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* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
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*
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
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package javax.crypto;
import java.security.Key;
import java.security.AlgorithmParameters;
import java.security.InvalidKeyException;
import java.security.InvalidAlgorithmParameterException;
import java.security.spec.AlgorithmParameterSpec;
/**
* This class defines the <i>Service Provider Interface</i> (<b>SPI</b>)
* for the <code>ExemptionMechanism</code> 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.
*
* @author Sharon Liu
*
* @since 1.4
*/
public abstract class ExemptionMechanismSpi {
/**
* Returns the length in bytes that an output buffer would need to be in
* order to hold the result of the next
* {@link #engineGenExemptionBlob(byte[], int) engineGenExemptionBlob}
* operation, given the input length <code>inputLen</code> (in bytes).
*
* <p>The actual output length of the next
* {@link #engineGenExemptionBlob(byte[], int) engineGenExemptionBlob}
* call may be smaller than the length returned by this method.
*
* @param inputLen the input length (in bytes)
*
* @return the required output buffer size (in bytes)
*/
protected abstract int engineGetOutputSize(int inputLen);
/**
* Initializes this exemption mechanism with a key.
*
* <p>If this exemption mechanism requires any algorithm parameters
* that cannot be derived from the given <code>key</code>, 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
* <code>InvalidKeyException</code> is raised.
*
* @param key the key for this exemption mechanism
*
* @exception InvalidKeyException if the given key is inappropriate for
* this exemption mechanism.
* @exception ExemptionMechanismException if problem(s) encountered in the
* process of initializing.
*/
protected abstract void engineInit(Key key)
throws InvalidKeyException, ExemptionMechanismException;
/**
* Initializes this exemption mechanism with a key and a set of algorithm
* parameters.
*
* <p>If this exemption mechanism requires any algorithm parameters and
* <code>params</code> 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
* <code>InvalidAlgorithmParameterException</code> is raised.
*
* @param key the key for this exemption mechanism
* @param params the algorithm parameters
*
* @exception InvalidKeyException if the given key is inappropriate for
* this exemption mechanism.
* @exception InvalidAlgorithmParameterException if the given algorithm
* parameters are inappropriate for this exemption mechanism.
* @exception ExemptionMechanismException if problem(s) encountered in the
* process of initializing.
*/
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.
*
* <p>If this exemption mechanism requires any algorithm parameters
* and <code>params</code> 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
* <code>InvalidAlgorithmParameterException</code> is raised.
*
* @param key the key for this exemption mechanism
* @param params the algorithm parameters
*
* @exception InvalidKeyException if the given key is inappropriate for
* this exemption mechanism.
* @exception InvalidAlgorithmParameterException if the given algorithm
* parameters are inappropriate for this exemption mechanism.
* @exception ExemptionMechanismException if problem(s) encountered in the
* process of initializing.
*/
protected abstract void engineInit(Key key, AlgorithmParameters params)
throws InvalidKeyException, InvalidAlgorithmParameterException,
ExemptionMechanismException;
/**
* Generates the exemption mechanism key blob.
*
* @return the new buffer with the result key blob.
*
* @exception ExemptionMechanismException if problem(s) encountered in the
* process of generating.
*/
protected abstract byte[] engineGenExemptionBlob()
throws ExemptionMechanismException;
/**
* Generates the exemption mechanism key blob, and stores the result in
* the <code>output</code> buffer, starting at <code>outputOffset</code>
* inclusive.
*
* <p>If the <code>output</code> buffer is too small to hold the result,
* a <code>ShortBufferException</code> is thrown. In this case, repeat this
* call with a larger output buffer. Use
* {@link #engineGetOutputSize(int) engineGetOutputSize} to determine
* how big the output buffer should be.
*
* @param output the buffer for the result
* @param outputOffset the offset in <code>output</code> where the result
* is stored
*
* @return the number of bytes stored in <code>output</code>
*
* @exception ShortBufferException if the given output buffer is too small
* to hold the result.
* @exception ExemptionMechanismException if problem(s) encountered in the
* process of generating.
*/
protected abstract int engineGenExemptionBlob
(byte[] output, int outputOffset)
throws ShortBufferException, ExemptionMechanismException;
}