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 *rhost, *tty, *user; 155 char rhostip[MAXHOSTNAMELEN] = ""; 156 157 retval = pam_get_user(pamh, &user, NULL); 158 if (retval != PAM_SUCCESS) 159 return (retval); 160 161 if (user == NULL || (pwd = getpwnam(user)) == NULL) 162 return (PAM_SERVICE_ERR); 163 164 PAM_LOG("Got user: %s", user); 165 166 retval = pam_get_item(pamh, PAM_RHOST, (const void **)&rhost); 167 if (retval != PAM_SUCCESS) 168 return (retval); 169 170 retval = pam_get_item(pamh, PAM_TTY, (const void **)&tty); 171 if (retval != PAM_SUCCESS) 172 return (retval); 173 174 if (*pwd->pw_passwd == '\0' && 175 (flags & PAM_DISALLOW_NULL_AUTHTOK) != 0) 176 return (PAM_NEW_AUTHTOK_REQD); 177 178 lc = login_getpwclass(pwd); 179 if (lc == NULL) { 180 PAM_LOG("Unable to get login class for user %s", user); 181 return (PAM_SERVICE_ERR); 182 } 183 184 PAM_LOG("Got login_cap"); 185 186 if (pwd->pw_change || pwd->pw_expire) 187 gettimeofday(&tp, NULL); 188 189 /* 190 * Check pw_expire before pw_change - no point in letting the 191 * user change the password on an expired account. 192 */ 193 194 if (pwd->pw_expire) { 195 warntime = login_getcaptime(lc, "warnexpire", 196 DEFAULT_WARN, DEFAULT_WARN); 197 if (tp.tv_sec >= pwd->pw_expire) { 198 login_close(lc); 199 return (PAM_ACCT_EXPIRED); 200 } else if (pwd->pw_expire - tp.tv_sec < warntime && 201 (flags & PAM_SILENT) == 0) { 202 pam_error(pamh, "Warning: your account expires on %s", 203 ctime(&pwd->pw_expire)); 204 } 205 } 206 207 retval = PAM_SUCCESS; 208 if (pwd->pw_change) { 209 warntime = login_getcaptime(lc, "warnpassword", 210 DEFAULT_WARN, DEFAULT_WARN); 211 if (tp.tv_sec >= pwd->pw_change) { 212 retval = PAM_NEW_AUTHTOK_REQD; 213 } else if (pwd->pw_change - tp.tv_sec < warntime && 214 (flags & PAM_SILENT) == 0) { 215 pam_error(pamh, "Warning: your password expires on %s", 216 ctime(&pwd->pw_change)); 217 } 218 } 219 220 /* 221 * From here on, we must leave retval untouched (unless we 222 * know we're going to fail), because we need to remember 223 * whether we're supposed to return PAM_SUCCESS or 224 * PAM_NEW_AUTHTOK_REQD. 225 */ 226 227 if (rhost && *rhost) { 228 memset(&hints, 0, sizeof(hints)); 229 hints.ai_family = AF_UNSPEC; 230 if (getaddrinfo(rhost, NULL, &hints, &res) == 0) { 231 getnameinfo(res->ai_addr, res->ai_addrlen, 232 rhostip, sizeof(rhostip), NULL, 0, 233 NI_NUMERICHOST|NI_WITHSCOPEID); 234 } 235 if (res != NULL) 236 freeaddrinfo(res); 237 } 238 239 /* 240 * Check host / tty / time-of-day restrictions 241 */ 242 243 if (!auth_hostok(lc, rhost, rhostip) || 244 !auth_ttyok(lc, tty) || 245 !auth_timeok(lc, time(NULL))) 246 retval = PAM_AUTH_ERR; 247 248 login_close(lc); 249 250 return (retval); 251 } 252 253 /* 254 * password management 255 * 256 * standard Unix and NIS password changing 257 */ 258 PAM_EXTERN int 259 pam_sm_chauthtok(pam_handle_t *pamh, int flags, 260 int argc __unused, const char *argv[] __unused) 261 { 262 #ifdef YP 263 struct ypclnt *ypclnt; 264 const char *yp_domain, *yp_server; 265 #endif 266 char salt[SALTSIZE + 1]; 267 login_cap_t * lc; 268 struct passwd *pwd, *old_pwd; 269 const char *user, *old_pass, *new_pass; 270 char *encrypted; 271 int pfd, tfd, retval; 272 273 if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF)) 274 pwd = getpwnam(getlogin()); 275 else { 276 retval = pam_get_user(pamh, &user, NULL); 277 if (retval != PAM_SUCCESS) 278 return (retval); 279 pwd = getpwnam(user); 280 } 281 282 if (pwd == NULL) 283 return (PAM_AUTHTOK_RECOVERY_ERR); 284 285 PAM_LOG("Got user: %s", user); 286 287 if (flags & PAM_PRELIM_CHECK) { 288 289 PAM_LOG("PRELIM round"); 290 291 if (getuid() == 0 && 292 (pwd->pw_fields & _PWF_SOURCE) == _PWF_FILES) 293 /* root doesn't need the old password */ 294 return (pam_set_item(pamh, PAM_OLDAUTHTOK, "")); 295 #ifdef YP 296 if (getuid() == 0 && 297 (pwd->pw_fields & _PWF_SOURCE) == _PWF_NIS) { 298 299 yp_domain = yp_server = NULL; 300 (void)pam_get_data(pamh, 301 "yp_domain", (const void **)&yp_domain); 302 (void)pam_get_data(pamh, 303 "yp_server", (const void **)&yp_server); 304 305 ypclnt = ypclnt_new(yp_domain, "passwd.byname", yp_server); 306 if (ypclnt == NULL) 307 return (PAM_BUF_ERR); 308 309 if (ypclnt_connect(ypclnt) == -1) { 310 ypclnt_free(ypclnt); 311 return (PAM_SERVICE_ERR); 312 } 313 314 retval = ypclnt_havepasswdd(ypclnt); 315 ypclnt_free(ypclnt); 316 if (retval == 1) 317 return (pam_set_item(pamh, PAM_OLDAUTHTOK, "")); 318 else if (retval == -1) 319 return (PAM_SERVICE_ERR); 320 } 321 #endif 322 if (pwd->pw_passwd[0] == '\0' 323 && openpam_get_option(pamh, PAM_OPT_NULLOK)) { 324 /* 325 * No password case. XXX Are we giving too much away 326 * by not prompting for a password? 327 * XXX check PAM_DISALLOW_NULL_AUTHTOK 328 */ 329 old_pass = ""; 330 } else { 331 retval = pam_get_authtok(pamh, 332 PAM_OLDAUTHTOK, &old_pass, NULL); 333 if (retval != PAM_SUCCESS) 334 return (retval); 335 } 336 PAM_LOG("Got old password"); 337 /* always encrypt first */ 338 encrypted = crypt(old_pass, pwd->pw_passwd); 339 if (old_pass[0] == '\0' && 340 !openpam_get_option(pamh, PAM_OPT_NULLOK)) 341 return (PAM_PERM_DENIED); 342 if (strcmp(encrypted, pwd->pw_passwd) != 0) 343 return (PAM_PERM_DENIED); 344 } 345 else if (flags & PAM_UPDATE_AUTHTOK) { 346 PAM_LOG("UPDATE round"); 347 348 retval = pam_get_authtok(pamh, 349 PAM_OLDAUTHTOK, &old_pass, NULL); 350 if (retval != PAM_SUCCESS) 351 return (retval); 352 PAM_LOG("Got old password"); 353 354 /* get new password */ 355 for (;;) { 356 retval = pam_get_authtok(pamh, 357 PAM_AUTHTOK, &new_pass, NULL); 358 if (retval != PAM_TRY_AGAIN) 359 break; 360 pam_error(pamh, "Mismatch; try again, EOF to quit."); 361 } 362 PAM_LOG("Got new password"); 363 if (retval != PAM_SUCCESS) { 364 PAM_VERBOSE_ERROR("Unable to get new password"); 365 return (retval); 366 } 367 368 if (getuid() != 0 && new_pass[0] == '\0' && 369 !openpam_get_option(pamh, PAM_OPT_NULLOK)) 370 return (PAM_PERM_DENIED); 371 372 if ((old_pwd = pw_dup(pwd)) == NULL) 373 return (PAM_BUF_ERR); 374 375 pwd->pw_change = 0; 376 lc = login_getclass(NULL); 377 if (login_setcryptfmt(lc, password_hash, NULL) == NULL) 378 openpam_log(PAM_LOG_ERROR, 379 "can't set password cipher, relying on default"); 380 login_close(lc); 381 makesalt(salt); 382 pwd->pw_passwd = crypt(new_pass, salt); 383 #ifdef YP 384 switch (old_pwd->pw_fields & _PWF_SOURCE) { 385 case _PWF_FILES: 386 #endif 387 retval = PAM_SERVICE_ERR; 388 if (pw_init(NULL, NULL)) 389 openpam_log(PAM_LOG_ERROR, "pw_init() failed"); 390 else if ((pfd = pw_lock()) == -1) 391 openpam_log(PAM_LOG_ERROR, "pw_lock() failed"); 392 else if ((tfd = pw_tmp(-1)) == -1) 393 openpam_log(PAM_LOG_ERROR, "pw_tmp() failed"); 394 else if (pw_copy(pfd, tfd, pwd, old_pwd) == -1) 395 openpam_log(PAM_LOG_ERROR, "pw_copy() failed"); 396 else if (pw_mkdb(pwd->pw_name) == -1) 397 openpam_log(PAM_LOG_ERROR, "pw_mkdb() failed"); 398 else 399 retval = PAM_SUCCESS; 400 pw_fini(); 401 #ifdef YP 402 break; 403 case _PWF_NIS: 404 yp_domain = yp_server = NULL; 405 (void)pam_get_data(pamh, 406 "yp_domain", (const void **)&yp_domain); 407 (void)pam_get_data(pamh, 408 "yp_server", (const void **)&yp_server); 409 ypclnt = ypclnt_new(yp_domain, 410 "passwd.byname", yp_server); 411 if (ypclnt == NULL) { 412 retval = PAM_BUF_ERR; 413 } else if (ypclnt_connect(ypclnt) == -1 || 414 ypclnt_passwd(ypclnt, pwd, old_pass) == -1) { 415 openpam_log(PAM_LOG_ERROR, "%s", ypclnt->error); 416 retval = PAM_SERVICE_ERR; 417 } else { 418 retval = PAM_SUCCESS; 419 } 420 ypclnt_free(ypclnt); 421 break; 422 default: 423 openpam_log(PAM_LOG_ERROR, "unsupported source 0x%x", 424 pwd->pw_fields & _PWF_SOURCE); 425 retval = PAM_SERVICE_ERR; 426 } 427 #endif 428 free(old_pwd); 429 } 430 else { 431 /* Very bad juju */ 432 retval = PAM_ABORT; 433 PAM_LOG("Illegal 'flags'"); 434 } 435 436 return (retval); 437 } 438 439 /* Mostly stolen from passwd(1)'s local_passwd.c - markm */ 440 441 static unsigned char itoa64[] = /* 0 ... 63 => ascii - 64 */ 442 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; 443 444 static void 445 to64(char *s, long v, int n) 446 { 447 while (--n >= 0) { 448 *s++ = itoa64[v&0x3f]; 449 v >>= 6; 450 } 451 } 452 453 /* Salt suitable for traditional DES and MD5 */ 454 void 455 makesalt(char salt[SALTSIZE]) 456 { 457 int i; 458 459 /* These are not really random numbers, they are just 460 * numbers that change to thwart construction of a 461 * dictionary. This is exposed to the public. 462 */ 463 for (i = 0; i < SALTSIZE; i += 4) 464 to64(&salt[i], arc4random(), 4); 465 salt[SALTSIZE] = '\0'; 466 } 467 468 PAM_MODULE_ENTRY("pam_unix"); 469