sha1.c

/* sha1.h
 *
 * The sha1 hash function.
 */

/* nettle, low-level cryptographics library
 *
 * Copyright (C) 2001 Peter Gutmann, Andrew Kuchling, Niels Möller
 *  
 * The nettle library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at your
 * option) any later version.
 * 
 * The nettle library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 * License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with the nettle library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

/* Here's the first paragraph of Peter Gutmann's posting,
 * <30ajo5$oe8@ccu2.auckland.ac.nz>: 
 *
 * The following is my SHA (FIPS 180) code updated to allow use of the "fixed"
 * SHA, thanks to Jim Gillogly and an anonymous contributor for the information on
 * what's changed in the new version.  The fix is a simple change which involves
 * adding a single rotate in the initial expansion function.  It is unknown
 * whether this is an optimal solution to the problem which was discovered in the
 * SHA or whether it's simply a bandaid which fixes the problem with a minimum of
 * effort (for example the reengineering of a great many Capstone chips).
 */

#include "sha1.h"

#include "macros.h"

#include <assert.h>
#include <string.h>

/* A block, treated as a sequence of 32-bit words. */
#define SHA1_DATA_LENGTH 16

/* The SHA f()-functions.  The f1 and f3 functions can be optimized to
   save one boolean operation each - thanks to Rich Schroeppel,
   rcs@cs.arizona.edu for discovering this */

/* #define f1(x,y,z) ( ( x & y ) | ( ~x & z ) )            Rounds  0-19 */
#define f1(x,y,z)   ( z ^ ( x & ( y ^ z ) ) )           /* Rounds  0-19 */
#define f2(x,y,z)   ( x ^ y ^ z )                       /* Rounds 20-39 */
/* #define f3(x,y,z) ( ( x & y ) | ( x & z ) | ( y & z ) ) Rounds 40-59 */
#define f3(x,y,z)   ( ( x & y ) | ( z & ( x | y ) ) )   /* Rounds 40-59 */
#define f4(x,y,z)   ( x ^ y ^ z )                       /* Rounds 60-79 */

/* The SHA Mysterious Constants */

#define K1  0x5A827999L                                 /* Rounds  0-19 */
#define K2  0x6ED9EBA1L                                 /* Rounds 20-39 */
#define K3  0x8F1BBCDCL                                 /* Rounds 40-59 */
#define K4  0xCA62C1D6L                                 /* Rounds 60-79 */

/* SHA initial values */

#define h0init  0x67452301L
#define h1init  0xEFCDAB89L
#define h2init  0x98BADCFEL