receivefile.java

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package com.valhalla.jbother.jabber.smack;

import java.io.*;
import java.net.*;
import java.nio.channels.SocketChannel;
import java.nio.channels.FileChannel;
import java.nio.channels.ByteChannel;

/**
 * Created by luke on Feb 8, 2005 10:45:47 AM
 */

/**
 * this class implements methods for proper authentication and acquiring data certain JID
 */

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

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



  /**
   * implementation of getByteChannel()
   * @return ByteChannel associated with the socket
   * @throws IOException
   */
  public ByteChannel getByteChannel() throws IOException, ConnectException
  {
    ByteChannel channel = null;
    try {
      channel =  SocketChannel.open(new InetSocketAddress(inetAddress,port));
    }
    catch(java.net.ConnectException e)
    {
      cleanUp();
    }
    return channel;
  }

  /**
   * implementation of getFileChannel()
   * @return FileChannel associated with output file
   * @throws FileNotFoundException
   */
  public FileChannel getFileChannel() throws FileNotFoundException {
    return new FileOutputStream(fileDetails.getDestFile()).getChannel();
  }

  /**
   * get the file. The process looks as follows:
   * <nl>
   *   <li>1) Target sends a list of SOCKS5 authentication methods to Initiator
   *   <li>2) Initiator picks one and returns it to Target
   *   <li>3) Target tries to connect to Initiator using SOCKS5 CONNECT with hostname consisting
   *      of magic sequence SHA1("SID + JID from + JID to") and port 0
   *   <li>4) Initiator verifies if this data is the same on its side, if so sends SOCKS5
   *      CONNECT with return code 0x00
   *   <li>5) Initiator puts the data to the socket
   * </nl>
   */

  /**
   * does SOCKS5 authentication
   * @return true if Initiator authenticated successfully
   */
  public boolean authenticate()
  {
    int count;

    if(isByteChannelNull()) {
      return false;
    }

    count = writeToSocket(Socks5Utils.createSOCKS5AuthenticationMethodsMessage());

    count = readFromSocket();

    if(buffer.get(1) != Socks5Utils.SOCKS_AUTH_NOAUTH )
    {
      System.err.println("Initiator does not support SOCKS5 NOAUTH authentication.");
      System.err.println("Cannot continue !");
      cleanUp();
      return false;
    }

    count = writeToSocket(Socks5Utils.
      createSOCKS5AuthenticationMessage(getSHA1HashString(sid + jidFrom + jidTo),0));

    count = readFromSocket();
    if (count == -1) {
      System.err.println("No response from other side!");
      cleanUp();
      return false;
    }

    if(buffer.get(1) != 0x00)
    {
      System.err.println("Initiator didn't accept SOCKS5 CONNECT request");
      System.err.println("Possible mismatch of stream ID, JID from or JID to");
      cleanUp();
      return false;
    }
    return true;
  }

  /**
   * gets the data from the socket and saves it to the file
   * @return true if operation succeeded
   */
  public boolean getFile() {
    return transferFromSocketToFile();
  }

}