gnu.java.security.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.

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)
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.
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.
Overrides:
clone in interface Object
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)
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.

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.

IMessageDigest.java -- Copyright (C) 2001, 2002, 2006 Free Software Foundation, Inc. This file is a part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.