/* * Copyright (c) 1999, 2007, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * 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). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ 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;}