Package org.bouncycastle.crypto.macs

Class SipHash

java.lang.Object
org.bouncycastle.crypto.macs.SipHash
All Implemented Interfaces:
Mac
Direct Known Subclasses:
SipHash128
public class SipHash extends Object implements Mac
Implementation of SipHash as specified in "SipHash: a fast short-input PRF", by Jean-Philippe Aumasson and Daniel J. Bernstein (https://131002.net/siphash/siphash.pdf).

"SipHash is a family of PRFs SipHash-c-d where the integer parameters c and d are the number of compression rounds and the number of finalization rounds. A compression round is identical to a finalization round and this round function is called SipRound. Given a 128-bit key k and a (possibly empty) byte string m, SipHash-c-d returns a 64-bit value..."

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected final int
    c
     
    protected final int
    d
     
    protected long
    k0
     
    protected long
    k1
     
    protected long
    m
     
    protected long
    v0
     
    protected long
    v1
     
    protected long
    v2
     
    protected long
    v3
     
    protected int
    wordCount
     
    protected int
    wordPos
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    SipHash()
    SipHash-2-4
    SipHash(int c, int d)
    SipHash-c-d

  • Method Summary

    Modifier and Type
    Method
    Description
    protected void
    applySipRounds(int n)
     
    long
    doFinal()
     
    int
    doFinal(byte[] out, int outOff)
    Compute the final stage of the MAC writing the output to the out parameter.
    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)
    Initialise the MAC.
    protected void
    processMessageWord()
     
    void
    reset()
    Reset the MAC.
    protected static long
    rotateLeft(long x, int n)
     
    void
    update(byte input)
    add a single byte to the mac for processing.
    void
    update(byte[] input, int offset, int length)
     

    Methods inherited from class java.lang.Object

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

  • Field Details

    • c

      protected final int c

    • d

      protected final int d

    • k0

      protected long k0

    • k1

      protected long k1

    • v0

      protected long v0

    • v1

      protected long v1

    • v2

      protected long v2

    • v3

      protected long v3

    • m

      protected long m

    • wordPos

      protected int wordPos

    • wordCount

      protected int wordCount

  • Constructor Details

    • SipHash

      public SipHash()
      SipHash-2-4

    • SipHash

      public SipHash(int c, int d)
      SipHash-c-d
      Parameters:
      c - the number of compression rounds
      d - the number of finalization rounds

  • Method Details

    • getAlgorithmName

      public 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.

    • 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.

    • 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.

    • update

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

    • update

      public void update(byte[] input, int offset, int length) throws DataLengthException, IllegalStateException
      Specified by:
      update in interface Mac
      Parameters:
      input - the array containing the input.
      offset - the index in the array the data begins at.
      length - 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 long doFinal() throws DataLengthException, IllegalStateException
      Throws:
      DataLengthException
      IllegalStateException

    • 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 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.

    • 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

    • processMessageWord

      protected void processMessageWord()

    • applySipRounds

      protected void applySipRounds(int n)

    • rotateLeft

      protected static long rotateLeft(long x, int n)