public void generujKlucze(String mail,char[] pas) {
    try {

      final KeyPairGenerator keyGen = KeyPairGenerator.getInstance(ALGORITHM);
      keyGen.initialize(1024);
      final KeyPair key = keyGen.generateKeyPair();

      File privateKeyFile = new File(PRIVATE_KEY_FILE+mail+".priv");
      File publicKeyFile = new File(PUBLIC_KEY_FILE+mail+".publ");

      // Create files to store public and private key
      if (privateKeyFile.getParentFile() != null) {
        privateKeyFile.getParentFile().mkdirs();
      }
      privateKeyFile.createNewFile();

      if (publicKeyFile.getParentFile() != null) {
        publicKeyFile.getParentFile().mkdirs();
      }
      publicKeyFile.createNewFile();

      // Saving the Public key in a file
      ObjectOutputStream publicKeyOS = new ObjectOutputStream(
          new FileOutputStream(publicKeyFile));
      publicKeyOS.writeObject(key.getPublic());
      publicKeyOS.close();

      // Saving the Private key in a file
      ObjectOutputStream privateKeyOS = new ObjectOutputStream(
          new FileOutputStream(privateKeyFile));
      privateKeyOS.writeObject(key.getPrivate());
      privateKeyOS.close();
    } catch (Exception e) {
      e.printStackTrace();
    }

  }