED) { 775 sockets[i].fd = fd; 776 if ((sockets[i].input = sshbuf_new()) == NULL) 777 fatal("%s: sshbuf_new failed", __func__); 778 if ((sockets[i].output = sshbuf_new()) == NULL) 779 fatal("%s: sshbuf_new failed", __func__); 780 if ((sockets[i].request = sshbuf_new()) == NULL) 781 fatal("%s: sshbuf_new failed", __func__); 782 sockets[i].type = type; 783 return; 784 } 785 old_alloc = sockets_alloc; 786 new_alloc = sockets_alloc + 10; 787 sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0])); 788 for (i = old_alloc; i < new_alloc; i++) 789 sockets[i].type = AUTH_UNUSED; 790 sockets_alloc = new_alloc; 791 sockets[old_alloc].fd = fd; 792 if ((sockets[old_alloc].input = sshbuf_new()) == NULL) 793 fatal("%s: sshbuf_new failed", __func__); 794 if ((sockets[old_alloc].output = sshbuf_new()) == NULL) 795 fatal("%s: sshbuf_new failed", __func__); 796 if ((sockets[old_alloc].request = sshbuf_new()) == NULL) 797 fatal("%s: sshbuf_new failed", __func__); 798 sockets[old_alloc].type = type; 799 } 800 801 static int 802 handle_socket_read(u_int socknum) 803 { 804 struct sockaddr_un sunaddr; 805 socklen_t slen; 806 uid_t euid; 807 gid_t egid; 808 int fd; 809 810 slen = sizeof(sunaddr); 811 fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen); 812 if (fd < 0) { 813 error("accept from AUTH_SOCKET: %s", strerror(errno)); 814 return -1; 815 } 816 if (getpeereid(fd, &euid, &egid) < 0) { 817 error("getpeereid %d failed: %s", fd, strerror(errno)); 818 close(fd); 819 return -1; 820 } 821 if ((euid != 0) && (getuid() != euid)) { 822 error("uid mismatch: peer euid %u != uid %u", 823 (u_int) euid, (u_int) getuid()); 824 close(fd); 825 return -1; 826 } 827 new_socket(AUTH_CONNECTION, fd); 828 return 0; 829 } 830 831 static int 832 handle_conn_read(u_int socknum) 833 { 834 char buf[1024]; 835 ssize_t len; 836 int r; 837 838 if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) { 839 if (len == -1) { 840 if (errno == EAGAIN || errno == EINTR) 841 return 0; 842 error("%s: read error on socket %u (fd %d): %s", 843 __func__, socknum, sockets[socknum].fd, 844 strerror(errno)); 845 } 846 return -1; 847 } 848 if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0) 849 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 850 explicit_bzero(buf, sizeof(buf)); 851 process_message(socknum); 852 return 0; 853 } 854 855 static int 856 handle_conn_write(u_int socknum) 857 { 858 ssize_t len; 859 int r; 860 861 if (sshbuf_len(sockets[socknum].output) == 0) 862 return 0; /* shouldn't happen */ 863 if ((len = write(sockets[socknum].fd, 864 sshbuf_ptr(sockets[socknum].output), 865 sshbuf_len(sockets[socknum].output))) <= 0) { 866 if (len == -1) { 867 if (errno == EAGAIN || errno == EINTR) 868 return 0; 869 error("%s: read error on socket %u (fd %d): %s", 870 __func__, socknum, sockets[socknum].fd, 871 strerror(errno)); 872 } 873 return -1; 874 } 875 if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0) 876 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 877 return 0; 878 } 879 880 static void 881 after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds) 882 { 883 size_t i; 884 u_int socknum, activefds = npfd; 885 886 for (i = 0; i < npfd; i++) { 887 if (pfd[i].revents == 0) 888 continue; 889 /* Find sockets entry */ 890 for (socknum = 0; socknum < sockets_alloc; socknum++) { 891 if (sockets[socknum].type != AUTH_SOCKET && 892 sockets[socknum].type != AUTH_CONNECTION) 893 continue; 894 if (pfd[i].fd == sockets[socknum].fd) 895 break; 896 } 897 if (socknum >= sockets_alloc) { 898 error("%s: no socket for fd %d", __func__, pfd[i].fd); 899 continue; 900 } 901 /* Process events */ 902 switch (sockets[socknum].type) { 903 case AUTH_SOCKET: 904 if ((pfd[i].revents & (POLLIN|POLLERR)) == 0) 905 break; 906 if (npfd > maxfds) { 907 debug3("out of fds (active %u >= limit %u); " 908 "skipping accept", activefds, maxfds); 909 break; 910 } 911 if (handle_socket_read(socknum) == 0) 912 activefds++; 913 break; 914 case AUTH_CONNECTION: 915 if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 && 916 handle_conn_read(socknum) != 0) { 917 goto close_sock; 918 } 919 if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 && 920 handle_conn_write(socknum) != 0) { 921 close_sock: 922 if (activefds == 0) 923 fatal("activefds == 0 at close_sock"); 924 close_socket(&sockets[socknum]); 925 activefds--; 926 break; 927 } 928 break; 929 default: 930 break; 931 } 932 } 933 } 934 935 static int 936 prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds) 937 { 938 struct pollfd *pfd = *pfdp; 939 size_t i, j, npfd = 0; 940 time_t deadline; 941 942 /* Count active sockets */ 943 for (i = 0; i < sockets_alloc; i++) { 944 switch (sockets[i].type) { 945 case AUTH_SOCKET: 946 case AUTH_CONNECTION: 947 npfd++; 948 break; 949 case AUTH_UNUSED: 950 break; 951 default: 952 fatal("Unknown socket type %d", sockets[i].type); 953 break; 954 } 955 } 956 if (npfd != *npfdp && 957 (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL) 958 fatal("%s: recallocarray failed", __func__); 959 *pfdp = pfd; 960 *npfdp = npfd; 961 962 for (i = j = 0; i < sockets_alloc; i++) { 963 switch (sockets[i].type) { 964 case AUTH_SOCKET: 965 if (npfd > maxfds) { 966 debug3("out of fds (active %zu >= limit %u); " 967 "skipping arming listener", npfd, maxfds); 968 break; 969 } 970 pfd[j].fd = sockets[i].fd; 971 pfd[j].revents = 0; 972 pfd[j].events = POLLIN; 973 j++; 974 break; 975 case AUTH_CONNECTION: 976 pfd[j].fd = sockets[i].fd; 977 pfd[j].revents = 0; 978 /* XXX backoff when input buffer full */ 979 pfd[j].events = POLLIN; 980 if (sshbuf_len(sockets[i].output) > 0) 981 pfd[j].events |= POLLOUT; 982 j++; 983 break; 984 default: 985 break; 986 } 987 } 988 deadline = reaper(); 989 if (parent_alive_interval != 0) 990 deadline = (deadline == 0) ? parent_alive_interval : 991 MINIMUM(deadline, parent_alive_interval); 992 if (deadline == 0) { 993 *timeoutp = -1; /* INFTIM */ 994 } else { 995 if (deadline > INT_MAX / 1000) 996 *timeoutp = INT_MAX / 1000; 997 else 998 *timeoutp = deadline * 1000; 999 } 1000 return (1); 1001 } 1002 1003 static void 1004 cleanup_socket(void) 1005 { 1006 if (cleanup_pid != 0 && getpid() != cleanup_pid) 1007 return; 1008 debug("%s: cleanup", __func__); 1009 if (socket_name[0]) 1010 unlink(socket_name); 1011 if (socket_dir[0]) 1012 rmdir(socket_dir); 1013 } 1014 1015 void 1016 cleanup_exit(int i) 1017 { 1018 cleanup_socket(); 1019 _exit(i); 1020 } 1021 1022 /*ARGSUSED*/ 1023 __dead static void 1024 cleanup_handler(int sig) 1025 { 1026 cleanup_socket(); 1027 #ifdef ENABLE_PKCS11 1028 pkcs11_terminate(); 1029 #endif 1030 _exit(2); 1031 } 1032 1033 static void 1034 check_parent_exists(void) 1035 { 1036 /* 1037 * If our parent has exited then getppid() will return (pid_t)1, 1038 * so testing for that should be safe. 1039 */ 1040 if (parent_pid != -1 && getppid() != parent_pid) { 1041 /* printf("Parent has died - Authentication agent exiting.\n"); */ 1042 cleanup_socket(); 1043 _exit(2); 1044 } 1045 } 1046 1047 __dead static void 1048 usage(void) 1049 { 1050 fprintf(stderr, 1051 "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n" 1052 " [-P pkcs11_whitelist] [-t life] [command [arg ...]]\n" 1053 " ssh-agent [-c | -s] -k\n"); 1054 exit(1); 1055 } 1056 1057 static void 1058 csh_setenv(const char *name, const char *value) 1059 { 1060 printf("setenv %s %s;\n", name, value); 1061 } 1062 1063 static void 1064 csh_unsetenv(const char *name) 1065 { 1066 printf("unsetenv %s;\n", name); 1067 } 1068 1069 static void 1070 sh_setenv(const char *name, const char *value) 1071 { 1072 printf("%s=%s; export %s;\n", name, value, name); 1073 } 1074 1075 static void 1076 sh_unsetenv(const char *name) 1077 { 1078 printf("unset %s;\n", name); 1079 } 1080 int 1081 main(int ac, char **av) 1082 { 1083 int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0; 1084 int sock, fd, ch, result, saved_errno; 1085 char *shell, *pidstr, *agentsocket = NULL; 1086 struct rlimit rlim; 1087 void (*f_setenv)(const char *, const char *); 1088 void (*f_unsetenv)(const char *); 1089 extern int optind; 1090 extern char *optarg; 1091 pid_t pid; 1092 char pidstrbuf[1 + 3 * sizeof pid]; 1093 size_t len; 1094 mode_t prev_mask; 1095 int timeout = -1; /* INFTIM */ 1096 struct pollfd *pfd = NULL; 1097 size_t npfd = 0; 1098 u_int maxfds; 1099 1100 ssh_malloc_init(); /* must be called before any mallocs */ 1101 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 1102 sanitise_stdfd(); 1103 1104 /* drop */ 1105 setegid(getgid()); 1106 setgid(getgid()); 1107 1108 if (getrlimit(RLIMIT_NOFILE, &rlim) == -1) 1109 fatal("%s: getrlimit: %s", __progname, strerror(errno)); 1110 1111 #ifdef WITH_OPENSSL 1112 OpenSSL_add_all_algorithms(); 1113 #endif 1114 1115 while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) { 1116 switch (ch) { 1117 case 'E': 1118 fingerprint_hash = ssh_digest_alg_by_name(optarg); 1119 if (fingerprint_hash == -1) 1120 fatal("Invalid hash algorithm \"%s\"", optarg); 1121 break; 1122 case 'c': 1123 if (s_flag) 1124 usage(); 1125 c_flag++; 1126 break; 1127 case 'k': 1128 k_flag++; 1129 break; 1130 case 'P': 1131 if (pkcs11_whitelist != NULL) 1132 fatal("-P option already specified"); 1133 pkcs11_whitelist = xstrdup(optarg); 1134 break; 1135 case 's': 1136 if (c_flag) 1137 usage(); 1138 s_flag++; 1139 break; 1140 case 'd': 1141 if (d_flag || D_flag) 1142 usage(); 1143 d_flag++; 1144 break; 1145 case 'D': 1146 if (d_flag || D_flag) 1147 usage(); 1148 D_flag++; 1149 break; 1150 case 'a': 1151 agentsocket = optarg; 1152 break; 1153 case 't': 1154 if ((lifetime = convtime(optarg)) == -1) { 1155 fprintf(stderr, "Invalid lifetime\n"); 1156 usage(); 1157 } 1158 break; 1159 default: 1160 usage(); 1161 } 1162 } 1163 ac -= optind; 1164 av += optind; 1165 1166 if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag)) 1167 usage(); 1168 1169 if (pkcs11_whitelist == NULL) 1170 pkcs11_whitelist = xstrdup(DEFAULT_PKCS11_WHITELIST); 1171 1172 if (ac == 0 && !c_flag && !s_flag) { 1173 shell = getenv("SHELL"); 1174 if (shell != NULL && (len = strlen(shell)) > 2 && 1175 strncmp(shell + len - 3, "csh", 3) == 0) 1176 c_flag = 1; 1177 } 1178 if (c_flag) { 1179 f_setenv = csh_setenv; 1180 f_unsetenv = csh_unsetenv; 1181 } else { 1182 f_setenv = sh_setenv; 1183 f_unsetenv = sh_unsetenv; 1184 } 1185 if (k_flag) { 1186 const char *errstr = NULL; 1187 1188 pidstr = getenv(SSH_AGENTPID_ENV_NAME); 1189 if (pidstr == NULL) { 1190 fprintf(stderr, "%s not set, cannot kill agent\n", 1191 SSH_AGENTPID_ENV_NAME); 1192 exit(1); 1193 } 1194 pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr); 1195 if (errstr) { 1196 fprintf(stderr, 1197 "%s=\"%s\", which is not a good PID: %s\n", 1198 SSH_AGENTPID_ENV_NAME, pidstr, errstr); 1199 exit(1); 1200 } 1201 if (kill(pid, SIGTERM) == -1) { 1202 perror("kill"); 1203 exit(1); 1204 } 1205 (*f_unsetenv)(SSH_AUTHSOCKET_ENV_NAME); 1206 (*f_unsetenv)(SSH_AGENTPID_ENV_NAME); 1207 printf("echo Agent pid %ld killed;\n", (long)pid); 1208 exit(0); 1209 } 1210 1211 /* 1212 * Minimum file descriptors: 1213 * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) + 1214 * a few spare for libc / stack protectors / sanitisers, etc. 1215 */ 1216 #define SSH_AGENT_MIN_FDS (3+1+1+1+4) 1217 if (rlim.rlim_cur < SSH_AGENT_MIN_FDS) 1218 fatal("%s: file descriptior rlimit %lld too low (minimum %u)", 1219 __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS); 1220 maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS; 1221 1222 parent_pid = getpid(); 1223 1224 if (agentsocket == NULL) { 1225 /* Create private directory for agent socket */ 1226 mktemp_proto(socket_dir, sizeof(socket_dir)); 1227 if (mkdtemp(socket_dir) == NULL) { 1228 perror("mkdtemp: private socket dir"); 1229 exit(1); 1230 } 1231 snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir, 1232 (long)parent_pid); 1233 } else { 1234 /* Try to use specified agent socket */ 1235 socket_dir[0] = '\0'; 1236 strlcpy(socket_name, agentsocket, sizeof socket_name); 1237 } 1238 1239 /* 1240 * Create socket early so it will exist before command gets run from 1241 * the parent. 1242 */ 1243 prev_mask = umask(0177); 1244 sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0); 1245 if (sock < 0) { 1246 /* XXX - unix_listener() calls error() not perror() */ 1247 *socket_name = '\0'; /* Don't unlink any existing file */ 1248 cleanup_exit(1); 1249 } 1250 umask(prev_mask); 1251 1252 /* 1253 * Fork, and have the parent execute the command, if any, or present 1254 * the socket data. The child continues as the authentication agent. 1255 */ 1256 if (D_flag || d_flag) { 1257 log_init(__progname, 1258 d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO, 1259 SYSLOG_FACILITY_AUTH, 1); 1260 if (c_flag) 1261 printf("setenv %s %s;\n", 1262 SSH_AUTHSOCKET_ENV_NAME, socket_name); 1263 else 1264 printf("%s=%s; export %s;\n", 1265 SSH_AUTHSOCKET_ENV_NAME, socket_name, 1266 SSH_AUTHSOCKET_ENV_NAME); 1267 printf("echo Agent pid %ld;\n", (long)parent_pid); 1268 fflush(stdout); 1269 goto skip; 1270 } 1271 pid = fork(); 1272 if (pid == -1) { 1273 perror("fork"); 1274 cleanup_exit(1); 1275 } 1276 if (pid != 0) { /* Parent - execute the given command. */ 1277 close(sock); 1278 snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid); 1279 if (ac == 0) { 1280 (*f_setenv)(SSH_AUTHSOCKET_ENV_NAME, socket_name); 1281 (*f_setenv)(SSH_AGENTPID_ENV_NAME, pidstrbuf); 1282 printf("echo Agent pid %ld;\n", (long)pid); 1283 exit(0); 1284 } 1285 if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 || 1286 setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) { 1287 perror("setenv"); 1288 exit(1); 1289 } 1290 execvp(av[0], av); 1291 perror(av[0]); 1292 exit(1); 1293 } 1294 /* child */ 1295 log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0); 1296 1297 if (setsid() == -1) { 1298 error("setsid: %s", strerror(errno)); 1299 cleanup_exit(1); 1300 } 1301 1302 (void)chdir("/"); 1303 1304 if (sock != STDERR_FILENO + 1) { 1305 if (dup2(sock, STDERR_FILENO + 1) == -1) { 1306 error("dup2: %s", strerror(errno)); 1307 cleanup_exit(1); 1308 } 1309 close(sock); 1310 sock = STDERR_FILENO + 1; 1311 } 1312 #if defined(F_CLOSEM) 1313 if (fcntl(sock + 1, F_CLOSEM, 0) == -1) { 1314 error("fcntl F_CLOSEM: %s", strerror(errno)); 1315 cleanup_exit(1); 1316 } 1317 #else 1318 { 1319 int nfiles; 1320 #if defined(_SC_OPEN_MAX) 1321 nfiles = sysconf(_SC_OPEN_MAX); 1322 #elif defined(RLIMIT_NOFILE) 1323 if (getrlimit(RLIMIT_CORE, &rlim) < 0) { 1324 error("getrlimit RLIMIT_NOFILE: %s", strerror(errno)); 1325 cleanup_exit(1); 1326 } 1327 nfiles = rlim.rlim_cur; 1328 #elif defined(OPEN_MAX) 1329 nfiles = OPEN_MAX; 1330 #elif defined(NOFILE) 1331 nfiles = NOFILE; 1332 #else 1333 nfiles = 1024; 1334 #endif 1335 for (fd = sock + 1; fd < nfiles; fd++) 1336 close(fd); 1337 } 1338 #endif 1339 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { 1340 if (dup2(fd, STDIN_FILENO) == -1 || 1341 dup2(fd, STDOUT_FILENO) == -1 || 1342 dup2(fd, STDERR_FILENO) == -1) { 1343 error("dup2: %s", strerror(errno)); 1344 cleanup_exit(1); 1345 } 1346 if (fd > STDERR_FILENO) 1347 close(fd); 1348 } 1349 1350 /* deny core dumps, since memory contains unencrypted private keys */ 1351 rlim.rlim_cur = rlim.rlim_max = 0; 1352 if (setrlimit(RLIMIT_CORE, &rlim) < 0) { 1353 error("setrlimit RLIMIT_CORE: %s", strerror(errno)); 1354 cleanup_exit(1); 1355 } 1356 1357 skip: 1358 1359 cleanup_pid = getpid(); 1360 1361 #ifdef ENABLE_PKCS11 1362 pkcs11_init(0); 1363 #endif 1364 new_socket(AUTH_SOCKET, sock); 1365 if (ac > 0) 1366 parent_alive_interval = 10; 1367 idtab_init(); 1368 signal(SIGPIPE, SIG_IGN); 1369 signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN); 1370 signal(SIGHUP, cleanup_handler); 1371 signal(SIGTERM, cleanup_handler); 1372 1373 #ifdef __OpenBSD__ 1374 if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1) 1375 fatal("%s: pledge: %s", __progname, strerror(errno)); 1376 #endif 1377 1378 while (1) { 1379 prepare_poll(&pfd, &npfd, &timeout, maxfds); 1380 result = poll(pfd, npfd, timeout); 1381 saved_errno = errno; 1382 if (parent_alive_interval != 0) 1383 check_parent_exists(); 1384 (void) reaper(); /* remove expired keys */ 1385 if (result < 0) { 1386 if (saved_errno == EINTR) 1387 continue; 1388 fatal("poll: %s", strerror(saved_errno)); 1389 } else if (result > 0) 1390 after_poll(pfd, npfd, maxfds); 1391 } 1392 /* NOTREACHED */ 1393 } 1394