javax.crypto.spec

Class DESKeySpec

java.lang.Object

javax.crypto.spec.DESKeySpec

All Implemented Interfaces:

KeySpec

public class DESKeySpec
extends Object
implements KeySpec

The key specification for a DES key.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DES_KEY_LEN The length of a DES key in bytes.

Constructor Summary

Constructors

Constructor and Description
DESKeySpec(byte[] key) Creates a new DESKeySpec from the first 8 bytes of the specified key data.
DESKeySpec(byte[] key, int offset) Creates a new DESKeySpec from the first 8 bytes of the specified key data starting at offset.

Method Summary

Modifier and Type	Method and Description
byte[]	getKey() Returns a copy of the key.
static boolean	isParityAdjusted(byte[] key, int offset) Returns whether the specified key data starting at offset is parity-adjusted.
static boolean	isWeak(byte[] key, int offset) Returns whether the specified key data starting at offset 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 length of a DES key in bytes.

See Also:

Constant Field Values

Constructor Detail

DESKeySpec

public DESKeySpec(byte[] key)
           throws InvalidKeyException

Creates a new DESKeySpec from the first 8 bytes of the specified key data.

Parameters:

key - the key data.

Throws:

InvalidKeyException - if the length of the specified key data is less than 8.

DESKeySpec

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

Creates a new DESKeySpec from the first 8 bytes of the specified key data starting at offset.

Parameters:

key - the key data

offset - the offset to start at.

Throws:

InvalidKeyException - if the length of the specified key data starting at offset is less than 8.

Method Detail

getKey

public byte[] getKey()

Returns a copy of the key.

Returns:

a copy of the key.

isParityAdjusted

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

Returns whether the specified key data starting at offset is parity-adjusted.

Parameters:

key - the key data.

offset - the offset to start checking at.

Returns:

true if the specified key data is parity-adjusted, false otherwise.

Throws:

InvalidKeyException - if the length of the key data starting at offset is less than 8, or the key is null.

isWeak

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

Returns whether the specified key data starting at offset is weak or semi-weak.

Parameters:

key - the key data.

offset - the offset to start checking at.

Returns:

true if the specified key data is weak or semi-weak.

Throws:

InvalidKeyException - if the length of the key data starting at offset is less than 8, or it is null.