javax.crypto
Class MacSpi

java.lang.Object
  |
  +--javax.crypto.MacSpi

Direct Known Subclasses:

JCEMac

public abstract class MacSpi

extends java.lang.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.

Constructor Summary

MacSpi()

Method Summary

java.lang.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(java.security.Key key, java.security.spec.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(java.security.Key key,
                                   java.security.spec.AlgorithmParameterSpec params)
                            throws java.security.InvalidKeyException,
                                   java.security.InvalidAlgorithmParameterException

Initializes the MAC with the given (secret) key and algorithm parameters.

Parameters:

key - - the (secret) key.

params - - the algorithm parameters.

Throws:

java.security.InvalidKeyException - if the given key is inappropriate for initializing this MAC.

java.security.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 java.lang.Object clone()
                       throws java.lang.CloneNotSupportedException

Returns a clone if the implementation is cloneable.

Overrides:

clone in class java.lang.Object

Returns:

a clone if the implementation is cloneable.

Throws:

java.lang.CloneNotSupportedException - if this is called on an implementation that does not support Cloneable.