/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2002 Danny Braniss
 * All rights reserved.
 * Copyright (c) 2001,2002 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/cdefs.h>
#include <pwd.h>
#include <stddef.h>
#include <string.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 OPT_ALLOW_ROOT "allow_root"

PAM_EXTERN int
pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
    int argc __unused, const char *argv[] __unused)
{
	struct passwd *pw;
	const char *user;
	const void *ruser, *rhost;
	int err, superuser;

	err = pam_get_user(pamh, &user, NULL);
	if (err != PAM_SUCCESS)
		return (err);

	if ((pw = getpwnam(user)) == NULL)
		return (PAM_USER_UNKNOWN);
	if (pw->pw_uid == 0 &&
	    openpam_get_option(pamh, OPT_ALLOW_ROOT) == NULL)
		return (PAM_AUTH_ERR);

	err = pam_get_item(pamh, PAM_RUSER, &ruser);
	if (err != PAM_SUCCESS)
		return (PAM_AUTH_ERR);

	err = pam_get_item(pamh, PAM_RHOST, &rhost);
	if (err != PAM_SUCCESS)
		return (PAM_AUTH_ERR);

	superuser = (strcmp(user, "root") == 0);
	err = ruserok(rhost, superuser, ruser, user);
	if (err != 0)
		return (PAM_AUTH_ERR);

	return (PAM_SUCCESS);
}

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_rhosts");