Package org.bouncycastle.crypto.macs

Class SkeinMac

  • All Implemented Interfaces:
    Mac
    public class SkeinMac
extends java.lang.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:
    SkeinEngine, SkeinParameters

    • Field Summary

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

      All Methods Instance Methods Concrete Methods 
      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.
      java.lang.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 Detail

      • SKEIN_256

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

      • SKEIN_512

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

      • SKEIN_1024

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

    • Constructor Detail

      • 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 Detail

      • getAlgorithmName

        public java.lang.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 java.lang.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:
        java.lang.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.