cryptix.provider.md
Class BlockMessageDigest
MessageDigest
cryptix.provider.md.BlockMessageDigest
(package private) abstract class BlockMessageDigest
extends MessageDigest
This is a superclass for message digests that operate internally on
blocks of data. It is not intended directly for use by application
programmers.
Copyright © 1995-1997
Systemics Ltd on behalf of the
Cryptix Development Team.
All rights reserved.
$Revision: 1.4 $
BlockMessageDigest(String algorithm) - Constructs a message digest with the specified algorithm name.
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protected long | bitcount()
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protected byte[] | engineDigest() - SPI: Calculates the final digest.
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protected abstract byte[] | engineDigest(byte[] data, int length) - SPI (for BlockMessageDigests only): Calculates the
final digest.
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protected abstract int | engineGetDataLength() - SPI: Returns the length of the block that this hash
function operates on.
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protected void | engineReset() - SPI: Resets the digest.
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protected abstract void | engineTransform(byte[] data) - SPI (for BlockMessageDigests only): Performs a
transformation on the given data, which is always one block long.
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protected void | engineUpdate(byte b) - SPI: Updates the message digest with a byte of new data.
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protected void | engineUpdate(byte[] data, int offset, int length) - SPI: Updates the message digest with new data.
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BlockMessageDigest
protected BlockMessageDigest(String algorithm)
Constructs a message digest with the specified algorithm name.
algorithm
- the standard name of the digest algorithm.
bitcount
protected long bitcount()
- number of bits hashed so far?
engineDigest
protected byte[] engineDigest()
SPI: Calculates the final digest. BlockMessageDigest
subclasses should not usually override this method.
- the digest as a byte array.
engineDigest
protected abstract byte[] engineDigest(byte[] data,
int length)
SPI (for BlockMessageDigests only): Calculates the
final digest. data[0..length-1]
contains the last
incomplete input block. length will be less than
engineDataLength()
.
data
- the last incomplete block.length
- the length in bytes of the last block.
- the digest as a byte array.
engineGetDataLength
protected abstract int engineGetDataLength()
SPI: Returns the length of the block that this hash
function operates on.
engineReset
protected void engineReset()
SPI: Resets the digest. Subclasses that override engineReset
should always call this implementation using super.engineReset()
.
engineTransform
protected abstract void engineTransform(byte[] data)
SPI (for BlockMessageDigests only): Performs a
transformation on the given data, which is always one block long.
engineUpdate
protected void engineUpdate(byte b)
SPI: Updates the message digest with a byte of new data.
b
- the byte to be added.
engineUpdate
protected void engineUpdate(byte[] data,
int offset,
int length)
SPI: Updates the message digest with new data.
data
- the data to be added.offset
- the start of the data in the array.length
- the number of bytes of data to add.