Class KMAC

  • All Implemented Interfaces:
    Digest, ExtendedDigest, Mac, Xof

    public class KMAC
    extends java.lang.Object
    implements Mac, Xof
    KMAC - MAC with optional XOF mode.

    From NIST Special Publication 800-185 - SHA-3 Derived Functions:cSHAKE, KMAC, TupleHash and ParallelHash

    • Constructor Summary

      Constructors 
      Constructor Description
      KMAC​(int bitLength, byte[] S)
      Base constructor.
    • 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.
      int doFinal​(byte[] out, int outOff, int outLen)
      Output the results of the final calculation for this digest to outLen number of bytes.
      int doOutput​(byte[] out, int outOff, int outLen)
      Start outputting the results of the final calculation for this digest.
      java.lang.String getAlgorithmName()
      Return the name of the algorithm the MAC implements.
      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.
      int getMacSize()
      Return the block size for this MAC (in bytes).
      void init​(CipherParameters params)
      Initialise the MAC.
      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)
      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
    • Constructor Detail

      • KMAC

        public KMAC​(int bitLength,
                    byte[] S)
        Base constructor.
        Parameters:
        bitLength - bit length of the underlying SHAKE function, 128 or 256.
        S - the customization string - available for local use.
    • Method Detail

      • init

        public void init​(CipherParameters params)
                  throws java.lang.IllegalArgumentException
        Description copied from interface: Mac
        Initialise the MAC.
        Specified by:
        init in interface Mac
        Parameters:
        params - the key and other data required by the MAC.
        Throws:
        java.lang.IllegalArgumentException - if the params argument is inappropriate.
      • 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 Digest
        Specified by:
        getAlgorithmName in interface Mac
        Returns:
        the name of the algorithm the MAC implements.
      • 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.
      • 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.
      • 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.
      • update

        public void update​(byte in)
                    throws java.lang.IllegalStateException
        Description copied from interface: Mac
        add a single byte to the mac for processing.
        Specified by:
        update in interface Digest
        Specified by:
        update in interface Mac
        Parameters:
        in - the byte to be processed.
        Throws:
        java.lang.IllegalStateException - if the MAC is not initialised.
      • update

        public void update​(byte[] in,
                           int inOff,
                           int len)
                    throws DataLengthException,
                           java.lang.IllegalStateException
        Description copied from interface: Digest
        update the message digest with a block of bytes.
        Specified by:
        update in interface Digest
        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.
        Throws:
        DataLengthException - if there isn't enough data in in.
        java.lang.IllegalStateException - if the MAC is not initialised.
      • doFinal

        public int doFinal​(byte[] out,
                           int outOff)
                    throws DataLengthException,
                           java.lang.IllegalStateException
        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 Digest
        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.
        Throws:
        DataLengthException - if there isn't enough space in out.
        java.lang.IllegalStateException - if the MAC is not initialised.
      • doFinal

        public int doFinal​(byte[] out,
                           int outOff,
                           int outLen)
        Description copied from interface: Xof
        Output the results of the final calculation for this digest to outLen number of bytes.
        Specified by:
        doFinal in interface Xof
        Parameters:
        out - output array to write the output bytes to.
        outOff - offset to start writing the bytes at.
        outLen - the number of output bytes requested.
        Returns:
        the number of bytes written
      • doOutput

        public int doOutput​(byte[] out,
                            int outOff,
                            int outLen)
        Description copied from interface: Xof
        Start outputting the results of the final calculation for this digest. Unlike doFinal, this method will continue producing output until the Xof is explicitly reset, or signals otherwise.
        Specified by:
        doOutput in interface Xof
        Parameters:
        out - output array to write the output bytes to.
        outOff - offset to start writing the bytes at.
        outLen - the number of output bytes requested.
        Returns:
        the number of bytes written
      • 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 Digest
        Specified by:
        reset in interface Mac