blowfishkeyspec.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.spec;

/*
 * $Id: BlowfishKeySpec.java,v 1.3 1998/10/05 05:47:54 dgh Exp $
 * $Author: dgh $
 *
 * 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/spec/BlowfishKeySpec.java,v $
 * $Revision: 1.3 $
 * $Date: 1998/10/05 05:47:54 $
 * $State: Exp $
 */

import java.security.spec.KeySpec;
import java.security.InvalidKeyException;

/**
 * A class that provides a specification for a Blowfish key.
 */
public class BlowfishKeySpec implements KeySpec
{
	public final static String ident = "$Id: BlowfishKeySpec.java,v 1.3 1998/10/05 05:47:54 dgh Exp $";

	private byte[]	bfKey;

	private static int MAXBFKEY_LENGTH = 56;
	private static int MINBFKEY_LENGTH = 16;

	/**
	 * Uses the first 56 bytes (if available) as the key, starting at 0
	 *
	 * @param key	the byte array to use as key material.
	 * @exception InvalidKeyException if the key material is too short.
	 */
	public BlowfishKeySpec(
		byte[]	key)
		throws InvalidKeyException
	{
		this(key, 0);
	}
	/**
	 * Uses the first 56 bytes (if available) in key, beginning at offset,
	 * as the Blowfish key
	 *
	 * @param key		the byte array to use as key material.
	 * @param offset	the offset to start at.
	 * @exception InvalidKeyException if the key material is too short.
	 */
	public BlowfishKeySpec(
		byte[]	key,
		int	offset)
		throws InvalidKeyException
	{
		int a = key.length - offset; // available bytes

		if (a < MINBFKEY_LENGTH)
		{
			throw new InvalidKeyException(
				"Key too short (min "
				+ MINBFKEY_LENGTH + " bytes)");
		}
		else if (a > MAXBFKEY_LENGTH)
		{
			a = MAXBFKEY_LENGTH;
		}
		bfKey = new byte[a];
		System.arraycopy(key, offset, bfKey, 0, a);
	}
	/**
	 * Returns the Blowfish key.
	 *
	 * @return the bytes making up the key.
	 */
	public byte[] getKey()
	{
		return bfKey;
	}
}