com.sshtools.common.util.X11Util.java Source code

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Here is the source code for com.sshtools.common.util.X11Util.java

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//Changes (c) CCLRC 2006
/*
 *  SSHTools - Java SSH2 API
 *
 *  Copyright (C) 2002 Lee David Painter.
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public License
 *  as published by the Free Software Foundation; either version 2 of
 *  the License, or (at your option) any later version.
 *
 *  You may also distribute it and/or modify it under the terms of the
 *  Apache style J2SSH Software License. A copy of which should have
 *  been provided with the distribution.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  License document supplied with your distribution for more details.
 *
 */

package com.sshtools.common.util;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import com.sshtools.j2ssh.io.IOUtil;
import com.sshtools.j2ssh.io.IOStreamConnector;
import java.util.StringTokenizer;
import java.io.BufferedReader;
import java.io.InputStreamReader;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import com.sshtools.j2ssh.configuration.ConfigurationLoader;
import com.sshtools.j2ssh.forwarding.XDisplay;

/**
 *
 *
 * @author $author$
 * @version $Revision: 1.5 $
 */
public class X11Util {
    // Logger

    /**  */
    protected static Log log = LogFactory.getLog(X11Util.class);
    static byte[] table = { 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x61, 0x62, 0x63, 0x64,
            0x65, 0x66 };

    public static X11Cookie getCookie(XDisplay xdisplay) {
        if (System.getProperty("os.name").startsWith("Windows"))
            return getRNDCookie();
        log.debug("Getting X11 cookie using xauth");
        try {
            String host = xdisplay.getHost();
            String display = host + ":" + xdisplay.getDisplay();
            String cmd = "xauth list " + display + " 2>/dev/null";
            if (host == null || host.equals("localhost") || host.equals("unix")) {
                cmd = "xauth list :" + xdisplay.getDisplay() + " 2>/dev/null";
            }

            Process process = null;
            InputStream in = null;
            OutputStream out = null;
            try {
                log.debug("Executing " + cmd);
                process = Runtime.getRuntime().exec(cmd);
                BufferedReader reader = new BufferedReader(new InputStreamReader(in = process.getInputStream()));
                out = process.getOutputStream();
                String line = null;
                String cookie = null;
                while ((line = reader.readLine()) != null) {
                    log.debug(line);
                    StringTokenizer t = new StringTokenizer(line);
                    try {
                        String fhost = t.nextToken();
                        String type = t.nextToken();
                        String value = t.nextToken();
                        if (cookie == null) {
                            cookie = value;
                            log.debug("Using cookie " + cookie);
                        }
                        return expand(type, cookie);
                    } catch (Exception e) {
                        log.error("Unexpected response from xauth.", e);
                        log.warn("Trying random data.");
                        return getRNDCookie();
                    }
                }
            } finally {
                IOUtil.closeStream(in);
                IOUtil.closeStream(out);
            }
            return getRNDCookie();
        } catch (Exception e) {
            log.warn("Had problem finding xauth data (" + e + ") trying random data.");
            return getRNDCookie();
        }
    }

    /**
     *
     *
     * @param displayNumber
     *
     * @return
     */
    private static String createCookie() {
        log.warn("Creating fake cookie");

        StringBuffer b = new StringBuffer();

        for (int i = 0; i < 16; i++) {
            int r = (int) (Math.random() * 256);
            String h = Integer.toHexString(r);

            if (h.length() == 1) {
                b.append(0);
            }

            b.append(h);
        }

        log.debug("Fake cookie is " + b.toString());

        return b.toString();
    }

    private static String createMatchingCookie(int length) {
        log.debug("Creating fake cookie");

        StringBuffer b = new StringBuffer();

        length = length / 2;

        for (int i = 0; i < 16; i++) {
            int r = (int) (Math.random() * 256);
            String h = Integer.toHexString(r);

            if (h.length() == 1) {
                b.append(0);
            }

            b.append(h);
        }

        log.debug("Fake cookie is " + b.toString());

        return b.toString();
    }

    private static X11Cookie expand(String authType, String realAuthData) {
        return new X11Cookie(authType, realAuthData, createMatchingCookie(realAuthData.length()));
    }

    private static X11Cookie getRNDCookie() {
        String auth = createCookie();
        return new X11Cookie("MIT-MAGIC-COOKIE-1", auth, auth);
    }

    public static class X11Cookie {
        String authType;
        String realAuthData;
        String fakeAuthData;

        public X11Cookie(String authType, String realAuthData, String fakeAuthData) {
            this.authType = authType;
            this.realAuthData = realAuthData;
            this.fakeAuthData = fakeAuthData;
        }

        public String getAuthType() {
            return authType;
        }

        public String getRealAuthData() {
            return realAuthData;
        }

        public String getFakeAuthData() {
            return fakeAuthData;
        }

    }
}