Class HMac

  • All Implemented Interfaces:
    Mac

    public class HMac
    extends java.lang.Object
    implements Mac
    HMAC implementation based on RFC2104 H(K XOR opad, H(K XOR ipad, text))
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
        HMac​(Digest digest)
      Base constructor for one of the standard digest algorithms that the byteLength of the algorithm is know for.
      private HMac​(Digest digest, int byteLength)  
    • Method Summary

      All Methods Static 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.
      java.lang.String getAlgorithmName()
      Return the name of the algorithm the MAC implements.
      private static int getByteLength​(Digest digest)  
      int getMacSize()
      Return the block size for this MAC (in bytes).
      Digest getUnderlyingDigest()  
      void init​(CipherParameters params)
      Initialise the MAC.
      void reset()
      Reset the mac generator.
      void update​(byte in)
      add a single byte to the mac for processing.
      void update​(byte[] in, int inOff, int len)  
      private static void xorPad​(byte[] pad, int len, byte n)  
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • digest

        private Digest digest
      • digestSize

        private int digestSize
      • blockLength

        private int blockLength
      • inputPad

        private byte[] inputPad
      • outputBuf

        private byte[] outputBuf
      • blockLengths

        private static java.util.Hashtable<java.lang.String,​java.lang.Integer> blockLengths
    • Constructor Detail

      • HMac

        public HMac​(Digest digest)
        Base constructor for one of the standard digest algorithms that the byteLength of the algorithm is know for.
        Parameters:
        digest - the digest.
      • HMac

        private HMac​(Digest digest,
                     int byteLength)
    • Method Detail

      • getByteLength

        private static int getByteLength​(Digest digest)
      • 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 Mac
        Returns:
        the name of the algorithm the MAC implements.
      • getUnderlyingDigest

        public Digest getUnderlyingDigest()
      • init

        public void init​(CipherParameters params)
        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.
      • 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.
      • update

        public void update​(byte in)
        Description copied from interface: Mac
        add a single byte to the mac for processing.
        Specified by:
        update in interface Mac
        Parameters:
        in - the byte to be processed.
      • update

        public void update​(byte[] in,
                           int inOff,
                           int len)
        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.
      • doFinal

        public int doFinal​(byte[] out,
                           int outOff)
        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.
      • reset

        public void reset()
        Reset the mac generator.
        Specified by:
        reset in interface Mac
      • xorPad

        private static void xorPad​(byte[] pad,
                                   int len,
                                   byte n)