How to break JmDNS (trunk as of 2012-05-25 - revision 340, fixed in revision 341)

jmdns.java

package javax.jmdns.test;

import java.net.DatagramPacket;
import java.net.InetAddress;
import java.util.Enumeration;
import java.util.logging.ConsoleHandler;
import java.util.logging.Level;
import java.util.logging.LogManager;
import java.util.logging.Logger;

import javax.jmdns.impl.DNSIncoming;
import javax.jmdns.impl.constants.DNSConstants;

import org.junit.Before;
import org.junit.Test;
/*
 * Tracked here:
 *   https://sourceforge.net/tracker/?func=detail&aid=3529498&group_id=93852&atid=605791
 *
 * Fixed in Subversion, revision 341
 */
public class BreakJmDNS {

    // This package is one of the packages sent by nmap when run as: nmap -v -sU -sV -F 127.0.0.1 
    private static final byte[] nmap_scan_package = new byte[] {
        0x30, (byte)0x82, 0x00, 0x2f, 0x02, 0x01, 0x00, 0x04, 0x06, 0x70, 0x75, 0x62, 0x6c, 0x69, 0x63, (byte)0xa0, (byte)0x82, 0x00, 0x20, 0x02, 0x04, 0x4c, 0x33, (byte)0xa7, 0x56, 0x02, 0x01, 0x00, 0x02, 0x01, 0x00, 0x30, (byte)0x82, 0x00, 0x10, 0x30, (byte)0x82, 0x00, 0x0c, 0x06, 0x08, 0x2b, 0x06, 0x01, 0x02, 0x01, 0x01, 0x05, 0x00, 0x05, 0x00
    };
    
    @Test
    public void snap() throws Exception {
        // The DNSIncoming constructor should probably do bounds checking on the following parts of the
        // package: questions, answers, authorities, additionals
        // The package above results in these values
        // questions   -> 513
        // answers     -> 4
        // authorities -> 1648
        // additionals -> 30050
        new DNSIncoming(new DatagramPacket(nmap_scan_package, nmap_scan_package.length, InetAddress.getByName(DNSConstants.MDNS_GROUP), DNSConstants.MDNS_PORT));
    }

    @Before
    public void enableLogging() {
        ConsoleHandler handler = new ConsoleHandler();
        handler.setLevel(Level.FINEST);
        for (Enumeration<String> enumerator = LogManager.getLogManager().getLoggerNames(); enumerator.hasMoreElements();) {
            String loggerName = enumerator.nextElement();
            Logger logger = Logger.getLogger(loggerName);
            logger.addHandler(handler);
            logger.setLevel(Level.FINEST);
        }
    }
}