rc4keyspec.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: RC4KeySpec.java,v 1.4 1998/10/05 05:47:56 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/RC4KeySpec.java,v $
 * $Revision: 1.4 $
 * $Date: 1998/10/05 05:47:56 $
 * $State: Exp $
 */

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

/**
 * A class that provides a specification for a RC4 key.
 */
public class RC4KeySpec implements KeySpec
{
	public final static String ident = "$Id: RC4KeySpec.java,v 1.4 1998/10/05 05:47:56 dgh Exp $";

	private byte[]	rc4Key;

	/**
	 * Uses the first 16 bytes in key as the RC4 key 
	 *
	 * @param key	the bytes making up the key.
	 * @exception InvalidKeyException if the key material is too short.
	 */
	public RC4KeySpec(
		byte[]	key)
		throws InvalidKeyException
	{
		this(key, 0, 16);
	}
	/**
	 * Uses the first len bytes in key as the RC4 key 
	 *
	 * @param key	the bytes making up the key.
	 * @param len	the size (in bytes) of the key.
	 * @exception InvalidKeyException if the key material is too short.
	 */
	public RC4KeySpec(
		byte[]	key,
		int	len)
		throws InvalidKeyException
	{
		this(key, 0, len);
	}
	/**
	 * Uses the first len bytes in key, beginning at offset, as the RC4 key
	 *
	 * @param key		the bytes making up the key.
	 * @param offset	the offset to start copying the key material.
	 * @param len		the size (in bytes) of the key.
	 * @exception InvalidKeyException if the key material is too short.
	 */
	public RC4KeySpec(
		byte[]	key,
		int	offset,
		int	len)
		throws InvalidKeyException
	{
		if (key.length - offset < len)
		{
			throw new InvalidKeyException("Key too short");
		}
		rc4Key = new byte[len];
		System.arraycopy(key, offset, rc4Key, 0, len);
	}
	/**
	 * Returns the RC4 key.
	 *
	 * @return the bytes making up the key.
	 */
	public byte[] getKey()
	{
		return rc4Key;
	}
}