Package org.bouncycastle.crypto.engines

Class ThreefishEngine

  • All Implemented Interfaces:
    BlockCipher
    public class ThreefishEngine
extends java.lang.Object
implements BlockCipher
    Implementation of the Threefish tweakable large block cipher in 256, 512 and 1024 bit block sizes.

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

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

    This implementation inlines all round functions, unrolls 8 rounds, and uses 1.2k of static tables to speed up key schedule injection.
    2 x block size state is retained by each cipher instance.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int BLOCKSIZE_1024
      1024 bit block size - Threefish-1024
      static int BLOCKSIZE_256
      256 bit block size - Threefish-256
      static int BLOCKSIZE_512
      512 bit block size - Threefish-512

    • Constructor Summary

      Constructors 
      Constructor Description
      ThreefishEngine​(int blocksizeBits)
      Constructs a new Threefish cipher, with a specified block size.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      static long bytesToWord​(byte[] bytes, int off)
      Read a single 64 bit word from input in LSB first order.
      java.lang.String getAlgorithmName()
      Return the name of the algorithm the cipher implements.
      int getBlockSize()
      Return the block size for this cipher (in bytes).
      void init​(boolean forEncryption, long[] key, long[] tweak)
      Initialise the engine, specifying the key and tweak directly.
      void init​(boolean forEncryption, CipherParameters params)
      Initialise the engine.
      int processBlock​(byte[] in, int inOff, byte[] out, int outOff)
      Process one block of input from the array in and write it to the out array.
      int processBlock​(long[] in, long[] out)
      Process a block of data represented as 64 bit words.
      void reset()
      Reset the cipher.
      static void wordToBytes​(long word, byte[] bytes, int off)
      Write a 64 bit word to output in LSB first order.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • BLOCKSIZE_256

        public static final int BLOCKSIZE_256
        256 bit block size - Threefish-256
        See Also:
        Constant Field Values

      • BLOCKSIZE_512

        public static final int BLOCKSIZE_512
        512 bit block size - Threefish-512
        See Also:
        Constant Field Values

      • BLOCKSIZE_1024

        public static final int BLOCKSIZE_1024
        1024 bit block size - Threefish-1024
        See Also:
        Constant Field Values

    • Constructor Detail

      • ThreefishEngine

        public ThreefishEngine​(int blocksizeBits)
        Constructs a new Threefish cipher, with a specified block size.
        Parameters:
        blocksizeBits - the block size in bits, one of BLOCKSIZE_256, BLOCKSIZE_512, BLOCKSIZE_1024.

    • Method Detail

      • init

        public void init​(boolean forEncryption,
                 CipherParameters params)
          throws java.lang.IllegalArgumentException
        Initialise the engine.
        Specified by:
        init in interface BlockCipher
        Parameters:
        params - an instance of TweakableBlockCipherParameters, or KeyParameter (to use a 0 tweak)
        forEncryption - if true the cipher is initialised for encryption, if false for decryption.
        Throws:
        java.lang.IllegalArgumentException - if the params argument is inappropriate.

      • init

        public void init​(boolean forEncryption,
                 long[] key,
                 long[] tweak)
        Initialise the engine, specifying the key and tweak directly.
        Parameters:
        forEncryption - the cipher mode.
        key - the words of the key, or null to use the current key.
        tweak - the 2 word (128 bit) tweak, or null to use the current tweak.

      • getAlgorithmName

        public java.lang.String getAlgorithmName()
        Description copied from interface: BlockCipher
        Return the name of the algorithm the cipher implements.
        Specified by:
        getAlgorithmName in interface BlockCipher
        Returns:
        the name of the algorithm the cipher implements.

      • getBlockSize

        public int getBlockSize()
        Description copied from interface: BlockCipher
        Return the block size for this cipher (in bytes).
        Specified by:
        getBlockSize in interface BlockCipher
        Returns:
        the block size for this cipher in bytes.

      • reset

        public void reset()
        Description copied from interface: BlockCipher
        Reset the cipher. After resetting the cipher is in the same state as it was after the last init (if there was one).
        Specified by:
        reset in interface BlockCipher

      • processBlock

        public int processBlock​(byte[] in,
                        int inOff,
                        byte[] out,
                        int outOff)
                 throws DataLengthException,
                        java.lang.IllegalStateException
        Description copied from interface: BlockCipher
        Process one block of input from the array in and write it to the out array.
        Specified by:
        processBlock in interface BlockCipher
        Parameters:
        in - the array containing the input data.
        inOff - offset into the in array the data starts at.
        out - the array the output data will be copied into.
        outOff - the offset into the out array the output will start at.
        Returns:
        the number of bytes processed and produced.
        Throws:
        DataLengthException - if there isn't enough data in in, or space in out.
        java.lang.IllegalStateException - if the cipher isn't initialised.

      • processBlock

        public int processBlock​(long[] in,
                        long[] out)
                 throws DataLengthException,
                        java.lang.IllegalStateException
        Process a block of data represented as 64 bit words.
        Parameters:
        in - a block sized buffer of words to process.
        out - a block sized buffer of words to receive the output of the operation.
        Returns:
        the number of 8 byte words processed (which will be the same as the block size).
        Throws:
        DataLengthException - if either the input or output is not block sized.
        java.lang.IllegalStateException - if this engine is not initialised.

      • bytesToWord

        public static long bytesToWord​(byte[] bytes,
                               int off)
        Read a single 64 bit word from input in LSB first order.

      • wordToBytes

        public static void wordToBytes​(long word,
                               byte[] bytes,
                               int off)
        Write a 64 bit word to output in LSB first order.