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 "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 typedef enum { 92 AUTH_UNUSED, 93 AUTH_SOCKET, 94 AUTH_CONNECTION 95 } sock_type; 96 97 typedef struct { 98 int fd; 99 sock_type type; 100 struct sshbuf *input; 101 struct sshbuf *output; 102 struct sshbuf *request; 103 } SocketEntry; 104 105 u_int sockets_alloc = 0; 106 SocketEntry *sockets = NULL; 107 108 typedef struct identity { 109 TAILQ_ENTRY(identity) next; 110 struct sshkey *key; 111 char *comment; 112 char *provider; 113 time_t death; 114 u_int confirm; 115 } Identity; 116 117 typedef struct { 118 int nentries; 119 TAILQ_HEAD(idqueue, identity) idlist; 120 } Idtab; 121 122 /* private key table, one per protocol version */ 123 Idtab idtable[3]; 124 125 int max_fd = 0; 126 127 /* pid of shell == parent of agent */ 128 pid_t parent_pid = -1; 129 time_t parent_alive_interval = 0; 130 131 /* pid of process for which cleanup_socket is applicable */ 132 pid_t cleanup_pid = 0; 133 134 /* pathname and directory for AUTH_SOCKET */ 135 char socket_name[PATH_MAX]; 136 char socket_dir[PATH_MAX]; 137 138 /* locking */ 139 #define LOCK_SIZE 32 140 #define LOCK_SALT_SIZE 16 141 #define LOCK_ROUNDS 1 142 int locked = 0; 143 u_char lock_pwhash[LOCK_SIZE]; 144 u_char lock_salt[LOCK_SALT_SIZE]; 145 146 extern char *__progname; 147 148 /* Default lifetime in seconds (0 == forever) */ 149 static long lifetime = 0; 150 151 static int fingerprint_hash = SSH_FP_HASH_DEFAULT; 152 153 static void 154 close_socket(SocketEntry *e) 155 { 156 close(e->fd); 157 e->fd = -1; 158 e->type = AUTH_UNUSED; 159 sshbuf_free(e->input); 160 sshbuf_free(e->output); 161 sshbuf_free(e->request); 162 } 163 164 static void 165 idtab_init(void) 166 { 167 int i; 168 169 for (i = 0; i <=2; i++) { 170 TAILQ_INIT(&idtable[i].idlist); 171 idtable[i].nentries = 0; 172 } 173 } 174 175 /* return private key table for requested protocol version */ 176 static Idtab * 177 idtab_lookup(int version) 178 { 179 if (version < 1 || version > 2) 180 fatal("internal error, bad protocol version %d", version); 181 return &idtable[version]; 182 } 183 184 static void 185 free_identity(Identity *id) 186 { 187 sshkey_free(id->key); 188 free(id->provider); 189 free(id->comment); 190 free(id); 191 } 192 193 /* return matching private key for given public key */ 194 static Identity * 195 lookup_identity(struct sshkey *key, int version) 196 { 197 Identity *id; 198 199 Idtab *tab = idtab_lookup(version); 200 TAILQ_FOREACH(id, &tab->idlist, next) { 201 if (sshkey_equal(key, id->key)) 202 return (id); 203 } 204 return (NULL); 205 } 206 207 /* Check confirmation of keysign request */ 208 static int 209 confirm_key(Identity *id) 210 { 211 char *p; 212 int ret = -1; 213 214 p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT); 215 if (p != NULL && 216 ask_permission("Allow use of key %s?\nKey fingerprint %s.", 217 id->comment, p)) 218 ret = 0; 219 free(p); 220 221 return (ret); 222 } 223 224 static void 225 send_status(SocketEntry *e, int success) 226 { 227 int r; 228 229 if ((r = sshbuf_put_u32(e->output, 1)) != 0 || 230 (r = sshbuf_put_u8(e->output, success ? 231 SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0) 232 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 233 } 234 235 /* send list of supported public keys to 'client' */ 236 static void 237 process_request_identities(SocketEntry *e, int version) 238 { 239 Idtab *tab = idtab_lookup(version); 240 Identity *id; 241 struct sshbuf *msg; 242 int r; 243 244 if ((msg = sshbuf_new()) == NULL) 245 fatal("%s: sshbuf_new failed", __func__); 246 if ((r = sshbuf_put_u8(msg, (version == 1) ? 247 SSH_AGENT_RSA_IDENTITIES_ANSWER : 248 SSH2_AGENT_IDENTITIES_ANSWER)) != 0 || 249 (r = sshbuf_put_u32(msg, tab->nentries)) != 0) 250 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 251 TAILQ_FOREACH(id, &tab->idlist, next) { 252 if (id->key->type == KEY_RSA1) { 253 #ifdef WITH_SSH1 254 if ((r = sshbuf_put_u32(msg, 255 BN_num_bits(id->key->rsa->n))) != 0 || 256 (r = sshbuf_put_bignum1(msg, 257 id->key->rsa->e)) != 0 || 258 (r = sshbuf_put_bignum1(msg, 259 id->key->rsa->n)) != 0) 260 fatal("%s: buffer error: %s", 261 __func__, ssh_err(r)); 262 #endif 263 } else { 264 u_char *blob; 265 size_t blen; 266 267 if ((r = sshkey_to_blob(id->key, &blob, &blen)) != 0) { 268 error("%s: sshkey_to_blob: %s", __func__, 269 ssh_err(r)); 270 continue; 271 } 272 if ((r = sshbuf_put_string(msg, blob, blen)) != 0) 273 fatal("%s: buffer error: %s", 274 __func__, ssh_err(r)); 275 free(blob); 276 } 277 if ((r = sshbuf_put_cstring(msg, id->comment)) != 0) 278 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 279 } 280 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 281 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 282 sshbuf_free(msg); 283 } 284 285 #ifdef WITH_SSH1 286 /* ssh1 only */ 287 static void 288 process_authentication_challenge1(SocketEntry *e) 289 { 290 u_char buf[32], mdbuf[16], session_id[16]; 291 u_int response_type; 292 BIGNUM *challenge; 293 Identity *id; 294 int r, len; 295 struct sshbuf *msg; 296 struct ssh_digest_ctx *md; 297 struct sshkey *key; 298 299 if ((msg = sshbuf_new()) == NULL) 300 fatal("%s: sshbuf_new failed", __func__); 301 if ((key = sshkey_new(KEY_RSA1)) == NULL) 302 fatal("%s: sshkey_new failed", __func__); 303 if ((challenge = BN_new()) == NULL) 304 fatal("%s: BN_new failed", __func__); 305 306 if ((r = sshbuf_get_u32(e->request, NULL)) != 0 || /* ignored */ 307 (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 || 308 (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0 || 309 (r = sshbuf_get_bignum1(e->request, challenge))) 310 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 311 312 /* Only protocol 1.1 is supported */ 313 if (sshbuf_len(e->request) == 0) 314 goto failure; 315 if ((r = sshbuf_get(e->request, session_id, sizeof(session_id))) != 0 || 316 (r = sshbuf_get_u32(e->request, &response_type)) != 0) 317 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 318 if (response_type != 1) 319 goto failure; 320 321 id = lookup_identity(key, 1); 322 if (id != NULL && (!id->confirm || confirm_key(id) == 0)) { 323 struct sshkey *private = id->key; 324 /* Decrypt the challenge using the private key. */ 325 if ((r = rsa_private_decrypt(challenge, challenge, 326 private->rsa) != 0)) { 327 fatal("%s: rsa_public_encrypt: %s", __func__, 328 ssh_err(r)); 329 goto failure; /* XXX ? */ 330 } 331 332 /* The response is MD5 of decrypted challenge plus session id */ 333 len = BN_num_bytes(challenge); 334 if (len <= 0 || len > 32) { 335 logit("%s: bad challenge length %d", __func__, len); 336 goto failure; 337 } 338 memset(buf, 0, 32); 339 BN_bn2bin(challenge, buf + 32 - len); 340 if ((md = ssh_digest_start(SSH_DIGEST_MD5)) == NULL || 341 ssh_digest_update(md, buf, 32) < 0 || 342 ssh_digest_update(md, session_id, 16) < 0 || 343 ssh_digest_final(md, mdbuf, sizeof(mdbuf)) < 0) 344 fatal("%s: md5 failed", __func__); 345 ssh_digest_free(md); 346 347 /* Send the response. */ 348 if ((r = sshbuf_put_u8(msg, SSH_AGENT_RSA_RESPONSE)) != 0 || 349 (r = sshbuf_put(msg, mdbuf, sizeof(mdbuf))) != 0) 350 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 351 goto send; 352 } 353 354 failure: 355 /* Unknown identity or protocol error. Send failure. */ 356 if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0) 357 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 358 send: 359 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 360 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 361 sshkey_free(key); 362 BN_clear_free(challenge); 363 sshbuf_free(msg); 364 } 365 #endif 366 367 static char * 368 agent_decode_alg(struct sshkey *key, u_int flags) 369 { 370 if (key->type == KEY_RSA) { 371 if (flags & SSH_AGENT_RSA_SHA2_256) 372 return "rsa-sha2-256"; 373 else if (flags & SSH_AGENT_RSA_SHA2_512) 374 return "rsa-sha2-512"; 375 } 376 return NULL; 377 } 378 379 /* ssh2 only */ 380 static void 381 process_sign_request2(SocketEntry *e) 382 { 383 u_char *blob, *data, *signature = NULL; 384 size_t blen, dlen, slen = 0; 385 u_int compat = 0, flags; 386 int r, ok = -1; 387 struct sshbuf *msg; 388 struct sshkey *key; 389 struct identity *id; 390 391 if ((msg = sshbuf_new()) == NULL) 392 fatal("%s: sshbuf_new failed", __func__); 393 if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0 || 394 (r = sshbuf_get_string(e->request, &data, &dlen)) != 0 || 395 (r = sshbuf_get_u32(e->request, &flags)) != 0) 396 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 397 if (flags & SSH_AGENT_OLD_SIGNATURE) 398 compat = SSH_BUG_SIGBLOB; 399 if ((r = sshkey_from_blob(blob, blen, &key)) != 0) { 400 error("%s: cannot parse key blob: %s", __func__, ssh_err(r)); 401 goto send; 402 } 403 if ((id = lookup_identity(key, 2)) == NULL) { 404 verbose("%s: %s key not found", __func__, sshkey_type(key)); 405 goto send; 406 } 407 if (id->confirm && confirm_key(id) != 0) { 408 verbose("%s: user refused key", __func__); 409 goto send; 410 } 411 if ((r = sshkey_sign(id->key, &signature, &slen, 412 data, dlen, agent_decode_alg(key, flags), compat)) != 0) { 413 error("%s: sshkey_sign: %s", __func__, ssh_err(r)); 414 goto send; 415 } 416 /* Success */ 417 ok = 0; 418 send: 419 sshkey_free(key); 420 if (ok == 0) { 421 if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 || 422 (r = sshbuf_put_string(msg, signature, slen)) != 0) 423 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 424 } else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0) 425 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 426 427 if ((r = sshbuf_put_stringb(e->output, msg)) != 0) 428 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 429 430 sshbuf_free(msg); 431 free(data); 432 free(blob); 433 free(signature); 434 } 435 436 /* shared */ 437 static void 438 process_remove_identity(SocketEntry *e, int version) 439 { 440 size_t blen; 441 int r, success = 0; 442 struct sshkey *key = NULL; 443 u_char *blob; 444 #ifdef WITH_SSH1 445 u_int bits; 446 #endif /* WITH_SSH1 */ 447 448 switch (version) { 449 #ifdef WITH_SSH1 450 case 1: 451 if ((key = sshkey_new(KEY_RSA1)) == NULL) { 452 error("%s: sshkey_new failed", __func__); 453 return; 454 } 455 if ((r = sshbuf_get_u32(e->request, &bits)) != 0 || 456 (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 || 457 (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0) 458 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 459 460 if (bits != sshkey_size(key)) 461 logit("Warning: identity keysize mismatch: " 462 "actual %u, announced %u", 463 sshkey_size(key), bits); 464 break; 465 #endif /* WITH_SSH1 */ 466 case 2: 467 if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0) 468 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 469 if ((r = sshkey_from_blob(blob, blen, &key)) != 0) 470 error("%s: sshkey_from_blob failed: %s", 471 __func__, ssh_err(r)); 472 free(blob); 473 break; 474 } 475 if (key != NULL) { 476 Identity *id = lookup_identity(key, version); 477 if (id != NULL) { 478 /* 479 * We have this key. Free the old key. Since we 480 * don't want to leave empty slots in the middle of 481 * the array, we actually free the key there and move 482 * all the entries between the empty slot and the end 483 * of the array. 484 */ 485 Idtab *tab = idtab_lookup(version); 486 if (tab->nentries < 1) 487 fatal("process_remove_identity: " 488 "internal error: tab->nentries %d", 489 tab->nentries); 490 TAILQ_REMOVE(&tab->idlist, id, next); 491 free_identity(id); 492 tab->nentries--; 493 success = 1; 494 } 495 sshkey_free(key); 496 } 497 send_status(e, success); 498 } 499 500 static void 501 process_remove_all_identities(SocketEntry *e, int version) 502 { 503 Idtab *tab = idtab_lookup(version); 504 Identity *id; 505 506 /* Loop over all identities and clear the keys. */ 507 for (id = TAILQ_FIRST(&tab->idlist); id; 508 id = TAILQ_FIRST(&tab->idlist)) { 509 TAILQ_REMOVE(&tab->idlist, id, next); 510 free_identity(id); 511 } 512 513 /* Mark that there are no identities. */ 514 tab->nentries = 0; 515 516 /* Send success. */ 517 send_status(e, 1); 518 } 519 520 /* removes expired keys and returns number of seconds until the next expiry */ 521 static time_t 522 reaper(void) 523 { 524 time_t deadline = 0, now = monotime(); 525 Identity *id, *nxt; 526 int version; 527 Idtab *tab; 528 529 for (version = 1; version < 3; version++) { 530 tab = idtab_lookup(version); 531 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) { 532 nxt = TAILQ_NEXT(id, next); 533 if (id->death == 0) 534 continue; 535 if (now >= id->death) { 536 debug("expiring key '%s'", id->comment); 537 TAILQ_REMOVE(&tab->idlist, id, next); 538 free_identity(id); 539 tab->nentries--; 540 } else 541 deadline = (deadline == 0) ? id->death : 542 MIN(deadline, id->death); 543 } 544 } 545 if (deadline == 0 || deadline <= now) 546 return 0; 547 else 548 return (deadline - now); 549 } 550 551 /* 552 * XXX this and the corresponding serialisation function probably belongs 553 * in key.c 554 */ 555 #ifdef WITH_SSH1 556 static int 557 agent_decode_rsa1(struct sshbuf *m, struct sshkey **kp) 558 { 559 struct sshkey *k = NULL; 560 int r = SSH_ERR_INTERNAL_ERROR; 561 562 *kp = NULL; 563 if ((k = sshkey_new_private(KEY_RSA1)) == NULL) 564 return SSH_ERR_ALLOC_FAIL; 565 566 if ((r = sshbuf_get_u32(m, NULL)) != 0 || /* ignored */ 567 (r = sshbuf_get_bignum1(m, k->rsa->n)) != 0 || 568 (r = sshbuf_get_bignum1(m, k->rsa->e)) != 0 || 569 (r = sshbuf_get_bignum1(m, k->rsa->d)) != 0 || 570 (r = sshbuf_get_bignum1(m, k->rsa->iqmp)) != 0 || 571 /* SSH1 and SSL have p and q swapped */ 572 (r = sshbuf_get_bignum1(m, k->rsa->q)) != 0 || /* p */ 573 (r = sshbuf_get_bignum1(m, k->rsa->p)) != 0) /* q */ 574 goto out; 575 576 /* Generate additional parameters */ 577 if ((r = rsa_generate_additional_parameters(k->rsa)) != 0) 578 goto out; 579 /* enable blinding */ 580 if (RSA_blinding_on(k->rsa, NULL) != 1) { 581 r = SSH_ERR_LIBCRYPTO_ERROR; 582 goto out; 583 } 584 585 r = 0; /* success */ 586 out: 587 if (r == 0) 588 *kp = k; 589 else 590 sshkey_free(k); 591 return r; 592 } 593 #endif /* WITH_SSH1 */ 594 595 static void 596 process_add_identity(SocketEntry *e, int version) 597 { 598 Idtab *tab = idtab_lookup(version); 599 Identity *id; 600 int success = 0, confirm = 0; 601 u_int seconds; 602 char *comment = NULL; 603 time_t death = 0; 604 struct sshkey *k = NULL; 605 u_char ctype; 606 int r = SSH_ERR_INTERNAL_ERROR; 607 608 switch (version) { 609 #ifdef WITH_SSH1 610 case 1: 611 r = agent_decode_rsa1(e->request, &k); 612 break; 613 #endif /* WITH_SSH1 */ 614 case 2: 615 r = sshkey_private_deserialize(e->request, &k); 616 break; 617 } 618 if (r != 0 || k == NULL || 619 (r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) { 620 error("%s: decode private key: %s", __func__, ssh_err(r)); 621 goto err; 622 } 623 624 while (sshbuf_len(e->request)) { 625 if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) { 626 error("%s: buffer error: %s", __func__, ssh_err(r)); 627 goto err; 628 } 629 switch (ctype) { 630 case SSH_AGENT_CONSTRAIN_LIFETIME: 631 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) { 632 error("%s: bad lifetime constraint: %s", 633 __func__, ssh_err(r)); 634 goto err; 635 } 636 death = monotime() + seconds; 637 break; 638 case SSH_AGENT_CONSTRAIN_CONFIRM: 639 confirm = 1; 640 break; 641 default: 642 error("%s: Unknown constraint %d", __func__, ctype); 643 err: 644 sshbuf_reset(e->request); 645 free(comment); 646 sshkey_free(k); 647 goto send; 648 } 649 } 650 651 success = 1; 652 if (lifetime && !death) 653 death = monotime() + lifetime; 654 if ((id = lookup_identity(k, version)) == NULL) { 655 id = xcalloc(1, sizeof(Identity)); 656 id->key = k; 657 TAILQ_INSERT_TAIL(&tab->idlist, id, next); 658 /* Increment the number of identities. */ 659 tab->nentries++; 660 } else { 661 sshkey_free(k); 662 free(id->comment); 663 } 664 id->comment = comment; 665 id->death = death; 666 id->confirm = confirm; 667 send: 668 send_status(e, success); 669 } 670 671 /* XXX todo: encrypt sensitive data with passphrase */ 672 static void 673 process_lock_agent(SocketEntry *e, int lock) 674 { 675 int r, success = 0, delay; 676 char *passwd; 677 u_char passwdhash[LOCK_SIZE]; 678 static u_int fail_count = 0; 679 size_t pwlen; 680 681 if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0) 682 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 683 if (pwlen == 0) { 684 debug("empty password not supported"); 685 } else if (locked && !lock) { 686 if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt), 687 passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0) 688 fatal("bcrypt_pbkdf"); 689 if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) { 690 debug("agent unlocked"); 691 locked = 0; 692 fail_count = 0; 693 explicit_bzero(lock_pwhash, sizeof(lock_pwhash)); 694 success = 1; 695 } else { 696 /* delay in 0.1s increments up to 10s */ 697 if (fail_count < 100) 698 fail_count++; 699 delay = 100000 * fail_count; 700 debug("unlock failed, delaying %0.1lf seconds", 701 (double)delay/1000000); 702 usleep(delay); 703 } 704 explicit_bzero(passwdhash, sizeof(passwdhash)); 705 } else if (!locked && lock) { 706 debug("agent locked"); 707 locked = 1; 708 arc4random_buf(lock_salt, sizeof(lock_salt)); 709 if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt), 710 lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0) 711 fatal("bcrypt_pbkdf"); 712 success = 1; 713 } 714 explicit_bzero(passwd, pwlen); 715 free(passwd); 716 send_status(e, success); 717 } 718 719 static void 720 no_identities(SocketEntry *e, u_int type) 721 { 722 struct sshbuf *msg; 723 int r; 724 725 if ((msg = sshbuf_new()) == NULL) 726 fatal("%s: sshbuf_new failed", __func__); 727 if ((r = sshbuf_put_u8(msg, 728 (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ? 729 SSH_AGENT_RSA_IDENTITIES_ANSWER : 730 SSH2_AGENT_IDENTITIES_ANSWER)) != 0 || 731 (r = sshbuf_put_u32(msg, 0)) != 0 || 732 (r = sshbuf_put_stringb(e->output, msg)) != 0) 733 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 734 sshbuf_free(msg); 735 } 736 737 #ifdef ENABLE_PKCS11 738 static void 739 process_add_smartcard_key(SocketEntry *e) 740 { 741 char *provider = NULL, *pin; 742 int r, i, version, count = 0, success = 0, confirm = 0; 743 u_int seconds; 744 time_t death = 0; 745 u_char type; 746 struct sshkey **keys = NULL, *k; 747 Identity *id; 748 Idtab *tab; 749 750 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 || 751 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) 752 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 753 754 while (sshbuf_len(e->request)) { 755 if ((r = sshbuf_get_u8(e->request, &type)) != 0) 756 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 757 switch (type) { 758 case SSH_AGENT_CONSTRAIN_LIFETIME: 759 if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) 760 fatal("%s: buffer error: %s", 761 __func__, ssh_err(r)); 762 death = monotime() + seconds; 763 break; 764 case SSH_AGENT_CONSTRAIN_CONFIRM: 765 confirm = 1; 766 break; 767 default: 768 error("process_add_smartcard_key: " 769 "Unknown constraint type %d", type); 770 goto send; 771 } 772 } 773 if (lifetime && !death) 774 death = monotime() + lifetime; 775 776 count = pkcs11_add_provider(provider, pin, &keys); 777 for (i = 0; i < count; i++) { 778 k = keys[i]; 779 version = k->type == KEY_RSA1 ? 1 : 2; 780 tab = idtab_lookup(version); 781 if (lookup_identity(k, version) == NULL) { 782 id = xcalloc(1, sizeof(Identity)); 783 id->key = k; 784 id->provider = xstrdup(provider); 785 id->comment = xstrdup(provider); /* XXX */ 786 id->death = death; 787 id->confirm = confirm; 788 TAILQ_INSERT_TAIL(&tab->idlist, id, next); 789 tab->nentries++; 790 success = 1; 791 } else { 792 sshkey_free(k); 793 } 794 keys[i] = NULL; 795 } 796 send: 797 free(pin); 798 free(provider); 799 free(keys); 800 send_status(e, success); 801 } 802 803 static void 804 process_remove_smartcard_key(SocketEntry *e) 805 { 806 char *provider = NULL, *pin = NULL; 807 int r, version, success = 0; 808 Identity *id, *nxt; 809 Idtab *tab; 810 811 if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 || 812 (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) 813 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 814 free(pin); 815 816 for (version = 1; version < 3; version++) { 817 tab = idtab_lookup(version); 818 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) { 819 nxt = TAILQ_NEXT(id, next); 820 /* Skip file--based keys */ 821 if (id->provider == NULL) 822 continue; 823 if (!strcmp(provider, id->provider)) { 824 TAILQ_REMOVE(&tab->idlist, id, next); 825 free_identity(id); 826 tab->nentries--; 827 } 828 } 829 } 830 if (pkcs11_del_provider(provider) == 0) 831 success = 1; 832 else 833 error("process_remove_smartcard_key:" 834 " pkcs11_del_provider failed"); 835 free(provider); 836 send_status(e, success); 837 } 838 #endif /* ENABLE_PKCS11 */ 839 840 /* dispatch incoming messages */ 841 842 static void 843 process_message(SocketEntry *e) 844 { 845 u_int msg_len; 846 u_char type; 847 const u_char *cp; 848 int r; 849 850 if (sshbuf_len(e->input) < 5) 851 return; /* Incomplete message. */ 852 cp = sshbuf_ptr(e->input); 853 msg_len = PEEK_U32(cp); 854 if (msg_len > 256 * 1024) { 855 close_socket(e); 856 return; 857 } 858 if (sshbuf_len(e->input) < msg_len + 4) 859 return; 860 861 /* move the current input to e->request */ 862 sshbuf_reset(e->request); 863 if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 || 864 (r = sshbuf_get_u8(e->request, &type)) != 0) 865 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 866 867 /* check wheter agent is locked */ 868 if (locked && type != SSH_AGENTC_UNLOCK) { 869 sshbuf_reset(e->request); 870 switch (type) { 871 case SSH_AGENTC_REQUEST_RSA_IDENTITIES: 872 case SSH2_AGENTC_REQUEST_IDENTITIES: 873 /* send empty lists */ 874 no_identities(e, type); 875 break; 876 default: 877 /* send a fail message for all other request types */ 878 send_status(e, 0); 879 } 880 return; 881 } 882 883 debug("type %d", type); 884 switch (type) { 885 case SSH_AGENTC_LOCK: 886 case SSH_AGENTC_UNLOCK: 887 process_lock_agent(e, type == SSH_AGENTC_LOCK); 888 break; 889 #ifdef WITH_SSH1 890 /* ssh1 */ 891 case SSH_AGENTC_RSA_CHALLENGE: 892 process_authentication_challenge1(e); 893 break; 894 case SSH_AGENTC_REQUEST_RSA_IDENTITIES: 895 process_request_identities(e, 1); 896 break; 897 case SSH_AGENTC_ADD_RSA_IDENTITY: 898 case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED: 899 process_add_identity(e, 1); 900 break; 901 case SSH_AGENTC_REMOVE_RSA_IDENTITY: 902 process_remove_identity(e, 1); 903 break; 904 #endif 905 case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES: 906 process_remove_all_identities(e, 1); /* safe for !WITH_SSH1 */ 907 break; 908 /* ssh2 */ 909 case SSH2_AGENTC_SIGN_REQUEST: 910 process_sign_request2(e); 911 break; 912 case SSH2_AGENTC_REQUEST_IDENTITIES: 913 process_request_identities(e, 2); 914 break; 915 case SSH2_AGENTC_ADD_IDENTITY: 916 case SSH2_AGENTC_ADD_ID_CONSTRAINED: 917 process_add_identity(e, 2); 918 break; 919 case SSH2_AGENTC_REMOVE_IDENTITY: 920 process_remove_identity(e, 2); 921 break; 922 case SSH2_AGENTC_REMOVE_ALL_IDENTITIES: 923 process_remove_all_identities(e, 2); 924 break; 925 #ifdef ENABLE_PKCS11 926 case SSH_AGENTC_ADD_SMARTCARD_KEY: 927 case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED: 928 process_add_smartcard_key(e); 929 break; 930 case SSH_AGENTC_REMOVE_SMARTCARD_KEY: 931 process_remove_smartcard_key(e); 932 break; 933 #endif /* ENABLE_PKCS11 */ 934 default: 935 /* Unknown message. Respond with failure. */ 936 error("Unknown message %d", type); 937 sshbuf_reset(e->request); 938 send_status(e, 0); 939 break; 940 } 941 } 942 943 static void 944 new_socket(sock_type type, int fd) 945 { 946 u_int i, old_alloc, new_alloc; 947 948 set_nonblock(fd); 949 950 if (fd > max_fd) 951 max_fd = fd; 952 953 for (i = 0; i < sockets_alloc; i++) 954 if (sockets[i].type == AUTH_UNUSED) { 955 sockets[i].fd = fd; 956 if ((sockets[i].input = sshbuf_new()) == NULL) 957 fatal("%s: sshbuf_new failed", __func__); 958 if ((sockets[i].output = sshbuf_new()) == NULL) 959 fatal("%s: sshbuf_new failed", __func__); 960 if ((sockets[i].request = sshbuf_new()) == NULL) 961 fatal("%s: sshbuf_new failed", __func__); 962 sockets[i].type = type; 963 return; 964 } 965 old_alloc = sockets_alloc; 966 new_alloc = sockets_alloc + 10; 967 sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0])); 968 for (i = old_alloc; i < new_alloc; i++) 969 sockets[i].type = AUTH_UNUSED; 970 sockets_alloc = new_alloc; 971 sockets[old_alloc].fd = fd; 972 if ((sockets[old_alloc].input = sshbuf_new()) == NULL) 973 fatal("%s: sshbuf_new failed", __func__); 974 if ((sockets[old_alloc].output = sshbuf_new()) == NULL) 975 fatal("%s: sshbuf_new failed", __func__); 976 if ((sockets[old_alloc].request = sshbuf_new()) == NULL) 977 fatal("%s: sshbuf_new failed", __func__); 978 sockets[old_alloc].type = type; 979 } 980 981 static int 982 prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp, 983 struct timeval **tvpp) 984 { 985 u_int i, sz; 986 int n = 0; 987 static struct timeval tv; 988 time_t deadline; 989 990 for (i = 0; i < sockets_alloc; i++) { 991 switch (sockets[i].type) { 992 case AUTH_SOCKET: 993 case AUTH_CONNECTION: 994 n = MAX(n, sockets[i].fd); 995 break; 996 case AUTH_UNUSED: 997 break; 998 default: 999 fatal("Unknown socket type %d", sockets[i].type); 1000 break; 1001 } 1002 } 1003 1004 sz = howmany(n+1, NFDBITS) * sizeof(fd_mask); 1005 if (*fdrp == NULL || sz > *nallocp) { 1006 free(*fdrp); 1007 free(*fdwp); 1008 *fdrp = xmalloc(sz); 1009 *fdwp = xmalloc(sz); 1010 *nallocp = sz; 1011 } 1012 if (n < *fdl) 1013 debug("XXX shrink: %d < %d", n, *fdl); 1014 *fdl = n; 1015 memset(*fdrp, 0, sz); 1016 memset(*fdwp, 0, sz); 1017 1018 for (i = 0; i < sockets_alloc; i++) { 1019 switch (sockets[i].type) { 1020 case AUTH_SOCKET: 1021 case AUTH_CONNECTION: 1022 FD_SET(sockets[i].fd, *fdrp); 1023 if (sshbuf_len(sockets[i].output) > 0) 1024 FD_SET(sockets[i].fd, *fdwp); 1025 break; 1026 default: 1027 break; 1028 } 1029 } 1030 deadline = reaper(); 1031 if (parent_alive_interval != 0) 1032 deadline = (deadline == 0) ? parent_alive_interval : 1033 MIN(deadline, parent_alive_interval); 1034 if (deadline == 0) { 1035 *tvpp = NULL; 1036 } else { 1037 tv.tv_sec = deadline; 1038 tv.tv_usec = 0; 1039 *tvpp = &tv; 1040 } 1041 return (1); 1042 } 1043 1044 static void 1045 after_select(fd_set *readset, fd_set *writeset) 1046 { 1047 struct sockaddr_un sunaddr; 1048 socklen_t slen; 1049 char buf[1024]; 1050 int len, sock, r; 1051 u_int i, orig_alloc; 1052 uid_t euid; 1053 gid_t egid; 1054 1055 for (i = 0, orig_alloc = sockets_alloc; i < orig_alloc; i++) 1056 switch (sockets[i].type) { 1057 case AUTH_UNUSED: 1058 break; 1059 case AUTH_SOCKET: 1060 if (FD_ISSET(sockets[i].fd, readset)) { 1061 slen = sizeof(sunaddr); 1062 sock = accept(sockets[i].fd, 1063 (struct sockaddr *)&sunaddr, &slen); 1064 if (sock < 0) { 1065 error("accept from AUTH_SOCKET: %s", 1066 strerror(errno)); 1067 break; 1068 } 1069 if (getpeereid(sock, &euid, &egid) < 0) { 1070 error("getpeereid %d failed: %s", 1071 sock, strerror(errno)); 1072 close(sock); 1073 break; 1074 } 1075 if ((euid != 0) && (getuid() != euid)) { 1076 error("uid mismatch: " 1077 "peer euid %u != uid %u", 1078 (u_int) euid, (u_int) getuid()); 1079 close(sock); 1080 break; 1081 } 1082 new_socket(AUTH_CONNECTION, sock); 1083 } 1084 break; 1085 case AUTH_CONNECTION: 1086 if (sshbuf_len(sockets[i].output) > 0 && 1087 FD_ISSET(sockets[i].fd, writeset)) { 1088 len = write(sockets[i].fd, 1089 sshbuf_ptr(sockets[i].output), 1090 sshbuf_len(sockets[i].output)); 1091 if (len == -1 && (errno == EAGAIN || 1092 errno == EWOULDBLOCK || 1093 errno == EINTR)) 1094 continue; 1095 if (len <= 0) { 1096 close_socket(&sockets[i]); 1097 break; 1098 } 1099 if ((r = sshbuf_consume(sockets[i].output, 1100 len)) != 0) 1101 fatal("%s: buffer error: %s", 1102 __func__, ssh_err(r)); 1103 } 1104 if (FD_ISSET(sockets[i].fd, readset)) { 1105 len = read(sockets[i].fd, buf, sizeof(buf)); 1106 if (len == -1 && (errno == EAGAIN || 1107 errno == EWOULDBLOCK || 1108 errno == EINTR)) 1109 continue; 1110 if (len <= 0) { 1111 close_socket(&sockets[i]); 1112 break; 1113 } 1114 if ((r = sshbuf_put(sockets[i].input, 1115 buf, len)) != 0) 1116 fatal("%s: buffer error: %s", 1117 __func__, ssh_err(r)); 1118 explicit_bzero(buf, sizeof(buf)); 1119 process_message(&sockets[i]); 1120 } 1121 break; 1122 default: 1123 fatal("Unknown type %d", sockets[i].type); 1124 } 1125 } 1126 1127 static void 1128 cleanup_socket(void) 1129 { 1130 if (cleanup_pid != 0 && getpid() != cleanup_pid) 1131 return; 1132 debug("%s: cleanup", __func__); 1133 if (socket_name[0]) 1134 unlink(socket_name); 1135 if (socket_dir[0]) 1136 rmdir(socket_dir); 1137 } 1138 1139 void 1140 cleanup_exit(int i) 1141 { 1142 cleanup_socket(); 1143 _exit(i); 1144 } 1145 1146 /*ARGSUSED*/ 1147 static void 1148 cleanup_handler(int sig) 1149 { 1150 cleanup_socket(); 1151 #ifdef ENABLE_PKCS11 1152 pkcs11_terminate(); 1153 #endif 1154 _exit(2); 1155 } 1156 1157 static void 1158 check_parent_exists(void) 1159 { 1160 /* 1161 * If our parent has exited then getppid() will return (pid_t)1, 1162 * so testing for that should be safe. 1163 */ 1164 if (parent_pid != -1 && getppid() != parent_pid) { 1165 /* printf("Parent has died - Authentication agent exiting.\n"); */ 1166 cleanup_socket(); 1167 _exit(2); 1168 } 1169 } 1170 1171 static void 1172 usage(void) 1173 { 1174 fprintf(stderr, 1175 "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n" 1176 " [-t life] [command [arg ...]]\n" 1177 " ssh-agent [-c | -s] -k\n"); 1178 exit(1); 1179 } 1180 1181 int 1182 main(int ac, char **av) 1183 { 1184 int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0; 1185 int sock, fd, ch, result, saved_errno; 1186 u_int nalloc; 1187 char *shell, *format, *pidstr, *agentsocket = NULL; 1188 fd_set *readsetp = NULL, *writesetp = NULL; 1189 #ifdef HAVE_SETRLIMIT 1190 struct rlimit rlim; 1191 #endif 1192 extern int optind; 1193 extern char *optarg; 1194 pid_t pid; 1195 char pidstrbuf[1 + 3 * sizeof pid]; 1196 struct timeval *tvp = NULL; 1197 size_t len; 1198 mode_t prev_mask; 1199 1200 ssh_malloc_init(); /* must be called before any mallocs */ 1201 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 1202 sanitise_stdfd(); 1203 1204 /* drop */ 1205 setegid(getgid()); 1206 setgid(getgid()); 1207 setuid(geteuid()); 1208 1209 platform_disable_tracing(0); /* strict=no */ 1210 1211 #ifdef WITH_OPENSSL 1212 OpenSSL_add_all_algorithms(); 1213 #endif 1214 1215 __progname = ssh_get_progname(av[0]); 1216 seed_rng(); 1217 1218 while ((ch = getopt(ac, av, "cDdksE:a:t:")) != -1) { 1219 switch (ch) { 1220 case 'E': 1221 fingerprint_hash = ssh_digest_alg_by_name(optarg); 1222 if (fingerprint_hash == -1) 1223 fatal("Invalid hash algorithm \"%s\"", optarg); 1224 break; 1225 case 'c': 1226 if (s_flag) 1227 usage(); 1228 c_flag++; 1229 break; 1230 case 'k': 1231 k_flag++; 1232 break; 1233 case 's': 1234 if (c_flag) 1235 usage(); 1236 s_flag++; 1237 break; 1238 case 'd': 1239 if (d_flag || D_flag) 1240 usage(); 1241 d_flag++; 1242 break; 1243 case 'D': 1244 if (d_flag || D_flag) 1245 usage(); 1246 D_flag++; 1247 break; 1248 case 'a': 1249 agentsocket = optarg; 1250 break; 1251 case 't': 1252 if ((lifetime = convtime(optarg)) == -1) { 1253 fprintf(stderr, "Invalid lifetime\n"); 1254 usage(); 1255 } 1256 break; 1257 default: 1258 usage(); 1259 } 1260 } 1261 ac -= optind; 1262 av += optind; 1263 1264 if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag)) 1265 usage(); 1266 1267 if (ac == 0 && !c_flag && !s_flag) { 1268 shell = getenv("SHELL"); 1269 if (shell != NULL && (len = strlen(shell)) > 2 && 1270 strncmp(shell + len - 3, "csh", 3) == 0) 1271 c_flag = 1; 1272 } 1273 if (k_flag) { 1274 const char *errstr = NULL; 1275 1276 pidstr = getenv(SSH_AGENTPID_ENV_NAME); 1277 if (pidstr == NULL) { 1278 fprintf(stderr, "%s not set, cannot kill agent\n", 1279 SSH_AGENTPID_ENV_NAME); 1280 exit(1); 1281 } 1282 pid = (int)strtonum(pidstr, 2, INT_MAX, &errstr); 1283 if (errstr) { 1284 fprintf(stderr, 1285 "%s=\"%s\", which is not a good PID: %s\n", 1286 SSH_AGENTPID_ENV_NAME, pidstr, errstr); 1287 exit(1); 1288 } 1289 if (kill(pid, SIGTERM) == -1) { 1290 perror("kill"); 1291 exit(1); 1292 } 1293 format = c_flag ? "unsetenv %s;\n" : "unset %s;\n"; 1294 printf(format, SSH_AUTHSOCKET_ENV_NAME); 1295 printf(format, SSH_AGENTPID_ENV_NAME); 1296 printf("echo Agent pid %ld killed;\n", (long)pid); 1297 exit(0); 1298 } 1299 parent_pid = getpid(); 1300 1301 if (agentsocket == NULL) { 1302 /* Create private directory for agent socket */ 1303 mktemp_proto(socket_dir, sizeof(socket_dir)); 1304 if (mkdtemp(socket_dir) == NULL) { 1305 perror("mkdtemp: private socket dir"); 1306 exit(1); 1307 } 1308 snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir, 1309 (long)parent_pid); 1310 } else { 1311 /* Try to use specified agent socket */ 1312 socket_dir[0] = '\0'; 1313 strlcpy(socket_name, agentsocket, sizeof socket_name); 1314 } 1315 1316 /* 1317 * Create socket early so it will exist before command gets run from 1318 * the parent. 1319 */ 1320 prev_mask = umask(0177); 1321 sock = unix_listener(socket_name, SSH_LISTEN_BACKLOG, 0); 1322 if (sock < 0) { 1323 /* XXX - unix_listener() calls error() not perror() */ 1324 *socket_name = '\0'; /* Don't unlink any existing file */ 1325 cleanup_exit(1); 1326 } 1327 umask(prev_mask); 1328 1329 /* 1330 * Fork, and have the parent execute the command, if any, or present 1331 * the socket data. The child continues as the authentication agent. 1332 */ 1333 if (D_flag || d_flag) { 1334 log_init(__progname, 1335 d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO, 1336 SYSLOG_FACILITY_AUTH, 1); 1337 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; 1338 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, 1339 SSH_AUTHSOCKET_ENV_NAME); 1340 printf("echo Agent pid %ld;\n", (long)parent_pid); 1341 fflush(stdout); 1342 goto skip; 1343 } 1344 pid = fork(); 1345 if (pid == -1) { 1346 perror("fork"); 1347 cleanup_exit(1); 1348 } 1349 if (pid != 0) { /* Parent - execute the given command. */ 1350 close(sock); 1351 snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid); 1352 if (ac == 0) { 1353 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n"; 1354 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name, 1355 SSH_AUTHSOCKET_ENV_NAME); 1356 printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf, 1357 SSH_AGENTPID_ENV_NAME); 1358 printf("echo Agent pid %ld;\n", (long)pid); 1359 exit(0); 1360 } 1361 if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 || 1362 setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) { 1363 perror("setenv"); 1364 exit(1); 1365 } 1366 execvp(av[0], av); 1367 perror(av[0]); 1368 exit(1); 1369 } 1370 /* child */ 1371 log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0); 1372 1373 if (setsid() == -1) { 1374 error("setsid: %s", strerror(errno)); 1375 cleanup_exit(1); 1376 } 1377 1378 (void)chdir("/"); 1379 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { 1380 /* XXX might close listen socket */ 1381 (void)dup2(fd, STDIN_FILENO); 1382 (void)dup2(fd, STDOUT_FILENO); 1383 (void)dup2(fd, STDERR_FILENO); 1384 if (fd > 2) 1385 close(fd); 1386 } 1387 1388 #ifdef HAVE_SETRLIMIT 1389 /* deny core dumps, since memory contains unencrypted private keys */ 1390 rlim.rlim_cur = rlim.rlim_max = 0; 1391 if (setrlimit(RLIMIT_CORE, &rlim) < 0) { 1392 error("setrlimit RLIMIT_CORE: %s", strerror(errno)); 1393 cleanup_exit(1); 1394 } 1395 #endif 1396 1397 skip: 1398 1399 cleanup_pid = getpid(); 1400 1401 #ifdef ENABLE_PKCS11 1402 pkcs11_init(0); 1403 #endif 1404 new_socket(AUTH_SOCKET, sock); 1405 if (ac > 0) 1406 parent_alive_interval = 10; 1407 idtab_init(); 1408 signal(SIGPIPE, SIG_IGN); 1409 signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN); 1410 signal(SIGHUP, cleanup_handler); 1411 signal(SIGTERM, cleanup_handler); 1412 nalloc = 0; 1413 1414 if (pledge("stdio cpath unix id proc exec", NULL) == -1) 1415 fatal("%s: pledge: %s", __progname, strerror(errno)); 1416 platform_pledge_agent(); 1417 1418 while (1) { 1419 prepare_select(&readsetp, &writesetp, &max_fd, &nalloc, &tvp); 1420 result = select(max_fd + 1, readsetp, writesetp, NULL, tvp); 1421 saved_errno = errno; 1422 if (parent_alive_interval != 0) 1423 check_parent_exists(); 1424 (void) reaper(); /* remove expired keys */ 1425 if (result < 0) { 1426 if (saved_errno == EINTR) 1427 continue; 1428 fatal("select: %s", strerror(saved_errno)); 1429 } else if (result > 0) 1430 after_select(readsetp, writesetp); 1431 } 1432 /* NOTREACHED */ 1433 } 1434