| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.drill.exec.server.rest; |
| |
| import javax.servlet.Filter; |
| import javax.servlet.FilterChain; |
| import javax.servlet.FilterConfig; |
| import javax.servlet.ServletException; |
| import javax.servlet.ServletRequest; |
| import javax.servlet.ServletResponse; |
| import javax.servlet.http.HttpServletRequest; |
| import javax.servlet.http.HttpSession; |
| import javax.ws.rs.HttpMethod; |
| import java.io.IOException; |
| |
| /** |
| * Generates and adds a CSRF token to a HTTP session. It is used to prevent CSRF attacks. |
| */ |
| public class CsrfTokenInjectFilter implements Filter { |
| |
| @Override |
| public void init(FilterConfig filterConfig) throws ServletException { |
| } |
| |
| @Override |
| public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { |
| HttpServletRequest httpRequest = (HttpServletRequest) request; |
| if (HttpMethod.GET.equalsIgnoreCase(httpRequest.getMethod())) { |
| // We don't create a session with this call as we need to check if there is a session already (i.e. if a user is logged in). |
| HttpSession session = httpRequest.getSession(false); |
| if (session != null) { |
| String csrfToken = (String) session.getAttribute(WebServerConstants.CSRF_TOKEN); |
| if (csrfToken == null) { |
| csrfToken = WebUtils.generateCsrfToken(); |
| httpRequest.getSession().setAttribute(WebServerConstants.CSRF_TOKEN, csrfToken); |
| } |
| } |
| } |
| chain.doFilter(request, response); |
| } |
| |
| @Override |
| public void destroy() { |
| } |
| } |