gnu.java.security.hash
Class BaseHash
- Cloneable, IMessageDigest
A base abstract class to facilitate hash implementations.
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.
|
BaseHash(String name, int hashSize, int blockSize)- Trivial constructor for use by concrete subclasses.
|
int | blockSize()- Returns the algorithm's (inner) block size in bytes.
|
abstract 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.
|
protected abstract byte[] | getResult()- Constructs the result from the contents of the current context.
|
int | hashSize()- Returns the output length in bytes of this message digest algorithm.
|
String | name()- Returns the canonical name of this algorithm.
|
protected abstract byte[] | padBuffer()- Returns the byte array to use as padding before completing a hash
operation.
|
void | reset()- Resets the current context of this instance clearing any eventually cached
intermediary values.
|
protected abstract void | resetContext()- Resets the instance for future re-use.
|
abstract boolean | selfTest()- A basic test.
|
protected abstract void | transform(byte[] in, int offset)- The block digest transformation per se.
|
void | update(byte b)- Continues a message digest operation using the input byte.
|
void | update(byte[] b)- 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[] b, int offset, int len)- 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.
|
clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait |
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.
BaseHash
protected BaseHash(String name,
int hashSize,
int blockSize) Trivial constructor for use by concrete subclasses.
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.
blockSize
public int blockSize()
Returns the algorithm's (inner) block size in bytes.
- blockSize in interface IMessageDigest
- the algorithm's inner block size in bytes.
digest
public byte[] digest()
Completes the message digest by performing final operations such as padding
and resetting the instance.
- digest in interface IMessageDigest
- the array of bytes representing the hash value.
getResult
protected abstract byte[] getResult()
Constructs the result from the contents of the current context.
- the output of the completed hash operation.
hashSize
public int hashSize()
Returns the output length in bytes of this message digest algorithm.
- hashSize in interface IMessageDigest
- the output length in bytes of this message digest algorithm.
padBuffer
protected abstract byte[] padBuffer()
Returns the byte array to use as padding before completing a hash
operation.
- the bytes to pad the remaining bytes in the buffer before
completing a hash operation.
reset
public void reset()
Resets the current context of this instance clearing any eventually cached
intermediary values.
- reset in interface IMessageDigest
resetContext
protected abstract void resetContext()
Resets the instance for future re-use.
selfTest
public abstract boolean selfTest()
A basic test. Ensures that the digest of a pre-determined message is equal
to a known pre-computed value.
- selfTest in interface IMessageDigest
true if the implementation passes a basic self-test.
Returns false otherwise.
transform
protected abstract void transform(byte[] in,
int offset) The block digest transformation per se.
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)
Continues a message digest operation using the input byte.
- update in interface IMessageDigest
b - the input byte to digest.
update
public void update(byte[] b)
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.
- update in interface IMessageDigest
update
public void update(byte[] b,
int offset,
int len) 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.
- update in interface IMessageDigest
offset - start of meaningful bytes in input block.
BaseHash.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.