Newbie need to encrypt/decrypt using password

Question

Hi all,
I need to encrypt some data store it in database and retrieve it at another time and decrypt it. The user will supply the password. I have no idea on how to do it. This encryption must be very strong like PGP. I can use the jars provided by Sun.
rgds
Antony Paul

Answer 1

package login.view;
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
//import org.myorg.SystemUnavailableException;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
import sun.misc.CharacterEncoder;
public final class PasswordService
private static PasswordService instance;
private PasswordService()
public synchronized String encrypt(String plaintext) throws Exception
MessageDigest md = null;
try
md = MessageDigest.getInstance("SHA"); //step 2
catch(NoSuchAlgorithmException e)
throw new Exception(e.getMessage());
try
md.update(plaintext.getBytes("UTF-8")); //step 3
catch(UnsupportedEncodingException e)
throw new Exception(e.getMessage());
byte raw[] = md.digest(); //step 4
String hash = (new BASE64Encoder()).encode(raw); //step 5
return hash; //step 6
public static synchronized PasswordService getInstance() //step 1
if(instance == null)
return new PasswordService();
else
return instance;
You can use this classas below.................
public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
HttpSession session=request.getSession(true);
//HttpSession session = new HttpSession();
LoginBean login =(login.view.LoginBean) form;
String LoginName= login.getLoginName();
String LoginPassword = login.getLoginPassword();
try
session.setAttribute("LoginPassword",PasswordService.getInstance().encrypt(LoginPassword));
catch(Exception e)
session.setAttribute("LoginName",LoginName);
return mapping.findForward("success");
}