encrption and decryption using cipher for Java ME

[mak zoe]

I am currently working on the encrption and decryption on Java ME
I search the net and found something similar using Java SE
However, the point is that... in Java ME, I can't found a class "keyGenerator" (in startApp)
(I use netbean and it's underlined in red)
What should I do for it? am I missing any unimported class??

The following is the code I am working on,,,

  import java.io.*;
import java.util.*;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.ShortBufferException;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.io.*;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
//import javax.crypto.KeyGenerator;


public class TestMidlet extends MIDlet implements CommandListener {


    private Display display;
    private Command exit = new Command("EXIT", Command.EXIT, 1);;
    private Command connect = new Command("Connect", Command.SCREEN, 1);
    private TextField tb;
    private Form menu;
    private TextField tb1;
    private TextField tb2;

    static String algorithm = "Blowfish";
       static Key key ;
       static Cipher cipher ;

    DB db;

    public TestMidlet() throws Exception {
        display = Display.getDisplay(this);

    }

    public void startApp() {
        displayMenu();
        
           try{
               key = KeyGenerator.getInstance("DES").generateKey();   //here!! what is the keyGenerator
               cipher = Cipher.getInstance(algorithm);
           }   catch (NoSuchAlgorithmException ex) {
            ex.printStackTrace();
           } catch (NoSuchPaddingException ex) {
            ex.printStackTrace();
           }
    }

    public void displayMenu() {
        menu = new Form("Connect");

        tb = new TextField("Please input imei: ","",30,TextField.ANY );

        tb1 = new TextField("Please input candidate/name: ","",30,TextField.ANY);

       tb2 = new TextField("Please input password: ","",30,TextField.PASSWORD);

        menu.append(tb);
        menu.append(tb1);
        menu.append(tb2);
        menu.addCommand(exit);
        menu.addCommand(connect);
        menu.setCommandListener(this);
        display.setCurrent(menu);
    }


    public void pauseApp() {}

    public void destroyApp(boolean unconditional) {}

    public void commandAction(Command command, Displayable screen) {
        if (command == exit) {
            destroyApp(false);
            notifyDestroyed();
        } else if (command == connect) {
            db  = new DB(this);
            db.start();
           
        }
    }

    private static byte[] encrypt(String input) throws InvalidKeyException, BadPaddingException,IllegalBlockSizeException, ShortBufferException {
     

      cipher.init(Cipher.ENCRYPT_MODE, key);
      byte[] inputBytes = input.getBytes();
      byte[] outputBytes = null;       
      int n = cipher.doFinal(inputBytes, 0, inputBytes.length, outputBytes, 0);
          return outputBytes;
  }

    public class DB implements Runnable {
        TestMidlet midlet;
        private Display display;
        String db;
        String user;
        String pwd;
        public DB(TestMidlet midlet) {
            this.midlet = midlet;
            display = Display.getDisplay(midlet);
        }

        public void start() {
            Thread t = new Thread(this);
            t.start();
        }

        public void run() {
            String url = "http://127.0.0.1:8080/servlets/servlet/RegistrateServlet";
        StringBuffer sqlResult = new StringBuffer(); // z is used to be set as default
        try{
            HttpConnection conn = (HttpConnection)Connector.open(url);
            conn.setRequestProperty("User-Agent", "Profile/MIDP-1.0, Configuration/CLDC-2.0");
            conn.setRequestProperty("Content-Language","en-US");
            conn.setRequestMethod(HttpConnection.POST);

            DataOutputStream out = (DataOutputStream)conn.openDataOutputStream();

            byte[] password = null;
            password=encrypt(tb2.getString()); //I tried here, not sent yet
            out.writeUTF("registration");
            out.writeUTF(tb.getString().trim());
            out.writeUTF(tb1.getString().trim());
            out.writeUTF(tb2.getString().trim());
            //out.write(password);
            /*out.writeInt(password.length);
            for (int i = 0; i <password.length; i++)
                out.write(password[i]);*/
            //here handle the password
            out.flush();
            out.close();
            
        

            DataInputStream in = (DataInputStream)conn.openDataInputStream();
            int ch;
            while ((ch = in.read())!= -1)
                sqlResult.append((char)ch);
            showAlert(sqlResult.toString());
            in.close();
            conn.close();
        } catch (Exception e) {
            System.err.println("Can't process (SQL) data: " + e);
        }


        }

        /* Display Error On screen*/
        public void showAlert(String err) {
            Alert a = new Alert("");
            a.setString(err);
            a.setTimeout(Alert.FOREVER);
            display.setCurrent(a);
        }

    };
}  

[Ulf Dittmer]

I'm not sure if JCE works on JME, but you have the KeyGenerator import commented out without which the compiler can't know about the class.

If JCE does not work on JME, check out the BouncyCastle API - it has a version that runs on JME.

[mak zoe]

Ulf Dittmer wrote:I'm not sure if JCE works on JME, but you have the KeyGenerator import commented out without which the compiler can't know about the class.

If JCE does not work on JME, check out the BouncyCastle API - it has a version that runs on JME.

I comment it out as it is not found in the library.

I tried BouncyCastle... but it requires signning...

[Ulf Dittmer]

This may help: http://www.ibm.com/developerworks/java/library/wi-secure/, although the fact that there is no JCE provider for JME by BouncyCastle indicates that there may be other problems. The BC lightweight API may be your best hope.