Class DESKeySpec

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

Constructor Detail

• DESKeySpec

  public DESKeySpec(byte[] key)
             throws 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:

  NullPointerException - if the given key material is null

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

• DESKeySpec

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

  NullPointerException - if the given key material is null

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

Method Detail

• getKey

  public byte[] getKey()

  Returns the DES key material.

  Returns:

  the DES key material. Returns a new array each time this method is called.

• 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 is null, or starting at offset inclusive, is shorter than 8 bytes.

• 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 is null, or starting at offset inclusive, is shorter than 8 bytes.