gnu.crypto.hash

Interface IMessageDigest

All Superinterfaces:
Cloneable
Known Implementing Classes:
BaseHash, Haval, MD2, MD4, MD5, RipeMD128, RipeMD160, Sha160, Sha256, Sha384, Sha512, Tiger, Whirlpool

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

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 Details

blockSize

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

Returns:
the algorithm's inner block size in bytes.


clone

public Object clone()
Returns a clone copy of this instance.

Returns:
a clone copy of this instance.


digest

public 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.


hashSize

public int hashSize()
Returns the output length in bytes of this message digest algorithm.

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


name

public String name()
Returns the canonical name of this algorithm.

Returns:
the canonical name of this instance.


reset

public void reset()
Resets the current context of this instance clearing any eventually cached intermediary values.


selfTest

public 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.


update

public void update(byte b)
Continues a message digest operation using the input byte.

Parameters:
b - the input byte to digest.


update

public 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.


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