gnu.crypto.hash
Class MD4

java.lang.Object
  gnu.crypto.hash.BaseHash
      gnu.crypto.hash.MD4

All Implemented Interfaces:

java.lang.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: 1.2 $

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

java.lang.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, digest, hashSize, name, reset, update, update

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MD4

public MD4()

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

Method Detail

clone

public java.lang.Object clone()

Description copied from interface: IMessageDigest

Returns a clone copy of this instance.

Specified by:

clone in interface IMessageDigest

Specified by:

clone in class BaseHash

getResult

protected byte[] getResult()

Description copied from class: BaseHash

Constructs the result from the contents of the current context.

Specified by:

getResult in class BaseHash

Returns:

the output of the completed hash operation.

resetContext

protected void resetContext()

Description copied from class: BaseHash

Resets the instance for future re-use.

Specified by:

resetContext in class BaseHash

selfTest

public boolean selfTest()

Description copied from interface: IMessageDigest

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

Specified by:

selfTest in class BaseHash

padBuffer

protected byte[] padBuffer()

Description copied from class: BaseHash

Returns the byte array to use as padding before completing a hash operation.

Specified by:

padBuffer in class BaseHash

Returns:

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

transform

protected void transform(byte[] in,
                         int i)

Description copied from class: BaseHash

The block digest transformation per se.

Specified by:

transform in class BaseHash

Parameters:

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

i - the index where the data to digest is located within the input buffer.