@Override
 public HttpHandler createHttpHandler(Predicate predicate, final HttpHandler next) {
   // this is a bit of a hack at the moment. Basically we only want to create a single mod_cluster
   // instance
   // not matter how many filter refs use it, also mod_cluster at this point has no way
   // to specify the next handler. To get around this we invoke the mod_proxy handler
   // and then if it has not dispatched or handled the request then we know that we can
   // just pass it on to the next handler
   final HttpHandler mcmp =
       managementAccessPredicate != null
           ? Handlers.predicate(managementAccessPredicate, config.create(modCluster, next), next)
           : config.create(modCluster, next);
   final HttpHandler proxyHandler = modCluster.getProxyHandler();
   HttpHandler theHandler =
       new HttpHandler() {
         @Override
         public void handleRequest(HttpServerExchange exchange) throws Exception {
           proxyHandler.handleRequest(exchange);
           if (!exchange.isDispatched() && !exchange.isComplete()) {
             exchange.setResponseCode(200);
             mcmp.handleRequest(exchange);
           }
         }
       };
   UndertowLogger.ROOT_LOGGER.debug("HttpHandler for mod_cluster MCMP created.");
   if (predicate != null) {
     return new PredicateHandler(predicate, theHandler, next);
   } else {
     return theHandler;
   }
 }
  private HttpHandler setupSecurityHandlers(HttpHandler initialHandler) {
    final DeploymentInfo deploymentInfo = super.getDeployment().getDeploymentInfo();
    final LoginConfig loginConfig = deploymentInfo.getLoginConfig();

    final Map<String, AuthenticationMechanismFactory> factoryMap =
        new HashMap<>(deploymentInfo.getAuthenticationMechanisms());
    if (!factoryMap.containsKey(BASIC_AUTH)) {
      factoryMap.put(BASIC_AUTH, BasicAuthenticationMechanism.FACTORY);
    }
    if (!factoryMap.containsKey(FORM_AUTH)) {
      factoryMap.put(FORM_AUTH, ServletFormAuthenticationMechanism.FACTORY);
    }
    if (!factoryMap.containsKey(DIGEST_AUTH)) {
      factoryMap.put(DIGEST_AUTH, DigestAuthenticationMechanism.FACTORY);
    }
    if (!factoryMap.containsKey(CLIENT_CERT_AUTH)) {
      factoryMap.put(CLIENT_CERT_AUTH, ClientCertAuthenticationMechanism.FACTORY);
    }
    if (!factoryMap.containsKey(ExternalAuthenticationMechanism.NAME)) {
      factoryMap.put(ExternalAuthenticationMechanism.NAME, ExternalAuthenticationMechanism.FACTORY);
    }
    HttpHandler current = initialHandler;
    current = new SSLInformationAssociationHandler(current);

    final SecurityPathMatches securityPathMatches = buildSecurityConstraints();
    current = new ServletAuthenticationCallHandler(current);
    if (deploymentInfo.isDisableCachingForSecuredPages()) {
      current =
          Handlers.predicate(Predicates.authRequired(), Handlers.disableCache(current), current);
    }
    if (!securityPathMatches.isEmpty()) {
      current = new ServletAuthenticationConstraintHandler(current);
    }
    current =
        new ServletConfidentialityConstraintHandler(
            deploymentInfo.getConfidentialPortManager(), current);
    if (!securityPathMatches.isEmpty()) {
      current = new ServletSecurityConstraintHandler(securityPathMatches, current);
    }
    List<AuthenticationMechanism> authenticationMechanisms = new LinkedList<>();
    authenticationMechanisms.add(
        new CachedAuthenticatedSessionMechanism()); // TODO: does this really need to be hard coded?

    String mechName = null;
    if (loginConfig != null || deploymentInfo.getJaspiAuthenticationMechanism() != null) {

      // we don't allow multipart requests, and always use the default encoding
      FormParserFactory parser =
          FormParserFactory.builder(false)
              .addParser(
                  new FormEncodedDataDefinition()
                      .setDefaultEncoding(deploymentInfo.getDefaultEncoding()))
              .build();

      List<AuthMethodConfig> authMethods = Collections.<AuthMethodConfig>emptyList();
      if (loginConfig != null) {
        authMethods = loginConfig.getAuthMethods();
      }

      for (AuthMethodConfig method : authMethods) {
        AuthenticationMechanismFactory factory = factoryMap.get(method.getName());
        if (factory == null) {
          throw UndertowServletMessages.MESSAGES.unknownAuthenticationMechanism(method.getName());
        }
        if (mechName == null) {
          mechName = method.getName();
        }

        final Map<String, String> properties = new HashMap<>();
        properties.put(
            AuthenticationMechanismFactory.CONTEXT_PATH, deploymentInfo.getContextPath());
        properties.put(AuthenticationMechanismFactory.REALM, loginConfig.getRealmName());
        properties.put(AuthenticationMechanismFactory.ERROR_PAGE, loginConfig.getErrorPage());
        properties.put(AuthenticationMechanismFactory.LOGIN_PAGE, loginConfig.getLoginPage());
        properties.putAll(method.getProperties());

        String name = method.getName().toUpperCase(Locale.US);
        // The mechanism name is passed in from the HttpServletRequest interface as the name
        // reported needs to be
        // comparable using '=='
        name = name.equals(FORM_AUTH) ? FORM_AUTH : name;
        name = name.equals(BASIC_AUTH) ? BASIC_AUTH : name;
        name = name.equals(DIGEST_AUTH) ? DIGEST_AUTH : name;
        name = name.equals(CLIENT_CERT_AUTH) ? CLIENT_CERT_AUTH : name;

        authenticationMechanisms.add(factory.create(name, parser, properties));
      }
    }

    ((DeploymentImpl) super.getDeployment()).setAuthenticationMechanisms(authenticationMechanisms);
    // if the JASPI auth mechanism is set then it takes over
    if (deploymentInfo.getJaspiAuthenticationMechanism() == null) {
      current = new AuthenticationMechanismsHandler(current, authenticationMechanisms);
    } else {
      current =
          new AuthenticationMechanismsHandler(
              current,
              Collections.<AuthenticationMechanism>singletonList(
                  deploymentInfo.getJaspiAuthenticationMechanism()));
    }

    current =
        new CachedAuthenticatedSessionHandler(current, super.getDeployment().getServletContext());
    List<NotificationReceiver> notificationReceivers = deploymentInfo.getNotificationReceivers();
    if (!notificationReceivers.isEmpty()) {
      current = new NotificationReceiverHandler(current, notificationReceivers);
    }

    // TODO - A switch to constraint driven could be configurable, however before we can support
    // that with servlets we would
    // need additional tracking within sessions if a servlet has specifically requested that
    // authentication occurs.
    SecurityContextFactory contextFactory = deploymentInfo.getSecurityContextFactory();
    if (contextFactory == null) {
      contextFactory = SecurityContextFactoryImpl.INSTANCE;
    }
    current =
        new SecurityInitialHandler(
            AuthenticationMode.PRO_ACTIVE,
            deploymentInfo.getIdentityManager(),
            mechName,
            contextFactory,
            current);
    return current;
  }