1 /* $NetBSD: ssh-agent.c,v 1.16 2015/08/13 10:33:21 christos Exp $ */ 2 /* $OpenBSD: ssh-agent.c,v 1.204 2015/07/08 20:24:02 markus Exp $ */ 3 /* 4 * Author: Tatu Ylonen <ylo@cs.hut.fi> 5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 6 * All rights reserved 7 * The authentication agent program. 8 * 9 * As far as I am concerned, the code I have written for this software 10 * can be used freely for any purpose. Any derived versions of this 11 * software must be clearly marked as such, and if the derived work is 12 * incompatible with the protocol description in the RFC file, it must be 13 * called by a name other than "ssh" or "Secure Shell". 14 * 15 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 #include "includes.h" 39 __RCSID("$NetBSD: ssh-agent.c,v 1.16 2015/08/13 10:33:21 christos Exp $"); 40 #include <sys/param.h> /* MIN MAX */ 41 #include <sys/types.h> 42 #include <sys/time.h> 43 #include <sys/queue.h> 44 #include <sys/resource.h> 45 #include <sys/socket.h> 46 #include <sys/stat.h> 47 #include <sys/un.h> 48 49 #ifdef WITH_OPENSSL 50 #include <openssl/evp.h> 51 #endif 52 53 #include <errno.h> 54 #include <fcntl.h> 55 #include <paths.h> 56 #include <signal.h> 57 #include <stdlib.h> 58 #include <stdio.h> 59 #include <string.h> 60 #include <limits.h> 61 #include <time.h> 62 #include <unistd.h> 63 #include <util.h> 64 65 #include "xmalloc.h" 66 #include "ssh.h" 67 #include "rsa.h" 68 #include "sshbuf.h" 69 #include "sshkey.h" 70 #include "authfd.h" 71 #include "compat.h" 72 #include "log.h" 73 #include "misc.h" 74 #include "getpeereid.h" 75 #include "digest.h" 76 #include "ssherr.h" 77 78 #ifdef ENABLE_PKCS11 79 #include "ssh-pkcs11.h" 80 #endif 81 82 typedef enum { 83 AUTH_UNUSED, 84 AUTH_SOCKET, 85 AUTH_CONNECTION 86 } sock_type; 87 88 typedef struct { 89 int fd; 90 sock_type type; 91 struct sshbuf *input; 92 struct sshbuf *output; 93 struct sshbuf *request; 94 } SocketEntry; 95 96 u_int sockets_alloc = 0; 97 SocketEntry *sockets = NULL; 98 99 typedef struct identity { 100 TAILQ_ENTRY(identity) next; 101 struct sshkey *key; 102 char *comment; 103 char *provider; 104 time_t death; 105 u_int confirm; 106 } Identity; 107 108 typedef struct { 109 int nentries; 110 TAILQ_HEAD(idqueue, identity) idlist; 111 } Idtab; 112 113 /* private key table, one per protocol version */ 114 Idtab idtable[3]; 115 116 int max_fd = 0; 117 118 /* pid of shell == parent of agent */ 119 pid_t parent_pid = -1; 120 time_t parent_alive_interval = 0; 121 122 /* pid of process for which cleanup_socket is applicable */ 123 pid_t cleanup_pid = 0; 124 125 /* pathname and directory for AUTH_SOCKET */ 126 char socket_name[PATH_MAX]; 127 char socket_dir[PATH_MAX]; 128 129 /* locking */ 130 #define LOCK_SIZE 32 131 #define LOCK_SALT_SIZE 16 132 #define LOCK_ROUNDS 1 133 int locked = 0; 134 char lock_passwd[LOCK_SIZE]; 135 char lock_salt[LOCK_SALT_SIZE]; 136 137 extern char *__progname; 138 139 /* Default lifetime in seconds (0 == forever) */ 140 static long lifetime = 0; 141 142 static int fingerprint_hash = SSH_FP_HASH_DEFAULT; 143 144 static void 145 close_socket(SocketEntry *e) 146 { 147 close(e->fd); 148 e->fd = -1; 149 e->type = AUTH_UNUSED; 150 sshbuf_free(e->input); 151 sshbuf_free(e->output); 152 sshbuf_free(e->request); 153 } 154 155 static void 156 idtab_init(void) 157 { 158 int i; 159 160 for (i = 0; i <=2; i++) { 161 TAILQ_INIT(&idtable[i].idlist); 162 idtable[i].nentries = 0; 163 } 164 } 165 166 /* return private key table for requested protocol version */ 167 static Idtab * 168 idtab_lookup(int version) 169 { 170 if (version < 1 || version > 2) 171 fatal("internal error, bad protocol version %d", version); 172 return &idtable[version]; 173 } 174 175 static void 176 free_identity(Identity *id) 177 { 178 sshkey_free(id->key); 179 free(id->provider); 180 free(id->comment); 181 free(id); 182 } 183 184 /* return matching private key for given public key */ 185 static Identity * 186 lookup_identity(struct sshkey *key, int version) 187 { 188 Identity *id; 189 190 Idtab *tab = idtab_lookup(version); 191 TAILQ_FOREACH(id, &tab->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, int version) 229 { 230 Idtab *tab = idtab_lookup(version); 231 Identity *id; 232 struct sshbuf *msg; 233 int r; 234 235 if ((msg = sshbuf_new()) == NULL) 236 fatal("%s: sshbuf_new failed", __func__); 237 if ((r = sshbuf_put_u8(msg, (version == 1) ? 238 SSH_AGENT_RSA_IDENTITIES_ANSWER : 239 SSH2_AGENT_IDENTITIES_ANSWER)) != 0 || 240 (r = sshbuf_put_u32(msg, tab->nentries)) != 0) 241 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 242 TAILQ_FOREACH(id, &tab->idlist, next) { 243 if (id->key->type == KEY_RSA1) { 244 #ifdef WITH_SSH1 245 if ((r = sshbuf_put_u32(msg, 246 BN_num_bits(id->key->rsa->n))) != 0 || 247 (r = sshbuf_put_bignum1(msg, 248 id->key->rsa->e)) != 0 || 249 (r = sshbuf_put_bignum1(msg, 250 id->key->rsa->n)) != 0) 251 fatal("%s: buffer error: %s", 252 __func__, ssh_err(r)); 253 #endif 254 } else { 255 u_char *blob; 256 size_t blen; 257 258 if ((r = sshkey_to_blob(id->key, &blob, &blen)) != 0) { 259 error("%s: sshkey_to_blob: %s", __func__, 260 ssh_err(r)); 261 continue; 262 } 263 if ((r = sshbuf_put_string(msg, blob, blen)) != 0) 264 fatal("%s: buffer error: %s", 265 __func__, ssh_err(r)); 266 free(blob); 267 } 268 if ((r = sshbuf_put_cstring(msg, id->comment)) != 0) 269 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 270 } 271 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 272 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 273 sshbuf_free(msg); 274 } 275 276 #ifdef WITH_SSH1 277 /* ssh1 only */ 278 static void 279 process_authentication_challenge1(SocketEntry *e) 280 { 281 u_char buf[32], mdbuf[16], session_id[16]; 282 u_int response_type; 283 BIGNUM *challenge; 284 Identity *id; 285 int r, len; 286 struct sshbuf *msg; 287 struct ssh_digest_ctx *md; 288 struct sshkey *key; 289 290 if ((msg = sshbuf_new()) == NULL) 291 fatal("%s: sshbuf_new failed", __func__); 292 if ((key = sshkey_new(KEY_RSA1)) == NULL) 293 fatal("%s: sshkey_new failed", __func__); 294 if ((challenge = BN_new()) == NULL) 295 fatal("%s: BN_new failed", __func__); 296 297 if ((r = sshbuf_get_u32(e->request, NULL)) != 0 || /* ignored */ 298 (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 || 299 (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0 || 300 (r = sshbuf_get_bignum1(e->request, challenge))) 301 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 302 303 /* Only protocol 1.1 is supported */ 304 if (sshbuf_len(e->request) == 0) 305 goto failure; 306 if ((r = sshbuf_get(e->request, session_id, sizeof(session_id))) != 0 || 307 (r = sshbuf_get_u32(e->request, &response_type)) != 0) 308 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 309 if (response_type != 1) 310 goto failure; 311 312 id = lookup_identity(key, 1); 313 if (id != NULL && (!id->confirm || confirm_key(id) == 0)) { 314 struct sshkey *private = id->key; 315 /* Decrypt the challenge using the private key. */ 316 if ((r = rsa_private_decrypt(challenge, challenge, 317 private->rsa) != 0)) { 318 fatal("%s: rsa_public_encrypt: %s", __func__, 319 ssh_err(r)); 320 goto failure; /* XXX ? */ 321 } 322 323 /* The response is MD5 of decrypted challenge plus session id */ 324 len = BN_num_bytes(challenge); 325 if (len <= 0 || len > 32) { 326 logit("%s: bad challenge length %d", __func__, len); 327 goto failure; 328 } 329 memset(buf, 0, 32); 330 BN_bn2bin(challenge, buf + 32 - len); 331 if ((md = ssh_digest_start(SSH_DIGEST_MD5)) == NULL || 332 ssh_digest_update(md, buf, 32) < 0 || 333 ssh_digest_update(md, session_id, 16) < 0 || 334 ssh_digest_final(md, mdbuf, sizeof(mdbuf)) < 0) 335 fatal("%s: md5 failed", __func__); 336 ssh_digest_free(md); 337 338 /* Send the response. */ 339 if ((r = sshbuf_put_u8(msg, SSH_AGENT_RSA_RESPONSE)) != 0 || 340 (r = sshbuf_put(msg, mdbuf, sizeof(mdbuf))) != 0) 341 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 342 goto send; 343 } 344 345 failure: 346 /* Unknown identity or protocol error. Send failure. */ 347 if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0) 348 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 349 send: 350 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 351 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 352 sshkey_free(key); 353 BN_clear_free(challenge); 354 sshbuf_free(msg); 355 } 356 #endif 357 358 /* ssh2 only */ 359 static void 360 process_sign_request2(SocketEntry *e) 361 { 362 u_char *blob, *data, *signature = NULL; 363 size_t blen, dlen, slen = 0; 364 u_int compat = 0, flags; 365 int r, ok = -1; 366 struct sshbuf *msg; 367 struct sshkey *key; 368 struct identity *id; 369 370 if ((msg = sshbuf_new()) == NULL) 371 fatal("%s: sshbuf_new failed", __func__); 372 if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0 || 373 (r = sshbuf_get_string(e->request, &data, &dlen)) != 0 || 374 (r = sshbuf_get_u32(e->request, &flags)) != 0) 375 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 376 if (flags & SSH_AGENT_OLD_SIGNATURE) 377 compat = SSH_BUG_SIGBLOB; 378 if ((r = sshkey_from_blob(blob, blen, &key)) != 0) { 379 error("%s: cannot parse key blob: %s", __func__, ssh_err(ok)); 380 goto send; 381 } 382 if ((id = lookup_identity(key, 2)) == NULL) { 383 verbose("%s: %s key not found", __func__, sshkey_type(key)); 384 goto send; 385 } 386 if (id->confirm && confirm_key(id) != 0) { 387 verbose("%s: user refused key", __func__); 388 goto send; 389 } 390 if ((r = sshkey_sign(id->key, &signature, &slen, 391 data, dlen, compat)) != 0) { 392 error("%s: sshkey_sign: %s", __func__, ssh_err(ok)); 393 goto send; 394 } 395 /* Success */ 396 ok = 0; 397 send: 398 sshkey_free(key); 399 if (ok == 0) { 400 if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 || 401 (r = sshbuf_put_string(msg, signature, slen)) != 0) 402 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 403 } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0) 404 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 405 406 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 407 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 408 409 sshbuf_free(msg); 410 free(data); 411 free(blob); 412 free(signature); 413 } 414 415 /* shared */ 416 static void 417 process_remove_identity(SocketEntry *e, int version) 418 { 419 size_t blen; 420 int r, success = 0; 421 struct sshkey *key = NULL; 422 u_char *blob; 423 #ifdef WITH_SSH1 424 u_int bits; 425 #endif /* WITH_SSH1 */ 426 427 switch (version) { 428 #ifdef WITH_SSH1 429 case 1: 430 if ((key = sshkey_new(KEY_RSA1)) == NULL) { 431 error("%s: sshkey_new failed", __func__); 432 return; 433 } 434 if ((r = sshbuf_get_u32(e->request, &bits)) != 0 || 435 (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 || 436 (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0) 437 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 438 439 if (bits != sshkey_size(key)) 440 logit("Warning: identity keysize mismatch: " 441 "actual %u, announced %u", 442 sshkey_size(key), bits); 443 break; 444 #endif /* WITH_SSH1 */ 445 case 2: 446 if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0) 447 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 448 if ((r = sshkey_from_blob(blob, blen, &key)) != 0) 449 error("%s: sshkey_from_blob failed: %s", 450 __func__, ssh_err(r)); 451 free(blob); 452 break; 453 } 454 if (key != NULL) { 455 Identity *id = lookup_identity(key, version); 456 if (id != NULL) { 457 /* 458 * We have this key. Free the old key. Since we 459 * don't want to leave empty slots in the middle of 460 * the array, we actually free the key there and move 461 * all the entries between the empty slot and the end 462 * of the array. 463 */ 464 Idtab *tab = idtab_lookup(version); 465 if (tab->nentries < 1) 466 fatal("process_remove_identity: " 467 "internal error: tab->nentries %d", 468 tab->nentries); 469 TAILQ_REMOVE(&tab->idlist, id, next); 470 free_identity(id); 471 tab->nentries--; 472 success = 1; 473 } 474 sshkey_free(key); 475 } 476 send_status(e, success); 477 } 478 479 static void 480 process_remove_all_identities(SocketEntry *e, int version) 481 { 482 Idtab *tab = idtab_lookup(version); 483 Identity *id; 484 485 /* Loop over all identities and clear the keys. */ 486 while ((id = TAILQ_FIRST(&tab->idlist)) != NULL) { 487 TAILQ_REMOVE(&tab->idlist, id, next); 488 free_identity(id); 489 } 490 491 /* Mark that there are no identities. */ 492 tab->nentries = 0; 493 494 /* Send success. */ 495 send_status(e, 1); 496 } 497 498 /* removes expired keys and returns number of seconds until the next expiry */ 499 static time_t 500 reaper(void) 501 { 502 time_t deadline = 0, now = monotime(); 503 Identity *id, *nxt; 504 int version; 505 Idtab *tab; 506 507 for (version = 1; version < 3; version++) { 508 tab = idtab_lookup(version); 509 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) { 510 nxt = TAILQ_NEXT(id, next); 511 if (id->death == 0) 512 continue; 513 if (now >= id->death) { 514 debug("expiring key '%s'", id->comment); 515 TAILQ_REMOVE(&tab->idlist, id, next); 516 free_identity(id); 517 tab->nentries--; 518 } else 519 deadline = (deadline == 0) ? id->death : 520 MIN(deadline, id->death); 521 } 522 } 523 if (deadline == 0 || deadline <= now) 524 return 0; 525 else 526 return (deadline - now); 527 } 528 529 /* 530 * XXX this and the corresponding serialisation function probably belongs 531 * in key.c 532 */ 533 #ifdef WITH_SSH1 534 static int 535 agent_decode_rsa1(struct sshbuf *m, struct sshkey **kp) 536 { 537 struct sshkey *k = NULL; 538 int r = SSH_ERR_INTERNAL_ERROR; 539 540 *kp = NULL; 541 if ((k = sshkey_new_private(KEY_RSA1)) == NULL) 542 return SSH_ERR_ALLOC_FAIL; 543 544 if ((r = sshbuf_get_u32(m, NULL)) != 0 || /* ignored */ 545 (r = sshbuf_get_bignum1(m, k->rsa->n)) != 0 || 546 (r = sshbuf_get_bignum1(m, k->rsa->e)) != 0 || 547 (r = sshbuf_get_bignum1(m, k->rsa->d)) != 0 || 548 (r = sshbuf_get_bignum1(m, k->rsa->iqmp)) != 0 || 549 /* SSH1 and SSL have p and q swapped */ 550 (r = sshbuf_get_bignum1(m, k->rsa->q)) != 0 || /* p */ 551 (r = sshbuf_get_bignum1(m, k->rsa->p)) != 0) /* q */ 552 goto out; 553 554 /* Generate additional parameters */ 555 if ((r = rsa_generate_additional_parameters(k->rsa)) != 0) 556 goto out; 557 /* enable blinding */ 558 if (RSA_blinding_on(k->rsa, NULL) != 1) { 559 r = SSH_ERR_LIBCRYPTO_ERROR; 560 goto out; 561 } 562 563 r = 0; /* success */ 564 out: 565 if (r == 0) 566 *kp = k; 567 else 568 sshkey_free(k); 569 return r; 570 } 571 #endif /* WITH_SSH1 */ 572 573 static void 574 process_add_identity(SocketEntry *e, int version) 575 { 576 Idtab *tab = idtab_lookup(version); 577 Identity *id; 578 int success = 0, confirm = 0; 579 u_int seconds; 580 char *comment = NULL; 581 time_t death = 0; 582 struct sshkey *k = NULL; 583 u_char ctype; 584 int r = SSH_ERR_INTERNAL_ERROR; 585 586 switch (version) { 587 #ifdef WITH_SSH1 588 case 1: 589 r = agent_decode_rsa1(e->request, &k); 590 break; 591 #endif /* WITH_SSH1 */ 592 case 2: 593 r = sshkey_private_deserialize(e->request, &k); 594 break; 595 } 596 if (r != 0 || k == NULL || 597 (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) { 598 error("%s: decode private key: %s", __func__, ssh_err(r)); 599 goto err; 600 } 601 602 while (sshbuf_len(e->request)) { 603 if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) { 604 error("%s: buffer error: %s", __func__, ssh_err(r)); 605 goto err; 606 } 607 switch (ctype) { 608 case SSH_AGENT_CONSTRAIN_LIFETIME: 609 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) { 610 error("%s: bad lifetime constraint: %s", 611 __func__, ssh_err(r)); 612 goto err; 613 } 614 death = monotime() + seconds; 615 break; 616 case SSH_AGENT_CONSTRAIN_CONFIRM: 617 confirm = 1; 618 break; 619 default: 620 error("%s: Unknown constraint %d", __func__, ctype); 621 err: 622 sshbuf_reset(e->request); 623 free(comment); 624 sshkey_free(k); 625 goto send; 626 } 627 } 628 629 success = 1; 630 if (lifetime && !death) 631 death = monotime() + lifetime; 632 if ((id = lookup_identity(k, version)) == NULL) { 633 id = xcalloc(1, sizeof(Identity)); 634 id->key = k; 635 TAILQ_INSERT_TAIL(&tab->idlist, id, next); 636 /* Increment the number of identities. */ 637 tab->nentries++; 638 } else { 639 sshkey_free(k); 640 free(id->comment); 641 } 642 id->comment = comment; 643 id->death = death; 644 id->confirm = confirm; 645 send: 646 send_status(e, success); 647 } 648 649 /* XXX todo: encrypt sensitive data with passphrase */ 650 static void 651 process_lock_agent(SocketEntry *e, int lock) 652 { 653 int r, success = 0, delay; 654 char *passwd, passwdhash[LOCK_SIZE]; 655 static u_int fail_count = 0; 656 size_t pwlen; 657 658 if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0) 659 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 660 if (pwlen == 0) { 661 debug("empty password not supported"); 662 } else if (locked && !lock) { 663 if (bcrypt_pbkdf(passwd, pwlen, (uint8_t *)lock_salt, sizeof(lock_salt), 664 (uint8_t *)passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0) 665 fatal("bcrypt_pbkdf"); 666 if (timingsafe_bcmp(passwdhash, lock_passwd, LOCK_SIZE) == 0) { 667 debug("agent unlocked"); 668 locked = 0; 669 fail_count = 0; 670 explicit_bzero(lock_passwd, sizeof(lock_passwd)); 671 success = 1; 672 } else { 673 /* delay in 0.1s increments up to 10s */ 674 if (fail_count < 100) 675 fail_count++; 676 delay = 100000 * fail_count; 677 debug("unlock failed, delaying %0.1lf seconds", 678 (double)delay/1000000); 679 usleep(delay); 680 } 681 explicit_bzero(passwdhash, sizeof(passwdhash)); 682 } else if (!locked && lock) { 683 debug("agent locked"); 684 locked = 1; 685 arc4random_buf(lock_salt, sizeof(lock_salt)); 686 if (bcrypt_pbkdf(passwd, pwlen, (uint8_t *)lock_salt, sizeof(lock_salt), 687 (uint8_t *)lock_passwd, sizeof(lock_passwd), 688 LOCK_ROUNDS) < 0) 689 fatal("bcrypt_pbkdf"); 690 success = 1; 691 } 692 explicit_bzero(passwd, pwlen); 693 free(passwd); 694 send_status(e, success); 695 } 696 697 static void 698 no_identities(SocketEntry *e, u_int type) 699 { 700 struct sshbuf *msg; 701 int r; 702 703 if ((msg = sshbuf_new()) == NULL) 704 fatal("%s: sshbuf_new failed", __func__); 705 if ((r = sshbuf_put_u8(msg, 706 (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ? 707 SSH_AGENT_RSA_IDENTITIES_ANSWER : 708 SSH2_AGENT_IDENTITIES_ANSWER)) != 0 || 709 (r = sshbuf_put_u32(msg, 0)) != 0 || 710 (r = sshbuf_put_stringb(e->output, msg)) != 0) 711 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 712 sshbuf_free(msg); 713 } 714 715 #ifdef ENABLE_PKCS11 716 static void 717 process_add_smartcard_key(SocketEntry *e) 718 { 719 char *provider = NULL, *pin; 720 int r, i, version, count = 0, success = 0, confirm = 0; 721 u_int seconds; 722 time_t death = 0; 723 u_char type; 724 struct sshkey **keys = NULL, *k; 725 Identity *id; 726 Idtab *tab; 727 728 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 || 729 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) 730 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 731 732 while (sshbuf_len(e->request)) { 733 if ((r = sshbuf_get_u8(e->request, &type)) != 0) 734 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 735 switch (type) { 736 case SSH_AGENT_CONSTRAIN_LIFETIME: 737 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) 738 fatal("%s: buffer error: %s", 739 __func__, ssh_err(r)); 740 death = monotime() + seconds; 741 break; 742 case SSH_AGENT_CONSTRAIN_CONFIRM: 743 confirm = 1; 744 break; 745 default: 746 error("process_add_smartcard_key: " 747 "Unknown constraint type %d", type); 748 goto send; 749 } 750 } 751 if (lifetime && !death) 752 death = monotime() + lifetime; 753 754 count = pkcs11_add_provider(provider, pin, &keys); 755 for (i = 0; i < count; i++) { 756 k = keys[i]; 757 version = k->type == KEY_RSA1 ? 1 : 2; 758 tab = idtab_lookup(version); 759 if (lookup_identity(k, version) == NULL) { 760 id = xcalloc(1, sizeof(Identity)); 761 id->key = k; 762 id->provider = xstrdup(provider); 763 id->comment = xstrdup(provider); /* XXX */ 764 id->death = death; 765 id->confirm = confirm; 766 TAILQ_INSERT_TAIL(&tab->idlist, id, next); 767 tab->nentries++; 768 success = 1; 769 } else { 770 sshkey_free(k); 771 } 772 keys[i] = NULL; 773 } 774 send: 775 free(pin); 776 free(provider); 777 free(keys); 778 send_status(e, success); 779 } 780 781 static void 782 process_remove_smartcard_key(SocketEntry *e) 783 { 784 char *provider = NULL, *pin = NULL; 785 int r, version, success = 0; 786 Identity *id, *nxt; 787 Idtab *tab; 788 789 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 || 790 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) 791 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 792 free(pin); 793 794 for (version = 1; version < 3; version++) { 795 tab = idtab_lookup(version); 796 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) { 797 nxt = TAILQ_NEXT(id, next); 798 /* Skip file--based keys */ 799 if (id->provider == NULL) 800 continue; 801 if (!strcmp(provider, id->provider)) { 802 TAILQ_REMOVE(&tab->idlist, id, next); 803 free_identity(id); 804 tab->nentries--; 805 } 806 } 807 } 808 if (pkcs11_del_provider(provider) == 0) 809 success = 1; 810 else 811 error("process_remove_smartcard_key:" 812 " pkcs11_del_provider failed"); 813 free(provider); 814 send_status(e, success); 815 } 816 #endif /* ENABLE_PKCS11 */ 817 818 /* dispatch incoming messages */ 819 820 static void 821 process_message(SocketEntry *e) 822 { 823 u_int msg_len; 824 u_char type; 825 const u_char *cp; 826 int r; 827 828 if (sshbuf_len(e->input) < 5) 829 return; /* Incomplete message. */ 830 cp = sshbuf_ptr(e->input); 831 msg_len = PEEK_U32(cp); 832 if (msg_len > 256 * 1024) { 833 close_socket(e); 834 return; 835 } 836 if (sshbuf_len(e->input) < msg_len + 4) 837 return; 838 839 /* move the current input to e->request */ 840 sshbuf_reset(e->request); 841 if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 || 842 (r = sshbuf_get_u8(e->request, &type)) != 0) 843 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 844 845 /* check wheter agent is locked */ 846 if (locked && type != SSH_AGENTC_UNLOCK) { 847 sshbuf_reset(e->request); 848 switch (type) { 849 case SSH_AGENTC_REQUEST_RSA_IDENTITIES: 850 case SSH2_AGENTC_REQUEST_IDENTITIES: 851 /* send empty lists */ 852 no_identities(e, type); 853 break; 854 default: 855 /* send a fail message for all other request types */ 856 send_status(e, 0); 857 } 858 return; 859 } 860 861 debug("type %d", type); 862 switch (type) { 863 case SSH_AGENTC_LOCK: 864 case SSH_AGENTC_UNLOCK: 865 process_lock_agent(e, type == SSH_AGENTC_LOCK); 866 break; 867 #ifdef WITH_SSH1 868 /* ssh1 */ 869 case SSH_AGENTC_RSA_CHALLENGE: 870 process_authentication_challenge1(e); 871 break; 872 case SSH_AGENTC_REQUEST_RSA_IDENTITIES: 873 process_request_identities(e, 1); 874 break; 875 case SSH_AGENTC_ADD_RSA_IDENTITY: 876 case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED: 877 process_add_identity(e, 1); 878 break; 879 case SSH_AGENTC_REMOVE_RSA_IDENTITY: 880 process_remove_identity(e, 1); 881 break; 882 #endif 883 case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES: 884 process_remove_all_identities(e, 1); /* safe for !WITH_SSH1 */ 885 break; 886 /* ssh2 */ 887 case SSH2_AGENTC_SIGN_REQUEST: 888 process_sign_request2(e); 889 break; 890 case SSH2_AGENTC_REQUEST_IDENTITIES: 891 process_request_identities(e, 2); 892 break; 893 case SSH2_AGENTC_ADD_IDENTITY: 894 case SSH2_AGENTC_ADD_ID_CONSTRAINED: 895 process_add_identity(e, 2); 896 break; 897 case SSH2_AGENTC_REMOVE_IDENTITY: 898 process_remove_identity(e, 2); 899 break; 900 case SSH2_AGENTC_REMOVE_ALL_IDENTITIES: 901 process_remove_all_identities(e, 2); 902 break; 903 #ifdef ENABLE_PKCS11 904 case SSH_AGENTC_ADD_SMARTCARD_KEY: 905 case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED: 906 process_add_smartcard_key(e); 907 break; 908 case SSH_AGENTC_REMOVE_SMARTCARD_KEY: 909 process_remove_smartcard_key(e); 910 break; 911 #endif /* ENABLE_PKCS11 */ 912 default: 913 /* Unknown message. Respond with failure. */ 914 error("Unknown message %d", type); 915 sshbuf_reset(e->request); 916 send_status(e, 0); 917 break; 918 } 919 } 920 921 static void 922 new_socket(sock_type type, int fd) 923 { 924 u_int i, old_alloc, new_alloc; 925 926 set_nonblock(fd); 927 928 if (fd > max_fd) 929 max_fd = fd; 930 931 for (i = 0; i < sockets_alloc; i++) 932 if (sockets[i].type == AUTH_UNUSED) { 933 sockets[i].fd = fd; 934 if ((sockets[i].input = sshbuf_new()) == NULL) 935 fatal("%s: sshbuf_new failed", __func__); 936 if ((sockets[i].output = sshbuf_new()) == NULL) 937 fatal("%s: sshbuf_new failed", __func__); 938 if ((sockets[i].request = sshbuf_new()) == NULL) 939 fatal("%s: sshbuf_new failed", __func__); 940 sockets[i].type = type; 941 return; 942 } 943 old_alloc = sockets_alloc; 944 new_alloc = sockets_alloc + 10; 945 sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0])); 946 for (i = old_alloc; i < new_alloc; i++) 947 sockets[i].type = AUTH_UNUSED; 948 sockets_alloc = new_alloc; 949 sockets[old_alloc].fd = fd; 950 if ((sockets[old_alloc].input = sshbuf_new()) == NULL) 951 fatal("%s: sshbuf_new failed", __func__); 952 if ((sockets[old_alloc].output = sshbuf_new()) == NULL) 953 fatal("%s: sshbuf_new failed", __func__); 954 if ((sockets[old_alloc].request = sshbuf_new()) == NULL) 955 fatal("%s: sshbuf_new failed", __func__); 956 sockets[old_alloc].type = type; 957 } 958 959 static int 960 prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp, 961 struct timeval **tvpp) 962 { 963 u_int i, sz; 964 int n = 0; 965 static struct timeval tv; 966 time_t deadline; 967 968 for (i = 0; i < sockets_alloc; i++) { 969 switch (sockets[i].type) { 970 case AUTH_SOCKET: 971 case AUTH_CONNECTION: 972 n = MAX(n, sockets[i].fd); 973 break; 974 case AUTH_UNUSED: 975 break; 976 default: 977 fatal("Unknown socket type %d", sockets[i].type); 978 break; 979 } 980 } 981 982 sz = howmany(n+1, NFDBITS) * sizeof(fd_mask); 983 if (*fdrp == NULL || sz > *nallocp) { 984 free(*fdrp); 985 free(*fdwp); 986 *fdrp = xmalloc(sz); 987 *fdwp = xmalloc(sz); 988 *nallocp = sz; 989 } 990 if (n < *fdl) 991 debug("XXX shrink: %d < %d", n, *fdl); 992 *fdl = n; 993 memset(*fdrp, 0, sz); 994 memset(*fdwp, 0, sz); 995 996 for (i = 0; i < sockets_alloc; i++) { 997 switch (sockets[i].type) { 998 case AUTH_SOCKET: 999 case AUTH_CONNECTION: 1000 FD_SET(sockets[i].fd, *fdrp); 1001 if (sshbuf_len(sockets[i].output) > 0) 1002 FD_SET(sockets[i].fd, *fdwp); 1003 break; 1004 default: 1005 break; 1006 } 1007 } 1008 deadline = reaper(); 1009 if (parent_alive_interval != 0) 1010 deadline = (deadline == 0) ? parent_alive_interval : 1011 MIN(deadline, parent_alive_interval); 1012 if (deadline == 0) { 1013 *tvpp = NULL; 1014 } else { 1015 tv.tv_sec = deadline; 1016 tv.tv_usec = 0; 1017 *tvpp = &tv; 1018 } 1019 return (1); 1020 } 1021 1022 static void 1023 after_select(fd_set *readset, fd_set *writeset) 1024 { 1025 struct sockaddr_un sunaddr; 1026 socklen_t slen; 1027 char buf[1024]; 1028 int len, sock, r; 1029 u_int i, orig_alloc; 1030 uid_t euid; 1031 gid_t egid; 1032 1033 for (i = 0, orig_alloc = sockets_alloc; i < orig_alloc; i++) 1034 switch (sockets[i].type) { 1035 case AUTH_UNUSED: 1036 break; 1037 case AUTH_SOCKET: 1038 if (FD_ISSET(sockets[i].fd, readset)) { 1039 slen = sizeof(sunaddr); 1040 sock = accept(sockets[i].fd, 1041 (struct sockaddr *)&sunaddr, &slen); 1042 if (sock < 0) { 1043 error("accept from AUTH_SOCKET: %s", 1044 strerror(errno)); 1045 break; 1046 } 1047 if (getpeereid(sock, &euid, &egid) < 0) { 1048 error("getpeereid %d failed: %s", 1049 sock, strerror(errno)); 1050 close(sock); 1051 break; 1052 } 1053 if ((euid != 0) && (getuid() != euid)) { 1054 error("uid mismatch: " 1055 "peer euid %u != uid %u", 1056 (u_int) euid, (u_int) getuid()); 1057 close(sock); 1058 break; 1059 } 1060 new_socket(AUTH_CONNECTION, sock); 1061 } 1062 break; 1063 case AUTH_CONNECTION: 1064 if (sshbuf_len(sockets[i].output) > 0 && 1065 FD_ISSET(sockets[i].fd, writeset)) { 1066 len = write(sockets[i].fd, 1067 sshbuf_ptr(sockets[i].output), 1068 sshbuf_len(sockets[i].output)); 1069 if (len == -1 && (errno == EAGAIN || 1070 errno == EINTR)) 1071 continue; 1072 if (len <= 0) { 1073 close_socket(&sockets[i]); 1074 break; 1075 } 1076 if ((r = sshbuf_consume(sockets[i].output, 1077 len)) != 0) 1078 fatal("%s: buffer error: %s", 1079 __func__, ssh_err(r)); 1080 } 1081 if (FD_ISSET(sockets[i].fd, readset)) { 1082 len = read(sockets[i].fd, buf, sizeof(buf)); 1083 if (len == -1 && (errno == EAGAIN || 1084 errno == EINTR)) 1085 continue; 1086 if (len <= 0) { 1087 close_socket(&sockets[i]); 1088 break; 1089 } 1090 if ((r = sshbuf_put(sockets[i].input, 1091 buf, len)) != 0) 1092 fatal("%s: buffer error: %s", 1093 __func__, ssh_err(r)); 1094 explicit_bzero(buf, sizeof(buf)); 1095 process_message(&sockets[i]); 1096 } 1097 break; 1098 default: 1099 fatal("Unknown type %d", sockets[i].type); 1100 } 1101 } 1102 1103 static void 1104 cleanup_socket(void) 1105 { 1106 if (cleanup_pid != 0 && getpid() != cleanup_pid) 1107 return; 1108 debug("%s: cleanup", __func__); 1109 if (socket_name[0]) 1110 unlink(socket_name); 1111 if (socket_dir[0]) 1112 rmdir(socket_dir); 1113 } 1114 1115 void 1116 cleanup_exit(int i) 1117 { 1118 cleanup_socket(); 1119 _exit(i); 1120 } 1121 1122 /*ARGSUSED*/ 1123 __dead static void 1124 cleanup_handler(int sig) 1125 { 1126 cleanup_socket(); 1127 #ifdef ENABLE_PKCS11 1128 pkcs11_terminate(); 1129 #endif 1130 _exit(2); 1131 } 1132 1133 static void 1134 check_parent_exists(void) 1135 { 1136 /* 1137 * If our parent has exited then getppid() will return (pid_t)1, 1138 * so testing for that should be safe. 1139 */ 1140 if (parent_pid != -1 && getppid() != parent_pid) { 1141 /* printf("Parent has died - Authentication agent exiting.\n"); */ 1142 cleanup_socket(); 1143 _exit(2); 1144 } 1145 } 1146 1147 __dead static void 1148 usage(void) 1149 { 1150 fprintf(stderr, 1151 "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n" 1152 " [-t life] [command [arg ...]]\n" 1153 " ssh-agent [-c | -s] -k\n"); 1154 exit(1); 1155 } 1156 1157 static void 1158 csh_setenv(const char *name, const char *value) 1159 { 1160 printf("setenv %s %s;\n", name, value); 1161 } 1162 1163 static void 1164 csh_unsetenv(const char *name) 1165 { 1166 printf("unsetenv %s;\n", name); 1167 } 1168 1169 static void 1170 sh_setenv(const char *name, const char *value) 1171 { 1172 printf("%s=%s; export %s;\n", name, value, name); 1173 } 1174 1175 static void 1176 sh_unsetenv(const char *name) 1177 { 1178 printf("unset %s;\n", name); 1179 } 1180 int 1181 main(int ac, char **av) 1182 { 1183 int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0; 1184 int sock, fd, ch, result, saved_errno; 1185 u_int nalloc; 1186 char *shell, *pidstr, *agentsocket = NULL; 1187 fd_set *readsetp = NULL, *writesetp = NULL; 1188 struct rlimit rlim; 1189 extern int optind; 1190 extern char *optarg; 1191 pid_t pid; 1192 char pidstrbuf[1 + 3 * sizeof pid]; 1193 struct timeval *tvp = NULL; 1194 size_t len; 1195 mode_t prev_mask; 1196 void (*f_setenv)(const char *, const char *); 1197 void (*f_unsetenv)(const char *); 1198 1199 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 1200 sanitise_stdfd(); 1201 1202 /* drop */ 1203 setegid(getgid()); 1204 setgid(getgid()); 1205 1206 #ifdef WITH_OPENSSL 1207 OpenSSL_add_all_algorithms(); 1208 #endif 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 (c_flag) { 1266 f_setenv = csh_setenv; 1267 f_unsetenv = csh_unsetenv; 1268 } else { 1269 f_setenv = sh_setenv; 1270 f_unsetenv = sh_unsetenv; 1271 } 1272 if (k_flag) { 1273 const char *errstr = NULL; 1274 1275 pidstr = getenv(SSH_AGENTPID_ENV_NAME); 1276 if (pidstr == NULL) { 1277 fprintf(stderr, "%s not set, cannot kill agent\n", 1278 SSH_AGENTPID_ENV_NAME); 1279 exit(1); 1280 } 1281 pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr); 1282 if (errstr) { 1283 fprintf(stderr, 1284 "%s=\"%s\", which is not a good PID: %s\n", 1285 SSH_AGENTPID_ENV_NAME, pidstr, errstr); 1286 exit(1); 1287 } 1288 if (kill(pid, SIGTERM) == -1) { 1289 perror("kill"); 1290 exit(1); 1291 } 1292 (*f_unsetenv)(SSH_AUTHSOCKET_ENV_NAME); 1293 (*f_unsetenv)(SSH_AGENTPID_ENV_NAME); 1294 printf("echo Agent pid %ld killed;\n", (long)pid); 1295 exit(0); 1296 } 1297 parent_pid = getpid(); 1298 1299 if (agentsocket == NULL) { 1300 /* Create private directory for agent socket */ 1301 mktemp_proto(socket_dir, sizeof(socket_dir)); 1302 if (mkdtemp(socket_dir) == NULL) { 1303 perror("mkdtemp: private socket dir"); 1304 exit(1); 1305 } 1306 snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir, 1307 (long)parent_pid); 1308 } else { 1309 /* Try to use specified agent socket */ 1310 socket_dir[0] = '\0'; 1311 strlcpy(socket_name, agentsocket, sizeof socket_name); 1312 } 1313 1314 /* 1315 * Create socket early so it will exist before command gets run from 1316 * the parent. 1317 */ 1318 prev_mask = umask(0177); 1319 sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0); 1320 if (sock < 0) { 1321 /* XXX - unix_listener() calls error() not perror() */ 1322 *socket_name = '\0'; /* Don't unlink any existing file */ 1323 cleanup_exit(1); 1324 } 1325 umask(prev_mask); 1326 1327 /* 1328 * Fork, and have the parent execute the command, if any, or present 1329 * the socket data. The child continues as the authentication agent. 1330 */ 1331 if (D_flag || d_flag) { 1332 log_init(__progname, 1333 d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO, 1334 SYSLOG_FACILITY_AUTH, 1); 1335 if (c_flag) 1336 printf("setenv %s %s;\n", 1337 SSH_AUTHSOCKET_ENV_NAME, socket_name); 1338 else 1339 printf("%s=%s; export %s;\n", 1340 SSH_AUTHSOCKET_ENV_NAME, socket_name, 1341 SSH_AUTHSOCKET_ENV_NAME); 1342 printf("echo Agent pid %ld;\n", (long)parent_pid); 1343 goto skip; 1344 } 1345 pid = fork(); 1346 if (pid == -1) { 1347 perror("fork"); 1348 cleanup_exit(1); 1349 } 1350 if (pid != 0) { /* Parent - execute the given command. */ 1351 close(sock); 1352 snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid); 1353 if (ac == 0) { 1354 (*f_setenv)(SSH_AUTHSOCKET_ENV_NAME, socket_name); 1355 (*f_setenv)(SSH_AGENTPID_ENV_NAME, pidstrbuf); 1356 printf("echo Agent pid %ld;\n", (long)pid); 1357 exit(0); 1358 } 1359 if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 || 1360 setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) { 1361 perror("setenv"); 1362 exit(1); 1363 } 1364 execvp(av[0], av); 1365 perror(av[0]); 1366 exit(1); 1367 } 1368 /* child */ 1369 log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0); 1370 1371 if (setsid() == -1) { 1372 error("setsid: %s", strerror(errno)); 1373 cleanup_exit(1); 1374 } 1375 1376 (void)chdir("/"); 1377 1378 if (sock != STDERR_FILENO + 1) { 1379 if (dup2(sock, STDERR_FILENO + 1) == -1) { 1380 error("dup2: %s", strerror(errno)); 1381 cleanup_exit(1); 1382 } 1383 close(sock); 1384 sock = STDERR_FILENO + 1; 1385 } 1386 #if defined(F_CLOSEM) 1387 if (fcntl(sock + 1, F_CLOSEM, 0) == -1) { 1388 error("fcntl F_CLOSEM: %s", strerror(errno)); 1389 cleanup_exit(1); 1390 } 1391 #else 1392 { 1393 int nfiles; 1394 #if defined(_SC_OPEN_MAX) 1395 nfiles = sysconf(_SC_OPEN_MAX); 1396 #elif defined(RLIMIT_NOFILE) 1397 if (getrlimit(RLIMIT_CORE, &rlim) < 0) { 1398 error("getrlimit RLIMIT_NOFILE: %s", strerror(errno)); 1399 cleanup_exit(1); 1400 } 1401 nfiles = rlim.rlim_cur; 1402 #elif defined(OPEN_MAX) 1403 nfiles = OPEN_MAX; 1404 #elif defined(NOFILE) 1405 nfiles = NOFILE; 1406 #else 1407 nfiles = 1024; 1408 #endif 1409 for (fd = sock + 1; fd < nfiles; fd++) 1410 close(fd); 1411 } 1412 #endif 1413 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { 1414 if (dup2(fd, STDIN_FILENO) == -1 || 1415 dup2(fd, STDOUT_FILENO) == -1 || 1416 dup2(fd, STDERR_FILENO) == -1) { 1417 error("dup2: %s", strerror(errno)); 1418 cleanup_exit(1); 1419 } 1420 if (fd > STDERR_FILENO) 1421 close(fd); 1422 } 1423 1424 /* deny core dumps, since memory contains unencrypted private keys */ 1425 rlim.rlim_cur = rlim.rlim_max = 0; 1426 if (setrlimit(RLIMIT_CORE, &rlim) < 0) { 1427 error("setrlimit RLIMIT_CORE: %s", strerror(errno)); 1428 cleanup_exit(1); 1429 } 1430 1431 skip: 1432 1433 cleanup_pid = getpid(); 1434 1435 #ifdef ENABLE_PKCS11 1436 pkcs11_init(0); 1437 #endif 1438 new_socket(AUTH_SOCKET, sock); 1439 if (ac > 0) 1440 parent_alive_interval = 10; 1441 idtab_init(); 1442 signal(SIGPIPE, SIG_IGN); 1443 signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN); 1444 signal(SIGHUP, cleanup_handler); 1445 signal(SIGTERM, cleanup_handler); 1446 nalloc = 0; 1447 1448 while (1) { 1449 prepare_select(&readsetp, &writesetp, &max_fd, &nalloc, &tvp); 1450 result = select(max_fd + 1, readsetp, writesetp, NULL, tvp); 1451 saved_errno = errno; 1452 if (parent_alive_interval != 0) 1453 check_parent_exists(); 1454 (void) reaper(); /* remove expired keys */ 1455 if (result < 0) { 1456 if (saved_errno == EINTR) 1457 continue; 1458 fatal("select: %s", strerror(saved_errno)); 1459 } else if (result > 0) 1460 after_select(readsetp, writesetp); 1461 } 1462 /* NOTREACHED */ 1463 } 1464