MD4 Digest
/******************************************************************************
* Copyright (c) 2000 The Legion Of The Bouncy Castle (http://www.bouncycastle.org)
* 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,
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* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
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*
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* USE OR OTHER DEALINGS IN THE SOFTWARE.
******************************************************************************/
/**
* implementation of MD4 as RFC 1320 by R. Rivest, MIT Laboratory for
* Computer Science and RSA Data Security, Inc.
* <p>
* <b>NOTE</b>: This algorithm is only included for backwards compatability
* with legacy applications, it's not secure, don't use it for anything new!
*
* @version $Id: MD4Digest.java,v 1.2 2004/06/27 17:00:55 bheineman Exp $
*/
public class MD4Digest extends GeneralDigest {
private static final int DIGEST_LENGTH = 16;
//
// round 1 left rotates
//
private static final int S11 = 3;
private static final int S12 = 7;
private static final int S13 = 11;
private static final int S14 = 19;
//
// round 2 left rotates
//
private static final int S21 = 3;
private static final int S22 = 5;
private static final int S23 = 9;
private static final int S24 = 13;
//
// round 3 left rotates
//
private static final int S31 = 3;
private static final int S32 = 9;
private static final int S33 = 11;
private static final int S34 = 15;
private int H1, H2, H3, H4; // IV's
private int[] X = new int[16];
private int xOff;
/**
* Standard constructor
*/
public MD4Digest() {
reset();
}
/**
* Copy constructor. This will copy the state of the provided
* message digest.
*/
public MD4Digest(MD4Digest t) {
super(t);
H1 = t.H1;
H2 = t.H2;
H3 = t.H3;
H4 = t.H4;
System.arraycopy(t.X, 0, X, 0, t.X.length);
xOff = t.xOff;
}
public String getAlgorithmName() {
return "MD4";
}
public int getDigestSize() {
return DIGEST_LENGTH;
}
protected void processWord(byte[] in, int inOff) {
X[xOff++] = (in[inOff] & 0xff) | ((in[inOff + 1] & 0xff) << 8)
| ((in[inOff + 2] & 0xff) << 16) | ((in[inOff + 3] & 0xff) << 24);
if (xOff == 16) {
processBlock();
}
}
protected void processLength(long bitLength) {
if (xOff > 14) {
processBlock();
}
X[14] = (int)(bitLength & 0xffffffff);
X[15] = (int)(bitLength >>> 32);
}
private void unpackWord(int word, byte[] out, int outOff) {
out[outOff] = (byte)word;
out[outOff + 1] = (byte)(word >>> 8);
out[outOff + 2] = (byte)(word >>> 16);
out[outOff + 3] = (byte)(word >>> 24);
}
public int doFinal(byte[] out, int outOff) {
finish();
unpackWord(H1, out, outOff);
unpackWord(H2, out, outOff + 4);
unpackWord(H3, out, outOff + 8);
unpackWord(H4, out, outOff + 12);
reset();
return DIGEST_LENGTH;
}
/**
* reset the chaining variables to the IV values.
*/
public void reset() {
super.reset();
H1 = 0x67452301;
H2 = 0xefcdab89;
H3 = 0x98badcfe;
H4 = 0x10325476;
xOff = 0;
for (int i = 0; i != X.length; i++) {
X[i] = 0;
}
}
/*
* rotate int x left n bits.
*/
private int rotateLeft(int x, int n) {
return(x << n) | (x >>> (32 - n));
}
/*
* F, G, H and I are the basic MD4 functions.
*/
private int F(int u, int v, int w) {
return(u & v) | (~u & w);
}
private int G(int u, int v, int w) {
return(u & v) | (u & w) | (v & w);
}
private int H(int u, int v, int w) {
return u ^ v ^ w;
}
protected void processBlock() {
int a = H1;
int b = H2;
int c = H3;
int d = H4;
//
// Round 1 - F cycle, 16 times.
//
a = rotateLeft((a + F(b, c, d) + X[ 0]), S11);
d = rotateLeft((d + F(a, b, c) + X[ 1]), S12);
c = rotateLeft((c + F(d, a, b) + X[ 2]), S13);
b = rotateLeft((b + F(c, d, a) + X[ 3]), S14);
a = rotateLeft((a + F(b, c, d) + X[ 4]), S11);
d = rotateLeft((d + F(a, b, c) + X[ 5]), S12);
c = rotateLeft((c + F(d, a, b) + X[ 6]), S13);
b = rotateLeft((b + F(c, d, a) + X[ 7]), S14);
a = rotateLeft((a + F(b, c, d) + X[ 8]), S11);
d = rotateLeft((d + F(a, b, c) + X[ 9]), S12);
c = rotateLeft((c + F(d, a, b) + X[10]), S13);
b = rotateLeft((b + F(c, d, a) + X[11]), S14);
a = rotateLeft((a + F(b, c, d) + X[12]), S11);
d = rotateLeft((d + F(a, b, c) + X[13]), S12);
c = rotateLeft((c + F(d, a, b) + X[14]), S13);
b = rotateLeft((b + F(c, d, a) + X[15]), S14);
//
// Round 2 - G cycle, 16 times.
//
a = rotateLeft((a + G(b, c, d) + X[ 0] + 0x5a827999), S21);
d = rotateLeft((d + G(a, b, c) + X[ 4] + 0x5a827999), S22);
c = rotateLeft((c + G(d, a, b) + X[ 8] + 0x5a827999), S23);
b = rotateLeft((b + G(c, d, a) + X[12] + 0x5a827999), S24);
a = rotateLeft((a + G(b, c, d) + X[ 1] + 0x5a827999), S21);
d = rotateLeft((d + G(a, b, c) + X[ 5] + 0x5a827999), S22);
c = rotateLeft((c + G(d, a, b) + X[ 9] + 0x5a827999), S23);
b = rotateLeft((b + G(c, d, a) + X[13] + 0x5a827999), S24);
a = rotateLeft((a + G(b, c, d) + X[ 2] + 0x5a827999), S21);
d = rotateLeft((d + G(a, b, c) + X[ 6] + 0x5a827999), S22);
c = rotateLeft((c + G(d, a, b) + X[10] + 0x5a827999), S23);
b = rotateLeft((b + G(c, d, a) + X[14] + 0x5a827999), S24);
a = rotateLeft((a + G(b, c, d) + X[ 3] + 0x5a827999), S21);
d = rotateLeft((d + G(a, b, c) + X[ 7] + 0x5a827999), S22);
c = rotateLeft((c + G(d, a, b) + X[11] + 0x5a827999), S23);
b = rotateLeft((b + G(c, d, a) + X[15] + 0x5a827999), S24);
//
// Round 3 - H cycle, 16 times.
//
a = rotateLeft((a + H(b, c, d) + X[ 0] + 0x6ed9eba1), S31);
d = rotateLeft((d + H(a, b, c) + X[ 8] + 0x6ed9eba1), S32);
c = rotateLeft((c + H(d, a, b) + X[ 4] + 0x6ed9eba1), S33);
b = rotateLeft((b + H(c, d, a) + X[12] + 0x6ed9eba1), S34);
a = rotateLeft((a + H(b, c, d) + X[ 2] + 0x6ed9eba1), S31);
d = rotateLeft((d + H(a, b, c) + X[10] + 0x6ed9eba1), S32);
c = rotateLeft((c + H(d, a, b) + X[ 6] + 0x6ed9eba1), S33);
b = rotateLeft((b + H(c, d, a) + X[14] + 0x6ed9eba1), S34);
a = rotateLeft((a + H(b, c, d) + X[ 1] + 0x6ed9eba1), S31);
d = rotateLeft((d + H(a, b, c) + X[ 9] + 0x6ed9eba1), S32);
c = rotateLeft((c + H(d, a, b) + X[ 5] + 0x6ed9eba1), S33);
b = rotateLeft((b + H(c, d, a) + X[13] + 0x6ed9eba1), S34);
a = rotateLeft((a + H(b, c, d) + X[ 3] + 0x6ed9eba1), S31);
d = rotateLeft((d + H(a, b, c) + X[11] + 0x6ed9eba1), S32);
c = rotateLeft((c + H(d, a, b) + X[ 7] + 0x6ed9eba1), S33);
b = rotateLeft((b + H(c, d, a) + X[15] + 0x6ed9eba1), S34);
H1 += a;
H2 += b;
H3 += c;
H4 += d;
//
// reset the offset and clean out the word buffer.
//
xOff = 0;
for (int i = 0; i != X.length; i++) {
X[i] = 0;
}
}
}
/**
* base implementation of MD4 family style digest as outlined in
* "Handbook of Applied Cryptography", pages 344 - 347.
*
* @version $Id: GeneralDigest.java,v 1.2 2004/06/27 17:00:55 bheineman Exp $
*/
abstract class GeneralDigest
// implements Digest - mdb: we don't care about this interface
{
private byte[] xBuf;
private int xBufOff;
private long byteCount;
/**
* Standard constructor
*/
protected GeneralDigest()
{
xBuf = new byte[4];
xBufOff = 0;
}
/**
* Copy constructor. We are using copy constructors in place
* of the Object.clone() interface as this interface is not
* supported by J2ME.
*/
protected GeneralDigest(GeneralDigest t)
{
xBuf = new byte[t.xBuf.length];
System.arraycopy(t.xBuf, 0, xBuf, 0, t.xBuf.length);
xBufOff = t.xBufOff;
byteCount = t.byteCount;
}
public void update(
byte in)
{
xBuf[xBufOff++] = in;
if (xBufOff == xBuf.length)
{
processWord(xBuf, 0);
xBufOff = 0;
}
byteCount++;
}
public void update(
byte[] in,
int inOff,
int len)
{
//
// fill the current word
//
while ((xBufOff != 0) && (len > 0))
{
update(in[inOff]);
inOff++;
len--;
}
//
// process whole words.
//
while (len > xBuf.length)
{
processWord(in, inOff);
inOff += xBuf.length;
len -= xBuf.length;
byteCount += xBuf.length;
}
//
// load in the remainder.
//
while (len > 0)
{
update(in[inOff]);
inOff++;
len--;
}
}
public void finish()
{
long bitLength = (byteCount << 3);
//
// add the pad bytes.
//
update((byte)128);
while (xBufOff != 0)
{
update((byte)0);
}
processLength(bitLength);
processBlock();
}
public void reset()
{
byteCount = 0;
xBufOff = 0;
for ( int i = 0; i < xBuf.length; i++ ) {
xBuf[i] = 0;
}
}
protected abstract void processWord(byte[] in, int inOff);
protected abstract void processLength(long bitLength);
protected abstract void processBlock();
}
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