Class KMAC

java.lang.Object
org.bouncycastle.crypto.macs.KMAC
All Implemented Interfaces:
Digest, EncodableDigest, EncodableService, ExtendedDigest, Mac, Xof, Memoable
public class KMAC extends Object implements Mac, Xof, Memoable, EncodableDigest
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(byte[] state)
     
    KMAC(int bitLength, byte[] S)
    Base constructor.
    KMAC(KMAC original)
     

  • Method Summary

    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)
    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.
    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.
    byte[]
    getEncodedState()
    Return an encoded byte array for the digest's internal state
    int
    getMacSize()
    Return the block size for this MAC (in bytes).
    void
    init(CipherParameters params)
    Initialise the MAC.
    void
    reset()
    Reset the MAC.
    void
    reset(Memoable other)
    Restore a copied object state into this object.
    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 Object

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

  • Constructor Details

    • 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.

    • KMAC

      public KMAC(KMAC original)

    • KMAC

      public KMAC(byte[] state)

  • Method Details

    • init

      public void init(CipherParameters params) throws 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:
      IllegalArgumentException - if the params argument is inappropriate.

    • getAlgorithmName

      public 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 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:
      IllegalStateException - if the MAC is not initialised.

    • update

      public void update(byte[] in, int inOff, int len) throws DataLengthException, 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.
      IllegalStateException - if the MAC is not initialised.

    • doFinal

      public int doFinal(byte[] out, int outOff) throws DataLengthException, 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.
      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

    • getEncodedState

      public byte[] getEncodedState()
      Description copied from interface: EncodableDigest
      Return an encoded byte array for the digest's internal state
      Specified by:
      getEncodedState in interface EncodableDigest
      Specified by:
      getEncodedState in interface EncodableService
      Returns:
      an encoding of the digests internal state.

    • 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

    • 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.