001    /* SecretKeyFactorySpi.java -- Secret key factory service provider interface.
002       Copyright (C) 2004  Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package javax.crypto;
040    
041    import java.security.InvalidKeyException;
042    import java.security.spec.InvalidKeySpecException;
043    import 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     */
059    public 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    }