org.bouncycastle.crypto.engines
Class DESEngine

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

All Implemented Interfaces:

BlockCipher

Direct Known Subclasses:

DESedeEngine

public class DESEngine
extends java.lang.Object
implements BlockCipher

a class that provides a basic DES engine.

Field Summary

private static int[]	bigbyte
protected static int	BLOCK_SIZE
private static short[]	bytebit
private static short[]	Df_Key what follows is mainly taken from "Applied Cryptography", by Bruce Schneier, however it also bears great resemblance to Richard Outerbridge's D3DES...
private static byte[]	pc1
private static byte[]	pc2
private static int[]	SP1
private static int[]	SP2
private static int[]	SP3
private static int[]	SP4
private static int[]	SP5
private static int[]	SP6
private static int[]	SP7
private static int[]	SP8
private static byte[]	totrot
private int[]	workingKey

Constructor Summary

DESEngine()
standard constructor.

Method Summary

protected void	desFunc(int[] wKey, byte[] in, int inOff, byte[] out, int outOff) the DES engine.
protected int[]	generateWorkingKey(boolean encrypting, byte[] key) generate an integer based working key based on our secret key and what we processing we are planning to do.
java.lang.String	getAlgorithmName() Return the name of the algorithm the cipher implements.
int	getBlockSize() Return the block size for this cipher (in bytes).
void	init(boolean encrypting, CipherParameters params) initialise a DES 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

protected static final int BLOCK_SIZE

See Also:

Constant Field Values

workingKey

private int[] workingKey

Df_Key

private static final short[] Df_Key

what follows is mainly taken from "Applied Cryptography", by Bruce Schneier, however it also bears great resemblance to Richard Outerbridge's D3DES...

bytebit

private static final short[] bytebit

bigbyte

private static final int[] bigbyte

pc1

private static final byte[] pc1

totrot

private static final byte[] totrot

pc2

private static final byte[] pc2

SP1

private static final int[] SP1

SP2

private static final int[] SP2

SP3

private static final int[] SP3

SP4

private static final int[] SP4

SP5

private static final int[] SP5

SP6

private static final int[] SP6

SP7

private static final int[] SP7

SP8

private static final int[] SP8

Constructor Detail

DESEngine

public DESEngine()

standard constructor.

Method Detail

init

public void init(boolean encrypting,
                 CipherParameters params)

initialise a DES 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

generateWorkingKey

protected int[] generateWorkingKey(boolean encrypting,
                                   byte[] key)

generate an integer based working key based on our secret key and what we processing we are planning to do. Acknowledgements for this routine go to James Gillogly & Phil Karn. (whoever, and wherever they are!).

desFunc

protected void desFunc(int[] wKey,
                       byte[] in,
                       int inOff,
                       byte[] out,
                       int outOff)

the DES engine.