/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2001,2003 Networks Associates Technology, Inc.
 * All rights reserved.
 *
 * This software was 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 <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/openpam.h>

static int
_pam_echo(pam_handle_t *pamh, int flags,
    int argc, const char *argv[])
{
	char msg[PAM_MAX_MSG_SIZE];
	const void *str;
	const char *p, *q;
	int err, i, item;
	size_t len;

	if (flags & PAM_SILENT)
		return (PAM_SUCCESS);
	for (i = 0, len = 0; i < argc && len < sizeof(msg) - 1; ++i) {
		if (i > 0)
			msg[len++] = ' ';
		for (p = argv[i]; *p != '\0' && len < sizeof(msg) - 1; ++p) {
			if (*p != '%' || p[1] == '\0') {
				msg[len++] = *p;
				continue;
			}
			switch (*++p) {
			case 'H':
				item = PAM_RHOST;
				break;
			case 'h':
				/* not implemented */
				item = -1;
				break;
			case 's':
				item = PAM_SERVICE;
				break;
			case 't':
				item = PAM_TTY;
				break;
			case 'U':
				item = PAM_RUSER;
				break;
			case 'u':
				item = PAM_USER;
				break;
			default:
				item = -1;
				msg[len++] = *p;
				break;
			}
			if (item == -1)
				continue;
			err = pam_get_item(pamh, item, &str);
			if (err != PAM_SUCCESS)
				return (err);
			if (str == NULL)
				str = "(null)";
			for (q = str; *q != '\0' && len < sizeof(msg) - 1; ++q)
				msg[len++] = *q;
		}
	}
	msg[len] = '\0';
	return (pam_info(pamh, "%s", msg));
}

PAM_EXTERN int
pam_sm_authenticate(pam_handle_t *pamh, int flags,
    int argc, const char *argv[])
{

	return (_pam_echo(pamh, flags, argc, argv));
}

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_EXTERN int
pam_sm_acct_mgmt(pam_handle_t *pamh, int flags,
    int argc, const char *argv[])
{

	return (_pam_echo(pamh, flags, argc, argv));
}

PAM_EXTERN int
pam_sm_open_session(pam_handle_t *pamh, int flags,
    int argc, const char *argv[])
{

	return (_pam_echo(pamh, flags, argc, argv));
}

PAM_EXTERN int
pam_sm_close_session(pam_handle_t *pamh, int flags,
    int argc, const char *argv[])
{

	return (_pam_echo(pamh, flags, argc, argv));
}

PAM_EXTERN int
pam_sm_chauthtok(pam_handle_t *pamh, int flags,
    int argc, const char *argv[])
{

	if (flags & PAM_PRELIM_CHECK)
		return (PAM_SUCCESS);
	return (_pam_echo(pamh, flags, argc, argv));
}

PAM_MODULE_ENTRY("pam_echo");