1 /* $OpenBSD: ssh-agent.c,v 1.204 2015/07/08 20:24:02 markus Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo (at) cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo (at) 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 39 #include <sys/param.h> /* MIN MAX */ 40 #include <sys/types.h> 41 #include <sys/param.h> 42 #include <sys/resource.h> 43 #include <sys/stat.h> 44 #include <sys/socket.h> 45 #ifdef HAVE_SYS_TIME_H 46 # include <sys/time.h> 47 #endif 48 #ifdef HAVE_SYS_UN_H 49 # include <sys/un.h> 50 #endif 51 #include "openbsd-compat/sys-queue.h" 52 53 #ifdef WITH_OPENSSL 54 #include <openssl/evp.h> 55 #include "openbsd-compat/openssl-compat.h" 56 #endif 57 58 #include <errno.h> 59 #include <fcntl.h> 60 #include <limits.h> 61 #ifdef HAVE_PATHS_H 62 # include <paths.h> 63 #endif 64 #include <signal.h> 65 #include <stdarg.h> 66 #include <stdio.h> 67 #include <stdlib.h> 68 #include <time.h> 69 #include <string.h> 70 #include <unistd.h> 71 #ifdef HAVE_UTIL_H 72 # include <util.h> 73 #endif 74 75 #include "xmalloc.h" 76 #include "ssh.h" 77 #include "rsa.h" 78 #include "sshbuf.h" 79 #include "sshkey.h" 80 #include "authfd.h" 81 #include "compat.h" 82 #include "log.h" 83 #include "misc.h" 84 #include "digest.h" 85 #include "ssherr.h" 86 87 #ifdef ENABLE_PKCS11 88 #include "ssh-pkcs11.h" 89 #endif 90 91 #if defined(HAVE_SYS_PRCTL_H) 92 #include <sys/prctl.h> /* For prctl() and PR_SET_DUMPABLE */ 93 #endif 94 95 typedef enum { 96 AUTH_UNUSED, 97 AUTH_SOCKET, 98 AUTH_CONNECTION 99 } sock_type; 100 101 typedef struct { 102 int fd; 103 sock_type type; 104 struct sshbuf *input; 105 struct sshbuf *output; 106 struct sshbuf *request; 107 } SocketEntry; 108 109 u_int sockets_alloc = 0; 110 SocketEntry *sockets = NULL; 111 112 typedef struct identity { 113 TAILQ_ENTRY(identity) next; 114 struct sshkey *key; 115 char *comment; 116 char *provider; 117 time_t death; 118 u_int confirm; 119 } Identity; 120 121 typedef struct { 122 int nentries; 123 TAILQ_HEAD(idqueue, identity) idlist; 124 } Idtab; 125 126 /* private key table, one per protocol version */ 127 Idtab idtable[3]; 128 129 int max_fd = 0; 130 131 /* pid of shell == parent of agent */ 132 pid_t parent_pid = -1; 133 time_t parent_alive_interval = 0; 134 135 /* pid of process for which cleanup_socket is applicable */ 136 pid_t cleanup_pid = 0; 137 138 /* pathname and directory for AUTH_SOCKET */ 139 char socket_name[PATH_MAX]; 140 char socket_dir[PATH_MAX]; 141 142 /* locking */ 143 #define LOCK_SIZE 32 144 #define LOCK_SALT_SIZE 16 145 #define LOCK_ROUNDS 1 146 int locked = 0; 147 char lock_passwd[LOCK_SIZE]; 148 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 int i; 172 173 for (i = 0; i <=2; i++) { 174 TAILQ_INIT(&idtable[i].idlist); 175 idtable[i].nentries = 0; 176 } 177 } 178 179 /* return private key table for requested protocol version */ 180 static Idtab * 181 idtab_lookup(int version) 182 { 183 if (version < 1 || version > 2) 184 fatal("internal error, bad protocol version %d", version); 185 return &idtable[version]; 186 } 187 188 static void 189 free_identity(Identity *id) 190 { 191 sshkey_free(id->key); 192 free(id->provider); 193 free(id->comment); 194 free(id); 195 } 196 197 /* return matching private key for given public key */ 198 static Identity * 199 lookup_identity(struct sshkey *key, int version) 200 { 201 Identity *id; 202 203 Idtab *tab = idtab_lookup(version); 204 TAILQ_FOREACH(id, &tab->idlist, next) { 205 if (sshkey_equal(key, id->key)) 206 return (id); 207 } 208 return (NULL); 209 } 210 211 /* Check confirmation of keysign request */ 212 static int 213 confirm_key(Identity *id) 214 { 215 char *p; 216 int ret = -1; 217 218 p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT); 219 if (p != NULL && 220 ask_permission("Allow use of key %s?\nKey fingerprint %s.", 221 id->comment, p)) 222 ret = 0; 223 free(p); 224 225 return (ret); 226 } 227 228 static void 229 send_status(SocketEntry *e, int success) 230 { 231 int r; 232 233 if ((r = sshbuf_put_u32(e->output, 1)) != 0 || 234 (r = sshbuf_put_u8(e->output, success ? 235 SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0) 236 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 237 } 238 239 /* send list of supported public keys to 'client' */ 240 static void 241 process_request_identities(SocketEntry *e, int version) 242 { 243 Idtab *tab = idtab_lookup(version); 244 Identity *id; 245 struct sshbuf *msg; 246 int r; 247 248 if ((msg = sshbuf_new()) == NULL) 249 fatal("%s: sshbuf_new failed", __func__); 250 if ((r = sshbuf_put_u8(msg, (version == 1) ? 251 SSH_AGENT_RSA_IDENTITIES_ANSWER : 252 SSH2_AGENT_IDENTITIES_ANSWER)) != 0 || 253 (r = sshbuf_put_u32(msg, tab->nentries)) != 0) 254 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 255 TAILQ_FOREACH(id, &tab->idlist, next) { 256 if (id->key->type == KEY_RSA1) { 257 #ifdef WITH_SSH1 258 if ((r = sshbuf_put_u32(msg, 259 BN_num_bits(id->key->rsa->n))) != 0 || 260 (r = sshbuf_put_bignum1(msg, 261 id->key->rsa->e)) != 0 || 262 (r = sshbuf_put_bignum1(msg, 263 id->key->rsa->n)) != 0) 264 fatal("%s: buffer error: %s", 265 __func__, ssh_err(r)); 266 #endif 267 } else { 268 u_char *blob; 269 size_t blen; 270 271 if ((r = sshkey_to_blob(id->key, &blob, &blen)) != 0) { 272 error("%s: sshkey_to_blob: %s", __func__, 273 ssh_err(r)); 274 continue; 275 } 276 if ((r = sshbuf_put_string(msg, blob, blen)) != 0) 277 fatal("%s: buffer error: %s", 278 __func__, ssh_err(r)); 279 free(blob); 280 } 281 if ((r = sshbuf_put_cstring(msg, id->comment)) != 0) 282 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 283 } 284 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 285 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 286 sshbuf_free(msg); 287 } 288 289 #ifdef WITH_SSH1 290 /* ssh1 only */ 291 static void 292 process_authentication_challenge1(SocketEntry *e) 293 { 294 u_char buf[32], mdbuf[16], session_id[16]; 295 u_int response_type; 296 BIGNUM *challenge; 297 Identity *id; 298 int r, len; 299 struct sshbuf *msg; 300 struct ssh_digest_ctx *md; 301 struct sshkey *key; 302 303 if ((msg = sshbuf_new()) == NULL) 304 fatal("%s: sshbuf_new failed", __func__); 305 if ((key = sshkey_new(KEY_RSA1)) == NULL) 306 fatal("%s: sshkey_new failed", __func__); 307 if ((challenge = BN_new()) == NULL) 308 fatal("%s: BN_new failed", __func__); 309 310 if ((r = sshbuf_get_u32(e->request, NULL)) != 0 || /* ignored */ 311 (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 || 312 (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0 || 313 (r = sshbuf_get_bignum1(e->request, challenge))) 314 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 315 316 /* Only protocol 1.1 is supported */ 317 if (sshbuf_len(e->request) == 0) 318 goto failure; 319 if ((r = sshbuf_get(e->request, session_id, sizeof(session_id))) != 0 || 320 (r = sshbuf_get_u32(e->request, &response_type)) != 0) 321 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 322 if (response_type != 1) 323 goto failure; 324 325 id = lookup_identity(key, 1); 326 if (id != NULL && (!id->confirm || confirm_key(id) == 0)) { 327 struct sshkey *private = id->key; 328 /* Decrypt the challenge using the private key. */ 329 if ((r = rsa_private_decrypt(challenge, challenge, 330 private->rsa) != 0)) { 331 fatal("%s: rsa_public_encrypt: %s", __func__, 332 ssh_err(r)); 333 goto failure; /* XXX ? */ 334 } 335 336 /* The response is MD5 of decrypted challenge plus session id */ 337 len = BN_num_bytes(challenge); 338 if (len <= 0 || len > 32) { 339 logit("%s: bad challenge length %d", __func__, len); 340 goto failure; 341 } 342 memset(buf, 0, 32); 343 BN_bn2bin(challenge, buf + 32 - len); 344 if ((md = ssh_digest_start(SSH_DIGEST_MD5)) == NULL || 345 ssh_digest_update(md, buf, 32) < 0 || 346 ssh_digest_update(md, session_id, 16) < 0 || 347 ssh_digest_final(md, mdbuf, sizeof(mdbuf)) < 0) 348 fatal("%s: md5 failed", __func__); 349 ssh_digest_free(md); 350 351 /* Send the response. */ 352 if ((r = sshbuf_put_u8(msg, SSH_AGENT_RSA_RESPONSE)) != 0 || 353 (r = sshbuf_put(msg, mdbuf, sizeof(mdbuf))) != 0) 354 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 355 goto send; 356 } 357 358 failure: 359 /* Unknown identity or protocol error. Send failure. */ 360 if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0) 361 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 362 send: 363 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 364 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 365 sshkey_free(key); 366 BN_clear_free(challenge); 367 sshbuf_free(msg); 368 } 369 #endif 370 371 /* ssh2 only */ 372 static void 373 process_sign_request2(SocketEntry *e) 374 { 375 u_char *blob, *data, *signature = NULL; 376 size_t blen, dlen, slen = 0; 377 u_int compat = 0, flags; 378 int r, ok = -1; 379 struct sshbuf *msg; 380 struct sshkey *key; 381 struct identity *id; 382 383 if ((msg = sshbuf_new()) == NULL) 384 fatal("%s: sshbuf_new failed", __func__); 385 if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0 || 386 (r = sshbuf_get_string(e->request, &data, &dlen)) != 0 || 387 (r = sshbuf_get_u32(e->request, &flags)) != 0) 388 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 389 if (flags & SSH_AGENT_OLD_SIGNATURE) 390 compat = SSH_BUG_SIGBLOB; 391 if ((r = sshkey_from_blob(blob, blen, &key)) != 0) { 392 error("%s: cannot parse key blob: %s", __func__, ssh_err(ok)); 393 goto send; 394 } 395 if ((id = lookup_identity(key, 2)) == NULL) { 396 verbose("%s: %s key not found", __func__, sshkey_type(key)); 397 goto send; 398 } 399 if (id->confirm && confirm_key(id) != 0) { 400 verbose("%s: user refused key", __func__); 401 goto send; 402 } 403 if ((r = sshkey_sign(id->key, &signature, &slen, 404 data, dlen, compat)) != 0) { 405 error("%s: sshkey_sign: %s", __func__, ssh_err(ok)); 406 goto send; 407 } 408 /* Success */ 409 ok = 0; 410 send: 411 sshkey_free(key); 412 if (ok == 0) { 413 if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 || 414 (r = sshbuf_put_string(msg, signature, slen)) != 0) 415 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 416 } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0) 417 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 418 419 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 420 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 421 422 sshbuf_free(msg); 423 free(data); 424 free(blob); 425 free(signature); 426 } 427 428 /* shared */ 429 static void 430 process_remove_identity(SocketEntry *e, int version) 431 { 432 size_t blen; 433 int r, success = 0; 434 struct sshkey *key = NULL; 435 u_char *blob; 436 #ifdef WITH_SSH1 437 u_int bits; 438 #endif /* WITH_SSH1 */ 439 440 switch (version) { 441 #ifdef WITH_SSH1 442 case 1: 443 if ((key = sshkey_new(KEY_RSA1)) == NULL) { 444 error("%s: sshkey_new failed", __func__); 445 return; 446 } 447 if ((r = sshbuf_get_u32(e->request, &bits)) != 0 || 448 (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 || 449 (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0) 450 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 451 452 if (bits != sshkey_size(key)) 453 logit("Warning: identity keysize mismatch: " 454 "actual %u, announced %u", 455 sshkey_size(key), bits); 456 break; 457 #endif /* WITH_SSH1 */ 458 case 2: 459 if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0) 460 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 461 if ((r = sshkey_from_blob(blob, blen, &key)) != 0) 462 error("%s: sshkey_from_blob failed: %s", 463 __func__, ssh_err(r)); 464 free(blob); 465 break; 466 } 467 if (key != NULL) { 468 Identity *id = lookup_identity(key, version); 469 if (id != NULL) { 470 /* 471 * We have this key. Free the old key. Since we 472 * don't want to leave empty slots in the middle of 473 * the array, we actually free the key there and move 474 * all the entries between the empty slot and the end 475 * of the array. 476 */ 477 Idtab *tab = idtab_lookup(version); 478 if (tab->nentries < 1) 479 fatal("process_remove_identity: " 480 "internal error: tab->nentries %d", 481 tab->nentries); 482 TAILQ_REMOVE(&tab->idlist, id, next); 483 free_identity(id); 484 tab->nentries--; 485 success = 1; 486 } 487 sshkey_free(key); 488 } 489 send_status(e, success); 490 } 491 492 static void 493 process_remove_all_identities(SocketEntry *e, int version) 494 { 495 Idtab *tab = idtab_lookup(version); 496 Identity *id; 497 498 /* Loop over all identities and clear the keys. */ 499 for (id = TAILQ_FIRST(&tab->idlist); id; 500 id = TAILQ_FIRST(&tab->idlist)) { 501 TAILQ_REMOVE(&tab->idlist, id, next); 502 free_identity(id); 503 } 504 505 /* Mark that there are no identities. */ 506 tab->nentries = 0; 507 508 /* Send success. */ 509 send_status(e, 1); 510 } 511 512 /* removes expired keys and returns number of seconds until the next expiry */ 513 static time_t 514 reaper(void) 515 { 516 time_t deadline = 0, now = monotime(); 517 Identity *id, *nxt; 518 int version; 519 Idtab *tab; 520 521 for (version = 1; version < 3; version++) { 522 tab = idtab_lookup(version); 523 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) { 524 nxt = TAILQ_NEXT(id, next); 525 if (id->death == 0) 526 continue; 527 if (now >= id->death) { 528 debug("expiring key '%s'", id->comment); 529 TAILQ_REMOVE(&tab->idlist, id, next); 530 free_identity(id); 531 tab->nentries--; 532 } else 533 deadline = (deadline == 0) ? id->death : 534 MIN(deadline, id->death); 535 } 536 } 537 if (deadline == 0 || deadline <= now) 538 return 0; 539 else 540 return (deadline - now); 541 } 542 543 /* 544 * XXX this and the corresponding serialisation function probably belongs 545 * in key.c 546 */ 547 #ifdef WITH_SSH1 548 static int 549 agent_decode_rsa1(struct sshbuf *m, struct sshkey **kp) 550 { 551 struct sshkey *k = NULL; 552 int r = SSH_ERR_INTERNAL_ERROR; 553 554 *kp = NULL; 555 if ((k = sshkey_new_private(KEY_RSA1)) == NULL) 556 return SSH_ERR_ALLOC_FAIL; 557 558 if ((r = sshbuf_get_u32(m, NULL)) != 0 || /* ignored */ 559 (r = sshbuf_get_bignum1(m, k->rsa->n)) != 0 || 560 (r = sshbuf_get_bignum1(m, k->rsa->e)) != 0 || 561 (r = sshbuf_get_bignum1(m, k->rsa->d)) != 0 || 562 (r = sshbuf_get_bignum1(m, k->rsa->iqmp)) != 0 || 563 /* SSH1 and SSL have p and q swapped */ 564 (r = sshbuf_get_bignum1(m, k->rsa->q)) != 0 || /* p */ 565 (r = sshbuf_get_bignum1(m, k->rsa->p)) != 0) /* q */ 566 goto out; 567 568 /* Generate additional parameters */ 569 if ((r = rsa_generate_additional_parameters(k->rsa)) != 0) 570 goto out; 571 /* enable blinding */ 572 if (RSA_blinding_on(k->rsa, NULL) != 1) { 573 r = SSH_ERR_LIBCRYPTO_ERROR; 574 goto out; 575 } 576 577 r = 0; /* success */ 578 out: 579 if (r == 0) 580 *kp = k; 581 else 582 sshkey_free(k); 583 return r; 584 } 585 #endif /* WITH_SSH1 */ 586 587 static void 588 process_add_identity(SocketEntry *e, int version) 589 { 590 Idtab *tab = idtab_lookup(version); 591 Identity *id; 592 int success = 0, confirm = 0; 593 u_int seconds; 594 char *comment = NULL; 595 time_t death = 0; 596 struct sshkey *k = NULL; 597 u_char ctype; 598 int r = SSH_ERR_INTERNAL_ERROR; 599 600 switch (version) { 601 #ifdef WITH_SSH1 602 case 1: 603 r = agent_decode_rsa1(e->request, &k); 604 break; 605 #endif /* WITH_SSH1 */ 606 case 2: 607 r = sshkey_private_deserialize(e->request, &k); 608 break; 609 } 610 if (r != 0 || k == NULL || 611 (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) { 612 error("%s: decode private key: %s", __func__, ssh_err(r)); 613 goto err; 614 } 615 616 while (sshbuf_len(e->request)) { 617 if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) { 618 error("%s: buffer error: %s", __func__, ssh_err(r)); 619 goto err; 620 } 621 switch (ctype) { 622 case SSH_AGENT_CONSTRAIN_LIFETIME: 623 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) { 624 error("%s: bad lifetime constraint: %s", 625 __func__, ssh_err(r)); 626 goto err; 627 } 628 death = monotime() + seconds; 629 break; 630 case SSH_AGENT_CONSTRAIN_CONFIRM: 631 confirm = 1; 632 break; 633 default: 634 error("%s: Unknown constraint %d", __func__, ctype); 635 err: 636 sshbuf_reset(e->request); 637 free(comment); 638 sshkey_free(k); 639 goto send; 640 } 641 } 642 643 success = 1; 644 if (lifetime && !death) 645 death = monotime() + lifetime; 646 if ((id = lookup_identity(k, version)) == NULL) { 647 id = xcalloc(1, sizeof(Identity)); 648 id->key = k; 649 TAILQ_INSERT_TAIL(&tab->idlist, id, next); 650 /* Increment the number of identities. */ 651 tab->nentries++; 652 } else { 653 sshkey_free(k); 654 free(id->comment); 655 } 656 id->comment = comment; 657 id->death = death; 658 id->confirm = confirm; 659 send: 660 send_status(e, success); 661 } 662 663 /* XXX todo: encrypt sensitive data with passphrase */ 664 static void 665 process_lock_agent(SocketEntry *e, int lock) 666 { 667 int r, success = 0, delay; 668 char *passwd, passwdhash[LOCK_SIZE]; 669 static u_int fail_count = 0; 670 size_t pwlen; 671 672 if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0) 673 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 674 if (pwlen == 0) { 675 debug("empty password not supported"); 676 } else if (locked && !lock) { 677 if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt), 678 passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0) 679 fatal("bcrypt_pbkdf"); 680 if (timingsafe_bcmp(passwdhash, lock_passwd, LOCK_SIZE) == 0) { 681 debug("agent unlocked"); 682 locked = 0; 683 fail_count = 0; 684 explicit_bzero(lock_passwd, sizeof(lock_passwd)); 685 success = 1; 686 } else { 687 /* delay in 0.1s increments up to 10s */ 688 if (fail_count < 100) 689 fail_count++; 690 delay = 100000 * fail_count; 691 debug("unlock failed, delaying %0.1lf seconds", 692 (double)delay/1000000); 693 usleep(delay); 694 } 695 explicit_bzero(passwdhash, sizeof(passwdhash)); 696 } else if (!locked && lock) { 697 debug("agent locked"); 698 locked = 1; 699 arc4random_buf(lock_salt, sizeof(lock_salt)); 700 if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt), 701 lock_passwd, sizeof(lock_passwd), LOCK_ROUNDS) < 0) 702 fatal("bcrypt_pbkdf"); 703 success = 1; 704 } 705 explicit_bzero(passwd, pwlen); 706 free(passwd); 707 send_status(e, success); 708 } 709 710 static void 711 no_identities(SocketEntry *e, u_int type) 712 { 713 struct sshbuf *msg; 714 int r; 715 716 if ((msg = sshbuf_new()) == NULL) 717 fatal("%s: sshbuf_new failed", __func__); 718 if ((r = sshbuf_put_u8(msg, 719 (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ? 720 SSH_AGENT_RSA_IDENTITIES_ANSWER : 721 SSH2_AGENT_IDENTITIES_ANSWER)) != 0 || 722 (r = sshbuf_put_u32(msg, 0)) != 0 || 723 (r = sshbuf_put_stringb(e->output, msg)) != 0) 724 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 725 sshbuf_free(msg); 726 } 727 728 #ifdef ENABLE_PKCS11 729 static void 730 process_add_smartcard_key(SocketEntry *e) 731 { 732 char *provider = NULL, *pin; 733 int r, i, version, count = 0, success = 0, confirm = 0; 734 u_int seconds; 735 time_t death = 0; 736 u_char type; 737 struct sshkey **keys = NULL, *k; 738 Identity *id; 739 Idtab *tab; 740 741 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 || 742 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) 743 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 744 745 while (sshbuf_len(e->request)) { 746 if ((r = sshbuf_get_u8(e->request, &type)) != 0) 747 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 748 switch (type) { 749 case SSH_AGENT_CONSTRAIN_LIFETIME: 750 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) 751 fatal("%s: buffer error: %s", 752 __func__, ssh_err(r)); 753 death = monotime() + seconds; 754 break; 755 case SSH_AGENT_CONSTRAIN_CONFIRM: 756 confirm = 1; 757 break; 758 default: 759 error("process_add_smartcard_key: " 760 "Unknown constraint type %d", type); 761 goto send; 762 } 763 } 764 if (lifetime && !death) 765 death = monotime() + lifetime; 766 767 count = pkcs11_add_provider(provider, pin, &keys); 768 for (i = 0; i < count; i++) { 769 k = keys[i]; 770 version = k->type == KEY_RSA1 ? 1 : 2; 771 tab = idtab_lookup(version); 772 if (lookup_identity(k, version) == NULL) { 773 id = xcalloc(1, sizeof(Identity)); 774 id->key = k; 775 id->provider = xstrdup(provider); 776 id->comment = xstrdup(provider); /* XXX */ 777 id->death = death; 778 id->confirm = confirm; 779 TAILQ_INSERT_TAIL(&tab->idlist, id, next); 780 tab->nentries++; 781 success = 1; 782 } else { 783 sshkey_free(k); 784 } 785 keys[i] = NULL; 786 } 787 send: 788 free(pin); 789 free(provider); 790 free(keys); 791 send_status(e, success); 792 } 793 794 static void 795 process_remove_smartcard_key(SocketEntry *e) 796 { 797 char *provider = NULL, *pin = NULL; 798 int r, version, success = 0; 799 Identity *id, *nxt; 800 Idtab *tab; 801 802 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 || 803 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) 804 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 805 free(pin); 806 807 for (version = 1; version < 3; version++) { 808 tab = idtab_lookup(version); 809 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) { 810 nxt = TAILQ_NEXT(id, next); 811 /* Skip file--based keys */ 812 if (id->provider == NULL) 813 continue; 814 if (!strcmp(provider, id->provider)) { 815 TAILQ_REMOVE(&tab->idlist, id, next); 816 free_identity(id); 817 tab->nentries--; 818 } 819 } 820 } 821 if (pkcs11_del_provider(provider) == 0) 822 success = 1; 823 else 824 error("process_remove_smartcard_key:" 825 " pkcs11_del_provider failed"); 826 free(provider); 827 send_status(e, success); 828 } 829 #endif /* ENABLE_PKCS11 */ 830 831 /* dispatch incoming messages */ 832 833 static void 834 process_message(SocketEntry *e) 835 { 836 u_int msg_len; 837 u_char type; 838 const u_char *cp; 839 int r; 840 841 if (sshbuf_len(e->input) < 5) 842 return; /* Incomplete message. */ 843 cp = sshbuf_ptr(e->input); 844 msg_len = PEEK_U32(cp); 845 if (msg_len > 256 * 1024) { 846 close_socket(e); 847 return; 848 } 849 if (sshbuf_len(e->input) < msg_len + 4) 850 return; 851 852 /* move the current input to e->request */ 853 sshbuf_reset(e->request); 854 if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 || 855 (r = sshbuf_get_u8(e->request, &type)) != 0) 856 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 857 858 /* check wheter agent is locked */ 859 if (locked && type != SSH_AGENTC_UNLOCK) { 860 sshbuf_reset(e->request); 861 switch (type) { 862 case SSH_AGENTC_REQUEST_RSA_IDENTITIES: 863 case SSH2_AGENTC_REQUEST_IDENTITIES: 864 /* send empty lists */ 865 no_identities(e, type); 866 break; 867 default: 868 /* send a fail message for all other request types */ 869 send_status(e, 0); 870 } 871 return; 872 } 873 874 debug("type %d", type); 875 switch (type) { 876 case SSH_AGENTC_LOCK: 877 case SSH_AGENTC_UNLOCK: 878 process_lock_agent(e, type == SSH_AGENTC_LOCK); 879 break; 880 #ifdef WITH_SSH1 881 /* ssh1 */ 882 case SSH_AGENTC_RSA_CHALLENGE: 883 process_authentication_challenge1(e); 884 break; 885 case SSH_AGENTC_REQUEST_RSA_IDENTITIES: 886 process_request_identities(e, 1); 887 break; 888 case SSH_AGENTC_ADD_RSA_IDENTITY: 889 case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED: 890 process_add_identity(e, 1); 891 break; 892 case SSH_AGENTC_REMOVE_RSA_IDENTITY: 893 process_remove_identity(e, 1); 894 break; 895 #endif 896 case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES: 897 process_remove_all_identities(e, 1); /* safe for !WITH_SSH1 */ 898 break; 899 /* ssh2 */ 900 case SSH2_AGENTC_SIGN_REQUEST: 901 process_sign_request2(e); 902 break; 903 case SSH2_AGENTC_REQUEST_IDENTITIES: 904 process_request_identities(e, 2); 905 break; 906 case SSH2_AGENTC_ADD_IDENTITY: 907 case SSH2_AGENTC_ADD_ID_CONSTRAINED: 908 process_add_identity(e, 2); 909 break; 910 case SSH2_AGENTC_REMOVE_IDENTITY: 911 process_remove_identity(e, 2); 912 break; 913 case SSH2_AGENTC_REMOVE_ALL_IDENTITIES: 914 process_remove_all_identities(e, 2); 915 break; 916 #ifdef ENABLE_PKCS11 917 case SSH_AGENTC_ADD_SMARTCARD_KEY: 918 case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED: 919 process_add_smartcard_key(e); 920 break; 921 case SSH_AGENTC_REMOVE_SMARTCARD_KEY: 922 process_remove_smartcard_key(e); 923 break; 924 #endif /* ENABLE_PKCS11 */ 925 default: 926 /* Unknown message. Respond with failure. */ 927 error("Unknown message %d", type); 928 sshbuf_reset(e->request); 929 send_status(e, 0); 930 break; 931 } 932 } 933 934 static void 935 new_socket(sock_type type, int fd) 936 { 937 u_int i, old_alloc, new_alloc; 938 939 set_nonblock(fd); 940 941 if (fd > max_fd) 942 max_fd = fd; 943 944 for (i = 0; i < sockets_alloc; i++) 945 if (sockets[i].type == AUTH_UNUSED) { 946 sockets[i].fd = fd; 947 if ((sockets[i].input = sshbuf_new()) == NULL) 948 fatal("%s: sshbuf_new failed", __func__); 949 if ((sockets[i].output = sshbuf_new()) == NULL) 950 fatal("%s: sshbuf_new failed", __func__); 951 if ((sockets[i].request = sshbuf_new()) == NULL) 952 fatal("%s: sshbuf_new failed", __func__); 953 sockets[i].type = type; 954 return; 955 } 956 old_alloc = sockets_alloc; 957 new_alloc = sockets_alloc + 10; 958 sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0])); 959 for (i = old_alloc; i < new_alloc; i++) 960 sockets[i].type = AUTH_UNUSED; 961 sockets_alloc = new_alloc; 962 sockets[old_alloc].fd = fd; 963 if ((sockets[old_alloc].input = sshbuf_new()) == NULL) 964 fatal("%s: sshbuf_new failed", __func__); 965 if ((sockets[old_alloc].output = sshbuf_new()) == NULL) 966 fatal("%s: sshbuf_new failed", __func__); 967 if ((sockets[old_alloc].request = sshbuf_new()) == NULL) 968 fatal("%s: sshbuf_new failed", __func__); 969 sockets[old_alloc].type = type; 970 } 971 972 static int 973 prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp, 974 struct timeval **tvpp) 975 { 976 u_int i, sz; 977 int n = 0; 978 static struct timeval tv; 979 time_t deadline; 980 981 for (i = 0; i < sockets_alloc; i++) { 982 switch (sockets[i].type) { 983 case AUTH_SOCKET: 984 case AUTH_CONNECTION: 985 n = MAX(n, sockets[i].fd); 986 break; 987 case AUTH_UNUSED: 988 break; 989 default: 990 fatal("Unknown socket type %d", sockets[i].type); 991 break; 992 } 993 } 994 995 sz = howmany(n+1, NFDBITS) * sizeof(fd_mask); 996 if (*fdrp == NULL || sz > *nallocp) { 997 free(*fdrp); 998 free(*fdwp); 999 *fdrp = xmalloc(sz); 1000 *fdwp = xmalloc(sz); 1001 *nallocp = sz; 1002 } 1003 if (n < *fdl) 1004 debug("XXX shrink: %d < %d", n, *fdl); 1005 *fdl = n; 1006 memset(*fdrp, 0, sz); 1007 memset(*fdwp, 0, sz); 1008 1009 for (i = 0; i < sockets_alloc; i++) { 1010 switch (sockets[i].type) { 1011 case AUTH_SOCKET: 1012 case AUTH_CONNECTION: 1013 FD_SET(sockets[i].fd, *fdrp); 1014 if (sshbuf_len(sockets[i].output) > 0) 1015 FD_SET(sockets[i].fd, *fdwp); 1016 break; 1017 default: 1018 break; 1019 } 1020 } 1021 deadline = reaper(); 1022 if (parent_alive_interval != 0) 1023 deadline = (deadline == 0) ? parent_alive_interval : 1024 MIN(deadline, parent_alive_interval); 1025 if (deadline == 0) { 1026 *tvpp = NULL; 1027 } else { 1028 tv.tv_sec = deadline; 1029 tv.tv_usec = 0; 1030 *tvpp = &tv; 1031 } 1032 return (1); 1033 } 1034 1035 static void 1036 after_select(fd_set *readset, fd_set *writeset) 1037 { 1038 struct sockaddr_un sunaddr; 1039 socklen_t slen; 1040 char buf[1024]; 1041 int len, sock, r; 1042 u_int i, orig_alloc; 1043 uid_t euid; 1044 gid_t egid; 1045 1046 for (i = 0, orig_alloc = sockets_alloc; i < orig_alloc; i++) 1047 switch (sockets[i].type) { 1048 case AUTH_UNUSED: 1049 break; 1050 case AUTH_SOCKET: 1051 if (FD_ISSET(sockets[i].fd, readset)) { 1052 slen = sizeof(sunaddr); 1053 sock = accept(sockets[i].fd, 1054 (struct sockaddr *)&sunaddr, &slen); 1055 if (sock < 0) { 1056 error("accept from AUTH_SOCKET: %s", 1057 strerror(errno)); 1058 break; 1059 } 1060 if (getpeereid(sock, &euid, &egid) < 0) { 1061 error("getpeereid %d failed: %s", 1062 sock, strerror(errno)); 1063 close(sock); 1064 break; 1065 } 1066 if ((euid != 0) && (getuid() != euid)) { 1067 error("uid mismatch: " 1068 "peer euid %u != uid %u", 1069 (u_int) euid, (u_int) getuid()); 1070 close(sock); 1071 break; 1072 } 1073 new_socket(AUTH_CONNECTION, sock); 1074 } 1075 break; 1076 case AUTH_CONNECTION: 1077 if (sshbuf_len(sockets[i].output) > 0 && 1078 FD_ISSET(sockets[i].fd, writeset)) { 1079 len = write(sockets[i].fd, 1080 sshbuf_ptr(sockets[i].output), 1081 sshbuf_len(sockets[i].output)); 1082 if (len == -1 && (errno == EAGAIN || 1083 errno == EWOULDBLOCK || 1084 errno == EINTR)) 1085 continue; 1086 if (len <= 0) { 1087 close_socket(&sockets[i]); 1088 break; 1089 } 1090 if ((r = sshbuf_consume(sockets[i].output, 1091 len)) != 0) 1092 fatal("%s: buffer error: %s", 1093 __func__, ssh_err(r)); 1094 } 1095 if (FD_ISSET(sockets[i].fd, readset)) { 1096 len = read(sockets[i].fd, buf, sizeof(buf)); 1097 if (len == -1 && (errno == EAGAIN || 1098 errno == EWOULDBLOCK || 1099 errno == EINTR)) 1100 continue; 1101 if (len <= 0) { 1102 close_socket(&sockets[i]); 1103 break; 1104 } 1105 if ((r = sshbuf_put(sockets[i].input, 1106 buf, len)) != 0) 1107 fatal("%s: buffer error: %s", 1108 __func__, ssh_err(r)); 1109 explicit_bzero(buf, sizeof(buf)); 1110 process_message(&sockets[i]); 1111 } 1112 break; 1113 default: 1114 fatal("Unknown type %d", sockets[i].type); 1115 } 1116 } 1117 1118 static void 1119 cleanup_socket(void) 1120 { 1121 if (cleanup_pid != 0 && getpid() != cleanup_pid) 1122 return; 1123 debug("%s: cleanup", __func__); 1124 if (socket_name[0]) 1125 unlink(socket_name); 1126 if (socket_dir[0]) 1127 rmdir(socket_dir); 1128 } 1129 1130 void 1131 cleanup_exit(int i) 1132 { 1133 cleanup_socket(); 1134 _exit(i); 1135 } 1136 1137 /*ARGSUSED*/ 1138 static void 1139 cleanup_handler(int sig) 1140 { 1141 cleanup_socket(); 1142 #ifdef ENABLE_PKCS11 1143 pkcs11_terminate(); 1144 #endif 1145 _exit(2); 1146 } 1147 1148 static void 1149 check_parent_exists(void) 1150 { 1151 /* 1152 * If our parent has exited then getppid() will return (pid_t)1, 1153 * so testing for that should be safe. 1154 */ 1155 if (parent_pid != -1 && getppid() != parent_pid) { 1156 /* printf("Parent has died - Authentication agent exiting.\n"); */ 1157 cleanup_socket(); 1158 _exit(2); 1159 } 1160 } 1161 1162 static void 1163 usage(void) 1164 { 1165 fprintf(stderr, 1166 "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n" 1167 " [-t life] [command [arg ...]]\n" 1168 " ssh-agent [-c | -s] -k\n"); 1169 exit(1); 1170 } 1171 1172 int 1173 main(int ac, char **av) 1174 { 1175 int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0; 1176 int sock, fd, ch, result, saved_errno; 1177 u_int nalloc; 1178 char *shell, *format, *pidstr, *agentsocket = NULL; 1179 fd_set *readsetp = NULL, *writesetp = NULL; 1180 #ifdef HAVE_SETRLIMIT 1181 struct rlimit rlim; 1182 #endif 1183 extern int optind; 1184 extern char *optarg; 1185 pid_t pid; 1186 char pidstrbuf[1 + 3 * sizeof pid]; 1187 struct timeval *tvp = NULL; 1188 size_t len; 1189 mode_t prev_mask; 1190 1191 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 1192 sanitise_stdfd(); 1193 1194 /* drop */ 1195 setegid(getgid()); 1196 setgid(getgid()); 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, "cDdksE:a:t:")) != -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 || D_flag) 1232 usage(); 1233 d_flag++; 1234 break; 1235 case 'D': 1236 if (d_flag || D_flag) 1237 usage(); 1238 D_flag++; 1239 break; 1240 case 'a': 1241 agentsocket = optarg; 1242 break; 1243 case 't': 1244 if ((lifetime = convtime(optarg)) == -1) { 1245 fprintf(stderr, "Invalid lifetime\n"); 1246 usage(); 1247 } 1248 break; 1249 default: 1250 usage(); 1251 } 1252 } 1253 ac -= optind; 1254 av += optind; 1255 1256 if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag)) 1257 usage(); 1258 1259 if (ac == 0 && !c_flag && !s_flag) { 1260 shell = getenv("SHELL"); 1261 if (shell != NULL && (len = strlen(shell)) > 2 && 1262 strncmp(shell + len - 3, "csh", 3) == 0) 1263 c_flag = 1; 1264 } 1265 if (k_flag) { 1266 const char *errstr = NULL; 1267 1268 pidstr = getenv(SSH_AGENTPID_ENV_NAME); 1269 if (pidstr == NULL) { 1270 fprintf(stderr, "%s not set, cannot kill agent\n", 1271 SSH_AGENTPID_ENV_NAME); 1272 exit(1); 1273 } 1274 pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr); 1275 if (errstr) { 1276 fprintf(stderr, 1277 "%s=\"%s\", which is not a good PID: %s\n", 1278 SSH_AGENTPID_ENV_NAME, pidstr, errstr); 1279 exit(1); 1280 } 1281 if (kill(pid, SIGTERM) == -1) { 1282 perror("kill"); 1283 exit(1); 1284 } 1285 format = c_flag ? "unsetenv %s;\n" : "unset %s;\n"; 1286 printf(format, SSH_AUTHSOCKET_ENV_NAME); 1287 printf(format, SSH_AGENTPID_ENV_NAME); 1288 printf("echo Agent pid %ld killed;\n", (long)pid); 1289 exit(0); 1290 } 1291 parent_pid = getpid(); 1292 1293 if (agentsocket == NULL) { 1294 /* Create private directory for agent socket */ 1295 mktemp_proto(socket_dir, sizeof(socket_dir)); 1296 if (mkdtemp(socket_dir) == NULL) { 1297 perror("mkdtemp: private socket dir"); 1298 exit(1); 1299 } 1300 snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir, 1301 (long)parent_pid); 1302 } else { 1303 /* Try to use specified agent socket */ 1304 socket_dir[0] = '\0'; 1305 strlcpy(socket_name, agentsocket, sizeof socket_name); 1306 } 1307 1308 /* 1309 * Create socket early so it will exist before command gets run from 1310 * the parent. 1311 */ 1312 prev_mask = umask(0177); 1313 sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0); 1314 if (sock < 0) { 1315 /* XXX - unix_listener() calls error() not perror() */ 1316 *socket_name = '\0'; /* Don't unlink any existing file */ 1317 cleanup_exit(1); 1318 } 1319 umask(prev_mask); 1320 1321 /* 1322 * Fork, and have the parent execute the command, if any, or present 1323 * the socket data. The child continues as the authentication agent. 1324 */ 1325 if (D_flag || d_flag) { 1326 log_init(__progname, 1327 d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO, 1328 SYSLOG_FACILITY_AUTH, 1); 1329 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; 1330 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, 1331 SSH_AUTHSOCKET_ENV_NAME); 1332 printf("echo Agent pid %ld;\n", (long)parent_pid); 1333 goto skip; 1334 } 1335 pid = fork(); 1336 if (pid == -1) { 1337 perror("fork"); 1338 cleanup_exit(1); 1339 } 1340 if (pid != 0) { /* Parent - execute the given command. */ 1341 close(sock); 1342 snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid); 1343 if (ac == 0) { 1344 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; 1345 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, 1346 SSH_AUTHSOCKET_ENV_NAME); 1347 printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf, 1348 SSH_AGENTPID_ENV_NAME); 1349 printf("echo Agent pid %ld;\n", (long)pid); 1350 exit(0); 1351 } 1352 if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 || 1353 setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) { 1354 perror("setenv"); 1355 exit(1); 1356 } 1357 execvp(av[0], av); 1358 perror(av[0]); 1359 exit(1); 1360 } 1361 /* child */ 1362 log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0); 1363 1364 if (setsid() == -1) { 1365 error("setsid: %s", strerror(errno)); 1366 cleanup_exit(1); 1367 } 1368 1369 (void)chdir("/"); 1370 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { 1371 /* XXX might close listen socket */ 1372 (void)dup2(fd, STDIN_FILENO); 1373 (void)dup2(fd, STDOUT_FILENO); 1374 (void)dup2(fd, STDERR_FILENO); 1375 if (fd > 2) 1376 close(fd); 1377 } 1378 1379 #ifdef HAVE_SETRLIMIT 1380 /* deny core dumps, since memory contains unencrypted private keys */ 1381 rlim.rlim_cur = rlim.rlim_max = 0; 1382 if (setrlimit(RLIMIT_CORE, &rlim) < 0) { 1383 error("setrlimit RLIMIT_CORE: %s", strerror(errno)); 1384 cleanup_exit(1); 1385 } 1386 #endif 1387 1388 skip: 1389 1390 cleanup_pid = getpid(); 1391 1392 #ifdef ENABLE_PKCS11 1393 pkcs11_init(0); 1394 #endif 1395 new_socket(AUTH_SOCKET, sock); 1396 if (ac > 0) 1397 parent_alive_interval = 10; 1398 idtab_init(); 1399 signal(SIGPIPE, SIG_IGN); 1400 signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN); 1401 signal(SIGHUP, cleanup_handler); 1402 signal(SIGTERM, cleanup_handler); 1403 nalloc = 0; 1404 1405 while (1) { 1406 prepare_select(&readsetp, &writesetp, &max_fd, &nalloc, &tvp); 1407 result = select(max_fd + 1, readsetp, writesetp, NULL, tvp); 1408 saved_errno = errno; 1409 if (parent_alive_interval != 0) 1410 check_parent_exists(); 1411 (void) reaper(); /* remove expired keys */ 1412 if (result < 0) { 1413 if (saved_errno == EINTR) 1414 continue; 1415 fatal("select: %s", strerror(saved_errno)); 1416 } else if (result > 0) 1417 after_select(readsetp, writesetp); 1418 } 1419 /* NOTREACHED */ 1420 } 1421
