1 /*- 2 * Copyright 2001 Mark R V Murray 3 * Copyright Frank Cusack fcusack@fcusack.com 1999-2000 4 * All rights reserved 5 * Copyright (c) 2002 Networks Associates Technology, Inc. 6 * All rights reserved. 7 * 8 * Portions of this software were developed for the FreeBSD Project by 9 * ThinkSec AS and NAI Labs, the Security Research Division of Network 10 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 11 * ("CBOSS"), as part of the DARPA CHATS research program. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, and the entire permission notice in its entirety, 18 * including the disclaimer of warranties. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. The name of the author may not be used to endorse or promote 23 * products derived from this software without specific prior 24 * written permission. 25 * 26 * ALTERNATIVELY, this product may be distributed under the terms of 27 * the GNU Public License, in which case the provisions of the GPL are 28 * required INSTEAD OF the above restrictions. (This clause is 29 * necessary due to a potential bad interaction between the GPL and 30 * the restrictions contained in a BSD-style copyright.) 31 * 32 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 33 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 34 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 35 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 36 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 37 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 38 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 41 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 42 * OF THE POSSIBILITY OF SUCH DAMAGE. 43 * --------------------------------------------------------------------------- 44 * 45 * This software may contain code from Naomaru Itoi: 46 * 47 * PAM-kerberos5 module Copyright notice. 48 * Naomaru Itoi <itoi@eecs.umich.edu>, June 24, 1997. 49 * 50 * ---------------------------------------------------------------------------- 51 * COPYRIGHT (c) 1997 52 * THE REGENTS OF THE UNIVERSITY OF MICHIGAN 53 * ALL RIGHTS RESERVED 54 * 55 * PERMISSION IS GRANTED TO USE, COPY, CREATE DERIVATIVE WORKS AND REDISTRIBUTE 56 * THIS SOFTWARE AND SUCH DERIVATIVE WORKS FOR ANY PURPOSE, SO LONG AS THE NAME 57 * OF THE UNIVERSITY OF MICHIGAN IS NOT USED IN ANY ADVERTISING OR PUBLICITY 58 * PERTAINING TO THE USE OR DISTRIBUTION OF THIS SOFTWARE WITHOUT SPECIFIC, 59 * WRITTEN PRIOR AUTHORIZATION. IF THE ABOVE COPYRIGHT NOTICE OR ANY OTHER 60 * IDENTIFICATION OF THE UNIVERSITY OF MICHIGAN IS INCLUDED IN ANY COPY OF ANY 61 * PORTION OF THIS SOFTWARE, THEN THE DISCLAIMER BELOW MUST ALSO BE INCLUDED. 62 * 63 * THE SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION FROM THE UNIVERSITY OF 64 * MICHIGAN AS TO ITS FITNESS FOR ANY PURPOSE, AND WITHOUT WARRANTY BY THE 65 * UNIVERSITY OF MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING 66 * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF MERCHANTABITILY AND FITNESS FOR A 67 * PARTICULAR PURPOSE. THE REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE 68 * LIABLE FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR 69 * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING OUT OF OR IN 70 * CONNECTION WITH THE USE OF THE SOFTWARE, EVEN IF IT HAS BEEN OR IS HEREAFTER 71 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. 72 * 73 * PAM-kerberos5 module is written based on PAM-kerberos4 module 74 * by Derrick J. Brashear and kerberos5-1.0pl1 by M.I.T. kerberos team. 75 * Permission to use, copy, modify, distribute this software is hereby 76 * granted, as long as it is granted by Derrick J. Brashear and 77 * M.I.T. kerberos team. Followings are their copyright information. 78 * ---------------------------------------------------------------------------- 79 * 80 * This software may contain code from Derrick J. Brashear: 81 * 82 * 83 * Copyright (c) Derrick J. Brashear, 1996. All rights reserved 84 * 85 * Redistribution and use in source and binary forms, with or without 86 * modification, are permitted provided that the following conditions 87 * are met: 88 * 1. Redistributions of source code must retain the above copyright 89 * notice, and the entire permission notice in its entirety, 90 * including the disclaimer of warranties. 91 * 2. Redistributions in binary form must reproduce the above copyright 92 * notice, this list of conditions and the following disclaimer in the 93 * documentation and/or other materials provided with the distribution. 94 * 3. The name of the author may not be used to endorse or promote 95 * products derived from this software without specific prior 96 * written permission. 97 * 98 * ALTERNATIVELY, this product may be distributed under the terms of 99 * the GNU Public License, in which case the provisions of the GPL are 100 * required INSTEAD OF the above restrictions. (This clause is 101 * necessary due to a potential bad interaction between the GPL and 102 * the restrictions contained in a BSD-style copyright.) 103 * 104 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 105 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 106 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 107 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 108 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 109 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 110 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 111 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 112 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 113 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 114 * OF THE POSSIBILITY OF SUCH DAMAGE. 115 * 116 * ---------------------------------------------------------------------------- 117 * 118 * This software may contain code from MIT Kerberos 5: 119 * 120 * Copyright Notice and Legal Administrivia 121 * ---------------------------------------- 122 * 123 * Copyright (C) 1996 by the Massachusetts Institute of Technology. 124 * 125 * All rights reserved. 126 * 127 * Export of this software from the United States of America may require 128 * a specific license from the United States Government. It is the 129 * responsibility of any person or organization contemplating export to 130 * obtain such a license before exporting. 131 * 132 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and 133 * distribute this software and its documentation for any purpose and 134 * without fee is hereby granted, provided that the above copyright 135 * notice appear in all copies and that both that copyright notice and 136 * this permission notice appear in supporting documentation, and that 137 * the name of M.I.T. not be used in advertising or publicity pertaining 138 * to distribution of the software without specific, written prior 139 * permission. M.I.T. makes no representations about the suitability of 140 * this software for any purpose. It is provided "as is" without express 141 * or implied warranty. 142 * 143 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 144 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 145 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 146 * 147 * Individual source code files are copyright MIT, Cygnus Support, 148 * OpenVision, Oracle, Sun Soft, and others. 149 * 150 * Project Athena, Athena, Athena MUSE, Discuss, Hesiod, Kerberos, Moira, 151 * and Zephyr are trademarks of the Massachusetts Institute of Technology 152 * (MIT). No commercial use of these trademarks may be made without 153 * prior written permission of MIT. 154 * 155 * "Commercial use" means use of a name in a product or other for-profit 156 * manner. It does NOT prevent a commercial firm from referring to the 157 * MIT trademarks in order to convey information (although in doing so, 158 * recognition of their trademark status should be given). 159 * 160 * The following copyright and permission notice applies to the 161 * OpenVision Kerberos Administration system located in kadmin/create, 162 * kadmin/dbutil, kadmin/passwd, kadmin/server, lib/kadm5, and portions 163 * of lib/rpc: 164 * 165 * Copyright, OpenVision Technologies, Inc., 1996, All Rights Reserved 166 * 167 * WARNING: Retrieving the OpenVision Kerberos Administration system 168 * source code, as described below, indicates your acceptance of the 169 * following terms. If you do not agree to the following terms, do not 170 * retrieve the OpenVision Kerberos administration system. 171 * 172 * You may freely use and distribute the Source Code and Object Code 173 * compiled from it, with or without modification, but this Source 174 * Code is provided to you "AS IS" EXCLUSIVE OF ANY WARRANTY, 175 * INCLUDING, WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY OR 176 * FITNESS FOR A PARTICULAR PURPOSE, OR ANY OTHER WARRANTY, WHETHER 177 * EXPRESS OR IMPLIED. IN NO EVENT WILL OPENVISION HAVE ANY LIABILITY 178 * FOR ANY LOST PROFITS, LOSS OF DATA OR COSTS OF PROCUREMENT OF 179 * SUBSTITUTE GOODS OR SERVICES, OR FOR ANY SPECIAL, INDIRECT, OR 180 * CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, INCLUDING, 181 * WITHOUT LIMITATION, THOSE RESULTING FROM THE USE OF THE SOURCE 182 * CODE, OR THE FAILURE OF THE SOURCE CODE TO PERFORM, OR FOR ANY 183 * OTHER REASON. 184 * 185 * OpenVision retains all copyrights in the donated Source Code. OpenVision 186 * also retains copyright to derivative works of the Source Code, whether 187 * created by OpenVision or by a third party. The OpenVision copyright 188 * notice must be preserved if derivative works are made based on the 189 * donated Source Code. 190 * 191 * OpenVision Technologies, Inc. has donated this Kerberos 192 * Administration system to MIT for inclusion in the standard 193 * Kerberos 5 distribution. This donation underscores our 194 * commitment to continuing Kerberos technology development 195 * and our gratitude for the valuable work which has been 196 * performed by MIT and the Kerberos community. 197 * 198 */ 199 200 #include <sys/cdefs.h> 201 __FBSDID("$FreeBSD$"); 202 203 #include <sys/types.h> 204 #include <sys/stat.h> 205 #include <errno.h> 206 #include <limits.h> 207 #include <pwd.h> 208 #include <stdio.h> 209 #include <stdlib.h> 210 #include <string.h> 211 #include <syslog.h> 212 #include <unistd.h> 213 214 #include <krb5.h> 215 #include <com_err.h> 216 217 #define PAM_SM_AUTH 218 #define PAM_SM_ACCOUNT 219 #define PAM_SM_PASSWORD 220 221 #include <security/pam_appl.h> 222 #include <security/pam_modules.h> 223 #include <security/pam_mod_misc.h> 224 225 #define COMPAT_HEIMDAL 226 /* #define COMPAT_MIT */ 227 228 extern krb5_cc_ops krb5_mcc_ops; 229 230 static int verify_krb_v5_tgt(krb5_context, krb5_ccache, char *, int); 231 static void cleanup_cache(pam_handle_t *, void *, int); 232 static const char *compat_princ_component(krb5_context, krb5_principal, int); 233 static void compat_free_data_contents(krb5_context, krb5_data *); 234 235 #define USER_PROMPT "Username: " 236 #define PASSWORD_PROMPT "Password:" 237 #define NEW_PASSWORD_PROMPT "New Password:" 238 239 enum { 240 PAM_OPT_AUTH_AS_SELF = PAM_OPT_STD_MAX, 241 PAM_OPT_CCACHE, 242 PAM_OPT_FORWARDABLE, 243 PAM_OPT_NO_CCACHE, 244 PAM_OPT_REUSE_CCACHE 245 }; 246 247 static struct opttab other_options[] = { 248 { "auth_as_self", PAM_OPT_AUTH_AS_SELF }, 249 { "ccache", PAM_OPT_CCACHE }, 250 { "forwardable", PAM_OPT_FORWARDABLE }, 251 { "no_ccache", PAM_OPT_NO_CCACHE }, 252 { "reuse_ccache", PAM_OPT_REUSE_CCACHE }, 253 { NULL, 0 } 254 }; 255 256 /* 257 * authentication management 258 */ 259 PAM_EXTERN int 260 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 261 int argc, const char *argv[]) 262 { 263 krb5_error_code krbret; 264 krb5_context pam_context; 265 krb5_creds creds; 266 krb5_principal princ; 267 krb5_ccache ccache, ccache_check; 268 krb5_get_init_creds_opt opts; 269 struct options options; 270 struct passwd *pwd; 271 int retval; 272 const char *sourceuser, *user, *pass, *service; 273 char *principal, *princ_name, *cache_name, luser[32], *srvdup; 274 275 pam_std_option(&options, other_options, argc, argv); 276 277 PAM_LOG("Options processed"); 278 279 retval = pam_get_user(pamh, &user, USER_PROMPT); 280 if (retval != PAM_SUCCESS) 281 return (retval); 282 283 PAM_LOG("Got user: %s", user); 284 285 retval = pam_get_item(pamh, PAM_RUSER, (const void **)&sourceuser); 286 if (retval != PAM_SUCCESS) 287 return (retval); 288 289 PAM_LOG("Got ruser: %s", sourceuser); 290 291 service = NULL; 292 pam_get_item(pamh, PAM_SERVICE, (const void **)&service); 293 if (service == NULL) 294 service = "unknown"; 295 296 PAM_LOG("Got service: %s", service); 297 298 krbret = krb5_init_context(&pam_context); 299 if (krbret != 0) { 300 PAM_VERBOSE_ERROR("Kerberos 5 error"); 301 return (PAM_SERVICE_ERR); 302 } 303 304 PAM_LOG("Context initialised"); 305 306 krb5_get_init_creds_opt_init(&opts); 307 308 if (pam_test_option(&options, PAM_OPT_FORWARDABLE, NULL)) 309 krb5_get_init_creds_opt_set_forwardable(&opts, 1); 310 311 PAM_LOG("Credentials initialised"); 312 313 krbret = krb5_cc_register(pam_context, &krb5_mcc_ops, FALSE); 314 if (krbret != 0 && krbret != KRB5_CC_TYPE_EXISTS) { 315 PAM_VERBOSE_ERROR("Kerberos 5 error"); 316 retval = PAM_SERVICE_ERR; 317 goto cleanup3; 318 } 319 320 PAM_LOG("Done krb5_cc_register()"); 321 322 /* Get principal name */ 323 if (pam_test_option(&options, PAM_OPT_AUTH_AS_SELF, NULL)) 324 asprintf(&principal, "%s/%s", sourceuser, user); 325 else 326 principal = strdup(user); 327 328 PAM_LOG("Created principal: %s", principal); 329 330 krbret = krb5_parse_name(pam_context, principal, &princ); 331 free(principal); 332 if (krbret != 0) { 333 PAM_LOG("Error krb5_parse_name(): %s", error_message(krbret)); 334 PAM_VERBOSE_ERROR("Kerberos 5 error"); 335 retval = PAM_SERVICE_ERR; 336 goto cleanup3; 337 } 338 339 PAM_LOG("Done krb5_parse_name()"); 340 341 /* Now convert the principal name into something human readable */ 342 princ_name = NULL; 343 krbret = krb5_unparse_name(pam_context, princ, &princ_name); 344 if (krbret != 0) { 345 PAM_LOG("Error krb5_unparse_name(): %s", error_message(krbret)); 346 PAM_VERBOSE_ERROR("Kerberos 5 error"); 347 retval = PAM_SERVICE_ERR; 348 goto cleanup2; 349 } 350 351 PAM_LOG("Got principal: %s", princ_name); 352 353 /* Get password */ 354 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, PASSWORD_PROMPT); 355 if (retval != PAM_SUCCESS) 356 goto cleanup2; 357 358 PAM_LOG("Got password"); 359 360 /* Verify the local user exists (AFTER getting the password) */ 361 if (strchr(user, '@')) { 362 /* get a local account name for this principal */ 363 krbret = krb5_aname_to_localname(pam_context, princ, 364 sizeof(luser), luser); 365 if (krbret != 0) { 366 PAM_VERBOSE_ERROR("Kerberos 5 error"); 367 PAM_LOG("Error krb5_aname_to_localname(): %s", 368 error_message(krbret)); 369 retval = PAM_USER_UNKNOWN; 370 goto cleanup2; 371 } 372 373 retval = pam_set_item(pamh, PAM_USER, luser); 374 if (retval != PAM_SUCCESS) 375 goto cleanup2; 376 377 retval = pam_get_item(pamh, PAM_USER, (const void **)&user); 378 if (retval != PAM_SUCCESS) 379 goto cleanup2; 380 381 PAM_LOG("PAM_USER Redone"); 382 } 383 384 pwd = getpwnam(user); 385 if (pwd == NULL) { 386 retval = PAM_USER_UNKNOWN; 387 goto cleanup2; 388 } 389 390 PAM_LOG("Done getpwnam()"); 391 392 /* Get a TGT */ 393 memset(&creds, 0, sizeof(krb5_creds)); 394 krbret = krb5_get_init_creds_password(pam_context, &creds, princ, 395 pass, NULL, pamh, 0, NULL, &opts); 396 if (krbret != 0) { 397 PAM_VERBOSE_ERROR("Kerberos 5 error"); 398 PAM_LOG("Error krb5_get_init_creds_password(): %s", 399 error_message(krbret)); 400 retval = PAM_AUTH_ERR; 401 goto cleanup2; 402 } 403 404 PAM_LOG("Got TGT"); 405 406 /* Generate a unique cache_name */ 407 asprintf(&cache_name, "MEMORY:/tmp/%s.%d", service, getpid()); 408 krbret = krb5_cc_resolve(pam_context, cache_name, &ccache); 409 free(cache_name); 410 if (krbret != 0) { 411 PAM_VERBOSE_ERROR("Kerberos 5 error"); 412 PAM_LOG("Error krb5_cc_resolve(): %s", error_message(krbret)); 413 retval = PAM_SERVICE_ERR; 414 goto cleanup; 415 } 416 krbret = krb5_cc_initialize(pam_context, ccache, princ); 417 if (krbret != 0) { 418 PAM_VERBOSE_ERROR("Kerberos 5 error"); 419 PAM_LOG("Error krb5_cc_initialize(): %s", error_message(krbret)); 420 retval = PAM_SERVICE_ERR; 421 goto cleanup; 422 } 423 krbret = krb5_cc_store_cred(pam_context, ccache, &creds); 424 if (krbret != 0) { 425 PAM_VERBOSE_ERROR("Kerberos 5 error"); 426 PAM_LOG("Error krb5_cc_store_cred(): %s", error_message(krbret)); 427 krb5_cc_destroy(pam_context, ccache); 428 retval = PAM_SERVICE_ERR; 429 goto cleanup; 430 } 431 432 PAM_LOG("Credentials stashed"); 433 434 /* Verify them */ 435 if ((srvdup = strdup(service)) == NULL) { 436 retval = PAM_BUF_ERR; 437 goto cleanup; 438 } 439 krbret = verify_krb_v5_tgt(pam_context, ccache, srvdup, 440 pam_test_option(&options, PAM_OPT_FORWARDABLE, NULL)); 441 free(srvdup); 442 if (krbret == -1) { 443 PAM_VERBOSE_ERROR("Kerberos 5 error"); 444 krb5_cc_destroy(pam_context, ccache); 445 retval = PAM_AUTH_ERR; 446 goto cleanup; 447 } 448 449 PAM_LOG("Credentials stash verified"); 450 451 retval = pam_get_data(pamh, "ccache", (const void **)&ccache_check); 452 if (retval == PAM_SUCCESS) { 453 krb5_cc_destroy(pam_context, ccache); 454 PAM_VERBOSE_ERROR("Kerberos 5 error"); 455 retval = PAM_AUTH_ERR; 456 goto cleanup; 457 } 458 459 PAM_LOG("Credentials stash not pre-existing"); 460 461 retval = pam_set_data(pamh, "ccache", ccache, cleanup_cache); 462 if (retval != 0) { 463 krb5_cc_destroy(pam_context, ccache); 464 PAM_VERBOSE_ERROR("Kerberos 5 error"); 465 retval = PAM_SERVICE_ERR; 466 goto cleanup; 467 } 468 469 PAM_LOG("Credentials stash saved"); 470 471 cleanup: 472 krb5_free_cred_contents(pam_context, &creds); 473 PAM_LOG("Done cleanup"); 474 cleanup2: 475 krb5_free_principal(pam_context, princ); 476 PAM_LOG("Done cleanup2"); 477 cleanup3: 478 if (princ_name) 479 free(princ_name); 480 481 krb5_free_context(pam_context); 482 483 PAM_LOG("Done cleanup3"); 484 485 if (retval != PAM_SUCCESS) 486 PAM_VERBOSE_ERROR("Kerberos 5 refuses you"); 487 488 return (retval); 489 } 490 491 PAM_EXTERN int 492 pam_sm_setcred(pam_handle_t *pamh, int flags, 493 int argc, const char *argv[]) 494 { 495 496 krb5_error_code krbret; 497 krb5_context pam_context; 498 krb5_principal princ; 499 krb5_creds creds; 500 krb5_ccache ccache_temp, ccache_perm; 501 krb5_cc_cursor cursor; 502 struct options options; 503 struct passwd *pwd = NULL; 504 int retval; 505 char *user; 506 char *cache_name, *cache_env_name, *p, *q; 507 508 uid_t euid; 509 gid_t egid; 510 511 pam_std_option(&options, other_options, argc, argv); 512 513 PAM_LOG("Options processed"); 514 515 if (flags & PAM_DELETE_CRED) 516 return (PAM_SUCCESS); 517 518 if (flags & PAM_REFRESH_CRED) 519 return (PAM_SUCCESS); 520 521 if (flags & PAM_REINITIALIZE_CRED) 522 return (PAM_SUCCESS); 523 524 if (!(flags & PAM_ESTABLISH_CRED)) 525 return (PAM_SERVICE_ERR); 526 527 PAM_LOG("Establishing credentials"); 528 529 /* Get username */ 530 retval = pam_get_item(pamh, PAM_USER, (const void **)&user); 531 if (retval != PAM_SUCCESS) 532 return (retval); 533 534 PAM_LOG("Got user: %s", user); 535 536 krbret = krb5_init_context(&pam_context); 537 if (krbret != 0) { 538 PAM_LOG("Error krb5_init_context(): %s", error_message(krbret)); 539 return (PAM_SERVICE_ERR); 540 } 541 542 PAM_LOG("Context initialised"); 543 544 euid = geteuid(); /* Usually 0 */ 545 egid = getegid(); 546 547 PAM_LOG("Got euid, egid: %d %d", euid, egid); 548 549 /* Retrieve the cache name */ 550 retval = pam_get_data(pamh, "ccache", (const void **)&ccache_temp); 551 if (retval != PAM_SUCCESS) 552 goto cleanup3; 553 554 /* Get the uid. This should exist. */ 555 pwd = getpwnam(user); 556 if (pwd == NULL) { 557 retval = PAM_USER_UNKNOWN; 558 goto cleanup3; 559 } 560 561 PAM_LOG("Done getpwnam()"); 562 563 /* Avoid following a symlink as root */ 564 if (setegid(pwd->pw_gid)) { 565 retval = PAM_SERVICE_ERR; 566 goto cleanup3; 567 } 568 if (seteuid(pwd->pw_uid)) { 569 retval = PAM_SERVICE_ERR; 570 goto cleanup3; 571 } 572 573 PAM_LOG("Done setegid() & seteuid()"); 574 575 /* Get the cache name */ 576 cache_name = NULL; 577 pam_test_option(&options, PAM_OPT_CCACHE, &cache_name); 578 if (cache_name == NULL) 579 asprintf(&cache_name, "FILE:/tmp/krb5cc_%d", pwd->pw_uid); 580 581 p = calloc(PATH_MAX + 16, sizeof(char)); 582 q = cache_name; 583 584 if (p == NULL) { 585 PAM_LOG("Error malloc(): failure"); 586 retval = PAM_BUF_ERR; 587 goto cleanup3; 588 } 589 cache_name = p; 590 591 /* convert %u and %p */ 592 while (*q) { 593 if (*q == '%') { 594 q++; 595 if (*q == 'u') { 596 sprintf(p, "%d", pwd->pw_uid); 597 p += strlen(p); 598 } 599 else if (*q == 'p') { 600 sprintf(p, "%d", getpid()); 601 p += strlen(p); 602 } 603 else { 604 /* Not a special token */ 605 *p++ = '%'; 606 q--; 607 } 608 q++; 609 } 610 else { 611 *p++ = *q++; 612 } 613 } 614 615 PAM_LOG("Got cache_name: %s", cache_name); 616 617 /* Initialize the new ccache */ 618 krbret = krb5_cc_get_principal(pam_context, ccache_temp, &princ); 619 if (krbret != 0) { 620 PAM_LOG("Error krb5_cc_get_principal(): %s", 621 error_message(krbret)); 622 retval = PAM_SERVICE_ERR; 623 goto cleanup3; 624 } 625 krbret = krb5_cc_resolve(pam_context, cache_name, &ccache_perm); 626 if (krbret != 0) { 627 PAM_LOG("Error krb5_cc_resolve(): %s", error_message(krbret)); 628 retval = PAM_SERVICE_ERR; 629 goto cleanup2; 630 } 631 krbret = krb5_cc_initialize(pam_context, ccache_perm, princ); 632 if (krbret != 0) { 633 PAM_LOG("Error krb5_cc_initialize(): %s", error_message(krbret)); 634 retval = PAM_SERVICE_ERR; 635 goto cleanup2; 636 } 637 638 PAM_LOG("Cache initialised"); 639 640 /* Prepare for iteration over creds */ 641 krbret = krb5_cc_start_seq_get(pam_context, ccache_temp, &cursor); 642 if (krbret != 0) { 643 PAM_LOG("Error krb5_cc_start_seq_get(): %s", error_message(krbret)); 644 krb5_cc_destroy(pam_context, ccache_perm); 645 retval = PAM_SERVICE_ERR; 646 goto cleanup2; 647 } 648 649 PAM_LOG("Prepared for iteration"); 650 651 /* Copy the creds (should be two of them) */ 652 while ((krbret = krb5_cc_next_cred(pam_context, ccache_temp, 653 &cursor, &creds) == 0)) { 654 krbret = krb5_cc_store_cred(pam_context, ccache_perm, &creds); 655 if (krbret != 0) { 656 PAM_LOG("Error krb5_cc_store_cred(): %s", 657 error_message(krbret)); 658 krb5_cc_destroy(pam_context, ccache_perm); 659 krb5_free_cred_contents(pam_context, &creds); 660 retval = PAM_SERVICE_ERR; 661 goto cleanup2; 662 } 663 krb5_free_cred_contents(pam_context, &creds); 664 PAM_LOG("Iteration"); 665 } 666 krb5_cc_end_seq_get(pam_context, ccache_temp, &cursor); 667 668 PAM_LOG("Done iterating"); 669 670 if (strstr(cache_name, "FILE:") == cache_name) { 671 if (chown(&cache_name[5], pwd->pw_uid, pwd->pw_gid) == -1) { 672 PAM_LOG("Error chown(): %s", strerror(errno)); 673 krb5_cc_destroy(pam_context, ccache_perm); 674 retval = PAM_SERVICE_ERR; 675 goto cleanup2; 676 } 677 PAM_LOG("Done chown()"); 678 679 if (chmod(&cache_name[5], (S_IRUSR | S_IWUSR)) == -1) { 680 PAM_LOG("Error chmod(): %s", strerror(errno)); 681 krb5_cc_destroy(pam_context, ccache_perm); 682 retval = PAM_SERVICE_ERR; 683 goto cleanup2; 684 } 685 PAM_LOG("Done chmod()"); 686 } 687 688 krb5_cc_close(pam_context, ccache_perm); 689 690 PAM_LOG("Cache closed"); 691 692 cache_env_name = malloc(strlen(cache_name) + 12); 693 if (!cache_env_name) { 694 PAM_LOG("Error malloc(): failure"); 695 krb5_cc_destroy(pam_context, ccache_perm); 696 retval = PAM_BUF_ERR; 697 goto cleanup2; 698 } 699 700 sprintf(cache_env_name, "KRB5CCNAME=%s", cache_name); 701 if ((retval = pam_putenv(pamh, cache_env_name)) != 0) { 702 PAM_LOG("Error pam_putenv(): %s", pam_strerror(pamh, retval)); 703 krb5_cc_destroy(pam_context, ccache_perm); 704 retval = PAM_SERVICE_ERR; 705 goto cleanup2; 706 } 707 708 PAM_LOG("Environment done: KRB5CCNAME=%s", cache_name); 709 710 cleanup2: 711 krb5_free_principal(pam_context, princ); 712 PAM_LOG("Done cleanup2"); 713 cleanup3: 714 krb5_free_context(pam_context); 715 PAM_LOG("Done cleanup3"); 716 717 seteuid(euid); 718 setegid(egid); 719 720 PAM_LOG("Done seteuid() & setegid()"); 721 722 return (retval); 723 } 724 725 /* 726 * account management 727 */ 728 PAM_EXTERN int 729 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused, 730 int argc, const char *argv[]) 731 { 732 krb5_error_code krbret; 733 krb5_context pam_context; 734 krb5_ccache ccache; 735 krb5_principal princ; 736 struct options options; 737 int retval; 738 const char *user; 739 740 pam_std_option(&options, other_options, argc, argv); 741 742 PAM_LOG("Options processed"); 743 744 retval = pam_get_item(pamh, PAM_USER, (const void **)&user); 745 if (retval != PAM_SUCCESS) 746 return (retval); 747 748 PAM_LOG("Got user: %s", user); 749 750 retval = pam_get_data(pamh, "ccache", (const void **)&ccache); 751 if (retval != PAM_SUCCESS) 752 return (PAM_SUCCESS); 753 754 PAM_LOG("Got ccache"); 755 756 krbret = krb5_init_context(&pam_context); 757 if (krbret != 0) { 758 PAM_LOG("Error krb5_init_context(): %s", error_message(krbret)); 759 return (PAM_PERM_DENIED); 760 } 761 762 PAM_LOG("Context initialised"); 763 764 krbret = krb5_cc_get_principal(pam_context, ccache, &princ); 765 if (krbret != 0) { 766 PAM_LOG("Error krb5_cc_get_principal(): %s", error_message(krbret)); 767 retval = PAM_PERM_DENIED;; 768 goto cleanup; 769 } 770 771 PAM_LOG("Got principal"); 772 773 if (krb5_kuserok(pam_context, princ, user)) 774 retval = PAM_SUCCESS; 775 else 776 retval = PAM_PERM_DENIED; 777 krb5_free_principal(pam_context, princ); 778 779 PAM_LOG("Done kuserok()"); 780 781 cleanup: 782 krb5_free_context(pam_context); 783 PAM_LOG("Done cleanup"); 784 785 return (retval); 786 787 } 788 789 /* 790 * password management 791 */ 792 PAM_EXTERN int 793 pam_sm_chauthtok(pam_handle_t *pamh, int flags, 794 int argc, const char *argv[]) 795 { 796 krb5_error_code krbret; 797 krb5_context pam_context; 798 krb5_creds creds; 799 krb5_principal princ; 800 krb5_get_init_creds_opt opts; 801 krb5_data result_code_string, result_string; 802 struct options options; 803 int result_code, retval; 804 const char *user, *pass; 805 char *princ_name, *passdup; 806 807 pam_std_option(&options, other_options, argc, argv); 808 809 PAM_LOG("Options processed"); 810 811 if (!(flags & PAM_UPDATE_AUTHTOK)) 812 return (PAM_AUTHTOK_ERR); 813 814 retval = pam_get_item(pamh, PAM_USER, (const void **)&user); 815 if (retval != PAM_SUCCESS) 816 return (retval); 817 818 PAM_LOG("Got user: %s", user); 819 820 krbret = krb5_init_context(&pam_context); 821 if (krbret != 0) { 822 PAM_LOG("Error krb5_init_context(): %s", error_message(krbret)); 823 return (PAM_SERVICE_ERR); 824 } 825 826 PAM_LOG("Context initialised"); 827 828 krb5_get_init_creds_opt_init(&opts); 829 830 PAM_LOG("Credentials options initialised"); 831 832 /* Get principal name */ 833 krbret = krb5_parse_name(pam_context, user, &princ); 834 if (krbret != 0) { 835 PAM_LOG("Error krb5_parse_name(): %s", error_message(krbret)); 836 retval = PAM_USER_UNKNOWN; 837 goto cleanup3; 838 } 839 840 /* Now convert the principal name into something human readable */ 841 princ_name = NULL; 842 krbret = krb5_unparse_name(pam_context, princ, &princ_name); 843 if (krbret != 0) { 844 PAM_LOG("Error krb5_unparse_name(): %s", error_message(krbret)); 845 retval = PAM_SERVICE_ERR; 846 goto cleanup2; 847 } 848 849 PAM_LOG("Got principal: %s", princ_name); 850 851 /* Get password */ 852 retval = pam_get_authtok(pamh, PAM_OLDAUTHTOK, &pass, PASSWORD_PROMPT); 853 if (retval != PAM_SUCCESS) 854 goto cleanup2; 855 856 PAM_LOG("Got password"); 857 858 memset(&creds, 0, sizeof(krb5_creds)); 859 krbret = krb5_get_init_creds_password(pam_context, &creds, princ, 860 pass, NULL, pamh, 0, "kadmin/changepw", &opts); 861 if (krbret != 0) { 862 PAM_LOG("Error krb5_get_init_creds_password()", 863 error_message(krbret)); 864 retval = PAM_AUTH_ERR; 865 goto cleanup2; 866 } 867 868 PAM_LOG("Credentials established"); 869 870 /* Now get the new password */ 871 for (;;) { 872 retval = pam_get_authtok(pamh, 873 PAM_AUTHTOK, &pass, NEW_PASSWORD_PROMPT); 874 if (retval != PAM_TRY_AGAIN) 875 break; 876 pam_error(pamh, "Mismatch; try again, EOF to quit."); 877 } 878 if (retval != PAM_SUCCESS) 879 goto cleanup; 880 881 PAM_LOG("Got new password"); 882 883 /* Change it */ 884 if ((passdup = strdup(pass)) == NULL) { 885 retval = PAM_BUF_ERR; 886 goto cleanup; 887 } 888 krbret = krb5_change_password(pam_context, &creds, passdup, 889 &result_code, &result_code_string, &result_string); 890 free(passdup); 891 if (krbret != 0) { 892 PAM_LOG("Error krb5_change_password(): %s", 893 error_message(krbret)); 894 retval = PAM_AUTHTOK_ERR; 895 goto cleanup; 896 } 897 if (result_code) { 898 PAM_LOG("Error krb5_change_password(): (result_code)"); 899 retval = PAM_AUTHTOK_ERR; 900 goto cleanup; 901 } 902 903 PAM_LOG("Password changed"); 904 905 if (result_string.data) 906 free(result_string.data); 907 if (result_code_string.data) 908 free(result_code_string.data); 909 910 cleanup: 911 krb5_free_cred_contents(pam_context, &creds); 912 PAM_LOG("Done cleanup"); 913 cleanup2: 914 krb5_free_principal(pam_context, princ); 915 PAM_LOG("Done cleanup2"); 916 cleanup3: 917 if (princ_name) 918 free(princ_name); 919 920 krb5_free_context(pam_context); 921 922 PAM_LOG("Done cleanup3"); 923 924 return (retval); 925 } 926 927 PAM_MODULE_ENTRY("pam_krb5"); 928 929 /* 930 * This routine with some modification is from the MIT V5B6 appl/bsd/login.c 931 * Modified by Sam Hartman <hartmans@mit.edu> to support PAM services 932 * for Debian. 933 * 934 * Verify the Kerberos ticket-granting ticket just retrieved for the 935 * user. If the Kerberos server doesn't respond, assume the user is 936 * trying to fake us out (since we DID just get a TGT from what is 937 * supposedly our KDC). If the host/<host> service is unknown (i.e., 938 * the local keytab doesn't have it), and we cannot find another 939 * service we do have, let her in. 940 * 941 * Returns 1 for confirmation, -1 for failure, 0 for uncertainty. 942 */ 943 static int 944 verify_krb_v5_tgt(krb5_context context, krb5_ccache ccache, 945 char *pam_service, int debug) 946 { 947 krb5_error_code retval; 948 krb5_principal princ; 949 krb5_keyblock *keyblock; 950 krb5_data packet; 951 krb5_auth_context auth_context; 952 char phost[BUFSIZ]; 953 const char *services[3], **service; 954 955 packet.data = 0; 956 957 /* If possible we want to try and verify the ticket we have 958 * received against a keytab. We will try multiple service 959 * principals, including at least the host principal and the PAM 960 * service principal. The host principal is preferred because access 961 * to that key is generally sufficient to compromise root, while the 962 * service key for this PAM service may be less carefully guarded. 963 * It is important to check the keytab first before the KDC so we do 964 * not get spoofed by a fake KDC. 965 */ 966 services[0] = "host"; 967 services[1] = pam_service; 968 services[2] = NULL; 969 keyblock = 0; 970 retval = -1; 971 for (service = &services[0]; *service != NULL; service++) { 972 retval = krb5_sname_to_principal(context, NULL, *service, 973 KRB5_NT_SRV_HST, &princ); 974 if (retval != 0) { 975 if (debug) 976 syslog(LOG_DEBUG, "pam_krb5: verify_krb_v5_tgt(): %s: %s", "krb5_sname_to_principal()", error_message(retval)); 977 return -1; 978 } 979 980 /* Extract the name directly. */ 981 strncpy(phost, compat_princ_component(context, princ, 1), 982 BUFSIZ); 983 phost[BUFSIZ - 1] = '\0'; 984 985 /* 986 * Do we have service/<host> keys? 987 * (use default/configured keytab, kvno IGNORE_VNO to get the 988 * first match, and ignore enctype.) 989 */ 990 retval = krb5_kt_read_service_key(context, NULL, princ, 0, 0, 991 &keyblock); 992 if (retval != 0) 993 continue; 994 break; 995 } 996 if (retval != 0) { /* failed to find key */ 997 /* Keytab or service key does not exist */ 998 if (debug) 999 syslog(LOG_DEBUG, "pam_krb5: verify_krb_v5_tgt(): %s: %s", "krb5_kt_read_service_key()", error_message(retval)); 1000 retval = 0; 1001 goto cleanup; 1002 } 1003 if (keyblock) 1004 krb5_free_keyblock(context, keyblock); 1005 1006 /* Talk to the kdc and construct the ticket. */ 1007 auth_context = NULL; 1008 retval = krb5_mk_req(context, &auth_context, 0, *service, phost, 1009 NULL, ccache, &packet); 1010 if (auth_context) { 1011 krb5_auth_con_free(context, auth_context); 1012 auth_context = NULL; /* setup for rd_req */ 1013 } 1014 if (retval) { 1015 if (debug) 1016 syslog(LOG_DEBUG, "pam_krb5: verify_krb_v5_tgt(): %s: %s", "krb5_mk_req()", error_message(retval)); 1017 retval = -1; 1018 goto cleanup; 1019 } 1020 1021 /* Try to use the ticket. */ 1022 retval = krb5_rd_req(context, &auth_context, &packet, princ, NULL, 1023 NULL, NULL); 1024 if (retval) { 1025 if (debug) 1026 syslog(LOG_DEBUG, "pam_krb5: verify_krb_v5_tgt(): %s: %s", "krb5_rd_req()", error_message(retval)); 1027 retval = -1; 1028 } 1029 else 1030 retval = 1; 1031 1032 cleanup: 1033 if (packet.data) 1034 compat_free_data_contents(context, &packet); 1035 krb5_free_principal(context, princ); 1036 return retval; 1037 } 1038 1039 /* Free the memory for cache_name. Called by pam_end() */ 1040 static void 1041 cleanup_cache(pam_handle_t *pamh __unused, void *data, int pam_end_status __unused) 1042 { 1043 krb5_context pam_context; 1044 krb5_ccache ccache; 1045 1046 if (krb5_init_context(&pam_context)) 1047 return; 1048 1049 ccache = (krb5_ccache)data; 1050 krb5_cc_destroy(pam_context, ccache); 1051 krb5_free_context(pam_context); 1052 } 1053 1054 #ifdef COMPAT_HEIMDAL 1055 #ifdef COMPAT_MIT 1056 #error This cannot be MIT and Heimdal compatible! 1057 #endif 1058 #endif 1059 1060 #ifndef COMPAT_HEIMDAL 1061 #ifndef COMPAT_MIT 1062 #error One of COMPAT_MIT and COMPAT_HEIMDAL must be specified! 1063 #endif 1064 #endif 1065 1066 #ifdef COMPAT_HEIMDAL 1067 static const char * 1068 compat_princ_component(krb5_context context __unused, krb5_principal princ, int n) 1069 { 1070 return princ->name.name_string.val[n]; 1071 } 1072 1073 static void 1074 compat_free_data_contents(krb5_context context __unused, krb5_data * data) 1075 { 1076 krb5_xfree(data->data); 1077 } 1078 #endif 1079 1080 #ifdef COMPAT_MIT 1081 static const char * 1082 compat_princ_component(krb5_context context, krb5_principal princ, int n) 1083 { 1084 return krb5_princ_component(context, princ, n)->data; 1085 } 1086 1087 static void 1088 compat_free_data_contents(krb5_context context, krb5_data * data) 1089 { 1090 krb5_free_data_contents(context, data); 1091 } 1092 #endif 1093