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 <pwd.h> 42 #include <radlib.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include <syslog.h> 46 #include <unistd.h> 47 48 #define PAM_SM_AUTH 49 50 #include <security/pam_appl.h> 51 #include <security/pam_modules.h> 52 #include <security/pam_mod_misc.h> 53 54 #define PAM_OPT_CONF "conf" 55 #define PAM_OPT_TEMPLATE_USER "template_user" 56 #define PAM_OPT_NAS_ID "nas_id" 57 58 #define MAX_CHALLENGE_MSGS 10 59 #define PASSWORD_PROMPT "RADIUS Password:" 60 61 static int build_access_request(struct rad_handle *, const char *, 62 const char *, const char *, const void *, size_t); 63 static int do_accept(pam_handle_t *, struct rad_handle *); 64 static int do_challenge(pam_handle_t *, struct rad_handle *, 65 const char *); 66 67 /* 68 * Construct an access request, but don't send it. Returns 0 on success, 69 * -1 on failure. 70 */ 71 static int 72 build_access_request(struct rad_handle *radh, const char *user, 73 const char *pass, const char *nas_id, const void *state, size_t state_len) 74 { 75 char host[MAXHOSTNAMELEN]; 76 77 if (rad_create_request(radh, RAD_ACCESS_REQUEST) == -1) { 78 syslog(LOG_CRIT, "rad_create_request: %s", rad_strerror(radh)); 79 return (-1); 80 } 81 if (nas_id == NULL && gethostname(host, sizeof host) != -1) 82 nas_id = host; 83 if ((user != NULL && 84 rad_put_string(radh, RAD_USER_NAME, user) == -1) || 85 (pass != NULL && 86 rad_put_string(radh, RAD_USER_PASSWORD, pass) == -1) || 87 (nas_id != NULL && 88 rad_put_string(radh, RAD_NAS_IDENTIFIER, nas_id) == -1)) { 89 syslog(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh)); 90 return (-1); 91 } 92 if (state != NULL && rad_put_attr(radh, RAD_STATE, state, 93 state_len) == -1) { 94 syslog(LOG_CRIT, "rad_put_attr: %s", rad_strerror(radh)); 95 return (-1); 96 } 97 if (rad_put_int(radh, RAD_SERVICE_TYPE, RAD_AUTHENTICATE_ONLY) == -1) { 98 syslog(LOG_CRIT, "rad_put_int: %s", rad_strerror(radh)); 99 return (-1); 100 } 101 return (0); 102 } 103 104 static int 105 do_accept(pam_handle_t *pamh, struct rad_handle *radh) 106 { 107 int attrtype; 108 const void *attrval; 109 size_t attrlen; 110 char *s; 111 112 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 113 if (attrtype == RAD_USER_NAME) { 114 s = rad_cvt_string(attrval, attrlen); 115 if (s == NULL) { 116 syslog(LOG_CRIT, 117 "rad_cvt_string: out of memory"); 118 return (-1); 119 } 120 pam_set_item(pamh, PAM_USER, s); 121 free(s); 122 } 123 } 124 if (attrtype == -1) { 125 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 126 return (-1); 127 } 128 return (0); 129 } 130 131 static int 132 do_challenge(pam_handle_t *pamh, struct rad_handle *radh, const char *user) 133 { 134 int retval; 135 int attrtype; 136 const void *attrval; 137 size_t attrlen; 138 const void *state; 139 size_t statelen; 140 struct pam_message msgs[MAX_CHALLENGE_MSGS]; 141 const struct pam_message *msg_ptrs[MAX_CHALLENGE_MSGS]; 142 struct pam_response *resp; 143 int num_msgs; 144 const void *item; 145 const struct pam_conv *conv; 146 147 state = NULL; 148 statelen = 0; 149 num_msgs = 0; 150 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 151 switch (attrtype) { 152 153 case RAD_STATE: 154 state = attrval; 155 statelen = attrlen; 156 break; 157 158 case RAD_REPLY_MESSAGE: 159 if (num_msgs >= MAX_CHALLENGE_MSGS) { 160 syslog(LOG_CRIT, 161 "Too many RADIUS challenge messages"); 162 return (PAM_SERVICE_ERR); 163 } 164 msgs[num_msgs].msg = rad_cvt_string(attrval, attrlen); 165 if (msgs[num_msgs].msg == NULL) { 166 syslog(LOG_CRIT, 167 "rad_cvt_string: out of memory"); 168 return (PAM_SERVICE_ERR); 169 } 170 msgs[num_msgs].msg_style = PAM_TEXT_INFO; 171 msg_ptrs[num_msgs] = &msgs[num_msgs]; 172 num_msgs++; 173 break; 174 } 175 } 176 if (attrtype == -1) { 177 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 178 return (PAM_SERVICE_ERR); 179 } 180 if (num_msgs == 0) { 181 msgs[num_msgs].msg = strdup("(null RADIUS challenge): "); 182 if (msgs[num_msgs].msg == NULL) { 183 syslog(LOG_CRIT, "Out of memory"); 184 return (PAM_SERVICE_ERR); 185 } 186 msgs[num_msgs].msg_style = PAM_TEXT_INFO; 187 msg_ptrs[num_msgs] = &msgs[num_msgs]; 188 num_msgs++; 189 } 190 msgs[num_msgs-1].msg_style = PAM_PROMPT_ECHO_ON; 191 if ((retval = pam_get_item(pamh, PAM_CONV, &item)) != PAM_SUCCESS) { 192 syslog(LOG_CRIT, "do_challenge: cannot get PAM_CONV"); 193 return (retval); 194 } 195 conv = (const struct pam_conv *)item; 196 if ((retval = conv->conv(num_msgs, msg_ptrs, &resp, 197 conv->appdata_ptr)) != PAM_SUCCESS) 198 return (retval); 199 if (build_access_request(radh, user, resp[num_msgs-1].resp, NULL, 200 state, statelen) == -1) 201 return (PAM_SERVICE_ERR); 202 memset(resp[num_msgs-1].resp, 0, strlen(resp[num_msgs-1].resp)); 203 free(resp[num_msgs-1].resp); 204 free(resp); 205 while (num_msgs > 0) 206 free(msgs[--num_msgs].msg); 207 return (PAM_SUCCESS); 208 } 209 210 PAM_EXTERN int 211 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 212 int argc __unused, const char *argv[] __unused) 213 { 214 struct rad_handle *radh; 215 const char *user, *tmpuser, *pass; 216 const char *conf_file, *template_user, *nas_id; 217 int retval; 218 int e; 219 220 conf_file = openpam_get_option(pamh, PAM_OPT_CONF); 221 template_user = openpam_get_option(pamh, PAM_OPT_TEMPLATE_USER); 222 nas_id = openpam_get_option(pamh, PAM_OPT_NAS_ID); 223 224 retval = pam_get_user(pamh, &user, NULL); 225 if (retval != PAM_SUCCESS) 226 return (retval); 227 228 PAM_LOG("Got user: %s", user); 229 230 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, PASSWORD_PROMPT); 231 if (retval != PAM_SUCCESS) 232 return (retval); 233 234 PAM_LOG("Got password"); 235 236 radh = rad_open(); 237 if (radh == NULL) { 238 syslog(LOG_CRIT, "rad_open failed"); 239 return (PAM_SERVICE_ERR); 240 } 241 242 PAM_LOG("Radius opened"); 243 244 if (rad_config(radh, conf_file) == -1) { 245 syslog(LOG_ALERT, "rad_config: %s", rad_strerror(radh)); 246 rad_close(radh); 247 return (PAM_SERVICE_ERR); 248 } 249 250 PAM_LOG("Radius config file read"); 251 252 if (build_access_request(radh, user, pass, nas_id, NULL, 0) == -1) { 253 rad_close(radh); 254 return (PAM_SERVICE_ERR); 255 } 256 257 PAM_LOG("Radius build access done"); 258 259 for (;;) { 260 switch (rad_send_request(radh)) { 261 262 case RAD_ACCESS_ACCEPT: 263 e = do_accept(pamh, radh); 264 rad_close(radh); 265 if (e == -1) 266 return (PAM_SERVICE_ERR); 267 if (template_user != NULL) { 268 269 PAM_LOG("Trying template user: %s", 270 template_user); 271 272 /* 273 * If the given user name doesn't exist in 274 * the local password database, change it 275 * to the value given in the "template_user" 276 * option. 277 */ 278 retval = pam_get_item(pamh, PAM_USER, 279 (const void **)&tmpuser); 280 if (retval != PAM_SUCCESS) 281 return (retval); 282 if (getpwnam(tmpuser) == NULL) { 283 pam_set_item(pamh, PAM_USER, 284 template_user); 285 PAM_LOG("Using template user"); 286 } 287 288 } 289 return (PAM_SUCCESS); 290 291 case RAD_ACCESS_REJECT: 292 rad_close(radh); 293 PAM_VERBOSE_ERROR("Radius rejection"); 294 return (PAM_AUTH_ERR); 295 296 case RAD_ACCESS_CHALLENGE: 297 retval = do_challenge(pamh, radh, user); 298 if (retval != PAM_SUCCESS) { 299 rad_close(radh); 300 return (retval); 301 } 302 break; 303 304 case -1: 305 syslog(LOG_CRIT, "rad_send_request: %s", 306 rad_strerror(radh)); 307 rad_close(radh); 308 PAM_VERBOSE_ERROR("Radius failure"); 309 return (PAM_AUTHINFO_UNAVAIL); 310 311 default: 312 syslog(LOG_CRIT, 313 "rad_send_request: unexpected return value"); 314 rad_close(radh); 315 PAM_VERBOSE_ERROR("Radius error"); 316 return (PAM_SERVICE_ERR); 317 } 318 } 319 } 320 321 PAM_EXTERN int 322 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused, 323 int argc __unused, const char *argv[] __unused) 324 { 325 326 return (PAM_SUCCESS); 327 } 328 329 PAM_MODULE_ENTRY("pam_radius"); 330