1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright 1998 Juniper Networks, Inc. 5 * All rights reserved. 6 * Copyright (c) 2001-2003 Networks Associates Technology, Inc. 7 * All rights reserved. 8 * Copyright (c) 2015-2018 The University of Oslo 9 * All rights reserved. 10 * 11 * Portions of this software were developed for the FreeBSD Project by 12 * ThinkSec AS and NAI Labs, the Security Research Division of Network 13 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 14 * ("CBOSS"), as part of the DARPA CHATS research program. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 3. The name of the author may not be used to endorse or promote 25 * products derived from this software without specific prior written 26 * permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include <sys/param.h> 45 #include <sys/socket.h> 46 #include <netdb.h> 47 #include <pwd.h> 48 #include <radlib.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <syslog.h> 52 #include <unistd.h> 53 54 #define PAM_SM_AUTH 55 56 #include <security/pam_appl.h> 57 #include <security/pam_modules.h> 58 #include <security/pam_mod_misc.h> 59 60 #define PAM_OPT_CONF "conf" 61 #define PAM_OPT_TEMPLATE_USER "template_user" 62 #define PAM_OPT_NAS_ID "nas_id" 63 #define PAM_OPT_NAS_IPADDR "nas_ipaddr" 64 #define PAM_OPT_NO_REPLYMSG "no_reply_message" 65 66 #define MAX_CHALLENGE_MSGS 10 67 #define PASSWORD_PROMPT "RADIUS Password:" 68 69 static int build_access_request(struct rad_handle *, const char *, 70 const char *, const char *, const char *, const char *, 71 const void *, size_t); 72 static int do_accept(pam_handle_t *, struct rad_handle *); 73 static int do_challenge(pam_handle_t *, struct rad_handle *, 74 const char *, const char *, const char *, const char *); 75 76 /* 77 * Construct an access request, but don't send it. Returns 0 on success, 78 * -1 on failure. 79 */ 80 static int 81 build_access_request(struct rad_handle *radh, const char *user, 82 const char *pass, const char *nas_id, const char *nas_ipaddr, 83 const char *rhost, const void *state, size_t state_len) 84 { 85 int error; 86 char host[MAXHOSTNAMELEN]; 87 struct sockaddr_in *haddr; 88 struct addrinfo hints; 89 struct addrinfo *res; 90 91 if (rad_create_request(radh, RAD_ACCESS_REQUEST) == -1) { 92 syslog(LOG_CRIT, "rad_create_request: %s", rad_strerror(radh)); 93 return (-1); 94 } 95 if (nas_id == NULL || 96 (nas_ipaddr != NULL && strlen(nas_ipaddr) == 0)) { 97 if (gethostname(host, sizeof host) != -1) { 98 if (nas_id == NULL) 99 nas_id = host; 100 if (nas_ipaddr != NULL && strlen(nas_ipaddr) == 0) 101 nas_ipaddr = host; 102 } 103 } 104 if ((user != NULL && 105 rad_put_string(radh, RAD_USER_NAME, user) == -1) || 106 (pass != NULL && 107 rad_put_string(radh, RAD_USER_PASSWORD, pass) == -1) || 108 (nas_id != NULL && 109 rad_put_string(radh, RAD_NAS_IDENTIFIER, nas_id) == -1)) { 110 syslog(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh)); 111 return (-1); 112 } 113 if (nas_ipaddr != NULL) { 114 memset(&hints, 0, sizeof(hints)); 115 hints.ai_family = AF_INET; 116 if (getaddrinfo(nas_ipaddr, NULL, &hints, &res) == 0 && 117 res != NULL && res->ai_family == AF_INET) { 118 haddr = (struct sockaddr_in *)res->ai_addr; 119 error = rad_put_addr(radh, RAD_NAS_IP_ADDRESS, 120 haddr->sin_addr); 121 freeaddrinfo(res); 122 if (error == -1) { 123 syslog(LOG_CRIT, "rad_put_addr: %s", 124 rad_strerror(radh)); 125 return (-1); 126 } 127 } 128 } 129 if (rhost != NULL && 130 rad_put_string(radh, RAD_CALLING_STATION_ID, rhost) == -1) { 131 syslog(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh)); 132 return (-1); 133 } 134 if (state != NULL && 135 rad_put_attr(radh, RAD_STATE, state, state_len) == -1) { 136 syslog(LOG_CRIT, "rad_put_attr: %s", rad_strerror(radh)); 137 return (-1); 138 } 139 if (rad_put_int(radh, RAD_SERVICE_TYPE, RAD_AUTHENTICATE_ONLY) == -1) { 140 syslog(LOG_CRIT, "rad_put_int: %s", rad_strerror(radh)); 141 return (-1); 142 } 143 return (0); 144 } 145 146 static int 147 do_accept(pam_handle_t *pamh, struct rad_handle *radh) 148 { 149 int attrtype; 150 const void *attrval; 151 size_t attrlen; 152 char *s; 153 154 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 155 switch (attrtype) { 156 case RAD_USER_NAME: 157 if ((s = rad_cvt_string(attrval, attrlen)) == NULL) 158 goto enomem; 159 pam_set_item(pamh, PAM_USER, s); 160 free(s); 161 break; 162 case RAD_REPLY_MESSAGE: 163 if ((s = rad_cvt_string(attrval, attrlen)) == NULL) 164 goto enomem; 165 if (!openpam_get_option(pamh, PAM_OPT_NO_REPLYMSG)) 166 pam_info(pamh, "%s", s); 167 free(s); 168 break; 169 default: 170 PAM_LOG("%s(): ignoring RADIUS attribute %d", 171 __func__, attrtype); 172 } 173 } 174 if (attrtype == -1) { 175 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 176 return (-1); 177 } 178 return (0); 179 enomem: 180 syslog(LOG_CRIT, "%s(): out of memory", __func__); 181 return (-1); 182 } 183 184 static int 185 do_reject(pam_handle_t *pamh, struct rad_handle *radh) 186 { 187 int attrtype; 188 const void *attrval; 189 size_t attrlen; 190 char *s; 191 192 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 193 switch (attrtype) { 194 case RAD_REPLY_MESSAGE: 195 if ((s = rad_cvt_string(attrval, attrlen)) == NULL) 196 goto enomem; 197 if (!openpam_get_option(pamh, PAM_OPT_NO_REPLYMSG)) 198 pam_error(pamh, "%s", s); 199 free(s); 200 break; 201 default: 202 PAM_LOG("%s(): ignoring RADIUS attribute %d", 203 __func__, attrtype); 204 } 205 } 206 if (attrtype < 0) { 207 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 208 return (-1); 209 } 210 return (0); 211 enomem: 212 syslog(LOG_CRIT, "%s(): out of memory", __func__); 213 return (-1); 214 } 215 216 static int 217 do_challenge(pam_handle_t *pamh, struct rad_handle *radh, const char *user, 218 const char *nas_id, const char *nas_ipaddr, const char *rhost) 219 { 220 int retval; 221 int attrtype; 222 const void *attrval; 223 size_t attrlen; 224 const void *state; 225 size_t statelen; 226 struct pam_message msgs[MAX_CHALLENGE_MSGS]; 227 const struct pam_message *msg_ptrs[MAX_CHALLENGE_MSGS]; 228 struct pam_response *resp; 229 int num_msgs; 230 const void *item; 231 const struct pam_conv *conv; 232 233 state = NULL; 234 statelen = 0; 235 num_msgs = 0; 236 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 237 switch (attrtype) { 238 239 case RAD_STATE: 240 state = attrval; 241 statelen = attrlen; 242 break; 243 244 case RAD_REPLY_MESSAGE: 245 if (num_msgs >= MAX_CHALLENGE_MSGS) { 246 syslog(LOG_CRIT, 247 "Too many RADIUS challenge messages"); 248 return (PAM_SERVICE_ERR); 249 } 250 msgs[num_msgs].msg = rad_cvt_string(attrval, attrlen); 251 if (msgs[num_msgs].msg == NULL) { 252 syslog(LOG_CRIT, 253 "rad_cvt_string: out of memory"); 254 return (PAM_SERVICE_ERR); 255 } 256 msgs[num_msgs].msg_style = PAM_TEXT_INFO; 257 msg_ptrs[num_msgs] = &msgs[num_msgs]; 258 num_msgs++; 259 break; 260 } 261 } 262 if (attrtype == -1) { 263 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 264 return (PAM_SERVICE_ERR); 265 } 266 if (num_msgs == 0) { 267 msgs[num_msgs].msg = strdup("(null RADIUS challenge): "); 268 if (msgs[num_msgs].msg == NULL) { 269 syslog(LOG_CRIT, "Out of memory"); 270 return (PAM_SERVICE_ERR); 271 } 272 msgs[num_msgs].msg_style = PAM_TEXT_INFO; 273 msg_ptrs[num_msgs] = &msgs[num_msgs]; 274 num_msgs++; 275 } 276 msgs[num_msgs-1].msg_style = PAM_PROMPT_ECHO_ON; 277 if ((retval = pam_get_item(pamh, PAM_CONV, &item)) != PAM_SUCCESS) { 278 syslog(LOG_CRIT, "do_challenge: cannot get PAM_CONV"); 279 return (retval); 280 } 281 conv = (const struct pam_conv *)item; 282 if ((retval = conv->conv(num_msgs, msg_ptrs, &resp, 283 conv->appdata_ptr)) != PAM_SUCCESS) 284 return (retval); 285 if (build_access_request(radh, user, resp[num_msgs-1].resp, nas_id, 286 nas_ipaddr, rhost, state, statelen) == -1) 287 return (PAM_SERVICE_ERR); 288 memset(resp[num_msgs-1].resp, 0, strlen(resp[num_msgs-1].resp)); 289 free(resp[num_msgs-1].resp); 290 free(resp); 291 while (num_msgs > 0) 292 free(msgs[--num_msgs].msg); 293 return (PAM_SUCCESS); 294 } 295 296 PAM_EXTERN int 297 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 298 int argc __unused, const char *argv[] __unused) 299 { 300 struct rad_handle *radh; 301 const char *user, *pass; 302 const void *rhost, *tmpuser; 303 const char *conf_file, *template_user, *nas_id, *nas_ipaddr; 304 int retval; 305 int e; 306 307 conf_file = openpam_get_option(pamh, PAM_OPT_CONF); 308 template_user = openpam_get_option(pamh, PAM_OPT_TEMPLATE_USER); 309 nas_id = openpam_get_option(pamh, PAM_OPT_NAS_ID); 310 nas_ipaddr = openpam_get_option(pamh, PAM_OPT_NAS_IPADDR); 311 pam_get_item(pamh, PAM_RHOST, &rhost); 312 313 retval = pam_get_user(pamh, &user, NULL); 314 if (retval != PAM_SUCCESS) 315 return (retval); 316 317 PAM_LOG("Got user: %s", user); 318 319 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, PASSWORD_PROMPT); 320 if (retval != PAM_SUCCESS) 321 return (retval); 322 323 PAM_LOG("Got password"); 324 325 radh = rad_open(); 326 if (radh == NULL) { 327 syslog(LOG_CRIT, "rad_open failed"); 328 return (PAM_SERVICE_ERR); 329 } 330 331 PAM_LOG("Radius opened"); 332 333 if (rad_config(radh, conf_file) == -1) { 334 syslog(LOG_ALERT, "rad_config: %s", rad_strerror(radh)); 335 rad_close(radh); 336 return (PAM_SERVICE_ERR); 337 } 338 339 PAM_LOG("Radius config file read"); 340 341 if (build_access_request(radh, user, pass, nas_id, nas_ipaddr, rhost, 342 NULL, 0) == -1) { 343 rad_close(radh); 344 return (PAM_SERVICE_ERR); 345 } 346 347 PAM_LOG("Radius build access done"); 348 349 for (;;) { 350 switch (rad_send_request(radh)) { 351 352 case RAD_ACCESS_ACCEPT: 353 e = do_accept(pamh, radh); 354 rad_close(radh); 355 if (e == -1) 356 return (PAM_SERVICE_ERR); 357 if (template_user != NULL) { 358 359 PAM_LOG("Trying template user: %s", 360 template_user); 361 362 /* 363 * If the given user name doesn't exist in 364 * the local password database, change it 365 * to the value given in the "template_user" 366 * option. 367 */ 368 retval = pam_get_item(pamh, PAM_USER, &tmpuser); 369 if (retval != PAM_SUCCESS) 370 return (retval); 371 if (getpwnam(tmpuser) == NULL) { 372 pam_set_item(pamh, PAM_USER, 373 template_user); 374 PAM_LOG("Using template user"); 375 } 376 377 } 378 return (PAM_SUCCESS); 379 380 case RAD_ACCESS_REJECT: 381 retval = do_reject(pamh, radh); 382 rad_close(radh); 383 PAM_VERBOSE_ERROR("Radius rejection"); 384 return (PAM_AUTH_ERR); 385 386 case RAD_ACCESS_CHALLENGE: 387 retval = do_challenge(pamh, radh, user, nas_id, 388 nas_ipaddr, rhost); 389 if (retval != PAM_SUCCESS) { 390 rad_close(radh); 391 return (retval); 392 } 393 break; 394 395 case -1: 396 syslog(LOG_CRIT, "rad_send_request: %s", 397 rad_strerror(radh)); 398 rad_close(radh); 399 PAM_VERBOSE_ERROR("Radius failure"); 400 return (PAM_AUTHINFO_UNAVAIL); 401 402 default: 403 syslog(LOG_CRIT, 404 "rad_send_request: unexpected return value"); 405 rad_close(radh); 406 PAM_VERBOSE_ERROR("Radius error"); 407 return (PAM_SERVICE_ERR); 408 } 409 } 410 } 411 412 PAM_EXTERN int 413 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused, 414 int argc __unused, const char *argv[] __unused) 415 { 416 417 return (PAM_SUCCESS); 418 } 419 420 PAM_MODULE_ENTRY("pam_radius"); 421