001/* KeyGeneratorSpi.java -- The key generator 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.InvalidAlgorithmParameterException;
042import java.security.SecureRandom;
043import java.security.spec.AlgorithmParameterSpec;
044
045/**
046 * The <i>Service Provider Interface</i> (<b>SPI</b>) for the {@link
047 * KeyGenerator} class.
048 *
049 * <p>Providers wishing to implement a key generator must subclass this
050 * and provide an appropriate implementation for all the abstract
051 * methods below, and provide an appropriate entry in the master {@link
052 * java.security.Provider} class (the service name for key generators is
053 * <code>"KeyGenerator"</code>).
054 *
055 * @author Casey Marshall (csm@gnu.org)
056 * @since 1.4
057 * @see KeyGenerator
058 */
059public abstract class KeyGeneratorSpi
060{
061
062  // Constructor.
063  // ------------------------------------------------------------------------
064
065  /** Create a new key generator SPI. */
066  public KeyGeneratorSpi()
067  {
068  }
069
070  // Abstract instance methods.
071  // ------------------------------------------------------------------------
072
073  /**
074   * Generate a key, returning it as a {@link SecretKey}.
075   *
076   * @return The generated key.
077   */
078  protected abstract SecretKey engineGenerateKey();
079
080  /**
081   * Initialize this key generator with parameters and a source of
082   * randomness.
083   *
084   * @param params The parameters.
085   * @param random The source of randomness.
086   * @throws java.security.InvalidAlgorithmParameterException If the
087   *         parameters are inappropriate for this instance.
088   */
089  protected abstract void engineInit(AlgorithmParameterSpec params,
090                                     SecureRandom random)
091    throws InvalidAlgorithmParameterException;
092
093  /**
094   * Initialize this key generator with a key size (in bits) and a
095   * source of randomness.
096   *
097   * @param keySize The target key size, in bits.
098   * @param random  The source of randomness.
099   * @throws java.security.InvalidParameterException If the
100   *         key size is illogical or unsupported.
101   */
102  protected abstract void engineInit(int keySize, SecureRandom random);
103
104  /**
105   * Initialize this key generator with a source of randomness; the
106   * implementation should use reasonable default parameters (such as
107   * generated key size).
108   *
109   * @param random The source of randomness.
110   */
111  protected abstract void engineInit(SecureRandom random);
112}