gnu.crypto.hash

Class MD4

Implemented Interfaces:
Cloneable, IMessageDigest

public class MD4
extends BaseHash

An implementation of Ron Rivest's MD4 message digest algorithm.

MD4 was the precursor to the stronger MD5 algorithm, and while not considered cryptograpically secure itself, MD4 is in use in various applications. It is slightly faster than MD5.

References:

  1. The MD4 Message-Digest Algorithm.
    R. Rivest.

Version:
$Revision: 1.5 $

Author:
Casey Marshall (rsdio@metastatic.org)

Field Summary

Fields inherited from class gnu.crypto.hash.BaseHash

blockSize, buffer, count, hashSize, name

Constructor Summary

MD4()
Public constructor.

Method Summary

Object
clone()
Returns a clone copy of this instance.
protected byte[]
getResult()
Constructs the result from the contents of the current context.
protected byte[]
padBuffer()
Returns the byte array to use as padding before completing a hash operation.
protected void
resetContext()
Resets the instance for future re-use.
boolean
selfTest()
A basic test.
protected void
transform(byte[] in, int i)
The block digest transformation per se.

Methods inherited from class gnu.crypto.hash.BaseHash

blockSize, clone, digest, getResult, hashSize, name, padBuffer, reset, resetContext, selfTest, transform, update, update

Constructor Details

MD4

public MD4()
Public constructor. Initializes the chaining variables, sets the byte count to 0, and creates a new block of 512 bits.

Method Details

clone

public Object clone()
Returns a clone copy of this instance.
Specified by:
clone in interface IMessageDigest
Overrides:
clone in interface BaseHash

Returns:
a clone copy of this instance.


getResult

protected byte[] getResult()
Constructs the result from the contents of the current context.
Overrides:
getResult in interface BaseHash

Returns:
the output of the completed hash operation.


padBuffer

protected byte[] padBuffer()
Returns the byte array to use as padding before completing a hash operation.
Overrides:
padBuffer in interface BaseHash

Returns:
the bytes to pad the remaining bytes in the buffer before completing a hash operation.


resetContext

protected void resetContext()
Resets the instance for future re-use.
Overrides:
resetContext in interface BaseHash


selfTest

public boolean selfTest()
A basic test. Ensures that the digest of a pre-determined message is equal to a known pre-computed value.
Specified by:
selfTest in interface IMessageDigest
Overrides:
selfTest in interface BaseHash

Returns:
true if the implementation passes a basic self-test. Returns false otherwise.


transform

protected void transform(byte[] in,
                         int i)
The block digest transformation per se.
Overrides:
transform in interface BaseHash

Parameters:
in - the blockSize long block, as an array of bytes to digest.


Copyright © 2001, 2002, 2003 Free Software Foundation, Inc. All Rights Reserved.