001    /* Key.java -- A abstract representation of a digital key
002       Copyright (C) 1998, 2000, 2002, 2005  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    package java.security;
039    
040    import 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     */
062    public 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