org.eclipse.jetty.websocket.common.AcceptHash Maven / Gradle / Ivy

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//
//  ========================================================================
//  Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//

package org.eclipse.jetty.websocket.common;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;

import org.eclipse.jetty.util.B64Code;
import org.eclipse.jetty.util.StringUtil;

/**
 * Logic for working with the Sec-WebSocket-Key and Sec-WebSocket-Accept headers.
 * 
 * This is kept separate from Connection objects to facilitate difference in behavior between client and server, as well as making testing easier.
 */
public class AcceptHash
{
    /**
     * Globally Unique Identifier for use in WebSocket handshake within Sec-WebSocket-Accept and Sec-WebSocket-Key http headers.
     * 
     * See Opening Handshake (Section 1.3)
     */
    private final static byte[] MAGIC;

    static
    {
        try
        {
            MAGIC = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11".getBytes(StringUtil.__ISO_8859_1);
        }
        catch (UnsupportedEncodingException e)
        {
            throw new RuntimeException(e);
        }
    }

    /**
     * Concatenate the provided key with the Magic GUID and return the Base64 encoded form.
     * 
     * @param key
     *            the key to hash
     * @return the Sec-WebSocket-Accept header response (per opening handshake spec)
     */
    public static String hashKey(String key)
    {
        try
        {
            MessageDigest md = MessageDigest.getInstance("SHA1");
            md.update(key.getBytes("UTF-8"));
            md.update(MAGIC);
            return new String(B64Code.encode(md.digest()));
        }
        catch (Exception e)
        {
            throw new RuntimeException(e);
        }
    }
}