1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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 __FBSDID("$FreeBSD$"); 41 42 #include <sys/param.h> 43 #include <sys/socket.h> 44 #include <sys/time.h> 45 #include <netinet/in.h> 46 #include <arpa/inet.h> 47 48 #include <login_cap.h> 49 #include <netdb.h> 50 #include <pwd.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <stdio.h> 54 #include <syslog.h> 55 #include <time.h> 56 #include <unistd.h> 57 58 #include <libutil.h> 59 60 #ifdef YP 61 #include <ypclnt.h> 62 #endif 63 64 #define PAM_SM_AUTH 65 #define PAM_SM_ACCOUNT 66 #define PAM_SM_PASSWORD 67 68 #include <security/pam_appl.h> 69 #include <security/pam_modules.h> 70 #include <security/pam_mod_misc.h> 71 72 #define PASSWORD_HASH "md5" 73 #define DEFAULT_WARN (2L * 7L * 86400L) /* Two weeks */ 74 #define SALTSIZE 32 75 76 #define LOCKED_PREFIX "*LOCKED*" 77 #define LOCKED_PREFIX_LEN (sizeof(LOCKED_PREFIX) - 1) 78 79 static void makesalt(char []); 80 81 static char password_hash[] = PASSWORD_HASH; 82 83 #define PAM_OPT_LOCAL_PASS "local_pass" 84 #define PAM_OPT_NIS_PASS "nis_pass" 85 86 /* 87 * authentication management 88 */ 89 PAM_EXTERN int 90 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 91 int argc __unused, const char *argv[] __unused) 92 { 93 login_cap_t *lc; 94 struct passwd *pwd; 95 int retval; 96 const char *pass, *user, *realpw, *prompt; 97 98 if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF)) { 99 user = getlogin(); 100 } else { 101 retval = pam_get_user(pamh, &user, NULL); 102 if (retval != PAM_SUCCESS) 103 return (retval); 104 } 105 pwd = getpwnam(user); 106 107 PAM_LOG("Got user: %s", user); 108 109 if (pwd != NULL) { 110 PAM_LOG("Doing real authentication"); 111 realpw = pwd->pw_passwd; 112 if (realpw[0] == '\0') { 113 if (!(flags & PAM_DISALLOW_NULL_AUTHTOK) && 114 openpam_get_option(pamh, PAM_OPT_NULLOK)) 115 return (PAM_SUCCESS); 116 PAM_LOG("Password is empty, using fake password"); 117 realpw = "*"; 118 } 119 lc = login_getpwclass(pwd); 120 } else { 121 PAM_LOG("Doing dummy authentication"); 122 realpw = "*"; 123 lc = login_getclass(NULL); 124 } 125 prompt = login_getcapstr(lc, "passwd_prompt", NULL, NULL); 126 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, prompt); 127 login_close(lc); 128 if (retval != PAM_SUCCESS) 129 return (retval); 130 PAM_LOG("Got password"); 131 if (strnlen(pass, _PASSWORD_LEN + 1) > _PASSWORD_LEN) { 132 PAM_LOG("Password is too long, using fake password"); 133 realpw = "*"; 134 } 135 if (strcmp(crypt(pass, realpw), realpw) == 0) 136 return (PAM_SUCCESS); 137 138 PAM_VERBOSE_ERROR("UNIX authentication refused"); 139 return (PAM_AUTH_ERR); 140 } 141 142 PAM_EXTERN int 143 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused, 144 int argc __unused, const char *argv[] __unused) 145 { 146 147 return (PAM_SUCCESS); 148 } 149 150 /* 151 * account management 152 */ 153 PAM_EXTERN int 154 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused, 155 int argc __unused, const char *argv[] __unused) 156 { 157 struct addrinfo hints, *res; 158 struct passwd *pwd; 159 struct timeval tp; 160 login_cap_t *lc; 161 time_t warntime; 162 int retval; 163 const char *user; 164 const void *rhost, *tty; 165 char rhostip[MAXHOSTNAMELEN] = ""; 166 167 retval = pam_get_user(pamh, &user, NULL); 168 if (retval != PAM_SUCCESS) 169 return (retval); 170 171 if (user == NULL || (pwd = getpwnam(user)) == NULL) 172 return (PAM_SERVICE_ERR); 173 174 PAM_LOG("Got user: %s", user); 175 176 retval = pam_get_item(pamh, PAM_RHOST, &rhost); 177 if (retval != PAM_SUCCESS) 178 return (retval); 179 180 retval = pam_get_item(pamh, PAM_TTY, &tty); 181 if (retval != PAM_SUCCESS) 182 return (retval); 183 184 if (*pwd->pw_passwd == '\0' && 185 (flags & PAM_DISALLOW_NULL_AUTHTOK) != 0) 186 return (PAM_NEW_AUTHTOK_REQD); 187 188 if (strncmp(pwd->pw_passwd, LOCKED_PREFIX, LOCKED_PREFIX_LEN) == 0) 189 return (PAM_AUTH_ERR); 190 191 lc = login_getpwclass(pwd); 192 if (lc == NULL) { 193 PAM_LOG("Unable to get login class for user %s", user); 194 return (PAM_SERVICE_ERR); 195 } 196 197 PAM_LOG("Got login_cap"); 198 199 if (pwd->pw_change || pwd->pw_expire) 200 gettimeofday(&tp, NULL); 201 202 /* 203 * Check pw_expire before pw_change - no point in letting the 204 * user change the password on an expired account. 205 */ 206 207 if (pwd->pw_expire) { 208 warntime = login_getcaptime(lc, "warnexpire", 209 DEFAULT_WARN, DEFAULT_WARN); 210 if (tp.tv_sec >= pwd->pw_expire) { 211 login_close(lc); 212 return (PAM_ACCT_EXPIRED); 213 } else if (pwd->pw_expire - tp.tv_sec < warntime && 214 (flags & PAM_SILENT) == 0) { 215 pam_error(pamh, "Warning: your account expires on %s", 216 ctime(&pwd->pw_expire)); 217 } 218 } 219 220 retval = PAM_SUCCESS; 221 if (pwd->pw_change) { 222 warntime = login_getcaptime(lc, "warnpassword", 223 DEFAULT_WARN, DEFAULT_WARN); 224 if (tp.tv_sec >= pwd->pw_change) { 225 retval = PAM_NEW_AUTHTOK_REQD; 226 } else if (pwd->pw_change - tp.tv_sec < warntime && 227 (flags & PAM_SILENT) == 0) { 228 pam_error(pamh, "Warning: your password expires on %s", 229 ctime(&pwd->pw_change)); 230 } 231 } 232 233 /* 234 * From here on, we must leave retval untouched (unless we 235 * know we're going to fail), because we need to remember 236 * whether we're supposed to return PAM_SUCCESS or 237 * PAM_NEW_AUTHTOK_REQD. 238 */ 239 240 if (rhost && *(const char *)rhost != '\0') { 241 memset(&hints, 0, sizeof(hints)); 242 hints.ai_family = AF_UNSPEC; 243 if (getaddrinfo(rhost, NULL, &hints, &res) == 0) { 244 getnameinfo(res->ai_addr, res->ai_addrlen, 245 rhostip, sizeof(rhostip), NULL, 0, 246 NI_NUMERICHOST); 247 } 248 if (res != NULL) 249 freeaddrinfo(res); 250 } 251 252 /* 253 * Check host / tty / time-of-day restrictions 254 */ 255 256 if (!auth_hostok(lc, rhost, rhostip) || 257 !auth_ttyok(lc, tty) || 258 !auth_timeok(lc, time(NULL))) 259 retval = PAM_AUTH_ERR; 260 261 login_close(lc); 262 263 return (retval); 264 } 265 266 /* 267 * password management 268 * 269 * standard Unix and NIS password changing 270 */ 271 PAM_EXTERN int 272 pam_sm_chauthtok(pam_handle_t *pamh, int flags, 273 int argc __unused, const char *argv[] __unused) 274 { 275 #ifdef YP 276 struct ypclnt *ypclnt; 277 const void *yp_domain, *yp_server; 278 #endif 279 char salt[SALTSIZE + 1]; 280 login_cap_t *lc; 281 struct passwd *pwd, *old_pwd; 282 const char *user, *old_pass, *new_pass; 283 char *encrypted; 284 time_t passwordtime; 285 int pfd, tfd, retval; 286 287 if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF)) 288 user = getlogin(); 289 else { 290 retval = pam_get_user(pamh, &user, NULL); 291 if (retval != PAM_SUCCESS) 292 return (retval); 293 } 294 pwd = getpwnam(user); 295 296 if (pwd == NULL) 297 return (PAM_AUTHTOK_RECOVERY_ERR); 298 299 PAM_LOG("Got user: %s", user); 300 301 if (flags & PAM_PRELIM_CHECK) { 302 303 PAM_LOG("PRELIM round"); 304 305 if (getuid() == 0 && 306 (pwd->pw_fields & _PWF_SOURCE) == _PWF_FILES) 307 /* root doesn't need the old password */ 308 return (pam_set_item(pamh, PAM_OLDAUTHTOK, "")); 309 #ifdef YP 310 if (getuid() == 0 && 311 (pwd->pw_fields & _PWF_SOURCE) == _PWF_NIS) { 312 313 yp_domain = yp_server = NULL; 314 (void)pam_get_data(pamh, "yp_domain", &yp_domain); 315 (void)pam_get_data(pamh, "yp_server", &yp_server); 316 317 ypclnt = ypclnt_new(yp_domain, "passwd.byname", yp_server); 318 if (ypclnt == NULL) 319 return (PAM_BUF_ERR); 320 321 if (ypclnt_connect(ypclnt) == -1) { 322 ypclnt_free(ypclnt); 323 return (PAM_SERVICE_ERR); 324 } 325 326 retval = ypclnt_havepasswdd(ypclnt); 327 ypclnt_free(ypclnt); 328 if (retval == 1) 329 return (pam_set_item(pamh, PAM_OLDAUTHTOK, "")); 330 else if (retval == -1) 331 return (PAM_SERVICE_ERR); 332 } 333 #endif 334 if (pwd->pw_passwd[0] == '\0' 335 && openpam_get_option(pamh, PAM_OPT_NULLOK)) { 336 /* 337 * No password case. XXX Are we giving too much away 338 * by not prompting for a password? 339 * XXX check PAM_DISALLOW_NULL_AUTHTOK 340 */ 341 old_pass = ""; 342 retval = PAM_SUCCESS; 343 } else { 344 retval = pam_get_authtok(pamh, 345 PAM_OLDAUTHTOK, &old_pass, NULL); 346 if (retval != PAM_SUCCESS) 347 return (retval); 348 } 349 PAM_LOG("Got old password"); 350 /* always encrypt first */ 351 encrypted = crypt(old_pass, pwd->pw_passwd); 352 if (old_pass[0] == '\0' && 353 !openpam_get_option(pamh, PAM_OPT_NULLOK)) 354 return (PAM_PERM_DENIED); 355 if (strcmp(encrypted, pwd->pw_passwd) != 0) 356 return (PAM_PERM_DENIED); 357 } 358 else if (flags & PAM_UPDATE_AUTHTOK) { 359 PAM_LOG("UPDATE round"); 360 361 retval = pam_get_authtok(pamh, 362 PAM_OLDAUTHTOK, &old_pass, NULL); 363 if (retval != PAM_SUCCESS) 364 return (retval); 365 PAM_LOG("Got old password"); 366 367 /* get new password */ 368 for (;;) { 369 retval = pam_get_authtok(pamh, 370 PAM_AUTHTOK, &new_pass, NULL); 371 if (retval != PAM_TRY_AGAIN) 372 break; 373 pam_error(pamh, "Mismatch; try again, EOF to quit."); 374 } 375 PAM_LOG("Got new password"); 376 if (retval != PAM_SUCCESS) { 377 PAM_VERBOSE_ERROR("Unable to get new password"); 378 return (retval); 379 } 380 381 if (getuid() != 0 && new_pass[0] == '\0' && 382 !openpam_get_option(pamh, PAM_OPT_NULLOK)) 383 return (PAM_PERM_DENIED); 384 385 if ((old_pwd = pw_dup(pwd)) == NULL) 386 return (PAM_BUF_ERR); 387 388 lc = login_getclass(pwd->pw_class); 389 if (login_setcryptfmt(lc, password_hash, NULL) == NULL) 390 openpam_log(PAM_LOG_ERROR, 391 "can't set password cipher, relying on default"); 392 393 /* set password expiry date */ 394 pwd->pw_change = 0; 395 passwordtime = login_getcaptime(lc, "passwordtime", 0, 0); 396 if (passwordtime > 0) 397 pwd->pw_change = time(NULL) + passwordtime; 398 399 login_close(lc); 400 makesalt(salt); 401 pwd->pw_passwd = crypt(new_pass, salt); 402 #ifdef YP 403 switch (old_pwd->pw_fields & _PWF_SOURCE) { 404 case _PWF_FILES: 405 #endif 406 retval = PAM_SERVICE_ERR; 407 if (pw_init(NULL, NULL)) 408 openpam_log(PAM_LOG_ERROR, "pw_init() failed"); 409 else if ((pfd = pw_lock()) == -1) 410 openpam_log(PAM_LOG_ERROR, "pw_lock() failed"); 411 else if ((tfd = pw_tmp(-1)) == -1) 412 openpam_log(PAM_LOG_ERROR, "pw_tmp() failed"); 413 else if (pw_copy(pfd, tfd, pwd, old_pwd) == -1) 414 openpam_log(PAM_LOG_ERROR, "pw_copy() failed"); 415 else if (pw_mkdb(pwd->pw_name) == -1) 416 openpam_log(PAM_LOG_ERROR, "pw_mkdb() failed"); 417 else 418 retval = PAM_SUCCESS; 419 pw_fini(); 420 #ifdef YP 421 break; 422 case _PWF_NIS: 423 yp_domain = yp_server = NULL; 424 (void)pam_get_data(pamh, "yp_domain", &yp_domain); 425 (void)pam_get_data(pamh, "yp_server", &yp_server); 426 ypclnt = ypclnt_new(yp_domain, 427 "passwd.byname", yp_server); 428 if (ypclnt == NULL) { 429 retval = PAM_BUF_ERR; 430 } else if (ypclnt_connect(ypclnt) == -1 || 431 ypclnt_passwd(ypclnt, pwd, old_pass) == -1) { 432 openpam_log(PAM_LOG_ERROR, "%s", ypclnt->error); 433 retval = PAM_SERVICE_ERR; 434 } else { 435 retval = PAM_SUCCESS; 436 } 437 ypclnt_free(ypclnt); 438 break; 439 default: 440 openpam_log(PAM_LOG_ERROR, "unsupported source 0x%x", 441 pwd->pw_fields & _PWF_SOURCE); 442 retval = PAM_SERVICE_ERR; 443 } 444 #endif 445 free(old_pwd); 446 } 447 else { 448 /* Very bad juju */ 449 retval = PAM_ABORT; 450 PAM_LOG("Illegal 'flags'"); 451 } 452 453 return (retval); 454 } 455 456 /* Mostly stolen from passwd(1)'s local_passwd.c - markm */ 457 458 static unsigned char itoa64[] = /* 0 ... 63 => ascii - 64 */ 459 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; 460 461 static void 462 to64(char *s, long v, int n) 463 { 464 while (--n >= 0) { 465 *s++ = itoa64[v&0x3f]; 466 v >>= 6; 467 } 468 } 469 470 /* Salt suitable for traditional DES and MD5 */ 471 static void 472 makesalt(char salt[SALTSIZE + 1]) 473 { 474 int i; 475 476 /* These are not really random numbers, they are just 477 * numbers that change to thwart construction of a 478 * dictionary. 479 */ 480 for (i = 0; i < SALTSIZE; i += 4) 481 to64(&salt[i], arc4random(), 4); 482 salt[SALTSIZE] = '\0'; 483 } 484 485 PAM_MODULE_ENTRY("pam_unix"); 486