gnu.crypto.hash

Class Haval

Implemented Interfaces:
Cloneable, IMessageDigest

public class Haval
extends BaseHash

The HAVAL message-digest algorithm is a variable output length, with variable number of rounds. By default, this implementation allows HAVAL to be used as a drop-in replacement for MD5.

References:

  1. HAVAL - A One-Way Hashing Algorithm with Variable Length of Output
    Advances in Cryptology - AUSCRYPT'92, Lecture Notes in Computer Science,
    Springer-Verlag, 1993;
    Y. Zheng, J. Pieprzyk and J. Seberry.
Version:
$Revision: 1.3 $

Field Summary

static int
HAVAL_128_BIT
static int
HAVAL_160_BIT
static int
HAVAL_192_BIT
static int
HAVAL_224_BIT
static int
HAVAL_256_BIT
static int
HAVAL_3_ROUND
static int
HAVAL_4_ROUND
static int
HAVAL_5_ROUND
static int
HAVAL_VERSION

Fields inherited from class gnu.crypto.hash.BaseHash

blockSize, buffer, count, hashSize, name

Constructor Summary

Haval()
Calls the constructor with two argument using HAVAL_128_BIT as the value for the output size (i.e.
Haval(int size)
Calls the constructor with two arguments using the designated output size, and HAVAL_3_ROUND for the value of number of rounds.
Haval(int size, int rounds)
Constructs a Haval instance with the designated output size (in bytes).

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, update

Field Details

HAVAL_128_BIT

public static final int HAVAL_128_BIT
Field Value:
16

HAVAL_160_BIT

public static final int HAVAL_160_BIT
Field Value:
20

HAVAL_192_BIT

public static final int HAVAL_192_BIT
Field Value:
24

HAVAL_224_BIT

public static final int HAVAL_224_BIT
Field Value:
28

HAVAL_256_BIT

public static final int HAVAL_256_BIT
Field Value:
32

HAVAL_3_ROUND

public static final int HAVAL_3_ROUND
Field Value:
3

HAVAL_4_ROUND

public static final int HAVAL_4_ROUND
Field Value:
4

HAVAL_5_ROUND

public static final int HAVAL_5_ROUND
Field Value:
5

HAVAL_VERSION

public static final int HAVAL_VERSION
Field Value:
1

Constructor Details

Haval

public Haval()
Calls the constructor with two argument using HAVAL_128_BIT as the value for the output size (i.e. 128 bits, and HAVAL_3_ROUND for the value of number of rounds.

Haval

public Haval(int size)
Parameters:
size - the output size in bytes of this instance.

Haval

public Haval(int size,
             int rounds)
Constructs a Haval instance with the designated output size (in bytes). Valid output size values are 16, 20, 24, 28 and 32. Valid values for rounds are in the range 3..5 inclusive.
Parameters:
size - the output size in bytes of this instance.
rounds - the number of rounds to apply when transforming data.

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.