MacSpi

public abstract class MacSpi
extends Object

java.lang.Object
   ↳ javax.crypto.MacSpi


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.

Summary

Public constructors

MacSpi()

Public methods

Object clone()

Returns a clone if the implementation is cloneable.

Protected methods

abstract byte[] engineDoFinal()

Completes the MAC computation and resets the MAC for further use, maintaining the secret key that the MAC was initialized with.

abstract int engineGetMacLength()

Returns the length of the MAC in bytes.

abstract void engineInit(Key key, AlgorithmParameterSpec params)

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

abstract void engineReset()

Resets the MAC for further use, maintaining the secret key that the MAC was initialized with.

void engineUpdate(ByteBuffer input)

Processes input.remaining() bytes in the ByteBuffer input, starting at input.position().

abstract void engineUpdate(byte input)

Processes the given byte.

abstract void engineUpdate(byte[] input, int offset, int len)

Processes the first len bytes in input, starting at offset inclusive.

Inherited methods

Public constructors

MacSpi

Added in API level 1
public MacSpi ()

Public methods

clone

Added in API level 1
public Object clone ()

Returns a clone if the implementation is cloneable.

Returns
Object a clone if the implementation is cloneable.

Throws
CloneNotSupportedException if this is called on an implementation that does not support Cloneable.

Protected methods

engineDoFinal

Added in API level 1
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
byte[] the MAC result.

engineGetMacLength

Added in API level 1
protected abstract int engineGetMacLength ()

Returns the length of the MAC in bytes.

Returns
int the MAC length in bytes.

engineInit

Added in API level 1
protected abstract void engineInit (Key key, 
                AlgorithmParameterSpec params)

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

Parameters
key Key: the (secret) key.

params AlgorithmParameterSpec: 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.

engineReset

Added in API level 1
protected abstract void engineReset ()

Resets the MAC for further use, maintaining the secret key that the MAC was initialized with.

engineUpdate

Added in API level 1
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 ByteBuffer: the ByteBuffer

engineUpdate

Added in API level 1
protected abstract void engineUpdate (byte input)

Processes the given byte.

Parameters
input byte: the input byte to be processed.

engineUpdate

Added in API level 1
protected abstract void engineUpdate (byte[] input, 
                int offset, 
                int len)

Processes the first len bytes in input, starting at offset inclusive.

Parameters
input byte: the input buffer.

offset int: the offset in input where the input starts.

len int: the number of bytes to process.