1 /* $OpenBSD: ssh-agent.c,v 1.213 2016/05/02 08:49:03 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 <sys/param.h> /* MIN MAX */ 38 #include <sys/types.h> 39 #include <sys/time.h> 40 #include <sys/queue.h> 41 #include <sys/resource.h> 42 #include <sys/socket.h> 43 #include <sys/stat.h> 44 #include <sys/un.h> 45 46 #ifdef WITH_OPENSSL 47 #include <openssl/evp.h> 48 #endif 49 50 #include <errno.h> 51 #include <fcntl.h> 52 #include <paths.h> 53 #include <signal.h> 54 #include <stdlib.h> 55 #include <stdio.h> 56 #include <string.h> 57 #include <limits.h> 58 #include <time.h> 59 #include <unistd.h> 60 #include <util.h> 61 62 #include "xmalloc.h" 63 #include "ssh.h" 64 #include "rsa.h" 65 #include "sshbuf.h" 66 #include "sshkey.h" 67 #include "authfd.h" 68 #include "compat.h" 69 #include "log.h" 70 #include "misc.h" 71 #include "digest.h" 72 #include "ssherr.h" 73 74 #ifdef ENABLE_PKCS11 75 #include "ssh-pkcs11.h" 76 #endif 77 78 typedef enum { 79 AUTH_UNUSED, 80 AUTH_SOCKET, 81 AUTH_CONNECTION 82 } sock_type; 83 84 typedef struct { 85 int fd; 86 sock_type type; 87 struct sshbuf *input; 88 struct sshbuf *output; 89 struct sshbuf *request; 90 } SocketEntry; 91 92 u_int sockets_alloc = 0; 93 SocketEntry *sockets = NULL; 94 95 typedef struct identity { 96 TAILQ_ENTRY(identity) next; 97 struct sshkey *key; 98 char *comment; 99 char *provider; 100 time_t death; 101 u_int confirm; 102 } Identity; 103 104 typedef struct { 105 int nentries; 106 TAILQ_HEAD(idqueue, identity) idlist; 107 } Idtab; 108 109 /* private key table, one per protocol version */ 110 Idtab idtable[3]; 111 112 int max_fd = 0; 113 114 /* pid of shell == parent of agent */ 115 pid_t parent_pid = -1; 116 time_t parent_alive_interval = 0; 117 118 /* pid of process for which cleanup_socket is applicable */ 119 pid_t cleanup_pid = 0; 120 121 /* pathname and directory for AUTH_SOCKET */ 122 char socket_name[PATH_MAX]; 123 char socket_dir[PATH_MAX]; 124 125 /* locking */ 126 #define LOCK_SIZE 32 127 #define LOCK_SALT_SIZE 16 128 #define LOCK_ROUNDS 1 129 int locked = 0; 130 u_char lock_pwhash[LOCK_SIZE]; 131 u_char lock_salt[LOCK_SALT_SIZE]; 132 133 extern char *__progname; 134 135 /* Default lifetime in seconds (0 == forever) */ 136 static long lifetime = 0; 137 138 static int fingerprint_hash = SSH_FP_HASH_DEFAULT; 139 140 static void 141 close_socket(SocketEntry *e) 142 { 143 close(e->fd); 144 e->fd = -1; 145 e->type = AUTH_UNUSED; 146 sshbuf_free(e->input); 147 sshbuf_free(e->output); 148 sshbuf_free(e->request); 149 } 150 151 static void 152 idtab_init(void) 153 { 154 int i; 155 156 for (i = 0; i <=2; i++) { 157 TAILQ_INIT(&idtable[i].idlist); 158 idtable[i].nentries = 0; 159 } 160 } 161 162 /* return private key table for requested protocol version */ 163 static Idtab * 164 idtab_lookup(int version) 165 { 166 if (version < 1 || version > 2) 167 fatal("internal error, bad protocol version %d", version); 168 return &idtable[version]; 169 } 170 171 static void 172 free_identity(Identity *id) 173 { 174 sshkey_free(id->key); 175 free(id->provider); 176 free(id->comment); 177 free(id); 178 } 179 180 /* return matching private key for given public key */ 181 static Identity * 182 lookup_identity(struct sshkey *key, int version) 183 { 184 Identity *id; 185 186 Idtab *tab = idtab_lookup(version); 187 TAILQ_FOREACH(id, &tab->idlist, next) { 188 if (sshkey_equal(key, id->key)) 189 return (id); 190 } 191 return (NULL); 192 } 193 194 /* Check confirmation of keysign request */ 195 static int 196 confirm_key(Identity *id) 197 { 198 char *p; 199 int ret = -1; 200 201 p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT); 202 if (p != NULL && 203 ask_permission("Allow use of key %s?\nKey fingerprint %s.", 204 id->comment, p)) 205 ret = 0; 206 free(p); 207 208 return (ret); 209 } 210 211 static void 212 send_status(SocketEntry *e, int success) 213 { 214 int r; 215 216 if ((r = sshbuf_put_u32(e->output, 1)) != 0 || 217 (r = sshbuf_put_u8(e->output, success ? 218 SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0) 219 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 220 } 221 222 /* send list of supported public keys to 'client' */ 223 static void 224 process_request_identities(SocketEntry *e, int version) 225 { 226 Idtab *tab = idtab_lookup(version); 227 Identity *id; 228 struct sshbuf *msg; 229 int r; 230 231 if ((msg = sshbuf_new()) == NULL) 232 fatal("%s: sshbuf_new failed", __func__); 233 if ((r = sshbuf_put_u8(msg, (version == 1) ? 234 SSH_AGENT_RSA_IDENTITIES_ANSWER : 235 SSH2_AGENT_IDENTITIES_ANSWER)) != 0 || 236 (r = sshbuf_put_u32(msg, tab->nentries)) != 0) 237 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 238 TAILQ_FOREACH(id, &tab->idlist, next) { 239 if (id->key->type == KEY_RSA1) { 240 #ifdef WITH_SSH1 241 if ((r = sshbuf_put_u32(msg, 242 BN_num_bits(id->key->rsa->n))) != 0 || 243 (r = sshbuf_put_bignum1(msg, 244 id->key->rsa->e)) != 0 || 245 (r = sshbuf_put_bignum1(msg, 246 id->key->rsa->n)) != 0) 247 fatal("%s: buffer error: %s", 248 __func__, ssh_err(r)); 249 #endif 250 } else { 251 u_char *blob; 252 size_t blen; 253 254 if ((r = sshkey_to_blob(id->key, &blob, &blen)) != 0) { 255 error("%s: sshkey_to_blob: %s", __func__, 256 ssh_err(r)); 257 continue; 258 } 259 if ((r = sshbuf_put_string(msg, blob, blen)) != 0) 260 fatal("%s: buffer error: %s", 261 __func__, ssh_err(r)); 262 free(blob); 263 } 264 if ((r = sshbuf_put_cstring(msg, id->comment)) != 0) 265 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 266 } 267 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 268 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 269 sshbuf_free(msg); 270 } 271 272 #ifdef WITH_SSH1 273 /* ssh1 only */ 274 static void 275 process_authentication_challenge1(SocketEntry *e) 276 { 277 u_char buf[32], mdbuf[16], session_id[16]; 278 u_int response_type; 279 BIGNUM *challenge; 280 Identity *id; 281 int r, len; 282 struct sshbuf *msg; 283 struct ssh_digest_ctx *md; 284 struct sshkey *key; 285 286 if ((msg = sshbuf_new()) == NULL) 287 fatal("%s: sshbuf_new failed", __func__); 288 if ((key = sshkey_new(KEY_RSA1)) == NULL) 289 fatal("%s: sshkey_new failed", __func__); 290 if ((challenge = BN_new()) == NULL) 291 fatal("%s: BN_new failed", __func__); 292 293 if ((r = sshbuf_get_u32(e->request, NULL)) != 0 || /* ignored */ 294 (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 || 295 (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0 || 296 (r = sshbuf_get_bignum1(e->request, challenge))) 297 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 298 299 /* Only protocol 1.1 is supported */ 300 if (sshbuf_len(e->request) == 0) 301 goto failure; 302 if ((r = sshbuf_get(e->request, session_id, sizeof(session_id))) != 0 || 303 (r = sshbuf_get_u32(e->request, &response_type)) != 0) 304 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 305 if (response_type != 1) 306 goto failure; 307 308 id = lookup_identity(key, 1); 309 if (id != NULL && (!id->confirm || confirm_key(id) == 0)) { 310 struct sshkey *private = id->key; 311 /* Decrypt the challenge using the private key. */ 312 if ((r = rsa_private_decrypt(challenge, challenge, 313 private->rsa) != 0)) { 314 fatal("%s: rsa_public_encrypt: %s", __func__, 315 ssh_err(r)); 316 goto failure; /* XXX ? */ 317 } 318 319 /* The response is MD5 of decrypted challenge plus session id */ 320 len = BN_num_bytes(challenge); 321 if (len <= 0 || len > 32) { 322 logit("%s: bad challenge length %d", __func__, len); 323 goto failure; 324 } 325 memset(buf, 0, 32); 326 BN_bn2bin(challenge, buf + 32 - len); 327 if ((md = ssh_digest_start(SSH_DIGEST_MD5)) == NULL || 328 ssh_digest_update(md, buf, 32) < 0 || 329 ssh_digest_update(md, session_id, 16) < 0 || 330 ssh_digest_final(md, mdbuf, sizeof(mdbuf)) < 0) 331 fatal("%s: md5 failed", __func__); 332 ssh_digest_free(md); 333 334 /* Send the response. */ 335 if ((r = sshbuf_put_u8(msg, SSH_AGENT_RSA_RESPONSE)) != 0 || 336 (r = sshbuf_put(msg, mdbuf, sizeof(mdbuf))) != 0) 337 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 338 goto send; 339 } 340 341 failure: 342 /* Unknown identity or protocol error. Send failure. */ 343 if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0) 344 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 345 send: 346 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 347 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 348 sshkey_free(key); 349 BN_clear_free(challenge); 350 sshbuf_free(msg); 351 } 352 #endif 353 354 static char * 355 agent_decode_alg(struct sshkey *key, u_int flags) 356 { 357 if (key->type == KEY_RSA) { 358 if (flags & SSH_AGENT_RSA_SHA2_256) 359 return "rsa-sha2-256"; 360 else if (flags & SSH_AGENT_RSA_SHA2_512) 361 return "rsa-sha2-512"; 362 } 363 return NULL; 364 } 365 366 /* ssh2 only */ 367 static void 368 process_sign_request2(SocketEntry *e) 369 { 370 u_char *blob, *data, *signature = NULL; 371 size_t blen, dlen, slen = 0; 372 u_int compat = 0, flags; 373 int r, ok = -1; 374 struct sshbuf *msg; 375 struct sshkey *key; 376 struct identity *id; 377 378 if ((msg = sshbuf_new()) == NULL) 379 fatal("%s: sshbuf_new failed", __func__); 380 if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0 || 381 (r = sshbuf_get_string(e->request, &data, &dlen)) != 0 || 382 (r = sshbuf_get_u32(e->request, &flags)) != 0) 383 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 384 if (flags & SSH_AGENT_OLD_SIGNATURE) 385 compat = SSH_BUG_SIGBLOB; 386 if ((r = sshkey_from_blob(blob, blen, &key)) != 0) { 387 error("%s: cannot parse key blob: %s", __func__, ssh_err(r)); 388 goto send; 389 } 390 if ((id = lookup_identity(key, 2)) == NULL) { 391 verbose("%s: %s key not found", __func__, sshkey_type(key)); 392 goto send; 393 } 394 if (id->confirm && confirm_key(id) != 0) { 395 verbose("%s: user refused key", __func__); 396 goto send; 397 } 398 if ((r = sshkey_sign(id->key, &signature, &slen, 399 data, dlen, agent_decode_alg(key, flags), compat)) != 0) { 400 error("%s: sshkey_sign: %s", __func__, ssh_err(r)); 401 goto send; 402 } 403 /* Success */ 404 ok = 0; 405 send: 406 sshkey_free(key); 407 if (ok == 0) { 408 if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 || 409 (r = sshbuf_put_string(msg, signature, slen)) != 0) 410 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 411 } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0) 412 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 413 414 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 415 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 416 417 sshbuf_free(msg); 418 free(data); 419 free(blob); 420 free(signature); 421 } 422 423 /* shared */ 424 static void 425 process_remove_identity(SocketEntry *e, int version) 426 { 427 size_t blen; 428 int r, success = 0; 429 struct sshkey *key = NULL; 430 u_char *blob; 431 #ifdef WITH_SSH1 432 u_int bits; 433 #endif /* WITH_SSH1 */ 434 435 switch (version) { 436 #ifdef WITH_SSH1 437 case 1: 438 if ((key = sshkey_new(KEY_RSA1)) == NULL) { 439 error("%s: sshkey_new failed", __func__); 440 return; 441 } 442 if ((r = sshbuf_get_u32(e->request, &bits)) != 0 || 443 (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 || 444 (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0) 445 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 446 447 if (bits != sshkey_size(key)) 448 logit("Warning: identity keysize mismatch: " 449 "actual %u, announced %u", 450 sshkey_size(key), bits); 451 break; 452 #endif /* WITH_SSH1 */ 453 case 2: 454 if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0) 455 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 456 if ((r = sshkey_from_blob(blob, blen, &key)) != 0) 457 error("%s: sshkey_from_blob failed: %s", 458 __func__, ssh_err(r)); 459 free(blob); 460 break; 461 } 462 if (key != NULL) { 463 Identity *id = lookup_identity(key, version); 464 if (id != NULL) { 465 /* 466 * We have this key. Free the old key. Since we 467 * don't want to leave empty slots in the middle of 468 * the array, we actually free the key there and move 469 * all the entries between the empty slot and the end 470 * of the array. 471 */ 472 Idtab *tab = idtab_lookup(version); 473 if (tab->nentries < 1) 474 fatal("process_remove_identity: " 475 "internal error: tab->nentries %d", 476 tab->nentries); 477 TAILQ_REMOVE(&tab->idlist, id, next); 478 free_identity(id); 479 tab->nentries--; 480 success = 1; 481 } 482 sshkey_free(key); 483 } 484 send_status(e, success); 485 } 486 487 static void 488 process_remove_all_identities(SocketEntry *e, int version) 489 { 490 Idtab *tab = idtab_lookup(version); 491 Identity *id; 492 493 /* Loop over all identities and clear the keys. */ 494 for (id = TAILQ_FIRST(&tab->idlist); id; 495 id = TAILQ_FIRST(&tab->idlist)) { 496 TAILQ_REMOVE(&tab->idlist, id, next); 497 free_identity(id); 498 } 499 500 /* Mark that there are no identities. */ 501 tab->nentries = 0; 502 503 /* Send success. */ 504 send_status(e, 1); 505 } 506 507 /* removes expired keys and returns number of seconds until the next expiry */ 508 static time_t 509 reaper(void) 510 { 511 time_t deadline = 0, now = monotime(); 512 Identity *id, *nxt; 513 int version; 514 Idtab *tab; 515 516 for (version = 1; version < 3; version++) { 517 tab = idtab_lookup(version); 518 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) { 519 nxt = TAILQ_NEXT(id, next); 520 if (id->death == 0) 521 continue; 522 if (now >= id->death) { 523 debug("expiring key '%s'", id->comment); 524 TAILQ_REMOVE(&tab->idlist, id, next); 525 free_identity(id); 526 tab->nentries--; 527 } else 528 deadline = (deadline == 0) ? id->death : 529 MIN(deadline, id->death); 530 } 531 } 532 if (deadline == 0 || deadline <= now) 533 return 0; 534 else 535 return (deadline - now); 536 } 537 538 /* 539 * XXX this and the corresponding serialisation function probably belongs 540 * in key.c 541 */ 542 #ifdef WITH_SSH1 543 static int 544 agent_decode_rsa1(struct sshbuf *m, struct sshkey **kp) 545 { 546 struct sshkey *k = NULL; 547 int r = SSH_ERR_INTERNAL_ERROR; 548 549 *kp = NULL; 550 if ((k = sshkey_new_private(KEY_RSA1)) == NULL) 551 return SSH_ERR_ALLOC_FAIL; 552 553 if ((r = sshbuf_get_u32(m, NULL)) != 0 || /* ignored */ 554 (r = sshbuf_get_bignum1(m, k->rsa->n)) != 0 || 555 (r = sshbuf_get_bignum1(m, k->rsa->e)) != 0 || 556 (r = sshbuf_get_bignum1(m, k->rsa->d)) != 0 || 557 (r = sshbuf_get_bignum1(m, k->rsa->iqmp)) != 0 || 558 /* SSH1 and SSL have p and q swapped */ 559 (r = sshbuf_get_bignum1(m, k->rsa->q)) != 0 || /* p */ 560 (r = sshbuf_get_bignum1(m, k->rsa->p)) != 0) /* q */ 561 goto out; 562 563 /* Generate additional parameters */ 564 if ((r = rsa_generate_additional_parameters(k->rsa)) != 0) 565 goto out; 566 /* enable blinding */ 567 if (RSA_blinding_on(k->rsa, NULL) != 1) { 568 r = SSH_ERR_LIBCRYPTO_ERROR; 569 goto out; 570 } 571 572 r = 0; /* success */ 573 out: 574 if (r == 0) 575 *kp = k; 576 else 577 sshkey_free(k); 578 return r; 579 } 580 #endif /* WITH_SSH1 */ 581 582 static void 583 process_add_identity(SocketEntry *e, int version) 584 { 585 Idtab *tab = idtab_lookup(version); 586 Identity *id; 587 int success = 0, confirm = 0; 588 u_int seconds; 589 char *comment = NULL; 590 time_t death = 0; 591 struct sshkey *k = NULL; 592 u_char ctype; 593 int r = SSH_ERR_INTERNAL_ERROR; 594 595 switch (version) { 596 #ifdef WITH_SSH1 597 case 1: 598 r = agent_decode_rsa1(e->request, &k); 599 break; 600 #endif /* WITH_SSH1 */ 601 case 2: 602 r = sshkey_private_deserialize(e->request, &k); 603 break; 604 } 605 if (r != 0 || k == NULL || 606 (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) { 607 error("%s: decode private key: %s", __func__, ssh_err(r)); 608 goto err; 609 } 610 611 while (sshbuf_len(e->request)) { 612 if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) { 613 error("%s: buffer error: %s", __func__, ssh_err(r)); 614 goto err; 615 } 616 switch (ctype) { 617 case SSH_AGENT_CONSTRAIN_LIFETIME: 618 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) { 619 error("%s: bad lifetime constraint: %s", 620 __func__, ssh_err(r)); 621 goto err; 622 } 623 death = monotime() + seconds; 624 break; 625 case SSH_AGENT_CONSTRAIN_CONFIRM: 626 confirm = 1; 627 break; 628 default: 629 error("%s: Unknown constraint %d", __func__, ctype); 630 err: 631 sshbuf_reset(e->request); 632 free(comment); 633 sshkey_free(k); 634 goto send; 635 } 636 } 637 638 success = 1; 639 if (lifetime && !death) 640 death = monotime() + lifetime; 641 if ((id = lookup_identity(k, version)) == NULL) { 642 id = xcalloc(1, sizeof(Identity)); 643 id->key = k; 644 TAILQ_INSERT_TAIL(&tab->idlist, id, next); 645 /* Increment the number of identities. */ 646 tab->nentries++; 647 } else { 648 sshkey_free(k); 649 free(id->comment); 650 } 651 id->comment = comment; 652 id->death = death; 653 id->confirm = confirm; 654 send: 655 send_status(e, success); 656 } 657 658 /* XXX todo: encrypt sensitive data with passphrase */ 659 static void 660 process_lock_agent(SocketEntry *e, int lock) 661 { 662 int r, success = 0, delay; 663 char *passwd; 664 u_char passwdhash[LOCK_SIZE]; 665 static u_int fail_count = 0; 666 size_t pwlen; 667 668 if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0) 669 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 670 if (pwlen == 0) { 671 debug("empty password not supported"); 672 } else if (locked && !lock) { 673 if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt), 674 passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0) 675 fatal("bcrypt_pbkdf"); 676 if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) { 677 debug("agent unlocked"); 678 locked = 0; 679 fail_count = 0; 680 explicit_bzero(lock_pwhash, sizeof(lock_pwhash)); 681 success = 1; 682 } else { 683 /* delay in 0.1s increments up to 10s */ 684 if (fail_count < 100) 685 fail_count++; 686 delay = 100000 * fail_count; 687 debug("unlock failed, delaying %0.1lf seconds", 688 (double)delay/1000000); 689 usleep(delay); 690 } 691 explicit_bzero(passwdhash, sizeof(passwdhash)); 692 } else if (!locked && lock) { 693 debug("agent locked"); 694 locked = 1; 695 arc4random_buf(lock_salt, sizeof(lock_salt)); 696 if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt), 697 lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0) 698 fatal("bcrypt_pbkdf"); 699 success = 1; 700 } 701 explicit_bzero(passwd, pwlen); 702 free(passwd); 703 send_status(e, success); 704 } 705 706 static void 707 no_identities(SocketEntry *e, u_int type) 708 { 709 struct sshbuf *msg; 710 int r; 711 712 if ((msg = sshbuf_new()) == NULL) 713 fatal("%s: sshbuf_new failed", __func__); 714 if ((r = sshbuf_put_u8(msg, 715 (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ? 716 SSH_AGENT_RSA_IDENTITIES_ANSWER : 717 SSH2_AGENT_IDENTITIES_ANSWER)) != 0 || 718 (r = sshbuf_put_u32(msg, 0)) != 0 || 719 (r = sshbuf_put_stringb(e->output, msg)) != 0) 720 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 721 sshbuf_free(msg); 722 } 723 724 #ifdef ENABLE_PKCS11 725 static void 726 process_add_smartcard_key(SocketEntry *e) 727 { 728 char *provider = NULL, *pin; 729 int r, i, version, count = 0, success = 0, confirm = 0; 730 u_int seconds; 731 time_t death = 0; 732 u_char type; 733 struct sshkey **keys = NULL, *k; 734 Identity *id; 735 Idtab *tab; 736 737 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 || 738 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) 739 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 740 741 while (sshbuf_len(e->request)) { 742 if ((r = sshbuf_get_u8(e->request, &type)) != 0) 743 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 744 switch (type) { 745 case SSH_AGENT_CONSTRAIN_LIFETIME: 746 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) 747 fatal("%s: buffer error: %s", 748 __func__, ssh_err(r)); 749 death = monotime() + seconds; 750 break; 751 case SSH_AGENT_CONSTRAIN_CONFIRM: 752 confirm = 1; 753 break; 754 default: 755 error("process_add_smartcard_key: " 756 "Unknown constraint type %d", type); 757 goto send; 758 } 759 } 760 if (lifetime && !death) 761 death = monotime() + lifetime; 762 763 count = pkcs11_add_provider(provider, pin, &keys); 764 for (i = 0; i < count; i++) { 765 k = keys[i]; 766 version = k->type == KEY_RSA1 ? 1 : 2; 767 tab = idtab_lookup(version); 768 if (lookup_identity(k, version) == NULL) { 769 id = xcalloc(1, sizeof(Identity)); 770 id->key = k; 771 id->provider = xstrdup(provider); 772 id->comment = xstrdup(provider); /* XXX */ 773 id->death = death; 774 id->confirm = confirm; 775 TAILQ_INSERT_TAIL(&tab->idlist, id, next); 776 tab->nentries++; 777 success = 1; 778 } else { 779 sshkey_free(k); 780 } 781 keys[i] = NULL; 782 } 783 send: 784 free(pin); 785 free(provider); 786 free(keys); 787 send_status(e, success); 788 } 789 790 static void 791 process_remove_smartcard_key(SocketEntry *e) 792 { 793 char *provider = NULL, *pin = NULL; 794 int r, version, success = 0; 795 Identity *id, *nxt; 796 Idtab *tab; 797 798 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 || 799 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) 800 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 801 free(pin); 802 803 for (version = 1; version < 3; version++) { 804 tab = idtab_lookup(version); 805 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) { 806 nxt = TAILQ_NEXT(id, next); 807 /* Skip file--based keys */ 808 if (id->provider == NULL) 809 continue; 810 if (!strcmp(provider, id->provider)) { 811 TAILQ_REMOVE(&tab->idlist, id, next); 812 free_identity(id); 813 tab->nentries--; 814 } 815 } 816 } 817 if (pkcs11_del_provider(provider) == 0) 818 success = 1; 819 else 820 error("process_remove_smartcard_key:" 821 " pkcs11_del_provider failed"); 822 free(provider); 823 send_status(e, success); 824 } 825 #endif /* ENABLE_PKCS11 */ 826 827 /* dispatch incoming messages */ 828 829 static void 830 process_message(SocketEntry *e) 831 { 832 u_int msg_len; 833 u_char type; 834 const u_char *cp; 835 int r; 836 837 if (sshbuf_len(e->input) < 5) 838 return; /* Incomplete message. */ 839 cp = sshbuf_ptr(e->input); 840 msg_len = PEEK_U32(cp); 841 if (msg_len > 256 * 1024) { 842 close_socket(e); 843 return; 844 } 845 if (sshbuf_len(e->input) < msg_len + 4) 846 return; 847 848 /* move the current input to e->request */ 849 sshbuf_reset(e->request); 850 if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 || 851 (r = sshbuf_get_u8(e->request, &type)) != 0) 852 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 853 854 /* check wheter agent is locked */ 855 if (locked && type != SSH_AGENTC_UNLOCK) { 856 sshbuf_reset(e->request); 857 switch (type) { 858 case SSH_AGENTC_REQUEST_RSA_IDENTITIES: 859 case SSH2_AGENTC_REQUEST_IDENTITIES: 860 /* send empty lists */ 861 no_identities(e, type); 862 break; 863 default: 864 /* send a fail message for all other request types */ 865 send_status(e, 0); 866 } 867 return; 868 } 869 870 debug("type %d", type); 871 switch (type) { 872 case SSH_AGENTC_LOCK: 873 case SSH_AGENTC_UNLOCK: 874 process_lock_agent(e, type == SSH_AGENTC_LOCK); 875 break; 876 #ifdef WITH_SSH1 877 /* ssh1 */ 878 case SSH_AGENTC_RSA_CHALLENGE: 879 process_authentication_challenge1(e); 880 break; 881 case SSH_AGENTC_REQUEST_RSA_IDENTITIES: 882 process_request_identities(e, 1); 883 break; 884 case SSH_AGENTC_ADD_RSA_IDENTITY: 885 case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED: 886 process_add_identity(e, 1); 887 break; 888 case SSH_AGENTC_REMOVE_RSA_IDENTITY: 889 process_remove_identity(e, 1); 890 break; 891 #endif 892 case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES: 893 process_remove_all_identities(e, 1); /* safe for !WITH_SSH1 */ 894 break; 895 /* ssh2 */ 896 case SSH2_AGENTC_SIGN_REQUEST: 897 process_sign_request2(e); 898 break; 899 case SSH2_AGENTC_REQUEST_IDENTITIES: 900 process_request_identities(e, 2); 901 break; 902 case SSH2_AGENTC_ADD_IDENTITY: 903 case SSH2_AGENTC_ADD_ID_CONSTRAINED: 904 process_add_identity(e, 2); 905 break; 906 case SSH2_AGENTC_REMOVE_IDENTITY: 907 process_remove_identity(e, 2); 908 break; 909 case SSH2_AGENTC_REMOVE_ALL_IDENTITIES: 910 process_remove_all_identities(e, 2); 911 break; 912 #ifdef ENABLE_PKCS11 913 case SSH_AGENTC_ADD_SMARTCARD_KEY: 914 case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED: 915 process_add_smartcard_key(e); 916 break; 917 case SSH_AGENTC_REMOVE_SMARTCARD_KEY: 918 process_remove_smartcard_key(e); 919 break; 920 #endif /* ENABLE_PKCS11 */ 921 default: 922 /* Unknown message. Respond with failure. */ 923 error("Unknown message %d", type); 924 sshbuf_reset(e->request); 925 send_status(e, 0); 926 break; 927 } 928 } 929 930 static void 931 new_socket(sock_type type, int fd) 932 { 933 u_int i, old_alloc, new_alloc; 934 935 set_nonblock(fd); 936 937 if (fd > max_fd) 938 max_fd = fd; 939 940 for (i = 0; i < sockets_alloc; i++) 941 if (sockets[i].type == AUTH_UNUSED) { 942 sockets[i].fd = fd; 943 if ((sockets[i].input = sshbuf_new()) == NULL) 944 fatal("%s: sshbuf_new failed", __func__); 945 if ((sockets[i].output = sshbuf_new()) == NULL) 946 fatal("%s: sshbuf_new failed", __func__); 947 if ((sockets[i].request = sshbuf_new()) == NULL) 948 fatal("%s: sshbuf_new failed", __func__); 949 sockets[i].type = type; 950 return; 951 } 952 old_alloc = sockets_alloc; 953 new_alloc = sockets_alloc + 10; 954 sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0])); 955 for (i = old_alloc; i < new_alloc; i++) 956 sockets[i].type = AUTH_UNUSED; 957 sockets_alloc = new_alloc; 958 sockets[old_alloc].fd = fd; 959 if ((sockets[old_alloc].input = sshbuf_new()) == NULL) 960 fatal("%s: sshbuf_new failed", __func__); 961 if ((sockets[old_alloc].output = sshbuf_new()) == NULL) 962 fatal("%s: sshbuf_new failed", __func__); 963 if ((sockets[old_alloc].request = sshbuf_new()) == NULL) 964 fatal("%s: sshbuf_new failed", __func__); 965 sockets[old_alloc].type = type; 966 } 967 968 static int 969 prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp, 970 struct timeval **tvpp) 971 { 972 u_int i, sz; 973 int n = 0; 974 static struct timeval tv; 975 time_t deadline; 976 977 for (i = 0; i < sockets_alloc; i++) { 978 switch (sockets[i].type) { 979 case AUTH_SOCKET: 980 case AUTH_CONNECTION: 981 n = MAX(n, sockets[i].fd); 982 break; 983 case AUTH_UNUSED: 984 break; 985 default: 986 fatal("Unknown socket type %d", sockets[i].type); 987 break; 988 } 989 } 990 991 sz = howmany(n+1, NFDBITS) * sizeof(fd_mask); 992 if (*fdrp == NULL || sz > *nallocp) { 993 free(*fdrp); 994 free(*fdwp); 995 *fdrp = xmalloc(sz); 996 *fdwp = xmalloc(sz); 997 *nallocp = sz; 998 } 999 if (n < *fdl) 1000 debug("XXX shrink: %d < %d", n, *fdl); 1001 *fdl = n; 1002 memset(*fdrp, 0, sz); 1003 memset(*fdwp, 0, sz); 1004 1005 for (i = 0; i < sockets_alloc; i++) { 1006 switch (sockets[i].type) { 1007 case AUTH_SOCKET: 1008 case AUTH_CONNECTION: 1009 FD_SET(sockets[i].fd, *fdrp); 1010 if (sshbuf_len(sockets[i].output) > 0) 1011 FD_SET(sockets[i].fd, *fdwp); 1012 break; 1013 default: 1014 break; 1015 } 1016 } 1017 deadline = reaper(); 1018 if (parent_alive_interval != 0) 1019 deadline = (deadline == 0) ? parent_alive_interval : 1020 MIN(deadline, parent_alive_interval); 1021 if (deadline == 0) { 1022 *tvpp = NULL; 1023 } else { 1024 tv.tv_sec = deadline; 1025 tv.tv_usec = 0; 1026 *tvpp = &tv; 1027 } 1028 return (1); 1029 } 1030 1031 static void 1032 after_select(fd_set *readset, fd_set *writeset) 1033 { 1034 struct sockaddr_un sunaddr; 1035 socklen_t slen; 1036 char buf[1024]; 1037 int len, sock, r; 1038 u_int i, orig_alloc; 1039 uid_t euid; 1040 gid_t egid; 1041 1042 for (i = 0, orig_alloc = sockets_alloc; i < orig_alloc; i++) 1043 switch (sockets[i].type) { 1044 case AUTH_UNUSED: 1045 break; 1046 case AUTH_SOCKET: 1047 if (FD_ISSET(sockets[i].fd, readset)) { 1048 slen = sizeof(sunaddr); 1049 sock = accept(sockets[i].fd, 1050 (struct sockaddr *)&sunaddr, &slen); 1051 if (sock < 0) { 1052 error("accept from AUTH_SOCKET: %s", 1053 strerror(errno)); 1054 break; 1055 } 1056 if (getpeereid(sock, &euid, &egid) < 0) { 1057 error("getpeereid %d failed: %s", 1058 sock, strerror(errno)); 1059 close(sock); 1060 break; 1061 } 1062 if ((euid != 0) && (getuid() != euid)) { 1063 error("uid mismatch: " 1064 "peer euid %u != uid %u", 1065 (u_int) euid, (u_int) getuid()); 1066 close(sock); 1067 break; 1068 } 1069 new_socket(AUTH_CONNECTION, sock); 1070 } 1071 break; 1072 case AUTH_CONNECTION: 1073 if (sshbuf_len(sockets[i].output) > 0 && 1074 FD_ISSET(sockets[i].fd, writeset)) { 1075 len = write(sockets[i].fd, 1076 sshbuf_ptr(sockets[i].output), 1077 sshbuf_len(sockets[i].output)); 1078 if (len == -1 && (errno == EAGAIN || 1079 errno == EINTR)) 1080 continue; 1081 if (len <= 0) { 1082 close_socket(&sockets[i]); 1083 break; 1084 } 1085 if ((r = sshbuf_consume(sockets[i].output, 1086 len)) != 0) 1087 fatal("%s: buffer error: %s", 1088 __func__, ssh_err(r)); 1089 } 1090 if (FD_ISSET(sockets[i].fd, readset)) { 1091 len = read(sockets[i].fd, buf, sizeof(buf)); 1092 if (len == -1 && (errno == EAGAIN || 1093 errno == EINTR)) 1094 continue; 1095 if (len <= 0) { 1096 close_socket(&sockets[i]); 1097 break; 1098 } 1099 if ((r = sshbuf_put(sockets[i].input, 1100 buf, len)) != 0) 1101 fatal("%s: buffer error: %s", 1102 __func__, ssh_err(r)); 1103 explicit_bzero(buf, sizeof(buf)); 1104 process_message(&sockets[i]); 1105 } 1106 break; 1107 default: 1108 fatal("Unknown type %d", sockets[i].type); 1109 } 1110 } 1111 1112 static void 1113 cleanup_socket(void) 1114 { 1115 if (cleanup_pid != 0 && getpid() != cleanup_pid) 1116 return; 1117 debug("%s: cleanup", __func__); 1118 if (socket_name[0]) 1119 unlink(socket_name); 1120 if (socket_dir[0]) 1121 rmdir(socket_dir); 1122 } 1123 1124 void 1125 cleanup_exit(int i) 1126 { 1127 cleanup_socket(); 1128 _exit(i); 1129 } 1130 1131 /*ARGSUSED*/ 1132 static void 1133 cleanup_handler(int sig) 1134 { 1135 cleanup_socket(); 1136 #ifdef ENABLE_PKCS11 1137 pkcs11_terminate(); 1138 #endif 1139 _exit(2); 1140 } 1141 1142 static void 1143 check_parent_exists(void) 1144 { 1145 /* 1146 * If our parent has exited then getppid() will return (pid_t)1, 1147 * so testing for that should be safe. 1148 */ 1149 if (parent_pid != -1 && getppid() != parent_pid) { 1150 /* printf("Parent has died - Authentication agent exiting.\n"); */ 1151 cleanup_socket(); 1152 _exit(2); 1153 } 1154 } 1155 1156 static void 1157 usage(void) 1158 { 1159 fprintf(stderr, 1160 "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n" 1161 " [-t life] [command [arg ...]]\n" 1162 " ssh-agent [-c | -s] -k\n"); 1163 exit(1); 1164 } 1165 1166 int 1167 main(int ac, char **av) 1168 { 1169 int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0; 1170 int sock, fd, ch, result, saved_errno; 1171 u_int nalloc; 1172 char *shell, *format, *pidstr, *agentsocket = NULL; 1173 fd_set *readsetp = NULL, *writesetp = NULL; 1174 struct rlimit rlim; 1175 extern int optind; 1176 extern char *optarg; 1177 pid_t pid; 1178 char pidstrbuf[1 + 3 * sizeof pid]; 1179 struct timeval *tvp = NULL; 1180 size_t len; 1181 mode_t prev_mask; 1182 1183 ssh_malloc_init(); /* must be called before any mallocs */ 1184 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 1185 sanitise_stdfd(); 1186 1187 /* drop */ 1188 setegid(getgid()); 1189 setgid(getgid()); 1190 1191 #ifdef WITH_OPENSSL 1192 OpenSSL_add_all_algorithms(); 1193 #endif 1194 1195 while ((ch = getopt(ac, av, "cDdksE:a:t:")) != -1) { 1196 switch (ch) { 1197 case 'E': 1198 fingerprint_hash = ssh_digest_alg_by_name(optarg); 1199 if (fingerprint_hash == -1) 1200 fatal("Invalid hash algorithm \"%s\"", optarg); 1201 break; 1202 case 'c': 1203 if (s_flag) 1204 usage(); 1205 c_flag++; 1206 break; 1207 case 'k': 1208 k_flag++; 1209 break; 1210 case 's': 1211 if (c_flag) 1212 usage(); 1213 s_flag++; 1214 break; 1215 case 'd': 1216 if (d_flag || D_flag) 1217 usage(); 1218 d_flag++; 1219 break; 1220 case 'D': 1221 if (d_flag || D_flag) 1222 usage(); 1223 D_flag++; 1224 break; 1225 case 'a': 1226 agentsocket = optarg; 1227 break; 1228 case 't': 1229 if ((lifetime = convtime(optarg)) == -1) { 1230 fprintf(stderr, "Invalid lifetime\n"); 1231 usage(); 1232 } 1233 break; 1234 default: 1235 usage(); 1236 } 1237 } 1238 ac -= optind; 1239 av += optind; 1240 1241 if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag)) 1242 usage(); 1243 1244 if (ac == 0 && !c_flag && !s_flag) { 1245 shell = getenv("SHELL"); 1246 if (shell != NULL && (len = strlen(shell)) > 2 && 1247 strncmp(shell + len - 3, "csh", 3) == 0) 1248 c_flag = 1; 1249 } 1250 if (k_flag) { 1251 const char *errstr = NULL; 1252 1253 pidstr = getenv(SSH_AGENTPID_ENV_NAME); 1254 if (pidstr == NULL) { 1255 fprintf(stderr, "%s not set, cannot kill agent\n", 1256 SSH_AGENTPID_ENV_NAME); 1257 exit(1); 1258 } 1259 pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr); 1260 if (errstr) { 1261 fprintf(stderr, 1262 "%s=\"%s\", which is not a good PID: %s\n", 1263 SSH_AGENTPID_ENV_NAME, pidstr, errstr); 1264 exit(1); 1265 } 1266 if (kill(pid, SIGTERM) == -1) { 1267 perror("kill"); 1268 exit(1); 1269 } 1270 format = c_flag ? "unsetenv %s;\n" : "unset %s;\n"; 1271 printf(format, SSH_AUTHSOCKET_ENV_NAME); 1272 printf(format, SSH_AGENTPID_ENV_NAME); 1273 printf("echo Agent pid %ld killed;\n", (long)pid); 1274 exit(0); 1275 } 1276 parent_pid = getpid(); 1277 1278 if (agentsocket == NULL) { 1279 /* Create private directory for agent socket */ 1280 mktemp_proto(socket_dir, sizeof(socket_dir)); 1281 if (mkdtemp(socket_dir) == NULL) { 1282 perror("mkdtemp: private socket dir"); 1283 exit(1); 1284 } 1285 snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir, 1286 (long)parent_pid); 1287 } else { 1288 /* Try to use specified agent socket */ 1289 socket_dir[0] = '\0'; 1290 strlcpy(socket_name, agentsocket, sizeof socket_name); 1291 } 1292 1293 /* 1294 * Create socket early so it will exist before command gets run from 1295 * the parent. 1296 */ 1297 prev_mask = umask(0177); 1298 sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0); 1299 if (sock < 0) { 1300 /* XXX - unix_listener() calls error() not perror() */ 1301 *socket_name = '\0'; /* Don't unlink any existing file */ 1302 cleanup_exit(1); 1303 } 1304 umask(prev_mask); 1305 1306 /* 1307 * Fork, and have the parent execute the command, if any, or present 1308 * the socket data. The child continues as the authentication agent. 1309 */ 1310 if (D_flag || d_flag) { 1311 log_init(__progname, 1312 d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO, 1313 SYSLOG_FACILITY_AUTH, 1); 1314 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; 1315 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, 1316 SSH_AUTHSOCKET_ENV_NAME); 1317 printf("echo Agent pid %ld;\n", (long)parent_pid); 1318 fflush(stdout); 1319 goto skip; 1320 } 1321 pid = fork(); 1322 if (pid == -1) { 1323 perror("fork"); 1324 cleanup_exit(1); 1325 } 1326 if (pid != 0) { /* Parent - execute the given command. */ 1327 close(sock); 1328 snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid); 1329 if (ac == 0) { 1330 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; 1331 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, 1332 SSH_AUTHSOCKET_ENV_NAME); 1333 printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf, 1334 SSH_AGENTPID_ENV_NAME); 1335 printf("echo Agent pid %ld;\n", (long)pid); 1336 exit(0); 1337 } 1338 if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 || 1339 setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) { 1340 perror("setenv"); 1341 exit(1); 1342 } 1343 execvp(av[0], av); 1344 perror(av[0]); 1345 exit(1); 1346 } 1347 /* child */ 1348 log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0); 1349 1350 if (setsid() == -1) { 1351 error("setsid: %s", strerror(errno)); 1352 cleanup_exit(1); 1353 } 1354 1355 (void)chdir("/"); 1356 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { 1357 /* XXX might close listen socket */ 1358 (void)dup2(fd, STDIN_FILENO); 1359 (void)dup2(fd, STDOUT_FILENO); 1360 (void)dup2(fd, STDERR_FILENO); 1361 if (fd > 2) 1362 close(fd); 1363 } 1364 1365 /* deny core dumps, since memory contains unencrypted private keys */ 1366 rlim.rlim_cur = rlim.rlim_max = 0; 1367 if (setrlimit(RLIMIT_CORE, &rlim) < 0) { 1368 error("setrlimit RLIMIT_CORE: %s", strerror(errno)); 1369 cleanup_exit(1); 1370 } 1371 1372 skip: 1373 1374 cleanup_pid = getpid(); 1375 1376 #ifdef ENABLE_PKCS11 1377 pkcs11_init(0); 1378 #endif 1379 new_socket(AUTH_SOCKET, sock); 1380 if (ac > 0) 1381 parent_alive_interval = 10; 1382 idtab_init(); 1383 signal(SIGPIPE, SIG_IGN); 1384 signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN); 1385 signal(SIGHUP, cleanup_handler); 1386 signal(SIGTERM, cleanup_handler); 1387 nalloc = 0; 1388 1389 if (pledge("stdio cpath unix id proc exec", NULL) == -1) 1390 fatal("%s: pledge: %s", __progname, strerror(errno)); 1391 1392 while (1) { 1393 prepare_select(&readsetp, &writesetp, &max_fd, &nalloc, &tvp); 1394 result = select(max_fd + 1, readsetp, writesetp, NULL, tvp); 1395 saved_errno = errno; 1396 if (parent_alive_interval != 0) 1397 check_parent_exists(); 1398 (void) reaper(); /* remove expired keys */ 1399 if (result < 0) { 1400 if (saved_errno == EINTR) 1401 continue; 1402 fatal("select: %s", strerror(saved_errno)); 1403 } else if (result > 0) 1404 after_select(readsetp, writesetp); 1405 } 1406 /* NOTREACHED */ 1407 } 1408