Class ExemptionMechanismSpi

java.lang.Object

javax.crypto.ExemptionMechanismSpi

public abstract class ExemptionMechanismSpi
extends Object

This class defines the Service Provider Interface (SPI) for the ExemptionMechanism 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 exemption mechanism.

Since:

1.4

Constructor Summary

Constructors

Constructor	Description
ExemptionMechanismSpi()	Constructor for subclasses to call.

Method Summary

Modifier and Type	Method	Description
protected abstract byte[]	engineGenExemptionBlob()	Generates the exemption mechanism key blob.
protected abstract int	engineGenExemptionBlob(byte[] output, int outputOffset)	Generates the exemption mechanism key blob, and stores the result in the output buffer, starting at outputOffset inclusive.
protected abstract int	engineGetOutputSize(int inputLen)	Returns the length in bytes that an output buffer would need to be in order to hold the result of the next engineGenExemptionBlob operation, given the input length inputLen (in bytes).
protected abstract void	engineInit(Key key)	Initializes this exemption mechanism with a key.
protected abstract void	engineInit(Key key, AlgorithmParameters params)	Initializes this exemption mechanism with a key and a set of algorithm parameters.
protected abstract void	engineInit(Key key, AlgorithmParameterSpec params)	Initializes this exemption mechanism with a key and a set of algorithm parameters.

Methods declared in class Object

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

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
String	toString()	Answers a string containing a concise, human-readable description of the receiver.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Constructor Details

ExemptionMechanismSpi

public ExemptionMechanismSpi()

Constructor for subclasses to call.

Method Details

engineGetOutputSize

protected abstract int engineGetOutputSize(int inputLen)

Returns the length in bytes that an output buffer would need to be in order to hold the result of the next engineGenExemptionBlob operation, given the input length inputLen (in bytes).

The actual output length of the next engineGenExemptionBlob call may be smaller than the length returned by this method.

Parameters:

inputLen - the input length (in bytes)

Returns:

the required output buffer size (in bytes)

engineInit

protected abstract void engineInit(Key key)
                            throws InvalidKeyException,
ExemptionMechanismException

Initializes this exemption mechanism with a key.

If this exemption mechanism requires any algorithm parameters that cannot be derived from the given key, the underlying exemption mechanism implementation is supposed to generate the required parameters itself (using provider-specific default values); in the case that algorithm parameters must be specified by the caller, an InvalidKeyException is raised.

Parameters:

key - the key for this exemption mechanism

Throws:

InvalidKeyException - if the given key is inappropriate for this exemption mechanism.

ExemptionMechanismException - if problem(s) encountered in the process of initializing.

engineInit

protected abstract void engineInit(Key key,
 AlgorithmParameterSpec params)
                            throws InvalidKeyException,
InvalidAlgorithmParameterException,
ExemptionMechanismException

Initializes this exemption mechanism with a key and a set of algorithm parameters.

If this exemption mechanism requires any algorithm parameters and params is null, the underlying exemption mechanism implementation is supposed to generate the required parameters itself (using provider-specific default values); in the case that algorithm parameters must be specified by the caller, an InvalidAlgorithmParameterException is raised.

Parameters:

key - the key for this exemption mechanism

params - the algorithm parameters

Throws:

InvalidKeyException - if the given key is inappropriate for this exemption mechanism.

InvalidAlgorithmParameterException - if the given algorithm parameters are inappropriate for this exemption mechanism.

ExemptionMechanismException - if problem(s) encountered in the process of initializing.

engineInit

protected abstract void engineInit(Key key,
 AlgorithmParameters params)
                            throws InvalidKeyException,
InvalidAlgorithmParameterException,
ExemptionMechanismException

Initializes this exemption mechanism with a key and a set of algorithm parameters.

If this exemption mechanism requires any algorithm parameters and params is null, the underlying exemption mechanism implementation is supposed to generate the required parameters itself (using provider-specific default values); in the case that algorithm parameters must be specified by the caller, an InvalidAlgorithmParameterException is raised.

Parameters:

key - the key for this exemption mechanism

params - the algorithm parameters

Throws:

InvalidKeyException - if the given key is inappropriate for this exemption mechanism.

InvalidAlgorithmParameterException - if the given algorithm parameters are inappropriate for this exemption mechanism.

ExemptionMechanismException - if problem(s) encountered in the process of initializing.

engineGenExemptionBlob

protected abstract byte[] engineGenExemptionBlob()
                                          throws ExemptionMechanismException

Generates the exemption mechanism key blob.

Returns:

the new buffer with the result key blob.

Throws:

ExemptionMechanismException - if problem(s) encountered in the process of generating.

engineGenExemptionBlob

protected abstract int engineGenExemptionBlob(byte[] output,
 int outputOffset)
                                       throws ShortBufferException,
ExemptionMechanismException

Generates the exemption mechanism key blob, and stores the result in the output buffer, starting at outputOffset inclusive.

If the output buffer is too small to hold the result, a ShortBufferException is thrown. In this case, repeat this call with a larger output buffer. Use engineGetOutputSize to determine how big the output buffer should be.

Parameters:

output - the buffer for the result

outputOffset - the offset in output where the result is stored

Returns:

the number of bytes stored in output

Throws:

ShortBufferException - if the given output buffer is too small to hold the result.

ExemptionMechanismException - if problem(s) encountered in the process of generating.