001/* Key.java -- A abstract representation of a digital key
002   Copyright (C) 1998, 2000, 2002, 2005  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
038package java.security;
039
040import java.io.Serializable;
041
042/**
043 * This interfaces models the base characteristics that all keys must
044 * have.  These are:  a key algorithm, an encoded form, and a format used
045 * to encode the key.  Specific key types inherit from this interface.
046 * Note that since this interface extends <code>Serializable</code>, all
047 * keys may be serialized. Keys are generally obtained through key generators,
048 * including {@link KeyFactory}.
049 *
050 * @author Aaron M. Renn (arenn@urbanophile.com)
051 * @see PublicKey
052 * @see PrivateKey
053 * @see KeyPair
054 * @see KeyPairGenerator
055 * @see KeyFactory
056 * @see KeySpec
057 * @see Identity
058 * @see Signer
059 * @since 1.1
060 * @status updated to 1.4
061 */
062public interface Key extends Serializable
063{
064  /**
065   * The version identifier used for serialization.
066   */
067  long serialVersionUID = 6603384152749567654L;
068
069  /**
070   * This method returns the name of the algorithm for this key.  This is a
071   * <code>String</code> such as "RSA".
072   *
073   * @return the name of the algorithm in use
074   */
075  String getAlgorithm();
076
077  /**
078   * This method returns the name of the encoding format for this key.  This
079   * is the name of the ASN.1 data format used for this key, such as
080   * "X.509" or "PKCS#8".  This method returns <code>null</code> if this key
081   * does not have an encoding format.
082   *
083   * @return the name of the encoding format for this key, or null
084   */
085  String getFormat();
086
087  /**
088   * This method returns the encoded form of the key.  If this key does not
089   * support encoding, this method returns <code>null</code>.
090   *
091   * @return the encoded form of the key, or null
092   */
093  byte[] getEncoded();
094} // interface Key