/*********************************************************************************************************************
 * Copyright (c) 2008, 2015 Empolis Information Management GmbH and brox IT Solutions GmbH. All rights reserved.
 * This program and the accompanying materials are made available under the terms of the Eclipse Public License v1.0 
 * which accompanies this distribution, and is available at http://www.eclipse.org/legal/epl-v10.html
**********************************************************************************************************************/
package org.eclipse.smila.http.server.jetty;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.eclipse.jetty.security.ConstraintSecurityHandler;
import org.eclipse.jetty.server.Request;
import org.eclipse.smila.http.server.util.CorsUtils;

/**
 * Special version of Jetty's {@link ConstraintSecurityHandler} that allows unauthenticated communication on a
 * configurable port. The use case for this is to configure SMILA with two HTTP ports: one allows unauthenticated access
 * and is used for internal communication by other services in the SMILA cluster, but is not accessible by external
 * client (e.g. blocked by a firewall). External clients can connect only to the second port which requires
 * authentication (and maybe the HTTPS protocol).
 *
 * <p>
 *
 * Example for usage in jetty.xml: Talking to port 8080 does not require authentication, on all other ports
 *
 * <pre>
 * &lt;Set name="handler">
 *   &lt;New id="security" class="org.eclipse.smila.http.server.jetty.PortConstraintSecurityHandler">
 *     &lt;Set name="NoAuthenticationPort">8080&lt;/Set>
 *     &lt;Set name="Strict">false&lt;/Set>
 *     &lt;Set name="Authenticator">
 *       &lt;New class="org.eclipse.jetty.security.authentication.BasicAuthenticator" />
 *     &lt;/Set>
 *     &lt;Set name="ConstraintMappings">
 *       &lt;Array type="org.eclipse.jetty.security.ConstraintMapping">
 *         &lt;Item>
 *           &lt;New class="org.eclipse.jetty.security.ConstraintMapping">
 *             &lt;Set name="PathSpec">/*&lt;/Set>
 *             &lt;Set name="Constraint">
 *               &lt;New class="org.eclipse.jetty.util.security.Constraint">
 *                 &lt;Set name="Authenticate">true&lt;/Set>
 *                 &lt;Set name="Roles">
 *                   &lt;Array type="java.lang.String">
 *                     &lt;Item>*&lt;/Item>
 *                   &lt;/Array>
 *                 &lt;/Set>
 *               &lt;/New>
 *             &lt;/Set>
 *           &lt;/New>
 *         &lt;/Item>
 *       &lt;/Array>
 *     &lt;/Set>
 *     &lt;Set name="handler">
 *       &lt;New id="Contexts" class="org.eclipse.jetty.server.handler.HandlerCollection" />
 *     &lt;/Set>
 *   &lt;/New>
 * &lt;/Set>
 * </pre>
 */
public class PortConstraintSecurityHandler extends ConstraintSecurityHandler {
  private int _noAuthenticationPort;

  /**
   * Sets port that allows unauthenticated access. If never set or set to a value less or equal to 0, this class behaves
   * exactly like {@link ConstraintSecurityHandler} and all ports require authentication.
   */
  public void setNoAuthenticationPort(final int noAuthenticationPort) {
    _noAuthenticationPort = noAuthenticationPort;
  }

  /**
   * @return port for unauthenticated access.
   */
  public int getNoAuthenticationPort() {
    return _noAuthenticationPort;
  }

  @Override
  protected boolean checkSecurity(final Request request) {
    if (_noAuthenticationPort > 0 && request.getLocalPort() == _noAuthenticationPort) {
      return false;
    }
    // needed for preflight CORS requests: OPTIONS requests should not require authentication
    if ("OPTIONS".equals(request.getMethod())) {
      return false;
    }
    return super.checkSecurity(request);
  }

  @Override
  public void handle(final String pathInContext, final Request baseRequest, final HttpServletRequest request,
    final HttpServletResponse response) throws IOException, ServletException {

    CorsUtils.setCorsResponseHandlers(request, response);

    super.handle(pathInContext, baseRequest, request, response);
  }
}