//
// MD4Managed.cs - Message Digest 4 Managed Implementation
//
// Author:
// Sebastien Pouliot (sebastien@ximian.com)
//
// (C) 2003 Motus Technologies Inc. (http://www.motus.com)
// Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Security.Cryptography;
namespace LumiSoft.Net {
internal abstract class _MD4 : HashAlgorithm {
protected _MD4 ()
{
// MD4 hash length are 128 bits long
HashSizeValue = 128;
}
public static new _MD4 Create ()
{
// for this to work we must register ourself with CryptoConfig
return Create ("MD4");
}
public static new _MD4 Create (string hashName)
{
// in case machine.config isn't configured to use any MD4 implementation
return (_MD4) CryptoConfig.CreateFromName (hashName) ?? new MD4Managed ();
}
}
// References:
// a. RFC1320: The MD4 Message-Digest Algorithm
// http://www.ietf.org/rfc/rfc1320.txt
internal class MD4Managed : _MD4 {
private readonly uint[] state;
private readonly byte[] buffer;
private readonly uint[] count;
private readonly uint[] x;
private const int S11 = 3;
private const int S12 = 7;
private const int S13 = 11;
private const int S14 = 19;
private const int S21 = 3;
private const int S22 = 5;
private const int S23 = 9;
private const int S24 = 13;
private const int S31 = 3;
private const int S32 = 9;
private const int S33 = 11;
private const int S34 = 15;
private readonly byte[] digest;
//--- constructor -----------------------------------------------------------
public MD4Managed ()
{
// we allocate the context memory
state = new uint [4];
count = new uint [2];
buffer = new byte [64];
digest = new byte [16];
// temporary buffer in MD4Transform that we don't want to keep allocate on each iteration
x = new uint [16];
// the initialize our context
Initialize ();
}
public override void Initialize ()
{
count [0] = 0;
count [1] = 0;
state [0] = 0x67452301;
state [1] = 0xefcdab89;
state [2] = 0x98badcfe;
state [3] = 0x10325476;
// Zeroize sensitive information
Array.Clear (buffer, 0, 64);
Array.Clear (x, 0, 16);
}
protected override void HashCore (byte[] array, int ibStart, int cbSize)
{
/* Compute number of bytes mod 64 */
var index = (int) ((count [0] >> 3) & 0x3F);
/* Update number of bits */
count [0] += (uint) (cbSize << 3);
if (count [0] < (cbSize << 3))
count [1]++;
count [1] += (uint) (cbSize >> 29);
int partLen = 64 - index;
int i = 0;
/* Transform as many times as possible. */
if (cbSize >= partLen) {
//MD4_memcpy((POINTER)&context->buffer[index], (POINTER)input, partLen);
Buffer.BlockCopy (array, ibStart, buffer, index, partLen);
MD4Transform (state, buffer, 0);
for (i = partLen; i + 63 < cbSize; i += 64) {
// MD4Transform (context->state, &input[i]);
MD4Transform (state, array, i);
}
index = 0;
}
/* Buffer remaining input */
//MD4_memcpy ((POINTER)&context->buffer[index], (POINTER)&input[i], inputLen-i);
Buffer.BlockCopy (array, ibStart + i, buffer, index, (cbSize-i));
}
protected override byte[] HashFinal ()
{
/* Save number of bits */
var bits = new byte [8];
Encode (bits, count);
/* Pad out to 56 mod 64. */
var index = ((count [0] >> 3) & 0x3f);
var padLen = (int) ((index < 56) ? (56 - index) : (120 - index));
HashCore (Padding (padLen), 0, padLen);
/* Append length (before padding) */
HashCore (bits, 0, 8);
/* Store state in digest */
Encode (digest, state);
// Zeroize sensitive information.
Initialize ();
return digest;
}
//--- private methods ---------------------------------------------------
private static byte[] Padding (int nLength)
{
if (nLength > 0) {
var padding = new byte [nLength];
padding [0] = 0x80;
return padding;
}
return null;
}
/* F, G and H are basic MD4 functions. */
private static uint F (uint x, uint y, uint z)
{
return ((x) & (y)) | ((~x) & (z));
}
private static uint G (uint x, uint y, uint z)
{
return ((x) & (y)) | ((x) & (z)) | ((y) & (z));
}
private static uint H (uint x, uint y, uint z)
{
return (x) ^ (y) ^ (z);
}
/* ROTATE_LEFT rotates x left n bits. */
private static uint ROL (uint x, byte n)
{
return ((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 */
private static void FF (ref uint a, uint b, uint c, uint d, uint x, byte s)
{
a += F (b, c, d) + x;
a = ROL (a, s);
}
private static void GG (ref uint a, uint b, uint c, uint d, uint x, byte s)
{
a += G (b, c, d) + x + 0x5a827999;
a = ROL (a, s);
}
private static void HH (ref uint a, uint b, uint c, uint d, uint x, byte s)
{
a += H (b, c, d) + x + 0x6ed9eba1;
a = ROL (a, s);
}
private static void Encode (byte[] output, uint[] input)
{
for (int i = 0, j = 0; j < output.Length; i++, j += 4) {
output [j] = (byte)(input [i]);
output [j+1] = (byte)(input [i] >> 8);
output [j+2] = (byte)(input [i] >> 16);
output [j+3] = (byte)(input [i] >> 24);
}
}
private static void Decode (uint[] output, byte[] input, int index)
{
for (int i = 0, j = index; i < output.Length; i++, j += 4) {
output [i] = (uint) ((input [j]) | (input [j+1] << 8) | (input [j+2] << 16) | (input [j+3] << 24));
}
}
private void MD4Transform (uint[] state, byte[] block, int index)
{
uint a = state [0];
uint b = state [1];
uint c = state [2];
uint d = state [3];
Decode (x, block, index);
/* Round 1 */
FF (ref a, b, c, d, x[ 0], S11); /* 1 */
FF (ref d, a, b, c, x[ 1], S12); /* 2 */
FF (ref c, d, a, b, x[ 2], S13); /* 3 */
FF (ref b, c, d, a, x[ 3], S14); /* 4 */
FF (ref a, b, c, d, x[ 4], S11); /* 5 */
FF (ref d, a, b, c, x[ 5], S12); /* 6 */
FF (ref c, d, a, b, x[ 6], S13); /* 7 */
FF (ref b, c, d, a, x[ 7], S14); /* 8 */
FF (ref a, b, c, d, x[ 8], S11); /* 9 */
FF (ref d, a, b, c, x[ 9], S12); /* 10 */
FF (ref c, d, a, b, x[10], S13); /* 11 */
FF (ref b, c, d, a, x[11], S14); /* 12 */
FF (ref a, b, c, d, x[12], S11); /* 13 */
FF (ref d, a, b, c, x[13], S12); /* 14 */
FF (ref c, d, a, b, x[14], S13); /* 15 */
FF (ref b, c, d, a, x[15], S14); /* 16 */
/* Round 2 */
GG (ref a, b, c, d, x[ 0], S21); /* 17 */
GG (ref d, a, b, c, x[ 4], S22); /* 18 */
GG (ref c, d, a, b, x[ 8], S23); /* 19 */
GG (ref b, c, d, a, x[12], S24); /* 20 */
GG (ref a, b, c, d, x[ 1], S21); /* 21 */
GG (ref d, a, b, c, x[ 5], S22); /* 22 */
GG (ref c, d, a, b, x[ 9], S23); /* 23 */
GG (ref b, c, d, a, x[13], S24); /* 24 */
GG (ref a, b, c, d, x[ 2], S21); /* 25 */
GG (ref d, a, b, c, x[ 6], S22); /* 26 */
GG (ref c, d, a, b, x[10], S23); /* 27 */
GG (ref b, c, d, a, x[14], S24); /* 28 */
GG (ref a, b, c, d, x[ 3], S21); /* 29 */
GG (ref d, a, b, c, x[ 7], S22); /* 30 */
GG (ref c, d, a, b, x[11], S23); /* 31 */
GG (ref b, c, d, a, x[15], S24); /* 32 */
HH (ref a, b, c, d, x[ 0], S31); /* 33 */
HH (ref d, a, b, c, x[ 8], S32); /* 34 */
HH (ref c, d, a, b, x[ 4], S33); /* 35 */
HH (ref b, c, d, a, x[12], S34); /* 36 */
HH (ref a, b, c, d, x[ 2], S31); /* 37 */
HH (ref d, a, b, c, x[10], S32); /* 38 */
HH (ref c, d, a, b, x[ 6], S33); /* 39 */
HH (ref b, c, d, a, x[14], S34); /* 40 */
HH (ref a, b, c, d, x[ 1], S31); /* 41 */
HH (ref d, a, b, c, x[ 9], S32); /* 42 */
HH (ref c, d, a, b, x[ 5], S33); /* 43 */
HH (ref b, c, d, a, x[13], S34); /* 44 */
HH (ref a, b, c, d, x[ 3], S31); /* 45 */
HH (ref d, a, b, c, x[11], S32); /* 46 */
HH (ref c, d, a, b, x[ 7], S33); /* 47 */
HH (ref b, c, d, a, x[15], S34); /* 48 */
state [0] += a;
state [1] += b;
state [2] += c;
state [3] += d;
}
}
}
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