Home | History | Annotate | Line # | Download | only in pam_radius
pam_radius.c revision 1.5
      1 /*	$NetBSD: pam_radius.c,v 1.5 2005/04/25 15:42:46 matt 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 1.5 2005/04/25 15:42:46 matt 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 
     57 #define PAM_SM_AUTH
     58 
     59 #include <security/pam_appl.h>
     60 #include <security/pam_modules.h>
     61 #include <security/pam_mod_misc.h>
     62 
     63 #define PAM_OPT_CONF		"conf"
     64 #define PAM_OPT_TEMPLATE_USER	"template_user"
     65 #define PAM_OPT_NAS_ID		"nas_id"
     66 #define PAM_OPT_NAS_IPADDR	"nas_ipaddr"
     67 
     68 #define	MAX_CHALLENGE_MSGS	10
     69 #define	PASSWORD_PROMPT		"RADIUS Password:"
     70 
     71 static int	 build_access_request(struct rad_handle *, const char *,
     72 		    const char *, const char *, const char *, const void *,
     73 		    size_t);
     74 static int	 do_accept(pam_handle_t *, struct rad_handle *);
     75 static int	 do_challenge(pam_handle_t *, struct rad_handle *,
     76 		    const char *);
     77 
     78 /*
     79  * Construct an access request, but don't send it.  Returns 0 on success,
     80  * -1 on failure.
     81  */
     82 static int
     83 build_access_request(struct rad_handle *radh, const char *user,
     84     const char *pass, const char *nas_id, const char *nas_ipaddr,
     85     const void *state, size_t state_len)
     86 {
     87 	int error;
     88 	char host[MAXHOSTNAMELEN];
     89 	struct sockaddr_in *haddr;
     90 	struct addrinfo hints;
     91 	struct addrinfo *res;
     92 
     93 	if (rad_create_request(radh, RAD_ACCESS_REQUEST) == -1) {
     94 		syslog(LOG_CRIT, "rad_create_request: %s", rad_strerror(radh));
     95 		return (-1);
     96 	}
     97 	if (nas_id == NULL ||
     98 	    (nas_ipaddr != NULL && strlen(nas_ipaddr) == 0)) {
     99 		if (gethostname(host, sizeof host) != -1) {
    100 			if (nas_id == NULL)
    101 				nas_id = host;
    102 			if (nas_ipaddr != NULL && strlen(nas_ipaddr) == 0)
    103 				nas_ipaddr = host;
    104 		}
    105 	}
    106 	if ((user != NULL &&
    107 	    rad_put_string(radh, RAD_USER_NAME, user) == -1) ||
    108 	    (pass != NULL &&
    109 	    rad_put_string(radh, RAD_USER_PASSWORD, pass) == -1) ||
    110 	    (nas_id != NULL &&
    111 	    rad_put_string(radh, RAD_NAS_IDENTIFIER, nas_id) == -1)) {
    112 		syslog(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh));
    113 		return (-1);
    114 	}
    115 	if (nas_ipaddr != NULL) {
    116 		memset(&hints, 0, sizeof(hints));
    117 		hints.ai_family = PF_INET;
    118 		if (getaddrinfo(nas_ipaddr, NULL, &hints, &res) == 0 &&
    119 		    res != NULL) {
    120 			haddr = (struct sockaddr_in *)res->ai_addr;
    121 			error = rad_put_addr(radh, RAD_NAS_IP_ADDRESS,
    122 			    haddr->sin_addr);
    123 			freeaddrinfo(res);
    124 			if (error == -1) {
    125 				syslog(LOG_CRIT, "rad_put_addr: %s",
    126 				    rad_strerror(radh));
    127 				return (-1);
    128 			}
    129 		}
    130 	}
    131 	if (state != NULL && rad_put_attr(radh, RAD_STATE, state,
    132 	    state_len) == -1) {
    133 		syslog(LOG_CRIT, "rad_put_attr: %s", rad_strerror(radh));
    134 		return (-1);
    135 	}
    136 	if (rad_put_int(radh, RAD_SERVICE_TYPE, RAD_AUTHENTICATE_ONLY) == -1) {
    137 		syslog(LOG_CRIT, "rad_put_int: %s", rad_strerror(radh));
    138 		return (-1);
    139 	}
    140 	return (0);
    141 }
    142 
    143 static int
    144 do_accept(pam_handle_t *pamh, struct rad_handle *radh)
    145 {
    146 	int attrtype;
    147 	const void *attrval;
    148 	size_t attrlen;
    149 	char *s;
    150 
    151 	while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) {
    152 		if (attrtype == RAD_USER_NAME) {
    153 			s = rad_cvt_string(attrval, attrlen);
    154 			if (s == NULL) {
    155 				syslog(LOG_CRIT,
    156 				    "rad_cvt_string: out of memory");
    157 				return (-1);
    158 			}
    159 			pam_set_item(pamh, PAM_USER, s);
    160 			free(s);
    161 		}
    162 	}
    163 	if (attrtype == -1) {
    164 		syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh));
    165 		return (-1);
    166 	}
    167 	return (0);
    168 }
    169 
    170 static int
    171 do_challenge(pam_handle_t *pamh, struct rad_handle *radh, const char *user)
    172 {
    173 	int retval;
    174 	int attrtype;
    175 	const void *attrval;
    176 	size_t attrlen;
    177 	const void *state;
    178 	size_t statelen;
    179 	struct pam_message msgs[MAX_CHALLENGE_MSGS];
    180 	const struct pam_message *msg_ptrs[MAX_CHALLENGE_MSGS];
    181 	struct pam_response *resp;
    182 	int num_msgs;
    183 	const void *item;
    184 	const struct pam_conv *conv;
    185 
    186 	state = NULL;
    187 	statelen = 0;
    188 	num_msgs = 0;
    189 	while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) {
    190 		switch (attrtype) {
    191 
    192 		case RAD_STATE:
    193 			state = attrval;
    194 			statelen = attrlen;
    195 			break;
    196 
    197 		case RAD_REPLY_MESSAGE:
    198 			if (num_msgs >= MAX_CHALLENGE_MSGS) {
    199 				syslog(LOG_CRIT,
    200 				    "Too many RADIUS challenge messages");
    201 				return (PAM_SERVICE_ERR);
    202 			}
    203 			msgs[num_msgs].msg = rad_cvt_string(attrval, attrlen);
    204 			if (msgs[num_msgs].msg == NULL) {
    205 				syslog(LOG_CRIT,
    206 				    "rad_cvt_string: out of memory");
    207 				return (PAM_SERVICE_ERR);
    208 			}
    209 			msgs[num_msgs].msg_style = PAM_TEXT_INFO;
    210 			msg_ptrs[num_msgs] = &msgs[num_msgs];
    211 			num_msgs++;
    212 			break;
    213 		}
    214 	}
    215 	if (attrtype == -1) {
    216 		syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh));
    217 		return (PAM_SERVICE_ERR);
    218 	}
    219 	if (num_msgs == 0) {
    220 		msgs[num_msgs].msg = strdup("(null RADIUS challenge): ");
    221 		if (msgs[num_msgs].msg == NULL) {
    222 			syslog(LOG_CRIT, "Out of memory");
    223 			return (PAM_SERVICE_ERR);
    224 		}
    225 		msgs[num_msgs].msg_style = PAM_TEXT_INFO;
    226 		msg_ptrs[num_msgs] = &msgs[num_msgs];
    227 		num_msgs++;
    228 	}
    229 	msgs[num_msgs-1].msg_style = PAM_PROMPT_ECHO_ON;
    230 	if ((retval = pam_get_item(pamh, PAM_CONV, &item)) != PAM_SUCCESS) {
    231 		syslog(LOG_CRIT, "do_challenge: cannot get PAM_CONV");
    232 		return (retval);
    233 	}
    234 	conv = (const struct pam_conv *)item;
    235 	if ((retval = conv->conv(num_msgs, msg_ptrs, &resp,
    236 	    conv->appdata_ptr)) != PAM_SUCCESS)
    237 		return (retval);
    238 	if (build_access_request(radh, user, resp[num_msgs-1].resp, NULL,
    239 	    NULL, state, statelen) == -1)
    240 		return (PAM_SERVICE_ERR);
    241 	memset(resp[num_msgs-1].resp, 0, strlen(resp[num_msgs-1].resp));
    242 	free(resp[num_msgs-1].resp);
    243 	free(resp);
    244 	while (num_msgs > 0)
    245 		free(msgs[--num_msgs].msg);
    246 	return (PAM_SUCCESS);
    247 }
    248 
    249 PAM_EXTERN int
    250 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
    251     int argc __unused, const char *argv[] __unused)
    252 {
    253 	struct rad_handle *radh;
    254 	const char *user, *pass;
    255 	const void *tmpuser;
    256 	struct passwd *pwd, pwres;
    257 	char pwbuf[1024];
    258 	const char *conf_file, *template_user, *nas_id, *nas_ipaddr;
    259 	int retval;
    260 	int e;
    261 
    262 	conf_file = openpam_get_option(pamh, PAM_OPT_CONF);
    263 	template_user = openpam_get_option(pamh, PAM_OPT_TEMPLATE_USER);
    264 	nas_id = openpam_get_option(pamh, PAM_OPT_NAS_ID);
    265 	nas_ipaddr = openpam_get_option(pamh, PAM_OPT_NAS_IPADDR);
    266 
    267 	retval = pam_get_user(pamh, &user, NULL);
    268 	if (retval != PAM_SUCCESS)
    269 		return (retval);
    270 
    271 	PAM_LOG("Got user: %s", user);
    272 
    273 	retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, PASSWORD_PROMPT);
    274 	if (retval != PAM_SUCCESS)
    275 		return (retval);
    276 
    277 	PAM_LOG("Got password");
    278 
    279 	radh = rad_open();
    280 	if (radh == NULL) {
    281 		syslog(LOG_CRIT, "rad_open failed");
    282 		return (PAM_SERVICE_ERR);
    283 	}
    284 
    285 	PAM_LOG("Radius opened");
    286 
    287 	if (rad_config(radh, conf_file) == -1) {
    288 		syslog(LOG_ALERT, "rad_config: %s", rad_strerror(radh));
    289 		rad_close(radh);
    290 		return (PAM_SERVICE_ERR);
    291 	}
    292 
    293 	PAM_LOG("Radius config file read");
    294 
    295 	if (build_access_request(radh, user, pass, nas_id, nas_ipaddr, NULL,
    296 	    0) == -1) {
    297 		rad_close(radh);
    298 		return (PAM_SERVICE_ERR);
    299 	}
    300 
    301 	PAM_LOG("Radius build access done");
    302 
    303 	for (;;) {
    304 		switch (rad_send_request(radh)) {
    305 
    306 		case RAD_ACCESS_ACCEPT:
    307 			e = do_accept(pamh, radh);
    308 			rad_close(radh);
    309 			if (e == -1)
    310 				return (PAM_SERVICE_ERR);
    311 			if (template_user != NULL) {
    312 
    313 				PAM_LOG("Trying template user: %s",
    314 				    template_user);
    315 
    316 				/*
    317 				 * If the given user name doesn't exist in
    318 				 * the local password database, change it
    319 				 * to the value given in the "template_user"
    320 				 * option.
    321 				 */
    322 				retval = pam_get_item(pamh, PAM_USER, &tmpuser);
    323 				if (retval != PAM_SUCCESS)
    324 					return (retval);
    325 				if (getpwnam_r(tmpuser, &pwres, pwbuf,
    326 					       sizeof(pwbuf), &pwd) != 0 ||
    327 				    pwd == NULL) {
    328 					pam_set_item(pamh, PAM_USER,
    329 					    template_user);
    330 					PAM_LOG("Using template user");
    331 				}
    332 
    333 			}
    334 			return (PAM_SUCCESS);
    335 
    336 		case RAD_ACCESS_REJECT:
    337 			rad_close(radh);
    338 			PAM_VERBOSE_ERROR("Radius rejection");
    339 			return (PAM_AUTH_ERR);
    340 
    341 		case RAD_ACCESS_CHALLENGE:
    342 			retval = do_challenge(pamh, radh, user);
    343 			if (retval != PAM_SUCCESS) {
    344 				rad_close(radh);
    345 				return (retval);
    346 			}
    347 			break;
    348 
    349 		case -1:
    350 			syslog(LOG_CRIT, "rad_send_request: %s",
    351 			    rad_strerror(radh));
    352 			rad_close(radh);
    353 			PAM_VERBOSE_ERROR("Radius failure");
    354 			return (PAM_AUTHINFO_UNAVAIL);
    355 
    356 		default:
    357 			syslog(LOG_CRIT,
    358 			    "rad_send_request: unexpected return value");
    359 			rad_close(radh);
    360 			PAM_VERBOSE_ERROR("Radius error");
    361 			return (PAM_SERVICE_ERR);
    362 		}
    363 	}
    364 }
    365 
    366 PAM_EXTERN int
    367 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
    368     int argc __unused, const char *argv[] __unused)
    369 {
    370 
    371 	return (PAM_SUCCESS);
    372 }
    373 
    374 PAM_MODULE_ENTRY("pam_radius");
    375