pam_krb5.c revision 85485
1/*- 2 * Copyright 2001 Mark R V Murray 3 * Copyright Frank Cusack fcusack@fcusack.com 1999-2000 4 * All rights reserved 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, and the entire permission notice in its entirety, 11 * including the disclaimer of warranties. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote 16 * products derived from this software without specific prior 17 * written permission. 18 * 19 * ALTERNATIVELY, this product may be distributed under the terms of 20 * the GNU Public License, in which case the provisions of the GPL are 21 * required INSTEAD OF the above restrictions. (This clause is 22 * necessary due to a potential bad interaction between the GPL and 23 * the restrictions contained in a BSD-style copyright.) 24 * 25 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 26 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 28 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 29 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 30 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 31 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 33 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 35 * OF THE POSSIBILITY OF SUCH DAMAGE. 36 * --------------------------------------------------------------------------- 37 * 38 * This software may contain code from Naomaru Itoi: 39 * 40 * PAM-kerberos5 module Copyright notice. 41 * Naomaru Itoi <itoi@eecs.umich.edu>, June 24, 1997. 42 * 43 * ---------------------------------------------------------------------------- 44 * COPYRIGHT (c) 1997 45 * THE REGENTS OF THE UNIVERSITY OF MICHIGAN 46 * ALL RIGHTS RESERVED 47 * 48 * PERMISSION IS GRANTED TO USE, COPY, CREATE DERIVATIVE WORKS AND REDISTRIBUTE 49 * THIS SOFTWARE AND SUCH DERIVATIVE WORKS FOR ANY PURPOSE, SO LONG AS THE NAME 50 * OF THE UNIVERSITY OF MICHIGAN IS NOT USED IN ANY ADVERTISING OR PUBLICITY 51 * PERTAINING TO THE USE OR DISTRIBUTION OF THIS SOFTWARE WITHOUT SPECIFIC, 52 * WRITTEN PRIOR AUTHORIZATION. IF THE ABOVE COPYRIGHT NOTICE OR ANY OTHER 53 * IDENTIFICATION OF THE UNIVERSITY OF MICHIGAN IS INCLUDED IN ANY COPY OF ANY 54 * PORTION OF THIS SOFTWARE, THEN THE DISCLAIMER BELOW MUST ALSO BE INCLUDED. 55 * 56 * THE SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION FROM THE UNIVERSITY OF 57 * MICHIGAN AS TO ITS FITNESS FOR ANY PURPOSE, AND WITHOUT WARRANTY BY THE 58 * UNIVERSITY OF MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING 59 * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF MERCHANTABITILY AND FITNESS FOR A 60 * PARTICULAR PURPOSE. THE REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE 61 * LIABLE FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR 62 * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING OUT OF OR IN 63 * CONNECTION WITH THE USE OF THE SOFTWARE, EVEN IF IT HAS BEEN OR IS HEREAFTER 64 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. 65 * 66 * PAM-kerberos5 module is written based on PAM-kerberos4 module 67 * by Derrick J. Brashear and kerberos5-1.0pl1 by M.I.T. kerberos team. 68 * Permission to use, copy, modify, distribute this software is hereby 69 * granted, as long as it is granted by Derrick J. Brashear and 70 * M.I.T. kerberos team. Followings are their copyright information. 71 * ---------------------------------------------------------------------------- 72 * 73 * This software may contain code from Derrick J. Brashear: 74 * 75 * 76 * Copyright (c) Derrick J. Brashear, 1996. All rights reserved 77 * 78 * Redistribution and use in source and binary forms, with or without 79 * modification, are permitted provided that the following conditions 80 * are met: 81 * 1. Redistributions of source code must retain the above copyright 82 * notice, and the entire permission notice in its entirety, 83 * including the disclaimer of warranties. 84 * 2. Redistributions in binary form must reproduce the above copyright 85 * notice, this list of conditions and the following disclaimer in the 86 * documentation and/or other materials provided with the distribution. 87 * 3. The name of the author may not be used to endorse or promote 88 * products derived from this software without specific prior 89 * written permission. 90 * 91 * ALTERNATIVELY, this product may be distributed under the terms of 92 * the GNU Public License, in which case the provisions of the GPL are 93 * required INSTEAD OF the above restrictions. (This clause is 94 * necessary due to a potential bad interaction between the GPL and 95 * the restrictions contained in a BSD-style copyright.) 96 * 97 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 98 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 99 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 100 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 101 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 102 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 103 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 104 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 105 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 106 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 107 * OF THE POSSIBILITY OF SUCH DAMAGE. 108 * 109 * ---------------------------------------------------------------------------- 110 * 111 * This software may contain code from MIT Kerberos 5: 112 * 113 * Copyright Notice and Legal Administrivia 114 * ---------------------------------------- 115 * 116 * Copyright (C) 1996 by the Massachusetts Institute of Technology. 117 * 118 * All rights reserved. 119 * 120 * Export of this software from the United States of America may require 121 * a specific license from the United States Government. It is the 122 * responsibility of any person or organization contemplating export to 123 * obtain such a license before exporting. 124 * 125 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and 126 * distribute this software and its documentation for any purpose and 127 * without fee is hereby granted, provided that the above copyright 128 * notice appear in all copies and that both that copyright notice and 129 * this permission notice appear in supporting documentation, and that 130 * the name of M.I.T. not be used in advertising or publicity pertaining 131 * to distribution of the software without specific, written prior 132 * permission. M.I.T. makes no representations about the suitability of 133 * this software for any purpose. It is provided "as is" without express 134 * or implied warranty. 135 * 136 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 137 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 138 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 139 * 140 * Individual source code files are copyright MIT, Cygnus Support, 141 * OpenVision, Oracle, Sun Soft, and others. 142 * 143 * Project Athena, Athena, Athena MUSE, Discuss, Hesiod, Kerberos, Moira, 144 * and Zephyr are trademarks of the Massachusetts Institute of Technology 145 * (MIT). No commercial use of these trademarks may be made without 146 * prior written permission of MIT. 147 * 148 * "Commercial use" means use of a name in a product or other for-profit 149 * manner. It does NOT prevent a commercial firm from referring to the 150 * MIT trademarks in order to convey information (although in doing so, 151 * recognition of their trademark status should be given). 152 * 153 * The following copyright and permission notice applies to the 154 * OpenVision Kerberos Administration system located in kadmin/create, 155 * kadmin/dbutil, kadmin/passwd, kadmin/server, lib/kadm5, and portions 156 * of lib/rpc: 157 * 158 * Copyright, OpenVision Technologies, Inc., 1996, All Rights Reserved 159 * 160 * WARNING: Retrieving the OpenVision Kerberos Administration system 161 * source code, as described below, indicates your acceptance of the 162 * following terms. If you do not agree to the following terms, do not 163 * retrieve the OpenVision Kerberos administration system. 164 * 165 * You may freely use and distribute the Source Code and Object Code 166 * compiled from it, with or without modification, but this Source 167 * Code is provided to you "AS IS" EXCLUSIVE OF ANY WARRANTY, 168 * INCLUDING, WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY OR 169 * FITNESS FOR A PARTICULAR PURPOSE, OR ANY OTHER WARRANTY, WHETHER 170 * EXPRESS OR IMPLIED. IN NO EVENT WILL OPENVISION HAVE ANY LIABILITY 171 * FOR ANY LOST PROFITS, LOSS OF DATA OR COSTS OF PROCUREMENT OF 172 * SUBSTITUTE GOODS OR SERVICES, OR FOR ANY SPECIAL, INDIRECT, OR 173 * CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, INCLUDING, 174 * WITHOUT LIMITATION, THOSE RESULTING FROM THE USE OF THE SOURCE 175 * CODE, OR THE FAILURE OF THE SOURCE CODE TO PERFORM, OR FOR ANY 176 * OTHER REASON. 177 * 178 * OpenVision retains all copyrights in the donated Source Code. OpenVision 179 * also retains copyright to derivative works of the Source Code, whether 180 * created by OpenVision or by a third party. The OpenVision copyright 181 * notice must be preserved if derivative works are made based on the 182 * donated Source Code. 183 * 184 * OpenVision Technologies, Inc. has donated this Kerberos 185 * Administration system to MIT for inclusion in the standard 186 * Kerberos 5 distribution. This donation underscores our 187 * commitment to continuing Kerberos technology development 188 * and our gratitude for the valuable work which has been 189 * performed by MIT and the Kerberos community. 190 * 191 */ 192 193#include <sys/cdefs.h> 194__FBSDID("$FreeBSD: head/lib/libpam/modules/pam_krb5/pam_krb5.c 85485 2001-10-25 15:51:50Z sobomax $"); 195 196#include <sys/types.h> 197#include <sys/stat.h> 198#include <errno.h> 199#include <limits.h> 200#include <pwd.h> 201#include <stdio.h> 202#include <stdlib.h> 203#include <strings.h> 204#include <syslog.h> 205#include <unistd.h> 206 207#include <krb5.h> 208#include <com_err.h> 209 210#define PAM_SM_AUTH 211#define PAM_SM_ACCOUNT 212#define PAM_SM_SESSION 213#define PAM_SM_PASSWORD 214 215#include <security/pam_appl.h> 216#include <security/pam_modules.h> 217 218#include "pam_mod_misc.h" 219 220#define COMPAT_HEIMDAL 221/* #define COMPAT_MIT */ 222 223extern krb5_cc_ops krb5_mcc_ops; 224 225static int verify_krb_v5_tgt(krb5_context, krb5_ccache, char *, int); 226static void cleanup_cache(pam_handle_t *, void *, int); 227static const char *compat_princ_component(krb5_context, krb5_principal, int); 228static void compat_free_data_contents(krb5_context, krb5_data *); 229 230#define USER_PROMPT "Username: " 231#define PASSWORD_PROMPT "Password:" 232#define NEW_PASSWORD_PROMPT "New Password:" 233#define NEW_PASSWORD_PROMPT_2 "New Password (again):" 234 235enum { PAM_OPT_AUTH_AS_SELF=PAM_OPT_STD_MAX, PAM_OPT_CCACHE, PAM_OPT_FORWARDABLE, PAM_OPT_NO_CCACHE, PAM_OPT_REUSE_CCACHE }; 236 237static struct opttab other_options[] = { 238 { "auth_as_self", PAM_OPT_AUTH_AS_SELF }, 239 { "ccache", PAM_OPT_CCACHE }, 240 { "forwardable", PAM_OPT_FORWARDABLE }, 241 { "no_ccache", PAM_OPT_NO_CCACHE }, 242 { "reuse_ccache", PAM_OPT_REUSE_CCACHE }, 243 { NULL, 0 } 244}; 245 246/* 247 * authentication management 248 */ 249PAM_EXTERN int 250pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc, const char **argv) 251{ 252 krb5_error_code krbret; 253 krb5_context pam_context; 254 krb5_creds creds; 255 krb5_principal princ; 256 krb5_ccache ccache, ccache_check; 257 krb5_get_init_creds_opt opts; 258 struct options options; 259 struct passwd *pwd; 260 int retval; 261 const char *sourceuser, *user, *pass; 262 char *principal, *princ_name, *service, *cache_name, luser[32]; 263 264 pam_std_option(&options, other_options, argc, argv); 265 266 PAM_LOG("Options processed"); 267 268 retval = pam_get_user(pamh, &user, USER_PROMPT); 269 if (retval != PAM_SUCCESS) 270 PAM_RETURN(retval); 271 272 PAM_LOG("Got user: %s", user); 273 274 retval = pam_get_item(pamh, PAM_RUSER, (const void **)&sourceuser); 275 if (retval != PAM_SUCCESS) 276 PAM_RETURN(retval); 277 278 PAM_LOG("Got ruser: %s", sourceuser); 279 280 service = NULL; 281 pam_get_item(pamh, PAM_SERVICE, (const void **)&service); 282 if (service == NULL) 283 service = "unknown"; 284 285 PAM_LOG("Got service: %s", service); 286 287 krbret = krb5_init_context(&pam_context); 288 if (krbret != 0) { 289 PAM_VERBOSE_ERROR("Kerberos 5 error"); 290 PAM_RETURN(PAM_SERVICE_ERR); 291 } 292 293 PAM_LOG("Context initialised"); 294 295 krb5_get_init_creds_opt_init(&opts); 296 297 if (pam_test_option(&options, PAM_OPT_FORWARDABLE, NULL)) 298 krb5_get_init_creds_opt_set_forwardable(&opts, 1); 299 300 PAM_LOG("Credentials initialised"); 301 302 krbret = krb5_cc_register(pam_context, &krb5_mcc_ops, FALSE); 303 if (krbret != 0 && krbret != KRB5_CC_TYPE_EXISTS) { 304 PAM_VERBOSE_ERROR("Kerberos 5 error"); 305 retval = PAM_SERVICE_ERR; 306 goto cleanup3; 307 } 308 309 PAM_LOG("Done krb5_cc_register()"); 310 311 /* Get principal name */ 312 if (pam_test_option(&options, PAM_OPT_AUTH_AS_SELF, NULL)) 313 asprintf(&principal, "%s/%s", sourceuser, user); 314 else 315 principal = strdup(user); 316 317 PAM_LOG("Created principal: %s", principal); 318 319 krbret = krb5_parse_name(pam_context, principal, &princ); 320 free(principal); 321 if (krbret != 0) { 322 PAM_LOG("Error krb5_parse_name(): %s", error_message(krbret)); 323 PAM_VERBOSE_ERROR("Kerberos 5 error"); 324 retval = PAM_SERVICE_ERR; 325 goto cleanup3; 326 } 327 328 PAM_LOG("Done krb5_parse_name()"); 329 330 /* Now convert the principal name into something human readable */ 331 princ_name = NULL; 332 krbret = krb5_unparse_name(pam_context, princ, &princ_name); 333 if (krbret != 0) { 334 PAM_LOG("Error krb5_unparse_name(): %s", error_message(krbret)); 335 PAM_VERBOSE_ERROR("Kerberos 5 error"); 336 retval = PAM_SERVICE_ERR; 337 goto cleanup2; 338 } 339 340 PAM_LOG("Got principal: %s", princ_name); 341 342 /* Get password */ 343 retval = pam_get_pass(pamh, &pass, PASSWORD_PROMPT, &options); 344 if (retval != PAM_SUCCESS) 345 goto cleanup2; 346 347 PAM_LOG("Got password"); 348 349 /* Verify the local user exists (AFTER getting the password) */ 350 if (strchr(user, '@')) { 351 /* get a local account name for this principal */ 352 krbret = krb5_aname_to_localname(pam_context, princ, 353 sizeof(luser), luser); 354 if (krbret != 0) { 355 PAM_VERBOSE_ERROR("Kerberos 5 error"); 356 PAM_LOG("Error krb5_aname_to_localname(): %s", 357 error_message(krbret)); 358 retval = PAM_USER_UNKNOWN; 359 goto cleanup2; 360 } 361 362 retval = pam_set_item(pamh, PAM_USER, luser); 363 if (retval != PAM_SUCCESS) 364 goto cleanup2; 365 366 retval = pam_get_item(pamh, PAM_USER, (const void **)&user); 367 if (retval != PAM_SUCCESS) 368 goto cleanup2; 369 370 PAM_LOG("PAM_USER Redone"); 371 } 372 373 pwd = getpwnam(user); 374 if (pwd == NULL) { 375 retval = PAM_USER_UNKNOWN; 376 goto cleanup2; 377 } 378 379 PAM_LOG("Done getpwnam()"); 380 381 /* Get a TGT */ 382 memset(&creds, 0, sizeof(krb5_creds)); 383 krbret = krb5_get_init_creds_password(pam_context, &creds, princ, 384 pass, NULL, pamh, 0, NULL, &opts); 385 if (krbret != 0) { 386 PAM_VERBOSE_ERROR("Kerberos 5 error"); 387 PAM_LOG("Error krb5_get_init_creds_password(): %s", 388 error_message(krbret)); 389 retval = PAM_AUTH_ERR; 390 goto cleanup2; 391 } 392 393 PAM_LOG("Got TGT"); 394 395 /* Generate a unique cache_name */ 396 asprintf(&cache_name, "MEMORY:/tmp/%s.%d", service, getpid()); 397 krbret = krb5_cc_resolve(pam_context, cache_name, &ccache); 398 free(cache_name); 399 if (krbret != 0) { 400 PAM_VERBOSE_ERROR("Kerberos 5 error"); 401 PAM_LOG("Error krb5_cc_resolve(): %s", error_message(krbret)); 402 retval = PAM_SERVICE_ERR; 403 goto cleanup; 404 } 405 krbret = krb5_cc_initialize(pam_context, ccache, princ); 406 if (krbret != 0) { 407 PAM_VERBOSE_ERROR("Kerberos 5 error"); 408 PAM_LOG("Error krb5_cc_initialize(): %s", error_message(krbret)); 409 retval = PAM_SERVICE_ERR; 410 goto cleanup; 411 } 412 krbret = krb5_cc_store_cred(pam_context, ccache, &creds); 413 if (krbret != 0) { 414 PAM_VERBOSE_ERROR("Kerberos 5 error"); 415 PAM_LOG("Error krb5_cc_store_cred(): %s", error_message(krbret)); 416 krb5_cc_destroy(pam_context, ccache); 417 retval = PAM_SERVICE_ERR; 418 goto cleanup; 419 } 420 421 PAM_LOG("Credentials stashed"); 422 423 /* Verify them */ 424 if (verify_krb_v5_tgt(pam_context, ccache, service, 425 pam_test_option(&options, PAM_OPT_FORWARDABLE, NULL)) == -1) { 426 PAM_VERBOSE_ERROR("Kerberos 5 error"); 427 krb5_cc_destroy(pam_context, ccache); 428 retval = PAM_AUTH_ERR; 429 goto cleanup; 430 } 431 432 PAM_LOG("Credentials stash verified"); 433 434 retval = pam_get_data(pamh, "ccache", (const void **)&ccache_check); 435 if (retval == PAM_SUCCESS) { 436 krb5_cc_destroy(pam_context, ccache); 437 PAM_VERBOSE_ERROR("Kerberos 5 error"); 438 retval = PAM_AUTH_ERR; 439 goto cleanup; 440 } 441 442 PAM_LOG("Credentials stash not pre-existing"); 443 444 retval = pam_set_data(pamh, "ccache", ccache, cleanup_cache); 445 if (retval != 0) { 446 krb5_cc_destroy(pam_context, ccache); 447 PAM_VERBOSE_ERROR("Kerberos 5 error"); 448 retval = PAM_SERVICE_ERR; 449 goto cleanup; 450 } 451 452 PAM_LOG("Credentials stash saved"); 453 454cleanup: 455 krb5_free_cred_contents(pam_context, &creds); 456 PAM_LOG("Done cleanup"); 457cleanup2: 458 krb5_free_principal(pam_context, princ); 459 PAM_LOG("Done cleanup2"); 460cleanup3: 461 if (princ_name) 462 free(princ_name); 463 464 krb5_free_context(pam_context); 465 466 PAM_LOG("Done cleanup3"); 467 468 if (retval != PAM_SUCCESS) 469 PAM_VERBOSE_ERROR("Kerberos 5 refuses you"); 470 471 PAM_RETURN(retval); 472} 473 474PAM_EXTERN int 475pam_sm_setcred(pam_handle_t *pamh, int flags, int argc, const char **argv) 476{ 477 478 krb5_error_code krbret; 479 krb5_context pam_context; 480 krb5_principal princ; 481 krb5_creds creds; 482 krb5_ccache ccache_temp, ccache_perm; 483 krb5_cc_cursor cursor; 484 struct options options; 485 struct passwd *pwd = NULL; 486 int retval; 487 char *user; 488 char *cache_name, *cache_env_name, *p, *q; 489 490 uid_t euid; 491 gid_t egid; 492 493 pam_std_option(&options, other_options, argc, argv); 494 495 PAM_LOG("Options processed"); 496 497 if (flags & PAM_DELETE_CRED) 498 PAM_RETURN(PAM_SUCCESS); 499 500 if (flags & PAM_REFRESH_CRED) 501 PAM_RETURN(PAM_SUCCESS); 502 503 if (flags & PAM_REINITIALIZE_CRED) 504 PAM_RETURN(PAM_SUCCESS); 505 506 if (!(flags & PAM_ESTABLISH_CRED)) 507 PAM_RETURN(PAM_SERVICE_ERR); 508 509 PAM_LOG("Establishing credentials"); 510 511 /* Get username */ 512 retval = pam_get_item(pamh, PAM_USER, (const void **)&user); 513 if (retval != PAM_SUCCESS) 514 PAM_RETURN(retval); 515 516 PAM_LOG("Got user: %s", user); 517 518 krbret = krb5_init_context(&pam_context); 519 if (krbret != 0) { 520 PAM_LOG("Error krb5_init_context(): %s", error_message(krbret)); 521 PAM_RETURN(PAM_SERVICE_ERR); 522 } 523 524 PAM_LOG("Context initialised"); 525 526 euid = geteuid(); /* Usually 0 */ 527 egid = getegid(); 528 529 PAM_LOG("Got euid, egid: %d %d", euid, egid); 530 531 /* Retrieve the cache name */ 532 retval = pam_get_data(pamh, "ccache", (const void **)&ccache_temp); 533 if (retval != PAM_SUCCESS) 534 goto cleanup3; 535 536 /* Get the uid. This should exist. */ 537 pwd = getpwnam(user); 538 if (pwd == NULL) { 539 retval = PAM_USER_UNKNOWN; 540 goto cleanup3; 541 } 542 543 PAM_LOG("Done getpwnam()"); 544 545 /* Avoid following a symlink as root */ 546 if (setegid(pwd->pw_gid)) { 547 retval = PAM_SERVICE_ERR; 548 goto cleanup3; 549 } 550 if (seteuid(pwd->pw_uid)) { 551 retval = PAM_SERVICE_ERR; 552 goto cleanup3; 553 } 554 555 PAM_LOG("Done setegid() & seteuid()"); 556 557 /* Get the cache name */ 558 cache_name = NULL; 559 pam_test_option(&options, PAM_OPT_CCACHE, &cache_name); 560 if (cache_name == NULL) 561 asprintf(&cache_name, "FILE:/tmp/krb5cc_%d", pwd->pw_uid); 562 563 p = calloc(PATH_MAX + 16, sizeof(char)); 564 q = cache_name; 565 566 if (p == NULL) { 567 PAM_LOG("Error malloc(): failure"); 568 retval = PAM_BUF_ERR; 569 goto cleanup3; 570 } 571 cache_name = p; 572 573 /* convert %u and %p */ 574 while (*q) { 575 if (*q == '%') { 576 q++; 577 if (*q == 'u') { 578 sprintf(p, "%d", pwd->pw_uid); 579 p += strlen(p); 580 } 581 else if (*q == 'p') { 582 sprintf(p, "%d", getpid()); 583 p += strlen(p); 584 } 585 else { 586 /* Not a special token */ 587 *p++ = '%'; 588 q--; 589 } 590 q++; 591 } 592 else { 593 *p++ = *q++; 594 } 595 } 596 597 PAM_LOG("Got cache_name: %s", cache_name); 598 599 /* Initialize the new ccache */ 600 krbret = krb5_cc_get_principal(pam_context, ccache_temp, &princ); 601 if (krbret != 0) { 602 PAM_LOG("Error krb5_cc_get_principal(): %s", 603 error_message(krbret)); 604 retval = PAM_SERVICE_ERR; 605 goto cleanup3; 606 } 607 krbret = krb5_cc_resolve(pam_context, cache_name, &ccache_perm); 608 if (krbret != 0) { 609 PAM_LOG("Error krb5_cc_resolve(): %s", error_message(krbret)); 610 retval = PAM_SERVICE_ERR; 611 goto cleanup2; 612 } 613 krbret = krb5_cc_initialize(pam_context, ccache_perm, princ); 614 if (krbret != 0) { 615 PAM_LOG("Error krb5_cc_initialize(): %s", error_message(krbret)); 616 retval = PAM_SERVICE_ERR; 617 goto cleanup2; 618 } 619 620 PAM_LOG("Cache initialised"); 621 622 /* Prepare for iteration over creds */ 623 krbret = krb5_cc_start_seq_get(pam_context, ccache_temp, &cursor); 624 if (krbret != 0) { 625 PAM_LOG("Error krb5_cc_start_seq_get(): %s", error_message(krbret)); 626 krb5_cc_destroy(pam_context, ccache_perm); 627 retval = PAM_SERVICE_ERR; 628 goto cleanup2; 629 } 630 631 PAM_LOG("Prepared for iteration"); 632 633 /* Copy the creds (should be two of them) */ 634 while ((krbret = krb5_cc_next_cred(pam_context, ccache_temp, 635 &cursor, &creds) == 0)) { 636 krbret = krb5_cc_store_cred(pam_context, ccache_perm, &creds); 637 if (krbret != 0) { 638 PAM_LOG("Error krb5_cc_store_cred(): %s", 639 error_message(krbret)); 640 krb5_cc_destroy(pam_context, ccache_perm); 641 krb5_free_cred_contents(pam_context, &creds); 642 retval = PAM_SERVICE_ERR; 643 goto cleanup2; 644 } 645 krb5_free_cred_contents(pam_context, &creds); 646 PAM_LOG("Iteration"); 647 } 648 krb5_cc_end_seq_get(pam_context, ccache_temp, &cursor); 649 650 PAM_LOG("Done iterating"); 651 652 if (strstr(cache_name, "FILE:") == cache_name) { 653 if (chown(&cache_name[5], pwd->pw_uid, pwd->pw_gid) == -1) { 654 PAM_LOG("Error chown(): %s", strerror(errno)); 655 krb5_cc_destroy(pam_context, ccache_perm); 656 retval = PAM_SERVICE_ERR; 657 goto cleanup2; 658 } 659 PAM_LOG("Done chown()"); 660 661 if (chmod(&cache_name[5], (S_IRUSR | S_IWUSR)) == -1) { 662 PAM_LOG("Error chmod(): %s", strerror(errno)); 663 krb5_cc_destroy(pam_context, ccache_perm); 664 retval = PAM_SERVICE_ERR; 665 goto cleanup2; 666 } 667 PAM_LOG("Done chmod()"); 668 } 669 670 krb5_cc_close(pam_context, ccache_perm); 671 672 PAM_LOG("Cache closed"); 673 674 cache_env_name = malloc(strlen(cache_name) + 12); 675 if (!cache_env_name) { 676 PAM_LOG("Error malloc(): failure"); 677 krb5_cc_destroy(pam_context, ccache_perm); 678 retval = PAM_BUF_ERR; 679 goto cleanup2; 680 } 681 682 sprintf(cache_env_name, "KRB5CCNAME=%s", cache_name); 683 if ((retval = pam_putenv(pamh, cache_env_name)) != 0) { 684 PAM_LOG("Error pam_putenv(): %s", pam_strerror(pamh, retval)); 685 krb5_cc_destroy(pam_context, ccache_perm); 686 retval = PAM_SERVICE_ERR; 687 goto cleanup2; 688 } 689 690 PAM_LOG("Environment done: KRB5CCNAME=%s", cache_name); 691 692cleanup2: 693 krb5_free_principal(pam_context, princ); 694 PAM_LOG("Done cleanup2"); 695cleanup3: 696 krb5_free_context(pam_context); 697 PAM_LOG("Done cleanup3"); 698 699 seteuid(euid); 700 setegid(egid); 701 702 PAM_LOG("Done seteuid() & setegid()"); 703 704 PAM_RETURN(retval); 705} 706 707/* 708 * account management 709 */ 710PAM_EXTERN int 711pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, int argc, const char **argv) 712{ 713 krb5_error_code krbret; 714 krb5_context pam_context; 715 krb5_ccache ccache; 716 krb5_principal princ; 717 struct options options; 718 int retval; 719 const char *user; 720 721 pam_std_option(&options, other_options, argc, argv); 722 723 PAM_LOG("Options processed"); 724 725 retval = pam_get_item(pamh, PAM_USER, (const void **)&user); 726 if (retval != PAM_SUCCESS) 727 PAM_RETURN(retval); 728 729 PAM_LOG("Got user: %s", user); 730 731 retval = pam_get_data(pamh, "ccache", (const void **)&ccache); 732 if (retval != PAM_SUCCESS) 733 PAM_RETURN(PAM_SUCCESS); 734 735 PAM_LOG("Got ccache"); 736 737 krbret = krb5_init_context(&pam_context); 738 if (krbret != 0) { 739 PAM_LOG("Error krb5_init_context(): %s", error_message(krbret)); 740 PAM_RETURN(PAM_PERM_DENIED); 741 } 742 743 PAM_LOG("Context initialised"); 744 745 krbret = krb5_cc_get_principal(pam_context, ccache, &princ); 746 if (krbret != 0) { 747 PAM_LOG("Error krb5_cc_get_principal(): %s", error_message(krbret)); 748 retval = PAM_PERM_DENIED;; 749 goto cleanup; 750 } 751 752 PAM_LOG("Got principal"); 753 754 if (krb5_kuserok(pam_context, princ, user)) 755 retval = PAM_SUCCESS; 756 else 757 retval = PAM_PERM_DENIED; 758 krb5_free_principal(pam_context, princ); 759 760 PAM_LOG("Done kuserok()"); 761 762cleanup: 763 krb5_free_context(pam_context); 764 PAM_LOG("Done cleanup"); 765 766 PAM_RETURN(retval); 767 768} 769 770/* 771 * session management 772 * 773 * logging only 774 */ 775PAM_EXTERN int 776pam_sm_open_session(pam_handle_t *pamh, int flags, int argc, const char **argv) 777{ 778 struct options options; 779 780 pam_std_option(&options, NULL, argc, argv); 781 782 PAM_LOG("Options processed"); 783 784 PAM_RETURN(PAM_SUCCESS); 785} 786 787PAM_EXTERN int 788pam_sm_close_session(pam_handle_t *pamh, int flags, int argc, const char **argv) 789{ 790 struct options options; 791 792 pam_std_option(&options, NULL, argc, argv); 793 794 PAM_LOG("Options processed"); 795 796 PAM_RETURN(PAM_SUCCESS); 797} 798 799/* 800 * password management 801 */ 802PAM_EXTERN int 803pam_sm_chauthtok(pam_handle_t *pamh, int flags, int argc, const char **argv) 804{ 805 krb5_error_code krbret; 806 krb5_context pam_context; 807 krb5_creds creds; 808 krb5_principal princ; 809 krb5_get_init_creds_opt opts; 810 krb5_data result_code_string, result_string; 811 struct options options; 812 int result_code, retval; 813 const char *user, *pass, *pass2; 814 char *princ_name; 815 816 pam_std_option(&options, other_options, argc, argv); 817 818 PAM_LOG("Options processed"); 819 820 if (!(flags & PAM_UPDATE_AUTHTOK)) 821 PAM_RETURN(PAM_AUTHTOK_ERR); 822 823 retval = pam_get_item(pamh, PAM_USER, (const void **)&user); 824 if (retval != PAM_SUCCESS) 825 PAM_RETURN(retval); 826 827 PAM_LOG("Got user: %s", user); 828 829 krbret = krb5_init_context(&pam_context); 830 if (krbret != 0) { 831 PAM_LOG("Error krb5_init_context(): %s", error_message(krbret)); 832 PAM_RETURN(PAM_SERVICE_ERR); 833 } 834 835 PAM_LOG("Context initialised"); 836 837 krb5_get_init_creds_opt_init(&opts); 838 839 PAM_LOG("Credentials options initialised"); 840 841 /* Get principal name */ 842 krbret = krb5_parse_name(pam_context, user, &princ); 843 if (krbret != 0) { 844 PAM_LOG("Error krb5_parse_name(): %s", error_message(krbret)); 845 retval = PAM_USER_UNKNOWN; 846 goto cleanup3; 847 } 848 849 /* Now convert the principal name into something human readable */ 850 princ_name = NULL; 851 krbret = krb5_unparse_name(pam_context, princ, &princ_name); 852 if (krbret != 0) { 853 PAM_LOG("Error krb5_unparse_name(): %s", error_message(krbret)); 854 retval = PAM_SERVICE_ERR; 855 goto cleanup2; 856 } 857 858 PAM_LOG("Got principal: %s", princ_name); 859 860 /* Get password */ 861 retval = pam_get_pass(pamh, &pass, PASSWORD_PROMPT, &options); 862 if (retval != PAM_SUCCESS) 863 goto cleanup2; 864 865 PAM_LOG("Got password"); 866 867 memset(&creds, 0, sizeof(krb5_creds)); 868 krbret = krb5_get_init_creds_password(pam_context, &creds, princ, 869 pass, NULL, pamh, 0, "kadmin/changepw", &opts); 870 if (krbret != 0) { 871 PAM_LOG("Error krb5_get_init_creds_password()", 872 error_message(krbret)); 873 retval = PAM_AUTH_ERR; 874 goto cleanup2; 875 } 876 877 PAM_LOG("Credentials established"); 878 879 /* Now get the new password */ 880 retval = pam_get_pass(pamh, &pass, NEW_PASSWORD_PROMPT, &options); 881 if (retval != PAM_SUCCESS) 882 goto cleanup; 883 884 retval = pam_get_pass(pamh, &pass2, NEW_PASSWORD_PROMPT_2, &options); 885 if (retval != PAM_SUCCESS) 886 goto cleanup; 887 888 PAM_LOG("Got new password twice"); 889 890 if (strcmp(pass, pass2) != 0) { 891 PAM_LOG("Error strcmp(): passwords are different"); 892 retval = PAM_AUTHTOK_ERR; 893 goto cleanup; 894 } 895 896 PAM_LOG("New passwords are the same"); 897 898 /* Change it */ 899 krbret = krb5_change_password(pam_context, &creds, (char *)pass, 900 &result_code, &result_code_string, &result_string); 901 if (krbret != 0) { 902 PAM_LOG("Error krb5_change_password(): %s", 903 error_message(krbret)); 904 retval = PAM_AUTHTOK_ERR; 905 goto cleanup; 906 } 907 if (result_code) { 908 PAM_LOG("Error krb5_change_password(): (result_code)"); 909 retval = PAM_AUTHTOK_ERR; 910 goto cleanup; 911 } 912 913 PAM_LOG("Password changed"); 914 915 if (result_string.data) 916 free(result_string.data); 917 if (result_code_string.data) 918 free(result_code_string.data); 919 920cleanup: 921 krb5_free_cred_contents(pam_context, &creds); 922 PAM_LOG("Done cleanup"); 923cleanup2: 924 krb5_free_principal(pam_context, princ); 925 PAM_LOG("Done cleanup2"); 926cleanup3: 927 if (princ_name) 928 free(princ_name); 929 930 krb5_free_context(pam_context); 931 932 PAM_LOG("Done cleanup3"); 933 934 PAM_RETURN(retval); 935} 936 937PAM_MODULE_ENTRY("pam_krb5"); 938 939/* 940 * This routine with some modification is from the MIT V5B6 appl/bsd/login.c 941 * Modified by Sam Hartman <hartmans@mit.edu> to support PAM services 942 * for Debian. 943 * 944 * Verify the Kerberos ticket-granting ticket just retrieved for the 945 * user. If the Kerberos server doesn't respond, assume the user is 946 * trying to fake us out (since we DID just get a TGT from what is 947 * supposedly our KDC). If the host/<host> service is unknown (i.e., 948 * the local keytab doesn't have it), and we cannot find another 949 * service we do have, let her in. 950 * 951 * Returns 1 for confirmation, -1 for failure, 0 for uncertainty. 952 */ 953static int 954verify_krb_v5_tgt(krb5_context context, krb5_ccache ccache, 955 char *pam_service, int debug) 956{ 957 krb5_error_code retval; 958 krb5_principal princ; 959 krb5_keyblock *keyblock; 960 krb5_data packet; 961 krb5_auth_context auth_context; 962 char phost[BUFSIZ], *services[3], **service; 963 964 packet.data = 0; 965 966 /* If possible we want to try and verify the ticket we have 967 * received against a keytab. We will try multiple service 968 * principals, including at least the host principal and the PAM 969 * service principal. The host principal is preferred because access 970 * to that key is generally sufficient to compromise root, while the 971 * service key for this PAM service may be less carefully guarded. 972 * It is important to check the keytab first before the KDC so we do 973 * not get spoofed by a fake KDC. 974 */ 975 services[0] = "host"; 976 services[1] = pam_service; 977 services[2] = NULL; 978 keyblock = 0; 979 retval = -1; 980 for (service = &services[0]; *service != NULL; service++) { 981 retval = krb5_sname_to_principal(context, NULL, *service, 982 KRB5_NT_SRV_HST, &princ); 983 if (retval != 0) { 984 if (debug) 985 syslog(LOG_DEBUG, "pam_krb5: verify_krb_v5_tgt(): %s: %s", "krb5_sname_to_principal()", error_message(retval)); 986 return -1; 987 } 988 989 /* Extract the name directly. */ 990 strncpy(phost, compat_princ_component(context, princ, 1), 991 BUFSIZ); 992 phost[BUFSIZ - 1] = '\0'; 993 994 /* 995 * Do we have service/<host> keys? 996 * (use default/configured keytab, kvno IGNORE_VNO to get the 997 * first match, and ignore enctype.) 998 */ 999 retval = krb5_kt_read_service_key(context, NULL, princ, 0, 0, 1000 &keyblock); 1001 if (retval != 0) 1002 continue; 1003 break; 1004 } 1005 if (retval != 0) { /* failed to find key */ 1006 /* Keytab or service key does not exist */ 1007 if (debug) 1008 syslog(LOG_DEBUG, "pam_krb5: verify_krb_v5_tgt(): %s: %s", "krb5_kt_read_service_key()", error_message(retval)); 1009 retval = 0; 1010 goto cleanup; 1011 } 1012 if (keyblock) 1013 krb5_free_keyblock(context, keyblock); 1014 1015 /* Talk to the kdc and construct the ticket. */ 1016 auth_context = NULL; 1017 retval = krb5_mk_req(context, &auth_context, 0, *service, phost, 1018 NULL, ccache, &packet); 1019 if (auth_context) { 1020 krb5_auth_con_free(context, auth_context); 1021 auth_context = NULL; /* setup for rd_req */ 1022 } 1023 if (retval) { 1024 if (debug) 1025 syslog(LOG_DEBUG, "pam_krb5: verify_krb_v5_tgt(): %s: %s", "krb5_mk_req()", error_message(retval)); 1026 retval = -1; 1027 goto cleanup; 1028 } 1029 1030 /* Try to use the ticket. */ 1031 retval = krb5_rd_req(context, &auth_context, &packet, princ, NULL, 1032 NULL, NULL); 1033 if (retval) { 1034 if (debug) 1035 syslog(LOG_DEBUG, "pam_krb5: verify_krb_v5_tgt(): %s: %s", "krb5_rd_req()", error_message(retval)); 1036 retval = -1; 1037 } 1038 else 1039 retval = 1; 1040 1041cleanup: 1042 if (packet.data) 1043 compat_free_data_contents(context, &packet); 1044 krb5_free_principal(context, princ); 1045 return retval; 1046} 1047 1048/* Free the memory for cache_name. Called by pam_end() */ 1049static void 1050cleanup_cache(pam_handle_t *pamh, void *data, int pam_end_status) 1051{ 1052 krb5_context pam_context; 1053 krb5_ccache ccache; 1054 1055 if (krb5_init_context(&pam_context)) 1056 return; 1057 1058 ccache = (krb5_ccache)data; 1059 krb5_cc_destroy(pam_context, ccache); 1060 krb5_free_context(pam_context); 1061} 1062 1063#ifdef COMPAT_HEIMDAL 1064#ifdef COMPAT_MIT 1065#error This cannot be MIT and Heimdal compatible! 1066#endif 1067#endif 1068 1069#ifndef COMPAT_HEIMDAL 1070#ifndef COMPAT_MIT 1071#error One of COMPAT_MIT and COMPAT_HEIMDAL must be specified! 1072#endif 1073#endif 1074 1075#ifdef COMPAT_HEIMDAL 1076static const char * 1077compat_princ_component(krb5_context context, krb5_principal princ, int n) 1078{ 1079 return princ->name.name_string.val[n]; 1080} 1081 1082static void 1083compat_free_data_contents(krb5_context context, krb5_data * data) 1084{ 1085 krb5_xfree(data->data); 1086} 1087#endif 1088 1089#ifdef COMPAT_MIT 1090static const char * 1091compat_princ_component(krb5_context context, krb5_principal princ, int n) 1092{ 1093 return krb5_princ_component(context, princ, n)->data; 1094} 1095 1096static void 1097compat_free_data_contents(krb5_context context, krb5_data * data) 1098{ 1099 krb5_free_data_contents(context, data); 1100} 1101#endif 1102