digesttool.java

jxta平台的开发包

/*
 * Copyright (c) 2001 Sun Microsystems, Inc.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *       Sun Microsystems, Inc. for Project JXTA."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact Project JXTA at http://www.jxta.org.
 *
 * 5. Products derived from this software may not be called "JXTA",
 *    nor may "JXTA" appear in their name, without prior written
 *    permission of Sun.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL SUN MICROSYSTEMS OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Project JXTA.  For more
 * information on Project JXTA, please see
 * <http://www.jxta.org/>.
 *
 * This license is based on the BSD license adopted by the Apache Foundation.
 *
 * $Id: DigestTool.java,v 1.7 2006/07/20 19:23:35 bondolo Exp $
 */

package net.jxta.impl.id.binaryID;

/**
 */
import net.jxta.impl.id.binaryID.*;
import java.io.*;
import org.apache.log4j.Logger;
import org.apache.log4j.Level;

import java.security.*;

/**
 * This is a utility class used to create pipe advertisement named and BinaryID for the pipeID to create
 * a private address space that can be hosted in the public discovery system or sent over unencrypted
 * channeds without revealing their intent or purpose. <p>
 *
 * We use a one-way hashing algorythum to create an ID from private information like
 * a user's social security number or a user's email address.
 * We search for the pipe by with this private information securly by creating the
 * matching hash using the same methods. <p>
 *
 * The purpose of this system is to create a way to search
 * for a pipe (or other BinaryID based system) without exposing the
 * pipe owner's clearTextID while allowing for  people that
 * know what they are looking for to find the right pipe. The
 * system also has the ability to create pipes that have a specific purpose.
 * For example, the email address is appended with a function name. Say you
 * have a pipe for messages and one for administrative purposes. You would
 * supply the email and a string for the function. The same combination can be
 * created by another peer to search for either of these pipes. <p>
 *
 * This implementation uses the "SHA-1" algorythum. This was selected for relitive
 * speed. It is used as a one-way conversion that cannot be reversed engineered to
 * create the original string. This allows you to publish the hash without the
 * possibility of the contents being decoded. This allows for public indexing of
 * data that is only known by the parties involved.<p>
 *
 * Note that this can also be used to generate safe password verification hash codes.
 *Sample useage:
 *<code>
 *        String clearTextID = "[e-mail]";
 *        String function = "eventPipe";
 *        System.out.println("clear text ID: "+clearTextID);
 *        System.out.println("function text: "+function);
 *        String digest1 = DigestID.generateHashString(clearTextID, function);
 *        String digest2 = DigestID.generateHashString(clearTextID);
 *        System.out.println("Digest1: '"+digest1+"'");
 *        System.out.println("Digest2: '"+digest2+"'");
 *        System.out.println("test1: "+DigestID.test(clearTextID, function,digest1));
 *        System.out.println("test2: "+DigestID.test(clearTextID, digest2));
 *        System.out.println("Digest1 != Digest2: "+DigestID.test(clearTextID, function,digest2));
 *</code><p>
 *
 * To use an algorythum other than SHA-1, you will need stronger encyption.
 * The BouncyCastle that comes with JXTA is just a minimum implimentation so
 * a good choice is  the normal bouncy castle (it is much larger, nearing a meg,
 * which is why it is not a part of the normal JXTA distribution. The full version
 * of bouncy includes SHA-128, SHA-256, SHA-384, and SHA-512.<p>
 * 
 * Here is how you create a provider from the full version of Bouncy. Once you do this, you can access the extended
 * Digest ecryption levels. 
 *<code>
 *       provider = new org.bouncycastle.jce.provider.BouncyCastleProvider();
 *       System.out.println("provider:"+provider.getName());
 *       Security.addProvider(provider);
 *</code><p>
 * Security Note<p>
 *<p>
 * This class should have all of its fields and properties marked as 'final' to prevent overriding the default behavior.
 * Failure to do so could allow a less scrupulous person to cause the BinaryID or hash codes to contain the original information.
 * Note that the class itself is not final to allow for additional convienience methods to be added. There
 * a no methods for creating ModuleClassBinaryID, ModuleSpecBinaryID, or CodatID because this is meant for general'
 * use, not for extending platform (you can write your own using similar code). <p>
 *
 * @version $Revision: 1.7 $
 * @author Daniel Brookshier <a HREF="mailto:[e-mail]">[e-mail]</a>
 */
public class DigestTool {
    private final static transient Logger LOG = Logger.getLogger(DigestTool.class.getName());
    /** varaible used for conditional compile of debug printing.*/
    public  static final boolean debug = true;
    /** Defualt SHA-1 digest algorithm type. This is a 20 byte hash function (note: that MD5 is only 16 so we don't use it). */
    public  static final String SHAOne  = "SHA-1";
    /** SHA-128 digest algorithm type. This is a 128 bit hash function (note: must have another provider registered to use). */
    public  static final String SHA128  = "SHA-128";
    /** SHA-256 digest algorithm type. This is a 256 bit hash function (note: must have another provider registered to use). */
    public  static final String SHA256  = "SHA-256";
    /** SHA-384 digest algorithm type. This is a 384 bit hash function (note: must have another provider registered to use). */
    public  static final String SHA384  = "SHA-384";
    /** SHA-512 digest algorithm type. This is a 512 bit hash function (note: must have another provider registered to use). */
    public  static final String SHA512  = "SHA-512";
    /** Tilde character used to seperate candidate strings from a function.*/
    public  final String functionSeperator = "~";
    String algorithmType;
    public DigestTool(){
        algorithmType=SHAOne;
    }
    public DigestTool(String algorithmType){
        this.algorithmType = algorithmType;
    }
     
    /** 
     * Create a PipeID based on the BinaryID type with a digest of the clearTextID and function.
     * 
     * @param peerGroupID Parent peer group ID.
     * @param clearTextID String used as the significant part of the address
     * @param function String used to diferentiate different clearTextID addresses (can be null).
     * @return PipeBinaryID with the digest hash of the string: clearTextID+"~"+function.
     */
    public final PipeBinaryID createPipeID(net.jxta.peergroup.PeerGroupID peerGroupID,String clearTextID, String function){
        byte[] digest = generateHash(clearTextID, function); 
        PipeBinaryID pipe = new PipeBinaryID(peerGroupID,digest,false); 
        return pipe;
    }
    /** 
     * Create a PeerGroupID based on the BinaryID type with a digest of the clearTextID and function.
     * 
     * @param peerGroupID Parent peer group ID.
     * @param clearTextID String used as the significant part of the address
     * @param function String used to diferentiate different clearTextID addresses (can be null).
     * @return PeerGroupBinaryID with the digest hash of the string: clearTextID+"~"+function.
     */
    public final PeerGroupBinaryID createPeerGroupID(net.jxta.peergroup.PeerGroupID parentPeerGroupID,String clearTextID, String function){
        byte[] digest = generateHash(clearTextID, function); 
        PeerGroupBinaryID peerGroupID = new PeerGroupBinaryID(parentPeerGroupID,digest,false); 
        return peerGroupID;
    }
    /** 
     * Create a PeerID based on the BinaryID type with a digest of the clearTextID and function.
     * 
     * @param peerGroupID Parent peer group ID.
     * @param clearTextID String used as the significant part of the address
     * @param function String used to diferentiate different clearTextID addresses (can be null).
     * @return PeerBinaryID with the digest hash of the string: clearTextID+"~"+function.
     */