pbekeyfactory.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: PBEKeyFactory.java,v 1.3 1999/01/28 04:47:28 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/PBEKeyFactory.java,v $
 * $Revision: 1.3 $
 * $Date: 1999/01/28 04:47:28 $
 * $State: Exp $
 */

import javax.crypto.spec.PBEKeySpec;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;
import java.security.InvalidKeyException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactorySpi;

/**
 * This class is used to convert password based keys into a format
 * usable by the ABA provider.  This class can convert PBEKeySpec
 * objects into an ABA PBEKey and visa versa.
 * <p>
 * This class should not be instantiated directly, instead use the
 * java.security.KeyFactory interface.
 *
 * @see java.security.KeyFactory
 */
public class PBEKeyFactory extends SecretKeyFactorySpi
{
	public final static String ident = "$Id: PBEKeyFactory.java,v 1.3 1999/01/28 04:47:28 leachbj Exp $";

	/**
	 * Generates a PBE SecretKey object from the provided key specification
	 * (key material).  This class supports the PBEKeySpec KeySpec class.
	 *
	 * @returns The secret key.
	 * @exception InvalidKeySpecException  The provided KeySpec was not
	 * 	a PBEKeySpec KeySpec.
	 */
	protected SecretKey engineGenerateSecret(
		KeySpec keySpec)
		throws InvalidKeySpecException
	{
		if (keySpec == null || !(keySpec instanceof PBEKeySpec))
		{
			throw new InvalidKeySpecException("Invalid KeySpec");
		}

		char[] password = ((PBEKeySpec)keySpec).getPassword();
		
		return new PBEKey(password);
	}
	/**
	 * Returns a specification (key material) of the given key object in
	 * the requested format.  Currently only the PBEKeySpec KeySpec
	 * class is supported.
	 *
	 * @param key the key 
	 * @param keySpec the requested format in which the key material shall
	 *		be returned, must be PBEKeySpec.class
	 * @returns the underlying key specification (key material) in the
	 *		requested format
	 * @exception InvalidKeySpecException if the provided key
	 *	is not a PBEKey or the requested KeySpec is not a
	 * 	PBEKeySpec.
	 */
	protected KeySpec engineGetKeySpec(
		SecretKey key,
		Class keySpec)
		throws InvalidKeySpecException
	{
		if (key instanceof PBEKey)
		{
			if (keySpec.equals(PBEKeySpec.class))
			{
				PBEKey pbeKey = (PBEKey)key;
				
				return new PBEKeySpec(pbeKey.getPassword());
			}
		}

		throw new InvalidKeySpecException(
			"Unsupported KeySpec requested.");
	}
	/**
	 * Translates a PBE 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 SecretKey engineTranslateKey(
		SecretKey key)
		throws InvalidKeyException
	{
		if (!key.getAlgorithm().equals("PBE"))
		{
			throw new InvalidKeyException("not a PBE key");
		}
		
		// To do this requires translating bytes into chars!
		byte[] bytes = key.getEncoded();
		char[] pwd = new char[bytes.length];
		for (int i = 0; i < pwd.length; i++)
			pwd[i] = (char)bytes[i];
		return new PBEKey(pwd);
	}
}