Added in API level 1

Summary: Ctors | Protected Methods | Inherited Methods

ExemptionMechanismSpi

public abstract class ExemptionMechanismSpi
extends Object

java.lang.Object
↳	javax.crypto.ExemptionMechanismSpi

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.

Summary

Public constructors
`ExemptionMechanismSpi()`

Protected methods
`abstract byte[]`	`engineGenExemptionBlob()` Generates the exemption mechanism key blob.
`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.
`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).
`abstract void`	`engineInit(Key key)` Initializes this exemption mechanism with a key.
`abstract void`	`engineInit(Key key, AlgorithmParameterSpec params)` Initializes this exemption mechanism with a key and a set of algorithm parameters.
`abstract void`	`engineInit(Key key, AlgorithmParameters params)` Initializes this exemption mechanism with a key and a set of algorithm parameters.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Public constructors

ExemptionMechanismSpi

Added in API level 1

public ExemptionMechanismSpi ()

Protected methods

engineGenExemptionBlob

Added in API level 1

protected abstract byte[] engineGenExemptionBlob ()

Generates the exemption mechanism key blob.

Returns
`byte[]`	the new buffer with the result key blob.

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

engineGenExemptionBlob

Added in API level 1

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.

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`	`byte`: the buffer for the result
`outputOffset`	`int`: the offset in `output` where the result is stored

Returns
`int`	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.

engineGetOutputSize

Added in API level 1

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`	`int`: the input length (in bytes)

Returns
`int`	the required output buffer size (in bytes)

engineInit

Added in API level 1

protected abstract void engineInit (Key key)

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`	`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

Added in API level 1

protected abstract void engineInit (Key key, 
                AlgorithmParameterSpec params)

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`	`Key`: the key for this exemption mechanism
`params`	`AlgorithmParameterSpec`: 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

Added in API level 1

protected abstract void engineInit (Key key, 
                AlgorithmParameters params)

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

Parameters
`key`	`Key`: the key for this exemption mechanism
`params`	`AlgorithmParameters`: 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.