Enlisting Java in the War Against Email Viruses, Part 2, A Much Faster Program

  private StringBuffer addToMboxStr(
                         StringBuffer mBoxStrBuf,
                         String tag,
                         String pathFileName){

Listing 1

    StringBuffer message = new StringBuffer(
                           "No message found");
    message = new StringBuffer(readLines(
                pathFileName,null,null));

Listing 2

    //Get a 24-char date string matching
    // the format required by Mozilla.
    String theDate = new Date().toString();
    theDate = "From - " +
                      theDate.substring(0,19) +
                         theDate.substring(23);
    //Create the UIDL string.
    String xUidl = "X-UIDL:" +
              pathFileName.substring(
                pathFileName.lastIndexOf(" "));
    //Create the two status strings.
    String xMozillaStatus =
                      "X-Mozilla-Status: 0000";
    String xMozillaStatus2 =
                 "X-Mozilla-Status2: 00000000";

    //Insert the strings at the beginning of the
    // message.
    message.insert(0,theDate + "\n" + xUidl
                 + "\n" + xMozillaStatus + "\n"
                     + xMozillaStatus2 + "\n");

Listing 3

    message.append("\n");

Listing 4

    message = message.insert(message.indexOf(
                           "Subject: ")+9,tag);

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    mBoxStrBuf.append(message);

    return mBoxStrBuf;

  }//end addToMboxStr

Listing 6

class VirPro01c extends Frame{
  //The following is the local folder where
  // message files are stored awaiting virus
  // scanning.  You may want to change this to a
  // different folder.
  String dataPath = "./Messages/";
  //The following is the local folder where the
  // messages are stored after they have been
  // scanned and written into the MBOX file.
  // They are automatically moved to this folder
  // after being deleted from the public email
  // server. You will want to manually empty this
  // folder periodically.
  String archivePath = "./Archives/";

  //The following is the path to the local folder
  // where you write files to cause them to be
  // treated as email folders.
  String emailPath =
                  "C:/Baldwin/DummyMailAccount/";

  //The following are working variables used by
  // the program for various purposes.
  BufferedReader inputStream;
  PrintWriter outputStream;
  Socket socket;
  String pathFileName;
  Vector msgToDelete = new Vector();
  StringBuffer mBoxStrBuf = new StringBuffer("");
  String newFolder;

Listing 7

  public static void main(String[] args){
    if(args.length != 3){
      System.out.println("Usage: java VirPro01c "
                + "pubServer userName password");
      System.exit(0);
    }//end if

    new VirPro01c(args[0],args[1],args[2]);
  }//end main

Listing 8

  VirPro01c(final String server,
            final String userName,
            final String password){

    newFolder = "A" + new Date().getTime();

Listing 9

    this.addWindowListener(
      new WindowAdapter(){
        public void windowClosing(WindowEvent e){
          System.exit(0);
        }//end windowClosing
      }//end WindowAdapter()
    );//end addWindowListener

    final Button startButton =
                             new Button("Start");
    final Button deleteButton = new Button(
                         "Delete Msg On Server");
    final TextArea textArea =
                             new TextArea(20,50);

Listing 10

    //Register an ActionListener on the
    // startButton.
    startButton.addActionListener(
      new ActionListener(){
        public void actionPerformed(
                                  ActionEvent e){
          startButton.setEnabled(false);
          //Get a directory listing.  Make
          // certain that dataDir contains only
          // message files.  Otherwise, you will
          // need to upgrade this code to include
          // a file name filter.
          File dataDir = new File(dataPath);
          String[] dirList = dataDir.list();

          //Now process the files in the
          // directory
          for(int msgCounter = 0;
                     msgCounter < dirList.length;
                                   msgCounter++){
            String fileName =
                             dirList[msgCounter];
            pathFileName = dataPath + fileName;

            //Create a tag containing the
            // original message number from the
            // server.  This message number will
            // be a three-digit string.
            String strMsgNumber =
                  pathFileName.substring(
                  pathFileName.indexOf(" "),
                  pathFileName.lastIndexOf(" ")).
                                          trim();
            int msgNumber = Integer.parseInt(
                                   strMsgNumber);
            String msgNumberStr;
            if(msgNumber < 10){
              msgNumberStr = "00" + msgNumber;
            }else if(msgNumber > 99){
              msgNumberStr = "" + msgNumber;
            }else{
              msgNumberStr = "0" + msgNumber;
            }//end else

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            mBoxStrBuf = addToMboxStr(mBoxStrBuf,
                          "{"+ msgNumberStr +"}",
                                   pathFileName);

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            textArea.append("Added " +
                            msgNumberStr + "\n");
            msgToDelete.add(pathFileName);
          }//end for loop on directory length

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          try{
            System.out.println("Writing: "
                        + emailPath + newFolder);
            //Write the updated string into the
            // MBOX file (email folder).
            DataOutputStream dataOut =
                         new DataOutputStream(
                         new FileOutputStream(
                         emailPath + newFolder));
            dataOut.writeBytes(
                         new String(mBoxStrBuf));
            dataOut.close();
          }catch(Exception ex){
            System.out.println(
                            "Writing MBOX file");
            ex.printStackTrace();
          }//end catch

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          deleteButton.setEnabled(true);

          textArea.append("\nDo you want to "
             + "delete messages from server?\n");

          //Alert the user
          try{
            Toolkit.getDefaultToolkit().beep();
            Thread.currentThread().sleep(300);
            Toolkit.getDefaultToolkit().beep();
            Thread.currentThread().sleep(300);
            Toolkit.getDefaultToolkit().beep();
          }catch(Exception ex){
            ex.printStackTrace();
          }//end catch
        }//end actionPerformed
      }//end ActionListener
    );//end addActionListener

Listing 15

/*File VirPro01c.java
Copyright 2004, R.G.Baldwin
Rev 02/22/04

This is a modification of VirPro01b.  Its purpose
is to create an MBOX file directly in the email
tree structure rather than to forward the
messages via email.  This version runs much
faster than VirPro01b.

This is one of a pair of programs designed to be
used together, in conjunction with a good virus
scanner program to prevent messages with viruses
from contaminating an email inbox.

This program should be run after the program
named VirPro01a has been run, and a virus checker
has been used to confirm that all files produced
by that program are free of viruses, or that any
files containing viruses have been removed from
the system.

See comments at the beginning of VirPro01a.java
for a description of this pair of programs.

This program writes clean email messages into an
MBOX file, which is located within the directory
tree belonging to an email client program.  Only
a few seconds are required to process one hundred
messages and write them into the file.

Each time the program is run, a new MBOX file is
created and populated with the messages
previously created by VirPro01a and scanned with
your favorite virus scanner program.  The name
of the file is based on the current date and time
prefixed with an upper case A.

The email client program should be terminated
before this program is run.  If not, the email
client program may not recognize the new email
folder corresponding to the MBOX file until the
email client program is stopped and then
restarted.

This program is designed to be used with a email
client program designed to handle files received
from a POP3 email server.  For technical
information on POP3,see RFC 1725 at
http://www.cis.ohio-state.edu/htbin/rfc/rfc1725.
html

Usage:  Enter the following at the command line:
java VirPro01c pubServer userName password

where the command-line parameters identify:
Your public email server
Your user name on the public server
Your password on the public server

Tested using SDK 1.4.2 under WinXP
************************************************/
import sun.net.smtp.SmtpClient;
import java.net.*;
import java.io.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;

class VirPro01c extends Frame{
  //The following is the local folder where
  // message files are stored awaiting virus
  // scanning.  You may want to change this to a
  // different folder.
  String dataPath = "./Messages/";
  //The following is the local folder where the
  // messages are stored after they have been
  // scanned and written into the MBOX file.
  // They are automatically moved to this folder
  // after being deleted from the public email
  // server. You will want to manually empty this
  // folder periodically.
  String archivePath = "./Archives/";

  //The following is the path to the local folder
  // where you write files to cause them to be
  // treated as email folders.  Note that this
  // doesn't have to be a valid email account so
  // long as the email client program it to be
  // valid.  In other words, you can create a new
  // account in your email client program using
  // dummy server names, etc.
  String emailPath =
                  "C:/Baldwin/DummyMailAccount/";

  //The following are working variables used by
  // the program for various purposes.
  BufferedReader inputStream;
  PrintWriter outputStream;
  Socket socket;
  String pathFileName;
  Vector msgToDelete = new Vector();
  StringBuffer mBoxStrBuf = new StringBuffer("");
  String newFolder;

  public static void main(String[] args){
    if(args.length != 3){
      System.out.println("Usage: java VirPro01c "
                + "pubServer userName password");
      System.exit(0);
    }//end if

    new VirPro01c(args[0],args[1],args[2]);
  }//end main
  //===========================================//

  //Constructor
  VirPro01c(final String server,
            final String userName,
            final String password){

    newFolder = "A" + new Date().getTime();

    //Register a window listener to service
    // the close button on the Frame.
    this.addWindowListener(
      new WindowAdapter(){
        public void windowClosing(WindowEvent e){
          System.exit(0);
        }//end windowClosing
      }//end WindowAdapter()
    );//end addWindowListener

    final Button startButton =
                             new Button("Start");
    final Button deleteButton = new Button(
                         "Delete Msg On Server");
    final TextArea textArea =
                             new TextArea(20,50);

    //Register an ActionListener on the
    // startButton.
    startButton.addActionListener(
      new ActionListener(){
        public void actionPerformed(
                                  ActionEvent e){
          startButton.setEnabled(false);
          //Get a directory listing.  Make
          // certain that dataDir contains only
          // message files.  Otherwise, you will
          // need to upgrade this code to include
          // a file name filter.
          File dataDir = new File(dataPath);
          String[] dirList = dataDir.list();

          //Now process the files in the
          // directory
          for(int msgCounter = 0;
                     msgCounter < dirList.length;
                                   msgCounter++){
            String fileName =
                             dirList[msgCounter];
            pathFileName = dataPath + fileName;

            //Create a tag containing the
            // original message number from the
            // server.  This message number will
            // be a three-digit string.
            String strMsgNumber =
                  pathFileName.substring(
                  pathFileName.indexOf(" "),
                  pathFileName.lastIndexOf(" ")).
                                          trim();
            int msgNumber = Integer.parseInt(
                                   strMsgNumber);
            String msgNumberStr;
            if(msgNumber < 10){
              msgNumberStr = "00" + msgNumber;
            }else if(msgNumber > 99){
              msgNumberStr = "" + msgNumber;
            }else{
              msgNumberStr = "0" + msgNumber;
            }//end else

            //Add the message to the MBOX file.
            // You can tag the subject with any
            // string that you want to pass as
            // the second parameter.  I will tag
            // with the message number as three
            // digits. That makes it easy to
            // confirm that all messages
            // seccessfully reached the email
            // account.
            mBoxStrBuf = addToMboxStr(mBoxStrBuf,
                          "{"+ msgNumberStr +"}",
                                   pathFileName);

            textArea.append("Added " +
                            msgNumberStr + "\n");
            msgToDelete.add(pathFileName);
          }//end for loop on directory length

          try{
            System.out.println("Writing: "
                        + emailPath + newFolder);
            //Write the updated string into the
            // MBOX file (email folder).
            DataOutputStream dataOut =
                         new DataOutputStream(
                         new FileOutputStream(
                         emailPath + newFolder));
            dataOut.writeBytes(
                         new String(mBoxStrBuf));
            dataOut.close();
          }catch(Exception ex){
            System.out.println(
                            "Writing MBOX file");
            ex.printStackTrace();
          }//end catch

          //Make it possible for the user to
          // delete all messages that were
          // successfully written into the MBOX
          // file.
          deleteButton.setEnabled(true);
          textArea.append("\nDo you want to "
             + "delete messages from server?\n");

          //Alert the user
          try{
            Toolkit.getDefaultToolkit().beep();
            Thread.currentThread().sleep(300);
            Toolkit.getDefaultToolkit().beep();
            Thread.currentThread().sleep(300);
            Toolkit.getDefaultToolkit().beep();
          }catch(Exception ex){
            ex.printStackTrace();
          }//end catch
        }//end actionPerformed
      }//end ActionListener
    );//end addActionListener

    //Register an action listener on the delete
    // button
    deleteButton.addActionListener(
      new ActionListener(){
        public void actionPerformed(
                                  ActionEvent e){
          deleteButton.setEnabled(false);
          textArea.append("\n");

          //Get connected to the email server
          int port = 110; //pop3 mail port
          try{
            //Get a socket, connected to the
            // specified server on the specified
            // port.
            socket = new Socket(server,port);

            //Get an input stream from the socket
            inputStream = new BufferedReader(
                     new InputStreamReader(
                       socket.getInputStream()));

            //Get an output stream to the socket.
            outputStream = new PrintWriter(
                     new OutputStreamWriter(
                       socket.getOutputStream()),
                                           true);

            //Display the msg received from the
            // server on the command-line screen
            // immediately following connection.
            String connectMsg =
                               validateOneLine();
            System.out.println(
                           "Connected to server "
                                   + connectMsg);

            //The communication process is now in
            // the AUTHORIZATION state.  Send the
            // user name and password to the
            // server.
            //Commands are sent in plain text,
            // upper case to the server.  Some
            // commands require an argument
            // following the command, as is the
            // case with USER.
            //Send the command.
            outputStream.println("USER "
                                     + userName);
            //Get response and confirm that the
            // response was +OK and was not -ERR.
            String userResponse =
                               validateOneLine();
            //Display the response on the
            // command-line screen.
            System.out.println("USER "
                                 + userResponse);
            //Send the password to the server
            outputStream.println("PASS "
                                     + password);
            //Validate the server's response as
            // +OK. Display the response in the
            // process.
            System.out.println("PASS "
                            + validateOneLine());
          }catch(Exception ex){
            ex.printStackTrace();
          }//end catch

          //Delete the collection of messages in
          // msgToDelete from the public email
          // server.  Also transfer the local
          // copies of the message files to the
          // archive folder.
          for(int cnt = 0;
                 cnt < msgToDelete.size();cnt++){
            pathFileName =
              (String)msgToDelete.elementAt(cnt);
            String strMsgNumber =
                pathFileName.substring(
                 pathFileName.indexOf(" "),
                  pathFileName.lastIndexOf(" ")).
                   trim();
            int msgNumber = Integer.parseInt(
                                   strMsgNumber);

            //Deletion of a message from the
            // server is accomplished by marking
            // the message for deletion while in
            // the TRANSACTION state.  The
            // message is actually deleted when
            // the client sends a QUIT command
            // to the server causing the server
            // to enter the UPDATE state.  If the
            // program aborts prematurely before
            // sending a QUIT command, marked
            // messages are not deleted from the
            // server.
            //Mark the message for deletion.
System.out.println(
            "Deletion is temporarily disabled.");
/*Deletion from the server temporarily disabled.
 *Do not enable this deletion code until you
 * understand exactly what you are doing.
            outputStream.println(
                            "DELE " + msgNumber);

            //Validate the response and display
            // it on the GUI.
            textArea.append(
                       "Msg: " + msgNumber + " "
                       + validateOneLine()+"\n");
            textArea.append(
                   "Marked:" + msgNumber + "\n");
*/

            //Now move the file that has been
            // processed and deleted from the
            // server to the archive folder
            // on the local disk.
            moveFile(pathFileName,archivePath);

          }//end for loop on msgToDelete.size()

          //Terminate the session with the
          // server causing the messages to
          // actually be deleted from the server.
          outputStream.println("QUIT");
          String quitResponse =
                               validateOneLine();
          //Display the response on the
          // command-line screen.
          System.out.println(
                         "QUIT " + quitResponse);

          //Server is now in the UPDATE mode.
          // It will delete all files marked
          // with the DELE command earlier.
          //Close the socket
          try{
            socket.close();
          }catch(Exception ex){
            ex.printStackTrace();
          }//end catch

          textArea.append("\n\nMessages deleted "
                             + "from server.\n");
        }//end actionPerformed
      }//end ActionListener
    );//end addActionListener

    //Configure the GUI by placing the
    // various components on it, setting the size
    // and making it visible.
    add(startButton);
    add(deleteButton);
    deleteButton.setEnabled(false);
    add(textArea);
    textArea.setText("");
    setLayout(new FlowLayout());

    setTitle("Copyright 2004, R.G.Baldwin");
    setBounds(274,0,400,400);
    //Make the GUI visible.
    setVisible(true);
  }//end constructor
  //===========================================//

  //Validate a one-line response.
  //The purpose of this method is to confirm that
  // the server returned +OK and not -ERR to the
  // previous command.
  //If +OK, the method returns the string
  // returned by the server.
  //If -ERR, the method displays the string
  // returned by the server and terminates the
  // session.
  private String validateOneLine(){
    try{
      String response = inputStream.readLine();
      if(response.startsWith("+OK")){
        return response;
      }else{
        System.out.println(response);
        //Terminate the session.
        outputStream.println("QUIT");
        socket.close();
        System.out.println(
                       "Premature QUIT on -ERR");
        System.exit(0);
      }//end else
    }catch(IOException e){
      System.out.println("\n" + e);
    }//end catch
    //The following return statement is requied
    // to satisfy the compiler.
    return "Make compiler happy";
  }//end validateOneLine()
  //===========================================//

  //Method moves a file from its current location
  // specified by pathFileName to a new location
  // specified by archivePath.
  private void moveFile(String pathFileName,
                             String archivePath){
    String fileName = pathFileName.substring(
              pathFileName.lastIndexOf('/') + 1);
    String archivePathFileName =
                          archivePath + fileName;

    boolean moved =
           new File(pathFileName).renameTo(
             new File(archivePathFileName));

    if(!moved)System.out.println(
      "Unable to move " + new File(pathFileName)
      + "\nto " + new File(archivePathFileName));
  }//end moveFile method
  //===========================================//

  //This method reads and saves lines of data
  // from a file starting with the line that
  // startsWith firstLine and ending with the
  // line that startsWith lastLine.  If lastLine
  // is null, data is saved to the end of the
  // file. If firstLine is null, data is saved
  // beginning with the first line in the file.
  // The lines of data from the file are saved by
  // concatenating them into a single string with
  // a newline inserted into the string at the
  // end of each line.
  //The name and path to the file is given by
  // pathFileName.
  private String readLines(String pathFileName,
               String firstLine,String lastLine){
    StringBuffer strBuf = new StringBuffer();
    try{
      BufferedReader inDataMsg
        = new BufferedReader(new FileReader(
                                  pathFileName));

      String data;
      boolean isSave = false;
      while((data = inDataMsg.readLine())
                                        != null){

        if(((firstLine == null) ||
                 (data.startsWith(firstLine))) &&
                              (isSave == false)){
          isSave = true;
        }//end if

        if(isSave){
          strBuf.append(data + "\n");
        }//end if

        if((lastLine != null) &&
                    (data.startsWith(lastLine))){
          break;//no need to read any more
        }//end if

      }//end while loop
      inDataMsg.close();//Close file
    }catch(Exception e){e.printStackTrace();}
    return new String(strBuf);
  }//end readLines
  //===========================================//
  private StringBuffer addToMboxStr(
                         StringBuffer mBoxStrBuf,
                         String tag,
                         String pathFileName){

    StringBuffer message = new StringBuffer(
                           "No message found");
    message = new StringBuffer(readLines(
                pathFileName,null,null));

    //Prepare the message for appending to the
    // end of the MBOX string.  This requires
    // the creation of four  new header lines
    // and the prepending of those four lines
    // onto the message.  Examples of those
    // four new header lines follow:

    //From - Wed Jan 21 15:59:09 2004
    //X-UIDL: 400ed7770000000b
    //X-Mozilla-Status: 0000
    //X-Mozilla-Status2: 00000000

    // The first line contains the date and
    // time. The second line contains the UIDL
    // from the email server.  The meaning of
    // the third and fourth lines can be found
    // at various web sites including
    // http://www.eyrich-net.org/mozilla/
    // X-Mozilla-Status.html?en
    // For a new message, the status values
    // given above are satisfactory.

    //Create Mozilla header lines and insert
    // them at the beginning of the message.
    // First get a 24-char date string matching
    // the format required by Mozilla.
    String theDate = new Date().toString();
    theDate = "From - " +
                      theDate.substring(0,19) +
                         theDate.substring(23);
    //Create the UIDL string.
    String xUidl = "X-UIDL:" +
                        pathFileName.substring(
                pathFileName.lastIndexOf(" "));
    //Create the two status strings.
    String xMozillaStatus =
                      "X-Mozilla-Status: 0000";
    String xMozillaStatus2 =
                 "X-Mozilla-Status2: 00000000";

    message.insert(0,theDate + "\n" + xUidl
                 + "\n" + xMozillaStatus + "\n"
                     + xMozillaStatus2 + "\n");
    //Append a new line at the end of the
    // message.
    message.append("\n");
    //Insert tag in subject line
    message = message.insert(message.indexOf(
                           "Subject: ")+9,tag);

    //Append this message at the end of the
    // string that will be used to create the
    // MBOX file.
    mBoxStrBuf.append(message);

    return mBoxStrBuf;

  }//end addToMboxStr
  //===========================================//

}//end class VirPro01c

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