javax.crypto.spec
Class DESKeySpec

java.lang.Object
  javax.crypto.spec.DESKeySpec

All Implemented Interfaces:

KeySpec

public class DESKeySpec
extends Object
implements KeySpec

This class specifies a DES key.

Version:

$Id: DESKeySpec.java 1913 2007-08-08 02:41:53Z jpeters $

Author:

Patric Kabus, Jan Peters

Field Summary

static int	DES_KEY_LEN The constant which defines the length of a DES key in bytes.
private byte[]	key_ The DES key material.
private static byte[][]	WEAK_KEYS An array of weak DES keys.

Constructor Summary

DESKeySpec(byte[] key)
Uses the first 8 bytes in key as the key material for the DES key.

DESKeySpec(byte[] key, int offset)
Uses the first 8 bytes in key, beginning at offset inclusive, as the key material for the DES key.

Method Summary

byte[]	getKey() Returns the DES key material.
static boolean	isParityAdjusted(byte[] key, int offset) Checks if the given DES key material, starting at offset inclusive, is parity-adjusted.
static boolean	isWeak(byte[] key, int offset) Checks if the given DES key material is weak or semi-weak.

Methods inherited from class java.lang.Object

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

Field Detail

DES_KEY_LEN

public static final int DES_KEY_LEN

The constant which defines the length of a DES key in bytes.

See Also:

Constant Field Values

WEAK_KEYS

private static final byte[][] WEAK_KEYS

An array of weak DES keys.

key_

private byte[] key_

The DES key material.

Constructor Detail

DESKeySpec

public DESKeySpec(byte[] key)
           throws InvalidKeyException

Uses the first 8 bytes in key as the key material for the DES key.

The bytes that constitute the DES key are those between key[0] and key[7] inclusive.

Parameters:

key - the buffer with the DES key material.

Throws:

InvalidKeyException - if the given key material is shorter than 8 bytes.

NullPointerException - if key is null.

DESKeySpec

public DESKeySpec(byte[] key,
                  int offset)
           throws InvalidKeyException

Uses the first 8 bytes in key, beginning at offset inclusive, as the key material for the DES key.

The bytes that constitute the DES key are those between key[offset] and key[offset+7] inclusive.

Parameters:

key - the buffer with the DES key material.

offset - the offset in key, where the DES key material starts.

Throws:

InvalidKeyException - if the given key material, starting at offset inclusive, is shorter than 8 bytes.

NullPointerException - if key is null.

Method Detail

getKey

public byte[] getKey()

Returns the DES key material.

Returns:

the DES key material.

isParityAdjusted

public static boolean isParityAdjusted(byte[] key,
                                       int offset)
                                throws InvalidKeyException

Checks if the given DES key material, starting at offset inclusive, is parity-adjusted.

Parameters:

key - the buffer with the DES key material.

offset - the offset in key, where the DES key material starts.

Returns:

true if the given DES key material is parity-adjusted, false otherwise.

Throws:

InvalidKeyException - if the given key material, starting at offset inclusive, is shorter than 8 bytes.

NullPointerException - if key is null.

isWeak

public static boolean isWeak(byte[] key,
                             int offset)
                      throws InvalidKeyException

Checks if the given DES key material is weak or semi-weak.

Parameters:

key - the buffer with the DES key material.

offset - the offset in key, where the DES key material starts.

Returns:

true if the given DES key material is weak or semi-weak, false otherwise.

Throws:

InvalidKeyException - if the given key material, starting at offset inclusive, is shorter than 8 bytes.

NullPointerException - if key is null.