001/* ExemptionMechanismSpi.java -- Exemption mechanism service provider interface.
002   Copyright (C) 2004  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package javax.crypto;
040
041import java.security.AlgorithmParameters;
042import java.security.InvalidAlgorithmParameterException;
043import java.security.InvalidKeyException;
044import java.security.Key;
045import java.security.spec.AlgorithmParameterSpec;
046
047/**
048 * The <i>Service Provider Interface</i> (<b>SPI</b>) for the {@link
049 * ExemptionMechanism} class.
050 *
051 * @author Casey Marshall (csm@gnu.org)
052 * @since 1.4
053 */
054public abstract class ExemptionMechanismSpi
055{
056
057  // Constructor.
058  // ------------------------------------------------------------------------
059
060  /**
061   * Create a new exemption mechanism SPI.
062   */
063  public ExemptionMechanismSpi()
064  {
065  }
066
067  // Abstract instance methods.
068  // ------------------------------------------------------------------------
069
070  /**
071   * Return a key blob for the key that this mechanism was initialized
072   * with.
073   *
074   * @return The key blob.
075   * @throws javax.crypto.ExemptionMechanismException If generating the
076   *         blob fails.
077   */
078  protected abstract byte[] engineGenExemptionBlob()
079    throws ExemptionMechanismException;
080
081  /**
082   * Generate a key blob for the key that this mechanism was initialized
083   * with, storing it into the given byte array.
084   *
085   * @param output       The destination for the key blob.
086   * @param outputOffset The index in the output array to start.
087   * @return The size of the key blob.
088   * @throws javax.crypto.ExemptionMechanismException If generating the
089   *         blob fails.
090   * @throws javax.crypto.ShortBufferException If the output array is
091   *         not large enough for the key blob.
092   */
093  protected abstract int engineGenExemptionBlob(byte[] output, int outputOffset)
094    throws ExemptionMechanismException, ShortBufferException;
095
096  /**
097   * Get the size of the output blob given an input key size. The actual
098   * blob may be shorter than the value returned by this method. Both
099   * values are in bytes.
100   *
101   * @param inputLength The input size.
102   * @return The output size.
103   */
104  protected abstract int engineGetOutputSize(int inputLength);
105
106  /**
107   * Initialize this mechanism with a key.
108   *
109   * @param key The key.
110   * @throws javax.crypto.ExemptionMechanismException If generating the
111   *         blob fails.
112   * @throws java.security.InvalidKeyException If the supplied key
113   *         cannot be used.
114   */
115  protected abstract void engineInit(Key key)
116    throws ExemptionMechanismException, InvalidKeyException;
117
118  /**
119   * Initialize this mechanism with a key and parameters.
120   *
121   * @param key    The key.
122   * @param params The parameters.
123   * @throws javax.crypto.ExemptionMechanismException If generating the
124   *         blob fails.
125   * @throws java.security.InvalidAlgorithmParameterExceptin If the
126   *         supplied parameters are inappropriate.
127   * @throws java.security.InvalidKeyException If the supplied key
128   *         cannot be used.
129   */
130  protected abstract void engineInit(Key key, AlgorithmParameters params)
131    throws ExemptionMechanismException, InvalidAlgorithmParameterException,
132           InvalidKeyException;
133
134  /**
135   * Initialize this mechanism with a key and parameters.
136   *
137   * @param key    The key.
138   * @param params The parameters.
139   * @throws javax.crypto.ExemptionMechanismException If generating the
140   *         blob fails.
141   * @throws java.security.InvalidAlgorithmParameterExceptin If the
142   *         supplied parameters are inappropriate.
143   * @throws java.security.InvalidKeyException If the supplied key
144   *         cannot be used.
145   */
146  protected abstract void engineInit(Key key, AlgorithmParameterSpec params)
147    throws ExemptionMechanismException, InvalidAlgorithmParameterException,
148           InvalidKeyException;
149}