JavaTM 2 Platform
Std. Ed. v1.4.0

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
MacSpi()
           
 
Method Summary
 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.
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

MacSpi

public MacSpi()
Method Detail

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.

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:
Cloneable

JavaTM 2 Platform
Std. Ed. v1.4.0

Submit a bug or feature
For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Java, Java 2D, and JDBC are trademarks or registered trademarks of Sun Microsystems, Inc. in the US and other countries.
Copyright 1993-2002 Sun Microsystems, Inc. 901 San Antonio Road
Palo Alto, California, 94303, U.S.A. All Rights Reserved.