Package org.bouncycastle.crypto.macs

Class SkeinMac

java.lang.Object
org.bouncycastle.crypto.macs.SkeinMac
All Implemented Interfaces:
Mac
public class SkeinMac extends Object implements Mac
Implementation of the Skein parameterised MAC function in 256, 512 and 1024 bit block sizes, based on the Threefish tweakable block cipher.

This is the 1.3 version of Skein defined in the Skein hash function submission to the NIST SHA-3 competition in October 2010.

Skein was designed by Niels Ferguson - Stefan Lucks - Bruce Schneier - Doug Whiting - Mihir Bellare - Tadayoshi Kohno - Jon Callas - Jesse Walker.

See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    SKEIN_1024
    1024 bit block size - Skein MAC-1024
    static final int
    SKEIN_256
    256 bit block size - Skein MAC-256
    static final int
    SKEIN_512
    512 bit block size - Skein MAC-512

  • Constructor Summary

    Constructors
    Constructor
    Description
    SkeinMac(int stateSizeBits, int digestSizeBits)
    Constructs a Skein MAC with an internal state size and output size.
    SkeinMac(SkeinMac mac)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    doFinal(byte[] out, int outOff)
    Compute the final stage of the MAC writing the output to the out parameter.
    String
    getAlgorithmName()
    Return the name of the algorithm the MAC implements.
    int
    getMacSize()
    Return the block size for this MAC (in bytes).
    void
    init(CipherParameters params)
    Initialises the Skein digest with the provided parameters.
    See SkeinParameters for details on the parameterisation of the Skein hash function.
    void
    reset()
    Reset the MAC.
    void
    update(byte in)
    add a single byte to the mac for processing.
    void
    update(byte[] in, int inOff, int len)
     

    Methods inherited from class java.lang.Object

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

  • Field Details

    • SKEIN_256

      public static final int SKEIN_256
      256 bit block size - Skein MAC-256
      See Also:

    • SKEIN_512

      public static final int SKEIN_512
      512 bit block size - Skein MAC-512
      See Also:

    • SKEIN_1024

      public static final int SKEIN_1024
      1024 bit block size - Skein MAC-1024
      See Also:

  • Constructor Details

    • SkeinMac

      public SkeinMac(int stateSizeBits, int digestSizeBits)
      Constructs a Skein MAC with an internal state size and output size.
      Parameters:
      stateSizeBits - the internal state size in bits - one of SKEIN_256, SKEIN_512 or SKEIN_1024.
      digestSizeBits - the output/MAC size to produce in bits, which must be an integral number of bytes.

    • SkeinMac

      public SkeinMac(SkeinMac mac)

  • Method Details

    • getAlgorithmName

      public String getAlgorithmName()
      Description copied from interface: Mac
      Return the name of the algorithm the MAC implements.
      Specified by:
      getAlgorithmName in interface Mac
      Returns:
      the name of the algorithm the MAC implements.

    • init

      public void init(CipherParameters params) throws IllegalArgumentException
      Initialises the Skein digest with the provided parameters.
      See SkeinParameters for details on the parameterisation of the Skein hash function.
      Specified by:
      init in interface Mac
      Parameters:
      params - an instance of SkeinParameters or KeyParameter.
      Throws:
      IllegalArgumentException - if the params argument is inappropriate.

    • getMacSize

      public int getMacSize()
      Description copied from interface: Mac
      Return the block size for this MAC (in bytes).
      Specified by:
      getMacSize in interface Mac
      Returns:
      the block size for this MAC in bytes.

    • reset

      public void reset()
      Description copied from interface: Mac
      Reset the MAC. At the end of resetting the MAC should be in the in the same state it was after the last init (if there was one).
      Specified by:
      reset in interface Mac

    • update

      public void update(byte in)
      Description copied from interface: Mac
      add a single byte to the mac for processing.
      Specified by:
      update in interface Mac
      Parameters:
      in - the byte to be processed.

    • update

      public void update(byte[] in, int inOff, int len)
      Specified by:
      update in interface Mac
      Parameters:
      in - the array containing the input.
      inOff - the index in the array the data begins at.
      len - the length of the input starting at inOff.

    • doFinal

      public int doFinal(byte[] out, int outOff)
      Description copied from interface: Mac
      Compute the final stage of the MAC writing the output to the out parameter.

      doFinal leaves the MAC in the same state it was after the last init.

      Specified by:
      doFinal in interface Mac
      Parameters:
      out - the array the MAC is to be output to.
      outOff - the offset into the out buffer the output is to start at.