1 /*- 2 * Copyright 1998 Juniper Networks, Inc. 3 * All rights reserved. 4 * Copyright (c) 2001,2002 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 enum { 55 PAM_OPT_CONF = PAM_OPT_STD_MAX, 56 PAM_OPT_TEMPLATE_USER, 57 PAM_OPT_NAS_ID 58 }; 59 60 static struct opttab other_options[] = { 61 { "conf", PAM_OPT_CONF }, 62 { "template_user", PAM_OPT_TEMPLATE_USER }, 63 { "nas_id", PAM_OPT_NAS_ID }, 64 { NULL, 0 } 65 }; 66 67 #define MAX_CHALLENGE_MSGS 10 68 #define PASSWORD_PROMPT "RADIUS Password:" 69 70 static int build_access_request(struct rad_handle *, const char *, 71 const char *, const char *, 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 *); 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 void *state, size_t state_len) 83 { 84 char host[MAXHOSTNAMELEN]; 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 && gethostname(host, sizeof host) != -1) 91 nas_id = host; 92 if ((user != NULL && 93 rad_put_string(radh, RAD_USER_NAME, user) == -1) || 94 (pass != NULL && 95 rad_put_string(radh, RAD_USER_PASSWORD, pass) == -1) || 96 (nas_id != NULL && 97 rad_put_string(radh, RAD_NAS_IDENTIFIER, nas_id) == -1)) { 98 syslog(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh)); 99 return (-1); 100 } 101 if (state != NULL && rad_put_attr(radh, RAD_STATE, state, 102 state_len) == -1) { 103 syslog(LOG_CRIT, "rad_put_attr: %s", rad_strerror(radh)); 104 return (-1); 105 } 106 if (rad_put_int(radh, RAD_SERVICE_TYPE, RAD_AUTHENTICATE_ONLY) == -1) { 107 syslog(LOG_CRIT, "rad_put_int: %s", rad_strerror(radh)); 108 return (-1); 109 } 110 return (0); 111 } 112 113 static int 114 do_accept(pam_handle_t *pamh, struct rad_handle *radh) 115 { 116 int attrtype; 117 const void *attrval; 118 size_t attrlen; 119 char *s; 120 121 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 122 if (attrtype == RAD_USER_NAME) { 123 s = rad_cvt_string(attrval, attrlen); 124 if (s == NULL) { 125 syslog(LOG_CRIT, 126 "rad_cvt_string: out of memory"); 127 return (-1); 128 } 129 pam_set_item(pamh, PAM_USER, s); 130 free(s); 131 } 132 } 133 if (attrtype == -1) { 134 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 135 return (-1); 136 } 137 return (0); 138 } 139 140 static int 141 do_challenge(pam_handle_t *pamh, struct rad_handle *radh, const char *user) 142 { 143 int retval; 144 int attrtype; 145 const void *attrval; 146 size_t attrlen; 147 const void *state; 148 size_t statelen; 149 struct pam_message msgs[MAX_CHALLENGE_MSGS]; 150 const struct pam_message *msg_ptrs[MAX_CHALLENGE_MSGS]; 151 struct pam_response *resp; 152 int num_msgs; 153 const void *item; 154 const struct pam_conv *conv; 155 156 state = NULL; 157 statelen = 0; 158 num_msgs = 0; 159 while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) { 160 switch (attrtype) { 161 162 case RAD_STATE: 163 state = attrval; 164 statelen = attrlen; 165 break; 166 167 case RAD_REPLY_MESSAGE: 168 if (num_msgs >= MAX_CHALLENGE_MSGS) { 169 syslog(LOG_CRIT, 170 "Too many RADIUS challenge messages"); 171 return (PAM_SERVICE_ERR); 172 } 173 msgs[num_msgs].msg = rad_cvt_string(attrval, attrlen); 174 if (msgs[num_msgs].msg == NULL) { 175 syslog(LOG_CRIT, 176 "rad_cvt_string: out of memory"); 177 return (PAM_SERVICE_ERR); 178 } 179 msgs[num_msgs].msg_style = PAM_TEXT_INFO; 180 msg_ptrs[num_msgs] = &msgs[num_msgs]; 181 num_msgs++; 182 break; 183 } 184 } 185 if (attrtype == -1) { 186 syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh)); 187 return (PAM_SERVICE_ERR); 188 } 189 if (num_msgs == 0) { 190 msgs[num_msgs].msg = strdup("(null RADIUS challenge): "); 191 if (msgs[num_msgs].msg == NULL) { 192 syslog(LOG_CRIT, "Out of memory"); 193 return (PAM_SERVICE_ERR); 194 } 195 msgs[num_msgs].msg_style = PAM_TEXT_INFO; 196 msg_ptrs[num_msgs] = &msgs[num_msgs]; 197 num_msgs++; 198 } 199 msgs[num_msgs-1].msg_style = PAM_PROMPT_ECHO_ON; 200 if ((retval = pam_get_item(pamh, PAM_CONV, &item)) != PAM_SUCCESS) { 201 syslog(LOG_CRIT, "do_challenge: cannot get PAM_CONV"); 202 return (retval); 203 } 204 conv = (const struct pam_conv *)item; 205 if ((retval = conv->conv(num_msgs, msg_ptrs, &resp, 206 conv->appdata_ptr)) != PAM_SUCCESS) 207 return (retval); 208 if (build_access_request(radh, user, resp[num_msgs-1].resp, NULL, 209 state, statelen) == -1) 210 return (PAM_SERVICE_ERR); 211 memset(resp[num_msgs-1].resp, 0, strlen(resp[num_msgs-1].resp)); 212 free(resp[num_msgs-1].resp); 213 free(resp); 214 while (num_msgs > 0) 215 free(msgs[--num_msgs].msg); 216 return (PAM_SUCCESS); 217 } 218 219 PAM_EXTERN int 220 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused, 221 int argc, const char *argv[]) 222 { 223 struct options options; 224 struct rad_handle *radh; 225 const char *user, *tmpuser, *pass; 226 char *conf_file, *template_user, *nas_id; 227 int retval; 228 int e; 229 230 pam_std_option(&options, other_options, argc, argv); 231 232 PAM_LOG("Options processed"); 233 234 conf_file = NULL; 235 pam_test_option(&options, PAM_OPT_CONF, &conf_file); 236 template_user = NULL; 237 pam_test_option(&options, PAM_OPT_TEMPLATE_USER, &template_user); 238 nas_id = NULL; 239 pam_test_option(&options, PAM_OPT_NAS_ID, &nas_id); 240 241 retval = pam_get_user(pamh, &user, NULL); 242 if (retval != PAM_SUCCESS) 243 return (retval); 244 245 PAM_LOG("Got user: %s", user); 246 247 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, PASSWORD_PROMPT); 248 if (retval != PAM_SUCCESS) 249 return (retval); 250 251 PAM_LOG("Got password"); 252 253 radh = rad_open(); 254 if (radh == NULL) { 255 syslog(LOG_CRIT, "rad_open failed"); 256 return (PAM_SERVICE_ERR); 257 } 258 259 PAM_LOG("Radius opened"); 260 261 if (rad_config(radh, conf_file) == -1) { 262 syslog(LOG_ALERT, "rad_config: %s", rad_strerror(radh)); 263 rad_close(radh); 264 return (PAM_SERVICE_ERR); 265 } 266 267 PAM_LOG("Radius config file read"); 268 269 if (build_access_request(radh, user, pass, nas_id, NULL, 0) == -1) { 270 rad_close(radh); 271 return (PAM_SERVICE_ERR); 272 } 273 274 PAM_LOG("Radius build access done"); 275 276 for (;;) { 277 switch (rad_send_request(radh)) { 278 279 case RAD_ACCESS_ACCEPT: 280 e = do_accept(pamh, radh); 281 rad_close(radh); 282 if (e == -1) 283 return (PAM_SERVICE_ERR); 284 if (template_user != NULL) { 285 286 PAM_LOG("Trying template user: %s", 287 template_user); 288 289 /* 290 * If the given user name doesn't exist in 291 * the local password database, change it 292 * to the value given in the "template_user" 293 * option. 294 */ 295 retval = pam_get_item(pamh, PAM_USER, 296 (const void **)&tmpuser); 297 if (retval != PAM_SUCCESS) 298 return (retval); 299 if (getpwnam(tmpuser) == NULL) { 300 pam_set_item(pamh, PAM_USER, 301 template_user); 302 PAM_LOG("Using template user"); 303 } 304 305 } 306 return (PAM_SUCCESS); 307 308 case RAD_ACCESS_REJECT: 309 rad_close(radh); 310 PAM_VERBOSE_ERROR("Radius rejection"); 311 return (PAM_AUTH_ERR); 312 313 case RAD_ACCESS_CHALLENGE: 314 retval = do_challenge(pamh, radh, user); 315 if (retval != PAM_SUCCESS) { 316 rad_close(radh); 317 return (retval); 318 } 319 break; 320 321 case -1: 322 syslog(LOG_CRIT, "rad_send_request: %s", 323 rad_strerror(radh)); 324 rad_close(radh); 325 PAM_VERBOSE_ERROR("Radius failure"); 326 return (PAM_AUTHINFO_UNAVAIL); 327 328 default: 329 syslog(LOG_CRIT, 330 "rad_send_request: unexpected return value"); 331 rad_close(radh); 332 PAM_VERBOSE_ERROR("Radius error"); 333 return (PAM_SERVICE_ERR); 334 } 335 } 336 } 337 338 PAM_EXTERN int 339 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused, 340 int argc __unused, const char *argv[] __unused) 341 { 342 343 return (PAM_SUCCESS); 344 } 345 346 PAM_MODULE_ENTRY("pam_radius"); 347