Quadcap Embeddable Database

com/quadcap/crypto/AbstractSymmetricKey.java

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package com.quadcap.crypto;

/* Copyright 2002 - 2003 Quadcap Software.  All rights reserved.
 *
 * This software is distributed under the Quadcap Free Software License.
 * This software may be used or modified for any purpose, personal or
 * commercial.  Open Source redistributions are permitted.  Commercial
 * redistribution of larger works derived from, or works which bundle
 * this software requires a "Commercial Redistribution License"; see
 * http://www.quadcap.com/purchase.
 *
 * Redistributions qualify as "Open Source" under  one of the following terms:
 *   
 *    Redistributions are made at no charge beyond the reasonable cost of
 *    materials and delivery.
 *
 *    Redistributions are accompanied by a copy of the Source Code or by an
 *    irrevocable offer to provide a copy of the Source Code for up to three
 *    years at the cost of materials and delivery.  Such redistributions
 *    must allow further use, modification, and redistribution of the Source
 *    Code under substantially the same terms as this license.
 *
 * Redistributions of source code must retain the copyright notices as they
 * appear in each source code file, these license terms, and the
 * disclaimer/limitation of liability set forth as paragraph 6 below.
 *
 * Redistributions in binary form must reproduce this Copyright Notice,
 * these license terms, and the disclaimer/limitation of liability set
 * forth as paragraph 6 below, in the documentation and/or other materials
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 *
 * The Software is provided on an "AS IS" basis.  No warranty is
 * provided that the Software is free of defects, or fit for a
 * particular purpose.  
 *
 * Limitation of Liability. Quadcap Software shall not be liable
 * for any damages suffered by the Licensee or any third party resulting
 * from use of the Software.
 */

import java.util.Random;

import java.nio.ByteBuffer;

/**
 * Base class for symmetric ciphers
 *
 * @author Stan Bailes
 */
public abstract class AbstractSymmetricKey implements SymmetricKey {
    /**
     * Initialize key from serialized representation
     */
    public abstract void init(String s) throws Exception;

    /**
     * Initialize: Create a random key
     */
    public abstract void init(Random r);

    /**
     * The key's block size
     */
    public abstract int getBlockSize();

    /**
     * Class wrapper for encryption as a key operation
     */
    class EncryptionKey implements Key {
        public void f(ByteBuffer m, ByteBuffer c) {
            encrypt(m, c);
        }
        public int blockSize() { return getBlockSize(); }
    }
    protected EncryptionKey ekey = new EncryptionKey();

    /**
     * Return the key used for decryption
     */
    public Key getEncryptionKey() { return ekey; }

    /**
     * Encrypt a buffer (must be multiple of 8 bytes)
     */
    public abstract void encrypt(ByteBuffer plain, ByteBuffer code);

    /**
     * Class wrapper for decryption as a key operation
     */
    class DecryptionKey implements Key {
        AbstractSymmetricKey            k = null;
        public DecryptionKey(AbstractSymmetricKey k) {
            this.k = k;
        }
        public int blockSize() { return getBlockSize(); }
        public void f(ByteBuffer m, ByteBuffer c) {
            if (k == null) {
                decrypt(m, c);
            } else {
                k.decrypt(m, c);
            }
        }
    }
    protected DecryptionKey dkey = new DecryptionKey(this);

    /**
     * Return the key used for encryption
     */
    public Key getDecryptionKey() { return dkey; }

    /**
     * Decrypt a buffer (must be a multiple of 8 bytes)
     */
    public abstract void decrypt(ByteBuffer code, ByteBuffer plain);

}