Module java.base
Package javax.crypto

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 java.lang.Object

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

  • 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.
      See Also: