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/*-
* 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.
*
* 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/param.h>
#include <pwd.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <taclib.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"
typedef int (*set_func)(struct tac_handle *, const char *);
static int do_item(pam_handle_t *, struct tac_handle *, int,
set_func, const char *);
static char *get_msg(struct tac_handle *);
static int set_msg(struct tac_handle *, const char *);
static int
do_item(pam_handle_t *pamh, struct tac_handle *tach, int item,
set_func func, const char *funcname)
{
int retval;
const void *value;
retval = pam_get_item(pamh, item, &value);
if (retval != PAM_SUCCESS)
return retval;
if (value != NULL && (*func)(tach, (const char *)value) == -1) {
syslog(LOG_CRIT, "%s: %s", funcname, tac_strerror(tach));
tac_close(tach);
return PAM_SERVICE_ERR;
}
return PAM_SUCCESS;
}
static char *
get_msg(struct tac_handle *tach)
{
char *msg;
msg = tac_get_msg(tach);
if (msg == NULL) {
syslog(LOG_CRIT, "tac_get_msg: %s", tac_strerror(tach));
tac_close(tach);
return NULL;
}
return msg;
}
static int
set_msg(struct tac_handle *tach, const char *msg)
{
if (tac_set_msg(tach, msg) == -1) {
syslog(LOG_CRIT, "tac_set_msg: %s", tac_strerror(tach));
tac_close(tach);
return -1;
}
return 0;
}
PAM_EXTERN int
pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
int argc __unused, const char *argv[] __unused)
{
int retval;
struct tac_handle *tach;
const char *conf_file, *template_user;
conf_file = openpam_get_option(pamh, PAM_OPT_CONF);
template_user = openpam_get_option(pamh, PAM_OPT_TEMPLATE_USER);
tach = tac_open();
if (tach == NULL) {
syslog(LOG_CRIT, "tac_open failed");
return (PAM_SERVICE_ERR);
}
if (tac_config(tach, conf_file) == -1) {
syslog(LOG_ALERT, "tac_config: %s", tac_strerror(tach));
tac_close(tach);
return (PAM_SERVICE_ERR);
}
if (tac_create_authen(tach, TAC_AUTHEN_LOGIN, TAC_AUTHEN_TYPE_ASCII,
TAC_AUTHEN_SVC_LOGIN) == -1) {
syslog(LOG_CRIT, "tac_create_authen: %s", tac_strerror(tach));
tac_close(tach);
return (PAM_SERVICE_ERR);
}
PAM_LOG("Done tac_open() ... tac_close()");
retval = do_item(pamh, tach, PAM_USER, tac_set_user, "tac_set_user");
if (retval != PAM_SUCCESS)
return (retval);
PAM_LOG("Done user");
retval = do_item(pamh, tach, PAM_TTY, tac_set_port, "tac_set_port");
if (retval != PAM_SUCCESS)
return (retval);
PAM_LOG("Done tty");
retval = do_item(pamh, tach, PAM_RHOST, tac_set_rem_addr,
"tac_set_rem_addr");
if (retval != PAM_SUCCESS)
return (retval);
for (;;) {
char *srvr_msg;
size_t msg_len;
const char *user_msg;
char *data_msg;
int sflags;
int status;
sflags = tac_send_authen(tach);
if (sflags == -1) {
syslog(LOG_CRIT, "tac_send_authen: %s",
tac_strerror(tach));
tac_close(tach);
return (PAM_AUTHINFO_UNAVAIL);
}
status = TAC_AUTHEN_STATUS(sflags);
openpam_set_option(pamh, PAM_OPT_ECHO_PASS,
TAC_AUTHEN_NOECHO(sflags) ? NULL : "");
switch (status) {
case TAC_AUTHEN_STATUS_PASS:
tac_close(tach);
if (template_user != NULL) {
const void *item;
const char *user;
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, &item);
if (retval != PAM_SUCCESS)
return (retval);
user = (const char *)item;
if (getpwnam(user) == NULL) {
pam_set_item(pamh, PAM_USER,
template_user);
PAM_LOG("Using template user");
}
}
return (PAM_SUCCESS);
case TAC_AUTHEN_STATUS_FAIL:
tac_close(tach);
PAM_VERBOSE_ERROR("TACACS+ authentication failed");
return (PAM_AUTH_ERR);
case TAC_AUTHEN_STATUS_GETUSER:
case TAC_AUTHEN_STATUS_GETPASS:
if ((srvr_msg = get_msg(tach)) == NULL)
return (PAM_SERVICE_ERR);
if (status == TAC_AUTHEN_STATUS_GETUSER)
retval = pam_get_user(pamh, &user_msg,
*srvr_msg ? srvr_msg : NULL);
else if (status == TAC_AUTHEN_STATUS_GETPASS)
retval = pam_get_authtok(pamh,
PAM_AUTHTOK, &user_msg,
*srvr_msg ? srvr_msg : "Password:");
free(srvr_msg);
if (retval != PAM_SUCCESS) {
/* XXX - send a TACACS+ abort packet */
tac_close(tach);
return (retval);
}
if (set_msg(tach, user_msg) == -1)
return (PAM_SERVICE_ERR);
break;
case TAC_AUTHEN_STATUS_GETDATA:
if ((srvr_msg = get_msg(tach)) == NULL)
return (PAM_SERVICE_ERR);
retval = pam_prompt(pamh,
openpam_get_option(pamh, PAM_OPT_ECHO_PASS) ?
PAM_PROMPT_ECHO_ON : PAM_PROMPT_ECHO_OFF,
&data_msg, "%s", *srvr_msg ? srvr_msg : "Data:");
free(srvr_msg);
if (retval != PAM_SUCCESS) {
/* XXX - send a TACACS+ abort packet */
tac_close(tach);
return (retval);
}
retval = set_msg(tach, data_msg);
memset(data_msg, 0, strlen(data_msg));
free(data_msg);
if (retval == -1)
return (PAM_SERVICE_ERR);
break;
case TAC_AUTHEN_STATUS_ERROR:
srvr_msg = (char *)tac_get_data(tach, &msg_len);
if (srvr_msg != NULL && msg_len != 0) {
syslog(LOG_CRIT, "tac_send_authen:"
" server detected error: %s", srvr_msg);
free(srvr_msg);
}
else
syslog(LOG_CRIT,
"tac_send_authen: server detected error");
tac_close(tach);
return (PAM_AUTHINFO_UNAVAIL);
break;
case TAC_AUTHEN_STATUS_RESTART:
case TAC_AUTHEN_STATUS_FOLLOW:
default:
syslog(LOG_CRIT,
"tac_send_authen: unexpected status %#x", status);
tac_close(tach);
return (PAM_AUTHINFO_UNAVAIL);
}
}
}
PAM_EXTERN int
pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
int argc __unused, const char *argv[] __unused)
{
return (PAM_IGNORE);
}
PAM_MODULE_ENTRY("pam_tacplus");
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