1 /* $NetBSD: pam_radius.c,v 1.8 2014/01/07 02:07:43 joerg Exp $ */ 2 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 * 9 * Portions of this software were developed for the FreeBSD Project by 10 * ThinkSec AS and NAI Labs, the Security Research Division of Network 11 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 12 * ("CBOSS"), as part of the DARPA CHATS research program. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. The name of the author may not be used to endorse or promote 23 * products derived from this software without specific prior written 24 * permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #ifdef __FreeBSD__ 41 __FBSDID("$FreeBSD: src/lib/libpam/modules/pam_radius/pam_radius.c,v 1.22 2004/06/25 12:32:45 kan Exp $"); 42 #else 43 __RCSID("$NetBSD: pam_radius.c,v 1.8 2014/01/07 02:07:43 joerg Exp $"); 44 #endif 45 46 #include <sys/param.h> 47 #include <sys/types.h> 48 #include <sys/socket.h> 49 #include <netdb.h> 50 #include <pwd.h> 51 #include <radlib.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <syslog.h> 55 #include <unistd.h> 56 #include <stdarg.h> 57 58 #define PAM_SM_AUTH 59 60 #include <security/pam_appl.h> 61 #include <security/pam_modules.h> 62 #include <security/pam_mod_misc.h> 63 64 #define PAM_OPT_CONF "conf" 65 #define PAM_OPT_TEMPLATE_USER "template_user" 66 #define PAM_OPT_NAS_ID "nas_id" 67 #define PAM_OPT_NAS_IPADDR "nas_ipaddr" 68 69 #define MAX_CHALLENGE_MSGS 10 70 #define PASSWORD_PROMPT "RADIUS Password:" 71 72 static int build_access_request(struct rad_handle *, const char *, 73 const char *, const char *, const char *, const void *, 74 size_t); 75 static int do_accept(pam_handle_t *, struct rad_handle *); 76 static int do_challenge(pam_handle_t *, struct rad_handle *, 77 const char *); 78 79 __printflike(2, 3) 80 static void 81 logit(int level, const char *fmt, ...) 82 { 83 va_list ap; 84 struct syslog_data data = SYSLOG_DATA_INIT; 85 86 openlog_r("pam_radius", LOG_PID, LOG_AUTHPRIV, &data); 87 va_start(ap, fmt); 88 vsyslog_r(level, &data, fmt, ap); 89 va_end(ap); 90 closelog_r(&data); 91 } 92 93 /* 94 * Construct an access request, but don't send it. Returns 0 on success, 95 * -1 on failure. 96 */ 97 static int 98 build_access_request(struct rad_handle *radh, const char *user, 99 const char *pass, const char *nas_id, const char *nas_ipaddr, 100 const void *state, size_t state_len) 101 { 102 int error; 103 char host[MAXHOSTNAMELEN]; 104 struct sockaddr_in *haddr; 105 struct addrinfo hints; 106 struct addrinfo *res; 107 108 if (rad_create_request(radh, RAD_ACCESS_REQUEST) == -1) { 109 logit(LOG_CRIT, "rad_create_request: %s", rad_strerror(radh)); 110 return (-1); 111 } 112 if (nas_id == NULL || 113 (nas_ipaddr != NULL && strlen(nas_ipaddr) == 0)) { 114 if (gethostname(host, sizeof host) != -1) { 115 if (nas_id == NULL) 116 nas_id = host; 117 if (nas_ipaddr != NULL && strlen(nas_ipaddr) == 0) 118 nas_ipaddr = host; 119 } 120 } 121 if ((user != NULL && 122 rad_put_string(radh, RAD_USER_NAME, user) == -1) || 123 (pass != NULL && 124 rad_put_string(radh, RAD_USER_PASSWORD, pass) == -1) || 125 (nas_id != NULL && 126 rad_put_string(radh, RAD_NAS_IDENTIFIER, nas_id) == -1)) { 127 logit(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh)); 128 return (-1); 129 } 130 if (nas_ipaddr != NULL) { 131 memset(&hints, 0, sizeof(hints)); 132 hints.ai_family = PF_INET; 133 if (getaddrinfo(nas_ipaddr, NULL, &hints, &res) == 0 && 134 res != NULL) { 135 haddr = (struct sockaddr_in *)res->ai_addr; 136 error = rad_put_addr(radh, RAD_NAS_IP_ADDRESS, 137 haddr->sin_addr); 138 freeaddrinfo(res); 139 if (error == -1) { 140 logit(LOG_CRIT, "rad_put_addr: %s", 141 rad_strerror(radh)); 142 return (-1); 143 } 144 } 145 } 146 if (state != NULL && rad_put_attr(radh, RAD_STATE, state, 147 state_len) == -1) { 148 logit(LOG_CRIT, "rad_put_attr: %s", rad_strerror(radh)); 149 return (-1); 150 } 151 if (rad_put_int(radh, RAD_SERVICE_TYPE, RAD_AUTHENTICATE_ONLY) == -1) { 152 logit(LOG_CRIT, "rad_put_int: %s", rad_strerror(radh)); 153 return (-1); 154 } 155 return (0); 156 } 157 158 static int 159 do_accept(pam_handle_t *pamh, struct rad_handle *radh) 160 { 161 int attrtype; 162 const void *attrval; 163 size_t attrlen; 164 char *s; 165 166 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 167 if (attrtype == RAD_USER_NAME) { 168 s = rad_cvt_string(attrval, attrlen); 169 if (s == NULL) { 170 logit(LOG_CRIT, 171 "rad_cvt_string: out of memory"); 172 return (-1); 173 } 174 pam_set_item(pamh, PAM_USER, s); 175 free(s); 176 } 177 } 178 if (attrtype == -1) { 179 logit(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 180 return (-1); 181 } 182 return (0); 183 } 184 185 static int 186 do_challenge(pam_handle_t *pamh, struct rad_handle *radh, const char *user) 187 { 188 int retval; 189 int attrtype; 190 const void *attrval; 191 size_t attrlen; 192 const void *state; 193 size_t statelen; 194 struct pam_message msgs[MAX_CHALLENGE_MSGS]; 195 const struct pam_message *msg_ptrs[MAX_CHALLENGE_MSGS]; 196 struct pam_response *resp; 197 int num_msgs; 198 const void *item; 199 const struct pam_conv *conv; 200 201 state = NULL; 202 statelen = 0; 203 num_msgs = 0; 204 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 205 switch (attrtype) { 206 207 case RAD_STATE: 208 state = attrval; 209 statelen = attrlen; 210 break; 211 212 case RAD_REPLY_MESSAGE: 213 if (num_msgs >= MAX_CHALLENGE_MSGS) { 214 logit(LOG_CRIT, 215 "Too many RADIUS challenge messages"); 216 return (PAM_SERVICE_ERR); 217 } 218 msgs[num_msgs].msg = rad_cvt_string(attrval, attrlen); 219 if (msgs[num_msgs].msg == NULL) { 220 logit(LOG_CRIT, 221 "rad_cvt_string: out of memory"); 222 return (PAM_SERVICE_ERR); 223 } 224 msgs[num_msgs].msg_style = PAM_TEXT_INFO; 225 msg_ptrs[num_msgs] = &msgs[num_msgs]; 226 num_msgs++; 227 break; 228 } 229 } 230 if (attrtype == -1) { 231 logit(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 232 return (PAM_SERVICE_ERR); 233 } 234 if (num_msgs == 0) { 235 msgs[num_msgs].msg = strdup("(null RADIUS challenge): "); 236 if (msgs[num_msgs].msg == NULL) { 237 logit(LOG_CRIT, "Out of memory"); 238 return (PAM_SERVICE_ERR); 239 } 240 msgs[num_msgs].msg_style = PAM_TEXT_INFO; 241 msg_ptrs[num_msgs] = &msgs[num_msgs]; 242 num_msgs++; 243 } 244 msgs[num_msgs-1].msg_style = PAM_PROMPT_ECHO_ON; 245 if ((retval = pam_get_item(pamh, PAM_CONV, &item)) != PAM_SUCCESS) { 246 logit(LOG_CRIT, "do_challenge: cannot get PAM_CONV"); 247 return (retval); 248 } 249 conv = (const struct pam_conv *)item; 250 if ((retval = conv->conv(num_msgs, msg_ptrs, &resp, 251 conv->appdata_ptr)) != PAM_SUCCESS) 252 return (retval); 253 if (build_access_request(radh, user, resp[num_msgs-1].resp, NULL, 254 NULL, state, statelen) == -1) 255 return (PAM_SERVICE_ERR); 256 memset(resp[num_msgs-1].resp, 0, strlen(resp[num_msgs-1].resp)); 257 free(resp[num_msgs-1].resp); 258 free(resp); 259 while (num_msgs > 0) 260 free(msgs[--num_msgs].msg); 261 return (PAM_SUCCESS); 262 } 263 264 PAM_EXTERN int 265 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 266 int argc __unused, const char *argv[] __unused) 267 { 268 struct rad_handle *radh; 269 const char *user, *pass; 270 const void *tmpuser; 271 struct passwd *pwd, pwres; 272 char pwbuf[1024]; 273 const char *conf_file, *template_user, *nas_id, *nas_ipaddr; 274 int retval; 275 int e; 276 277 conf_file = openpam_get_option(pamh, PAM_OPT_CONF); 278 template_user = openpam_get_option(pamh, PAM_OPT_TEMPLATE_USER); 279 nas_id = openpam_get_option(pamh, PAM_OPT_NAS_ID); 280 nas_ipaddr = openpam_get_option(pamh, PAM_OPT_NAS_IPADDR); 281 282 retval = pam_get_user(pamh, &user, NULL); 283 if (retval != PAM_SUCCESS) 284 return (retval); 285 286 PAM_LOG("Got user: %s", user); 287 288 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, PASSWORD_PROMPT); 289 if (retval != PAM_SUCCESS) 290 return (retval); 291 292 PAM_LOG("Got password"); 293 294 radh = rad_open(); 295 if (radh == NULL) { 296 logit(LOG_CRIT, "rad_open failed"); 297 return (PAM_SERVICE_ERR); 298 } 299 300 PAM_LOG("Radius opened"); 301 302 if (rad_config(radh, conf_file) == -1) { 303 logit(LOG_ALERT, "rad_config: %s", rad_strerror(radh)); 304 rad_close(radh); 305 return (PAM_SERVICE_ERR); 306 } 307 308 PAM_LOG("Radius config file read"); 309 310 if (build_access_request(radh, user, pass, nas_id, nas_ipaddr, NULL, 311 0) == -1) { 312 rad_close(radh); 313 return (PAM_SERVICE_ERR); 314 } 315 316 PAM_LOG("Radius build access done"); 317 318 for (;;) { 319 switch (rad_send_request(radh)) { 320 321 case RAD_ACCESS_ACCEPT: 322 e = do_accept(pamh, radh); 323 rad_close(radh); 324 if (e == -1) 325 return (PAM_SERVICE_ERR); 326 if (template_user != NULL) { 327 328 PAM_LOG("Trying template user: %s", 329 template_user); 330 331 /* 332 * If the given user name doesn't exist in 333 * the local password database, change it 334 * to the value given in the "template_user" 335 * option. 336 */ 337 retval = pam_get_item(pamh, PAM_USER, &tmpuser); 338 if (retval != PAM_SUCCESS) 339 return (retval); 340 if (getpwnam_r(tmpuser, &pwres, pwbuf, 341 sizeof(pwbuf), &pwd) != 0 || 342 pwd == NULL) { 343 pam_set_item(pamh, PAM_USER, 344 template_user); 345 PAM_LOG("Using template user"); 346 } 347 348 } 349 return (PAM_SUCCESS); 350 351 case RAD_ACCESS_REJECT: 352 rad_close(radh); 353 PAM_VERBOSE_ERROR("Radius rejection"); 354 return (PAM_AUTH_ERR); 355 356 case RAD_ACCESS_CHALLENGE: 357 retval = do_challenge(pamh, radh, user); 358 if (retval != PAM_SUCCESS) { 359 rad_close(radh); 360 return (retval); 361 } 362 break; 363 364 case -1: 365 logit(LOG_CRIT, "rad_send_request: %s", 366 rad_strerror(radh)); 367 rad_close(radh); 368 PAM_VERBOSE_ERROR("Radius failure"); 369 return (PAM_AUTHINFO_UNAVAIL); 370 371 default: 372 logit(LOG_CRIT, 373 "rad_send_request: unexpected return value"); 374 rad_close(radh); 375 PAM_VERBOSE_ERROR("Radius error"); 376 return (PAM_SERVICE_ERR); 377 } 378 } 379 } 380 381 PAM_EXTERN int 382 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused, 383 int argc __unused, const char *argv[] __unused) 384 { 385 386 return (PAM_SUCCESS); 387 } 388 389 PAM_MODULE_ENTRY("pam_radius"); 390