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.
Public Constructor Summary
Protected Method Summary
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 | |
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 Method Summary
Public Constructors
public ExemptionMechanismSpi ()
Protected Methods
protected abstract byte[] engineGenExemptionBlob ()
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. |
---|
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 | 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. |
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)
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 | 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. |
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 | 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. |
protected abstract void engineInit (Key key, AlgorithmParameters 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 | 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. |