sendfile.java

网站即时通讯系统

package com.valhalla.jbother.jabber.smack;

import javax.swing.*;
import java.io.*;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.FileChannel;
import java.nio.channels.ByteChannel;


/**
 * Created by luke on Feb 8, 2005 10:45:11 AM
 */

/**
 * this class implements methods for proper authentication and sending data to a certain JID
 */

public class SendFile extends FileTransfer
{
  private static String fId = "$Id$";

  private ServerSocketChannel fServerSocketChannel;

  public SendFile(StreamInitiation.FileDetails aFileDetails,
                  String aHostname,
                  int aPort,
                  String aSid,
                  String aJidFrom,
                  String aJidTo)
  {
    super(aFileDetails,aHostname,aPort,aSid,aJidFrom,aJidTo);
  }


  /**
   * this method will block here until someone will connect to this serverChannel
   * I'm not sure if this works...
   */
  public ByteChannel getByteChannel() throws IOException, java.net.ConnectException, java.net.SocketException
  {
    fServerSocketChannel = ServerSocketChannel.open();
    try {
      fServerSocketChannel.socket().bind(new InetSocketAddress(inetAddress,port));
    }
    catch(java.net.SocketException e)
    {
      cleanUp();
      return null;
    }
    return fServerSocketChannel.accept();
  }

  public FileChannel getFileChannel() throws FileNotFoundException  {
    return new FileInputStream(fileDetails.getFile()).getChannel();
  }

  /**
   * authenticate with Target. This includes:
   * <ul>
   *   <li> finding out what types of SOCKS5 authentication provides the other end,
   *   <li> replying with "no authentication" type of authentication (sic!),
   *   <li> reading a SOCKS5 CONNECT request, with hostname containing hashed (using <b>now broken</b>
   *        SHA1 of ( SID + Initiator JID + TARGET JID ) and comparing it with expected value taken from
   *        own values of SID and 2 JIDs,
   *   <li>
   * </ul>
   * @return true if authentication succeeded, false otherwise
   */
  public boolean authenticate()
  {
    int count = readFromSocket();

    // first, check what kinds of SOCKS5 authentication methods provide the other end
    if(! Socks5Utils.providesSOCKS5NoAuthMethod(buffer))
    {
      System.err.println("Target does not provide SOCKS5 NOAUTH authentication method");
      return false;
    }

    // send the reply to the Target: OK, we decide to go for no authentication
    byte[] reply = new byte[2];
    reply[0] = Socks5Utils.SOCKS_VERSION;
    reply[1] = Socks5Utils.SOCKS_AUTH_NOAUTH;

    count = writeToSocket(reply);

    // next the Target should send CONNECT message with specially formatted host part
    // we need to verify if SHA1 hashes match and reply accordingly
    count = readFromSocket();

    if( buffer.get(1) == Socks5Utils.SOCKS_COMMAND_CONNECT
      && buffer.get(3) == Socks5Utils.SOCKS_ATYP_DOMAINNAME )
    {
      byte[] hostname = new byte[count - 7];
      for(int i=0; i<hostname.length; i++) {
        hostname[i] = buffer.get(i + 5);
      }

      String sha1Checksum = new String(hostname);

      // this is what we expect, according to our information
      String expectedChecksum = getSHA1HashString(sid + jidFrom + jidTo);

      if( sha1Checksum.equals(expectedChecksum) == false )
      {
        //DEBUG
          System.out.println("SHA1 checksums not matching!! aborting file transfer");
          return false;
      }
    }

    // ok, send the confirmation that checksum is all right. this means that we need
    // to change the 2nd byte to 0x00 (OK) and re-send the SOCKS5 packet
    buffer.flip();
    buffer.put(1,(byte)0x00);
    writeToSocket(buffer);

    count = writeToSocket(buffer);
    return true;
  }

  /**
   * send file to the socket
   * @return true if no problems, false otherwise
   */
  public boolean sendFile() {
    return transferFromFileToSocket();
  }

  public void cleanUp()
  {
    super.cleanUp();
    try {
      fServerSocketChannel.close();
    }
    catch (IOException e)
    {
      e.printStackTrace();
    }
  }
}