/**
* 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.hadoop.gateway.webappsec.filter;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;
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.HttpServletResponse;
public class CSRFPreventionFilter implements Filter {
private static final String CUSTOM_HEADER_PARAM = "csrf.customheader";
private static final String CUSTOM_METHODS_TO_IGNORE_PARAM = "csrf.methodstoignore";
private String headerName = "X-XSRF-Header";
private String mti = "GET,OPTIONS,HEAD";
private Set<String> methodsToIgnore = null;
@Override
public void init( FilterConfig filterConfig ) throws ServletException {
String customHeader = filterConfig.getInitParameter(CUSTOM_HEADER_PARAM);
if (customHeader != null) {
headerName = customHeader;
}
String customMTI = filterConfig.getInitParameter(CUSTOM_METHODS_TO_IGNORE_PARAM);
if (customMTI != null) {
mti = customMTI;
}
String[] methods = mti.split(",");
methodsToIgnore = new HashSet<String>();
for (int i = 0; i < methods.length; i++) {
methodsToIgnore.add(methods[i]);
}
}
@Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
HttpServletRequest httpRequest = (HttpServletRequest)request;
if ( methodsToIgnore.contains( httpRequest.getMethod() ) || httpRequest.getHeader(headerName) != null ) {
chain.doFilter(request, response);
} else {
((HttpServletResponse)response).sendError(HttpServletResponse.SC_BAD_REQUEST, "Missing Required Header for Vulnerability Protection");
}
}
/* (non-Javadoc)
* @see javax.servlet.Filter#destroy()
*/
@Override
public void destroy() {
// TODO Auto-generated method stub
}
}