Class MacSpi

java.lang.Object
javax.crypto.MacSpi
public abstract class MacSpi extends Object
This class defines the Service Provider Interface (SPI) for the Mac class. All the abstract methods in this class must be implemented by each cryptographic service provider who wishes to supply the implementation of a particular MAC algorithm.

Implementations are free to implement the Cloneable interface.

Since:
1.4

  • Constructor Summary

    Constructors
    Constructor
    Description
    MacSpi()
    Constructor for subclasses to call.

  • Method Summary

    Modifier and Type
    Method
    Description
    Object
    clone()
    Returns a clone if the implementation is cloneable.
    protected abstract byte[]
    engineDoFinal()
    Completes the MAC computation and resets the MAC for further use, maintaining the secret key that the MAC was initialized with.
    protected abstract int
    engineGetMacLength()
    Returns the length of the MAC in bytes.
    protected abstract void
    engineInit(Key key, AlgorithmParameterSpec params)
    Initializes the MAC with the given (secret) key and algorithm parameters.
    protected abstract void
    engineReset()
    Resets the MAC for further use, maintaining the secret key that the MAC was initialized with.
    protected abstract void
    engineUpdate(byte input)
    Processes the given byte.
    protected abstract void
    engineUpdate(byte[] input, int offset, int len)
    Processes the first len bytes in input, starting at offset inclusive.
    protected void
    engineUpdate(ByteBuffer input)
    Processes input.remaining() bytes in the ByteBuffer input, starting at input.position().

    Methods declared in class Object

    equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    boolean
    equals(Object o)
    Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    May cause performance issues, deadlocks and hangs.
    final Class<? extends Object>
    getClass()
    Answers the unique instance of java.lang.Class which represents the class of the receiver.
    int
    hashCode()
    Answers an integer hash code for the receiver.
    final void
    notify()
    Causes one thread which is waiting on the receiver to be made ready to run.
    final void
    notifyAll()
    Causes all threads which are waiting on the receiver to be made ready to run.
    String
    toString()
    Answers a string containing a concise, human-readable description of the receiver.
    final void
    wait()
    Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
    final void
    wait(long time)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
    final void
    wait(long time, int frac)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

  • Constructor Details

    • MacSpi

      public MacSpi()
      Constructor for subclasses to call.

  • Method Details

    • engineGetMacLength

      protected abstract int engineGetMacLength()
      Returns the length of the MAC in bytes.
      Returns:
      the MAC length in bytes.

    • engineInit

      protected abstract void engineInit(Key key, AlgorithmParameterSpec params) throws InvalidKeyException, InvalidAlgorithmParameterException
      Initializes the MAC with the given (secret) key and algorithm parameters.
      Parameters:
      key - the (secret) key.
      params - the algorithm parameters.
      Throws:
      InvalidKeyException - if the given key is inappropriate for initializing this MAC.
      InvalidAlgorithmParameterException - if the given algorithm parameters are inappropriate for this MAC.

    • engineUpdate

      protected abstract void engineUpdate(byte input)
      Processes the given byte.
      Parameters:
      input - the input byte to be processed.

    • engineUpdate

      protected abstract void engineUpdate(byte[] input, int offset, int len)
      Processes the first len bytes in input, starting at offset inclusive.
      Parameters:
      input - the input buffer.
      offset - the offset in input where the input starts.
      len - the number of bytes to process.

    • engineUpdate

      protected void engineUpdate(ByteBuffer input)
      Processes input.remaining() bytes in the ByteBuffer input, starting at input.position(). Upon return, the buffer's position will be equal to its limit; its limit will not have changed.

      Subclasses should consider overriding this method if they can process ByteBuffers more efficiently than byte arrays.

      Parameters:
      input - the ByteBuffer
      Throws:
      NullPointerException - if input is null
      Since:
      1.5

    • engineDoFinal

      protected abstract byte[] engineDoFinal()
      Completes the MAC computation and resets the MAC for further use, maintaining the secret key that the MAC was initialized with.
      Returns:
      the MAC result.

    • engineReset

      protected abstract void engineReset()
      Resets the MAC for further use, maintaining the secret key that the MAC was initialized with.

    • clone

      public Object clone() throws CloneNotSupportedException
      Returns a clone if the implementation is cloneable.
      Overrides:
      clone in class Object
      Returns:
      a clone if the implementation is cloneable.
      Throws:
      CloneNotSupportedException - if this is called on an implementation that does not support Cloneable.