/*
* Copyright 2014 Attila Szegedi, Daniel Dekany, Jonathan Revusky
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package freemarker.debug.impl;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import java.net.ServerSocket;
import java.net.Socket;
import java.security.MessageDigest;
import java.security.SecureRandom;
import java.util.Arrays;
import java.util.Random;
import freemarker.debug.Debugger;
import freemarker.log.Logger;
import freemarker.template.utility.SecurityUtilities;
import freemarker.template.utility.UndeclaredThrowableException;
/**
*/
class DebuggerServer
{
private static final Logger logger = Logger.getLogger("freemarker.debug.server");
// TODO: Eventually replace with Yarrow
private static final Random R = new SecureRandom();
private final byte[] password;
private final int port;
private final Serializable debuggerStub;
private boolean stop = false;
private ServerSocket serverSocket;
public DebuggerServer(Serializable debuggerStub)
{
port = SecurityUtilities.getSystemProperty("freemarker.debug.port", Debugger.DEFAULT_PORT).intValue();
try
{
password = SecurityUtilities.getSystemProperty("freemarker.debug.password", "").getBytes("UTF-8");
}
catch (UnsupportedEncodingException e)
{
throw new UndeclaredThrowableException(e);
}
this.debuggerStub = debuggerStub;
}
public void start()
{
new Thread(new Runnable()
{
public void run()
{
startInternal();
}
}, "FreeMarker Debugger Server Acceptor").start();
}
private void startInternal()
{
try
{
serverSocket = new ServerSocket(port);
while(!stop)
{
Socket s = serverSocket.accept();
new Thread(new DebuggerAuthProtocol(s)).start();
}
}
catch(IOException e)
{
logger.error("Debugger server shut down.", e);
}
}
private class DebuggerAuthProtocol implements Runnable
{
private final Socket s;
DebuggerAuthProtocol(Socket s)
{
this.s = s;
}
public void run()
{
try
{
ObjectOutputStream out = new ObjectOutputStream(s.getOutputStream());
ObjectInputStream in = new ObjectInputStream(s.getInputStream());
byte[] challenge = new byte[512];
R.nextBytes(challenge);
out.writeInt(220); // protocol version
out.writeObject(challenge);
MessageDigest md = MessageDigest.getInstance("SHA");
md.update(password);
md.update(challenge);
byte[] response = (byte[])in.readObject();
if(Arrays.equals(response, md.digest()))
{
out.writeObject(debuggerStub);
}
else
{
out.writeObject(null);
}
}
catch(Exception e)
{
logger.warn("Connection to " + s.getInetAddress().getHostAddress() + " abruply broke", e);
}
}
}
public void stop()
{
this.stop = true;
if(serverSocket != null)
{
try
{
serverSocket.close();
}
catch(IOException e)
{
logger.error("Unable to close server socket.", e);
}
}
}
}