1 /*- 2 * Copyright 1998 Juniper Networks, Inc. 3 * All rights reserved. 4 * Copyright (c) 2002-2003 Networks Associates Technology, Inc. 5 * All rights reserved. 6 * 7 * Portions of this software was developed for the FreeBSD Project by 8 * ThinkSec AS and NAI Labs, the Security Research Division of Network 9 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 10 * ("CBOSS"), as part of the DARPA CHATS research program. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. The name of the author may not be used to endorse or promote 21 * products derived from this software without specific prior written 22 * permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <sys/param.h> 41 #include <sys/socket.h> 42 #include <sys/time.h> 43 #include <netinet/in.h> 44 #include <arpa/inet.h> 45 46 #include <login_cap.h> 47 #include <netdb.h> 48 #include <pwd.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <stdio.h> 52 #include <syslog.h> 53 #include <unistd.h> 54 55 #include <libutil.h> 56 57 #ifdef YP 58 #include <ypclnt.h> 59 #endif 60 61 #define PAM_SM_AUTH 62 #define PAM_SM_ACCOUNT 63 #define PAM_SM_PASSWORD 64 65 #include <security/pam_appl.h> 66 #include <security/pam_modules.h> 67 #include <security/pam_mod_misc.h> 68 69 #define PASSWORD_HASH "md5" 70 #define DEFAULT_WARN (2L * 7L * 86400L) /* Two weeks */ 71 #define SALTSIZE 32 72 73 static void makesalt(char []); 74 75 static char password_hash[] = PASSWORD_HASH; 76 77 #define PAM_OPT_LOCAL_PASS "local_pass" 78 #define PAM_OPT_NIS_PASS "nis_pass" 79 80 char *tempname = NULL; 81 82 /* 83 * authentication management 84 */ 85 PAM_EXTERN int 86 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 87 int argc __unused, const char *argv[] __unused) 88 { 89 login_cap_t *lc; 90 struct passwd *pwd; 91 int retval; 92 const char *pass, *user, *realpw, *prompt; 93 94 if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF)) { 95 pwd = getpwnam(getlogin()); 96 } else { 97 retval = pam_get_user(pamh, &user, NULL); 98 if (retval != PAM_SUCCESS) 99 return (retval); 100 pwd = getpwnam(user); 101 } 102 103 PAM_LOG("Got user: %s", user); 104 105 if (pwd != NULL) { 106 PAM_LOG("Doing real authentication"); 107 realpw = pwd->pw_passwd; 108 if (realpw[0] == '\0') { 109 if (!(flags & PAM_DISALLOW_NULL_AUTHTOK) && 110 openpam_get_option(pamh, PAM_OPT_NULLOK)) 111 return (PAM_SUCCESS); 112 realpw = "*"; 113 } 114 lc = login_getpwclass(pwd); 115 } else { 116 PAM_LOG("Doing dummy authentication"); 117 realpw = "*"; 118 lc = login_getclass(NULL); 119 } 120 prompt = login_getcapstr(lc, "passwd_prompt", NULL, NULL); 121 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, prompt); 122 login_close(lc); 123 if (retval != PAM_SUCCESS) 124 return (retval); 125 PAM_LOG("Got password"); 126 if (strcmp(crypt(pass, realpw), realpw) == 0) 127 return (PAM_SUCCESS); 128 129 PAM_VERBOSE_ERROR("UNIX authentication refused"); 130 return (PAM_AUTH_ERR); 131 } 132 133 PAM_EXTERN int 134 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused, 135 int argc __unused, const char *argv[] __unused) 136 { 137 138 return (PAM_SUCCESS); 139 } 140 141 /* 142 * account management 143 */ 144 PAM_EXTERN int 145 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused, 146 int argc __unused, const char *argv[] __unused) 147 { 148 struct addrinfo hints, *res; 149 struct passwd *pwd; 150 struct timeval tp; 151 login_cap_t *lc; 152 time_t warntime; 153 int retval; 154 const char *user; 155 const void *rhost, *tty; 156 char rhostip[MAXHOSTNAMELEN] = ""; 157 158 retval = pam_get_user(pamh, &user, NULL); 159 if (retval != PAM_SUCCESS) 160 return (retval); 161 162 if (user == NULL || (pwd = getpwnam(user)) == NULL) 163 return (PAM_SERVICE_ERR); 164 165 PAM_LOG("Got user: %s", user); 166 167 retval = pam_get_item(pamh, PAM_RHOST, &rhost); 168 if (retval != PAM_SUCCESS) 169 return (retval); 170 171 retval = pam_get_item(pamh, PAM_TTY, &tty); 172 if (retval != PAM_SUCCESS) 173 return (retval); 174 175 if (*pwd->pw_passwd == '\0' && 176 (flags & PAM_DISALLOW_NULL_AUTHTOK) != 0) 177 return (PAM_NEW_AUTHTOK_REQD); 178 179 lc = login_getpwclass(pwd); 180 if (lc == NULL) { 181 PAM_LOG("Unable to get login class for user %s", user); 182 return (PAM_SERVICE_ERR); 183 } 184 185 PAM_LOG("Got login_cap"); 186 187 if (pwd->pw_change || pwd->pw_expire) 188 gettimeofday(&tp, NULL); 189 190 /* 191 * Check pw_expire before pw_change - no point in letting the 192 * user change the password on an expired account. 193 */ 194 195 if (pwd->pw_expire) { 196 warntime = login_getcaptime(lc, "warnexpire", 197 DEFAULT_WARN, DEFAULT_WARN); 198 if (tp.tv_sec >= pwd->pw_expire) { 199 login_close(lc); 200 return (PAM_ACCT_EXPIRED); 201 } else if (pwd->pw_expire - tp.tv_sec < warntime && 202 (flags & PAM_SILENT) == 0) { 203 pam_error(pamh, "Warning: your account expires on %s", 204 ctime(&pwd->pw_expire)); 205 } 206 } 207 208 retval = PAM_SUCCESS; 209 if (pwd->pw_change) { 210 warntime = login_getcaptime(lc, "warnpassword", 211 DEFAULT_WARN, DEFAULT_WARN); 212 if (tp.tv_sec >= pwd->pw_change) { 213 retval = PAM_NEW_AUTHTOK_REQD; 214 } else if (pwd->pw_change - tp.tv_sec < warntime && 215 (flags & PAM_SILENT) == 0) { 216 pam_error(pamh, "Warning: your password expires on %s", 217 ctime(&pwd->pw_change)); 218 } 219 } 220 221 /* 222 * From here on, we must leave retval untouched (unless we 223 * know we're going to fail), because we need to remember 224 * whether we're supposed to return PAM_SUCCESS or 225 * PAM_NEW_AUTHTOK_REQD. 226 */ 227 228 if (rhost && *(const char *)rhost != '\0') { 229 memset(&hints, 0, sizeof(hints)); 230 hints.ai_family = AF_UNSPEC; 231 if (getaddrinfo(rhost, NULL, &hints, &res) == 0) { 232 getnameinfo(res->ai_addr, res->ai_addrlen, 233 rhostip, sizeof(rhostip), NULL, 0, 234 NI_NUMERICHOST); 235 } 236 if (res != NULL) 237 freeaddrinfo(res); 238 } 239 240 /* 241 * Check host / tty / time-of-day restrictions 242 */ 243 244 if (!auth_hostok(lc, rhost, rhostip) || 245 !auth_ttyok(lc, tty) || 246 !auth_timeok(lc, time(NULL))) 247 retval = PAM_AUTH_ERR; 248 249 login_close(lc); 250 251 return (retval); 252 } 253 254 /* 255 * password management 256 * 257 * standard Unix and NIS password changing 258 */ 259 PAM_EXTERN int 260 pam_sm_chauthtok(pam_handle_t *pamh, int flags, 261 int argc __unused, const char *argv[] __unused) 262 { 263 #ifdef YP 264 struct ypclnt *ypclnt; 265 void *yp_domain, *yp_server; 266 #endif 267 char salt[SALTSIZE + 1]; 268 login_cap_t * lc; 269 struct passwd *pwd, *old_pwd; 270 const char *user, *old_pass, *new_pass; 271 char *encrypted; 272 int pfd, tfd, retval; 273 274 if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF)) 275 pwd = getpwnam(getlogin()); 276 else { 277 retval = pam_get_user(pamh, &user, NULL); 278 if (retval != PAM_SUCCESS) 279 return (retval); 280 pwd = getpwnam(user); 281 } 282 283 if (pwd == NULL) 284 return (PAM_AUTHTOK_RECOVERY_ERR); 285 286 PAM_LOG("Got user: %s", user); 287 288 if (flags & PAM_PRELIM_CHECK) { 289 290 PAM_LOG("PRELIM round"); 291 292 if (getuid() == 0 && 293 (pwd->pw_fields & _PWF_SOURCE) == _PWF_FILES) 294 /* root doesn't need the old password */ 295 return (pam_set_item(pamh, PAM_OLDAUTHTOK, "")); 296 #ifdef YP 297 if (getuid() == 0 && 298 (pwd->pw_fields & _PWF_SOURCE) == _PWF_NIS) { 299 300 yp_domain = yp_server = NULL; 301 (void)pam_get_data(pamh, "yp_domain", &yp_domain); 302 (void)pam_get_data(pamh, "yp_server", &yp_server); 303 304 ypclnt = ypclnt_new(yp_domain, "passwd.byname", yp_server); 305 if (ypclnt == NULL) 306 return (PAM_BUF_ERR); 307 308 if (ypclnt_connect(ypclnt) == -1) { 309 ypclnt_free(ypclnt); 310 return (PAM_SERVICE_ERR); 311 } 312 313 retval = ypclnt_havepasswdd(ypclnt); 314 ypclnt_free(ypclnt); 315 if (retval == 1) 316 return (pam_set_item(pamh, PAM_OLDAUTHTOK, "")); 317 else if (retval == -1) 318 return (PAM_SERVICE_ERR); 319 } 320 #endif 321 if (pwd->pw_passwd[0] == '\0' 322 && openpam_get_option(pamh, PAM_OPT_NULLOK)) { 323 /* 324 * No password case. XXX Are we giving too much away 325 * by not prompting for a password? 326 * XXX check PAM_DISALLOW_NULL_AUTHTOK 327 */ 328 old_pass = ""; 329 } else { 330 retval = pam_get_authtok(pamh, 331 PAM_OLDAUTHTOK, &old_pass, NULL); 332 if (retval != PAM_SUCCESS) 333 return (retval); 334 } 335 PAM_LOG("Got old password"); 336 /* always encrypt first */ 337 encrypted = crypt(old_pass, pwd->pw_passwd); 338 if (old_pass[0] == '\0' && 339 !openpam_get_option(pamh, PAM_OPT_NULLOK)) 340 return (PAM_PERM_DENIED); 341 if (strcmp(encrypted, pwd->pw_passwd) != 0) 342 return (PAM_PERM_DENIED); 343 } 344 else if (flags & PAM_UPDATE_AUTHTOK) { 345 PAM_LOG("UPDATE round"); 346 347 retval = pam_get_authtok(pamh, 348 PAM_OLDAUTHTOK, &old_pass, NULL); 349 if (retval != PAM_SUCCESS) 350 return (retval); 351 PAM_LOG("Got old password"); 352 353 /* get new password */ 354 for (;;) { 355 retval = pam_get_authtok(pamh, 356 PAM_AUTHTOK, &new_pass, NULL); 357 if (retval != PAM_TRY_AGAIN) 358 break; 359 pam_error(pamh, "Mismatch; try again, EOF to quit."); 360 } 361 PAM_LOG("Got new password"); 362 if (retval != PAM_SUCCESS) { 363 PAM_VERBOSE_ERROR("Unable to get new password"); 364 return (retval); 365 } 366 367 if (getuid() != 0 && new_pass[0] == '\0' && 368 !openpam_get_option(pamh, PAM_OPT_NULLOK)) 369 return (PAM_PERM_DENIED); 370 371 if ((old_pwd = pw_dup(pwd)) == NULL) 372 return (PAM_BUF_ERR); 373 374 pwd->pw_change = 0; 375 lc = login_getclass(pwd->pw_class); 376 if (login_setcryptfmt(lc, password_hash, NULL) == NULL) 377 openpam_log(PAM_LOG_ERROR, 378 "can't set password cipher, relying on default"); 379 login_close(lc); 380 makesalt(salt); 381 pwd->pw_passwd = crypt(new_pass, salt); 382 #ifdef YP 383 switch (old_pwd->pw_fields & _PWF_SOURCE) { 384 case _PWF_FILES: 385 #endif 386 retval = PAM_SERVICE_ERR; 387 if (pw_init(NULL, NULL)) 388 openpam_log(PAM_LOG_ERROR, "pw_init() failed"); 389 else if ((pfd = pw_lock()) == -1) 390 openpam_log(PAM_LOG_ERROR, "pw_lock() failed"); 391 else if ((tfd = pw_tmp(-1)) == -1) 392 openpam_log(PAM_LOG_ERROR, "pw_tmp() failed"); 393 else if (pw_copy(pfd, tfd, pwd, old_pwd) == -1) 394 openpam_log(PAM_LOG_ERROR, "pw_copy() failed"); 395 else if (pw_mkdb(pwd->pw_name) == -1) 396 openpam_log(PAM_LOG_ERROR, "pw_mkdb() failed"); 397 else 398 retval = PAM_SUCCESS; 399 pw_fini(); 400 #ifdef YP 401 break; 402 case _PWF_NIS: 403 yp_domain = yp_server = NULL; 404 (void)pam_get_data(pamh, "yp_domain", &yp_domain); 405 (void)pam_get_data(pamh, "yp_server", &yp_server); 406 ypclnt = ypclnt_new(yp_domain, 407 "passwd.byname", yp_server); 408 if (ypclnt == NULL) { 409 retval = PAM_BUF_ERR; 410 } else if (ypclnt_connect(ypclnt) == -1 || 411 ypclnt_passwd(ypclnt, pwd, old_pass) == -1) { 412 openpam_log(PAM_LOG_ERROR, "%s", ypclnt->error); 413 retval = PAM_SERVICE_ERR; 414 } else { 415 retval = PAM_SUCCESS; 416 } 417 ypclnt_free(ypclnt); 418 break; 419 default: 420 openpam_log(PAM_LOG_ERROR, "unsupported source 0x%x", 421 pwd->pw_fields & _PWF_SOURCE); 422 retval = PAM_SERVICE_ERR; 423 } 424 #endif 425 free(old_pwd); 426 } 427 else { 428 /* Very bad juju */ 429 retval = PAM_ABORT; 430 PAM_LOG("Illegal 'flags'"); 431 } 432 433 return (retval); 434 } 435 436 /* Mostly stolen from passwd(1)'s local_passwd.c - markm */ 437 438 static unsigned char itoa64[] = /* 0 ... 63 => ascii - 64 */ 439 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; 440 441 static void 442 to64(char *s, long v, int n) 443 { 444 while (--n >= 0) { 445 *s++ = itoa64[v&0x3f]; 446 v >>= 6; 447 } 448 } 449 450 /* Salt suitable for traditional DES and MD5 */ 451 void 452 makesalt(char salt[SALTSIZE]) 453 { 454 int i; 455 456 /* These are not really random numbers, they are just 457 * numbers that change to thwart construction of a 458 * dictionary. This is exposed to the public. 459 */ 460 for (i = 0; i < SALTSIZE; i += 4) 461 to64(&salt[i], arc4random(), 4); 462 salt[SALTSIZE] = '\0'; 463 } 464 465 PAM_MODULE_ENTRY("pam_unix"); 466