blowfishkeygenerator.java

面向应用的智能安全代理平台和工具包是一个综合网络应用的安全共性需求而设计和实现的一个通用性的网络信息安全应用支撑平台

package au.net.aba.crypto.provider;

/*
 * $Id: BlowfishKeyGenerator.java,v 1.5 1998/10/27 05:10:54 leachbj Exp $
 * $Author: leachbj $
 *
 * Copyright (C) 1996-1998 Australian Business Access Pty Ltd.
 * All rights reserved.         
 *       
 * Use, modification, copying and distribution of this software is subject the
 * terms and conditions of the ABA Public Licence. See the file
 * "PUBLIC_LICENCE" for additional information.
 *
 * If you have not received a copy of the Public Licence, you must destroy all
 * copies of this file immediately. 
 *
 * $Source: /aba/CVSROOT/jdk1.1/src/au.net.aba/crypto/provider/BlowfishKeyGenerator.java,v $
 * $Revision: 1.5 $
 * $Date: 1998/10/27 05:10:54 $
 * $State: Exp $
 */
import java.security.InvalidAlgorithmParameterException;
import java.security.spec.AlgorithmParameterSpec;
import java.security.SecureRandom;
import javax.crypto.KeyGeneratorSpi;
import javax.crypto.SecretKey;

/**
 * This class is used for generating random Blowfish keys.  This class
 * should not be instantiated directly, instead use the
 * javax.crypto.KeyGenerator interface.
 * <p>
 * There is no AlgorithmParameterSpec class defined for Blowfish so this
 * generator can only be initialised using the keysize,random
 * initialisation.
 * <p>
 * The default keysize is 192 bits and can be any multiple of 8 up to
 * 448 bits.
 */
public class BlowfishKeyGenerator extends KeyGeneratorSpi
{
	public final static String ident = "$Id: BlowfishKeyGenerator.java,v 1.5 1998/10/27 05:10:54 leachbj Exp $";

	static final int	DEF_KEY_SIZE = 192;		/* standard key size in bits */

	private SecureRandom		rand;
	private int			strength = DEF_KEY_SIZE;

	/**
	 * Generates a random secret key of the currently configured
	 * keysize and using the configured random source.
	 *
	 * @return a secret key representing a Blowfish key.
	 */
	protected SecretKey engineGenerateKey()
	{
		byte[]		bytes;

		bytes = new byte[(strength + 7) / 8];

		if (rand == null)
		{
			rand = new SecureRandom();
		}

		rand.nextBytes(bytes);

		return new BlowfishKey(bytes);
	}
	/**
	 * Initialises this key generator for a certain strength, using the
	 * given source of randomness.
	 *
	 * @param strength the strength of the key. This is an
	 *    algorithm-specific metric specified in number of bits.
	 * @param random the source of randomness for this key generator
	 */
	protected void engineInit(
			int             strength,
			SecureRandom    random)
	{
		this.strength = strength;
		this.rand = random;
	}
	/**
	 * Initialises the key generator with the given random number source.
	 *
	 * @param random        a source of random numbers for this generator.
	 */
	protected void engineInit(
		SecureRandom	random)
	{
		rand = random;
	}
	/**
	 * This method is not implemented as there is no AlgorithmParameterSpec
	 * defined for Blowfish.  (Use one of the other initialisation methods!)
	 *
	 * @param params	The algorithm parameter specs for this
	 * 	generator.
	 * @param random	A source of random numbers for this generator.
	 * @exception InvalidAlgorithmParameterException	An invalid
	* 	parameter specification is provided.
	 */
	protected void engineInit(
		AlgorithmParameterSpec	params,
		SecureRandom		random)
		throws InvalidAlgorithmParameterException
	{
		throw new InvalidAlgorithmParameterException("Not Implemented");
	}
}