/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright 1998 Juniper Networks, Inc.
* All rights reserved.
* Copyright (c) 2001-2003 Networks Associates Technology, Inc.
* All rights reserved.
* Copyright (c) 2015-2018 The University of Oslo
* All rights reserved.
*
* Portions of this software were developed for the FreeBSD Project by
* ThinkSec AS and NAI Labs, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
* ("CBOSS"), as part of the DARPA CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netdb.h>
#include <pwd.h>
#include <radlib.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#define PAM_SM_AUTH
#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/pam_mod_misc.h>
#define PAM_OPT_CONF "conf"
#define PAM_OPT_TEMPLATE_USER "template_user"
#define PAM_OPT_NAS_ID "nas_id"
#define PAM_OPT_NAS_IPADDR "nas_ipaddr"
#define PAM_OPT_NO_REPLYMSG "no_reply_message"
#define MAX_CHALLENGE_MSGS 10
#define PASSWORD_PROMPT "RADIUS Password:"
static int build_access_request(struct rad_handle *, const char *,
const char *, const char *, const char *, const char *,
const void *, size_t);
static int do_accept(pam_handle_t *, struct rad_handle *);
static int do_challenge(pam_handle_t *, struct rad_handle *,
const char *, const char *, const char *, const char *);
/*
* Construct an access request, but don't send it. Returns 0 on success,
* -1 on failure.
*/
static int
build_access_request(struct rad_handle *radh, const char *user,
const char *pass, const char *nas_id, const char *nas_ipaddr,
const char *rhost, const void *state, size_t state_len)
{
int error;
char host[MAXHOSTNAMELEN];
struct sockaddr_in *haddr;
struct addrinfo hints;
struct addrinfo *res;
if (rad_create_request(radh, RAD_ACCESS_REQUEST) == -1) {
syslog(LOG_CRIT, "rad_create_request: %s", rad_strerror(radh));
return (-1);
}
if (nas_id == NULL ||
(nas_ipaddr != NULL && strlen(nas_ipaddr) == 0)) {
if (gethostname(host, sizeof host) != -1) {
if (nas_id == NULL)
nas_id = host;
if (nas_ipaddr != NULL && strlen(nas_ipaddr) == 0)
nas_ipaddr = host;
}
}
if ((user != NULL &&
rad_put_string(radh, RAD_USER_NAME, user) == -1) ||
(pass != NULL &&
rad_put_string(radh, RAD_USER_PASSWORD, pass) == -1) ||
(nas_id != NULL &&
rad_put_string(radh, RAD_NAS_IDENTIFIER, nas_id) == -1)) {
syslog(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh));
return (-1);
}
if (nas_ipaddr != NULL) {
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_INET;
if (getaddrinfo(nas_ipaddr, NULL, &hints, &res) == 0 &&
res != NULL && res->ai_family == AF_INET) {
haddr = (struct sockaddr_in *)res->ai_addr;
error = rad_put_addr(radh, RAD_NAS_IP_ADDRESS,
haddr->sin_addr);
freeaddrinfo(res);
if (error == -1) {
syslog(LOG_CRIT, "rad_put_addr: %s",
rad_strerror(radh));
return (-1);
}
}
}
if (rhost != NULL &&
rad_put_string(radh, RAD_CALLING_STATION_ID, rhost) == -1) {
syslog(LOG_CRIT, "rad_put_string: %s", rad_strerror(radh));
return (-1);
}
if (state != NULL &&
rad_put_attr(radh, RAD_STATE, state, state_len) == -1) {
syslog(LOG_CRIT, "rad_put_attr: %s", rad_strerror(radh));
return (-1);
}
if (rad_put_int(radh, RAD_SERVICE_TYPE, RAD_AUTHENTICATE_ONLY) == -1) {
syslog(LOG_CRIT, "rad_put_int: %s", rad_strerror(radh));
return (-1);
}
return (0);
}
static int
do_accept(pam_handle_t *pamh, struct rad_handle *radh)
{
int attrtype;
const void *attrval;
size_t attrlen;
char *s;
while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) {
switch (attrtype) {
case RAD_USER_NAME:
if ((s = rad_cvt_string(attrval, attrlen)) == NULL)
goto enomem;
pam_set_item(pamh, PAM_USER, s);
free(s);
break;
case RAD_REPLY_MESSAGE:
if ((s = rad_cvt_string(attrval, attrlen)) == NULL)
goto enomem;
if (!openpam_get_option(pamh, PAM_OPT_NO_REPLYMSG))
pam_info(pamh, "%s", s);
free(s);
break;
default:
PAM_LOG("%s(): ignoring RADIUS attribute %d",
__func__, attrtype);
}
}
if (attrtype == -1) {
syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh));
return (-1);
}
return (0);
enomem:
syslog(LOG_CRIT, "%s(): out of memory", __func__);
return (-1);
}
static int
do_reject(pam_handle_t *pamh, struct rad_handle *radh)
{
int attrtype;
const void *attrval;
size_t attrlen;
char *s;
while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) {
switch (attrtype) {
case RAD_REPLY_MESSAGE:
if ((s = rad_cvt_string(attrval, attrlen)) == NULL)
goto enomem;
if (!openpam_get_option(pamh, PAM_OPT_NO_REPLYMSG))
pam_error(pamh, "%s", s);
free(s);
break;
default:
PAM_LOG("%s(): ignoring RADIUS attribute %d",
__func__, attrtype);
}
}
if (attrtype < 0) {
syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh));
return (-1);
}
return (0);
enomem:
syslog(LOG_CRIT, "%s(): out of memory", __func__);
return (-1);
}
static int
do_challenge(pam_handle_t *pamh, struct rad_handle *radh, const char *user,
const char *nas_id, const char *nas_ipaddr, const char *rhost)
{
int retval;
int attrtype;
const void *attrval;
size_t attrlen;
const void *state;
size_t statelen;
struct pam_message msgs[MAX_CHALLENGE_MSGS];
const struct pam_message *msg_ptrs[MAX_CHALLENGE_MSGS];
struct pam_response *resp;
int num_msgs;
const void *item;
const struct pam_conv *conv;
state = NULL;
statelen = 0;
num_msgs = 0;
while ((attrtype = rad_get_attr(radh, &attrval, &attrlen)) > 0) {
switch (attrtype) {
case RAD_STATE:
state = attrval;
statelen = attrlen;
break;
case RAD_REPLY_MESSAGE:
if (num_msgs >= MAX_CHALLENGE_MSGS) {
syslog(LOG_CRIT,
"Too many RADIUS challenge messages");
return (PAM_SERVICE_ERR);
}
msgs[num_msgs].msg = rad_cvt_string(attrval, attrlen);
if (msgs[num_msgs].msg == NULL) {
syslog(LOG_CRIT,
"rad_cvt_string: out of memory");
return (PAM_SERVICE_ERR);
}
msgs[num_msgs].msg_style = PAM_TEXT_INFO;
msg_ptrs[num_msgs] = &msgs[num_msgs];
num_msgs++;
break;
}
}
if (attrtype == -1) {
syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh));
return (PAM_SERVICE_ERR);
}
if (num_msgs == 0) {
msgs[num_msgs].msg = strdup("(null RADIUS challenge): ");
if (msgs[num_msgs].msg == NULL) {
syslog(LOG_CRIT, "Out of memory");
return (PAM_SERVICE_ERR);
}
msgs[num_msgs].msg_style = PAM_TEXT_INFO;
msg_ptrs[num_msgs] = &msgs[num_msgs];
num_msgs++;
}
msgs[num_msgs-1].msg_style = PAM_PROMPT_ECHO_ON;
if ((retval = pam_get_item(pamh, PAM_CONV, &item)) != PAM_SUCCESS) {
syslog(LOG_CRIT, "do_challenge: cannot get PAM_CONV");
return (retval);
}
conv = (const struct pam_conv *)item;
if ((retval = conv->conv(num_msgs, msg_ptrs, &resp,
conv->appdata_ptr)) != PAM_SUCCESS)
return (retval);
if (build_access_request(radh, user, resp[num_msgs-1].resp, nas_id,
nas_ipaddr, rhost, state, statelen) == -1)
return (PAM_SERVICE_ERR);
memset(resp[num_msgs-1].resp, 0, strlen(resp[num_msgs-1].resp));
free(resp[num_msgs-1].resp);
free(resp);
while (num_msgs > 0)
free(msgs[--num_msgs].msg);
return (PAM_SUCCESS);
}
PAM_EXTERN int
pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
int argc __unused, const char *argv[] __unused)
{
struct rad_handle *radh;
const char *user, *pass;
const void *rhost, *tmpuser;
const char *conf_file, *template_user, *nas_id, *nas_ipaddr;
int retval;
int e;
conf_file = openpam_get_option(pamh, PAM_OPT_CONF);
template_user = openpam_get_option(pamh, PAM_OPT_TEMPLATE_USER);
nas_id = openpam_get_option(pamh, PAM_OPT_NAS_ID);
nas_ipaddr = openpam_get_option(pamh, PAM_OPT_NAS_IPADDR);
pam_get_item(pamh, PAM_RHOST, &rhost);
retval = pam_get_user(pamh, &user, NULL);
if (retval != PAM_SUCCESS)
return (retval);
PAM_LOG("Got user: %s", user);
retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, PASSWORD_PROMPT);
if (retval != PAM_SUCCESS)
return (retval);
PAM_LOG("Got password");
radh = rad_open();
if (radh == NULL) {
syslog(LOG_CRIT, "rad_open failed");
return (PAM_SERVICE_ERR);
}
PAM_LOG("Radius opened");
if (rad_config(radh, conf_file) == -1) {
syslog(LOG_ALERT, "rad_config: %s", rad_strerror(radh));
rad_close(radh);
return (PAM_SERVICE_ERR);
}
PAM_LOG("Radius config file read");
if (build_access_request(radh, user, pass, nas_id, nas_ipaddr, rhost,
NULL, 0) == -1) {
rad_close(radh);
return (PAM_SERVICE_ERR);
}
PAM_LOG("Radius build access done");
for (;;) {
switch (rad_send_request(radh)) {
case RAD_ACCESS_ACCEPT:
e = do_accept(pamh, radh);
rad_close(radh);
if (e == -1)
return (PAM_SERVICE_ERR);
if (template_user != NULL) {
PAM_LOG("Trying template user: %s",
template_user);
/*
* If the given user name doesn't exist in
* the local password database, change it
* to the value given in the "template_user"
* option.
*/
retval = pam_get_item(pamh, PAM_USER, &tmpuser);
if (retval != PAM_SUCCESS)
return (retval);
if (getpwnam(tmpuser) == NULL) {
pam_set_item(pamh, PAM_USER,
template_user);
PAM_LOG("Using template user");
}
}
return (PAM_SUCCESS);
case RAD_ACCESS_REJECT:
retval = do_reject(pamh, radh);
rad_close(radh);
PAM_VERBOSE_ERROR("Radius rejection");
return (PAM_AUTH_ERR);
case RAD_ACCESS_CHALLENGE:
retval = do_challenge(pamh, radh, user, nas_id,
nas_ipaddr, rhost);
if (retval != PAM_SUCCESS) {
rad_close(radh);
return (retval);
}
break;
case -1:
syslog(LOG_CRIT, "rad_send_request: %s",
rad_strerror(radh));
rad_close(radh);
PAM_VERBOSE_ERROR("Radius failure");
return (PAM_AUTHINFO_UNAVAIL);
default:
syslog(LOG_CRIT,
"rad_send_request: unexpected return value");
rad_close(radh);
PAM_VERBOSE_ERROR("Radius error");
return (PAM_SERVICE_ERR);
}
}
}
PAM_EXTERN int
pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
int argc __unused, const char *argv[] __unused)
{
return (PAM_SUCCESS);
}
PAM_MODULE_ENTRY("pam_radius");
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