/*
 * Copyright (c) 1999
 *      Mark Murray.  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 MARK MURRAY 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 MARK MURRAY 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: src/lib/libcrypt/crypt.c,v 1.14.2.2 2001/05/24 12:20:02 markm Exp $
 */

#include <sys/types.h>
#include <string.h>
#include <libutil.h>
#include <unistd.h>
#include "crypt.h"

/*
 * XXX - NOTE:
 *
 * The deprecated sha256/512 functions are somehow sensitive to the
 * order of this crypt_types array as well as their respective "name" members.
 *
 * In order to ensure that both existing passwords will continue to work and
 * that new passwords will be more secure by using the new algorithms even
 * without updating the existing login.conf, this array is now scanned
 * backwards. This could be reverted in the future when the deprecated SHA
 * functionality is removed.
 */
static const struct {
        const char *const name;
        char *(*const func)(const char *, const char *);
        const char *const magic;
} crypt_types[] = {
#ifdef HAS_DES
        {
                "des",
                crypt_des,
                NULL
        },
#endif
        {
                "md5",
                crypt_md5,
                "$1$"
        },
#ifdef HAS_BLOWFISH
        {
                "blf",
                crypt_blowfish,
                "$2"
        },
#endif
        {
                "sha256",
                crypt_deprecated_sha256,
                "$3$"
        },
        {
                "sha512",
                crypt_deprecated_sha512,
                "$4$"
        },
        {
                "sha256",
                crypt_sha256,
                "$5$"
        },
        {
                "sha512",
                crypt_sha512,
                "$6$"
        }
};

static int crypt_type = -1;

static void
crypt_setdefault(void)
{
        char *def;
        int i;

        if (crypt_type != -1)
                return;
        def = auth_getval("crypt_default");
        if (def == NULL) {
                crypt_type = 0;
                return;
        }
        for (i = sizeof(crypt_types) / sizeof(crypt_types[0]) - 1; i >= 0; i--) {
                if (strcmp(def, crypt_types[i].name) == 0) {
                        crypt_type = i;
                        return;
                }
        }
        crypt_type = 0;
}

const char *
crypt_get_format(void)
{

        crypt_setdefault();
        return (crypt_types[crypt_type].name);
}

int
crypt_set_format(const char *type)
{
        int i;

        crypt_setdefault();
        for (i = sizeof(crypt_types) / sizeof(crypt_types[0]) - 1; i >= 0; i--) {
                if (strcmp(type, crypt_types[i].name) == 0) {
                        crypt_type = i;
                        return (1);
                }
        }
        return (0);
}

char *
crypt(const char *passwd, const char *salt)
{
        int i;

        crypt_setdefault();
        for (i = sizeof(crypt_types) / sizeof(crypt_types[0]) - 1; i >= 0; i--) {
                if (crypt_types[i].magic != NULL && strncmp(salt,
                    crypt_types[i].magic, strlen(crypt_types[i].magic)) == 0)
                        return (crypt_types[i].func(passwd, salt));
        }
        return (crypt_types[crypt_type].func(passwd, salt));
}