freebsd-dev/lib/libpam/modules/pam_radius/pam_radius.c
John Polstra 9a10bb17e1 Build structure for contribified Linux-PAM, plus some home-grown
modules for FreeBSD's standard authentication methods.  Although
the Linux-PAM modules are present in the contrib tree, we don't
use any of them.

The main library "libpam" is composed of sources taken from three
places.  First are the standard Linux-PAM libpam sources from the
contrib tree.  Second are the Linux-PAM "libpam_misc" sources, also
from the contrib tree.  In Linux these form a separate library.
But as Mike Smith pointed out to me, that seems pointless, so I
have combined them into the libpam library.  Third are some additional
sources from the "src/lib/libpam" tree with some common functions
that make it easier to write modules.  Those I wrote myself.

This work has been donated to FreeBSD by Juniper Networks, Inc.
1998-11-18 01:44:37 +00:00

299 lines
8.0 KiB
C

/*-
* Copyright 1998 Juniper Networks, Inc.
* All rights reserved.
*
* 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.
*
* 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.
*
* $FreeBSD$
*/
#include <sys/param.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_modules.h>
#include "pam_mod_misc.h"
#define MAX_CHALLENGE_MSGS 10
#define PASSWORD_PROMPT "RADIUS password:"
/* Option names, including the "=" sign. */
#define OPT_CONF "conf="
#define OPT_TMPL "template_user="
static int build_access_request(struct rad_handle *, 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 *);
/*
* 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 void *state, size_t state_len)
{
char host[MAXHOSTNAMELEN];
if (rad_create_request(radh, RAD_ACCESS_REQUEST) == -1) {
syslog(LOG_CRIT, "rad_create_request: %s", rad_strerror(radh));
return -1;
}
if ((user != NULL &&
rad_put_string(radh, RAD_USER_NAME, user) == -1) ||
(pass != NULL &&
rad_put_string(radh, RAD_USER_PASSWORD, pass) == -1) ||
(gethostname(host, sizeof host) != -1 &&
rad_put_string(radh, RAD_NAS_IDENTIFIER, host) == -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) {
if (attrtype == RAD_USER_NAME) {
s = rad_cvt_string(attrval, attrlen);
if (s == NULL) {
syslog(LOG_CRIT,
"rad_cvt_string: out of memory");
return -1;
}
pam_set_item(pamh, PAM_USER, s);
free(s);
}
}
if (attrtype == -1) {
syslog(LOG_CRIT, "rad_get_attr: %s", rad_strerror(radh));
return -1;
}
return 0;
}
static int
do_challenge(pam_handle_t *pamh, struct rad_handle *radh, const char *user)
{
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, 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((void *)msgs[--num_msgs].msg);
return PAM_SUCCESS;
}
PAM_EXTERN int
pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc,
const char **argv)
{
struct rad_handle *radh;
const char *user;
const char *pass;
const char *conf_file = NULL;
const char *template_user = NULL;
int options = 0;
int retval;
int i;
int e;
for (i = 0; i < argc; i++) {
size_t len;
pam_std_option(&options, argv[i]);
if (strncmp(argv[i], OPT_CONF, (len = strlen(OPT_CONF))) == 0)
conf_file = argv[i] + len;
else if (strncmp(argv[i], OPT_TMPL,
(len = strlen(OPT_TMPL))) == 0)
template_user = argv[i] + len;
}
if ((retval = pam_get_user(pamh, &user, NULL)) != PAM_SUCCESS)
return retval;
if ((retval = pam_get_pass(pamh, &pass, PASSWORD_PROMPT,
options)) != PAM_SUCCESS)
return retval;
if ((radh = rad_open()) == NULL) {
syslog(LOG_CRIT, "rad_open failed");
return PAM_SERVICE_ERR;
}
if (rad_config(radh, conf_file) == -1) {
syslog(LOG_ALERT, "rad_config: %s", rad_strerror(radh));
rad_close(radh);
return PAM_SERVICE_ERR;
}
if (build_access_request(radh, user, pass, NULL, 0) == -1) {
rad_close(radh);
return PAM_SERVICE_ERR;
}
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) {
const void *item;
const char *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, &item);
if (retval != PAM_SUCCESS)
return retval;
user = (const char *)item;
if (getpwnam(user) == NULL)
pam_set_item(pamh, PAM_USER,
template_user);
}
return PAM_SUCCESS;
case RAD_ACCESS_REJECT:
rad_close(radh);
return PAM_AUTH_ERR;
case RAD_ACCESS_CHALLENGE:
if ((retval = do_challenge(pamh, radh, user)) !=
PAM_SUCCESS) {
rad_close(radh);
return retval;
}
break;
case -1:
syslog(LOG_CRIT, "rad_send_request: %s",
rad_strerror(radh));
rad_close(radh);
return PAM_AUTHINFO_UNAVAIL;
default:
syslog(LOG_CRIT,
"rad_send_request: unexpected return value");
rad_close(radh);
return PAM_SERVICE_ERR;
}
}
}
PAM_EXTERN int
pam_sm_setcred(pam_handle_t *pamh, int flags, int argc, const char **argv)
{
return PAM_SUCCESS;
}