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 java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • 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.