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.
Since:
1.4

  • Field Summary

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

  • Constructor Summary

    Constructors
    Constructor
    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
    Description
    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 declared in class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
    boolean
    equals(Object o)
    Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    May cause performance issues, deadlocks and hangs.
    final Class<? extends Object>
    getClass()
    Answers the unique instance of java.lang.Class which represents the class of the receiver.
    int
    hashCode()
    Answers an integer hash code for the receiver.
    final void
    notify()
    Causes one thread which is waiting on the receiver to be made ready to run.
    final void
    notifyAll()
    Causes all threads which are waiting on the receiver to be made ready to run.
    String
    toString()
    Answers a string containing a concise, human-readable description of the receiver.
    final void
    wait()
    Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
    final void
    wait(long time)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
    final void
    wait(long time, int frac)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

  • Field Details

    • DES_KEY_LEN

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

  • Constructor Details

    • 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.
      ArrayIndexOutOfBoundsException - if offset is negative.

  • Method Details

    • 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.
      ArrayIndexOutOfBoundsException - if offset is negative.

    • 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.
      ArrayIndexOutOfBoundsException - if offset is negative.