org.bouncycastle.crypto.engines
Class SkipjackEngine

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

All Implemented Interfaces:

BlockCipher

public class SkipjackEngine
extends java.lang.Object
implements BlockCipher

a class that provides a basic SKIPJACK engine.

Field Summary

(package private) static int	BLOCK_SIZE
private boolean	encrypting
(package private) static short[]	ftable
private int[]	key0
private int[]	key1
private int[]	key2
private int[]	key3

Constructor Summary

SkipjackEngine()

Method Summary

int	decryptBlock(byte[] in, int inOff, byte[] out, int outOff)
int	encryptBlock(byte[] in, int inOff, byte[] out, int outOff)
private int	g(int k, int w) The G permutation
java.lang.String	getAlgorithmName() Return the name of the algorithm the cipher implements.
int	getBlockSize() Return the block size for this cipher (in bytes).
private int	h(int k, int w) the inverse of the G permutation.
void	init(boolean encrypting, CipherParameters params) initialise a SKIPJACK cipher.
int	processBlock(byte[] in, int inOff, byte[] out, int outOff) Process one block of input from the array in and write it to the out array.
void	reset() Reset the cipher.

Methods inherited from class java.lang.Object

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

Field Detail

BLOCK_SIZE

static final int BLOCK_SIZE

See Also:

Constant Field Values

ftable

static short[] ftable

key0

private int[] key0

key1

private int[] key1

key2

private int[] key2

key3

private int[] key3

encrypting

private boolean encrypting

Constructor Detail

SkipjackEngine

public SkipjackEngine()

Method Detail

init

public void init(boolean encrypting,
                 CipherParameters params)

initialise a SKIPJACK cipher.

Specified by:

init in interface BlockCipher

Parameters:

encrypting - 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.

getAlgorithmName

public java.lang.String getAlgorithmName()

Description copied from interface: BlockCipher

Return the name of the algorithm the cipher implements.

Specified by:

getAlgorithmName in interface BlockCipher

Returns:

the name of the algorithm the cipher implements.

getBlockSize

public int getBlockSize()

Description copied from interface: BlockCipher

Return the block size for this cipher (in bytes).

Specified by:

getBlockSize in interface BlockCipher

Returns:

the block size for this cipher in bytes.

processBlock

public int processBlock(byte[] in,
                        int inOff,
                        byte[] out,
                        int outOff)

Description copied from interface: BlockCipher

Process one block of input from the array in and write it to the out array.

Specified by:

processBlock in interface BlockCipher

Parameters:

in - the array containing the input data.

inOff - offset into the in array the data starts at.

out - the array the output data will be copied into.

outOff - the offset into the out array the output will start at.

Returns:

the number of bytes processed and produced.

reset

public void reset()

Description copied from interface: BlockCipher

Reset the cipher. After resetting the cipher is in the same state as it was after the last init (if there was one).

Specified by:

reset in interface BlockCipher

g

private int g(int k,
              int w)

The G permutation

encryptBlock

public int encryptBlock(byte[] in,
                        int inOff,
                        byte[] out,
                        int outOff)

h

private int h(int k,
              int w)

the inverse of the G permutation.

decryptBlock

public int decryptBlock(byte[] in,
                        int inOff,
                        byte[] out,
                        int outOff)