org.bouncycastle.crypto.engines
Class ISAACEngine

java.lang.Object
  org.bouncycastle.crypto.engines.ISAACEngine

All Implemented Interfaces:

StreamCipher

public class ISAACEngine
extends java.lang.Object
implements StreamCipher

Implementation of Bob Jenkin's ISAAC (Indirection Shift Accumulate Add and Count). see: http://www.burtleburtle.net/bob/rand/isaacafa.html

Field Summary

private int	a
private int	b
private int	c
private int[]	engineState
private int	index
private boolean	initialised
private byte[]	keyStream
private int[]	results
private int	sizeL
private int	stateArraySize
private byte[]	workingKey

Constructor Summary

ISAACEngine()

Method Summary

private int	byteToIntLittle(byte[] x, int offset)
java.lang.String	getAlgorithmName() Return the name of the algorithm the cipher implements.
void	init(boolean forEncryption, CipherParameters params) initialise an ISAAC cipher.
private byte[]	intToByteLittle(int x)
private byte[]	intToByteLittle(int[] x)
private void	isaac()
private void	mix(int[] x)
void	processBytes(byte[] in, int inOff, int len, byte[] out, int outOff) process a block of bytes from in putting the result into out.
void	reset() reset the cipher.
byte	returnByte(byte in) encrypt/decrypt a single byte returning the result.
private void	setKey(byte[] keyBytes)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

sizeL

private final int sizeL

See Also:

Constant Field Values

stateArraySize

private final int stateArraySize

See Also:

Constant Field Values

engineState

private int[] engineState

results

private int[] results

a

private int a

b

private int b

c

private int c

index

private int index

keyStream

private byte[] keyStream

workingKey

private byte[] workingKey

initialised

private boolean initialised

Constructor Detail

ISAACEngine

public ISAACEngine()

Method Detail

init

public void init(boolean forEncryption,
                 CipherParameters params)

initialise an ISAAC cipher.

Specified by:

init in interface StreamCipher

Parameters:

forEncryption - whether or not we are for encryption.

params - the parameters required to set up the cipher.

Throws:

java.lang.IllegalArgumentException - if the params argument is inappropriate.

returnByte

public byte returnByte(byte in)

Description copied from interface: StreamCipher

encrypt/decrypt a single byte returning the result.

Specified by:

returnByte in interface StreamCipher

Parameters:

in - the byte to be processed.

Returns:

the result of processing the input byte.

processBytes

public void processBytes(byte[] in,
                         int inOff,
                         int len,
                         byte[] out,
                         int outOff)

Description copied from interface: StreamCipher

process a block of bytes from in putting the result into out.

Specified by:

processBytes in interface StreamCipher

Parameters:

in - the input byte array.

inOff - the offset into the in array where the data to be processed starts.

len - the number of bytes to be processed.

out - the output buffer the processed bytes go into.

outOff - the offset into the output byte array the processed data starts at.

getAlgorithmName

public java.lang.String getAlgorithmName()

Description copied from interface: StreamCipher

Return the name of the algorithm the cipher implements.

Specified by:

getAlgorithmName in interface StreamCipher

Returns:

the name of the algorithm the cipher implements.

reset

public void reset()

Description copied from interface: StreamCipher

reset the cipher. This leaves it in the same state it was at after the last init (if there was one).

Specified by:

reset in interface StreamCipher

setKey

private void setKey(byte[] keyBytes)

isaac

private void isaac()

mix

private void mix(int[] x)

byteToIntLittle

private int byteToIntLittle(byte[] x,
                            int offset)

intToByteLittle

private byte[] intToByteLittle(int x)

intToByteLittle

private byte[] intToByteLittle(int[] x)