/*
 * Copyright (c) 2010
 * 	The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Nolan Lum <nol888@gmail.com>
 *
 * 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. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
 * COPYRIGHT HOLDERS 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/types.h>
#include <string.h>
#include <sha256.h>
#include "crypt.h"

/*
 * New password crypt.
 */

#define SHA256_SIZE 32
 
char*
crypt_deprecated_sha256(const char *pw, const char *salt)
{
        /*
         * Magic constant (prefix) used to run over the password data.
         *
         * XXX:
         *
         * A bug below (sizeof instead of strlen) mandates the extra data after
         * the closing $. This data is what just happened to be (consistently
         * miraculously) on the stack following magic on 64-bit.
         */
	static const char *magic = "$3$\0sha5";

	static char         passwd[120], *p;
	static const char *sp, *ep;
	unsigned char final[SHA256_SIZE];
	int sl;
	SHA256_CTX ctx;
	unsigned long l;

	/* Refine the salt. */
	sp = salt;

	/* If it starts with the magic string, then skip that. */
	if (!strncmp(sp, magic, strlen(magic)))
		sp += strlen(magic);

	/* Stop at the first '$', max 8 chars. */
	for (ep = sp; *ep && *ep != '$' && ep < (sp + 8); ep++)
		continue;

	/* Get the actual salt length. */
	sl = ep - sp;
	
	SHA256_Init(&ctx);

	/* Hash in the password first. */
	SHA256_Update(&ctx, pw, strlen(pw));
	
        /*
         * Then the magic string
         *
         * XXX: sizeof instead of strlen, must retain
         */
	SHA256_Update(&ctx, magic, sizeof(magic));
	
	/* Then the raw salt. */
	SHA256_Update(&ctx, sp, sl);
	
	/* Finish and create the output string. */
	SHA256_Final(final, &ctx);
	strcpy(passwd, magic);
	strncat(passwd, sp, sl);
	strcat(passwd, "$");
	
	p = passwd + strlen(passwd);
	
	l = (final[ 0] << 16) | (final[11] << 8) | final[21];
	_crypt_to64(p, l, 4); p += 4;
	l = (final[ 1] << 16) | (final[12] << 8) | final[22];
	_crypt_to64(p, l, 4); p += 4;
	l = (final[ 2] << 16) | (final[13] << 8) | final[23];
	_crypt_to64(p, l, 4); p += 4;
	l = (final[ 3] << 16) | (final[14] << 8) | final[24];
	_crypt_to64(p, l, 4); p += 4;
	l = (final[ 4] << 16) | (final[15] << 8) | final[25];
	_crypt_to64(p, l, 4); p += 4;
	l = (final[ 5] << 16) | (final[16] << 8) | final[26];
	_crypt_to64(p, l, 4); p += 4;
	l = (final[ 6] << 16) | (final[17] << 8) | final[27];
	_crypt_to64(p, l, 4); p += 4;
	l = (final[ 7] << 16) | (final[18] << 8) | final[28];
	_crypt_to64(p, l, 4); p += 4;
	l = (final[ 8] << 16) | (final[19] << 8) | final[29];
	_crypt_to64(p, l, 4); p += 4;
	l = (final[ 9] << 16) | (final[20] << 8) | final[30];
	_crypt_to64(p, l, 4); p += 4;
	l = (final[10] << 16) | (final[31] << 8);
	_crypt_to64(p, l, 4); p += 4;
	*p = '\0';
	
	/* Clear memory. */
	memset(final, 0, sizeof(final));

	return (passwd);
}