java code to digitally sign and verify an email

[anandi soni]

please help me if anyone knows how to send digitally signed emails.
I have tried by using opensslagian by using keytool also but.its not working.

the program I'm doing is:

package algorithmImpl;



import java.io.File;
import java.io.IOException;
import java.security.GeneralSecurityException;
import java.security.Key;
import java.util.Date;
import java.util.Properties;

import javax.activation.DataHandler;
import javax.activation.FileDataSource;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

import net.suberic.crypto.EncryptionKeyManager;
import net.suberic.crypto.EncryptionManager;
import net.suberic.crypto.EncryptionUtils;
   
   
public class digitalsigningemail {  
public static void main(String[] args) { 
	 digitalsigningemail sign = new digitalsigningemail();
	 try {
		sign.test();
	} catch (MessagingException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
	 
	 
	 
  	 
	 
    } //main  



public void test()throws MessagingException  {
    Properties props = new Properties();
    Session session = Session.getInstance(props);
    MimeMessage msg = new MimeMessage(session);
    msg.setFrom(new InternetAddress("[e-mail]"));
    msg.setRecipient(Message.RecipientType.TO, new InternetAddress("[e-mail]"));
    msg.setSubject("Testovaci podepsany mail");

    // create and fill the first message part
    MimeBodyPart mbp1 = new MimeBodyPart();
    mbp1.setText("Text testovaciho podepsaneho mailu");
    msg.setContent("Testovaci podepsany mail", "text/plain");

    // create the second message part
    MimeBodyPart mbp2 = new MimeBodyPart();

    // attach the file to the message
    FileDataSource fds = new FileDataSource(new File("D:/workspace/Email client/rawMsg.txt"));
    mbp2.setDataHandler(new DataHandler(fds));
    mbp2.setFileName(fds.getName());

    // create the Multipart and add its parts to it
    Multipart mp = new MimeMultipart();
    mp.addBodyPart(mbp1);
    mp.addBodyPart(mbp2);

    // add the Multipart to the message
    msg.setContent(mp);

    // set the Date: header
    msg.setSentDate(new Date());
    msg.saveChanges();
    try{
    msg = signMessage(msg, session);
    }catch(IOException e){e.printStackTrace();}
    catch(GeneralSecurityException ge){ge.printStackTrace();}
    Transport transport = session.getTransport("smtp");
    transport.connect("smtp.server", null, null);

    transport.sendMessage(msg, msg.getAllRecipients());
}

protected MimeMessage signMessage(MimeMessage mimeMessage, Session session)throws MessagingException,IOException,GeneralSecurityException {
	 
	 
	 
        // Getting of the S/MIME EncryptionUtilities.
	    EncryptionUtils encUtils = EncryptionManager.getEncryptionUtils(EncryptionManager.SMIME);

        // Loading of the S/MIME keystore from the file (stored as resource).
        char[] keystorePass = getCertificatePassword().toCharArray();
        System.out.println(getCertificatePassword());
        EncryptionKeyManager encKeyManager = encUtils.createKeyManager();
        encKeyManager.loadPrivateKeystore(getClass().getResourceAsStream("C:/newopenssl/mtech1.p12"), keystorePass);

        // Getting of the S/MIME private key for signing.
        Key privateKey = encKeyManager.getPrivateKey(getPrivateKeyAlias(), keystorePass);

        // Signing the message.
        
    
	return encUtils.signMessage(session, mimeMessage, privateKey);
}

private String getPrivateKeyAlias() {
    return "mtech";
}

private String getCertificatePassword() {
    return "mtech1";
}

}