gnu.crypto.hash

Interface IMessageDigest

All Superinterfaces:

Cloneable

All Known Implementing Classes:

BaseHash, MD4, MD5

public interface IMessageDigest
extends Cloneable

The basic visible methods of any hash algorithm.

A hash (or message digest) algorithm produces its output by iterating a basic compression function on blocks of data.

Version:

$Revision: 1.9 $

Method Summary

Modifier and Type	Method and Description
int	blockSize() Returns the algorithm's (inner) block size in bytes.
Object	clone() Returns a clone copy of this instance.
byte[]	digest() Completes the message digest by performing final operations such as padding and resetting the instance.
int	hashSize() Returns the output length in bytes of this message digest algorithm.
String	name() Returns the canonical name of this algorithm.
void	reset() Resets the current context of this instance clearing any eventually cached intermediary values.
boolean	selfTest() A basic test.
void	update(byte b) Continues a message digest operation using the input byte.
void	update(byte[] in, int offset, int length) Continues a message digest operation, by filling the buffer, processing data in the algorithm's HASH_SIZE-bit block(s), updating the context and count, and buffering the remaining bytes in buffer for the next operation.

Method Detail

name

String name()

Returns the canonical name of this algorithm.

Returns:

the canonical name of this instance.

hashSize

int hashSize()

Returns the output length in bytes of this message digest algorithm.

Returns:

the output length in bytes of this message digest algorithm.

blockSize

int blockSize()

Returns the algorithm's (inner) block size in bytes.

Returns:

the algorithm's inner block size in bytes.

update

void update(byte b)

Continues a message digest operation using the input byte.

Parameters:

b - the input byte to digest.

update

void update(byte[] in,
            int offset,
            int length)

Continues a message digest operation, by filling the buffer, processing data in the algorithm's HASH_SIZE-bit block(s), updating the context and count, and buffering the remaining bytes in buffer for the next operation.

Parameters:

in - the input block.

offset - start of meaningful bytes in input block.

length - number of bytes, in input block, to consider.

digest

byte[] digest()

Completes the message digest by performing final operations such as padding and resetting the instance.

Returns:

the array of bytes representing the hash value.

reset

void reset()

Resets the current context of this instance clearing any eventually cached intermediary values.

selfTest

boolean selfTest()

A basic test. Ensures that the digest of a pre-determined message is equal to a known pre-computed value.

Returns:

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

clone

Object clone()

Returns a clone copy of this instance.

Returns:

a clone copy of this instance.