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()
    Creates and returns a copy of this object.
    boolean
    equals(Object obj)
    Indicates whether some other object is "equal to" this one.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    Finalization is deprecated and subject to removal in a future release.
    final Class<?>
    getClass()
    Returns the runtime class of this Object.
    int
    hashCode()
    Returns a hash code value for this object.
    final void
    notify()
    Wakes up a single thread that is waiting on this object's monitor.
    final void
    notifyAll()
    Wakes up all threads that are waiting on this object's monitor.
    String
    toString()
    Returns a string representation of the object.
    final void
    wait()
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
    final void
    wait(long timeoutMillis)
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
    final void
    wait(long timeoutMillis, int nanos)
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

  • 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.

  • 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.

    • 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.