nonanalou commented on code in PR #28: URL: https://github.com/apache/sling-org-apache-sling-xss/pull/28#discussion_r965741414
########## src/main/java/org/apache/sling/xss/impl/style/BatikCssCleaner.java: ########## @@ -0,0 +1,82 @@ +/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + ~ 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.sling.xss.impl.style; + +import java.io.IOException; +import java.io.StringReader; + +import org.apache.batik.css.parser.Parser; +import org.apache.sling.xss.impl.xml.AntiSamyPolicy.CssPolicy; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import org.w3c.css.sac.CSSException; +import org.w3c.css.sac.InputSource; + +public class BatikCssCleaner { + + private final Logger logger = LoggerFactory.getLogger(getClass()); + private final CssPolicy cssPolicy; + + private static final String CDATA_PRE = "<![CDATA["; + private static final String CDATA_POST = "]]>"; + + public BatikCssCleaner(CssPolicy cssPolicy) { + this.cssPolicy = cssPolicy; + } + + /** + * Parses a CSS stylesheet and returns it in a safe form + * + * @param untrustedCss a complete CSS stylesheet + * @return the cleaned CSS stylesheet text + */ + public String cleanStylesheet(String untrustedCss) { + try { + if ( untrustedCss.startsWith(CDATA_PRE) && untrustedCss.endsWith(CDATA_POST) ) + untrustedCss = untrustedCss.substring(CDATA_PRE.length(), untrustedCss.length() - CDATA_POST.length()); + Parser parser = new Parser(); + ValidatingDocumentHandler handler = new ValidatingDocumentHandler(cssPolicy, false); + parser.setDocumentHandler(handler); + parser.parseStyleSheet(new InputSource(new StringReader(untrustedCss))); + return handler.getValidCss(); + } catch (CSSException | IOException e) { + logger.debug("Unexpected error while cleaning stylesheet", e); Review Comment: The caller `apply` and `text` method does not allow me to throw a checked exception. (1) should i modify the caller method signature to throw a checked exception? (2) or should i re-throw the `(CSSException | IOException e)` as runtime-Exception? (3)or should i simply return an empty string and log the error? -- 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. To unsubscribe, e-mail: dev-unsubscr...@sling.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
