/*
* $Id: md4.c,v 1.7 2006/12/13 00:49:14 heas Exp $
*
* Copyright (c) 1995-1998 by Cisco systems, Inc.
*
* Permission to use, copy, modify, and distribute this software for
* any purpose and without fee is hereby granted, provided that this
* copyright and permission notice appear on all copies of the
* software and supporting documentation, the name of Cisco Systems,
* Inc. not be used in advertising or publicity pertaining to
* distribution of the program without specific prior permission, and
* notice be given in supporting documentation that modification,
* copying and distribution is by permission of Cisco Systems, Inc.
*
* Cisco Systems, Inc. makes no representations about the suitability
* of this software for any purpose. THIS SOFTWARE IS PROVIDED ``AS
* IS'' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
* WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE.
*/
/*
* md4c.c - RSA Data Security, Inc., MD4 message-digest algorithm
*/
/* Copyright (C) 1990-2, RSA Data Security, Inc. All rights reserved.
*
* License to copy and use this software is granted provided that it
* is identified as the "RSA Data Security, Inc. MD4 Message-Digest
* Algorithm" in all material mentioning or referencing this software
* or this function.
*
* License is also granted to make and use derivative works provided
* that such works are identified as "derived from the RSA Data
* Security, Inc. MD4 Message-Digest Algorithm" in all material
* mentioning or referencing the derived work.
*
* RSA Data Security, Inc. makes no representations concerning either
* the merchantability of this software or the suitability of this
* software for any particular purpose. It is provided "as is"
* without express or implied warranty of any kind.
*
* These notices must be retained in any copies of any part of this
* documentation and/or software.
*/
#include <config.h>
#include <string.h>
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_STDINT_H
# include <stdint.h>
#endif
#include "md4.h"
typedef unsigned char *POINTER;
typedef uint16_t UINT2;
typedef uint32_t UINT4;
/* Constants for MD4Transform routine. */
#define S11 3
#define S12 7
#define S13 11
#define S14 19
#define S21 3
#define S22 5
#define S23 9
#define S24 13
#define S31 3
#define S32 9
#define S33 11
#define S34 15
static void MD4Transform(UINT4 [4], const unsigned char [64]);
static void Encode(unsigned char *, UINT4 *, unsigned int);
static void Decode(UINT4 *, const unsigned char *, unsigned int);
static unsigned char PADDING[64] = {
0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
/* F, G and H are basic MD4 functions. */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
/* ROTATE_LEFT rotates x left n bits. */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
/* FF, GG and HH are transformations for rounds 1, 2 and 3 */
/* Rotation is separate from addition to prevent recomputation */
#define FF(a, b, c, d, x, s) { \
(a) += F ((b), (c), (d)) + (x); \
(a) = ROTATE_LEFT ((a), (s)); \
}
#define GG(a, b, c, d, x, s) { \
(a) += G ((b), (c), (d)) + (x) + (UINT4)0x5a827999; \
(a) = ROTATE_LEFT ((a), (s)); \
}
#define HH(a, b, c, d, x, s) { \
(a) += H ((b), (c), (d)) + (x) + (UINT4)0x6ed9eba1; \
(a) = ROTATE_LEFT ((a), (s)); \
}
/* MD4 initialization. Begins an MD4 operation, writing a new context. */
void
MD4Init(MD4_CTX *context) /* context */
{
context->count[0] = context->count[1] = 0;
/* Load magic initialization constants. */
context->state[0] = 0x67452301;
context->state[1] = 0xefcdab89;
context->state[2] = 0x98badcfe;
context->state[3] = 0x10325476;
}
/*
* MD4 block update operation. Continues an MD4 message-digest operation,
* processing another message block, and updating the context.
*/
void
MD4Update(MD4_CTX *context, /* context */
const unsigned char *input, /* input block */
unsigned int inputLen) /* length of input block */
{
unsigned int i, index, partLen;
/* Compute number of bytes mod 64 */
index = (unsigned int)((context->count[0] >> 3) & 0x3F);
/* Update number of bits */
if ((context->count[0] += ((UINT4)inputLen << 3)) < ((UINT4)inputLen << 3))
context->count[1]++;
context->count[1] += ((UINT4)inputLen >> 29);
partLen = 64 - index;
/* Transform as many times as possible. */
if (inputLen >= partLen) {
memcpy((POINTER) &context->buffer[index], (POINTER)input, partLen);
MD4Transform(context->state, context->buffer);
for (i = partLen; i + 63 < inputLen; i += 64)
MD4Transform (context->state, &input[i]);
index = 0;
} else
i = 0;
/* Buffer remaining input */
memcpy((POINTER) &context->buffer[index], (POINTER)&input[i], inputLen-i);
}
/*
* MD4 finalization. Ends an MD4 message-digest operation, writing the
* message digest and zeroizing the context.
*/
void
MD4Final(unsigned char digest[16], /* message digest */
MD4_CTX *context) /* context */
{
unsigned char bits[8];
unsigned int index, padLen;
/* Save number of bits */
Encode (bits, context->count, 8);
/* Pad out to 56 mod 64. */
index = (unsigned int)((context->count[0] >> 3) & 0x3f);
padLen = (index < 56) ? (56 - index) : (120 - index);
MD4Update (context, PADDING, padLen);
/* Append length (before padding) */
MD4Update (context, bits, 8);
/* Store state in digest */
Encode (digest, context->state, 16);
/* Zeroize sensitive information. */
memset ((POINTER)context, 0, sizeof (*context));
}
/* MD4 basic transformation. Transforms state based on block. */
static void
MD4Transform(UINT4 state[4], const unsigned char block[64])
{
UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
Decode (x, block, 64);
/* Round 1 */
FF (a, b, c, d, x[ 0], S11); /* 1 */
FF (d, a, b, c, x[ 1], S12); /* 2 */
FF (c, d, a, b, x[ 2], S13); /* 3 */
FF (b, c, d, a, x[ 3], S14); /* 4 */
FF (a, b, c, d, x[ 4], S11); /* 5 */
FF (d, a, b, c, x[ 5], S12); /* 6 */
FF (c, d, a, b, x[ 6], S13); /* 7 */
FF (b, c, d, a, x[ 7], S14); /* 8 */
FF (a, b, c, d, x[ 8], S11); /* 9 */
FF (d, a, b, c, x[ 9], S12); /* 10 */
FF (c, d, a, b, x[10], S13); /* 11 */
FF (b, c, d, a, x[11], S14); /* 12 */
FF (a, b, c, d, x[12], S11); /* 13 */
FF (d, a, b, c, x[13], S12); /* 14 */
FF (c, d, a, b, x[14], S13); /* 15 */
FF (b, c, d, a, x[15], S14); /* 16 */
/* Round 2 */
GG (a, b, c, d, x[ 0], S21); /* 17 */
GG (d, a, b, c, x[ 4], S22); /* 18 */
GG (c, d, a, b, x[ 8], S23); /* 19 */
GG (b, c, d, a, x[12], S24); /* 20 */
GG (a, b, c, d, x[ 1], S21); /* 21 */
GG (d, a, b, c, x[ 5], S22); /* 22 */
GG (c, d, a, b, x[ 9], S23); /* 23 */
GG (b, c, d, a, x[13], S24); /* 24 */
GG (a, b, c, d, x[ 2], S21); /* 25 */
GG (d, a, b, c, x[ 6], S22); /* 26 */
GG (c, d, a, b, x[10], S23); /* 27 */
GG (b, c, d, a, x[14], S24); /* 28 */
GG (a, b, c, d, x[ 3], S21); /* 29 */
GG (d, a, b, c, x[ 7], S22); /* 30 */
GG (c, d, a, b, x[11], S23); /* 31 */
GG (b, c, d, a, x[15], S24); /* 32 */
/* Round 3 */
HH (a, b, c, d, x[ 0], S31); /* 33 */
HH (d, a, b, c, x[ 8], S32); /* 34 */
HH (c, d, a, b, x[ 4], S33); /* 35 */
HH (b, c, d, a, x[12], S34); /* 36 */
HH (a, b, c, d, x[ 2], S31); /* 37 */
HH (d, a, b, c, x[10], S32); /* 38 */
HH (c, d, a, b, x[ 6], S33); /* 39 */
HH (b, c, d, a, x[14], S34); /* 40 */
HH (a, b, c, d, x[ 1], S31); /* 41 */
HH (d, a, b, c, x[ 9], S32); /* 42 */
HH (c, d, a, b, x[ 5], S33); /* 43 */
HH (b, c, d, a, x[13], S34); /* 44 */
HH (a, b, c, d, x[ 3], S31); /* 45 */
HH (d, a, b, c, x[11], S32); /* 46 */
HH (c, d, a, b, x[ 7], S33); /* 47 */
HH (b, c, d, a, x[15], S34); /* 48 */
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
/* Zeroize sensitive information. */
memset ((POINTER)x, 0, sizeof (x));
}
/*
* Encodes input (UINT4) into output (unsigned char). Assumes len is a
* multiple of 4.
*/
static void
Encode(unsigned char *output, UINT4 *input, unsigned int len)
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4) {
output[j] = (unsigned char)(input[i] & 0xff);
output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
}
}
/*
* Decodes input (unsigned char) into output (UINT4). Assumes len is a
* multiple of 4.
*/
static void
Decode(UINT4 *output, const unsigned char *input, unsigned int len)
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4)
output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
(((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
}
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