salcho commented on a change in pull request #430: URL: https://github.com/apache/struts/pull/430#discussion_r472852667
########## File path: core/src/main/java/org/apache/struts2/interceptor/csp/CspInterceptor.java ########## @@ -0,0 +1,78 @@ +/* + * 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.struts2.interceptor.csp; + +import com.opensymphony.xwork2.ActionInvocation; +import com.opensymphony.xwork2.interceptor.AbstractInterceptor; +import com.opensymphony.xwork2.interceptor.PreResultListener; +import java.net.URI; +import java.util.Optional; +import javax.servlet.http.HttpServletResponse; + +/** + * Interceptor that implements Content Security Policy on incoming requests used to protect against + * common XSS and data injection attacks. Uses {@link CspSettings} to add appropriate Content Security Policy header + * to the response. These headers determine what the browser will consider a policy violation and the browser's behavior + * when a violation occurs. A detailed explanation of CSP can be found <a href="https://csp.withgoogle.com/docs/index.html";>here</a>. + * + * @see <a href="https://csp.withgoogle.com/docs/index.html";>https://csp.withgoogle.com/docs/index.html/</a> + * @see CspSettings + * @see DefaultCspSettings + **/ +public final class CspInterceptor extends AbstractInterceptor implements PreResultListener { + private final CspSettings settings = new DefaultCspSettings(); + + @Override + public String intercept(ActionInvocation invocation) throws Exception { + invocation.addPreResultListener(this); + return invocation.invoke(); + } + + public void beforeResult(ActionInvocation invocation, String resultCode) { + HttpServletResponse response = invocation.getInvocationContext().getServletResponse(); + settings.addCspHeaders(response); + } + + public void setReportUri(String reportUri) { + Optional<URI> uri = buildUri(reportUri); + if (!uri.isPresent()) { + throw new IllegalArgumentException("Could not parse configured report URI for CSP interceptor: " + reportUri); + } + + if (!uri.get().isAbsolute() && !reportUri.startsWith("/")) { + throw new IllegalArgumentException("Illegal configuration: report URI is not relative to the root. Please set a report URI that starts with /"); + } + + settings.setReportUri(reportUri); + } + + private static Optional<URI> buildUri(String reportUri) { Review comment: no particular reason, really - just because it has no dependencies with the instance and it's a utility method. I don't have a strong opinion on this, would you like to have this method be non-static? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
