/**
    * Waffle (https://github.com/dblock/waffle)
    *
    * Copyright (c) 2010 - 2015 Application Security, Inc.
    *
    * 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
   *
   * Contributors:
   *     Application Security, Inc.
   */
  package waffle.spring;
  
  import java.io.IOException;
  
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.security.core.AuthenticationException;
  import org.springframework.security.web.AuthenticationEntryPoint;
  
  import waffle.servlet.spi.SecurityFilterProviderCollection;
  
  /**
   * Sends back a request for a Negotiate Authentication to the browser.
   * 
   * @author dblock[at]dblock[dot]org
   */
  public class NegotiateSecurityFilterEntryPoint implements AuthenticationEntryPoint {
  
      /** The Constant LOGGER. */
      private static final Logger              LOGGER = LoggerFactory.getLogger(NegotiateSecurityFilterEntryPoint.class);
      
      /** The provider. */
      private SecurityFilterProviderCollection provider;
  
      /**
       * Instantiates a new negotiate security filter entry point.
       */
      public NegotiateSecurityFilterEntryPoint() {
          NegotiateSecurityFilterEntryPoint.LOGGER.debug("[waffle.spring.NegotiateEntryPoint] loaded");
      }
  
      /* (non-Javadoc)
       * @see org.springframework.security.web.AuthenticationEntryPoint#commence(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, org.springframework.security.core.AuthenticationException)
       */
      @Override
      public void commence(final HttpServletRequest request, final HttpServletResponse response,
              final AuthenticationException ex) throws IOException, ServletException {
  
          NegotiateSecurityFilterEntryPoint.LOGGER.debug("[waffle.spring.NegotiateEntryPoint] commence");
  
          if (this.provider == null) {
              throw new ServletException("Missing NegotiateEntryPoint.Provider");
          }
  
          response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
          response.setHeader("Connection", "keep-alive");
          this.provider.sendUnauthorized(response);
          response.flushBuffer();
      }
  
      /**
       * Gets the provider.
       *
       * @return the provider
       */
      public SecurityFilterProviderCollection getProvider() {
          return this.provider;
      }
  
      /**
       * Sets the provider.
       *
       * @param value
       *            the new provider
       */
      public void setProvider(final SecurityFilterProviderCollection value) {
          this.provider = value;
      }
  }