javax.crypto.spec

Class DESKeySpec

  1. java.lang.Object
  2. extended byjavax.crypto.spec.DESKeySpec
All implemented interfaces:
java.security.spec.KeySpec

  1. public class DESKeySpec
  2. extends java.lang.Object
  3. implements java.security.spec.KeySpec
This class specifies a DES key.
Since:
1.4
Version:
1.21, 01/07/04
Author:
Jan Luehe

Field Summary

Modifier and Type Field and Description
  1. static
  2. int
DES_KEY_LEN
The constant which defines the length of a DES key in bytes.

Constructor Summary

Constructor and Description
DESKeySpec(byte[] key)
Creates a DESKeySpec object using the first 8 bytes in key as the key material for the DES key.
DESKeySpec(byte[] key,int offset)
Creates a DESKeySpec object using the first 8 bytes in key, beginning at offset inclusive, as the key material for the DES key.

Method Summary

Modifier and Type Method and Description
  1. byte[]
getKey()
Returns the DES key material.
  1. static
  2. boolean
isParityAdjusted(byte[] key,int offset)
Checks if the given DES key material, starting at offset inclusive, is parity-adjusted.
  1. static
  2. 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

  1. public static final int DES_KEY_LEN
The constant which defines the length of a DES key in bytes.
See Also:

Constructor Detail

DESKeySpec

  1. public DESKeySpec(byte[] key)
  2. throws java.security.InvalidKeyException
Creates a DESKeySpec object using 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. The first 8 bytes of the buffer are copied to protect against subsequent modification.
Throws:
java.lang.NullPointerException - if the given key material is null
java.security.InvalidKeyException - if the given key material is shorter than 8 bytes.

DESKeySpec

  1. public DESKeySpec(byte[] key,
  2. int offset)
  3. throws java.security.InvalidKeyException
Creates a DESKeySpec object using 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. The first 8 bytes of the buffer beginning at offset inclusive are copied to protect against subsequent modification.
offset - the offset in key, where the DES key material starts.
Throws:
java.lang.NullPointerException - if the given key material is null
java.security.InvalidKeyException - if the given key material, starting at offset inclusive, is shorter than 8 bytes.

Method Detail

getKey

  1. public byte[] getKey()
Returns the DES key material.
Returns:
the DES key material. Returns a new array each time this method is called.

isParityAdjusted

  1. public static boolean isParityAdjusted( byte[] key,
  2. int offset)
  3. throws java.security.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:
java.security.InvalidKeyException - if the given key material is null, or starting at offset inclusive, is shorter than 8 bytes.

isWeak

  1. public static boolean isWeak(byte[] key,
  2. int offset)
  3. throws java.security.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:
java.security.InvalidKeyException - if the given key material is null, or starting at offset inclusive, is shorter than 8 bytes.