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 #include <sys/param.h> 43 #include <sys/socket.h> 44 #include <netdb.h> 45 #include <pwd.h> 46 #include <radlib.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <syslog.h> 50 #include <unistd.h> 51 52 #define PAM_SM_AUTH 53 54 #include <security/pam_appl.h> 55 #include <security/pam_modules.h> 56 #include <security/pam_mod_misc.h> 57 58 #define PAM_OPT_CONF "conf" 59 #define PAM_OPT_TEMPLATE_USER "template_user" 60 #define PAM_OPT_NAS_ID "nas_id" 61 #define PAM_OPT_NAS_IPADDR "nas_ipaddr" 62 #define PAM_OPT_NO_REPLYMSG "no_reply_message" 63 64 #define MAX_CHALLENGE_MSGS 10 65 #define PASSWORD_PROMPT "RADIUS Password:" 66 67 static int build_access_request(struct rad_handle *, const char *, 68 const char *, const char *, const char *, const char *, 69 const void *, size_t); 70 static int do_accept(pam_handle_t *, struct rad_handle *); 71 static int do_challenge(pam_handle_t *, struct rad_handle *, 72 const char *, const char *, const char *, const char *); 73 74 /* 75 * Construct an access request, but don't send it. Returns 0 on success, 76 * -1 on failure. 77 */ 78 static int 79 build_access_request(struct rad_handle *radh, const char *user, 80 const char *pass, const char *nas_id, const char *nas_ipaddr, 81 const char *rhost, const void *state, size_t state_len) 82 { 83 int error; 84 char host[MAXHOSTNAMELEN]; 85 struct sockaddr_in *haddr; 86 struct addrinfo hints; 87 struct addrinfo *res; 88 89 if (rad_create_request(radh, RAD_ACCESS_REQUEST) == -1) { 90 syslog(LOG_CRIT, "rad_create_request: %s", rad_strerror(radh)); 91 return (-1); 92 } 93 if (nas_id == NULL || 94 (nas_ipaddr != NULL && strlen(nas_ipaddr) == 0)) { 95 if (gethostname(host, sizeof host) != -1) { 96 if (nas_id == NULL) 97 nas_id = host; 98 if (nas_ipaddr != NULL && strlen(nas_ipaddr) == 0) 99 nas_ipaddr = host; 100 } 101 } 102 if ((user != NULL && 103 rad_put_string(radh, RAD_USER_NAME, user) == -1) || 104 (pass != NULL && 105 rad_put_string(radh, RAD_USER_PASSWORD, pass) == -1) || 106 (nas_id != NULL && 107 rad_put_string(radh, RAD_NAS_IDENTIFIER, nas_id) == -1)) { 108 syslog(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh)); 109 return (-1); 110 } 111 if (nas_ipaddr != NULL) { 112 memset(&hints, 0, sizeof(hints)); 113 hints.ai_family = AF_INET; 114 if (getaddrinfo(nas_ipaddr, NULL, &hints, &res) == 0 && 115 res != NULL && res->ai_family == AF_INET) { 116 haddr = (struct sockaddr_in *)res->ai_addr; 117 error = rad_put_addr(radh, RAD_NAS_IP_ADDRESS, 118 haddr->sin_addr); 119 freeaddrinfo(res); 120 if (error == -1) { 121 syslog(LOG_CRIT, "rad_put_addr: %s", 122 rad_strerror(radh)); 123 return (-1); 124 } 125 } 126 } 127 if (rhost != NULL && 128 rad_put_string(radh, RAD_CALLING_STATION_ID, rhost) == -1) { 129 syslog(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh)); 130 return (-1); 131 } 132 if (state != NULL && 133 rad_put_attr(radh, RAD_STATE, state, state_len) == -1) { 134 syslog(LOG_CRIT, "rad_put_attr: %s", rad_strerror(radh)); 135 return (-1); 136 } 137 if (rad_put_int(radh, RAD_SERVICE_TYPE, RAD_AUTHENTICATE_ONLY) == -1) { 138 syslog(LOG_CRIT, "rad_put_int: %s", rad_strerror(radh)); 139 return (-1); 140 } 141 return (0); 142 } 143 144 static int 145 do_accept(pam_handle_t *pamh, struct rad_handle *radh) 146 { 147 int attrtype; 148 const void *attrval; 149 size_t attrlen; 150 char *s; 151 152 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 153 switch (attrtype) { 154 case RAD_USER_NAME: 155 if ((s = rad_cvt_string(attrval, attrlen)) == NULL) 156 goto enomem; 157 pam_set_item(pamh, PAM_USER, s); 158 free(s); 159 break; 160 case RAD_REPLY_MESSAGE: 161 if ((s = rad_cvt_string(attrval, attrlen)) == NULL) 162 goto enomem; 163 if (!openpam_get_option(pamh, PAM_OPT_NO_REPLYMSG)) 164 pam_info(pamh, "%s", s); 165 free(s); 166 break; 167 default: 168 PAM_LOG("%s(): ignoring RADIUS attribute %d", 169 __func__, attrtype); 170 } 171 } 172 if (attrtype == -1) { 173 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 174 return (-1); 175 } 176 return (0); 177 enomem: 178 syslog(LOG_CRIT, "%s(): out of memory", __func__); 179 return (-1); 180 } 181 182 static int 183 do_reject(pam_handle_t *pamh, struct rad_handle *radh) 184 { 185 int attrtype; 186 const void *attrval; 187 size_t attrlen; 188 char *s; 189 190 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 191 switch (attrtype) { 192 case RAD_REPLY_MESSAGE: 193 if ((s = rad_cvt_string(attrval, attrlen)) == NULL) 194 goto enomem; 195 if (!openpam_get_option(pamh, PAM_OPT_NO_REPLYMSG)) 196 pam_error(pamh, "%s", s); 197 free(s); 198 break; 199 default: 200 PAM_LOG("%s(): ignoring RADIUS attribute %d", 201 __func__, attrtype); 202 } 203 } 204 if (attrtype < 0) { 205 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 206 return (-1); 207 } 208 return (0); 209 enomem: 210 syslog(LOG_CRIT, "%s(): out of memory", __func__); 211 return (-1); 212 } 213 214 static int 215 do_challenge(pam_handle_t *pamh, struct rad_handle *radh, const char *user, 216 const char *nas_id, const char *nas_ipaddr, const char *rhost) 217 { 218 int retval; 219 int attrtype; 220 const void *attrval; 221 size_t attrlen; 222 const void *state; 223 size_t statelen; 224 struct pam_message msgs[MAX_CHALLENGE_MSGS]; 225 const struct pam_message *msg_ptrs[MAX_CHALLENGE_MSGS]; 226 struct pam_response *resp; 227 int num_msgs; 228 const void *item; 229 const struct pam_conv *conv; 230 231 state = NULL; 232 statelen = 0; 233 num_msgs = 0; 234 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 235 switch (attrtype) { 236 237 case RAD_STATE: 238 state = attrval; 239 statelen = attrlen; 240 break; 241 242 case RAD_REPLY_MESSAGE: 243 if (num_msgs >= MAX_CHALLENGE_MSGS) { 244 syslog(LOG_CRIT, 245 "Too many RADIUS challenge messages"); 246 return (PAM_SERVICE_ERR); 247 } 248 msgs[num_msgs].msg = rad_cvt_string(attrval, attrlen); 249 if (msgs[num_msgs].msg == NULL) { 250 syslog(LOG_CRIT, 251 "rad_cvt_string: out of memory"); 252 return (PAM_SERVICE_ERR); 253 } 254 msgs[num_msgs].msg_style = PAM_TEXT_INFO; 255 msg_ptrs[num_msgs] = &msgs[num_msgs]; 256 num_msgs++; 257 break; 258 } 259 } 260 if (attrtype == -1) { 261 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 262 return (PAM_SERVICE_ERR); 263 } 264 if (num_msgs == 0) { 265 msgs[num_msgs].msg = strdup("(null RADIUS challenge): "); 266 if (msgs[num_msgs].msg == NULL) { 267 syslog(LOG_CRIT, "Out of memory"); 268 return (PAM_SERVICE_ERR); 269 } 270 msgs[num_msgs].msg_style = PAM_TEXT_INFO; 271 msg_ptrs[num_msgs] = &msgs[num_msgs]; 272 num_msgs++; 273 } 274 msgs[num_msgs-1].msg_style = PAM_PROMPT_ECHO_ON; 275 if ((retval = pam_get_item(pamh, PAM_CONV, &item)) != PAM_SUCCESS) { 276 syslog(LOG_CRIT, "do_challenge: cannot get PAM_CONV"); 277 return (retval); 278 } 279 conv = (const struct pam_conv *)item; 280 if ((retval = conv->conv(num_msgs, msg_ptrs, &resp, 281 conv->appdata_ptr)) != PAM_SUCCESS) 282 return (retval); 283 if (build_access_request(radh, user, resp[num_msgs-1].resp, nas_id, 284 nas_ipaddr, rhost, state, statelen) == -1) 285 return (PAM_SERVICE_ERR); 286 memset(resp[num_msgs-1].resp, 0, strlen(resp[num_msgs-1].resp)); 287 free(resp[num_msgs-1].resp); 288 free(resp); 289 while (num_msgs > 0) 290 free(msgs[--num_msgs].msg); 291 return (PAM_SUCCESS); 292 } 293 294 PAM_EXTERN int 295 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 296 int argc __unused, const char *argv[] __unused) 297 { 298 struct rad_handle *radh; 299 const char *user, *pass; 300 const void *rhost, *tmpuser; 301 const char *conf_file, *template_user, *nas_id, *nas_ipaddr; 302 int retval; 303 int e; 304 305 conf_file = openpam_get_option(pamh, PAM_OPT_CONF); 306 template_user = openpam_get_option(pamh, PAM_OPT_TEMPLATE_USER); 307 nas_id = openpam_get_option(pamh, PAM_OPT_NAS_ID); 308 nas_ipaddr = openpam_get_option(pamh, PAM_OPT_NAS_IPADDR); 309 pam_get_item(pamh, PAM_RHOST, &rhost); 310 311 retval = pam_get_user(pamh, &user, NULL); 312 if (retval != PAM_SUCCESS) 313 return (retval); 314 315 PAM_LOG("Got user: %s", user); 316 317 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, PASSWORD_PROMPT); 318 if (retval != PAM_SUCCESS) 319 return (retval); 320 321 PAM_LOG("Got password"); 322 323 radh = rad_open(); 324 if (radh == NULL) { 325 syslog(LOG_CRIT, "rad_open failed"); 326 return (PAM_SERVICE_ERR); 327 } 328 329 PAM_LOG("Radius opened"); 330 331 if (rad_config(radh, conf_file) == -1) { 332 syslog(LOG_ALERT, "rad_config: %s", rad_strerror(radh)); 333 rad_close(radh); 334 return (PAM_SERVICE_ERR); 335 } 336 337 PAM_LOG("Radius config file read"); 338 339 if (build_access_request(radh, user, pass, nas_id, nas_ipaddr, rhost, 340 NULL, 0) == -1) { 341 rad_close(radh); 342 return (PAM_SERVICE_ERR); 343 } 344 345 PAM_LOG("Radius build access done"); 346 347 for (;;) { 348 switch (rad_send_request(radh)) { 349 350 case RAD_ACCESS_ACCEPT: 351 e = do_accept(pamh, radh); 352 rad_close(radh); 353 if (e == -1) 354 return (PAM_SERVICE_ERR); 355 if (template_user != NULL) { 356 357 PAM_LOG("Trying template user: %s", 358 template_user); 359 360 /* 361 * If the given user name doesn't exist in 362 * the local password database, change it 363 * to the value given in the "template_user" 364 * option. 365 */ 366 retval = pam_get_item(pamh, PAM_USER, &tmpuser); 367 if (retval != PAM_SUCCESS) 368 return (retval); 369 if (getpwnam(tmpuser) == NULL) { 370 pam_set_item(pamh, PAM_USER, 371 template_user); 372 PAM_LOG("Using template user"); 373 } 374 375 } 376 return (PAM_SUCCESS); 377 378 case RAD_ACCESS_REJECT: 379 retval = do_reject(pamh, radh); 380 rad_close(radh); 381 PAM_VERBOSE_ERROR("Radius rejection"); 382 return (PAM_AUTH_ERR); 383 384 case RAD_ACCESS_CHALLENGE: 385 retval = do_challenge(pamh, radh, user, nas_id, 386 nas_ipaddr, rhost); 387 if (retval != PAM_SUCCESS) { 388 rad_close(radh); 389 return (retval); 390 } 391 break; 392 393 case -1: 394 syslog(LOG_CRIT, "rad_send_request: %s", 395 rad_strerror(radh)); 396 rad_close(radh); 397 PAM_VERBOSE_ERROR("Radius failure"); 398 return (PAM_AUTHINFO_UNAVAIL); 399 400 default: 401 syslog(LOG_CRIT, 402 "rad_send_request: unexpected return value"); 403 rad_close(radh); 404 PAM_VERBOSE_ERROR("Radius error"); 405 return (PAM_SERVICE_ERR); 406 } 407 } 408 } 409 410 PAM_EXTERN int 411 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused, 412 int argc __unused, const char *argv[] __unused) 413 { 414 415 return (PAM_SUCCESS); 416 } 417 418 PAM_MODULE_ENTRY("pam_radius"); 419