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/* md4.h
*
* The MD4 hash function, described in RFC 1320.
*/
/* nettle, low-level cryptographics library
*
* Copyright (C) 2003 Niels Möller, Marcus Comstedt
*
* 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., 51 Franklin Street, Fifth Floor, Boston,
* MA 02111-1301, USA.
*/
/* Based on the public domain md5 code, and modified by Marcus
Comstedt */
#if HAVE_CONFIG_H
# include "config.h"
#endif
#include <assert.h>
#include <string.h>
#include "md4.h"
#include "macros.h"
#include "nettle-write.h"
/* A block, treated as a sequence of 32-bit words. */
#define MD4_DATA_LENGTH 16
static void
md4_transform(uint32_t *digest, const uint32_t *data);
static void
md4_compress(struct md4_ctx *ctx, const uint8_t *block);
/* FIXME: Could be an alias for md5_init */
void
md4_init(struct md4_ctx *ctx)
{
/* Same constants as for md5. */
const uint32_t iv[_MD4_DIGEST_LENGTH] =
{
0x67452301,
0xefcdab89,
0x98badcfe,
0x10325476,
};
memcpy(ctx->state, iv, sizeof(ctx->state));
ctx->count_low = ctx->count_high = 0;
ctx->index = 0;
}
void
md4_update(struct md4_ctx *ctx,
unsigned length,
const uint8_t *data)
{
MD_UPDATE(ctx, length, data, md4_compress, MD_INCR(ctx));
}
void
md4_digest(struct md4_ctx *ctx,
unsigned length,
uint8_t *digest)
{
uint32_t data[MD4_DATA_LENGTH];
unsigned i;
assert(length <= MD4_DIGEST_SIZE);
MD_PAD(ctx, 8, md4_compress);
for (i = 0; i < MD4_DATA_LENGTH - 2; i++)
data[i] = LE_READ_UINT32(ctx->block + 4*i);
/* There are 512 = 2^9 bits in one block
* Little-endian order => Least significant word first */
data[MD4_DATA_LENGTH-1] = (ctx->count_high << 9) | (ctx->count_low >> 23);
data[MD4_DATA_LENGTH-2] = (ctx->count_low << 9) | (ctx->index << 3);
md4_transform(ctx->state, data);
_nettle_write_le32(length, digest, ctx->state);
md4_init(ctx);
}
/* MD4 functions */
#define F(x, y, z) (((y) & (x)) | ((z) & ~(x)))
#define G(x, y, z) (((y) & (x)) | ((z) & (x)) | ((y) & (z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define ROUND(f, w, x, y, z, data, s) \
( w += f(x, y, z) + data, w = w<<s | w>>(32-s) )
/* Perform the MD4 transformation on one full block of 16 32-bit words. */
static void
md4_transform(uint32_t *digest, const uint32_t *data)
{
uint32_t a, b, c, d;
a = digest[0];
b = digest[1];
c = digest[2];
d = digest[3];
ROUND(F, a, b, c, d, data[ 0], 3);
ROUND(F, d, a, b, c, data[ 1], 7);
ROUND(F, c, d, a, b, data[ 2], 11);
ROUND(F, b, c, d, a, data[ 3], 19);
ROUND(F, a, b, c, d, data[ 4], 3);
ROUND(F, d, a, b, c, data[ 5], 7);
ROUND(F, c, d, a, b, data[ 6], 11);
ROUND(F, b, c, d, a, data[ 7], 19);
ROUND(F, a, b, c, d, data[ 8], 3);
ROUND(F, d, a, b, c, data[ 9], 7);
ROUND(F, c, d, a, b, data[10], 11);
ROUND(F, b, c, d, a, data[11], 19);
ROUND(F, a, b, c, d, data[12], 3);
ROUND(F, d, a, b, c, data[13], 7);
ROUND(F, c, d, a, b, data[14], 11);
ROUND(F, b, c, d, a, data[15], 19);
ROUND(G, a, b, c, d, data[ 0] + 0x5a827999, 3);
ROUND(G, d, a, b, c, data[ 4] + 0x5a827999, 5);
ROUND(G, c, d, a, b, data[ 8] + 0x5a827999, 9);
ROUND(G, b, c, d, a, data[12] + 0x5a827999, 13);
ROUND(G, a, b, c, d, data[ 1] + 0x5a827999, 3);
ROUND(G, d, a, b, c, data[ 5] + 0x5a827999, 5);
ROUND(G, c, d, a, b, data[ 9] + 0x5a827999, 9);
ROUND(G, b, c, d, a, data[13] + 0x5a827999, 13);
ROUND(G, a, b, c, d, data[ 2] + 0x5a827999, 3);
ROUND(G, d, a, b, c, data[ 6] + 0x5a827999, 5);
ROUND(G, c, d, a, b, data[10] + 0x5a827999, 9);
ROUND(G, b, c, d, a, data[14] + 0x5a827999, 13);
ROUND(G, a, b, c, d, data[ 3] + 0x5a827999, 3);
ROUND(G, d, a, b, c, data[ 7] + 0x5a827999, 5);
ROUND(G, c, d, a, b, data[11] + 0x5a827999, 9);
ROUND(G, b, c, d, a, data[15] + 0x5a827999, 13);
ROUND(H, a, b, c, d, data[ 0] + 0x6ed9eba1, 3);
ROUND(H, d, a, b, c, data[ 8] + 0x6ed9eba1, 9);
ROUND(H, c, d, a, b, data[ 4] + 0x6ed9eba1, 11);
ROUND(H, b, c, d, a, data[12] + 0x6ed9eba1, 15);
ROUND(H, a, b, c, d, data[ 2] + 0x6ed9eba1, 3);
ROUND(H, d, a, b, c, data[10] + 0x6ed9eba1, 9);
ROUND(H, c, d, a, b, data[ 6] + 0x6ed9eba1, 11);
ROUND(H, b, c, d, a, data[14] + 0x6ed9eba1, 15);
ROUND(H, a, b, c, d, data[ 1] + 0x6ed9eba1, 3);
ROUND(H, d, a, b, c, data[ 9] + 0x6ed9eba1, 9);
ROUND(H, c, d, a, b, data[ 5] + 0x6ed9eba1, 11);
ROUND(H, b, c, d, a, data[13] + 0x6ed9eba1, 15);
ROUND(H, a, b, c, d, data[ 3] + 0x6ed9eba1, 3);
ROUND(H, d, a, b, c, data[11] + 0x6ed9eba1, 9);
ROUND(H, c, d, a, b, data[ 7] + 0x6ed9eba1, 11);
ROUND(H, b, c, d, a, data[15] + 0x6ed9eba1, 15);
digest[0] += a;
digest[1] += b;
digest[2] += c;
digest[3] += d;
}
static void
md4_compress(struct md4_ctx *ctx, const uint8_t *block)
{
uint32_t data[MD4_DATA_LENGTH];
unsigned i;
/* Endian independent conversion */
for (i = 0; i<16; i++, block += 4)
data[i] = LE_READ_UINT32(block);
md4_transform(ctx->state, data);
}
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