jonelo.jacksum.adapt.gnu.crypto.hash

Class BaseHash

Implemented Interfaces:
IMessageDigest

public abstract class BaseHash
extends java.lang.Object
implements IMessageDigest

A base abstract class to facilitate hash implementations.

Field Summary

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.
protected String
name
The canonical name prefix of the hash.

Constructor Summary

BaseHash(String name, int hashSize, int blockSize)
Trivial constructor for use by concrete subclasses.

Method Summary

int
blockSize()
abstract Object
clone()
byte[]
digest()
protected abstract byte[]
getResult()
Constructs the result from the contents of the current context.
int
hashSize()
String
name()
protected abstract byte[]
padBuffer()
Returns the byte array to use as padding before completing a hash operation.
void
reset()
protected abstract void
resetContext()
Resets the instance for future re-use.
abstract boolean
selfTest()
protected abstract void
transform(byte[] in, int offset)
The block digest transformation per se.
void
update(byte b)
void
update(byte[] b, int offset, int len)

Field Details

blockSize

protected int blockSize
The hash (inner) block size in bytes.

buffer

protected byte[] buffer
Temporary input buffer.

count

protected long count
Number of bytes processed so far.

hashSize

protected int hashSize
The hash (output) size in bytes.

name

protected String name
The canonical name prefix of the hash.

Constructor Details

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 Details

blockSize

public int blockSize()

clone

public abstract Object clone()

digest

public byte[] digest()

getResult

protected abstract byte[] getResult()
Constructs the result from the contents of the current context.
Returns:
the output of the completed hash operation.

hashSize

public int hashSize()

name

public String name()

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.

reset

public void reset()

resetContext

protected abstract void resetContext()
Resets the instance for future re-use.

selfTest

public abstract boolean selfTest()

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.

update

public void update(byte b)

update

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