MacSpi

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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.

Public Constructor Summary

MacSpi()

Public Method Summary

Object
clone()
Returns a clone if the implementation is cloneable.

Protected Method Summary

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 Method Summary

Public Constructors

public MacSpi ()

Public Methods

public Object clone ()

Returns a clone if the implementation is cloneable.

Returns
  • a clone if the implementation is cloneable.
Throws
CloneNotSupportedException if this is called on an implementation that does not support Cloneable.

Protected Methods

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.

protected abstract int engineGetMacLength ()

Returns the length of the MAC in bytes.

Returns
  • the MAC length in bytes.

protected abstract void engineInit (Key key, AlgorithmParameterSpec params)

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.

protected abstract void engineReset ()

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

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

protected abstract void engineUpdate (byte input)

Processes the given byte.

Parameters
input the input byte to be processed.

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.