001/* SecretKeyFactorySpi.java -- Secret key factory 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.InvalidKeyException;
042import java.security.spec.InvalidKeySpecException;
043import java.security.spec.KeySpec;
044
045/**
046 * The <i>Service Provider Interface</i> (<b>SPI</b>) for the {@link
047 * SecretKeyFactory} class.
048 *
049 * <p>Providers wishing to implement a secret key factory must
050 * subclass this and provide an appropriate implementation for all the
051 * abstract methods below, and provide an appropriate entry in the
052 * master {@link java.security.Provider} class (the service name for
053 * secret key factories is <code>"SecretKeyFactory"</code>).
054 *
055 * @author Casey Marshall (csm@gnu.org)
056 * @since 1.4
057 * @see SecretKeyFactory
058 */
059public abstract class SecretKeyFactorySpi
060{
061
062  // Constructor.
063  // ------------------------------------------------------------------------
064
065  /**
066   * Create a new secret key factory SPI.
067   */
068  public SecretKeyFactorySpi()
069  {
070  }
071
072  // Abstract instance methods.
073  // ------------------------------------------------------------------------
074
075  /**
076   * Translate a {@link java.security.KeySpec} into a {@link SecretKey}.
077   *
078   * @param keySpec The key specification.
079   * @return The secret key.
080   * @throws java.security.spec.InvalidKeySpecException If the key specification
081   *         cannot be translated into a secret key.
082   */
083  protected abstract SecretKey engineGenerateSecret(KeySpec keySpec)
084    throws InvalidKeySpecException;
085
086  /**
087   * Translate a {@link SecretKey} into a {@link java.security.KeySpec}.
088   *
089   * @param key     The secret key.
090   * @param keySpec The desired key specification class.
091   * @return The key specification.
092   * @throws java.security.spec.InvalidKeySpecException If the secret key cannot
093   *         be translated into the desired key specification.
094   */
095  protected abstract KeySpec engineGetKeySpec(SecretKey key, Class keySpec)
096    throws InvalidKeySpecException;
097
098  /**
099   * Translate a secret key into a different representation.
100   *
101   * @param key The secret key to translate.
102   * @return The translated key.
103   * @throws java.security.InvalidKeyException If the specified secret
104   *         key cannot be translated.
105   */
106  protected abstract SecretKey engineTranslateKey(SecretKey key)
107    throws InvalidKeyException;
108}