com.safenetinc.luna.provider.digest

Class BaseHash

java.lang.Object

java.security.MessageDigestSpi

java.security.MessageDigest

com.safenetinc.luna.provider.digest.BaseHash

All Implemented Interfaces:

Cloneable

Direct Known Subclasses:

Sha224, Sha256, Sha384, Sha512

public abstract class BaseHash
extends MessageDigest
implements Cloneable

A base abstract class to facilitate hash implementations.

Version:

$Revision: 1.7 $

Field Summary

Fields

Modifier and Type	Field and Description
protected int	blockSize The hash (inner) block size in bytes.
protected byte[]	buffer Temporary input buffer.
protected long	count Number of bytes processed so far.
protected int	hashSize The hash (output) size in bytes.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BaseHash(String name, int hashSize, int blockSize) Trivial constructor for use by concrete subclasses.

Method Summary

Modifier and Type	Method and Description
abstract Object	clone()
byte[]	engineDigest()
int	engineGetDigestLength()
void	engineReset()
void	engineUpdate(byte b)
void	engineUpdate(byte[] b, int offset, int len)
protected abstract byte[]	getResult() Constructs the result from the contents of the current context.
protected abstract byte[]	padBuffer() Returns the byte array to use as padding before completing a hash operation.
protected abstract void	resetContext() Resets the instance for future re-use.
protected abstract void	transform(byte[] in, int offset) The block digest transformation per se.

Methods inherited from class java.security.MessageDigest

digest, digest, digest, getAlgorithm, getDigestLength, getInstance, getInstance, getInstance, getProvider, isEqual, reset, toString, update, update, update, update

Methods inherited from class java.security.MessageDigestSpi

engineDigest, engineUpdate

Methods inherited from class java.lang.Object

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

Field Detail

hashSize

protected int hashSize

The hash (output) size in bytes.

blockSize

protected int blockSize

The hash (inner) block size in bytes.

count

protected long count

Number of bytes processed so far.

buffer

protected byte[] buffer

Temporary input buffer.

Constructor Detail

BaseHash

protected BaseHash(String name,
                   int hashSize,
                   int blockSize)

Trivial constructor for use by concrete subclasses.

Parameters:

name - the canonical name prefix of this instance.

hashSize - the block size of the output in bytes.

blockSize - the block size of the internal transform.

Method Detail

engineGetDigestLength

public int engineGetDigestLength()

Overrides:

engineGetDigestLength in class MessageDigestSpi

engineUpdate

public void engineUpdate(byte b)

Specified by:

engineUpdate in class MessageDigestSpi

engineUpdate

public void engineUpdate(byte[] b,
                         int offset,
                         int len)

Specified by:

engineUpdate in class MessageDigestSpi

engineDigest

public byte[] engineDigest()

Specified by:

engineDigest in class MessageDigestSpi

engineReset

public void engineReset()

Specified by:

engineReset in class MessageDigestSpi

clone

public abstract Object clone()

Overrides:

clone in class MessageDigest

padBuffer

protected abstract byte[] padBuffer()

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

Returns:

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

getResult

protected abstract byte[] getResult()

Constructs the result from the contents of the current context.

Returns:

the output of the completed hash operation.

resetContext

protected abstract void resetContext()

Resets the instance for future re-use.

transform

protected abstract void transform(byte[] in,
                                  int offset)

The block digest transformation per se.

Parameters:

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

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