1 /*- 2 * Copyright 1998 Juniper Networks, Inc. 3 * All rights reserved. 4 * Copyright (c) 2001-2003 Networks Associates Technology, Inc. 5 * All rights reserved. 6 * 7 * Portions of this software were 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 <netdb.h> 43 #include <pwd.h> 44 #include <radlib.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <syslog.h> 48 #include <unistd.h> 49 50 #define PAM_SM_AUTH 51 52 #include <security/pam_appl.h> 53 #include <security/pam_modules.h> 54 #include <security/pam_mod_misc.h> 55 56 #define PAM_OPT_CONF "conf" 57 #define PAM_OPT_TEMPLATE_USER "template_user" 58 #define PAM_OPT_NAS_ID "nas_id" 59 #define PAM_OPT_NAS_IPADDR "nas_ipaddr" 60 61 #define MAX_CHALLENGE_MSGS 10 62 #define PASSWORD_PROMPT "RADIUS Password:" 63 64 static int build_access_request(struct rad_handle *, const char *, 65 const char *, const char *, const char *, const char *, 66 const void *, size_t); 67 static int do_accept(pam_handle_t *, struct rad_handle *); 68 static int do_challenge(pam_handle_t *, struct rad_handle *, 69 const char *, const char *, const char *, const char *); 70 71 /* 72 * Construct an access request, but don't send it. Returns 0 on success, 73 * -1 on failure. 74 */ 75 static int 76 build_access_request(struct rad_handle *radh, const char *user, 77 const char *pass, const char *nas_id, const char *nas_ipaddr, 78 const char *rhost, const void *state, size_t state_len) 79 { 80 int error; 81 char host[MAXHOSTNAMELEN]; 82 struct sockaddr_in *haddr; 83 struct addrinfo hints; 84 struct addrinfo *res; 85 86 if (rad_create_request(radh, RAD_ACCESS_REQUEST) == -1) { 87 syslog(LOG_CRIT, "rad_create_request: %s", rad_strerror(radh)); 88 return (-1); 89 } 90 if (nas_id == NULL || 91 (nas_ipaddr != NULL && strlen(nas_ipaddr) == 0)) { 92 if (gethostname(host, sizeof host) != -1) { 93 if (nas_id == NULL) 94 nas_id = host; 95 if (nas_ipaddr != NULL && strlen(nas_ipaddr) == 0) 96 nas_ipaddr = host; 97 } 98 } 99 if ((user != NULL && 100 rad_put_string(radh, RAD_USER_NAME, user) == -1) || 101 (pass != NULL && 102 rad_put_string(radh, RAD_USER_PASSWORD, pass) == -1) || 103 (nas_id != NULL && 104 rad_put_string(radh, RAD_NAS_IDENTIFIER, nas_id) == -1)) { 105 syslog(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh)); 106 return (-1); 107 } 108 if (nas_ipaddr != NULL) { 109 memset(&hints, 0, sizeof(hints)); 110 hints.ai_family = AF_INET; 111 if (getaddrinfo(nas_ipaddr, NULL, &hints, &res) == 0 && 112 res != NULL && res->ai_family == AF_INET) { 113 haddr = (struct sockaddr_in *)res->ai_addr; 114 error = rad_put_addr(radh, RAD_NAS_IP_ADDRESS, 115 haddr->sin_addr); 116 freeaddrinfo(res); 117 if (error == -1) { 118 syslog(LOG_CRIT, "rad_put_addr: %s", 119 rad_strerror(radh)); 120 return (-1); 121 } 122 } 123 } 124 if (rhost != NULL && 125 rad_put_string(radh, RAD_CALLING_STATION_ID, rhost) == -1) { 126 syslog(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh)); 127 return (-1); 128 } 129 if (state != NULL && 130 rad_put_attr(radh, RAD_STATE, state, state_len) == -1) { 131 syslog(LOG_CRIT, "rad_put_attr: %s", rad_strerror(radh)); 132 return (-1); 133 } 134 if (rad_put_int(radh, RAD_SERVICE_TYPE, RAD_AUTHENTICATE_ONLY) == -1) { 135 syslog(LOG_CRIT, "rad_put_int: %s", rad_strerror(radh)); 136 return (-1); 137 } 138 return (0); 139 } 140 141 static int 142 do_accept(pam_handle_t *pamh, struct rad_handle *radh) 143 { 144 int attrtype; 145 const void *attrval; 146 size_t attrlen; 147 char *s; 148 149 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 150 if (attrtype == RAD_USER_NAME) { 151 s = rad_cvt_string(attrval, attrlen); 152 if (s == NULL) { 153 syslog(LOG_CRIT, 154 "rad_cvt_string: out of memory"); 155 return (-1); 156 } 157 pam_set_item(pamh, PAM_USER, s); 158 free(s); 159 } 160 } 161 if (attrtype == -1) { 162 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 163 return (-1); 164 } 165 return (0); 166 } 167 168 static int 169 do_challenge(pam_handle_t *pamh, struct rad_handle *radh, const char *user, 170 const char *nas_id, const char *nas_ipaddr, const char *rhost) 171 { 172 int retval; 173 int attrtype; 174 const void *attrval; 175 size_t attrlen; 176 const void *state; 177 size_t statelen; 178 struct pam_message msgs[MAX_CHALLENGE_MSGS]; 179 const struct pam_message *msg_ptrs[MAX_CHALLENGE_MSGS]; 180 struct pam_response *resp; 181 int num_msgs; 182 const void *item; 183 const struct pam_conv *conv; 184 185 state = NULL; 186 statelen = 0; 187 num_msgs = 0; 188 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 189 switch (attrtype) { 190 191 case RAD_STATE: 192 state = attrval; 193 statelen = attrlen; 194 break; 195 196 case RAD_REPLY_MESSAGE: 197 if (num_msgs >= MAX_CHALLENGE_MSGS) { 198 syslog(LOG_CRIT, 199 "Too many RADIUS challenge messages"); 200 return (PAM_SERVICE_ERR); 201 } 202 msgs[num_msgs].msg = rad_cvt_string(attrval, attrlen); 203 if (msgs[num_msgs].msg == NULL) { 204 syslog(LOG_CRIT, 205 "rad_cvt_string: out of memory"); 206 return (PAM_SERVICE_ERR); 207 } 208 msgs[num_msgs].msg_style = PAM_TEXT_INFO; 209 msg_ptrs[num_msgs] = &msgs[num_msgs]; 210 num_msgs++; 211 break; 212 } 213 } 214 if (attrtype == -1) { 215 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 216 return (PAM_SERVICE_ERR); 217 } 218 if (num_msgs == 0) { 219 msgs[num_msgs].msg = strdup("(null RADIUS challenge): "); 220 if (msgs[num_msgs].msg == NULL) { 221 syslog(LOG_CRIT, "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 } 228 msgs[num_msgs-1].msg_style = PAM_PROMPT_ECHO_ON; 229 if ((retval = pam_get_item(pamh, PAM_CONV, &item)) != PAM_SUCCESS) { 230 syslog(LOG_CRIT, "do_challenge: cannot get PAM_CONV"); 231 return (retval); 232 } 233 conv = (const struct pam_conv *)item; 234 if ((retval = conv->conv(num_msgs, msg_ptrs, &resp, 235 conv->appdata_ptr)) != PAM_SUCCESS) 236 return (retval); 237 if (build_access_request(radh, user, resp[num_msgs-1].resp, nas_id, 238 nas_ipaddr, rhost, state, statelen) == -1) 239 return (PAM_SERVICE_ERR); 240 memset(resp[num_msgs-1].resp, 0, strlen(resp[num_msgs-1].resp)); 241 free(resp[num_msgs-1].resp); 242 free(resp); 243 while (num_msgs > 0) 244 free(msgs[--num_msgs].msg); 245 return (PAM_SUCCESS); 246 } 247 248 PAM_EXTERN int 249 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 250 int argc __unused, const char *argv[] __unused) 251 { 252 struct rad_handle *radh; 253 const char *user, *pass; 254 const void *rhost, *tmpuser; 255 const char *conf_file, *template_user, *nas_id, *nas_ipaddr; 256 int retval; 257 int e; 258 259 conf_file = openpam_get_option(pamh, PAM_OPT_CONF); 260 template_user = openpam_get_option(pamh, PAM_OPT_TEMPLATE_USER); 261 nas_id = openpam_get_option(pamh, PAM_OPT_NAS_ID); 262 nas_ipaddr = openpam_get_option(pamh, PAM_OPT_NAS_IPADDR); 263 pam_get_item(pamh, PAM_RHOST, &rhost); 264 265 retval = pam_get_user(pamh, &user, NULL); 266 if (retval != PAM_SUCCESS) 267 return (retval); 268 269 PAM_LOG("Got user: %s", user); 270 271 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, PASSWORD_PROMPT); 272 if (retval != PAM_SUCCESS) 273 return (retval); 274 275 PAM_LOG("Got password"); 276 277 radh = rad_open(); 278 if (radh == NULL) { 279 syslog(LOG_CRIT, "rad_open failed"); 280 return (PAM_SERVICE_ERR); 281 } 282 283 PAM_LOG("Radius opened"); 284 285 if (rad_config(radh, conf_file) == -1) { 286 syslog(LOG_ALERT, "rad_config: %s", rad_strerror(radh)); 287 rad_close(radh); 288 return (PAM_SERVICE_ERR); 289 } 290 291 PAM_LOG("Radius config file read"); 292 293 if (build_access_request(radh, user, pass, nas_id, nas_ipaddr, rhost, 294 NULL, 0) == -1) { 295 rad_close(radh); 296 return (PAM_SERVICE_ERR); 297 } 298 299 PAM_LOG("Radius build access done"); 300 301 for (;;) { 302 switch (rad_send_request(radh)) { 303 304 case RAD_ACCESS_ACCEPT: 305 e = do_accept(pamh, radh); 306 rad_close(radh); 307 if (e == -1) 308 return (PAM_SERVICE_ERR); 309 if (template_user != NULL) { 310 311 PAM_LOG("Trying template user: %s", 312 template_user); 313 314 /* 315 * If the given user name doesn't exist in 316 * the local password database, change it 317 * to the value given in the "template_user" 318 * option. 319 */ 320 retval = pam_get_item(pamh, PAM_USER, &tmpuser); 321 if (retval != PAM_SUCCESS) 322 return (retval); 323 if (getpwnam(tmpuser) == NULL) { 324 pam_set_item(pamh, PAM_USER, 325 template_user); 326 PAM_LOG("Using template user"); 327 } 328 329 } 330 return (PAM_SUCCESS); 331 332 case RAD_ACCESS_REJECT: 333 rad_close(radh); 334 PAM_VERBOSE_ERROR("Radius rejection"); 335 return (PAM_AUTH_ERR); 336 337 case RAD_ACCESS_CHALLENGE: 338 retval = do_challenge(pamh, radh, user, nas_id, 339 nas_ipaddr, rhost); 340 if (retval != PAM_SUCCESS) { 341 rad_close(radh); 342 return (retval); 343 } 344 break; 345 346 case -1: 347 syslog(LOG_CRIT, "rad_send_request: %s", 348 rad_strerror(radh)); 349 rad_close(radh); 350 PAM_VERBOSE_ERROR("Radius failure"); 351 return (PAM_AUTHINFO_UNAVAIL); 352 353 default: 354 syslog(LOG_CRIT, 355 "rad_send_request: unexpected return value"); 356 rad_close(radh); 357 PAM_VERBOSE_ERROR("Radius error"); 358 return (PAM_SERVICE_ERR); 359 } 360 } 361 } 362 363 PAM_EXTERN int 364 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused, 365 int argc __unused, const char *argv[] __unused) 366 { 367 368 return (PAM_SUCCESS); 369 } 370 371 PAM_MODULE_ENTRY("pam_radius"); 372