1 /*- 2 * Copyright 1998 Juniper Networks, Inc. 3 * All rights reserved. 4 * Copyright (c) 2002 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 enum { 78 PAM_OPT_AUTH_AS_SELF = PAM_OPT_STD_MAX, 79 PAM_OPT_NULLOK, 80 PAM_OPT_LOCAL_PASS, 81 PAM_OPT_NIS_PASS 82 }; 83 84 static struct opttab other_options[] = { 85 { "auth_as_self", PAM_OPT_AUTH_AS_SELF }, 86 { "nullok", PAM_OPT_NULLOK }, 87 { "local_pass", PAM_OPT_LOCAL_PASS }, 88 { "nis_pass", PAM_OPT_NIS_PASS }, 89 { NULL, 0 } 90 }; 91 92 char *tempname = NULL; 93 94 /* 95 * authentication management 96 */ 97 PAM_EXTERN int 98 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 99 int argc, const char *argv[]) 100 { 101 login_cap_t *lc; 102 struct options options; 103 struct passwd *pwd; 104 int retval; 105 const char *pass, *user, *realpw, *prompt; 106 107 pam_std_option(&options, other_options, argc, argv); 108 109 PAM_LOG("Options processed"); 110 111 if (pam_test_option(&options, PAM_OPT_AUTH_AS_SELF, NULL)) { 112 pwd = getpwnam(getlogin()); 113 } else { 114 retval = pam_get_user(pamh, &user, NULL); 115 if (retval != PAM_SUCCESS) 116 return (retval); 117 pwd = getpwnam(user); 118 } 119 120 PAM_LOG("Got user: %s", user); 121 122 if (pwd != NULL) { 123 PAM_LOG("Doing real authentication"); 124 realpw = pwd->pw_passwd; 125 if (realpw[0] == '\0') { 126 if (!(flags & PAM_DISALLOW_NULL_AUTHTOK) && 127 pam_test_option(&options, PAM_OPT_NULLOK, NULL)) 128 return (PAM_SUCCESS); 129 realpw = "*"; 130 } 131 lc = login_getpwclass(pwd); 132 } else { 133 PAM_LOG("Doing dummy authentication"); 134 realpw = "*"; 135 lc = login_getclass(NULL); 136 } 137 prompt = login_getcapstr(lc, "passwd_prompt", NULL, NULL); 138 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, prompt); 139 login_close(lc); 140 if (retval != PAM_SUCCESS) 141 return (retval); 142 PAM_LOG("Got password"); 143 if (strcmp(crypt(pass, realpw), realpw) == 0) 144 return (PAM_SUCCESS); 145 146 PAM_VERBOSE_ERROR("UNIX authentication refused"); 147 return (PAM_AUTH_ERR); 148 } 149 150 PAM_EXTERN int 151 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused, 152 int argc __unused, const char *argv[] __unused) 153 { 154 155 return (PAM_SUCCESS); 156 } 157 158 /* 159 * account management 160 */ 161 PAM_EXTERN int 162 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused, 163 int argc, const char *argv[]) 164 { 165 struct addrinfo hints, *res; 166 struct options options; 167 struct passwd *pwd; 168 struct timeval tp; 169 login_cap_t *lc; 170 time_t warntime; 171 int retval; 172 const char *rhost, *tty, *user; 173 char rhostip[MAXHOSTNAMELEN]; 174 175 pam_std_option(&options, other_options, argc, argv); 176 177 PAM_LOG("Options processed"); 178 179 retval = pam_get_user(pamh, &user, NULL); 180 if (retval != PAM_SUCCESS) 181 return (retval); 182 183 if (user == NULL || (pwd = getpwnam(user)) == NULL) 184 return (PAM_SERVICE_ERR); 185 186 PAM_LOG("Got user: %s", user); 187 188 retval = pam_get_item(pamh, PAM_RHOST, (const void **)&rhost); 189 if (retval != PAM_SUCCESS) 190 return (retval); 191 192 retval = pam_get_item(pamh, PAM_TTY, (const void **)&tty); 193 if (retval != PAM_SUCCESS) 194 return (retval); 195 196 if (*pwd->pw_passwd == '\0' && 197 (flags & PAM_DISALLOW_NULL_AUTHTOK) != 0) 198 return (PAM_NEW_AUTHTOK_REQD); 199 200 lc = login_getpwclass(pwd); 201 if (lc == NULL) { 202 PAM_LOG("Unable to get login class for user %s", user); 203 return (PAM_SERVICE_ERR); 204 } 205 206 PAM_LOG("Got login_cap"); 207 208 if (pwd->pw_change || pwd->pw_expire) 209 gettimeofday(&tp, NULL); 210 211 /* 212 * Check pw_expire before pw_change - no point in letting the 213 * user change the password on an expired account. 214 */ 215 216 if (pwd->pw_expire) { 217 warntime = login_getcaptime(lc, "warnexpire", 218 DEFAULT_WARN, DEFAULT_WARN); 219 if (tp.tv_sec >= pwd->pw_expire) { 220 login_close(lc); 221 return (PAM_ACCT_EXPIRED); 222 } else if (pwd->pw_expire - tp.tv_sec < warntime && 223 (flags & PAM_SILENT) == 0) { 224 pam_error(pamh, "Warning: your account expires on %s", 225 ctime(&pwd->pw_expire)); 226 } 227 } 228 229 retval = PAM_SUCCESS; 230 if (pwd->pw_change) { 231 warntime = login_getcaptime(lc, "warnpassword", 232 DEFAULT_WARN, DEFAULT_WARN); 233 if (tp.tv_sec >= pwd->pw_change) { 234 retval = PAM_NEW_AUTHTOK_REQD; 235 } else if (pwd->pw_change - tp.tv_sec < warntime && 236 (flags & PAM_SILENT) == 0) { 237 pam_error(pamh, "Warning: your password expires on %s", 238 ctime(&pwd->pw_change)); 239 } 240 } 241 242 /* 243 * From here on, we must leave retval untouched (unless we 244 * know we're going to fail), because we need to remember 245 * whether we're supposed to return PAM_SUCCESS or 246 * PAM_NEW_AUTHTOK_REQD. 247 */ 248 249 if (rhost) { 250 memset(&hints, 0, sizeof(hints)); 251 hints.ai_family = AF_UNSPEC; 252 if (getaddrinfo(rhost, NULL, &hints, &res) == 0) { 253 getnameinfo(res->ai_addr, res->ai_addrlen, 254 rhostip, sizeof(rhostip), NULL, 0, 255 NI_NUMERICHOST|NI_WITHSCOPEID); 256 } 257 if (res != NULL) 258 freeaddrinfo(res); 259 } 260 261 /* 262 * Check host / tty / time-of-day restrictions 263 */ 264 265 if (!auth_hostok(lc, rhost, rhostip) || 266 !auth_ttyok(lc, tty) || 267 !auth_timeok(lc, time(NULL))) 268 retval = PAM_AUTH_ERR; 269 270 login_close(lc); 271 272 return (retval); 273 } 274 275 /* 276 * password management 277 * 278 * standard Unix and NIS password changing 279 */ 280 PAM_EXTERN int 281 pam_sm_chauthtok(pam_handle_t *pamh, int flags, 282 int argc, const char *argv[]) 283 { 284 #ifdef YP 285 struct ypclnt *ypclnt; 286 const char *yp_domain, *yp_server; 287 #endif 288 struct options options; 289 char salt[SALTSIZE + 1]; 290 login_cap_t * lc; 291 struct passwd *pwd, *old_pwd; 292 const char *user, *old_pass, *new_pass; 293 char *encrypted; 294 int pfd, tfd, retval; 295 296 pam_std_option(&options, other_options, argc, argv); 297 298 PAM_LOG("Options processed"); 299 300 if (pam_test_option(&options, PAM_OPT_AUTH_AS_SELF, NULL)) 301 pwd = getpwnam(getlogin()); 302 else { 303 retval = pam_get_user(pamh, &user, NULL); 304 if (retval != PAM_SUCCESS) 305 return (retval); 306 pwd = getpwnam(user); 307 } 308 309 if (pwd == NULL) 310 return (PAM_AUTHTOK_RECOVERY_ERR); 311 312 PAM_LOG("Got user: %s", user); 313 314 if (flags & PAM_PRELIM_CHECK) { 315 316 PAM_LOG("PRELIM round"); 317 318 if (getuid() == 0 && 319 (pwd->pw_fields & _PWF_SOURCE) == _PWF_FILES) 320 /* root doesn't need the old password */ 321 return (pam_set_item(pamh, PAM_OLDAUTHTOK, "")); 322 323 if (pwd->pw_passwd[0] == '\0' 324 && pam_test_option(&options, PAM_OPT_NULLOK, NULL)) { 325 /* 326 * No password case. XXX Are we giving too much away 327 * by not prompting for a password? 328 * XXX check PAM_DISALLOW_NULL_AUTHTOK 329 */ 330 old_pass = ""; 331 } else { 332 retval = pam_get_authtok(pamh, 333 PAM_OLDAUTHTOK, &old_pass, NULL); 334 if (retval != PAM_SUCCESS) 335 return (retval); 336 } 337 PAM_LOG("Got old password"); 338 /* always encrypt first */ 339 encrypted = crypt(old_pass, pwd->pw_passwd); 340 if ((old_pass[0] == '\0' && pwd->pw_passwd[0] != '\0') || 341 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 ((old_pwd = pw_dup(pwd)) == NULL) 368 return (PAM_BUF_ERR); 369 370 pwd->pw_change = 0; 371 lc = login_getclass(NULL); 372 if (login_setcryptfmt(lc, password_hash, NULL) == NULL) 373 openpam_log(PAM_LOG_ERROR, 374 "can't set password cipher, relying on default"); 375 login_close(lc); 376 makesalt(salt); 377 pwd->pw_passwd = crypt(new_pass, salt); 378 #ifdef YP 379 switch (old_pwd->pw_fields & _PWF_SOURCE) { 380 case _PWF_FILES: 381 #endif 382 retval = PAM_SERVICE_ERR; 383 if (pw_init(NULL, NULL)) 384 openpam_log(PAM_LOG_ERROR, "pw_init() failed"); 385 else if ((pfd = pw_lock()) == -1) 386 openpam_log(PAM_LOG_ERROR, "pw_lock() failed"); 387 else if ((tfd = pw_tmp(-1)) == -1) 388 openpam_log(PAM_LOG_ERROR, "pw_tmp() failed"); 389 else if (pw_copy(pfd, tfd, pwd, old_pwd) == -1) 390 openpam_log(PAM_LOG_ERROR, "pw_copy() failed"); 391 else if (pw_mkdb(pwd->pw_name) == -1) 392 openpam_log(PAM_LOG_ERROR, "pw_mkdb() failed"); 393 else 394 retval = PAM_SUCCESS; 395 pw_fini(); 396 #ifdef YP 397 break; 398 case _PWF_NIS: 399 yp_domain = yp_server = NULL; 400 (void)pam_get_data(pamh, 401 "yp_domain", (const void **)&yp_domain); 402 (void)pam_get_data(pamh, 403 "yp_server", (const void **)&yp_server); 404 ypclnt = ypclnt_new(yp_domain, 405 "passwd.byname", yp_server); 406 if (ypclnt == NULL) { 407 retval = PAM_BUF_ERR; 408 } else if (ypclnt_connect(ypclnt) == -1 || 409 ypclnt_passwd(ypclnt, pwd, old_pass) == -1) { 410 openpam_log(PAM_LOG_ERROR, "%s", ypclnt->error); 411 retval = PAM_SERVICE_ERR; 412 } else { 413 retval = PAM_SUCCESS; 414 } 415 ypclnt_free(ypclnt); 416 break; 417 default: 418 openpam_log(PAM_LOG_ERROR, "unsupported source 0x%x", 419 pwd->pw_fields & _PWF_SOURCE); 420 retval = PAM_SERVICE_ERR; 421 } 422 #endif 423 free(old_pwd); 424 } 425 else { 426 /* Very bad juju */ 427 retval = PAM_ABORT; 428 PAM_LOG("Illegal 'flags'"); 429 } 430 431 return (retval); 432 } 433 434 /* Mostly stolen from passwd(1)'s local_passwd.c - markm */ 435 436 static unsigned char itoa64[] = /* 0 ... 63 => ascii - 64 */ 437 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; 438 439 static void 440 to64(char *s, long v, int n) 441 { 442 while (--n >= 0) { 443 *s++ = itoa64[v&0x3f]; 444 v >>= 6; 445 } 446 } 447 448 /* Salt suitable for traditional DES and MD5 */ 449 void 450 makesalt(char salt[SALTSIZE]) 451 { 452 int i; 453 454 /* These are not really random numbers, they are just 455 * numbers that change to thwart construction of a 456 * dictionary. This is exposed to the public. 457 */ 458 for (i = 0; i < SALTSIZE; i += 4) 459 to64(&salt[i], arc4random(), 4); 460 salt[SALTSIZE] = '\0'; 461 } 462 463 PAM_MODULE_ENTRY("pam_unix"); 464