dhkeyfactory.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: DHKeyFactory.java,v 1.8 1999/02/17 01:43:05 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/DHKeyFactory.java,v $
 * $Revision: 1.8 $
 * $Date: 1999/02/17 01:43:05 $
 * $State: Exp $
 */
import java.security.*;

import javax.crypto.interfaces.*;
import javax.crypto.spec.*;

import java.security.*;
import java.security.spec.*;

/**
 * This class is used to convert Diffie-Hellman keys into a format
 * usable by the ABA provider.  Currently this class can only convert
 * from a KeySpec into a Key.  The supported KeySpec classes are
 * DHPublicKeySpec and DHPrivateKeySpec.
 * <p>
 * Not currently finished.
 * <p>
 * This class should not be instantiated directly, instead use the
 * java.security.KeyFactory interface.
 *
 * @see java.security.KeyFactory
 */
public class DHKeyFactory extends KeyFactorySpi
{
	public final static String ident = "$Id: DHKeyFactory.java,v 1.8 1999/02/17 01:43:05 leachbj Exp $";

	/**
	 * Generates a Diffie-Hellman PrivateKey object from the provided key
	 * specification (key material).  This class supports the
	 * DHPrivateKeySpec KeySpec class.
	 *
	 * @returns The private key.
	 * @exception InvalidKeySpecException  The provided KeySpec was not
	 * 	a DHPrivateKeySpec KeySpec.
	 */
	protected PrivateKey engineGeneratePrivate(
		KeySpec		keySpec)
		throws InvalidKeySpecException
	{
		if (keySpec instanceof DHPrivateKeySpec)
		{
			DHPrivateKeySpec privKeySpec;

			privKeySpec = (DHPrivateKeySpec)keySpec;
			return new DHPrivKey(privKeySpec.getX(),
				privKeySpec.getP(), privKeySpec.getG());

		}

		throw new InvalidKeySpecException(
			"Bad key specification");
	}
	/**
	 * Generates a Diffie-Hellman PublicKey object from the provided key
	 * specification (key material).  This class supports the
	 * DHPublicKeySpec KeySpec class.
	 *
	 * @returns The private key.
	 * @exception InvalidKeySpecException  The provided KeySpec was not
	 * 	a DHPublicKeySpec KeySpec.
	 */
	protected PublicKey engineGeneratePublic(
		KeySpec	keySpec)
		throws InvalidKeySpecException
	{
		if (keySpec instanceof DHPublicKeySpec)
		{
			DHPublicKeySpec pubKeySpec;

			pubKeySpec = (DHPublicKeySpec)keySpec;
			return new DHPubKey(pubKeySpec.getY(),
				pubKeySpec.getP(), pubKeySpec.getG());
		}

		throw new InvalidKeySpecException(
			"Bad key specification");
	}
	/**
	 * Returns a specification (key material) of the given key object in
	 * the requested format. 
	 * <p>
	 * Currently supports standard DH keys, DHPublicKeySpec and
	 * DHPrivateKeySpec KeySpec classes.
	 *
	 * @param key the key 
	 * @param keySpec the requested format in which the key material shall
	 *		be returned 
	 * @returns the underlying key specification (key material) in the
	 *		requested format
	 * @exception InvalidKeySpecException if the requested key
	 *	specification is inappropriate for the given key, or the given
	 *	key cannot be dealt with (e.g., the given key has an
	 *	unrecognised format). 
	 */
	protected KeySpec engineGetKeySpec(
		Key	key,
		Class	spec)
		throws InvalidKeySpecException
	{
		if (key instanceof DHPublicKey)
		{
			if (DHPublicKeySpec.class.isAssignableFrom(spec))
			{
				DHPublicKey dh;
				DHParameterSpec params;

				dh = (DHPublicKey)key;
				params = dh.getParams();

				return new DHPublicKeySpec(dh.getY(),
					params.getP(), params.getG());
			}
		}
		else if (key instanceof DHPrivateKey)
		{
			if (DHPrivateKeySpec.class.isAssignableFrom(spec))
			{
				DHPrivateKey dh;
				DHParameterSpec params;

				dh = (DHPrivateKey)key;
				params = dh.getParams();

				return new DHPrivateKeySpec(dh.getX(),
					params.getP(), params.getG());
			}
		}

		throw new InvalidKeySpecException("Invalid Key or KeySpec.");
	}
	/**
	 * Translates a Diffie-Hellman key object, whose provider may be
	 * unknown or potentially untrusted, into a corresponding key
	 * object of this key factory.
	 *
	 * @param key - the key whose provider is unknown or untrusted 
	 * @returns the translated key 
	 * @exception InvalidKeyException if the given key cannot be processed
	 * 	by this key factory. 
	 */
	protected Key engineTranslateKey(
		Key	key)
		throws InvalidKeyException
	{
		return null;
	}
}