Package org.bouncycastle.crypto.digests

Class SkeinDigest

  • All Implemented Interfaces:
    Digest, ExtendedDigest, Memoable
    public class SkeinDigest
extends java.lang.Object
implements ExtendedDigest, Memoable
    Implementation of the Skein parameterised hash 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-1024
      static int SKEIN_256
      256 bit block size - Skein-256
      static int SKEIN_512
      512 bit block size - Skein-512

    • Constructor Summary

      Constructors 
      Constructor Description
      SkeinDigest​(int stateSizeBits, int digestSizeBits)
      Constructs a Skein digest with an internal state size and output size.
      SkeinDigest​(SkeinDigest digest)  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      Memoable copy()
      Produce a copy of this object with its configuration and in its current state.
      int doFinal​(byte[] out, int outOff)
      close the digest, producing the final digest value.
      java.lang.String getAlgorithmName()
      return the algorithm name
      int getByteLength()
      Return the size in bytes of the internal buffer the digest applies it's compression function to.
      int getDigestSize()
      return the size, in bytes, of the digest produced by this message digest.
      void init​(SkeinParameters params)
      Optionally initialises the Skein digest with the provided parameters.
      See SkeinParameters for details on the parameterisation of the Skein hash function.
      void reset()
      reset the digest back to it's initial state.
      void reset​(Memoable other)
      Restore a copied object state into this object.
      void update​(byte in)
      update the message digest with a single byte.
      void update​(byte[] in, int inOff, int len)
      update the message digest with a block of bytes.

      • 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-256
        See Also:
        Constant Field Values

      • SKEIN_512

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

      • SKEIN_1024

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

    • Constructor Detail

      • SkeinDigest

        public SkeinDigest​(int stateSizeBits,
                   int digestSizeBits)
        Constructs a Skein digest 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/digest size to produce in bits, which must be an integral number of bytes.

      • SkeinDigest

        public SkeinDigest​(SkeinDigest digest)

    • Method Detail

      • reset

        public void reset​(Memoable other)
        Description copied from interface: Memoable
        Restore a copied object state into this object.

        Implementations of this method should try to avoid or minimise memory allocation to perform the reset.

        Specified by:
        reset in interface Memoable
        Parameters:
        other - an object originally copied from an object of the same type as this instance.

      • copy

        public Memoable copy()
        Description copied from interface: Memoable
        Produce a copy of this object with its configuration and in its current state.

        The returned object may be used simply to store the state, or may be used as a similar object starting from the copied state.

        Specified by:
        copy in interface Memoable

      • getAlgorithmName

        public java.lang.String getAlgorithmName()
        Description copied from interface: Digest
        return the algorithm name
        Specified by:
        getAlgorithmName in interface Digest
        Returns:
        the algorithm name

      • getDigestSize

        public int getDigestSize()
        Description copied from interface: Digest
        return the size, in bytes, of the digest produced by this message digest.
        Specified by:
        getDigestSize in interface Digest
        Returns:
        the size, in bytes, of the digest produced by this message digest.

      • getByteLength

        public int getByteLength()
        Description copied from interface: ExtendedDigest
        Return the size in bytes of the internal buffer the digest applies it's compression function to.
        Specified by:
        getByteLength in interface ExtendedDigest
        Returns:
        byte length of the digests internal buffer.

      • init

        public void init​(SkeinParameters params)
        Optionally initialises the Skein digest with the provided parameters.
        See SkeinParameters for details on the parameterisation of the Skein hash function.
        Parameters:
        params - the parameters to apply to this engine, or null to use no parameters.

      • reset

        public void reset()
        Description copied from interface: Digest
        reset the digest back to it's initial state.
        Specified by:
        reset in interface Digest

      • update

        public void update​(byte in)
        Description copied from interface: Digest
        update the message digest with a single byte.
        Specified by:
        update in interface Digest
        Parameters:
        in - the input byte to be entered.

      • update

        public void update​(byte[] in,
                   int inOff,
                   int len)
        Description copied from interface: Digest
        update the message digest with a block of bytes.
        Specified by:
        update in interface Digest
        Parameters:
        in - the byte array containing the data.
        inOff - the offset into the byte array where the data starts.
        len - the length of the data.

      • doFinal

        public int doFinal​(byte[] out,
                   int outOff)
        Description copied from interface: Digest
        close the digest, producing the final digest value. The doFinal call leaves the digest reset.
        Specified by:
        doFinal in interface Digest
        Parameters:
        out - the array the digest is to be copied into.
        outOff - the offset into the out array the digest is to start at.