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
Constructor | Description |
---|---|
ExemptionMechanismSpi() |
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 |
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 |
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 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Constructor Detail
ExemptionMechanismSpi
public ExemptionMechanismSpi()
Method Detail
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 inoutput
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.