martin-g commented on a change in pull request #399: WICKET-6727: Configurable Content-Security-Policy URL: https://github.com/apache/wicket/pull/399#discussion_r368903438
########## File path: wicket-core/src/main/java/org/apache/wicket/csp/ContentSecurityPolicyEnforcer.java ########## @@ -0,0 +1,173 @@ +/* + * 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.wicket.csp; + +import java.util.HashMap; +import java.util.Map; +import java.util.function.Predicate; + +import org.apache.wicket.Application; +import org.apache.wicket.MetaDataKey; +import org.apache.wicket.core.request.handler.BufferedResponseRequestHandler; +import org.apache.wicket.core.request.handler.IPageClassRequestHandler; +import org.apache.wicket.request.IRequestHandler; +import org.apache.wicket.request.IRequestHandlerDelegate; +import org.apache.wicket.request.cycle.IRequestCycleListener; +import org.apache.wicket.request.cycle.RequestCycle; +import org.apache.wicket.request.http.WebResponse; +import org.apache.wicket.settings.SecuritySettings; +import org.apache.wicket.util.lang.Args; + +/** + * An {@link IRequestCycleListener} that adds {@code Content-Security-Policy} and/or + * {@code Content-Security-Policy-Report-Only} headers based on the supplied configuration. + * + * Build the CSP configuration like this: + * + * <pre> + * {@code + * myApplication.getCSP().blocking().clear() + * .add(CSPDirective.DEFAULT_SRC, CSPDirectiveSrcValue.NONE) + * .add(CSPDirective.SCRIPT_SRC, CSPDirectiveSrcValue.SELF) + * .add(CSPDirective.IMG_SRC, CSPDirectiveSrcValue.SELF) + * .add(CSPDirective.FONT_SRC, CSPDirectiveSrcValue.SELF)); + * + * myApplication.getCSP().reporting().strict(); + * } + * </pre> + * + * See {@link CSPHeaderConfiguration} for more details on specifying the configuration. + * + * @see <a href="https://www.w3.org/TR/CSP2/";>https://www.w3.org/TR/CSP2</a> + * @see <a href= + * "https://developer.mozilla.org/en-US/docs/Web/Security/CSP";>https://developer.mozilla.org/en-US/docs/Web/Security/CSP</a> + * + * @author Sven Haster + * @author Emond Papegaaij + */ +public class ContentSecurityPolicyEnforcer implements IRequestCycleListener +{ + public static MetaDataKey<String> NONCE_KEY = new MetaDataKey<>() + { + private static final long serialVersionUID = 1L; + }; + + private final Application application; + + private Map<CSPHeaderMode, CSPHeaderConfiguration> configs = new HashMap<>(); + + private Predicate<IPageClassRequestHandler> protectedPageFilter = handler -> true; + + public ContentSecurityPolicyEnforcer(Application application) + { + this.application = Args.notNull(application, "application"); + } + + public CSPHeaderConfiguration blocking() + { + return configs.computeIfAbsent(CSPHeaderMode.BLOCKING, x -> new CSPHeaderConfiguration()); + } + + public CSPHeaderConfiguration reporting() + { + return configs.computeIfAbsent(CSPHeaderMode.REPORT_ONLY, x -> new CSPHeaderConfiguration()); + } + + /** + * Sets the predicate that determines which requests must be protected by the CSP. When the + * predicate evaluates to false, the request for the page will not be protected. + * + * @param protectedPageFilter + * @return {@code this} for chaining. + */ + public ContentSecurityPolicyEnforcer + setProtectedPageFilter(Predicate<IPageClassRequestHandler> protectedPageFilter) + { + this.protectedPageFilter = protectedPageFilter; + return this; + } + + protected boolean mustProtect(IRequestHandler handler) + { + if (handler instanceof IRequestHandlerDelegate) + { + return mustProtect(((IRequestHandlerDelegate) handler).getDelegateHandler()); + } + if (handler instanceof IPageClassRequestHandler) + { + return mustProtectPageRequest((IPageClassRequestHandler) handler); + } + return !(handler instanceof BufferedResponseRequestHandler); + } + + protected boolean mustProtectPageRequest(IPageClassRequestHandler handler) + { + return protectedPageFilter.test(handler); + } + + @Override + public void onRequestHandlerResolved(RequestCycle cycle, IRequestHandler handler) + { + if (!mustProtect(handler) || !(cycle.getResponse() instanceof WebResponse)) + { + return; + } + + WebResponse webResponse = (WebResponse) cycle.getResponse(); + if (!webResponse.isHeaderSupported()) + { + return; + } + + configs.entrySet().stream().filter(entry -> entry.getValue().isSet()).forEach(entry -> { + CSPHeaderMode mode = entry.getKey(); + CSPHeaderConfiguration config = entry.getValue(); + String headerValue = config.renderHeaderValue(this, cycle); + webResponse.setHeader(mode.getHeader(), headerValue); + if (config.isAddLegacyHeaders()) + { + webResponse.setHeader(mode.getLegacyHeader(), headerValue); + } + }); + } + + /** + * Returns true if any of the headers includes a directive with a nonce. + * + * @return If a nonce is used in the CSP. + */ + public boolean isNonceEnabled() + { + return configs.values().stream().anyMatch(CSPHeaderConfiguration::isNonceEnabled); + } + + public String getNonce(RequestCycle cycle) + { + String nonce = cycle.getMetaData(NONCE_KEY); + if (nonce == null) + { + nonce = getSecuritySettings().getRandomSupplier().getRandomBase64(12); Review comment: magic number `12` ---------------------------------------------------------------- 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: us...@infra.apache.org With regards, Apache Git Services
