pam_unix.c revision 1.8
1 /* $NetBSD: pam_unix.c,v 1.8 2005/04/19 03:15:37 christos Exp $ */ 2 3 /*- 4 * Copyright 1998 Juniper Networks, Inc. 5 * All rights reserved. 6 * Copyright (c) 2002-2003 Networks Associates Technology, Inc. 7 * All rights reserved. 8 * 9 * Portions of this software was developed for the FreeBSD Project by 10 * ThinkSec AS and NAI Labs, the Security Research Division of Network 11 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 12 * ("CBOSS"), as part of the DARPA CHATS research program. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 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 written 24 * permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #ifdef __FreeBSD__ 41 __FBSDID("$FreeBSD: src/lib/libpam/modules/pam_unix/pam_unix.c,v 1.49 2004/02/10 10:13:21 des Exp $"); 42 #else 43 __RCSID("$NetBSD: pam_unix.c,v 1.8 2005/04/19 03:15:37 christos Exp $"); 44 #endif 45 46 47 #include <sys/types.h> 48 49 #include <ctype.h> 50 #include <errno.h> 51 #include <fcntl.h> 52 #include <pwd.h> 53 #include <grp.h> 54 #include <limits.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <stdio.h> 58 #include <login_cap.h> 59 #include <time.h> 60 #include <tzfile.h> 61 #include <unistd.h> 62 63 #include <util.h> 64 65 #ifdef YP 66 #include <rpc/rpc.h> 67 #include <rpcsvc/ypclnt.h> 68 #include <rpcsvc/yppasswd.h> 69 #endif 70 71 #define PAM_SM_AUTH 72 #define PAM_SM_ACCOUNT 73 #define PAM_SM_PASSWORD 74 75 #include <security/pam_appl.h> 76 #include <security/pam_modules.h> 77 #include <security/pam_mod_misc.h> 78 79 /* 80 * authentication management 81 */ 82 PAM_EXTERN int 83 /*ARGSUSED*/ 84 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 85 int argc __unused, const char *argv[] __unused) 86 { 87 login_cap_t *lc; 88 struct passwd *pwd, pwres; 89 int retval; 90 const char *pass, *user, *realpw; 91 char pwbuf[1024]; 92 93 if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF)) { 94 (void) getpwnam_r(getlogin(), &pwres, pwbuf, sizeof(pwbuf), 95 &pwd); 96 } else { 97 retval = pam_get_user(pamh, &user, NULL); 98 if (retval != PAM_SUCCESS) 99 return (retval); 100 PAM_LOG("Got user: %s", user); 101 (void) getpwnam_r(user, &pwres, pwbuf, sizeof(pwbuf), &pwd); 102 } 103 104 if (pwd != NULL) { 105 PAM_LOG("Doing real authentication"); 106 realpw = pwd->pw_passwd; 107 if (realpw[0] == '\0') { 108 if (!(flags & PAM_DISALLOW_NULL_AUTHTOK) && 109 openpam_get_option(pamh, PAM_OPT_NULLOK)) 110 return (PAM_SUCCESS); 111 realpw = "*"; 112 } 113 lc = login_getpwclass(pwd); 114 } else { 115 PAM_LOG("Doing dummy authentication"); 116 realpw = "*"; 117 lc = login_getclass(NULL); 118 } 119 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, NULL); 120 login_close(lc); 121 if (retval != PAM_SUCCESS) 122 return (retval); 123 PAM_LOG("Got password"); 124 if (strcmp(crypt(pass, realpw), realpw) == 0) 125 return (PAM_SUCCESS); 126 127 PAM_VERBOSE_ERROR("UNIX authentication refused"); 128 return (PAM_AUTH_ERR); 129 } 130 131 PAM_EXTERN int 132 /*ARGSUSED*/ 133 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused, 134 int argc __unused, const char *argv[] __unused) 135 { 136 137 return (PAM_SUCCESS); 138 } 139 140 /* 141 * account management 142 */ 143 PAM_EXTERN int 144 /*ARGSUSED*/ 145 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused, 146 int argc __unused, const char *argv[] __unused) 147 { 148 struct passwd *pwd, pwres; 149 struct timeval now; 150 login_cap_t *lc; 151 time_t warntime; 152 int retval; 153 const char *user; 154 char pwbuf[1024]; 155 156 retval = pam_get_user(pamh, &user, NULL); 157 if (retval != PAM_SUCCESS) 158 return (retval); 159 160 if (user == NULL || 161 getpwnam_r(user, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 || 162 pwd == NULL) 163 return (PAM_SERVICE_ERR); 164 165 PAM_LOG("Got user: %s", user); 166 167 if (*pwd->pw_passwd == '\0' && 168 (flags & PAM_DISALLOW_NULL_AUTHTOK) != 0) 169 return (PAM_NEW_AUTHTOK_REQD); 170 171 lc = login_getpwclass(pwd); 172 if (lc == NULL) { 173 PAM_LOG("Unable to get login class for user %s", user); 174 return (PAM_SERVICE_ERR); 175 } 176 177 PAM_LOG("Got login_cap"); 178 179 if (pwd->pw_change || pwd->pw_expire) 180 (void) gettimeofday(&now, NULL); 181 182 warntime = (time_t)login_getcaptime(lc, "password-warn", 183 (quad_t)(_PASSWORD_WARNDAYS * SECSPERDAY), 184 (quad_t)(_PASSWORD_WARNDAYS * SECSPERDAY)); 185 186 /* 187 * Check pw_expire before pw_change - no point in letting the 188 * user change the password on an expired account. 189 */ 190 191 if (pwd->pw_expire) { 192 if (now.tv_sec >= pwd->pw_expire) { 193 login_close(lc); 194 return (PAM_ACCT_EXPIRED); 195 } else if (pwd->pw_expire - now.tv_sec < warntime && 196 (flags & PAM_SILENT) == 0) { 197 pam_error(pamh, "Warning: your account expires on %s", 198 ctime(&pwd->pw_expire)); 199 } 200 } 201 202 if (pwd->pw_change) { 203 /* XXX How to handle _PASSWORD_CHGNOW? --thorpej */ 204 if (now.tv_sec >= pwd->pw_change) { 205 login_close(lc); 206 return (PAM_NEW_AUTHTOK_REQD); 207 } else if (pwd->pw_change - now.tv_sec < warntime && 208 (flags & PAM_SILENT) == 0) { 209 pam_error(pamh, "Warning: your password expires on %s", 210 ctime(&pwd->pw_change)); 211 } 212 } 213 214 login_close(lc); 215 216 return (PAM_SUCCESS); 217 } 218 219 #ifdef YP 220 /* 221 * yp_check_user: 222 * 223 * Helper function; check that a user exists in the NIS 224 * password map. 225 */ 226 static int 227 yp_check_user(const char *domain, const char *user) 228 { 229 char *val; 230 int reason, vallen; 231 232 val = NULL; 233 reason = yp_match(domain, "passwd.byname", user, (int)strlen(user), 234 &val, &vallen); 235 if (reason != 0) { 236 if (val != NULL) 237 free(val); 238 return (0); 239 } 240 free(val); 241 return (1); 242 } 243 244 static int 245 /*ARGSUSED*/ 246 yp_set_password(pam_handle_t *pamh, struct passwd *opwd, 247 struct passwd *pwd, const char *old_pass, const char *domain) 248 { 249 char *master; 250 int r, rpcport, status; 251 struct yppasswd yppwd; 252 CLIENT *client; 253 uid_t uid; 254 int retval = PAM_SERVICE_ERR; 255 struct timeval tv; 256 257 /* 258 * Find the master for the passwd map; it should be running 259 * rpc.yppasswdd. 260 */ 261 if ((r = yp_master(domain, "passwd.byname", &master)) != 0) { 262 pam_error(pamh, "Can't find master NIS server. Reason: %s", 263 yperr_string(r)); 264 return (PAM_SERVICE_ERR); 265 } 266 267 /* 268 * Ask the portmapper for the port of rpc.yppasswdd. 269 */ 270 if ((rpcport = getrpcport(master, YPPASSWDPROG, 271 YPPASSWDPROC_UPDATE, IPPROTO_UDP)) == 0) { 272 pam_error(pamh, 273 "Master NIS server not runing yppasswd daemon.\n\t" 274 "Can't change NIS password."); 275 return (PAM_SERVICE_ERR); 276 } 277 278 /* 279 * Be sure the port is privileged. 280 */ 281 if (rpcport >= IPPORT_RESERVED) { 282 pam_error(pamh, "yppasswd daemon is on an invalid port."); 283 return (PAM_SERVICE_ERR); 284 } 285 286 uid = getuid(); 287 if (uid != 0 && uid != pwd->pw_uid) { 288 pam_error(pamh, "You may only change your own password: %s", 289 strerror(EACCES)); 290 return (PAM_SERVICE_ERR); 291 } 292 293 /* 294 * Fill in the yppasswd structure for yppasswdd. 295 */ 296 memset(&yppwd, 0, sizeof(yppwd)); 297 yppwd.oldpass = strdup(old_pass); 298 if ((yppwd.newpw.pw_passwd = strdup(pwd->pw_passwd)) == NULL) 299 goto malloc_failure; 300 if ((yppwd.newpw.pw_name = strdup(pwd->pw_name)) == NULL) 301 goto malloc_failure; 302 yppwd.newpw.pw_uid = pwd->pw_uid; 303 yppwd.newpw.pw_gid = pwd->pw_gid; 304 if ((yppwd.newpw.pw_gecos = strdup(pwd->pw_gecos)) == NULL) 305 goto malloc_failure; 306 if ((yppwd.newpw.pw_dir = strdup(pwd->pw_dir)) == NULL) 307 goto malloc_failure; 308 if ((yppwd.newpw.pw_shell = strdup(pwd->pw_shell)) == NULL) 309 goto malloc_failure; 310 311 client = clnt_create(master, YPPASSWDPROG, YPPASSWDVERS, "udp"); 312 if (client == NULL) { 313 pam_error(pamh, "Can't contact yppasswdd on %s: Reason: %s", 314 master, yperr_string(YPERR_YPBIND)); 315 goto out; 316 } 317 318 client->cl_auth = authunix_create_default(); 319 tv.tv_sec = 2; 320 tv.tv_usec = 0; 321 r = clnt_call(client, YPPASSWDPROC_UPDATE, 322 xdr_yppasswd, &yppwd, xdr_int, &status, tv); 323 if (r) 324 pam_error(pamh, "RPC to yppasswdd failed."); 325 else if (status) 326 pam_error(pamh, "Couldn't change NIS password."); 327 else { 328 pam_info(pamh, "The NIS password has been changed on %s, " 329 "the master NIS passwd server.", master); 330 retval = PAM_SUCCESS; 331 } 332 333 out: 334 if (yppwd.oldpass != NULL) 335 free(yppwd.oldpass); 336 if (yppwd.newpw.pw_passwd != NULL) 337 free(yppwd.newpw.pw_passwd); 338 if (yppwd.newpw.pw_name != NULL) 339 free(yppwd.newpw.pw_name); 340 if (yppwd.newpw.pw_gecos != NULL) 341 free(yppwd.newpw.pw_gecos); 342 if (yppwd.newpw.pw_dir != NULL) 343 free(yppwd.newpw.pw_dir); 344 if (yppwd.newpw.pw_shell != NULL) 345 free(yppwd.newpw.pw_shell); 346 return (retval); 347 348 malloc_failure: 349 pam_error(pamh, "memory allocation failure"); 350 goto out; 351 } 352 #endif /* YP */ 353 354 static int 355 local_set_password(pam_handle_t *pamh, struct passwd *opwd, 356 struct passwd *pwd) 357 { 358 char errbuf[200]; 359 int tfd, pfd; 360 361 pw_init(); 362 tfd = pw_lock(0); 363 if (tfd < 0) { 364 pam_error(pamh, "The password file is busy, waiting..."); 365 tfd = pw_lock(10); 366 if (tfd < 0) { 367 pam_error(pamh, "The password file is still busy, " 368 "try again later."); 369 return (PAM_SERVICE_ERR); 370 } 371 } 372 373 pfd = open(_PATH_MASTERPASSWD, O_RDONLY, 0); 374 if (pfd < 0) { 375 pam_error(pamh, "%s: %s", _PATH_MASTERPASSWD, strerror(errno)); 376 pw_abort(); 377 return (PAM_SERVICE_ERR); 378 } 379 380 if (pw_copyx(pfd, tfd, pwd, opwd, errbuf, sizeof(errbuf)) == 0) { 381 pam_error(pamh, "Unable to update password entry: %s", 382 errbuf); 383 pw_abort(); 384 return (PAM_SERVICE_ERR); 385 } 386 387 if (pw_mkdb(pwd->pw_name, opwd->pw_change == pwd->pw_change) < 0) { 388 pam_error(pamh, "Unable to rebuild local password database."); 389 pw_abort(); 390 return (PAM_SERVICE_ERR); 391 } 392 393 return (PAM_SUCCESS); 394 } 395 396 /* 397 * password management 398 * 399 * standard Unix and NIS password changing 400 */ 401 PAM_EXTERN int 402 /*ARGSUSED*/ 403 pam_sm_chauthtok(pam_handle_t *pamh, int flags, 404 int argc __unused, const char *argv[] __unused) 405 { 406 struct passwd *pwd, old_pwd; 407 login_cap_t *lc; 408 const char *user, *passwd_db, *new_pass, *old_pass, *p; 409 int retval, tries, min_pw_len = 0, pw_expiry = 0; 410 char salt[_PASSWORD_LEN+1]; 411 char old_pwbuf[1024]; 412 #ifdef YP 413 char *domain; 414 int r; 415 #endif 416 417 if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF)) 418 (void) getpwnam_r(getlogin(), &old_pwd, old_pwbuf, 419 sizeof(old_pwbuf), &pwd); 420 else { 421 retval = pam_get_user(pamh, &user, NULL); 422 if (retval != PAM_SUCCESS) 423 return (retval); 424 (void) getpwnam_r(user, &old_pwd, old_pwbuf, 425 sizeof(old_pwbuf), &pwd); 426 } 427 428 if (pwd == NULL) 429 return (PAM_AUTHTOK_RECOVERY_ERR); 430 431 PAM_LOG("Got user: %s", user); 432 433 /* 434 * Determine which password type we're going to change, and 435 * remember it. 436 * 437 * NOTE: domain does not need to be freed; its storage is 438 * allocated statically in libc. 439 */ 440 passwd_db = openpam_get_option(pamh, "passwd_db"); 441 if (passwd_db == NULL) { 442 #ifdef YP 443 /* Prefer YP, if configured. */ 444 if (_yp_check(NULL)) { 445 /* If _yp_check() succeeded, then this must. */ 446 if ((r = yp_get_default_domain(&domain)) != 0) { 447 pam_error(pamh, 448 "Unable to get NIS domain, reason: %s", 449 yperr_string(r)); 450 return (PAM_SERVICE_ERR); 451 } 452 if (yp_check_user(domain, user)) 453 passwd_db = "nis"; 454 } 455 #endif 456 /* Otherwise we always use local files. */ 457 if (passwd_db == NULL) { 458 /* XXX Any validation to do here? */ 459 passwd_db = "files"; 460 } 461 462 if (passwd_db == NULL) { 463 pam_error(pamh, "Unable to determine Unix password DB"); 464 return (PAM_SERVICE_ERR); 465 } else if ((retval = openpam_set_option(pamh, "passwd_db", 466 passwd_db)) != PAM_SUCCESS) { 467 return (retval); 468 } 469 } else { 470 /* Check to see if the specified password DB is usable. */ 471 #ifdef YP 472 if (strcmp(passwd_db, "nis") == 0) { 473 if (_yp_check(NULL) == 0) { 474 pam_error(pamh, "NIS not in use."); 475 return (PAM_SERVICE_ERR); 476 } 477 if ((r = yp_get_default_domain(&domain)) != 0) { 478 pam_error(pamh, 479 "Unable to get NIS domain, reason: %s", 480 yperr_string(r)); 481 return (PAM_SERVICE_ERR); 482 } 483 if (yp_check_user(domain, user) == 0) { 484 pam_error(pamh, 485 "User %s does not exist in NIS.", user); 486 return (PAM_USER_UNKNOWN); 487 } 488 goto known_passwd_db; 489 } 490 #endif 491 if (strcmp(passwd_db, "files") == 0) { 492 /* XXX Any validation to do here? */ 493 goto known_passwd_db; 494 } 495 pam_error(pamh, "Unknown Unix password DB: %s", passwd_db); 496 return (PAM_SERVICE_ERR); 497 } 498 known_passwd_db: 499 500 if (flags & PAM_PRELIM_CHECK) { 501 PAM_LOG("PRELIM round"); 502 503 if (strcmp(passwd_db, "files") == 0) { 504 if (getuid() == 0) { 505 /* Root doesn't need the old password. */ 506 return (pam_set_item(pamh, PAM_OLDAUTHTOK, "")); 507 } 508 } 509 510 if (pwd->pw_passwd[0] == '\0') { 511 /* 512 * No password case. 513 * XXX Are we giviing too much away by not prompting 514 * XXX for a password? 515 * XXX Check PAM_DISALLOW_NULL_AUTHTOK 516 */ 517 return (pam_set_item(pamh, PAM_OLDAUTHTOK, "")); 518 } else { 519 retval = pam_get_authtok(pamh, PAM_OLDAUTHTOK, 520 &old_pass, NULL); 521 if (retval != PAM_SUCCESS) 522 return (retval); 523 if (strcmp(crypt(old_pass, pwd->pw_passwd), 524 pwd->pw_passwd) != 0) 525 return (PAM_PERM_DENIED); 526 return (PAM_SUCCESS); 527 } 528 } 529 530 if (flags & PAM_UPDATE_AUTHTOK) { 531 char option[LINE_MAX], *key, *opt; 532 533 PAM_LOG("UPDATE round"); 534 535 if ((lc = login_getclass(pwd->pw_class)) != NULL) { 536 min_pw_len = (int) login_getcapnum(lc, 537 "minpasswordlen", (quad_t)0, (quad_t)0); 538 pw_expiry = (int) login_getcapnum(lc, 539 "passwordtime", (quad_t)0, (quad_t)0); 540 login_close(lc); 541 } 542 543 retval = pam_get_authtok(pamh, PAM_OLDAUTHTOK, &old_pass, NULL); 544 if (retval != PAM_SUCCESS) 545 return (retval); 546 547 /* Get the new password. */ 548 for (tries = 0;;) { 549 pam_set_item(pamh, PAM_AUTHTOK, NULL); 550 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &new_pass, 551 NULL); 552 if (retval == PAM_TRY_AGAIN) { 553 pam_error(pamh, 554 "Mismatch; try again, EOF to quit."); 555 continue; 556 } 557 if (retval != PAM_SUCCESS) { 558 PAM_VERBOSE_ERROR("Unable to get new password"); 559 return (retval); 560 } 561 /* Successfully got new password. */ 562 if (new_pass[0] == '\0') { 563 pam_info(pamh, "Password unchanged."); 564 return (PAM_SUCCESS); 565 } 566 if (min_pw_len > 0 && strlen(new_pass) < min_pw_len) { 567 pam_error(pamh, "Password is too short."); 568 continue; 569 } 570 if (strlen(new_pass) <= 5 && ++tries < 2) { 571 pam_error(pamh, 572 "Please enter a longer password."); 573 continue; 574 } 575 for (p = new_pass; *p && islower((unsigned char)*p); ++p); 576 if (!*p && ++tries < 2) { 577 pam_error(pamh, 578 "Please don't use an all-lower case " 579 "password.\nUnusual capitalization, " 580 "control characters or digits are " 581 "suggested."); 582 continue; 583 } 584 /* Password is OK. */ 585 break; 586 } 587 pw_getpwconf(option, sizeof(option), pwd, 588 #ifdef YP 589 strcmp(passwd_db, "nis") == 0 ? "ypcipher" : 590 #endif 591 "localcipher"); 592 opt = option; 593 key = strsep(&opt, ","); 594 595 if (pw_gensalt(salt, _PASSWORD_LEN, key, opt) == -1) { 596 pam_error(pamh, "Couldn't generate salt."); 597 return (PAM_SERVICE_ERR); 598 } 599 600 pwd->pw_passwd = crypt(new_pass, salt); 601 pwd->pw_change = pw_expiry ? pw_expiry + time(NULL) : 0; 602 603 retval = PAM_SERVICE_ERR; 604 if (strcmp(passwd_db, "files") == 0) 605 retval = local_set_password(pamh, &old_pwd, pwd); 606 #ifdef YP 607 if (strcmp(passwd_db, "nis") == 0) 608 retval = yp_set_password(pamh, &old_pwd, pwd, old_pass, 609 domain); 610 #endif 611 return (retval); 612 } 613 614 PAM_LOG("Illegal flags argument"); 615 return (PAM_ABORT); 616 } 617 618 PAM_MODULE_ENTRY("pam_unix"); 619
Indexes created Tue Sep 23 14:10:03 GMT 2025