1 /* 2 * Copyright (c) 2000 Markus Friedl. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 */ 24 /* 25 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 26 * Use is subject to license terms. 27 */ 28 29 #include "includes.h" 30 RCSID("$OpenBSD: auth.c,v 1.45 2002/09/20 18:41:29 stevesk Exp $"); 31 32 #ifdef HAVE_LOGIN_H 33 #include <login.h> 34 #endif 35 #if defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW) 36 #include <shadow.h> 37 #endif /* defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW) */ 38 39 #ifdef HAVE_LIBGEN_H 40 #include <libgen.h> 41 #endif 42 43 #include "xmalloc.h" 44 #include "match.h" 45 #include "groupaccess.h" 46 #include "log.h" 47 #include "buffer.h" 48 #include "servconf.h" 49 #include "auth.h" 50 #include "auth-options.h" 51 #include "canohost.h" 52 #include "bufaux.h" 53 #include "uidswap.h" 54 #include "tildexpand.h" 55 #include "misc.h" 56 #include "bufaux.h" 57 #include "packet.h" 58 #include "channels.h" 59 #include "session.h" 60 61 #ifdef HAVE_BSM 62 #include "bsmaudit.h" 63 #include <bsm/adt.h> 64 #endif /* HAVE_BSM */ 65 66 /* import */ 67 extern ServerOptions options; 68 69 /* Debugging messages */ 70 Buffer auth_debug; 71 int auth_debug_init; 72 73 /* 74 * Check if the user is allowed to log in via ssh. If user is listed 75 * in DenyUsers or one of user's groups is listed in DenyGroups, false 76 * will be returned. If AllowUsers isn't empty and user isn't listed 77 * there, or if AllowGroups isn't empty and one of user's groups isn't 78 * listed there, false will be returned. 79 * If the user's shell is not executable, false will be returned. 80 * Otherwise true is returned. 81 */ 82 int 83 allowed_user(struct passwd * pw) 84 { 85 struct stat st; 86 const char *hostname = NULL, *ipaddr = NULL; 87 char *shell; 88 int i; 89 #ifdef WITH_AIXAUTHENTICATE 90 char *loginmsg; 91 #endif /* WITH_AIXAUTHENTICATE */ 92 #if !defined(USE_PAM) && defined(HAVE_SHADOW_H) && \ 93 !defined(DISABLE_SHADOW) && defined(HAS_SHADOW_EXPIRE) 94 struct spwd *spw; 95 96 /* Shouldn't be called if pw is NULL, but better safe than sorry... */ 97 if (!pw || !pw->pw_name) 98 return 0; 99 100 #define DAY (24L * 60 * 60) /* 1 day in seconds */ 101 spw = getspnam(pw->pw_name); 102 if (spw != NULL) { 103 time_t today = time(NULL) / DAY; 104 debug3("allowed_user: today %d sp_expire %d sp_lstchg %d" 105 " sp_max %d", (int)today, (int)spw->sp_expire, 106 (int)spw->sp_lstchg, (int)spw->sp_max); 107 108 /* 109 * We assume account and password expiration occurs the 110 * day after the day specified. 111 */ 112 if (spw->sp_expire != -1 && today > spw->sp_expire) { 113 log("Account %.100s has expired", pw->pw_name); 114 return 0; 115 } 116 117 if (spw->sp_lstchg == 0) { 118 log("User %.100s password has expired (root forced)", 119 pw->pw_name); 120 return 0; 121 } 122 123 if (spw->sp_max != -1 && 124 today > spw->sp_lstchg + spw->sp_max) { 125 log("User %.100s password has expired (password aged)", 126 pw->pw_name); 127 return 0; 128 } 129 } 130 #else 131 /* Shouldn't be called if pw is NULL, but better safe than sorry... */ 132 if (!pw || !pw->pw_name) 133 return 0; 134 #endif 135 136 /* 137 * Get the shell from the password data. An empty shell field is 138 * legal, and means /bin/sh. 139 */ 140 shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; 141 142 /* deny if shell does not exists or is not executable */ 143 if (stat(shell, &st) != 0) { 144 log("User %.100s not allowed because shell %.100s does not exist", 145 pw->pw_name, shell); 146 return 0; 147 } 148 if (S_ISREG(st.st_mode) == 0 || 149 (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) { 150 log("User %.100s not allowed because shell %.100s is not executable", 151 pw->pw_name, shell); 152 return 0; 153 } 154 155 if (options.num_deny_users > 0 || options.num_allow_users > 0) { 156 hostname = get_canonical_hostname(options.verify_reverse_mapping); 157 ipaddr = get_remote_ipaddr(); 158 } 159 160 /* Return false if user is listed in DenyUsers */ 161 if (options.num_deny_users > 0) { 162 for (i = 0; i < options.num_deny_users; i++) 163 if (match_user(pw->pw_name, hostname, ipaddr, 164 options.deny_users[i])) { 165 log("User %.100s not allowed because listed in DenyUsers", 166 pw->pw_name); 167 return 0; 168 } 169 } 170 /* Return false if AllowUsers isn't empty and user isn't listed there */ 171 if (options.num_allow_users > 0) { 172 for (i = 0; i < options.num_allow_users; i++) 173 if (match_user(pw->pw_name, hostname, ipaddr, 174 options.allow_users[i])) 175 break; 176 /* i < options.num_allow_users iff we break for loop */ 177 if (i >= options.num_allow_users) { 178 log("User %.100s not allowed because not listed in AllowUsers", 179 pw->pw_name); 180 return 0; 181 } 182 } 183 if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { 184 /* Get the user's group access list (primary and supplementary) */ 185 if (ga_init(pw->pw_name, pw->pw_gid) == 0) { 186 log("User %.100s not allowed because not in any group", 187 pw->pw_name); 188 return 0; 189 } 190 191 /* Return false if one of user's groups is listed in DenyGroups */ 192 if (options.num_deny_groups > 0) 193 if (ga_match(options.deny_groups, 194 options.num_deny_groups)) { 195 ga_free(); 196 log("User %.100s not allowed because a group is listed in DenyGroups", 197 pw->pw_name); 198 return 0; 199 } 200 /* 201 * Return false if AllowGroups isn't empty and one of user's groups 202 * isn't listed there 203 */ 204 if (options.num_allow_groups > 0) 205 if (!ga_match(options.allow_groups, 206 options.num_allow_groups)) { 207 ga_free(); 208 log("User %.100s not allowed because none of user's groups are listed in AllowGroups", 209 pw->pw_name); 210 return 0; 211 } 212 ga_free(); 213 } 214 215 #ifdef WITH_AIXAUTHENTICATE 216 if (loginrestrictions(pw->pw_name, S_RLOGIN, NULL, &loginmsg) != 0) { 217 if (loginmsg && *loginmsg) { 218 /* Remove embedded newlines (if any) */ 219 char *p; 220 for (p = loginmsg; *p; p++) { 221 if (*p == '\n') 222 *p = ' '; 223 } 224 /* Remove trailing newline */ 225 *--p = '\0'; 226 log("Login restricted for %s: %.100s", pw->pw_name, loginmsg); 227 } 228 return 0; 229 } 230 #endif /* WITH_AIXAUTHENTICATE */ 231 232 /* We found no reason not to let this user try to log on... */ 233 return 1; 234 } 235 236 Authctxt * 237 authctxt_new(void) 238 { 239 Authctxt *authctxt = xmalloc(sizeof(*authctxt)); 240 memset(authctxt, 0, sizeof(*authctxt)); 241 return authctxt; 242 } 243 244 void 245 auth_log(Authctxt *authctxt, int authenticated, char *method, char *info) 246 { 247 void (*authlog) (const char *fmt,...) = verbose; 248 char *authmsg, *user_str; 249 250 if (authctxt == NULL) 251 fatal("%s: INTERNAL ERROR", __func__); 252 253 /* Raise logging level */ 254 if (authenticated == 1 || !authctxt->valid) 255 authlog = log; 256 else if (authctxt->failures >= AUTH_FAIL_LOG || 257 authctxt->attempt >= options.max_auth_tries_log || 258 authctxt->init_attempt >= options.max_init_auth_tries_log) 259 authlog = notice; 260 261 if (authctxt->method) { 262 authmsg = "Failed"; 263 if (authctxt->method->postponed) 264 authmsg = "Postponed"; /* shouldn't happen */ 265 if (authctxt->method->abandoned) 266 authmsg = "Abandoned"; 267 if (authctxt->method->authenticated) { 268 if (userauth_check_partial_failure(authctxt)) 269 authmsg = "Partially accepted"; 270 else 271 authmsg = "Accepted"; 272 } 273 else 274 authmsg = "Failed"; 275 } 276 else { 277 authmsg = authenticated ? "Accepted" : "Failed"; 278 } 279 280 if (authctxt->user == NULL || *authctxt->user == '\0') 281 user_str = "<implicit>"; 282 else if (!authctxt->valid) 283 user_str = "<invalid username>"; 284 else 285 user_str = authctxt->user; 286 287 authlog("%s %s for %s from %.200s port %d%s", 288 authmsg, 289 (method != NULL) ? method : "<unknown authentication method>", 290 user_str, 291 get_remote_ipaddr(), 292 get_remote_port(), 293 info); 294 295 #ifdef WITH_AIXAUTHENTICATE 296 if (authenticated == 0 && strcmp(method, "password") == 0) 297 loginfailed(authctxt->user, 298 get_canonical_hostname(options.verify_reverse_mapping), 299 "ssh"); 300 #endif /* WITH_AIXAUTHENTICATE */ 301 302 } 303 304 #ifdef HAVE_BSM 305 void 306 audit_failed_login_cleanup(void *ctxt) 307 { 308 Authctxt *authctxt = (Authctxt *)ctxt; 309 adt_session_data_t *ah; 310 311 /* 312 * This table lists the different variable combinations evaluated and 313 * what the resulting PAM return value is. As the table shows 314 * authctxt and authctxt->valid need to be checked before either of 315 * the authctxt->pam* variables. 316 * 317 * authctxt-> authctxt-> 318 * authctxt valid authctxt->pam pam_retval PAM rval 319 * -------- ---------- ------------- ------------ -------- 320 * NULL ANY ANY ANY PAM_ABORT 321 * OK zero (0) ANY ANY PAM_USER_UNKNOWN 322 * OK one (1) NULL PAM_SUCCESS PAM_PERM_DENIED 323 * OK one (1) NULL !PAM_SUCCESS authctxt-> 324 * pam_retval 325 * OK one (1) VALID ANY authctxt-> 326 * pam_retval (+) 327 * (+) If not set then default to PAM_PERM_DENIED 328 */ 329 330 if (authctxt == NULL) { 331 /* Internal error */ 332 audit_sshd_login_failure(&ah, PAM_ABORT, NULL); 333 return; 334 } 335 336 if (authctxt->valid == 0) { 337 audit_sshd_login_failure(&ah, PAM_USER_UNKNOWN, NULL); 338 } else if (authctxt->pam == NULL) { 339 if (authctxt->pam_retval == PAM_SUCCESS) { 340 audit_sshd_login_failure(&ah, PAM_PERM_DENIED, 341 authctxt->user); 342 } else { 343 audit_sshd_login_failure(&ah, authctxt->pam_retval, 344 authctxt->user); 345 } 346 } else { 347 audit_sshd_login_failure(&ah, AUTHPAM_ERROR(authctxt, 348 PAM_PERM_DENIED), authctxt->user); 349 } 350 } 351 #endif /* HAVE_BSM */ 352 353 /* 354 * Check whether root logins are disallowed. 355 */ 356 int 357 auth_root_allowed(char *method) 358 { 359 switch (options.permit_root_login) { 360 case PERMIT_YES: 361 return 1; 362 break; 363 case PERMIT_NO_PASSWD: 364 if (strcmp(method, "password") != 0 && 365 strcmp(method, "keyboard-interactive") != 0) 366 return 1; 367 break; 368 case PERMIT_FORCED_ONLY: 369 if (forced_command) { 370 log("Root login accepted for forced command."); 371 return 1; 372 } 373 break; 374 } 375 log("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr()); 376 return 0; 377 } 378 379 380 /* 381 * Given a template and a passwd structure, build a filename 382 * by substituting % tokenised options. Currently, %% becomes '%', 383 * %h becomes the home directory and %u the username. 384 * 385 * This returns a buffer allocated by xmalloc. 386 */ 387 char * 388 expand_filename(const char *filename, struct passwd *pw) 389 { 390 Buffer buffer; 391 char *file; 392 const char *cp; 393 394 if (pw == 0) 395 return NULL; /* shouldn't happen */ 396 /* 397 * Build the filename string in the buffer by making the appropriate 398 * substitutions to the given file name. 399 */ 400 buffer_init(&buffer); 401 for (cp = filename; *cp; cp++) { 402 if (cp[0] == '%' && cp[1] == '%') { 403 buffer_append(&buffer, "%", 1); 404 cp++; 405 continue; 406 } 407 if (cp[0] == '%' && cp[1] == 'h') { 408 buffer_append(&buffer, pw->pw_dir, strlen(pw->pw_dir)); 409 cp++; 410 continue; 411 } 412 if (cp[0] == '%' && cp[1] == 'u') { 413 buffer_append(&buffer, pw->pw_name, 414 strlen(pw->pw_name)); 415 cp++; 416 continue; 417 } 418 buffer_append(&buffer, cp, 1); 419 } 420 buffer_append(&buffer, "\0", 1); 421 422 /* 423 * Ensure that filename starts anchored. If not, be backward 424 * compatible and prepend the '%h/' 425 */ 426 file = xmalloc(MAXPATHLEN); 427 cp = buffer_ptr(&buffer); 428 if (*cp != '/') 429 snprintf(file, MAXPATHLEN, "%s/%s", pw->pw_dir, cp); 430 else 431 strlcpy(file, cp, MAXPATHLEN); 432 433 buffer_free(&buffer); 434 return file; 435 } 436 437 char * 438 authorized_keys_file(struct passwd *pw) 439 { 440 return expand_filename(options.authorized_keys_file, pw); 441 } 442 443 char * 444 authorized_keys_file2(struct passwd *pw) 445 { 446 return expand_filename(options.authorized_keys_file2, pw); 447 } 448 449 /* return ok if key exists in sysfile or userfile */ 450 HostStatus 451 check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host, 452 const char *sysfile, const char *userfile) 453 { 454 Key *found; 455 char *user_hostfile; 456 struct stat st; 457 HostStatus host_status; 458 459 /* Check if we know the host and its host key. */ 460 found = key_new(key->type); 461 host_status = check_host_in_hostfile(sysfile, host, key, found, NULL); 462 463 if (host_status != HOST_OK && userfile != NULL) { 464 user_hostfile = tilde_expand_filename(userfile, pw->pw_uid); 465 if (options.strict_modes && 466 (stat(user_hostfile, &st) == 0) && 467 ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || 468 (st.st_mode & 022) != 0)) { 469 log("Authentication refused for %.100s: " 470 "bad owner or modes for %.200s", 471 pw->pw_name, user_hostfile); 472 } else { 473 temporarily_use_uid(pw); 474 host_status = check_host_in_hostfile(user_hostfile, 475 host, key, found, NULL); 476 restore_uid(); 477 } 478 xfree(user_hostfile); 479 } 480 key_free(found); 481 482 debug2("check_key_in_hostfiles: key %s for %s", host_status == HOST_OK ? 483 "ok" : "not found", host); 484 return host_status; 485 } 486 487 488 /* 489 * Check a given file for security. This is defined as all components 490 * of the path to the file must be owned by either the owner of 491 * of the file or root and no directories must be group or world writable. 492 * 493 * XXX Should any specific check be done for sym links ? 494 * 495 * Takes an open file descriptor, the file name, a uid and and 496 * error buffer plus max size as arguments. 497 * 498 * Returns 0 on success and -1 on failure 499 */ 500 int 501 secure_filename(FILE *f, const char *file, struct passwd *pw, 502 char *err, size_t errlen) 503 { 504 uid_t uid; 505 char buf[MAXPATHLEN], homedir[MAXPATHLEN]; 506 char *cp; 507 int comparehome = 0; 508 struct stat st; 509 510 if (pw == NULL) 511 return 0; 512 513 uid = pw->pw_uid; 514 515 if (realpath(file, buf) == NULL) { 516 snprintf(err, errlen, "realpath %s failed: %s", file, 517 strerror(errno)); 518 return -1; 519 } 520 521 /* 522 * A user is not required to have all the files that are subject to 523 * the strict mode checking in his/her home directory. If the 524 * directory is not present at the moment, which might be the case if 525 * the directory is not mounted until the user is authenticated, do 526 * not perform the home directory check below. 527 */ 528 if (realpath(pw->pw_dir, homedir) != NULL) 529 comparehome = 1; 530 531 /* check the open file to avoid races */ 532 if (fstat(fileno(f), &st) < 0 || 533 (st.st_uid != 0 && st.st_uid != uid) || 534 (st.st_mode & 022) != 0) { 535 snprintf(err, errlen, "bad ownership or modes for file %s", 536 buf); 537 return -1; 538 } 539 540 /* for each component of the canonical path, walking upwards */ 541 for (;;) { 542 if ((cp = dirname(buf)) == NULL) { 543 snprintf(err, errlen, "dirname() failed"); 544 return -1; 545 } 546 strlcpy(buf, cp, sizeof(buf)); 547 548 debug3("secure_filename: checking '%s'", buf); 549 if (stat(buf, &st) < 0 || 550 (st.st_uid != 0 && st.st_uid != uid) || 551 (st.st_mode & 022) != 0) { 552 snprintf(err, errlen, 553 "bad ownership or modes for directory %s", buf); 554 return -1; 555 } 556 557 /* If we passed the homedir then we can stop. */ 558 if (comparehome && strcmp(homedir, buf) == 0) { 559 debug3("secure_filename: terminating check at '%s'", 560 buf); 561 break; 562 } 563 /* 564 * dirname should always complete with a "/" path, 565 * but we can be paranoid and check for "." too 566 */ 567 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 568 break; 569 } 570 return 0; 571 } 572 573 struct passwd * 574 getpwnamallow(const char *user) 575 { 576 #ifdef HAVE_LOGIN_CAP 577 extern login_cap_t *lc; 578 #ifdef BSD_AUTH 579 auth_session_t *as; 580 #endif 581 #endif 582 struct passwd *pw; 583 584 if (user == NULL || *user == '\0') 585 return (NULL); /* implicit user, will be set later */ 586 587 parse_server_match_config(&options, user, 588 get_canonical_hostname(options.verify_reverse_mapping), get_remote_ipaddr()); 589 590 pw = getpwnam(user); 591 if (pw == NULL) { 592 log("Illegal user %.100s from %.100s", 593 user, get_remote_ipaddr()); 594 return (NULL); 595 } 596 if (!allowed_user(pw)) 597 return (NULL); 598 #ifdef HAVE_LOGIN_CAP 599 if ((lc = login_getclass(pw->pw_class)) == NULL) { 600 debug("unable to get login class: %s", user); 601 return (NULL); 602 } 603 #ifdef BSD_AUTH 604 if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 || 605 auth_approval(as, lc, pw->pw_name, "ssh") <= 0) { 606 debug("Approval failure for %s", user); 607 pw = NULL; 608 } 609 if (as != NULL) 610 auth_close(as); 611 #endif 612 #endif 613 if (pw != NULL) 614 return (pwcopy(pw)); 615 return (NULL); 616 } 617 618 619 /* 620 * The fatal_cleanup method to kill the hook. Since hook has been put into 621 * new process group all descendants will be killed as well. 622 */ 623 static void 624 kill_hook(void *arg) 625 { 626 pid_t pid; 627 628 pid = *(pid_t*)arg; 629 debug("killing hook and all it's children, process group: %ld", pid); 630 xfree(arg); 631 (void)killpg(pid, SIGTERM); 632 } 633 634 /* 635 * Runs the PreUserauthHook. 636 * Returns -1 on execution error or the exit code of the hook if execution is 637 * successful. 638 */ 639 int 640 run_auth_hook(const char *path, const char *user, const char *method) 641 { 642 struct stat st; 643 int i, status, ret = 1; 644 u_int envsize, argsize; 645 char buf[256]; 646 char **env, **args; 647 pid_t pid, *ppid; 648 649 if (path == NULL || user == NULL || method == NULL) { 650 return (-1); 651 } 652 653 /* Initialize the environment/arguments for the hook. */ 654 envsize = 4; /* 3 env vars + EndOfList marker */ 655 argsize = 4; /* 2 args + exe name + EndOfList marker */ 656 env = xmalloc(envsize * sizeof (char *)); 657 args = xmalloc(argsize * sizeof (char *)); 658 env[0] = NULL; 659 660 /* we use the SSH env handling scheme */ 661 child_set_env_silent(&env, &envsize, "PATH", "/usr/bin:/bin"); 662 child_set_env_silent(&env, &envsize, "IFS", " \t\n"); 663 664 (void) snprintf(buf, sizeof (buf), "%.50s %d %.50s %d", 665 get_remote_ipaddr(), get_remote_port(), 666 get_local_ipaddr(packet_get_connection_in()), get_local_port()); 667 child_set_env_silent(&env, &envsize, "SSH_CONNECTION", buf); 668 669 args[0] = xstrdup(path); 670 args[1] = xstrdup(method); 671 args[2] = xstrdup(user); 672 args[3] = NULL; 673 674 /* 675 * sanity checks 676 * note: the checks do not make sure that the file checked is actually 677 * the same which is executed. However, in this case it shouldn't be a 678 * major issue since the hook is rather static and the worst case would 679 * be an uncorrect message in the log or a hook is run even though the 680 * permissions are not right. 681 */ 682 683 /* check if script does exist */ 684 if (stat(path, &st) < 0) { 685 log("Error executing PreUserauthHook \"%s\": %s", path, 686 strerror(errno)); 687 goto cleanup; 688 } 689 690 /* Check correct permissions for script (uid of SSHD, mode 500) */ 691 if (st.st_uid != getuid() || ((st.st_mode & 0777) != 0500)) { 692 log("PreUserauthHook has invalid permissions (should be 500, is" 693 " %o) or ownership (should be %d, is %d)", 694 (uint) st.st_mode & 0777, getuid(), st.st_uid); 695 goto cleanup; 696 } 697 698 if ((pid = fork()) == 0) { 699 /* 700 * We put the hook and all its (possible) descendants into 701 * a new process group so that in case of a hanging hook 702 * we can wipe out the whole "family". 703 */ 704 if (setpgid(0, 0) != 0) { 705 log("setpgid: %s", strerror(errno)); 706 _exit(255); 707 } 708 (void) execve(path, args, env); 709 /* child is gone so we shouldn't get here */ 710 log("Error executing PreUserauthHook \"%s\": %s", path, 711 strerror(errno)); 712 _exit(255); 713 } else if (pid == -1) { 714 log("Error executing PreUserauthHook \"%s\": %s", path, 715 strerror(errno)); 716 goto cleanup; 717 } 718 719 /* make preparations to kill hook if it is hanging */ 720 ppid = xmalloc(sizeof (pid_t)); 721 *ppid = pid; 722 fatal_add_cleanup((void (*)(void *))kill_hook, (void *) ppid); 723 724 if (waitpid(pid, &status, 0) == -1) { 725 log("Error executing PreUserauthHook \"%s\": %s", path, 726 strerror(errno)); 727 goto cleanup; 728 } 729 730 ret = WEXITSTATUS(status); 731 732 if (ret == 255) { 733 ret = -1; /* execve() failed, error msg already logged */ 734 } else if (ret != 0) { 735 log("PreUserauthHook \"%s\" failed with exit code %d", 736 path, ret); 737 } else { 738 debug("PreUserauthHook \"%s\" finished successfully", path); 739 } 740 741 cleanup: 742 for (i = 0; args[i] != NULL; i++) { 743 xfree(args[i]); 744 } 745 for (i = 0; env[i] != NULL; i++) { 746 xfree(env[i]); 747 } 748 xfree(args); 749 xfree(env); 750 751 fatal_remove_cleanup((void (*)(void *))kill_hook, (void *) ppid); 752 753 return (ret); 754 } 755 756 void 757 auth_debug_add(const char *fmt,...) 758 { 759 char buf[1024]; 760 va_list args; 761 762 if (!auth_debug_init) 763 return; 764 765 va_start(args, fmt); 766 vsnprintf(buf, sizeof(buf), fmt, args); 767 va_end(args); 768 buffer_put_cstring(&auth_debug, buf); 769 } 770 771 void 772 auth_debug_send(void) 773 { 774 char *msg; 775 776 if (!auth_debug_init) 777 return; 778 while (buffer_len(&auth_debug)) { 779 msg = buffer_get_string(&auth_debug, NULL); 780 packet_send_debug("%s", msg); 781 xfree(msg); 782 } 783 } 784 785 void 786 auth_debug_reset(void) 787 { 788 if (auth_debug_init) 789 buffer_clear(&auth_debug); 790 else { 791 buffer_init(&auth_debug); 792 auth_debug_init = 1; 793 } 794 } 795