1/*- 2 * This pam_krb5 module contains code that is: 3 * Copyright (c) Derrick J. Brashear, 1996. All rights reserved. 4 * Copyright (c) Frank Cusack, 1999-2001. All rights reserved. 5 * Copyright (c) Jacques A. Vidrine, 2000-2001. All rights reserved. 6 * Copyright (c) Nicolas Williams, 2001. All rights reserved. 7 * Copyright (c) Perot Systems Corporation, 2001. All rights reserved. 8 * Copyright (c) Mark R V Murray, 2001. All rights reserved. 9 * Copyright (c) Networks Associates Technology, Inc., 2002-2005. 10 * All rights reserved. 11 * Copyright (c) 2008-2009 Apple Inc. All rights reserved. 12 * 13 * Portions of this software were developed for the FreeBSD Project by 14 * ThinkSec AS and NAI Labs, the Security Research Division of Network 15 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 16 * ("CBOSS"), as part of the DARPA CHATS research program. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notices, and the entire permission notice in its entirety, 23 * including the disclaimer of warranties. 24 * 2. Redistributions in binary form must reproduce the above copyright 25 * notice, this list of conditions and the following disclaimer in the 26 * documentation and/or other materials provided with the distribution. 27 * 3. The name of the author may not be used to endorse or promote 28 * products derived from this software without specific prior 29 * written permission. 30 * 31 * ALTERNATIVELY, this product may be distributed under the terms of 32 * the GNU Public License, in which case the provisions of the GPL are 33 * required INSTEAD OF the above restrictions. (This clause is 34 * necessary due to a potential bad interaction between the GPL and 35 * the restrictions contained in a BSD-style copyright.) 36 * 37 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 38 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 39 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 40 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 41 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 42 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 43 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 47 * OF THE POSSIBILITY OF SUCH DAMAGE. 48 */ 49 50#include <sys/cdefs.h> 51 52#include <sys/types.h> 53#include <sys/stat.h> 54#include <errno.h> 55#include <limits.h> 56#include <pwd.h> 57#include <stdio.h> 58#include <stdlib.h> 59#include <string.h> 60#include <unistd.h> 61 62#define KRB5_DEPRECATED_FUNCTION(x) /* no warnings for now :`( */ 63 64#include <Heimdal/krb5.h> 65#include <Heimdal/com_err.h> 66 67#include <CoreFoundation/CoreFoundation.h> 68#include <OpenDirectory/OpenDirectory.h> 69 70#define PAM_SM_AUTH 71#define PAM_SM_ACCOUNT 72#define PAM_SM_PASSWORD 73 74#include <security/pam_appl.h> 75#include <security/pam_modules.h> 76#include <security/openpam.h> 77 78/* _krb5_kcm_get_initial_ticket is SPI, so define it here for now */ 79krb5_error_code _krb5_kcm_get_initial_ticket(krb5_context context, 80 krb5_ccache id, 81 krb5_principal client, 82 krb5_principal server, 83 const char *password); 84 85 86#define COMPAT_HEIMDAL 87/* #define COMPAT_MIT */ 88 89static int verify_krb_v5_tgt(krb5_context, krb5_ccache, char *, int); 90static const char *compat_princ_component(krb5_context, krb5_principal, int); 91static void compat_free_data_contents(krb5_context, krb5_data *); 92 93#define USER_PROMPT "Username: " 94#define PASSWORD_PROMPT "Password:" 95#define NEW_PASSWORD_PROMPT "New Password:" 96 97#define PAM_OPT_CCACHE "ccache" 98#define PAM_OPT_DEBUG "debug" 99#define PAM_OPT_DEFAULT_PRINCIPAL "default_principal" 100#define PAM_OPT_FORWARDABLE "forwardable" 101#define PAM_OPT_NO_FORWARDABLE "noforward" 102#define PAM_OPT_NO_CCACHE "no_ccache" 103#define PAM_OPT_USE_KCMINIT "use_kcminit" 104#define PAM_OPT_REUSE_CCACHE "reuse_ccache" 105#define PAM_OPT_USE_FIRST_PASS "use_first_pass" 106 107#define PAM_OPT_AUTH_AS_SELF "auth_as_self" 108#define PAM_OPT_DEBUG "debug" 109 110#define PAM_LOG(...) \ 111 openpam_log(PAM_LOG_DEBUG, __VA_ARGS__) 112 113#define PAM_VERBOSE_ERROR(...) \ 114openpam_log(PAM_LOG_ERROR, __VA_ARGS__) 115 116#ifdef COMPAT_MIT 117#define krb5_get_err_text(c,e) error_message(e) 118#endif 119 120#include "Common.h" 121 122static const char *password_key = "KRB5PWD"; 123static const char *user_key = "KRB5USER"; 124 125 126/* 127 * authentication management 128 */ 129PAM_EXTERN int 130pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 131 int argc __unused, const char *argv[] __unused) 132{ 133 krb5_error_code krbret; 134 krb5_context pam_context; 135 krb5_creds creds; 136 krb5_principal princ; 137 krb5_ccache ccache; 138 krb5_get_init_creds_opt *opts = NULL; 139 struct passwd *pwd; 140 struct passwd pwdbuf; 141 char pwbuffer[2 * PATH_MAX]; 142 int retval, have_tickets = 0; 143 const void *ccache_data; 144 const char *user; 145 char *pass; 146 const void *sourceuser, *service; 147 char *principal = NULL, *princ_name = NULL, *ccache_name, luser[32], *srvdup; 148 149 retval = pam_get_user(pamh, &user, USER_PROMPT); 150 if (retval != PAM_SUCCESS) 151 return (retval); 152 153 PAM_LOG("Got user: %s", user); 154 155 retval = pam_get_item(pamh, PAM_RUSER, &sourceuser); 156 if (retval != PAM_SUCCESS) 157 return (retval); 158 159 PAM_LOG("Got ruser: %s", (const char *)sourceuser); 160 161 service = NULL; 162 pam_get_item(pamh, PAM_SERVICE, &service); 163 if (service == NULL) 164 service = "unknown"; 165 166 PAM_LOG("Got service: %s", (const char *)service); 167 168 krbret = krb5_init_context(&pam_context); 169 if (krbret != 0) { 170 PAM_VERBOSE_ERROR("Kerberos 5 error"); 171 return (PAM_SERVICE_ERR); 172 } 173 174 /* Get principal name */ 175 if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF)) 176 asprintf(&principal, "%s/%s", (const char *)sourceuser, user); 177 else if (NULL == openpam_get_option(pamh, PAM_OPT_DEFAULT_PRINCIPAL)) 178 od_principal_for_user(pamh, user, &principal); 179 else 180 principal = strdup(user); 181 if (principal == NULL) { 182 PAM_LOG("Failed to determine Kerberos principal name."); 183 retval = PAM_SERVICE_ERR; 184 goto cleanup3; 185 } 186 187 PAM_LOG("Context initialised"); 188 189 /* if we are running with KCMINIT, just store the password in the kcm cache */ 190 if (openpam_get_option(pamh, PAM_OPT_USE_KCMINIT)) { 191 PAM_LOG("Stashing kcm credentials in enviroment for kcminit: %s", principal); 192 193 retval = pam_get_authtok(pamh, PAM_AUTHTOK, (const char **)&pass, PASSWORD_PROMPT); 194 if (retval != PAM_SUCCESS) { 195 PAM_LOG("no password: %s", principal); 196 goto cleanup3; 197 } 198 199 retval = pam_setenv(pamh, user_key, principal, 1); 200 if (retval != PAM_SUCCESS) 201 goto cleanup3; 202 203 retval = pam_setenv(pamh, password_key, pass, 1); 204 if (retval != PAM_SUCCESS) { 205 goto cleanup3; 206 } 207 208 free(principal); 209 krb5_free_context(pam_context); 210 211 return (PAM_IGNORE); 212 } 213 214 krbret = krb5_get_init_creds_opt_alloc(pam_context, &opts); 215 if (krbret) { 216 retval = PAM_SERVICE_ERR; 217 goto cleanup3; 218 } 219 220 if (NULL != openpam_get_option(pamh, PAM_OPT_NO_FORWARDABLE) && 221 NULL != openpam_get_option(pamh, PAM_OPT_FORWARDABLE)) { 222 PAM_VERBOSE_ERROR("Do not set both \"%s\" and \"%s\".", PAM_OPT_FORWARDABLE, PAM_OPT_NO_FORWARDABLE); 223 retval = PAM_SERVICE_ERR; 224 goto cleanup3; 225 } 226 227 PAM_LOG("Created principal: %s", principal); 228 229 krbret = krb5_parse_name(pam_context, principal, &princ); 230 free(principal); 231 if (krbret != 0) { 232 PAM_LOG("Error krb5_parse_name(): %s", 233 krb5_get_err_text(pam_context, krbret)); 234 PAM_VERBOSE_ERROR("Kerberos 5 error"); 235 retval = PAM_SERVICE_ERR; 236 goto cleanup3; 237 } 238 239 PAM_LOG("Done krb5_parse_name()"); 240 241 /* Now convert the principal name into something human readable */ 242 princ_name = NULL; 243 krbret = krb5_unparse_name(pam_context, princ, &princ_name); 244 if (krbret != 0) { 245 PAM_LOG("Error krb5_unparse_name(): %s", 246 krb5_get_err_text(pam_context, krbret)); 247 PAM_VERBOSE_ERROR("Kerberos 5 error"); 248 retval = PAM_SERVICE_ERR; 249 goto cleanup2; 250 } 251 252 PAM_LOG("Got principal: %s", princ_name); 253 254 /* Get password */ 255 retval = pam_get_authtok(pamh, PAM_AUTHTOK, (const char **)&pass, PASSWORD_PROMPT); 256 if (retval != PAM_SUCCESS) 257 goto cleanup2; 258 259 PAM_LOG("Got password"); 260 261 /* Verify the local user exists (AFTER getting the password) */ 262 if (strchr(user, '@')) { 263 /* get a local account name for this principal */ 264 krbret = krb5_aname_to_localname(pam_context, princ, 265 sizeof(luser), luser); 266 if (krbret != 0) { 267 PAM_VERBOSE_ERROR("Kerberos 5 error"); 268 PAM_LOG("Error krb5_aname_to_localname(): %s", 269 krb5_get_err_text(pam_context, krbret)); 270 retval = PAM_USER_UNKNOWN; 271 goto cleanup2; 272 } 273 274 retval = pam_set_item(pamh, PAM_USER, luser); 275 if (retval != PAM_SUCCESS) 276 goto cleanup2; 277 278 PAM_LOG("PAM_USER Redone"); 279 } 280 281 if (getpwnam_r(user, &pwdbuf, pwbuffer, sizeof(pwbuffer), &pwd) != 0 || pwd == NULL) { 282 retval = PAM_USER_UNKNOWN; 283 goto cleanup2; 284 } 285 286 PAM_LOG("Done getpwnam()"); 287 288 /* Get a TGT */ 289 if (NULL == openpam_get_option(pamh, PAM_OPT_NO_FORWARDABLE)) { 290 krb5_get_init_creds_opt_set_forwardable(opts, 1); 291 krb5_get_init_creds_opt_set_proxiable(opts, 1); 292 293 PAM_LOG("Attempting to get forwardable TGT."); 294 memset(&creds, 0, sizeof(krb5_creds)); 295 krbret = krb5_get_init_creds_password(pam_context, &creds, princ, 296 pass, NULL, pamh, 0, NULL, opts); 297 if (krbret != 0) { 298 krb5_get_init_creds_opt_set_forwardable(opts, 0); 299 krb5_get_init_creds_opt_set_proxiable(opts, 0); 300 } else { 301 PAM_LOG("Have a forwardable TGT."); 302 have_tickets = 1; 303 } 304 } 305 306 if (!have_tickets) { 307 PAM_LOG("Attempting to get non-forwardable TGT."); 308 memset(&creds, 0, sizeof(krb5_creds)); 309 krbret = krb5_get_init_creds_password(pam_context, &creds, princ, 310 pass, NULL, pamh, 0, NULL, opts); 311 if (krbret != 0) { 312 PAM_VERBOSE_ERROR("Kerberos 5 error"); 313 PAM_LOG("Error krb5_get_init_creds_password(): %s", 314 krb5_get_err_text(pam_context, krbret)); 315 retval = PAM_AUTH_ERR; 316 goto cleanup2; 317 } 318 } 319 320 PAM_LOG("Got TGT"); 321 322 /* Generate a temporary cache */ 323 krbret = krb5_cc_new_unique(pam_context, "FILE", NULL, &ccache); 324 if (krbret != 0) { 325 PAM_VERBOSE_ERROR("Kerberos 5 error"); 326 PAM_LOG("Error krb5_cc_gen_new(): %s", 327 krb5_get_err_text(pam_context, krbret)); 328 retval = PAM_SERVICE_ERR; 329 goto cleanup; 330 } 331 krbret = krb5_cc_initialize(pam_context, ccache, princ); 332 if (krbret != 0) { 333 PAM_VERBOSE_ERROR("Kerberos 5 error"); 334 PAM_LOG("Error krb5_cc_initialize(): %s", 335 krb5_get_err_text(pam_context, krbret)); 336 retval = PAM_SERVICE_ERR; 337 goto cleanup; 338 } 339 krbret = krb5_cc_store_cred(pam_context, ccache, &creds); 340 if (krbret != 0) { 341 PAM_VERBOSE_ERROR("Kerberos 5 error"); 342 PAM_LOG("Error krb5_cc_store_cred(): %s", 343 krb5_get_err_text(pam_context, krbret)); 344 krb5_cc_destroy(pam_context, ccache); 345 retval = PAM_SERVICE_ERR; 346 goto cleanup; 347 } 348 if (0 == strcmp("FILE", krb5_cc_get_type(pam_context, ccache))) 349 chown(krb5_cc_get_name(pam_context, ccache), pwd->pw_uid, pwd->pw_gid); 350 351 PAM_LOG("Credentials stashed"); 352 353 /* Verify them */ 354 if ((srvdup = strdup(service)) == NULL) { 355 retval = PAM_BUF_ERR; 356 goto cleanup; 357 } 358 krbret = verify_krb_v5_tgt(pam_context, ccache, srvdup, 359 openpam_get_option(pamh, PAM_OPT_DEBUG) ? 1 : 0); 360 free(srvdup); 361 if (krbret == -1) { 362 PAM_VERBOSE_ERROR("Kerberos 5 error"); 363 krb5_cc_destroy(pam_context, ccache); 364 retval = PAM_AUTH_ERR; 365 goto cleanup; 366 } 367 368 PAM_LOG("Credentials stash verified"); 369 370 retval = pam_get_data(pamh, "ccache", &ccache_data); 371 if (retval == PAM_SUCCESS) { 372 krb5_cc_destroy(pam_context, ccache); 373 PAM_VERBOSE_ERROR("Kerberos 5 error"); 374 retval = PAM_AUTH_ERR; 375 goto cleanup; 376 } 377 378 PAM_LOG("Credentials stash not pre-existing"); 379 380 asprintf(&ccache_name, "%s:%s", krb5_cc_get_type(pam_context, 381 ccache), krb5_cc_get_name(pam_context, ccache)); 382 if (ccache_name == NULL) { 383 PAM_VERBOSE_ERROR("Kerberos 5 error"); 384 retval = PAM_BUF_ERR; 385 goto cleanup; 386 } 387 retval = pam_setenv(pamh, "krb5_ccache", ccache_name, 1); 388 if (retval != 0) { 389 krb5_cc_destroy(pam_context, ccache); 390 PAM_VERBOSE_ERROR("Kerberos 5 error"); 391 retval = PAM_SERVICE_ERR; 392 goto cleanup; 393 } 394 395 PAM_LOG("Credentials stash saved"); 396 397cleanup: 398 krb5_free_cred_contents(pam_context, &creds); 399 PAM_LOG("Done cleanup"); 400cleanup2: 401 krb5_free_principal(pam_context, princ); 402 PAM_LOG("Done cleanup2"); 403cleanup3: 404 if (princ_name) 405 free(princ_name); 406 407 if (opts) 408 krb5_get_init_creds_opt_free(pam_context, opts); 409 410 krb5_free_context(pam_context); 411 412 PAM_LOG("Done cleanup3"); 413 414 if (retval != PAM_SUCCESS) 415 PAM_LOG("Kerberos 5 refuses you"); 416 417 return (retval); 418} 419 420PAM_EXTERN int 421pam_sm_setcred(pam_handle_t *pamh, int flags, 422 int argc __unused, const char *argv[] __unused) 423{ 424#ifdef _FREEFALL_CONFIG 425 return (PAM_SUCCESS); 426#else 427 428 krb5_error_code krbret; 429 krb5_context pam_context; 430 krb5_principal princ = NULL; 431 krb5_creds creds; 432 krb5_ccache ccache_temp, ccache_perm = NULL; 433 krb5_cc_cursor cursor; 434 struct passwd *pwd = NULL; 435 struct passwd pwdbuf; 436 char pwbuffer[2 * PATH_MAX]; 437 int retval; 438 const char *cache_type, *cache_name, *q; 439 const void *user; 440 const void *cache_data; 441 char *cache_name_buf = NULL, *p = NULL, *cache_type_colon_name = NULL; 442 int use_kcminit; 443 444 uid_t euid; 445 gid_t egid; 446 447 if (flags & PAM_DELETE_CRED) { 448 retval = PAM_SUCCESS; 449 goto cleanup4; 450 } 451 452 if (flags & PAM_REFRESH_CRED) { 453 retval = PAM_SUCCESS; 454 goto cleanup4; 455 } 456 457 if (flags & PAM_REINITIALIZE_CRED) { 458 retval = PAM_SUCCESS; 459 goto cleanup4; 460 } 461 462 if (!(flags & PAM_ESTABLISH_CRED)) { 463 retval = PAM_SERVICE_ERR; 464 goto cleanup4; 465 } 466 467 /* If a persistent cache isn't desired, stop now. */ 468 if (openpam_get_option(pamh, PAM_OPT_NO_CCACHE)) { 469 retval = PAM_SUCCESS; 470 goto cleanup4; 471 } 472 473 PAM_LOG("Establishing credentials"); 474 475 /* Get username */ 476 retval = pam_get_item(pamh, PAM_USER, &user); 477 if (retval != PAM_SUCCESS) 478 goto cleanup4; 479 480 PAM_LOG("Got user: %s", (const char *)user); 481 482 krbret = krb5_init_context(&pam_context); 483 if (krbret != 0) { 484 PAM_LOG("Error krb5_init_secure_context() failed"); 485 retval = PAM_SERVICE_ERR; 486 goto cleanup4; 487 } 488 489 PAM_LOG("Context initialised"); 490 491 euid = geteuid(); /* Usually 0 */ 492 egid = getegid(); 493 494 PAM_LOG("Got euid, egid: %d %d", euid, egid); 495 496 use_kcminit = (openpam_get_option(pamh, PAM_OPT_USE_KCMINIT) != NULL); 497 498 if (!use_kcminit) { 499 /* Retrieve the temporary cache */ 500 if ((cache_data = pam_getenv(pamh, "krb5_ccache")) == NULL) { 501 PAM_LOG("Error pam_getenv failed."); 502 retval = PAM_IGNORE; 503 goto cleanup3; 504 } 505 krbret = krb5_cc_resolve(pam_context, cache_data, &ccache_temp); 506 if (krbret != 0) { 507 PAM_LOG("Error krb5_cc_resolve(\"%s\"): %s", (const char *)cache_data, 508 krb5_get_err_text(pam_context, krbret)); 509 retval = PAM_SERVICE_ERR; 510 goto cleanup3; 511 } 512 } 513 /* Get the uid. This should exist. */ 514 if (getpwnam_r(user, &pwdbuf, pwbuffer, sizeof(pwbuffer), &pwd) != 0 || pwd == NULL) { 515 retval = PAM_USER_UNKNOWN; 516 goto cleanup3; 517 } 518 519 PAM_LOG("Done getpwnam()"); 520 521 /* Avoid following a symlink as root */ 522 if (0 == egid && 0 != setegid(pwd->pw_gid)) { 523 retval = PAM_SERVICE_ERR; 524 goto cleanup3; 525 } 526 if (0 == euid && 0 != seteuid(pwd->pw_uid)) { 527 retval = PAM_SERVICE_ERR; 528 goto cleanup3; 529 } 530 531 PAM_LOG("Done setegid() & seteuid()"); 532 533 534 if (use_kcminit) { 535 const char *principal, *password; 536 krb5_principal princ = NULL; 537 538 principal = pam_getenv(pamh, user_key); 539 if (principal == NULL) { 540 PAM_LOG("pam_sm_setcred: krb5 user %s doesn't have a principal", (char *)user); 541 retval = PAM_SERVICE_ERR; 542 goto cleanup3; 543 } 544 545 password = pam_getenv(pamh, password_key); 546 if (password == NULL) { 547 PAM_LOG("pam_sm_setcred: krb5 user %s doesn't have a password", (char *)user); 548 retval = PAM_SERVICE_ERR; 549 goto cleanup3; 550 } 551 552 krbret = krb5_parse_name(pam_context, principal, &princ); 553 if (krbret != 0) { 554 retval = PAM_SERVICE_ERR; 555 goto cleanup3; 556 } 557 558 krbret = krb5_cc_new_unique(pam_context, "API", NULL, &ccache_perm); 559 if (krbret) { 560 krb5_free_principal(pam_context, princ); 561 retval = PAM_SERVICE_ERR; 562 goto cleanup3; 563 } 564 PAM_LOG("pam_sm_setcred: init credential cache"); 565 566 krbret = krb5_cc_initialize(pam_context, ccache_perm, princ); 567 if (krbret) { 568 krb5_free_principal(pam_context, princ); 569 krb5_cc_close(pam_context, ccache_perm); 570 retval = PAM_SERVICE_ERR; 571 goto cleanup3; 572 } 573 574 PAM_LOG("pam_sm_setcred: storing credential for: %s", principal); 575 krbret = _krb5_kcm_get_initial_ticket(pam_context, ccache_perm, princ, NULL, password); 576 krb5_free_principal(pam_context, princ); 577 if (krbret) { 578 PAM_LOG("kcm init failed: %d", krbret); 579 retval = PAM_SERVICE_ERR; 580 goto cleanup3; 581 } 582 retval = PAM_SUCCESS; 583 } else { 584 585 /* Initialize the new ccache */ 586 krbret = krb5_cc_get_principal(pam_context, ccache_temp, &princ); 587 if (krbret != 0) { 588 PAM_LOG("Error krb5_cc_get_principal(): %s", 589 krb5_get_err_text(pam_context, krbret)); 590 retval = PAM_SERVICE_ERR; 591 goto cleanup3; 592 } 593 594 /* Get the cache name */ 595 cache_name = openpam_get_option(pamh, PAM_OPT_CCACHE); 596 if (cache_name == NULL) { 597 krbret = krb5_cc_default(pam_context, &ccache_perm); 598 } 599 else { 600 size_t len = (PATH_MAX + 16); 601 p = calloc(len, sizeof(char)); 602 q = cache_name; 603 604 if (p == NULL) { 605 PAM_LOG("Error malloc(): failure"); 606 retval = PAM_BUF_ERR; 607 goto cleanup3; 608 } 609 cache_name = cache_name_buf = p; 610 611 /* convert %u and %p */ 612 while (*q) { 613 if (*q == '%') { 614 q++; 615 if (*q == 'u') { 616 len -= snprintf(p, len, "%d", pwd->pw_uid); 617 p += strlen(p); 618 } 619 else if (*q == 'p') { 620 len -= snprintf(p, len, "%d", getpid()); 621 p += strlen(p); 622 } 623 else { 624 /* Not a special token */ 625 *p++ = '%'; 626 len--; 627 q--; 628 } 629 q++; 630 } 631 else { 632 *p++ = *q++; 633 len--; 634 } 635 } 636 637 PAM_LOG("Got cache_name: %s", cache_name); 638 639 krbret = krb5_cc_resolve(pam_context, cache_name, &ccache_perm); 640 if (krbret != 0) { 641 PAM_LOG("Error krb5_cc_resolve(): %s", 642 krb5_get_err_text(pam_context, krbret)); 643 retval = PAM_SERVICE_ERR; 644 goto cleanup2; 645 } 646 } 647 krbret = krb5_cc_initialize(pam_context, ccache_perm, princ); 648 if (krbret != 0) { 649 PAM_LOG("Error krb5_cc_initialize(): %s", 650 krb5_get_err_text(pam_context, krbret)); 651 retval = PAM_SERVICE_ERR; 652 goto cleanup2; 653 } 654 655 PAM_LOG("Cache initialised"); 656 657 /* Prepare for iteration over creds */ 658 krbret = krb5_cc_start_seq_get(pam_context, ccache_temp, &cursor); 659 if (krbret != 0) { 660 PAM_LOG("Error krb5_cc_start_seq_get(): %s", 661 krb5_get_err_text(pam_context, krbret)); 662 krb5_cc_destroy(pam_context, ccache_perm); 663 retval = PAM_SERVICE_ERR; 664 goto cleanup2; 665 } 666 667 PAM_LOG("Prepared for iteration"); 668 669 /* Copy the creds (should be two of them) */ 670 while ((krbret = krb5_cc_next_cred(pam_context, ccache_temp, 671 &cursor, &creds) == 0)) { 672 krbret = krb5_cc_store_cred(pam_context, ccache_perm, &creds); 673 if (krbret != 0) { 674 PAM_LOG("Error krb5_cc_store_cred(): %s", 675 krb5_get_err_text(pam_context, krbret)); 676 krb5_cc_destroy(pam_context, ccache_perm); 677 krb5_free_cred_contents(pam_context, &creds); 678 retval = PAM_SERVICE_ERR; 679 goto cleanup2; 680 } 681 krb5_free_cred_contents(pam_context, &creds); 682 PAM_LOG("Iteration"); 683 } 684 krb5_cc_end_seq_get(pam_context, ccache_temp, &cursor); 685 686 PAM_LOG("Done iterating"); 687 } 688 689 /* Get the cache type and name */ 690 cache_type = krb5_cc_get_type(pam_context, ccache_perm); 691 cache_name = krb5_cc_get_name(pam_context, ccache_perm); 692 PAM_LOG("Got cache_name: %s:%s", cache_type, cache_name); 693 694 if (0 == strcmp(cache_type, "FILE")) { 695 if (chown(cache_name, pwd->pw_uid, pwd->pw_gid) == -1) { 696 PAM_LOG("Error chown(): %s", strerror(errno)); 697 krb5_cc_destroy(pam_context, ccache_perm); 698 retval = PAM_SERVICE_ERR; 699 goto cleanup2; 700 } 701 PAM_LOG("Done chown()"); 702 703 if (chmod(cache_name, (S_IRUSR | S_IWUSR)) == -1) { 704 PAM_LOG("Error chmod(): %s", strerror(errno)); 705 krb5_cc_destroy(pam_context, ccache_perm); 706 retval = PAM_SERVICE_ERR; 707 goto cleanup2; 708 } 709 PAM_LOG("Done chmod()"); 710 } else { 711 (void)krb5_cc_switch(pam_context, ccache_perm); 712 } 713 714 asprintf(&cache_type_colon_name, "%s:%s", cache_type, cache_name); 715 if (NULL == cache_type_colon_name) 716 goto cleanup2; 717 retval = pam_setenv(pamh, "KRB5CCNAME", cache_type_colon_name, 1); 718 free(cache_type_colon_name); 719 if (retval != PAM_SUCCESS) { 720 PAM_LOG("Error pam_setenv(): %s", pam_strerror(pamh, retval)); 721 krb5_cc_destroy(pam_context, ccache_perm); 722 retval = PAM_SERVICE_ERR; 723 goto cleanup2; 724 } 725 726 PAM_LOG("Environment done: KRB5CCNAME=%s", cache_name); 727 728 krb5_cc_close(pam_context, ccache_perm); 729 730 PAM_LOG("Cache closed"); 731 732cleanup2: 733 if (NULL != princ) 734 krb5_free_principal(pam_context, princ); 735 PAM_LOG("Done cleanup2"); 736cleanup3: 737 krb5_free_context(pam_context); 738 PAM_LOG("Done cleanup3"); 739 740 seteuid(euid); 741 setegid(egid); 742 743 PAM_LOG("Done seteuid() & setegid()"); 744 745 if (cache_name_buf != NULL) 746 free(cache_name_buf); 747cleanup4: 748 pam_unsetenv(pamh, user_key); 749 pam_unsetenv(pamh, password_key); 750 PAM_LOG("Done cleanup4"); 751 752 return (retval); 753#endif 754} 755 756/* 757 * account management 758 */ 759PAM_EXTERN int 760pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused, 761 int argc __unused, const char *argv[] __unused) 762{ 763 krb5_error_code krbret; 764 krb5_context pam_context; 765 krb5_ccache ccache; 766 krb5_principal princ; 767 int retval; 768 const void *user; 769 const void *ccache_name; 770 771 if (openpam_get_option(pamh, PAM_OPT_USE_KCMINIT)) 772 return (PAM_SUCCESS); 773 774 retval = pam_get_item(pamh, PAM_USER, &user); 775 if (retval != PAM_SUCCESS) 776 return (retval); 777 778 PAM_LOG("Got user: %s", (const char *)user); 779 780 retval = pam_get_data(pamh, "ccache", &ccache_name); 781 if (retval != PAM_SUCCESS) 782 return (PAM_SUCCESS); 783 784 PAM_LOG("Got credentials"); 785 786 krbret = krb5_init_context(&pam_context); 787 if (krbret != 0) { 788 PAM_LOG("Error krb5_init_secure_context() failed"); 789 return (PAM_PERM_DENIED); 790 } 791 792 PAM_LOG("Context initialised"); 793 794 krbret = krb5_cc_resolve(pam_context, (const char *)ccache_name, &ccache); 795 if (krbret != 0) { 796 PAM_LOG("Error krb5_cc_resolve(\"%s\"): %s", (const char *)ccache_name, 797 krb5_get_err_text(pam_context, krbret)); 798 krb5_free_context(pam_context); 799 return (PAM_PERM_DENIED); 800 } 801 802 PAM_LOG("Got ccache %s", (const char *)ccache_name); 803 804 805 krbret = krb5_cc_get_principal(pam_context, ccache, &princ); 806 if (krbret != 0) { 807 PAM_LOG("Error krb5_cc_get_principal(): %s", 808 krb5_get_err_text(pam_context, krbret)); 809 retval = PAM_PERM_DENIED;; 810 goto cleanup; 811 } 812 813 PAM_LOG("Got principal"); 814 815 if (krb5_kuserok(pam_context, princ, (const char *)user)) 816 retval = PAM_SUCCESS; 817 else 818 retval = PAM_PERM_DENIED; 819 krb5_free_principal(pam_context, princ); 820 821 PAM_LOG("Done kuserok()"); 822 823cleanup: 824 krb5_free_context(pam_context); 825 PAM_LOG("Done cleanup"); 826 827 return (retval); 828 829} 830 831/* 832 * password management 833 */ 834PAM_EXTERN int 835pam_sm_chauthtok(pam_handle_t *pamh, int flags, 836 int argc __unused, const char *argv[] __unused) 837{ 838 krb5_error_code krbret; 839 krb5_context pam_context; 840 krb5_creds creds; 841 krb5_principal princ; 842 krb5_get_init_creds_opt *opts = NULL; 843 krb5_data result_code_string, result_string; 844 int result_code, retval; 845 char *pass; 846 const void *user; 847 char *princ_name = NULL, *passdup; 848 849 if (!(flags & PAM_UPDATE_AUTHTOK)) 850 return (PAM_AUTHTOK_ERR); 851 852 retval = pam_get_item(pamh, PAM_USER, &user); 853 if (retval != PAM_SUCCESS) 854 return (retval); 855 856 PAM_LOG("Got user: %s", (const char *)user); 857 858 krbret = krb5_init_context(&pam_context); 859 if (krbret != 0) { 860 PAM_LOG("Error krb5_init_secure_context() failed"); 861 return (PAM_SERVICE_ERR); 862 } 863 864 PAM_LOG("Context initialised"); 865 866 krb5_get_init_creds_opt_alloc(pam_context, &opts); 867 868 PAM_LOG("Credentials options initialised"); 869 870 /* Get principal name */ 871 krbret = krb5_parse_name(pam_context, (const char *)user, &princ); 872 if (krbret != 0) { 873 PAM_LOG("Error krb5_parse_name(): %s", 874 krb5_get_err_text(pam_context, krbret)); 875 retval = PAM_USER_UNKNOWN; 876 goto cleanup3; 877 } 878 879 /* Now convert the principal name into something human readable */ 880 princ_name = NULL; 881 krbret = krb5_unparse_name(pam_context, princ, &princ_name); 882 if (krbret != 0) { 883 PAM_LOG("Error krb5_unparse_name(): %s", 884 krb5_get_err_text(pam_context, krbret)); 885 retval = PAM_SERVICE_ERR; 886 goto cleanup2; 887 } 888 889 PAM_LOG("Got principal: %s", princ_name); 890 891 /* Get password */ 892 retval = pam_get_authtok(pamh, PAM_OLDAUTHTOK, (const char **)&pass, PASSWORD_PROMPT); 893 if (retval != PAM_SUCCESS) 894 goto cleanup2; 895 896 PAM_LOG("Got password"); 897 898 memset(&creds, 0, sizeof(krb5_creds)); 899 krbret = krb5_get_init_creds_password(pam_context, &creds, princ, 900 pass, NULL, pamh, 0, "kadmin/changepw", opts); 901 if (krbret != 0) { 902 PAM_LOG("Error krb5_get_init_creds_password(): %s", 903 krb5_get_err_text(pam_context, krbret)); 904 retval = PAM_AUTH_ERR; 905 goto cleanup2; 906 } 907 908 PAM_LOG("Credentials established"); 909 910 /* Now get the new password */ 911 for (;;) { 912 retval = pam_get_authtok(pamh, 913 PAM_AUTHTOK, (const char **)&pass, NEW_PASSWORD_PROMPT); 914 if (retval != PAM_TRY_AGAIN) 915 break; 916 pam_error(pamh, "Mismatch; try again, EOF to quit."); 917 } 918 if (retval != PAM_SUCCESS) 919 goto cleanup; 920 921 PAM_LOG("Got new password"); 922 923 /* Change it */ 924 if ((passdup = strdup(pass)) == NULL) { 925 retval = PAM_BUF_ERR; 926 goto cleanup; 927 } 928 krbret = krb5_set_password(pam_context, &creds, passdup, NULL, 929 &result_code, &result_code_string, &result_string); 930 free(passdup); 931 if (krbret != 0) { 932 PAM_LOG("Error krb5_change_password(): %s", 933 krb5_get_err_text(pam_context, krbret)); 934 retval = PAM_AUTHTOK_ERR; 935 goto cleanup; 936 } 937 if (result_code) { 938 PAM_LOG("Error krb5_change_password(): (result_code)"); 939 retval = PAM_AUTHTOK_ERR; 940 goto cleanup; 941 } 942 943 PAM_LOG("Password changed"); 944 945 if (result_string.data) 946 free(result_string.data); 947 if (result_code_string.data) 948 free(result_code_string.data); 949 950cleanup: 951 krb5_free_cred_contents(pam_context, &creds); 952 PAM_LOG("Done cleanup"); 953cleanup2: 954 krb5_free_principal(pam_context, princ); 955 PAM_LOG("Done cleanup2"); 956cleanup3: 957 if (princ_name) 958 free(princ_name); 959 960 if (opts) 961 krb5_get_init_creds_opt_free(pam_context, opts); 962 963 krb5_free_context(pam_context); 964 965 PAM_LOG("Done cleanup3"); 966 967 return (retval); 968} 969 970PAM_MODULE_ENTRY("pam_krb5"); 971 972/* 973 * This routine with some modification is from the MIT V5B6 appl/bsd/login.c 974 * Modified by Sam Hartman <hartmans@mit.edu> to support PAM services 975 * for Debian. 976 * 977 * Verify the Kerberos ticket-granting ticket just retrieved for the 978 * user. If the Kerberos server doesn't respond, assume the user is 979 * trying to fake us out (since we DID just get a TGT from what is 980 * supposedly our KDC). If the host/<host> service is unknown (i.e., 981 * the local keytab doesn't have it), and we cannot find another 982 * service we do have, let her in. 983 * 984 * Returns 1 for confirmation, -1 for failure, 0 for uncertainty. 985 */ 986/* ARGSUSED */ 987static int 988verify_krb_v5_tgt(krb5_context context, krb5_ccache ccache, 989 char *pam_service, int debug) 990{ 991 krb5_error_code retval; 992 krb5_principal princ; 993 krb5_keyblock *keyblock; 994 krb5_data packet; 995 krb5_auth_context auth_context; 996 char phost[BUFSIZ]; 997 const char *services[3], **service; 998 999 packet.data = 0; 1000 1001 /* If possible we want to try and verify the ticket we have 1002 * received against a keytab. We will try multiple service 1003 * principals, including at least the host principal and the PAM 1004 * service principal. The host principal is preferred because access 1005 * to that key is generally sufficient to compromise root, while the 1006 * service key for this PAM service may be less carefully guarded. 1007 * It is important to check the keytab first before the KDC so we do 1008 * not get spoofed by a fake KDC. 1009 */ 1010 services[0] = "host"; 1011 services[1] = pam_service; 1012 services[2] = NULL; 1013 keyblock = 0; 1014 retval = -1; 1015 for (service = &services[0]; *service != NULL; service++) { 1016 retval = krb5_sname_to_principal(context, NULL, *service, 1017 KRB5_NT_SRV_HST, &princ); 1018 if (retval != 0) { 1019 if (debug) 1020 openpam_log(PAM_LOG_DEBUG, 1021 "pam_krb5: verify_krb_v5_tgt(): %s: %s", 1022 "krb5_sname_to_principal()", 1023 krb5_get_err_text(context, retval)); 1024 return -1; 1025 } 1026 1027 /* Extract the name directly. */ 1028 strncpy(phost, compat_princ_component(context, princ, 1), 1029 BUFSIZ); 1030 phost[BUFSIZ - 1] = '\0'; 1031 1032 /* 1033 * Do we have service/<host> keys? 1034 * (use default/configured keytab, kvno IGNORE_VNO to get the 1035 * first match, and ignore enctype.) 1036 */ 1037 retval = krb5_kt_read_service_key(context, NULL, princ, 0, 0, 1038 &keyblock); 1039 if (retval != 0) { 1040 krb5_free_principal(context, princ); 1041 princ = NULL; 1042 continue; 1043 } 1044 break; 1045 } 1046 if (retval != 0) { /* failed to find key */ 1047 /* Keytab or service key does not exist */ 1048 if (debug) 1049 openpam_log(PAM_LOG_DEBUG, 1050 "pam_krb5: verify_krb_v5_tgt(): %s: %s", 1051 "krb5_kt_read_service_key()", 1052 krb5_get_err_text(context, retval)); 1053 retval = 0; 1054 goto cleanup; 1055 } 1056 if (keyblock) 1057 krb5_free_keyblock(context, keyblock); 1058 1059 /* Talk to the kdc and construct the ticket. */ 1060 auth_context = NULL; 1061 retval = krb5_mk_req(context, &auth_context, 0, (char *)*service, phost, 1062 NULL, ccache, &packet); 1063 if (auth_context) { 1064 krb5_auth_con_free(context, auth_context); 1065 auth_context = NULL; /* setup for rd_req */ 1066 } 1067 if (retval) { 1068 if (debug) 1069 openpam_log(PAM_LOG_DEBUG, 1070 "pam_krb5: verify_krb_v5_tgt(): %s: %s", 1071 "krb5_mk_req()", 1072 krb5_get_err_text(context, retval)); 1073 retval = -1; 1074 goto cleanup; 1075 } 1076 1077 /* Try to use the ticket. */ 1078 retval = krb5_rd_req(context, &auth_context, &packet, princ, NULL, 1079 NULL, NULL); 1080 if (retval) { 1081 if (debug) 1082 openpam_log(PAM_LOG_DEBUG, 1083 "pam_krb5: verify_krb_v5_tgt(): %s: %s", 1084 "krb5_rd_req()", 1085 krb5_get_err_text(context, retval)); 1086 retval = -1; 1087 } 1088 else 1089 retval = 1; 1090 1091cleanup: 1092 if (packet.data) 1093 compat_free_data_contents(context, &packet); 1094 krb5_free_principal(context, princ); 1095 return retval; 1096} 1097 1098#ifdef COMPAT_HEIMDAL 1099#ifdef COMPAT_MIT 1100#error This cannot be MIT and Heimdal compatible! 1101#endif 1102#endif 1103 1104#ifndef COMPAT_HEIMDAL 1105#ifndef COMPAT_MIT 1106#error One of COMPAT_MIT and COMPAT_HEIMDAL must be specified! 1107#endif 1108#endif 1109 1110#ifdef COMPAT_HEIMDAL 1111/* ARGSUSED */ 1112static const char * 1113compat_princ_component(krb5_context context __unused, krb5_principal princ, int n) 1114{ 1115 return princ->name.name_string.val[n]; 1116} 1117 1118/* ARGSUSED */ 1119static void 1120compat_free_data_contents(krb5_context context __unused, krb5_data * data) 1121{ 1122 krb5_xfree(data->data); 1123} 1124#endif 1125 1126#ifdef COMPAT_MIT 1127static const char * 1128compat_princ_component(krb5_context context, krb5_principal princ, int n) 1129{ 1130 return krb5_princ_component(context, princ, n)->data; 1131} 1132 1133static void 1134compat_free_data_contents(krb5_context context, krb5_data * data) 1135{ 1136 krb5_free_data_contents(context, data); 1137} 1138#endif 1139